Radial piston type hydraulic pump-motor

摘要

A radial piston type hydraulic pump-motor comprises a cylinder block formed with a plurality of radial cylinders circumferentially equally spaced and each opened at its radially outer end; a plurality of piston assemblies each radially slidably accommodated in each of the radial cylinders of the cylinder block to provide a cylinder chamber defined by the radial cylinder and the piston assembly; a plurality of inlet-outlet passages formed in the cylinder block, each having one end opened at said cylinder chamber and the other end opened exteriorly of the cylinder block; a housing accommodating therein the cylinder block and the piston assemblies and having a radially inner face held in contact with the radially outer ends of the piston assemblies, the improvement is characterized in that the radially outer end of the piston assemblies is in contact with the radially inner face of the housing at its axially spaced two points.