Good Practice Guidance for Mining and Biodiversity

GEAR MATERIALS, PROPERTIES,  AND MANUFACTURE......Page 1
Contents......Page 3
Preface......Page 7
Gear Nomenclature......Page 9
Types of Gears thatOperate on Intersecting Shafts......Page 14
Proper Gear Selection......Page 16
Basic Applied Stresses (Ref 2)......Page 17
Strength (Ref 2)......Page 19
Gear Materials......Page 20
Metal Removal Processes......Page 21
Inspection......Page 23
Prehardening Processes......Page 24
Through Hardening andCase Hardening......Page 25
REFERENCES......Page 26
Lubrication Regimes......Page 27
Lubrication-Related Failure......Page 29
Hertzian Fatigue......Page 30
Wear......Page 31
Scuffing......Page 33
Elastohydrodynamic Lubrication......Page 35
Lubricant Selection......Page 39
Application of Gear Lubricants......Page 41
Case History: Failure of a24-Unit Speed-Increaser Gearbox......Page 43
REFERENCES......Page 45
Wrought Gear Steels......Page 47
Surface-Hardening Steels......Page 48
Gear Steel Requirements......Page 52
ProcessingCharacteristics of Gear Steels......Page 53
Bending FatigueStrength of Carburized Steels......Page 54
Stages of Fatigue and Fracture......Page 59
Intergranular Fracture and Fatigue......Page 61
Austenitic Grain Size and Fatigue......Page 64
Surface Oxidation and Fatigue......Page 65
Retained Austenite and Fatigue......Page 66
Subzero Cooling and Fatigue......Page 67
Residual Stresses,Shot Peening, and Fatigue......Page 68
Other Properties ofInterest for Carburized Steels......Page 70
Other Ferrous Alloys for Gears......Page 74
Tool Steels......Page 79
Nonferrous Alloys......Page 80
REFERENCES......Page 82
Classification ofPlastics for Gear Applications......Page 85
Plastic Gear Materials......Page 87
Plastic Gear Manufacture......Page 90
REFERENCES......Page 96
Machining, Grinding, and Finishing......Page 97
Machining Processes for Gears......Page 98
Selection of Machining Process......Page 106
Cutter Material and Construction......Page 112
Speed and Feed......Page 115
Cutting Fluids......Page 119
Computer Numerical Control (CNC)Milling and Hobbing Machines......Page 121
Grinding of Gears......Page 122
Honing of Gears......Page 130
Lapping of Gears......Page 132
Superfinishing......Page 133
REFERENCES......Page 134
SELECTED REFERENCES......Page 135
Casting......Page 137
Forming......Page 139
Forging......Page 141
REFERENCES......Page 145
Powder Metallurgy......Page 147
Capabilities and Limitations......Page 148
Gear Forms......Page 150
Gear Tolerances......Page 151
Gear Design and Tooling......Page 152
Gear Performance......Page 155
Quality Control and Inspection......Page 156
Examples of P/M Gears......Page 157
SELECTED REFERENCES......Page 161
Through-Hardening Processes......Page 163
Distortion of Through-Hardened Gears......Page 165
Case History: Designand Manufacture of a Rack......Page 166
SELECTED REFERENCES......Page 170
Gas Carburizing:Processing and Equipment......Page 171
Quenching and Hardening......Page 174
Tempering ofCarburized and Quenched Gears......Page 176
Selection ofMaterials for Carburized Gears......Page 177
Carbon Content and Case Properties......Page 183
Core Hardness of Gear Teeth......Page 189
Problems Associated with Carburizing......Page 192
Heat Treat Distortion ofCarburized and Hardened Gears......Page 196
Grinding Stock Allowance on ToothFlanks to Compensate for Distortion......Page 209
Shot Peening ofCarburized and Hardened Gears......Page 216
Applications and Costs......Page 219
Vacuum Carburizing......Page 220
REFERENCES......Page 234
The Gas Nitriding Process......Page 235
Controlled Nitriding (Ref 4, 5)......Page 248
SELECTED REFERENCES......Page 252
Carbonitriding......Page 253
Hardenability of Case......Page 254
SELECTED REFERENCES......Page 255
Induction Hardening......Page 257
Flame Hardening......Page 261
SELECTED REFERENCES......Page 263
Fatigue Failures......Page 265
Impact......Page 279
Wear......Page 281
Scuffing......Page 283
Causes of Gear Failures......Page 284
Conducting the Failure Analysis (Ref 7)......Page 285
Examples of Gear Failure Analysis......Page 291
ACKNOWLEDGMENTS......Page 298
SELECTED REFERENCES......Page 299
Gear Tooth Contact......Page 301
Life Determined by Contact Stress......Page 305
Life Determined by Bending Stress......Page 310
Gear Tooth Failure byBreakage after Pitting......Page 312
Flaws and Gear Life......Page 314
Bores and Shafts......Page 315
REFERENCES......Page 316
Gear Durability and Failure......Page 317
Common Modes of Gear Failure......Page 319
Stress Calculations for Test Parameters......Page 320
Specimen Characterization......Page 323
Tests Simulating Gear Action......Page 324
Single-Tooth Single-Overloadand Impact Testing......Page 329
Gear Power-Circulating(PC), or Four-Square, Tests......Page 331
SELECTED REFERENCES......Page 335