Skewed Patents (Class 310/156.47)
  • Patent number: 10274846
    Abstract: An electromagnetic drive includes a stator, having a stator holder and an actuating element which is movable by electromagnetic interaction with the stator. The stator holder has at least two electrically conductive paths running separately from and adjacent to one another. In each case, the two paths running separately from and adjacent to one another form a path pair, and the paths of the path pair are connected to one another in electrically conductive fashion at their respective ends. The paths of the path pair are arranged such that the stator and/or the actuating element induces eddy currents acting in opposite directions in the paths.
    Type: Grant
    Filed: February 27, 2018
    Date of Patent: April 30, 2019
    Assignee: Carl Zeiss SMT GmbH
    Inventors: Jasper Wesselingh, Axel Lorenz
  • Patent number: 10224788
    Abstract: A motor which is capable of realizing further space saving and cost reduction. A cylindrical outer rotor 11 is rotatable around a central axis CL thereof. A plurality of magnets 13 are arranged at equal intervals on an inner circumferential surface of the outer rotor 11. Three Hall elements 15 to 17 are arranged to oppose the respective magnets 13 and detect switching of magnetic poles caused by movement of the respective magnets 13 passing through each vicinity of the Hall elements 15 to 17 when the outer rotor 11 rotates. The Hall element 17 is comprised of a linear Hall element that outputs a linear signal representing a linear change of a magnetic flux density caused by movement of the respective magnets 13. One of the respective magnets 13 is arranged offset along the central axis CL as compared to the other magnets 13.
    Type: Grant
    Filed: July 8, 2016
    Date of Patent: March 5, 2019
    Assignee: TOYO DENSO KABUSHIKI KAISHA
    Inventors: Takehiko Endo, Junichi Takahashi
  • Patent number: 10186917
    Abstract: A rotor assembly for an electric machine or power generation system, includes a shaft having a rotational axis, a first cylindrical section rotatably supported by the shaft and having a first rotor core, and a second cylindrical section, axially spaced from the first cylindrical section along the rotational axis, the second cylindrical section rotatably supported by the shaft, and wherein a set of magnet surface polarities are arranged to improve power output.
    Type: Grant
    Filed: May 24, 2016
    Date of Patent: January 22, 2019
    Assignee: Unison Industries, LLC
    Inventor: Arslan Amjad
  • Patent number: 10103611
    Abstract: A machine learning apparatus, which learns a condition associated with arrangement positions of magnets on a core of a motor rotor, includes: a state observation unit that observes a state variable composed of data relating to arrangement positions of a plurality of the magnets arranged on the core, data relating to a magnitude of cogging torque generated when the plurality of the magnets are arranged at the respective arrangement positions, and data relating to a magnetic flux density of each of the magnets; and a learning unit that learns the condition associated with the arrangement positions of the magnets on the core in accordance with a training data set constituted by the state variable.
    Type: Grant
    Filed: September 27, 2016
    Date of Patent: October 16, 2018
    Assignee: FANUC CORPORATION
    Inventor: Yoshinori Murakami
  • Patent number: 10003228
    Abstract: A rotor includes pole portions, a first permanent magnet, a second permanent magnet, and a third permanent magnet. Each pole portion includes a center, a back, and a front rotor core portion. A first slot is embedded in the center rotor core portion. A second slot is embedded in the back rotor core portion. A third slot is embedded in the front rotor core portion. The center rotor core portion is mounted axially between the front rotor core portion and the back rotor core portion. The permanent magnets are mounted, respectively, in the slots of each pole portion. A maximum length of the first permanent magnet is greater than twice a maximum length of the second permanent magnet. The maximum length of the second permanent magnet is equal to a maximum length of the third permanent magnet. The permanent magnets are aligned relative to a pole axis of each pole portion.
    Type: Grant
    Filed: August 25, 2015
    Date of Patent: June 19, 2018
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Thomas A. Lipo, Zhentao Stephen Du
  • Patent number: 10003227
    Abstract: An interior permanent magnet machine includes a rotor having a central axis and a plurality of axial segments. The axial segments include a first axial segment and a second axial segment positioned adjacent to each other in an axial direction. Each of the axially-spaced segments includes at least one pole defining a respective angular configuration characterized by respective first, second and third angles. The first axial segment defines a first set of angular configurations and the second axial segment defines a second set of angular configurations. The rotor is configured to have an axially asymmetric configuration such that the first set of angular configurations is different from the second set of angular configurations.
