This pump comprises: a housing; a stator which is disposed in the housing and comprises a coil; and pump gears disposed so as to correspond to the stator, wherein the pump gears comprise an outer gear and an inner gear, which is disposed inside the outer gear, and the outer gear is formed of magnetic material.

Systems and methods are provided for pumps that deliver optimized torque characteristics and volumetric efficiency. A system includes a housing defining a surface and a rotor defining a face. A face clearance is defined between the face and the surface. The face clearance is variable in magnitude and determinative of target performance characteristics of the pump system. The housing is made of a material selected to have a thermal expansion characteristic and the rotor is made of a second material selected to have another thermal expansion characteristic. The thermal expansion characteristics deliver the target performance characteristics of the pump system.

Systems and methods are provided for pumps that deliver optimized torque characteristics and volumetric efficiency. A system includes a housing defining a surface and a rotor defining a face. A face clearance is defined between the face and the surface. The face clearance is variable in magnitude and determinative of target performance characteristics of the pump system. The housing is made of a material selected to have a thermal expansion characteristic and the rotor is made of a second material selected to have another thermal expansion characteristic. The thermal expansion characteristics deliver the target performance characteristics of the pump system.

A pump-motor unit includes: a housing structure; an impeller for delivering a fluid; an electric drive motor accommodated in the motor space and including a rotor coupled to the impeller in order to rotationally drive it and a stator with a stator centring structure. The housing structure includes a pump space portion, a motor space portion, a housing centring portion axially between the pump space portion and the motor space portion, and a motor space opening on an end-facing side, through which the rotor and the stator can be axially inserted into the motor space. The housing centring portion encloses the stator centring structure in order to centre the stator.

A rotary pump includes a housing featuring a delivery space which the housing surrounds and axially delineates on the end sides; an inner rotor rotatable in the delivery space; an outer rotor rotatable about a pump rotational axis in the delivery space and forming delivery cells with the inner rotor; and a circumferential bearing wall which mounts and surrounds the outer rotor rotatably about the pump rotation axis in radial sliding contact. The circumferential bearing wall includes multiple blind pockets which are radially open towards the outer rotor and/or the outer rotor includes multiple blind pockets which are radially open towards the circumferential bearing wall.

A pump is provided. The pump includes a fluid inlet section; a fluid outlet section; a stator axially between the fluid inlet section and the fluid outlet section; a rotor axially between the fluid inlet section and the fluid outlet section, the rotor and the stator defining a fluid flow space radially therebetween; a movable inlet guide configured for guiding fluid flow from the fluid inlet section into the fluid flow space; and a movable outlet guide configured for guiding fluid flow from the fluid flow space into the fluid outlet section. The rotor is rotatable inside of the stator by electromagnetic forces urging the rotor towards the stator. Rotation of the stator and movement of the inlet guide and the outlet guide create a pressure in a first portion of the fluid flow space that forces fluid from the fluid flow space through the fluid outlet section and create a vacuum in a second portion of the fluid flow space that pulls fluid from the fluid inlet section into the fluid flow space. A method of forming a pump is also provided.

A hydraulic geroller (gerotor) motor, wherein an inner rotor of a revolving group has a plurality of lobes circumferentially spaced along an outer periphery of the inner rotor, and an orbiter of the revolving group includes an orbiting ring and rounded vane portions preferably formed by roller vanes contained in inner recesses of the orbiting ring for common orbiting with the orbiting ring about the fixed longitudinal axis. The orbiter also has fixed for orbiting therewith, fluid windows for directing fluid from the fluid ports to the revolving group. The windows may be formed in an integral portion of the orbiter or in a valve plate mounted for common orbiting with the orbiting orbiter. The valve plate cooperates with a stationary commutator plate or assembly to provide an efficient arrangement for the delivery and exhaust of hydraulic pressure fluid to and from the hydraulic motor.

An air ejection port for ejecting air-mixed oil is structured with a first air ejection port provided on the inner peripheral side from an inscribed circle of an outer rotor and a second air ejection port provided on the outer peripheral side from a circumscribed circle of the inner rotor, the air ejection port can have an enlarged port area as the total of area of the first air ejection port and area of the second air ejection port in a state without being in communication with either of a suction port and a discharge port, and a disadvantage that a pump chamber of a previous stroke and a pump chamber of a subsequent stroke communicate with each other through the air ejection port can be avoided.

A lubricating oil supply apparatus may include a rotational portion that rotates together with a rotational shaft and a fixed portion that maintains a fixed location thereof and supplies oil through a space that circles with respect to a rotational center of the rotational portion, thereby supplying oil regardless of a rotational direction of the rotational shaft.

An internal gear pump includes a housing having a pump chamber in which an inner rotor and an outer rotor are arranged. A suction port in communication with a suction path and a discharge port in communication with a discharge path are formed at the housing. The pump chamber includes an inner wall having a suction region at a suction port-side and a discharge region at a discharge port-side. The suction region includes a first suction region extending towards the suction path from a pressing point, where the outer rotor is pressed when the internal gear pump is in operation, and a second suction region between the first suction region and the discharge region. A groove that enlarges a clearance between the outer rotor and the inner wall is formed in the first suction region, but the groove is not formed in the second suction region.