1、Designing Cost-Efficient MECHANISMS Lawrence J. KammDesigning Cost-Efficient MechanismsDesigning Cost-Efficient Mechanisms Minimum Constraint Design, Designing with Commercial Components, and Topics in Design Engineering Lawrence J. Kamm Published by: Society of Automotive Engineers, Inc. 400 Common
2、wealth Drive Warrendale, PA 15096-0001 U.S.A. Phone: (412) 776-4841 Fax: (412) 776-5760 Copyright 1993 Society of Automotive Engineers, Inc. eISBN: 978-0-7680-5950-2Library of Congress Cataloging-in-Publication Data Kamm, Lawrence J. Designing cost-efficient mechanisms : minimum constraint design, d
3、esigning with commercial components, and topics in design engineering / Lawrence J. Kamm. p. cm. Originally published: New York : McGraw-Hill, c1990. Includes bibliographical references and index. ISBN 1-56091-409-2 : $27.00 1. Machine design. 2. Value analysis (Cost control) I. Title. TJ230.K25 199
4、3 621.815-dc20 93-2266 CIP A hardcover edition of this book was published in 1990 by McGraw-Hill, Inc. It is here reprinted by arrangement with McGraw-Hill and Lawrence J. Kamm. Copyright 1993 Society of Automotive Engineers, Inc. ISBN 1-56091-409-2 All rights reserved. Printed in the United States
5、of America. Permission to photocopy for internal or personal use, or the internal or personal use of specific clients, is granted by SAE for libraries and other users registered with the Copyright Clearance Center (CCC), provided that the base fee of $.50 per page is paid directly to CCC, 27 Congres
6、s St., Salem, MA 01970. Special requests should be addressed to the SAE Publications Group. 1-56091-409-2/93 $.50. SAE Order No. R-135Contents Preface xix Part 1 Minimum Constraint Design (MinCD), Semi-MinCD, and Redundant Constraint Design (RedCD) Chapter 1. General Description 3 Chapter 2. Degrees
7、 of Constraint 5 2.1 Disadvantages and Benefits of RedCD 5 2.1.1 Disadvantages 5 2.1.1.1 Fart-to-Part Variation 5 2.1.1.2 Assembly Stresses and Strains 6 2.1.1.3 Deformation in Normal Service 6 2.1.1.4 Damage Deformation 6 2.1.1.5 Thermal Deformation 6 2.1.1.6 Wear Deformation 7 2.1.2 Benefits 7 2.1
8、.2.1 Deformation to Assemble 7 2.1.2.2 Operating Deformation 7 2.1.2.3 Load-Spreading Deformation 7 2.2 Theory of MinCD 8 2.2.1 Axes 8 2.2.2 Freedoms and Constraints 8 2.2.3 An Example of Pure MinCD 9 2.2.4 Degree of Purity 10 2.2.5 Further Theory 11 2.2.6 Rules and Principles 11 2.2.7 Rotary Constr
9、aints 12 2.2.8 Matched Sets 12 2.2.9 Relative Constraint 13 2.2.10 Needed Theory 14 2.3 Examples of Bad RedCD 14 2.3.1.1 Three Bearings on One Shaft 14 2.3.1.2 Dovetail Slides 14 2.3.1.3 Bolted Feet 15 2.3.1.4 Lead Screw 16 2.3.1.5 Chairs and Tables 17 vvi Contents 2.4 Examples of Good RedCD 17 2.4.
