Salient Pole Patents (Class 310/269)
  • Patent number: 5825108
    Abstract: The motor comprises a rotor (30) fixed for rotation with a shaft (36) of a member to be driven and a crown-like stator (10) obtained by blanking a lamination stack (12) provided with coil supporting teeth (11). Within the stator crown (10) there are obtained by blanking the lamination stack (12) a plurality of receptacles (13, 15, 17) for seating electric and electronic components associated with the stator. The components comprise a transformer (24), an inductance coil (25), and a plurality of MOSs (23). The stator crown (10) is co-molded with a covering of electrically insulating plastic material to cover the receptacles (13, 15, 17) and the teeth (11) and form a tank (22) for receiving a printed circuit (21). The permanent magnet rotor is fitted with stacks of small pieces (19) obtained by blanking lamination portions within the stator crown (10). The stacks of small pieces face the magnets (31) so as to close the respective magnetic circuits.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: October 20, 1998
    Assignee: Bitron S.p.A.
    Inventor: Pietro De Filippis
  • Patent number: 5793136
    Abstract: A differential motor/generator apparatus comprising a stator region, a first rotating member and a second rotating member. The stator region includes at least one stator component and an opening. The stator member includes at least one pair of torroid regions each having at least one winding positioned thereon in parallel. The first rotating member is associated with the stator region and is positionable within the opening of the stator region. The second rotor member is rotatably associated with the stator region and includes a cavity. A portion of the stator region and the first rotor member are positionable within the cavity of the second rotating member. This enables the first and the second rotating members to rotate about a common axis of rotation.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: August 11, 1998
    Inventor: Sabid Redzic
  • Patent number: 5777420
    Abstract: A rotor assembly for use within a superconducting electric motor includes a superconducting winding formed of high temperature superconductor and during operation, generates a flux path within the rotor assembly; and a high permeability magnetic material, positioned within at least a portion of the flux path so as to decrease the overall reluctance of the flux path. The rotor assembly may include a support member having an internal volume and formed of a non-magnetic, high-strength resilient material. The support member supports on its outer surface the superconducting winding and within its internal volume, the high permeability magnetic material. The magnetic material may be in the form of a core member to provide the low reluctance portion to the flux path generated by the superconducting winding.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: July 7, 1998
    Assignee: American Superconductor Corporation
    Inventors: Bruce B. Gamble, Gregory L. Snitchler
  • Patent number: 5719456
    Abstract: A variable reluctance electric motor includes a stator having a plurality of radially inwardly extending poles which are divided into a plurality of longitudinal sections. The cross sectional shapes of the first stator pole sections are different from the cross sectional shapes of the second stator pole sections. A rotor is supported within the stator for relative rotational movement and includes a plurality of radially outwardly extending poles which are divided into a plurality of longitudinal sections. The cross sectional shapes of the first rotor pole sections are different from the cross sectional shapes of the second rotor pole sections. The first rotor poles are longitudinally aligned with the first stator poles so as to interact therewith when electrical current is supplied to windings provided on the stator poles.
    Type: Grant
    Filed: May 18, 1994
    Date of Patent: February 17, 1998
    Assignee: Dana Corporation
    Inventor: Serguei F. Kolomeitsev
  • Patent number: 5712521
    Abstract: A hybrid synchronous machine with transverse magnetic flux, whose structure provides smaller ohmic losses and a higher efficiency than in conventional motors with high torque per machine weight. Each phase of the hybrid synchronous machine with transverse magnetic flux according to the invention is fitted with two rings of ferromagnetic material which are cogged on the circumference on both sides, between which a magnetized disk is inserted transversally to the direction of the stator winding, and the assembly thus formed is fixed to the rotor armature with the cogged rings being axially shifted between each other. The described structure of the hybrid synchronous machine with transverse magnetic flux solves the technical problem of high density of transverse magnetic field in the air gap, and also effectively solves the problem of installing permanent rotor magnets by means of a magnetized disk instead of individual inserted magnets.
    Type: Grant
    Filed: November 23, 1992
    Date of Patent: January 27, 1998
    Inventor: Andrej Detela
  • Patent number: 5698923
    Abstract: A stator insulating bobbin is disclosed including a plurality of insulating elements. These insulating elements are configured and dimensioned to substantially enclose and insulate an inner surface of a stator assembly. Each of the insulating elements includes a first flange portion and a second flange portion joined by an intermediate web portion.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: December 16, 1997
    Assignee: AlliedSignal Inc.
