Circumferential Flux Path And Circumferential Pole Shoes Patents (Class 310/156.55)
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Patent number: 8207645Abstract: In a magnet-exciting rotating electric machine system, a rotor surface has magnetic salient poles and island-shaped magnetic poles alternately in circumferential direction, and the island-shaped magnetic poles are constituted so that magnetic flux coming from an external source does not flow through. A magnetic excitation part magnetizes the island-shaped magnetic poles and the magnetic salient poles collectively in the same direction, and then control a flux amount flowing through an armature. The armature has armature coils that face the magnetic salient pole and the island-shaped magnetic pole simultaneously so that driving torque fluctuation or power generation voltage waveform distortion is controlled. The magnetic excitation part changes magnetization state of a field magnet irreversibly, or changes an excitation current to an excitation coil to control a flux crossing the armature.Type: GrantFiled: December 24, 2009Date of Patent: June 26, 2012Assignee: Kura Laboratory CorporationInventor: Yoshikazu Ichiyama
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Patent number: 8120215Abstract: A motor and a control unit therefor comprise: salient rotor poles and salient stator poles, which are arranged along circumferences of phases A, B and C with an even interval therebetween; magnetic paths for passing magnetic fluxes, the paths permitting the magnetic fluxes passing through the salient rotor and stator poles of each phase to return to the rotor side; and substantially looped windings arranged between the salient stator poles of individual phases and the magnetic paths for passing magnetic fluxes, wherein currents are supplied to the windings in synchronization with the rotational position of the rotor to thereby output torque. Since the structures of the stator, the rotor and the windings are simple, productivity is enhanced, whereby high quality, small size and low cost can be realized.Type: GrantFiled: May 16, 2006Date of Patent: February 21, 2012Assignee: Denso CorporationInventor: Masayuki Nashiki
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Patent number: 8033007Abstract: Some embodiments of the present disclosure provide a method of making a rotor of an electric brushless motor configured to be light weight and prevent vibrations generated during an operation of the motor to be transferred to the shaft of the rotor. The method includes providing a shaft elongated in a rotational axis, providing a single body magnet comprising alternately magnetized portions, and providing a vibration absorption portion interposed between the shaft and single body magnet. The vibration absorption portion absorbs vibrations generated during the operation of the motor and may include an elastic or a non-elastic material. The method further includes providing a non-elastic portion configured to inhibit the expansion of the vibration absorption portion when the vibration portion is elastic.Type: GrantFiled: August 14, 2008Date of Patent: October 11, 2011Assignee: SNTech, Inc.Inventor: Young-Chun Jeung
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Patent number: 7982350Abstract: Embodiments of the invention provide for conical magnets for rotors in electrodynamic machines, methods to design the same, and rotor-stator structures for electrodynamic machines. In various embodiments, a rotor-stator structure for electrodynamic machine can include field pole members and conical magnets. According to at least some embodiments, one or more of the conical magnets can include a magnetic region configured to confront one or more air gaps. The magnetic region can be substantially coextensive with one or more acute angles to the axis of rotation. The magnetic region can also include a surface positioned at multiple radial distances from the axis of rotation in a plane perpendicular to the axis of rotation.Type: GrantFiled: April 3, 2008Date of Patent: July 19, 2011Assignee: NovaTorque, Inc.Inventors: Donald Burch, John Patrick Petro, Jeremy Franz Mayer
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Patent number: 7948138Abstract: A rotor is provided with a rotor core, a magnet inserted into the rotor core and a filling portion arranged in a space between the rotor core and the magnet. The space between the rotor core and a radially outer side surface of the magnet has a uniform width in a central portion (portion (A)) with respect to a width direction (of arrow (DR4)) of the magnet. A width of the space in an end portion (portion (B)) with respect to the width direction (of arrow (DR4)) of the magnet is larger than that of the space in the portion (A).Type: GrantFiled: November 17, 2005Date of Patent: May 24, 2011Assignee: Toyota Jidosha Kabushiki KaishaInventors: Hiroyuki Hattori, Akihide Takehara
