Engineering Principles of Agricultural Machines

559 Pages·2005·38.7 MB·English

by  Ajit K. Srivastava & Carroll E. Goering

Engineering
Principles of
Agricultural
Machines

2nd Edition

Ajit K. Srivastava
Michigan State University
Carroll E. Goering
University of Illinois
Roger P. Rohrbach
North Carolina State University
Dennis R. Buckmaster
The Pennsylvania State University
Copyright  2006 by the
American Society of Agricultural and Biological Engineers
All rights reserved.

ASABE is an educational and scientific organization
dedicated to the advancement of engineering
applicable to agricultural, food, and biological systems.

Editing by Peg McCann
Cover design by Melissa Miller
Production assistance by
Patricia Howard and Marcia Stults McCavit

Cover photo of a Massey Ferguson combine
courtesy of AGCO Corporation.

This book may not be reproduced
in whole or in part by any means
without the permission of the publisher.
For information, contact the
American Society of Agricultural and Biological Engineers
2950 Niles Road, St. Joseph, MI 49085-9659 USA
Phone: [phone] Fax: [phone] E-mail: [email protected]

Library of Congress Card Number (LCCN) 2005937948
International Standard Book Number (ISBN) 1-892769-50-6
ASAE Publication 801M0206

The American Society of Agricultural and Biological Engineers is
not responsible for the statements and opinions advanced
in its meetings or printed in its publications.
They represent the views of the individuals to whom
they are credited and are not binding on the Society as a whole.
PREFACE
We are pleased to offer the second edition of the textbook Engineering Principles
of Agricultural Machines. To arrive at the revisions in the second edition, we called
some instructors of the first edition and conducted lengthy phone interviews to seek
their thoughts and suggestions for revisions. We interviewed Dr. Dennis Buckmaster
of Penn State University, Dr. Dan Humburg of South Dakota State University, Dr. Lei
Tian of the University of Illinois, and Dr. Ranal Taylor of Kansas State University.
Based on their input we prepared a survey form listing the many changes suggested.
The survey forms were sent to all instructors, in the U.S. and abroad, who were using
the textbook. We compiled the responses and rated each suggestion. We also held a
user forum during the 2005 ASABE conference in Tampa, Florida to share the results
of our survey and to seek additional input. Items receiving a 3 or higher score on a 5-
point scale were marked for inclusion in the revised edition.
The changes can be divided in four categories. These are: reorganization of chap-
ters into shorter modules to allow instructors greater flexibility in selecting topics to
match their needs; the addition of a new chapter on agricultural information systems in
response to the growth in precision agriculture technology since the first edition;
addition of simulation problems; and adding a supplemental CD that includes a
spreadsheet and many simulations. We feel the CD will add a new dimension to
student learning and give them the opportunity to develop a deeper understanding of
the process under study as affected by the various system parameters.
We are very pleased that Dr. Dennis Buckmaster has joined the list of authors.
Dennis has been an avid user of the textbook and has developed much supplemental
simulation material during the course of teaching principles of agricultural machines at
Penn State University. We have included much of his material in the accompanying
CD. Dennis also revised the chapter on hay and forage harvesting.
Finally, we would like to thank the many people who have been helpful in the
process of preparing this edition. We thank Monte Dickson for providing a thorough
review of the new chapter on agricultural information systems (Chapter 6). We would
also like to acknowledge Frank Zoz for letting us include his traction prediction model
in the CD, and Al Hanson for letting us use his engine simulator in the CD.
As always, we welcome your feedback and suggestions for improvement. Please
feel free to contact any of us. Additions and changes will be posted to the ASABE
Technical Library at http://asae.frymulti.com/toc.asp (scroll down to the listing of
textbooks). For specific questions we ask that you direct your inquiries to Ajit
Srivastava for Chapters 1, 4, 8, 10, 12, and 14; to Carroll Goering for Chapters 2, 3, 5,
6, 7, 9, and 15; to Roger Rohrbach for Chapter 13; and to Dennis Buckmaster for
Chapter 11 and the accompanying CD.
Ajit Srivastava ([email protected])
Carroll Goering ([email protected])
Roger Rohrbach ([email protected])
Dennis Buckmaster ([email protected])
The authors wish to dedicate this edition to their wives
Barbara Srivastava,
Carol Goering,
Jeanette Rohrbach,
and
Corinne Buckmaster
for their unwavering support and encouragement throughout our lives.
CONTENTS

