Pub.ES-100-2 BASIC HYDRAULICSANDCOMPONENTS BASIC HYDRAULICS AND COMPONENTS OIL HYDRAULIC EQUIPMENT ■ Overseas Business Department Hamamatsucho Seiwa Bldg., 4-8, Shiba-Daimon 1-Chome, Minato-ku, Tokyo 105-0012 JAPAN TEL. +81-3-3432-2110 FAX. +81-3-3436-2344 Preface This book provides an introduction to hydraulics for those unfamiliar with hydraulic systems and components, such as new users, novice salespeople, and fresh recruits of hydraulics suppliers. To assist those people to learn hydraulics, this book offers the explanations in a simple way with illustrations, focusing on actual hydraulic applications. The first edition of the book was issued in 1986, and the last edition (Pub. JS-100-1A) was revised in 1995. In the ten years that have passed since then, this book has become partly out-of-date. As hydraulic technologies have advanced in recent years, SI units have become standard in the industrial world, and electro-hydraulic control systems and mechatronics equipment are commercially available. Considering these current circumstances, this book has been wholly revised to include SI units, modify descriptions, and change examples of hydraulic equipment. Conventional hydraulic devices are, however, still used in many hydraulic drive applications and are valuable in providing basic knowledge of hydraulics. Therefore, this edition follows the preceding edition in its general outline and key text. This book principally refers hydraulic products of Yuken Kogyo Co., Ltd. as example, but does mention some products of other companies, with their consent, for reference to equipment that should be understood. We acknowledge courtesy from those companies who have given us support for this textbook. This edition was originally designed for the Japanese learners and is translated into English, hoping to help assist future engineers of hydraulics in the international community. Some of the descriptions and figures in Chapters 11, 14, and 15 are extracted from “Oil-Hydraulics - Handbook (Revised in 2001)”issued by the Japan Fluid Power Association (JFPA). We express our deep appreciation to the Association. ・Units For US units, use the following conversion formula:- 1 [MPa] ＝ 145.04 [psi] 1 [cm3/rev] ＝ 6.102×10-2[cu.in/rev] 1 [L/min] ＝ 0.2642 [U.S.GPM] 1 [kg] ＝ 2.205 [lbs.] 1 [kW] ＝ 1.360 [HP] 1 [m] ＝ 39.37 [in] 1 [N] ＝ 0.2248 [lbf] °F＝9/5 ℃＋32 BASIC HYDRAULICS AND COMPONENTS TABLE of CONTENTS PREFACE 1．WORLD OF HYDRAULICS…………………………………………………………………………… 1 1-1 Introduction 1-2 Basis of Hydraulics 2．HYDRAULIC PUMPS ………………………………………………………………………………… 5 2-1 Comparison of the Pumps 2-2 Piston Pumps 2-3 Vane Pumps 2-4 Gear Pumps 2-5 Screw Pumps 2-6 Reciprocal Pumps 3．PRESSURE CONTROL VALVES …………………………………………………………………… 16 3-1 Relief Valves 3-2 Sequence Valves 3-3 Counterbalance Valves 3-4 Unloading Relief Valves 3-5 Pressure Reducing Valves/Pressure Reducing and Check Valves 3-6 Brake Valves 3-7 Balancing Valves (Pressure Reducing and Relieving Valves) 3-8 Pressure Switches 4．