Abstract: Disclosed are various embodiments for Torque Tunnel Halbach Array electric machines having a rotor comprising a plurality of rotor assemblies configured to form a magnetic torque tunnel having at least a first magnetic pole tunnel segment and a second magnetic pole tunnel segment, each of the rotor assemblies having a plurality of flux shaping Halbach Arrays configured to focus the Flux Density Distribution in the magnetic torque tunnel and a stator having a plurality of coils configured to form a coil winding assembly, the coil winding assembly positioned within the magnetic torque tunnel, such that at least one of the plurality of coils is surrounded by the first magnetic pole tunnel segment or the second magnetic pole tunnel segment, alternatively the rotor may be the coil winding assembly and the stator may be the magnetic torque tunnel.

Abstract: Disclosed are various embodiments for an electric machine where the stator is a coil assembly and the rotor is a magnetic toroidal cylindrical tunnel or where the rotor is a coil assembly and the stator is a magnetic toroidal cylindrical tunnel.

Abstract: An electric motor with a rotor and a stator, where the rotor and/or the stator can comprise two or more sections, and a torque ripple caused by the magnetic field(s) associated with a section of the rotor (or stator) can at least partially counters torque ripple caused by the magnetic field(s) associated with other section(s) of the rotor (or stator).

Abstract: An interior permanent magnet machine includes a stator having electromagnetic windings. The machine also includes a rotor that is disposed concentrically with the stator and is disposed about a rotor axis, the rotor comprising a rotor core defined by a first rotor lamination that is arranged to receive a first magnet set according to a first rotor topology and a second magnet set according to a second rotor topology.

Abstract: An electric power system for a vehicle includes at least one electric machine, one or more power rectifiers, and a plurality of DC channels. The at least one electric machine includes a plurality of tooth-wound multi-phase windings that are substantially magnetically decoupled, and the at least one electric machine is mechanically balanced even if one of the plurality of windings is de-energized. The one or more power rectifiers are configured to produce rectified power from the power generated by the at least one electric machine. The plurality of DC channels are formed after the at least one power rectifier and are configured to provide DC power to one or more loads within a vehicle.

Abstract: Disclosed a rare-earth permanent-magnetic axial coreless generator with double magnetic circuits, including a main shaft, a coreless stator winding, an inner rotor structure connected with the main shaft and an outer rotor structure. The outer rotor structure and the inner rotor structure are spaced apart by the coreless stator winding and are connected with the main shaft; the coreless stator winding is arranged between the inner rotor structure and the outer rotor structure, to establish a generator structure with two magnetic field air gaps; when the main shaft drives the outer rotor structure and the inner rotor structure to rotate simultaneously under the action of an external force, a rotating magnetic field with double magnetic circuits is generated in the generator; and the coreless stator winding can simultaneously cut magnetic lines of the rotating magnetic field with double magnetic circuits by using contact surfaces inside and outside the winding.

Abstract: A hybrid axle assembly that includes a housing assembly, a differential assembly received in the housing assembly, and an inside-out motor. The differential assembly is rotatable about a differential axis and has a differential input and a pair of differential outputs. The inside-out motor has a stator, which is fixedly coupled to the housing, and a rotor. The stator is disposed circumferentially about the differential input. The rotor is disposed circumferentially about the stator such that the stator is disposed radially between the differential input and the rotor. The rotor is drivingly coupled to the differential input.

Abstract: A compact washing machine capable of improving detergency or reducing a washing time is provided. A drum 30 may be rotatably installed in a tub 20 installed in the inside of a housing 10 in the state in which an opening 12 is toward an opening of the drum 30. A pulsator 40 having a protrusion 45 extending in a radial direction may be rotatably installed on a bottom of the drum 30. During washing operation, a controller 60 may control a driving device 50 to rotate the pulsator 40 and the drum 30 in opposite directions.

Abstract: The present invention discloses a new two-stator and two-rotor combined energy-saving motor, which relates to the technical field of motor. The motor comprises a motor shell, two rotors and two stators, wherein the stators and the rotors are arranged in the motor shell, each rotor comprises an outer rotor part, an inner rotor part and a flange, the outer rotor part is arranged outside the cylindrical inner rotor part, the outer rotor part and the inner rotor part are connected by flange; an inner stator zone is formed between the outer rotor part and the inner rotor part, and one of the stators is arranged in the inner stator zone of the rotor; an outer stator zone is formed between the outer rotor part and the motor shell, and the other of the stator is arranged in the outer stator zone.

