Abstract: An electric motor, a hoisting machine and also an elevator system are disclosed. The electric motor includes a stator, which stator includes slots, into which slots a concentrated winding is fitted. The electric motor also includes a rotating rotor, which rotor includes permanent magnets placed consecutively in a ring in the direction of the rotational movement. The ratio (LM/LP) of the width of a permanent Lp magnet at the point (LM) of the center line of the magnet and the width (LP)? of a magnetic pole of the rotor is at least ? and at most ?.

Abstract: Disclosed is an electric motor-driven compressor having a structure capable of improving the performance of an electric motor of the electric motor-driven compressor for the vehicle. The electric motor-driven compressor has an angle which is formed by two straight lines passing through a center of the rotor and making contact with both end portions of one permanent magnet, and is in a range of about 48.7° to about 51°. The cogging torque and the torque ripples are minimized, the power of the electric motor is improved, and the electric motor is easily controlled.

Abstract: A motor including a rotor and a stator. The rotor includes a rotor core, magnet pole portions, and core pole portions. First magnetic pole portions, which are the magnet pole portions or the core pole portions, each include a first and second opposing parts arranged in an axial direction. Each first opposing part includes an auxiliary groove, and each second opposing part does not include an auxiliary groove. Where M(°) represents an open angle of the first magnetic pole portion, G(°) represents an open angle of the void, and L represents the number of teeth, an angle D1 from a center line in the circumferential direction of the first magnetic pole portion to the side surface in the auxiliary groove that is closer to the center line in the circumferential direction satisfies D1=M/2+G?a×360(°)/L (where a is a natural number).

Abstract: A rotary electric machine configured with a stator, rotor, and permanent magnets disposed in an inverted V-shape that becomes gradually narrower from a side of a center of rotation of the rotor. The rotor is provided with a plurality of support portions that extend radially about the center of rotation, and gap portions are respectively formed in correspondence with the plurality of support portions at positions spaced by a predetermined distance from an edge portion of the permanent magnets in a flowing direction of magnetic flux between the permanent magnets and the stator. The gap portions are formed to have such a length that causes magnetic saturation during generation of low torque in a low-current state and that causes no magnetic saturation during generation of maximum torque in a high-current state in which electricity at a high current is supplied to the stator coil.

Abstract: A magnet element (37) and a method of its manufacture for assembly into a rotor (38), the magnet element (37) having magnetic domains aligned anisotropically to form a domain alignment pattern (42), wherein the magnetic domain alignment pattern (42) in the magnet element (37) has an orientation that varies substantially continuously across at least part of the magnet element (37) between its lateral edges from at least partially radial to at least partially tangential.

Abstract: A permanent magnet rotating electric machine includes: a stator including: a stator core having teeth, and an armature winding wound around each of the teeth to configure the multiple phases; and a rotor including a rotor core, and permanent magnets provided in order around the rotor core. The rotor is arranged to be spaced apart from the stator with an air gap therebetween. Each of the permanent magnets has a curved surface opposed to the stator and is configured to satisfy the following relationship: 0.65 ? Rm × h ? ? 1 W ? ( h ? ? 1 + g ) ? 1.37 where Rm denotes a radius of curvature of the curved surface, h1 denotes a thickness of a central portion of the permanent magnet in the peripheral direction, W denotes a width of the permanent magnet in the peripheral direction, and g denotes an air gap length of the air gap.

Abstract: An arrangement to compensate a non-uniform air gap, which is located in an electric machine is provided. The electrical machine includes a stator arrangement and a rotor arrangement. The rotor arrangement rotates around a longitudinal axis. At least parts of the rotor arrangement interact with parts of the stator arrangement to generate electrical power. The air gap is defined by the distance between the parts of the rotor arrangement and the parts of the stator arrangement. The parts of the stator arrangement are opposite to the parts of the rotor arrangement along a certain length. The cross section of the air gap changes along this length thus the air gap is not uniform in view to the referred certain length. The flux density of magnets, which are part of the rotor arrangement, is changed in dependency to the cross section of the air-gap.

