Power Transmission Engineering / PTE December 2008

December 2008

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Motion Control Technical Articles • Don’t Sweat the Guitar Fret • Couplings, Part II

• Enhanced Product Testing • Improved Sealing a SNAP Technology

• High-Load Bearings Guide Power Play Chinese Gearboxes • Techno Art in Motion

www.powertransmission.com Ad-849-PTE.qxp 10/22/08 9:20 AM Page 1

CUSTOM BEVEL GEAR MANUFACTURING The strong silent types.

Huco Dynatork air motors are · designed for quiet, high-speed · positioning performance. Dynatork air motors feature very low noise levels · compared to other air motors, combined with high torque output (up to 550Nm) and low · air consumption.The unique Dynatork design makes them the world’s only · precise stepable air motor. Dynatork air motors can stop-start · and drive instantly under load. Near instant reversing under load is achieved through the use of · 5 port control valves. Maximum torque is transmitted at start and can be adjusted with a pressure regulator. Speed control can be instantly adjusted to fine limits and programmed control devices can be utilized. BREAKDOWN Air motors from Dynatork are increasingly being specified for hazardous or sensitive applications SERVICES including food processing, paint systems, wood working, and paper converting.These motors can operate underwater and are not affected by airline condensate. Models are available with non-lubricated gas supply eliminating contamination in clean environments. Plastic and stainless steel models are ideal for use in wet, corrosive applications.

*Compared to vane style motors

www.huco.com/pte1208

Altra Industrial Motion The Power of One. The Strength of Many. Warner Electric Boston Gear TB Wood’s Formsprag Clutch Wichita Clutch Marland Clutch Industrial Clutch Nuttall Gear Warner Linear Delroyd Worm Gear Stieber Clutch Ameridrives Couplings Inertia Dynamics Matrix International Huco Dynatork Bibby Transmissions Twiflex Limited

Ad#849-PTE DECEMBER PpowerpowerttransmissionraTnsmissioneengineeringEngineeringC® o n t2 e 0 n 0t s 8 TECHNICAL ARTICLES

Design and Application Criteria for Connecting Couplings, Part II Creative couplings are presented 26

Extended Equipment Life through Improved Sealing Technology How to improve MTBF and uptime 32

FEATURE ARTICLES

Music in Motion Motion system enhances guitar production 13

BSA—the Forum that Keeps Bearing Companies Rolling Bearing Specialists Association profile 16

New System has Product Testing Under Control Upgrades improve testing and validation machinery 18

High-Capacity Bearings Carry the Load for Chinese Gearbox Manufacturer High-load bearings enable new gearbox design

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DEPARTMENTS Product News New equipment and products update 6 Events AHR Expo and other upcoming events of interest 41 Industry News Trends, announcements, etc. 44 Classified Our products and services marketplace 47 Advertiser Index Contact information for companies in this issue 47 Power Play Former M.D. finds fulfillment in motion art 48

ON L I N E

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Randall Publishing makes every effort to ensure that the processes described in POWER TRANSMISSION ENGINEERING conform to sound engineering practice. Neither the authors nor the publisher can be held responsible for injuries sustained while following the procedures described. Postmaster: Send address changes to POWER TRANSMISSION ENGINEERING, 1425 Lunt Avenue, P.O. Box 1426, Elk Grove Village, IL, 60007. ©Contents copyrighted by RANDALL PUBLISHING, INC., 2008. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. Contents of ads are subject to Publisher’s approval.

2006 powertransmissionengineering december 2008 www.powertransmission.com THETHE GGEAREAR IINDUSTRY’SNDUSTRY’S IINFORMATIONNFORMATION SSOURCEOURCE DECEMBER

E V E N T S A “Whodunnit?!” IN GEARBOX FAILURE Forensics isn’t just for tough- talking crime-busting scientists—most GEAR TECHNOLOGY commonly found on your television; the tactic also holds the key to successful gearbox design and manufacture. At AGMA’s Gearbox CSI: Forensic Analysis of Gear and Bearing Failures— Useful Tools for Optimizing Gearbox brings you technical articles on gear and Design, fi nd out just how to follow the integrated process of identifying Ray Drago engages a student in discussion. gearbox failure and determining the gearbox manufacturer,” says Raymond conditions that lead to specifi c failures, Drago, who presents the course along the gearbox systems that will operate in order to avoid future errors. with colleague Joseph Lenski. well in their specifi c environment.” B-10 bearing life and basic gear “The seminar will present Drago and Lenski have worked gear drive design, manufacturing, testing service factor calculations may be the methodologies that can be used to solve with each other for over 40 years in most well-known methods to predict fatigue, scoring and wear problems,” the gear industry spanning an array of gearbox failure, but upon forensic Drago says. “Each failure discussed is concentrations that include aerospace, analysis, failures result from any also accompanied by a discussion of consumer products, medical devices number of contributing factors: design, the actions taken to avoid a recurrence and various industrial applications. fabrication, lubrication and the handling of the failure and to avoid trading the They have performed extensive R&D and troubleshooting, from fundamentals to of gears and bearings. “If a failure is problem solved for one created by the developing new gear and bearing not properly addressed, the problem solution.” designs. Drago currently serves as the will continue to occur and will result Primarily aimed towards gearbox chief engineer and founder of Drive in greater downtime and cost to the designers, many other gear professionals Systems Technology, Inc., a mechanical can benefi t from the seminar, including power transmission consulting purchasers, specifi ers and users who organization, and Lenski holds the title cutting-edge research. If you need to learn can learn how to get the most out of of chief bearing specialist for the fi rm. their gearboxes and help solve and do This seminar “addresses a broad away with service problems. Gearbox range of topics that include design, maintenance people, overhaulers and

operators who are often responsible continued for purchasing, maintaining and about gears, there’s no better place than replacing gear systems will beneﬁ t by understanding the underlying causes of failure, which “is a crucial factor in the economical and long-lasting solution of problems that may occur in these very expensive [gearbox] systems,” Drago Gear Technology,—and it’s Free! says. “Further, by understanding the speciﬁ c nature of the failures and their Joe Lenski. causative agents, these operators are also better prepared to specify exactly

www.geartechnology.com Ray Drago. ��November/December 2008 Also, if you purchase or specify gears, ��GEARTECHNOLOGY � 7003 bearings, motors, speed reducers, gear InductionInductio Hardening of Gears n Hardenin drives or other mechanical components, and Critical Componentsg of Gea rs Part II visit www.powertransmission.com for the most Dr.Valery Rudnev Management Summary Induction hardening is a heat treating technique that c Gear Spi n Hardening ( be used to selectively harden portions of a gear, such as Spin hardening is the mostU s popularing En c induci an rcling Induc the fl anks, roots and tips of teeth, providing impr hardening approach, and it is particularly appropr tors) hardness, wear resistance and contact fatigue strength tion gear oved gears having fi ne- and medium-size teeth (Figure without affecting the metallurgy of the core and other are rotated during heating to ensure an even dist iate for comprehensive online directory of power 8). Gears parts of the component that don’t require change. T energy. Single-turn or multi-turn inductors tha article provides an overview of the process and spe ribution of whole gear can be used (Ref. 1). considerations for heat treating gears. Part I, his t encircle the was published in the September/October 2008 is cial When applying encircling coils, there are fi ve para which that play major roles in obtaining the required ha covered gear materials, desired microstructure, c sue, tern: frequency, power, cycle time, coil geom meters design and tooth-by-tooth induction hardening rdness pat- transmission components and the online version, visit oil quenching conditions. Figure 9 illustrates a dive etry and com/issues/0908/) http://www.geartechnology.(For induction hardening patterns that were obtained with rsity of various heating concepts. Part II used covers with spin it. hardening and in heat time, frequency and power (Ref. 1). variations As a rule, when it is necessary to harden only the a higher frequency and high power density should be tooth tips, their manufacturers. applied continued

nt, mployme nds in E GEAR INDUSTRYh on Tre nt and esearc vestme E ts of R Tool In HHE ResultsResul of Researchch onine Trends in Employment, TT ing, Ma OOFF utsourc AATTEE Outsourcing,O Machine Tool Investment and STATESSTATESTT OFOF THETHE Other Gear Industry Businessare manufactured. Practices They work for gear manufacturing job shops (47 percent), captive shops at OEMs (50 percent) and Gear Technology conducted an anonymous shops manufacturing gears for maintenance, spares and In October, their own use (3 percent). survey of gear manufacturers. Invitations were sent by e- The survey covers gear manufacturing around the world, mail to thousands of individuals around the world. More with 58 percent of respondents working in the United States, than 300 individuals at gear industry locations responded and 42 percent outside the United States. to the online survey, answering questions about their A full breakdown of respondents can be found atcontinued the end manufacturing operations and current challenges facing of this article. their businesses. mistic s are Opti The respondents considered here all work at locations spondent Years dustry Re Next Five Figure 8—Examples of gears th of Gear In e over the where gears, splines, sprockets, worms and similar products 85% o Compet at use spin-hardening techniqu ir Ability t About the es. www.geartechnology.com What Factors Are ��November/December 2008 ��GEARTECHNOLOGY Presenting Signiﬁ cant Challenges Slightly � 4007 30,000 to Your Business? imistic istic Fairly Opt Optim 49% 10%

Undecided ly “Availability of capital.” 11% Slight tic 20,000 —Corporate executive at a U.S. manufacturer of Pessimis replacement gearing 1% ly Extremely Extreme stic “Available heat treatment capacity in the U.S. Optimistic Pessimi Collaborative supply chain partners that understand 26% Fairly 1% tic the alternative energy market and know how to support Pessimis 10,000 growth.” 1% —Purchasing professional at a U.S. gearbox assembly plant Their escribe ndents D ology? “Business insurance.” Respo d Techn How Do tions an —Corporate executive at a U.S. manufacturer of marine g Opera ufacturin Subscribe transmission units Man till ing We S It's Amaz mers Facilities and ve Custo ss, “Commercial viability of OEM customer(s).” Ha World Cla Equipment 2% y —Chief engineer at a U.S. manufacturer of pump shafts st Centur Beginning to 21 for construction/off-road equipment 6% Show Their 1 itive “Congress. Stock market. Drugs.” Age Compet —Corporate executive at a U.S. manufacturer of oilﬁ eld 7% with Most for gears in Our Industry ood, but “Continuous product updating.” G 51% oom for —R&D supervisor at an Italian speed reducer R manufacturer Improvement 24% “Cost reduction initiatives.” � 3005 —Production worker at an Indian automotive gearbox TECHNOLOGY FREE manufacturer) ��GEAR ��November/December 2008 www.geartechnology.com online at www.geartechnology.com November/December 2008 TECHNOLOGY 3004 GEAR www.geartechnologycontinued.com

december 2008 powertransmissionengineering 11211 VOL. 2, NO. 6 PpowerpowerttransmissionraTnsmissioneengineeringEngineering ® Randall Publishing, Inc. 1425 Lunt Avenue Phone: 847-437-6604 P.O. Box 1426 Fax: 847-437-6618 Elk Grove Village, IL 60007

EDITORIAL Publisher & Editor-in-Chief Michael Goldstein [email protected] Managing Editor William R. Stott [email protected] Senior Editor Jack McGuinn [email protected] Associate Editor Matthew Jaster [email protected] Assistant Editor Lindsey Snyder [email protected] Editorial Consultant Paul R. Goldstein

ART Art Director Kathleen O'Hara [email protected] ADVERTISING Advertising Sales Manager Ryan King, RK Media, Inc. [email protected] Matt Matteucci [email protected] CIRCULATION Circulation Manager Carol Tratar [email protected]

RANDALL PUBLISHING STAFF President MichaelMichael Goldstein Vice President Ric Richardhard Goldstein Accounting Luann Harrold

December 2008 Cover photos courtesy of Opto22.

PpowerpowerttransmissionraTnsmissioneengineeringEngineering ®

Motion Control Technical Articles  Don’t Sweat the Guitar Fret  Couplings, Part II

 Enhanced Product Testing  Improved Sealing a SNAP Technology

 High-Load Bearings Guide Power Play Chinese Gearboxes  Techno Art in Motion

www.powertransmission.com

400 powertransmissionengineering december 2008 www.powertransmission.com N E W WhatS Can Handle a Crowd of 80,000 and is Still Asking for More?

■ Find suppliers for the products you need

■ Latest news, Updated as it happens

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PMAC, a motion computer, which options designers have with the Power

Hybrid System fuses a controller with a full-fl edged, PMAC is to write programs using LAYS BRICK FOR Linux operating system into a compact Delta Tau’s script language or a popular NEXT-GEN CONTROLLERS and powerful tool for most commercial, programming language like C or C++. industrial or military applications. The main difference is “a script language “What really distinguishes the is generally easier to use, but more limited There are a lot of different hybrids Power PMAC is that it’s a hybrid beast,” in its functionality,” Wilson says. “You out there these days. Hybrid cars are says Curt Wilson, vice president of don’t have access to all of the powerful on the tip of tongues from Tokyo to engineering for Delta Tau Data Systems, tools that you have in a language like C. Detroit as we plunge ever further into Inc. “It can be used as a dedicated C is very open, very powerful, but it’s our pockets to cover oil costs. But any controller, but it also gives sophisticated diffi cult for the novice and potentially multitude of factors combined for programmers the access to a general dangerous for the unaware.” a specifi c purpose warrant a hybrid purpose computer. Same processor. A designer could by accident write classifi cation. The two-faced term could Same hardware. Same environment.” over critical memory, which is easy to refer to anything really: hybrid machine, The Power PMAC provides do in C and would result in a crash. It’s hybrid coupling, hybrid security—in advantages over both traditional what computer hackers look to achieve, reference to fi nances—and even dedicated controllers and general- according to Wilson. mythological hybrids like the griffi n, purpose computing engines because Delta Tau considered the pros and centaur or mermaid. it permits the user to choose for each cons of these software writing tools The latest item bearing the hybrid aspect of an application which approach when the Power PMAC was conceived label to hit the power transmission is more suitable. four years ago and realized the benefi ts market is Delta Tau Data System’s Power One of the most signifi cant each has for users looking to fulfi ll varying needs. “With each generation of controller, we listen to what people tell us, both customers, and probably more importantly, the accounts we didn’t get, and why didn’t we get them,” he says. “One of the important things we noticed was in accounts where there were very serious programmers who were used to all the tools of a language like C; these people were very hesitant to use a controller that they sensed was limited by the simplifi cation of the script programming approach.” The script language simplifi es some tasks in a way that compensates for issues a standard language may run into. Wilson cites two particular tasks as the most important ones the script language takes care of. “It’s handling, under the hood and invisibly to you, what’s called the type matching of variables. It converts them automatically as needed. [Secondly] it has what we call a sequencing engine that is automatically sequencing program execution move by move.” Another key feature is the embedded Power PC processor, which is about 10 times faster for fl oating point math calculations. “The fl oating point math is so fast and effi cient in this processor; we can do things we couldn’t 006 powertransmissionengineering december 2008 www.powertransmission.com product news

do in previous generations. We’re talking about sophisticated fl oating- point algorithms,” Wilson says. This type of processer features low heat dissipation, so there is no fan required to prevent the chip from overheating. It also has built-in peripheral interfaces like Ethernet, USB and PCI, which add to the compact, effi ciency factors while allowing the Power PMAC to be accessed from any computer in any location. There are many other new features in the Power PMAC like a built-in web browser and a fully integrated development environment. Also, “as a full fl edged computer, it has an organized fi le system like your PC,” Wilson says. “It allows you to write software for what are called both real time tasks—things that must happen now—and what are called background tasks in C or C++. It supports up to 32 independent axes in a single coordinate system.” The Power PMAC is equipped with about 100 times more memory than traditional controllers. “The huge memory permits programs that run for days to be completely loaded into the memory and then run. With previous controllers, you had to sort of dribble it in as you were running, which is much more diffi cult. This makes it much easier. Just load the whole thing in and say ‘run.’” The Power PMAC is being offi cially and there are already visions for further of projects. As they get more and released to the market come the New developing the product in the future. more complex, you’ve got to manage Year, but it has been pre-released for “We will be building one that fi ts in your the complexity in more formal ways. sampling purposes to selected cus- computer’s PCI expansion slot,” Wilson That’s what things like the integrated tomers, who have overall provided very says. “We’re also planning an enclosed development environment [IDE, which positive feedback, Wilson says. One controller/drive combination—both provides for seamless C/C++ and script user is faced with a particularly diffi cult the brains and the power circuitry. By application development] do, and a lot control program, which requires a combining the controller and drive in a of people like to work through an IDE custom servo algorithm that closes the single package it dramatically reduces as much as possible for these complex feedback loop as effi ciently as possible— both size and cost to the users, and it projects.” 10,000 times per second. Using the reduces the complexity of wire because Power PMAC, this user is able to write it’s all internal.” For more information: the algorithm in C, and with the high- In closing, Wilson alludes that the Delta Tau Data Systems, Inc speed processor, it executes about 100 Power PMAC’s introduction responds 21314 Lassen Street times faster than the previous controller to current market trends, and motion Chatsworth, CA 91311 Phone: (818) 998-2095 would allow. system designers will fi nd the product Fax: (818) 998- 7807 better equipped to fulfi ll their needs. Delta Tau may have set the bar [email protected] a little higher for motion control “People continue to push the envelope www.deltatau.com technology with the Power PMAC, on speed and accuracy and complexity www.powertransmission.com december 2008 powertransmissionengineering 2117 product news

