Abstract: A hydraulic system with a hydraulic pump driven directly by an internal-combustion engine reduces the dimension, weight and number of component parts used in the state of the art systems while optimizing energy exploitation. A plurality of elements, one of which is a cam shaft adjusting device, are supplied with hydraulic pressure fluid by one and the same pump. A series of simplified hydraulic connections enables equivalent devices to be driven simultaneously by one or more pump circuits.

Abstract: A suction-restricted radial piston pump is described, in particular for use with automotive vehicles. The pump delivers a flow constant over a broad speed range and involving low losses in output and generating only negligible noise. In one embodiment, a control slot (13), on the pressure side, is subdivided into several grooves (27,28) which at least in part are in communication, through check valves (32), with the pressure connection (20). An alternative embodiment provides a shape of the pressure-sided control slot in which the introducing end thereof is comparatively narrow to reduce noise at a high speed and the outlet-sided end thereof with a wider width sufficient to meet the required output. According to a third embodiment, the suction-sided slot (12) is provided with a narrow width section and a subsequent wider width section.

Abstract: A hydraulic actuating system and method comprises a pump which continuously circulates hydraulic fluid out of a reservoir into a pressure line limited to a predetermined maximum pressure by a pressure-limiting valve and a control valve connected to the pressure line controlling flow of hydraulic fluid to an operating cylinder. A clearance volume in communication with the pressure line collects compressed air entrained in the hydraulic fluid flow which upon opening of the inlet valve expands to displace a portion of the volume of flow of hydraulic fluid required for actuation of the operating cylinder.

Abstract: An arrangement for controlling the pressure of a hydraulic braking fluid supplied to a brake actuating cylinder includes an elongated hollow valve member mounted for axial movement in a bore of a housing. A compression spring acts on the valve member in one axial direction, and a control piston acts on the valve member in the opposite axial direction. Control pressure is admitted into an actuating compartment to act on the control piston and via the same on the valve member. The valve member forms a first valve arrangement with the control piston and a second valve arrangement with a part which is rigid with the housing. The first and second valve arrangement respectively controlled the communication of a slave unit with a low-pressure supply reservoir and with an actuating pressure source. The compression spring urges the valve member toward a position in which the first valve arrangement is open and the second valve arrangement is closed.

Abstract: There is disclosed a pressure-regulating valve which serves to control friction brakes dependent on the braking effect of a hydrodynamic brake. In order to achieve a full pressure decrease in the friction brakes, these are connected to an unpressurized reservoir while the hydrodynamic brake is operating at full effect.