Abstract: A hydraulic actuating system is proposed in particular for gas exchange valves of reciprocating-piston internal combustion engines having a pressure source for the hydraulic medium and having at least one pressure accumulator, which can be connected to the pressure source; and has a piston which can be displaced in a drilled hole, a compression spring and a supporting element, for the compression spring with a central opening (3), which supporting element is fixed by a spring ring wherein the supporting element is configured as a spring supporting plate (1), the axial extension of which is considerably shorter than that of the piston.

Abstract: A hydraulic assembly (5) for a cylinder head (2) of an internal combustion engine having a hydraulically variable valve train (1) is provided. A high pressure chamber (11), a medium pressure chamber (12) and a low pressure chamber (16), which serves as a hydraulic medium reservoir, are configured in the hydraulic assembly. The low pressure chamber communicates through a throttling point (17) with the medium pressure chamber, which throttling point is formed by a displaceable valve body (19) and, depending on the position of the valve body, provides flow cross-sections of different sizes in order to minimize the leakage out of the hydraulic assembly.

Abstract: A hydraulic housing of an electrohydraulic valve controller of an internal combustion engine which has a hydraulic housing body and guide cylinder for a pump piston that is joined to the hydraulic housing body. The guide cylinder is joined to the hydraulic housing body by a friction welded connection.

Abstract: Join connection for a piston guiding unit, preferably made from steel, in which a piston, in particular a brake or pump piston, is guided movably. The piston guiding unit is screwed to a housing which is preferably produced from aluminum, and the thread of the screw connection has a thread-forming contour.

Abstract: A hydraulic assembly (5) for a cylinder head (2) of an internal combustion engine having a hydraulically variable valve train (1) is provided. A high pressure chamber (11), a medium pressure chamber (12) and a low pressure chamber (16), which serves as a hydraulic medium reservoir, are configured in the hydraulic assembly. The low pressure chamber communicates through a throttling point (17) with the medium pressure chamber, which throttling point is formed by a displaceable valve body (19) and, depending on the position of the valve body, provides flow cross-sections of different sizes in order to minimize the leakage out of the hydraulic assembly.