机械设计中的机械零件 英文版PDF电子书下载

PARTⅠ Principles of Design and Stress Analysis 1

Appendix 1 Properties of Areas 1

Appendices 1

Index 1

1 The Nature of Mechanical Design 2

Appendix 2 Preferred Basic Sizes and Screw Threads 3

The Big Picture 3

You Are the Designer 4

1-1 Objectives of This Chapter 4

Appendix 3 Design Properties of Carbon and Alloy Steels 6

1-2 The Mechanical Design Process 7

Appendix 4 Properties of Heat-treated Steels 8

1-4 Functions and Design Requirements 9

1-3 Skills Neededin Mechanical Design 9

1-5 Criteria for Evaluating Machine Design Decisions 10

1-6 Example of the Integration of Machine Elements into a Mechanical Design 11

1-8 Design Calculations 13

1-7 Computational Aids in This Book 13

1-9 Preferred Basic Sizes,Screw Threads,and Standard Shapes 14

Appendix 5 Properties of Carburized Steels 14

Appendix 6 Properties of Stainless Steel 15

Appendix 7 Properties of Structural Steels 16

Appendix 8 Design Properties of Cast Iron 17

Appendix 9 Typical Properties of Aluminum 18

Appendix 10 Typical Properties of Zinc Casting Alloys 19

Appendix 11 Properties of Titanium Alloys 20

1-10 Unit Systems 20

Appendix 12 Properties of Bronzes 21

1-11 Distinction among Weight,Force,and Mass 22

Appendix 13 Typical Properties of Selected Plastics 22

References 22

Problems 23

Appendix 14 Beam-Deflection Formulas 23

2 Materials in Mechanical Design 24

The Big Picture 25

You Are the Designer 26

2-1 Objectives of This Chapter 26

2-2 Properties of Metals 26

Appendix 15 Stress Concentration Factors 32

2-3 Classification of Metals and Alloys 33

2-4 Variability of Material Properties Data 34

2-5 Carbon and Alloy Steel 35

Appendix 16 Steel Structural Shapes 36

2-6 Conditions for Steels and Heat Treatment 38

Appendix 17 Aluminum Structural Shapes 42

2-7 Stainless Steels 42

2-10 Cast Iron 43

2-9 Tool Steels 43

2-8 Structural Steel 43

Appendix 18 Conversion Factors 44

2-11 Powdered Metals 45

Appendix 19 Hardness Conversion Table 45

Answers to Selected Problems 46

2-12 Aluminum 46

2-13 Zinc Alloys 47

2-14 Titanium 48

2-15 Copper,Brass,and Bronze 49

2-17 Plastics 50

2-16 Nickel-based Alloys 50

2-18 Composite Materials 52

References 64

Problems 65

3 Stress and Deformation Analysis 67

The Big Picture 68

You Are the Designer 68

3-3 Representing Stresses on a Stress Element 69

3-2 Philosophy of a Safe Design 69

3-1 Objectives of This Chapter 69

3-4 Direct Stresses:Tension and Compression 70

3-5 Deformation under Direct Axial Loading 72

3-6 Direct Shear Stress 72

3-7 Relationship among Torque,Power,and Rotational Speed 74

3-8 Torsional Shear Stress 75

3-9 Torsional Deformation 77

3-10 Torsion in Members Having Noncircular Cross Sections 77

3-11 Torsion in Closed,Thin-walled Tubes 79

3-12 Open Tubes and a Comparison with Closed Tubes 80

3-13 Vertical Shearing Stress 81

3-14 Special Shearing Stress Formulas 83

3-15 Stress Due to Bending 84

3-16 Flexural Center for Beams 86

3-17 Beam Deflections 87

3-18 Equations for Deflected Beam Shape 89

3-19 Beams with Concentrated Bending Moments 91

3-20 Combined Normal Stresses:Superposition Principle 95

3-21 Stress Concentrations 97

3-22 Notch Sensitivity and Strength Reduction Factor 100

Problems 101

References 101

4 Combined Stresses and Mohr's Circle 112

The Big Picture 113

You Are the Designer 113

4-1 Objectives of This Chapter 115

4-2 General Case of Combined Stress 115

4-3 Mohr's Circle 122

4-4 Mohr's Circle Practice Problems 128

4-5 Case When Both Principal Stresses Have the Same Sign 132

4-6 Mohr's Circle for Special Stress Conditions 135

4-7 Analysis of Complex Loading Conditions 138

Problems 139

5 Design for Different Types of Loading 140

The Big Picture 141

You Are the Designer 142

5-1 Objectives of This Chapter 143

5-2 Types of Loading and Stress Ratio 143

5-4 Factors Affecting the Endurance Strength 149

5-3 Endurance Strength 149

5-5 Estimating Actual Endurance Strength,sn' 154

5-7 Predictions of Failure 157

5-6 Design for Different Types of Loading 157

5-8 Design Factors 159

5-9 Methods of Computing Design Factor or Design Stress 160

5-10 General Design Procedure 163

5-11 Design Examples 167

Problems 178

References 178

The Big Picture 189

6 Columns 189

6-1 Objectives of This Chapter 190

You Are the Designer 190

6-3 End Fixity and Effective Length 191

