Synchronous Patents (Class 310/162)
  • Patent number: 7576465
    Abstract: The invention relates to an electric synchronous machine. There is a need for a dual rotor electric synchronous machine which has a mechanism for adjusting the rotor relative angular displacement while the machine is running in order to reduce back emf. There is a need for such an adjusting mechanism which can carry high torque loads. An electric synchronous machine is provided with a housing, first and second shafts rotatably supported in the housing, each with a corresponding rotor fixed thereon, both having permanent magnet field poles. Each rotor is surrounded by a corresponding annular stator, and stator coils are wound through both stators. A planetary transmission is coupled between the first and second shafts and operable during rotation of the first and second shafts to adjust an angular orientation of the second shaft with respect to the first shaft.
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: August 18, 2009
    Assignee: Deere & Company
    Inventor: Ronald Dean Bremner
  • Publication number: 20090195090
    Abstract: A motor including a mounting shaft having a hollow channel and a bearing attached to each end, a cylindrical hub having a hollow core for the mounting shaft, and plural rows of plural Molded Magnetic Flux Channels with a hollow core and a channel forming a U-shaped recess and mounted the surface of the hub, each row corresponding to a motor phase. Each magnetic flux channel forms two pole pieces divided by the channel. The motor also includes plural phase windings, one passing through each row of plural Molded Magnetic Flux Channels, a rotating drum having plural rows of permanent magnets on an inner surface, each row pair corresponding to and aligned with one of the plural rows of Molded Magnetic Flux Channels. The rotating drum connected with the bearing, and drive electronics for driving the plural phase windings, wherein the plural Molded Magnetic Flux Channels increases torque and motor efficiency.
    Type: Application
    Filed: February 16, 2009
    Publication date: August 6, 2009
    Inventor: Norman Rittenhouse
  • Patent number: 7569962
    Abstract: An A-phase brushless motor, where A is an integer greater than or equal to 2, includes a stator and a rotor. The stator has q stator poles, where q is an integer greater than or equal to A. The stator poles form S stator pole sets each consisting of A stator poles each of which corresponds to one of A phases, where S is an integer equal to (q/A). The rotor has p rotor poles, where p is an integer greater than or equal to 2, and is so arranged that the rotor poles face the stator poles. Further, in the brushless motor, p?q, and the stator poles are arranged in a circumferential direction of the motor such that a difference in electrical angular position between any adjacent two of the A stator poles in each of the S stator pole sets is equal to (360°/A).
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: August 4, 2009
    Assignee: Denso Corporation
    Inventors: Tomokazu Ishikawa, Masayuki Nashiki
  • Publication number: 20090134734
    Abstract: The motor, which is an incorporated N-phased motor, comprises a rotor having four or more poles with N-poles and S-poles being alternately arranged in the circumferential direction, a stator having a stator core in which magnetic circuits are magnetically separated within an electrical angle of 360°, and an (N?1) number (N is a positive integer) of windings. The motor is configured so that currents of the windings can effectively work on the magnetic circuits.
    Type: Application
    Filed: July 19, 2006
    Publication date: May 28, 2009
    Applicant: DENSO CORPORATION
    Inventor: Masayuki Nashiki
  • Patent number: 7535149
    Abstract: To reduce the torque ripple of permanent-magnet excited synchronous motors (1) having tooth coils (6), constructive means are proposed for damping or eliminating the fifth and/or seventh harmonic wave of the rotor field which mainly cause torque ripple.