    Inventors: William M. Scherzinger, Yefim Novoselsky, Leon Kasdan
  • Patent number: 5682073
    Abstract: A hybrid excitation type permanent magnet synchronous motor is provided with an armature and a rotor core arranged to be rotated relative to the armature. Permanent magnets are installed on the rotor core and generate magnetic flux which passes through the armature through a gap between the rotor and armature. Salient pole portions are integral with the rotor core and are not covered with the permanent magnets. The salient pole portions are arranged opposite to the armature through a gap such that the magnetic flux generated by the permanent magnets is effected by the magnetic flux passing through the salient pole portions. A direct current excitation coil generates the magnetic flux passing through the salient pole portions. Therefore, an operable speed area of the motor is increased without using demagnetization control and without degrading the efficiency.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: October 28, 1997
    Assignee: Kabushiki Kaisha Meidensha
    Inventor: Takayuki Mizuno
  • Patent number: 5677587
    Abstract: A small motor includes a rotor fastened to a rotor shaft; a drive magnet disposed facing to the rotor; and bearings for rotatably supporting the rotor shaft with the rotor fastened thereto, wherein a magnetization pattern of the magnet is shaped in such a manner that magnetic forces contributing to the rotation drive of the rotor are balanced, and magnetic forces contributing to the rotor core attraction are unbalanced, thereby biasing the rotor shaft in fixed directions within the bearings.
    Type: Grant
    Filed: January 19, 1994
    Date of Patent: October 14, 1997
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventors: Hiroshi Sakashita, Jun Yamashita
  • Patent number: 5672921
    Abstract: A superconducting field winding assemblage for an electrical machine, such as a rotary generator or a linear motor. The field winding assemblage includes at least two pole assemblies. Each pole assembly has a direction of motion, a solid core, a superconductive coil assembly generally surrounding the solid core, and a first cooling conduit. The superconductive coil assembly has a generally longitudinally extending axis positioned generally perpendicular to the direction of motion and has an epoxy-impregnated, generally racetrack-shaped superconductive coil having a minor axis positioned generally parallel to the direction of motion. The first cooling tube contains a gaseous cryogen (such as gaseous helium) and is positioned to be in thermal contact with the superconductive coil.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: September 30, 1997
    Assignee: General Electric Company
    Inventors: Kenneth Gordon Herd, Evangelos Trifon Laskaris
  • Patent number: 5663605
    Abstract: In several embodiments of the present invention, an alternator is disclosed. The alternator includes a rotor having both wound-field and permanent magnet poles. The wound-field and permanent magnet poles are disposed about the circumference of the rotor.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: September 2, 1997
    Assignee: Ford Motor Company
    Inventors: Paul Michael Evans, Roy David Schultz
  • Patent number: 5627418
    Abstract: A combined linear-rotary stepping motor shares stator iron plates and mover iron cores for a linear motor portion and a rotary motor portion without lengthening the length in the shaft direction.The combined linear-rotary stepping motor includes a stator 1 having a stator iron core 10 provided with a plurality of salient poles 11, 12, 13, . . . composed of the salient poles having a plurality of first stator teeth 24 formed in inner peripheral surfaces thereof in the direction of a shaft 21 and the salient poles having a plurality of second stator teeth 25 formed in inner peripheral surfaces thereof in the circumferential direction and a mover 2 having mover iron cores 22a and 22b supported within the stator 1 movably in the shaft direction and rotatably and provided with a plurality of mover teeth 26 formed in outer peripheral surfaces thereof at an equal pitch in the shaft direction and the circumferential direction in opposing relation to the first and second stator teeth 24, 25.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: May 6, 1997
    Assignee: Oriental Motor Co., Ltd.
    Inventors: Hirobumi Satomi, Takao Iwasa
  • Patent number: 5559386
    Abstract: A high efficiency salient pole reluctance synchronous motor comprises a rotor and at least two poles having polar surfaces with a substantially constant gap through the central region thereof and increasing toward the side regions thereof, so that the gap .delta.m, measured in the central region, and the gap .delta.M measured on the pole horns, meet the relationship ##EQU1## In the rotor there is provided a cage secondary assembly which is shorted by front rings.