    Type: Grant
    Filed: July 1, 2015
    Date of Patent: June 19, 2018
    Assignee: GM Global Technology Operations LLC
    Inventors: Sinisa Jurkovic, Mohammad Faizul Momen, Khwaja M. Rahman
  • Patent number: 9953750
    Abstract: A sintered Nd base magnet segment has a coercive force high at the periphery and lower toward the inside. A method for preparing the magnet includes the steps of: (a) providing a sintered Nd base magnet block having surfaces and a magnetization direction, (b) coating the surfaces of the magnet block excluding the surface perpendicular to the magnetization direction with a Dy or Tb oxide powder, a Dy or Tb fluoride powder, or a Dy or Tb-containing alloy powder, (c) treating the coated block at a high temperature for causing Dy or Tb to diffuse into the block, and (d) cutting the block in a plane perpendicular to the magnetization direction into a magnet segment having a coercive force distribution on the cut section that the coercive force is high at the periphery and lower toward the inside and a constant coercive force distribution in the magnetization direction.
    Type: Grant
    Filed: February 24, 2014
    Date of Patent: April 24, 2018
    Assignee: SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Koji Miyata, Takehisa Minowa, Hajime Nakamura, Koichi Hirota, Masakatsu Honshima
  • Patent number: 9812913
    Abstract: A rotating electric machine includes a stator having a stator coil and a rotor provided rotatably around a specific rotation axis with respect to the stator. The rotor includes a plurality of magnets, a plurality of magnetically-assisted salient pole members provided between poles of any adjacent two magnets from among the plurality of magnets, and a magnetoresistance variation unit provided in the magnetically-assisted salient pole member along an axial direction of the rotation axis at a position offset in a circumferential direction of the rotation axis from a q-axis passing through a salient pole center of the magnetically-assisted salient pole member. The amount of offset of the magnetoresistance variation unit from the q-axis varies depending on positions of the magnetically-assisted salient pole members so that torque fluctuations cancel each other when power is applied.
    Type: Grant
    Filed: February 18, 2016
    Date of Patent: November 7, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Yasuyuki Saito, Tsuyoshi Goto, Kenichi Nakayama, Noriaki Hino, Shinji Sugimoto
  • Patent number: 9755462
    Abstract: An interior permanent magnet machine includes a wound stator, and a rotor core defining a plurality of pole cavities. Each of the pole cavities includes a cross section, perpendicular to a central axis of rotation, that defines a cross sectional shape having a centerline. The cross sectional shape of each of the pole cavities includes a radially inner barrier portion, a radially outer barrier portion, and a central portion. The centerline of the cross sectional shape of each of the radially outer barrier portion and the radially inner barrier portion, of each pole cavity, is defined by a generally arcuate segment. The centerline of the cross sectional shape of the central portion, of each pole cavity, is defined by a linear segment. One of a plurality of rare earth magnets, having no heavy rare earth elements, is disposed within the central portion of one of the plurality of pole cavities.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: September 5, 2017
    Assignee: GM Global Technology Operations LLC
    Inventors: Sinisa Jurkovic, Khwaja M. Rahman
  • Publication number: 20150108867
    Abstract: An IPM motor for a vacuum pump suitable for use as a motor for a small vacuum pump is provided. The IPM motor for a vacuum pump includes: a rotor core in which a rotor shaft of the vacuum pump is pressed and which also has magnets embedded therein; and a stator core which surrounds the rotor core and around which stator windings are wound. The magnets per pole embedded in the rotor core are each split into two pieces and inserted in respective magnet slots in the rotor core. A hole for stress concentration relaxation is provided at either end of each pair of magnet slots in which permanent magnets split into two pieces are embedded in each pole. The rotor core has a multilayer structure having a plurality of rotor core laminations stacked vertically in an axial direction of the rotor shaft. The rotor core laminations stacked vertically are positioned with a skew angle determined by using the holes for stress concentration relaxation.
    Type: Application
    Filed: March 27, 2013
    Publication date: April 23, 2015
    Inventors: Isao Nakagawa, Manabu Nonaka
  • Patent number: 8987966
    Abstract: An electric motor has a wound stator and a permanent magnet rotor. The rotor includes a shaft, a hub fixed on the shaft, a plurality of rotor core segments and magnets fixed around the hub, and a pair of covers fixed to axial ends of the rotor core segments. The hub and covers are formed on the rotor core segments by inserting molding and one of the covers has openings to allow the magnets to be inserted into spaces formed between adjacent rotor core segments such that the rotor core segments and magnets are alternately arranged in a circumferential direction of the rotor.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: March 24, 2015
    Assignee: Johnson Electric S.A.
