Abstract: Disclosed is a BLDC motor, including: a stator which is provided with a plurality of teeth extending toward an inner side of a core and pole shoes each extending to be formed at radial inner end parts of the teeth; and rotors which are disposed at an inner side of the stator surrounded by the pole shoes while being spaced apart from the stator and have a plurality of permanent magnets coupled to cores thereof. Inner circumferential surfaces of the circumferential end parts of the pole shoe may be formed so that a distance of the inner circumferential surfaces of the circumferential end parts of the pole shoe from the outer circumferential surface of the rotor increases as the inner circumferential surfaces of the circumferential both end parts of the pole shoe is far away circumferentially from a central line CL of the pole shoe.

Abstract: A rotor includes first and second rotor cores, a field magnet, interpole magnets and holding members. The first and second rotor cores each have claw-like magnetic poles arranged in the circumferential direction in an outer periphery of a core base at even intervals and formed to protrude radially outward. The field magnet is placed between the core bases in the axial direction of the rotor and magnetized in the axial direction to cause the magnetic poles of the first and second rotor cores to function as first and second magnetic poles, respectively. The interpole magnets are each arranged between a circumferentially adjacent pair of the magnetic poles and magnetized in the circumferential direction so as to have the same polarity as the magnetic poles, which are opposed thereto in the circumferential direction. The holding members hold the interpole magnets to restrict radially outward movement of the interpole magnets.

Abstract: A rotor is provided with a first rotation member having a plurality of first claw poles in a circumferential direction and a second rotation member having a plurality of second claw poles in a circumferential direction. By of fitting each second claw pole in a cutout portion between first claw poles and by fitting each first claw pole in a cutout portion between second claw poles, the first rotation member and the second rotation member are assembled to each other. At least either one of the first rotation member and the second rotation member is formed of a magnet. Based on a magnetic field generated by the magnet, the first claw poles and the second claw poles have alternating north poles and south poles in the circumferential direction.

Abstract: A rotor includes at least one of a group of one or more auxiliary magnets that are located between first and second claw poles in a circumferential direction and magnetized to be magnetic poles of the same polarity as the first and second claw poles and another group of one or more auxiliary magnets that are located on a rear side of the first and second claw poles and magnetized to have radially outer portions of the same polarity as the first and second magnetic poles. The auxiliary magnets are arranged to protrude beyond at least one of axial end surfaces of the first and second core bases.

Abstract: A stepping motor uses a low-cost ferrite magnet instead of an expensive rare-earth magnet. The stepping motor has characteristics equivalent or superior to those of a conventional stepping motor. The stepping motor is provided with a rotor 300, a stator yoke 200, and bearings 501 and 502 which rotatably hold the rotor 300 with respect to the stator yoke 200. The rotor 300 has a columnar shape and has plural magnetic poles arranged in the circumferential direction of the outer circumferential surface. The stator yoke 200 has an outer cylindrical portion and an inner circumferential portion which surrounds the rotor 300 and which has plural first pole teeth and plural second pole teeth. The outer diameter “d” of the rotor 300 and the outer diameter “D” of the stator yoke 200 are set so that the ratio of “d/D” is greater than 0.6.

Abstract: An AC alternator for a vehicle has a rotor having a pair of pole cores, and a stator. A plurality of claw magnetic pole parts are formed in the pole cores. A permanent magnet is placed between a pair of the claw magnetic pole parts so as to prevent leakage of magnetic flux through the area between the adjacent claw magnetic pole parts. The stator and the rotor are placed in the AC alternator so that the stator faces the rotor at a spacing of predetermined intervals. Flanges are formed at both sides of each of the claw magnetic pole parts. The presence of the flanges fixes the permanent magnets to the pole cores, and prevents them from moving toward the outer radius direction measured from the rotary shaft of the rotor. In particular, the thickness of each of the flange parts is increased from the front end part to the bottom part thereof.

Abstract: A small electric motor is disclosed, such as a claw pole motor. An exemplary small electric motor includes a housing, a stator having at least two stator windings, a rotor having a rotational axis, and a flexible conductor foil for the electrical connection of the stator windings. The conductor foil includes winding connection contacts, external connection contacts and conductor paths between the winding connection contacts and the external connection contacts. Taps of the stator windings are electrically contacted with the winding connection contacts of the conductor foil. The conductor foil can be configured as an elongated strip having at least two connection portions which are arranged in spaced-apart relationship with each other and include winding connection contacts.