    Type: Grant
    Filed: October 18, 1994
    Date of Patent: September 24, 1996
    Assignee: Giovanni Torti
    Inventor: Giorgio Gurrieri
  • Patent number: 5519272
    Abstract: The rotary electrical component has first and second windings thereon and the connector comprises a body having first and second spaced apart sections which receive respective ends of the windings to be interconnected. An electrically conductive element extends between the two sections for connection to the winding ends. The sections include supports for resisting outward movement of the winding ends due to centrifugal force so as to reduce the likelihood of disconnection between the winding ends and the conductive element.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: May 21, 1996
    Assignee: Lucas Industries PLC
    Inventor: Kyriacos Christofi
  • Patent number: 5457350
    Abstract: A laminated core for a rotating electric machine comprising a plurality of single sheet cores, each single-sheet core being formed by arranging a plurality of salient poles continuously on a beltlike yoke plate and winding the beltlike yoke plate so as to be cylindrical while joining both ends of the beltlike yoke plate, wherein the laminated core is cylindrical and has a plurality of salient poles confronting a magnet, each salient pole having a winding and the laminated core is formed by laminating a plurality of the single-sheet cores.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: October 10, 1995
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventors: Hirotaka Sakamaki, Masayuki Ishikawa, Hidetoshi Shimada, Shizunori Mitsuma, Hiroshi Zenisawa, Kiyoshi Nagashima, Noboru Takarasawa
  • Patent number: 5455473
    Abstract: A device for field weakening in a doubly-salient variable reluctance motor having permanent magnets in the stator. The field weakening increases the constant power range of the motor and is accomplished by controlled movement of steel insets toward and away from the sides of the stator proximate the permanent magnets to provide a controllable by-pass flux path thereabout. Alternatively, the field weakening may be accomplished by a flux by-pass collar which may be angularly positioned around the stator to bridge the permanent magnets of the motor with discrete magnetic sections, thereby providing an alternate by-pass flux path around the permanent magnets in addition to the main air gap flux path. A third alternative means for maintaining a constant power range is accomplished by controlled axial sliding of the permanent magnets themselves into and out from the stator.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: October 3, 1995
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Thomas A. Lipo, Yuefeng Liao, Feng Liang
  • Patent number: 5432390
    Abstract: A switched reluctance motor includes a stator having a central bore for rotation of a rotor therein. The stator has four equally spaced teeth extending radially inwardly from the yoke of the stator to define the central bore. A rotor assembly for rotation in the central bore of the stator is included. The rotor assembly has three teeth extending radially outwardly from the central axis of the motor to terminate in close proximity to the stator teeth. Stator windings associated with the stator teeth generate a magnetic field in the central bore to cause rotation of the rotor assembly.
    Type: Grant
    Filed: May 15, 1992
    Date of Patent: July 11, 1995
    Assignee: Emerson Electric Co.
    Inventor: Ilija J. Obradovic
  • Patent number: 5422525
    Abstract: A switched reluctance machine comprises a stator having an even plurality of salient stator poles, each of which having a stator winding disposed thereon and electrically coupled one to another to form diametrically opposed pole pairs which may be coupled to an external source of electrical energy, a rotor having an even plurality of salient rotor poles, and at least one compensation coil disposed on each of the rotor poles. The compensation coils are electrically coupled one to another to form diametrically opposed compensation pairs in which flows a flux generating current when one of the stator windings of a pole pair is either open of shorted. The flux generated equalizes the unbalance forces resulting from the faulted stator winding, thereby increasing the fault tolerant capability of the switched reluctance machine.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: June 6, 1995
    Assignee: Sundstrand Corporation
    Inventor: Hassan Mansir
  • Patent number: 5418415
    Abstract: Inexpensive, maintenance-free and high efficiency reluctance motors and generators have a construction that makes it possible to decrease pulsating torque and additional harmonic core loses. Each salient pole of the rotor core of the reluctance motor and generator has a shape such that the gap permeance varies in proportion to cos (N.theta..sub.2), where .theta..sub.2 represents an angular position with respect to the origin set to the center of a salient pole, or a shape analogous to the shape. In order to make up for a reduction of reluctance torque due to the shape, slits are provided inside the rotor core which cause a large reluctance for the quadrature-axis flux without interfering with the direct-axis flux.
    Type: Grant
    Filed: March 3, 1994
    Date of Patent: May 23, 1995
    Inventor: Akira Ishizaki
  • Patent number: 5410203
    Abstract: The invention relates to a reluctance motor having a ferromagnetic stationary member (3) and a ferromagnetic member (5) which is movable relative thereto, which exhibit an air gap (4) between spaced-apart pole faces (3c, 5c) of salient pole parts (3b, 5b), one of the members being provided with excitation coils, which surround ferromagnetic cores (3a, 5a) providing a ferromagnetic coupling between the pole parts of this member, the ferromagnetic cores being dimensioned to have such cross-sections that during the magnetisation of these cores by the excitation current the cores are magnetically saturated at the same time as the salient pole parts.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: April 25, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Peter Lurkens
  • Patent number: 5386162
    Abstract: A multiple phase switched reluctance motor (30). A stator assembly (32) has a plurality of inwardly salient teeth (34a-34l) terminating at a central bore (36) and at least one redundant pole set for each motor phase. A rotor assembly (38) disposed for rotation in the bore has a plurality of rotor teeth (42a-42d). The number of rotor teeth is proportional to the number of stator teeth. The pole redundancy helps distribute ovalizing forces on the motor assembly. This lessens the effect of these forces and reduces motor noise produced by the assembly in response to the forces. The stator may have multiple teeth per pole and the rotor a multiple of the determined rotor teeth. The number of rotor teeth exceeds the number of stator teeth so the rotor teeth overlap the stator teeth. This improves starting torque in a desired direction of motor rotation.
