Abstract: A hydraulic system for a motor vehicle includes a hydraulic pump which has a hydraulic steering device including a steering motor and a steering valve which is movable from an intermediate position in opposing directions and by which hydraulic fluid lines to and from the steering motor are controlled. A ventilator motor with the bypass line are placed in series with the steering device between the latter and the hydraulic pump. The bypass valve aids the distribution of fluid flow through the ventilator motor and the bypass line for adjustment of the fluid flow in accordance with required cooling power. The bypass valve can be adjusted to allow more hydraulic fluid to flow through the bypass line during actuation of the steering valve, thereby to lower the system pressure for reduced cost and complexity of the hydraulic pump.

Abstract: An injection system for an internal combustion engine having a plurality of cylinders is known which has a hydraulic pump with a delivery outlet to which a delivery line common to the cylinders is connected, and a plurality of injection units each of which is associated with a different cylinder and, in normal drive operation, can be controlled pulsewise by connection with the delivery line. There is also known an exhaust-brake system having a plurality of decompression valves each of which is associated with a different cylinder and, in brake operation, can be controlled pulsewise outside the exhaust stroke, in particular at the end of the compression stroke, by alternate pressure action on and pressure relief of the hydraulic actuating element. The purpose is to create a system with which, at little expense and at favorable cost, the "injection" and "exhaust-brake" functions can be satisfied.

Abstract: The present invention proceeds from an engine brake for a multi-cylinder internal combustion engine with decompression valves actuatable by pressurization of hydraulic pistons outside of the exhaust stroke of the working piston of the internal combustion engine, in particular at the end of the compression stroke. A radial piston pump is provided with internally supported radial pistons. The pump housing has a first housing section with the radial pistons, and a space for the eccentric which controls the radial pistons and a second housing section with the control outputs.

Abstract: The invention is based on a hydraulic system, in particular of an engine brake for an internal combustion engine, having at least one hydraulic actuating element, a positive displacement pump by which pressurized fluid can be pumped from a low-pressure region into a high-pressure region, and a distributor unit (14) having a control output (13) which is connected via a control line with the actuating element, which control output can be pressurized from the high-pressure region and connected to the low-pressure region. In order to obtain the desired control of the actuating elements over a wide range of cycle times and speeds of rotation of the internal combustion engine with a pump of relatively small displacement, a return valve which opens towards the high-pressure region is provided, via which the control line can be connected to the high-pressure region after it has been pressurized from the high-pressure region and before it is connected to the low-pressure region.

Abstract: A device presenting a high-pressure pump, and a low-pressure pump connected pstream from the first. To prevent damage in the event of a fault on the device, the connection between the low- and high-pressure pumps is provided with a cutoff valve which is closed in the event of a fault on the low-pressure pump to prevent the intake of solid particles by the high-pressure pump. Also, in the event of a fault on one of the injectors, detected on the basis of the operating conditions of the engine, the low-pressure pump is disconnected to prevent seriously damaging the engine.

Abstract: A pump comprising a number of radial cylinders arranged a given angular distance apart about a drive shaft and each housing including a piston resting radially on a respective pad by virtue of the action of a return spring. The connection between the piston and pad comprises a retainer for preventing in-service detachment of the pad, which rests on a respective flat portion of a cam mounted for rotation on an eccentric portion of the shaft. The force on the pad produced by sliding friction between the pad and the flat portion of the cam and directed perpendicular to the axis of the cylinder is absorbed by the piston.

Abstract: A pump having a number of radial cylinders each housing a sliding piston. Each cylinder is closed by a respective head, and comprises an intake valve and a delivery valve having respective seats inside a plate. The intake valve is located at the end of an intake channel having a first portion through the plate, a second portion formed between the head and the plate and perpendicular to the axis of the cylinder, and a third portion parallel to the cylinder axis. The delivery valve presents a truncated-cone-shaped seal communicating with the pumping chamber via a conduit also extending through the plate; and the two plungers are made of ceramic and guided by a respective retainer.

Abstract: A pumping apparatus is disclosed comprising a tank containing a fluid to be umped, a main pumping stage for pumping a controlled amount of said fluid at a predetermined pressure, a supply pump for supplying fluid from said tank to said main pumping stage in excess to said controlled amount, and feedback means for feeding the excess fluid back to said tank along a given drain path; wherein the improvement includes at least part of said drain path running in regions of said main pumping stage subjected to severe thermal and/or mechanical stress.

Abstract: An engine brake for a multicylinder internal combustion engine includes valves that can be periodically opened briefly, in each case outside the exhaust stroke. In the vicinity of the applicable valve drive, a hydraulic piston is provided that is triggered synchronously with the engine rpm via an associated control line by a hydraulic pressure distributor fed by a pump. To improve the accuracy of control over the entire engine rpm range, the various valves are assigned a central positive displacement pump that runs synchronously with the camshaft rpm and whose outlet line leads to the hydraulic pressure distributor, which has a distributor disk. In engine braking operation, an alternating connection of the applicable control line to either the pump outlet line or a low-pressure region of the hydraulic control circuit is effected synchronously with the engine rpm by means of the distributor disk.

Abstract: An engine brake for a multicylinder internal combustion engine includes valves that can be periodically opened briefly, in each case outside the exhaust stroke. In the vicinity of the applicable valve drive, a hydraulic piston is provided that is triggered synchronously with the engine rpm via an associated control line by a hydraulic pressure distributor fed by a pump. To improve the accuracy of control over the entire engine rpm range, the various valves are assigned a central positive displacement pump that runs synchronously with the camshaft rpm and whose outlet line leads to the hydraulic pressure distributor, which has a distributor disk. In engine braking operation, an alternating connection of the applicable control line to either the pump outlet line or a low-pressure region of the hydraulic control circuit is effected synchronously with the engine rpm by means of the distributor disk.

Abstract: The invention relates to a pump, in particular to an axial piston pump of the swash plate type, wherein the suction pressure medium is fed into the swash plate chamber, so as to be arranged in layers of different pressure. The pressure medium is removed from a desired pressure layer and supplied to the pump chamber so as to obtain a desired pump flow characteristic.

Abstract: A hydraulic pump for a power steering apparatus is provided. Said pump comprises a housing, an outer gerotor element and a rotating inner gerotor element arranged within said outer gerotor element. A plurality of pressure chambers is defined and a pressure valve is assigned to each pressure chamber at the output side of the pump.

Abstract: A radial piston machine has a cylindrical housing which encloses a rotary shaft formed with an eccentric. A plurality of stationary piston rods is connected to the inner wall of the housing and radially directed toward the shaft. The free ends of piston rods are provided with ball-and-socket joints permitting universal rotary movement of the pistons. Each piston slidably engages the inner wall of an assigned cylinder which at its bottom wall slidably engages the eccentric. In a modification, the spherical surface of the stationary ball joint directly engages the inner wall of the cylinder.