A high-pressure cleaning apparatus including a high-pressure pump that includes a suction chamber, at least one pump chamber in which liquid is pressurized, and a pressure chamber arranged downstream of the pump chamber is disclosed. The high-pressure pump includes a return line via which the pressure chamber is in flow communication with the suction chamber, and a valve unit by which a free cross-sectional area of the return line is changeable. The high-pressure cleaning apparatus also includes a drive unit associated with the valve unit, a control unit coupled to the drive unit and a pressure sensor coupled to the control unit for detecting liquid pressure on the pressure side of the pump chamber. Depending on the signal of the pressure sensor, the liquid pressure can be controllable to a predetermined or predeterminable liquid pressure by changing of the free cross-sectional area of the return line.

A drive device for a high pressure cleaning appliance includes a motor, the motor shaft of which is rotatably mounted on a motor flange and is coupled to a swash plate arrangement by a planetary gearing, wherein the planetary gearing comprises a sun gear, which is connected to the motor shaft in a rotationally-fixed manner and meshes with planetary gears that are rotatably mounted on a planet carrier and are in engagement with an internally toothed ring gear, and wherein the swash plate arrangement is positioned in an oil housing. So that the drive device has a longer service life and enables a greater selection of materials in the production thereof, the motor flange and the oil housing form separate components, wherein the motor flange comprises the ring gear and the oil housing is fixed to the motor flange, wherein the motor flange forms a centering for the oil housing.

A high-pressure cleaning apparatus including a high-pressure pump that includes a suction chamber, at least one pump chamber in which liquid is pressurized, and a pressure chamber arranged downstream of the pump chamber is disclosed. The high-pressure pump includes a return line via which the pressure chamber is in flow communication with the suction chamber, and a valve unit by which a free cross-sectional area of the return line is changeable. The high-pressure cleaning apparatus also includes a drive unit associated with the valve unit, a control unit coupled to the drive unit and a pressure sensor coupled to the control unit for detecting liquid pressure on the pressure side of the pump chamber. Depending on the signal of the pressure sensor, the liquid pressure can be controllable to a predetermined or predeterminable liquid pressure by changing of the free cross-sectional area of the return line.