    Type: Grant
    Filed: April 6, 1993
    Date of Patent: January 31, 1995
    Assignee: Emerson Electric Co.
    Inventor: Gary E. Horst
  • Patent number: 5323074
    Abstract: An armature core comprises a core element made of a magnetic material, wherein the core element has an annular portion. A plurality of salient poles are radially formed on the core element. A plurality of rib portions are formed on the salient poles, respectively; coils are wound around the rib portions. An insulating layer is formed on the surface of the core element. The insulating layer being provided with an area where surface of the core element excludes the insulating layer.
    Type: Grant
    Filed: May 15, 1992
    Date of Patent: June 21, 1994
    Assignee: Sankyo Seiki Mfg. Co., Ltd.
    Inventors: Hiroshi Sakashita, Eiji Arasaki
  • Patent number: 5317227
    Abstract: A rotor for a dynamoelectric machine, without windings and rotatable about a central longitudinal axis, having an axially extending rotatable body and a toroidal magnet coaxially mounted on the body is constructed to provide magnetic exitation for the rotor. The rotatable body contains a first set of circumferentially spaced axially extending salient poles with circumferentially spaced recesses therebetween and a second set of similar poles at an opposite axial location. The toroidal magnet is coaxially mounted on the body between the first and second set of salient poles. A second toroidal magnet may also be mounted on the body and a magnetic spacer placed in between both toroidal magnets.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: May 31, 1994
    Assignee: REM Technologies, Inc.
    Inventors: Rodolfo Palma, William H. Miller
  • Patent number: 5304882
    Abstract: A new class of doubly-salient variable reluctance motors which provides greater output torque, higher efficiency, quicker response, and a simple structure in comparison to conventional reluctance motors by utilizing a specific stator/rotor pole arrangement and by altering the magnetic structure of the motor by using permanent magnets to provide a linearly increasing flux linkage over the entire area of pole overlap.
    Type: Grant
    Filed: May 11, 1992
    Date of Patent: April 19, 1994
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Thomas A. Lipo, Yuefeng Liao
  • Patent number: 5294857
    Abstract: In order to compensate for the effects of mechanical oscillations of the salient pole rotor in a synchronous machine in a simple manner, control coils are provided which generate a controllable quadrature-axis magnetic field. The control coils are arranged on the salient pole rotor in such a way that the quadrature-axis magnetic field generated by the control coils is superimposed in the air gap on the controllable direct-axis magnetic field generated by exciting coils enclosing each pole body of the salient pole rotor.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: March 15, 1994
    Assignee: Siemens Aktiengesellschaft
    Inventors: Herbert Auinger, Hermann Waldmann
  • Patent number: 5274287
    Abstract: The object of the present invention is to obtain a motor capable of producing a large torque and operating with good efficiency in a high-speed region. A reluctance type motor according to the present invention, when one armature coil (32a) is deactivated through one switching element connected to a negative voltage terminal, prevents the magnetic energy stored in the magnetic core from returning to the electric power source by means of a back-flow preventing diode (21a). The magnetic energy is used to charge a small-capacitance capacitor (47a) to hold it to a high voltage. Thus, a trailing-off of current becomes steep. After a predetermined time has elapsed, a next armature coil (32e) is activated. As an applied voltage is a high voltage charged in the capacitor, the exciting current builds up sharply. Since the building-up and the trailing-off of the exciting current of the armature coil can be made sharp, the rotational speed can also be increased up to several 10 thousand rpm.
    Type: Grant
    Filed: November 5, 1992
    Date of Patent: December 28, 1993
    Assignee: Kabushikigaisha Sekogiken
    Inventor: Itsuki Bahn
  • Patent number: 5239217
    Abstract: A multiple phase switched reluctance motor (30). A stator assembly (32) has a plurality of inwardly salient teeth (34a-341) terminating at a central bore (36). A rotor assembly (38) is disposed for rotation in the bore and has a plurality of rotor teeth (42a-42d). The stator assembly has at least one redundant pole set for each motor phase. The rotor assembly has a corresponding proportional number of rotor teeth. The redundancy of the poles helps distribute ovalizing forces on the motor assembly. This lessens the effect of these forces and reduces motor noise produced by the assembly in response to the forces. In addition, the stator can have multiple teeth per pole and the rotor a multiple of the determined rotor teeth. The number of rotor teeth exceeds the number of stator teeth so the rotor teeth overlap the stator teeth. This improves starting torque in a desired direction of motor rotation.
