Design Of Transmission Systems

lt. Design of Fle:dble Elements
1.1 Belt Drives.. ..................................................................... 1.1
1.1.1 Introduction....................................................... 1.1
1.1.2 Types of Belt drives......................................... 1.1
1.1.3 Types of Belts ................................................... 1.2
1.1.5 Flat Belt Drives................................................ 1.3
1.1.6 Advantages of Flat-belt drive......................... 1.3
1.1.7 Disadvantages................................................... 1.4
1.1.8 Types of Flat belt drives................................. 1.4
1.1.9 Design Based on Basic Equations................. 1.8
1.1.10 Design Based on Manufacturer's Data........ 1.12
Design of Flat Belt Drives (Problems) ... ... ... 1.29
1.2. Design of V-Belt Drive ................................................... 1.45
1.2.1 Introduction....................................................... 1.45
1.2.2 Advantages ........................................................ 1.45
1.2.3 Disadvantages ................................................... 1.46
1.2.4 The Cross-section of V-belt.............................. 1.46
1.2.5 Types of V - belts ............................................ 1.46
Design of V-Belts .... ............................................................... 1.47
1.3. Design of Wire Ropes..................................................... 1.91
1.3.1 Wire Ropes ........................................................ 1.91
1.3.2 Advantages of wire ropes ................................ 1.91
1.3.3 Disadvantages of wire ropes ........................... 1.92
1.3.4 Construction of Wire rope ............................... 1.92
1.3.5 Designation of wire ropes................................ 1.93
1.3.6 Classification of wire ropes............................. 1.93
Contents 2
1.3.7 Faüures of wire rope ....................................... 1.97
1.3.8 Design procedure for wire rope ...................... 1.97
1.3.9 Design of wire rope sheaves ........................... 1.113
Sheave materials ............................................. 1.114
1.3.10 Design of wire rope drums ........................... 1.114
1.4. Design of Chain Drive ................................................... 1.118
1.4.1 Chain Drives ..................................................... 1.118
1.4.2 Advantages: ....................................................... 1.118
1.4.3 Disadvantages ................................................... 1.119
1.4.4 Applications: ...................................................... 1.119
1.4.5 Types of chains: ................................................ 1.119
1.4.6 Components of Chain Drive ............................ 1.120
1.4.7 Design Procedure .............................................. 1.122
1.4.8 Chordal action of a roller chain .................... 1.130
1.4.9 Design of Chain Drives ................................... 1.131
1.2. Spur Gears and Parallel Axis Belical Gears
2.1 Introduction. ..................................................................... 2.1
2.1.1 Advantages of Gear drives.............................. 2.1
2.1.2 Disadvantages ................................................... 2.2
2.2 Classification of Gears .................................................... 2.2
2.3 Terminology of Spur Gear.............................................. 2.4
2.4 Gear Tooth Failures ........................................................ 2.6
2.5 Law of Gearing ............................................................... 2.7
2.5.1 Advantages of Involute gears.......................... 2.8
2.5.2 Disadvantages of Involute Teeth ... ... ... ... ... ... .. 2.9
2.5.3 Advantages of Cycloidal Gears... ... ... ... ... ... ... .. 2.9
2.5.4 Disadvantages ................................................... 2.10
3 Design of Transmission Systems
2.6 Speed Ratio and Number of Teeth ............................... 2.10
2.7 Minimum Number of Teeth ........................................... 2.11
2.8 Force Analysis [SPUR GEAR] ....................................... 2.11
2.9 Tooth Stresses (The Lewis Bending Equation) ........... 2.14
2.10 Dynamic Effects (Dynamic Tooth Load) ..................... 2.19
2.11 Wear Tooth Load (or) Fatigue Strength of Gear ...... 2.21
2.12 Factor of Safety [F.O.S] ................................................ 2.25
2.13 Gear Materials ............................................................... 2.26
2.13.1 Metallic materials .......................................... 2.26
2.13.2 Non-metallic materials ................................... 2.26
2.13.3 Selection of gear materials ........................... 2.27