10、1.1 Cylinder Head 17 2.4.1.2 Flanged Joint and Bolt Circle 17 2.5 Examples of MinCD 17 2.5.1 The Ubiquitous Tripod 17 2.5.1.1 Surveyors Instrument Tripod 17 2.5.1.2 One-Leg Stool 18 2.5.1.3 Three-Leg Chairs 19 2.5.1.4 Kettles 20 2.5.1.5 Ancient Tripods 20 2.5.1.6 Tension Tripods 20 2.5.1.7 Tripod De
11、rricks 20 2.5.1.8 Surface Plates 21 2.5.1.9 Machine Tools 21 2.5.1.10 Jigs and Fixtures 21 2.5.1.11 Tricycles 22 2.5.1.12 Trailers 23 2.5.1.13 Bell Striker 23 2.5.2 Examples of MinCD in Industry 23 2.5.2.1 Lathe Chucks 23 2.5.2.2 Robot Grippers 23 2.5.2.3 Straight-Line Mechanism 24 2.5.2.4 Larger St
12、raight-Line Mechanism 25 2.5.2.5 Large Linear-Motion Mechanism 25 2.5.2.6 Large Storage and Retrieval Robot 26 2.5.2.7 Safety Caging 28 2.5.2.8 Assembly 29 2.5.2.9 Tandem Shafts 30 2.6 MinCD with Flexible Bodies 30 2.6.1 Examples of Flexible Body 30 2.6.1.1 Long Machine Beds 30 2.6.1.2 Robot Spar 31
13、 2.6.1.3 Flexible Cart 31 2.6.2 Classes of Flexible Body 32 2.6.2.1 Thin 32 2.6.2.2 Long 32 2.6.2.3 Large 32 2.7 Load Dividers 32 Chapter 3. Kinds of Constraint 35 3.1 Hard Constraints 35 3.1.1 Examples of Hard Constraints 35 3.1.1.1 Point and Surface 35 3.1.1.2 Ball and Surface 35 3.1.1.3 Roller an
14、d Surface 36 3.1.1.4 Shaft-and-Sleeve Bearing 36 3.1.1.5 Ball and Socket 36 3.1.1.6 Bolted Feet 36 3.1.2 Examples of Wheel Constraints 36 3.1.2.1 Single Narrow Wheel 36 3.1.2.2 Pair of Wheels Tight on a Common Axle 36 3.1.2.3 Pair of Wheels Loose on a Common Axis 37 3.1.3 Examples of Wheels on Track
15、s 37 3.1.3.1 Two Flanges on One Wheel 37Contents vii 3.1.3.2 One Flange on Each Wheel of a Pair 37 3.1.3.3 Traditional Railroad Wheels 37 3.1.3.4 V Grooves 37 3.1.4 Examples of Rotary Hard Constraints 37 3.1.4.1 Jaw Clutch 37 3.1.4.2 Splined Shaft 37 3.1.4.3 U Joint, Splined Shaft, U Joint 38 3.1.4.
16、4 Independent Rotary Constraint 38 3.2 Centering Constraints 38 3.2.1 Hard Centering 38 3.2.2 Soft Centering 39 3.3 Human Constraints 40 3.4 Soft Constraints 42 3.4.1 Uses for Soft Constraints 42 3.4.1.1 Shock and Vibration Isolation 42 3.4.1.2 Oscillation Damping 42 3.4.1.3 Contact Stress Reduction
17、 43 3.4.1.4 Scratch and Dent Prevention 43 3.4.1.5 Pressure Distribution 43 3.4.1.6 Overtravel Cushioning 43 3.4.1.7 Separation of Sliding Parts 44 3.4.2 Seating Forces 45 3.4.3 Materials Used in Soft Constraints 46 3.4.4 Effects Used in Soft Constraints 46 3.4.4.1 Elasticity 46 3.4.4.2 Hysteresis 4
18、6 3.4.4.3 Viscosity 46 3.4.4.4 Buoyancy 47 3.4.4.5 Eddy Currents 48 3.4.4.6 Magnetic Attraction and Repulsion 48 3.4.4.7 Gravity 48 3.4.4.8 Fluid Pressure 49 3.4.5 Devices Used for Soft Constraint 49 3.4.5.1 Dashpots 49 3.4.5.2 Cylinders 50 3.4.5.3 Motors 51 3.4.5.4 Voice Colls 51 3.4.5.5 Clutches a
19、nd Brakes 51 3.4.5.6 Shock Mounts 51 3.4.6 Inflated Constraint Devices 52 3.4.6.1 Inflated Seal 52 3.4.6.2 Air Springs 52 3.4.7 Part Grippers 53 3.4.7.1 Inflated Tube 53 3.4.7.2 Expanding O Rings 53 3.4.7.3 Vacuum Grippers 53 3.4.7.4 Ventricles 54 3.4.7.5 Squeeze Valve 54 3.4.7.6 Air Tube Clutch and