    Type: Grant
    Filed: May 18, 1992
    Date of Patent: August 24, 1993
    Assignee: Emerson Electric Co.
    Inventor: Gary E. Horst
  • Patent number: 5194771
    Abstract: A brushless core motor featuring improved positional relationship between magneto-sensitive elements and core windings to prevent distortion of the output from the elements, enable a reduction in the thickness of the motor, and assure reduced and uniformly distributed leakage of magnetic flux. The motor includes an armature core having a plurality of salient poles, a plurality of windings in "m" phases (the term "m" expresses an integer.gtoreq.two) which are wound on the salient poles, a rotor magnet rotatable in an opposed relation with the salient poles, and "n" magneto-sensitive elements (the term "n"=an integer satisfying the relation of m.gtoreq.n) for detecting the magnetic poles of the rotor magnet in order to effect electric conduction control of the windings in the m phases. The magneto-sensitive elements are disposed in the vicinity of the rotor magnet, and, of the salient poles, having no windings are disposed adjacent the magneto-sensitive elements.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: March 16, 1993
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventors: Noboru Otsuki, Hajime Masuya
  • Patent number: 5177390
    Abstract: A rotor for use in a generator or a motor wherein damper bars extend through rotor laminations and at least one of the damper bars extends from the laminations to provide support for a coil portion. In a preferred manner the damper bar extends from opposing ends of the laminations.
    Type: Grant
    Filed: September 17, 1991
    Date of Patent: January 5, 1993
    Assignee: Kohler Co.
    Inventor: Richard D. Van Maaren
  • Patent number: 5148090
    Abstract: This invention determines the configurations of a rotor (10) and a stator (12) and conductance periods and conductance phases of the conductance currents to obtain a smooth rotation of a variable reluctance motor as an AC servo motor. When the number of phases of a motor is m, the number of salient poles (R.sub.j) of a rotor (10) is an integer n, and the number of salient poles (S.sub.k) of a stator (12 ) is r.multidot.m, n is a whole multiple of r, and where the configuration of the stator salient pole (S.sub.k) is rectangular and the configuration of the rotor salient pole (R.sub.j) is sinusoidal, AC sine wave currents shifted by 2n.pi./(r.multidot.m) each and having two times as large a period as that of a magnetic permeance fluctuation caused by a rotation of the rotor (10), are conducted to the phases of the motor.
    Type: Grant
    Filed: May 23, 1990
    Date of Patent: September 15, 1992
    Assignee: Fanuc Ltd.
    Inventors: Hideaki Oku, Takeshi Nakamura
  • Patent number: 5138213
    Abstract: The invention relates to a brushless d.c. motor comprising a first motor section (1), which exhibits circumferentially alternating permanent-magnetic north and south poles adjacent the magnetic air gap (17), and comprising a second motor section (9) having electrically energizable salient soft-magnetic pole shanks (11) extending towards the magnetic air gap, the soft-magnetic pole shanks (11) extending with their iron cross-section, which traverses the exciter coils (15), up to the proximity of the magnetic air gap (17), the pole tips (19) of the pole shanks (11) being rounded to reduce the cross-section towards the air gap.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: August 11, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Roland Sottek
  • Patent number: 5128576
    Abstract: A rotor assembly for an electric motor includes a plurality of laminations disposed in a stack, a tension rod extending axially through the rotor lamination stack, and end clamps disposed at each end of the rotor lamination stack and secured to the tension rod for compressing the stack to hold the laminations of the stack fixedly in position by compression. A method of stamping rotor and stator laminations for a doubly salient electric motor from a single piece of metal includes the steps of stamping a rotor lamination out of the piece of metal, and stamping the stator lamination out of the piece of metal offset from the stamping of the rotor lamination so that a tooth of the rotor lamination stamping is taken from the gap between two teeth of the stator lamination stamping. The centroids of the rotor and stator laminations in their stamped locations in the piece of metal are offset from one another.
    Type: Grant
    Filed: January 28, 1987
    Date of Patent: July 7, 1992
    Assignee: Emerson Electric Co.
    Inventor: Ilija J. Obradovic
  • Patent number: 5122697
    Abstract: A hybrid single-phase variable reluctance motor includes a stator with four inwardly salient teeth evenly spaced around a central core. A phase winding is operatively associated with two diametrically opposed stator teeth. Energization of the phase winding causes a temporary magnetization of those two teeth. A rotor disposed for rotation in the central bore has two outwardly salient teeth disposed generally at 180 degrees with respect to each other. A single permanent magnet is disposed adjacent the central bore at the end of one of the stator teeth other than the two having phase windings. A position sensor is disposed at the fourth stator tooth for detecting the rotational position of the rotor in the central bore. The position sensor is disposed in one quadrant of the motor in which the flux resulting from the permanent magnet and the flux resulting from the energization of the phase winding are in the same direction.
