Alliedsignal Inc.

Lucas Aerospace Power Transmission

Howard J Bradt

Joseph A Stocco

Steven B Croke

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.

Variable displacement high pressure pump with internal power limiting

A variable displacement piston pump (10) including a plurality of axially aligned pumping cylinders (24) with a drive shaft (40) extending there between having a tiltable swash plate (30) disposed in a relatively dry cavity at one end of the drive shaft (40) for operating the pumping cylinders, and a reaction thrust plate (38) on the other end of the drive shaft (40), for providing reaction force in the drive shaft (40) opposite that provided by the swash plate (30). An inlet shaft seal (72) prevents fluid, which enters the pump at the inlet port (12), from filling the mounting housing (17) and submerging the mount shaft (44) portion of rotating assembly (16) and its supported swash plate (30). Two needle roller bearings (67) support the swash plate (30) and transmit torque from the drive coupling (19) to the swash plate (30). A high pressure fluid restrictor (70) meters hydraulic control fluid to the two needle bearings (67 ).

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Whitesboro, NY, United States of America

Howard J Bradt