Abstract: An embodiment of a motorized optical scanner of a Light Detection and Ranging (LiDAR) system used in a motor vehicle is provided. The scanner includes a reflective piece including a substrate and a reflective surface. The scanner further includes a first shaft and a second shaft attached to a first end and a second end of the substrate respectively. The first end and the second end are opposite ends of the substrate along a longitudinal direction of the substrate. The scanner further includes a first bearing and a second bearing coupled to the first shaft and the second shaft respectively. The first bearing and the second bearing are substantially concentric. Movement of the second shaft causes the reflective surface to optically transmit one or more light beams to a field-of-view.

Abstract: An electric motor includes an end turn ring and a cooling structure that is in a thermally conductive relationship with the end turn ring.

Abstract: A coil segment forming apparatus includes a second bending section for bending a first bent body consisting of a pair of slot insertion portions that are substantially parallel to each other and a linking portion for connecting the pair of slot insertion portions formed in the same plane. The bending of the first bent body is carried out in a plane perpendicular to the aforementioned same plane. The second bending section has a plurality of pairs of press jigs arranged to oppose to each other in directions intersecting with the aforementioned same plane for pinching and pressing the linking portion, and a plurality of drive mechanisms for moving respectively the plurality of pairs of press jigs in directions intersecting with the aforementioned same plane based on moving amounts respectively set depending on forming conditions of the coil segment to be formed.

Abstract: In the rotating electric machine, a first terminal and a second terminal extend from two of the slots and a third terminal extends from one of the slots, which is located between the two slots. The first terminal and the second terminal are connected to each other with use of a bus bar. The bus bar has: a first end portion to be connected to a distal end portion of the first terminal; a second end portion to be connected to a distal end portion of the second terminal; and an interconnecting portion configured to couple the first end portion and the second end portion to each other, which is arranged in the circumferential direction on the stator core side of the first end portion and the second end portion so as to pass on the slot side of the third terminal.

Abstract: An electrical motor is provided to reduce torque ripple. Torque ripple is a variation in torque output as the rotor rotates. The motor has a stator and a rotor. The stator slots are used for windings. The rotor slots define a plurality of poles. The number of slots in the stator are equal to the number of slots in the rotor.

Abstract: The invention provides a winding (40) for a rotating electrical machine (1) comprising a flexible PCB (45) having a plurality of conductors (60) on a first surface and a plurality of conductors (60) on a second surface, said conductors having a shape optimizing the performance of the machine, and a method for designing such a winding.

Abstract: In a 4-pole, 6-slot, 18-segment electric motor, one forward winding coil (91) and two reverse winding coils (92, 93) are wound on each tooth (12). When the forward winding coils are formed of coils corresponding to a U phase, a V phase, and a W phase and the reverse winding coils are formed of coils corresponding to a “?U” phase, a “?V” phase, and a “?W” phase, the coils, which correspond to a U phase, a “?W” phase, a “?W” phase, a V phase, a “?U” phase, a “?U” phase, a W phase, a “?V” phase, and a “?V” phase, are electrically connected in this order between the adjacent segments.

Abstract: In each coil (10), between a first radial section formed by a winding-start section (10a) and a second radial section formed by a winding-end section (10b) of a winding (10A), the circumferential lengths of the winding lap sections formed by said winding change in a continuous or stepped manner. For a first coil, the sequences within two slots (22) of the winding constituting the first coil are reversed with respect to one another by a twisted section (10d) between a first coil end (12a) and a second coil end (12b) of the first coil. The first coil and next second coil form a lap winding in which the twisted sections of the first and second coils are three-dimensionally entwined. The lap winding of said twisted sections continues for the third and subsequent coils, and the first coil end and the second coil end of each coil are continuous without spaces at the end surfaces of a core (20).

Abstract: A rotating electrical machine includes a stator and a rotor rotatably mounted on the stator. The stator includes a plurality of slots into which coils are insertable, a plurality of types of unit coils inserted into the slots at slot pitches differing for every type of unit coil, and a plurality of coil groups formed by arranging the unit coils in a lap winding so that the unit coils are overlapped in a radial direction of the stator. The coil groups have the same arrangement configuration before insertion into the slots and are inserted into the slots so as to be shifted from each other by a predetermined slot pitch.