    Type: Grant
    Filed: June 2, 2004
    Date of Patent: May 19, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventor: Detlef Potoradi
  • Patent number: 7518332
    Abstract: A brushless synchronous motor is provided in a simple configuration and at a low cost. The brushless synchronous motor comprises a rotor having salient magnets arranged in a circumferential direction, a stator having driving magnetic poles arranged in the circumferential direction, and an exciting coil wound around each driving magnetic pole, where the rotor is made in a non-circular profile. For example, the rotor may comprise a cylindrical body which has at least one flat surface perpendicular to one magnetic pole direction of the rotor, or a cylindrical body having an elliptic profile with a longer diameter in one magnetic pole direction of the rotor. A detector circuit is associated with each of a predetermined number of exciting coils for outputting a detection signal indicative of the impedance of the exciting coil in accordance with the distance between the driving magnetic pole and rotor, to detect a rotating angle of the rotor.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: April 14, 2009
    Assignee: Ebara Corporation
    Inventors: Toshiharu Nakazawa, Atsushi Ooyama
  • Patent number: 7501735
    Abstract: A self-magnetized motor includes a stator adapted to rotate by electromagnetic interaction with a rotator, a plurality of slot teeth formed on and surrounding a through-hole of the stator, and an excitation pole adjacent at least one slot tooth having fewer projections than remaining ones of the slot teeth. The projections are formed on ends of the slot teeth facing the through-hole of the stator. According to one non-limiting embodiment, the excitation pole may be formed between two slot teeth having fewer projections.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: March 10, 2009
    Assignee: LG Electronics Inc.
    Inventors: Moo Hong Seo, Jin Soo Park, Sung Ho Lee, Jang Ho Shim, Jae Min Kim, Jae Hak Choi
  • Patent number: 7474029
    Abstract: A machine includes a stator and a rotor having a plurality of poles. Each pole is formed at least in part by a plurality of permanent magnets recessed within the rotor at a predetermined distance from an outer surface of the rotor. The distance is predetermined to minimize rotor flux variation near the outer surface during rotation of the rotor relative to the stator. Eddy current losses are thereby reduced.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: January 6, 2009
    Assignee: General Motors Corporation
    Inventors: Khwaja M. Rahman, James M. Nagashima
  • Publication number: 20080296991
    Abstract: A synchronous reluctance motor is described. The synchronous reluctance motor includes a core configured to rotate about a central axis and having first and second groups of flux barriers formed therein. Each flux barrier is defined as an opening in the core. Each of the first and second groups includes a first flux barrier and a second flux barrier with the second flux barrier disposed outside the first flux barrier in a radial direction from the central axis of the core. Each of the second flux barriers of the first and second groups has at least two connection parts crossing the opening of the second flux barrier.
    Type: Application
    Filed: November 20, 2007
    Publication date: December 4, 2008
    Applicant: LG ELECTRONICS INC.
    Inventors: Kyung Hoon Lee, Jun Ho Ahn
  • Publication number: 20080278010
    Abstract: A switched reluctance motor has a rotor and a stator. The stator has first and second stator magnetic pole groups sequentially placed in an axial direction of the rotor. First and second stator magnetic poles in each group are alternately arranged on a same circumference. The first stator magnetic poles are placed every electrical angle 2? and reversely magnetized to each other. The second stator magnetic poles are placed every electrical angle 2? and reversely magnetized to each other. The first magnetic pole is apart from the second magnetic pole by electrical angle ?. Each stator magnetic pole in the first stator magnetic pole group is apart from that in the second magnetic pole group by electrical angle ?/2 in the circumferential direction.
    Type: Application
    Filed: April 23, 2008
    Publication date: November 13, 2008
    Applicant: DENSO CORPORATION
    Inventors: Tomokazu Ishikawa, Masayuki Nashiki, Yuuichirou Itou
  • Publication number: 20080150384
    Abstract: A three-phase line synchronous generator with an exciter and generator stage. The exciter stage includes an exciter stator having n poles and an exciter rotor having n poles and disposed for rotation within the exciter stator, and the generator stage includes a generator stator having n poles and a generator rotor having n poles. The generator rotor being mechanically coupled to the exciter rotor and disposed for rotation within the generator stator, wherein the poles of the stators, or the poles of the rotors, are angularly displace by one pole pitch.
