Abstract: A positive-displacement pump, in particular a vane-type pump for the delivery of a fluid for a consumer of a steering system includes a rotor, a cam ring, a housing-side control plate, and a cover-side control plate that form, in an assembled state, a rotor assembly. The housing-side control plate is arranged adjacent to a housing face surface in an axial direction and the cover-side control plate is arranged adjacent to a cover face surface in the axial direction. The rotor assembly is movable in the axial direction between the housing face surface and the cover face surface.

Abstract: Described is a radial piston pump with a pump housing (3), which has a plurality of cylinder bores (5) arrayed in star shape around a cam (4), for the reception of pistons (6) and possesses inlet (7) and outlet (8) when penetrate to each cylinder inner chamber (9) with a therein compressible working volume. In accord with the invention, each cylinder inner chamber (9) is provided with at least one relief opening, which connects the working volumes during a compression stroke of the piston (6) with a space of lesser pressure for the reduction of the pressure gradient and also thereby reducing the noise of the pump.

Abstract: Described is a radial piston pump with a pump housing (3), which has a plurality of cylinder bores (5) arrayed in star shape around a cam (4), for the reception of pistons (6) and possesses inlet (7) and outlet (8) when penetrate to each cylinder inner chamber (9) with a therein compressible working volume. In accord with the invention, each cylinder inner chamber (9) is provided with at least one relief opening, which connects the working volumes during a compression stroke of the piston (6) with a space of lesser pressure for the reduction of the pressure gradient and also thereby reducing the noise of the pump.