Abstract: Two inner gears are overlapped with each other through a partition wall and are eccentrically arranged at an inner peripheral side of an outer gear, and eccentric directions of both the inner gears are shifted from each other by 180° to the opposite side. By this, loads in an outer diameter direction due to a rise in fuel pressure affect one outer gear from the two inner gears oppositely to each other by 180°, so that an eccentric load is not generated, and sliding resistance of the outer gear to a cylindrical casing becomes small. Further, the number of teeth of the outer gear is made odd, and the number of teeth of the inner gears is made even.

Abstract: When a pump operates, a check valve body leaves a check valve seat due to a pump side fuel pressure for opening a fluid passage inside a pressure adjusting valve body. When the pump does not operate, the check valve body contacts the check valve seat due to an engine side fuel pressure for closing the fluid passage. Thus, the engine side fuel is prevented from flowing-back to the pump. When the pump stops operating and the engine side fuel pressure exceeds a pressure corresponding to an urging force of a coil spring, the pressure adjusting valve body leaves the pressure adjusting valve seat with the check valve body, so that a gap is provided between the pressure adjusting valve body and the pressure adjusting valve seat for releasing the engine side fuel having excess pressure.

Abstract: A commutator is composed of a contact unit, a base member made of insulation material and a terminal unit. The contact unit has a flat brush-contact surface and a connection surface opposite the brush contact surface. The contact unit also has a plurality of commutator segments. The terminal unit has a plurality of conductive terminal members. The base member supports the commutator segments. The commutator also has an electrical connection structure having a set of a convex member and a concave member and a plurality of connection members disposed between the convex member and the concave member to connect the plurality of the commutator segments and terminal members respectively.

Abstract: A motor having a lap winding structure and a manufacturing method therefor, wherein inserts of two different coils are installed side by side in one slot of a stator in a circumferential direction of the stator. All the coils are inserted in slots in succession. Further, a stator having semi-closed type slots formed by protuberances oriented in different directions, is used to control a reduction in the magnetic flux at the inlet of a slot and also to prevent coils from coming off. In a motor having coils of a plurality of phases for generating a rotating magnetic field at a stator, the contact portion of the coil of the desired phase among the coils of the plurality of phases and a portion rising from a slot toward the axis of a core are aligned and disposed to have a shape which prevents them from interferring with end portions of the coils of other phases.

Abstract: An electric motor, wherein a space factor of a coil in a stator or a rotor is enhanced, and which has a central part core comprising a plurality of laminated electromagnetic steel plates stamped out into a predetermined slot sectional shape and an end part core which is disposed on at least one end part toward a laminating direction of the central part core and a core shape of the end part core is different from the core shape of the central part core.

Abstract: In a motor for driving a fuel pump, each contact part of a commutator which slidingly contacts brushes is made of a carbon material. The carbon material is a mixture of natural carbon and amorphous carbon so that the contact part has a longer durability. The weight percentage of the amorphous carbon to be mixed is in the range of 5-30, most preferably about 20. The brush may also be made of a mixture of natural carbon and amorphous carbon.

Abstract: A fuel pump comprises a pump unit and a motor unit. The pump unit is a trochoid gear type having rotors in a pump chamber defined by a pair of side plates and a cylindrical housing. A disk plate is attached to the side plate to provide an arcuate-shaped pressure pulsation reducing passage jointly with the side plate. Protrusions or recesses are provided in the passage to cause turbulence in fuel flowing through the passage. This turbulence scatters pressure pulsation in the fuel thereby to reduce the pressure pulsation.

Abstract: When differential pressure between fuel flowing into a fuel control valve and fuel flowing out of the valve reaches a predetermined value, the biasing force of a compressed coil spring is countered and a shaft in the valve moves to the fuel upstream side so that a valve member is seated to terminate communication between the fuel inlet passage and the fuel outlet passage. This maintains fuel pressure at the fuel inlet passage and at the fuel outlet passage at different levels so that the fuel supply system maintains a high fuel pressure in the fuel rail to suppress fuel vapor generation during engine stoppage while also yet still providing an appropriate fuel injection pressure during rapid deceleration of the vehicle.

Abstract: A fuel supply device is composed of a rotary pump, a brush-less motor having a stator and a rotor connected to the rotary pump and a circuit unit for supplying drive current to the brush-less motor. The circuit unit has a plurality of one-chip IC units on which a plurality of switching transistors and a circuit for detecting position of the rotor are integrally formed. The stator has a plurality of phase coils each of which is connected to one of the switching transistors of each of the one-chip IC units to be supplied with divided portion of the drive current from one of the switching transistors. Each of the phase coils is divided to a plurality of parallel coils having the same phase and each of the parallel coils is connected to one of the switching transistors.

Abstract: A fuel pump is composed of a permanent-magnet motor section and a pump section. The yoke of the motor section is designed as a part of the magnetic circuit which is saturated with magnetic flux. The quantity of the discharged fuel is adjusted by covering from outside an auxiliary yoke which is changeable according to a difference between the actual quantity of the discharged fuel and a required quantity of the fuel.