    Type: Application
    Filed: July 27, 2007
    Publication date: June 26, 2008
    Inventors: Leo G. Nickoladze, Hildegard K. Marks
  • Patent number: 7385329
    Abstract: In electric machines, core losses limit, at high fundamental frequency, the permissible full-load power. The aim of the invention is to develop a design which enables a high power density at high magnetic reversal frequencies and which is easy to produce. To this end, the primary part comprises coils which, for the majority of their length, run in the direction of movement and which are surrounded in this area on three sides by soft magnetic material. In the direction of movement, at least two coils are arranged one behind the other. Coils of different phase are arranged perpendicular to the direction of movement inside different running tracks. In the secondary part, at least two oppositely magnetized hard magnets with three collector segments, which are flatly adjacent in a manner that is perpendicular to the direction of movement, form magnet poles having a high flux concentration.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: June 10, 2008
    Inventor: Wolfgang Hill
  • Publication number: 20080100168
    Abstract: The invention relates to an electric synchronous machine. There is a need for a dual rotor electric synchronous machine which has a mechanism for adjusting the rotor relative angular displacement while the machine is running in order to reduce back emf. There is a need for such an adjusting mechanism which can carry high torque loads. an electric synchronous machine is provided with a housing, first and second shafts rotatably supported in the housing, each with a corresponding rotor fixed thereon, both having permanent magnet field poles. Each rotor is surrounded by a corresponding annular stator, and stator coils are wound through both stators. A planetary transmission is coupled between the first and second shafts and operable during rotation of the first and second shafts to adjust an angular orientation of the second shaft with respect to the first shaft.
    Type: Application
    Filed: October 26, 2006
    Publication date: May 1, 2008
    Inventor: Ronald Dean Bremner
  • Publication number: 20080100164
    Abstract: An inductor-type synchronous machine includes field stators having field elements by which an N-pole and an S-pole are concentrically formed, rotors to which a rotating shaft is fixed and has N-pole inductors disposed so as to face the N-pole of the field elements and S-pole inductors disposed so as to face the S-pole of the field elements, and an armature stator having armature coils disposed so as to face the N-pole inductors and the S-pole inductors.
    Type: Application
    Filed: December 16, 2005
    Publication date: May 1, 2008
    Inventors: Toru Okazaki, Shingo Ohashi, Hidehiko Sugimoto, Toshio Takeda
  • Patent number: 7315102
    Abstract: An axial gap motor is described which comprises a rotor shaft rotatable about its axis in case. A rotor is fixed to the rotor shaft to rotate therewith. The rotor includes a plurality of magnets. A stator is disposed about the rotor shaft at a position to coaxially face the rotor. The stator includes a plurality of coils. The magnets of the rotor have each opposed pole faces that extend in a direction other than a direction that is perpendicular to the axis of the rotor shaft.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: January 1, 2008
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Yuusuke Minagawa
  • Patent number: 7259490
    Abstract: The present invention concerns a synchronous machine with preferably salient poles with pole windings which are galvanically connected together. The invention further concerns a wind power installation and a method of monitoring a synchronous machine of a wind power installation. The object of the invention is to develop a synchronous machine and a method of operating a synchronous machine, such that the risk of a fire is reduced.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: August 21, 2007
    Inventor: Aloys Wobben
  • Publication number: 20070188038
    Abstract: A self magnetizing motor is disclosed, which comprises a stator which is comprised of a plurality of sheets including a plurality of stator slots and exciter slots formed at fixed intervals along an outer circumferential surface of the center, a teeth provided between each of the stator slots, and an exciter pole formed between the exciter slots; an exciter coil which is wound on each exciter slot; and a rotor which is rotatably inserted into the center (C) of the stator, and is provided with an exciter magnetizable portion on an outer circumferential surface to be magnetized by the exciter coil; wherein the exciter pole is positioned at the part of the stator to form a back yoke of an increased size. Preferably, the exciter pole is positioned at corner of the stator so that a rear stator portion of the exciter pole is increased in size.
    Type: Application
    Filed: December 8, 2006
    Publication date: August 16, 2007
    Applicant: LG ELECTRONICS INC.
