Patent ID: 7340988

Claim:
A hydraulic machine having axial pistons, such as a motor or a pump, comprising: a cylinder block mounted in a casing to rotate about a first axis of rotation in a preferred direction of rotation, the cylinder block comprising a plurality of cylinders in which pistons are mounted to move in translation parallel to the first axis of rotation; a swash plate supporting a sliding disk suitable for being driven, relative to the swash plate, in rotation about a second axis of rotation which is inclined relative to the first axis of rotation; coupling rods for coupling together the sliding disk and the pistons, each coupling rod being connected firstly to a piston via a first spherical joint and secondly to the sliding disk via a second spherical joint; and a synchronization system for providing synchronization between the cylinder block and the sliding disk which, for each coupling rod, has a first drive surface that is stationary relative to the coupling rod and that is suitable for coming into contact with a second drive surface that is stationary relative to the sliding disk, clearance being provided between said first and second drive surfaces; wherein the second drive surfaces are off-center relative to the second spherical joints such that a reference amount of clearance between a second drive surface and a first drive surface is small in the zone in which said surfaces come into contact at the time of synchronization in the preferred direction of rotation.