Damper Winding Patents (Class 310/183)
  • Patent number: 10615653
    Abstract: A lamination for use in an integrated drive generator is formed from a plurality of plates having a body including a pair of opposed cylindrical surfaces. Non-cylindrical ditches are defined circumferentially intermediate the pair of cylindrical surfaces. A plurality of passages are formed in an outer periphery of the cylindrical surfaces including relatively large holes extending through a slot to the outer periphery. Grooves are formed intermediate the relatively large holes.
    Type: Grant
    Filed: January 4, 2018
    Date of Patent: April 7, 2020
    Assignee: Hamilton Sundstrand Corporation
    Inventors: Derek R. Hochstetler, Ted A. Martin, Duane C. Johnson, Glenn C. Lemmers, Jr.
  • Patent number: 10608508
    Abstract: Unique systems, methods, techniques and apparatuses of an exciterless synchronous machine are disclosed. One exemplary embodiment is a salient pole rotor for an electric machine including one set of pole pairs including a first, second, and third pole pair; a field winding; a set of energy harvest windings, each winding mounted to each of the plurality of pole pairs and structured to receive a harmonic component of AC power from a stator; and a DC power supply structured to receive the harmonic component from the set of energy harvest windings, convert the harmonic component to DC power, and output the DC power to the field winding. The set of energy harvest windings are arranged in a first sequence on the first pole pair, a second sequence on the second pole pair, and a third sequence on the third pole pair, and each sequence is different.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: March 31, 2020
    Assignee: ABB Schweiz AG
    Inventors: Chenjie Lin, Ghanshyam Shrestha, Jing Xu, Joonas Puukko
  • Patent number: 10594191
    Abstract: An electric machine is provided. The electric machine may include a rotor disposed on a shaft and an endplate. The endplate may define a coolant capture ring. The coolant capture ring may have tapered side walls that extend from an outer portion of the endplate toward the shaft at a periphery thereof. The coolant capture ring may be configured to deflect coolant captured by the coolant capture ring and expelled by the shaft due to centrifugal forces associated with the rotation of the shaft.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: March 17, 2020
    Assignee: Ford Global Technologies, LLC
    Inventors: Cyrille Goldstein, Joel Hetrick
  • Patent number: 10236736
    Abstract: A damper finger segment is radially disposed between a retaining ring and a damper ring arrangement at a rotor end of a generator arrangement, in particular of a high power turbogenerator, having a multitude of plate-like finger elements with a longitudinal extension and arranged parallel to each other. Each neighboring pair of finger elements encloses a gap and all finger elements are joined at one end of each finger element by a band-like strip section having a longitudinal extension being oriented orthogonally to the longitudinal extension of the finger elements. At least one slot is provided in each plate-like finger element and/or in the band-like strip section. The at least one slot has a slot axis oriented parallel to the longitudinal extension of the plate-like finger elements.
    Type: Grant
    Filed: January 21, 2015
    Date of Patent: March 19, 2019
    Assignee: General Electric Technology GmbH
    Inventors: Bartolomeus Irwanto, Yvonne Riedling, Gunter Scherf
  • Patent number: 10148154
    Abstract: It allows a more complete cooling of the generator, comprising: a magnetic core with a crown (3) from the periphery whereof emerge teeth (4) which have coiled windings (5); an external cooling circuit (9) to carry a coolant fluid; at least one through-hole (12) running along the interior of each tooth (4), and at least one first duct (13), to connect the through-hole (12) with the external cooling circuit (9) and with the through-hole (12) so that it allows the passage of the coolant fluid, the first duct (13, 16) being interposed between one end (7, 8) of the tooth (4) and the winding (5).
    Type: Grant
    Filed: May 19, 2014
    Date of Patent: December 4, 2018
    Inventors: Teresa Arlabán Gabeiras, José Miguel García Sayés, Miguel Núñez Polo
  • Patent number: 9819248
    Abstract: Cooling assemblies and methods, including, for example, at least one bar (e.g., electrically insulated and/or thermally conductive bar(s)), members (e.g., i-beams, rectangular members, and the like), stator laminations, rotor laminations, and/or combinations thereof, such as those configured to cool electric machines (e.g., electric motors and generators).