    Inventors: Sung-Ho LEE, Jae-Hak CHOI, Jae-Min KIM
  • Patent number: 7233092
    Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrated windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2). Outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction may be tapered toward inside from a rotor rim in a radial direction and to form a recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: June 19, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Murakami, Yukio Honda, Shizuka Yokote, Yoshinari Asano, Yukitoshi Wada, Hideo Hirose, Yasuaki Matsushita
  • Patent number: 7221071
    Abstract: The electric machine (M) comprises an armature (A) and an inductor (B), the inductor (B) having for each pair of poles (N, S) of the armature (A), n teeth (20) identical to one another and n slots (21) and being provided with a winding (W) housed in the said n slots. The armature (A) has its surface facing the air gap (G) divided into 2N elements or samples (1–12) with N being a whole multiple of n, having substantially the same extent in the said direction of relative displacement, and having a respective magnetic potential value. Each sample (1–12) of the armature (A) is associated with a value of total magnetic permeance (pi) at the air gap (G) in a predetermined alignment condition between the inductor (B) and the armature (A). The armature (A) comprises a plurality of magnetically distinct ferromagnetic bodies (30, 31, 32; . . . ) each of which couples at least two armature samples in such a way as to ensure a substantial magnetic equipotentiality.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: May 22, 2007
    Assignees: C.R.F. Societa Consortile per Azioni, Tree di Fratta Antonino S.A.S.
    Inventor: Antonino Fratta
  • Patent number: 7141905
    Abstract: A permanent magnet synchronous machine includes a stator, and a rotor which defines with the stator an air gap. The stator includes a plurality of teeth which are disposed in spaced-apart circumferential relationship and separated from one another by a tooth pitch. Each of the teeth has a shaft which terminates in a tooth head adjacent the air gap, with the tooth heads of neighboring teeth being separated from one another by a slot. The tooth heads are constructed to prevent saturation. The rotor has permanent magnets which are aligned in flux concentration direction and arranged to define a pole pitch, wherein a pitch ratio of tooth pitch to pole pitch is ?2.5.
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: November 28, 2006
    Assignee: Siemens Aktiengesellschaft
    Inventor: Rolf Vollmer
  • Patent number: 7129602
    Abstract: A method and apparatus for cooling a transverse flow synchronous machine is provided which uses a coolant that is entrained by the rotor rotation during operation of the synchronous machine and is sprayed into the intermediate spaces between the plurality of stepped elements along the surface of the outer stator thereby forming a coolant-air mixture.
    Type: Grant
    Filed: September 11, 2002
    Date of Patent: October 31, 2006
    Assignee: Voith Turbo GmbH & Co. KG
    Inventors: Andreas Lange, Wolfram Angerer, Uwe Mühlberger
  • Patent number: 7119471
    Abstract: A synchronous motor includes a housing 20, a stator assembly 30 mounted within the housing 20, a rotor assembly 40 rotationally mounted within the housing 20, a rotor shaft 50 having an upper mounting surface 52 attached to the rotor assembly 40, a bearing assembly 60 coupled to the housing 20 and positioned axially between the rotor assembly 40 and the upper mounting surface 52, a slip ring assembly 70 supported by the housing 20 and positioned axially at least partially within the stator assembly 30 and the rotor assembly 40, and an encoder assembly 80 adjacent the slip ring assembly 70.
    Type: Grant
    Filed: July 9, 2004
    Date of Patent: October 10, 2006
    Assignee: Motor Kinetics, Inc.
    Inventors: Alexander D. Kiderman, John Howison Schroeder, Thomas C. Joos
  • Patent number: 7102265
    Abstract: The four-pole synchronous motor comprises a stator core having first magnetic pole cores formed at both ends of a connection body part of crisscrossed connection body parts and second magnetic pole cores formed at both ends of the connection body part. The first magnetic pole cores include magnetic flux acting surface parts extended toward both sides thereof in a circumferential direction. A shape of each magnetic flux acting surface part on one side of a longitudinal centerline of the first magnetic pole cores is different from that on the other side so as to be magnetically asymmetrical with respect to the longitudinal centerline.
    Type: Grant
    Filed: June 2, 2003
    Date of Patent: September 5, 2006
    Inventors: Katsuyuki Totsu, Fumito Komatsu
  • Patent number: 7034425
    Abstract: A hybrid synchronous electric machine driven by the transverse magnetic flux has a rotor and a stator, the rotor armature has a massive cogged iron rings (12) in close vicinity of active parts of the motor, and cogged iron rings (14, 15) as component parts of the rotor are provided with cross-cut insulating gaps. Eddy current losses are low because eddy currents in cogged iron rings are impeded by cross-cut insulating gaps therein. Eddy currents in all passive parts of the motor (rotor armature (11), stator armature (1), ball bearing (9) and the like) are negligible since the current induced in the copper ring (12) neutralizes all the dissipated magnetic flux outside the active area of the motor. A hybrid synchronous electric machine which has low eddy current losses and high energy efficiency can be realized.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: April 25, 2006
    Assignee: Harmonic Drive Systems Inc.
