US Patent 7328647 Hydraulic device

The invention concerns a hydraulic device with a housing and a rotor which can rotate in the housing and has fixedly mounted pistons. Around the piston there are drum sleeves which each, together with a piston, form a chamber of variable volume and which are supported by a drum plate with an axis which intersects the axis of the rotor at an angle. Clamping means hold the drum sleeve against the drum plate and the clamping means are designed in such a manner that the drum sleeves can make a movement along the drum plate which is double of the radial movement which occurs in the event of synchronous rotation between the drum plate and a drum sleeve.