Patent ID: 6874994

Claim:
A hydraulic pump/motor, comprising: a drive shaft mounted in a manifold block on a central axis; a torque plate coupled to said drive shaft for torque transmission therebetween; a hydrostatic fluid bearing between said torque plate and said manifold block for axially supporting said torque plate on a pressurized fluid film on said manifold block, said hydrostatic bearing including recesses surrounded by lands in an axially facing surface of said torque plate adjacent said manifold block, said recesses communicating with hollow pistons for supplying fluid under pressure to said recesses for creating a pressurized fluid cushion for supporting said torque plate axially on said manifold block; a bent axis motive unit having a base connected to said manifold block for arcuate translation about a swivel axis transverse to said central axis; a cylinder block supported for rotation on said base about a cylinder block axis and having said hollow pistons in blind cylinders in said cylinder block, said pistons having spherical piston heads engaged in spherical sockets in said torque plate; fluid flow channels communicating through said torque plate for convey fluid pressurized in said cylinders when said pistons are driven into said cylinders by rotation of said cylinder block about said cylinder block axis when said cylinder block is tilted at an angle to present said cylinder block to said torque plate at a diverging angle from said central axis.