    Inventors: Jian Zhao, Yue Li, Mao Xiong Jiang, Ya Ming Zhang, Xiao Ning Zhu
  • Patent number: 8952587
    Abstract: Apparatus and method for tuning the magnetic field of windmill generators to obtain efficient operation over a broad RPM range. The windmill generator includes fixed windings (or stator) inside a rotating rotor carrying permanent magnets. The permanent magnets are generally cylindrical and have North and South poles formed longitudinally in the magnets. Magnetically conducting circuits are formed by the magnets residing in magnetic conducting pole pieces (for example, low carbon or soft steel, and/or laminated insulated layers, of non-magnetizable material). Rotating the permanent magnets, or rotating non-magnetically conducting shunting pieces, inside the pole pieces, either strengthens or weakens the resulting magnetic field to adjust the windmill generators for low RPM torque or for efficient high RPM efficiency. Varying the rotor magnetic field adjusts the voltage output of the windmill generators allowing the windmill generator to maintain a fixed voltage output.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: February 10, 2015
    Inventor: Louis J. Finkle
  • Patent number: 8933605
    Abstract: A brushless motor has a stator and a rotor rotatably installed inside of the stator. The stator includes a stator core with teeth protruding inwardly and windings wound on the teeth. The rotor includes a shaft, a rotor core fixed on the shaft, and a ring magnet fixed to the circumferential outer surface of the rotor core. The magnet includes a plurality of magnetic poles radially magnetized so that north poles and south poles are arranged alternately in the circumferential direction. Boundary lines between magnetic poles are skewed by an angle relative to an axis of the shaft.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: January 13, 2015
    Assignee: Johnson Electric S.A.
    Inventors: Mao Xiong Jiang, Yue Li, Tao Zhang, San Ruan Xiao, Lik Hon Chan
  • Publication number: 20140363314
    Abstract: A brushless motor includes a stator comprising a stator core with teeth protruding inwardly and windings wound on the teeth, and a rotor comprising a shaft, a rotor core fixed to the shaft, and a ring magnet fixed to the circumferential outer surface of the rotor core. The ring magnet includes a plurality of magnetic poles radially magnetized so that north poles and south poles are arranged alternately in the circumferential direction, boundary lines between adjacent magnetic poles being skewed by an angle ? relative to an axis of the shaft. A plurality of grooves are formed in a circumferential outer surface of the rotor core. Each groove extends from one axial end to the other axial end of the rotor core, has a circumferential width smaller than each of the magnetic poles, and is covered by the ring magnet with a void formed between the groove and the ring magnet.
    Type: Application
    Filed: August 22, 2014
    Publication date: December 11, 2014
    Inventors: Mao Xiong JIANG, Yue LI, Tao ZHANG, San Yuan XIAO, Lik Hon CHAN
  • Patent number: 8884485
    Abstract: A permanent magnet machine is provided with a rotor positioned at least partially within a stator. The rotor includes first and second ring segments oriented axially around a central axis. The rotor defines first and second configurations in the first and second ring segments, respectively. The first configuration is sufficiently different from the second configuration such that torque ripple may be minimized. A first layer of slots, defining a slot outer edge, may be formed in the rotor. In one embodiment, a stator-to-slot gap varies between the first and second ring segments. In another embodiment, a stator-rotor gap varies between the first and second ring segments. In another embodiment, a bridge thickness varies between the first and second ring segments. Thus the rotor exhibits axial asymmetry.
    Type: Grant
    Filed: April 17, 2012
    Date of Patent: November 11, 2014
    Assignee: GM Global Technology Operations
    Inventors: Sinisa Jurkovic, Khwaja M. Rahman, Xinyu Zhou, Xu Han, Qiang Niu
  • Patent number: 8860276
    Abstract: An electromagnetic steel sheet formed body to be used in a rotor core in which a forward rotational direction and a reverse rotational direction are assigned to a clockwise direction along a circumferential direction around an axial center when viewed from a visual line including the axial center, wherein a first hollow portion, a second hollow portion, and a rib partitioning the first hollow portion and the second hollow portion is formed at the electromagnetic steel sheet formed body such that permanent magnets constituting a plurality of poles are arranged substantially at regular intervals at predetermined pole pitch angles along the circumferential direction, and that the permanent magnet disposed at one pole is arranged in a segmented manner as the first permanent magnet and the second permanent magnet, when viewed from the visual line, and wherein the first hollow portion when viewed from the visual line is located closer to a side of the forward rotational direction than a centerline passing through a
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: October 14, 2014
    Assignee: Honda Motor Co., Ltd.