Abstract: A method for manufacturing a coil that is formed by winding a conductor in a loop shape and stacking loops of the conductor and that includes a slot placement portion to be placed in a slot of a stator core, and a coil end placement portion to be placed outside the slot. The method preferably involves a winding step, a protrusion forming step, a crank forming step, an opening step, and an arc forming step. The winding step forms a winding having slot placement and coil end placement portions. The protrusion forming step forms a protruding shape that protrudes in a radially outward direction of the winding. In the crank forming step a stepped portion. The opening step of forming the winding so that an interval between the pair of expected slot placement portions gradually increases. The arc forming step forms an arc-shaped portion curved in the stacking direction.

Abstract: A motor driving apparatus includes a rotor, a first yoke including a first magnetic portion, a first coil configured to, if energized, excite the first magnetic portion, a second yoke including a second magnetic portion, a second coil configured to, if energized, excite the second magnetic portion, a detecting portion including a first detection element, a second detection element, a third detection element, and a fourth detection element, each detection element being configured to detect a rotation position of the rotor, and a controller configured to switch a pole excited by the first magnetic portion and the second magnetic portion by switching an energization direction of the first coil and the second coil based on an output of the detecting portion.

Abstract: A permanent magnet excited electric machine includes a stator and a moving part movable relative to the stator. One of the stator and moving part has an electric winding system in the form of a single or multiple 3-phase system. The other one of the stator and moving part has permanent magnets. The winding system, in the form of a delta connection, has an inductance such that the related total reactance xB during rated operation according to xB=?B·LY·PB/(Z3P·Ui,B2) is at least 0.8, wherein B is the electric angular frequency of the winding system during rated operation, LY is the phase inductance of the winding system in star connection, PB is the power of the machine during rated operation, Z3P is the number of 3-phase systems of the machine, and Ui,B is the amount of the induced conductor voltage during rated operation.

Abstract: A multipolar motor is simply wire-wound and an output thereof is capable of being switched. The motor includes at least 8 magnetic poles, an armature including at least 10 tooth sections; a commutator including at least 20 commutator segments, and brush-sets including 2 positive electrode brushes and 2 negative electrode brushes. A hook-holding section arranged to hook-hold conductor wires is installed on each of the commutator segments. Further, a group of coils is defined by using a single conductor wire that is wound onto each of the plurality of tooth sections and hooked onto the plurality of hook holding sections. This motor can switch the state in which the brush-set is energized.

Abstract: A method of manufacturing an annular-shaped stator structure includes forming an elongate stator body, the elongate stator body extending along a longitudinal axis, the elongate stator body including first and second ends and a plurality of slots. Electrically-conductive wires are inserted into the slots of the elongate stator body, whereby each of the electronically conductive wires includes a first end and a second end. The elongate stator body is then formed into an annular shape. The first end of the annular-shaped stator body is coupled to the second end of the annular-shaped stator body, and the first end of each electrically-conductive wire is coupled to that wire's respect second end.

Abstract: A stator having a common varnish and weld insulation includes a stator lamination core and a motor winding wound around the stator lamination core. The motor winding includes a plurality of magnet wires configured such that they are substantially parallel to each other. Each magnet wire has two distal ends configured such that each distal end is welded to one distal end of an adjacent magnet wire, thereby forming a plurality of welded tips. The stator further includes a resin coating the welded tips and the stator. The resin serves as both a primary insulation for the welded tips, and as a varnish for the stator. This dual function of the resin may eliminate the need for separate insulation for the welded tips and varnish for the stator, and allow the resin to be applied to the welded tips and to the stator at substantially the same time.

Abstract: A commutated DC motor (10) includes a stator (12) and a rotor (14) mounted in the stator (12). The stator (12) has 2P magnetic poles, wherein P is an integer greater than 1. The rotor (14) includes a rotor shaft (81) with a rotor core (85), and a commutator (83) fixed thereto. The rotor core (85) has multiple teeth defining m×P slots therebetween, wherein m is an odd integer greater than 1. The commutator (83) has k×m×P segments, wherein k is 1 or 2. A rotor winding (87) formed by winding a single continuous wire is received in the slots of the rotor core (85) and connected to the segments of the commutator (83), and has k×m winding units. Each winding unit includes P coils in series connection and is directly connected to only two segments.