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Patent number: 7911104Abstract: A retention system in which rotor pole pieces are retained within complementarily shaped channels in a rotor hub, permanent magnets are secured between the pole pieces and within clamp members, and wedge-shaped pieces are used to apply positive locking forces along the axial length of each clamp member and of adjacent pole pieces. A curable resin preferably in disposed within gaps between the permanent magnets and the clamp members.Type: GrantFiled: March 10, 2009Date of Patent: March 22, 2011Assignee: DRS Power Technology, Inc.Inventors: Costin Ifrim, Michael R. Pothier, James S. Smith, Art O'Leary
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Patent number: 7911107Abstract: A motor is provided, which includes: a rotor having rotor pole groups, in which N-poles and S-poles are alternately arranged in the circumferential direction; an N number (N is a positive integer) of stator pole groups, in which a plurality of stator poles are arranged for individual phases along or in the vicinity of the respective circumferences so as to be positioned at substantially the same rotational phase position in terms of electrical angle; and an (N?1) number of loop windings axially arranged between the stator pole groups, with the same phase being arranged at axial ends, wherein each of the loop windings is arranged radially inner than the outer diameter of each rotor pole group. This simplified winding structure can enhance productivity, reduce size, enhance efficiency and reduce cost.Type: GrantFiled: May 23, 2006Date of Patent: March 22, 2011Assignee: Denso CorporationInventor: Masayuki Nashiki
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Patent number: 7804216Abstract: For an electrical reluctance rotary machine, a stator has a winding as an armature, and a rotor has permanent magnet implanting slots provided in a rotor core at lateral sides magnetic poles configured to produce reluctance torque along directions of magnetic flux passing through the magnetic poles to produce reluctance torque, and permanent magnets inserted in the permanent magnet implanting slots so as to cancel magnetic flux of the armature intersecting that magnetic flux, to control a magnetic field leaking at ends of the magnetic poles, having circumferential magnetic unevenness. The electrical reluctance rotary machine is configured to meet a relationship, such that 1.6 ? P × W pm R ? 1.9 where Wpm [mm] is a width of permanent magnet, R [mm] is a radius of the rotor, and P is the number of poles.Type: GrantFiled: October 19, 2007Date of Patent: September 28, 2010Assignees: Kabushiki Kaisha Toshiba, Toshiba Industrial Products Manufacturing CorporationInventors: Norio Takahashi, Kazuto Sakai, Masanori Arata, Yutaka Hashiba, Wataru Ito, Motoyasu Mochizuki, Mikio Takabatake, Masakatsu Matsubara, Takashi Hanai
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Patent number: 7705502Abstract: An interior permanent magnet machine having angled slots.Type: GrantFiled: April 14, 2006Date of Patent: April 27, 2010Assignee: Emerson Electric Co.Inventors: Keith I. Hoemann, Todd A. Walls
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Patent number: 7692348Abstract: The invention is directed to an arrangement for fastening permanent magnets to rapidly rotating rotors of electric machines. It is the object of the invention to find a novel possibility for fastening permanent magnets to the rotor of rapidly rotating electric machines which allows the magnets to be fixed so as to be secure against centrifugal forces for high rotating speeds and under confined spatial conditions without a frictionally engaging connection of magnet holders to the rotor.Type: GrantFiled: October 19, 2007Date of Patent: April 6, 2010Assignee: ESW GmbHInventor: Thomas Gruenhagen
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Patent number: 7667364Abstract: A brushless motor includes a stator and a rotor. The stator includes an annular stator core having teeth arranged with a spacing in a circumferential direction of the annular stator core; and coils wound around the teeth respectively. The rotor includes a rotor core and magnetic poles of segment magnets arranged annularly along a circumferential direction of the rotor core. The segment magnets are stacked at a plurality of stages in an axial direction of the rotor core. A length direction of each of the segment magnets is parallel with the axial direction of the rotor core. The following expression is satisfied: (2×?/P)+?<(360/P) where P is the number of the magnetic poles of the segment magnets at each stage, ? (electrical angle) is the effective pole angular aperture on the outer peripheral surface of the rotor core, and ? is the skew angle equivalent to a phase shift angle between the corresponding magnetic poles of the segment magnets at the adjacent stages.Type: GrantFiled: July 17, 2008Date of Patent: February 23, 2010Assignee: Jtekt CorporationInventors: Noboru Niguchi, Masaru Horikawa