Abstract: An exemplary heat dissipation fan includes a rotor and a stator. The stator includes a stator core. The rotor is rotatably mounted around the stator. The rotor includes a hub and a magnet ring received in the hub. The hub includes a top wall and a peripheral side wall depending from the top wall. The magnet ring is attached to the side wall and surrounding the stator. The magnet ring has a larger thickness as measured in a radial direction at a first end which is far away from the top wall than a second end which is adjacent to top wall, such that an attracting force formed between the first end of the magnet ring and the stator core is larger than that formed between the second end of the magnet ring and the stator core.

Abstract: A manufacturing method for a permanent magnet includes the steps of a) producing a permanent magnet (1), b) fracturing the permanent magnet (1) to obtain two or more separate pieces (13), and c) restoring the permanent magnet (1) by fitting the fracture surfaces of adjacent separate pieces (13) together.

Abstract: A periodic magnetic field generation device is provided with a field pole of a Halbach array structure in which main pole permanent magnets magnetized in a direction of a generated field and sub pole permanent magnets magnetized in a direction opposite to the direction of magnetic poles of the main pole permanent magnets are alternately disposed linearly or circularly so as to be adjacent to each other. A part of each of the main pole permanent magnets on a side on which the magnetic field is generated is replaced by a soft magnetic member, and a relation between a length A of the soft magnetic member on the side of the generated field along a moving direction and a length B of each main pole permanent magnet on a side of a back yoke along the moving direction is A<B.

Abstract: A permanent magnet motor includes: a rotor and a stator; and a plurality of permanent magnets placed on either the rotor or the stator. Each permanent magnet is an R—Fe—B based rare-earth sintered magnet including a light rare-earth element RL (at least one of Nd and Pr) as a major rare-earth element R, and partially includes a high coercivity portion in which a heavy rare-earth element RH (at least one element selected from the group consisting of Dy, Ho and Tb) is diffused in a relatively higher concentration than in the other portion.

Abstract: Improvement of torque densities, miniaturization and weight saving for outer rotor type motors or permanent-magnet-field-type DC motors can be efficiently achieved by high-energy densification of a magnet. However, torque pulsation or armature reaction gives negative influences thereto. Further, in application of a slotless (coreless) structure eliminating the torque pulsation or the armature reaction, the magnetic resistance of motor magnetic circuits will be enhanced. For solving the above problems, there is provided an annular magnet that is opened in a reverse direction relative to the opening direction of a U-shaped segment fabricated in constantly-directed magnetic fields, the annular magnet having an anisotropic distribution where angles relative to inner peripheral tangent lines can be continuously changed in the range of approximately 0 to 90 degrees, and having energy density (BH)max of 160 to 186 kJ/m3.

Abstract: A rotor (1) for an electric motor with permanent magnets (10) has a principal axis (D), comprises a laminated core (2) delimited by a first and a second end wall (4, 5) and by a lateral surface (6) and has a hole (7) for coupling to a motor shaft (8) and a plurality of longitudinal slots (9) for housing the magnets (10); the rotor also comprises positioning devices (20) for stabilizing the magnets (10) in the slots (9).

Abstract: Numerous arrangements for permanent magnets are disclosed that can focus the flux produced by the magnets. Depending on the particular application in which the disclosed designs and techniques are used, efficiency and reliability may be increased by minimizing flux leakage, increasing peak flux density, and shaping the flux fields to improve the effective coercivity of the flux focusing permanent magnet arrangement when loaded, and to achieve customized voltage and current waveforms. The disclosed magnet assemblies may be incorporated into a machine, such as a motor/generator, having windings and may be disposed for movement relative to the windings. The magnet assembly may be mounted on a support formed of one or more ferromagnetic materials, such as a back iron The disclosed flux focusing magnet assemblies may be formed using a variety of manufacturing methods.

Abstract: A motor rotor includes an annular body and a plurality of magnetic bodies installed on an inner lateral surface of the annular body in an irregular manner, to prevent a rotating motor from generating a cogging effect, disperse the frequency of the cogging torque, and reduce the amplitude. Accordingly, noises generated while the motor is operating are reduced, the periodicity of a cogging torque is changed, and cogging torque is reduced.

