MECHANICAL ENGINEERING DRAWING
1 Introduction 1 11 Machine Design 1 12 Basic Procedure of Machine Design 2 13 Basic Requirements of Machine Elements 3 14 Design of Machine Elements 4 15 Traditional Design Methods 8 16 Design Synthesis 8 17 Use of Standards in Design 9 18 Selection of Preferred Sizes 11 19 Aesthetic Considerations in Design 14 110 Ergonomic Considerations in Design 15 111 Concurrent Engineering 17 Short Answer Questions 19 Problems for Practice 19 2 Engineering Materials 20 21 Stress–Strain Diagrams 20 22 Mechanical Properties of Engineering Materials 23 23 Cast Iron 26 24 BIS System of Designation of Steels 29 25 Plain-carbon Steels 30 26 Free-cutting Steels 32 27 Alloy Steels 32 28 Overseas Standards 34 29 Heat Treatment of Steels 36 210 Case Hardening of Steels 37 211 Cast Steel 38 Contents 212 Aluminium Alloys 39 213 Copper Alloys 41 214 Die-casting Alloys 43 215 Ceramics 44 216 Plastics 45 217 Fibre-reinforced Plastics 48 218 Natural and Synthetic Rubbers 49 219 Creep 50 220 Selection of Material 51 221 Weighted Point Method 51 Short Answer Questions 53 3 Manufacturing Considerations in Design 55 31 Selection of Manufacturing Method 55 32 Design Considerations of Castings 57 33 Design Considerations of Forgings 59 34 Design Considerations of Machined Parts 61 35 Hot and Cold Working of Metals 62 36 Design Considerations of Welded Assemblies 62 37 Design for Manufacture and Assembly (DFMA) 64 38 Tolerances 65 39 Types of Fits 66 310 BIS System of Fits and Tolerances 67 311 Selection of Fits 69 312 Tolerances and Manufacturing Methods 69 313 Selective Assembly 70 314 Tolerances For Bolt Spacing 72 315 Surface Roughness 73 Short Answer Questions 73 Problems for Practice 74 4 Design Against Static Load 76 41 Modes of Failure 76 42 Factor of Safety 77 43 Stress–strain Relationship 79 44 Shear Stress and Shear Strain 80 45 Stresses Due To Bending Moment 81 46 Stresses Due To Torsional Moment 82 47 Eccentric Axial Loading 83 48 Design of Simple Machine Parts 84 49 Cotter Joint 85 410 Design Procedure for Cotter Joint 90 411 Knuckle Joint 94 412 Design Procedure for Knuckle Joint 99 413 Principal Stresses 104 414 Theories of Elastic Failure 106 415 Maximum Principal Stress Theory 107 416 Maximum Shear Stress Theory 108 417 Distortion-Energy Theory 110 418 Selection and Use of Failure Theories 112 419 Levers 117 420 Design of Levers 118 421 Fracture Mechanics 128 422 Curved Beams 130 423 Thermal Stresses 135 424 Residual Stresses 136 Short Answer Questions 137 Problems for Practice 138 5 Design Against Fluctuating Load 141 51 Stress Concentration 141 52 Stress Concentration Factors 142 53 Reduction of Stress Concentration 145 54 Fluctuating Stresses 149 55 Fatigue Failure 151 56 Endurance Limit 152 57 Low-cycle and High-cycle Fatigue 153 58 Notch Sensitivity 154 59 Endurance Limit—Approximate Estimation 155 510 Reversed Stresses—Design for Finite and Infi nite Life 159 511 Cumulative Damage in Fatigue 166 512 Soderberg and Goodman Lines 167 513 Modifi ed Goodman Diagrams 168 514 Gerber Equation 174 515 Fatigue Design under Combined Stresses 177 516 Impact Stresses 180 Short Answer Questions 182 Problems for Practice 182 6 Power Screws 184 61 Power Screws 184 62 Forms of Threads 185 63 Multiple Threaded Screws 187 