Rotary Motion Control

ROTARY MOTION CONTROL

Technical Data Sheet

Roller Pinion Gear System

Nexen offers an advanced new technology that revolutionizes rotary motion. The Roller Pinion Gear system (RPG) provides zero backlash, very high positional accuracy, virtually no velocity ripple, 99% efficiency, high rigidity, low maintenance, corrosion resistance, and long life. This opens up new design possibilities and provides the capability to achieve much higher levels of performance in machine designs.

Precision Operation Maintains Accurate Positioning The RPG system features an innovative ring gear and roller pinion technology that provides extremely accurate rotary motion control. The Roller Pinion Gear system also offers backlash-free performance by maintaining opposing contact with two or more teeth at all times.

Patented Tooth Design Ensures Quiet Operation The RPG system is designed with bearing supported rollers that move smoothly along the face of each tooth. This reduces the noise levels by eliminating tooth slap common to traditional gear systems and chain drives. This low friction design is more than 99% efficient in rotary power transmission.

Solid and Segmented Ring Gears Provide Easy Integration and Unlimited Diameters Nexen can provide solid ring gears up to 750 mm in diameter. Ring gears larger than this become segmented and can be virtually any diameter. Arc segments can also be provided.

Rugged Design Capable of High Speeds The RPG system maintains accurate positioning at meshing pitch circle peripheral speeds as high as 11 m/sec (36.1 ft/sec). Even at these speeds, the extremely-low friction design does not create heat or significant wear on components. Applications

working head center column

table

pinion ring

Synchronized dual-shaft drive Programmable indexing table Index table with hollow center column

Cables

Winding and feeding device with less pulsation - Pivoting drive for robots Used in combination with RPS rack film, paper, sheet and thin wire

Multiple tables orbiting the ring gear Drive system for radar and satellite dishes, solar tracking, and telescopes

The Nexen RPG Advantage Eliminates Many of the Short Comings of Other Rotary Drive Technologies

The RPG’s unique design eliminates many of the limitations of current rotary drive systems like:

Spur Gears: Backlash limits positional accuracy, tooth meshing can be noisy and introduce vibration that can affect control systems, and tend to have high wear and maintenance. Velocity ripple can interfere with scanning, measuring, and coating operations. Chain Drives: Backlash limits positional accuracy, meshing can be noisy and introduce vibration that can affect control systems, and tend to have high wear and maintenance due to stretch. Velocity ripple can interfere with scanning, measuring, and coating operations. Belt Drives: Limited by low load capacity, accuracy, and rigidity. Also suffers from backlash and belt stretch. Direct Drive Rotary Stages: Limited by low torque capacity, high cost, and strong magnetic fields.

Zero Backlash/High Precision

The RPG’s innovative meshing action provides backlash of less than 3.2 µm [0.00013 in.] and positional accuracy up to ± 30 µm [± 0.00118 in.] tangentially at the meshing pitch circle due to an extremely precise manufacturing and inspection process. The RPG also has almost no velocity ripple making it ideal for applications that involve scanning, measuring, coating, or where uniformity of motion is critical.

Ring Gear Configurations

The RPG system is available as a solid ring gear when the diameter is under 750 mm. For larger ring gears segments can be combined to make ring gears of any size. Arc segments can also be provided for applications that only need limited rotation. Ring gears can have internal or external teeth.

Speed

The RPG system can achieve tangential meshing pitch circle speeds, up to 11 m/s (36.1 ft/s), while providing high positional accuracy.

Noise

Due to the smooth, backlash free way that the rollers engage the teeth, the RPG system is nearly silent at low speeds and less than 75 dB at full speed. This is much lower than traditional gear and chain systems with their tooth slap.

Maintenance/Life

The RPG system has very low maintenance. Typically lubrication is required every two million pinion revolutions or six months. The RPG system has life ratings up to 336,000,000 m [1,102,200,000 ft] of circumferential travel and is based on providing its full published positional accuracy. Some gear or chain systems can provide good initial performance but quickly degrade. The RPG system continues to operate beyond its life rating with diminished performance.

Surface Treatment

The RPG system has the Raydent surface treatment, providing stainless steel-like performance without the related high cost and low wear characteristics. Raydent is not a typical blackening or surface coating that can break down and flake off. Instead, Raydent permeates the metal surface and permanently bonds with it forming a ceramic oxide surface layer that will not flake off and is highly resistant to acids, alkalies, and solvents.

