Embedded Patents (Class 310/156.56)
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Patent number: 7042127Abstract: A permanent magnet embedded motor including a rotor which is provided with a plurality of slits and a plurality of permanent magnets embedded into the slits and a stator which is provided with an iron core having a plurality of slots to which a coil is wound and is arranged to face the rotor via a gap. The slit includes a permanent magnet embedded part into which the permanent magnet is embedded in a direction perpendicular to the radial direction of the rotor and an “L”-shaped air gap part integrally provided on both ends of the permanent magnet embedded part. An angle “?1” for one pole of the rotor and an angle “?2” of the “L”-shaped air gap part are set to be 0.1??2/?1?0.3. Further, a radius “R” of a circumscribed circle of the rotor and a radius “R1” for forming an outer peripheral face of the rotor at a portion of the “L”-shaped air gap part are preferably set to be 0.1?(R?R1)/R?0.3.Type: GrantFiled: April 1, 2004Date of Patent: May 9, 2006Assignee: NIDEC Sankyo CorporationInventors: Toshifumi Tsuruta, Hideki Kanebako, Noboru Otsuki, Dongning Zhang
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Patent number: 7032859Abstract: A counter rotating ducted fan having a permanent magnet drive. comprising a ducted housing having an iron core stator and a pair of counter rotating propeller blades rotationally mounted on a propeller shaft positioned axially within the housing Each of the propeller blades includes a plurality of individual propeller blades of an even number. Permanent magnets are mounted in permanent magnet insertion holes located at the tip of each of the individual propeller blades. When excited by an electrical current a pair of excitation windings mounted within the iron core stator control the rotational speed and direction of the pair of counter rotating propeller blades.Type: GrantFiled: July 23, 2004Date of Patent: April 25, 2006Assignee: The United States of America as represented by the Secretary of the NavyInventor: John Anthony Mohr
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Patent number: 7019427Abstract: A synchronous motor includes a stator, a rotor and permanent magnets. The rotor includes a rotor iron core rotatable relative to the stator, and a plurality of conductor bars accommodated within corresponding slots in the rotor iron core. The conductor bars have their opposite ends shortcircuited by respective shortcircuit rings to form a starter cage conductor. The rotor also has a plurality of magnet retaining slots defined therein at a location on an inner side of the conductor bars, in which hole permanent magnets are embedded.Type: GrantFiled: January 14, 2005Date of Patent: March 28, 2006Assignees: Matsushita Electric Industrial Co., Ltd., Matsushita Refrigeration CompanyInventors: Kenji Sasaki, Teruo Tamura, Michihiro Yoshida, Toru Takimoto, Hideyuki Taniguchi, Hiroyuki Uesaka
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Patent number: 7002276Abstract: An armature of the prior art has a lamination packet which leads to a high loss of magnetic flux in the lamination, since it completely encloses the magnets that are disposed in the lamination. An armature (1) of the invention comprises at least one lamination (1) that only partly encloses the magnets (24). Losses in the magnetic flux are thus reduced.Type: GrantFiled: November 12, 2001Date of Patent: February 21, 2006Assignee: Robert Bosch GmbHInventors: Susanne Evans, Juergen Herp, Matthias Henschel, Harald Bux
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Patent number: 6989619Abstract: A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from the pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). Improvements of a laminated rotor, an end pole structure, and an arrangement of the PM elements for providing an arrangement of the flux paths from the auxiliary field coil assemblies are also disclosed.Type: GrantFiled: May 18, 2004Date of Patent: January 24, 2006Assignee: UT-Battelle LLCInventor: John S. Hsu
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Patent number: 6987343Abstract: A motor includes 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 salient pole portions, the rotor units being coupled to each other in an axial direction. A stator generates a field for driving the rotor. The permanent magnet type rotor unit and the reluctance type rotor unit have an angular deviation therebetween in the direction of rotation to obtain desired torque characteristics. The reluctance type rotor unit has slits for preventing flux leakage from the permanent magnets. The slits are formed with the angular deviation in the direction of rotation from respective positions symmetric about a center of the salient pole portions. Flux leakage is thus prevented to avoid deterioration in characteristics.Type: GrantFiled: December 9, 2004Date of Patent: January 17, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaki Tagome, Yasuhiro Kondo, Naoyuki Kadoya