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: November 14, 2017
    Assignee: TECO-Westinghouse Motor Company
    Inventors: Devdatta P. Kulkarni, Gabriel Rupertus, Edward Chen, Lex Ramsey
  • Patent number: 9608551
    Abstract: Technologies for reducing peak fault output current in a DC power generation system include a generator having a reduced damper winding and a controller to control a rectifier array to generate a DC power output. In some embodiments, the generator may have no damper windings, may have damper windings including a reduced number of damper bars, and/or may have damper windings having separated end ring mounts for each damper bar. The controller is configured to control the rectifier array so as to reduce oscillations of the DC output that may be due to the reduced damper windings. To do so, the controller is configured to generate the control signal based on an oscillation component of the DC power output. For example, the controller may generate an oscillation correction signal based on the DC power output and adjust a firing angle set point of the rectifier array based on the oscillation correction signal.
    Type: Grant
    Filed: August 17, 2015
    Date of Patent: March 28, 2017
    Assignee: ABB Schweiz AG
    Inventors: Wen Ouyang, Jiaqi Liang, Li Qi
  • Patent number: 9559557
    Abstract: This rotating electrical machine has a rotor, stator core, field windings for multiple poles, and armature windings for the multiple poles. The rotor is rotatably supported about a shaft. Convex-shaped multiple salient pole sections are formed on the outer circumference of the rotor while arranged in the circumferential direction. The stator core is provided along the outer circumference of the rotor with an air gap from the rotor. Convex-shaped multiple teeth are formed on the inner circumference of the stator core while arranged in the circumferential direction. The field windings for the multiple poles are wound around each of the multiple teeth while insulated from the field windings.
    Type: Grant
    Filed: August 11, 2011
    Date of Patent: January 31, 2017
    Assignees: Toshiba Mitsubishi-Electric Industrial Systems Corporation, Kanazawa Institute of Technology
    Inventors: Toshihiro Tsuda, Mitsuhiro Kawamura, Tadashi Fukami, Kazuo Shima
  • Patent number: 8896178
    Abstract: A synchronous motor drive system improves the design flexibility regarding torque characteristics as compared with conventionally available design flexibility. A synchronous motor has a rotor and a stator. Each of at least two adjacent stator teeth has a slit formed at the tip thereof. Each of a plurality of stator teeth has a main coil wound therearound in concentrated winding. Between each two adjacent teeth having a slit, a sub-coil is wound around in a manner of being accommodated in the respective slits. The drive device separately controls electric current supplied to the main coils and electric current supplied to the sub-coil.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: November 25, 2014
    Assignee: Panasonic Corporation
    Inventors: Noriyoshi Nishiyama, Makoto Kitabatake
  • Patent number: 8796898
    Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: August 5, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yutaka Hashiba, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
  • Patent number: 8729764
    Abstract: A damper circuit for damping a synchronous servo-motor having at least one winding, at least one main damper resistor, connection means for connecting the main damper resistor in series with the winding, and at least one additional damper cell including at least one additional damper resistor connected in parallel with the main damper resistor via a static switch connected to a control module for controlling the switch as a function of a voltage of the winding. The control module has a shunt in parallel with the main damper resistor. The shunt has an output connected to the control input of the switch and a divider bridge connected to the shunt to form a comparator between the voltage of the winding and a conduction voltage of the shunt.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: May 20, 2014
    Assignee: Sagem Defense Securite
    Inventors: Tony Fourmont, Franck Delnaud, Jérôme Piaton, Roland Casimir
  • Patent number: 8723386
    Abstract: The invention relates to an electrical machine, especially an alternator (10) comprising a stator winding (11) with a total of seven phase conductors (P1 to P7) which are interconnected in series at the same electrical angle (a). The aim of the invention is to dampen magnet noise and to increase machine performance. For this purpose, at least every other electrically subsequent phase conductor (P) is skipped when the phase conductors (P1 to P7) are connected in series.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: May 13, 2014
    Assignee: Robert Bosch GmbH
    Inventors: Gerd Wolf, Norbert Pfitzke
  • Publication number: 20140103774
    Abstract: A wound-field synchronous machine includes a stator and a rotor. Around the rotor is a rotor sleeve including a damper bar assembly forming an amortisseur circuit.