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Patent number: 7567006Abstract: In a magnet-exciting rotating electric machine, a magnetic field pole part opposing an armature is composed to be divided into a surface magnetic pole part and a magnetic excitation part so as to be capable of being relatively displaced. The magnetic excitation part supplies a magnetic flux to a magnetic salient pole. The magnetic flux from the field magnet is divided into a main magnetic flux pathway that circulates through the armature side and a bypass magnetic flux pathway that does not pass through the armature, and thereby, the magnetic flux of the main magnetic flux pathway is changed. The magnetic resistances of the main magnetic flux pathway and the bypass magnetic flux pathway are composed so that total magnetic flux amount from the field magnet is maintained constant, and then a magnetic force preventing the relative displacement is maintained small.Type: GrantFiled: February 14, 2008Date of Patent: July 28, 2009Assignee: Kura Laboratory CorporationInventor: Yoshikazu Ichiyama
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Patent number: 7535145Abstract: A rotor 31 has permanent magnets 31a disposed on a surface of a disk-shaped back yoke 31b in such a manner that long sides of each permanent magnet extend in a radial direction and that a South pole and a North pole of the permanent magnet 31a are arranged in a circumferential direction. The four permanent magnets 31a are equally spaced from one another in the circumferential direction, and circumferentially-opposed magnetic poles of any two adjacent permanent magnets 31a are of the same magnetic polarity. Rotor cores 31c of a generally fan-shape are fixed to the back yoke to generally cover the four permanent magnets 31a. A flux barrier 31d for reducing the short-cutting of magnetic flux of the permanent magnet 31a is provided between any two adjacent rotor cores 31c, and is disposed at a radially-extending central portion of the permanent magnet 31a.Type: GrantFiled: June 15, 2006Date of Patent: May 19, 2009Assignee: Fujitsu General LimitedInventor: Masanori Murakami
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Publication number: 20090066174Abstract: A method of balancing an embedded permanent magnet motor rotor includes the steps of: a) providing a non-magnetic cylindrical shaft having an axis of rotation and a generally cylindrical surface with an even number of recessed slots defining an even number of ribs therebetween; b) machining an axial slot having a cross-section with a top opening, a bottom and two sides in a center portion of each of the recessed slots; c) sliding at least one balance weight into at least one of the axial slots; and d) inserting locating rods into the axial slot on each side of the at least one balance weight.Type: ApplicationFiled: September 12, 2007Publication date: March 12, 2009Applicant: CANOPY TECHNOLOGIES, LLCInventor: Andrew P. Watson
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Publication number: 20080278016Abstract: In a rotor of a magneto generator in which permanent magnets are attached to the inner circumference of a peripheral wall of a cup-shaped formed flywheel, and a plurality of trigger poles are arranged on the outer circumference of the flywheel; the plurality of trigger poles are simultaneously punched out by press working to form a protrusion ring which is formed of a separate member from the flywheel, and the protrusion ring is integrally incorporated to the flywheel to configure the rotor.Type: ApplicationFiled: December 4, 2007Publication date: November 13, 2008Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Shigehiko SORACHI, Hirohisa YOKOTA
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Publication number: 20080218023Abstract: In a three-phase brushless motor, a rotor has a stacked structure including first to third stages which include segment magnets to which a skew process is applied. When the number of poles P in the circumferential direction is set to P, an angle of skew is set to ?=360/(6P/2) [deg]. That is, the magnet segments are respectively arranged so that the magnet segment of the second stage is shifted by a rotating angle of ?/3 in the circumferential direction from the magnet segment of the first stage and the magnet segment of the third stage is shifted by a rotating angle of 2?/3 in the circumferential direction.Type: ApplicationFiled: March 3, 2008Publication date: September 11, 2008Applicant: JTEKT CorporationInventors: Noboru NIGUCHI, Hirohide INAYAMA
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Publication number: 20080203848Abstract: The present invention relates to an electrical multipole motor/generator or electrical machine with axial magnetic flux, wherein the machine has a number of stator pole cores being larger than the number of rotor pole shoes. Thus, a motor/generator or electrical machine is provided in which the machine comprises a rotor secured to a shaft with an axis of rotation, where the rotor comprises magnets or means for producing a magnetic field and a number set to N of pole shoes. The machine further comprises a first stator with air gaps formed between the rotor and the first stator, where the first stator comprises a number set to M of separate pole cores or pole legs having corresponding separate coils or set of windings wound on and surrounding said pole cores or pole legs, wherein N and M are larger than one and M is larger than N. N may be an equal number, and M may be equal to 2N, or M may be equal to 3N, or M may be equal to 4N.Type: ApplicationFiled: September 18, 2003Publication date: August 28, 2008Applicant: NEG Micon Control Systems A/SInventors: Ole Nymann, Kim Dam Larsen, Uffe Dam