    Inventor: Andrej Detela
  • Patent number: 6979924
    Abstract: The invention relates to a motor comprising a stator core having plural teeth and slots provided among the teeth, a winding applied on the teeth by a single turn, and a rotor incorporating plural permanent magnets, which is rotated and driven by utilizing reluctance torque in addition to magnet torque. By turning thus divided teeth by a single winding, the occupation rate of the winding in the slots can be raised. As a result, a motor of small size and large output can be presented.
    Type: Grant
    Filed: November 28, 2001
    Date of Patent: December 27, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noriyoshi Nishiyama, Tomokazu Nakamura, Yasufumi Ikkai, Yukio Honda, Hiroshi Murakami, Shinichiro Kawano
  • Patent number: 6940205
    Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrating windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2), and yet outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction are tapered toward inside from a rotor rim in a radial direction and thus form recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.
    Type: Grant
    Filed: March 7, 2000
    Date of Patent: September 6, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Murakami, Yukio Honda, Shizuka Yokote, Yoshinari Asano, Yukitoshi Wada, Hideo Hirose, Yasuaki Matsushita
  • Patent number: 6940238
    Abstract: A single coil, direct current permanent magnet brushless motor including a stator including six alternately-wound coils connected into a single coil having first and second ends, the oppositely-wound coils forming stator poles, and six magnets of alternating polarity coupled to a rotor and rotatably journaled in the stator. A sensor, such as a dual output Hall sensor, is used for sensing rotation of the rotor. A drive circuit, such as an H-bridge circuit, is coupled to the first and second ends of the single coil to drive the motor. The H-bridge circuit includes two high-side switches for alternately receiving signals from the Hall sensor, and two low-side switches alternately receiving signals from the Hall sensor. A high-side switching signal can be controlled by an inverted low-side switching signal. A voltage boost circuit is also provided, having capacitors to provide a boosted voltage to alternately turn on the high-side switches of the H-bridge.
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: September 6, 2005
    Assignee: McMillan Electric Company
    Inventor: Sten R. Gerfast
  • Patent number: 6900571
    Abstract: The present invention aims to strengthen the durability against the centrifugal force acted on a rotor of a synchronous induction motor to increase reliability of the motor. The rotor for the synchronous induction motor of the invention includes: at least one pair of slits forming salient poles in a direction of a d axis in which the magnetic flux can flow easily and in a direction of a q axis in which the magnetic flux can hardly flow; and plural slots located at an outer circumference side of the slits and connected to at least one end of the slits in the direction of the d axis to generate induction torque. Conductive material is filled in at least the slots among the slits and the slots. The rotor is provided with a rotor cover made of a non-magnetic body as a reinforcing member to strengthen the rotor against the centrifugal force acted at the outer side of the direction of a diameter.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: May 31, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hayato Yoshino, Hitoshi Kawaguchi, Yoshio Takita
  • Patent number: 6864611
    Abstract: A synchronous generator comprising a stator and a motor movable relative to the stator. The generator contains a plurality of poles for generating electrical energy. The time behavior of the voltage induced in one or several stator windings essentially approximates the current time behavior in one stator winding or the sum of at least several component currents. The poles are positioned asymmetrically on the rotor.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: March 8, 2005
    Inventor: Aloys Wobben
  • Patent number: 6856061
    Abstract: A synchronous resolver has: a stator including a plurality of stator poles disposed at regular intervals along the circumferential direction of a ring-shaped stator base portion, the stator poles comprise a plurality of phases; coil bobbins former-wounded stator coils therearound are respectively fitted with and mounted on their associated ones of the stator poles; and, a rotor shiftable in angle with respect to the stator to thereby vary a reluctance component in a gap existing between the stator and the rotor, wherein the coil bobbins are set the positions of the stator coils freely in such a manner that the resolver signals of the respective phases balance well.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: February 15, 2005
    Assignee: NSK Ltd.
