Ebook: Tractors and their Power Units

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.