    Inventor: Daijiro Takizawa
  • Patent number: 8810102
    Abstract: The invention relates to an electric machine, in particular to a generator for supplying the electrical system of a motor vehicle, comprising a laminated rotor (20) with an energiser winding (29), which provides the energisation for the machine preferably in conjunction with permanent magnets (24, 25) arranged on the rotor periphery. According to the invention, the rotor laminate bundle (21) is made up of at least two part bundles (21a, b) in the axial direction with grooves (40) running into each other and with poles offset relative to each other (32 to 38). A machine with reduced detent torque is thus obtained with grooves (40) aligned parallel to the axis, in which the energiser windings (29) can be placed with a high filling factor and without production difficulties and without the risk of damaging the winding insulation.
    Type: Grant
    Filed: July 21, 2009
    Date of Patent: August 19, 2014
    Assignee: Robert Bosch GmbH
    Inventor: Kurt Reutlinger
  • Patent number: 8796896
    Abstract: An electric motor, especially a brushless PMDC motor, has a stator and a rotor rotatably installed inside of the stator. The stator has a housing with an open end, an end cap fixed to the open end of the housing, a stator core fixed to an inner surface of the housing, and windings wound on the stator core. The rotor includes a plurality of permanent magnetic poles. The housing has a flange bent inwardly from the open end of the housing and abutting against the end cap inwardly and axially to thereby fix the end cap to the housing. The length of the flange measured along the circumferential direction of the housing is greater than half of that of the housing.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: August 5, 2014
    Assignee: Johnson Electric S.A.
    Inventors: James Ching Sik Lau, Mao Xiong Jiang, Gang Li, Ke Lin Zhou, Hong Min Wei, Jie Chai, Tao Zhang
  • Patent number: 8786156
    Abstract: A rotating electric machine for vehicular use includes: a stator that includes a stator core and a stator winding wound at the stator core; and a rotor that is rotatably disposed relative to the stator and includes a rotor core formed by laminating a plurality of electromagnetic steel sheets with a plurality of magnet insertion holes formed therein and includes a plurality of permanent magnets each held in each of the plurality of magnet insertion holes to form a magnetic pole. Each of the plurality of permanent magnets extends along a rotor axis and is formed in a shape assuming at least two different lengths along a circumference of the rotor.
    Type: Grant
    Filed: August 12, 2010
    Date of Patent: July 22, 2014
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Noriaki Hino, Yutaka Matsunobu, Shinji Sugimoto, Akinori Kamiya, Yasuyuki Saito
  • Patent number: 8680731
    Abstract: A permanent-magnetic type rotary electric machine includes a stator having teeth that are arranged in the peripheral direction thereof and around which armature windings of plural phases are wound, and a rotor having plural permanent magnets arranged so that the poles of the permanent magnets are alternately different in the peripheral direction thereof, higher harmonic waves being contained in a no-load induced voltage waveform. A (6p?1)-th higher harmonic wave and a (6p?1)-th higher harmonic wave (p represents a positive integer) when an electrical angle of 360° is set as a fundamental wave in the no-load induced voltage waveform are made substantially coincident with each other in amplitude and phase.
    Type: Grant
    Filed: August 12, 2009
    Date of Patent: March 25, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Satoru Akutsu, Hideya Nishikawa, Yoshihito Asao, Masatsugu Nakano
  • Patent number: 8653710
    Abstract: A rotor has rotor cores divided in the axial direction. A permanent magnet is mounted at the position of each of the magnetic poles of cores. The permanent magnet of each magnetic pole is configured by a single tabular member that penetrates the two divided cores in the axial direction. Convex parts are respectively provided on the outer peripheries of the respective magnetic poles of the rotor cores along the axial direction of the rotor. The convex parts are provided to positions that are displaced for each of the two divided cores. The magnetic flux density increases in the convex parts, which becomes the magnetic pole center. Since the convex parts positions are displaced to each other, a skew function can be exhibited even if the permanent magnet is mounted at the same position.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: February 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Norio Takahashi, Kazuto Sakai, Yutaka Hashiba, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Tadashi Tokumasu
  • Patent number: 8648511
    Abstract: A magnetic component part for a rotor assembly of an electromechanical transducer is provided. The magnetic component part includes a base element having a first side and an opposing second side, a permanent magnet, attached to the base element at the first side, and a mounting structure fixed to the base element at the second side and adapted to be mechanically connected to a support structure of the rotor assembly. The permanent magnet is located in an offset position with respect to a central axis of the mounting structure, which central axis extends from the mounting structure through the second side to the first side. A rotor assembly, an electromechanical transducer and a wind turbine, which are all equipped with at least four magnetic component parts are also provided as well as a method for manufacturing a rotor assembly including at least four magnetic component parts.