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Patent number: 6987342Abstract: The invention relates to a rotor for an electric motor comprising an essentially cylindrical rotor core having a central aperture and comprising permanent magnets which are embedded in the rotor core and extend essentially like spokes through the rotor core, the rotor core being formed as an integral body and the selected permanent magnets being bridged at their radially inner or outer ends by recesses in the rotor core.Type: GrantFiled: March 25, 2004Date of Patent: January 17, 2006Assignee: Minebea Co., Ltd.Inventor: Helmut Hans
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Patent number: 6987341Abstract: The present invention is a motor of rotor with built-in permanent magnet, which includes an annular stator and a rotor. The annular stator has a cylindrical interior into which the rotor is inserted. A space is formed between a circumference surface of cylindrical interior and rotor. The rotor further includes a rotor core, and a plurality of openings are formed surrounding the rotor core. Each opening is with two parallel surfaces, a top surface and a bottom surface, and each of them is a flat plate figure. A suitable distance is between two side surfaces and an outer circumference of the rotor, and the two side surfaces of adjacent openings are spaced by a channel fo suitable width. A plurality of permanent magnets are arranged in openings by way of interlaced magnetic poles, and the shape of permanent matches the shape of the opening.Type: GrantFiled: August 4, 2004Date of Patent: January 17, 2006Assignee: Industrial Technology Research InstituteInventors: Yu-Choung Chang, Ching-Feng Lai, Ching-Huan Tseng
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Patent number: 6972504Abstract: A method and apparatus in which a rotor (11) and a stator (17) define a radial air gap (20) for receiving AC flux and at least one, and preferably two, DC excitation assemblies (23, 24) are positioned at opposite ends of the rotor (20) to define secondary air gaps (21, 22). Portions of PM material (14a, 14b) are provided as boundaries separating the rotor pole portions (12a, 12b) of opposite polarity from other portions of the rotor (11) and from each other to define PM poles (12a, 12b) for conveying the DC flux to or from the primary air gap (20) and for inhibiting flux from leaking from the pole portions prior to reaching the primary air gap (20). The portions of PM material (14a, 14b) are spaced from each other so as to include reluctance poles (15) of ferromagnetic material between the PM poles (12a, 12b) to interact with the AC flux in the primary-air gap (20).Type: GrantFiled: December 21, 2004Date of Patent: December 6, 2005Assignee: UT-Battelle LLCInventor: John S. Hsu
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Patent number: 6967424Abstract: The present invention relates to a rotor assembly for an electrical machine, comprising: a rotor body of generally cylindrical shape having a substantially cylindrical surface configured for facing an air-gap between the rotor assembly and a stator of the electrical machine, and permanent magnets embedded in said rotor body, wherein grooves are formed in said air-gap facing surface for manipulating the distribution of magnetic flux created by said permanent magnets.Type: GrantFiled: January 16, 2004Date of Patent: November 22, 2005Assignee: Minebea Co., Ltd.Inventor: Vladimir Vladimirovich Popov
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Patent number: 6956311Abstract: A magnetic motor includes rotors having permanent magnets and rotatably disposed around a rotating axis, a magnetic sensor disposed at a periphery of the rotors and a plurality of electro-magnetic coils, and control means which controls electric current to the coils based on detection of magnetism from the magnets by means of the sensor. The rotor is equidistantly divided in a circumferential direction into the same number of regions as that of the coils. Each region includes a portion wherein a plurality of magnets are disposed in a circumferential direction and a portion wherein no magnets are disposed. Each magnet is disposed inclined against a radial line extending outwardly from the rotating axis. The control means switches the direction of electric current to the coils based on the signal from the sensor and supplies current after a lapse of predetermined time from the detection of magnetism by the sensor.Type: GrantFiled: February 27, 2002Date of Patent: October 18, 2005Inventor: Akira Hosaka
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Patent number: 6949856Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings wound around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles, wherein said three-phase windings are concentratively wound around each of said stator salient poles, said windings of each phase are wound around at more than one stator salient p9ole, and said windings of each phase have a phase difference of voltage between at least one of the windings and the other.Type: GrantFiled: March 16, 2004Date of Patent: September 27, 2005Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 6946766Abstract: An interior permanent magnet machine including a rotor stack defining at least two adjacent magnet retention slots and a plurality of permanent magnets positioned within the interior of the rotor, wherein the radial thickness of the rotor that is above a given magnet retention slot transitions from a first radial thickness to a bridge region having a second radial thickness that is less than the first radial thickness. The bridge region is positioned between the two magnet retention slots and the transition to the bridge region occurs within an area falling within a defined angular expanse.Type: GrantFiled: August 28, 2002Date of Patent: September 20, 2005Assignee: Emerson Electric Co.Inventors: Horst E. Gary, Richard E. Hartsfield, Jr., Mark E. Carrier