2.14 Design of Straight Tooth Spur Gear Based on
Strength and Wear Consideration [Lewis and
Buckingham Equation Method] ............................................ 2.28
2.15 Design of Spur Gear [Hertz Method] ......................... 2.77
2.16 Helical Gears ................................................................. 2.123
2.17 Beam Strength of Helical Gears (Lewis Equation
for Helical Gears) .................................................................. 2.124
2.18 Dynamic Load on Helical Gear Tooth (Effective
Load on Gear Tooth) ............................................................. 2.126
2.19 Wear Strength of Helical Gears (Wear Tooth Load)2.127
2.20 Pressure Angle in the Normal and Transverse
Plane ........................................................................................ 2.129
2.20.1 Pressure angle ............................... 2.129
2.20.2 Transverse Pressure Angle t .......... 2.129
2.20.3 Normal Pressure Angle n ··············2.129
Formative or Equivalent Number of teeth
for Helical gears .............................................. 2.130
Contents 4
2.21 Force Analysis of Helical Gears .................................. 2.131
2.22 Design of Straight Tooth Helical and Double
Helical Gear Based on Strength and Wear
Considerations ........................................................................ 2.135
ls. Design of Bevel, Worm and Cross Helical Gears 1
3.1 Introduction. ..................................................................... 3.1
3.2 Types of Bevel Gears ...................................................... 3.1
3.3 Bevel Gear Nomenclature............................................... 3.4
3.4 Formative (or) Equivalent (or) Virtual Number of
Teeth For Bevel Gears .......................................................... 3.7
3.5 Tooth Stress (or) Strength of Bevel Gears.................. 3.7
3.6 Dynamic Load For Bevel Gears .................................... 3.8
3.7 Wear Strength For Bevel Gears.................................... 3.8
3.8 Force Acting on the Bevel Gear.................................... 3.9
3.9 Basic Dimensions of Bevel Gear Pair .......................... 3.12
3.11 Design of Straight Bevel Gears Using Lewis and
Buckingham Equations .......................................................... 3.18
3.1l.(a) Design Procedure For Bevel Gear (Based on
Hertz Method) ... ..................................................................... 3.64
3.12 Design of Worm and Worm Wheel ............................. 3.153
3.13 Terms Used in Worm Gearing .................................... 3.154
3.14 Efficiency of Worm Gearing ......................................... 3.157
3.15 Strength of Worm Gear Tooth ..................................... 3.157
3.16 Dynamic Load on Worm Gear Tooth ......................... 3.158
3.17 Wear Strength of Worm Gears .................................... 3.158
3.18 Thermal Rating of Worm Gearing .............................. 3.158
3.19 Forces Acting on Worm Gears ..................................... 3.159
5 Design of Transmission Systems
3.20 Merits and Demerits of Worm Gear Drives .............. 3.160
3.20.1 Merits of Worm Gear Drives ........................ 3.160
3.20.2 Demerits of Worm Gear Drives .................... 3.160
3.21 Basic Dimensions of Worm Gear ................................ 3.161
3.22 Design of Worm and Worm Gear Using Lewis
and Buckingham's Equation .................................................. 3.163
3.23 Design of Worm and Worm Wheel [Based on
Hertz Method] ........................................................................ 3.192
3.24 Screw or Skew gears (Crossed Helical Gears) .......... 3.214
14. Design of Speed Reducers (Gear Boxes)
4.1 Gear Box..... ..................................................................... 4.1
4.2 Types of Ge ar Boxes ....... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...... 4.1
4.2.1 Applications....................................................... 4.2
4.2.2 Requirements of Speed Gear Boxes . ... ... ... ... .. 4.3
4.2.3 Method of changing speed in gear boxes...... 4.3
4.2.4 Requirements to obtain optimum design...... 4.3
4.2.5 Main components of gear box........................ 4.4
4.2.6 Speed Changing................................................ 4.4
4.3 Speed Diagram (Or) Ray Diagram................................ 4.4
4.3.1 Geometrie progression and standard step
ratio............................................................................ 4.6
4.4 Structural Fonnula .......................................................... 4.11
4.5 Construction of Ray Diagram ........................................ 4.12
4.6 Kinematic Layout ............................................................ 4.13
