Defining Non-uniform Air Gap Patents (Class 310/216.092)
  • Patent number: 11799338
    Abstract: An embodiment relates to a motor comprising: a shaft; a rotor engaged with the shaft; and a stator disposed outside the rotor, wherein the stator includes a stator core formed by stacking a plurality of sheets and a coil wound around the stator core, the stator core including a yoke having a hole formed therein, a tooth protruding radially from the yoke, and an adhesive member disposed in the hole, the hole being disposed on an imaginary line L extending radially along the side of the tooth. Accordingly, the motor can form a stator core by stacking sheets, and reduce noise and vibration by filling an adhesive member in a hole formed in the stator core.
    Type: Grant
    Filed: August 27, 2019
    Date of Patent: October 24, 2023
    Assignee: LG INNOTEK CO., LTD.
    Inventors: Seong Jin Kim, Gi Chang Moon, Jin Su Pyeon
  • Patent number: 11489392
    Abstract: A bobbin structure of an armature of a three-phase motor having 6N (N is a natural number) slots and 3N coils per phase, the bobbin structure including: a main pole into which a winding bobbin around which a coil is wound is inserted; and an auxiliary pole into which an empty bobbin around which the coil is not wound is inserted. The main pole and the auxiliary pole are placed in a circumferential direction with respect to a rotation axis, and a contact portion where the empty bobbin and the winding bobbin are in contact with each other is formed on each of an outer peripheral side and an inner peripheral side of the slot formed between the main pole and the auxiliary pole.
    Type: Grant
    Filed: December 18, 2019
    Date of Patent: November 1, 2022
    Assignee: SANYO DENKI CO., LTD.
    Inventors: Manabu Horiuchi, Hiroki Sagara, Jun Kitajima, Mai Shimizu, Takashi Matsushita
  • Patent number: 11056938
    Abstract: A rotor includes a rotor core in which laminate steel plates extending in a radial direction with respect to a central axis are laminated in an axial direction, and magnets are inserted into the rotor core. Each of the laminate steel plates includes a base portion positioned on a radially outer side of the central axis, and pieces separately disposed on a radially outer side of the base portion with penetrating portions therebetween, and arranged side by side at predetermined intervals in a circumferential direction. The magnets are inserted into the penetrating portions and arranged side by side at predetermined intervals in the circumferential direction. Space portions are provided between the magnets adjacent to each other in the circumferential direction. A circumferential length of the pieces is shorter than a circumferential length of the magnets.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: July 6, 2021
    Assignee: NIDEC CORPORATION
    Inventors: Takayuki Migita, Takeshi Honda, Hirofumi Muto, Osamu Fujimoto, Hiroshi Kitagaki, Yasuaki Nakahara
  • Patent number: 10916983
    Abstract: A permanent-magnet motor includes a through-hole expansion portion provided in a through-hole for inserting a permanent magnet into the rotor core of a permanent-magnet motor, and a bridge portion that surrounds adjacent through-hole expansion portions and forms part of the outer circumferential surface of the rotor core; the bridge portion has a small-thickness portion that is formed to be smaller than that of a portion, other than the bridge portion, of the rotor core.
    Type: Grant
    Filed: May 10, 2016
    Date of Patent: February 9, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroshi Aida, Masafumi Okazaki, Satoru Akutsu, Yoshihito Asao, Yuji Takizawa
  • Patent number: 10574099
    Abstract: An electric motor/generator includes a stator-core enclosing a rotor-core, which are each formed from stacked annular laminates. The stator-core laminates are configured to reduce vibration, and each have teeth extending radially inward from a root of an annular stator yoke/back-iron, to a flux-cap. Each tooth is formed to have opposite, lateral-edges spaced a distance-apart that changes between the root to the flux-cap, to establish a variable tooth-stiffness and a predetermined mechanical-resonance of the tooth. The opposite lateral-edges may each be configured with either a linear or a non-linear, curved edge-profile, and to have the variable tooth-stiffness and the lateral-edge distance-apart changing or decreasing between the root and the flux-cap. Each tooth may also have an edge-profile that is different from at least one adjacent tooth, and which is configured with a variable tooth-stiffness and a predetermined mechanical resonance that is different from the at least one adjacent tooth.
    Type: Grant
    Filed: March 30, 2017
    Date of Patent: February 25, 2020
    Assignee: Ford Global Technologies, LLC
    Inventors: Wei Xu, Zhichun Ma, Shuzhen Liu, Jiyao Wang
  • Patent number: 10256681
    Abstract: An electric motor comprising a rotor rotatable about a rotor axis and a stator at least substantially circumscribing the rotor is provided. The stator includes a generally toroidal core including a plurality of arcuately spaced apart, radially inwardly extending teeth. Each of the teeth presents a radially innermost face that extends along a curved contour. A portion of the contour has a radius of curvature that corresponds to a circle having a center. The center is radially offset from the rotor axis. Furthermore, each of the teeth includes a radially extending arm having an end and a crown extending relative to the end. The crown presents a pair of arcuately spaced apart endmost tips, each of which has a rotor-facing side. The rotor-facing side includes a tapered portion that turns away from the rotor.