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Patent number: 6936945Abstract: A structure of a rotor used in a synchronous motor employing both of permanent magnets and a stator using concentrated windings is disclosed. Slits (13) provided in a section of a rotor laminated in a direction of a rotary shaft are shaped like an arc or a bow, and the shape protrudes toward an outside rim of rotor (12). Permanent magnets (14) are inserted into slits (13). This structure produces less magnetic salient poles than a conventional rotor, so that a magnetic flux density can be lowered, and an efficient motor with less loss is obtainable.Type: GrantFiled: June 14, 2001Date of Patent: August 30, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hiroshi Murakami, Noriyoshi Nishiyama, Taro Kishibe, Haruhiko Kado, Toshiyuki Tamamura, Hisakazu Kataoka, Masayuki Shinto, Osaaki Morino
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Patent number: 6933644Abstract: A magnetic levitation motor which rotates a rotor in a levitated state with respect to a stator by a direct-current magnetic field and stator windings. The magnetic levitation motor comprises: a direct-current magnetic field generating device (4) which forms a magnetic flux having a radial pattern with an axis at the center in a stator (2) and a rotor (3); a first stator winding (6) for generating a levitation control magnetic flux (5) to control levitation of the rotor (3) in a radial direction; and a second stator winding (7) for generating a rotating magnetic field to rotate the rotor (3). The rotor (3) is provided with a yoke portion (9) and a motor magnet (10) which are opposed to a stator core (8) of the stator (2). A part of a bias magnetic flux (11) and a part of a levitation control magnetic flux (5) form a magnetic circuit directly reaching the stator core from the yoke, thereby increasing a levitation force of the rotor.Type: GrantFiled: May 17, 2002Date of Patent: August 23, 2005Assignee: Kabushiki Kaisha Sankyo Seiki SeisakushoInventor: Hideki Kanebako
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Rotor assembly for an electrical machine and permanent magnet motor comprising such a rotor assembly
Patent number: 6927519Abstract: Rotor assembly for an electrical machine, wherein a body of generally cylindrical shape having an inner opening for coaxially mounting the body on a shaft, permanent magnets embedded in said body, wherein at least one of the permanent magnets is split in at least two magnet sections which extend from about the inner opening towards the outer periphery of the body and are inclined towards a plane, which extends in a radial direction of the body.Type: GrantFiled: August 6, 2003Date of Patent: August 9, 2005Assignee: Minebea Co., Ltd.Inventor: Vladimir Vladimirovich Popov -
Patent number: 6919663Abstract: A low-ripple multi-phase internal rotor motor has a slotted stator (28) separated by an air gap (39) from a central rotor (36). The rotor has a plurality of permanent magnets (214), preferably neodymium-boron, arranged in pockets (204) formed in a lamination stack (37), thereby defining a plurality of poles (206) separated by respective gaps (210). In a preferred embodiment, the motor is three-phase, with four rotor poles and six stator poles. As a result, when the first and third rotor poles are so aligned, with respect to their opposing stator poles, as to generate a reluctance torque, the second and fourth rotor poles are aligned to generate oppositely phased reluctance torques, so that these torques cancel each other, and essentially no net reluctance torque is exerted on the rotor. In order to magnetically separate the rotor magnets from each other, a hollow space (224, 238) is formed at the interpolar-gap-adjacent end face (216, 218) of each rotor magnet.Type: GrantFiled: March 18, 2003Date of Patent: July 19, 2005Assignee: ebm-papst St. Georgen GmbH & Co. KGInventor: Dorin Iles-Klumpner
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Patent number: 6919662Abstract: A motor including: 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 salient pole portions, the rotor units being coupled to each other in an axial direction; and a stator for generating a field for driving the rotor. The permanent magnet type rotor unit and the reluctance type rotor unit are given an angle deviation therebetween in the direction of rotation to obtain desired torque characteristics. The reluctance type rotor unit has slits for preventing flux leakage from the permanent magnets. The slits are formed with the angle deviation in the direction of rotation from respective positions symmetric about a center of the salient pole portions. Flux leakage is thus prevented to avoid deterioration in characteristics.Type: GrantFiled: April 25, 2002Date of Patent: July 19, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaki Tagome, Yasuhiro Kondo, Naoyuki Kadoya
