Abstract: The invention refers to a piston assembly for a radial piston hydraulic motor. The essence of the solution lies in that a longitudinal axis (12) of a roller (11) substantially coincides with an axis through centre of gravity of a piston body (2). The roller is placed in a bed (10) of a bearing bush (6) which is located inside the piston (1) in a manner that the edges thereof slip through grooves (14) in the lower inner portion of the piston (1). The roller (1) being inserted this way is afterwards rotated in a certain angle, together with the bearing bush (6), thus, preventing the roller (11) from falling out of the piston (1).

Abstract: The invention refers to a piston assembly for a radial piston hydraulic motor. The essence of the solution lies in that a longitudinal axis (12) of a roller (11) substantially coincides with an axis through centre of gravity of a piston body (2). The roller is placed in a bed (10) of a bearing bush (6) which is located inside the piston (1) in a manner that the edges thereof slip through grooves (14) in the lower inner portion of the piston (1). The roller (1) being inserted this way is afterwards rotated in a certain angle, together with the bearing bush (6), thus, preventing the roller (11) from falling out of the piston (1).

Abstract: A piston assembly of a hydraulic radial piston-type machine, an essential characteristic thereof being the arrangement of a roller element in a piston head. The portion of contact surface of the roller element lying close to a crown of the piston is always arranged in the area between the piston crown and a step extending radially inwards and dividing the head of the piston from the guide portion.