Patent ID: 7028600

Claim:
A hydraulic radial piston engine comprising: a multi-stroke lifting ring ( 15 ) which is fixed to a casing, a rotor ( 18 ) which is mounted opposite the lifting ring ( 15 ) such that it is rotatable about an axis of rotation ( 19 ) and has multiple piston seats ( 35 ) aligned radially with respect to the axis of rotation ( 19 ), multiple pistons ( 50 ), of which in each case one is displaceably mounted in a piston seat ( 35 ) and which, over at least part of its length, has a guide and sealing cross section that differs from a circular shape and matches a guide and sealing cross section of the piston seats ( 35 ), which differs from a circular shape and remains constant as far as outside of the rotor, and cylindrical rollers ( 58 ) which are borne by the pistons ( 50 ) in bearing seats ( 56 ) and are aligned with their axes of rotation ( 59 ) in direction of axis of rotation of the rotor ( 18 ), via which the pistons ( 50 ) are supportable on the lifting ring ( 15 ) and which have two end faces ( 60 ) that face away from each other and run at right angles to their axis of rotation ( 59 ), wherein the piston seats ( 35 ) have two flat wall sections ( 44 ) aligned at right angles to the axis of rotation ( 59 ) of the rollers ( 58 ), and distance between the two end faces ( 60 ) of a roller ( 58 ) is only slightly smaller than distance between the two flat wall sections ( 44 ) of the piston seats ( 35 ).