Abstract: A motor having a rotor and a stator is disclosed. A motor having a rotor and as stator is disclosed. The rotor is a consequent-pole rotor having a rotor core, a plurality of magnets, and a plurality of salient poles. The stator includes a plurality of teeth. The stator is arranged to be opposite to the rotor with a gap along the radial direction. The gap between the stator and the rotor is set to satisfy an expression 1<B/A, where A represents the shortest gap distance between the stator and the magnets, and B represents the shortest gap distance between the stator and the salient poles.

Abstract: To reduce the cogging torque of servomotors, electric power steering motors, and others, there is provided a permanent magnet motor comprising: a rotor 10 comprising a rotor yoke 11 and a plurality of permanent magnets (M1-M10); and a stator 20 comprising a stator yoke 22, salient magnetic poles 21, and armature windings 23, wherein at least one of the permanent magnets is disposed in an adjustment position that is displaced from a corresponding reference position in at least one of the circumferential, radial, and axial directions of the rotor yoke, and the plurality of permanent magnets excluding the permanent magnet disposed in the adjustment position is disposed in the reference positions, and wherein the adjustment position is set so that the permanent magnet motor in which at least one of the plurality of permanent magnets is disposed in the adjustment position has a smaller cogging torque than a permanent magnet motor in which all of the plurality of permanent magnets are disposed in the reference posi

Abstract: An electrical machine has at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles in each group is sited in its reference position. At least one magnet pole in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots. The displacement of the magnet poles provides a pronounced reduction in cogging.

Abstract: An apparatus and method for driving a motor of an air conditioner are disclosed. A method for driving a motor of an air conditioner includes driving the motor in response to a predetermined speed command, sequentially detecting first and second mechanical angles in response to the speed command or a reference speed being spaced apart from the speed command by a predetermined range, calculating a maximum speed mechanical angle corresponding to a maximum speed ripple of the motor on the basis of the detected first and second mechanical angles, and compensating for load torque of the motor on the basis of the calculated the maximum speed mechanical angle. As a result, the speed ripple is decreased during the constant speed operation.

Abstract: A micro rotor is disclosed and includes a plurality of circular or annular plate-shaped thick film magnets which each include an isotropic magnet with a thickness t1 having an in-plane remanence Mr of 0.95 T or more and a coercivity HcJ of 400 kA/m or more and a non-magnetic material with a thickness t2 adapted to isolate two adjacent isotropic magnets where the ratio of t1/t2 is eight or more and which are stacked on one another in multiple layers in the rotation axis direction, wherein at least two pole pairs are provided and a mean magnetic path of in-plane direction having a permeance (B/?oH) of five or more achieved by the magnet alone is provided, whereby eddy current is reduced. Also disclosed are a radial gap type brushless DC motor, a PM stepping motor and an electric generator which incorporate the above described micro 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 ?/2 plus a predetermined angle ??, 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: In a three-phase permanent-magnet synchronous machine, a pole gap and a skew of permanent magnets on the rotor are designed such that oscillating torques which are caused by the fifth and seventh harmonics of the stator field and of the rotor field are mutually reduced. In particular, the skew can be chosen as a function of the pole gap, such that the majority of the respective oscillating torques is neutralized. This results in minimal torque ripple.

Abstract: To improve tranquility and controllability of an iron core-equipped permanent magnet motor with an improved maximum energy product (BH)max by improving shape compatibility of a radial anisotropic magnet, there is provided a radial anisotropic magnet manufacturing method of fixing magnet powder in a net shape so as to maintain a magnetic anisotropic (C-axis) angle of a magnet with respect to a tangential line and for performing a deformation with a flow so as to have a predetermined circular arc shape or a predetermined annular shape. Particularly, by performing a deformation with a viscous flow or an extension flow, a deformability of the magnet is improved, and thus shape compatibility with respect to a thickness is. improved. A C-axis angle ? with respect to a tangential direction is controlled at an arbitrary position and an arbitrary angle so as to reduce cogging torque without separating a magnetic pole into segments.

