Axial piston fluid translating unit with sealed barrel plate

Abstract

Axial piston fluid translating units commonly experience undesirable shaft deflections and barrel tilting during operation. A fluid translating unit includes a barrel plate interposed the end of a barrel and a porting surface defined within a housing thereof. The barrel plate is axially spaced from an end of the barrel and is in face sealing engagement with the porting surface. The barrel plate defines a plurality of fluid ports, each communicating between one of a plurality of barrel cylinder bores and the porting surface. In one aspect a plurality of counterbores are provided in the barrel in surrounding relation to the fluid ports. A plurality of seal rings having a sealing end defining an annular seal face of a predetermined width for face sealing engagement with the barrel plate. The seal rings are each disposed in one of the counterbores in circumferential sealing relation of a predetermined length which is no greater than the width of the sealing face. A plurality of annular springs are disposed in the counterbores for urging the seal rings into sealing engagement with the other of the barrel and the barrel plate. This arrangement permits tilting of the barrel without damaging contact or excessive leakage between the barrel plate and the porting surface.