A fluid pumping system comprises a housing, an electric motor, a rotatable first input, a rotatable second input driven by the electric motor, a gerotor including an inner rotor, an outer rotor; and a cam ring in sliding receipt of the outer rotor. The cam ring is selectively rotatable by one of the first input and the second input. The inner rotor is rotatable by the other of the first input and the second input. The housing includes a first fluid inlet passage on a first side of the cam ring and a second fluid inlet passage on an opposite side of the cam ring. Fluid entering a cavity between the inner rotor and the outer rotor flows parallel to the axis of rotation of the first input. The cam ring includes a radially extending outlet port and pumped fluid flows radially out of the cavity.

The invention relates to fluid drive systems used in fluid wells and brake systems for permanent magnet wellhead direct drives. The braking controller connects or disconnects a brake resistor from a back EMF. A variable frequency drive (VFD) drives the motor and communicates with the control circuitry of the brake controller. The control circuitry monitors the brake resistor and depending on the rotational speed and direction of the motor and operating state of the VFD, disconnects or connects the brake resistor. If the direction of the motor is in reverse and above a threshold speed, it connects the brake resistor. If the direction of the motor is in reverse and below the threshold speed, the control circuitry dissipates stored back EMF through the brake controller. The amount of stored back EMF corresponds to the time to empty a pump.

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 motor includes a rotor and a stator, the stator having a stator core and an electrical insulator assembly at each end of the stator core. The electrical insulator assemblies each have an outer wall part extending in a circumferential direction and facing a yoke of the stator core and a plurality of extending parts extending radially inward from the outer wall part and facing teeth of the stator core. The outer wall part has a radial thickness and includes a plurality of radial notches for guiding extensions of the stator winding between an inner peripheral surface and an outer peripheral surface of the outer wall part. The outer peripheral surface of the outer wall part adjacent to the notches is configured such that the radial thickness of the outer wall part gradually decreases toward the notch along a circumferential direction of the yoke.

A liquid pump includes: a casing; a feed pipe bringing liquid from outside the casing to inside the casing; a pump mechanism provided in the casing and including a suction hole for sucking in the liquid and a discharge hole for discharging the liquid sucked in via the suction hole; a suction space positioned in the casing on a suction-hole inlet side and making a flow path formed by the feed pipe and the suction hole communicate with each other; and a discharge space positioned on a discharge-hole outlet side in the casing and communicating with the discharge hole. The suction space includes a gas accumulation area that is positioned above a center of an opening at casing-side end of the feed pipe, when viewed vertically and that accumulates gas brought into the casing through the feed pipe together with the liquid to separate the gas from the liquid.

A liquid pump of the present disclosure includes a container, a shaft, a bearing, a pump mechanism, a storage space, and a liquid supply passage. The shaft is disposed in the container. The bearing supports the shaft. The pump mechanism pumps a liquid by rotation of the shaft. The storage space is defined in the container at a position outside the pump mechanism. The storage space stores the liquid to be taken into the pump mechanism or the liquid to be discharged to outside of the container after being expelled from the pump mechanism. The liquid supply passage is a flow path including an inlet open to the storage space and supplying the liquid stored in the storage space to the bearing.

A stepping motor-driven system includes a stepping motor, an output device, and a belt and pulley system operably coupling the stepping motor with the output device to impart rotation therebetween. The belt and pulley system includes an input pinion engaged with the stepping motor, an output pinion engaged with the output device, and a timing belt. The timing belt is disposed about the input and output pinions, inhibits elongation, and defines a plurality of spaced-apart grooves on an inwardly-facing surface thereof that are wider than the teeth of the pinions and are configured to receive the teeth of the pinions in meshed engagement therewith. As a result, a gap is defined within each groove. The gaps permit backlash of the timing belt in response to changes in a rotational speed input to the belt and pulley system from the stepping motor, thereby inhibiting loss of control.

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 motor-pump system includes a first housing part, a hydraulic pump, an electric motor, and a sensor board. The hydraulic pump includes an outer gerotor rotationally supported on the first housing part and an inner gerotor rotationally supported on the first housing part. The electric motor includes a stator assembly rotationally fixed in the first housing part and a rotor assembly with a non-ferrous sensor target, fixed to the outer gerotor. The sensor board includes a plurality of sensor traces for inductively sensing a signal from the non-ferrous sensor target when the outer gerotor is rotated.

A fluid delivery system includes a reservoir for storing fluid, a rotary pump having a first pump port and a second pump port, a first fluid conduit connecting the first pump port to the reservoir, and a second fluid conduit connecting the second pump port to the reservoir. The rotary pump rotates in a first delivery direction in a normal mode and in a second delivery direction in an alternative mode. A first valve separates the first pump port from the reservoir when the rotary pump is in its alternative mode, and a second valve separates the second pump port from the reservoir when the rotary pump is in its normal mode.