    Type: Grant
    Filed: April 30, 1990
    Date of Patent: June 16, 1992
    Assignee: Emerson Electric Co.
    Inventor: Gary E. Horst
  • Patent number: 5117144
    Abstract: An electric motor with solely one direction of rotation and electronic speed control, includes two mutually rotatable parts with ferromagnetic cores separated by an air gap. The stator core is provided with a peripherally extending ring of magnet pole groups each including at least one pair of salient magnet poles, the one being ferromagnetic and the other permanently magnetic. All magnet pole groups are connected magnetically to a common magnetizing winding, which magnetizes all magnet pole groups simultaneously in a manner such that the ferromagnetic pole and the permanent pole of each group is magnetized in the same direction. The rotor core is provided with a peripherally extending ring of salient ferromagnetic reluctance poles with twice the pole pitch of the stator.
    Type: Grant
    Filed: February 25, 1991
    Date of Patent: May 26, 1992
    Inventor: Vilmos Torok
  • Patent number: 5099165
    Abstract: A brushless d.c. motor having a number of permanent magnetic pole pairs and a number of salient poles wherein the ratio between the number of permanent magnetic pole pairs and the number of salient poles is greater than unity but less than 2:1 and the ratio between the widths of the salient poles and the widths of the permanent magnetic pole pairs is greater than 0.2 but not greater than 1.2.
    Type: Grant
    Filed: December 18, 1990
    Date of Patent: March 24, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Bernd Ackermann
  • Patent number: 5086246
    Abstract: A dynamoelectric machine has a stator with a stator core and a plurality of spaced apart radially extending ventilation ducts. A rotor mounted for rotation within the stator has a shaft with a plurality of salient poles. Each salient pole has a winding on it and each pole with its winding constitutes a pole member. Adjacent pole members define between them an interpolar space. Cooling air enters each interpolar space from each end when the machine is operating, moves generally axially as portions of the air change direction to move radially outwards through the air gap separating the rotor and stator and then through the ventilation ducts. The air flow, in a radial outward direction, tends to be less at the ends of the rotor and through the ventilation ducts adjacent the ends of the stator. The invention places a baffle at each end of each interpolar space.
    Type: Grant
    Filed: February 5, 1991
    Date of Patent: February 4, 1992
    Assignee: General Electric Canada Inc.
    Inventors: James H. Dymond, Nick N. Saidi, John M. Young
  • Patent number: 5057733
    Abstract: Modular coil cores for an electric motor eliminate tedious coil winding on pole members by making either the pole caps or the complete pole members of the stator yoke engageable with and disengageable from the stator yoke itself.
    Type: Grant
    Filed: November 8, 1989
    Date of Patent: October 15, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Sonoda, Takafumi Asada
  • Patent number: 5036238
    Abstract: A rotor of a salient-pole type rotary machine is disclosed in which field coils are held by a coil brace disposed between adjacent magnetic poles. In addition to the coil brace, a holder provided with an elastic member is also disposed between the magnetic poles, and another elastic member is disposed between the coil brace and the said holder, whereby the said two elastic members are utilized for the fixing of the field coils and for the pressing force of the coil brace. And the whole of the coil holding mechanism is separated from a spider. This construction permits the field coils to be held in place without any great change in the holding force under any dimensional change.
    Type: Grant
    Filed: July 11, 1990
    Date of Patent: July 30, 1991
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masaaki Tajima
  • Patent number: 5023502
    Abstract: Retention tang structure (61-64) is provided on the hub (52) of a switched reluctance motor rotor (50) for retaining electrically insulating material (65-68) in gaps (57-60) between the rotor poles (53-56), and minimizing magnetic flux path lines through the tangs. A one-piece unitary harness (92) is also provided and is molded in-situ axially around the laminated rotor stack and further structurally enhances the hold-together strength thereof. The electrically insulating molded material is integrally formed both in the gaps (57-60) between the rotor poles (53-56) and on the axial ends (88, 90) of the laminated stack to provide in combination axial runners (65-68) of molded material extending axially along the gaps (57-60) and integral with annular end rings (94, 96) of molded material on the axial ends (88, 90), which combination structurally enhances the hold-together strength of the laminated stack.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: June 11, 1991
    Assignee: A. O. Smith Corporation
    Inventor: J. Herbert Johnson
  • Patent number: 5001378
    Abstract: A homopolar, transverse pole rotor (14) having a central cylindrical body (24) with a set of circumferentially spaced, axially extending salient poles (28) at each end thereof, is constructed to reduce windage losses. Integral shrouds (29, 31) are placed on either side of each set of salient poles, and a relief is machined into the outer surface of each shroud to form an accentuated pole tip (64) which ensures magnetic centering of the rotor. To further minimize windage losses, the diameter of the central cylindrical body (24) can be reduced, and non-magnetic material can be secured within interpole recesses. Mechanical fasteners (66), dove tails (72) or tensioned circumferential banding (82) can be used to secure the non-magnetic interpole pieces to the rotor.
