Abstract: A rotor for a high speed permanent magnet motor comprises a central spindle (20), and a plurality of magnet discs (21) stacked on the spindle (20) and axially clamped by a clamping device (24-26, 28) on the spindle (20) to form an axially pre-tensioned disc packet core (16). Each magnet disc (21) has at least one electrically insulating layer, and a reinforcement disc (23) is provided between the magnet discs (21) and/or between at least one of the magnet discs (21) and the clamping device (24-26, 28). The reinforcement discs (23) are clamped such that a clamping force generated frictional engagement is obtained between the reinforcement discs (23) and the magnet discs (21) by which centrifugal forces are transferred from the magnet discs (21) to the reinforcement discs (23) during motor operation, thereby relieving the magnet discs (21) of tensile stress.

Abstract: An rotary electric machine 1 comprises stator 2 having a stator core 4 wounded with stator windings 5 and a rotor 3 having a rotor core 7 rotatable and opposite to the stator core 4 through a gap. The rotor core 4 of the roraty electric machine 1 is composed of a plurality of projecting pole magnetic core portions 73 arranged in a side of the gap and along the circumferential direction and a plurality of rotor yoke portions 76 for forming a magnetic path conducting magnetic fluxes of each of the projecting pole magnetic core portions 73, and the rotor core is divided in the circumferential direction on a unit of each of the projecting pole magnetic core portions 73 and each of the rotor yokes 76 opposite to each of the projecting pole magnetic core portions 73. It is possible to provide a rotary electric machine which is high in material use factor at manufacturing a rotor core and small in size and light in weight, and to provide an electric vehicle using the rotary electric machine.

Abstract: A rotor according to the prior art has a top part and a bottom part, where the bottom part has stays that are mechanically connected to the top part. However, this has the disadvantage that very strict tolerances must be respected and the type of fastening is not secure. A rotor according to the invention has a ring, which presses stays and thus, by means of positive and frictional engagement, magnets against a tubular element, which in turn is disposed on a bottom part. The bottom part, together with a rotor shaft and a top part, constitutes a rotor.

Abstract: A system for forming a precision shaft for a permanent magnet motor employs a working surface region of the precision shaft and a coaxially arranged rotor region. A cutting tool is used to make a first machining or cutting pass along the entire length of the working and rotor regions. Subsequent passes of the cutting tool are limited to the working region of the motor shaft to form a threaded ball screw shaft portion. The rotor region, however, remains with but a continuous shallow groove that is surrounded by a helical shaft portion having the original diameter of the precision shaft. Thus, preparation of the shaft to effect bonding of the magnetic rotor does not affect the shaft diameter. The depth of the shallow groove in the rotor region is approximately between 0.001″ and 0.004″, and preferably 0.003″. The permanent magnet rotor is bonded to the rotor surface region of the precision shaft by an A+B heat cured type of epoxy.

Abstract: A rotor assembly is provided in which the rotor assembly comprises includes a first core portion, wherein the first core portion has at least one first core protrusion, and a second core portion, wherein the second core portion has at least one second core protrusion. The first core portion and the second core portion are configured to be matingly coupled to each other so as to form an assembled rotor assembly. In addition, the rotor assembly comprises includes a plurality number of magnetizable members wherein respective ones of the plurality of magnetizable members are coupled to each of the first core protrusions and coupled to each of the second core protrusions. The plurality of magnetizable members are adapted to be coupled to a magnetizing fixture prior to mating the first and second core portions so as to magnetize the magnetizable members.

Abstract: Several embodiments of magnet retainers for rotating electrical machines that provide excellent magnet retention even if very thin high strength magnets are employed and without requiring adhesives.

Abstract: A method for determining a dimension in a motor is described. By applying Fourier analysis, a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave. Based upon the above, a determination of an angle &dgr; (22) is described, wherein the fifth harmonic term of the sequence of terms is minimized. An electronic motor having a rotor (26) and a set of slot on said rotor surface (36) having a set of magnets (46) with a width &dgr; (22) along the circumference (30) of said rotor surface (36) is described. The width &dgr; (22) is determined by a method that includes applying Fourier analysis thereby a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave.

