1、,拖拉机发展历史 A tractor is a vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction
2、to mechanize agricultural tasks, especially tillage but nowadays a great variety of tasks.Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised.,绪论,山东理工大学农业工程与食品科学学院,The first powered farm implements i
3、n the early 19th century were portable engines steam engines on wheels that could be used to drive mechanical farm machinery by way of a flexible belt. Around 1850, the first traction engines were developed from these, and were widely adopted for agricultural use. The first tractors were steam-power
4、ed plowing engines. Steam tractors were used to direct-haul plows(in US), but in the UK and elsewhere plowing engines were used for cable-hauled plowing instead. In 1892, John Froelich invented and built the first gasoline/petrol-powered tractor in Clayton County, Iowa, USA. Henry Ford introduced th
5、e Fordson, the first mass-produced tractor in 1917. in the U.S. and by 1923, Fordson had 77% of the U.S. market. The Fordson dispensed with a frame, using the strength of the engine block to hold the machine together,1882 Harrison Machine Works steam-powered tractor,A very early, hand-built gasoline powered tractor,A 1958 Series II Field Marshall the classic standard tread farm tractor,Volvo T25, 1956, Gasoline tractor,A modern steerable all-tracked power unit planting wheat in North Dakota,A modern 4-wheel drive farm tractor,Cutaway of modern tractor,