    Inventors: Masatoshi Nishizawa, Masaki Kuwahara, Masamitsu Kamimura
  • Publication number: 20040239200
    Abstract: A single phase synchronous AC motor includes a laminated iron stator (1) carrying a single phase winding (3, 4) and a permanent magnet rotor (2) located within a stator bore (5). The stator bore is elongate in shape and is generally symmetrical about a minor axis (13) and a major axis (14). A permanent magnet reluctance torque smoothes out the twice electrical frequency torque pulsation due to the single phase winding. Substantially constant torque is obtained at all rotor positions when rated load torque is applied. The motor may be designed such that constant torque is achieved for any rate value of load torque corresponding to a factional value of the permanent magnet reluctance torque. The motor may be designed to obtain a useful ratio of pullout to rated torque for operation from a mains AC supply.
    Type: Application
    Filed: March 8, 2004
    Publication date: December 2, 2004
    Inventor: Richard Johnston Strahan
  • Patent number: 6815859
    Abstract: In a synchronous reluctance motor having a rotor having a plurality of pairs of an outer side slot formed at an outer periphery side and an inner side slot formed at inner side of the rotor. The distance between the outer periphery of the rotor and the outer side slot is determined to be the width of the stator magnetic pole portion of the stator multiplied by 0.7 to 1.3. A first total magnetic flux amount of an outer side permanent magnet disposed in the outer side slot is determined to be larger than or equal to a second total magnetic flux amount of an inner side permanent magnet disposed in the inner side slot.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: November 9, 2004
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Masafumi Sakuma, Tomohiro Fukushima
  • Publication number: 20040207281
    Abstract: A hybrid synchronous electric machine driven by the transverse magnetic flux has a rotor and a stator, the rotor armature has a massive cogged iron rings (12) in close vicinity of active parts of the motor, and cogged iron rings (14, 15) as component parts of the rotor are provided with cross-cut insulating gaps. Eddy current losses are low because eddy currents in cogged iron rings are impeded by cross-cut insulating gaps therein. Eddy currents in all passive parts of the motor (rotor armature (11), stator armature (1), ball bearing (9) and the like) are negligible since the current induced in the copper ring (12) neutralizes all the dissipated magnetic flux outside the active area of the motor. A hybrid synchronous electric machine which has low eddy current losses and high energy efficiency can be realized.
    Type: Application
    Filed: June 1, 2004
    Publication date: October 21, 2004
    Inventor: Andrej Detela
  • Patent number: 6798104
    Abstract: A rotary electric machine includes a stator core having a plurality of slots disposed at an inner periphery, an armature winding disposed in the slots and a rotor disposed inside the inner periphery of the stator. The rotor includes a first rotor portion and a second rotor portion, which are disposed magnetically in parallel with each other. The first rotor portion has a plurality of permanent-magnet poles, and a second rotor portion has a plurality of salient induction poles.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: September 28, 2004
    Assignee: Denso Corporation
    Inventors: Hiroaki Kajiura, Masahiro Seguchi
  • Patent number: 6794791
    Abstract: The invention concerns a machine forming a motor or generator including a stator and a rotor. The rotor is a passive rotor, consisting of two ferromagnetic discs whereof at least one is toothed. The stator includes a fixed polyphase field coil arranged in an air gap defined by the space provided between the two discs and generating a rotating magnetic field, and a field coil likewise fixed. The invention is applicable to a cylindrical rotary machine or to a machine with linear displacement.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: September 21, 2004
    Assignee: Centre National de la Recherche Scientifique (C.N.R.S.)
