This internal gear pump accommodates: a ring-shaped internally toothed gear provided with internal teeth, and an externally toothed gear provided with external teeth which internally mesh with the internal teeth of the internally toothed gear, said externally toothed gear being eccentrically disposed inside the internally toothed gear. The number of internal teeth is one greater than the number of external teeth. In any one of the external teeth and the internal teeth, a tooth tip section and a meshing section are formed by a curve having one continuous curvature. The curve is formed by an equation with which the maximum curvature is at the apex of the tooth tip, and the curvature gradually reduces towards the tooth bottom section.

A pump includes: a housing in which a pump chamber accommodating an inner rotor and an outer rotor is formed in a pump chamber formation surface, and an O-ring groove is formed around the pump chamber; an O-ring that is placed in the O-ring groove; and a plate that is attached to the pump chamber formation surface and closely contacts the O-ring to close the pump chamber. Inter-hole grooves connecting to an outer edge of the pump chamber formation surface are formed around the O-ring groove.

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.

A variable displacement oil pump includes an adjustable member that is configured to shift according to changes in pressure inside a control oil chamber. The adjustable member has a long hole. A guide pin is disposed inside the long hole. The guide pin is fixed to either a housing or a cover of the variable displacement oil pump. The width of the long hole is larger at a part of the long hole farther away from a fixed end of the guide pin in its lengthwise direction than at a part thereof closer to the fixed end.

An electrically driven motor includes a motor rotor having a rotor core and a plurality of permanent magnets attached onto an outer circumferential portion of the rotor core. The electrically driven motor also includes a stator having a plurality of slots. In the electrically driven motor, a plurality of projections rotor teeth are disposed at positions of the outer circumferential portion of the rotor core which are spaced apart from each other by a predetermined interval of distance and which include a magnetic pole center of at least one permanent magnet. The plurality of rotor teeth extend all the way to a location of the teeth of the stator.

A gerotor pump having an inner rotor and an outer rotor, which is also the rotor of an electric drive, having a housing and a flange which closes the housing with the motor compartment, the rotor being arranged on a shaft and sealing against the flange at a gap, wherein, in addition to the gap, there is at least one device with which at least a partial pressure compensation takes place between the suction region of the gerotor pump and the motor compartment of the gerotor pump.

An electric oil pump includes a motor including a motor shaft, a pump assembly including a vane pump driven by the motor to suction and discharge oil, and an inverter to drive the motor. The motor includes a rotor, a stator on a side outward from the rotor in a radial direction, and a motor housing containing the rotor and the stator. The motor housing includes a suction port through which the vane pump suctions oil from outside, and a discharge port through which the vane pump discharges oil to outside. The motor housing includes flat surface portions in a portion of an outer periphery thereof. The suction port and the discharge port are located in a first surface of side surfaces which are the flat surface portions of the motor housing and are parallel or substantially parallel to the axial direction.

An internal gear pump (100) comprises: a rotor/torque ring comprising an internally lobed (140) rotor (130) and a torque ring (120) extending beyond at least a first end (134) of the rotor; an externally lobed (160) idler (150) encircled by the rotor; a hollow shaft (190) supporting the idler; a pressure relief element (200) positioned to shift between a first condition and a second condition; and a spring (210) biasing the pressure relief element toward the first condition from the second condition. The torque ring has at least one pressure relief port (240A, 240B) positioned so that: in the first condition, the pressure relief element blocks a path from an interior volume (235) of the pump to the pressure relief port; and in the second condition, relative to the first condition the pressure relief element does not block the path.

A positive displacement pump for pumping oil in a motor vehicle transmission comprises a pump stage that has a central kidney-shaped suction cavity and two kidney-shaped pressure cavities. Oil is selectively pumped via one kidney-shaped pressure cavity or the other kidney-shaped pressure cavity in accordance with the direction of rotation of the pump stage. This makes it possible to create, with little complexity, two operating stages for the positive displacement pump.

In an oil pump, an inner rotor and an outer rotor rotate to discharge the oil through a discharge port. The discharge port has an outer extension portion located on a radially inner side with respect to a root circle of the outer rotor and on a radially outer side of a tip circle of the outer rotor and an inner extension portion located on the radially inner side with respect to the tip circle of the outer rotor and on the radially outer side with respect to a root circle of the inner rotor. An inter-tooth chamber facing a partitioning portion that partitions the suction port from the discharge port comes into communication with the outer extension portion and the inner extension portion. Then, a tip seal portion defining the inter-tooth chamber intersects an outer edge of an opening of the discharge port.