Yaskawa

REDUCES PARTS IN COMPACT DRIVE

The J1000 AC drive from Yaskawa design, side-by-side mounting and the 150 percent at 3 Hz, a 5-digit LED Electric America, Inc. claims to be capacity to run a larger motor with keypad, vibration resistance to 50 Hz the world’s smallest compact drive normal duty rating. An over-excitation and a swing PWM function to decrease with 70 percent less space required. braking feature allows the drive to limit motor noise. With fewer parts used in the drive’s stop times without external braking Applications for the J1000 include construction, mean time between resistors. industries such as material handling, failure (MTBF) is increased to 28 years, The J1000 AC drive can store ﬁ les food and beverage, fan and pump control, and other component lifetimes are also for programming several drives quickly packaging, agricultural machines and extended, such as fans, capacitors and or backing-up the system, and it is industrial washers. The drive is RoHS thermal optimization, according to the equipped so hardware or software can compliant and has CE, UL and cUL company’s press release. function for this purpose. The drive is global certiﬁ cation. “The new J1000 was designed with maintained by lifetime monitors, which three main principles in mind consisting constantly supervise how well the key For more information: of quality, reduced cost of ownership and components are working. Yaskawa Electric America, Inc. maintainability,” says Todd Ammerman, The J1000 drive is sized from 1/8 2121 Norman Drive South Yaskawa MicroDrive product manager. to 7.5 hp. Voltage classes are all 50/60 Waukegan, IL 600085 Phone: (800) YASKAWA “All of these allow for the customer to Hz; they are 200-240 V single-phase, Fax: (847) 887-7310 get the most out of their products at a 200-240 V three-phase and 380-480 www.yaskawa.com cost-effective price.” V three-phase. Other standard features The goal to reduce cost of include an open loop V/f control with ownership is accomplished by compact a 40:1 speed range, starting torque of

medium voltage control, the OneGear OneGear line of products can be used with full Product Line voltage and solid-state, reduced voltage applications and it supports operating OFFERS MAXIMUM voltages up to 15 kV. OneGear uses MOTOR USE vacuum-contactor and circuit-breaker switching technology for ﬂ exible The Allen-Bradley OneGear solutions. Each product is available with product line from Rockwell Automation arc-resistant cabinets, and they provide supplies a full range of motor and power remote monitoring, diagnostic capability control center options. The line includes and detailed motor protection, so the the full voltage non-reversing controller, maximum motor utilization can be intelligent protection systems and 10 achieved without damage or downtime. kV to 15 kV SMC Flex controllers. “OneGear is a complete line of medium Designed for next generation voltage control products that have been

8006 powertransmissionengineering december 2008 www.powertransmission.com product news

designed to meet global standards,” controllers, as well as main and tie NEMA, which is restricted to North says Ralph Paling, manager, integrated breaker units,” Paling says. “OneGear America alone.” marketing communications at Rockwell will offer a complete line of non-variable Automation. speed medium voltage control.” For more information: The inaugural products are only a When asked how the product Rockwell Automation Response Center start for the OneGear line. “Over the line may help to expand Rockwell 1070-1 Hampshire Avenue South next three years, OneGear will expand Automation’s customer base, Paling Bloomington, MN 55438 Phone: (800) 223-5354 x 2118 and feature a complete line of motor points out that, “OneGear allows www.ab.com/mvb/onegear.html control products which will include Rockwell Automation to market reversing, multi-speed and synchronous these products globally, instead of just

Redesigned Air Motors

MINIMIZE NEED FOR COMPRESSORS

A redesigned series of air motors from Huco Dynatork has reduced the need for air compressors in paint stirring applications. Plants in both the United States and the U.K. have switched from traditional vane motors to air motors. According to the company’s press release, one automobile plant is saving over $150,000 annually on power and equipment costs. Via an integral rotary valve, air up to 100 psi is supplied to each of the displaying similar characteristics to a supplied as fully submersible units for three pistons in turn. The free-ﬂ oating stepper motor. lubricated or non-lubricated operation. pistons transmit torque on start-up that “The original purchasing criteria The air motors are available with can be adjusted via a pressure regulator, for the motors, given by the U.K. maximum torques up to 16 Nm or resulting in high torque at variable low automaker, were greater reliability 550 Nm with gearbox. Huco has also speed and low noise. on 24/7 operation and freedom from introduced a new controller that holds Because the Dynatork air motor lubrication to avoid the possibility of the motor speed constant under variable traps the compressed air within the contamination,” said David Lockett, load for paint and other liquid stirring piston/cylinder, allowing for maximum joint managing director of Huco applications where torque reduces as the energy conversion, the unit is easier to Dynatork. “However, by changing to paint or liquid levels fall. seal than a vane motor cylinder. The the air motor, this manufacturer has air motor consumes up to 80 percent gained considerably more. The company For more information: less air than a vane motor, providing has now installed 42 Dynatork motors Huco Dynatork (Altra Industrial Motion a signiﬁ cant cost savings even at which have provided a capital saving of Co.) maximum torque. It can be used in two 600 scfm compressors and an overall Merchant Drive Hertford, England SG13 7BL harsh and hazardous environments power saving of 152 kVA per year.” Phone: (44) 1992 501900 thanks to redesigned internal air Available in aluminum, stainless www.huco.com passages that replace the external tube steel for harsh environments and structure, and it can operate in constant plastic for high-pressure washdown start-stop applications under loads environments, the air motors can be

www.powertransmission.com december 2008 powertransmissionengineering 2119 product news product news

The ProJet CP 3000 and CPX 3DDynamometer Production 3000 use standard investment-casting Systems materials and processes for investment System Family casting of ﬁ nal parts that are produced with 3D Systems’ VisiJet CP200 or EMPLOY DISSOLVABLE WAX CPX200 wax build, a new material, and SUPPORTCOMPATIBLE TECHNIQUE WITH VARIOUS TESTING APPLICATIONS Visijet S200 dissolvable wax support material, which together create wax The ProJet CP 3000 3D production patterns for casting. The 3D printers are system from 3D Systems Corporation capable of complex or highly-detailed produces high-speed, high-volume geometric shapes, which traditional casting patterns from digital data for CNC or milling procedures cannot foundry prototyping and end-use produce. parts applications such as medium- The dissolvable wax support system to large-sized mechanical parts for leaves smooth support-side surfaces engines, pneumatics, aerospace, while both build and support materials general manufacturing and other do not require special handling and are heavy equipment. The company also environmentally friendly. The process released the ProJet CPX 3000 system, does not entail production patterns which specializes in high-resolution from photocurable materials, which may production of extremely detailed wax be subject to thermal expansion during patterns for medical instruments and casting, effectively limiting the part-size devices, mechanical parts, replicas and and geometries capable of being cast. other uses. The CP 3000 production system

www.powertransmission.com april 2008 powertransmissionengineering 15 1000 powertransmissionengineering december 2008 www.powertransmission.com product news

has a large x-y-z build volume (11.75 x 7.3 x 8 inches) and a single-pass print- Digital Module Range head design, so it can build one large or several smaller patterns across the INCREASES POWER OUTPUT, SUITS MEDICAL USES x-y build area without giving up build time. Longer unattended operation is possible with both production systems by optimum use of the z-direction build volume—in the CP 3000 case— facilitated by part stacking and nesting features for the patterns produced. “We are very pleased to be able to deliver the new ProJet CP 3000 3D production system, the fi rst high-volume wax pattern production system designed specifi cally for general foundry casting applications,” says Buddy Byrum, senior director of 3D printing solutions for 3D Systems. “The ability of this new precision manufacturing tool to quickly produce easy-to-cast precision wax patterns directly from CAD should reduce our customers’ cycle time and production costs, resulting in improved fi nal part quality and functionality.” The ProJet CPX 3000 production system has two optional build modes. A new range of digitally controlled bit microcontroller for integrating A high-defi nition, HD, mode creates output modules has been added to the maintenance processes, which effectively small to large parts that have excellent NV-Power family of confi gurable AC- replaces discrete components such as surface fi nish. In the extreme high DC power supplies from TDK-Lambda comparators and op amps. This feature defi nition, XHD, mode, a 16 micron Americas. The new range increases reduces the parts count to 50 percent, layer thickness is provided for parts power output up to 1,450 W peak rating making room for 40 percent more board with fragile, fi ne-feature detail common for 10 seconds. They suit the industry space for power components while in micro-casting applications. demand for low-profi le confi gurable power densities are capable of up to 19 “We are delighted to deliver a true, power solutions from 350 W to over W/in³. fast, 100 percent wax-based investment 1,000 W for broadcast instrumentation, The new range of output modules casting solution, ideal for foundry and medical equipment, ATE, automation, are components designed for use with other industry segments that addresses routers, servers and security networks. the NV-350 and NV-700 series power all of the required professional casting This trend for low-profi le supplies. requirements and is packed with real power solutions “is being driven by Up to 350 W of output power with cost savings,” Byrum says. requirements for higher effi ciency power <180 VAC mains is possible with the supplies, smaller equipment, portable NV-350 series. It provides up to 660 For more information: equipment and the increasing need for W continuous with >180 VAC mains, 3D Systems Corporation standard product easily adaptable to and up to six outputs users choose can 333 Three D Systems Circle custom output voltages,” says Dorrel be achieved in a 1.6 x 3.75 x 10.8-inch Rock Hill, SC 29730 Phone: (803) 326-3900 Vernon, senior product manager at package. www.3dsystems.com TDK-Lambda. The NV-700 series supplies up to [email protected] The modules’ digital control is 700 W of output power with <180 VAC useful for customizing an application mains and up to 660 W continuous with based on specifi c requirements. An >180 VAC mains. As many as eight user integrated magnetic transformer outputs can be provided in a 1.6 x 4.92 x makes the modules smaller and more 10.8-inch package. effi cient. The NV-Power uses an eight- continued

www.powertransmission.com december 2008 powertransmissionengineering 2111 product news

The modules include EMC- in this standard is reinforced insulation the user. improving design features such as for medical applications. “The new digitally controlled Lambda’s patented Multi Resonant “Reinforced or double insulated module range was designed for full Topology (MRT). “[This] is an power supplies must withstand a compliance to reinforced insulation electronic design by which switching dielectric test at 4 kV for medical specifi cations, eliminating the need losses are dramatically reduced, and applications, whereas the corresponding for end users to design in additional therefore enables higher effi ciencies fi gure for industrial use is just 3 kV,” isolation on the end equipment.” to be achieved—typically around 90 Vernon says. “Any shortcoming in Suitable medical applications percent,” Vernon says. “MRT also isolation would result in a higher risk include MRI, ultrasound, optical lasers, features soft switching, which minimizes of electric shock for a patient or system x-ray equipment, blood/chemical the generation of switching spikes and operator. analyzers, surgical equipment, chargers, harmonics, ensuring that the power “Power supplies that are approved hospital beds, incubators and patient supplies offer excellent EMC/EMI to less than 4 kV may be used in medical monitors. performance.” applications as part of a reinforced barrier, This new range of modules in provided that the insulation provided by For more information: particular appeals to medical equipment the power supply is regarded as a lesser TDK-Lambda Americas, Inc. applications because the input to output ‘basic’ or ‘supplementary’ barrier,” he 3055 Del Sol Blvd. isolation meets the 4 kVAC reinforced says. “In this case additional isolation is San Diego, CA 92154 Telephone: (619) 575-4400 requirements for medical use. TDK- required within the end equipment to Fax: (619) 429-1011 Lambda conforms to the international achieve the requirements of a reinforced www.tdk-lambda.com standard IEC601. A substantial category barrier between the mains supply and

Transformer Relays

REMOVE TRIPPING, MAGNETIZING INRUSH

Schweitzer Engineering Labora- away with tripping caused by external total winding. Internal error damage tories, Inc. introduces the SEL-787 faults and magnetizing inrush states. is reduced using a sub-cycle adaptive and SEL-487E transformer protection Both products feature differential element, and the relay relays, which employ simultaneous Commissioning Assistant software that monitors and controls breakers and harmonic blocking and restraint to do recognizes unsuitable CT conﬁ gurations disconnect switches with front-panel and produces compensating settings. LCD one-line diagrams. They can combine with substation “With transformer manufacturing control systems using serial ports, dual lead-times exceeding two years and failover Ethernet connections and prices doubling in the past four years, various protocols. no one can afford to be caught off guard The SEL-787 relay can replace most losing a transformer,” says Joe Mooney, electromechanical relays to safeguard SEL R&D manager. “We developed two-winding transformers in industrial these advanced transformer relays to plants, utilities and other mission- provide the best return on investment critical facilities. It connects to networks for every power transformer.” using Modbus, DeviceNet, DNP3 and IEC 61850 protocols, and it takes plug- For more information: in modules for AC voltage and neutral Schweitzer Engineering Laboratories, Inc. current, I/O, communications or RTD 2350 NE Hopkins Court inputs. Pullman, WA 99163 Phone: (509) 332-1890 The SEL-487E shields and Fax: (509) 332-7990 monitors transformers with two to ﬁ ve www.selinc.com windings. The relay can identify turn- to-turn faults that are 2 percent of the

12006 powertransmissionengineering december 2008 www.powertransmission.com Music in Motion WOODWORKING PROCESS GETS MUCH NEEDED UPGRADE FOR GUITAR MANUFACTURER

Matthew Jaster, Associate Editor

Experienced guitar players will tell you the feel of the fret board is one of the most important factors when selecting a guitar. Some will even sacrifi ce the tonal characteristics for just the right “feel” from the neck and fret board. Guitar manufacturers believe the machining of the fret board is a key operation that contributes to the instrument’s quality and playability. Engineers at C.F. Martin & Co., an acoustic guitar manufacturer based in Pennsylvania, thought its own fret board machining process was in need of an upgrade. In the original process, the required fi nish was produced by a special swinging jig that held the fret board while putting it through a motorized sanding belt. This handmade process made it easy for particles to clog the sanding belt, causing vibration. In order to achieve the required quality of the fi nish, the fret boards often had to be put through the process twice. Fred Walters, engineering project manager at Martin, enlisted the assistance of Brian Rasley, a local machine builder and CNC applications consultant in Pennsylvania, to determine if the machining process could be improved. “We were in the initial planning stages to upgrade the process when Rasley came along with a few ideas for a new system,” Walter says. “This seemed to be a much better solution to the old method that was done by hand.” Rasley found several issues that needed to be addressed in order to meet C.F. Martin & Co. is celebrating its 175th anniversary as the oldest surviving guitar continued manufacturer worldwide.

www.powertransmission.com december 2008 powertransmissionengineering 12113 Martin Guitar’s standards: “Lunn jumped on board immediately interface (HMI touch screen) that • The belt would clog because and was very helpful as we developed allows Martin to load the optimum several boards would run on the the machine concept and how to employ sanding routine based on the different same tangent point some of Baldor’s newest products,” wood used. Included in the HMI • All the material was being Rasley says. “He came to the shop screens are diagnostics, a belt changing passed over the belt on the fi rst several times to help with integrating, process, sander speeds, initial offset and run wiring, etc. until we had motion.” secondary offset. • The operator had to be very The upgraded system includes two “The machine is safe, versatile and skilled to run the fi ngerboards vector motors that power the sanding can accomplish much more than the old • There was only one belt in belts, two servo motors that raise the system could accomplish,” Cooper says. operation sanders and a servo motor that swings “The key is the accuracy. It’s the most • The tooling changeover was too the fret board in an arc. The swinging important aspect of the upgrade.” long arm is powered by a linear motion axis The architecture of the machine • The jig wasn’t rigid and would that moves it across the sanding belts. is based on a Powerlink-compatible fl ex while sanding Lunn believes converting a machine controller called NextMove • It was diffi cult to run Micarta, handcrafted process requires precision e100 that controls all six axes of a material frequently used at and repeatability on the part of the new movement. By using Powerlink, the Martin machine. electrical design of the machine is • The ivoroid binding would burn “This was achieved with a motion simplifi ed. Programming was also and spark sometimes controller, linear and rotary servo motors made easier by using Baldor’s MINT • They couldn’t do the fl at sanding and a very well built and robust design environment, an in-house programmable on the previous system of the system,” Lunn says. “Considering language from Baldor that can handle Rasley concluded that the company Brian Rasley had not used Baldor motion motion, I/O and HMI tasks. needed a more adaptable system to control products previously, he designed Rasley said his team had to learn incorporate at least four different radii. and built a system that incorporated our MINT programmingprogramming onon the fl y for the He also designed a quick-change tool products and performed perfectly from project. system for changing the radii tooling. the fi rst test run.” “I can’t say it was easy, but we did With the help of David Lunn, the Arthur Cooper, Rasley Enterprises' fi nd that it’s very robust and has a very East Coast regional motion control systems programmer, developed an open architecture. The hardest part was specialist at Baldor Electric, Rasley built algorithm for controlling the sanding the learning curve. Once we learned the a machine with Ethernet-compatible process that removes the material in language, we were off and running.” motion control components that small increments while minimizing The result of the new fret board employs six axes of motion to automate the clogging effects of the sawdust. He machining process has been noteworthy. the sanding process. also programmed a human-machine The machine has been in service since December 6, 2007 and the company is now capable of hitting its daily quota in a shorter period of time. The new machine can run more than 320 pieces in an eight-hour shift. (Previously, 150–200 pieces were sometimes run in an eight-hour shift.) Rasley says the company has gone from 40 percent rework to 3 percent. Production has increased by approximately 60 percent. “Now, they’re looking at the upstream wood milling process so the fi ngerboard rework will probably drop down to 1/2 percent,” Rasley says. “We hit all the issues mentioned earlier and a few more that weren’t on my original list.” The biggest benefi t is the incremental cutting where each pass removes a programmed amount of material. While the arm is swinging through the arc, the machine is moving across the width of the belt; thus, no tangent point clogging. The machine uses a cog free linear motor that moves it 14 inches per second and stops within With assistance from Rasley Enterprises and Baldor, C.F. Martin & Co. has updated its fret board machining process. .002" of the programmed location when

1400 powertransmissionengineering december 2008 www.powertransmission.com ALIFAX ACK & Specialists CREW Linear Power For 55 years Halifax Rack and Screw has manufactured precision engineered gear rack, lead screws, pinions and nuts. Worldwide Leader in high quality gear rack and pinion manufacturing. North America inventory and The new system can run more than 320 support materials. pieces in an eight-hour shift. Worldwide service. in rapid mode. Two weeks or less delivery on most The operators involved in the stock and modified stock. assembly and fi nal setup of the guitars Extensive line of lead screws, power have noticed the quality of the new screws and nuts. fret boards. They can now manage the Phone: 877-664-6735 fret boards more precisely, adjusting Fax: 800-229-7905 the relationship between the front Web: www.halifaxrs.com (roughing) sanding and the rear (fi nishing) sanding to accommodate different style belts as they experiment to fi nd optimum belt performance. Rasley is servicing the machine under a one-year warranty, and says there have been several upgrades to the code as well as additional features to Power improve the operation. He has quoted several other motion control projects, including an automated side press Up! machine for Martin and a deep-hole drilling machine for a Pennsylvania lumber company.

