An electrical oil pump comprising a pump housing containing an electromotively driven pump rotor, and a discharge branch arranged on the housing side and receiving a non-return valve, said valve comprising a preferably spherical closing body arranged such that it can move between a valve seat and a supporting surface, and a closing body holder which is inserted into the discharge branch, forms the supporting surface and comprises through-flow sections, said holder being inserted into the discharge branch for captive holding therein.

A pump device includes a rotating body, a pump housing including a suction port and a discharge port, and a relief valve. In the pump device, a fluid is sucked from the suction port and discharged from the discharge port by rotation of the rotating body. The relief valve includes a valve body and a biasing member. The discharge port includes an one end in a direction in which the discharge port extends. The one end is shallower than a middle portion of the discharge port. The pump housing includes a relief flow path through which the fluid flows when the relief valve opens. The relief flow path is provided so as to be open to a groove bottom surface of the one end of the discharge port.

A device is provided for pumping fluid from a wellbore up to surface. The device includes a stator unit, a rotor unit run within the stator unit on a rod string, the rotor unit and the stator unit engaging with one another to form an annular space therebetween for passage of fluid. An upstream check valve on the rod string uphole of the rotor unit is moveable from an open position in which fluid is passable through the annular space, and a closed position in which fluid passage through the annular space is prevented. A hollow rod section extends through the rod string in fluid communication with the annular space both downstream and upstream of the upstream check valve, for entry of fluid into a downhole end of the hollow rod section, passage of fluid upstream therefrom and exit of fluids from an uphole end of the hollow rod section, back into the annular space. A method is further provided for pumping fluid from a wellbore after shutdown.

An integrated housing containing a drive motor which is coupled to a pair of gears which are housed within a pump housing. There are a plurality of inflow-outflow openings which are located on opposite sides of the pump, outside of the centroid of the pump housing. A pump housing is continuous with a hydraulic cylinder. Fluid passage ways run through the integrated housing to control the integrated hydraulic cylinder. Valves within the integrated housing regulate fluid flow.

A vane oil pump includes a rotor including a plurality of slits, a housing having an inner circumferential cam surface such that a first pump unit and a second pump unit taking in and discharging oil in accordance with rotation of the rotor are separately disposed in a rotational direction of the rotor, a plurality of vanes respectively fitted in the slits of the rotor, and a pressure adjusting device configured to adjust a second discharge pressure of the second pump unit to a lower pressure than a first discharge pressure of the first pump unit. A back pressure groove is disposed on the housing and is provided to supply back pressure oil to a bottom portion of each slit.

A power transmitting component having a first shaft and a pump. The first shaft has a longitudinal bore, a pump mount and a feed conduit. The pump mount has a circumferentially extending surface, a drive portion and a channel that extends circumferentially about the first shaft. The channel is disposed along a longitudinal axis of the first shaft between the drive portion and the circumferentially extending surface. The feed conduit intersects and fluidly couples the longitudinal bore and the channel. The pump has a pump housing, a first rotor and a pump outlet. The pump housing is mounted about the circumferentially extending surface and is disposed circumferentially about the channel. The first rotor is coupled to the drive portion for rotation therewith. The pump outlet is coupled in fluid communication with the channel.

A pump unit which has at least one high-pressure port and at least one low-pressure port, having a motor and a hydraulic pump which has at least one high-pressure outlet and at least one low-pressure outlet, wherein the high-pressure outlet is connected to the high-pressure port via at least one pressure-regulating valve.

A hydraulic-mechatronic system, for a vehicle that is connected to a target system, includes a housing with a fluid reservoir containing fluid, a communication port, a hydraulic pump, an electric motor for driving the hydraulic pump, at least one check valve, and a relief valve fluidly connected to the target system and the fluid reservoir. The relief valve moves between a first valve position, which is inactive and directs fluid to the communication port, and at least a second valve position, which is active and directs fluid from the communication port to the fluid reservoir. The hydraulic pump may rotate in forward and reverse directions. During operation of the hydraulic pump in the reverse direction, the relief valve is active such that the hydraulic-mechatronic system limits delivery of fluid through the communication port and instead directs fluid flow into the fluid reservoir of the housing.

A check valve (1) is described, the check valve (1) including a valve housing having a first port (2) and a second port (3) connected to a valve chamber (4), a valve seat (5) having a valve seat axis (6) and being arranged between the first port (2) and the valve chamber (4), and a valve element (7) movably arranged within the valve chamber (4) between the valve seat (5) and a stop face (8) opposite the valve seat (5), wherein the valve housing includes a first part (9) having the first port (2) and a second part (10) having the second port (3) and being connected to the first part (9). Such a check valve should have a simple design. To this end the second port (3) opens into the stop face (8) by means of an array of holes (12), wherein the cross section area of the holes (12) is smaller than the smallest cross section area of the valve element (7).

Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.