Abstract: In an electrical actuator having a motor in which a plurality of teeth including a continuous winding are formed into a stator core of a ring shape, one wire being continuously wound around the teeth adjacent to each other in the continuous winding, the stator core is configured that step sections of an uneven shape in the axial direction are arranged in butting sections between the teeth connected by the continuous winding, and the uneven shapes are fitted to each other.

Abstract: A rotating electromechanical apparatus includes a cylindrical ironless stator coil comprising a plurality of wires, a magnetic rotor arranged with the stator coil, wherein the magnetic field flux associated with the rotor interacts with the stator coil wires by electromagnetic induction, a cylindrical bobbin arranged to support the wires, a strand woven on at least the outer circumference of the wire-wrapped cylindrical bobbin, and a curable potting material potting the wires, bobbin and strand to provide an ironless composite stator coil when cured.

Abstract: A winding for an n-phase electric motor is disclosed. The inventive winding comprises a number of consecutive winding groups of n individual windings, wherein at any point in time an individual winding of a first group exhibits one direction of current flow and wherein at the same point in time a corresponding individual winding of an adjacent group exhibits the opposite direction of current flow. There is also disclosed a method for preparing such winding. It is further disclosed a magnetic unit adapted for such winding, comprising permanent magnets being essentially triangular in cross-section. Further, there is disclosed electric motors using the inventive winding concept, as well as geodetic instruments taking advantage thereof. An electric motor according to the disclosed inventive concept is particularly well suited for direct drive.

Abstract: According to one embodiment, there is provided a 3-phase 4-pole 2-layer armature winding of a rotating electrical machine. A winding of each phase of the armature winding forms a series coil. Each series coil includes upper coil pieces and lower coil pieces which are connected each other at a connection side coil end and a counter-connection side coil end, the upper coil pieces and lower coil pieces being placed in 42 slots provided in an armature core. At least one coil piece of the upper and lower coil pieces, provided in at least one of an innermost position and an outermost position from the center of a phase belt of each phase, is replaced with a coil piece of an adjacent phase.

Abstract: Stator winding (10) for an electric machine, in particular for a generator of a motor vehicle, the stator winding (10) being embodied as an ordered stator winding (10), and the stator winding (10) being embodied in at least two axially spaced-apart levels (22, 24) in a winding head (13). The invention also relates to an electric machine and a method for manufacturing a stator winding (10) of an electric machine.

Abstract: To provide a stator capable of achieving downsizing and high output power and a stator manufacturing method, a stator comprises a split stator core and slots formed between the teeth, and protrusion-formed coils each being made of a flat rectangular conductor and placed in the slots. Each protrusion-formed coil has a shape including, in a coil end portion, a lead-side protrusion or a non-lead-side protrusion formed to protrude upward in an axial direction of the stator core from a first oblique side portion, a second oblique side portion, a third oblique side portion, and a fourth oblique side portion, and a first oblique side portion, a second oblique side portion, a third oblique side portion, and a fourth oblique side portion. The lead-side protrusion or the non-lead-side protrusion is designed with a height to avoid interference between the protrusion-formed coils placed in the stator core.

Abstract: A stator of a motor includes a stator core having a plurality of teeth forming slots between any two adjacent teeth and a plurality of phase coils provided in the slots, each formed by wave winding and made of a continuous wire. Each phase coil includes a first wave winding bundle and a second wave winding bundle that is passed through a first slot and a second slot. The first slot is located adjacent to one side of a group of slots through which the phase coils other than said each phase coil are passed and the second slot is located adjacent to the other side of the group of slots. The first wave winding bundle is passed through a third slot and a fourth slot. The third slot is located adjacent to the first slot on the opposite side of the first slot from the group of slots and the fourth slot is located adjacent to the second slot on the opposite side of the second slot from the group of slots.

Abstract: A stator for a multi-phase electric motor comprises a plurality of teeth for each phase. The windings on two teeth from one phase are formed from a single length of conductor. The windings on a first one of the teeth being formed at least in part from two sections of the conductor spaced apart along the length of the conductor, and the windings on a second one of the teeth being formed from an intermediate section of the conductor between the spaced apart sections.

Abstract: A rotating electric machine includes an annular stator including a coil formed by winding a part of a coil wire around a stator core, and the coil wire includes the coil wound around stator teeth, a terminal portion drawn out from one end portion of the coil over a yoke portion, and a wiring drawn out from the other end portion of the coil over the yoke portion and connected to a terminal portion of another coil wire including another coil provided at a distance from the coil in a circumferential direction of the stator.