Design of Gear Box ............................................................... 4.129
4. 7 Constant Mesh Gear Box ............................................... 4.208
4.7.1 Constant Mesh Gear Box Gear Shifting ...... .4.210
Contents 6
4.8 Speed Reducer Unit ......................................................... 4.211
4.8.1 Wo17n Reducer .................................................. 4.211
4.8.2 Helical &ducer ................................................. 4.212
4.8.3 Bevel &ducer ................................................... 4.212
4.9 Variable Speed Gear Box ............................................... 4.212
4.9.1 Fluid coupling (or) Fluid fly wheel ............... 4.212
4.9.2 Torq~ Convertor .............................................. 4.215
4.9.2.1 Torque Converter Gear Box ........................ .4.215
4.9.2.2 Torq~ converter principles .......................... 4.216
4.9.2.3 Advantages . .................................................... 4.219
4.9.2.4 Applications .................................................... 4.220
15. Cams, Clutches and Brakes
5.1 Cams: (Cam and Follower)............................................. 5.1
5.1.1 Introduction....................................................... 5.1
5.1.2 Classification of Cam Mechanisms................ 5.2
5.1.3 Types of Cam.................................................... 5.3
5.1.4 Type of Cam followers..................................... 5.3
5.1.5 Nomenclature of a Cam-Drive........................ 5.4
5.1.6 Basic Curves ..................................................... 5.6
5.14 Simple Ha17nonic Motion SHM ...................... 5.16
5.1.7 Designing CAM" ................................................. 5.29
5.1.8 Cam Profile Layout .......................................... 5.31
5.1.9 Pressure angle ............................................ 5.31
5.1.10 Uruler Cutting ................................................. 5.33
5.1.11 Contact Stress ................................................. 5.35
5.1.12 Force Deternlination ....................................... 5.36
5.2 Clutches ............................................................................ 5.47
7 Design of Transmission Systems
5.2.1 Definition ........................................................... 5.47
5.2.2 Classification of Clutch ................................... 5.48
5.2.3 Working principle of friction clutch ............... 5.48
5.2.4 Material for friction surface ........................... 5.49
5.2.5 Types of friction clutches ................................ 5.49
5.2.6 Advantages and Disadvantages of friction
clutch. .... ..................................................................... 5.49
5.27 Design considerations for friction clutches .... 5.50
5.28 Design of a Dise (or) plate clutch .................. 5.50
5.2.9 Cane Clutch....................................................... 5.69
5.2.9.1 Design of cane clutch: ................................... 5.70
1. Uniform pressure ........................................ 5.71
2. Uniform wear .............................................. 5.72
5.2.10 Centrifugai Clutches ....................................... 5.78
5.2.10.1 Designing of centrifugai clutch ................. 5.79
5.2.10.2 Internai expanding rim clutches ............... 5.80
5.2.11 Electromagnetic clutch ................................... 5.80
5.3 Brakes .......... ..................................................................... 5.83
5.3.1 Introduction: ...................................................... 5.83
5.3.2 Difference between clutch and brahe............. 5.83
5.3.3 Brake friction materials .................................. 5.83
5.3.4 Types of Brahes ................................................ 5.84
5.3.5 Single Black Shoe Brahe................................. 5.84
5.3.6 Simple band brahe........................................... 5.96
5.3. 7 Differentiai Band brahe................................... 5.99
5.3.8 Double shoe brahe ............................................ 5.113
5.3.8 Internai Expanding Brahe .............................. 5.120
5.3.10 Energy considerations .................................... 5.135
Contents 8
5.3.11 Temperature Rise ........................................... 5.136
5.3.12 Friction Materials ........................................... 5.137
5.4 Geneva Mechanism .......................................................... 5.138
5.5 Ratchet aod Pawl Mechaoism ....................................... 5.147
2 Marks Q&A ......................................................................... .
University Solved Question Papers ..................................... .
Index ........................................................................................ .