Chapter 1: Development of OffRoad Vehicles

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Chapter 1 Development of Off-Road Vehicles

• BAE 517 - Lecture 1

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Tractor

• Words origin came from England. Was used as a
  synonym for traction engine.
• The word tractor appears in an 1890 patent for
  track-laying, steamtraction engine.
• Poor traction plaqued early steamtraction engine
  designers. Solution bigger wheels (36 ton
  traction engine with 5 m wide by 3 m dia. rear
  wheels).
• Other solutions included the development of
  track-type tractors in the early 1900s.

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Gasoline Engine

• Need for reducing the number of workers required
  to operate steamtraction engines.
• First comparisons of steam and gas engines
  occurred at the Winnipeg Tractor Trials
  (1908-1912).
• First U.S. demonstration was held in Omaha,
  Nebraska in 1911 as an exhibition, not
  competition.
• Nebraska passes tractor test law in 1919.

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Nebraska Tractor Test Law

• All tractor makes and models sold in Nebraska
  must be tested, with published results.
• Manufacturers required to provide a reasonable
  supply of repair parts.
• Tractor tests attained worldwide recognition
• Tractor tests provided standards for performance.

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History of Vehicle Development

• 1858 - Fawkes steam plowing engine.
• 1873 Parvins steamer first track laying device
  in U.S.
• 1876 Otto received patents for IC engine.
• 1889 One company builds tractor with IC engine.
• 1908 Winnipeg Tractor Trials
• 1911 First tractor demonstration in Omaha, NE.

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History of Vehicle Development Cont.

• 1917 First cast iron used in tractor chassis
  (Fordson).
• 1917 First oil cooled clutch faces (Fordson).
• 1919 Nebraska Tractor Test Law passed.
• 1919 First PTO introduced (International 8-16).

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History of Vehicle Development Cont.

• 1920 First tractor tested in Nebraska (John
  Deere Waterloo Boy).
• 1924 First successful row-crop tractor marketed
  (McCormick-Deering Farmall Regular).
• 1927 Mechanical rockshaft lift for mounted
  equipment introduced (John Deere Model GP).
• 1931 Caterpillar introduces diesel engine (84
  Hp).

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History of Vehicle Development Cont.

• 1932 Firestone Rubber introduces first rubber
  tires (Allis-Chalmers Model U).
• 1936 Hydraulic rockshaft replaces mechanical
  rockshaft (John Deere Model A).
• High compression engine introduced by Oliver,
  used fuel with octane rating of 70, improved fuel
  economy and more power (Oliver HC 70).

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History of Vehicle Development Cont.

• 1938 Machinery companies hire styling
  consultants (IH hire Raymond Lowery and Deere
  hires Henry Dreyfuss Associates).
• 1938 Weight transfer hitch introduced by Ford,
  hydraulics lifted hitch to improve traction (Ford
  9N).
• 1941 LPG tractor engines introduced by
  Minneapolis Moline.
• 1940-1949
• Remote hydraulic cylinders were adopted to and
  standardized by SAE and ASAE.
• Live power take-off introduced.

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History of Vehicle Development Cont.

• 1950-1959
• Power of tractors increases rapidly.
• Percentage of diesel tractors increases.
• Large 4WD tractors developed for the wheatlands.
• LPG tractors decline.
• Refinements include power steering, automatic
  transmissions, and more forward gear ratios.

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History of Vehicle Development Cont.

• 1960-1969
• Power of tractors continues to increase.
• Most large tractors are diesel.
• More emphasis on operator comfort and safety.
• Full power-shift transmission become available.
• Ergonomic seats with suspensions are widely
  adopted.
• Radial-ply tires are introduced.

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History of Vehicle Development Cont.

• 1970-1979
• Turbochargers and intercoolers added to diesel
  tractors.
• ROPS available, and beginning in 1976 were
  required for all new tractors sold for use by
  employees.
• Cabs common on large tractors.
• Sound pressure level measurements added to
  Nebraska Tractor Tests (1970).
• Last gasoline engines tractors tested at Nebraska
  (1978).
• Percentage of tractors over 75 kW in North
  America continues to increase.

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History of Vehicle Development Cont.

• 1980-2000
• Tractors equipped with electronic controls and
  sensing.
• Nebraska conforms to OECD internationally
  accepted codes.
• First Nebraska 3-point hitch lift test conducted
  (1984).
• Introduction of rubber-belted agricultural
  vehicles.
• Tractor power appears to reach upper limit of 300
  kW.
• Number of utility (landscape and garden tractors)
  expands rapidly.

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Types of Off-Road Vehicles

• Crawler
• Standard Row-Crop
• High-Clearance
• Utility
• Orchard
• Lawn and Garden
• Multipurpose

• Power Tiller
• Tree Skidder
• Skid-Steer Loader
• Two Wheel Drive (2WD)
• Front Wheel Assist (FWA)
• Four Wheel Drive (4WD)

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Global Variations in Tractors

• Rice tires are used in Japan.
• Power/weight ratios are greater for tractors in
  Japan.
• Radial-ply tires are common in Europe.
• Tractors outside of North America have up to four
  PTO speeds.
• Crawler tractors are more popular in Europe and
  UK.
• Power tillers are common in Asia.

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Implement Applications

• Attachments/implements are coupled to tractors
  using the following methods
• Towed (single hitch point)
• Mounted/Integral (three point hitch)
• Semi-Mounted/Semi-Integral (two point hitch)
• Frame Mounted

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Energy Conversion Devices

• Human/Animal Energy
• Piston Engines
• Compression Ignition (Diesel) Engines
• Spark Ignition (Gasoline) Engines
• Gas Turbines
• Wankel Rotary Engines
• Free-Piston Engines
• Sterling Engines

• Steam Piston Engine
• Steam Turbine Engine
• Thermoelectricity
• Fuel Cell
• Solar Cell
• Electric Motor and Generator
• Storage Battery
• Magnetohydrodynamic Device

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Carnot Efficiency
where e Carnot Efficiency Th High
Temperature Tl Low Temperature
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Future Engine Designs

• Piston CI engine is well established and not
  likely to be replaced soon.
• Ceramics will likely be incorporated into designs
  of the future for increased operating temperature
  and reduced wear.
• Look for electric drives for cooling (air and
  water movement) and lubrication.

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Trends in Tractor Design

• Total weight reduction of tractor and implements.
• Front and rear mounted implements.
• Lighter, high power tractors will transfer power
  through PTO.
• Power transfer will be controlled automatically.
• Driver comfort and safety will be improved.