Abstract: A magneto-generator, a method of manufacturing the same and a resin molding die for manufacturing the same. In the magneto-generator, a guard ring is omitted with the performance of the magneto-generator being enhanced. The magneto-generator is manufactured by making use of a resin molding die (21) having an outer peripheral surface (21d) to be positioned in opposition to an inner peripheral surface of a flywheel (11) and projections (21a) provided in the outer peripheral surface (21d) for holding a plurality of magnets (12) at predetermined positions, respectively. The magnets (12) are positioned and held stationarily at predetermined positions by the aforementioned projections, respectively, and spaces defined between the resin molding die (21) and the inner peripheral surface of the flywheel (11) are filled with a resin. After hardening of the resin, the resin molding die (21) is detached from the flywheel (11).

Abstract: In the embodiments described in the specification, permanent magnets are retained on a permanent magnet rotor rim by inverted U-shaped retainers and in one embodiment the outer surfaces of the retainers converge inwardly in the radially outward direction and engage corresponding surfaces of adjacent pole pieces which converge inwardly in the radially outward direction. In another embodiment the U-shaped retainers are affixed to the rotor rim by screws accessible through openings in the radially outer wall of the retainers and a further embodiment each retainer has outwardly projecting flanges which are affixed to the rotor rim by screws.

Abstract: A magnetic material fixing structure of motor rotor including multiple overlapping silicon steel plates. An outer circumference of each silicon steel plate is recessed to form multiple receptacles at equal intervals. A magnetic material is disposed in each receptacle. The receptacle has two lateral faces, a bottom face and an opening opposite to the bottom face. Each of adjoining sections of the two lateral faces and the bottom face is formed with a dented section dividing the lateral faces and bottom face of each receptacle into multiple resilient plates. When inlaying the magnetic material into the receptacle, the resilient plates are deformed to resiliently tightly clamp the magnetic material.

Abstract: A rotor has magnets segmented in a circumferential direction of a periphery of a shaft, wherein magnetizing directions of the segmented magnets continuously vary, and a non-magnetic material or a ferromagnetic material is interposed in a circumferential gap between the segmented magnets. Further, a method of manufacturing a rotor comprises steps of arranging coils so that a longitudinal direction of each of the coils is along an axis of the shaft and magnetizing the segmented magnets. Still further, a rotary machine uses the rotor.

Abstract: A miniature PMDC motor 10 has a permanent magnet stator comprising two arcuate ceramic magnets 20 fitted to a can-like housing 11 and circumferentially separated by interdisposed rubber magnets 21 wedging or nipping the ceramic magnets 20 in place within the housing 11 without the use of circumferential magnet stops formed in the side of the housing.

Abstract: Squirrel cage type asynchronous motors such as alternating current induction motors and high speed asynchronous induction motors having a unitary rotor and shaft assembly and a method of making such a one piece, solid rotor and shaft to achieve a more stable and higher strength rotor and shaft with an increased critical frequency. The solid rotor and shaft includes a central rotor portion having a substantially larger diameter than the opposing shaft portions extending from either end of the rotor portion. Conductor bar passages are formed adjacent the outer circumferential surface of the rotor portion to accept the respective number of conductor bars making up the secondary winding in the solid rotor and shaft.

Abstract: An improved DC electrical starting motor and method for starting internal combustion engines that reduces starter motor noise in the period after the engine starts by damping the vibrations caused by motor cogging as it coasts to a halt, is done by reducing cogging torque and or rigidifying the starter motor housing. In addition several new structures foe reducing cogging torque are disclosed.

Abstract: In the embodiments described in the specification, permanent magnets are retained on a permanent magnet rotor rim by inverted U-shaped retainers and in one embodiment the outer surfaces of the retainers converge inwardly in the radially outward direction and engage corresponding surfaces of adjacent pole pieces which converge inwardly in the radially outward direction. In another embodiment the U-shaped retainers are affixed to the rotor rim by screws accessible through openings in the radially outer wall of the retainers and a further embodiment each retainer has outwardly projecting flanges which are affixed to the rotor rim by screws.

Abstract: A rotor assembly is comprised of a rotor core and at least one magnet. The rotor core has a support protrusion projecting radially outwardly from the core exterior surface. The at least one magnet is positioned on the support protrusion and is supported in a radially outward spaced relation from the core exterior surface. The radially outward spacing defines a radial spacing between the core exterior surface and the at least one magnet. A connection is located in the radial spacing and holds the at least one magnet to the core exterior surface. A method of assembling the rotor core assembly comprises the steps of providing the rotor core with a support protrusion projecting radially outwardly from the core exterior surface. Providing at least one magnet.