    Type: Application
    Filed: October 16, 2012
    Publication date: April 17, 2014
    Inventors: Roy D. Rasmussen, William Louis Wentland, John F. Bangura
  • Patent number: 8674575
    Abstract: An increase of the magnetization current can be restrained during demagnetization and magnetization, and a variable speed operation can be achieved at a high power output over a wide range of from a low speed to a high speed. A rotor 1 is configured by a rotor core 2, permanent magnets 3 having a small value as the product of the coercivity and the thickness in the magnetization direction thereof, and permanent magnets 4 having a large value as the product. When reducing a flux linkage of the permanent magnets 3, a magnetic field directed to the reverse direction of the magnetization direction of the permanent magnets 3 due to a current of an armature coil is caused to act on them. When increasing a flux linkage of the permanent magnets 3, a magnetic field directed to the same direction as the magnetization direction of the permanent magnets 3 due to a current of an armature coil is caused to act on them.
    Type: Grant
    Filed: June 19, 2009
    Date of Patent: March 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuto Sakai, Yutaka Hashiba, Yosuke Otsubo, Yusuke Matsuoka, Norio Takahashi, Tadashi Tokumasu
  • Patent number: 8653710
    Abstract: A rotor has rotor cores divided in the axial direction. A permanent magnet is mounted at the position of each of the magnetic poles of cores. The permanent magnet of each magnetic pole is configured by a single tabular member that penetrates the two divided cores in the axial direction. Convex parts are respectively provided on the outer peripheries of the respective magnetic poles of the rotor cores along the axial direction of the rotor. The convex parts are provided to positions that are displaced for each of the two divided cores. The magnetic flux density increases in the convex parts, which becomes the magnetic pole center. Since the convex parts positions are displaced to each other, a skew function can be exhibited even if the permanent magnet is mounted at the same position.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: February 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Norio Takahashi, Kazuto Sakai, Yutaka Hashiba, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Tadashi Tokumasu
  • Publication number: 20140028141
    Abstract: A rotor for a generator comprises a stack of laminate plates and conductive end caps on either side thereof. The laminate plates and the end caps have holes near a periphery thereof, and conductive rods are positioned in the holes, and secured to the end caps. The stack, the end caps and the rods are then skewed by a desired angle with respect to a centerline of the rotor. The resulting rotor core may then be mounted to a rotor shaft, and wound, with the windings also being skewed due to skewing of the core. The end caps and rods form a damper cage that aids in reducing harmonics.
    Type: Application
    Filed: June 4, 2013
    Publication date: January 30, 2014
    Inventor: Randall J. DuVal
  • Publication number: 20130181568
    Abstract: A brushless starter generator includes a wound field generator having a rotor that includes a damper winding, wherein the damper winding includes a plurality of poles. Also included is at least one pole face disposed within each of the plurality of poles, wherein the at least one pole face comprises a slot opening. Further included is at least one damper bar relatively entirely filling the slot opening.
    Type: Application
    Filed: January 16, 2012
    Publication date: July 18, 2013
    Inventor: John F. Bangura
  • Publication number: 20090230804
    Abstract: A rotor assembly for an electromechanical machine includes a rotor core, an outer sleeve and an inner sleeve. The rotor core includes an outer diameter, and the outer sleeve is positioned about the outer diameter. The inner sleeve is positioned between the rotor core and the outer sleeve. One of the outer sleeve and the inner sleeve dampens electromagnetic flux generated by the rotor assembly.