For More Information: Baldor Electric Company 5711 R.S. Boreham, Jr. St. Fort Smith, AR 72901 Phone: (479) 646-4711 Fax: (479) 648-5792 www.baldor.com

C.F. Martin Guitar & Co. 510 Sycamore Street If you have a background in gears, bearings, motors, belts, couplings, Nazareth, PA 18064 sensors or actuators, we’d like to talk to you. Powerplay, the new back page Phone: (610) 759-2837 feature in PTE, is all about your industry. If you’ve got a funny anecdote, an Fax: (610) 759-5757 interesting observation or perhaps a limerick on motion control, feel free to www.martinguitar.com send it our way. This column is dedicated to the stories too radical to make Rasley Enterprises Inc. the cut in industry or product news. We need story ideas, and we’re confi- 905 Lower South Main St. dent you can provide them. Bangor, PA 18013 The rules are quite simple: submit a story idea about the power trans- Phone: (610) 588-9520 mission industry, make it entertaining as well as informative, and become [email protected] a PTE magazine editor-at-large today (salary not included). Submit your www.rasleyenterprises.com award-winning material to [email protected].

www.powertransmission.comwww.powertransmission.comdecemberapril 20020088 powerpowertransmissiontransmissionengineeringengineering 12121150 BSA IS THE FORUM THAT KEEPS BEARING COMPANIES ROLLING

Jack McGuinn, Senior Editor

In today’s increasingly competitive global economy, indus- pany Bearing Service Inc. “Recent international expansion of tries and the companies that serve them are always looking members and participating manufacturers reaches all over the for an edge. Price and quality being routinely accepted as a world. Th e amount of inventory carried by all BSA members given, businesses—large and small—are always looking for a combined is more than any manufacturer has or could af- little help. ford.” For the worldwide bearing industry, that help exists in the Indeed, the not-for-profi t BSA provides synergy be- form of the Bearing Specialists of America (BSA), a collective tween its manufacturing members and distributor companies. of 48 dues paying member companies with more than 2,000 Founded in 1966 by a merger of the Anti-Friction Bearing branches and 45 bearing manufacturers. Th e association’s Distributors Association and the Association of Bearing Spe- scope reaches from North America to Europe, Japan, Brazil cialists, the group serves to provide a forum for networking to and New Zealand. In essence, the BSA exists to serve and rep- share ideas, to off er interactive educational activities and to resent authorized distributors who stock and sell warranted meld the disparate mix of companies into one unifi ed industry ball, roller and other anti-friction bearings for any number of voice. And that voice speaks for a $33 billion industry, with 30 applications. It’s a perfect example of strength through num- million bearings made daily, according to BSA fi gures. bers. “Th e BSA provides a highly effi cient forum to communi- “Any (bearing) manufacturer, large or small, that partic- cate and share information with our manufacturers’ most im- ipates in BSA can have access to a well-trained sales force portant distributor customers,” says William C. Moore, senior unequaled in size to that which BSA member companies pro- vice president of sales development and channel management vide,” says Douglas Savage, president of BSA member com- for SKF Service Division USA. “Nowhere else do we have access to the number of distributor executives and the time to discuss issues and ideas in a sustained fashion.” Th e networking and knowledge sharing that the BSA prides itself for happens in various ways. Th ere is an annual convention, as well as Fall and Winter meetings of BSA committees. Th ey include the Educational Services, Information Technology & Supply Chain and the Distribution-Manufac- turer Relations committees. As for governance, BSA has a board of offi cers and directors who serve at no pay. Perhaps BSA’s greatest contribution is in its sales training activities open to all member companies. Some examples: • Th e Certifi ed Bearing Specialist (CBS) program. Th e only program of its kind in the industry, the CBS qualifi es the specifi c skill sets necessary to cer- tify as a bearing industry professional and specialist. Annual conference provide valuable networking opportuni- Much like an ISO quality program certifi cation, hav- ties for BSA members. ing BSA-certifi ed employees provides a company 0016 powertransmissionengineering december 2008 www.powertransmission.com with credibility in the eyes of its customers. and price quotes to member companies of both groups. Th e • Employee training aids. Th ese include the BSA In- single-format, single-system program is now used by manu- House Training Guide, a detailed primer for indus- facturers, distributors and OEMs. It allows manufacturers and try education. It is used widely for new and reme- distributors to interface regarding inventories, pricing and the dial training. like; streamlines operating effi ciencies and improves accuracy • Bearing Briefs. A bulletin that provides mem- by eliminating manual keyboarding; and reduces now-costly bers with up-to-date information on specifi c topics transportation charges and simply the general cost of doing of note, both technical and otherwise. business. • Online sales training. Sales programs developed and In addition, BSA is a sponsor of the Association Education presented by noted online sales guru Joe Ellers, Alliance (AEA), whose stated mission is “to identify, evaluate tailored specifi cally for the bearing industry. and develop, at an aff ordable cost, educational programs for Also of note, BSA in 2005 published a white paper, “Value use by member associations.” Th e centerpiece of the program of Distribution: 2005; Critical Resources for Bearings Con- is the annual University of Industrial Distribution, a program sumers.” Th e paper provided insights on how leading edge devoted to the special needs of wholesale distributors, “along bearing customers measure distribution value and how to le- with a number of webinars and live training programs cover- verage it to the utmost in doing business. ing topics of interest to BSA member distributors,” according How does a company gain membership? Applicant distrib- to the BSA website. utor companies must for at least two years be involved in the On the political side of the street, BSA is a member of the “stocking, selling and distributing as an authorized distributor lobbying trade group Th e National Association of Wholesal- of a full range of basic types and sizes of new, factory-war- er-Distributors (NAW). NAW pursues government relations ranted bearings for replacement or maintenance purposes,” ac- issues, educational eff orts and a number of other industry-recording to BSA bylaws. Th e product off erings must be diverse lated initiatives. enough to enable the applicant company to “serve and, in fact, Lastly, BSA also has partnered with the National Asso- the applicant must serve, on an eff ective and timely basis, the ciation of Manufacturers and the Coalition for the Future of industrial replacement and maintenance requirements of its Manufacturing. accounts or potential accounts.” Other requirements include “Bearings are a critical component in industry and vital to maintaining a full-time sales force; an adequately equipped the success of the bearing and power transmission distribu- and staff ed offi ce including shipping and warehouse facilities; tor,” says Chuck Kitchen, vice president of Interstate Bearing having a warehouse inventory of new bearings large enough to Systems and vice chairman of the BSA Distribution–Manu- eff ectively service its customers; having personnel capable of facturer Relations Committee. “Technology and practices are drawing specifi cations and recommending changeover appli- ever changing, and so, too, must we. Members of BSA are cations; and to generally assist its customers regarding other among the elite in the bearing industry and are serious about technical, bearing-related issues. the business. While yes, we do compete, we all have a common With those factors in place, BSA’s sales training eff orts goal—to be the best. And BSA provides that forum.” dovetail nicely with a member company’s revenue goals. As For more information: mentioned, BSA enlisted the Ellers method of web-based Bearing Specialists Association sales training programs. Th ey address both inside and direct 800 Roosevelt Road, C 312 sales needs, as well as those of sales managers. Th e training Glen Ellyn, IL 60137 Phone: (630) 858-3838 modules are completely self-paced for incremental progress, Fax: (630)790-3095 with each one taking up to 10 months to complete. Each [email protected] module contains: www.bsahome.org • Content and pre-assignment materials • Audio training lectures which can also be downloaded as MP3 selections • PowerPoint presentation notes for each audio presentation • Corresponding action items to begin implementing • Module tests • Sales manager companion for each module Th ere are also occasional live Q&A teleconferences. As is the case with most professional associations, BSA works at partnering with other groups to its own members’ benefi t. Possibly most notable, it partnered with the Power Transmission Distributors Association (PTDA) in 1998 William C. Moore to develop an electronic format for uploading product info www.powertransmission.com december 2008 powertransmissionengineering 1217 Control System Upgrades Product Testing and Validation Machinery

OPTO 22 EMBEDS SNAP MOTION CONTROL SUBSYSTEM IN PRODUCTION EQUIPMENT TO CONTROL, MONITOR AND GATHER OPERATIONAL DATA

David Crump, Opto 22

orous testing before they’re shipped to customers. Th e G4 Handler is the machine used to perform these tests. Built by Opto 22 manufacturing engineer Ron Schmidt, the machine individually tests each G4 module twice. Perform- ing these tests requires large trays with 50 G4 modules at a time to be loaded into the G4 Handler. Th e trays move back and forth and left and right on X and Y axes, while the machine puts each one through several tests. Th ese include an in-rush current test, minimum and maximum current load tests, as well as inductive, capacitive, and resistive tests, which ensure that the modules can handle signals for varying types of electrical A close-up of the G4 Handler SNAP Pac Motion Control System. equipment such as transformers, power supplies, motors and lights. In the center of Opto 22’s Temecula, pany’s best selling products. “Th e G4 Handler even tests the California factory sits the G4 Handler, “Th e G4 Handling machine will test small LED on each module that lets a large machine used for fi nal assembly our G4 style digital input and output you know when it’s operating,” Schmidt and testing of all of the company’s G4 modules as well as insert the screw into says. modules—single point input/output the modules,” says Ron Koss, produc- However, all this testing fi rst relies modules used mainly for applications tion manager. “Th ese modules will then on the trays of modules moving fl uidly involving the sending and receiving of be used to either sense or switch an AC back and forth. Accomplishing this re- digital signals. Since the introduction of or DC voltage.” quired the use of multiple servos—elec- the G4 in the mid-1980s, Opto 22 has Th e G4s are guaranteed for life, so in tric motors coupled with a position sold millions of these modules, and 20 order to make this guarantee, the com- feedback device used to aff ect mechani- years later, they remain one of the company must submit the modules to rig- cal motion for a specifi ed distance. Re- 0018 powertransmissionengineering december 2008 www.powertransmission.com cently, the servos on the G4 Handler, in service for close to two decades, needed to be replaced. Unfortunately, Schmidt and the maintenance engineers at Opto 22 could not fi nd an economical replacement. Th ey made the decision to replace the G4 Handler’s servo motors with stepper motors. Th is approach is somewhat uncommon, but for Opto 22’s purposes it was a viable and much more aff ordable option. Another reason for switching to steppers was because the G4 Handler upgrade coincided with the release of Opto 22’s SNAP PAC Motion Con- trol Subsystem, which is specifi cally designed for use in motion control applications that utilize steppers, such as Spotlight on the G4 Handler’s air cylinder. winding, cut-off , assembly and packaging. Combining a SNAP PAC programmable automation controller, a SNAP Motion Communication Module, a SNAP Motion Breakout Board and PAC Control, which is the control programming component of Opto 22’s PAC Project software suite, the SNAP Mo- tion Control Subsystem accomplishes multi-axis stepper motor control along with traditional analog, digital and serial-based automation. Th e subsystem was developed in late 2006 and introduced early in 2007 as part of Opto 22’s fl agship SNAP PAC System product line. “With operation of the G4 Han- dler machine already including a host of digital functions and now with a clear The G4 Handler testing modules. need for stepper motion as well, we knew it was an ideal opportunity to test ers,” Riley explains. “Th e encoders con- “Th at older generation Mistic system drive the Motion Subsystem in a quirky vert the movement of the stepper motor was used mainly for digital functions and unique situation where we would be into a pulse that can be measured and that take place within the G4 Handler, embedding Opto 22 SNAP PAC I/O in used to confi rm that the steppers are, in like powering on and off , and activating a machine used to test Opto 22 G4 I/ fact, where they’re supposed to be.” the machine’s reject arm—a small com- O,” Schmidt says. Meanwhile, Schmidt began disman- ponent that removes and dumps any G4 Schmidt worked with Opto 22 de- tling the G4 Handler—fi rst stripping module that fails testing,” Schmidt says. sign engineer Nick Riley, who devel- out the servos and then redressing the According to Schmidt, switching oped the Motion Subsystem, to match belts and harnesses that enable the ma- to the new SNAP PAC System’s high the G4 Handler’s servos to equivalent chine to move trays of modules side to density modules saved signifi cant space, stepper controllers that had enough side and back and forth. Next, the ma- as they provided 16 times the density of torque to adequately move the G4 Han- chine’s Mistic I/O system was removed the old system. Th e overall consolidation dler components. and replaced with the new SNAP PAC benefi t was considerable, and Schmidt “For verifi cation purposes, we also System’s more dense and versatile multi- was able to condense the functionality of continued needed steppers that included encod- channel I/O. www.powertransmission.com december 2008 powertransmissionengineering 12119 six single-channel bricks down to a sin- and Y axes based on the commands sent processes, including position, velocity, gle rack. Th anks to the new SNAP PAC by the SNAP PAC. acceleration, and time delays for the System’s high I/O density, Schmidt was “In this application, one of the major trays of modules as they move back and able to replace an entire 16-channel I/O benefi ts of using the SNAP PAC Sys- forth into proper position for testing. brick with a single 16-channel SNAP tem—and one that our customers who “For the stepping, I programmed the module. have similar motion control needs appre- Motion Subsystem to position the trays “With the PAC system, you can ciate most—is the ability to consolidate underneath the test heads, so in succes- do inputs, outputs, analog, digital, mo- all I/O functions in a single platform,” sion, each G4 module can be properly tion control, serial—we have so much Schmidt says. “In other words, you don’t tested,” Spignese explains. “I was also input/output capabilities that you can need multiple devices or components able to specify smooth stops or abrupt do almost anything you’d like,” Riley to handle typical digital points—like a stops as needed.” says. “With our system—PAC control machine’s limit switches—and then an- Spignese has also programmed the system—you have a single develop- other system for recording analog read- SNAP PAC to record production data, ment environment, which means you ings—like machine temperatures—and specifi c module test results (i.e., pass/ only need one software suite to program then a third system to execute the ma- fails) and this data will be made avail- everything. You don’t need multiple sys- chine’s motion control. With the Opto able to Opto 22 production supervisors tems or multiple programming environ- platform, all sensor and component in- and other authorized personnel. Specifi - ments.” terfacing and all control is performed cally, the OptoDataLink component of Other functions handled by the by a single system, and all functions are PAC Control will enable data exchange SNAP PAC include activating a bolt defi ned using a single development en- between the SNAP PAC System and feeder that inserts a small securing vironment.” company enterprise databases—like screw into each G4 module, control of Th e SNAP Motion Control Subsys- Microsoft SQL Server and Microsoft the air cylinders that rise up and down tem was programmed with PAC Project, Access. In this instance, possessing a as they apply the high voltage test heads the programming suite used with Opto multi-domain control system like the to the modules as well as miscellaneous 22 SNAP PAC Systems. PAC Project SNAP PAC, with its data acquisition analog functions. includes programming software that capabilities as well as connectivity and Th e SNAP PAC System also con- features both scripting and fl owchart- data integration software tools, has trols the Motion Control Subsystem. ing, an HMI development application, proved most benefi cial. Th e Motion Communication Module debugging tools and the OptoMotion While outfi tting the G4 Handler resides on the same rack as the digi- command set, which supports several with the Motion Control Subsystem, tal and analog modules and uses an Magellan Motion Processor commands. Schmidt made a few other changes to RS-485 serial interface to connect to a Kathy Spignese from Opto 22’s prod- make the machine more effi cient and breakout board that, in turn, connects uct support team used these OptoMo- easier to use, including making all the to and drives the G4 Handler’s stepper tion commands to specifi cally defi ne the controls more accessible. Previously, the motors to move the tray tables on the X parameters of the G4 Handler’s motion G4 Handler’s machine controls con- sisted of a collection of switches and indicators situated in various locations on the machine. However, during the motion control upgrade, a good deal of internal space was saved through rewiring these controls to an OptoTerminal-G70 operator interface terminal. Th e terminal serves as a centralized control interface—installed at shoulder level—from which all machine controls are more easily reached. It also aids greatly when training operators on how to use the G4 Handler. For more information: Opto 22 43044 Business Park Drive Temecula, CA 92590-3614 Phone: (800) 321-6786, (951) 695-3000 Fax: (800) 832-6786, (951) 695-2712 www.opto22.com Opto 22 employees raise the control’s interface to improve accessibility. [email protected]

0020 powertransmissionengineering december 2008 www.powertransmission.com High-Capacity Bearings CARRY THE LOAD FOR CHINESE GEARBOX MANUFACTURER

SKF’s new HCCRB bearings allow for heavier loads in various–sized wind turbines.