Abstract: A brushless motor includes a two-phase winding stator having 4×n winding poles and auxiliary poles provided between the winding poles, and a rotor constituted by 6×n permanent magnet rotating poles having divided angle. The two-phase brushless motor can be driven by a control device for the two-phase motor which can transform electric power and rectify electronically. The two-phase brushless DC motor can increase a permeance coefficient of the rotor, improve the efficiency and the starting of the motor, and reduce torque ripple and noise thereof.

Abstract: A rotor for an electrical machine includes a rotor hub and a plurality of permanent magnet segments affixed around a perimeter of the rotor hub. A first plurality of the permanent magnet segments have a substantially uniform arcuate span and are formed of a single unitary piece of material. A multi-piece permanent magnet segment includes at least two pieces, each having a smaller arcuate span than the first plurality of segments. The magnetization direction vector of one piece different than the magnetization direction vector of at least one other piece in each multi-piece segment.

Abstract: Provided is a synchronous motor comprising a rotor that includes magnetic poles arranged at equal intervals in the circumferential direction, and a stator that includes stator teeth arranged at intervals in the circumferential direction. Stator teeth other than a reference tooth are displaced from positions corresponding to integral multiples of the phase difference of two-phase alternating currents with respect the stator tooth in electrical angle. Both a first-type coil supplied with a first phase and a second-type coil supplied with a second phase are wound by concentrated winding on the stator teeth arranged at the displaced positions.

Abstract: A brushless motor has a stator and a rotor. The stator has a stator core and stator windings. The stator core has a stator yoke and teeth extending radially inwardly from the stator yoke. The stator windings are formed by concentrated coils wound on the teeth. The rotor has a rotor shaft, a rotor core fixed to the rotor shaft and magnets fixed in slots formed in the rotor core. Each magnet is plate shaped and extends in both axial and radial directions of the rotor and each magnet is magnetically charged across its thickness so that a rotor pole is formed between two adjacent magnets. The ratio of the radial thickness (Y) of the stator yoke to the width (T) of the tooth body is from 0.4 to 0.7.

Abstract: There is provided a permanent magnet motor capable of reducing cogging torque and torque ripple while suppressing a decrease in motor output. In a permanent magnet motor 1 including a rotor 3 in which a plurality of permanent magnets 5 are arranged in a ring shape as a magnetic field unit, the transverse cross section of the permanent magnet 5 has an inside periphery 51 formed by a first arc 511 having the center of curvature O1 and the radius of curvature R1, and an outside periphery 52 formed by a second arc 521 having the center of curvature O2 and the radius of curvature R2, a third arc 522 having the center of curvature O3 and the radius of curvature R3 and joined to one end of the second arc 521, and a fourth arc 523 having the center of curvature O4 and the radius of curvature R4 and joined to the other end of the second arc 521. The above-described centers of curvature are disposed at different positions.

Abstract: Embodiments of the invention relate generally to electric motors, alternators, generators and the like, and more particularly, to stator structures and rotor-stator structures for motors that can be configured to, for example, reduce detent.

Abstract: An axial gap motor includes: a rotor; and a stator, wherein: the rotor includes a plurality of main permanent magnet parts and a plurality of auxiliary permanent magnet parts, the auxiliary permanent magnet parts being disposed near an end portion of each of the main permanent magnet parts and a magnetizing direction of each of the auxiliary permanent magnet parts corresponding to a direction perpendicular to the direction of the rotational axis; each of the stators includes a plurality of teeth arranged in a circumferential direction and protruding toward the rotor along the rotational axis, and a circumferential distance between a circumferential direction first end and a circumferential direction second end of each of the auxiliary permanent magnet parts on a surface opposite the stator is larger than a slot width of a slot defined between the teeth adjacent in the circumferential direction.

