An inner gear includes an insertion hole, which extends through the inner gear in an axial direction, and a first balance groove, which is axially recessed at an axial end portion of the inner gear and is communicated with the insertion hole. First and second chamfered portions are formed in an inner peripheral edge of the inner gear, which is adjacent to the insertion hole. A joint member has a leg inserted into the insertion hole. An inserting direction of the leg into the insertion hole is defined as a first direction, and a direction, which is opposite from the first direction, is defined as a second direction. In a view taken in a direction perpendicular to the axial direction, at least a part of a first direction side end portion of the leg is axially placed between a first chamfered end plane and a first groove end plane.

A screw spindle pump having a spindle housing in which a drive spindle and at least one running spindle meshing therewith are received in spindle bores, and an external housing which accommodates the spindle housing, an axial inlet connection and a radial outlet connection being provided on the external housing. The spindle housing has an axial fluid outlet for the fluid conveyed via the drive spindle and the running spindle through the spindle housing, as well as a drive motor having a drive shaft which runs through a bore in a housing wall, which axially closes the interior of the external housing, io and which is coupled to the drive spindle. A part of the fluid flowing out of the fluid outlet of the spindle housing flows through the seal-free bore along the drive shaft into the drive motor, cools this drive motor and flows back into the external housing.

A screw spindle pump, including a spindle housing, in which a drive spindle and a running spindle meshing therewith are received in spindle bores. The drive spindle has a cylindrical spindle core and at least two circumferential spindle profiles, and, on an end face, in a depression axially delimited by a planar bottom surface and in which the two profile valleys open out between the two spindle profiles offset by 180°, there is a disk-shaped coupling element, which has an insertion receptacle for a drive shaft of a drive motor and which is coupled to the drive spindle for conjoint rotation therewith via a form-fitting engagement with axially protruding projections that laterally delimit the depression and engage in lateral receptacles of the coupling element. The bottom surface is delimited by the spindle core in the region of the openings of the two profile valleys, and the coupling element has a rounded configuration, corresponding to the shape of the spindle core, in the element regions that adjoin the regions of the opening. The diameter of the coupling element, in the region of the rounded element regions, is no greater than the diameter of the spindle core.

A balance shaft module includes a balance shaft for receiving a driving force from a crankshaft of an engine by a driving gear and rotating inside a balance shaft housing, an oil pump gear being geared with the driving gear to rotate along with the driving gear, an oil pump shaft having the oil pump gear press-fitted therein and rotating as the oil pump gear rotates, and an oil pump assembly mounted in the oil pump shaft and pumping oil as the oil pump shaft rotates, wherein a pair of support rings is provided at both side surfaces of the oil pump gear to support both side portions of the oil pump gear in the oil pump shaft.

A method for fixing rotary pistons in a rotary piston pump and a method for dismantling rotary pistons of a rotary piston pump, where the rotary piston pump has two counter-rotating rotary arranged in a pump space on drive shafts. The rotary pistons each include a seating for the drive shafts. The respective drive shaft is arranged and fixed with an end region in the seating of the respective rotary piston. A diameter of the drive shafts in the end region can be widened elastically. In an operational state, in which the rotary pistons are arranged on the respective drive shafts, a frictional connection is formed between the respective seating of the rotary piston and the end region of the respective drive shaft.

This disclosure concerns an advanced nutating positive displacement device having a high power to mass ratio and low production cost. This device in one example forms an exemplary pump as will be discussed in detail. The examples disclosed herein are of the rotary positive displacement type, but in a class by themselves. The devices are formed by a nutating rotor having a face comprising lobes and valleys, and a fixed stator also having a face with lobes and valleys. The face of the rotor opposes and cooperates with the face of the stator. The opposing faces define chambers that change volume with rotation of the rotor.

A fuel system includes a fuel gathering system in fluid communication with a fuel storage container, and a fluid pump assembly in fluid communication with the fuel gathering system. The fluid pump assembly includes a main gear pump stage and a first flow attenuator. A main driven gear is meshed with a main drive gear in a main pump conduit, and a main pump bearing assembly rotatably supports the main drive gear and the main driven gear. The first flow attenuator is disposed around the main pump conduit, and includes a substantially polygonal fluid opening. Edges of the opening are substantially aligned with an undercut bearing portion on at least one of an inlet side and an outlet side of the main pump conduit to define a non-round fluid boundary.

A high-pressure fuel pump includes a drive shaft, and a vane pump and a plunger pump which are driven by the drive shaft. The vane pump is configured to supply pre-pressurized fuel to the plunger pump. The drive shaft includes a cam configured to drive a piston rod of the plunger pump such that the plunger pump alternately executes a fuel suction stroke and a fuel discharge stroke. The drive shaft further includes a shaft portion for driving a rotor of the vane pump. The vane pump is configured such that for each fuel suction stroke of the plunger pump the vane pump provides a fuel supply cycle that is advanced by a phase angle relative to the fuel suction stroke.

A disposable metering pump is made of plastic for products having solid fractions. The disposable metering pump has two rotors (10) which are coupled to each other by means of gears (11), can be driven in opposite directions, and are supported in a pump housing (5). Each rotor (10) has a rotor shaft, the rotor shaft ends (15) of which are supported in the walls of the pump housing (5). Each rotor (10) has two rotor blade walls (13), which are arranged diametrically opposite on the rotor shaft. One partially cylindrical rotor blade shoe (14) is formed at each of the peripheral ends of the rotor blade walls. The rotor blade shoes (14) lie against the cylindrical inner wall regions of the pump housing (5) in a sliding and sealing manner.

A conical screw compressor or pump comprises an inner element configured to rotate around a first axis and an outer element configured to rotate around a second axis. An outer surface of the inner element and an inner surface of the outer element comprise cooperating grooves and teeth that intermesh on rotation. The first axis and the second axis are each stationary and the first axis is inclined relative to the second axis. The inner element and the outer element are configured to be, in operation, synchronously rotated, thereby to reduce or eliminate force exerted by the inner element on the outer element or vice versa.