Th e signing of a contract for more than 5,000 sets of SKF’s With a range of gearboxes suitable for wind turbines from 200 latest high-capacity cylindrical roller bearings (HCCRB) for kW to 2 MW, NGC will boost the competitiveness of their wind turbines will impart added load-carrying capacity, more brand. NGC is a leading supplier in China for gearboxes for reliability and longer life to the Nanjing Gear Company’s wind turbines. It is also a leading supplier in China for high- (NGC) line of gearboxes for wind generation applications. speed and heavy-load gearboxes for many industries, including About 50 percent of the bearings are destined for gearboxes steel and mining. of European and American manufacture, with the remaining Th e HCCRB bearings will be of diﬀ ering sizes—from 150 half going to Chinese and other Asian-country customers. mm bore diameter up to approximately 300 mm—and utilized continued

www.powertransmission.com december 2008 powertransmissionengineering 2211 in all of the classical cylindrical bearing positions in the wind Th e bearings are made of standard-bearing steel 100Cr6, turbine gearboxes where non-separate mounting is acceptable. and the rings and/or rollers are black-oxidized for wind turbine Th is is typically the case in planetary wheels. applications. Krauss points out that the oxidation “assists in re- H. Yueming, NGC general manager, says SKF was chosen ducing wear in the running-in phase of the bearings in such for what represents NGC’s biggest buy from the company to heavily loaded applications.” date because “In the wind power business, we attach great im- Increasing load carrying capacity. According to ISO inter- portance on high quality and innovation. We chose SKF be- national standard 281, there are two ways to increase the load- cause we know that the most important component to ensure carrying capacity while maintaining standardized boundary reliability of the gearbox is the bearing. We will have the best dimensions: bearing supplier in the world to ensure the quality of the gear- 1. Increase the roller dimensions while maintaining the boxes we produce.” He adds, “We also believe that SKF will same number of rollers. provide the best technical service in the bearing fi eld and we 2. Increase the number of rollers and maintain the roller hope to develop long-term cooperation to make technology ex- dimensions. changes to enhance our capabilities.” Th ere are technical problems with the fi rst method because Zhou Zhijin, NGC vice-general manager, comments, “Suc- increasing roller dimensions reduces the inner and outer ring cessful prototype tests and technical information from SKF thicknesses as well as the width of the side fl anges. Th is reduc- experts at their cylindrical roller bearing development center tion results in less ring stiff ness and fl ange strength, which in in Germany were very infl uential in fi nalizing the decision to turn increases the risk of reduced bearing life due to increased select the new high-capacity version.” wear, fretting corrosion, ring creep or even ring fracture. While the HCCRBs are a new product off ering for SKF, Th e second method off ered theoretical improvements— they weren’t developed exclusively for NGC. commonly known by bearing companies—and many have ap- “No, not specifi cally,” says Albert Krauss, SKF product man- plied it to its fullest extent. ager for cylindrical roller bearings. “NGC was just the fi rst cus- A design that allows the maximum number of rollers is the tomer who is using them in series for their gearboxes. However, full-complement design. Th e rollers are placed between the the NGC items are tailor-made for their” gearbox applications. rings, leaving no space for a cage. Such bearings have limita- Krauss adds that the HCCRBs are not yet available in all sizes, tions because the rollers are always in direct contact with each “But beyond the planetary bearings, which are usually” custom- other, causing sliding, increased friction and heat generation. made, “there will be a range of standard dimensions available in Under certain circumstances—among them higher speeds— the future.” the above-mentioned characteristics lead to wear and prema- Unique feature of the HCCRB. Th e unique feature of the ture bearing failure. HCCRB is that load-carrying capacity has been increased sub- Bearings with cages (the vast majority of bearings produced stantially, while maintaining the boundary and internal dimen- worldwide) do not have this problem because the rollers sit sions of standard, cylindrical roller bearings. In eff ect, a bearing in cage pockets, preventing them from contacting each other. was created that boasts load-carrying capacity comparable to a However, the addition of the cage takes up space, which reduces full-complement bearing, but with the added benefi ts of a bear- the maximum number of rollers possible. ing with a cage. Along with the higher carrying capacity, the How Cage Feature was Developed new design off ers increased life. Calculations show that in one Th e unique feature of the HCCRB was achieved by a com- particular application, the SKF Explorer version of the HC- pletely new window-type cage design that resulted in two ver- CRB will have an increase in bearing rating life of 35 percent sions: when compared with the standard, full-complement version, 1. An outer ring shoulder-guided cage (code JA). and 43 percent when compared to a standard caged version. 2. An inner ring shoulder-guided cage (code JB). All of which begs the question—will these bearings serve as With these cages, an extra one or two rollers per row can the gold standard for wind turbine applications? be added to the bearings for the standard range, all of them “We believe so,” says Krauss. “Most of the gearbox manu- separated by a cage. For customized bearings, even more rollers facturers are testing them, and some of them have already de- are possible. It is these rollers that deliver the additional carry- cided to use HCCRBs in their new gearboxes.” ing capacity, while the cage increases bearing life and overall

Bearing Execution Standard SKF Explorer* Customized bearing for Full complement Integrated standard High-capacity High-capacity wind gearbox application cylindrical roller bearing cylindrical roller bearing cylindrical roller bearing with an cylindrical roller bearing with with a machined outer ring guided cage (JA) an inner ring guided cage (JB) brass cage

Number of rollers per row 29 28 26 24 Relative calculated bearing 100 135 109 92 *SKF Explorer bearings with increased load-carrying capacity.

2002 powertransmissionengineering december 2008 www.powertransmission.com performance compared to a full-complement version. Th e new cages diff er from the standard cage in a number of ways that are not readily apparent. Most noticeable is that the standard cage is oriented around the connection circle of the mid-points of all rollers, while the new cages are moved toward the outer ring (JA type) or the inner ring (JB type), thus allowing more space for more rollers (Fig. 1). Th e new cage designs were tested with prototype HCCRB bearings for more than one year in many diff erent tests to fully evaluate their capabilities and compare them with bearings fi t- Figure 1—Type JA left; Type JB right. ted with standard cages and full-complement bearings. All tests showed no limitations of the new bearing designs compared to 1 2 standard designs. In fact, the new cage designs provide the following additional benefi ts: 1. Improved oil fl ow via the decreased cross section of the cage, which reduces heat generation. 2. Lower weight that reduces inertia forces. 3. Reduced slip in low-load conditions, which reduces the risk of smearing. Comparisons of Diff erent Designs in Wind Turbine Gearbox Figure 2 shows a gearbox application where the bearing un- 3 4 der consideration is supporting a planetary wheel. Calculations of four diff erent bearing types show that the two new HCCRB bearings signifi cantly outperform both the standard caged ver- Figure 2—(1) Full-complement bearing; (2) HCCRB version sion and the standard full complement version. JB; (3) standard CRB with brass cage; (4) HCCRB version JA. Th e new HCCRB bearings will enable NGC to off er higher load carrying capacity to their customers while aff ording them either enhanced gearbox reliability or a smaller gearbox, depending on the expected loads to be transmitted through it. And with wind turbine designs increasing in size and MW output all over the world, this positions NGC for greater new- business potential for large-sized turbines. For more information: SKF Group Communication P.O. Box 2350, NL-3430 DT Nieuwegein The Netherlands Phone: +31 (0) 30 607 56 08 Mobile: +31 (0) 653 944 111 Fax: +31 (0) 30 604 38 12 [email protected] Nanjing Gear Co. headquarters. www.skf.com

www.powertransmission.com december 2008 powertransmissionengineering 12123 0024 powertransmissionengineering december 2008 www.powertransmission.com www.powertransmission.com december 2008 powertransmissionengineering12521 Selection and Performance CRITERIA FOR POWER TRANSMISSION COUPLINGS— PART II Eugene I. Rivin

“A flexible coupling, although it is relatively small and cheap compared to the machines it connects, is a critical aspect of any shaft system, and a good deal of attention must be paid to its choice at the design stage.” —from the Resolution of the First International Conference on Flexible Couplings

Introduction in the misalignment-compensation di- or less compensating ability. Part I of this article appeared in the rections (compression of rubber ring). For torsionally fl exible and com- October 2008 issue. It provided an over- Figure 9b shows a torsionally fl exible bination-purpose couplings, torsional view and general classifi cations of power coupling with a metal fl exible element stiff ness is usually an indicator of pay- transmission couplings, along with selec- (Bibby-style coupling). Th e fl exible el- load capacity. In such cases, the basic tion and performance criteria for rigid ement is a spring steel band wrapped design criterion can be formulated as a couplings and misalignment-compen- around judiciously shaped teeth on ratio between the stiff ness in the basic sating couplings. Part II continues the each hub and deforming between the misalignment direction and the tor- discussion with selection and perfor- teeth. Th e deformations become more sional stiff ness. In the following analy- mance criteria for torsionally fl exible and restrained with increasing transmitted sis, only radial misalignment is consid- combination-purpose couplings. torque; thus the coupling has a strongly ered. Since couplings are often used as Torsionally Flexible Couplings and nonlinear torsional stiff ness character- the cheapest connectors between shafts, Combination Purpose Couplings istic of the hardening type. Th e lowest and since end users often do not have Torsionally fl exible couplings usu- stiff ness is at zero torque (Fig. 9c) in- full understanding of what is important ally have high torsional compliance (as creasing towards the rated torque (Fig. for their applications, it is of interest to compared with the torsional compli- 9d), becoming very high at the allowed analyze what design parameters are im- ance of shafts and other transmission peak torque (Fig. 9e) and approaching portant for various applications. components) in order to enhance their a rigid condition at an overload/shock Torsional Flexibility infl uence on transmission dynamics. torque (Fig. 9f ). Since some misalign- Torsional fl exibility is introduced Figure 9a shows an example of a purely ment-compensating ability is desirable into transmission systems when there is torsionally fl exible coupling with an for many applications, use of purely tor- a danger of developing resonance con- elastomeric fl exible element having sionally fl exible couplings, with combi- ditions and/or transient dynamic over- low stiff ness in the torsional direction nation-purpose couplings being used as loads. Th eir infl uence on transmission (shear of rubber ring) and high stiff ness torsionally fl exible couplings with more dynamics can be due to one or more of

0026 powertransmissionengineering december 2008 www.powertransmission.com the following factors: torsional compli- would not have any noticeable eff ect at such as a wheel of the vehicle or a cut- ance, damping or nonlinearity of load- low output rpm, compliance of a cou- ter of a mininga combine) would be very defl ection characteristics. pling installed in the low-speed part of eff ective, but the coupling size and cost

Reduction of torsional stiff ness of the the system (close to the working organ, might becomebecome excessiveexcessive duecontinued to high transmission and, consequently, shift of its natural frequencies. If a resonance condition occurs before installation (or change) of the coupling, then shifting c of natural frequency due to use of a No torque high torsional-compliance coupling can d Normal (rated) torque eliminate resonance; thus dynamic loads e and torsional vibrations will be substan- Maximum (peak) torque tially reduced. However, in many trans- f missions (e.g., vehicle transmissions), Overload (impact) frequencies of the disturbances acting on the system and natural frequencies a (especially in variable speed transmis- b sions) may vary widely. In such instanc- Fig. 9—Torsionally-flexible, radially-rigid couplings: a) Dynaflex LCD, Lord Corp.; b) es, a simple shift of the natural frequen- all-metal Bibby coupling. cies of the drive may lead to a resonance Nomenclature occurring at other working conditions, but the probability of its occurrence is D External diameter not lessened. A reduction in the natu- d Internal diameter c ral frequency of a drive, for example, is No torque advisable for the drive of a milling ma- L Length d Normal (rated) torque chine only at the highest spindle speeds e and may be harmful if introduced in the Fcom Radial force, or bending moment Maximum (peak) torque low-speed stages. f Ft Tangential force A shift of natural frequencies of the Overload (impact) drive may be benefi cial in transmissions Ref Effective radius with narrow variations in working con- T Transmitted torque ditions. If, however, a drive is operated b in the pre-resonance region, an increase µ Friction coefficient in torsional compliance would lead to increased amplitudes of torsional vibra- k Stiffness factor tions, and thus to a nonuniform rota- kcom Combined stiffness of elastic connectors tion. In some cases excessive torsional compliance may lead to a dynamic in- E Radial misalignment stability of the transmission and create D Pitch Diameter intensive self-excited torsional vibra- p tions. θ Angular misalignment An important feature of multispeed L Sound pressure level or variable-speed transmissions is the eq changing of eff ective torsional compli- η Efficiency ances of components with changing output speeds due to changing reduc- ksh Shear stiffness tion coeffi cients, although the physical ψ Relative energy displacement condition of the components does not change (Ref. 1). As a result, the role of V Potential energy the coupling as a compliant member can dramatically change depending on Pt Tangential force confi guration of the drive. While com- W Energy per coupling revolution pliance of a coupling of any reasonable size installed in the high-speed part of β Loss factor of rubber the system (close to the driving motor) www.powertransmission.com december 2008 powertransmissionengineering 2127 ��= .4 ��= 1.5 torques transmitted to the spindle at low rpm. Increasing eff ective damping capacity of a transmission by using a high T = O damping coupling or special dampers. When the damping of a system is in- O, 1S O, 1S creased without changing its torsional stiff ness, the amplitude of torsional vi-

Fig. 10—Dynamic load in a milling machine drive with: a) manufacturer-supplied brations is reduced at the resonance and motor coupling (δ = 0.4); b) high damping motor coupling (δ = 1.5). in the near-resonance zones. Increased damping is especially advisable when a b there is a wide frequency-spectrum of disturbances acting on a drive; e.g., for the drives of universal milling machines. Th e eﬀ ect of increased damping ina torsionally ﬂ exible coupling of a milling machine transmission is illustrated in

