A vacuum pump having a housing which limits a working space and having a rotor, rotatably mounted in the housing about a rotor axis, the rotor guides a vane being movably mounted in the radial direction, the vane has a transverse extent, and the vane divides the working space into a suction side having a suction inlet and a pressure side having a pressure outlet, the housing has at least one oil outlet, the oil outlet is closed by a relief valve, the relief valve assumes an open position, when a limit pressure lying above a nominal pressure is exceeded in the working space, and the transverse extent of the vane is large enough that when the vane passes the oil outlet, the oil outlet is closed by the vane, so that there is no fluid connection between the suction side and the pressure side over the oil outlet.

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 gear pump could be said to include a first gear and a second gear intermeshed with the first gear. An inlet side is configured to have an inlet connection connected thereto. A discharge side is configured to have a first discharge connection connected thereto. At least one shaft is in operable communication with each of the first and second gears. A bearing is configured to support at least one of the shafts via an inner bore and having an outer peripheral surface. A valve bore is formed into bearing between the inner bore and the outer peripheral surface. A second discharge connection is formed into the bearing. A tap provides fluidic communication between the valve bore and a pad defined in the inner bore. A valve is positioned in the valve bore. The valve includes a moving valve member. A spring biases the moving valve member in a direction toward the second discharge connection. A fuel pump system is also disclosed.

A vane rotary compressor may include a main bearing and a sub bearing provided with a plurality of back pressure pockets each having a different pressure formed on a surface facing the cylinder, a rotational shaft radially supported by the main bearing and the sub bearing, a roller provided with a back pressure chamber that communicates with the plurality of back pressure pockets and having a plurality of vanes configured to divide a compression space into a plurality of compression chambers. At least one of the main bearing or the sub bearing is provided with an oil supply passage that communicates with a back pressure pocket having a relatively low pressure among the plurality of back pressure pockets. Accordingly, oil may be smoothly supplied to a back pressure pocket having a low pressure.

A rotary fluid pressure device, such as a low-speed, high-torque gerotor motor, is provided with a valve drive shaft that is partially inserted into and engaged with a main drive shaft as the main drive shaft engages a rotating output shaft and engages a rotating and orbiting star member of a positive displacement device. The device is also provided with a drive retainer configured to retain the engagement of the main drive shaft and the valve drive shaft.

The invention relates to an oscillating piston pump for liquid and gaseous fluids, comprising: a pump housing having at least two sector-shaped working chambers, which are diametrically opposed relative to a pivot axis arranged in-between; an oscillating piston, having at least two displacement portions which extend diametrically relative to the pivot axis and are each received pivotably in one of the working chambers; an electric drive, which moves the oscillating piston alternately on a pivot movement between two turning points delimited within the working chambers; a group of outlet valves, which ensure the discharge of a volume displaced from the working chambers to a pump outlet; and a group of inlet valves, which ensure the entry of a volume flowing into the working chambers from a pump inlet. The group of outlet valves or inlet valves is arranged on both sides of each working chamber and communicates through the pump housing with the pump outlet or the pump inlet. The other group of inlet valves or outlet valves is arranged in the oscillating piston and communicates via a cavity in the oscillating piston with the pump inlet or the pump outlet.

A gear pump comprising:a pair of gears (2) able to interact with a fluid crossing the pump (1);a housing seating (3) of said pair of gears (2), said housing seating (3) comprising a rest plane (30) of a shim (4);a delivery conduit (6) which develops from said housing seating (3) and comprising an inlet mouth (60). The inlet mouth (60) of the delivery conduit (6) is at a distance from an intersection (7) between a rest plane (30) of the shim (4) and remaining parts of the housing seating (3).

An oil pump is provided with an inner rotor having external teeth, an outer rotor disposed in a loose-fit state within a pump chamber and having internal teeth meshed with the external teeth, a ring-shaped pressure chamber provided adjacent to the pump chamber in a direction of a rotation axis, a discharge opening for connecting the pump chamber and the pressure chamber, and a cylindrical discharge passage having one end connected to the pressure chamber and the other end serving as a connection opening. A portion of the discharge passage is located to open inside of the outer periphery of the pressure chamber when viewed in the rotation axis direction. The one end reaches to a middle of the pressure chamber when viewed in a radial direction of the rotation axis, and the discharge passage and the pressure chamber are in direct communication with each other.

A transfer device that includes a case that houses a transfer mechanism; a strainer that suctions oil stored in a lower portion of the case; a valve body that has a hydraulic supply circuit that supplies a hydraulic pressure to the transfer mechanism and a suction oil path that discharges an extra hydraulic pressure that is extra for the hydraulic supply circuit; a first suction inlet that communicates with one of the suction oil path and the strainer and a second suction inlet that communicates with the other of the suction oil path and the strainer, and a balanced vane pump.

The invention relates to a pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, comprising at least one cylinder (14), a piston (15) which is displaceably arranged in the cylinder (14), and a pressure valve (30) for selectively controlling the supply of fuel to the internal combustion engine, wherein the pressure valve (30) has a closure part (38, 46, 51) provided with a cavity (44, 49, 53) that opens to the outside on an end surface (43, 48, 52) facing the piston (15) of the closure part (38, 46, 51).