An apparatus for reducing noise of a gear pump through uneven pitch-simulated control includes a calculation unit to calculate different control current values for each tooth of a teeth order by applying a teeth number, the teeth order, and a teeth angle of the gear pump in which a plurality of teeth are evenly formed, a storage unit to map and store the teeth order and the different control current values corresponding to the teeth order for each tooth, and a current controller to variably generate the control current value mapped corresponding to the teeth order when each tooth reaches a reference position when the gear pump rotates by a motor, wherein the control current value is added to a reference current value of a motor control signal and applied to the motor.

An electric oil pump includes: a pump unit 2, rotating to make oil flow; a motor 3 driving the pump unit; a control unit 4 exerting driving control on the motor; and a housing 1 accommodating the pump unit, the motor, and the motor control unit. In the electric oil pump, the motor control unit 4 directly receives detection information of a temperature sensor 5 detecting a temperature of the oil and exerts driving control on the motor based on the detection information.

An internal gear pump includes a pinion, a ring arranged around the pinion, and a cylindrical wall arranged around the ring. A support element, on which the pinion and the ring are supported, carries high-pressure liquid towards a recess located at the junction between the ring and the cylindrical wall, and also carries low-pressure liquid towards another recess located at another point of the junction between the ring and the cylindrical wall. The recess allows the load of the ring on the cylindrical wall to be reduced.

A suction side end part of a suction guide passage and a discharge side end part of a discharge guide passage are opposed to each other with a gap therebetween. At a deviation angle at which contraction of a pump chamber starts, an outer peripheral part of the discharge side end part is formed along an inner tooth, and an inner peripheral part of the discharge side end part is formed along an outer tooth. A working tool that rotates and cuts circularly is moved around on a pump housing in a single continuous line to form an outline of the discharge guide passage, thereby forming the discharge guide passage. The working tool is moved around on the pump housing in a single continuous line to form an outline of the suction guide passage, thereby forming the suction guide passage.

An outer gear and an inner gear expand and contract volume of pump chambers formed between both the gears, and rotate to suction fuel into the pump chambers and then discharge fuel from the pump chambers sequentially. The inner gear includes an insertion hole that is depressed along its axial direction. A joint member includes a main body portion that is fitted to a rotary shaft, a foot portion that extends from the main body portion along the axial direction and is inserted in the insertion hole with a clearance therebetween, and a protruding portion that protrudes from the foot portion toward a rotation progress side of the inner gear and has its width in the axial direction further narrowed toward a top portion of the protruding portion.

This pump comprises: a housing comprising a body and a first partition which separates first and second areas; a stator disposed in the housing; a circuit board disposed in the first area; a pump gear disposed in the second area; and magnets disposed on the pump gear, wherein the second area includes a second space defined by the first partition wall and the body, and the stator is inserted into the body.

A toothing for a gerotor pump comprises a plurality of outer teeth (10) at a gerotor inner element (1) and a plurality of inner teeth (20) greater by one at a gerotor outer element (2), wherein a centre (M1) of the gerotor inner element (1) is offset from a centre (M2) of the gerotor outer element (2) by an eccentricity (e), the outer teeth (10) thereby meshing with the inner teeth (20). A contour of the outer teeth (10) at the gerotor inner element (1) is essentially defined by a curve of a single ellipse from a tooth tip (11) continuously via tooth flanks (13) to a transition radius (14) towards a tooth space or a tooth root (12); wherein the principal axis of the ellipse is arranged radially to the gerotor inner element (1) and the centre of the ellipse determines a radius (R.sub.min) at the gerotor inner element (1) which corresponds to the maximum meshing depth of the gerotor outer element (2) between the outer teeth (10) at the meshing.

Reversible gerotor pump system comprising a cylindrical housing with a 180° slot, an eccentric ring with a locking pin fixed thereto and movably engaged in the slot; an outer rotor and inner rotor with meshed teeth, and shaft for driving inner rotor and system. The eccentric ring has convex profile on the outer diameter. A positive contact system, which can be a spring-and-plunger system or frictional disc brake system is provided to increases frictional force between the eccentric ring and the outer rotor. The locking pin moves in the slot with clearance at both rotation directions to provide a self-damping effect. The suction port has prolongations at both upstream and the downstream sides to increase filling time such that the pump can have a fill speed of above 5000 rpm, and the volumetric efficiency is at least 90% at 5000 rpm.

A hydraulic device having: a plurality of main piston-cylinder arrangements, each of the respective pistons having a fixed stroke length and configured for axial reciprocation within their respective cylinder; a plurality of flow control valves for switching between a lockdown state and an unlocked state of one or more of the plurality of main piston cylinder arrangements during operation of the hydraulic device; and one or more control valves for directing the plurality of flow control valves between their respective unlock and lock positions.

A hydraulic device having: a plurality of main piston-cylinder arrangements, each of the respective pistons having a fixed stroke length and configured for axial reciprocation within their respective cylinder; a plurality of flow control valves for switching between a lockdown state and an unlocked state of one or more of the plurality of main piston cylinder arrangements during operation of the hydraulic device; and one or more control valves for directing the plurality of flow control valves between their respective unlock and lock positions.