Chapter 1
Agricultural Mechanization and Some Methods of Study 1
Introduction..............................................................................................................1
1.1 History of Mechanized Agriculture.................................................................1
1.2 Farming Operations and Related Machines...................................................3
1.3 Functional Analysis of Agricultural Machines...............................................4
1.3.1 Basic processes of agricultural machines.................................................5
1.3.2 Process diagrams......................................................................................6
1.4 Dimensional Analysis.....................................................................................7
1.4.1 Scope........................................................................................................7
1.4.2 Physical dimensions.................................................................................7
1.4.3 Units of measurement..............................................................................8
1.4.4 Developing a prediction equation............................................................9
1.4.5 Buckingham’s Theorem.........................................................................10
1.4.6 Systematic calculation of the dimensionless products.............................12
1.4.7 Transformation of dimensionless products............................................13
Problems.................................................................................................................14

Chapter 2
Engine Power for Agricultural Machines 15
Introduction............................................................................................................15
2.1 The power in fuel..........................................................................................15
2.2 Combustion...................................................................................................16
2.2.1 Combustion chemistry...........................................................................16
2.2.2 Energy release in combustion................................................................19
2.3 Thermodynamic limits to Engine Performance............................................21
2.4 Heat Losses and Power at the Pistons..........................................................25
2.5 Mechanical Losses and Power at the Flywheel.............................................26
2.6 Engine Torque and Efficient Engine Loading..............................................28
2.7 Control of Engine Speed...............................................................................29
2.8 Engine performance simulator.....................................................................33
2.9 Turbocharging and Intercooling Engines.....................................................35
2.9.1 Operation of turbochargers....................................................................36
2.9.2 Intercoolers............................................................................................39
2.9.3 Turbocharging and intercooling for versatility......................................39
Problems.................................................................................................................41
Simulation Problems...............................................................................................43

Chapter 3
Electrical Power for Agricultural Machines 45
Introduction............................................................................................................45
3.1 Motor Components........................................................................................45
3.2 Motor Classifications....................................................................................46
3.3 Principles of Operation Of Induction Motors...............................................47
3.4 Types of Single-Phase Induction Motors.....................................................49
3.4.1 Split-phase induction motors..................................................................49
3.4.2 Capacitor-start, induction-run motors....................................................50
3.4.3 Two-value-capacitor, induction-run motors...........................................52
3.4.4 Repulsion-start, induction-run motors....................................................52
3.5 Three-Phase Induction Motors.....................................................................53
3.6 Dual-Voltage Motors....................................................................................54
3.7 Torque-Speed Characteristics of Induction Motors.......................................56
3.8 Motor Nameplate Information.....................................................................57
3.9 Motor Starters...............................................................................................59
3.10 Motor Enclosures..........................................................................................59
3.11 Variable- Speed Electric Motors..................................................................59
3.12 Motor Efficiency...........................................................................................60
Problems.................................................................................................................61
Simulation Problems...............................................................................................63