How the RPG System Works

The RPG system achieves its incredible performance by using a pinion consisting of bearing supported pins that engage a unique tooth profile. Two or more rollers engage the ring gear teeth in opposition at all times eliminating backlash. There is no tooth slap or sliding friction as with traditional spur gear or chain drive systems, instead the RPG rollers approach the tooth face in a tangent path and then roll smoothly down the tooth face. This provides a smooth, quiet, low friction, fatigue free, high efficiency rotary drive system.

The RPG tooth design is conceptually different from traditional spur gear designs. It behaves like a cam and follower versus the sliding action of spur gears. As illustrated in the figures below, a cycloidal curve is created when a point drawn on a circle at point P rolls on a curved surface to point P' without slipping. When multiple points are placed on the circle at regular intervals, the cycloidal curves are repeatedly created on the curved surface, and develop into a tooth-like profile.

A roller is placed at each point to act as pinion teeth and modifies the tooth profile to create the ring gear teeth. Normally, this concept will not provide zero backlash, but a technical innovation was developed to modify the tooth geometry allowing two rollers to remain loaded in opposition at all times, eliminating the backlash as the rollers engage the ring gear. The rollers meet the ring gear teeth smoothly and eliminate the backlash, low precision, tooth slap, sliding friction, fatigue, and noise associated with traditional spur gear and chain drive systems. Both the rollers and tooth faces are hardened to the upper RC50’s for exceptionally long service life.

Rollers in P Opposition

Angular Transmission Accuracy

The variations shown in the graph below represent minor errors occurring throughout the ring gears rotation. The individual spikes indicate meshing errors and larger wave patterns demonstrate pinion rotational error. As the horizontal limits demonstrate, there is no cumulative error. This pattern continues regardless of ring gear diameter, even when crossing segment joints. This is possible due to the use of special joining plates that align the segments and ensure that the angular accuracy is passed from segment to segment.

150

c 100 e s

c 50 arc sec 50 arc sec r a 50 n i r o r

r 0 e r a l

u 50 g 44 arc sec 44 arc sec n a 100

150 0 36 72 108 144 180 216 252 288 324 360 angular position of ring gear in degrees

Maximum angular transmission error is 94 arcsec and is calculated by the following formula: Θer = Θ2 - (Θ1 X R)

(Θer = Angular Transmission Error Θ1 = Pinion Angle, Θ2 = Ring Gear Angle, R = Reduction Ratio) Based on RPS16G with 1:5 ratio. Individual spikes represent individual tooth /roller meshing error, repeated wave trends represent pinion error. A similar pattern will be generated for other RPS sizes and ring gear angular accuracy and backlash will improve as its diameter increases. See general specifications and calculations for other ring gear diameters.

Precision Roller Pinion Selection Process

Proper RPS size selection requires the application data listed below. These specifications are needed to determine; load mass, load acceleration, force due to acceleration, force due to gravity, force due to friction and total force of the load. Sample calculations are shown along with worksheet space to calculate your own application.

Friction Coefficient (µ) This Curve will select the smallest RPG size Rolling Bearing 0.005 ~ 0.02 Velocity Sliding Bearing 0.1 ~ 0.2

Shock Factor** (K) Shockless Smooth Operation 1.0 ~ 1.2 Normal Operation 1.2 ~ 1.5 Operation with Impact 1.5 ~ 3.0 t Time

Application Example: Programmable electronics assembly indexing table 1 meter in diameter 8 stations equally spaced 60 indexes per minute desired Dwell time 0.33 sec Additional information below

Application Data Required Specifications For RPS Selection Example Data Customer Application Data Weight to be Driven* (W) kg 20.0 kg Rotational Moment of Inertia (I) kgm2 10.0 kgm2 Indexes Per Revolution ( R ) IPR 8 IPR Index Time (It) Seconds 0.66 sec or Known Angular Acceleration (ω) rad/sec2 Dwell Time (dt) Seconds 0.33 sec Shock/Service Factor** (K) see table above 1.2 Coefficient of Friction (μ)

Other Forces *** (F1), (F2), etc. Nm Angle Gear Rotates Relative To Horizontal Plane ° 0° Maximum Allowable Ring Gear Tooth Peak OD mm 400 mm Minimum Allowable Ring Gear ID mm 200 mm Required Angular Positional Accuracy (P) ±arcsec ±60 arcsec Revolutions Per Day RPD 10800 RPD

* Weight to be Driven should include everything in motion. ** Shock Factor indicates the smoothness of operation *** Other Forces may include gravitational forces if rotation is not in the horizontal plane with imbalanced loads, springs, counter balances, fluid dampening systems, wind resistance etc.