    Type: Grant
    Filed: January 7, 2015
    Date of Patent: April 9, 2019
    Assignee: Nidec Motor Corporation
    Inventor: Ryan M. Bastien
  • Patent number: 9481778
    Abstract: Disclosed herein are gel and plastic compositions comprising tightened layers of polymerized vinyl monomers, as well as methods of making the same, where the layers are tightened in having smaller pores. The tightened layers comprise tightened inner layers and exterior layers, and the compositions comprise polymer-attached (pendant) initiator or helper residues.
    Type: Grant
    Filed: September 9, 2010
    Date of Patent: November 1, 2016
    Assignee: Northeastern University
    Inventors: Roger W. Giese, Gang Shao
  • Patent number: 9468684
    Abstract: The present disclosure relates to a hydrogel composition and methods of using the same. The hydrogel composition may include precursors that react with each other upon contact as well as precursors that react upon contact with an initiator. In embodiments, the resulting hydrogels may have varying levels of crosslinking with both denser and less dense regions.
    Type: Grant
    Filed: February 5, 2015
    Date of Patent: October 18, 2016
    Assignee: Covidien LP
    Inventors: Steven Bennett, Nathaniel Mast, Kevin Lavigne, Walter Skalla
  • Patent number: 8957563
    Abstract: An electric machine is provided with a rotor configured to be rotatable within a stator. A first and second tooth are disposed circumferentially along an outer perimeter of the rotor and at least partially define a first slot. The first and the second tooth define a respective first and second outer edge extending between a respective tooth base and a respective tooth tip. An arc radius from the origin to the outer perimeter of the rotor varies along the first outer edge of the first tooth, thereby creating a first non-uniform gap between the rotor and the stator. The arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge of the second tooth, thereby creating a second non-uniform gap between the rotor and the stator. The rotor geometry is configured to reduce torque ripple without skewing either the rotor or the stator.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: February 17, 2015
    Assignee: GM Global Technology Operations LLC
    Inventors: Khwaja M. Rahman, Constantin C. Stancu, Sinisa Jurkovic, Xinyu Zhou, Qiang Niu, Xu Han
  • Publication number: 20150022036
    Abstract: Various embodiments include apparatuses adapted to include a dynamoelectric machine rotor with a modified outer surface. In some embodiments apparatuses include a dynamoelectric machine rotor including a rotor body having a spindle, pole regions, the pole regions having a non-uniform radial distance from an axis of rotation of the rotor to an outer surface of the pole regions and a plurality of slots in the outer surface of the rotor body, the plurality of slots being spaced apart in a circumferential direction of the rotor body, each of the plurality of slots extending in an axial direction of the rotor body.
    Type: Application
    Filed: July 19, 2013
    Publication date: January 22, 2015
    Applicant: General Electric Company
    Inventors: Venkata Subramanya Sarma Devarakonda, Patrick Robert Davis, James Jonathan Grant, Paul August Quail, John Russell Yagielski
  • Publication number: 20140368081
    Abstract: A rotor of a permanent-magnet embedded motor includes a rotor core having magnet insertion holes along a circumferential direction and a magnet inserted into each of the holes, wherein a gap is formed at opposite ends of a hole at a time of inserting the magnet therein, an outer peripheral face of the core is formed by a first curved surface formed from a magnetic pole center to between poles, with a radial distance from a shaft center of the core being largest at the pole center on the peripheral face, and a second curved surface formed from an interpolar portion toward the pole center to intersect with the first curved surface, with the radial distance from the shaft center being smallest in the interpolar portion on the peripheral face, and wherein a length of the first curved surface is larger than a length of the second curved surface.
    Type: Application
    Filed: December 26, 2011
    Publication date: December 18, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Koji Yabe, Kazuhiko Baba
  • Patent number: 8847456
    Abstract: An arrangement to ensure an air gap in an electrical machine is provided. The electrical machine has a stator arrangement and a rotor arrangement, the rotor arrangement rotating around a longitudinal axis. An air gap is defined by a distance between parts of the rotor arrangement and parts of the stator arrangement, wherein the parts of the stator arrangement are opposite to the parts of the rotor arrangement along a certain length. The stator arrangement includes a lamination stack which is constructed to support a winding of a stator-coil, and the rotor arrangement includes a plurality of permanent magnets. A cross section of the air gap changes along the certain length such that the air gap is not uniform in view to the certain length. The cross section of the air gap is configured by a change in a shape of the lamination stack along the certain length.