Abstract: A composite powder metal disk for a rotor assembly in an induction machine. The disk includes a magnetically conducting powder metal segment and a plurality of axially extending slots around the exterior surface of the disk. In each slot is a conductor, for example cast aluminum or copper bars, enclosed within the slot by a magnetically non-conducting powder metal segment. A rotor assembly is also provided having a plurality of the composite powder metal disks mounted axially along a shaft with their magnetic configurations aligned. A method for making the powder metal disks is further provided including filling a die with the powder metals, compacting the powders, and sintering the compacted powders.

Abstract: A motor comprising: a rotor including a permanent magnet type rotor unit having a plurality of permanent magnets and a reluctance type rotor unit having a plurality of magnetic salient pole portions and a plurality of slits for preventing flux leakage, the rotor units being coupled to each other in an axial direction; and a stator for generating a field for driving the rotor. Elongated holes for preventing the short-circuit of magnetic fluxes are arranged near edges of the permanent magnet of the permanent magnet type rotor unit. The elongated holes or notches are arranged within a range defined so that 0.95&agr;≦&thgr;≦1.

Abstract: An electromagnetic machine is provided. The machine includes a stator extending along a longitudinal axis and having an inner surface defining a rotor receipt cavity. The rotor extends along and is rotatable about the longitudinal axis within the rotor receipt cavity. A plurality of ring assemblies are supported on the rotor and a plurality of magnets are circumferentially spaced about the rotor and extend through the ring assembly. Each magnet is generally parallel to the axis of the rotor.

Abstract: A permanent magnet motor assembly for use in a flywheel is disclosed, including a rotor, a stator, and a coil positioned in the stator. One or more magnets is attached to the rotor such that magnetic field lines are directed radially toward the coil for generating torque and thus driving the motor. A shield covers the magnet, preventing the magnetic flux lines from impacting a plate on the stator and causing excess heat and energy losses. The shield can be a cup or a snap-fit ring preferably made of magnetic steel which directs stray magnetic flux lines toward the rotor to be converted into useful work.

Abstract: The rotor has a core with an internal space. Permanent magnets are arranged on the core. These permanent magnets are surrounded by an outer cylinder, which is connected flush to closure disks which bear stub shafts. Channels run out from the internal space in the radial direction to the region of the permanent magnets. A resin mass is first introduced into the internal space. The rotor is thereafter heated and run up to centrifuging rotational speed. As a result, the molten resin mass flows through the channels to the region of the permanent magnets and fills up all the cavities present there and also cracks which form in the brittle permanent magnets on running up to speed. The resin mass hardens while the rotor is kept at centrifuging rotational speed. Each surface region of the permanent magnets is thus reliably protected against corrosion.

Abstract: A high-power electrodynamic machine operates at a relatively high rotational speed and has dual rotors. In a preferred generator embodiment, one relatively massive first rotor having a magnetic device integral therewith is dedicated to the main generator. The exciter generator, which is relatively less massive, is isolated on a second rotor, which has a magnetic device integral to it. Only three bearings are required. The distance between the two bearings for the first rotor is relatively short, and the first rotor is relatively stiff, both of which facilitate operation of the first rotor below the critical speed. The junction of the first and second rotors further includes support of a junction end of the second rotor. The second rotor is driven by a prime mover via the first rotor. Means for providing electrical connections between the magnetic devices of the first and second rotors is also provided.

Abstract: A flux ring for a motor of a power tool has an annular housing which fits inside the motor can of the motor. At least one magnet is on the ring. The at least one magnet includes a portion formed from an isotropic magnetic material and a portion formed from an anisotropic magnetic material. Preferably, the isotropic magnetic material is sandwiched by the anisotropic magnetic material. The magnets being molded onto the flux ring in a two shot process.

Abstract: A rotor core, rotating in the vicinity of a generating coil, comprises a balance weight section and a pair of magnetic poles, provided on opposite sides of the balance weight section 2 with respect to a center of rotation O of the rotor core 1 to sandwich a magnet, and confronting through a magnetic gap G. A magnet holding section 9 for preventing the magnet 5 flying out through the magnetic gap G due to centrifugal force, is provided integrally contiguous to each of the magnetic poles so as to connect between the two magnetic poles.

Abstract: In the magnet retention channel arrangement for a high speed rotor described in the specification, a rotor has an array of radially projecting, angularly spaced pole pieces and a magnet retention channel arrangement inserted between each adjacent pair of pole pieces. Each magnet retention channel arrangement has ferromagnetic side walls and a nonmagnetic alloy cap and nonmagnetic alloy dovetail feet affixed to opposite edges of the ferromagnetic side walls by welding or by a hot isostatic pressed powder metallurgy technique. The channels contain permanent magnets and the ferromagnetic side walls couple the flux from the magnets to the pole pieces with substantially no magnetic discontinuities and the nonmagnetic alloy cap and nonmagnetic core avoids magnetic shorting.