20、 Brake 54 3.4.7.7 Inflatable Actuator 55 3.5 Flexible Constraints 55 3.5.1.1 Flexures 55 3.5.1.2 Flexible Couplings 57 3.5.1.3 Torsion Flexures 58 3.5.1.4 Suspension Flexures 58viii Contents 3.5.1.5 Bimetal 59 3.5.1.6 Tape 59 3.5.1.7 Electrical Flexures 59 3.5.1.8 Tension Flexures 61 3.5.1.9 Hoses 6
21、1 3.5.1.10 Flexible Hose and Cable Supports 61 3.5.1.11 Energy Storage Flexures 62 3.5.1.12 Balancing Springs 62 3.5.1.13 Flexible Containers 62 3.5.1.14 Musical Instruments 62 3.5.1.15 Clock Crystals 62 3.5.1.16 Latches 62 3.6 Adjustable Constraints 63 3.6.1 Reasons for Adjustability 63 3.6.2 Adjus
22、table Parameters 63 3.6.2.1 Straightness 63 3.6.2.2 Squareness, Plumbness, and Levelness 63 3.6.2.3 Angle 63 3.6.2.4 Phase 63 3.6.2.5 Distance 63 3.6.2.6 Alignment and Parallelism 63 3.6.2.7 Force and Pressure 63 3.6.2.8 Electrical Parameters 64 3.6.3 Adjustment Techniques 65 3.6.3.1 Adjusting Screw
23、s 65 3.6.3.2 Eccentrics 66 3.6.3.3 Shims 66 3.6.3.4 Wedges 66 3.6.3.5 Phasing Hubs 66 3.6.3.6 Adhesives and Grout 66 3.6.3.7 Hammers and Files 66 3.6.3.8 Part Replacement 66 3.6.4 Adjustment Measurements 66 3.6.5 Geometrical Instruments 67 3.6.5.1 Level 67 3.6.5.2 Square 67 3.6.5.3 Angle Scales 67 3
24、.6.5.4 Plumb Line 67 3.6.5.5 Linear-Distance Instruments 68 3.6.5.6 Optical Measuring Systems 68 3.6.6 Other Instuments 68 3.6.6.1 Human Touch, Hearing, and Vision 68 3.6.6.2 Transducers 69 3.7 Variable Constraints 69 3.7.1.1 Cams 69 3.7.1.2 Linkages 70 3.7.1.3 Lead Screws 70 3.7.1.4 Air Cylinders 7
25、0 3.7.1.5 Hydraulic Cylinders 70 3.7.1.6 Electric Motors 71 3.7.1.7 Gears 72 3.7.1.8 Rack and Pinion 72 3.7.1.9 Chain, Tape, and Rope 73 3.7.1.10 Belt and Pulley 73 3.7.1.11 Servos 74Contents ix 3.8 Friction Constraints 74 3.8.1 Friction Devices 74 3.8.1.1 Collets 74 3.8.1.2 Chucks and Vises 75 3.8.
26、1.3 Wedges 75 3.8.1.4 Taper Pins 75 3.8.1.5 Setscrews 75 3.8.1.6 Belt and Pulley 75 3.8.1.7 Friction Variable-Speed Drives 75 3.8.2 Screw Thread Retention 75 3.8.2.1 Plastic Inserts 75 3.8.2.2 Self-Tapping Screws 75 3.8.2.3 Deformed Threads 75 3.8.2.4 Tapered Threads 75 3.8.2.5 Adhesives 76 3.8.2.6
27、Lockwashers 76 3.8.2.7 Locknuts 76 3.9 Self-Aligning Elements 76 3.9.1.1 Caster 76 3.9.1.2 Single Gimbal 77 3.9.1.3 Two Gimbals 77 3.9.1.4 Two Gimbals (Alternate) 77 3.9.1.5 Three Gimbals 77 3.9.1.6 Sliding Gimbals 78 3.9.1.7 Universal Joints 79 3.9.1.8 Self-Aligning Linear Ball Bearing 79 3.9.1.9 S
28、pherical Joint (“Ball Joint“) 79 3.9.1.10 Spherical Bearing Mount 81 3.9.1.11 Leveling Pads 82 3.9.1.12 Spherical Bearing 83 3.9.1.13 Spherical Washers 85 3.9.1.14 Self-Aligning Roller Bearing 86 3.9.1.15 Linear Chained Roller Bearing 86 3.9.1.16 Ball Caster 87 3.9.1.17 Spline 87 3.9.1.18 Active Sel
29、f-Alignment 91 Chapter 4. Beneficial Non-MinCD 93 4.1 Semi-MinCD 93 4.2 Matched Sets 93 4.3 Finite Area Contacts 94 4.4 MinCD to Semi-MinCD Conversion 94 4.4.1.1 Conversion of Fig. 2.1 94 4.4.1.2 Heavily Loaded Slide 94 4.4.1.3 Lathe Carriage 94 4.4.1.4 Bolted Foot 95 4.4.1.5 Zero-Looseness Hinge 95
