At the time of the writing of the fourth edirion of this textbook, the agricultural economy in the United States and Canada was depressed. The prices paid to farmers for their grain crops were very low, and consequently most farmers in North America could not afford to buy a new tractor when needed; there- fore, the sales of tractors and other farm machines were much below normal. The farmer who was the victim of the depressed economy was forced to "make do." Instead of purchasing a new tractor when the old one needed to be replaced, the farmer usually purchased a used or second-hand tractor or repaired the old one. In a strict sense, tractors usually do not wear out; instead, they become obsolete. The farmer who owns an obsolete tractor would prefer to replace it with one having more power, more speeds, more conveniences, a better hydraulic system, lower operating cost, or all of the above. But farmers in the United States, Canada, and other industrial nations will continue to want to purchase tractors that have all of the features, in- cluding microprocessors, found on other vehicles.
Auflage
Sprache
Verlagsort
Verlagsgruppe
Kluwer Academic Publishers Group
Zielgruppe
Für höhere Schule und Studium
Für Beruf und Forschung
Editions-Typ
Illustrationen
Maße
Höhe: 250 mm
Breite: 176 mm
Gewicht
ISBN-13
978-0-442-25897-9 (9780442258979)
Copyright in bibliographic data is held by Nielsen Book Services Limited or its licensors: all rights reserved.
Schweitzer Klassifikation
1 Development of the Tractor.- Tractor Types.- Some World Variations in Tractors.- Functions of a Farm Tractor.- Sources of Energy.- Energy Conversion Devices.- The Future Engine.- Trends in Tractor Design.- 2 Thermodynamic Principles of Internal-Combustion Engines.- Specific Heat.- Entropy.- Energy Changes.- Constant-Volume Changes.- Constant-Pressure Changes.- Isothermal Changes.- Adiabatic or Constant-Entropy Changes.- General or Polytropic Changes.- Changes in an Adiabatic Expansion of a Perfect Gas.- Determination of the Value of n from an Actual Compression Line.- Equations for Nonflow Processes.- 3 Internal-Combustion Engine Cycles.- Simplifying Assumptions.- The Ideal Air-Standard Otto Cycle.- The Ideal Air-Standard Diesel Cycle.- Actual Cycles and Causes for Deviation from the Ideal.- 4 Fuels and Combustion.- Sources of Fuels.- Chemical Composition of Petroleum.- Petroleum Refining.- Combustion.- Gasoline Tests and Their Significance.- Antiknock Quality.- Factors Affecting the Octane Number Requirement.- Volatility.- Distillation.- Reid Vapor Pressure Test.- Sulfur Content.- Corrosion Test.- Gum Content.- Gravity.- Heating Values.- Gasoline Additives.- Diesel Fuel Tests and Their Significance.- Cetane Number.- Heating Value of Diesel Fuel.- Viscosity.- Carbon Residue.- Flash Point.- Pour Point and Cloud Point.- Ash Content.- Diesel Fuel Additives.- Alternate Fuels.- 5 Engine Design.- Engine Design-General.- Stroke-to-Bore Ratio.- Crankshafts and Firing Orders.- Tractor Engine.- Valve Design.- Valve Materials, Design, and Application.- Valve Timing.- Valve Clearance Adjustment.- Valve Seats.- Valve-Opening Area.- Cams.- Combustion Chamber Design.- Effect of Compression Ratio.- Piston Crank Kinematics.- Inertia Force of Connecting Rod.- Inertia Force of Single-Cylinder Engines.- Crank Effort.- Flywheels.- Balance of Single-Cylinder Engines.- Balance of Multicylinder Engines.- Principles of CI Engine Operation.- Construction of Diesel Engines.- Combustion Chamber Design.- Fuel-Injection Systems.- Fuel Injectors.- Turbochargers.- Matching of Turbocharger to Engine.- Aftercooling.- Engine Noise.- 6 Electrical Systems.- Battery.- Starting Motor.- Electrical Charging.- Battery Ignition System with Breaker Points.- Magneto Ignition System.