Abstract: The present invention relates to a two-phase brushless DC motor which can increase a pemerance coefficient of a rotor to the maximum to thereby improve efficiency and starting feature of the motor, and to reduce torque ripple and noise thereof. The brushless motor of the present invention includes a two-phase winding stator having 4×n winding poles and auxiliary poles provided between the winding poles, and a rotor constituted by 6×n permanent magnet rotating poles having divided angle. Auxiliary poles between the stator poles can be provided. The two-phase brushless motor of the present invention can be driven by a control device for the two-phase motor which can transform electric power and rectify electronically.

Abstract: A complementary permanent magnet structure capable of minimizing the cogging torque for a rotating electric machine, the complementary permanent magnet structure comprising: a magnetic pole core being cylinder shaped with even numbered arc-shaped magnetic sets positioned with equal distances on the circumference thereof, each magnetic set being composed of a first permanent magnet unit and a second permanent magnet unit; and an armature core being ring shaped with a plurality of slots; wherein the ratio of the number of the slots to the number of magnetic poles of the magnetic pole core is 3/2; wherein the first permanent magnet unit and the second permanent magnet unit are positioned correspondingly to generate two complementary cogging torques with 180 degrees of electrical angle difference.

Abstract: The permanent magnet type rotary machine is capable of reducing cogging torque even if permanent magnets are displaced in the axial direction and which is capable of reducing production cost and increasing torque. At least a stator unit of a first phase out of two stator units, which are stacked with a phase difference of (360°/(2P)), is stacked m-th, from one end of the stack of the stator units, to face magnetic poles of one of the permanent magnets. The other stator unit of the second phase, whose excitation cycle is shifted ¼ cycle with respect to that of the stator unit of the first phase, is stacked ((nQ/2)+m)-th, from the one end of the stack, to face magnetic poles of another permanent magnet. Note that, P is number of the magnetic poles of the permanent magnet; m is an integer of (nQ/2) or less, and one or more; Q is an even number of two or more; and n is an integer of one or more, and the product of n×Q is an integer of four or more.

Abstract: An armature for a linear motor is described. The armature includes a first of a pair of magnetic structures comprising a first plurality of maglettes each having a magnetic polarity vector; an angle between two adjacent magnetic polarity vectors in the first plurality of maglettes having a first magnitude; and a second of the pair of magnetic structures comprising a second plurality of maglettes each having a magnetic polarity vector; an angle between two adjacent magnetic polarity vectors in the second plurality of maglettes having a second magnitude, the first plurality of maglettes including a first outer maglette that is adjacent to a second outer maglette of the second plurality of maglettes, an angle between the magnetic polarity vectors of the first and second outer maglettes having a third magnitude that is different than at least one of the first and the second magnitudes.

Abstract: A rotor is deployed such that the rotor becomes coaxially rotatable with a stator. A shaft is fixed onto the axis of a rotor iron-core. 1-pole constituting magnet slots are deployed into V-character pattern along an outer circumference portion of the rotor iron-core. Permanent magnets are embedded into the magnet slots. For the 1 pole, the 2 pieces of same-polarity permanent magnets are embedded into the V-character pattern. The configuration of each embedded permanent magnet is designed as follows: From the thickness of the permanent-magnet edge portion on the inner-diameter side of the rotor iron-core, which becomes the center of the V-character pattern, the thickness of the permanent magnet gradually increases toward the outer-diameter side of the rotor iron-core, which become the right and left edge portions of the V-character pattern. Simultaneously, curved lines are provided on both edge portions of the permanent magnet.

Abstract: To reduce the cogging torque of servomotors, electric power steering motors, and others, there is provided a permanent magnet motor comprising: a rotor 10 comprising a rotor yoke 11 and a plurality of permanent magnets (M1-M10); and a stator 20 comprising a stator yoke 22, salient magnetic poles 21, and armature windings 23, wherein at least one of the permanent magnets is disposed in an adjustment position that is displaced from a corresponding reference position in at least one of the circumferential, radial, and axial directions of the rotor yoke, and the plurality of permanent magnets excluding the permanent magnet disposed in the adjustment position is disposed in the reference positions, and wherein the adjustment position is set so that the permanent magnet motor in which at least one of the plurality of permanent magnets is disposed in the adjustment position has a smaller cogging torque than a permanent magnet motor in which all of the plurality of permanent magnets are disposed in the reference posi

Abstract: A motor having a rotor including first outer surface segments providing uniform air gaps and second outer surface segments providing non-uniform air gaps. The rotor has an outer surface contour comprising a number of first outer surface segments defined by arcs having a first radius centered on a central longitudinal axis and a number of second outer surface segments defined by lines other than arcs having a first radius centered on a central longitudinal axis.