Abstract: A motor includes a shaft, a rotor, and a stator. The rotor includes first and second rotor cores, and a field magnet. Second claw magnetic pole portions of second rotor core are arranged between first claw magnetic pole portions of the first rotor core. The field magnet causes the first claw magnetic pole portions to function as first magnetic poles, and the second claw magnetic pole portions to function as second magnetic poles. Radially inner surfaces of the teeth of a stator core face radially outer surfaces of the first and second claw magnetic poles. Either radially outer surfaces of the first and second claw magnetic pole portions or radially inner surfaces of the teeth each have a cross-sectional shape in a direction orthogonal to the axial direction that is not concentric to a circle of which center is an axis of the rotation shaft.

Abstract: Provided is a Lundell type rotating machine with high efficiency and high output, which has a rigid and magnetically advantageous magnet retention structure. A rotor iron core includes laminated magnetic-pole members mechanically and magnetically coupled to two laminated magnetic end plates, which extend in an axial direction so as to be brought into meshing engagement with each other to constitute a Lundell type rotor iron core, and permanent magnets provided between the magnetic-pole members. The magnetic-pole members are retained in predetermined positions between the magnetic end plates by dovetail grooves of a non-magnetic retention body over substantially the entire lengths. The permanent magnets are held in direct contact with the magnetic-pole members so as to be interposed therebetween. Thus, the magnet retention structure which is mechanically rigid and magnetically highly efficient even when increased in size can be obtained.

Abstract: A disk drive device includes: a hub on which a recording disk is to be mounted; a base configured to rotatably support the hub via a bearing; a core that is fixed to the base and includes a circular portion and S salient poles (where S is a natural number greater than or equal to 3) extending from the circular portion in the diameter direction; a three-phase coil that is formed by being wound around each of the S salient poles; and a magnet that is fixed to the hub and faces the S salient poles in the diameter direction, and that is provided with P driving magnetic poles in the circumferential direction (where P is a natural number greater than or equal to 2).

Abstract: A permanent magnet machine is provided comprising a stator and a rotor, the rotor being adapted to rotate relative to the stator, the rotor comprising a plurality of permanent magnets separated in the circumferential direction from each other by axially extending rotor pole pieces for concentrating the magnetic flux from the permanent magnets, the stator having a structure that defines axial limits of an air gap between the stator and the rotor for communicating magnetic flux between the stator and the rotor, wherein that at least some of the permanent magnets extend axially outside the axial limits of the air gap as defined by the stator structure.

Abstract: A bobbin is mounted to a rotor such that a rotation arresting portion is housed in a space that is formed by a rotation arresting portion housing recess portion and a stepped portion so as to restrict circumferential movement, and a permanent magnet is made into a quadrangular prism that has a rectangular bottom surface, and is held by a magnet holding seat by placing a bottom surface on an upper surface of a magnet holding portion, and fixing to the magnet holding seat a cover that is mounted from radially outside to restrict circumferential, axial, and radial movement.

Abstract: The electromechanical transducer (2) includes a rotor (4) and two coil (6, 8), the rotor being formed of first, second and third parts (10, 11, 12) made of magnetic material with respectively first, second and third superposed central zones (14, 15, 16), a first, axially polarized, bipolar magnet (18) being arranged between the first and second central zones and a second bipolar magnet (20) axially polarized in an opposite direction to that of the first magnet being arranged between the second and third central zones.

Abstract: An interfitting groove is disposed in a bottom portion of a trough portion so as to have a groove direction that is axial and so as to extend axially outward from axially inside, and a rotation arresting portion housing recess portion is recessed into an axially inner opening edge portion of the interfitting groove on a first yoke portion. A magnet holding seat that holds a permanent magnet is disposed in the trough portion by an interfitting portion being fitted into the interfitting groove such that radial movement is restricted. A rotation arresting portion that is disposed so as to project axially outward from a flange portion of the bobbin is housed inside a space that is constituted by the rotation arresting portion housing recess portion and an external shape reduced portion that extends axially inward from the interfitting groove such that rotation of the bobbin around the shaft is restricted.

