Textile Mechanisms in Spinning and Weaving Machines | Ganapathy Nagarajan

Textile Mechanisms in Spinning and Weaving Machines
by Ganapathy Nagarajan
Contents
Preface xi
Foreword xiii
1. Belt, rope and chain drives 1
1.1 Introduction 1
1.2 Selection of belt drive 1
1.3 Types of belt drives 2
1.4 Types of belts 2
1.5 Flat belt drives 3
1.6 Velocity ratio of belt drive 9
1.7 Power transmitted by a belt 18
1.8 Ratio of driving tensions for flat belt drive 22
1.9 Centrifugal tension 23
1.10 Initial tension in the belt 27
1.11 V-belt drive 30
1.12 Rope drive 34
1.13 Chain drives 38
2. Gear trains 42
2.1 Introduction 42
2.2 Nomenclature of gears 42
3. Rotary motion 72
3.1 Introduction 72
3.2 Linear displacement 72
3.3 Angular displacement 72
3.4 Speed 73
3.5 Transmission of rotary movement in machines 73
3.6 Classification of gears 76
3.7 Gears in textile machines 78
4. Equations of movement 95
4.1 Acceleration 95
4.2 Retardation 95
5. Parallelogram of velocities 101
5.1 Introduction 101
5.2 Velocity 102
6. Force, mass and momentum 107
6.1 Introduction 107
6.2 Definitions and units 107
6.3 Units of force 108
6.4 Momentum in quantity of motion 108
7. Work and power 112
7.1 Introduction 112
7.2 Units of work (in SI units) 112
7.3 Graphical representation of work 113
7.4 Useful definitions 113
7.5 Work done by a varying force 115
8. Resolution of forces 120
8.1 Introduction 120
8.2 Lines of representation of forces 120
8.3 Law of Polygon of forces 122
8.4 Law of Triangle of Forces 123
8.5 Tension and compression 123
8.6 Graphical methods 124
8.7 Resolution and composition of a force 129
8.8 Resolution of a number of coplanar forces 130
9. Centre of gravity 143
9.1 Introduction 143
9.2 Centre of gravity of irregular bodies 143
9.3 Centre of gravity of levers 143
10. Principle of moments 146
10.1 Moment of force 146
10.2 Geometrical representation of moments 146
10.3 Types of moments 147
10.4 Clockwise moments 147
10.5 Anti-clockwise moments 147
10.6 Varignon’s Principle of Moments or Law of Moments 147
10.7 Moments on bent lever 155
10.8 Moments of bent lever in weighting arrangement 155
10.9 Bent lever in weighting of single yarns 157
10.10 Bent lever on Lea strength tester 157
11. Friction 174
11.1 Introduction 174
11.2 Types of friction 174
11.3 Limiting friction 175
11.4 Coefficient of friction (Fig. 11.2) 176
11.5 Laws of solid friction 177
11.6 Friction of shaft in its bearings 179
11.7 Friction clutches 180
11.8 Power transmission 183
12. Coil friction 190
12.1 Introduction 190
12.2 Friction on curved surface 196
12.3 Coefficient of friction on solid surface 197
12.4 Transmission of power by belts and rope drives 198
12.5 Transmission of power by V-belts and rope drives 203
12.6 Brakes 204
13. Lifting machines and velocity ratio 221
13.1 Introduction 221
13.2 Definitions 221
13.3 Velocity ratio 222
13.4 Velocity ratio on simple pulleys 224
13.5 Weston differential pulley block 229
13.6 Types of machines 231
13.7 Law of a machine 232
14. Stress, strain and elasticity 242
14.1 Stress 242
14.2 Energy 244
15. Momentum energy impulsive forces and impact 252
15.1 Momentum 252
15.2 Law of Conservation of Momentum 252
15.3 Collision of two bodies 253
15.4 Collision of inelastic bodies 254
15.5 Collision of elastic bodies 255
15.6 Coefficient of Restitution(e) 256
15.7 Impulse 257
15.8 Energy 257
15.9 Potential energy 258
15.10 Kinetic energy 258
15.11 Strain energy 258
15.12 Law of Conservation of Energy 258
16. Motion in a circle 273
16.1 Introduction 273
16.2 Centripetal force 273
16.3 Centrifugal force 274
16.4 Conical pendulum 274
16.5 Tension in rotating masses 276
17. Simple harmonic motion 285
17.1 Introduction 285
17.2 Definitions of few terms 285
17.3 Simple pendulum 291
17.4 Helical springs 292
18. Moments of inertia and kinetic energy of rotating bodies 298
18.1 Mass moment of inertia 298
18.2 Fundamental equation for a rotating body 299
18.3 Kinetic energy of a rotating body 300
18.4 Compound pendulum 304
18.5 Centre of percussion 305
19. Practical methods of finding moment of inertia 314
19.1 Introduction 314
19.2 Flywheel 314
19.3 Methods of finding Moment of Inertia of fly wheels 314
19.4 Bifilar suspension 317
19.5 Referring Moment of Inertia 324
19.6 Moment of inertia referred to its driving shaft 327
19.7 Winding mechanics 331
20. Cams 338
20.1 Introduction 338
20.2 Classification of cams 338
20.3 Classification of followers 339
20.4 Cams in textile machines 341
20.5 Construction of the cam design 347
20.6 Terms in Cam profile 348
20.7 Scutcher feed regulating mechanism (Fig. 20.15) 350
20.8 Cone drum construction (Fig. 20.16) 351
20.9 Design of cone drum profile (Fig. 20.17) 352
20.10 Design of cone drums in speed frame (Fig. 20.18) 354
20.11 Tappets 356
20.12 Construction of shedding tappet 356
20.13 Determination of tappet lift 357
20.14 Determination of NPC and FPC 358
20.15 Relation between dwell period and type of heald 358movement
20.16 Tappet design for plain weave 358
20.17 Design of tappet for twill weave 361
20.18 Construction of a shedding tappet for three-shaft weave 362
20.19 Cranks and eccentrics 364