    Inventors: Abdel Hamid Ben Ahmed, Bernard Multon, Jérome Delamare, Corentin Kerzreho, Jean-Yves Cognard, Nicolas Bernard
  • Patent number: 6787958
    Abstract: An electrical motor or generator comprises a rotor 79 without windings, a stator 78 having armature windings comprising at least two coils A1, A2 having active portions positioned within armature winding slots 81 in a stator iron, and field windings F having active portions positioned within field winding slots 80 in the stator iron. An electronic control circuit is provided for controlling the currents in the coils A1, A2 in synchronism with rotation of the rotor such that periods in which a magnetomotive force is generated in one direction by current flow in one of the coils alternate with periods in which a magnetomotive force is generated in the opposite direction by current flow in another of the coils. The armature winding slots and the field winding slots are equal in number and alternate with one another in the stator iron.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: September 7, 2004
    Assignees: Black & Decker Inc., University of Warwick
    Inventor: Richard Thomas Walter
  • Publication number: 20040130231
    Abstract: An electric machine (M) comprises a field (A) and an armature (B) between which is defined an air gap (G). The field (A) has at least one pair of poles (N, S) and the armature (B) has n teeth (20) and n slots (21) per pair of poles (N, S) of the field (A).
    Type: Application
    Filed: February 20, 2004
    Publication date: July 8, 2004
    Inventor: Antonino Fratta
  • Publication number: 20040084984
    Abstract: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.
    Type: Application
    Filed: October 27, 2003
    Publication date: May 6, 2004
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Toshihito Yanashima, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai, Eiichi Murata, Noboru Onodera, Shigemi Koiso, Kazuhiro Enomoto, Yoshitomo Nakayama
  • Patent number: 6713924
    Abstract: A three-phase brushless motor includes a rotor with a permanent magnet having P (P is an integer not less than two) polarities and a stator facing the rotor and having plural coils shaped in approx, triangle or trapezoid. A space between adjacent coils is (360/P)×(5/3) degree. Three position-detectors, which detect the position of the rotor, is placed at intervals of (360/P)×(2/3) degree in an area where no coils are placed. This structure allows the coils to be optimally shaped and placed, and realizes to reduce a number of coils as well as improve the motor characteristics.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: March 30, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Shinji Fukushima
  • Patent number: 6713923
    Abstract: 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: Grant
    Filed: July 30, 2002
    Date of Patent: March 30, 2004
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Haruyoshi Hino, Shinya Naito
  • Patent number: 6664688
    Abstract: To provide a rotor for a motor capable of effecting improved torque variation due to improvement in the induced voltage waveform and of effecting improved magnet torque in a permanent magnet type synchronous motor utilizing reluctance torque. A rotor 11 comprises a core 12 made of a ferromagnetic material, a given member of permanent magnets 14 are mounted in the outer surface of the core 12 circumferentially at equal intervals, and arrangement of the permanent magnets 14 is such that polarities N, S of the permanent magnets on the sides facing a stator are disposed alternately. Also, in the core 12 between the center axis of the core and the permanent magnets 14 are embedded arc-shaped permanent magnets 16 corresponding to the permanent magnets 14, respectively, and arrangement of the permanent magnets 14 is the same as that of the corresponding permanent magnets 16.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: December 16, 2003
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Shinya Naito, Haruyoshi Hino
  • Patent number: 6590308
    Abstract: A high power density synchronous machine is disclosed comprising: a stator having conventional stator coils arranged in an annulus around a vacuum cylindrical cavity; a magnetically saturated cylindrical magnetic solid rotor core; a race-track super-conducting coil winding extending around the rotor core, and a coil supportextending through the core and attaching to opposite long sides of the coil winding.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: July 8, 2003
    Assignee: General Electric Company
    Inventors: Richard Dawson, Yu Wang, Evangelos Trifon Laskaris
  • Publication number: 20030107289
    Abstract: Synchronous motors according to the invention operate at higher efficiency, with lower cost, reduced mass and reduced cogging. Magnet dimensions are selected that reduce cogging forces to a negligible amount even though there are fewer slots than normal. Optionally, it is possible to use non-overlapping windings with deeper and open slots. The approach is applicable to both rotary and linear motors and motors using either permanent magnets or electromagnets in the field structure. It is particularly relevant to linear or rotary motors that have a large air gap, and to small motors that must deliver a high ratio of thrust or torque to motor mass.