    Type: Grant
    Filed: September 1, 1989
    Date of Patent: March 19, 1991
    Assignee: REM Technologies, Inc.
    Inventors: William H. Miller, Warren R. Brook, James J. Grant
  • Patent number: 4983867
    Abstract: A stepping motor includes a stator having a plurality of magnetic poles wound with windings of three phases or four phases, and a rotor formed by a pair of rotary plates each having a multiplicity of gear-like salient poles and an axially magnetized permanent magnet sandwiched between the rotary plates. Where the number of magnetic poles of the stator is represented by m, the number of gear-like salient poles of the rotary plate is Z, and n is an integer equal to or larger than 1, in order to obtain a minute step angle, m, n and Z are selected to satisfy the following relationship: when m=9, and a 3-phase winding stator, Z=9n.+-.3.
    Type: Grant
    Filed: June 28, 1990
    Date of Patent: January 8, 1991
    Assignee: Japan Servo Co., Ltd.
    Inventor: Masafumi Sakamoto
  • Patent number: 4977344
    Abstract: A rotor assembly for an electric motor includes a plurality of laminations disposed in a stack, a tension rod extending axially through the rotor lamination stack, and end clamps disposed at each end of the rotor lamiantion stack and secured to the tension rod for compressing the stack to hold the laminations of the stack fixedly in position by compression. A method of stamping rotor and stator laminations for a doubly salient electric motor from a single piece of metal includes the steps of stamping a rotor lamination out of the piece of metal, and stamping the stator lamination out of the piece of metal offset from the stamping of the rotor lamination so that a tooth of the rotor lamiantion stamping is taken from the gap between two teeth of the stator lamination stamping. The centroids of the rotor and stator laminations in their stamped locations in the piece of metal are offset from one another.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: December 11, 1990
    Assignee: Emerson Electric Co.
    Inventor: Ilija J. Obradovic
  • Patent number: 4947066
    Abstract: A variable reluctance motor having untapered stator teeth and more rotor teeth than stator teeth. Two stator teeth are formed on each stator pole. The rotor tooth ratio (of tooth width to gap between teeth width) is equal to the stator tooth ratio for the two teeth on each stator pole. The rotor tooth ratio is in the range of about 0.70 to about 0.90, preferably about 0.78. With this configuration the motor has very low torque ripple. The stator teeth are magnetically saturated, so the motor can be operated at current levels above the saturation point, producing a linear torque to current function and high output torque.
    Type: Grant
    Filed: November 1, 1988
    Date of Patent: August 7, 1990
    Assignee: Servo Products Co.
    Inventors: Bogdan A. Ghibu, Michael F. Bent
  • Patent number: 4943746
    Abstract: Apparatus and method for dissipating heat in a generator. A rotor having support wedges between each of its poles is mounted on a bored shaft in which a bored spindle having helical grooves along its outer diameter is fixed. A cooling medium is circulated through the bored shaft upon rotation of the shaft. The shaft has at least one outlet and one inlet through which the cooling medium can radially exit and return, respectively. Each of the support wedges has an inlet and an outlet between which a bore extends. In a preferred embodiment, a manifold is disposed about the bored shaft and mated to each of the support wedges so as to circulate the cooling medium from the bored shaft to the support wedges and back to the bored shaft, thereby dissipating heat from the generator rotor. In alternate embodiments more than one manifold is used to circulate the cooling medium through the support wedges.
    Type: Grant
    Filed: March 20, 1989
    Date of Patent: July 24, 1990
    Assignee: Allied-Signal Inc.
    Inventors: William M. Scherzinger, Tsuwei Chu, Leon M. Kasdan
  • Patent number: 4937486
    Abstract: In an end-plate-less formed pole (1) for electric machines with salient poles, combined clamping and support elements (26, 27) which are used both for clamping together the single laminations (2) and for supporting the pole coils (41) are provided in the area close to the axis, in addition to the conventional clamping elements (8, 10). In addition, these elements are used for anchoring the damper plates (44, 45) and flexible link pieces (46) of the damper rods (43).