Figure 10 (natural frequencies fn1 = 10

Hz, fn2 = 20 Hz). Figure 10a shows the resonance for an OEM coupling (ﬂ ex- d ible element made from neoprene rub- c ber, log decrement δ ≈ 0.4). After this element was made from a butyl rubber (same compliance, but δ ≈ 1.5), the peak torque amplitude was reduced by ~ 1.8 times, the clearance opening (source of intensive noise) was eliminated, and

oscillations with fn2 excited by the second harmonic of the excitation force, became visible (Fig. 11b). A common e misconception about using high-damping elastomers for coupling elements is their alleged high heat generation at resonance. Due to vibratory torque amplitude reduction with high-damping couplings, the heat generation at the resonance is decreasing when the high- damping coupling is used (Ref. 1). Th e infl uence of a fl exible element on the total energy dissipation in a transmission increases with increasing of its damping capacity, of the torque amplitude in the �� f element and of its compliance. For maximum effi ciency, the fl exible element of a coupling must therefore have as high an internal energy dissipation as possible; it must also possess maximum permissible compliance, and must be located in the part of the system where the intensity of vibrations is the greatest. Introducing nonlinearity in the Fig. 11—Some combination purpose couplings: a) spider (jaw) coupling; b) modi- transmission system. A nonlinear dy- fied spider coupling (lip providing bulging space for the rubber element); c) fin- namic system may automatically detune ger-sleeve coupling; d) toroid shell coupling; e) rubber disc coupling; f) Centaflex away from resonance at a fi xed-fre- coupling. quency excitation. For example, when 0028 6 powertransmissionengineering december 2008 www.powertransmission.com damping is low, a relative change of the might be noisier than it would be with a tion), and α is angle of rotation of the stiff ness by a factor of 1.3 reduces the coupling type optimal for the given ap- coupling. Equation 15 shows that the resonance amplitude by ~1.7 times, but plication, etc. total radial force F fl uctuates both2 in F k a relative change of stiff ness by a factor Figure 11 shows some popular de- magnitude and in direction2 duringr one 2 k   2k t cos   2 sin  (15) of 2 reduces the resonance amplitude by signs of combination-purpose cou- revolution.com e k t ~1.85 times. Th us, nonlinear torsionally plings. For a coupling with Z ≥ 6, fl exible couplings can be very eff ective Combination-purpose couplings do in transmissions where high-intensity not have a compensating member. As a (16) k = F = n (k + k ) torsional vibrations may develop and result, compensation of misalignment is com e 2 t r where the coupling compliance con- accomplished, at least partially, by the or F is constantconstant and is directeddirected alongalong stitutes a major portion of the overall same mode(s) of deformation of the the misalignment vector. compliance. fl exible element as used for transmitting Th e ratio kr /kt var variesies with c chang-hang- Vehicles usually have variable speed the payload. To better understand the ing rubber durometer H, and fforor ttypicalypical 2 4 4 transmissions. Th e same is often true for behavior of combination-purpose cou- spider proportions,End kr /kt = 0.26–0.3Gd 2 forfor k  F ; k  k , (17) production machines. In order to keep plings, an analysis of the compensating mediumt H = 40–50,3 andr 2kr /kt 3= 0.4r for2 k 3.74 D 2k t cos 8D n 2 sin  (15) the coupling size small, it is usually in- performance of a typical coupling with hardcom rubbere spiders, H = 70–75. k 2 F 2 k rt 2 stalled close to the driving motor/en- a spider-like fl exible element is helpful. k A  spring/tubular 2k t cos spider  coupling2 sin  (15) gine, where it rotates with a relatively Th e coupling in Figure 12 shows a sche- modificom catione is shown in Figure k8t (Ref. high speed and transmits a relatively matic of the jaw coupling in Figure 11a. 4). In this design, each leg of the spider k F = =nk nR 2, (18) small torque. At the lower speeds of an It consists of hubs 1 and 2 connected can be representedkcom =tor byt a (effcoilkt + springkr) load- e 2 output member, the installed power is with a rubber spider 3 having an even ed radially by the transmitted torque. k = F = n (k + k ) not fully utilized and the absolute values number Z = 2n of legs, with “n” legs (“n” For the tightlycom e coiled 2 extensiont r spring of torque (and of amplitudes of torsion- might be odd) loaded when hubs are ro- kt; al vibrations) transmitted by the high- tating in the forward direction and the � k com � 1 1.8 speed shaft are small. In vehicles, the other n legs loaded during the reverse for Z =2 4, 4  4  (17);  End� k � GdR 2 R 2 installed power is not fully utilized most rotation. Deformation of each leg is in- kt  tor; k m ar x  eff , ex (17) 3.274 D 34 8 D 34n of the time. Th us, an important advan- dependent. Th e radial (compensation)  End Gd k  ; k2  2 , (17) tage of couplings with nonlinear load- stiff ness of the coupling with Z = 4 is t thus kr /kt = 31/53n r= 0.02/n3 ≈ 0. 3.74 D kcom 1.158 D n� 40 � 50 k com � 1.25 ,H 65 � 75; defl ection characteristics is feasibility forThZ e≥ torsional 6, stiff� ness2 of ,Hboth spider 2 � 2 k tor Rex k tor Rex of making a resonably small coupling F 2 kcouplingr 2 designs is k   2k t cos   sin  2 (15) with low torsional stiff ness and high com (15) 2 ktor = nk Reff , (18) e k t t rated torque. An overwhelming major- (18) 2 k = nk R 2, (18) ity of power transmission systems are F 2 k r 2 tor t eff k   2k t cos   2 sin  (15) loaded with less than 0.5 Tr for 80–90%com k where 0 the.9 eff ective radius Reff = e k t com  2 of the total “up” time. A nonlinear cou- where F is radialradial forceforkce causedcaused F = byb ny the(k +ra-ra- k ) ~0.75Rex = 0.75(Dex/2). Th ee r ratiosatios be- be- com = t r k R e 2 tor ex k com 1 1.8 pling with a hardening load-defl ection dial misalignment e and actingacting onon the tweenfor Z torsional = 4, � and compensation�   stiff -; � � 2 R 2 characteristic such as one in Figure 14 connected shafts, k is stiff ness of one ness values are asktor follows: m a x R eff ex t k com 1 1.8 � �   provides low torsional(a) stiff ness for mostk leg = F in = compression n (k + k ) (tangential direc- for Z = 4, 2 ; 4 com t r 2 10 � � R e 2 ktor m a x R effcontinued ex of the time, but since8 its stiff ness at the tion), kr is stiff ness in shear (radial direc- 5 k A kcom 1.15 � 40 � 50 k com � 1.25 ,H 65 � 75; rated torque is much4 higher, its size can 2 4 4 forcomZ ≥ 6, � 2 ,H 2 � 3  End e Gd  , k R k tor R (19) be relatively small.2 180° – a r y 2 tor ex ex k  l ;l k  , k com 1.15 com (17)1.25 t 3 r 3 tor Rex k k 103 for Zd≥ 6, � ,H � 40 � 50 � ,H � 65 � 75; Compensation8 Ability of 3.74 D 8 D n r 2 2 e k tor Rex k tor Rex 5 t Combination-PurposeKtor 4 Couplings. 2 4 l 4 kr Nm 3  End Gd A huge rad variety of combination- 2 kt  3 ; k r  3e , (17) purpose couplings is commercially3 .74 D 8 D n 102 k com 0.9 8 d2 available. Unfortunately, selection of a R 2  2 5 ktor =l nk Reff , 0 (18) 4 t k tor R ex coupling type for3 a specifi c application k com 0.9 x 4 5 8 10 20 30 40 50 80 100 200 300 500  2 is often based not on anRATED assessment TORQUE, Nm of k 1 R k tor R ex r performance (b) characteristics3 of various k = nk R 2, 2 (18) 2 tor t eff couplings, but on the coupling cost or e 103 8 k d other non-technical considerations. � com � 1 1.8k 3 5 for Z = 4,  3 com ; A Kcom 4 2 2  As a result, bearings of the shafts con- � k � 2 R R 2 , (19) N 3 tor m a x eff k ex R mm 2 tor ex nected by the coupling may need to be k com A 2  , (19) 10 � k com � 1 1.8 2 more frequently replaced80 than whenfor Z an = 4,   ; k R Fig. 12—Schematic2 of a spider2 coupling: hubs (1,tor 2) andex rubber spider (3). 50 � � R R kcom 1.15 k com 1.25 optimized coupling40 is used; the device ktor m a x f o r Z eff≥ 6, ex ,H � 40 � 50 � ,H � 65 � 75; 30 � 2 2 4 5 8 10 20 30 50 80 200 400 R k tor R 40 100 300www.powertransmission.com k tor decemberex 2008 powertransmissionex engineering12921 RATED TORQUE, Nm (c) kcom 1.15 k com 1.25 200 � 40 � 50 116� ,H 65 � 75; for Z ≥ 6, � 2 ,H 113 118b2 � k tor Rex k tor Rex Dex 100 114 mm 80 50 2 40 k 0.9 4 5 8 10 20 30 50 80 100 200 400 com  117b RATED TORQUE, Nm 2118a (d) k tor R ex 115 2 D 112 2 117a k com 0.9 � 1  111 D1 0.8 2 121 0.5 k tor R ex 0.4 4 5 8 10 20 30 50 80 100 200 400 RATED TORQUE, Nm 120 k com A  2 , (19) k R 2 tor ex 119 0 k com A d1  2 , (19) k R tor ex d2 2 F 2 k r 2 k   2k t cos   22sin  (15) com eF 2 kktr 2 k   2k t cos   2 sin  (15) com e k t

k = F = n (k + k ) com e 2 t r k = F = n (k + k ) com e 2 t r 2 F 2 k r 2 k   2k t cos   2 sin  (15) com Fe k 2 2 tr 2 2 4 4 F 2 k rk 2  2k t cos   2 sin   End Gd(15) k   2k t cos   sincom  e k (15) com 2 t kt  2 4 ; k r  4 , (17) e k t 3.74EndD 3 8GdD 3n kt  ; k r  , (17) 3.74 D 3 8 D 3n k = F = n (k + k ) com e 2 t r F = n kcom = (kt + kr) k = F = n (k + k ) e 2 com e 2 t r 2 ktor = nkt Reff , (18) 2 ktor = nkt Reff , (18) 2 4 4  End Gd kt  2 34 ; k r  34 , (17) 2 4 4 3.74EndD 8GdD n  k  ; k  , � k c o m � (17)1 1.8 End Gd t 3 r 3 for Z = 4,   ; kt  ; k r  , 3 . 74 D 8 D n (17) 2 2 3 3 � kk com � R1 1.8R 3.74 D 8 D n for Z = 4, � tor m � a x  eff  ex ; � � 2 R 2 ktor m a x R eff ex 2 ktor = nk Reff , k com 1.15 (18) k com 1.25 t for Z ≥ 6, � ,H � 40 � 50 � ,H � 65 � 75; 2 R 2 k R 2 k = nk R , k k tor com 1.15 ex (18) ktorcom 1.25ex 2 tor t eff for Z ≥ 6, � ,H � 40 � 50 � ,H � 65 � 75; ktor = nkt Reff , (18) 2 2 k tor Rex k tor Rex

k com 1 1.8 for Z = 4, � �   ; � � 2 2 k com R1 1.8R k com 0.9 for Z = 4, � tor m� a x  eff  ex ;  (18b) A alallowslows oonene to select a coupling design � k com � 1 1.8 2 2 2 for Z = 4,   ; � k � R R k torcom R0.9 better suited to a specifi c application. If � k � R 2 R 2 tor m a x eff ex  ex tor m a x eff ex (18a) In general,general, the ratioratio 2of radialradial (com-(com- the main purpose is to reduce misalign- k tor R kcom 1.15 � 40 � 50 k com � 1.25 ,H 65 � 75;ex for Z ≥ 6, � 2 ,H pensating)2 stiff �ness and torsional stiff - ment-caused loading of the connected R k tor R kcomtor 1.15ex com ex for Z ≥ 6, k ,H � 40 � 50 kness �of1.25 a combination-purpose,H 65 � 75; fl exible shafts and their bearings for a given kcom 1.15 k com 1.25� 2 2 � for Z ≥ 6, ,H � 40 � 50 � ,HR 65 � 75; k tor R � 2 k tor 2 �ex coupling excan be represented as value of torsional stiff ness, then the k tor Rex k tor Rex k A c o m least value of A is the best, togtogetherether with  2 , (19) k A for the spring spider coupling per Fig- toc o r m R e x (19) a large external radius. If the main  2 , (19) urek 8, Z = 06,.9 k R purpose is to modify the dynamic char- com  tor ex 2 wherewhere the “Coupling Design IndexIndex”” acteristics of the transmission, then kk comtor 0R.ex9 k com 0.9  2 minimization of ktor is important.important.  k R 2 tor ex Comparison of Combination k tor R ex (a) Coupling Designs. 104 8 Th e bulk of designs of torsionally 5 k com A fl exible or combination-purpose cou-  , 4 (19) 2 3 plings employ elastomeric (rubber) fl ex- kk RA 2 e y ctoomr ex 180° – a r k com A  2 , (19) iblel elements.l Couplings with metal  , k R 3 (19) d 2 tor ex 10 r k R 8 springs possess the advantages of being tor ex e 5 t more durable and of having character- Ktor 4 l kr Nm 3 istics less dependent on frequency and rad 2 e amplitude of torsional vibrations. How-

2 ever, they may have a larger number 10 d 8 of partsR and higher cost, especially for 2 5 l 4 smaller sizes. As a result, couplings0 with 3 x 4 5 8 10 20 30 40 50 80 100 200 300 500 metal fl exible elements, as of now, have RATED TORQUE, Nm found 1 their main applicationsR in large kr (b) 3 transmissions, usually for 2rated torques 2 e1,000 N-m and up. Use of the modifi ed 103 spider coupling in Figure 8 may change 8 d3 5 this situation. 3 Kcom 4 2 N 3 Couplings with elastomeric fl exible mm 2 elements can be classifi ed in two sub- 102 groups: 80 (a) Couplings in which the fl ex- 50 40 30 ible element contacts each hub along a 4 5 8 10 20 30 50 80 200 400 40 100 300 continuous surface (shear couplings as RATED TORQUE, Nm in Figure 9a, toroidal shell couplings, (c) couplings with a solid rubber disc/cone, 200 116 113etc.). Usually, torque118b transmission in Dex 100 these couplings is accommodated 114 by mm 80 50 shear deformation of rubber;2 40 4 5 8 10 20 30 50 80 100 200 400 (b) Couplings in which the fl exible 117b RATED TORQUE, Nm element118a consists of several independent (d) or interconnected sections (rubber disk 115 2 112 D2 and fi nger sleeve couplings as in Figure 117a � 1 11111c, spider couplings Das1 in Figures 11a 0.8 121 0.5 and 11b, couplings with rubber blocks, 0.4 4 5 8 10 20 30 50 80 100 200 400 etc.). Usually, torque transmission in 120 RATED TORQUE, Nm these couplings is accommodated large- ly by compression or “squeeze” of rub- 2 Fig. 13—Basic characteristics of some combination-purpose couplings; a) torsional ber; thus they are119 usually smaller for a stiffness; b) radial stiffness; c) external diameter; d) coupling design index.  - 0 spider coupling in Fig. 10b; ∆ - spider coupling with straight rectangular legs; + given rated torque. - finger sleeve coupling; o – toroid shell (tire) coupling;  – rubber disc coupling; Comparative evaluationd1 of the com- – Centaflex coupling; • – test results for coupling in Fig. 12 (same coupling at vari- mercially available couplings based on ous transmitted torque). available manufacturer-suppliedd data2 on 0030 6 powertransmissionengineering december 2008 www.powertransmission.com fl exible couplings is presented in Fig- for the opposite direction (118), between References ure 13. Plots in Figures 13a–d give data hubs (111 and 113) attached to the con- 1. Rivin, E.I. Stiff ness and Damping on torsional stiff ness ktor, radial stiff ness nected shafts. Th is design combines the in Mechanical Design, 1999, Marcel k , external diameter D , andand designdesign desirable nonlinearity with a signifi cantly Dekker, Inc., NY. radrad (a) ex 4 index A. 10 smaller size for a given Tr (due(due toto thethe useuse 2. “Torsionally Rigid Misalignment 8 Th e “modifi ed 5spider” coupling in of multiple cylindrical elements with the Compensating Coupling,” U.S. Patent 4 3 e Figure 11b is diff erent2 from the con- same relative compressiona inr each space 5,595,540.y 180° – l l ventional spider coupling103 shown sche- between protruding blades, and due to 3. “Universaldr Cardan Joint with Elasto- 8 e matically in Figure 11a5 by four features: high allowable compressiont of the rub- meric Bearings,” U.S. Patent 6,926,611. Ktor 4 l kr Nm 3 its legs are tapered,rad instead2 of uniform ber cylinders (Ref. 6),e thus allowing use 4. “Spider Coupling,” U.S. Patent width, and made thicker2 even in the of smaller diameters and, consequently, 6,733,393. 10 d 8 R 2 smallest cross section,5 at the expense many sets of cylinders aroundl the cir- 5. “Torsional Connection with Radially 4 0 of reduced thickness 3of protrusions on cumference). Test results for such cou- Spaced Multiple Flexiblex Elements,” 4 5 8 10 20 30 40 50 80 100 200 300 500 RATED TORQUE, Nm  k the hubs; lips on the edges provide ad- pling for Tr = 350 Nm are shown1 as inR U.S. Patent 5,630,758.r (b) 3 2 ditional space for bulging2 of the rub- Figure 13; in this case the data does not 6. Rivin, E.I. “Shaped Elastomeric Com- e ber when the legs are10 3compressed; and refer to diff erent Tr, but to the same cou- ponents for Vibration Control Devices,” 8 d3 5 3 the spider is made Kofcom a4 very soft rubber. pling at diff erent transmitted torques.2 Sound and Vibration, 1999, Vol. 33, No. N 3 Th ese features substantiallymm 2 reduce stiff - 7, pp. 18–23. ness values while retaining102 the small size 80 50 characteristic of the spider40 couplings. 30 4 5 8 10 20 30 50 80 200 400 Data for “toroid shell” couplings40 100in 300 RATED TORQUE, Nm Figure 13 are for the(c) coupling as shown in Figure 10d. 200 113 116 118b Th e “spider coupling”Dex 100 for Tr = 7 N- 114 mm 80 50 2 m has the number of40 legs Z = 4 while 4 5 8 10 20 30 50 80 100 200 400 117b larger sizes have Z = 6 or 8. Th RATED isis explainsexplains TORQUE, Nm 118a (d) 115 diff erences in A (A = 21.96, closeclose to the- D 112 2 117a oretical 1.8, for Z = 4; A = 0.98–1.28, � 1 111 D1 0.8 121 close to theoretical 0.5 1.15–1.25, for Z = 0.4 6 or 8). 4 5 8 10 20 30 50 80 100 200 400 RATED TORQUE, Nm 120 Values of A are quite consistent for a 2 given type of coupling. Some variations 119 0 can be explained by diff erences in design d1 proportions and rubber blends between the sizes. d2 Plots in Figure 13 help to select a coupling type best suited for a particular application, but do not address issues of damping and nonlinearity. Damping can be easily modifi ed by proper selec- Fig. 14—Torsionally flexible coupling with flexible element composed of radially compressed rubber cylinders. tion of the elastomer. High damping is benefi cial for transmission dynamics, Eugene I. Rivin and may even reduce thermal exposure was a Principal Staff Engineer at Ford of the coupling. Motor Co., from 1976-1981. Since 1981 he has been professor at Wayne State Univ. Major professional achievements of Dr. Rivin are in transmission A coupling with a hardening nonlin- dynamics, vibration/noise control, machine tools/tooling, robotics, advanced machine ele- ear characteristic may have high torsional ments, creative problem solving. He published many monographs, book chapters and compliance for the most frequently used articles. Most recent books: “Mechanical Design of Robots,” 1988; “Stiff - sub-rated (fractional) loading in a rela- ness and Damping in Mechanical Design,” 1999; “Passive Vibration Isola- tively small coupling. Accordingly, the tion,” 2003; “Innovation on Demand,” 2005 (with V. Fey). He authored/ misalignment-compensating properties co-authored 60+ patents, with some inventions widely implemented worldwide. of a highly nonlinear coupling would be Out of this number, 18 patents relate to power transmission components (gears, superior at fractional loads. Th e coupling fl exible and rigid couplings, keys and other rigid interfaces/connections for machine tools and in Figure 14 (Ref. 5) employs radially other mechanical systems). He is an elected Fellow of the International Academy of Produc- compressed rubber cylinders for torque tion Engineering Research (CIRP), of ASME, and of SME. transmission in one direction (117) and www.powertransmission.com december 2008 powertransmissionengineering 12131 Improved Sealing

Technology EXTENDS EQUIPMENT LIFE

David C. Roberts

(Presented at Power-Gen International, December 11–13, 2007, New Orleans)

Failed Bearing Raceway Failed Roller Bearings Figure 1—Failed roller bearing elements.