64 Terminology of Power Screw 187 65 Torque Requirement—Lifting Load 189 66 Torque Requirement—Lowering Load 189 67 Self-locking Screw 190 68 Effi ciency of Square Threaded Screw 190 69 Effi ciency of Self-locking Screw 192 610 Trapezoidal and Acme Threads 192 611 Collar Friction Torque 193 612 Overall Effi ciency 194 613 Coeffi cient of Friction 194 614 Design of Screw and Nut 194 615 Design of Screw Jack 206 616 Differential and Compound Screws 214 617 Recirculating Ball Screw 215 Short-Answer Questions 216 Problems for Practice 217 7 Threaded Joints 219 71 Threaded Joints 219 72 Basic Types of Screw Fastening 220 73 Cap Screws 222 74 Setscrews 223 75 Bolt of Uniform Strength 224 76 Locking Devices 225 77 Terminology of Screw Threads 227 78 ISO Metric Screw Threads 228 79 Materials and Manufacture 230 710 Bolted Joint—Simple Analysis 231 711 Eccentrically Loaded Bolted Joints in Shear 233 712 Eccentric Load Perpendicular to Axis of Bolt 235 713 Eccentric Load on Circular Base 242 714 Torque Requirement for Bolt Tightening 248 715 Dimensions of Fasteners 249 716 Design of Turnbuckle 251 717 Elastic Analysis of Bolted Joints 254 718 Bolted Joint under Fluctuating Load 257 Short-Answer Questions 269 Problems for Practice 269 8 Welded and Riveted Joints 272 81 Welded Joints 272 82 Welding Processes 273 83 Stress Relieving of Welded Joints 274 84 Butt Joints 274 85 Fillet Joints 275 86 Strength of Butt Welds 276 87 Strength of Parallel Fillet Welds 277 88 Strength of Transverse Fillet Welds 278 89 Maximum Shear Stress in Parallel Fillet Weld 281 810 Maximum Shear Stress in Transverse Fillet Weld 282 811 Axially Loaded Unsymmetrical Welded Joints 284 812 Eccentric Load in the Plane of Welds 285 813 Welded Joint Subjected to Bending Moment 290 814 Welded Joint Subjected to Torsional Moment 294 815 Strength of Welded Joints 295 816 Welded Joints Subjected to Fluctuating Forces 296 817 Welding Symbols 297 818 Weld Inspection 298 819 Riveted Joints 298 820 Types of Rivet Heads 301 821 Types of Riveted Joints 303 822 Rivet Materials 305 823 Types of Failure 306 824 Strength Equations 306 825 Effi ciency of Joint 307 826 Caulking and Fullering 307 827 Longitudinal Butt Joint for Boiler Shell 311 828 Circumferential Lap Joint for Boiler Shells 318 829 Eccentrically Loaded Riveted Joint 321 Short-Answer Questions 325 Problems for Practice 325 9 Shafts, Keys and Couplings 330 91 Transmission Shafts 330 92 Shaft Design on Strength Basis 331 93 Shaft Design on Torsional Rigidity Basis 333 94 ASME Code for Shaft Design 334 95 Design of Hollow Shaft on Strength Basis 342 96 Design of Hollow Shaft on Torsional Rigidity Basis 344 97 Flexible Shafts 346 98 Keys 346 99 Saddle Keys 347 910 Sunk Keys 348 911 Feather Key 349 912 Woodruff Key 350 913 Design of Square and Flat Keys 350 914 Design of Kennedy Key 352 915 Splines 354 916 Couplings 356 917 Muff Coupling 357 918 Design Procedure for Muff Coupling 357 919 Clamp Coupling 359 920 Design Procedure for Clamp Coupling 360 921 Rigid Flange Couplings 362 922 Design Procedure for Rigid Flange Coupling 364 923 Bushed-pin Flexible Coupling 368 924 Design Procedure for Flexible Coupling 371 925 Design for Lateral Rigidity 376 926 Castigliano’s Theorem 380 927 Area Moment Method 382 928 Graphical