Abstract: An electromagnetic driving system controls an electromagnetic driving device by a simulator. The driving system includes a simulation system. The simulation system includes a preprocessor for generating initial data used in the simulation, an analyzer for executing coupling analysis for magnetic field analysis, circuit analysis and control mode analysis, a postprocessor for displaying the output data of the system on a display, and a library for storing data given to and provided by the system. The simulation system is combined with the electromagnetic driving device to control the electromagnetic driving device.

Abstract: The present invention provides a regenerative pump for supplying fuel into an injection device for an internal combustion engine. The regenerative pump has a longer pressurizing passage and a slanted discharge port connected thereto and formed at an outer periphery thereof. The pressure loss in the pump is small because the fuel flows smoothly into the discharge port from the pressurizing passage, and accordingly the efficiency of the pump is high and the pump can be made small in size at the same time.

Abstract: A liquid pump has a DC motor and a pump in a cylindrical casing. A pair of brushes are slidably contacted with a commutator of an armature while being biased by springs. The specific resistance of the positive brush is lower than the specific resistance of the negative brush to enable the voltage drop at the brushes to be decreased and motor efficiency to be increased without increasing commutator wearing speed. The biasing force provided by the spring biasing the positive brush is lower than the biasing force provided by the spring biasing the negative brush.

Abstract: A fuel supply apparatus includes a flow control valve, a housing, a movable portion, a compression coil spring and a coil constructed integrally with a fuel pump (or separately from the fuel pump). The movable portion may be made of magnetic material and attracted to the fuel downstream side against the spring force of the compression coil spring by an electromagnetic attracting force generated by an electric current supplied to the coil. A fuel drain opening can be created by aligning a first communication passage to release an excess part of the fuel passing through fuel passages back to the fuel tank through the drain passage in accordance with an engine operation condition.

Abstract: In order to reduce noise generated in a westco pump when fluid hits a finishing end of a pump channel, finishing ends of grooves formed in a side wall of a casing body and a casing cover to form a pump channel are shifted by an amount equal to 1/2 of the pitch of blade elements in relation to the rotating direction of an impeller. As a result, the timings the fluid under high pressure hits the finishing ends of the grooves are staggered, thus decreasing the collision sound.

Abstract: A disk-shaped impeller having on its periphery a multiple radial vanes and a multiple radial impeller grooves is rotatably disposed in a pump housing. On each end surfaces of the impeller there are formed a plurality of C-shaped grooves. As the impeller is rotated at a higher speed, the fluid in the C-shaped grooves in the impeller acquires a velocity component in an impeller's axial direction to generate a force sufficient to push a pump cover and a pump casing in the axial direction. Accordingly, since it is avoided for the impeller to adhere either the pump cover or the pump casing, the space between the impeller and the housing inner wall is reduced while the possible leakage of the fluid is reduced.

Abstract: A regenerative pump includes a casing which a recessed fluid flow passage interconnecting a suction port and a discharge port is formed in an arcuate shape. An impeller is provided rotatably with respect to the casing and formed with a plurality of vane members which face the recessed fluid flow passage. A recessed damping portion is formed in a terminal end portion of the recessed fluid flow passage on a discharge port side thereof to begin at a position corresponding to the discharge port and extend along a rotating direction of the impeller. The recessed damping portion has a depth which is smaller than that of a main depth of the recessed fluid flow passage and substantially constant.

Abstract: A regenerative pump according to the present invention includes a rotatable impeller disposed in a housing. The impeller has a plurality of radially extending vane members spaced apart about a periphery of the impeller. Each vane member has circumferentially-facing upstream and downstream surfaces, relative to an operational direction of impeller rotation. At least one of the upstream and downstream surfaces of each vane member has a proximal portion which is inclined or curved away from the operational rotation direction, and a distal portion which is inclined or curved towards the operational rotation direction. The curved/inclined surface advantageously enhances pump efficiency.

Abstract: A Westco type fuel pump includes an impeller (32) which has a plurality of vane grooves (322) and a plurality of vane plates (323) provided alternately along its outer periphery. Each vane groove (322) is constituted by groove portions (322a, 322b) formed in both sides of the impeller (32), respectively, with a partition wall (321) provided between the groove portions (322a, 322b). The partition wall has an outer peripheral surface (3210) located radially inside an outer peripheral surface (3230) of each vane plate (323) and has a predetermined thickness in an axial direction of the impeller. As the impeller (32) rotates, two vortex flows of fuel are generated along bottom surfaces (3221, 3222) of the groove portions (322a, 322b) and then smoothly merge together at a position outside the outer peripheral surface (3210) of the partition wall, thereby reducing a flow dead zone (96) in a pump flow passage (33).

Abstract: There is disclosed a trochoid pump in which a friction between a rotor and its support portion is reduced, thereby reducing a drive torque and wear of these parts. An inner rotor of the trochoid-type fuel pump is rotatably supported by a bushing through a bearing. An outer rotor is rotatably received in an inner periphery of a spacer. A first groove is formed in a portion of the outer periphery of the bushing disposed close to a discharge port, and a discharge fuel is introduced into this groove. A second groove is formed in a portion of the inner periphery of the spacer disposed close to the discharge port, and the discharge fuel is introduced into this groove. Although the inner rotor is urged toward the bushing by the fuel pressure of the discharge port, the urging force to urge the inner rotor toward the bushing is weakened by the discharge fuel introduced into the first groove, thereby reducing a friction.