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Patent number: 6917133Abstract: An air conditioner comprising a compressor including a compression unit and a permanent magnet rotating electric machine, wherein the permanent magnet rotating electric machine includes a stator, into which concentratively wound armature windings are inserted in such a way as to surround a plurality of teeth formed in a stator core, and a rotor having permanent magnets accommodated into a plurality of permanent magnet inserting holes formed in a rotor core. Each pair of adjacent ones of said permanent magnets is arranged generally in one of a convex V-shaped configuration and a convex U-shaped configuration with respect to a rotor axis, and a substantially V-shaped recess portion is formed between adjacent poles in outer circumferential surface portions of the rotor core.Type: GrantFiled: February 20, 2003Date of Patent: July 12, 2005Assignee: Hitachi, Ltd.Inventors: Haruo Koharagi, Masaharu Senoh, Keiji Noma, Kohei Ishii, Kazuo Sato, Satoshi Kikuchi, Miyoshi Takahashi, Kouki Yamamoto
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Patent number: 6897595Abstract: An improved electric motor design wherein the interior surface of the stator has a plurality of corrugations intersected by annular grooves formed therein and a corresponding number of rotor disks having permanent magnets secured to their outer surface, the permanent magnets being positioned to rotate within the grooves. The magnets alternate in polarity about each disk as well as being offset about the circumference from disk to disk so that one disk set will align with the pole face created by the intersection of the corrugations and the adjacent annular grooves and the other disk set will be offset from the corrugations and pole faces. Alternately energizing coils positioned within a plurality of notches formed in the outer surface of the stator with alternating current causes the magnets and their associated disks to reposition themselves in a manner that causes the motor shaft to rotate as well as shaping the core flux field for more efficient use, thereby increasing motor torque.Type: GrantFiled: March 29, 2004Date of Patent: May 24, 2005Inventor: Kevin J. Chiarenza
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Patent number: 6897590Abstract: Rotor assembly for an electrical machine, including a body of generally cylindrical shape having an inner opening, wherein slots are provided in the body, the slots extending from the inner opening towards the outer periphery of the body; permanent magnets disposed in said slots; wherein at least one of the slots comprises an end section near the outer periphery of the body having an area of enlarged width.Type: GrantFiled: August 6, 2003Date of Patent: May 24, 2005Assignee: Minebea Co., Ltd.Inventor: Vladimir Vladimirovich Popov
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Patent number: 6891298Abstract: A rotor for an interior permanent magnet machine that tends to reduce magnet chattering that includes a rotor stack defining at least one magnet retention slot and a permanent magnet positioned within the magnet retention slot, where the magnet retention slot is formed such that movement of the permanent magnet towards at least one end of the slot will tend to cause the magnet to become wedged within the slot.Type: GrantFiled: August 28, 2002Date of Patent: May 10, 2005Assignee: Emerson Electric Co.Inventor: Horst E. Gary
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Patent number: 6888270Abstract: A composite powder metal disk for a rotor assembly in a circumferential type interior permanent magnet machine. The disk includes an inner ring of magnetically conducting powder metal compacted and sintered to a high density. The disk further includes an outer ring of permanent magnets separated by magnetically non-conducting powder metal compacted and sintered to a high density. The permanent magnets additionally are radially embedded by magnetically conducting powder metal compacted and sintered to a high density with optional intermediate non-conducting powder metal bridges extending radially from the permanent magnets to the outer surface of the disk. 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 composite powder metal disks is further provided including filling a die with the powder metals, compacting the powders, and sintering the compacted powders.Type: GrantFiled: November 12, 2003Date of Patent: May 3, 2005Assignee: Delphi Technologies, Inc.Inventors: Frederick B. Reiter, Jr., James L. Lobsinger, Tom L. Stuart, Frank A. Wilder
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Patent number: 6885122Abstract: A motor/generator (1) comprises a permanent magnets (3) having a V-shaped surface projecting in the center of a rotor (2). These permanent magnets (3) are disposed so that the V-shaped surface faces the center of the rotor (2). In this way, the permanent magnets (3) are prevented from sliding on the fitting surfaces (21) of the insertion holes (20), and the permanent magnets (3) can be fixed at predetermined positions. Further, magnetic losses caused by the rotor (2) can be reduced, and efficiency of the motor/generator can be improved.Type: GrantFiled: July 24, 2002Date of Patent: April 26, 2005Assignee: Nissan Motor Co., Ltd.Inventors: Yutaro Kaneko, Shinichiro Kitada, Toshio Kikuchi, Takashi Tsuneyoshi
