Abstract: A hydraulically-operated piston machine includes at least one cylinder and a piston axially movably guided in the cylinder. The piston is connected to a crankshaft or the like by means of a connecting rod. The connecting rod and the piston each have spherically-shaped bearing surfaces serving for connecting the connecting rod and the piston with each other in an articulated manner. The connecting rod defines at its end connected to the piston a radially outwardly facing spherical surface portion which is arranged concentrically with the spherical bearing surface of the connecting rod. The spherical surface portion rests against the surface of a recess defined in the piston, so that a hollow space is defined between the surface of the recess and the spherical surface portion. The piston defines a bore for effecting communication of fluids between the interior of the cylinder and the hollow space.

Abstract: A hydraulic radial piston machine with steplessly adjustable volumetric displacement and piston stroke has a bank of pistons with axes in a common plane transverse to the shaft and machine axes. A radially displaceable supporting member pivotably connected to a shaft longitudinal portion turnable from the machine longitudinal axis supports the pistons. The longitudinal portion is pivotably connected at one end to a further longitudinal shaft portion. The second end connects to a turning link transmission which rotates. Rotation of the first--mentioned longitudinal shaft portion causes the supporting member to travel a circular path around the machine axis. A force--loaded translating operating displacing member steplessly varies the diameter of this circle to steplessly adjust piston stroke.