    Type: Grant
    Filed: January 20, 2011
    Date of Patent: February 11, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: James Kenneth Booth, Soeren Gundtoft
  • Publication number: 20140035420
    Abstract: A permanent magnet motor (10) with reduced torque ripple and noise comprises a stator (20) and a rotor (30) divided into a plurality of rotor units (33). The rotors units include a plurality of structural features (38, 39, 40) to attach a plurality of magnetic components (35, 36). The rotor units are circumferentially staggered so that each rotor unit incrementally offsets from an adjacent rotor unit, thereby reducing the changes in magnetic flux as the rotor (30) spins, and thus reducing output ripples. The total offset between two end rotor units may be configured to be between a circumferential width of an outer surface of a structural feature (39) and an average circumferential width of a magnetic component (35).
    Type: Application
    Filed: August 1, 2013
    Publication date: February 6, 2014
    Applicant: JOHNSON ELECTRIC S.A.
    Inventors: Yue LI, Maoxiong JIANG, Jian ZHAO, Yaming ZHANG, Hongjiang ZHAO, Haijun HUA
  • Patent number: 8593028
    Abstract: A magnet for a generator is provided. The magnet includes a base magnet with a main surface having a length and a width and a skewed magnet module arranged at the main surface. A rotor of a generator including the magnet is provided as well as a generator with a stator and rotor including the magnet.
    Type: Grant
    Filed: November 18, 2011
    Date of Patent: November 26, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventor: Mohammad Kimiabeigi
  • Patent number: 8421294
    Abstract: A rotor includes permanent magnets arranged such that magnetic poles of N poles and S poles are arranged alternately in a rotation circumferential direction. The permanent magnets form a plurality of rows in a rotation axis direction. The rotor includes a change section in which arrangements of the magnetic poles change with respect to the rotation axis direction due to the permanent magnets being arranged such that arrangements of the magnetic poles change, in the rotation circumferential direction, between the permanent magnets in the plurality of rows. A stator includes tooth sections opposed to the rotor to surround the rotor, and auxiliary slots each of which is selectively formed at one portion of a front end portion of each tooth section in the rotation axis direction such that substantially a center of the auxiliary slot in the rotation axis direction is opposed to the change section.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: April 16, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shinichi Yamaguchi, Hisashi Otsuka, Haruyuki Hasegawa
  • Patent number: 8421292
    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.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: April 16, 2013
    Assignee: Hitachi Metals, Ltd.
    Inventors: Mitsutoshi Natsumeda, Yoshinori Takayama, Motoharu Shimizu
  • Patent number: 8368273
    Abstract: A rotary electric machine includes a stator having stator windings; and a rotor rotatably disposed in the stator, said rotor having a rotor core provided with a plurality of magnets and a plurality of magnetic auxiliary salient poles formed between poles of the magnets. In this rotary electric machine: a magnetic air gap is provided in an axial direction of the rotor in a position shifted in a circumferential direction from a q axis passing through a center of the magnetic auxiliary salient pole within the magnetic auxiliary salient pole; and an amount of shifting the magnetic air gap from the q axis in the circumferential direction differs according to a position of the magnetic air gap in the axial direction so as to cancel torque pulsation in energization caused due to the magnetic air gap.
    Type: Grant
    Filed: July 13, 2012
    Date of Patent: February 5, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Noriaki Hino, Yutaka Matsunobu, Shinji Sugimoto, Akinori Kamiya
  • Patent number: 8362668
    Abstract: A rotor for a rotating electrical machine suppresses demagnetization of permanent magnets without deteriorating motor characteristics, is low-cost, and is highly reliable. The rotor has a plurality of rotor cores that are stacked together, a plurality of permanent magnets axially divided by the rotor cores and circumferentially arranged on each of the rotor cores, to circumferentially form magnetic irregularities, and a rotor blank made of nonmagnetic material arranged between those of the rotor cores that are adjacent to each other.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: January 29, 2013
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Industrial Products Manufacturing Corporation
    Inventors: Norio Takahashi, Mikio Takabatake, Masanori Arata, Kazuto Sakai, Yutaka Hashiba, Wataru Ito, Tadashi Tokumasu, Masakatsu Matsubara
  • Patent number: 8344569
    Abstract: A generator for a wind power has teeth which are surrounded by windings and separated by slots, and permanent magnets that form the poles of the exciter field. The ratio of the number of slots to the product of the numbers of poles and winding phases is fractional and >1. Alternatively or additionally, the front and/or rear edges of successive poles or groups of poles are oppositely inclined to the axis of rotation.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: January 1, 2013
    Assignee: Vensys Energy AG
    Inventor: Stephan Jöckel
  • Patent number: 8288909
    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.