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Patent number: 6876117Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: GrantFiled: September 7, 2004Date of Patent: April 5, 2005Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 6858961Abstract: 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????1.Type: GrantFiled: August 28, 2002Date of Patent: February 22, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaki Tagome, Yasuhiro Kondo
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Patent number: 6856051Abstract: A composite powder metal disk for a rotor assembly in a circumferential type interior permanent magnet machine. The disk includes an inner ring of magnetically conducting powder metal compacted and sintered to a high density. The disk further includes an outer ring of permanent magnets separated by magnetically non-conducting powder metal compacted and sintered to a high density. The permanent magnets additionally are radially embedded by magnetically conducting powder metal compacted and sintered to a high density with optional intermediate non-conducting powder metal bridges extending radially from the permanent magnets to the outer surface of the disk. 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 composite powder metal disks is further provided including filling a die with the powder metals, compacting the powders, and sintering the compacted powders.Type: GrantFiled: October 3, 2001Date of Patent: February 15, 2005Assignee: Delphi Technologies, Inc.Inventors: Frederick B. Reiter, Jr., James L. Lobsinger, Tom L. Stuart, Frank A. Wilder
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Patent number: 6853106Abstract: A brushless motor capable of increasing energy density by effective utilization of reluctance torque. The brushless motor comprises a stator (5) and a rotor (1) having a lateral surface opposed to the stator (5). The stator (5) comprises a plurality of radially extending iron cores (10) and a plurality of windings (11) for generating a magnetic field in each iron core (10). The rotor (1) comprises a plurality of permanent magnets (2) and a magnetic field line inducing body disposed between each permanent magnet (2) and the lateral surface.Type: GrantFiled: May 31, 2001Date of Patent: February 8, 2005Assignees: Mitsubishi Heavy Industries, Ltd.Inventors: Kenji Fujiwara, Akira Nishio, Yoshiki Kato, Masahiro Hirano, Takatoshi Kogure, Tsutomu Baba
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Patent number: 6847143Abstract: A rotary electrical machine, especially an alternator or an alternator-starter for a motor vehicle, comprises a stator (S), a rotor (R) and permanent magnets incorporated in the rotor and/or the stator, in which the said magnets are formed into at least two groups each of which is defined by a specific type of composition, with each sub-assembly being a combination of a magnet containing rare earths with a ferrite magnet, at least one of the magnets being arranged radially so as to generate an orthoradial magnetic flux.Type: GrantFiled: March 17, 2000Date of Patent: January 25, 2005Assignee: Valeo Equipements Electriques MoteurInventor: Dokou Antoine Akemakou
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Patent number: 6841916Abstract: An improved electric motor design wherein the stator and rotor configuration is arranged to produce a core flux efficiently shaped and utilized to enhance motor torque without substantially increasing the electrical power furnished to the motor. The internal surface of the stator, or coil, has a plurality of corrugations and annular grooves formed therein and a corresponding number of rotor disks having permanent magnets secured to the outer surface, the permanent magnets being positioned to rotate within the grooves. The magnets are opposed in polarity disk to disk as well as being offset about the circumference so that one disk set will align with one set of corrugations and the other disk set align with the pole face created by the intersection of the corrugations and the adjacent annular grooves.Type: GrantFiled: June 10, 2003Date of Patent: January 11, 2005Inventor: Kevin J. Chiarenza
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Publication number: 20040232794Abstract: A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from said pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). A method of non-diffused flux enhancement and flux weakening for a radial gap machine is also disclosed.Type: ApplicationFiled: September 23, 2003Publication date: November 25, 2004Inventor: John S. Hsu
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Patent number: 6822360Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnetic pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: GrantFiled: January 9, 2003Date of Patent: November 23, 2004Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 6815858Abstract: A permanent magnet rotating electric machine uses no skewing under a predetermined current and voltage condition to prevent torque from decreasing and to decrease pulsation torque to make the machine less vibrating and less noisy. The permanent magnet rotating electric machine includes a stator with multi-phase stator windings and a rotor with a plurality of permanent magnets internally embedded in a rotor core. The core shape of the rotor is uniform in the depth (longitudinal) direction with no skewing in the arrangement of the permanent magnets. The permanent magnets are symmetrical with respect to the rotation direction, but irregular with respect to the depth direction, for each pole. A magnetic flux generated from the between-pole permanent magnets almost equals a magnetic flux generated from the pole-center permanent magnet.Type: GrantFiled: September 18, 2002Date of Patent: November 9, 2004Assignee: Hitachi, Ltd.Inventors: Yutaka Matsunobu, Fumio Tajima, Shouichi Kawamata, Takashi Yasuhara
