A pump housing (4) for an eccentric screw pump, comprising a housing casing (5) extending along a housing longitudinal axis (L), a first end-face opening (6), to which a shaft seal (7) for a connection shaft (8) can be connected, and a second end-face opening (10), to which a stator (I) can be connected, and comprising a tubular inlet nozzle (11), oriented transversely to the housing longitudinal axis (L), for feeding a medium that is to be conveyed, which inlet nozzle is connected to the housing casing (5) tangentially, offset in relation to the housing longitudinal axis (L). The geometry of the inlet nozzle (11) is designed in such a way that, as the medium flows into the housing interior through the inlet nozzle (II), a flow (S) is generated which has a radial direction component (RI) directed away outwardly from the housing longitudinal axis (L) and/or an axial direction component (R2) directed towards the first end-face opening (6).

A rotary compressor includes a cylinder with a vane slot and a suction port. A vane is slidably disposed in the vane slot. The suction port guides fluid to a compression chamber at one circumferential end of the vane slot. The suction port may be formed in a recessed manner in a radial direction such that at least an end of the suction port in contact with an inner circumferential surface of the cylinder forms a slot shape extending between opposite axial side surfaces of the cylinder. A circumferential length of the suction port is reduced from conventional suction ports as a result of the slot configuration, thereby advancing the compression start angle, and a partition wall portion between the suction port and the vane slot may have elasticity, thereby suppressing close contact between the vane and the vane slot.

A crankshaft assembly, a compressor and a refrigeration device are provided. The crankshaft assembly has an eccentric shaft component, a spindle component and a main screw oil pump. The eccentric shaft component has an eccentric cavity, and the spindle component has a first cavity communicated with the eccentric cavity. A first through-hole and a second through-hole in a first spindle are each communicated with the first cavity. An outer surface of the first spindle is provided with a first spiral oil groove connecting the first through-hole and the second through-hole. An outer surface of the main screw oil pump is provided with a second spiral oil groove along its length direction, and a spiral direction of the second spiral oil groove is opposite that of the first spiral oil groove.

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.

A variable displacement oil pump includes: a pump constituting section; a movable member; an urging mechanism; a control hydraulic chamber group; a drain mechanism arranged to discharge the oil from a specific one control hydraulic chamber of the control hydraulic chamber group; and a control valve which into which the oil of an upstream side that is discharged from the discharge portion, or the oil from the control hydraulic chamber is introduced as a control hydraulic pressure, which is arranged to supply the oil of the upstream side that is discharged from the discharge portion to the specific one control hydraulic chamber, or to discharge the oil from the specific one control hydraulic chamber by the drain mechanism to regulate the pressure of the specific one control hydraulic chamber.

A pump, including: inner gerotor; a crankshaft; an outer gerotor; an inlet assembly with inlet ports; an outlet assembly with outlet ports; and magnetic actuators. The inner gerotor includes lobes and a central opening. The crankshaft: passes through the central opening; is rotatable about an axis of rotation; and includes a first longitudinal axis not co-linear with the axis of rotation. The outer gerotor includes recesses. The magnetic actuators are sequentially energized to create magnetic fields to displace the inner gerotor with respect to the crankshaft to: displace a first lobe out of a first recess and draw fluid through an inlet port into the first recess; and displace a second lobe into a second recess and expel second fluid out of the second recess and through an outlet port.

A rotor unit for an eccentric screw pump, comprising a drive shaft which is drivable by means of a drive element of the eccentric screw pump, a helical rotor, and a flex shaft connecting the drive shaft to the rotor, wherein the flex shaft is at least in part accommodated within in the drive shaft, and wherein between the flex shaft and the drive shaft a gap extending around the flex shaft is provided, which allows for a radial movement of the flex shaft within the drive shaft.

A rotary fluid transmission device contains: a rotor, a drive shaft, a first holder, and a second holder. The first holder includes a circular bush and an annular chamber. The rotor includes a C-shaped piston which has an external face and an internal face. In addition, the annular chamber has a first reservoir defined between the internal face and the circular bush, and the annular chamber has a second reservoir defined between the external face and the inner fringe. The circular seat includes two clamp arms, and a respective clamp arm is rotatably engaged with a blade. The blade includes two abutting faces, and the C-shaped piston has two edge faces. The first holder includes two first conduits and two second conduits, the two first conduits are in communication with the first reservoir, and the two second conduits are in communication with the second reservoir.

A reversible gerotor pump system is provided. The gerotor pump system includes a cylindrical housing with a 180 slot, an eccentric ring with a locking pin fixed thereto and movably engaged in the slot; an outer rotor and inner rotor with meshed teeth, and shaft for driving inner rotor and system. The eccentric ring has a convex profile on the outer diameter. A positive contact system, which can be a spring-and-plunger system or frictional disc brake system is provided to increase frictional force between the eccentric ring and the outer rotor. The locking pin moves in the slot with clearance at both rotation directions to provide a self-damping effect. The suction port has prolongations at both upstream and the downstream sides to increase filling time such that the pump can have a fill speed of above 5000 rpm, and the volumetric efficiency is at least 90% at 5000 rpm.

Some embodiments are directed to a positive displacement pump comprising: a pipe having a first end secured to a transmission area and a second end ending in a cylinder secured to a discharge area, the pipe comprising a suction opening and the discharge area comprising a discharge opening, a drive shaft with one end situated at the cylinder, a piston pressed against the cylinder by elastic means so as to prevent fluid from moving between the pipe and the discharge area, in which the pump further comprises means for moving the piston elastically away from the cylinder and keeping it at a predetermined distance from same. Some other embodiments are directed to a method for cleaning this pump.