    Type: Application
    Filed: February 28, 2008
    Publication date: September 17, 2009
    Inventors: Craig R. Legros, Laurence D. Vanek
  • Patent number: 7336013
    Abstract: In accordance with one embodiment, the present technique provides a bushing that is configured to electrically and mechanically couple a conductor bar of a rotor assembly to an end ring of the rotor assembly. The exemplary bushing has an interior surface that is configured to abut against the conductor bar and an exterior surface that is configured to abut the perimetric surface of an end slot. Advantageously, the bushing, because of a good fit in the end slot and around the conductor bar, provides a good electrical connection between the conductor bar and the end ring. Moreover, the exemplary bushing also provides interferences fits that at least partially secure the end ring to the rotor core.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: February 26, 2008
    Assignee: Reliance Electric Technologies, LLC
    Inventor: William P. Pizzichil
  • Patent number: 7119472
    Abstract: A very simple and reliable process for cancelling the reaction field (10) induced by a rotor (4) is proposed, wherein the rotor (4) is rotating in a static magnetic field (7) in a static outer core (3), and wherein the rotor (4) comprises at least two conductors (6) aligned substantially parallel to the axis (8) of the rotor (4). The armature reaction (10) is cancelled by means of a set of auxiliary windings (11) located on the static outer core (3) wherein said auxiliary windings (11) are fed with a direct current (DC) cancelling the reaction field (10). Preferentially, the process is applied to a brushless exciter and the auxiliary windings (11) have the same geometry as the conductors (6) of the rotor (4) and are all equally fed with a direct current corresponding to the current induced in the conductors (6) of the rotor (4) when the rotor is rotating in the static magnetic field (7).
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: October 10, 2006
    Assignee: ALSTOM Technology Ltd.
    Inventor: Alain Lacaze
  • Patent number: 7078842
    Abstract: An electric AC machine with a primary section and a secondary section is disclosed. The primary section has a region facing the secondary section and a region facing away from the secondary section. The region facing the secondary section has windings adapted to receive an AC current. The winding of the primary section has at least one phase conductor which at least partially extends in or on the region of the primary section facing away from the secondary section, thereby producing a magnetic field that extends outside the secondary section. This arrangement can reduce overvoltages and eliminate voltage breakdowns at the star point of winding strands of a synchronous motor.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: July 18, 2006
    Assignee: Siemens Aktiengesellschaft
    Inventors: Thomas Hoppe, Dietmar Stoiber
  • Patent number: 6870293
    Abstract: To provide a motor which can suppress vibration and noise during an operation of a concentrated winding motor and can achieve low vibration and low noise with high efficiency. Skew is formed on at least one of a stator (10) provided with concentrated windings and a rotor (20), and the windings (13—13) of different phases in a groove (19) for windings are brought into contact with each other directly or via an insulating material.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: March 22, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hisakazu Kataoka, Hiroshi Murakami, Hideharu Hiwaki, Sunao Hashimoto, Yasuharu Odachi, Hirohito Hayashi
  • Publication number: 20040113507
    Abstract: A dynamo-electric machine is so constituted as to easily change the characteristics of a dynamo-electric machine comprising permanent magnets and comprises a field control coil so as to adopt the dynamo-electric machine comprising common components to various applications. In this dynamo-electric machine, the field control coil is so adopted to a field which a magnetic pole and an iron pole supply to core teeth so as to superpose magnetic fluxes of different strengths. A permanent magnet is disposed in a recess of the inner peripheral face of a yoke to form a magnetic pole by a permanent magnet, and an iron pole by a yoke section between adjacent permanent magnets, and the inner peripheral face of the permanent magnet is located below the yoke section, thereby differentiating the strengths of magnetic fluxes.
    Type: Application
    Filed: September 23, 2003
    Publication date: June 17, 2004
    Inventors: Takeshi Yoda, Yumiko Kimura, Hidekazu Uchiyama
  • Publication number: 20040036375
    Abstract: Ventilation devices, in particular for electric motor drives regularly comprise a fan wheel (1), which is driven by a shaft via an electromagnetic induction coupling. In order to reduce the complexity of manufacture, a stack of magnetic sheets (2) is cast in the aluminum hub of the fan wheel (1). Thus, aluminum also assumes at the same time the function of a damper winding.