Abstract: A control unit configured to control at least one motor of a vehicle is described that perform operations including receiving a target torque and a target speed for controlling the at least one motor, and determining, based on the target speed, a critical speed zone of the at least one motor. The critical speed zone defines a particular torque input to the at least one motor that induces torque ripple when the at least one motor is operating at any of a range of motor speeds. The operations performed by the control unit further include determining whether a current speed of the at least one motor is within the critical speed zone, and while determining that the current speed is within the critical speed zone, controlling a torque input to the at least one motor by avoiding the particular torque input defined by the critical speed zone.

Abstract: A rotating electric machine includes a stator having a winding head at each axial end and including a rotor, which is rotatably mounted in an opening in the stator and which has a rotor shaft and a laminated rotor core. The electric machine includes a bearing unit for the rotatable mounting of the rotor shaft with respect to the laminated rotor core, a transmission unit, a coupling unit, which is designed to provide at least two coupling states for coupling the rotation of the rotor shaft to the laminated rotor core and, in at least one of the coupling states, to couple the rotor shaft to the laminated rotor core by means of the transmission unit.

Abstract: An electric machine includes a housing, a rotor rotatably supported by the housing for rotation about a longitudinal axis and a stator assembly fixed secured to the housing spaced apart from a surface of the rotor and concentric with the rotor about the longitudinal axis. The stator assembly includes a stator winding comprising circumferentially spaced apart stator teeth about the longitudinal axis, the stator teeth having remote ends proximate the surface of the rotor. A plurality of sealed cooling channels extend parallel to the longitudinal axis and are disposed between remote ends of successive teeth. The cooling channels are formed in resin of the stator assembly, the cooling channels being fluidly connected to ports in a closed system to circulate cooling fluid to cool the stator assembly and configured to remove heat from the stator assembly proximate the rotor surface. Other aspects include methods of making such machines.

Abstract: An accumulator for storing fluid that includes a shell that defines an interior volume of the accumulator. The shell includes at least one port for providing fluid to a fluid system. The accumulator also includes an accumulator shaft disposed in the interior volume and extending at least partially across the interior volume from a first interior surface of the shell along a longitudinal axis of the shell, e.g., a central axis. The accumulator includes a piston-plate disposed in the interior volume such that the piston-plate and a second interior surface of the shell define a chamber in the interior volume. The accumulator further includes a motor disposed in the interior volume. The accumulator is configured such that rotational movement of the motor translates to linear movement of the piston-plate along the accumulator shaft.

Abstract: The present disclosure includes a washing machine including an inner rotor and an outer rotor. An outer rotor and an inner rotor may be rotated in a synchronous rotation mode or a counter rotation mode by converting the number of magnetic poles of the outer rotor. When the outer rotor becomes inoperable when the outer rotor is set to the number of magnetic poles for performing the counter rotation mode, it is converted to the number of magnetic poles for performing the synchronous rotation mode while the outer rotor is stopped.

Abstract: An electric machine is provided which includes a rotor disk extending along a radial direction and a having a rotor magnet embedded within the rotor disk. The electric machine further includes a stator assembly in axial or radial magnetic flux communication with the rotor magnets to generate a torque.

Abstract: A direct drive brushless motor including a plurality of rotational components and a plurality of non-rotational components. Ones of the pluralities of rotational and non-rotational components form a dual magnetic circuit. The plurality of rotational components includes a center rotation shaft circumscribed by a plurality of coils and a coil termination plate configured to support the plurality of coils. The plurality of non-rotational components includes a plurality of outer magnets arranged around the plurality of coils in a Halbach configuration and a plurality of inner magnets arranged in a Halbach configuration between the coils and the shaft. A flex cable having one or more leads provides electrical current to the plurality of coils without the use of brushes.

Abstract: An electric machine may include a rotor defining a cavity containing a magnet, an outer periphery and a top bridge therebetween. The top bridge defines at least two segments. Each of the segments has a width that is minimum closest to a Q-axis, is maximum closest to a D-axis, and monotonically increases from the minimum to the maximum such that during operation a rate of change of rotor magnetomotive force associated with each segment differs.

