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.

Abstract: A valve for cooling a reversible hydraulic machine includes a valve piston in a connecting channel extending between supply and discharge passages. Pressure in these passages displaces the spring-centered piston from neutral position to an end position. A central reduced-diameter portion of the piston carries a spring-centered closing member which closes a discharge conduit leading to a leakage space when the piston is in its central position. When the piston is displaced out of the neutral position toward one of the end positions, pressure from one of the connecting passages which has the lower pressure prevailing therein is permitted to propagate through one of the spring-receiving spaces delimited by the closing member and through an annular throttling gap present between the closing member and the central portion of the piston into the other spring receiving space and from there into the discharge conduit and into the leakage space.

Abstract: A compressed air starting device includes a starter with a starter motor operated at least indirectly from a pneumatic pressure reservoir and a meshing unit controlled by a signal input. A main valve is provided in the supply line between the pressure reservoir and the starter motor and a signal connection is provided between the meshing unit and the main valve. The compressed air starting device includes a control device with a sensor input for the pressure level in the pressure reservoir, a signal output connected to the signal input of the starter, a signal input for introducing the starter signal as well as an input for supplying the auxiliary energy required for generating signals. The auxiliary energy may be compressed air taken from the pressure reservoir. Electrical, mechanical or hydraulic energy can also be used as the auxiliary energy.

Abstract: A geared compression air starter having a lead rotor, a driven rotor and a hollow shaft. A driven trunnion of the driven rotor engages with external teeth thereof into external teeth of the hollow shaft to connect the driven rotor with the hollow shaft. A freewheeling unit couples the hollow shaft with an axially displaceable engagement shaft so that the central axes of the engagement and of the hollow shaft can be positioned coaxially with respect to a central axis of the lead rotor. An engagement cylinder is connected with the engagement shaft by means of a piston rod which extends through the lead rotor, and the engagement cylinder is integrated into an end cover of the starter housing.

Abstract: A piston machine, particularly a hydraulically-actuated piston machine, comprises at least one cylinder having an axis, a piston axially slidable in the cylinder and having a piston bottom with an inner surface, a piston rod turnably connected with the piston and having a piston rod shaft, a turning member mounted on the piston rod and having a side which is opposite to the piston rod shaft and has a convex circular surface, a pressing member having a shell surface which is in sliding contact with the circular surface of the turning member, the pressing member having a side which is opposite to the turning member and is provided with a convex circular surface abutting against the inner surface of the piston bottom, the circular surface of the pressing member and one of the circular surfaces of the turning member and the shell surface of the pressing member having central axes with central axes projections along their common orthogonals forming an angle of approximately 90.degree..

Abstract: The hydrostatic actuator in a constant displacement type radial piston pump or engine includes two telescopically arranged component parts separating a high pressure side from a low pressure side for a working medium, and defining a variable pressure space therebetween. The pressure space communicates with the high pressure side via a flow restrictor and with the low pressure side via a pressure limiting valve. The telescopically arranged components parts act as piston-like members and adjust the gaps between the outer end faces of the component parts and their control surfaces of the actuator in response to the pressure in the pressure space.

Abstract: A radial or axial piston type hydraulic motor has a plurality of cylinders connected by pressure conduits to a pressure fluid distributor. A check valve spring-biased in closing direction is built in at least one pressure conduit and has a first surface portion acted upon by pressure from the cylinder, a second surface portion which is exposable to pressure fluid from the distributor to act on the check valve either in opening direction or in closing direction and a third surface portion exposed to a control pressure in opening direction. The second surface portion being at least as large as the first surface portion and larger than the third surface portion, and the combined area of the first and second surface portions exceeding the surface area of the second surface portion.