Selecting an RPG Gear Set

If the acceleration and deceleration times vary or there are other changes in velocity, calculate the acceleration forces for each interval and use the highest one for RPG selection purposes. Compare the Torque calculation to the pinion Maximum Dynamic Torque ratings in the Specifications table on page 8 to select the ideal RPG size.

Application Calculations

Calculations Application Example Customer Calculations Acceleration Time 0.66 s ÷ 2 = 0.33 s At (s) = It (s) ÷ 2 Rotation Per Index θ = 2� ÷ 8 = 0.79 rad θ (rad) = 2� ÷ IPR Max Angular Speed* ω = 0.79 rad ÷ 0.66 s x 2 = 2.39 rad/s ω = θ (rad) ÷ It (s) x 2 Angular Acceleration α = 2.39 rad/s ÷ 0.33 s = 7.25 rad/s2 α (rad/s²) = ω (rad/s) ÷ At (s) Ring Gear Torque 2 2 τG = 10 kgm x 7.25 rad/s = 72.50 Nm τG (Nm) = I (kg/m²) x α (rad/s²) Ring Gear Torque with Shock Factor

τS = 72.50 Nm x 1.2 = 87.00 Nm τS (Nm) = τG x K

* Maximum rotational speed is assumed to be twice the average speed due to starting at zero and linearly accelerating to the mid point of the index. If a non-linear acceleration curve is used, use the highest known speed and acceleration.

Based on the allowed gear diameters listed in the application data section, we can see that RPS16 7:1 part number 966554 is the only one that meets all criteria.

Compare the Ring Gear Torque calculated above to the allowable ring gear torques in the specifications table. From this we see that the RPS16G 7:1 has more than enough torque, and meets the ring gear ID and OD envelope requirements.

Next verify that maximum pinion RPM is not exceeded: RPM = ω x Gear Ratio x 9.55 = 2.39 rad/sec x 7 x 9.55 = 159.8 RPM

The maximum RPM listed in the specifications table on page 8 for the RPS16G pinion is 1500 RPM so the RPG16G 7:1 gear system is an acceptable choice.

Compare selected gear set accuracy with the application requirements. The RPS25G 7:1 gear set is rated for ±40 arcsec which is more precise than the required ± 60 arcsec so is acceptable.

If the application requirements call for a more powerful or larger diameter gear set than the listed offerings, refer to page 11 “Specifications For Determining Custom Gear Performance” to evaluate possible RPS custom gear sets.