30、 4.5 Useful RedCD 95 4.5.1.1 Large Distributed Load 95 4.5.1.2 Necessary Deformation 96 4.5.1.3 Varying Load Distribution 96 4.6 RedCD Components 97 4.6.1.1 V-Band Fastener 97x Contents 4.6.1.2 Retaining Rings 98 4.6.1.3 Screw Threads 100 4.6.1.4 “Piano Hinge“ 101 4.6.1.5 Flanged Joint 101 4.7 Self-
31、improving RedCD 101 4.7.1.1 Wearing In 101 4.7.1.2 Flat Lapping 101 4.7.1.3 Parabolic Lapping 101 4.7.1.4 Bearing-Ball Lapping 101 4.7.1.5 Circle Divider 102 4.7.1.6 Lead-Screw Lapping 103 4.7.1.7 Hand Scraping 103 4.7.1.8 Conical Bearings 104 Exercises in MinCD, Semi-MinCD, and RedCD 104 Part 2 Des
32、igning with Commercial Components Chapter 5. General Discussion 107 5.1 Commercial versus Special 107 5.1.1 Advantages of Commercial Components 107 5.1.1.1 Development Costs 107 5.1.1.2 Manufacturing Costs 107 5.1.1.3 Experience 107 5.1.1.4 Approvals 107 5.1.2 Advantages of Your Own Design 107 5.1.2
33、.1 Suitability 107 5.1.2.2 Costs 108 5.1.2.3 Design Integration 108 5.1.2.4 Independence 108 5.1.2.5 Management Considerations 108 5.1.2.6 Combining Ideas 108 5.2 Approved Products 108 5.2.1 Your Company 108 5.2.2 Other Organizations 109 5.2.3 Your Customer 109 5.3 Sources of Information 110 5.3.1 Y
34、our Program of Study 110 5.3.1.1 Catalogs 110 5.3.1.2 Advertisements 110 5.3.1.3 Trade Shows 110 5.3.2 Purchasing Directories 111 5.3.3 Manufacturers Representatives and Salespeople 111 5.4 Big Companies versus Small Companies 111 5.5 Components in This Book 112 5.6 Organization of This Book Section
35、 112 5.7 Breadth and Depth 112 5.8 How to Use This Book 113 Chapter 6. Rotary Motion 115 6.1 Bearings 115 6.1.1 Rolling Bearings 115Contents xi 6.1.1.1 Ball Bearings 115 6.1.1.2 Roller Bearings 116 6.1.2 Bearing Housings 116 6.1.3 Sliding Bearings 117 6.1.3.1 Hydrodynamic Lubrication 117 6.1.3.2 Hyd
36、rostatic Lubrication 117 6.1.3.3 Dry 117 6.1.4 Flexure Bearings 118 6.2 Spindle Assemblies 118 6.3 Coupling Hubs to Shafts 118 6.3.1 Interference Couplings 118 6.3.2 Tapers and Collets 119 6.4 Collars and Retaining Rings 119 6.5 Shafting 119 6.6 Clutches and Brakes 120 6.6.1 Torque-Generating Effect
37、s 121 6.6.1.1 Dry Friction 121 6.6.1.2 Lubricated Friction 121 6.6.1.3 Hydrodynamic Forces 121 6.6.1.4 Viscous Drag 121 6.6.1.5 Magnetic Particle 121 6.6.1.6 Eddy-Current Drag 122 6.6.1.7 Hysteresis Drag 122 6.6.1.8 Positive Engagement 122 6.6.1.9 Generators and Motors 122 6.6.2 Control Effects 122
38、6.6.2.1 Electricity 123 6.6.2.2 Compressed Air 123 6.6.2.3 Hydraulics 123 6.6.2.4 Centrifugal Force 123 6.6.2.5 Torque 123 6.6.2.6 Angular Position 124 6.6.2.7 Human 124 6.7 Rotation Transmission 124 6.7.1 Shaft Couplings 124 6.7.2 Gears 125 6.7.3 Gearless Speed Reducers 125 6.7.4 Friction Drives 12
39、5 6.7.4.1 V Belts 125 6.7.4.2 Multi-V Belts 125 6.7.4.3 Flat Belts 126 6.7.4.4 Tooth Belts 126 6.7.4.5 Round Belts 126 6.7.5 Chains 126 6.7.6 Indexing Drives 127 6.7.7 Variable-Speed Drives 127 6.7.7.1 Variable-Speed Motors 127 6.7.7.2 Motor and Slip Clutch 127 6.7.7.3 Friction 128 6.7.7.4 V Belt 12
40、8 6.7.7.5 Hydraulic 128 6.7.7.6 Gearshift 128xii Contents Chapter 7. Linear Motion 129 7.1 Bearings, Wheels, and Tracks 129 7.1.1 Roller and Track Matched Sets 129 7.1.1.1 Round Tracks 129 7.1.1.2 Nonround Tracks 130 7.1.1.3 Roller-Bearing Systems 130 7.1.2 Complete Matched Sets 130 7.2 Wheels 131 7