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Publication number: 20040212266Abstract: The invention relates to a rotor for an electric motor comprising an essentially cylindrical rotor core having a central aperture and comprising permanent magnets which are embedded in the rotor core and extend essentially like spokes through the rotor core, the rotor core being formed as an integral body and the selected permanent magnets being bridged at their radially inner or outer ends by recesses in the rotor core.Type: ApplicationFiled: March 25, 2004Publication date: October 28, 2004Inventor: Helmut Hans
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Publication number: 20040212267Abstract: An essentially ring shaped core back for an electrical machine comprising a plurality of stacked, ring shaped sheets of soft magnetic material, a barrier of electrical resistance arranged between two adjacent sheets of soft magnetic material for reducing effects of eddy currents. At least each sheet of soft magnetic material in a subset of said plurality of stacked, ring shaped sheets of soft magnetic material includes a plurality of circumferentially arranged tooth openings that are extending axially through each sheet in said subset of said plurality of stacked, ring shaped sheets of soft magnetic material, additionally, each sheet of said subset of said plurality of stacked, ring shaped sheets of soft magnetic material includes a first inner closing portion and a second inner closing portion that are arranged between each tooth opening and an inner perimeter of said ring shaped sheet of soft magnetic material.Type: ApplicationFiled: April 14, 2004Publication date: October 28, 2004Applicant: Hoganas ABInventors: Alan Jack, Barrie Mecrow, Phillip George Dickinson, Mats Persson, Chris Manning
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Publication number: 20040194286Abstract: A method includes the steps of 1) providing a ring-shaped permanent magnet having radially inner and outer surfaces and opposite first and second side surfaces; 2) overmolding a casing material about the magnet to yield a magnet assembly, the casing material comprising a material that contracts as it cools from a molten state and that includes a portion located along the radially outer surface and the first side surface; and 3) mounting the assembly about a rotor shaft.Type: ApplicationFiled: April 28, 2004Publication date: October 7, 2004Inventor: Mitchell Rose
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Patent number: 6794784Abstract: Permanent magnets are arranged to be supported by the provision of permanent magnet position-locating projections (12) in permanent magnet embedding holes (5). By optimizing the shape of thin-wall regions (18) and (19) within rotor core (4), leakage of flux generated from the permanent magnets is reduced and the strength of the thin-wall regions where stress is concentrated is ensured.Type: GrantFiled: May 24, 2001Date of Patent: September 21, 2004Assignees: Kabushiki Kaisha Toshiba, Toshiba Industrial Products Manufacturing CorporationInventors: Norio Takahashi, Yutaka Hashiba, Kazuto Sakai, Masanori Arata, Yukihiko Kazao, Takashi Araki, Masakatsu Matsubara, Yasuo Hirano
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Patent number: 6781274Abstract: A rotor of a synchronous motor and a method of manufacturing the same. The rotor of the synchronous motor comprises a main core, formed from a plurality of laminated thin iron sheets, the thin iron sheets having a hole at a center for receiving a rotating shaft, and a number of magnet holes and induced conductor holes radially disposed in the thin iron sheets at a predetermined space differently from the hole. A plurality of magnets are inserted into the magnet holes of the main core. Supplementary cores, having a hole and induced conductor holes corresponding to the hole and the induced conductor holes of the main core, are disposed at the ends of the main core wherein the magnet is inserted. An induced conductor formed by ingoting through the induced conductor holes of the main core and the induced conductor holes of the supplementary cores. Consequently, through the induced conductor and the magnet, the efficiency of the motor can be improved.Type: GrantFiled: November 13, 2001Date of Patent: August 24, 2004Assignee: Hong Sik JeongInventor: Seok-jin Lee