Pre-Configured Gear Specifications

Product Number 966659 966679 Model Number RPS16P-C020.00MMP2 RPS25P-C030.00MMP2 Module 4.75 7.50 Number of Rollers 10 10 Maximum Nm 25.5 88.0 Dynamic Torque [in-lb] [226] [774] Maximum Static Nm 50.9 176.0 Roller Torque [in-lb] [450] [1558] Pinion Torque mm 8.7 6.9 Circle Diameter [in] [1.92] [3.03] Maximum RPM 1500 1920 Bore Size mm [in] 20.0 [0.787] 30.0 [1.181] Weight kg [lb] 0.8 [1.76] 2.2 [4.85] Moment of kgm2 0.000412 0.002680 Inertia [lbft2] [0.009777] [0.063597] Product Number 966550 966551 966552 966553 966554 966560 966561 966562 966563 RPS16G- RPS16G- RPS16G- RPS16G- RPS16G- RPS25G- RPS25G- RPS25G- RPS25G- Model Number C0030T/ C0040T/ C0050T/ C0060T/ C0070T/ C0030T/ C0040T/ C0050T/ C0060T/ 360-EP3U 360-EP3U 360-EP3U 360-GP3U 360-EP3U 360-GP3U 360-GP3U 360-EP3U 360-EP3U Number of Teeth 30 40 50 60 70 30 40 50 60 Ring Maximum RPM 500 375 300 250 214 640 480 384 320 Gear kg 1.7 2.4 3.3 4.8 4.6 6.0 9.1 12.2 15.1 Weight [lb] [3.75] [5.29] [7.28] [10.58] [10.14] [13.23] [20.06] [29.90] [33.30] Moment of kgm2 0.0062 0.01688 0.03763 0.07700 0.11284 0.05501 0.15800 0.33900 0.64541 Inertia [lbft2] [0.14618] [0.40569] [0.89297] [1.82724] [2.67773] [1.30541] [3.74940] [8.04459] [15.31581] Estimated Revolutions Life* (Millions) 21.444 16.083 12.866 10.722 9.190 21.221 15.915 12.732 10.610 Reduction Ratio 3:1 4:1 5:1 6:1 7:1 3:1 4:1 5:1 6:1 Maximum Nm 70 90 110 140 160 240 330 410 490 Allowable [lbft] Dynamic Torque [51.6] [66.4] [81.1] [103.3] [118.0] [177.0] [243.4] [302.4] [361.4] Maximum Nm 140 180 220 280 320 480 660 820 980 Allowable Static [lbft] Torque [103.2] [132.8] [182.2] [206.6] [236.0] [354.0] [486.8] [604.8] [722.8] Center to Center mm 98.0 122.0 146.0 170.0 193.5 154.0 193.0 230.0 268.0 Distance [in] [3.86] [4.80] [5.75] [6.69] [7.62] [6.06] [7.60] [9.06] [10.55] Positional arcsec Accuracy** ± 90 ± 70 ± 60 ± 50 ± 40 ± 60 ± 50 ± 40 ± 30 System Meshing Error arcsec per Pitch** 60 45 35 30 25 40 30 25 20 Repetitive Positioning arcsec 30 25 20 15 15 20 15 15 10 Precision**

Maximum arcsec Backlash 18.5 13.9 11.1 9.3 7.9 11.7 8.8 7.0 5.9 Operating °C -5 to 40 Temp. Range*** [°F] [23 to104] Rack Grease Part Number 853901

* Life rating is an estimate rounded down to the next 1,000 revolutions and based on maintaining published accuracy specifications and operated with allowable dynamic loading for 60,000,000 pinion revolutions (10,000 hours) at a constant 100 rpm when properly installed and receiving recommended lubrication intervals while operated in a clean, dry, 20° C [68° F] environment. Application and environmental conditions, and lubrication intervals will impact expected product life. The RPG system will continue to operate beyond this point with deteriorating accuracy. Additional ring gear life may be achieved by replacing the pinion before excessive ring gear wear occurs. ** Positional accuracy dependent on proper installation and measured at 20° C (68° F). To be conservative, transmitting accuracy has been rounded up to the next 10 arcsec, others have been rounded up to the next 5 arcsec. Specifications are with systems assembled to Nexen specifications, operated at 20ºC [68º F], and are subject to variations due to mounting surface irregularities, rigidity, installation accuracy, proper maintenance, and ambient temperature. *** For applications outside of this temperature range or with wide temperature swings contact Nexen.

Standard Gear Dimensions RPS16G

B E J

A F

D K H

~56.0 [~2.205]

42.0 20.0 [1.654] [0.787] Minimum 18.0 Shaft Insertion 2.0 [0.709] 2.0 [0.079] 12.0 12.0 [0.079] [0.472] [0.472] 16.0 [0.630]

Ø 42.0 Ø 20.0H7 Ø 67.0 [Ø 1.654] C2 [Ø 0.787H7] [Ø 2.638]

P.C.D. 33.0 [1.299] 11.0 5-M4 ~52.0 [0.433] [~2.047] mm [in]

