Chapter 1: Development of Off-Road Vehicles

1. Chapter 1: Development of Off-Road Vehicles BAE 517 - Lecture 1

2. 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.

3. 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.

4. 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.

5. 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.

6. 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).

7. 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).

8. 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).

9. 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.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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)

24. 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.

25. 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

26. 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

27. Carnot Efficiency

28. 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.

29. 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.