Chapter 4
Mechanical Power Transmission 65
Introduction............................................................................................................65
4.1 V-Belt Drives................................................................................................65
4.1.1 V-belt types and standardization............................................................66
4.1.2 V-belt drive geometry............................................................................67
4.1.3 Kinematics of V-belt drives...................................................................68
4.1.4 Mechanics of V-belt drives....................................................................69
4.1.5 Stresses and service life.........................................................................72
4.1.6 Variable-speed V-belt drives..................................................................74
4.1.7 V-belt drive design.................................................................................76
4.2 Chain Drives.................................................................................................76
4.2.1 Types of chains and standardization......................................................76
4.2.2 Geometry of chain drives.......................................................................79
4.2.3 Kinematics of chain drives.....................................................................79
4.2.4 Design of chain drives............................................................................82
4.3 Power-Take-Off Drives.................................................................................83
4.4 Overload Safety Devices...............................................................................87
4.4.1 Shear devices.........................................................................................87
4.4.2 Jump clutch devices...............................................................................88
4.4.3 Friction devices......................................................................................89
Problems.................................................................................................................90

Chapter 5
Fluid power, mechatronics, and control 91
Introduction............................................................................................................91
5.1 Basic Principles and Elements Of Fluid Power............................................91
5.2 Pumps............................................................................................................92
5.3 Valves...........................................................................................................96
5.3.1 Pressure control valves...........................................................................96
5.3.2 Volume control valves...........................................................................98
5.3.3 Directional control valves......................................................................99
5.4 Actuators.....................................................................................................102
5.4.1 Hydraulic motors.................................................................................102
5.4.2 Hydraulic cylinders..............................................................................102
5.5 Reservoirs, Fluids, Filters, and Lines.........................................................104
5.6 Types of Fluid Power Systems...................................................................107
5.6.1 Open-center systems............................................................................107
5.6.2 Pressure-compensated systems............................................................109
5.6.3 Load-sensing systems..........................................................................109
5.7 Pressure Transients......................................................................................111
5.8 Hydrostatic Transmissions..........................................................................112
5.9 Mechatronics and System Control.............................................................114
5.9.1 An introduction to mechatronics..........................................................114
5.9.2 System control.....................................................................................115
Problems...............................................................................................................117
Simulation Problems.............................................................................................121

Chapter 6
Precision agriculture 123
Introduction..........................................................................................................123
6.1 Sensors........................................................................................................124
6.1.1 Sensor types.........................................................................................124
6.1.2 Sensor applications..............................................................................124
6.1.3 Advanced sensors.................................................................................124
6.2 Global Positioning System..........................................................................125
6.2.1 GPS for civilian use.............................................................................125
6.2.2 Military GPS........................................................................................125
6.2.3 Differential GPS...................................................................................125
6.2.4 Carrier-phase GPS...............................................................................126
6.2.5 Real-time kinematic GPS.....................................................................126
6.2.6 Accuracy measures..............................................................................126
6.2.7 Coordinate transformation...................................................................127
6.3 Geographic Information System.................................................................130
6.3.1 Data input to a FIS...............................................................................130
6.3.2 Map coordination.................................................................................131
6.3.3 Data analysis in the FIS.......................................................................133
6.3.4 Data persistence...................................................................................133
6.4 Variable Rate Applications.........................................................................133
6.4.1 Approaches..........................................................................................133
6.4.2 Applications.........................................................................................134
6.4.3 Application resolution..........................................................................134
6.4.4 Control systems....................................................................................134
6.4.5 Automatic guidance.............................................................................135
6.5 Controller Area Networks...........................................................................135
Problems...............................................................................................................137

Chapter 7
Tractor Hitching, Traction, and Testing 139
Introduction..........................................................................................................139
7.1 Hitching Systems........................................................................................139
7.1.1 Principles of hitching...........................................................................139
7.1.2 Types of hitches...................................................................................139
7.1.3 Hitching and weight transfer................................................................142
7.1.4 Control of hitches.................................................................................144
7.2 Tires and Traction.......................................................................................144
7.2.1 Basic tire design...................................................................................146
7.2.2 Traction models...................................................................................149
7.2.3 Traction predictor spreadsheet.............................................................153
7.3 Soil Compaction..........................................................................................154
7.4 Traction Aids...............................................................................................155
7.5 Tractor Testing............................................................................................156
7.5.1 Basic principles of tractor testing.........................................................156
7.5.2 Official tractor tests..............................................................................158
Problems...............................................................................................................165
Simulation Problems.............................................................................................166

