Rotor and/or stator designs and methods thereof to improve progressive cavity motor or pump durability. In one or more implementations, the rotor may have a variable outer diameter or variable stiffness along an axial length thereof. The stator may similarly have a variable inner diameter or variable stiffness, which may compliment or diverge from the variable outer diameter or variable stiffness of the rotor.

A rotary pump is presented for use in a medicament delivery device, where the pump has a back plate having an inner surface and a rotor housing is positioned adjacent to the back plate having a peripheral wall. A front plate support is connected to the back plate and a flexible front plate is positioned between the front plate support and the rotor housing. The pump is rotated using a planetary gear transmission, where an eccentric shaft is operatively connected to the planetary gear mechanism. A rotor is rotationally fixed to the eccentric shaft and movably positioned within the rotor housing. The rotor has three lobes, where each lobe has two peripheral curved surfaces sharing a common apex, where a first portion of each peripheral surface adjacent to the apex defines a non-smooth curve.

An electric hydraulic pump for a transmission includes: a motor including a motor cover, a motor case coupled with the motor cover, and a stator and a rotor disposed within the motor cover and the motor case; and a pump including a pump case forming a pump chamber, and a gear rotor which is disposed within the pump chamber, connected with the rotor through a motor shaft and receives rotational power of the motor. In particular, a plurality of oil circulation holes are formed in the motor cover and a connecting hole is formed in the motor cover corresponding to the pump case, and an oil flow channel is formed within the pump case for connecting the connecting hole and an oil inlet of the pump chamber.

An oil field pump is installed within a pipe that connects to an oil field, and feeds accumulated extraction oil in a predetermined direction, the oil filed pump including a rotor with an internal flow path for the extraction oil, a stator installed on the outer circumference of the rotor, a thrust bearing that supports the axial weight of the rotor and the stator, a supply pipe that supplies a portion of the extraction oil in the flow path to the thrust bearing, and a filter that is installed at further upstream on the flow path than the supply pipe along the flow direction of the extraction oil, and traps foreign matter.

A device for pumping a viscous fluid includes two positive displacement rotary pumps, a first pump (1) and a second pump (2), wherein each pump has an inlet (3, 4) for fluid at a suction side and an outlet (5, 6) for fluid on a discharge side, wherein the inlet (3) of the first pump (1) is connected to a reservoir of the viscous fluid by a connection (14) pipe or hose, wherein the apparatus further includes an intermediate part or connection (7) having an inlet (8), a first outlet (9) and a flow path (10) for fluid, wherein the outlet (5) of the first pump is connected to the inlet (8) of the intermediate part and the outlet (9) of the intermediate part is connected to the inlet (4) of the second pump, such that during the pumping the viscous fluid is forced from the reservoir through the first pump (1), through the intermediate part (7) and through the second pump (2) to the outlet (6) of the second pump.

A pump for applying fluid, the pump including: a pump housing, including: a fluid inlet on a low-pressure side; an fluid outlet on a high-pressure side; a circumferential wall surrounding the pump delivery chamber; and an end-facing wall featuring an outer end-facing surface facing axially away from the delivery chamber and at which the outlet emerges; a delivery member, moveable in the delivery chamber, for delivering the fluid from the low-pressure side to the high-pressure side; a gasket including a gasket loop which surrounds the outlet to seal it off on the outer end-facing surface of the end-facing wall; a female joining element featuring an axially extending hollow space; and a male joining element protruding through or from the pump housing or the gasket. The male joining element is in a joining engagement, which can be subjected to axial tensile stress, with the female joining element in the hollow space.

A progressing cavity device operates as a motor to impart torque to a bit. A stator of the device defines an internal profile having uphole stages with a first dimension being less than a second dimension of downhole stage. A rotor has an external profile with a constant outer dimension along its length. Disposed in the stator, the rotor defines cavities with the stator and is rotatable with pumped fluid progressing in the cavities from the uphole to downhole to transfer torque to the drive toward the downhole end. Although the rotor is subjected at the downhole end to a reactive torque from the bit, the interference fit of the rotor's constant dimension with the stator's downhole stages is less than with the uphole stages, which can mitigate issues with heat buildup in the downhole stages. The device can also operates as a progressing cavity pump.

A pump housing of an oil pump includes a suction port that supplies oil to a pump room, a discharge port that discharges oil from the pump room, and a seal portion that suppresses leakage of oil from the pump room to outside of the pump room. A shaft of the oil pump includes a small diameter portion and a large diameter portion having different diameters, the small diameter portion is connected to the inner rotor, and the shaft and the inner rotor integrally rotate. The seal portion is in contact with a side surface of the inner rotor extending in a diameter direction of the shaft, and also extends to a region in the diameter direction on an inner side smaller than the large diameter portion in the diameter direction.

A mud motor includes a rotor and a stator. Drilling fluid received by cavities of the mud motor drives the rotor to rotate within the stator. The rotor includes one or more rotor lobes extending helically and defining a rotor pitch. The stator includes two or more stator lobes extending helically and defining a stator pitch. The rotor and the stator together define a tapered profile of the mud motor that varies proceeding from a top end of the mud motor to a bottom end of the mud motor. At least one of the rotor pitch or the stator pitch vary as proceeding from the top end of the mud motor to the bottom end of the mud motor.

The present disclosure provides a motor unit and a motor-control device using the same, wherein the motor includes a motor element, a housing and a bearing. The motor element is contained within the housing, the bearing is fastened on a lower-edge portion of the housing and protrudes therefrom. The motor-control device includes a main body, and the motor unit mounted on the main body.