Abstract: An anisotropic permanent magnet motor includes a stator and a rotor opposed to teeth of the stator with a gap therebetween, and the rotor includes an anisotropic permanent magnet disposed on a surface of a rotor yoke. The anisotropic permanent magnet has an orientation direction set in a direction normal to the outer-peripheral surface in a range of both ?r°/2 from a magnetic pole center and continuously inclined toward a magnetic pole end with respect to a direction normal to the outer-peripheral surface.

Abstract: An electric machine includes a rotor having at least one pole pair, the at least one pole pair including a first magnetic pole and a second magnetic pole having opposite polarities. The first magnetic pole may include a first inner radial permanent-magnet layer and a first outer radial permanent-magnet layer. The second magnetic pole may include a second inner radial permanent-magnet layer and a second outer radial permanent-magnet layer. An outer end of the first inner radial permanent-magnet layer and an outer end of the second inner radial permanent-magnet layer may be separated by an angle of between about 27 and about 55 electrical degrees. The electric machine may also include a stator having a stator core with an odd number of stator slots per pole pair of the rotor.

Abstract: A micro rotor is disclosed and includes a plurality of circular or annular plate-shaped thick film magnets which each include an isotropic magnet with a thickness t1 having an in-plane remanence Mr of 0.95 T or more and a coercivity HcJ of 400 kA/m and a non-magnetic material with a thickness t2 adapted to isolate two adjacent isotropic magnets where the ratio of t1/t2 is eight or more and which are stacked on one another in multiple layers in the rotation axis direction, wherein at least two pole pairs are provided and a mean magnetic path of in-plane direction having a permeance (B/?oH) of five or more achieved by the magnet alone is provided, whereby eddy current is reduced. Also disclosed are a radial gap type brushless DC motor, a PM stepping motor and an electric generator which incorporate the above described micro rotor.

Abstract: A compacted magnetic core with a high resistance, which comprises compacted magnetic powder of an iron powder or an alloy powder containing iron as a main ingredient and a layer of a rare earth metal fluoride or an alkaline earth metal fluoride on the surface of the powder, wherein the rare earth metal fluoride or the alkaline earth metal fluoride contains fluorine-depleted crystal lattice at a rate of 10% or less.

Abstract: A permanent magnet motor includes stator, rotor, and shaft; multiple rotor magnetic poles are disposed on the rotor; each rotor magnetic pole contains an arc surface and a first inclined section and a second inclined section extending respectively from both sides of the arc surface; a trap is formed between two second inclined section of two abutted rotor magnetic poles connected by a tangent section; multiple magnets are respectively disposed in each rotor magnetic pole; both ends of each magnet being disposed at where close to two second inclined sections; and a central portion of each magnet is indented inwardly towards a center of the rotor to effectively upgrade performance efficiency of the motor.

Abstract: For an electrical reluctance rotary machine, a stator has a winding as an armature, and a rotor has permanent magnet implanting slots provided in a rotor core at lateral sides magnetic poles configured to produce reluctance torque along directions of magnetic flux passing through the magnetic poles to produce reluctance torque, and permanent magnets inserted in the permanent magnet implanting slots so as to cancel magnetic flux of the armature intersecting that magnetic flux, to control a magnetic field leaking at ends of the magnetic poles, having circumferential magnetic unevenness. The electrical reluctance rotary machine is configured to meet a relationship, such that 1.6 ? P × W pm R ? 1.9 where Wpm [mm] is a width of permanent magnet, R [mm] is a radius of the rotor, and P is the number of poles.