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Publication number: 20040145263Abstract: For the purpose of preventing demagnetization of a magnet (32) without any cost increase and improving the max torque and the efficiency of an electric motor (20) by suppressing deterioration of magnetic flux density, a permanent magnet-type electric motor (20) comprises a stator (21) and a rotor (25) disposed in the stator (21), in which a plurality of permanent magnets (32), (32) forming a magnetic pole are inserted in magnet insertion portions (31), (31) of a yoke (26) in such manner that the magnets (32), (32) form in line in the circumferential direction thereof, wherein each magnet (32) is divided into a central magnet (33) that is positioned at the central portion in the width direction of the magnet insertion portion (31) and end magnets (34), (34) that are positioned at end portions of the magnet insertion portion (31), and the end magnets (34), (34) have greater coercive forces than the central magnet (33), whereas the central magnet (33) has a greater magnetic flux density than the end magnets (34)Type: ApplicationFiled: November 19, 2003Publication date: July 29, 2004Inventors: Hiroaki Kojima, Jun Kageyama, Akio Yamagiwa
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Patent number: 6768238Abstract: A rotor for permanent magnet synchronous machines with a reduction in the stray flux transmitted through the rotor shaft includes substantially ring-shaped punched sheet metal plates with a central opening for receiving the rotor shaft, and a plurality of recesses arranged in the circumferential direction, wherein at least two permanent magnets can be inserted in each of the recesses. A corresponding intermediate sheet metal segment is arranged or can be arranged in each of the recesses between the permanent magnets. At least one of the recesses is shaped so as to form an air gap between the surface of the intermediate sheet metal segment that is oriented radially inwardly towards the center and an edge of the recess that is oriented radially outwardly from the center, when the permanent magnets are inserted radially towards the outside. The air gap aids in attenuating the stray flux.Type: GrantFiled: October 31, 2002Date of Patent: July 27, 2004Assignee: Siemens AktiengesellschaftInventors: Axel Knauff, Rolf Vollmer
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Patent number: 6759776Abstract: A permanent magnetic type electric rotating machine includes: a stator having armature winding arranged in several slots formed in a stator core; and a rotor having permanent magnets held in several permanent magnetic insertion holes formed in a rotor core, in which a peripheral surface of the rotor core is configured to be a combination of arcs around two points different from a center of the rotor core for each magnetic pole in such a manner that when an axis extending in a central direction of a magnetic pole of the rotor is a d axis, and an axis extending in a direction between magnetic poles that is offset from the central direction of the magnetic pole by 90 electrical degrees is a q axis, a radial distance from a center of the rotor core to a periphery of the rotor is reduced gradually from the d axis to the q axis.Type: GrantFiled: March 20, 2002Date of Patent: July 6, 2004Assignee: Hitachi, Ltd.Inventors: Ryoichi Takahata, Shinichi Wakui, Haruo Koharagi, Satoshi Kikuchi, Miyoshi Takahashi
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Patent number: 6759777Abstract: A permanent magnetic type electric rotating machine includes: a stator having armature winding arranged in several slots formed in a stator core; and a rotor having permanent magnets held in several permanent magnetic insertion holes formed in a rotor core, in which a peripheral surface of the rotor core is configured to be a combination of arcs around two points different from a center of the rotor core for each magnetic pole in such a manner that when an axis extending in a central direction of a magnetic pole of the rotor is a d axis, and an axis extending in a direction between magnetic poles that is offset from the central direction of the magnetic pole by 90 electrical degrees is a q axis, a radial distance from a center of the rotor core to a periphery of the rotor is reduced gradually from the d axis to the q axis.Type: GrantFiled: July 30, 2002Date of Patent: July 6, 2004Assignee: Hitachi, Ltd.Inventors: Ryoichi Takahata, Shinichi Wakui, Haruo Koharagi, Satoshi Kikuchi, Miyoshi Takahashi
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Publication number: 20040103521Abstract: A composite powder metal disk for a rotor assembly in a circumferential type interior permanent magnet machine. The disk includes an inner ring of magnetically conducting powder metal compacted and sintered to a high density. The disk further includes an outer ring of permanent magnets separated by magnetically non-conducting powder metal compacted and sintered to a high density. The permanent magnets additionally are radially embedded by magnetically conducting powder metal compacted and sintered to a high density with optional intermediate non-conducting powder metal bridges extending radially from the permanent magnets to the outer surface of the disk. 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 composite powder metal disks is further provided including filling a die with the powder metals, compacting the powders, and sintering the compacted powders.Type: ApplicationFiled: November 12, 2003Publication date: June 3, 2004Applicant: DELPHI TECHNOLOGIES, INC.Inventors: Frederick B. Reiter, James L. Lobsinger, Tom L. Stuart, Frank A. Wilder