    Type: Grant
    Filed: August 9, 2013
    Date of Patent: September 30, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventor: Henrik Stiesdal
  • Patent number: 8847460
    Abstract: A permanent magnet motor includes a permanent magnet rotor, a stator surrounding the rotor having a plurality of teeth radially inwardly oriented toward a longitudinal axis of the stator wherein each tooth has a tooth length and a tooth tip surface geometry. An asymmetric air gap is defined by variations in the tooth lengths and tooth tip surface geometries.
    Type: Grant
    Filed: May 9, 2011
    Date of Patent: September 30, 2014
    Assignee: GM Global Technology Operations LLC
    Inventors: Sinisa Jurkovic, Xinyu Zhou, Qiang Niu, Khwaja M. Rahman, John C. Morgante, Xu Han, Edward L. Kaiser
  • Patent number: 8841813
    Abstract: A brushless synchronous motor includes a rotor having a number n of embedded permanent magnets and being rotatable relative to a stator having a number of stator teeth provided with a three-phase stator winding, while forming an air gap. An angle between two adjacent permanent magnets is 360°/n where n>8, an angle between two adjacent stator teeth is 360°/n+2, and an inner contour of the stator facing the rotor has a curved structure with curvature valleys provided at ends of the stator teeth.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: September 23, 2014
    Assignee: Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Wuerzburg
    Inventors: Jacek Junak, Grzegorz Ombach
  • Patent number: 8816562
    Abstract: A stator for an electric rotating machine includes a stator core that has slots, a stator coil, and an impregnant applied to the inner surface of the stator core. The stator core has a plurality of teeth that divide the slots. Teeth having chamfered surfaces between a projected tip surface and each side surface of the teeth and teeth without chamfered surfaces are intermingled. At least one bent corner part formed at an end of the projected tip surface of the teeth is formed in an arcuate surface. A relationship (R1>R2) is satisfied, where R1 represents a curvature radius of arcuate surfaces formed in the curved corner part where the projected tip surface and the chamfered surface abut and R2 represents a curvature radius of the arcuate surfaces formed in the curved corner part where the projected tip surface and the side surface abut.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: August 26, 2014
    Assignee: Denso Corporation
    Inventors: Shigenori Yoneda, Toshiaki Oohara
  • Patent number: 8766503
    Abstract: An accommodating recess (21A, 21B) has a magnet accommodating portion (19A, 19B) for accommodating a permanent magnet (17A, 17B) and a cavity (20A, 20B), which is located at the q-axis side of the magnet accommodating portion. The cavity opens through a rotor outer circumferential surface (162). A starting point (Pa1, Pb1) of an outer cavity forming surface (201A, 201B) is located on the rotor outer circumferential surface. The outer cavity forming surface intersects either a magnetic pole surface or an imaginary extended plane (23A, 23B) of a magnetic pole facing surface (191A, 191B). The rotor outer circumferential surface (162) includes portions of an imaginary annular line (E). A starting point (Pa1, Pb1) of the outer cavity forming surface (201A, 201B) is located between the d-axis and an intersection point (Qa, Qb) between the imaginary annular line and the imaginary extended plan of the magnetic pole facing surface.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toyota Jidoshokki
    Inventors: Masanao Kagami, Ryo Umeyama, Yoshiyuki Nakane
  • Patent number: 8754563
    Abstract: A recording disk is to be mounted on a hub. A base rotatably supports the hub through a bearing. A stator core is fixed to the base and includes an annular portion and a salient pole extending radially therefrom. A magnet faces the salient pole radially and is rotated with the hub. The magnet has a plurality of magnetic poles in the circumferential direction such that each of the plurality of magnetic poles faces the salient pole. The salient pole includes a rod-shaped body around which a wire is wound and a tooth portion that is provided radially outside the rod-shaped body and extends circumferentially. The circumferential end located at the end in the circumferential direction of the tooth portion is located radially inside a circumscribed circle passing through the tip located at the radially outermost end of the tooth portion.
    Type: Grant
    Filed: June 14, 2011
    Date of Patent: June 17, 2014
    Assignee: Samsung Electro-Mechanics Japan Advanced Technology Co., Ltd
    Inventors: Kazuyoshi Nagai, Akira Suzuki
  • Patent number: 8754564
    Abstract: The present disclosure relates to a hydrogel composition and methods of using the same. The hydrogel composition may include precursors that react with each other upon contact as well as precursors that react upon contact with an initiator. In embodiments, the resulting hydrogels may have varying levels of crosslinking with both denser and less dense regions.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: June 17, 2014
    Assignee: Covidien LP
    Inventors: Steven Bennett, Nathaniel Mast, Kevin Lavigne, Walter Skalla, Timothy Sargeant, Joshua Stopek
  • Publication number: 20140117807
    Abstract: A motor includes a plurality of tooth bodies extending from a rotor core. A pole shoe extends from an end of at least one tooth body at opposite sides where both sides of the pole shoe have a curved outer part opposite to each other and asymmetric to each other in that a radius of curvature of the curved outer part of the one side of the pole shoe that is in a rotational direction of the rotor has a smaller radius than a radius of curvature of the other side of the pole shoe that is not in the rotational direction of the rotor.
