Patent ID: 6354186
Filing Date: 2002-03-12
Classification: F04B

Abstract:
A displacement pump, comprising:a rotatable drive shaft; a piston having a piston cavity disposed therein; a piston shoe being pivotally connected to said piston, said piston shoe having a shoe passage in fluid communication with the piston cavity; a hydrostatic thrust bearing plate having at least one thrust pad; a drive plate being disposed between the piston shoe and the thrust pad and being connected to the drive shaft, said drive plate having a bearing surface proximate to the thrust pad, a pumping surface proximate to the piston shoe, and a communication port fluidly connecting the bearing surface to the pumping surface, said drive plate being rotatable with the drive shaft to a position at which said piston cavity is in fluid communication with said thrust pad via the shoe passage and the communication port; said thrust pad having a hydrostatic bearing pad area contiguous to said drive plate and a thrust pad sill surrounding said hydrostatic bearing pad area, said thrust pad sill being engageable with said drive plate.