Abstract: A rotating electrical machine rotor which comprises: a rotary shaft; two field spiders which have the same diameter ranging between 90 and 120 mm and which are mounted centred on the shaft, each field spider comprising a circular radial plate; prongs extending axially toward the other field spider so as to nest tangentially between two adjacent axial peripheral prongs of the other field spider; an interpolar tangential space left between the opposing parallel lateral faces of two consecutive prongs of each field spider; and at least one ferromagnetic interpolar element the width (Lf) of which is defined orthogonal to the lateral faces of the adjacent prongs. According to the invention, the active width (Lf) of the ferromagnetic element is between 5 mm and 6 mm.

Abstract: The present invention provides an electrical machine 1 with reduced cogging. The magnet poles 3 of the electrical machine are comprised of at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles 3 in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole 3 is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles 3 in each group is sited in its reference position. At least one magnet pole 3 in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots.

Abstract: An actuator includes a rotor, a stator containing the rotor, and a bearing to support the rotor to be rotatable with respect to the stator about the central axis of the rotor and an axis perpendicular to the central axis. The rotor includes rotor central magnetic poles, a rotor upper magnetic pole, and a rotor lower magnetic pole. The stator includes stator central magnetic poles larger in number than the rotor central magnetic poles, stator upper magnetic poles, stator lower magnetic poles, central coils to appropriately magnetize the stator central magnetic poles, upper coils to appropriately magnetize the stator upper magnetic poles, and lower coils to appropriately magnetize the stator lower magnetic poles. The length of each stator central magnetic pole along a central axis of the stator is larger than a length of each rotor central magnetic pole along the central axis of the rotor.

Abstract: The present invention relates to a rotary electric machine comprising: a concentrated winding stator having teeth and coils placed on the teeth, the teeth having end faces that are convex towards the rotor; and a rotor comprising an armature defining a cylindrical surface and permanent magnets, the permanent magnets having inside faces that are cylinder portions matching the shape of the cylindrical surface of the armature, and outside faces that are plane and that face towards the stator.

Abstract: A brushless motor including a rotor which has ten permanent magnets each containing rare earth neodymium and provided around a rotor yoke and an outside diameter of 45 mm to 55 mm, and a stator which has a stator core having twelve slots and an outside diameter of 75 mm to 85 mm and whose magnetomotive force at maximum current is 700 AT or more. The stator core is configured such that a teeth width b is 0.14 times or more of the outside diameter of the rotor.

Abstract: In a radially anisotropic sintered magnet of annular shape, the remanence in a radial direction of the annulus increases and decreases at intervals of 90° in a circumferential direction of the annulus, and the remanence in a radial direction over the entire circumference of the annulus has a maximum of 0.95-1.60 T and a minimum equal to 50-95% of the maximum. In a permanent magnet motor comprising a plurality of stator teeth, the radially anisotropic annular sintered magnet is incorporated after it is magnetized in 4n poles (wherein n is an integer of 1 to 20) so that the boundary between N and S poles is located within the range that is centered at the radial direction where the remanence exhibits the minimum and extends ±10° therefrom in a circumferential direction. The radially anisotropic annular sintered magnet undergoes neither fracture nor cracking during the sintering and aging/cooling steps even when it is shaped to a low inner/outer diameter ratio and has satisfactory magnetic properties.

Abstract: A claw-pole motor includes a rotor having permanent magnets; and a stator having stator rings assigned to three phases, which are coaxially stacked along the same axis. Winding attachment portions are formed between adjacent stator rings, and an annular winding is installed in each winding attachment portion for generating a magnetic field for rotating the rotor. Each stator ring has a main body and claw-shaped induction poles which protrude from the main body in radial directions. The claw-shaped induction poles of the three phases are serially arranged along a circumference of the stator rings and also face the permanent magnets. An interval between adjacent claw-shaped induction poles along the circumference of predetermined two of the stator rings of the three phases is smaller than an interval between adjacent claw-shaped induction poles along the circumference of any other pair of the stator rings.