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Publication number: 20080197739Abstract: A motor is provided, which includes: a rotor having rotor pole groups, in which N-poles and S-poles are alternately arranged in the circumferential direction; an N number (N is a positive integer) of stator pole groups, in which a plurality of stator poles are arranged for individual phases along or in the vicinity of the respective circumferences so as to be positioned at substantially the same rotational phase position in terms of electrical angle; and an (N?1) number of loop windings axially arranged between the stator pole groups, with the same phase being arranged at axial ends, wherein each of the loop windings is arranged radially inner than the outer diameter of each rotor pole group. This simplified winding structure can enhance productivity, reduce size, enhance efficiency and reduce cost.Type: ApplicationFiled: May 23, 2006Publication date: August 21, 2008Applicant: DENSO CORPORATIONInventor: Masayuki Nashiki
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Patent number: 7388309Abstract: A rotary electric machine includes a rotor including a plurality of magnet sections arranged along a rotational direction of the rotor so that polarities of the magnet sections change alternately, and a stator including armature coils, and being disposed to confront the rotor across an air gap. Permanent magnet flux which is not linked with one of the air gap and the armature coils is higher than permanent magnet flux which is linked with the air gap and the armature coils in a no-load state.Type: GrantFiled: September 15, 2005Date of Patent: June 17, 2008Assignee: Nissna Motor Co., Ltd.Inventors: Minoru Arimitsu, Kan Akatsu
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Patent number: 7388310Abstract: The invention relates to a synchronous electric motor comprising a stator (10) and at least one rotor (20) with permanent magnets (21), characterized by an embodiment with Xd>Xq; where Xd is the direct reactance and Xq the quadrature reactance.Type: GrantFiled: March 29, 2004Date of Patent: June 17, 2008Assignee: Moteurs Leroy-SomerInventors: Atef Abou-Akar, Jacques Saint-Michel
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Patent number: 7250702Abstract: The invention relates to an electric machine comprising a stator (10, 40) provided with a plurality of teeth (11, 41), each tooth supporting at lest one individual coil (13, 46, 47), an external rotor (30) which is radially arranged outside the stator and provided with constant magnets, an internal rotor (20) radially arranged inside the stator, provided with constant magnets and connected to the external rotor (30). At least one of the external (30) and internal (20) rotors is disposed in a flux concentration.Type: GrantFiled: March 5, 2004Date of Patent: July 31, 2007Assignee: Moteurs Leroy-SomerInventors: Atef Abou Akar, Eric Coupart, Jacques Saint-Michel
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Patent number: 7148598Abstract: A rotor assembly for an electric motor includes a spoke permanent magnet rotor and a shaft connected thereto. The spoke permanent magnet rotor has an axis of rotation, permanent magnet material, and ferro-magnetic material. The permanent magnet material extends outwardly relative to the axis of rotation to form a plurality of outwardly extending spoke portions of permanent magnet material. The ferro-magnetic material is positioned adjacent to the outwardly extending spoke portions of permanent magnet material. The shaft supports the spoke permanent magnet rotor for rotation about the axis of rotation. The permanent magnet material may circumferentially surround the axis of rotation to form a center portion of permanent magnet material. Further, the axis of rotation may pass through the permanent magnet material. The spoke permanent magnet rotor may be formed using a compaction process and/or an injection molding process.Type: GrantFiled: October 23, 2003Date of Patent: December 12, 2006Assignee: A.O. Smith CorporationInventors: Dan M. Ionel, Robert J. Heideman, Ronald P. Bartos
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Rotor assembly for an electrical machine and permanent magnet motor comprising such a rotor assembly
Patent number: 6927519Abstract: Rotor assembly for an electrical machine, wherein a body of generally cylindrical shape having an inner opening for coaxially mounting the body on a shaft, permanent magnets embedded in said body, wherein at least one of the permanent magnets is split in at least two magnet sections which extend from about the inner opening towards the outer periphery of the body and are inclined towards a plane, which extends in a radial direction of the body.Type: GrantFiled: August 6, 2003Date of Patent: August 9, 2005Assignee: Minebea Co., Ltd.Inventor: Vladimir Vladimirovich Popov -