Abstract: A rotary motor comprising an annular rotatable bearing having an inner surface having a diameter equal to or greater than 0.5 meters and an outer surface, the bearing including a plurality of magnetic rotor teeth elements positioned around a circumference of the outer surface and a stator including a plurality of permanent magnets and a plurality of energizable coils, the stator mounted separately from and positioned with respect to the bearing such that the plurality of rotor teeth elements of the bearing are radially proximate to the permanent magnets of the stator. Upon application of alternating current in a flux switch pattern in the plurality of energizable coils of the stator, torque is applied to the plurality of magnetic rotor teeth elements.

Abstract: Provided is a washing machine motor capable of efficiently generating torque by improving a winding factor of coils with a relatively simple configuration. The washing machine motor (12) has an outer rotor (20), an inner rotor (30), and a stator (60). The outer rotor (20) and the inner rotor (30) share coils (63) of the stator (60), and a composite current is supplied to the coils (63) such that the outer rotor (20) and the inner rotor (30) are independently driven. The outer rotor (20) has forty eight outer magnets (24) arranged such that the N and S poles thereof are continuously and alternately aligned in the circumferential direction thereof. The inner rotor (30) has forty-two inner magnets (34) arranged such that the N and S poles thereof are continuously and alternately aligned in the circumferential direction thereof. The stator (60) has thirty-six I-shaped cores (61) and the coils (63).

Abstract: A high performance rotating electrical machine which aims at downsizing, and challenges inevitable technical problems such as deterioration of efficiency ? caused by copper loss and temperature rise inside the rotating electrical machine due to heat generation induced by eddy current generated in magnetic body.

Abstract: Present invention relates to a high performance rotating electrical machine which aims at downsizing, and challenges inevitable technical problems such as deterioration of efficiency ? caused by copper loss and temperature rise inside the rotating electrical machine due to heat generation induced by eddy current generated in magnetic body.

Abstract: A washing machine comprises an outer tub, an inner tub, a pulsator and a driving means having two rotors, a stator and a deceleration mechanism. One rotor drives the pulsator, and the other rotor drives the inner tub. During washing, the two rotors drive the pulsator and the inner tub to rotate in the same or opposite directions, and during dehydration, the pulsator and the inner tub rotate in the same direction and at the same speed. The automatic washing machine saves on energy consumption, has stable output and has high transmission efficiency.

Abstract: A fan includes a fan housing and a motor accommodated therein. The motor has a stator and a rotor, which is connected to a fan wheel. The fan housing consists of at least a housing upper part and a housing lower part. The housing upper part has an axial opening on the axial inner face of which facing the housing lower part the stator is arranged. On the axial outer face of the axial opening at least electronics are arranged.

Abstract: A power train apparatus may include an engine including a crankshaft and an engine block, a motor housing connected to the engine block and of which a housing opening is formed, a rotor portion connected to the crankshaft through the housing opening, of which a magnet is connected to a first side thereof and the rotor portion to which a balance portion is formed for compensating for imbalance rotational energy transmitted from the crankshaft; a stator portion disposed between the rotor portion and the motor housing and connected to the motor housing and a transmission connected to the engine block.

Abstract: The present invention relates to a steer-by-wire and independent-drive integrated wheel-side electric drive device, including a first double-rotor motor and a second double-rotor motor, fixedly arranged coaxially along an axial direction of a motor, an inner rotor of the first double-rotor motor is connected with a first drive shaft and is used for driving a wheel on one side to rotate; an inner rotor of the second double-rotor motor is connected with a second drive shaft and is used for driving a wheel on the other side to rotate; an outer rotor of the first double-rotor motor and an outer rotor of the second double-rotor motor are respectively connected with a driving gear by virtue of an output shaft.

Abstract: A power train may include an engine having a crankshaft and an engine block, a motor housing connected to the engine block and of which a housing hole is formed, a rotor portion connected to the crankshaft through the housing hole and of which a magnet is connected to a first side thereof, a stator portion disposed between the rotor portion and the motor housing, connected to the motor housing and including a coil corresponding to the rotor portion, a transmission connected to the engine block and a clutch selectively transmitting rotation of the rotor portion to the transmission.

Abstract: A double-stator switched reluctance motor includes an annular rotor, an outer stator disposed outside the rotor, and an inner stator disposed inside the rotor. Phases of the salient poles in a rotational direction of the rotor are different from each other in at least one of a set of first stator salient poles and second stator salient poles and a set of first rotor salient poles and second rotor salient poles.