    Type: Application
    Filed: October 1, 2002
    Publication date: June 12, 2003
    Inventors: Richard D. Thornton, Tracy M. Clark
  • Patent number: 6563246
    Abstract: A rotary electric machine includes a stator core having a plurality of slots disposed at an inner periphery, an armature winding disposed in the slots and a rotor disposed inside the inner periphery of the stator. The rotor includes a first rotor portion and a second rotor portion, which are disposed magnetically in parallel with each other. The first rotor portion has a plurality of permanent-magnet poles, and a second rotor portion has a plurality of salient induction poles.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: May 13, 2003
    Assignee: Denso Corporation
    Inventors: Hiroaki Kajiura, Masahiro Seguchi
  • Publication number: 20030025416
    Abstract: Electrical generators are provided with toroidally wound stator windings electrically connected in series; a high permeability stator core, preferably an amorphous magnetic alloy material, glassy metal or HYPERCO™ 50 laminations; and a rotor. The toroidally wound stator coils and the stator core trap essentially all of the flux fields generated by the stator coils within the stator core. Since there is essentially no magnetic field leaving the stator, there is essentially no flux field interaction with the field generated by the rotor. The reduction of flux field interaction also reduces counter torque.
    Type: Application
    Filed: June 13, 2002
    Publication date: February 6, 2003
    Inventors: Steven L. Sullivan, David L. Goulet, Donald Hofmann
  • Patent number: 6509664
    Abstract: A hybrid synchronous machine includes a cylindrical element having slots; excitation windings situated in at least some of the slots; and permanent magnets situated in at least some of the slots, the permanent magnets comprising radially magnetized permanent magnets.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: January 21, 2003
    Assignee: General Electric Company
    Inventors: Manoj Ramprasad Shah, Gerald Burt Kliman
  • Publication number: 20030011267
    Abstract: An electric synchronous machine with improved torque characteristic has a stator and a rotor, wherein the stator includes a winding, preferably a three-phase AC winding, with an average coil width &tgr;sp. The rotor is provided with permanent magnets and has a pole pair number of 2p with a pole pitch width &tgr;p, wherein the pitch ratio &tgr;sp/&tgr;p is ≧2.5.
    Type: Application
    Filed: January 25, 2002
    Publication date: January 16, 2003
    Inventor: Rolf Vollmer
  • Publication number: 20020190595
    Abstract: A single phase line start permanent magnet synchronous motor is started by an interaction between magnetic fields of the coil and of the secondary conductor, and an normal operation can be performed using only the permanent magnet and the operating condenser of small capacity, only the main coil, or only the operating condenser when the synchronous rotating speed is reached and the rotation is started, and therefore an additional direct current supplying device for supplying the direct current and the position sensor for sensing the rotational position of the rotor can be excluded, the structure can be made compactly by constructing the driving circuit simply, and manufacturing cost can be reduced.
    Type: Application
    Filed: January 10, 2002
    Publication date: December 19, 2002
    Inventors: Seung Do Han, Hyoun Jeong Shin, Kwan Yeul Cho, Yoon Hyeo Kim
  • Patent number: 6462449
    Abstract: A rotating electric machine whereof the rotor includes a magnetic core provided with radial teeth, uniformly distributed at its periphery, annular magnets arranged on either side of the core axial ends and magnetic end flanges pressing the annular magnets against the core, magnetic bars linking the end flanges together, housed in the spaces between the radial teeth, additional magnets being interposed between each of the bars and at least the side walls of the core radial teeth defining the spaces. The stator includes a magnetic core, excitation coils arranged on either side of the core, a stator coil wound on the core and a magnetic ring in contact with the core and provided with radial rims co-operating with the axial rims of the rotor end flanges to form paths for the return flux.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: October 8, 2002
    Assignee: Centre National de la Recherche Scientifique (C.N.R.S.)
    Inventors: Jean Lucidarme, Mohamed Gabsi, Michel Lecrivain, Hamid Ben Ahmed
  • Publication number: 20020140309
    Abstract: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 3, 2002
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Toshihito Yanashima, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai, Eiichi Murata, Noboru Onodera, Shigemi Koiso, Kazuhiro Enomoto, Yoshitomo Nakayama