    Type: Application
    Filed: March 1, 2013
    Publication date: May 1, 2014
    Applicant: LG Electronics Inc.
    Inventors: Youngboong Kim, Sanghwa Do, Jungpyo Hong, Byeonghwa Lee, Seungdo Han, Hokyoung Lim
  • Patent number: 8664826
    Abstract: An electric motor (1) has a stator (2) and a radially symmetric, permanent magnet excited rotor (4) coaxial with the stator (2). The rotor (4) rotates relative to the stator (2) about a common motor axis (X). The stator (2) has a radially symmetric iron core (6) with a defined number (N) of stator teeth (10) which are each adjacent to one another via stator slots (8) and slot openings (8a) in the circumferential direction. The rotor (4) has pole magnets (14) adjacent to one another. A circumferential gap (18) is formed radially between the pole magnets (14) and the stator teeth (10). Each stator tooth (10) has on its surface (20) facing the gap (18) and adjacent to the slot openings (8a) on both sides in the circumferential direction a relief-like topographic region (22) radially enlarging the gap (18) with least one concave recess (24) and a smooth profile.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: March 4, 2014
    Assignee: EBM-Papst Mulfingen GmbH & Co. KG
    Inventor: Jens Krotsch
  • Publication number: 20140028148
    Abstract: An interior permanent magnet machine is described. The machine includes a rotor rotatable about a central machine axis. The rotor includes a plurality of permanent magnet openings and a plurality of permanent magnets disposed therein. The permanent magnet openings are separated by rotor webs configured to facilitate reducing leakage flux through the rotor webs. The machine also includes a stator disposed coaxially with the rotor and separated from the rotor by a circumferential air gap. The stator includes a plurality of stator teeth that define a plurality of stator slots therebetween. The stator teeth include a stator tooth tip configured to facilitate reducing cogging torque and torque ripple.
    Type: Application
    Filed: July 27, 2012
    Publication date: January 30, 2014
    Inventors: Kerry B. Shelton, Subhash Marutirao Brahmavar, Marshall Miers
  • Publication number: 20130334925
    Abstract: An IPM type rotor having a continuous skew structure obtained by a simple means, without constituting a permanent magnet as a complicated shape and forming an inclined magnetizing pattern on the permanent magnet. A rotor core has a recess formed on an outer circumferential surface of the rotor core. The recess is formed so as to extend along a boundary line of magnetic poles of a desired skew structure. Therefore, even when each permanent magnet has the cuboid shape, the magnetic flux may be uniformed during the magnetic flux is transmitted through the magnetic steel plate having high permeability, whereby the magnetic flux within the gap having low permeability becomes dominant. As a result, the rotor having the continuous skew structure is obtained.
    Type: Application
    Filed: April 19, 2013
    Publication date: December 19, 2013
    Applicant: FANUC Corporation
    Inventors: Hidetoshi UEMATSU, Yasuo KAWAI
  • Patent number: 8598763
    Abstract: A field element core has a perimeter exposed around a rotation axis and a plurality of field magnet insertion holes circularly disposed around the rotation axis P. A radius between the perimeter and the rotation axis P decreases in a monotonically non-increasing manner from a pole center toward an interpole and then increases in a monotonically non-decreasing manner in a region between the pole center and the interpole in a circumferential direction.
    Type: Grant
    Filed: April 22, 2009
    Date of Patent: December 3, 2013
    Assignee: Daikin Industries, Ltd.
    Inventors: Keiji Aota, Yoshihito Sanga, Akio Yamagiwa
  • Publication number: 20130300249
    Abstract: A single-phase brushless motor has both superior start-up stability and low cogging torque. In the outer-rotor-type single-phase brushless motor, when a gap width between the rotor and one edge of the salient pole surface is defined as d1, a gap width between the rotor and the other edge of the salient pole surface is defined as d2, and a minimum gap width between the rotor and the salient pole surface is defined as d3, the formula d3<d1<d2 is satisfied, and the gap width is d3 at a position shifted toward the one edge of the salient pole surface from the center of the arc shape which forms the salient pole surface.