Abstract: A five-phase motor includes a stator and a movable member movable relative to the stator in a preset direction. The stator includes a stator core provided with five slots within 360 electrical degrees thereof. The five slots are arranged in the preset direction at preset first pitches. The stator includes at least one set of five-phase stator windings. The five-phase stator windings are arranged in the five slots relative to each other such that each of the five-phase stator windings is wound at a preset second pitch. The second pitch substantially corresponds to two of the first pitches.

Abstract: A group of three stator windings for a stator of an electric machine, a stator arrangement, a generator, and wind turbine are provided. The first winding head segments of the three stator windings differ in form such that the first winding head segments of at least two of the three stator windings are differently tilted in radial direction of the electric machine and the length of the three stator windings is substantially the same.

Abstract: A multipolar motor is simply wire-wound and an output thereof is capable of being switched. The motor includes at least 8 magnetic poles, an armature including at least 10 tooth sections; a commutator including at least 20 commutator segments, and brush-sets including 2 positive electrode brushes and 2 negative electrode brushes. A hook-holding section arranged to hook-hold conductor wires is installed on each of the commutator segments. Further, a group of coils is defined by using a single conductor wire that is wound onto each of the plurality of tooth sections and hooked onto the plurality of hook holding sections. This motor can switch the state in which the brush-set is energized.

Abstract: An electric rotating machine includes a multi-phase stator coil that is wound on a stator core in a distributed winding manner. Each of phase windings of the stator coil is formed of an electric wire bundle which includes a plurality of insulation-coated electric wires that are electrically connected to one another. Each of the electric wire bundles forming the phase windings has in-slot portions, which are respectively received in corresponding slots of the stator core, and turn portions that are located outside the slots of the stator core to connect adjacent pairs of the in-slot portions. Each of the electric wire bundles further includes a plurality of insulating layers that are respectively formed at predetermined positions, at which the turn portions of the electric wire bundle overlap those of the other electric wire bundles, so as to surround the electric wires of the electric wire bundle.

Abstract: In one aspect, a stator is provided having a first cylindrical surface with a plurality circumferentially spaced winding slots, each winding slot extending along an axial length of the first cylindrical surface and formed to embed a segment of a single stator winding, Each stator winding is pre-formed as a closed loop and two substantially parallel segments of each stator winding formed to be embedded in a first and a second winding slot of the stator, with the second winding slot being the third adjacent winding slot to the first winding slot. Each of the three stator windings has a first winding head segment leaving the winding slots in axial direction of the stator, the first winding head segment of a first winding of the three stator windings describing in space in parts a combination of a rotation about an axis and a translation along that axis.

Abstract: Provided is a DC motor capable of eliminating a DC current reverse rectification performed in a conventional DC motor and enabling rotation of maximum torque at all rotation angle and having a shape and a function for facilitating a combination with a speed change gear mechanism. Also provided is a planetary gear dynamo using the shape and the function of the present invention and capable of reducing inverse torque when the function is used as a generator.

Abstract: An electric motor has a rotor (52) rotatable around a rotation axis (56) and has a stator (60) arranged around said rotor (52), which stator is equipped with poles (11? to 16?). Each pole has an individual winding (11 to 16), and the latter together form a winding arrangement (30) that serves to generate a rotating field. Arranged approximately concentrically with the rotation axis (56) is an arrangement having electrical connection elements (U, V, W, U?, V?, W?). The latter are equipped with mounting elements (34, V1, W1, U?1, V?1, 32, 36) to each of which an associated end of an individual winding is mechanically and electrically connected. A connection arrangement (40) has a plurality of conductors (42, 44, 46) each of which is connected, by means of a welded connection (155), to the connection elements of the stator in order to electrically interconnect them in a predetermined fashion.

Abstract: The invention relates to a generator, especially for motor vehicles, which comprises a generator stator (36) having winding slots and subcoils (10 21) lying in said winding slots (35). The subcoils (10 21) are connected to each other via a bridge circuit (3) in order to produce a DC voltage from a multiphase AC voltage produced by a rotary field. The generator is configured as a multiphase generator (30), preferably a three-phase or six-phase generator (30). The aim of the invention is to reduce magnetic nose and torque ripple merely by modifying the subcoil wiring. For this purpose, the subcoils (10 21) are connected to an angular ring and the bridge circuit (3) connected to the ring has a lower phase number than corners of the angular ring circuit (1).