    Type: Application
    Filed: March 24, 2003
    Publication date: February 26, 2004
    Inventor: Ekkehard Pittius
  • Patent number: 6265801
    Abstract: A permanent magnet electrical rotating machine wherein the slots of stator core 2A of stator 1A are rectangular enclosed slots 4A in which triangular projecting gaps 3a are formed on the inner periphery side of this stator core 2A. The stator core 2A is cooled by passing gas through the projecting gaps 3a. The magnet flux that reaches stator core 2A from permanent magnets 6 by passing through retaining ring 8 and air gap 9 is caused to pass the inner periphery sides of the projecting gaps a of the stator core 2A. By this means, oscillation of magnetic flux density in the peripheral direction is prevented, eddy currents in the retaining ring 8 which accompany this oscillation are reduced and temperature rise prevented.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: July 24, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yutaka Hashiba, Tadashi Tokumasu, Kazuto Sakai, Norio Takahashi
  • Patent number: 6255754
    Abstract: In an electric motor, a conductive ring surrounds, and shields, each pole of stationary magnet. When a changing magnetic flux, produced by an armature, penetrates the ring, by Lenz's Law, the changing flux causes the ring to produce a counter-flux, which adds to the changing flux. Consequently, the total flux within the ring tends to remain constant. Maintaining this constant flux tends to reduce noise and vibration which the changing rotor flux otherwise causes.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: July 3, 2001
    Assignee: Valeo Electrical Systems, Inc.
    Inventors: Jack Winfield Savage, John Riden Suriano
  • Patent number: 6201322
    Abstract: An apparatus for stabilizing the spin axis of a rotating system, the rotating system having a rotor and motor means to cause rotation of the rotor about the spin axis and a magnet, windings, a source of drive current and an actuator combined with the motor means and forming a source of actuator current energizing the windings to generate a radial force which stabilizes the position of the spin axis and dampens other than rotational movements of the rotor.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: March 13, 2001
    Assignee: Seagate Technology LLC
    Inventors: Gunter K. Heine, Hans Leuthold, Christian Fleury
  • Patent number: 6054787
    Abstract: The present invention provides an electric motor with a reduced number of windings on one of the coil windings. The effect of this is that when the motor is in operation, the current that flows through the coil with the reduced number of windings differs from the others, and this difference can be detected to allow accurate control of the motor. To avoid any mechanical imbalance caused by this difference in the number of windings, mechanical compensation means is provided on the arm with the reduced number of windings. Preferably this comprise a further winding that is not electrically connected to the motor circuit.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: April 25, 2000
    Assignee: Ngai Keung Metal & Plastic Manufactory Ltd
    Inventor: Andrew Shun Pui Chiu
  • Patent number: 6008561
    Abstract: A reluctance machine including one or more damping windings placed within the stator or within the rotor which are used to store and provide energy so as to reduce unwanted machine vibration and noise, improve current commutation, and improve the efficiency and torque output of the machine.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: December 28, 1999
    Assignee: Emerson Electric Co.
    Inventor: Yifan Tang
  • Patent number: 5811906
    Abstract: Damper winding (13) for an elevator motor provided with permanent magnets (14). The damper winding consists of frames (16) surrounding each permanent magnet (14). Each one of the frames is electrically connected to the adjacent frame (16) or the frames are integrated together. The damper winding (13) can be used as a jig for positioning the magnets when these are being fixed to the rotor disc (6). In one of the embodiments, the magnets and damper winding are fixed to the rotor disc by a form-fit interlocking arrangement.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: September 22, 1998
    Assignee: Kone Oy
    Inventors: Harri Hakala, Esko Aulanko, Jorma Mustalahti
  • Patent number: 5550417
    Abstract: Electrically-conductive, segmental, slot wedges, with electrically-conductive inserts therebetween, and electrically-conductive interconnects, between end ones of the wedges and the annular, end retaining ring, of a rotor, define an amortisseur winding for the rotor. The inserts are spring-loaded in end slots formed in the wedges, and in an embodiment of the invention, are formed of beryllium copper and are silver-plated. As is typical of rotors in electrical, rotating equipment, the slot wedges are formed of aluminum.