Abstract: There is provided a vehicle AC generator in which the contact face of at least one of a pair of cases that make contact with the respective axis-direction end faces of a stator core is provided with a cooling air path that connects the outer circumferential surface of a coil end portion with the outer circumferential surface of the stator core and has an opening in the axis direction at the outer circumferential surface of the stator core so that the coolability of the coil end portions of the stator coil is raised, and the amount of cooling air is increased so that the overall coolability of the AC generator is improved.

Abstract: An automotive generator that includes a Lundell rotor. First and second protruding portions are disposed so as to project from inner wall surfaces of portions of first and second yoke portions at root portions of first and second claw-shaped magnetic pole portions, and first and second recess portions are recessed into inner wall surfaces of portions of the first and second yoke portions that face the second and first protruding portions. In addition, a shape of a region in which the field coil is disposed is configured into a wave shape that has a cross-sectional shape in a plane that includes a central axis of the pole core that is approximately constant in a circumferential direction and that zigzags alternately in an axial direction at positions of each of the first and second claw-shaped magnetic pole portions.

Abstract: Disclosed herein is an electric machine rotor. The rotor includes, a rotatable shaft, a plurality of pole segments attached to the shaft, and a plurality of magnets attached to the plurality of pole segments such that one of the plurality of magnets is positioned circumferentially between adjacent pole segments and each of the plurality of magnets has nonparallel circumferentially opposing sides.

Abstract: The permanent magnet type rotary machine is capable of reducing cogging torque caused by variation of amounts of magnetic flux in magnetic circuits. The permanent magnet type rotary machine comprises: a stator constituted by stator units, which are coaxially stacked and in each of which a coil is sandwiched between stator yokes; and a rotor including a permanent magnet having magnetic poles, which respectively face magnetic pole teeth of the stator yokes, the rotor being rotatably supported by an output shaft. The stator units in one phase is divided into n (n is an integer one or more), and magnetic centers of at least one pair of the magnetic pole teeth of the adjacent stator yokes, which are vertically arranged, are shifted with a prescribed phase difference so as to mutually cancel their cogging torque.

Abstract: A dynamoelectric machine including first and second permanent magnets held by first and second magnet seats on first and second yoke portions so as to face inner circumferential surfaces of tip end portions of first and second claw-shaped magnetic pole portions. The first and second permanent magnets are magnetically oriented in a reverse direction to orientation of a magnetic field that the field coil produces. The dynamoelectric machine enables permanent magnet holding reliability to be increased, induced voltage during no-load de-energization to be suppressed, and thermal demagnetization of magnets due to high-frequency magnetic fields that are induced by stator slots to be avoided.

Abstract: The invention relates to a claw pole generator comprising a claw pole rotor, two magnet wheel halves (21, 23) which are mounted on a drive shaft (15) and are provided with claw-shaped magnet poles (22, 24) that mesh with each other, and an annular closing member (10) located between adjacent magnet poles (21, 23). The magnet wheel halves (21, 23) can be inserted into pockets (11) of the closing member (10) along with the magnet poles (22, 24) thereof such that the closing member (10) overlaps the magnet poles (22, 24) on the edge in at least some areas. Also disclosed is a closing member (10).

Abstract: An alternator has a rotor rotated on its own axis to generate electric power in a stator. The rotor has pole cores with claw portions arranged along the circumferential direction, and a holder unit is disposed between two adjacent claw portions in each pair. Each holder unit has a magnet accommodating holder and a magnet covering holder. Each holder has one bottom wall, four side walls and one opening. The magnet accommodating holder accommodates a magnet. The magnet covering holder is placed between the claw portions and accommodates the magnet accommodating holder while covering the magnet exposed to the opening of the magnet accommodating holder. The magnet accommodating holder has convex portions existing in the respective side and bottom walls and being in elastic contact with the magnet.

Abstract: A rotor core which has relatively high rigidity, can ensure sufficient magnetic performance, and can be produced at a cheaper cost with a relatively small-scale facility. A claw-equipped core and a yoke are manufactured separately. After fitting the yoke to a fitting portion formed in the claw-equipped core, a part of the claw-equipped core in the vicinity of the fitting portion is axially pressed to plastically flow into an annular groove formed in the yoke, thereby integrally joining the claw-equipped core and the yoke to each other. Thus, a large-scaled manufacturing facility is not required, and claws of the claw-equipped core are hard to open in the radial direction even under the action of a centrifugal force during high-speed rotation. A stator core and the claws of the claw-equipped core can be positioned closer to each other, and deterioration of magnetic performance can be avoided.