- Ignition Timing.- Spark Plugs.- Sensors.- Environmental Problems.- 7 Engine Accessories.- Speed Control.- Principles of Centrifugal Governor Action.- Spark Arresters.- Mufflers.- Air Cleaners.- Air Inlet Location.- Precleaners.- Dry-Type Air Cleaner.- Dust Composition.- Air Cleaner Tests.- Engine Cooling Systems.- Cooling Load.- Heat Transfer.- Air Cooling.- Radiator Design.- Radiator Construction.- Temperature Control.- Antifreeze Materials and Coolants.- Corrosion and Radiator Deposits.- Pressure Cooling.- Quantity of Air.- Fans.- Engine Cooling Summary.- 8 Lubrication.- Types of Lubricants.- Properties of Lubricants.- Viscosity.- Classification of Oil by Viscosity.- Classification by Service.- Universal Tractor Oils.- Oil Additives.- Journal Bearing Design.- Oil Contamination.- Oil Filters.- Lubricating Oil Systems.- 9 Human Factors in Tractor Design.- Operator Exposure to Environmental Factors.- Operator Exposure to Noise.- Operator Exposure to Vibration.- The Operator-Machine Interface.- Noise and Vibration Control.- Operator Seating.- Sound Control in Operator Enclosures.- Spatial, Visual, and Control Requirements of the Operator.- Rollover Protection for Wheeled Agricultural Tractors.- Thermal Comfort in Operator Enclosures.- Safety.- 10 Traction.- Traction Mechanics.- Mohr-Coulomb Failure Criteria.- Traction Performance Equations.- Traction Prediction from Dimensional Analysis.- Performance of Four-Wheel, Tandem, and Dual Tires.- Tire Size, Load, and Air Pressure Relationship.- Radial-Ply Construction.- Tread Design.- Effect of Lug Spacing.- Traction Improvement.- Tracks.- Tire Testing.- Traction Devices for Paddy Fields.- 11 Mechanics of the Tractor Chassis.- Simplifying Assumptions.- Equations of Motion.- Static Equilibrium Analysis-Force Analysis.- Static Equilibrium Analysis-Maximum Achievable Drawbar Pull.- Static Equilibrium Analysis-Four-Wheel-Drive.- Longitudinal Stability.- The Tractor as a 2-Degree-of-Freedom Vibratory System.- Transient and Steady-State Handling.- Lateral Stability in a Steady-State Turn.- Three-Dimensional Static Analysis.- Center of Gravity Determination.- Moment of Inertia Determination.- 12 Hydraulic Systems and Controls.- Hydraulic Component Symbols.- Hydraulic Components.- Motor Performance.- Accumulators.- Valves.- Hydraulic Fluids.- Classification of Hydraulic Controls.- Draft Sensing.- Automatic Control.- Complete Hydraulic System.- Power Steering.- Noise in Hydraulic Systems.- Hitches.- Tractor Kinetic Energy.- Integral Hitch Systems.- Three-Point Hitches.- Quick-Attaching Coupler for Three-Point Hitches.- 13 Transmissions and Drive Trains.- Complete Drive Train.- Transmission Types.- Friction Brakes and Clutches.- Spur and Helical Gears.- Bevel Gears.- Gear Design.- Planetary Gear Systems.- Differentials.- Transmission Drive Shafts.- Antifriction Bearings.- Drive Train Speeds and Loads.- Electronic Transmission Controls.- Torsional Vibration.- Computer Simulation.- 14 Tractor Tests and Performance.- Tractor Performance Criteria.- Power Measurement Methods.- Absorption Dynamometers.- Electric Direct Current Dynamometers.- Shop-Type Dynamometers.- Drawbar Dynamometers.- Torsion Dynamometers.- Chassis Dynamometer.- Power Estimating-Field Method.- Air-Supply Measurement.- Engine Pressure Indicators.- Fuel Flow Meter.- The Nebraska Tractor Tests.- Globalization of the Tractor Industry.- Correction for Atmospheric Conditions.- Torque Curves.- Engine Performance.- Efficiency of Tractor Engines.- Actual Power Output and Fuel Consumption.- Tractor Reliability.- Appendixes.- A Standards for Agricultural Tractors.- B Standard Graphical Symbols.- C Agricultural Tractor Tire Loadings, Torque Factors, and Inflation Pressures-SAE J709d.- D Conversion Factors.