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: August 27, 1996
    Assignee: Dresser-Rand Company
    Inventors: Darrell R. Morrison, James L. Nessa, James J. McClurg
  • Patent number: 5528097
    Abstract: A system for supporting a retaining ring on an end of body portion of a rotor in an electrodynamic system includes an end wedge which is adapted to be in contact with a retaining ring, a damper bar having a first surface which abuts the end wedge member and a second, oppositely facing surface; and a filler block positioned between the second surface of the damper bar and a field winding portion of a rotor. The filler block has a tapered surface which defines a stress-reducing gap between the field winding portion and the retaining ring, so as to minimize stress in the slot cell and field windings during high-speed rotation of the rotor.
    Type: Grant
    Filed: December 3, 1993
    Date of Patent: June 18, 1996
    Assignee: Westinghouse Electric Corporation
    Inventors: William C. Gardner, Robert L. Murphy, Albert C. Sismour, Jr.
  • 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: 5177392
    Abstract: An improved disk-type machine having a plurality of alternating stator and/or rotor sections is disclosed. The stator of the machine has microlaminated stator teeth molded from cut steel particles, mounted on a large disk of composite fiber material which is the main structural component of each stator section. The stator teeth are preferably molded in place during disk manufacture. The stator is designed to operate in a machine having an even number of axial air gaps, but has only a single winding for each stator. One layer of the winding is located on each side of the central supporting disk and the ends of the windings are connected through connectors molded into or mounted on the disk. Multiturn coils may be employed by making a plurality of these connections for each coil. The interior rotor sections of the machine are likewise constructed on supporting rotor disks of composite material, and have pole pieces molded into place during disk manufacture which are wound on both sides of the supporting disk.
    Type: Grant
    Filed: January 14, 1991
    Date of Patent: January 5, 1993
    Assignee: Westinghouse Electric Corp.
    Inventor: Dennis J. Scott
  • 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: 5140203
    Abstract: A control motor for a servo-valve includes elements of a control motor including a yoke, permanent magnet, control coil and armature mounted to one another. An output member transmits the pivotal movements of the armature. A frequency dependent passive electric dampening means is formed as an annular disc, and located adjacent the control means to compensate for non-linearities in frequency response.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: August 18, 1992
    Assignee: Mannesmann Rexroth GmbH
    Inventors: Herbert Reder, Hans-Georg Schubert
  • Patent number: 4887020
    Abstract: A self-excited brushless alternator having a rotating field winding excited by an alternating current exciter whose rotating armature rotates with the rotating field winding and is permanently connected to the field winding via a field rectifier also mounted to rotate with the field winding. The exciter has an exciter stator primary winding and a rotary exciter secondary winding connected via a rotray field rectifier to the rotary main field winding of the alternator. The primary excitation for the exciter is derived, via magnetic coupling, from a rotary auxiliary magnetic field produced by a feedback winding in series with the main field winding and rotating herewith. A common magnetic circuit couples the rotary feedback winding with an auxiliary stator secondary winding and the exciter primary and secondary windings.
    Type: Grant
    Filed: October 27, 1987
    Date of Patent: December 12, 1989
    Assignee: U.S. Philips Corporation
    Inventor: Gary R. Graham
  • Patent number: 4885526
    Abstract: A compensation circuit for electrical generators is disclosed. In an electrical generator, the electrical current generated in the armature coil induces a magnetic flux in the flux path of the generator. The compensating circuit of the invention includes a conductor that surrounds a portion of the flux path of the generator. This conductor known as the compensating coil, is supplied with a compensating circuit which has a reactive component. The compensating current induces a secondary magnetic flux that has a component that opposes the flux induced by the armature current. In a further embodiment of the invention, a twin generator--generator or twin generator--motor is employed. The compensating coil surrounds the flux path of one of the generators and the other generator or motor is used to supply compensating current to the compensating coil.