6-2 Properties of the Cross Section of a Column 191

6-5 Transition Slenderness Ratio 193

6-4 Slenderness Ratio 193

6-6 Long Column Analysis:The Euler Formula 194

6-7 Short Column Analysis:The J.B.Johnson Formula 198

6-8 Column Analysis Spreadsheet 200

6-9 Efficient Shapes for Column Cross Sections 203

6-10 The Design of Columns 204

6-11 Crooked Columns 209

6-12 Eccentrically Loaded Columns 210

References 216

Problems 216

PART Ⅱ Design of a Mechanical Drive 221

7 Belt Drives and Chain Drives 225

The Big Picture 226

You Are the Designer 228

7-1 Objectives of This Chapter 228

7-2 Types of Belt Drives 228

7-3 V-Belt Drives 230

7-4 V-Belt Drive Design 233

7-5 Chain Drives 241

7-6 Design of Chain Drives 243

References 253

Problems 254

8 Kinematics of Gears 256

The Big Picture 257

You Are the Designer 261

8-1 Objectives of This Chapter 262

8-2 Spur Gear Styles 262

8-3 Spur Gear Geometry:Involute-Tooth Form 263

8-4 Spur Gear Nomenclature and Gear-Tooth Features 265

8-5 Interference between Mating Spur Gear Teeth 275

8-6 Velocity Ratio and Gear Trains 277

8-7 Helical Gear Geometry 284

8-8 Bevel Gear Geometry 289

8-9 Types of Wormgearing 294

8-10 Geometry of Worms and Wormgears 296

8-11 Typical Geometry of Wormgear Sets 299

8-12 Train Value for Complex Gear Trains 303

8-13 Devising Gear Trains 305

References 312

Problems 313

9 Spur Gear Design 318

The Big Picture 319

9-1 Objectives of This Chapter 320

You Are the Designer 320

9-2 Concepts from Previous Chapters 321

9-3 Forces on Gear Teeth 322

9-4 Gear Manufacture 325

9-5 Gear Quality 327

9-6 Allowable Stress Numbers 328

9-7 Gear Materials 330

9-8 Stresses in Gear Teeth 337

9-9 Selection of Gear Material Based on Bending Stress 346

9-10 Pitting Resistance of Gear Teeth 351

9-11 Selection of Gear Material Based on Contact Stress 355

9-12 Design of Spur Gears 360

9-13 Gear Design for the Metric Module System 365

9-14 Computer-aided Spur Gear Design and Analysis 367

9-15 Use of the Spur Gear Design Spreadsheet 371

9-16 Power-transmitting Capacity 373

9-17 Practical Considerations for Gears and Interfaces with Other Elements 383

References 386

Problems 387

10 Helical Gears,Bevel Gears,and Wormgearing 392

The Big Picture 393

10-1 Objectives of This Chapter 395

10-2 Forces on Helical Gear Teeth 395

You Are the Designer 395

10-3 Stresses in Helical Gear Teeth 398

10-4 Pitting Resistance for Helical Gear Teeth 402

10-5 Design of Helical Gears 403

10-6 Forces on Straight Bevel Gears 405

10-7 Bearing Forces on Shafts Carrying Bevel Gears 408

10-8 Bending Moments on Shafts Carrying Bevel Gears 412

10-9 Stresses in Straight Bevel Gear Teeth 412

10-10 Design of Bevel Gears for Pitting Resistance 415

10-11 Forces,Friction,and Efficiency in Wormgear Sets 417

10-12 Stress in Wormgear Teeth 423

10-13 Surface Durability of Wormgear Drives 424

References 429

Problems 430

11 Keys,Couplings,and Seals 433

The Big Picture 434

You Are the Designer 435

11-1 Objectives of This Chapter 435

11-2 Keys 436

11-3 Materials for Keys 440

11-4 Stress Analysis to Determine Key Length 440

11-5 Splines 445

11-6 Other Methods of Fastening Elements 447

to Shafts 449

11-7 Couplings 454

11-8 Universal Joints 455

11-9 Retaining Rings and Other Means of Axial 457

Location 459

11-10 Types of Seals 462

11-11 Seal Materials 465

References 469

Problems 469

12 Shaft Design 471

The Big Picture 472

You Are the Designer 473

12-1 Objectives of This Chapter 473

12-2 Shaft Design Procedure 473

12-3 Forces Exerted on Shafts by Machine Elements 476

12-4 Stress Concentrations in Shafts 480

12-5 Design Stresses for Shafts 483

12-6 Shafts in Bending and Torsion Only 487

12-7 Shaft Design Example 489

12-8 Recommended Basic Sizes for Shafts 493

12-9 Additional Design Examples 494

12-10 Spreadsheet Aid for Shaft Design 502

References 503

Problems 504

13 Tolerances and Fits 515

The Big Picture 516

You Are the Designer 517

13-1 Objectives of This Chapter 517

13-2 Factors Affecting Tolerances and Fits 518

13-3 Tolerances,Production Processes,and Cost 518

13-4 Preferred Basic Sizes 520

13-5 Clearance Fits 522

13-6 Interference Fits 526

13-7 Transition Fits 528

13-8 Robust Product Design 528

13-9 Stresses for Force Fits 529

References 533

Problems 533