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Patent number: 6741003Abstract: To decrease torque ripples and cogging torque, a rotor for an electrical motor, an electrical generator, or the like, includes lengths of permanent magnets embedded in a plurality of slit sections in respective layers. In an embodiment having three layers, the permanent magnets have lengths L1, L2 and L3 in order as viewed from the outside circumference side of the rotor core and generate respective total magnetic fluxes of &PHgr;1, &PHgr;2, &PHgr;3, respectively, when the rotor is assembled in a rotary electric device. The lengths have a relation L1<L2<L3, and the magnetic fluxes have a relation &PHgr;1<&PHgr;2<&PHgr;3.Type: GrantFiled: January 17, 2003Date of Patent: May 25, 2004Assignee: Yamaha Hatsudoki Kabushiki KaisaInventors: Shinya Naito, Haruyoshi Hino
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Publication number: 20040095034Abstract: Rotor assembly for an electrical machine, wherein a body of generally cylindrical shape having an inner opening for coaxially mounting the body on a shaft, permanent magnets embedded in said body, wherein at least one of the permanent magnets is split in at least two magnet sections which extend from about the inner opening towards the outer periphery of the body and are inclined towards a plane, which extends in a radial direction of the body.Type: ApplicationFiled: August 6, 2003Publication date: May 20, 2004Inventor: Vladimir Vladimirovich Popov
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Publication number: 20040095033Abstract: Rotor assembly for an electrical machine, including a body of generally cylindrical shape having an inner opening, wherein slots are provided in the body, the slots extending from the inner opening towards the outer periphery of the body; permanent magnets disposed in said slots; wherein at least one of the slots comprises an end section near the outer periphery of the body having an area of enlarged width.Type: ApplicationFiled: August 6, 2003Publication date: May 20, 2004Inventor: Vladimir Vladimirovich Popov
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Patent number: 6734592Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings wound around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles, wherein said three-phase windings are concentratively wound around each of said stator salient poles, said windings of each phase are wound around at more than one stator salient pole, and said windings of each phase have a phase difference of voltage between at least one of the windings and the other.Type: GrantFiled: May 10, 2002Date of Patent: May 11, 2004Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Publication number: 20040080228Abstract: An electric motor, more particularly, a rotor structure of an electric motor comprises: a stator including a plurality of teeth and coil wound on the teeth to form rotary magnetic flux by applied electric source; a rotary shaft; and a rotor rotatably installed in the stator, the rotor including a shaft insertion hole so that the rotary shaft can be inserted therethrough and fixed, wherein, the rotor includes a plurality of permanent magnet insertion slots of ‘V’ or ‘U’ shape formed in radial direction as centering around the shaft insertion hole, and permanent magnets are inserted and fixed into the permanent magnet insertion slots respectively, and a plurality of air gap expanding portions, on which air gaps from the teeth of the stator are expanded, are formed on an outer circumferential surface of the rotor.Type: ApplicationFiled: April 14, 2003Publication date: April 29, 2004Inventors: Jun-Ho Ahn, Kwan-Yuhl Cho, Hyoun-Jeong Shin
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Patent number: 6727623Abstract: An interior permanent magnet machine is disclosed that, in one exemplary embodiment, includes a stator defining a number of stator poles, a rotor, a number of permanent magnets positioned within the interior of the rotor and at least two impedance reduction slits associated with each permanent magnet where the impedance reduction slits are positioned radially outward of the permanent magnets. In further embodiments, each impedance reduction slit is positioned such that at least a portion of the slit is within a defined region.Type: GrantFiled: August 28, 2002Date of Patent: April 27, 2004Assignee: Emerson Electric Co.Inventors: Gary E. Horst, Alan D. Crapo
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Patent number: 6713923Abstract: To provide an orientation device capable of efficiently orientating resinous magnets filled in slits of a rotor core. An orientation device comprising a plurality of permanent magnets 5 disposed at the same intervals as slits 2 in the rotor core 1 with their magnetic poles of the same polarity adjacent to each other, along the outside circumference of a rotor core housing section 4 for housing the rotor core 1, and a plurality of pole pieces 6 disposed between the plurality of permanent magnets 5, wherein the width of the pole piece 6 at the end 6a on the side of the rotor core housing section 4 is no larger than the maximum width &agr; max of an outermost slit 2a of the rotor core 1 between opposite ends thereof.Type: GrantFiled: July 30, 2002Date of Patent: March 30, 2004Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Haruyoshi Hino, Shinya Naito