    Type: Grant
    Filed: March 23, 1988
    Date of Patent: December 5, 1989
    Assignee: Electro Erg Limited
    Inventor: Leslie I. Szabo
  • Patent number: 4716329
    Abstract: To eliminate armature or rotor reaction or leakage flux (leakage reactance) in an electric rotating machine, a short-circuit coil winding is wound on and through the rotor or an armature core of the machine. The short-circuit coil winding is wound at a right angle to the main coil to exclude any intervention. Due to placement of a non-magnetic material in the armature core, the leakage flux which flows in the non-magnetic material is reduced and the flux of the stator and the rotor flows separately along both sides to the inner part of the armature or rotor ring core. Due to the non-magnetic material, the flux which occurs due to the current of the transformer m.m.f. of this short-circuit ring coil extends substantially into the airgap, therefore to abate the effect of armature reaction flux in the airgap.
    Type: Grant
    Filed: June 24, 1980
    Date of Patent: December 29, 1987
    Assignee: Jang Kyun Oh
    Inventor: Sang S. Oh
  • Patent number: 4451752
    Abstract: In a stator provided with interpoles, a magnetic flux adjusting winding is provided adjacent to the radially inner end of each interpole core for adjusting the magnetic flux passing through the half of the circumferential width of the interpole core, so that the intensity of the magnetic flux passing through the radially inner end of the interpole core becomes substantially uniform along the end face of the interpole core, whereby the waveform of the commutating emf is simulated to that of the reactance voltage to widen the width of the no-spark zone during commutation thereby improving the commutation performance without appreciably modifying the original shape or structure of the stator.
    Type: Grant
    Filed: June 10, 1982
    Date of Patent: May 29, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Tahara, Takayuki Matsui, Haruo Koharagi, Seizi Yamashita, Noriyoshi Takahashi
  • Patent number: 4439704
    Abstract: The invention relates to a permanent magnet-excited rotor for a synchronous machine that has a short circuit cage with shorting rings at both end faces. The lamination stack of the rotor is secured against centrifugal stresses and has slots that extend longitudinally and radially for receiving the permanent magnets. To achieve high strength of the lamination stack against centrifugal stress while preserving the full magnetic strength of the permanent magnets even if the lamination stack is heated to a high temperature in order to case the short circuit cage in place, the slots are closed at the outer circumference of the rotor and recesses large enough to permit the magnets to be inserted into the slots in the axial direction after the cage has been formed are provided in at least one shorting ring.
    Type: Grant
    Filed: December 5, 1980
    Date of Patent: March 27, 1984
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hans-Joachim Adelski, Josef Pflaugner
  • Patent number: 4329609
    Abstract: The invention relates to a rotor with a damper for an alternator with projecting poles. The squirrel cage type screen damper, includes not only conventional polar bars (10) sunk in projecting pole pieces (6a, 6b), but also interpolar bars (22) having wings (26) arranged between consecutive projecting pole pieces and ensuring damping of the components of the variable magnetic flux which are of large space pitch. Application to the production of electric power, in particular by submerged hydro-electric bulb units.
    Type: Grant
    Filed: June 25, 1980
    Date of Patent: May 11, 1982
    Assignee: Alsthom Atlantique
    Inventors: Jean Allegre, Gilbert Merouge, Gilbert Ruelle
  • Patent number: 4249098
    Abstract: A rotor component of an asynchronous electrical motor of the squirrel-cage type comprises a cylindrical array of circumferentially spaced short-circuited conductor bars having the opposite end portions thereof seated in corresponding circular grooves provided in the surfaces of annular conductive end rings. The ends of the conductor bars are soldered to adjoining surface portions of the grooves by placing solder in the gaps between the bar ends and groove surfaces and directly heating only the end rings so as to bring them up to the working temperature for effecting the soldering operation. The end rings are heated up circumferentially in a section-by-section manner so that soldering of the conductor bar ends to the end rings also takes place in a section-by-section manner.