Integration Method 383 929 Critical Speed of Shafts 385 Short-Answer Questions 388 Problems for Practice 389 10 Springs 393 101 Springs 393 102 Types of Springs 393 103 Terminology of Helical Springs 395 104 Styles of End 396 105 Stress and Defl ection Equations 397 106 Series and Parallel Connections 399 107 Spring Materials 401 108 Design of Helical Springs 403 109 Spring Design—Trial-and-Error Method 405 1010 Design against Fluctuating Load 405 1011 Concentric Springs 425 1012 Optimum Design of Helical Spring 430 1013 Surge in Spring 432 1014 Helical Torsion Springs 433 1015 Spiral Springs 435 1016 Multi-Leaf Spring 437 1017 Nipping of Leaf Springs 439 1018 Belleville Spring 441 1019 Shot Peening 443 Short-Answer Questions 443 Problems for Practice 444 11 Friction Clutches 448 111 Clutches 448 112 Torque Transmitting Capacity 450 113 Multi-disk Clutches 456 114 Friction Materials 459 115 Cone Clutches 461 116 Centrifugal Clutches 465 117 Energy Equation 467 118 Thermal Considerations 469 Short-Answer Questions 470 Problems for Practice 471 12 Brakes 472 121 Brakes 472 122 Energy Equations 472 123 Block Brake with Short Shoe 475 124 Block Brake with Long Shoe 480 125 Pivoted Block Brake with Long Shoe 482 126 Internal Expanding Brake 485 127 Band Brakes 490 128 Disk Brakes 493 129 Thermal Considerations 496 Short-Answer Questions 496 Problems for Practice 497 13 Belt Drives 499 131 Belt Drives 499 132 Belt Constructions 501 133 Geometrical Relationships 503 134 Analysis of Belt Tensions 504 135 Condition for Maximum Power 507 136 Condition for Maximum Power (Alternative Approach) 507 137 Characteristics of Belt Drives 509 138 Selection of Flat-belts from Manufacturer’s Catalogue 514 139 Pulleys for Flat Belts 517 1310 Arms of Cast-iron Pulley 520 1311 V-belts 522 1312 Selection of V-belts 534 1313 V-grooved Pulley 535 1314 Belt-Tensioning Methods 540 1315 Ribbed V-belts 540 Short-Answer Questions 542 Problems for Practice 542 14 Chain Drives 544 141 Chain Drives 544 142 Roller Chains 546 143 Geometric Relationships 548 144 Polygonal Effect 549 145 Power Rating of Roller Chains 549 146 Sprocket Wheels 551 147 Design of Chain Drive 553 148 Chain Lubrication 555 149 Silent Chain 562 Short-Answer Questions 562 Problems for Practice 563 15 Rolling Contact Bearings 564 151 Bearings 564 152 Types of Rolling-contact Bearings 565 153 Principle of Self-aligning Bearing 568 154 Selection of Bearing-type 569 155 Static Load Carrying Capacity 569 156 Stribeck’s Equation 569 157 Dynamic Load Carrying Capacity 571 158 Equivalent Bearing Load 571 159 Load-Life Relationship 572 1510 Selection of Bearing Life 572 1511 Load Factor 573 1512 Selection of Bearing from Manufacturer’s Catalogue 573 1513 Selection of Taper Roller Bearings 580 1514 Design for Cyclic Loads and Speeds 588 1515 Bearing with Probability of Survival other than 90 Per Cent 592 1516 Needle Bearings 595 1517 Bearing Failure—Causes and Remedies 596 1518 Lubrication of Rolling Contact Bearings 596 1519 Mounting of Bearing 597 Short-Answer Questions 598 Problems for Practice 599 16 Sliding Contact Bearings 601 161 Basic Modes of Lubrication 601 162 Viscosity 604 163 Measurement of Viscosity 605 164 Viscosity Index 605 165 Petroff’s Equation 606 166 McKee’s Investigation 607 167 