    Type: Grant
    Filed: January 14, 2010
    Date of Patent: October 16, 2012
    Assignee: Converteam UK Ltd
    Inventor: Paul Eaton Clark
  • Patent number: 8283827
    Abstract: A brushless, liquid or air cooled, direct current motor formed from a three stack stator and three section rotor assembly using an integrated water cooled or air cooled housing and over-molding techniques.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: October 9, 2012
    Inventors: Robert M. Jones, Joseph M. Lisiecki
  • Patent number: 8247940
    Abstract: A rotary electric machine includes a stator having stator windings; and a rotor rotatably disposed in the stator, said rotor having a rotor core provided with a plurality of magnets and a plurality of magnetic auxiliary salient poles formed between poles of the magnets. In this rotary electric machine: a magnetic air gap is provided in an axial direction of the rotor in a position shifted in a circumferential direction from a q axis passing through a center of the magnetic auxiliary salient pole within the magnetic auxiliary salient pole; and an amount of shifting the magnetic air gap from the q axis in the circumferential direction differs according to a position of the magnetic air gap in the axial direction so as to cancel torque pulsation in energization caused due to the magnetic air gap.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: August 21, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Noriaki Hino, Yutaka Matsunobu, Shinji Sugimoto, Akinori Kamiya
  • Patent number: 8247941
    Abstract: A brushless motor has a 2P3S×n structure, in which a ratio (W) of a circumferential width (Wm) of each of magnets to a length (Wp) of a chord formed between endpoints of an arc with a center angle ?p=360°/pole-number 3n, the arc being included in an inner-diameter circle C2 of each of the magnets, is in a range of 0.76<W=Wm/Wp<0.86. Therefore, in the brushless motor of the 2P3S×n structure, a skew angle may be set in a range of 36°??skew?57° in terms of electrical angle, while a content ratio of a fifth harmonic component contained in an induced voltage of the brushless motor may be set in a range of 4.5% to 6.5% with respect to a fundamental wave.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: August 21, 2012
    Assignee: Mitsuba Corporation
    Inventor: Masayuki Okubo
  • Patent number: 8227951
    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.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: July 24, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Udo Grossmann, Rolf Vollmer, Michael Zastrow
  • Publication number: 20120068568
    Abstract: An axial-winding motor includes a stator and a rotor. The stator has a winding assembly, a first magnetic-conducting plate and a second magnetic-conducting plate. The first and second magnetic-conducting plates are coupled with two ends of the winding assembly in an axial direction of the winding assembly. The first magnetic-conducting plate includes a plurality of first pole pieces on an outer periphery thereof, and the second magnetic-conducting plate includes a plurality of second pole pieces on an outer periphery thereof. The rotor is rotatably coupled with the stator and has a plurality of magnetic pole faces facing the stator. One of the first pole pieces is at least partially overlapped with adjacent one of the second pole pieces in an axial direction of the stator.
    Type: Application
    Filed: November 3, 2010
    Publication date: March 22, 2012
    Inventors: Alex Horng, Yen-Ming Chen, Chung-Ken Cheng
  • Patent number: 8134273
    Abstract: According to the invention, the torque ripple of electrical machines is supposed to be further reduced. For this purpose, it is provided to dispose the magnetic poles, for example, on the surface of a rotor in a plurality of sections (A1, A2) at different angles. The result are helix angles (?1, ?2), which have different amounts. Also more than two different helix angles, up to a continuous course of the boundary lines (G4) between the poles, can be implemented.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: March 13, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Rolf Vollmer, Marcus Ziegler
  • Publication number: 20120042974
    Abstract: A brushless motor has a stator and a rotor rotatably installed inside of the stator. The stator includes a stator core with teeth protruding inwardly and windings wound on the teeth. The rotor includes a shaft, a rotor core fixed on the shaft, and a ring magnet fixed to the circumferential outer surface of the rotor core. The magnet includes a plurality of magnetic poles radially magnetized so that north poles and south poles are arranged alternately in the circumferential direction. Boundary lines between magnetic poles are skewed by an angle relative to an axis of the shaft.