Introduction technological developments to extend ball and roller bearing failures occur due Th e primary sources of bearing failure time between failures are considered. In to surface fatigue. Either the bearings or are lack of lubrication and contaminant examining MTTR, new products avail- the raceways will begin to pit, resulting ingress. Industrial sealing devices are the able to facilitate and streamline the repair in audible noise (Ref. 1). As the rolling primary protection against bearing fail- process are the central focus. elements continue to degrade, noise and ure. When the sealing device fails, bearing Understanding Bearing Failure vibration increase and, eventually, the failure is imminent. Th erefore, extending Whether the equipment in ques- rolling elements will fracture. Th is ruins the life of sealing devices extends bear- tion is a pulverizer, a turbine, conveyance the bearing system and possibly damages ing life and in turn improves equipment equipment or something else altogether, connected elements. uptime. Th e primary measurements of there is usually a bearing system either A standardized method of predicting equipment uptime are: Mean Time Be- driving or being driven by the equip- bearing failure is the L10 life (also called tween Failures (MTBF) and Mean Time ment. In any application where power is B90 or C90 life), which is based on the To Repair (MTTR). Each of these met- transmitted from one point to the next, a theorem that 90% of a random sample rics is discussed in detail, including their bearing system is used to support rotat- of bearings can be expected to meet or primary methods of calculation. Once ing elements (usually a shaft) and to sup- exceed a stated number of revolutions at established as measurable values, atten- port the related loads, while at the same a given size and load. In actual application is then given to improving MTBF time reducing power losses due to fric- tions, bearing failure is not so straight- and MTTR through sealing innovation. Th e most common types of bearings forward. tions. In examining MTBF, common are ball and roller bearings. Most bearing systems fail to meet causes of premature seal failure and new Under textbook conditions, typical their predicted life due to issues other 0032 powertransmissionengineering december 2008 www.powertransmission.com than fatigue failure. It has been reported appropriately prepared. Th erefore, most when the seal lip is in direct contact with that only 1% (of bearings) actually fail radial lip seals require a shaft surface the shaft, resulting in power losses. As due to pure fatigue. Conversely, the ma- fi nish of 10 to 20 µin (0.25 to 0.50 µm) hydrodynamic sealing is achieved, this jority of bearing failures are from a lu- Ra. In addition to the appropriate sur- power loss is reduced. Further, the direct brication-related issue. Th is means that face fi nish, the shaft must have the ap- contact of the sealing lip against the shaft most bearing failures can be either pre- propriate surface hardness. Most seal leads to seal abrasion and eventual fail- vented or have their service life extended manufacturers recommend a minimum ure. Th e friction and abrasion properties (Ref. 2). Th us by determining the modes hardness of 30 Rockwell C (RC). If the of the sealing material, therefore, play an of failure and methods of prevention of surface hardness of the shaft is less than important role in seal performance. Oth- these lubrication-related issues, bearing this value, grooving of the shaft can oc- er factors that will aff ect seal performance life can be drastically improved, avoiding cur, resulting in leakage. include, but are not limited to, operating the costly expense of bearing failure. It is also necessary to understand that temperature, pressure, misalignment and Understanding the Sealing System single-lip seals are unidirectional—they runout and bore condition. Th e primary system to protect and can either act to retain lubricant or ex- Labyrinth Seals. As the need for extend the life of bearings is the sealing clude debris, but cannot necessarily do energy conservation has increased, non- system. When compared to the costs of both. For the seal orientation shown in contact seals have become more com- repairing or replacing the bearing system, Figure 2, the seal will only retain oil. It monplace in industry. Th e most common the sealing system is much more eco- will not act to exclude foreign debris type of non-contact seal is the labyrinth nomical to address. Typically, the sealing from the bearing system. To exclude de- seal. Traditional labyrinth seals use a tor- system protects the bearing in two ways: bris in a light-duty environment, a seal tuous pathway to block both the escape it reduces excessive bearing temperatures with a dust or scraper lip may be used. of fl uids and the ingress of contami- by retaining lubricant, and it prevents For heavily contaminated environments, nants. Th ey include a static portion that damage from foreign material by exclud- a positive excluder lip design is required is mated to the application housing and ing external debris. Common sealing (Fig. 3). has one or more inside diameter grooves. devices for rotating equipment include: Although in principle radial lip seals A dynamic portion of the seal is mated compression packings, labyrinth seals, ride on a meniscus of oil, in practice this is to the shaft and has one or more protru- mechanical face seals, radial lip seals and not always the case. Th ere will be periods, sions (sometimes referred to as teeth or continued hybrid combinations of these seals. For particularly at start-up and shut-down, decades, radial lip seals have been the most common form of industrial bearing protection. In recent years, labyrinth seals (or bearing isolators) have increased in popularity due to their non-contact features. Radial Lip Seals. A common misconception about radial lip seals is that the lip portion of the seal is intended to be in direct contact with the sealing surface at all times. While this was the AIR SIDE case with early lip seal designs, modern lip seals include specialized geometries to MENISCUS CONTACT create a hydrodynamic sealing element. WIDTH FILM THICKNESS Th ese designs may include “raised heli- 0.00018" (0.0046mm) cal or parabolic ribs, triangular pads, or SHAFT sinuous wavy lip elements” (Ref. 3). Th e Figure 2—Meniscus film thickness is typically 0.00018". hydrodynamic eff ect causes lubricant to recirculate under the sealing lip and back into the bearing system, causing the seal to ride on a thin meniscus of oil, which signifi cantly reduces friction and seal element abrasion. Th e meniscus fi lm is OIL SEAL WITH DUST LIP LIP SEAL WITH GYLON EXCLUDER DUAL OPPOSED LIP SEAL RH SIDE OF SEAL RETAINS LUBRICANT RH SIDE OF SEAL RETAINS LUBRICANT WILL BOTH RETAIN & EXCLUDE typically 0.00018" (0.0046 mm) thick LH SIDE EXCLUDES LIGHT DEBRIS LH SIDE EXCLUDES MEDIUM TO HEAVY DEBRIS MAY BE USED TO SEPARATE TWO FLUIDS (Fig. 2). In order to achieve hydrodynamic Figure 3—For heavily contaminated environments, a positive excluder lip design is required. sealing, it is necessary that the shaft be www.powertransmission.com december 2008 powertransmissionengineering 3321 PT MTBF = N

knives) that run inside the grooves of the vs. downtime is involved. In quantifying Th e maintainability indicator deals with static portion of the seal. For this reason, equipment performance, there are two the time required to retain or restore the static portion of the seal is referred established standard indicators defi ned equipment to a state such that it will con- to as the stator, while the dynamic por- as follows: tinue to function as designed. Th e prima- tion of the seal is referred to as the rotor • Reliability—the probability that ry value used to measure this indicator is (Fig. 4). the equipment will perform its intended the Mean Time To Repair (MTTR). It Th e principle of operation for a basic function, within stated conditions, for a is defi ned as follows: labyrinth seal is based in statistical mo- specifi ed period of time. RT tion of a particle on either side of the • Maintainability—the probability MTTR = (2) N labyrinth. Th e more complex the path- that the equipment will be retained in, way, the less likely that the particle can or restored to, a condition where it can Where: penetrate from one side of the labyrinth perform its intended function within a MTTR = Mean Time To Repair to the other. Early labyrinth seals were specifi ed period of time. RT = Total Repair Time considered an option only in applications Th e reliability indicator is quantifi ed N = Number of Failures Th at Occur where some degree of leakage was allow- by comparing the productive time to the able. Today, labyrinth seals have evolved number of failures occurring within a Innovations in Sealing Technology into bearing isolators (hybrid labyrinth specifi ed time period. Th e most common Improve MTBF designs), which utilize basic labyrinth method of measurement is the Mean In order to improve the MTBF, the technology along with other methods of Time Between Failures (MTBF). Th is life of the operating components must be retention/exclusion including centrifugal value is calculated by the total productive extended. It has already been noted that force, pressure diff erential and drain back time, which only refers to events occur- bearing failures rarely occur due to actual design. Today, bearing isolators can pro- ring during the manufacture of product, fatigue of the bearing surfaces, more of- vide a much higher-performing sealing divided by the total number of failures ten occurring due to lubrication related solution than traditional labyrinth seals. during the given productive time. Th e issues. Th erefore, by improving the sys- Standards for Equipment Reliability result is the “average time the equipment tem’s ability to retain bearing lubrication and Maintainability performed its intended function between and prevent bearing contamination, the With a basic understanding of pri- failures” (Ref. 4). life of the bearing system will be extend- mary sealing methods, the issue of im- PT ed signifi cantly. proving equipment effi ciency through MTBF = (1) Th ere are two modes where seal fail- N innovative sealing technology can be ure aff ects MTBF. In the fi rst case, the addressed. First, however, a method is Where: seal fails, the failure is noted, and the required to measure equipment perfor- MTBF = Mean Time Between Failures system is shut down to replace the seal. mance. Th e basic factors used in measur- PT = Productive Time Some amount of downtime is incurred to ing equipment performance are based in N = Number of Failures Th at Occur replace the seal. In the second case, the statistics. Primarily, the ratio of uptime During Productive Time seal fails, but the failure is not noted until bearing failure occurs. Signifi cantly more downtime (and cost) is incurred than in the fi rst case. However, in both cases extending seal life is vital to reducing APPLICATION HOUSING MTBF and the signifi cant costs associ- ated with bearing failure. RT MTTR = Understanding Seal Failure N STATOR In determining how to improve seal life, it is fi rst necessary to understand

LABYRINTH how seals fail. Modes of failure include PATHWAY thermal degradation, excessive wear due ROTOR to abrasion, lack of lubrication, chemical degradation and changes in physical SHAFT properties while in service. As noted earlier, in an ideal sealing application, the seal lip never directly TRADITIONAL LABYRINTH SEAL contacts the shaft surface, but rather rides on a thin fi lm of oil called a meniscus. In Figure 4—The static portion of the seal is referred to as the stator, while the dy- typical applications, there are likely peri- namic portion of the seal is referred to as the rotor. ods of dry running of the sealing element 3400 powertransmissionengineering december 2008 www.powertransmission.com (this condition is especially noted during sion resistance chemical resistance, and between the sealing lip and the shaft start-up). Th is condition increases the physical property retention. reduces, making the seal less capable of under-lip temperature and may cause the Abrasion Resistance handling misalignments in the system. seal lip to become hard and brittle. When In order to improve a material’s wear Abrasion may continue to the point this occurs, the seal lip can no longer fol- resistance, a method of quantifying this where this interference becomes virtually low the eccentricities of the shaft and property is needed. Th e most common nonexistent. Th erefore the less a material leakage results. Th e direct contact of the method of measuring a material’s resis- abrades away, the longer it will continue seal lip and the shaft also contributes to tance to abrasion is the Taber wear test to perform. the abrasion of seal material. Th is abra- (ASTM D4060). Th e Taber wear test Chemical and Physical Properties sion will eventually decrease the seal’s starts with precisely weighed sample Two common methods of determin- radial cross-section such that the seal lip specimens of a particular elastomer. Th e ing a material’s ability to retain its physi- no longer completely contacts the shaft, specimens are “mounted to a rotating cal properties over time are heat aging again resulting in leakage. A lack of lu- turntable and subjected to the wearing testing and ASTM 903 oil immersion brication or actual dry running of the seal action of two abrasive wheels, which are testing. Th is testing requires that prop- exacerbates these conditions. applied at a specifi c pressure” (Ref. 5). erties such as hardness, tensile strength, When exposed to chemicals not When the test is completed, the speci- elongation and volume are measured compatible with the seal material, abnor- mens are re-weighed to determine how prior to exposing the sample to heat or mal swelling may occur. Also, over the much material was abraded away. Results oil, and are retested after a specifi ed time course of a seal’s service life, the physi- are reported in mg loss/1,000 cycles. of exposure. cal properties of the sealing elastomer Th erefore, the lower the reported value, When exposed to chemicals or may signifi cantly change, again resulting the better the seal’s durability. heat, all elastomers will experience in leakage. Properties subject to change Typical nitrile rubbers have a Taber some change in physical properties. Th e include hardness (durometer), tensile wear factor of 500 mg loss/1,000 cycles baseline for property retention is per- strength, elongation, volume, wear width or greater. Garlock Klozure’s new Mill- fection—no changes when exposed to and Taber wear factor. Right N has a Taber wear factor of 145.5 chemicals or heat. However, no elasto- Material Innovations mg loss/1,000 cycles—a 73% improve- mer will perform perfectly in service. Th e Improve Seal Life ment in wear resistance over industrial- goal is to get the elastomer to perform Th e factors that contribute to seal grade nitrile rubber. Similarly, the resis- as close to perfection as possible. Th is is failure are directly related to the proper- tance of HNBR was increased 65%, and a diffi cult task since the processing and ties of the materials used to manufacture that of FKM, 90% (Table 1). formulation required to maintain certain sealing products. For contact seals, elasto- Industrial grade nitrile rubber (NBR) properties may have an opposite eff ect on mers are typically used due to their resil- loses 548 mg per 1,000 cycles in testing. others. Th erefore, material formulation ient nature, although some thermoplastic Compare this to Mill-Right N, where and development often ends up being a materials are also utilized. Common seal- only 145.5 mg are lost under the same trade-off between the retention of vari- ing materials include acrylonitrile bu- testing conditions. Th e material loss of ous properties. tadiene (Buna-N, NBR); hydrogenated Mill-Right N is only one-fourth that of If the properties of a sealing material nitrile rubber (HNBR), fl uoroelastomer industrial grade NBR. Th erefore, seals change in service, this will have a signifi - (FKM—Viton), silicones, and polytetra- made from Mill-Right N are likely to be cant eff ect on the overall performance. fl uoroethylene (PTFE—Tefl on). in service signifi cantly longer than those For instance, changes in volume may af- In addition to these materials, Gar- made from industrial grade nitrile. fect sealing eff ectiveness in two ways: 1) lock Klozure engineered the Mill-Right Th e improvement in material abra- If the material shrinks in service, the nec- family of elastomers. Th ese elastomers sion resistance is highly signifi cant, as it essary interferences will be decreased; 2) off er signifi cant improvements in per- directly relates to service life. As abrasion If the material swells, interference will be formance over industrial-grade sealing occurs, the lip geometries responsible for excessive. A decrease in interference may materials. Specifi c areas these elastomers hydrodynamic sealing begin to disap- aff ect the seal’s misalignment and reten- focus on include improvements in abra- pear. Further, the required interference tion capabilities. An increase in interfer- continued Table 1–Taber Wear Factor Comparison Industrial Garlock Industrial Garlock Industrial Garlock Grade Klozure Grade Klozure Grade Klozure NBR Mill-Right N HMBR Mill-Right ES FKM Mill-Right V Taber Wear Factor 548.0 145.5 113.2 39.2 481.4 49.2 (mg loss/1000)

www.powertransmission.com december 2008 powertransmissionengineering 3521 ence may reduce the hydrodynamic eff ect low coeffi cient of friction and does not an elastomer in following shaft eccentric- and result in excessive temperatures. absorb moisture from its environment. ities in a sealing system. Th e advantages Th e Mill-Right materials have im- However, unfi lled PTFE has a tendency of this type of seal include the ability to proved the retention of physical prop- to cold fl ow (permanently deform under run dry without abrading, an extremely erties. Th e radar charts located in the load) while in service, making it ques- low coeffi cient of friction and the abil- accompanying appendices show the spe- tionable as a sealing material. Also, be- ity to handle high-pressure applications cifi c improvements regarding each prop- ing a very rigid material, when used as a up to and even exceeding 150 psi. How- erty. Th e baseline of perfection is noted radial lip seal, PTFE often lacks the abil- ever, these seals will not handle excessive on these graphs. Th e deviation from ity to consistently follow the shaft eccen- shaft-to-bore misalignment or speeds in perfection is noted for both the specifi c tricities found in a typical sealing system excess of 2,000 feet-per-minute. Exam- Mill-Right material and the industrial (Refs. 6 and 7). ples of ps seals are shown in Figure 5. grade material. In the 1960s, Garlock developed a Sealing Product Innovations— Other Material Innovations—Gylon new method of manufacturing PTFE Bearing Isolators On April 6, 1938, DuPont chemist and named this proprietary material Gy- Radial lip seals can provide a con- Dr. Roy J. Plunkett discovered polytet- lon. Originally intended for use in gasket sistent, reliable sealing system for most rafl uoroethylene (PTFE). Th is was a applications, this new material incorpo- applications. However, there are draw- remarkable discovery, since up to that rated special fi llers to increase stability backs. Th e elastomer materials can be time it was believed that chlorinated and such that cold fl ow in service was vir- aggressive when applied to the surface of fl uorinated ethylenes could not be po- tually eliminated. Later this technology a soft shaft material. If the shaft surface lymerized. In 1945, DuPont registered was applied to radial lip seals. Garlock hardness is less than 30 RC, grooving can this new material as Tefl on. PTFE has Klozure’s ps seals employ a thin Gylon occur over time. Th is groove becomes a desirable sealing qualities because it is gasket rolled into a radial lip confi gura- leak path for lubricant or an ingress for virtually inert to all chemicals, has a very tion. Th is thin feature reacts similarly to contaminants. Th e radial lip seal can also induce a power loss in the system due to the drag force of the seal against the shaft surface. Although this power loss may be small relative to the power consumption of the entire system, increasing demands for power conservation may drive end users to seek alternative sealing methods. In conveyance systems where multiple idle rollers may be driven from a primary ® ® GarlockGarlock KloKlozurezure P/SP/S-I-I Seal Seal GarlockGarlock KloKlozurezure P/SP/S-II-II SealSeal source, frictional losses from sealing devices can add up signifi cantly. Other considerations include the fact that most radial lip seals cannot run dry and that most radial lip seals are unidirectional in sealing capacity. For these and other reasons, bearing isolators are becoming more commonplace in industrial sealing ® GarlockGarlock Klo Klozurezure XPS™XPS Repair-In-Place Repair-In-Plac Seale Seal systems (Table 2).