Abstract: A claw-pole rotor for an electrical machine, in particular a rotary current generator, having two pole wheels (26, 27), which each carry claw poles (28 and 29, respectively), which each originate in a plate region (50) and have a pole root (53), and on a circumference of the claw-pole rotor (20), claw poles (28, 29) of the pole wheels (26, 27) are located in alternation, and located between the claw poles or interstices (90), and a claw pole (28, 29) has a radially outward-oriented cylindrical-jacketlike surface (43), by which a pivot axis (65) is defined, and a chamfer (68) extends on the one hand in a circumferential direction and on the other in an edge direction of a claw pole (28 and 29, respectively), wherein the chamfer (68) has a center portion m in the edge direction that intersects a transition plane (59) which demarcates the pole root (53) and the freely projecting part of the claw pole (28 and 29, respectively), and the center portion m amounts to 8/10 of the length, oriented in the edge direction

Abstract: In a tandem AC generator for a vehicle having dual armature core-Lundel type field core pairs placed in series, an intermediate ring as a cylindrical spacer is placed between the dual armature cores. One armature core, the intermediate ring, and the other armature core are pressed and tightly fastened to each other in the direction of a rotary shaft by front and rear housings by a through bolt. A circumference wall part of the front housing accommodates one armature core and the intermediate ring completely and further accommodates a part of an outer circumference surface of the other armature core. This simple construction of the tandem AC generator provides improved and superior vibration proof.

Abstract: In a vehicular alternator having a permanent magnet protection mechanism, each magnet holder of a non-magnetic characteristic if a rectangle prism shape accommodates each permanent magnet disposed between adjacent claw poles. The magnet holders are connected in a ring shape along a circumferential direction of the alternator by using each connecting plate part which extends from each magnet holder in approximate circumferential direction toward an inner side of and at a front tip part of each claw pole. The connecting plate parts and the magnet holders are made from a non-magnetic plate by cutting and bending. Making the surfaces and the connecting plate part of each magnet holder from the non-magnetic plate by cutting and bending provides a high accuracy magnet position in the alternator with low manufacturing cost.

Abstract: A bicycle generator hub is mounted to the front fork of a bicycle and includes a hub shaft, a hub shell, bearings, a generator mechanism and first and second magnetic flux recirculation members. The hub shaft is non-rotatably mounted to the front fork. The hub shell is disposed around the surface of the hub shaft. The bearings are disposed between the hub shell and the hub shaft to enable the hub shell to rotate relative to the hub shaft. The generator mechanism has a coil mounted to the hub shaft and a magnet unit disposed such that the generator mechanism generates electric power via the rotation of the hub shell relative to the hub shaft. The first and second magnetic flux recirculation members are disposed on the hub shaft or the hub shell and return a leaked magnetic flux to the coil.

Abstract: A claw-pole type stepping motor which includes a stator in which coils are arranged in association with a pair of inner and outer yokes and a pair of pole tooth sections thereby forming a magnetic circuit; and a rotor magnet which is rotatably disposed opposite to the pair of pole tooth sections, each of the pair of pole tooth sections being prepared discretely from each of the inner and outer yokes by punching out a soft magnetic steel plate so as to form a piece having a belt portion and a plurality of pole teeth integrally connected to the belt portion and thereafter rolling into a cylindrical shape. Thus, it becomes possible to set arbitrarily individual dimensions of each of the pole teeth as required by the characteristics of a motor, thereby providing an excellent high output and miniature motor.

Abstract: A rotor assembly for an alternator includes an electrical wire defining an excitation winding. A first pole piece and a second pole piece each have a generally circular body defining an axis of rotation and an outer radial periphery. A plurality of pole fingers are spaced radially about and extend axially from the outer radial periphery of each pole piece parallel to the axis of rotation. Each pole piece includes a plurality of mounting surfaces spaced radially about the outer radial periphery between the pole fingers. A plurality of permanent magnets are positioned on the mounting surfaces, each of the permanent magnets being secured to the pole pieces by a threaded fastener extending therethrough and engaging the pole pieces.