Ring Gear Mounting Holes A B D E G H J K Product Number Bolt / Pin Center to Center Outer Inner F Angular Pinning Mounting Bolt Diameter Number of Teeth Circle Distance Diameter Diameter Pitch Hole Size Hole Size of Boss Diameter 6 Holes, 2 Holes 98.0 162.0 70.0H7 90.0 Ø7.0[0.276] Thru 106.0 966550 30 30° 60° Ø6.0H7 [3.858] [6.378] [2.756H7] [3.543] Ø11.0[0.443] [4.173] [0.236H7] 6.5[0.256] 8 Holes, 2 Holes 122.0 210.0 120.0H7 145.0 Ø7.0[0.276] Thru 161.0 966551 40 15° 45° Ø6.0H7 [4.803] [8.268] [4.720H7] [5.709] Ø110[0.443] [6.339] [0.236H7] 6.5[0.256] 12 Holes, 2 Holes 146.0 257.0 160.0H7 180.0 Ø7.0[0.276] Thru 206.0 966552 50 15° 30° Ø6.0H7 [5.748] [10.118] [6.299H7] [7.087] Ø11.0[0.443] [8.110] [0.236H7] 6.5[0.256] 12 Holes, 2 Holes 170.0 305.0 190.0H7 220.0 Ø9.0[0.354] Thru 246.0 966553 60 15° 30° Ø8.H7 [6.693] [12.008] [7.480H7] [8.661] Ø14.0[0.551] [9.690] [0.315H7] 8.5[0.335] 12 Holes, 2 Holes 193.5 353.0 260.0H7 285.0 Ø9.0[0.354] Thru 301.0 966554 70 15° 30° Ø8.0H7 [7.618] [13.898] [10.236H7 [11.221] Ø14.0[0.551] [11.850] [0.315H7] 8.5[0.335] Visit www.nexengroup.com or contact Nexen’s technical support group for up to date technical specifications, drawings, CAD files, and User Manual to review installation requirements before designing a system.

Standard Gear Dimensions B RPS25G E

G A F

D K

~72.0 28.0 [~2.835] [1.102] 54.0 2.0 [2.126] 2.0 [0.079] Minimum [0.079] 26.0 Shaft Insertion 24.0 [1.024] [0.945] 14.0 14.0 [0.551] [0.551]

Ø 63.0 Ø 30.0H7 Ø 101.0 [Ø 2.480] C2 [Ø 1.181H7] [Ø 3.976]

P.C.D. 51.0 [2.008]

12.0 5-M6 [0.472] mm [in] ~66.0 [~2.598] Ring Gear Mounting Holes A B D E G H J K Product Number Bolt / Pin Center to Center Outer Inner F Angular Pinning Mounting Bolt Hole Diameter Number of Teeth Circle Distance Diameter Diameter Pitch Hole Size Size of Boss Diameter 6 Holes, 2 Holes 154.0 254.0 120.0H7 145.0 Ø9.0[0.354] Thru 176.0 966560 30 30° 60° Ø8.0H7 [6.063] [10.000] [4.720H7] [5.709] Ø14.0[0.551] [6.929] [0.315H7] 8.5[0.335] 12 Holes, 2 Holes 193.0 331.0 190.0H7 220.0 Ø9.0[0.354] Thru 246.0 966561 40 15° 30° Ø8.0H7 [7.596] [13.032] [7.480H7] [8.662] Ø14.0[0.551] [9.691] [31.05H7] 8.5[0.335] 12 Holes, 2 Holes 230.0 405.0 260.0H7 285.0 Ø9.0[0.354] Thru 326.0 966562 50 15° 30° Ø8.0H7 [9.055] [15.945] [10.236H7] [11.221] Ø14.0[0.551] [12.835] [0.315H7] 8.5[0.335] 16 Holes, 2 Holes 268.0 481.0 330.0H7 360.0 Ø11.0[0.433] Thru 406.0 966563 60 15° 22.5° Ø10.0H7 [10.551] [18.937] [12.992H7] [14.173] Ø17.5[0.709] [15.984] [0.394H7] 10.5[0.413] Visit www.nexengroup.com or contact Nexen’s technical support group for up to date technical specifications, drawings, CAD files, and User Manual to review installation requirements before designing a system. 10 Specifications For Determining Custom Gear Set Performance