    Type: Grant
    Filed: April 4, 1989
    Date of Patent: June 26, 1990
    Assignee: Asea Brown Boveri, Ltd.
    Inventor: Josef Schwanda
  • Patent number: 4917579
    Abstract: A transporter includes at least one elongated transporting element (1) which is made of a material capable of changing its volume in response to the application of voltage or magnetic fields thereacross. The transporting element, optionally together with a further transporting element or some other part of the transporter, defines an elongated transporting channel (7). Means are provided for generating fields in predetermined regions along the transporting element (1) and in a given order of sequence, such as to impart substantially peristaltic motion to the element. These means include at least three mutually adjacent conductors (3, 4, 5) which extend substantially helically in relation to the transporting element (1) and to which different phases of a multi-phase alternating voltage or alternating current source are applied.
    Type: Grant
    Filed: February 28, 1989
    Date of Patent: April 17, 1990
    Assignee: KAILEG AB
    Inventor: Mikael Torma
  • Patent number: 4906883
    Abstract: A winding arrangement for a rotor pole in a synchronous machine having edgewise wound conductors forming a coil for the pole, the pole having at each end an end plate to provide curved corner portions for the winding. The conductor has a slot extending through it with the walls of the slot parallel to the edges of the conductor. The slot is provided in the conductor at the corner region where the edgewise wound conductor is to bend around the corner. The slot reduces the upset which occurs at the inner edge of the conductor where it bends, and it also permits the conductor to follow the curved corner portion more closely.
    Type: Grant
    Filed: March 22, 1989
    Date of Patent: March 6, 1990
    Assignee: General Electric Canada Inc.
    Inventor: Gordon W. Herzog
  • Patent number: 4894572
    Abstract: A disk-type brushless fan motor comprises a stator yoke having a suitable cutaway portion formed therein for allowing generation of a cogging torque to allow self-starting of a magnet rotor of the motor. A printed circuit board underlies the stator yoke, and a position detecting element is located on a face of the printed circuit board opposing to the cutaway portion of the stator yoke. The printed circuit board has one or more small cutaway portions formed along an outer periphery thereof within a range of the cutaway portion of the stator yoke, and opposite leads or terminals of a pair of armature coils located on the stator yoke extend through the cutaway portions of the printed circuit board in order to establish electric connection to electric parts located on the rear side of the printed circuit board.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: January 16, 1990
    Assignee: Shicoh Engineering Co., Ltd.
    Inventor: Manabu Shiraki
  • Patent number: 4885495
    Abstract: An end plate for a squirrel cage amortisseur winding is made from four angular segments, each of the segments being of the same shape and size, the segments having portions thereof cut out along the annular inner surface and the outer edges to accommodate close nesting of the angular segments across both the width and length of a sheet of raw material to minimize waste as they are cut therefrom.
    Type: Grant
    Filed: July 18, 1988
    Date of Patent: December 5, 1989
    Assignee: Century Electric, Inc.
    Inventor: Hollis D. Sisk
  • Patent number: 4881002
    Abstract: A miniature motor comprising a stator having permanent magnets constituting a two-pole field, and a rotor having rotor windings wound on a rotor core of a three-pole construction, in which the rotor core is formed in such a manner that the cross-sectional shape of the rotor core normal to the motor shaft is made symmetrical with respect to the radial center line of each pole thereof and that the gap between the permanent magnets and a predetermined range from the center line of the arc-shaped outer periphery of the rotor core facing the permanent magnet is made larger than the gap between the permanent magnet and at least part of the other range of the outer periphery of the rotor core.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: November 14, 1989
    Assignee: Mabuchi Motor Co., Ltd.
    Inventor: Hitoshi Yamaguchi
  • Patent number: 4874977
    Abstract: A stator assembly is associated with a rotor to form an alternator. The stator assembly has pole legs with pole faces, past which magnets on the rotor rotate. At least one coil bobbin with a coil thereon is slidably received over at least one of the pole legs, said at least one pole leg having a notch in a side thereof. A bobbin locking clip is positioned in a gap between a central aperture wall of the bobbin and the one side of the pole leg having the notch. The clip of springy material has two springy tabs for engagement in the notch and an embossment on a main body surface thereof, so as to provide three-point contact. The bobbin and coil to be wound thereon can be manufactured separate from the stator assembly, and then the bobbin with the coil can be slid on the pole legs after assembly. The stator is also assembled such that rivets are provided at a central portion, and rivets are provided near end faces of pole legs on which bobbins are not provided.
    Type: Grant
    Filed: May 9, 1988
    Date of Patent: October 17, 1989
    Assignee: F & B Mfg. Co.
    Inventor: Edward J. Safranek