Preface
I am pleased to present a book on “Textile Mechanisms for Spinning and Weaving Machines” for the students of Textile Technology and also for industry professionals. This book gives an exhaustive account on mechanics in textile machinery in spinning, weaving processes in which every textile students must know about the applied mechanics in textile machineries. The book has been written in both SI conventional and still in use F.P.S. systems. The object of this book is to present the subject matter in a most concise, compact and more solved practical problems in a lucid manner.

The aim of the book is to analyze the various mechanisms involved; and many difficult problems are solved in steps which would be of interest to readers. This should help the students to develop an analytical thinking about the machineries. A number of problems involving work energy, impulse-momentum and principle of moments have been taken in to consideration and incorporated in relevant chapters.

The chapters are divided into many sections in order to isolate individual pieces of information as an aid to study. The work is intentionally pitched at a fairly easy level so as to be of the utmost use to as wide range of students not only in India but also for the students studying textile courses in other developed countries.

The subject matter has been amply illustrated by incorporating a good number of solved unsolved and well-graded examples of every variety. At the end of each chapter, numerical questions have been asked so that the students can practice the same which may be asked in their University Examinations.

Although, every care has been taken to check mistakes and misprints, yet it is difficult to attain perfection. Any errors, omissions and suggestions for further improvement will be thankfully acknowledged and the same will be incorporated in the next edition.

I am grateful to my parents, family and my professors who have helped me directly and indirectly to bring out this book. I would like to thank Woodhead Publishing India, who accepted my proposal to publish this book, although other books on this topic are already available. Finally, I hope this book will be of good use to the students of Textile Technology, and I dedicate this book to the great Almighty who has helped and gave me fillip to bring out my maiden book publication.

I look forward in receiving your comments and suggestions to update this book.

G. Nagarajan