41、.2.1 Wheels for Flat Paths 131 7.3 Wheel Steering 132 7.4 Wheel and Track Matched Sets 132 7.5 Hydrostatic Sliding Bearings 132 7.6 Lead Screws and Nuts 133 7.7 Belts, Chains, and Ropes 133 Chapter 8. Power 135 8.1 Available Forms of Power 135 8.2 Power Sources 135 8.2.1 Electricity 135 8.2.1.1 Moto
42、rs 136 8.2.1.2 Other Electric Actuators 137 8.2.1.3 Heaters 137 8.2.1.4 Electrical Controls 137 8.2.1.5 Wiring Devices 138 8.2.2 Hydraulics 138 8.2.2.1 Cylinders 138 8.2.2.2 Motors 139 8.2.2.3 Control Devices 139 8.2.2.4 Plumbing 139 8.2.3 Pneumatics 140 8.2.4 Explosives 141 8.2.5 Springs 141 8.2.6
43、Flywheels 142 8.2.7 Heat Engines 142 8.2.8 Fuel Burning 142 8.2.9 Human Power 142 Chapter 9. Other Components 145 9.1 Semifinished Materials 145 9.2 Structural Systems 146 9.3 Enclosures 146 9.4 Machine Modules 147 9.5 Fasteners 148 9.5.1 Threaded Fasteners 148 9.5.1.1 Data and Specifications 148 9.
44、5.1.2 Threaded Inserts 148 9.5.1.3 Sheet-Metal Nuts 148 9.5.1.4 Other Forms 148 9.5.2 Thread Locking 149 9.5.2.1 Lockwashers 149Contents xiii 9.5.2.2 Locknuts 149 9.5.2.3 Lock Wire 150 9.5.2.4 Castellated Nuts 150 9.5.2.5 Insert Nuts 150 9.5.2.6 Insert Bolts 150 9.5.2.7 Deformed Nuts 150 9.5.2.8 Adh
45、esives 150 9.5.3 Nonthreaded Fasteners 150 9.5.3.1 Rivets 150 9.5.3.2 Other Fasteners 151 9.5.3.3 Latches 151 9.6 Vibration and Shock Absorbers 151 9.6.1 Shock Mounts 151 9.6.2 Shock Absorbers 152 9.7 Springs 152 9.8 Lubrication 153 9.9 Seals and Guards 154 9.10 Sensors and Displays 154 9.10.1 Param
46、eters 155 9.11 Sequence Controls 156 9.11.1 Timers 156 9.11.2 Drum Controllers 156 9.11.3 Relay Circuits 156 9.11.4 Programmable Controllers (PLC) 157 9.11.5 Computers 157 9.11.6 Nonelectrical Controllers 157 9.12 Tooling Components 158 9.13 Permanent Magnets 158 9.14 Lamps 158 9.15 Nameplates 158 9
47、.16 Pumps and Blowers 159 9.17 Miscellaneous 159 Exercises in Design with Commercial Components 159 Part 3 Topics in Design Engineering Chapter 10. Designing with Uncommon Manufacturing Processes 163 Chapter 11. Manufacturing Engineering 167 11.1 What Is Manufacturing Engineering? 167 11.1.1.1 Stand
48、ard Machines 167 11.1.1.2 Special Machines for Sale 168 11.1.1.3 Special Machines for Your Company 168 11.1.1.4 R Engineering Work 169 11.2.1.3 Motivation 169 11.2.1.4 Offices 170 11.2.1.5 Education 170xiv Contents Chapter 12. Optimum Level of Mechanization and Automation 171 12.1 Classification 171
49、 12.1.1 Fully Automatic 172 12.1.2 Powered Machines with Human Control 172 12.1.3 Combination Human and Automatic 173 12.1.4 Human Work with Power Tools 173 12.1.5 Human Workers with Special Hand Tools 173 12.2 Assembly Kits 174 12.3 The Benefits of Automation 174 12.4 Justifying the Cost of Automation 174 12.5 Policy Questions 175 Chapter 13. Robots 177 13.1 History and Myth 177 13.2 Robot Reality 178 13.2.1 End Effectors 178 13.2.1.1 Fabricating Tools 178 13.2.1.2 Material-Handling Tools 178 13.2.1.3 Sensors 178 13.2.1.4 Military Components 179 13.2.1.5 Quick-Change Grippers 179 13.3