Figure 5—Garlock Klozure P/S–Seals. Bearing isolators, developed from labyrinth seals, incorporate the concept Table 2–Comparison of Common Capabilities of of a tortuous path for fl uid sealing with Radial Lip Seals and Bearing Isolators concepts such as centrifugal force, pres- Radial Lip Seals Bearing Isolators sure diff erential, and drain-back design. Require Min 30 RC Shaft YES NO Bearing isolators can incorporate a unit- Surface ized two-piece design consisting of a ro- Noted Power Loss YES NO tor and a stator. Th e rotor is mated to the Dry Running NO YES shaft by means of an o-ring, while the Offer Both Retention & NO* YES stator is mated to the housing bore in Exclusion a similar fashion. Th e stator is statically Pressure Sealing YES NO engaged in the housing bore, while the *Assuming single lip oil seal rotor rotates with the shaft. Any wear occurs internal to the bearing isolator. 3600 powertransmissionengineering december 2008 www.powertransmission.com Th is is minimized by using low-friction rubber seal to create a seal with a single seal. Some seals include a reinforced heel materials of construction, resulting in a split point. Th e seal can be opened along molded into the rubber to improve bore highly extended service life. Typically, the axis of rotation to allow easy assem- retention. Due to the heel reinforcement, these bearing isolators, when properly bly over the diameter of the shaft. Some this type of seal does not require a cover specifi ed and installed, will have service split seals include a garter spring which plate for housing bores under 10 inches lives equal to or greater than the bearing needs to be assembled around the shaft (254 mm) in diameter (Fig. 9). system. onto the seal during installation. Th is Split Bearing Isolators. A project re- One industry that has pushed the can be cumbersome and even a possible cently developed and currently in fi eld demand for non-contact seals is wind source of equipment failure if the spring testing at the time of this writing is the power generation. Testing by Chitren becomes dislodged during installation split bearing isolator (Fig. 10). Th is seal & Drago, targeting wind power appli- of the seal into the housing bore. Some uses the same labyrinth technology, in- cations, showed that an average oil seal split seals can include a molded-in fi n- cluding a unitized rotor and stator in- consumes 285 watts of power during ger spring, which eliminates the need for corporated into a seal that is split into normal operation, while during start-up a garter spring and contributes to even two halves at the 3 o’clock and 9 o’clock the power consumption spikes to 670 load distribution at the contact point on positions. Th is new seal has performance watts. Under similar conditions, a bear- the shaft. specifi cations similar to previous bearing isolator only consumes 120 watts Most split seals require a cover plate ing isolator seals, but it allows for easier during normal operation, with spikes in order to be retained within the hous- installation. up to 150 watts during start-up. Other ing bore. Otherwise, they may “walk” out Th e First Repair-in-Place Seal. case study data showed the service life of of the equipment. A cover plate is simply While many innovations seek to re- bearing isolators to be up to 65 times that a fl at metal plate (either whole or split) duce MTTR, few if any have been able of traditional oil seals (Ref. 8). that can be bolted against the housing to to completely eliminate it. Th e Garlock Innovations in Sealing Technology retain a split seal (Fig. 8). Klozure XPS mechanical seal was re- Improve MTTR It is vital that the seal width and bore cently developed with this concept in To signifi cantly improve MTTR, it is depth be properly fi tted so that there is mind—to completely eliminate the need necessary to identify the steps involved in appropriate axial retention of the split continued suffi ciently repairing equipment and the time related to each step. In seal maintenance and repair, the most time-consum- STATOR ing steps include the disassembly and reassembly of bearing equipment. Th is BORE LABYRINTH PATHWAY may include the disassembly of pillow UNITIZING blocks, motor housings, pump housings, ELEMENT etc., with the necessary realignments and adjustments required after reassembly. ROTOR One of the main reasons for this is that SHAFT solid seals must be installed over the free end of a shaft with all attached compo- Figure 6—Garlock Klozure Guardian Bearing Isolator. nents removed from the assembly. Th e innovation of a split seal allows the user to install the sealing device without having to completely disassemble the equipment, drastically reducing maintenance time. While the concept of splitting an elastomeric seal has existed for several decades, this concept has only recently been applied to bearing isolator seals. Another innovation to improve MTTR is that seals that can be repaired without removing the seal from service, known as repair-in-place seals. Split Radial Lip Seals. A split radial lip seal is a relatively simple concept. It involves removing a section of an all- Figure 7—Garlock Klozure Model 23 Split Seal.

www.powertransmission.com december 2008 powertransmissionengineering 3217 for seal replacement (Fig. 11). failure of the primary sealing elements is and gear boxes. Common sealing media Th e XPS seal uses ps-type seal- noted, or when dictated by the preven- may include water, caustics and petro- ing technology, which involves a thinly tive maintenance cycle, a simple turn of leum-based lubricants. When the last formed Gylon lip running on a hard- the deployment screw moves a fresh set set of sealing lips has exhausted its ser- ened sleeve. Th e seal includes a total of of sealing lips into place without any sig- vice life, the cartridge-based deployment six Gylon lips; however, only two are ini- niﬁ cant downtime. section can be refurbished, allowing the tially deployed. Four additional sealing Common sealing applications for the XPS seal to be reloaded for further in- elements are stored behind the primary XPS mechanical seal may include boil- place repairs (Ref. 9). elements on a deployment sleeve. When ers, scrubbers, pumps, motors, conveyors

HOUSING

COVERPLATE

SPLIT SEAL SHAFT

Figure 8—Split Seal with cover plate. Figure 9—Garlock Klozure Model 26 Split Seal.

PLACE SPLITSPLIT HALVES OF PRESS STATORSTATOR HALVES INTOINTO SLIDE ROTOR HALVES AROUND STATORSTATOR AROUND SHAFTSHAFT HOUSING BORE SHAFSHAFTT

SNAP ROTOR HALVES INTO TTHREADHREAD IN RRETAININGETAINING BBOLTOLT 1 TTHREADHREAD IN RRETAININGETAINING BBOLTOLT 2 PLACE AROUND SSTATORTATOR Figure 10—Installation of Garlock Klozure Guardian Split

0038 powertransmissionengineering december 2008 www.powertransmission.com Conclusion per Saddle River: Prentice Hall, 2000. Improving equipment life is not 2. Melanson, John. “Understanding Bear- a simple task. Equipment needs to be ing Failure,” Machinery and Equipment broken down into systems, systems into MRO, Vol. 23, No. 2, April, 2007. sub-systems, and sub-systems into com- 3. Brink, Robert V., Daniel E. Czernik ponents. However, since the bearing sys- and Leslie A. Horve. Handbook of Fluid tem is one of the key elements of power Sealing, New York: McGraw-Hill, Inc., generation equipment, signifi cantly 1993. improving its life will have a profound 4. SEMI E10-0701, Specifi cation for eff ect on the overall equipment perfor- Defi nition and Measurement of Equip- mance. Appropriate sealing devices are ment Reliability, Availability, and Main- critical to bearing effi cacy. Utilizing tools tainability (RAM), 1986, 2001. such as Mean-Time-Between-Failures 5. Taber Industries, 2007, and Mean-Time-To-Repair provides the http://www.taberindustries.com/Prod- necessary metrics to gauge system per- ucts/abraser/taber_abraser_description. formance. New innovations such as ad- asp?ct=1&s c=1. vanced sealing materials and non-contact 6. DuPont. News Article, “History of seals help to improve these indicators, Tefl on.” as well as to meet requirements for in- http://www.teflon.com/NASApp/Teflon/ creased power conservation. Innovations Tefl onPageServlet?pageId=/consumer/na/ such as split seals and bearing isolators, eng/news/news_detail.tefl on_history.html as well as repair-in-place technology, can 7. Barbalace, Roberta C. “DuPont’s signifi cantly reduce maintenance costs. Tefl on Cover-Up,” Mar. 22, 2006, Improving equipment life is a contin- http://environmentalchemistry.com/yogi/ uous process. Demands for increased effi - environmental/200603tefl oncoverup.html ciency and decreased power consumption 8. Chitren, Elizabeth and Jim Drago. will continue. Th us the need to innovate “PE—Improved Life for Dynamic Seals will continue, building on existing tech- in Wind Turbine Applications,” Present- nologies and developing new ones. ed at WindPower 2005 Conference and Exhibition, May 15–18, 2005. References 9. Wood, John. P/S Technology, Applica- See Appendix-Mill-Right Data, pg 40. 1. Norton, Robert L. Machine Design— tions and Selection, 2006. an Integrated Approach, 2nd edition, Up-

GLAND ELEMENT CHAMBER DEPLOYMENT SCREW

DRIVE COLLAR COATED SLEEVE

SPRINGS DEPLOYED ELEMENTS

DEPLOYMENT SLEEVE

Figure 11—Garlock Klozure XPS Mechanical Seal. continued

www.powertransmission.com december 2008 powertransmissionengineering 3219 Appendix—Mill-Right Data Mill-Right N Radar Chart These charts compare Mill-Right N’s ability to retain its physical properties over time with that of industrial grade nitrile rubber.

Garlock Klozure Mill-Right N Vs. Nitrile Hardness Change (points)† 25 20 15 10 5 Taber Wear Factor* 0 Tensile Change (%)† -5 -10 -15 -20 -25

Wear Width (in (x100))‡ Elongation Change (%)†

* ASTMD4060 Taber Wear Index Factor Mill-Right N † ASTM 903 Oil Immersion (70hrs @ 200F (93C)) Nitrile ‡ Garlock Klozure 4-Hour Dry Run Perfection Volume Change (%)†

Garlock Klozure Mill-Right ES Vs. HNBR Hardness Change (points)† 25 20 15 10 5 Taber Wear Factor* 0 Tensile Change (%)† -5 -10 -15 -20 -25

Wear Width (in (x100))‡ Elongation Change (%)†

Mill-Right ES * ASTMD4060 Taber Wear Index Factor HNBR † ASTM 903 Oil Immersion (70hrs @ 300F (149C)) Perfection ‡ Garlock Klozure 4-Hour Dry Run Volume Change (%)†

Garlock Klozure Mill-Right V Vs. Fluoroelastomer

Hardness Change (points)† 25

5 Taber Wear Factor* Tensile Change (%)† -5

-15

-25

Wear Width (in (x100))‡ Elongation Change (%)†

* ASTMD4060 Taber Wear Index Factor Mill-Right V † ASTM 903 Oil Immersion (70hrs @ 300F Fluoroelastomer (149C)) Perfection Volume Change (%)†

0040 6 powertransmissionengineering december 2008 www.powertransmission.com events

HVAC&R INDUSTRY EMBRACES GREEN AT AHR Expo As if there wasn’t enough green at last year’s green-themed AHR Expo, this year organizers have planned a full blown green invasion of the HVAC&R industry. The International Air-Condi- tioning, Heating, Refrigerating Exposition is the largest trade show for the HVAC&R professional with more than 70 educational sessions, 375,000 net square feet of exhibit space and 50,000 anticipated attendees from more than 120 countries. After a successful installment in New York, the 61st AHR Expo returns to the site of its historically largest shows, McCormick Place, Chicago. “At the last AHR Expo (2008 in New York) we started to set in motion The AHR Expo will span 375,000 net square feet of exhibit space at Chicago’s features that acknowledged the growing McCormick Place. (Courtesy of Oscar Einzig) emphasis on green in the HVAC&R industry,” says Clay Stevens, president of International Exposition Company, which is responsible for producing and managing the show. “We recognized the critical role played by our industry in saving energy and assuring a safe and healthy indoor environment. “The 2009 show will take the green and sustainable emphasis to the next level.” Placing signifi cant emphasis on environmentally friendly and energy- effi cient products and technologies, some of the contemporary subjects encompassed by the show include green building, sustainable design, renewable energy, effi ciency and indoor air quality. Several more green seminars and sessions are scheduled in comparison to the 2008 program. The U.S Environmental Protection Agency’s Energy Star Program will have a booth while conducting an educational session as well. The American Society of Heating, Refrigerating and Air- Many of the new products and technologies on display emphasize environmen- Conditioning Engineers (ASHRAE) tally-friendly features and energy efficiency. (Courtesy of Oscar Einzig)

www.powertransmission.com december 2008 powertransmissionengineering 2141 events

Classroom will be on site thanks to the Partnership for Environmental Leadership, a collaborative effort of six eco-conscious industry associations. The trailer is a hands-on learning environment, which features new technologies for sustainability in mechanical service and construction including tips to improve building energy effi ciency while considering occupant health, safety and comfort. Some of the new technology demonstrations featured in 2008 included solar collectors or hot water systems, HVAC system design software, micro-computer control system for green technology boilers and carbon neutral building design. The 2008 AHR Expo took place in New York City and attracted tens of thousands of Onsite training opportunities attendees worldwide. The 2009 expo returns to Chicago, the site of its most successful past shows. (Courtesy of Oscar Einzig.) will be available in coordination with MCAA’s LEED AP training programs will present various seminars on a Corporation’s Evergreen 23XRV chiller, and the UA/MSCA’s Green Awareness number of green topics. Exhibitors can which is, according to the company, the Training and Certifi cation Program. submit their greenest products to the world’s fi rst integrated variable speed, “As a leading information resource expo’s Innovation Awards in the “Green water cooled, screw chiller. The product for the HVAC/R industry, it is critical Building” category. is ideal for effi ciently chilled water that the AHR Expo keep its attendees Last year the award went to Carrier plants. on the cutting edge of the latest ‘green’ The Green Mechanical Council will products and issues,” Stevens says. host two educational programs free for The show also refl ects a commitment interested attendees, including a three- to green principles with the choice of hour workshop focusing on defi ning venue. McCormick Place uses many common phrases and terms, pointing recycled and environmentally friendly out misconceptions to overcome and products, which include renewable identifying the trends that are making and fully compostable cold beverage green practices mainstream. cups, fl atware and packaged food Any exhibiting companies that boxes as well as entirely recycled paper showcase products for improving indoor products in the restrooms. Organizers air quality will be provided with an feel a responsibility to help disseminate Indoor Air Quality (IAQ) designation information about the latest industry sign to display. trends and help companies keep up with A day-long educational program the times. entitled LEED Implementation for “Every one of the last few years has Building Operations and Maintenance seen the green theme gain in emphasis will be presented by the U.S. Green and importance. HVAC buyers and Building Council (USGBC). The course manufacturers (sellers) alike are now is designed for professionals in charge taking green issues more seriously. of implementing LEED (Leadership The degree to which products and in Energy and Environmental Design) systems help buildings measure up to building standards and includes green standards now impacts the whole successful project strategies through selection and decision-making process,” different credit categories while guiding Stevens says. attendees towards certifi cation. Attendees check out the latest HVAC+R products. (Courtesy of Oscar Einzig.) The HVAC Mobile Green

0042 powertransmissionengineering december 2008 www.powertransmission.com calendarevents