    Type: Grant
    Filed: June 29, 1976
    Date of Patent: February 3, 1981
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Urs Karlen, Horst Kirschner
  • Patent number: 4210836
    Abstract: A permanent magnet generator is provided which is intended for use in close physical relation to an associated main generator, such as an aircraft generator. To prevent severe modulation of the output voltage of the permanent magnet generator due to stray magnetic fields from the main generator, short-circuited windings are provided encircling the magnetic circuit of the permanent magnet generator in a manner to minimize the effect of such stray magnetic fields.
    Type: Grant
    Filed: April 10, 1978
    Date of Patent: July 1, 1980
    Assignee: Westinghouse Electric Corp.
    Inventor: Carroll C. Kouba
  • Patent number: 4150312
    Abstract: A disclosed process includes arranging field yoke segments, pole face segments, and one or more pieces of ceramic magnet material so that the yoke segments and pole face segments can be relied upon to establish low reluctance paths for magnetic flux associated with the ceramic magnet material. The process includes holding the ceramic magnet material sandwiched between the yoke pieces and pole pieces within a cavity of a casting fixture; admitting a molten metallic material to the cavity and adjacent to the yoke, pole, and ceramic material pieces; permitting the molten material to solidify; and thereafter removing the field assembly from the cavity with the ceramic pieces completely surrounded and encased by the pole pieces, yoke pieces, and solidified material. In a more preferred form, molten aluminum at a temperature of at least about 660.degree. C. is used as the molten metallic material even though the resulting thermal shock causes a fracturing or shattering of the ceramic material.
    Type: Grant
    Filed: February 24, 1978
    Date of Patent: April 17, 1979
    Assignee: General Electric Company
    Inventors: Fredrick J. Armstrong, Robert A. Susdorf
  • Patent number: 4117360
    Abstract: A self-supporting amortisseur winding in the form of a thin copper cage is situated about the solid rotor of a high-speed, permanent magnet synchronous machine in order to keep commutating reactance low. A high-strength wire is wound, with high tension, circumferentially about the cage to counteract the effects of centrifugal force on the cage when the machine is operating.
    Type: Grant
    Filed: April 15, 1977
    Date of Patent: September 26, 1978
    Assignee: General Electric Company
    Inventor: Eike Richter
  • Patent number: 4099076
    Abstract: An improved rotor assembly for a generator used in a multi-channel parallel electrical generating system. A plurality of laminated sections, each having N outwardly extending poles, are stacked to form a rotor. Field windings are wound around the N poles and damper turns are wound around adjacent pole pairs to reduce the mutual flux coupling between the rotor and the stator, thereby reducing the fundamental component of torque between the rotor and the stator.
    Type: Grant
    Filed: May 18, 1977
    Date of Patent: July 4, 1978
    Assignee: Sundstrand Corporation
    Inventor: David J. Hucker
  • Patent number: 4082973
    Abstract: This invention relates to a synchronous electric motor comprising a housing accommodating a stator having a.c. windings and a winding for producing a coaxial direct field and a rotor provided with a cage winding, the poles of which being arranged in axial, relatively spaced transverse planes, wherein radially extending connecting elements are arranged in the interpolar space between the cage windings and the rotor, said connecting rings being formed by rings arranged on the rotor shaft and made from non-magnetic material.
    Type: Grant
    Filed: April 13, 1976
    Date of Patent: April 4, 1978
    Assignee: Heemaf B.V.
    Inventor: Lodewijk Schiethart
  • Patent number: 4028574
    Abstract: A synchronous motor incorporates a rotor structure having solid poles. In order to improve the starting characteristic of the motor and protect the pole claws against burning, conductive bars are arranged at each side of the pole below the pole shoe and are electrically connected with the pole to form a quadrature-winding which provides a conductive path for currents induced at the pole surfaces by the time-variable quadrature-field and causes such currents to close around the quadrature-field thereby eliminating current from pole-to-pole by way of the claws. The quadrature-winding also forms a circuit parallel to the solid pole surfaces which thereby improves the asynchronous torque characteristics at low slip rates and reduces the oscillating torque.
    Type: Grant
    Filed: March 20, 1975
    Date of Patent: June 7, 1977
    Assignee: BBC Brown Boveri & Company Limited
    Inventor: Muzaffer Canay