DIRECTIONAL CONTROL VALVES ……………………………………………………………… 22 4-1 Classification of Directional Control Valves 4-2 Structure and Characteristics of Directional Valves 4-2-1 Solenoid Operated Directional Valves 4-2-2 Solenoid Controlled Pilot Operated Directional Valves 4-2-3 Poppet Type Solenoid Controlled Pilot Operated Directional Control Valves 4-2-4 Shut-off Type Solenoid Operated Directional Valves (Poppet Type Two-Way Solenoid Operated Directional Valves) 4-2-5 Pilot Operated Directional Valves 4-2-6 Manually Operated Directional Valves 4-2-7 Check Valves 4-2-8 Pilot Operated Check Valves 4-2-9 Multiple Control Valves 5．FLOW CONTROL VALVES…………………………………………………………………………… 32 5-1 Restrictors/One Way Restrictors 5-2 Flow Control Valves/Flow Control and Check Valves 5-3 Deceleration Valves/Deceleration and Check Valves 5-4 Feed Control Valves 5-5 Pilot Operated Flow Control and Check Valves 6．MODULAR VALVES …………………………………………………………………………………… 37 7．LOGIC VALVES ………………………………………………………………………………………… 38 8．PROPORTIONAL ELECTRO-HYDRAULIC CONTROL VALVES …………………………… 41 8-1 Proportional Electro-Hydraulic Pilot Relief Valves 8-2 Proportional Electro-Hydraulic Relief Valves 8-3 Proportional Electro-Hydraulic Relieving and Reducing Valves 8-4 Proportional Electro-Hydraulic Flow Control (and Check) Valves ■ TABLE of CONTENTS 8-5 Proportional Electro-Hydraulic Flow Control and Relief Valves 8-6 Proportional Electro-Hydraulic Directional and Flow Control Valves 8-7 Power Amplifiers For Proportional Electro-Hydraulic Control Valves 8-8 Setting Adjusters 8-9 Circuit Example of Proportional Electro-Hydraulic Control Valves 8-10 Hybrid Proportional Electro-Hydraulic Control Valves 9．SERVOMECHANISM & SERVO VALVES………………………………………………………… 49 9-1 Servomechanism (Tracking Mechanism) 9-2 Servo Valve Selection 9-3 Electro-Hydraulic Two-Stage Servo Valves 9-4 Direct Drive Servo Valves 9-5 Servo Amplifiers 9-6 Sensors 9-7 Hydraulic Power Source 9-8 Servo Systems with Pump Speed Control 9-9 Related Terms 10．ACTUATORS…………………………………………………………………………………………… 58 10-1 Hydraulic Cylinders 10-2 Hydraulic Motors 10-3 Oscillating Motors 11．HYDRAULIC ACCESSORIES ……………………………………………………………………… 63 11-1 Filters 11-2 Accumulators 11-3 Heat Exchangers 11-4 Measuring Instruments 11-5 Valves 11-6 Others 12．HYDRAULIC UNITS ………………………………………………………………………………… 71 12-1 Reservoirs 12-2 Others 13．TROUBLESHOOTING FOR HYDRAULIC EQUIPMENT …………………………………… 73 14．HYDRAULIC FLUIDS ………………………………………………………………………………… 75 14-1 Selection 14-2 Petroleum-Based Fluid 14-3 Viscosity 14-4 Contamination Control 14-5 Application Limit 14-6 Contamination Measurement Instruments 14-7 Fire Resistance Fluid 14-8 Biodegradable Fluid 15．HYDRAULIC CIRCUITS……………………………………………………………………………… 82 15-1 Unload Circuits 15-2 Pressure Control Circuits 15-3 Speed Control Circuits 15-4 Filter Circuits 15-5 Synchronizing Circuits 15-6 Intensifying Circuits 15-7 Brake Circuits 15-8 Closed Circuits Appendix: Main Formulas …………………………………………………………………………………… 92 TABLE of CONTENTS ■ “Hydraulics”is one of drive systems to control machinery and eq “Hydraulics”is 1 safety. required at to be hydraulics”is environmentally friendly;“water history of some typical water and oil hydraulics. Recently, pro before that, It was in the early 1900’ ■ 4. Patentapplicationforthewaterhydraulic pressmachine： 5. Water hydraulic crane, water hydraulic accumulator, manufact 