Abstract: An electrohydraulic control arrangement comprising at least one terminal plate having an inlet port connected to a pump pumping fluid under pressure from a tank and an outlet port connected to a return conduit leading to the tank and a plurality of consumer plates having consumer ports connected to consumers of pressure fluid. All plates are arranged side by side and held in abutting relationship by tightening screws extending through axially aligned bores through said plates. The plates are further provided with three axially aligned fluid channels therethrough, one to be connected to the inlet port and the two others to the outlet port. The selective connection of the fluid channels to the respective ports is accomplished in the terminal plate by a control slide movable by auxiliary valves, one of which is controlled by an electromagnet and by an additional control slide in each of the consumer plates, the position of which is controlled by two additional auxiliary valves.

Abstract: An external gear type hydraulic pump or motor wherein the trunnions of gears in the chamber of the housing are surrounded by annular bearing members. The peripheral surface of each bearing member defines with the adjacent internal surface of the housing an arcuate gap whose width increases in a direction toward the respective end face of the corresponding gear. To this end, portions of or the entire peripheral surfaces of bearing members and/or portions of or the entire internal surfaces of the housing have a conical or spherical shape. The gaps are located in the low-pressure zone and reduce the likelihood of wear upon those end faces of bearing members which are adjacent to the end faces of the gears because the bearing members can tilt in response to increasing load without localized rubbing against the gears. Additional gaps can be provided between the end faces of the gears and the adjacent end faces of the bearing members to further reduce the likelihood of uneven wear upon the bearing members.

Abstract: A gear-type fluid displacing machine includes a housing having a chamber and two side sections overlying opposite ends of the chamber, a pair of mating gears in the chamber for generating a high pressure area therein as the gears rotate, and annular bearing members surrounding trunnions associated with the gears at opposite ends of the chamber each of the bearing members having an end which faces one of the side sections of the housing and being formed with a groove. The sealing arrangement includes a generally U-shaped resilient sealing element in each of the grooves and having an open side in communication with the high pressure area. The sealing element has at least one wedge-shaped leg which is pressed into sealing contact with an associated side section by its own resilience and by the force exerted by the pressure fluid entering the open side of the element from the high pressure area.

Abstract: An external gear pump wherein the gears are installed in an eight-shaped compartment of a central housing section which is flanked by two covers. The outlet port of the housing communicates with two arcuate recesses for metallic inserts which are biased against the adjacent gears by fluid pressure in the outlet port whereby the inserts urge the gears against those portions of the internal surface of the central housing section which are located opposite the recesses. Such portions of the internal surface are formed with narrow first cutouts which communicate with the outlet port. The internal surface is further formed with relatively wide additional cutouts which are located between the first cutouts and the recesses and communicate with the inlet port. The force which is produced by fluid in the cutouts opposes the force which urges the gears against the internal surface of the central housing section to thus reduce the force with which the stubs of the gear shafts are urged against the housing.

Abstract: A source of hydraulic fluid is connected with a user by a hydraulic circuit in which a pump is interposed so as to supply the hydraulic fluid under pressure to the user. A housing is interposed in the circuit, having a bore communicating with the circuit. An air venting passage communicates with the bore and a valve body is located in the bore upstream of the passage and defines a throttling gap through which air in the circuit can pass into and out of the passage, but at which subsequent flow of hydraulic fluid will create sufficient pressure to displace the valve body to a position in which it seals the air venting passage.