Abstract: A multiphase motor is provided. The motor includes a rotor rotatable about an axis and a sectioned stator. The sectioned stator includes one or more stator sections. Each stator section has a core section including a yoke and a plurality of arcuately spaced apart teeth that extend generally radially from the yoke. The stator includes a plurality of electrically conductive wire windings. Each of the windings corresponds with a respective power phase. Each stator section is wound with each of the windings such that each stator section includes windings for all of the power phases.

Abstract: An energy efficient vehicle is provided. Wheels are disposed on the front and rear sides of the car body. A gasoline engine in the car body is used to drive an electricity generator to produce electric energy transferred to a capacitive battery, and then to a multi-loop disc-type dynamic motor. The multi-loop disc-type dynamic motor drives the car by rotating the wheels through a transmission and a differential. The multi-loop disc-type dynamic motor can produce large torque and horsepower through multiple stator rings disposed on a stator base and multiple permanent magnetic sheets disposed on the multiple annular ribs of a rotor base. Therefore, the electricity can be saved to elevate the endurance of the vehicle, and the vehicle does not need to stop for charging.

Abstract: A stator of a rotary electric machine includes a stator core and a coil. The stator core includes slots extending in an axial direction of the stator core and a first axial end surface in the axial direction. The coil is attached to the stator core and includes slot coils disposed in the slots and connection coils. At least one of the slot coils includes a slit in a part positioned in a slot among the slots. The slit extends through the at least one of the slot coils from a first axial end side of the stator core toward a second axial end side of the stator core opposite to the first axial end side in the axial direction. The connection coils are connected to the slot coils at a contact portion at a position outward from the first axial end surface in the axial direction.

Abstract: A coil group 23G is composed of windings 23U to 23W for U phase, V phase, and W phase. One ends 23U1 to 23W1 of the windings for the respective phases composing the coil group 23G are connected to respective power supply bus bars 25U to 25W, and the other ends 23U2 and 23W2 of the windings for the phases positioned at both ends in the circumferential direction in the coil group 23G extend toward the other end 23V2 of the winding for the rest of the phases, whereby the other ends 23U2 to 23W2 of the windings for the respective phases are mutually connected.

Abstract: Disclosed herein is a rotor for motor including a rotor tube disposed inside a stator, a rotor core that is formed on a circumferential surface of the rotor tube and integrally formed with the rotor tube, and magnets coupled to the rotor core. The rotor for motor provides an advantageous effect of preventing the deformation of the rotor tube in the process of assembling the rotor tube and the rotor core.

Abstract: A double-stator rotating electric machine includes a rotor and a pair of outer and inner stators. The outer stator has a first multi-phase coil wound thereon so as to form magnetic poles upon energization of the first multi-phase coil. The inner stator has a second multi-phase coil wound thereon so as to form magnetic poles upon energization of the second multi-phase coil. The number of the magnetic poles formed by the outer stator is equal to the number of the magnetic poles formed by the inner stator. Each of the magnetic poles formed by the outer stator is located at the same circumferential position as and has an opposite polarity to a corresponding one of the magnetic poles formed by the inner stator. The rotor has yoke portions each of which radially extends so as to form a magnetic flux passage magnetically connecting the outer and inner stators.

Abstract: The disclosure relates to printed circuit board motors and specifically to printed circuit boards used in motors and generators. Windings formed from copper on printed circuit boards have been used for purposes of forming antennas, inductors, transformers, and stators that can be incorporated in permanent magnet brushless DC (permanent magnet synchronous) machines. For energy conversion devices using modern permanent magnet materials and PCB stators, the magnetic field is not strongly confined by magnetically susceptible materials. Thus, the interaction between fields from adjacent turns in a winding, and/or windings on adjacent layers (for a multilayer configuration) may be significant. The structures disclosed hereinafter reduce the effective resistance in the windings, and therefore reduce the associated losses to achieve a reduced current density in portions of the rotating energy conversion devices.

Abstract: This invention presents a highly efficient electric motor which can be embodied in several configurations, including a standard motor, a hub motor, a linear motor, or other motor configuration. As a regenerative device, the motor may also act as a part-time or full-time electrical generator. There is provided a motor composed of a stator and a rotor. The stator has an array of coils arranged therein. The rotor has an array of magnets arranged therein. Each of the coils includes a first winding of wire wrapped around a core, and the wire has a non-circular cross-section. The wire can be a flattened wire.