Abstract: A rotor of a motor has a cylindrical magnet coaxially disposed with a shaft. The shaft and the magnet are bonded with thermosetting resin formed by injection molding. Since the molding shrinkage of the thermosetting resin is so small that a high preciseness is achieved in the motor structure. This precision structure can reduce vibration due to unbalance of a rotor. Also, an annealing process, in which a motor is left at a temperature higher than the limit temperature for operating the motor, can be eliminated. As a result, the efficiency of producing the motor can be improved.

Abstract: The present invention relates a rotary electric machine having

Abstract: A miniature vibration motor structure includes a housing having a hole for receiving and positioning one end of a shaft whose other end is positioned in a fixing plate. A rotor includes a bearing integrally combined with an annular permanent magnet. The bearing of the rotor is supported and rotated on the shaft. The bearing or the annular permanent magnet is provided with a recess or protruding block, so that the center of gravity and the center of rotation of the rotor are not in concert with each other. A stator seat is wound with a coil and has a power inlet for supplying an electric power into the stator seat. The stator seat has poles which may be induced with the permanent magnet of the rotor.

Abstract: The alternator rotor includes a polygonal shaped rotating core defining a plurality of flat faces. A plurality of polygonal shaped permanent magnets cooperate with the flat faces of the core. The permanent magnets form voids between adjacent permanent magnets. A plurality of titanium or titanium alloy filler pieces is positioned, respectively, in the voids created between adjacent permanent magnets. A compressive outer sleeve encloses the core, permanent magnets, and titanium filler pieces to form the alternator rotor.

Abstract: A rotor mounting assembly includes a first resilient ring, a second resilient ring and a spacer. The resilient rings and the spacer are fabricated from center punch laminates produced from a stator bore punch process. The second resilient ring includes at least one aperture in addition to a central bore. A method of fabricating the rotor mounting assembly includes positioning a press pin through the aperture to contact the first resilient ring which allows a press to simultaneously presses both resilient rings onto a knurled rotor shaft, reducing manufacturing cost.

Abstract: The method of manufacturing rare earth thick film magnet comprising a step of forming an alloy layer of 30-100 &mgr;m thick having a general formula RXBYTMZ on a substrate by a physical deposition process, and a step of heat-treating the alloy layer to form a thick film magnetic layer having R2TM14B phase as a main phase. In the general formula, R is at least one of rare earth elements, B is boron, TM is iron or its alloy partly substituted by cobalt. X is 0.1-0.2, Y is 0.05-0.2 and Z=1−X−Y. Further, the method of the present invention includes a step of laminating a plurality of alloy layers formed on a substrate together with the substrate. A motor comprising rare earth thick film magnet of the present invention is extremely small while obtaining high output.

Abstract: Bearings for rotatably supporting a rotor are disposed on an inner side of a hollow cylindrical portion of the rotor which is disposed in a rotating magnetic field formed by a group of stator windings and on an outer periphery of which magnetic poles for generating torque are arranged, thereby shortening the axial length of the rotor and making a motor compact. A motor of the invention includes: a stator in which a plurality of split cores with windings wound therearound are arranged in an annular form to generate a rotating magnetic field; a rotor for generating torque by the rotating magnetic field; and a housing for fixing the stator and for rotatably holding the rotor at an annularly central position of the stator, wherein only one end side of the stator is fixed to the housing.

Abstract: A plurality of permanent magnets 6 are embedded in a cylindrical rotor core 8 and arranged in a circumferential direction of the rotor core 8. A pair of side rings 81 are mounted on the axial ends of the rotor core 8. The outer diameter of each side ring 81 is set smaller than the outer diameter of the rotor core 8. With this structure, an eddy current generated in each side ring 81 can be suppressed to thereby prevent abnormal heating and accordingly prevent thermal demagnetization of the permanent magnets 6.

Abstract: A rotor according to the prior art has a top part and a bottom part, where the bottom part has stays that are mechanically connected to the top part. However, this has the disadvantage that very strict tolerances must be respected and the type of fastening is not secure. A rotor (1) according to the invention has a ring (42), which presses stays (45) and thus, by means of positive and frictional engagement, magnets (40) against a tubular element (38), which in turn is disposed on a bottom part. The bottom part (4), together with a rotor shaft (7) and a top part (64), constitutes a rotor (1).