    Type: Application
    Filed: April 26, 2013
    Publication date: November 14, 2013
    Applicant: MINEBEA CO., LTD.
    Inventors: Yuji OMURA, Tomoaki NAKANO, Masaaki NISHIZAWA, Takahiro SAKAGUCHI, Shinichi UCHIKAWA, Tomoyuki TSUKADA
  • Publication number: 20130270961
    Abstract: An internal permanent magnet motor includes a rotor having main polar surfaces and inter-polar surfaces that are each formed by connecting circular arcs of a plurality of eccentric circles that are not concentric with the rotor center. As such, a technique of adjusting air gap thickness is realized to achieve the purpose of reducing the cogging torque of the motor and regular layered variation of air gap thickness is employed to reduce higher harmonics occurring in the operation of the motor. Further, the present invention uses specific air gap thickness of the inter-polar surfaces and maintaining the inter-polar surfaces at a predetermined width to increase the quadrature axis inductance of the motor in order to increase the reluctance torque of the motor and improve torque of the motor.
    Type: Application
    Filed: April 16, 2012
    Publication date: October 17, 2013
    Inventor: MING TSUNG CHU
  • Publication number: 20130229085
    Abstract: A brushless DC motor, comprising a stator having paired stator teeth, a rotor having paired magnetic poles and a rotating shaft fixed in the center of the rotor, wherein each of the stator teeth is wound with a winding, in each cross section of the stator, the connecting line between the intersection point of a tooth top arc of the stator tooth and the tooth axis of the stator tooth and the center of the tooth top arc can form a mechanical eccentric angle ? with the tooth axis of the stator tooth, which is more than 0 degree and smaller than 90 degrees. The tooth top circle of the stator tooth is designed to be an arc, which is eccentric relative to the rotating center of the rotor, such that the brushless DC motor can eliminate the starting “dead point” and start successfully.
    Type: Application
    Filed: January 22, 2013
    Publication date: September 5, 2013
    Applicant: ZHEJIANG YILIDA VENTILATOR CO., LTD.
    Inventors: Qizhong Zhang, Wei Zhang
  • Publication number: 20130229080
    Abstract: A rotary magnetic motor having a rotor configured to magnetically interact with a stator to obtain rotation of the rotor about its axis. The stator has a magnetic structure of a generally involute shape around the axis of rotation. The stator magnetic structure has a plurality of permanent magnets defining a first magnetic face of a first polarity. The rotor has a magnetic structure of a generally circular shape around the axis and inside the stator magnetic structure. The rotor has a plurality of permanent magnets defining a second magnetic face of a second polarity. The magnetic attraction and repulsing of the aligned magnetic faces with a progressively narrowing radial gap, resulting from the involute shape, rotate the rotor inside the stator. A magnetic pulse mechanism discharges a magnetic pulse of the first polarity to provide an additional pull to continue the rotation of the rotor through its full cycle.
    Type: Application
    Filed: March 4, 2012
    Publication date: September 5, 2013
    Inventor: Arnold Jones
  • Patent number: 8519593
    Abstract: A brushless DC motor provided with nine slots and eight poles includes a stator including a stator core having pole teeth on the outer circumference thereof and a coil wound around each pole tooth; a rotor disposed at an outside position of the outer circumference of the stator via a gap and having a multiply magnetized permanent magnet with plural magnetic poles; a pole tooth surface formed at a portion of the pole tooth and facing an inner circumference of the rotor; a recessed portion formed on the pole tooth surface; and a slot formed between the adjacent pole teeth and extending a first angular range around a rotational center of the rotor; in which the recessed portion extends in a second angular range around the rotational center of the rotor, the second angular range is 1.2 to 3.0 times the first angular range, the recessed portion has a radial depth which is 0.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: August 27, 2013
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Yuuki Takahashi
  • Publication number: 20130207508
    Abstract: A rotary electric machine includes a rotor core in which first magnetic pole portions having permanent magnets and second magnetic pole portions having no permanent magnets are alternately arranged in a circumferential direction; and a stator core which is arranged to face an outer periphery of the rotor core. The rotor core is configured such that an average gap length between the stator core and the second magnetic pole portions is larger than an average gap length between the stator core and the first magnetic pole portions.
    Type: Application
    Filed: February 13, 2013
    Publication date: August 15, 2013
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventor: Kabushiki Kaisha Yaskawa Denki
  • Patent number: 8505674
    Abstract: A steering drive for a motor vehicle comprising a steering wheel, a steering column, on which the steering wheel is disposed, a connecting rod, which interacts with the steering column to deflect the wheels of the motor vehicle, an electric motor, which is provided for boosting the steering thrust, as well as a belt drive, the electric motor interacting with the connecting rod via the belt drive. Said electric motor comprises a stator having twelve stator teeth as well as a rotor having ten rotor poles, the rotor poles being spaced apart from each other by an air gap and embodied as sinus poles.