Abstract: The disclosure relates to printed circuit board motors and specifically to printed circuit boards used in motors and generators. Windings formed from copper on printed circuit boards have been used for purposes of forming antennas, inductors, transformers, and stators that can be incorporated in permanent magnet brushless DC (permanent magnet synchronous) machines. For energy conversion devices using modern permanent magnet materials and PCB stators, the magnetic field is not strongly confined by magnetically susceptible materials. Thus, the interaction between fields from adjacent turns in a winding, and/or windings on adjacent layers (for a multilayer configuration) may be significant. The structures disclosed hereinafter reduce the effective resistance in the windings, and therefore reduce the associated losses to achieve a reduced current density in portions of the rotating energy conversion devices.

Abstract: A superconducting synchronous motor having a simple and stable structure is provided. The superconducting synchronous motor according to one embodiment of the present invention comprises: a rotary shaft; a rotation core mounted at the rotary shaft so as to be rotated by connecting with the rotary shaft; and hooked magnetic poles extending from one end of the rotation core in a longitudinal direction. Each of the hooked magnetic poles is composed of first and second inductors of a magnetic material alternately engaged with each other and a superconducting wire to be wound, and comprises a first superconducting field winding and a second superconducting field winding fixed closely at the other end of a first inductor rotation core and the other end of a second inductor rotation core, respectively. Each of the first superconducting field winding and the second superconducting field winding excites the first inductor and the second inductor to different poles.

Abstract: There is provided a method for inspecting a laminated iron core structured by laminating a plurality of iron core pieces-having a predetermined shape and including therein a cooling flow path allowing refrigerant to flow therethrough, the refrigerant being supplied and discharged through openings formed at different positions. The method includes arranging a light projecting part and a light receiving part of a photosensor in the openings of the cooling flow path, respectively, and detecting light from the light projecting part by the light receiving part to thereby inspect a penetrating state of the cooling flow path.

Abstract: The present disclosure relates to a radial and axial flux motor using integrated windings, which includes a rotor which includes a rotor core having a shape of a hollow cylindrical case, and permanent magnets for an inner lateral surface and permanent magnets for a ceiling surface that are coupled to the inner lateral surface and the ceiling surface of the rotor core respectively, and which is rotated about a shaft, and a stator which includes a stator core and windings coupled to the stator core and which is installed in the rotor. Therefore, a radial flux motor and an axial flux motor are integrated into one motor to be able to increase both efficiency and output.

Abstract: An electrical machine includes a rotor comprising a rotor core and a plurality of permanent magnets embedded radially within the rotor core to form a plurality of rotor poles. The electrical machine further includes a stator comprising a stator core disposed concentrically outside the rotor and including a plurality of stator teeth defining a plurality of stator slots there between. An arithmetic sum or difference of twice the number of stator teeth and the number of the stator poles equals the number of rotor poles.

Abstract: This disclosure relates in general to a new and improved electric motor/generator, and in particular to an improved system and method for producing rotary motion from a electro-magnetic motor or generating electrical power from a rotary motion input by concentrating magnetic forces due to electromagnetism or geometric configurations.

Abstract: A slim type motor for a washing machine having a direct drive system and having a heat radiating structure includes: a stator in which stator cores around which coils are wound are disposed in an annular form in an annular stator support whose central portion is open, in order to emit heat generated in the inside of the motor to the outside; a rotor in which a number of permanent magnets are arranged in a back yoke mounted on a circular rotor support, to thus form an air gap with respect to the stator; and a rotating shaft that is coupled to the central portion of the rotor support and is driven by a torque of the rotor.

Abstract: A switched reluctance apparatus and method of operating the same. The apparatus has an inner stator having a plurality of poles, a rotor disposed radially outward of the inner stator and having a plurality of segments serving as poles, and an outer stator disposed radially outward of the rotor and having a plurality of poles. A respective winding is disposed between every pair of adjacent poles of either stator. The apparatus operates with a plurality of separately excitable phases, a given phase being excited by energizing the windings corresponding to the given phase. Excitation of a given phase causes induction of magnetic fluxes traversing a region substantially confined to the region of the stators and rotor segments corresponding to the given phase, and causes a substantial amount of flux to enter rotor segments not in the radial direction but perpendicular to the radial direction.