Patent number: 6919662Abstract: A motor including: a rotor including a permanent magnet type rotor unit having a plurality of permanent magnets and a reluctance type rotor unit having a plurality of salient pole portions, the rotor units being coupled to each other in an axial direction; and a stator for generating a field for driving the rotor. The permanent magnet type rotor unit and the reluctance type rotor unit are given an angle deviation therebetween in the direction of rotation to obtain desired torque characteristics. The reluctance type rotor unit has slits for preventing flux leakage from the permanent magnets. The slits are formed with the angle deviation in the direction of rotation from respective positions symmetric about a center of the salient pole portions. Flux leakage is thus prevented to avoid deterioration in characteristics.Type: GrantFiled: April 25, 2002Date of Patent: July 19, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaki Tagome, Yasuhiro Kondo, Naoyuki Kadoya
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Patent number: 6891299Abstract: A rotary electric machine including a flux-concentrating rotor with permanent magnets disposed between pole pieces, and a stator with teeth having a free end deprived of pole swellings and a concentrated winding. The pole pieces and the magnets are configured so as to minimize the difference Ld?Lq where Ld is inductance on a forward axis and Lq is inductance on a quadrature axis.Type: GrantFiled: April 30, 2001Date of Patent: May 10, 2005Assignee: Moteurs Leroy-SomerInventors: Eric Coupart, Pascal Gauthier, Jacques Saint-Michel, Christophe Gilles, André Eydelie, Laurent Jadeau, Philippe Augier, Jean-Marie Guillot
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Patent number: 6885122Abstract: A motor/generator (1) comprises a permanent magnets (3) having a V-shaped surface projecting in the center of a rotor (2). These permanent magnets (3) are disposed so that the V-shaped surface faces the center of the rotor (2). In this way, the permanent magnets (3) are prevented from sliding on the fitting surfaces (21) of the insertion holes (20), and the permanent magnets (3) can be fixed at predetermined positions. Further, magnetic losses caused by the rotor (2) can be reduced, and efficiency of the motor/generator can be improved.Type: GrantFiled: July 24, 2002Date of Patent: April 26, 2005Assignee: Nissan Motor Co., Ltd.Inventors: Yutaro Kaneko, Shinichiro Kitada, Toshio Kikuchi, Takashi Tsuneyoshi
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Patent number: 6882066Abstract: In a unipolar transverse flux machine, in particular a motor, having a rotor, which is comprised of two coaxial, ferromagnetic, toothed rotor rings, and a permanent magnet ring, which is magnetized in an axially unipolar fashion and is clamped axially between these rotor rings, and having a stator, which is concentric to the rotor shaft and has U-shaped stator yokes that represent the magnet poles, yoke elements, and a stator winding, in order to achieve an extremely flat design and to assure a definite start in a particular direction, the stator winding is embodied with two coils, whose one coil side extends respectively over a group of stator yokes and yoke elements arranged in succession in the circumference direction, along the side of the yoke elements remote from the rotor shaft, between the yoke legs, where the group spanned by the coil side of the one coil is disposed spatially offset on the stator circumference and electrically offset by 90° in relation to the group spanned by the coil side of the otType: GrantFiled: July 17, 2001Date of Patent: April 19, 2005Assignee: Robert Bosch GmbHInventor: Guenter Kastinger
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Patent number: 6873073Abstract: A rotor core, rotating in the vicinity of a generating coil, comprises a balance weight section and a pair of magnetic poles, provided on opposite sides of the balance weight section 2 with respect to a center of rotation O of the rotor core 1 to sandwich a magnet, and confronting through a magnetic gap G. A magnet holding section 9 for preventing the magnet 5 flying out through the magnetic gap G due to centrifugal force, is provided integrally contiguous to each of the magnetic poles so as to connect between the two magnetic poles.Type: GrantFiled: June 25, 2002Date of Patent: March 29, 2005Assignee: Oppama Industry Co., Ltd.Inventors: Masao Iwata, Kiyoshige Enomoto, Yoshiki Kitamura, Shigeyuki Suzuki
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Patent number: 6858961Abstract: A motor comprising: a rotor including a permanent magnet type rotor unit having a plurality of permanent magnets and a reluctance type rotor unit having a plurality of magnetic salient pole portions and a plurality of slits for preventing flux leakage, the rotor units being coupled to each other in an axial direction; and a stator for generating a field for driving the rotor. Elongated holes for preventing the short-circuit of magnetic fluxes are arranged near edges of the permanent magnet of the permanent magnet type rotor unit. The elongated holes or notches are arranged within a range defined so that 0.95????1.Type: GrantFiled: August 28, 2002Date of Patent: February 22, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaki Tagome, Yasuhiro Kondo