    Type: Grant
    Filed: May 25, 2011
    Date of Patent: August 13, 2013
    Assignee: Robert Bosch GmbH
    Inventors: Achim Neubauer, Michael Pesch
  • Publication number: 20130147309
    Abstract: An electric machine is provided with a rotor configured to be rotatable within a stator. A first and second tooth are disposed circumferentially along an outer perimeter of the rotor and at least partially define a first slot. The first and the second tooth define a respective first and second outer edge extending between a respective tooth base and a respective tooth tip. An arc radius from the origin to the outer perimeter of the rotor varies along the first outer edge of the first tooth, thereby creating a first non-uniform gap between the rotor and the stator. The arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge of the second tooth, thereby creating a second non-uniform gap between the rotor and the stator. The rotor geometry is configured to reduce torque ripple without skewing either the rotor or the stator.
    Type: Application
    Filed: December 7, 2011
    Publication date: June 13, 2013
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Khwaja M. Rahman, Constantin C. Stancu, Sinisa Jurkovic, Xinyu Zhou, Qiang Niu, Xu Han
  • Patent number: 8436504
    Abstract: An electric machine having a stator surrounding a rotor with an air gap therebetween. The stator has slots in its inner margin for accommodating stator coil windings. Stator teeth defined by the slots have irregular shapes to modify a variable flux flow pattern in the air gap to reduce harmonic torque components with minimal effect on an average value of rotor torque.
    Type: Grant
    Filed: January 11, 2010
    Date of Patent: May 7, 2013
    Assignee: Ford Global Technologies, LLC
    Inventors: Feng Liang, Michael W. Degner, Alfredo R. Munoz, Wen Ouyang
  • 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: 8400040
    Abstract: A permanent magnet type rotary electric machine has a rotor having a rotor core and permanent magnets buried into the rotor core by being incorporated into respective permanent magnet slots. The permanent magnet slot per one pole is divided at least into four slots along an outer circumferential direction in the rotor core, and in respective rest core-portions between adjacent divided permanent magnet slots in the rotor core, a width of a first rest core-portion at the middle of each pole and a width of a second rest core-portion between adjacent poles of different polarities are formed larger than that of the others.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: March 19, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Daisuke Kori, Hiroyuki Mikami, Seikichi Masuda, Mamoru Kimura
  • Publication number: 20130052061
    Abstract: A brushless motor has a stator and an outer rotor. The stator includes a stator core having 6N teeth and 6N coils wound respectively around the teeth where N is an integer equal to or greater than 1. The rotor includes 6N±2 permanent magnets. The permanent magnets are arranged circumferentially around the stator core and face the teeth across an air gap. The radial thickness of the air gap is uneven along the circumferential direction of the motor.
    Type: Application
    Filed: August 24, 2012
    Publication date: February 28, 2013
    Inventors: Yue LI, Jin Yun Gan, Chui You Zhou, Cheng Xue, Ya Ming Zhang
  • Patent number: 8378533
    Abstract: A pump motor includes a stator, a rotor and a housing accommodating the stator and the rotor. The stator has a plurality of teeth, each of the teeth being provided with a cap portion at its tip end. The rotor is arranged inside the stator in an opposing relationship with the cap portion of each of the teeth. The housing includes a fluid path defined therein. The fluid path includes a substantially annular gap axially extending between the stator and the rotor. The cap portion includes a first opposing surface and a second opposing surface provided in an opposing relationship with the rotor to define a portion of the fluid path, the distance between the first opposing surface and an outer circumferential surface of the rotor being greater than the distance between the second opposing surface and the outer circumferential surface of the rotor.