System Specifications RPG16 RPG20 RPG25 RPG32 RPG40 RPG4014 mm 16 20 25 32 40 40 Tooth/Roller Pitch [in] [0.630] [0.787] [0.984] [1.260] [1.575] [1.575] Maximum / Average Degrees 30.7 / 23.5 30.1 / 23.5 30.7 / 23.5 30.1 / 23.5 30.0 / 23.5 30.0 / 23.5 Pressure Angle mm 4.8 6.0 7.5 9.5 12.0 12.0 Module [in] [0.19] [0.24] [0.30] [0.37] [0.47] [0.47] Torque Circle Tangential Positional ±μm 30 30 30 30 30 30 Accuracy [±in] [0.00118] [0.00118] [0.00118] [0.00118] [0.00118] [0.00118] Maximum Torque Circle Tangential μm 3.2 3.2 3.2 3.2 3.2 3.2 Backlash [in] [0.00013] [0.00013] [0.00013] [0.00013] [0.00013] [0.00013] Maximum Torque Circle Tangential m/s 4 5 8 11 6 6 Speed [ft/s] [13.1] [16.4] [26.2] [36.1] [19.7] [19.7] Maximum Dynamic Torque Circle N 1000 1500 2200 3600 6000 14000 Tangential Thrust [lbf] [225] [337] [495] [809] [1349] [3147] Maximum Static Torque Circle N 2000 3000 4400 7200 12000 21000 Tangential Thrust [lbf] [450] [674] [990] [1618] [2698] [4721] Estimated Torque Circle m 9,600,000 12,000,000 15,000,000 23,040,000 28,800,000 336,000,000 Tangential Life* [ft] [31,496,000] [39,370,000] [49,230,000] [75,590,000] [94,480,000] [1,102,200,000] Roller Pinion RPG16 RPG20 RPG25 RPG32 RPG40 RPG4014 Product Number 966659 966669 966679 966689 966699 966693 Number of Rollers 10 10 10 12 12 14 Maximum RPM 1500 1500 1920 1719 750 643 Nm 25.5 47.7 87.5 220.0 458.4 1247.8 Maximum Dynamic Torque [in-lb] [226] [422] [774] [1946] [4057] [11044] Nm 50.9 95.5 175.1 440.0 916.8 1871.6 Maximum Static Torque [in-lb] [450] [884] [1558] [3894] [8119] [16565] mm 20.0 25.0 30.0 45.0 60.0 60.0 Mounting Bore Diameter [in] [0.79] [0.98] [1.18] [1.77] [2.36] [2.36] mm 1.91 61.5 76.9 116.9 147.7 172.3 Torque Circle Diameter [in] [48.7] [2.42] [3.03] [4.60] [5.81] [6.78] Tangential Distance per mm 160.0 200.0 250.0 384.0 480.0 560.0 Revolution [in] [6.30] [7.87] [9.84] [15.12] [18.90] [22.1] kg 0.8 1.3 2.2 6.4 12.4 20.9 Mass Weight [lb] [1.76] [2.87] [4.85] [14.11] [27.34] [46.08] kgm² 0.00041 0.00105 0.00268 0.01690 0.05940 0.11800 Moment Of Inertia [lbft²] [0.0098] [0.0249] [0.0636] [0.4010] [1.4096] [2.8005] Ring Gear Or Arc Segment RPG16 RPG20 RPG25 RPG32 RPG40 RPG4014 kg 0.07 0.16 0.24 0.52 1.35 1.74 Approximate Mass Per Tooth [lb] [0.154] [0.353] [0.529] [1.146] [2.976] [3.836]

** See page 8 note * for life rating details Useful Formulas Ring Gear Dynamic Torque (N) = Pinion Dynamic Tangential Thrust X Ring Gear Torque Circle Radius (m) Ring Gear Static Torque (N) = 2 X Ring Gear Dynamic Torque Gear System Ratio = Ring Gear Torque Circle Diameter (m) / Pinion Torque Circle Diameter (m) Positional Accuracy In Radians Based On Ring Gear Torque Circle Radius = Tangential Positional Accuracy (m) / Ring Gear Torque Circle Radius (m) Backlash In Radians Based On Ring Gear Torque Circle Radius = Pinion Tangential Backlash (m) / Ring Gear Torque Circle Radius (m) Convert Radians To Arc Seconds = Radians X 206264.8 Ring Gear Mass (kg) = Ring Gear Torque Circle Radius (m) X 6.283 X Tooth Mass (kg) ** 2 2 Ring Gear Inertia (kgm ) = Ring Gear Mass (kg) X Ring Gear Torque Circle Radius (m2) ** ** For Segments Divide By Fraction Of Full Ring Gear

11 Scanning systems Indexing Systems medical products Robotics Industries & Applications Automotive Aerospace Semiconductors Material Fabrication

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In accordance with Nexen’s established policy of constant product improvement, the specifications contained in this document are subject to change without notice. Technical data listed in this document are based on the latest information available at the time of printing and are Nexen Group, Inc. (800) 843-7445 also subject to change without notice. For current information, please 560 Oak Grove Parkway Fax: (651) 286-1099 consult www.nexengroup.com Vadnais Heights, MN 55127 www.nexengroup.com Nexen has sales offices throughout the United States, Europe, Japan, and Australia.