VARIABLE DISPLACEMENT HIGH PRESSURE PUMP WITH INTERNAL POWER LIMITING ARRANGEMENT

摘要

File No. 390 88-001 (LA 8810) VARIABLE DISPLACEMENT HIGH PRESSURE PUMP A variable displacement piston pump includes a plurality of axially aligned pumping cylinders with a drive shaft extending therebetween having a pivotable swash plate disposed in a relatively dry cavity at one end of the drive shaft for operating the pumping cylinders, and a reaction thrust plate on the other end of the drive shaft for providing a reaction force on the drive shaft opposite that provided by the swash plate. An inlet shaft seal prevents fluid, which enters the pump at the inlet port, from filling the mounting housing and submerging the mount shaft portion of a rotating assembly supporting the swash plate. Two needle roller bearings support the swash plate and transmit torque from the drive coupling to the swash plate. A high pressure fluid restrictor meters hydraulic control fluid to the two needle bearings. Pump power is limited by a pressure compensator arrangement which receives direct feedback of swash plate pivoted position, whereby a minimum pressure at a predetermined pump flow is established.