    Type: Application
    Filed: August 19, 2011
    Publication date: February 23, 2012
    Inventors: Mao Xiong JIANG, Yue Li, Tao Zhang, San Ruan Xao, Lik Hon Chan
  • Patent number: 8097993
    Abstract: Apparatus and method for tuning the magnetic field of brushless motors and alternators to obtain efficient operation over a broad RPM range. The motor or alternator includes fixed windings (or stator) around a rotating rotor carrying permanent magnets. The permanent magnets are cylindrical and have North (N) and South (S) poles formed longitudinally in the cylindrical magnets. The magnets reside in magnetic conducing pole pieces (for example, low carbon or soft steel, and/or laminated insulated layers, of non-magnetizable material). Rotating the cylindrical permanent magnets inside the pole pieces either strengthens or weakens the resulting magnetic field to adjust the motor or alternator for low RPM torque or for efficient high RPM efficiency. Varying the rotor magnetic field adjusts the voltage output of the alternators allowing, for example, a windmill generator, to maintain a fixed voltage output. Other material used in the rotor is generally non-magnetic, for example, stainless steel.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: January 17, 2012
    Inventors: Louis J. Finkle, Andrea Furia
  • Publication number: 20120007458
    Abstract: An electrical machine comprising a stator and a rotor rotatable relative to the stator with an air gap therebetween is disclosed. The stator is provided with a first plurality of sources of magnetic field which is equally spaced in a circumferential configuration over the stator. The rotor is provided with a second plurality of sources of magnetic field which is equally spaced in a circumferential configuration over the rotor. The magnetic sources of at least one plurality are electromagnets; each electromagnet comprises at least one magnet coil resting on a magnet conductor. The magnetic conductor comprises at least one member made of magnetically isotropic and/or anisotropic materials.
    Type: Application
    Filed: January 5, 2010
    Publication date: January 12, 2012
    Inventors: Eliyahu Rozinsky, Viktor Kislev, Ruslan Shabinski
  • Publication number: 20110175480
    Abstract: A magnetic component part for a rotor assembly of an electromechanical transducer is provided. The magnetic component part includes a base element having a first side and an opposing second side, a permanent magnet, attached to the base element at the first side, and a mounting structure fixed to the base element at the second side and adapted to be mechanically connected to a support structure of the rotor assembly. The permanent magnet is located in an offset position with respect to a central axis of the mounting structure, which central axis extends from the mounting structure through the second side to the first side. A rotor assembly, an electromechanical transducer and a wind turbine, which are all equipped with at least four magnetic component parts are also provided as well as a method for manufacturing a rotor assembly including at least four magnetic component parts.
    Type: Application
    Filed: January 20, 2011
    Publication date: July 21, 2011
    Inventors: James Kenneth Booth, Soeren Gundtoft
  • Patent number: 7939958
    Abstract: Apparatuses and methods for an improved wind turbine and blade assembly are disclosed. The wind turbine has a wind turbine assembly being rotatably driven by the blade assembly. The wind turbine assembly has a shaft connected to an inner wheel by a supporting structure. A magnet array is disposed circumferentially about the inner wheel. A transformer array is disposed circumferentially about an outer wheel. The shaft rotates the inner wheel with the magnet array within the outer wheel having the transformer array for producing electricity. Blades are held in a neutral position into the wind by tensioning means.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: May 10, 2011
    Inventor: Bill Todorof
  • Patent number: 7939982
    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.
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: May 10, 2011
    Assignee: Nidec Motor Corporation
    Inventor: Gary E. Horst
  • Patent number: 7928622
    Abstract: In a brushless motor including a rotor having 2n magnetic poles and a stator having 3n slots, the magnetic poles of the rotor are composed of segment magnets arranged in three columns extending in an axial direction. The magnets of each column are displaced from the magnet of either adjacent column in a circumferential direction, forming a 3-stage step-skew structure. The segment magnets have a skew angle ?skew ranging from 36° to 57° in terms of electrical angle.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: April 19, 2011
    Assignee: Mitsuba Corporation
    Inventor: Masayuki Okubo
  • Patent number: 7906880
    Abstract: In a brushless motor including a rotor having 2n poles and a stator having 3n slots, segment magnets are arranged in three columns in the axial direction, thus constituting rotor poles. The segment magnets of adjacent columns, which are identical in polarity, are displaced in the circumferential direction, thus forming a three-stage step-skew structure. The skew angle ?skew of each segment magnet is set to an electrical angle of 60° to 75°. The center angle of ?m of each segment magnet is set to 46.8° to 52.7°.