Abstract: A permanent-magnet type brushless motor has a rotor which is made by integrally forming a rotating magnetic pole comprising a cylindrical multi-pole anisotropic magnet, a shaft and an elastic insulating supporting member having rigidity lower than at least that of the shaft. The multi-pole anisotropic magnet causes its magnetic flux to flow to form the closed magnetic circuit, thereby eliminating the necessity of forming the closed magnetic circuit using an inner stator core in the magnet required for the radial anisotropic magnet. A cylindrical casing holding therein a stator core.

Abstract: The present invention relates to a magnet holder for a starter motor which includes one end rolled in an inner surface of a yoke housing and the other end inserted between a magnet and a shunt for thereby being fixed together with a magnet without welding a shunt to a yoke housing. The magnet holder for a starter motor includes a bend formation portion disposed based on a rolled shape in an inner surface of a yoke housing by a certain width, and a holder member arranged in such a manner that the shunt and magnet are closely contacted at one side of the bend formation portion for supporting a plurality of the same at a certain interval and deployed in a circumferential direction for preventing the shunt and magnet from being moved in an axial direction of the yoke housing in a magnet fixing holder for a starter motor installed in an inner surface of a yoke housing and closely fixing a magnet to a shunt.

Abstract: A control device for an object includes a first wheel and a second wheel that rotate in opposite directions on a shaft affixed to a frame. The first and second wheels have openings to accept magnets that are free to slide up and down in the openings. As the wheels rotate, the magnets are urged outwards due to centrifugal force. The wheels have titanium sleeves fitted around the outer surfaces of the wheels, which have openings smaller in size than the openings of the wheels, so as to maintain the magnets within the openings even as the wheels rotate. Solenoid stations are provided around the wheels, and as a result of magnetic pulses provided from at least one of the solenoid stations, in synchronism with rotation of the wheels, a magnet is urged inwards to a center of the wheel in which it is disposed, to thereby result in a force vector that causes movement of the frame to thereby control the object.

Abstract: A method for determining a dimension in a motor is described. By applying Fourier analysis, a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave. Based upon the above, a determination of an angle &dgr; is described, wherein the fifth harmonic term of the sequence of terms is minimized. An electric motor having a rotor and a set of slot on said rotor surface having a set of magnets with a width &dgr; along the circumference of said rotor surface is described. The width &dgr; is determined by a method that includes applying Fourier analysis thereby a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave. Based upon the above, a determination of an angle &dgr; is described, wherein the fifth harmonic term of the sequence of terms is minimized.

Abstract: An electric motor including a permanent-magnet rotor having embedded magnets held in place by several segments. The embedded magnets are secured by segments including non-circular openings near their centers. Several non-magnetic, non-conductive bars extend through the non-circular openings of the segments to secure the segments in relation to the shaft. The motor is capable of producing high torque while only requiring a minimum amount of space.

Abstract: Provided are a super-high speed permanent magnet type synchronous motor which causes less loss in a rotor even though it is driven by an inverter adapted to be operated with a fundamental frequency around 1 kHz, and an air compressor. The air compressor having a super-high speed permanent magnet type synchronous motor which is composed of a stator in which armature windings are wound in a plurality of slots formed in a stator core, and a rotor including a shaft made of a conductive magnetic material, a conductive permanent magnet laid around the outer periphery of the shaft, and a reinforcing member made of carbon fibers and laid around the outer periphery of the permanent magnet, wherein a laminated electromagnetic steel sheet is interposed between the shaft and the permanent magnet, and the laminated electromagnetic steel sheet has a high tensile strength higher than 70 kg/mm2.

Abstract: A rotor piece has a plurality of holes 12. Each hole holds therein a plurality of substantially divided permanent magnets 14 that are arranged in a circumferential direction. Therefore, each permanent magnet is small and the flow passage of eddy currents becomes narrow, so that the magnitude of eddy currents becomes small. The total eddy currents in all the permanent magnets is also reduced, so that the eddy current loss can be reduced and the heat generation of the motor can be reduced. Adjacent ones of the substantially divided permanent magnets may be interconnected at portions thereof. One or more of the substantially divided permanent magnets 14 in one or more holes may be ferrite magnets, with other permanent magnets being rare-earth magnets.

Abstract: A magnet generator has multiple magnets received in a positioning seat of the rotator and a plurality of faces each corresponding to one of the magnets and formed on an outside face of the stator. With such an arrangement, when the generator of the invention is in operation, the generated rotation torque is greatly increased so as to drive a working disk with more power.