Abstract: A magnetic gear mechanism including a simplified assembly of a magnetic flux modulating section in the magnetic gear mechanism which improves the strength thereof. In the magnetic flux modulating section of the magnetic gear mechanism, the magnetic flux modulating section being formed of a magnetic member and a non-magnetic member, a piece of the magnetic member and a piece of the non-magnetic member are separately produced. The piece of the magnetic member is sandwiched between circumferential projections provided in pieces of the non-magnetic member, and the magnetic member and the non-magnetic member and bearing holding sections form a structure in which the magnetic member and the non-magnetic member are fitted into the bearing holding sections by using recessed portions provided in the bearing holding sections and axial projections provided in the pieces of the non-magnetic member. This structure simplifies production and improves strength.

Abstract: A radial gap motor/generator that may be air or liquid cooled. The motor/generator has a stator in radially spaced relation to at least one thin annular induction structure. The motor/generator has at least two spaced apart annular rings each having an inner surface and outer surface, the annular rings having a permanent magnet structure embedded between the inner surface and outer surface of the annular rings. The motor/generator has at least two spaced apart radial gaps, the first gap between the first annular ring and the induction structure and the second gap between the second annular ring and the induction structure, the stator being disposed between the gaps. The motor/generator may include multiple gaps and multiple annular induction structures to increase the overall power density of the system.

Abstract: An ankle module for a prosthetic foot can have an adapter portion pivotally coupled to a base portion. The base portion can be coupled to the prosthetic foot. The adapter portion can have a coupling member that removably couples the prosthetic foot to a prosthetic pylon or socket. The adapter portion can also have cylinders housing pistons slidably displaceable within the cylinders. An actuator is selectively actuatable to place the cylinders in fluid communication, allowing a fluid to flow between the cylinders as an angular position of the adapter portion is adjusted relative to the base portion, thereby adjusting the dorsi-plantar position between the adapter portion and the base portion of the ankle module. The actuator can be selectively actuatable to fluidly isolate the cylinders from each other so that the angular position of the adapter portion relative to the base portion remains substantially fixed.

Abstract: A double-stator includes outer and inner stators each having magnetic poles. Outer-stator and inner-stator windings are connected in series in phases, thereby generating winding magnetomotive force. Outer magnets and inner magnets of a rotor are arranged in a rotor core in the circumferential direction, the outer and inner magnets being alternated between a radially outward portion and a radially inward portion, at a pitch equal to that of the poles of the outer and inner stators so as to be magnetized so that a radially outer side thereof will serve as N poles or S poles and that a radially inner side thereof will serve as S poles or N poles. The rotor core includes outer poles formed between the outer magnets circumferentially adjacent to each other in the radially outward portion, and inner poles formed between the inner magnets circumferentially adjacent to each other in the radially inward portion.

Abstract: The invention relates to a vehicle drive system, comprising an electromechanical converter, in particular an electric variable transmission. The converter is provided with a primary shaft having a rotor mounted thereon, a secondary shaft having an interrotor mounted thereon and a stator, fixedly mounted to a housing of the electromechanical converter. Viewed from the primary shaft in radial direction, the rotor, the interrotor and the stator are arranged concentrically relative to each other. Further, the primary shaft is arranged for being driven by an output shaft of an engine and the secondary shaft is arranged for driving an input shaft of a transmission unit.

Abstract: A method, apparatus, article of manufacture and system for producing a field pole member for electrodynamic machinery are disclosed to, among other things, reduce magnetic flux path lengths and to eliminate back-iron for increasing torque and/or efficiency per unit size (or unit weight) and for reducing manufacturing costs. For example, a field pole member structure can either reduce the length of magnetic flux paths or substantially straighten those paths through the field pole members, or both. In one embodiment, a method provides for the construction of field pole members for electrodynamic machines.

Abstract: In an in-wheel motor driving device, since an involute speed reduction gear with a small difference in number of teeth which can be made small in size can be disposed on an inner side of an inner rotor type motor, a size of the in-wheel motor driving device in the direction of a rotational axis can be reduced. Further, in the inner rotor type motor, since a first stator is disposed so as to face a radially outer side of a large-diameter rotor, heat generated in the first stator is easily dissipated. On the other hand, in an outer rotor type motor, since a second stator is disposed so as to face a radially inner side of a small-diameter rotor, a torque radius of the small-diameter rotor can be made large, thereby making it possible to ensure a large torque capacity. Because of this, the outer rotor type motor can be made smaller in diameter than the inner rotor type motor, thereby making it possible to ensure a large space within a wheel.