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Publication number: 20040217667Abstract: The present invention relates to a rotor assembly for an electrical machine, comprising: a rotor body of generally cylindrical shape having a substantially cylindrical surface configured for facing an air-gap between the rotor assembly and a stator of the electrical machine, and permanent magnets embedded in said rotor body, wherein grooves are formed in said air-gap facing surface for manipulating the distribution of magnetic flux created by said permanent magnets.Type: ApplicationFiled: January 16, 2004Publication date: November 4, 2004Inventor: Vladimir Vladimirovich Popov
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Patent number: 6812609Abstract: An electric machine with a rotor and a stator, in which electric coils and permanent magnets are disposed. These coils and magnets influence each other when the rotor revolves. The magnets are cylindrical and are disposed tangentially on a circumference of the rotor. The coils do not have an iron core and at least one section of the coils extends transversely across the circumference of the rotor. The coils are fitted in the stator individually and are bent so that they extend on both axial sides of the rotor and surround the magnets located in the rotor.Type: GrantFiled: October 23, 2003Date of Patent: November 2, 2004Inventor: Werner Anwander
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Publication number: 20040150283Abstract: A permanent magnet synchronous machine with improved torque and power characteristics. A circumferential-oriented rotor assembly is provided with alternating permanent magnets and magnetic pole pieces. In order to reduce the amount of leakage flux in the rotor and increase the effective length of the permanent magnet, a trapezoidal or otherwise tapered permanent magnet structure is used. By alternating trapezoidal permanent magnet, and magnetic pole pieces, a higher intensity magnetic field is created in the air gap utilizing the same radial space in the motor without altering the weight or volume of the motor compared to conventional machines.Type: ApplicationFiled: January 31, 2003Publication date: August 5, 2004Inventors: Raymond Mark Calfo, Mark Peter Krefta
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Patent number: 6768238Abstract: A rotor for permanent magnet synchronous machines with a reduction in the stray flux transmitted through the rotor shaft includes substantially ring-shaped punched sheet metal plates with a central opening for receiving the rotor shaft, and a plurality of recesses arranged in the circumferential direction, wherein at least two permanent magnets can be inserted in each of the recesses. A corresponding intermediate sheet metal segment is arranged or can be arranged in each of the recesses between the permanent magnets. At least one of the recesses is shaped so as to form an air gap between the surface of the intermediate sheet metal segment that is oriented radially inwardly towards the center and an edge of the recess that is oriented radially outwardly from the center, when the permanent magnets are inserted radially towards the outside. The air gap aids in attenuating the stray flux.Type: GrantFiled: October 31, 2002Date of Patent: July 27, 2004Assignee: Siemens AktiengesellschaftInventors: Axel Knauff, Rolf Vollmer
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Publication number: 20040119356Abstract: An electric machine with a rotor and a stator, in which electric coils and permanent magnets are disposed. These coils and magnets influence each other when the rotor revolves. The magnets are cylindrical and are disposed tangentially on a circumference of the rotor. The coils do not have an iron core and at least one section of the coils extends transversely across the circumference of the rotor. The coils are fitted in the stator individually and are bent so that they extend on both axial sides of the rotor and surround the magnets located in the rotor.Type: ApplicationFiled: October 23, 2003Publication date: June 24, 2004Inventor: Werner Anwander
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Patent number: 6741010Abstract: A rotor disc (14), for use in an electrical machine (10), has at least one circumferential rotor rim (16) mounted thereon. The rotor rim (16) comprises at least one row of alternate magnets (20) and laminated pole pieces (18). The laminations in each pole piece (18) are mounted concentrically on a bolt (22) that extends through the rotor disc (14). A clearance (23) is provided between the laminations in each pole piece (18) and the bolt (22). The clearance (23) insulates the bolt (22) from the laminated pole pieces (18), which are made from a ferromagnetic material such as silicon-iron alloy, to minimize power losses due to eddy currents.Type: GrantFiled: January 8, 2001Date of Patent: May 25, 2004Assignee: Rolls Royce PLCInventor: Geoffrey A Wilkin
