A gear pump includes: an inner rotor having external teeth; an outer rotor having a tubular inner housing portion in which the inner rotor is rotatably housed in an eccentric state, and internal teeth meshing with the external teeth; a first core having a tubular rotor housing portion in which the inner and outer rotors are housed, and a flange portion projecting radially outward from a tube wall of the rotor housing portion; a board-shaped second core having a contact portion in contact with the flange portion in an axial direction, and closing an opening of the rotor housing portion; and a housing opposing the second core and made of a resin. A gap is formed between opposing surfaces of the second core and the housing in a state where the flange portion is in contact with the contact portion and the housing opposes the second core.

A pump assembly comprising at least one housing and two gear wheels. The housing comprises at least one base plate and a cover element, which are interconnectable to form a pressure chamber. An outer circumferential surface of each of the two gear wheels has a toothing, and the gear wheels intermesh via the toothings to convey a fluid. The gear wheels are arranged along an axial direction in the pressure chamber between the base plate and the cover element. The pressure chamber is formed in the housing at least by two bores. The first gear wheel is arranged in a first bore and the second gear wheel is arranged in a second bore. Centering pins are provided for aligning the bores and the gear wheels with respect to one another, wherein all centering pins are arranged exclusively in the cover element or exclusively in the base plate.

A low pressure gear pump and wear plate is disclosed. The wear plate may comprise a sidewall, a drive portion, a driven portion, and a transition portion. The sidewall is free of a sealing member or a recess configured to receive the sealing member. The drive portion includes a drive inlet lip, a drive outlet lip, a drive recessed trough and a drive bore. The drive bore is configured to receive the drive shaft of the gear pump. The driven portion may that include a driven inlet lip, a driven outlet lip, a driven recessed trough, and a driven bore. The driven bore is configured to receive the driven shaft of the gear pump. The transition portion may include a transition aperture configured to receive a first fastener configured to mount the wear plate to the gear housing. The wear plate is made of bronze, aluminum or non-magnetic material.

A rotary pump includes a housing featuring a delivery space which the housing surrounds and axially delineates on the end sides; an inner rotor rotatable in the delivery space; an outer rotor rotatable about a pump rotational axis in the delivery space and forming delivery cells with the inner rotor; and a circumferential bearing wall which mounts and surrounds the outer rotor rotatably about the pump rotation axis in radial sliding contact. The circumferential bearing wall includes multiple blind pockets which are radially open towards the outer rotor and/or the outer rotor includes multiple blind pockets which are radially open towards the circumferential bearing wall.

An inner gear includes: sliding surface parts that are provided annularly at an outer peripheral part including a plurality of outer teeth on both sides of the inner gear in its axial direction and that slide on a pump housing; recessed parts that are respectively provided radially inward of the sliding surface parts to respectively form fuel chambers, into which fuel flows, between the recessed parts and the pump housing; and a communication hole that communicates between the recessed parts. The inner gear further includes an inclined surface part that is provided at an edge portion of a communicating edge portion on a rotation advance side of the inner gear, to avoid an adjacent part adjacent to an inner peripheral edge portion of each of the sliding surface parts and that is inclined further toward a rear side in a direction to a central part of the communication hole.

The application relates to an internal gear machine for reversing duty having a housing with a chamber, in the chamber there are disposed an externally toothed pinion and an internally toothed ring gear, which mesh with one another, the rotational axes of which run parallel to and spaced apart from one another. The chamber in the housing is axially bounded and is connected via pressure pockets provided in the housing to pressure connections in the internal gear machine. According to the invention, a switching valve is arranged in each connection between the pressure pockets and the pressure connections or compression spaces, which valve opens or closes the connection.

A method of manufacturing pumps of different performances for use in a blood treatment device, preferably a dialysis machine, having a pump housing or a pump housing portion for supportingly holding two gear wheels in meshing engagement. The method includes the step of primary shaping of a universal pump housing blank with all features common to the different pumps as well as with such oversizes as to allow machining for manufacturing all different pumps from the same primary-shaped pump housing blank. The method also includes the step of individualizing the universal pump housing blank by machining in the region of the oversizes to achieve the respective performance.

A suction groove is formed in an inside wall surface of a pump cover and is communicated with a suction passage of the pump cover. The suction groove extends along a rotational path of external teeth of an inner rotor and a rotational path of internal teeth of an outer rotor. An edge of a portion of the pump cover, which forms the suction groove, includes chamfered edge parts, which are chamfered, and unchamfered edge parts, which are not chamfered and are not rounded. Each of the unchamfered edge parts is located in a direct-inflow region of the suction groove, which overlaps with the suction passage in a view taken in a direction of a rotational axis, and each of the chamfered edge parts is located in a corresponding one of peripheral regions, which are other than the direct-inflow region.

A variable displacement oil pump includes: a variable displacement mechanism that is able to change a discharge amount per rotation of an input shaft. The variable displacement mechanism includes a pump housing, an oil pressure chamber provided in the pump housing, and a capacity adjustment member displaced by oil pressure from the oil pressure chamber. The capacity adjustment member is configured to be operated when receiving control oil pressure that is supplied from a control valve to the oil pressure chamber. The pump housing has an oil release hole that is opened to face the oil pressure chamber and that penetrates a wall section of the pump housing to partially release oil.

A screw spindle pump having a spindle housing, in which a drive spindle and at least one running spindle which meshes therewith are received in spindle bores, and having an outer housing which encloses the spindle housing and on which an axial inlet port and a radial outlet port are provided, wherein the spindle housing has an axial fluid outlet for the fluid delivered through the spindle housing by the drive spindle and the running spindle, which axial fluid outlet communicates with a fluid chamber, which is formed between the spindle housing and the outer housing, extends around 360°, and in turn communicates with the radial outlet port.