14 Rolling Contact Bearings 535

The Big Picture 536

You Are the Designer 537

14-2 Types of Rolling Contact Bearings 538

14-1 Objectives of This Chapter 538

14-3 Thrust Bearings 542

14-4 Mounted Bearings 542

14-5 Bearing Materials 544

14-6 Load/Life Relationship 544

14-7 Bearing Manufacturers' Data 545

14-8 Design Life 549

14-9 Bearing Selection:Radial Loads Only 551

14-10 Bearing Selection:Radial and Thrust Loads Combined 552

14-11 Mounting of Bearings 554

14-12 Tapered Roller Bearings 556

14-13 Practical Considerations in the Application of Bearings 558

14-14 Importance of Oil Film Thickness in Bearings 562

14-15 Life Prediction under Varying Loads 563

References 564

Problems 565

15 Completion of the Design of a Power Transmission 567

The Big Picture 568

15-1 Objectives of This Chapter 568

15-2 Description of the Power Transmission to Be Designed 568

15-3 Design Alternatives and Selection of the Design Approach 570

15-5 General Layout and Design Details of the Reducer 572

15-4 Design Alternatives for the Gear-Type Reducer 572

15-6 Final Design Details for the Shafts 592

15-7 Assembly Drawing 595

References 597

PART Ⅲ Design Details and Other Machine Elements 599

16 Plain Surface Bearings 600

The Big Picture 601

You Are the Designer 603

16-1 Objectives of This Chapter 603

16-2 The Bearing Design Task 603

16-3 Bearing Parameter,μn/p 605

16-4 Bearing Materials 606

16-5 Design of Boundary-lubricated Bearings 608

16-6 Full-Film Hydrodynamic Bearings 614

16-7 Design of Full-Film Hydrodynamically Lubricated Bearings 615

16-8 Practical Considerations for Plain Surface Bearings 621

16-9 Hydrostatic Bearings 622

References 625

Problems 626

17 Power Screws and Ball Screws 627

The Big Picture 628

You Are the Designer 629

17-1 Objectives of This Chapter 630

17-2 Power Screws 630

17-3 Ball Screws 636

References 639

Problems 639

18 Fasteners 641

The Big Picture 642

You Are the Designer 644

18-2 Other Types of Fasteners and Accessories 644

18-1 Objectives of This Chapter 644

18-3 Bolt Materials and Strength 646

18-4 Thread Designations 648

18-5 Performance of Bolted Joints 650

18-6 Other Means of Fastening 653

References 654

Problems 654

19 Springs 655

The Big Picture 656

You Are the Designer 657

19-1 Objectives of This Chapter 657

19-2 Kinds of Springs 658

19-3 Helical Compression Springs 661

19-4 Stresses and Deflection for Helical Compression Springs 670

19-5 Analysis of Spring Characteristics 672

19-6 Design of Helical Compression Springs 674

19-7 Extension Springs 683

19-8 Helical Torsion Springs 687

References 694

Problems 695

20 Machine Frames,Bolted Connections,and Welded Joints 697

The Big Picture 698

You Are the Designer 699

20-1 Objectives of This Chapter 699

20-2 Machine Frames and Structures 699

20-3 Eccentrically Loaded Bolted Joints 704

20-4 Welded Joints 707

References 715

Problems 716

21 Electric Motors 719

The Big Picture 720

You Are the Designer 721

21-1 Objectives of This Chapter 721

21-2 Motor Selection Factors 722

21-3 AC Power and General Information about AC Motors 723

21-4 Principles of Operation of AC Induction Motors 724

21-5 AC Motor Performance 726

21-6 Three-Phase,Squirrel-Cage Induction Motors 727

21-7 Single-Phase Motors 730

21-8 AC Motor Frame Types and Enclosures 733

21-9 Controls forAC Motors 736

21-10 DC Power 744

21-11 DC Motors 745

21-12 DC Motor Control 748

21-13 Other Types of Motors 750

References 751

Problems 751

22 Motion Control:Clutches and Brakes 754

The Big Picture 755

22-2 Descriptions of Clutches and Brakes 757

22-1 Objectives of This Chapter 757

You Are the Designer 757

22-3 Types of Friction Clutches and Brakes 759

22-4 Performance Parameters 763

22-5 Time Required to Accelerate a Load 765

22-6 Inertia of a System Referred to the Clutch Shaft Speed 767

22-7 Effective Inertia for Bodies Moving Linearly 769

22-8 Energy Absorption:Heat-Dissipation Requirements 770

22-9 Response Time 771

22-10 Friction Materials and Coefficient of Friction 773

22-11 Plate-Type Clutch or Brake 774

22-12 Caliper Disc Brakes 776

22-13 Cone Clutch or Brake 776

22-14 Drum Brakes 778

22-15 Band Brakes 782

22-16 Other Types of Clutches and Brakes 784

Problems 786

References 786

23 Design Projects 789

23-2 Design Projects 790

23-1 Objectives of This Chapter 790