A compressor includes: a driving unit including a stator, a rotor, and a rotary shaft provided in the rotor, having an oil guide path formed at an inner side in a radius direction; a compression unit coupled to the rotary shaft, having a cylinder and a piston reciprocating in the cylinder by a driving force of the driving unit; and an oil supply unit coupled to a lower end of the rotary shaft, supplying oil toward the compression unit. The oil supply unit includes a rotary portion for supplying oil toward the oil guide path while being rotated together with the rotary shaft and a fixed portion having an inner space partitioned to accommodate at least a portion of the rotary portion, and the oil guide path is formed to pass through the rotary shaft along a length direction.

A flexible impeller pump designed for use in dispensing a flowable food product is disclosed. The flexible impeller pump includes a cover, impeller assembly and a pump body that are assembled to create the pump without other separate components. The components can be permanently connected to each other to create a disposable pump or can be disassembled for cleaning and reuse. The impeller assembly includes an impeller shaft and a flexible impeller molded over the impeller shaft to prevent separation. The impeller assembly is received within the pump body and the cover is secured to the pump body. The cover includes a seal that is molded over the pump body to prevent separation of the seal from the cover. The impeller shaft extends through the pump body and is coupled to a drive shaft of an electric motor that is operable to drive the impeller pump.

An eccentric screw pump, comprising a rotor that extends along a longitudinal axis of the rotor from a drive end to a free end, a stator housing with an internal cavity that extends along the longitudinal axis from a stator inlet opening to a stator outlet opening and that is designed to accommodate the rotor, a drive motor with a drive shaft that is coupled with the rotor to transmit a torque, a first cardan joint which is placed within the transmission of the torque between the drive shaft and the rotor, and a stator outlet flange that is arranged in flow direction behind the rotor. The stator outlet flange comprises a flange connection plane that is oriented non-vertically to the longitudinal axis.

A progressive cavity pump includes a sealed drive between the rotor and universal joint. The universal joint includes a socket configured to receive a drive shaft of the rotor. A cover, such as a locking nut, is disposed over the connection between the rotor and universal joint. Seals are retained in place by the locking nut to prevent abrasive materials from entering into the interface between the rotor and the universal joint.

A structure of rotor connection of multi-axial multi-stage roots pump comprises a rotor body, a rotor shaft is arranged on one end face of the rotor body, a sub-shaft cavity is opened in the rotor shaft, and the locating keyways are symmetrically opened on both sides inside the sub-shaft cavity; a sub-shaft is arranged on the other end face of the rotor body, the sub-shafts and the sub-shaft cavities of two adjacent rotor bodies are matched, locating keyways are symmetrically opened on both sides of the sub-shaft, and the keyways are installed and fixed through sub-rotor shaft keys in the locating keyways. The invention overcomes the disadvantages of the prior art, and the first-stage rotor body is limited and fixed by the bearing, while the second-stage rotor body is only radially limited by the bearing in the first-stage rotor body. The rotor shaft on the other side is also fixed and limited by the bearing, so the thermal expansion displacement and thermal stress of the second-stage rotor body are completely independent during operation. The thermal expansion displacement of the first-stage rotor body does not affect the second-stage rotor body, and it can also synchronously drive the second-stage rotor body.

A gear pump that is used to pump fluid, such as oil, in a vehicle. The gear pump comprises a gear assembly having a drive shaft including a drive shaft key; a set of drive gears mounted on the drive shaft, with a drive gear of the set of drive gears being keyed with the drive shaft key; a driven shaft including a driven shaft key; a set of driven gears mounted on the driven shaft, with a driven gear of the driven gear set being keyed with the driven shaft key; and a torque drive feature associated with the drive shaft or the driven shaft, wherein the torque drive feature is configured to check keying with the driven shaft key.

A flexible impeller pump designed for use in dispensing a flowable food products. The flexible impeller pump includes a cover, impeller assembly and a pump body that are assembled to create the pump without other separate components. The components can be permanently connected to each other to create a disposable pump or can be disassembled for cleaning and reuse. The impeller assembly includes an impeller shaft and a flexible impeller molded over the impeller shaft to prevent separation. The impeller assembly is received within the pump body and the cover is secured to the pump body. The cover includes a seal that is molded over the pump body to prevent separation of the seal from the cover. The impeller shaft extends through the pump body and is coupled to a drive shaft of an electric motor that is operable to drive the impeller pump.

A gerotor pump assembly, and a system and method for operating a gerotor pump assembly, result in a lubrication strategy for operating in a loss-of-prime mode. An inner drive gear may be rotated in a first direction and in a second opposite direction about an axis of rotation. The inner drive gear has a number of projections extending outwardly therefrom. An outer driven gear surrounds the inner drive gear and defines a number of recessions along an inner surface configured to engage with the projections of the inner drive gear. The outer driven gear and the inner drive gear further define at least one dynamically-changing fluid cavity therebetween. The inner drive gear and the outer driven gear define an oil transfer volume clearance between a projection and a recession in a fully engaged position. Oil is maintained within the oil transfer volume clearance as the inner drive gear is rotated.

A water pump for a marine engine includes a drive flange for rotating a drive shaft, a housing having an internal cavity and a removable cap assembly. The removable cap assembly includes a cap lock ring secured to the housing, a cartridge extending into the internal cavity of the housing and an impeller rotatable inside the cartridge. The cap lock ring and cartridge are snap-fit together. The rotatable drive shaft has splines, which mate with a splined portion of an impeller to rotate the impeller. To replace the impeller, an operator twists the cap lock ring off the housing without any tools and pulls the cap assembly away from the housing disengaging the impeller from the drive shaft. A new cap assembly replaces the worn cap assembly.

A coupling element for connecting a helix-shaped eccentric screw pump rotor to a drive shaft, with a drive shaft receiving portion and a rotor connecting portion arranged at an opposite end of the coupling element from the drive shaft receiving portion, the rotor connecting portion is constituted as a hollow cylinder for receiving a rotor end of the screw pump rotor, wherein the hollow cylinder has at least two inner circumferential surfaces which are complementary to the rotor and have a radius which is fixed with respect to the cross-sectional center of the hollow cylinder.