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Publication number: 20040095033Abstract: Rotor assembly for an electrical machine, including a body of generally cylindrical shape having an inner opening, wherein slots are provided in the body, the slots extending from the inner opening towards the outer periphery of the body; permanent magnets disposed in said slots; wherein at least one of the slots comprises an end section near the outer periphery of the body having an area of enlarged width.Type: ApplicationFiled: August 6, 2003Publication date: May 20, 2004Inventor: Vladimir Vladimirovich Popov
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Patent number: 6713923Abstract: 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: GrantFiled: July 30, 2002Date of Patent: March 30, 2004Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Haruyoshi Hino, Shinya Naito
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Patent number: 6703746Abstract: An electric traction motor for a vehicle including a housing, a wound stator field located in the housing, a rotor magnetically interacting with the wound stator field, high energy magnets configured in the rotor, and low energy magnets configured in the rotor.Type: GrantFiled: March 1, 2002Date of Patent: March 9, 2004Assignee: General Motors CorporationInventors: Francois J. Biais, Khwaja M. Rahman
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Patent number: 6570288Abstract: An outer rotor type brushless direct current motor has an outer rotor including a plurality of permanent magnets attached along the inner circumference of an annular yoke such that the magnetic poles face the S magnetic poles. Thin sections are formed by chamfering the radially outer periphery of the two end sections in the circumferential direction of each of the permanent magnets. Magnetic flux passage sections of the yoke providing connection between the thin sections of adjacent permanent magnets are expanded radially inwards. In accordance with the above-mentioned arrangement, the cross section of the magnetic path in the magnetic flux passage sections is increased, thereby suppressing the occurrence of magnetic saturation and preventing the maximum torque of the permanent magnets from decreasing while reducing their size. Moreover, because the magnetic flux passage sections of the yoke are expanded radially inwards, the external dimensions of the yoke do not increase.Type: GrantFiled: June 13, 2001Date of Patent: May 27, 2003Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Masaaki Kaizuka, Kazuma Okuda, Kazunari Takahashi, Masaharu Hosoda
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Patent number: 6555940Abstract: To decrease torque ripples and cogging torque, a rotor for an electrical motor, an electrical generator, or the like, includes lengths of permanent magnets embedded in a plurality of slit sections in respective layers. In an embodiment having three layers, the permanent magnets have lengths L1, L2 and L3 in order as viewed from the outside circumference side of the rotor core and generate respective total magnetic fluxes of &PHgr;1, &PHgr;2, &PHgr;3, respectively, when the rotor is assembled in a rotary electric device. The lengths have a relation L1<L2<L3, and the magnetic fluxes have a relation &PHgr;1<&PHgr;2<&PHgr;3.Type: GrantFiled: August 30, 2001Date of Patent: April 29, 2003Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Shinya Naito, Haruyoshi Hino
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Patent number: 6472789Abstract: The invention relates to an electric rotary machine having a stator with several slots for receiving field coils and a rotor having excitation means with main permanent magnets housed in a rotor structure to define a plurality of successive North and South poles (N. S.). The invention is characterized in that the rotor structure has a plurality of barrier zones substantially impermeable to the magnetic current which are arranged with respect to the main magnets such that a substantial part of a magnetic current input in a main magnet is derived at least from one South pole and adjacent to the magnet and a substantial part of a magnetic current output by one magnet is directed toward at least one North pole adjacent to the magnet. Thus, the invention provides a lighter, less costly and more efficient rotor. The invention is applicable to starters or AC-starters for motor vehicles.Type: GrantFiled: April 20, 2001Date of Patent: October 29, 2002Assignee: Valeo Equipement Electriques MoteurInventor: Antoine Dokou Akemakou