Chapter 8
Soil Tillage 169
Introduction..........................................................................................................169
8.1 Tillage Methods and Equipment................................................................169
8.1.1 Primary tillage in conventional tillage systems....................................170
8.1.2 Secondary tillage in conventional tillage systems................................179
8.1.3 Tillage in conservation tillage systems................................................184
8.2 Mechanics of Tillage Tools.........................................................................185
8.2.1 Soil texture...........................................................................................185
8.2.2 Physical properties of soils..................................................................187
8.2.3 Mechanical properties of soils.............................................................189
8.2.4 Mechanics of a simple tillage tool.......................................................200
8.3 Performance of Tillage Implements...........................................................207
8.3.1 Moldboard plows.................................................................................207
8.3.2 Disk implements..................................................................................209
8.3.3 Cultivators............................................................................................211
8.3.4 Rotary tillers.........................................................................................214
8.4 Hitching of Tillage Implements.................................................................215
8.4.1 Forces on tillage tools..........................................................................215
8.4.2 Pull-type implements...........................................................................221
8.4.3 Mounted implements............................................................................226
Problems...............................................................................................................229

Chapter 9
Crop Planting 231
Introduction..........................................................................................................231
9.1 Methods and Equipment.............................................................................231
9.1.1 Broadcast seeding................................................................................231
9.1.2 Drilling.................................................................................................232
9.1.3 Precision planting.................................................................................233
9.1.4 Transplanting.......................................................................................234
9.2 Functional Processes...................................................................................235
9.2.1 Seed metering.......................................................................................235
9.2.2 Seed transport.......................................................................................245
9.2.3 Furrow opening and covering..............................................................255
9.2.4 Transplanting.......................................................................................258
9.3 Evaluating Planter and Transplanter Performance......................................262
9.3.1 Broadcast seeders.................................................................................262
9.3.2 Drills....................................................................................................264
9.3.3 Precision planters.................................................................................264
9.3.4 Transplanters........................................................................................265
Problems...............................................................................................................265
Chapter 10
Chemical Application 269
Introduction..........................................................................................................269
10.1 Application of Granular Chemicals............................................................269
10.1.1 Methods for application of granular chemicals....................................270
10.1.2 Equipment for application of granular chemicals................................270
10.1.3 Functional processes of granular chemical applications.....................273
10.2 Application of Liquid Chemicals...............................................................280
10.2.1 Methods for application of liquid chemicals........................................280
10.2.2 Equipment for application of liquid chemicals....................................280
10.2.3 Functional processes of applying liquid chemicals..............................286
10.3 Performance Evaluation..............................................................................310
10.3.1 Uniformity of coverage of granular chemical application..................310
10.3.2 Calibration of fertilizer spreaders.........................................................312
10.3.3 Liquid chemical application.................................................................315
10.3.4 Sprayer calibration...............................................................................321
Problems...............................................................................................................322

Chapter 11
Hay and Forage Harvesting 325
Introduction..........................................................................................................325
11.1 Methods and Equipment.............................................................................325
11.2 Functional Processes...................................................................................331
11.2.1 Cutting mechanics and plant structure.................................................331
11.2.2 Cutting and chopping...........................................................................343
11.2.3 Curing and preservation of forage........................................................370
11.2.4 Windrowing.........................................................................................374
11.2.5 Baling...................................................................................................380
11.3 Performance Evaluation..............................................................................392
Problems...............................................................................................................395

Chapter 12
Grain Harvesting 403
Introduction..........................................................................................................403
12.1 Methods and Equipment.............................................................................403
12.1.1 Direct harvesting..................................................................................403
12.1.2 Cutting and windrowing.......................................................................408
12.2 Functional Processes...................................................................................409
12.2.1 Gathering, cutting, pickup, and feeding...............................................410
12.2.2 Threshing.............................................................................................415
12.2.3 Separation............................................................................................420
12.2.4 Cleaning...............................................................................................427