Viscous Flow through Rectangular Slot 608 168 Hydrostatic Step Bearing 609 169 Energy Losses in Hydrostatic Bearing 611 1610 Reynold’s Equation 619 1611 Raimondi and Boyd Method 622 1612 Temperature Rise 624 1613 Bearing Design—Selection of Parameters 625 1614 Bearing Constructions 634 1615 Bearing Materials 635 1616 Sintered Metal Bearings 637 1617 Lubricating Oils 637 1618 Additives for Mineral Oils 639 1619 Selection of Lubricants 640 1620 Greases 641 1621 Bearing Failure—Causes and Remedies 641 1622 Comparison of Rolling and Sliding Contact Bearings 642 Short-Answer Questions 643 Problems for Practice 644 17 Spur Gears 646 171 Mechanical Drives 646 172 Gear Drives 647 156 Stribeck’s Equation 569 157 Dynamic Load Carrying Capacity 571 158 Equivalent Bearing Load 571 159 Load-Life Relationship 572 1510 Selection of Bearing Life 572 1511 Load Factor 573 1512 Selection of Bearing from Manufacturer’s Catalogue 573 1513 Selection of Taper Roller Bearings 580 1514 Design for Cyclic Loads and Speeds 588 1515 Bearing with Probability of Survival other than 90 Per Cent 592 1516 Needle Bearings 595 1517 Bearing Failure—Causes and Remedies 596 1518 Lubrication of Rolling Contact Bearings 596 1519 Mounting of Bearing 597 Short-Answer Questions 598 Problems for Practice 599 16 Sliding Contact Bearings 601 161 Basic Modes of Lubrication 601 162 Viscosity 604 163 Measurement of Viscosity 605 164 Viscosity Index 605 165 Petroff’s Equation 606 166 McKee’s Investigation 607 167 Viscous Flow through Rectangular Slot 608 168 Hydrostatic Step Bearing 609 169 Energy Losses in Hydrostatic Bearing 611 1610 Reynold’s Equation 619 1611 Raimondi and Boyd Method 622 1612 Temperature Rise 624 1613 Bearing Design—Selection of Parameters 625 1614 Bearing Constructions 634 1615 Bearing Materials 635 1616 Sintered Metal Bearings 637 1617 Lubricating Oils 637 1618 Additives for Mineral Oils 639 1619 Selection of Lubricants 640 1620 Greases 641 1621 Bearing Failure—Causes and Remedies 641 1622 Comparison of Rolling and Sliding Contact Bearings 642 Short-Answer Questions 643 Problems for Practice 644 17 Spur Gears 646 171 Mechanical Drives 646 172 Gear Drives 647 173 Classifi cation of Gears 647 174 Selection of Type of Gears 648 175 Law of Gearing 649 176 Terminology of Spur Gears 650 177 Standard Systems of Gear Tooth 653 178 Gear Trains 656 179 Interference and Undercutting 657 1710 Backlash 658 1711 Force Analysis 658 1712 Gear Tooth Failures 665 1713 Selection of Material 666 1714 Gear Blank Design 667 1715 Number of Teeth 670 1716 Face Width 671 1717 Beam Strength of Gear Tooth 672 1718 Permissible Bending Stress 673 1719 Effective Load on Gear Tooth 674 1720 Estimation of Module Based on Beam Strength 677 1721 Wear Strength of Gear Tooth 678 1722 Estimation of Module Based on Wear Strength 680 1723 Internal Gears 688 1724 Gear Lubrication 690 Short-Answer Questions 690 Problems for Practice 690 18 Helical Gears 694 181 Helical Gears 694 182 Terminology of Helical Gears 694 183 Virtual Number of Teeth 695 184 Tooth Proportions 696 185 Force Analysis 697 186 Beam Strength of Helical Gears 702 187 Effective Load on Gear Tooth 702 188 Wear Strength of Helical Gears 703 189 Herringbone Gears 706 1810 Crossed Helical Gears 708 Short-Answer Questions 709 