3. Hydrostaticlaws：BlaisePascal(1623～1662) 2. Basesofhydrodynamics：Galileo(1564～1642) 1. Hydrostaticsprinciples：Archimedes(287～212B.C.) WORLD OFHYDRAULIC DRIVE Joseph Bramah+HenryMaudsley( plant usingwaterhydraulicdrivesystems： ･･･ Forcemultiplier[Pascal “water hydraulics,”the origin of the fluid power systems, emerg Application Trend Pascal (1623-1662) 1651 Bramah (1749-1714) 1800 Vane pump, remote control s that practical hydraulic applications were first seen in the WORLD OFHYDRAULICDRIVE Armstrong (1810-1900) 1832 Accumulator, rotary hydraulic machine 1-2 BasisofHydraulics 1-1 Introduction Fig. 1.1HydraulicApplicationTrendsandMilestones , s principle;1653] Twedell Intensifier Hydraulic applicationtrendsandmilestones self-seal 1877 Hydraulic mains 1881 1st electric power station F by F.Conrad,A.Adelsorp,PureWaterHydraulicSystemsandAppli R ) luid Power Systems, 9thBath InternationalFluid esearch Student Press ltd.,p.158/180.1997. Janney & Williams 1906 Axial piston pump 1-1 Introduction uring Hele-Shaw & Beacham 1914 Radial piston pump Constantinesco (1890-1964) AC hydraulics Massey & Fergusson 1925 Agricultual machinery 10. Pressurebalancedvanepump：1925, HarryF.Vickers Earnst 9. Radialpistonpump：H.S.Hele-Shaw 8. Axialpistonpump：1902-1906,Harvey Williams+ReynoldsJann 7. Powertransmissionsystem：J.W.Hall, Pittler,Lentz,Manley 6. Fluidpower(waterhydraulics)supplycompany： Selfcontained hydraulic press duction machinery and their drive systems have been Towler High pressure hydraulics tracting attention again because of its cleanliness and uipment, comparable with pneumatics and electricity. Dowty 1933 Liquid spring 1845-1849, WilliamArmstrong(1810～1900) 1884, TheLondonHydraulicPowerCompany 1945 1950 MIT-Gas servos Power Workshop. 1960 NASA work Armstrong 1970 Moon landing ed. Figure 1.1 traces the development Water hydraulic Oil hydraulic cations. 1980 1990 Water high pressure systems marketplace. A hundred years 1994 Nessie technology 2000 ey Hydraulics, which owes much to the high lubricity of mineral oils being used as working fluids, offer compact, high- power, and easy-to-control system components in various industrial fields. Table 1.1 shows shipments of hydraulic products per applicable industrial field, based on survey data from the Japan Fluid Power Association. In 2004, total shipments exceeded 270 billion yen, excluding hydraulic products manufactured in-house by construction machinery suppliers and power steering pumps for automobiles. Table 1.1 Shipments of Hydraulic Equipment per Applicable Field (Calendar Year Basis) (Unit: 1 Million Yen. Figures in brackets indicate the percentage shares.) Applicable Field 1999 2000 2001 2002 2003 2004 Civil Engineering Machinery 77,387（36.8） 85,350（36.3） 74,101（35.8） 74,267（38.2） 93,164（39.8） 113,824（41.3） Agricultural Machinery 7,625（ 3.6） 8,045（ 3.4） 7,548（ 3.6） 7,745（ 4.0） 8,052（ 3.4） 10,214（ 3.7） Plastic Processing Machinery 9,649（ 4.6） 10,906（ 4.6） 6,469（ 3.1） 7,045（ 3.6） 8,916（ 3.8） 8,207（ 3.0） Machine Tools 18,143（ 8.6） 20,869（ 8.9） 18,120（ 8.8） 13,987（ 7.2） 17,775（ 7.6） 22,236（ 8.1） Primary Metal Processing 4,829（ 2.3） 4,190（ 1.8） 4,400（ 2.1） 4,257（ 2.2） 5,074（ 2.2） 6,843（ 2.5） Machinery Secondary