Abstract: Dynamoelectric device and stator bar therefor, where the stator bar includes a linear portion for positioning in a slot of a stator core, the slot extending in a radial direction relative to an axis of the stator, and an end arm portion having an involute-on-cone bend relative to the linear portion and an elongated cross-section that is substantially aligned with the radial direction of the slot.

Abstract: [Object] A winding method of an electric motor, an electric motor, and a seatbelt device provided with the same in which a burden is not applied to a coil wire, disconnection or damage on the coil wire can be reduced, and productivity can be improved are provided.

Abstract: A direct current motor including a rotor, a stator, a brush holder, and a brush. The rotor includes a core, a plurality of commutator segments, and a plurality of segment coils. The core has a plurality of teeth arranged along a circumferential direction of the rotor. A slot is formed between adjacent ones of the teeth in the circumferential direction. The plurality of commutator segments are arranged along the circumferential direction of the rotor inward from the plurality of teeth in the radial direction of the rotor. Each segment coil includes a plurality of segment conductors electrically connected to each other. The plurality of segment conductors in each segment coil extends through the slots along the axial direction of the rotor.

Abstract: In a method for winding the stator of a multiphase electric motor a plurality of mutually spaced stator teeth are assigned to each phase, wherein all the teeth of the stator are wound without a break in the winding wire, and wherein the winding wire is taken via a contact-making element of a contact-making device before or after the winding of all the stator teeth assigned to a phase.

Abstract: A total number of windings in an armature is an even number. The windings are divided into a first winding group and a second winding group. The windings of the first winding group are arranged one after another at generally equal angular intervals without overlapping with each other. The windings of the second winding group are arranged one after another at generally equal angular intervals without overlapping with each other and are wound separately from the windings of the first winding group.

Abstract: In a rotating machinery having armature windings constituted by a lot of strands, when the armature winding is constituted by four layers, a step number of the strands becomes half with respect to two layers of armature windings so as to facilitate manufacturing an armature winding of 540 degree transposition in which a transposition pitch is elongated and a circulating current loss is reduced, but since an output voltage becomes twice, for securing a voltage limit value caused by an isolation resisting force, one layer of armature windings are constituted by sub windings separated into at least two layers in a vertical direction, a transposition is independently applied to each of the sub windings, the sub windings are connected to the armature windings of the other slot while keeping an isolation of the sub winding at an armature winding end region by at least two connecting methods, and the sub winding constructs a parallel circuit by the armature windings of a plurality of slots.

Abstract: The invention relates to a synchronous motor (3) comprising a stator (3) with 18 stator teeth (2). The stator comprises stator coils (7) surrounding the stator teeth (2). The rotor (5) has eight pole magnets (6), each stator coil (7) surrounding at least two stator teeth (2).

Abstract: In a stator for an electric machine and a method for manufacturing a winding for the stator of such an electric machine L-shaped wire segments having a rectangular cross-section are inserted into slots arranged around the stator The long leg of the L-shaped wire segment is then inserted, into or through, a respective slot and the wire segment is then bent into an S-shape resulting in a second short leg while reducing a length of the long leg. The first short leg of each one of a majority of the wire segments is then electrically connected to the first short leg of another one of the wire segments and the second short leg of each one of a majority of the wire segments is electrically connected to the second short leg of yet another one of the wire segments.

Abstract: An apparatus and method are shown for improving the efficiency of motors, generators and machines by using a closed ferromagnetic frame upon which is mounted a plurality of solenoid coils. Two of the solenoid coils are wired together so that they act as one in a closed wiring circuit. An associated armature assembly includes a carousel which carries additional solenoid coils and is rotated through an opening provided in an extension to the closed frame. The individual solenoid coils located on the carousel supply power to the two original solenoid coils on the ferromagnetic frame giving the basic circulation system amplification each time a solenoid enters the electric/magnetic field created by the frame uprights.

Abstract: A method for mounting coil onto stator for rotary electric machine. The method includes forming coil pieces by winding wire with flat cross section into single row lamination state including wire layers aligned along perpendicular line to flat surfaces of wire. The coil is formed for first portion to be inserted in slot and second portion not inserted in slot appear alternately along the coil. The method displaces wire layers at the first portion changing the single row lamination state to connectively laminated state where wire layers at portion to be inserted in slot each adjacent pair of the wire layers partially overlap with respect to direction perpendicular to flat wire surfaces. The method includes inserting wires of first portion into slot, passing each wire layer through slot opening successively from the top wire layer of lamination and displacing each wire layer at first portion from each other.

