Abstract:
In an on-vehicle alternator, both the magnetic flux variation frequency and maximum flux density are decreased sufficiently to thereby decrease the internal iron loss and thereby realize an increase in the current generation efficiency. The on-vehicle alternator comprises a rotor wherein magnetic pole cores that are polarized by a rotor coil to alternately different polarities are circumferentially disposed on the outer periphery thereof at prescribed equi-angular intervals. A permanent magnet which is embedded within a resin-made retainer body is provided between the magnetic pole cores and has side faces, as viewed circumferentially, which are polarized respectively to the same polarities as those of adjacent respective magnetic pole cores to thereby vary the magnetic flux quantity directed toward stator coils so as to exhibit a circumferential gentle curve. A rectifier is constructed using SiC-MOS transistors so that it is conductive and operative to thereby charge a battery with the current developed in the stator coils only when the alternating current voltages generated in the stator coils have become higher than the battery voltage.
Abstract:
A labyrinth formed between a pulley and a housing of a rotary machine such as an alternator is arranged to have a plurality of differently-shaped air gaps. When the size of a first air gap between a belt guide of the pulley is .delta.1, the size of a second air gap formed between a cylindrical base portion of the pulley and a bearing box of the housing is .delta.2, a third air gap formed between a front wall and a flange portion of the bearing box is .delta.3 and a fourth air gap formed between a boss portion and a bearing seal member is .delta.4, the air gap is arranged to satisfy the following inequality: .delta.1 .delta.3, .delta.3>.delta.4.
Abstract:
To directly mount a generator to an engine block without causing overheating of the generator or a rectifier, a voltage regulator incorporates a rectifier which employs monocrystalline silicon carbide (SIC) MOS power transistors as semiconductor rectifying devices. This voltage regulator is fixed to housings of a generator, and the housings of the generator are directly mounted to an engine block. In this construction, it is possible to prevent overheating of the rectifier in the voltage regulator as well as of armature windings and a field coil of the generator regardless of an increase in the amount of heat transferred to the generator due to direct mounting.
Abstract:
Cooling wind is introduced into an electric-parts-chamber through openings formed at the bottom of a cover, then taken into the intake side of a cooling fan through the air intakes formed in the wall end of a housing from the electric-parts-chamber. The cooling wind is accelerated by the fan to be driven off from the outlets formed in the peripheral wall of the housing. The cylindrical portion of the positive side cooling fins of the rectifier is extended to the space between the outer periphery of the fan and the outlets. The inner diameter of the cylindrical portion is longer than that of the rear coil end. Thus, the coil end and the cylindrical portion of the positive side cooling fin are cooled sufficiently by the cooling wind blowing thereon at high speed, so that the rectifier can endure large thermal load with reduced wind noise even if the size of the alternator is small.
Abstract:
A power supply system has a three-phase alternating current generator, a storage battery, and a three-phase rectifying device connected between the alternating current generator and the storage battery. The rectifying device includes three SiC-MOSFETS which are turned on when the corresponding alternating voltage is positive and turned off when the corresponding alternating voltage is negative. A duty control device switches each of the three SiC-MOSFETS on and off according to a selected duty ratio so that the alternating current generator can generate an optimum voltage in proportion to a rotational speed of a rotor of the alternating current generator.
Abstract:
A rotary electric machine such as an alternator or a motor has an engine-cooling water-pump in an integral unit. The rotary electric machine is composed of a frame secured to a front surface of an engine, an electric machine unit , a pump unit and a driving unit. The frame has a wall portion and a water passage formed on a rear surface of the wall portion and connected between the engine cooling system and the engine. The electric machine unit has a stator disposed in thermal contact with a front surface of the wall portion and a rotor fixed to a shaft of the driving unit. The pump unit is fixed to the frame and has a pump impeller disposed in the water passage to take cooling water from the cooling system to the engine through the cooling water passage. The driving member includes a pulley driven by an engine and a shaft supported by the wall portion through a bearing to drive the rotor and the impeller.
Abstract:
A stator which may be employed in an electric rotating machine. The stator includes a stator winding which includes in-slot portions disposed in slots of a stator core. The in-slot portions are arrayed in each of the slots in a form of multiple layers aligned in a radial direction of the stator core. The stator winding is made up of a first winding and a second winding which are connected together through a joint. The first winding is defined by a portion of the stator winding between the joint and an end of the stator winding which is to be connected to an external. The second winding includes the in-slot portion placed within at least one of the slots as an outermost layer that is one of the layers placed most outwardly in the radial direction of the stator core. This results in a great decrease in leakage current.
Abstract:
An electric rotary machine has a stator, a second rotor, and a first rotor which are arranged in order on a coaxial shaft. The first rotor has a plurality of magnetic poles having a different polarity. The stator has stator winding wires. The second rotor has a magnetic iron core and short circuit conductors. The magnetic iron core has first magnetic passage parts, second magnetic passage parts, and conductor holder parts. Both ends of the short circuit conductor is electrically connected to make a short circuit. The short circuit conductors are fitted to the corresponding conductor holder parts. No short circuit conductor surrounds each of the first magnetic passage parts. The short circuit conductors surround each of the second magnetic passage parts. The first magnetic passage parts and the second magnetic passage parts are alternately arranged along a circumferential direction of the second rotor.
Abstract:
A synchronous machine comprises a stator and a rotor that faces the stator and rotates on a shaft thereof in a circumferential direction. The rotor has magnetic salient poles that generate reluctance torque and magnet-originating magnetic poles that generate magnet torque by using permanent magnets embedded in the rotor. The machine comprises means for shifting a magnetically substantial central position of magnetic flux emanating from the permanent magnets in the circumferential direction, by an electrical angle π/2 plus a predetermined angle Δθ, from a reference position taken as a central position between paired magnetic salient poles composing each magnetic pole of the machine among the magnetic salient poles. Hence a maximum amplitude of a sum between a harmonic component of the magnet torque and the reluctance torque is changed from that obtained at the reference position without the shift.
Abstract:
An electric rotating machine includes a stator, a rotor, and a plurality of magnetic shields. The stator includes a stator core and a stator coil wound on the stator core. The stator core has a plurality of stator teeth arranged in the circumferential direction of the stator core. The rotor includes a rotor core that has a plurality of magnetic salient poles formed therein. The magnetic salient poles face the stator teeth through an air gap formed therebetween. Each of the magnetic shields is provided, either on the forward side of a corresponding one of the stator teeth or on the backward side of a corresponding one of the magnetic salient poles with respect to the rotational direction of the rotor, to create a magnetic flux which suppresses generation of a negative electromagnetic force that hinders rotation of the rotor.