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Patent number: 6384504Abstract: An electric machine comprising a stator and a rotor (2) separated by an air gap (12), (a) the rotor (2) being composed with permanent magnets (8) magnetized substantially in circumferential direction, and with one magnetic flux conducting piece assembly (10) of at least one magnetic flux conducting piece (10a; 10b) between two adjacent permanent magnets each; (b) the permanent magnets (8)—when looking at the overall geometry—each having an increasing circumferential width from the head portion on the side of the air gap to the foot portion; (c) and the conducting piece assemblies (10) between two adjacent permanent magnets (8)—when looking at the overall geometry—each having a decreasing circumferential width from the head portion on the side of the air gap to the foot portion, characterized in (d) that the conducting pieces (10a; 10b) at the foot end each have a widened portion in circumferential direction, having at least one shoulder (20) through which they are supported on an aType: GrantFiled: February 28, 2000Date of Patent: May 7, 2002Assignee: Magnet-Motor Gesellschaft für magnetmotorische Technik mbHInventors: Peter Ehrhart, Gerhard Reiner, Ludwig Lindner, Christian Lucas, Fritz Walter
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Publication number: 20020047433Abstract: Rotary synchronous machine includes a stator and a rotor. The stator includes a magnetic field core and an armature core magnetically separated from each other. The rotor includes a plurality of magnetic substance segments which are magnetically separated from each other in a direction of rotation but are magnetically coupled with both of the magnetic field core and armature core. The rotor and magnetic field core are arranged to cause an axial thrust to the rotor depending on the intensity of electric currents passed through filed windings. Namely, the rotor and magnetic field core are arranged in such a manner that magnetic attraction (magnetic coupling) occurs between the rotor and the magnetic field core in a same direction as a rotational axis or at a predetermined non-normal angle relative to the rotational axis. Thus, thrust is produced based on the magnetic attraction between the rotor and the magnetic field core.Type: ApplicationFiled: July 28, 1999Publication date: April 25, 2002Inventors: TOKUZOU SEKIYAMA, SATORU MATSUBARA, SATOSHI NISHIDA, HIROSHI SHIBUYA
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Patent number: 6342745Abstract: A reluctance type rotating machine includes a stator 1 having armature windings 2 arranged on an inner periphery of the stator 1, a rotor 3 having a magnetic unevenness in the circumferential direction and a plurality of permanent magnets 6 arranged for negating the armature windings' flux passing between adjoining poles. Each magnet 6 is magnetized in a direction different from a direction to facilitate the rotor's magnetization. A magnetic portion 7 is provided between the pole and the interpole of the rotor 3. Owing to the provision of the magnetic portion 7, when the armature windings are not excited, more than 30% of the permanent magnets' flux is distributed in the rotor 3 Similarly, when the machine is loaded, the permanent magnets' interlinkage flux is more than 10% of composite interlinkage flux composed of armature current and the permanent magnets.Type: GrantFiled: September 13, 2000Date of Patent: January 29, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Kazuto Sakai, Masanori Arata, Mikio Takabatake, Yoshio Hashidate, Ryoichi Kurosawa, Yosuke Nakazawa, Tadashi Tokumasu
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Patent number: 6323572Abstract: To obtain the magnetic flux increase of the air gap, a radial slit for inserting a magnet is provided in a respective pole iron core, and the length of the magnet is adjusted to a radial direction and to an axial direction. In particular, when it is desired to strengthen the magnetic flux, a strong magnetic flux magnet and a magnet which is inserted fully into the slit are used. Further, forming an attachment and detachment structure, it is possible to carry out easily the alternation and the adjustment of the characteristics of a magnet type electric motor and a generator.Type: GrantFiled: November 17, 1999Date of Patent: November 27, 2001Inventor: Yukio Kinoshita
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Patent number: 6268677Abstract: A rotor is provided for a permanent magnet type rotating machine having a stator 1 with armature windings 11. The rotor 3 includes a rotor core 31 and a plurality of permanent magnets 32 arranged in the rotor core 31 so as to negate magnetic flux of the armature windings 11 passing through interpoles 3b. The rotor 3 is constructed so that the average of magnetic flux in an air gap 2 between the rotor 3 and the stator 1, which is produced by the permanent magnets 32 at the armature windings' de-energized, ranges from 0.1 [T] to 0.7 [T] and the ratio (Lq/Ld) of self-inductance of the magnetic portion in a hard-magnetizing direction (q-axis) to self-inductance in an easy-magnetizing direction (d-axis) under a rated load condition ranges from 0.1 to 0.8. Under these conditions, it is possible to realize the rotating machine which operates as an induction machine at the machine's starting and also operates as an synchronous machine at the rated driving due to smooth pull-in.Type: GrantFiled: March 29, 2000Date of Patent: July 31, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Mikio Takabatake, Masanori Arata, Kazuto Sakai, Yutaka Hashiba, Yoshio Hashidate, Norio Takahashi, Koji Oishi, Shiro Amemori