    Type: Grant
    Filed: November 5, 2009
    Date of Patent: February 19, 2013
    Assignee: Nidec Corporation
    Inventors: Hideaki Suzuki, Kyohei Asahi
  • Patent number: 8365628
    Abstract: A method for designing a pole piece for a power assist steering system, includes: selecting a number of teeth, k, for the pole piece where k=n/2 and n represents an even number of poles; and selecting a ratio between an angle made by an inner tooth tip and an outer tooth tip, ?tp, and an angle made by a magnet pole width, ?mp, to provide a desired torque function for the steering system.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: February 5, 2013
    Assignee: Steering Solutions IP Holding Corporation
    Inventors: Mohammad S. Islam, Christian E. Ross, Matthew W. Mielke
  • Patent number: 8350439
    Abstract: This motor includes a stator whereupon a plurality of magnetic poles are arranged at first prescribed intervals on the outer circumference section, and a rotor which is rotatively arranged on the outer circumference of the stator by having a prescribed space in between and has permanent magnets magnetized to different polarities at second prescribed intervals. The magnetic pole of the stator forms an extending section which extends from a magnetic pole base section in a direction parallel to the permanent magnet, and the extending length of the extending section in the direction parallel to the permanent magnet is same as that of the magnetic pole base section in the direction parallel to the permanent magnet or shorter.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: January 8, 2013
    Assignee: Panasonic Corporation
    Inventors: Yuichi Yoshikawa, Hiroshi Murakami, Atsuyoshi Koshiba, Koji Kadowaki, Haruki Kato, Yasuo Kunishige
  • Patent number: 8344570
    Abstract: A rotor (21) is an interior permanent magnet rotor formed of a rotor core (24) in which a plurality of permanent magnets (25) are embedded at predetermined intervals. First protruding portions (26) and second protruding portions (27) are formed on an outer peripheral face of the rotor, the first protruding portions (26) each opposing the vicinity of a central portion of each of the permanent magnets and having a substantially arc-shaped cross section protruding outward and the second protruding portions (27) each opposing the vicinity of an end portion of each of the permanent magnets and protruding outward. One first protruding portion and two second protruding portions correspond to one permanent magnet. The formation of the first and second protruding portions as described above on the outer peripheral face of the rotor makes it possible to sufficiently reduce the torque ripple and the noise caused by the distortion of air-gap magnetic flux distribution.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: January 1, 2013
    Assignee: Panasonic Corporation
    Inventors: Kiyomi Kawamura, Takashi Ogawa, Hiroshi Murakami, Yuichi Yoshikawa, Yasuyuki Yokouchi
  • Publication number: 20120256514
    Abstract: A brushless synchronous motor includes a rotor having a number n of embedded permanent magnets and being rotatable relative to a stator having a number of stator teeth provided with a three-phase stator winding, while forming an air gap. An angle between two adjacent permanent magnets is 360°/n where n>8, an angle between two adjacent stator teeth is 360°/n+2, and an inner contour of the stator facing the rotor has a curved structure with curvature valleys provided at ends of the stator teeth.
    Type: Application
    Filed: April 2, 2012
    Publication date: October 11, 2012
    Applicant: BROSE FAHRZEUGTEILE GMBH & CO. KOMMANDITGESELLSCHAFT
    Inventors: Jacek Junak, Grzegorz Ombach
  • Publication number: 20120139386
    Abstract: An electric motor according to the present invention includes a rotor core, a stator core provided so as to face the rotor core in the radial direction, and a permanent magnet buried in the vicinity of an outer circumferential part of the rotor core, wherein the outer circumferential part of the rotor core and an inner circumferential part of the stator core are formed in such a manner that a radial gap length between the outer circumferential part of the rotor core and the inner circumferential part of the stator core for one magnetic pole of the permanent magnet becomes a gap length along a gap length regulated by an expression capable of making magnetic flux density distribution between the outer circumferential part of the rotor core and the inner circumferential part of the stator core a sinusoidal waveform.
    Type: Application
    Filed: November 4, 2011
    Publication date: June 7, 2012
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventor: Sohji MURAKAMI
  • Publication number: 20120133239
    Abstract: According to one embodiment, a magnet embedded rotor includes a rotor iron core and a permanent magnet. The rotor iron core is formed of a magnet into a cylindrical shape and provided with holes. The rotor iron core includes a nonmagnetic portion, salient poles, a notch groove, a bridge, and a first protrusion. The nonmagnetic portion prevents magnetic-flux short circuiting. The salient poles are located on the outer circumferential side of the holes. The notch groove is located between an adjacent pair of the salient poles. The bridge is located between the notch groove and the nonmagnetic portion. The first protrusion protrudes outward from the center of the notch groove. The permanent magnet is embedded in each hole. The radius of each salient pole gradually decreases from the center toward the notch groove. The radius of the first protrusion is equal to that of the center of the salient pole.
    Type: Application
    Filed: November 23, 2011
    Publication date: May 31, 2012
    Inventors: Yoshihiro TAEMA, Masaki YAMADA, Takeaki ASHIMORI, Tomooki HASEGAWA
  • Publication number: 20120126654
    Abstract: A permanent magnet brushless motor is provided. The motor includes a stator having a tubular-shaped member and a plurality of tooth members extending radially inwardly from the tubular-shaped member. Each tooth member has an arcuate-shaped convex surface disposed proximate to an interior region defined by the stator. Each arcuate-shaped convex surface is defined by a first radius that is rotated about a respective center point that is disposed radially outside of the stator. The motor further includes a rotor disposed within the interior region of the stator.
    Type: Application
    Filed: October 3, 2011
    Publication date: May 24, 2012
    Applicant: NEXTEER (BEIJING) TECHNOLOGY CO., LTD.