Abstract: An electric motor is disclosed with an air-cored winding which is composed of a plurality of single coils made of wire, wherein the single coils overlap each other in an imbricated manner and the single coils are preformed to form an offset at least in the region of two opposite corners, so that half of the legs are located in a first plane and half of the legs are located in a second plane. A more inexpensive and more robust assembly of air-cored windings for electric motors can thereby be achieved.

Abstract: A stator coil assembly includes a cylindrical support tube with first and second pluralities of stator coils disposed radially around the support tube. Each stator coil includes first, second, third, and fourth linear segments, each having first and second planar broad sides. The second and fourth linear segments extend in parallel along a first axis with the first and second broad sides of the second and fourth linear segments lying in a common plane. The first and third linear segments extend in parallel along a second axis perpendicular to the first axis. Transition segments having first and second planar broad sides each join a pair of linear segments. The transition segments of the first and second pluralities of stator coils define curvatures toward and away from the center axis, respectively, such that the first and third linear segments are disposed at a substantially equal radial distance from the center axis.

Abstract: To provide an aircraft propulsion system which can secure the optimum thrust and thrust vector for flight conditions, as well as the optimum sectional area for the engine, and which is highly compatible with the environment. An electrical generator is coupled to a turbofan engine, the electrical generator is driven by output power of the turbofan engine to output electric power, and an electromagnetic driving fan is driven by the electric power. On the other hand, after bringing each of coils in the electromagnetic driving fan to a superconductive state, liquid hydrogen is introduced to a heat exchanger, collects the energy of exhaust as heat, is then vaporized, and thereafter supplied to a combustor and to a fuel cell. Further, the electromagnetic driving fan is changed in its rotational phase by a rotating mechanism portion, is made movable in a width direction of a wing and a wing chord direction by a slide mechanism portion, and can be stored inside or outside the wing by a storage mechanism portion.

Abstract: A motor with three gaps produces higher torque than existing one or two gap motors. The motor uses both one radial and two axial gaps to produce torque. A single stator is provided with an essentially “U” shaped rotor shell having permanent magnets with back iron. The stator has loops of coil windings separated by pole pieces. Current flowing in three segments of the coils interacts with the fields from the permanent magnets to produce more torque. The plane of the coils extends through the centerline of the stator. In a given plane through the motor axis, the same polarity of the magnets on the rotor face the stator.

Abstract: Stable electrical connections between coils and a commutator are realized without causing slackening of the coils wound on individual magnetic teeth. An armature of a rotary motor includes an armature core structured splittably into magnetic tooth members which are individually wound by concentrated-winding type coils, and a commutator having the same number of segments as the number of the magnetic tooth members, the individual segments having connecting terminals, wherein an end portion of the coil concentratedly wound on one of the magnetic tooth members is connected generally in a straight line to the connecting terminal of the segment which is located at a position offset in a circumferential direction by a specific angle from the aforementioned one magnetic tooth member, and a conductor line connected to the connecting terminal of the segment is concentratedly wound on another magnetic tooth member adjacent to the aforementioned one magnetic tooth member.

Abstract: The invention relates to a generator, especially for motor vehicles, which comprises a generator stator (36) having winding slots and subcoils (10 21) lying in said winding slots (35). The subcoils (10 21) are connected to each other via a bridge circuit (3) in order to produce a DC voltage from a multiphase AC voltage produced by a rotary field. The generator is configured as a multiphase generator (30), preferably a three-phase or six-phase generator (30). The aim of the invention is to reduce magnetic nose and torque ripple merely by modifying the subcoil wiring. For this purpose, the subcoils (10 21) are connected to an angular ring and the bridge circuit (3) connected to the ring has a lower phase number than corners of the angular ring circuit (1).

Abstract: Provided is a DC motor capable of eliminating a DC current reverse rectification performed in a conventional DC motor and enabling rotation of maximum torque at all rotation angle and having a shape and a function for facilitating a combination with a speed change gear mechanism. Also provided is a planetary gear dynamo using the shape and the function of the present invention and capable of reducing inverse torque when the function is used as a generator.