December 10–12—Introduction January 26–30—AWS Certified advanced design and manufacturing to Metallurgical Lab Practices. Welding Supervisor Seminar. event, cumulatively attracting 45,000 ASM International Headquarters, Hilton Suites Atlanta Perimeter, manufacturing professionals. Materials Park, OH. This beginning Atlanta. If you’re involved in the welding level course is designed for people with fi eld, consider this fi ve-day intensive February 17–19—Expo Manu- basic or limited familiarity to a materials supervisor training and certifi cation factura. Cintermex, Monterrey, lab or metallurgical lab practices and course. The course focuses on Mexico. This international manu- non-technical professionals like those necessary knowledge supervisors need facturing trade show is Mexico’s in sales or purchasing. The students will to improve productivity, throughput, rendition of IMTS in its 14th learn metallography through sectioning, weld quality, safety and environment. installment. The event includes over mounting, grinding, polishing and It focuses on the science more than 350 companies, representing over 600 etching samples. For more information, the art of welding in addition to the brands from around the world, 8,500 visit www.asminternational.org. economics of welding. The program professionals are expected to attend attracts engineers involved with design in search of equipment, machinery, January 12–15—ProMat 2009. drawings, foremen, lead welders, line processes and solutions for industries McCormick Place South, Chicago, IL. leaders, purchasing personnel, corporate that include automotive, aeronautical, The Material Handling Industry of welding instructors and detailers or electrical appliance and medical devices. America sponsors ProMat 2009, which drawing preparation personnel. The A conference program includes keynote is addressing the changing workforce, seminar is offered in various locations speeches, seminars, presentations and latest manufacturing equipment and across the country For more info, visit manufacturing solutions that include technologies as well as distribution www.aws.org/certifi cation/CWS. Six Sigma practices and other effi ciency and supply chain issues. There will be standards. For more information, visit over 800 exhibits and an educational February 3–6, World of Concrete. www.expomanufactura.com.mx, or conference with a keynote address Las Vegas Convention Center, Las contact Shane Poblete at (301) 493- entitled “Building the Workforce of the Vegas. World of Concrete is an annual 5500. Future.” The conference will also feature international event for the commercial more than 100 educational sessions concrete and masonry construction February 24–26—Houstex 2009. covering trends, best practices and industries, which attracts over 1,700 cutting edge equipment and technology George R. Brown Convention Center, suppliers spanning more than 900,000 solutions for improving productivity and Houston. Organized by the Society of net square feet of exhibits. On display profi ts throughout the supply chain. For Manufacturing Engineers, this event are new products, technologies, tools and more information, contact Carol Miller looks to stimulate ideas, expertise and equipment. Outdoor exhibits and event at [email protected], (800) 345-1815 or business connections in manufacturing areas bring hands-on demonstrations, www.mhia.org. technology. On showcase will be resources and techniques. More than advanced machine tools and production January 19–21—Northwest Food 150 seminars are held beginning a systems for industries including energy, Manufacturing and Packaging day before the exhibition. For more medical and aerospace. An advanced Convention and Exposition. information, visit www.worldofconcrete. technology conference will address Oregon Convention Center, Portland, com. “Manufacturing Processes for Oil and OR. The 95th installment of this Gas.” Houstex is co-located with the annual show attracts 4,000 food February 10–12—Pacific Design International Pump Users Symposium, processing industry professionals from and Manufacturing Show. and attendee badges provide full access all parts of the country. More than Anaheim Convention Center, Anaheim, to both shows. For more information, 450 booths are on display for CEOs, CA. This show is co-located with visit www.sme.org/houstex. plant managers, purchasing managers, Automation Technology Expo (ATX) production and quality assurance West, WestPack, MD&M West, managers and mechanics. Educational Electronics West, PLASTEC West sessions will focus on topics that include Pavilion and Green Manufacturing energy and environment, government Expo. The annual show in its 11th year affairs, radio frequency identifi cation features over 350 exhibiting companies (RFID) workshop and productivity and and pavilions that include CAD/CAM innovation. For more information, visit and rapid prototyping, enterprise www.nfpamembers.org. software technology and contract manufacturing. This is the West’s largest

www.powertransmission.com december 2008 powertransmissionengineering 21436 industry news

frequency drives for AC motors in heating, ventilation, air Danfoss conditioning, water, wastewater, food and beverage, material handling, petrochemical and other industrial applications. DOUBLING ILLINOIS FACILITY Once the expansion is completed, the facility will be LEED- certifi ed and registered with the U.S. Green Building Council, which is a rating system that promotes sustainable design and construction with the purpose of increasing operating effi ciency. “As both our domestic sales and export business for Danfoss VLT drives have grown exponentially, so has our need for increased production capacity and additional offi ce space,” says David Holmgren, purchasing manager. “The expansion will allow Danfoss to accommodate the 250 additional employees we have identifi ed will be required to support our growth while maintaining the level of service our customers have come to expect from us.” The new building will fully occupy the 18-acre area the Domestic and global growth for Danfoss Drives has company moved into—but did not fi ll—in 2001, and Danfoss compelled the company to begin a major expansion to its Drives purchased an additional 17 acres of adjacent land for Loves Park, IL facility. In order to meet the increased demand, further possible expansion in the future. A groundbreaking additional equipment and personnel is required, so the larger ceremony took place September 16, and Danfoss hopes the facility will include production and offi ce space. new facility will be completed and fully operational by the The Loves Park facility designs and produces variable third quarter 2009.

strategic initiatives of the company and assist Carl with his New CEO transition.” “I am honored to have the confi dence of the Board to ANNOUNCED BY ALTRA serve as chief executive offi cer,” Christenson says. “Mike has been a tremendous mentor and has assembled a fi rst-class Altra Holdings, Inc appointed Carl Christenson to management team under his leadership. I am excited to have succeed Michael L. Hurt, P.E. as chief executive offi cer, the opportunity to lead such a dynamic company into its next effective January 1, 2009. Christenson is currently the phase of growth.” company’s president and chief operating offi cer. Hurt has been Christenson has over 27 years of experience. He was CEO since Altra was founded in 2004, and he will continue director of Altra starting in July 2007 and president and chief with the company as executive chairman and chairman of the operating offi cer since January 2005. Prior to joining Altra, Board of Directors through 2009. Christenson was president of Kaydon Bearings. He has also “I am very proud of the organization we have built over held management positions at TB Wood’s Corporation—now the past four years,” Hurt says, “Carl Christenson has been an an Altra subsidiary—and positions at the Torrington Company. important part of our leadership He has an M.S. and a B.S. in mechanical engineering from the team since the company’s University of Massachusetts and an M.B.A. from Rensselaer inception, and I believe he Polytechnic. has the qualities and talents “Carl brings decades of relevant experience to this new necessary to be successful as our role,” says Larry McPherson, chairman of the nominating and CEO. I have worked closely corporate governance committee. “He was extremely effective with Carl for over 20 years, as the company’s president and chief operating offi cer, and and I am confi dent that Carl we believe he will be equally effective as the company’s new will fl ourish in this new role. CEO. We appreciate Mike Hurt’s tremendous contributions While I am looking forward to to the success of the company over the past several years and spending more time with my are fortunate that he will continue to be an important part of family, I plan to continue to this organization even after the transition.” Carl Christenson be actively involved in various

0044 6 powertransmissionengineering december 2008 www.powertransmission.com industry news

Baldor ACQUIRES MASKA INC. Baldor Electric Company has acquired Maska, Inc., a designer, manufacturer and marketer of sheaves, bushings, couplings and related mechanical power transmission components headquartered in Ste-Claire, Quebec. Maska employs 180 people mostly located in Canada but also in a new Chinese facility. The company’s 2007 sales were around $33 million. The transaction provides Baldor with a second plant in China for supporting international growth and a market share of sheaves and bushings in North America. “We are excited to announce the addition of Maska to our line of mechanical power transmission products,” says John McFarland, chairman and CEO of Baldor. “Over the past fi ve years the management team at Maska has increased sales and profi ts by nearly 50 percent. Their two automated and effi cient facilities produce a large variety and some of the highest quality products available in the marketplace. Maska’s sheaves and bushings complement our Dodge line with each having success in different parts of the market.”

Complete Renold Linear Axis Drive Solutions The World Leader in ACQUIRES INDIAN CHAIN BUSINESS, Achieve a compact linear axis Rack & Pinion Drive drive by combining our Technologies SUPPLIES NYC TRANSIT ® Precision Servo Reducers PpowertransmissionTengineeringE VOL. 2, NO. 2 Renold PLC has acquired a 75 percent interest in L.G. with our Standard Range Balakrishnan & Bros. Ltd., a manufacturer and distributor of of Rack & Pinion Drives. industrial chains in India. The sale allows Renold to bring Choose from Helical & its products into the Indian market with an established Straight versions, in an production base and sales distribution network. LGB employs assortment of materials, 500 people at its headquarters in Tamil Nadu. sizes and quality levels, Renold has also been awarded a contract from Mitsubishi to meet almost any axis drive requirements. to supply couplings and gearboxes for the New York City EDITORIAL Metro North Transit Authority. The components will be part of the propulsion systems in a ﬂ eet of rail cars due out in 2009. “This is another signiﬁ cant contract win for Renold and augments our order book, which at the end of June was already 32 percent ahead of 12 months ago,” says Bob Davies, Renold chief executive. Renold’s order book was 36 percent higher at the end of August 2008 than it was in August 2007, according to a press release. ATLANTA Drive Systems, Inc. Call Toll-Free at: (800) 505-1715 Or Visit Us at: www.atlantadrives.com ART

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40 powertransmissionengineering april 2008 www.powertransmission.com industry news

The Tradition Continues…….

For over 62 years, Dorris Co., ( a SGC Service Engineering Company) has manufactured enclosed Helical Speed Reducers. COMPLETES EXPANSION

• Shaft Mounted Drives A 12,000 square-foot expansion to Service Engineering, AGMA Sizes 107 thru 700 Inc.’s Greenfi eld Indiana plant was completed for a ribbon- • Screw Conveyor Drives, cutting ceremony October 31. The 41-year-old company AGMA Sizes 107 thru 407 • Base Mounted Drives manufactures automation, parts handling and feeder bowl Ratios of 1.5:1 to 250:1 equipment for the medical, pharmaceutical, electronics, • Custom Designed Gear Drives automotive, cosmetics, consumables, fasteners, and ordnance Markets include: industries. • Bulk Material Handling, “We are in the fi nal stage of an expansion that is being done Feed & Grain, & Aggregate in conjunction with a major capital equipment reinvestment,” • Unit Material Handling Cranes, says Ryan Jennings, service engineering president. “The Storage & Retrieval changes that we are making will revolutionize the way our • Other Applications, Mixers, Agitators, Food Processing products are manufactured, and by taking these steps, we Laundry and Aerators maintain our position as the leader in our industry. “This investment in technology puts us literally on the cutting edge,” Jennings says. We now have the capabilities 17430 Malyn Blvd. Fraser, MI 48026 to cut, bend and weld more effi ciently than anyone in our Toll Free: (800) 325-2520 industry. Our customers demand that our equipment be Ph: (586) 293-5260 Fax: (586) 293-5290 available to them at the best possible value and at the shortest available lead time. Service Engineering plans to accomplish www.DorrisCo.com both, and we will do it with consistency and at a volume that our competition simply cannot.” Find Power Transmission Product Suppliers at Timken

EXPANDS, TARGETING WIND ENERGY MARKET

In anticipation of strong growth in the renewable energy sector, The Timken Company announced plans to expand production capacity at the Tyger River facility in Union, SC. Timken is making this investment in an effort to fortify its capability to supply highly-engineered large-bore bearings used in wind turbine main-rotor shafts and gear drives. The Tyger River facility expansion enables Timken to serve North American demand and bring increased capabilities to create prototypes for new wind-turbine programs. The development will start in 2009 in hopes to begin new production by 2010. “This investment exempliﬁ es how we’re reshaping our www.powertransmission.com portfolio to grow and optimize our business from top to bottom,” says James W. Grifﬁ th, Timken president and Gears • Bearings • Motors • Speed Reduc- CEO. “We stand to achieve greater returns by refocusing ers Couplings • Clutches • Brakes • Linear existing assets and investing in new capacity to serve our most promising market sectors, which certainly includes wind Motion ... and much more energy.”

0046 powertransmissionengineering december 2008 www.powertransmission.com classifieds advertiser index

Atlanta Drive Systems McInnes Rolled Rings Service Engineering Page 45 Page 4 Phone: (800) 505-1715 Phone: (800) 569-1420 COMPLETES EXPANSION Fax: (732) 282-0450 Fax: (814) 459-8443 [email protected] [email protected] www.atlantadrives.com www.mcinnesrolledrings.com Gear Manufacturing B&R Machine and Gear Nelson Engineering Inside Back Cover Page 47 Phone: (731) 456-2636 or (800) 238-0651 Phone: (714) 893-7999 Fax: (731) 456-3073 [email protected] [email protected] www.nel-eng.com www.brgear.com SETCO Page 45 Circle Gear and Machine Phone: (800) 543-0470 Page 47 Fax: (513) 941-6913 Phone: (708) 652-1000 [email protected] Fax: (708) 652-1100 www.setcousa.com [email protected] www.circlegear.com Stock Drive Products/Sterling Instrument Dorris Co. Back Cover Page 46 Phone: (516) 328-3300 Phone: (586) 293-5260 Fax: (516) 326-8827 Fax: (586) 293-5290 [email protected] [email protected] www.sdp-si.com Gear Manufacturing www.dorrisco.com Huco Dynatork Forest City Gear Inside Front Cover Pages 24–25 Phone: (800) 825-6544 Phone: (815) 623-2168 www.huco.com/pte1208 Fax: (815) 623-6620 [email protected] www.fcgear.com

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Gear Manufacturing Fax: (607) 735-0836 Tooth Cutting, Grinding & Shaving Services Available [email protected] All Sizes & Configurations. English & Metric, Spur, Helical, Internal, Herringbone, Worm & Wormgear, Internal & External Splines, www.hilliardcorp.com Involute & Straight Sided Spline, Straight and Spiral Bevels, Racks, Sprockets, Ratchets, Serrations, Reverse Engineering, Design Analysis, Complete Machine Shop including CNC Machining, Documented Quality Control Program, Inspection Lab KH Gears including Complete Gear Tooth Diagnostics. Page 15 Circle Gear and Machine I R C L Phone: +(86) 756-5586-852 C E C Quality Custom Gearing Since 1951 G C 1501 South 55th Ct. • Cicero, IL 60804 www.khcorp.cn G E O A R C Ph: 708-652-1000 • Fax: 708-652-1100 www.circlegear.com Please email your inquiries to [email protected]

www.powertransmission.com december 2008 powertransmissionengineering 2147 power play Beauty in Algorithms It too tookk the intr introductionoduction outside of ZurichZurich in 2003. of fractals and chaos theory to While Shapiro has a deep get Bruce Shapiro interested affi nity for all his creations, his in motion control. While favorite installation, entitled conducting medical research on “Ribbon Dancers,” debuted in his PC, Shapiro began comput- 2006 at the Science Center of Iowa ing images of the Mandelbrot in Des Moines. While the project Set on his computer. He was is still a two-axis NC device, the intrigued by the fact he could geometry is now spherical and there use an algorithm to compute the is no limit to travel in either axis. value of each pixel on screen to The result is two colorful ribbons create beautiful images. that continuously “dance” near the After discovering some ceiling of the science center. stepper motors in a bin at an “This is the fi rst of my projects electronic junk shop, he had a that truly required closing the revelation. loop (for safety reasons), and “Although I didn’t know moving from stepper to servo- how to run the stepper motors, based systems has been somewhat I understood immediately of a religious experience for me,” that they break motion into Shapiro says. controllable pieces—motion Shapiro’s work in motion pixels. And then the light bulb control has also been a signifi cant went on. Might it be possible teaching tool for students interested to use algorithmic control of in science and mathematics. His motion pixels to create beautiful very fi rst project was an Easter egg movement?” coloring machine called “Eggbot.” He’s been pursuing the Shapiro teaches a course entitled, question ever since. “From Bits to Bytes… to Bots,” at Shapiro, an M.D. by the Science Museum of Minnesota vocation, practiced several years that instructs children how to build as an internist in California and their own version of the machine. Minnesota before retiring to “The wonderful thing about pursue his interest in motion motion control is that it provides control. He was able to purchase a tremendous incentive to fi guring the necessary components at out where you goofed. Do-it- local “tech-junk” shops in the yourself robots never work perfectly Minneapolis/St. Paul area, the fi rst time,” Shapiro says. “It’s material that had fl owed out of this Sherlock Holmes process that monthly auctions at automation- leads to deep learning.” based companies like 3M and Currently, Shapiro is working Honeywell. on the fourth installment of a The early focus of his series called “Pipedream.” This is work was on what Shapiro a large array of clear, fl uid-fi lled called “studio machines,” do- vertical tubes. By controlling it-yourself CNC machines that solenoid valves, he can introduce he designed as static sculptures. air in the tubes so that the resulting These custom machines would bubbles create images. “Pipedream later become performance CNC machines, projects was “Sisyphus,” a two-axis, polar IV” is scheduled for installation at Discovery combining electronics, mechanics and coordinate NC device which moves a magnet World in Milwaukee in January 2009. programming to create motion control art. beneath a fi eld of sand. A steel ball pulled For more information on Bruce Shapiro’s (A popular example of this art form is the by the invisible magnet rolls through the Art of Motion Control and to watch a video Fountains of Bellagio in Las Vegas created fi eld, creating highly intricate dune patterns. of his work, visit www.taomc.com. by WET Design.) “Sisyphus III” was permanently installed One of Shapiro’s earliest performance at Technorama, the Swiss Science Center

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