Problems for Practice 710 19 Bevel Gears 711 191 Bevel Gears 711 192 Terminology of Bevel Gears 713 193 Force Analysis 715 194 Beam Strength of Bevel Gears 720 195 Wear Strength of Bevel Gears 722 196 Effective Load on Gear Tooth 722 197 Spiral Bevel Gears 727 Short-Answer Questions 728 Problems for Practice 728 20 Worm Gears 730 201 Worm Gears 730 202 Terminology of Worm Gears 731 203 Proportions of Worm Gears 733 204 Force Analysis 735 205 Friction in Worm Gears 737 206 Selection of Materials 741 207 Strength Rating of Worm Gears 742 208 Wear Rating of Worm Gears 744 209 Thermal Considerations 745 Short-Answer Questions 747 Problems for Practice 747 21 Flywheel 749 211 Flywheel 749 212 Flywheel and Governor 750 213 Flywheel Materials 750 214 Torque Analysis 751 215 Coeffi cient of Fluctuation of Energy 752 216 Solid Disk Flywheel 753 217 Rimmed Flywheel 755 218 Stresses in Rimmed Flywheel 756 Short-Answer Questions 767 Problems for Practice 767 22 Cylinders and Pressure Vessels 768 221 Thin Cylinders 768 222 Thin Spherical Vessels 769 223 Thick Cylinders—Principal Stresses 770 224 Lame’s Equation 771 225 Clavarino’s and Birnie’s Equations 772 226 Cylinders with External Pressure 774 227 Autofrettage 775 228 Compound Cylinder 775 229 Gaskets 779 2210 Gasketed Joint 780 2211 Unfi red Pressure Vessels 783 2212 Thickness of Cylindrical and Spherical Shells 785 2213 End Closures 785 2214 Openings in Pressure Vessel 791 Short-Answer Questions 794 Problems for Practice 794 23 Miscellaneous Machine Elements 796 231 Oil Seals 796 232 Wire Ropes 797 233 Stresses in Wire Ropes 800 234 Rope Sheaves and Drums 804 235 Buckling of Columns 806 Short-Answer Questions 812 Problems for Practice 812 24 Statistical Considerations in Design 814 241 Frequency Distribution 814 242 Characteristics of Frequency Curves 816 243 Measures of Central Tendency and Dispersion 817 244 Probability 819 245 Probability Distribution 819 246 Normal Curve 821 247 Population Combinations 823 248 Design and Natural Tolerances 825 249 Reliability 829 2410 Probabilistic Approach to Design 830 Short-Answer Questions 840 Problems for Practice 841 25 Design of IC Engine Components 843 251 Internal Combustion Engine 843 252 Cylinder and Cylinder Liner 844 253 Bore and Length of Cylinder 845 254 Thickness of Cylinder Wall 845 255 Stresses in Cylinder Wall 846 256 Cylinder Head 847 257 Design of Studs for Cylinder Head 847 258 Piston 853 259 Piston Materials 854 2510 Thickness of Piston Head 854 2511 Piston Ribs and Cup 855 2512 Piston Rings 856 2513 Piston Barrel 857 2514 Piston Skirt 858 2515 Piston Pin 858 2516 Connecting Rod 867 2517 Buckling of Connecting Rod 868 2518 Cross-section for Connecting Rod 869 2519 Big and Small End Bearings 871 2520 Big End Cap and Bolts 873 2521 Whipping Stress 875 2522 Crankshaft 880 2523 Design of Centre Crankshaft 881 2524 Centre Crankshaft at Top-Dead Centre Position 881 2525 Centre Crankshaft at Angle of Maximum Torque 883 2526 Side Crankshaft at Top-Dead Centre Position 892 2527 Side Crankshaft at Angle of Maximum Torque 895 2528 Valve-Gear Mechanism 903 2529 Design of Valves 904 2530 Design of Rocker Arm 906 2531 Design of Valve Spring 910 2532 Design of Push Rod 911 Short-Answer Questions 922 Problems for Practice 923 References 927