Abstract: An internally meshing gear-pump, or motor comprises inlet and outlet ports 27,28 for the working fluid through a sealing plate 5 mounted on the shaft 1, an externally-toothed gear 2 is longitudinally displaceable relative to internally-toothed gears 3,4 to vary the pump or motor displacement, a sealing member 6 is secured to the end-face of the gear 2 which separates the displacement chambers 29,30 from the varying volume spaces which may be filled by controlled working fluid formed in both longitudinal and diametrically opposite regions 11,12. When the gear 2 is moved longitudinally from the maximum displacement position to the extreme left to a reduced capacity position and thus varies the output of the pump or motor mounting these machines back-to-back or in other combinations, a continuously variable and or differential transmission of working fluid may be obtained. Additionally electrical windings 85,86 may be mounted in the casings 7,8.

Abstract: A gear pump in which one rotating, toothed pump gear is supported axially displaceable in the pump casing and engaging an axially displaceable sliding part at least on the one face wall of the pump gear. The sliding part is adapted to overlap the operating space or zone of engagement of the displaceable pump gear against the other, axially stationary pump gear, with hydraulic relief provided by the pump casing and/or the sliding part by pocket-like recesses on the side diametrically opposing the pressure side of the pump across the displaceable pump gear, the recesses hydraulically communicating with the pressure side of the pump.

Abstract: A hydraulic clutch device which uses a gear pump design as its main element which, in effect, has nowhere to pump.Its center gear is driven by the input shaft while its housing unit can also rotate and comprises the output shaft.The center gear meshes with two outer gears and also slides axially so that the amount of its teeth that mesh with the outside gears can be varied. The axial movement of the center gear being achieved with hydraulic pressures and vacuums supplied from within the clutch itself and controlled by a central control slide valve which runs through the center of the input shaft and is controlled by a manually operated lever attached to the supporting framework and coupled to the slide valve with a throwout bearing device.By moving the center gear over so that it fully meshes with the outer gears the clutch is engaged, and by moving the center gear over the other way so that only a small portion of it meshes with the outside gears the clutch is disengaged.

Abstract: The invention deals with a screw compressor with housing, such housing containing a working chamber with two parallel cylindrical intersecting bore holes. The working chamber is bordered by two even end walls vertical with the longitudinal axes of the bore holes; two helical or screw rotors are arranged in the working chamber revolving and engaging and sealed against the chamber walls so that they do not touch the latter, whereby there is axial clearance due to the manner of construction between the frontal walls of the chamber and the fronts of the helical part of the rotor, whereby the screw compressor is provided with a control for volume which causes the output to be decreased by returning the gas sucked into gaps to the suction chamber before compression starts.