    Inventors: Mohammad S. Islam, Mohammed Rakibul Islam
  • Publication number: 20120104905
    Abstract: The disclosure relates to a three-phase electric motor that uses high magnetic energy permanent magnets and that has a low detent torque. The motor consists of a rotor with N pairs of poles and of a stator portion with teeth extending radially from an annular gear. The teeth have windings and the ends thereof comprise an arc of circle, the middle of which is located on a radius R1 and two sides defining an alpha angle, the vertex of which is located on a radius R2. The ratio R2/R1 is substantially equal to (1+/?0.26/N), and the alpha angle is between 110 and 135°.
    Type: Application
    Filed: May 11, 2010
    Publication date: May 3, 2012
    Applicant: MOVING MAGNET TECHNOLOGIES (MMT)
    Inventors: Daniel Prudham, Pierre-Daniel Pfister, Thibaut Richard
  • Publication number: 20120049689
    Abstract: The present disclosure relates to a hydrogel composition and methods of using the same. The hydrogel composition may include precursors that react with each other upon contact as well as precursors that react upon contact with an initiator. In embodiments, the resulting hydrogels may have varying levels of crosslinking with both denser and less dense regions.
    Type: Application
    Filed: August 31, 2011
    Publication date: March 1, 2012
    Inventors: Steven Bennett, Nathaniel Mast, Kevin Lavigne, Walter Skalla, Timothy Sargeant, Joshua Stopek, Saumya Banerjee, Arpan Desai
  • Publication number: 20120043849
    Abstract: The stator for the electric rotating machine includes a stator core that has slots, a stator coil, and an impregnant applied to the inner surface of the stator core. The stator core has a plurality of teeth that divide the slots. The teeth with chamfered surfaces and ones without chamfered surfaces are intermingled between a projected tip surface and each side surfaces of the teeth. At least one of bent corner parts formed at both ends of the projected tip surface of the teeth is formed in an arcuated surface. A relationship (R1>R2) is satisfied, where R1 represents a curvature radius of arcuated surfaces formed in the curved corner part where the projected tip surface and the chamfered surface abut and R2 represents a curvature radius of the arcuated surfaces formed in the curved corner part where the projected tip surface and the side surface abut.
    Type: Application
    Filed: August 5, 2011
    Publication date: February 23, 2012
    Applicant: DENSO CORPORATION
    Inventors: Shigenori Yoneda, Toshiaki Oohara
  • Publication number: 20110304238
    Abstract: A recording disk is to be mounted on a hub. A base rotatably supports the hub through a bearing. A stator core is fixed to the base and includes an annular portion and a salient pole extending radially therefrom. A magnet faces the salient pole radially and is rotated with the hub. The magnet has a plurality of magnetic poles in the circumferential direction such that each of the plurality of magnetic poles faces the salient pole. The salient pole includes a rod-shaped body around which a wire is wound and a tooth portion that is provided radially outside the rod-shaped body and extends circumferentially. The circumferential end located at the end in the circumferential direction of the tooth portion is located radially inside a circumscribed circle passing through the tip located at the radially outermost end of the tooth portion.
    Type: Application
    Filed: June 14, 2011
    Publication date: December 15, 2011
    Applicant: ALPHANA TECHNOLOGY CO., LTD.
    Inventors: Kazuyoshi NAGAI, Akira SUZUKI
  • Publication number: 20110254474
    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: Application
    Filed: October 14, 2009
    Publication date: October 20, 2011
    Inventors: Yasuyuki Saito, Tsuyoshi Goto, Kenichi Nakayama, Noriaki Hino, Shinji Sugimoto
  • Publication number: 20110169369
    Abstract: An electric machine having a stator surrounding a rotor with an air gap therebetween. The stator has slots in its inner margin for accommodating stator coil windings. Stator teeth defined by the slots have irregular shapes to modify a variable flux flow pattern in the air gap to reduce harmonic torque components with minimal effect on an average value of rotor torque.
    Type: Application
    Filed: January 11, 2010
    Publication date: July 14, 2011
    Applicant: FORD GLOBAL TECHNOLOGIES, LLC
    Inventors: Feng Liang, Michael W. Degner, Alfredo R. Munoz, Wen Ouyang
  • Patent number: 7969058
    Abstract: Permanent magnet motors with improved torque ripple and methods for designing the same have been provided. The permanent magnet motor can include a stator having a hollow core and defining a plurality of slots; a winding disposed in each of the slots; a rotor rotatably disposed inside the hollow core of the stator; and a plurality of permanent magnets supported by the rotor. Each of the slots has a slot opening, and at least one of the slot openings can be off-center with respect to the respective slot.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: June 28, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Khwaja M. Rahman, Peter J. Savagian, Matthew D. Laba