A comprehensive test program was conducted to determine hydraulic power usage of an agricultural tractor in actual field operation. The data can be used to optimize the design of high efficiency hydraulic systems. The method by which the data was reduced to provide single merit values for each test parameter is applicable to similar evaluation of other features. The closed center, constant pressure system was one of the first to use a variable displacement pump to provide high pressure and flow capacity without high losses when the system was used at partial power levels. (1) The heart of this system was an effecient piston pump which combined the function of three open center gear pumps and provided a constant pressure regardless of the flow demanded. As variable displacement pumps became more available and increased hydraulic power demands made open center systems less practical, closed center systems have been adopted by many manufacturers. Many of these systems added a pressure sensing circuit to provide variable pressure and flow which should provide lower losses in some conditions. Most, however, retained a separate open center steering pump. (Wassmann)
Agricultural tractor hydraulic power use
Anwendung hydraulischer Energie bei Ackerschleppern
Proc. of the 37th nat. conf. on fluid power ; 35 ; 155-158
1981
4 Seiten, 5 Bilder, 7 Quellen
Conference paper
English
Agricultural Tractor Hydraulic Power Use
SAE Technical Papers | 1981
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