Abstract: A rotary feed system for a machine tool capable of feeding, for example, an off-center or a centrally-supplied tool with a coolant, has at the downstream end of a shaft delivering a fluid medium, a rotary distributing valve which is actuated by a fluid, e.g. compressed air applied to one or two vanes of the rotary piston within a generally annular or segmental working compartment.

Abstract: In a rotary coupling for conducting a medium under pressure from a stationary machine part to a rotating machine part, a radially movable bushing is provided between a housing and a rotatable shaft of the rotating machine part. The radial gap between the housing and the bushing is bridged or spanned by a plurality of elastic sealing members to provide radial adjustability. A ceramic coating to minimize radial differences due to thermal expansion during frictional heating can also be provided on the shaft.

Abstract: A method of and apparatus for testing axles for motor vehicles and especially the drive axles for trucks, has a testing stand in which the axles are supported and connected to a drive motor and load. In addition to the driving forces which can thus be applied to the axle shaft, the axle housing can be loaded to represent truck loading and can be subjected to torsional stresses like those which are generated when the truck is inclined in driving. The shaft ends are laterally loaded as well to represent reaction forces from the wheel disks. The method and apparatus enable total testing of the functions of the axle under simultaneous drive and carrying conditions in a single operation on the stand.

Abstract: A rotary connector for fluid transmission between a housing part and a shaft via rings has a bypass provided with a valve which connects the intermediate pressure space with either the leakage space or the main pressure space upon a drop in the main pressure below the pressure in the intermediate pressure space to provide inverse gap control and thereby prevent the sliding ring from pressing mechanically agains the counter-ring and generating sliding friction, heat and wear.

Abstract: A liquid feed device for conducting a pressurized medium from a stationary housing to a rotatable component is so constructed that the applied force of a sealing surface of a sliding shoe of the housing on the running surface of the movable structural component is regulated so that on the one hand an effective seal between the sealing surface and the running surface independent of the operating conditions of the system is guaranteed and on the other hand the frictional forces operating are kept as small as possible.

Abstract: A controllable two-way valve for pressure and/or flow control uses a cup-shaped piston, the bottom of which forms a large effective surface area exposed to a control flow through a slit which cooperates with an edge of the slider also serving to define the main flow cross section between an inlet and an outlet. A stationary compensating piston within this slider vents the interior of the slider and a control valve set connected to a spring chamber through which the control flow passes regulates the pressure applied to the slider in the spring compartment.

Abstract: A hydrostatic clutch of the type in which an input shaft has a casing in which a positive displacement gear pump is received and an output shaft is connected to the gear pump. According to the invention the gear pump includes a gear pump body provided with intake and pressure passages, the body being limitedly rotatable in the casing so that upon reversal of the rotation of the input shaft, the passages of the body will switch over as to communication with openings of the casing and thereby reverse the pump.

Abstract: The pump has a casing, bearing members having portions for radial and axial mounting situated in the casing, at least one displacement element having journals rotatably received in the bearing members, a drive shaft extending from outside into the casing and sealed with respect to the casing by a sealing ring and drivably connected to one of the journals. At least the surfaces of each displacement element, of the journals, of the further elements and of the portion of the shaft inside the sealing ring are plasma-nitrided and the portions for axially mounting the journals are coated with a ceramic material. Also the portion of the shaft inside the sealing ring and the journals may be encased by a ceramic material.

Abstract: A pump has a stator formed with intake and output ports connected to the lubricating system of an internal-combustion engine of an automotive vehicle for flow therethrough, a rotor in the stator positively driven by the engine output, an adjustment element operatively connected to the stator and rotor and displaceable between one end position corresponding to relatively great flow through the pump when the rotor is rotated by the output and an opposite end position corresponding to substantially no flow through the pump when the rotor is rotated by the engine output, and a biasing unit for urging the adjustment element toward the one end position with a fixed force. An abutment unit is connected to the adjustment element of the pump for limiting displacement of same from an intermediate position between its end positions into the opposite end position corresponding to no flow through the pump.

Abstract: The apparatus serves to pass an arbitrary pressure medium from a stationary housing (1) to a rotating shaft (4) provided with supply bores (3) in such a manner that there is little leakage or noise and the apparatus is ventable. Sliding pads (8) rest on a lateral contact face (12) of an indexing ring (13) rotating with the shaft (4) and axially displaceable thereon. The sliding pads (8) are supported in an axially displaceable manner on hollow pistons (7) secured to the housing (1). The indexing ring (13) has pins (19) for guiding and coupling it, which are supported in axial bores (21), provided with springs (22), of a shaft ring (16) secured on the shaft (4). The indexing ring (13) has axial check valves (23), each having a valve plug (25) whose end face (29) is located in the plane of the contact face (12) of the indexing ring (13) for the sliding pads (8).