    Type: Grant
    Filed: March 3, 2009
    Date of Patent: March 15, 2011
    Assignee: Mitsuba Corporation
    Inventors: Masayuki Okubo, Mikio Kawamura
  • Patent number: 7902709
    Abstract: A permanent magnet included in a rotor of a brush-less motor is a radial anisotropic magnet in which multi-poles are magnetized in the circumferential direction and is skew magnetized along the axial direction in such a manner that a surface to one end part of an upper side from a central part in the axial direction and a surface to an end part of a lower side from the central part are axially shifted by a predetermined angle in the circumferential direction from each other. In accordance with this skew-magnetization, coggings including irregularly varying components generated in the rotor owing to the three-dimensional shapes of coil ends provided at opposite ends of a tooth 611a for fixing a winding have opposite phases to each other, so that the coggings are cancelled with each other. Accordingly, the coggings can be reduced or cancelled.
    Type: Grant
    Filed: March 10, 2008
    Date of Patent: March 8, 2011
    Assignee: JTEKT Corporation
    Inventor: Noboru Niguchi
  • Patent number: 7898123
    Abstract: The permanent magnet type rotary machine is capable of reducing cogging torque caused by variation of amounts of magnetic flux in magnetic circuits. The permanent magnet type rotary machine comprises: a stator constituted by stator units, which are coaxially stacked and in each of which a coil is sandwiched between stator yokes; and a rotor including a permanent magnet having magnetic poles, which respectively face magnetic pole teeth of the stator yokes, the rotor being rotatably supported by an output shaft. The stator units in one phase is divided into n (n is an integer one or more), and magnetic centers of at least one pair of the magnetic pole teeth of the adjacent stator yokes, which are vertically arranged, are shifted with a prescribed phase difference so as to mutually cancel their cogging torque.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: March 1, 2011
    Assignee: Shinano Kenshi Kabushiki Kaisha
    Inventor: Hiroaki Usui
  • Patent number: 7876013
    Abstract: A brushless motor has rotor cores dividedly formed as plural sections in an axial direction, segment magnets secured to outer circumferential surfaces of the rotor cores, and magnet holders secured to the rotor cores, respectively, for holding the segment magnet. Each of the rotor cores has holder-positioning grooves to which holder arms are fitted, and bridge parts formed corresponding to the holder positioning grooves. Each of the magnet holders has joint grooves fitted in the bridge parts and displaced from the holder arms by a step angle, the bridge parts being fitted in the joint grooves, thereby assembling a rotor.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: January 25, 2011
    Assignee: Mitsuba Corporation
    Inventors: Masayuki Okubo, Satoru Negishi, Koji Nara, Takeshi Yamazaki
  • Patent number: 7859159
    Abstract: An electric motor having a stator and a mover is disclosed. The stator has excitation coils of three phases, and the mover is movable relative to the stator. The mover has an opposed surface facing the excitation coils. Field poles or protrusions are provided on the opposite surface. The field poles or the protrusions extend helically about the axis of the mover. Each excitation coil extends helically in the same direction as the field pole or the protrusion about the axis of the mover so as to face the field pole or the protrusion.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: December 28, 2010
    Assignee: Asmo Co., Ltd.
    Inventor: Yasuhide Ito
  • Patent number: 7839040
    Abstract: A permanent-magnet generator rotor comprising a first rotor shaft end portion having in the axial center a hollow portion through which a bolt is passed; a second shaft end portion having in the axial center a hollow portion and a bearing portion through which the bolt is passed. A magnetic cylindrical body is sandwiched between the first and second shaft end portions. The permanent-magnet generator rotor includes the magnetic cylindrical body fixed between the first and second shaft ends, a permanent magnet held on the outer circumferential surface of the magnetic cylindrical body; a non-magnetic cylindrical body shrink-fit onto the outer circumferential surface of the permanent magnet; a stator disposed around the permanent magnet; and the bolt penetrating through the first and second shaft ends; the hollow portions in the generator, and the magnetic cylindrical body.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: November 23, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Hayasaka, Hideaki Nagashima, Manabu Sasaki
  • Publication number: 20100283348
    Abstract: Provided is a brushless motor of a 2P3S×n structure, in which a ratio (W) of a circumferential width (Wm) of each of magnets (16a to 16c) to a length (Wp) of a chord formed between endpoints of an arc with a center angle ?p=360°/pole-number 3n, the arc being included in an inner-diameter circle C2 of each of the magnets (16a to 16c), is in a range of 0.76<W=Wm/Wp<0.86. Therefore, in the brushless motor of the 2P3S×n structure, a skew angle may be set in a range of 36°??skew?57° in terms of electrical angle, while a content ratio of a fifth harmonic component contained in an induced voltage of the brushless motor may be set in a range of 4.5% to 6.5% with respect to a fundamental wave.
    Type: Application
    Filed: January 30, 2009
    Publication date: November 11, 2010
    Inventor: Masayuki Okubo