One example of a gerotor pump includes an inner rotor comprising multiple teeth, the inner rotor configured to rotate about a first longitudinal gerotor pump axis. The gerotor pump also includes a hollow outer rotor including an outer surface and an inner surface having substantially identical contours, the inner surface configured to engage with the multiple teeth and to rotate about a second longitudinal gerotor pump axis. The pump includes a pump housing within which the inner rotor and the outer rotor are disposed, wherein the outer surface of the outer rotor defines gaps between the pump housing and the outer rotor.

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 submersible fluid system for operating submersed in a body of water includes an electric machine and a fluid-end. The fluid-end includes a fluid-end housing having an inlet to a fluid rotor, the fluid rotor coupled to the electric machine and carried to rotate in the housing by a bearing in the housing. A fluid separator system receives a multiphase fluid and communicates a flow of the fluid to the inlet and a substantially liquid flow extracted from the multiphase fluid to the bearing.

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 hydraulic system includes a hydraulic gear pump with a first gear having a plurality of first gear teeth and a second gear having a plurality of second gear teeth. The hydraulic system also includes a control valve and a control circuit. The control circuit controls the pump to adjust at least one of a flow in the hydraulic system to a flow set point or a pressure in the hydraulic system to a pressure set point, and concurrently establishes an opening of the control valve to adjust at least one of the flow to the flow set point or the pressure to the pressure set point. The control circuit establishes a position of a first tooth relative to a position of a second tooth to seal a fluid path from the outlet of the hydraulic gear pump to the inlet of the hydraulic gear pump.

A gerotor pump includes an inner rotor comprising multiple teeth, the inner rotor configured to rotate about a first longitudinal gerotor pump axis. The gerotor pump also includes a hollow outer rotor including an outer surface and an inner surface having substantially identical contours, the inner surface configured to engage with the multiple teeth and to rotate about a second longitudinal gerotor pump axis. The pump includes a pump housing within which the inner rotor and the outer rotor are disposed, wherein the outer surface of the outer rotor defines gaps between the pump housing and the outer rotor.

A rotatory compressor and a refrigerating cycle device are provided. The rotatory compressor includes a lubricating oil in an interior of a hermetically sealed housing, and an electric motor and a rotatory compressing mechanism disposed in the housing. An internal pressure of the housing is substantially equal to a suction pressure of the compressing mechanism. The compressing mechanism includes a first bearing and a second bearing at least one of which includes an exhaust muffler. A refrigerant of the exhaust muffler flows through the sliding vane chamber and is discharged from an exhaust pipe of the compressing mechanism.

A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid-driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid-driven system to a flow set point and a pressure in the fluid-driven actuator system to a pressure set point and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.

A pump arrangement is disclosed including a magnetically drivable micropump for pumping a liquid pumping medium, a bearing carrier as a base part, and an outer magnet and an inner magnet which transmit a torque to the micropump via an axial shaft. Three radial bearing pieces for the rotational mounting (guidance) of the shaft and of the micropump are positioned and fixed in the bearing carrier. The micropump is held in an eccentric bearing by a cover arranged at an end. A duct structure for a forced flow is provided including at least one radial duct portion in the cover and an axial duct portion in the bearing carrier to flush and/or to lubricate the bearings actively with the pumping medium. One of the bearings is arranged closer to the inner magnet and/or another of the bearings is arranged closer to the micropump.

A pump housing receives an outer rotor and an inner rotor. A joint member couples between a rotatable shaft and the inner rotor to transmit a rotational torque from the rotatable shaft to the inner rotor. A radial bearing is shaped into a cylindrical tubular form. A cylindrical inner peripheral surface of the radial bearing rotatably and slidably supports the rotatable shaft. A cylindrical outer peripheral surface of the radial bearing rotatably and slidably supports an inner peripheral surface of the inner rotor. A lubrication groove is formed in the cylindrical outer peripheral surface of the radial bearing and accumulates fluid, which is present in an inside of the pump housing.