Specific Magnetization Patents (Class 310/156.43)
  • Patent number: 8547086
    Abstract: There is provided a coercivity performance determination device for a coercivity distribution magnet that is capable of determining, in a short period of time, with precision, and at as low a testing cost as possible, whether or not each part of one coercivity distribution magnet has a coercivity that is equal to or greater than the required coercivity. A coercivity determining device of the present invention comprises: a substantially C-shaped magnetic body; excitation means that generates a magnetic flow in the magnetic body; and a flux meter that measures the residual magnetic flux of the coercivity distribution magnet. Protrusions are provided at corresponding positions on two opposing end faces of the magnetic body, and the coercivity distribution magnet is held between the two protrusions to form an annular magnetic circuit. An external magnetic field generation means is formed by magnetic regions caused by the protrusions and non-magnetic regions comprising the air in the periphery thereof.
    Type: Grant
    Filed: August 11, 2010
    Date of Patent: October 1, 2013
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Masafumi Suzuki, Mayumi Nakanishi
  • Publication number: 20130241324
    Abstract: A rotor includes a shaft and a plurality of permanent magnets which are arranged around the shaft in a circumferential direction for permanent excitation. At least one of the permanent magnets is attached to the shaft by a material joint or formfit. A flux conducting device for conducting a magnetic flux of the permanent magnets has a plurality of separate soft-magnetic flux conducting elements, with each flux conducting element being mounted between two of the permanent magnets and fixed thereto so as to be indirectly held in place on the shaft. At least one of the flux conducting elements has at least one contact area sized to cover an outer edge of one of the permanent magnets in the radial direction.
    Type: Application
    Filed: March 15, 2013
    Publication date: September 19, 2013
    Applicant: Siemens Aktiengesellschaft
    Inventors: Daniel Mader, Rolf Vollmer
  • Publication number: 20130234556
    Abstract: Rotor formed by groups of materials (4) that orientate the magnetic field and magnets (2) in spiral lines, with the two magnetic poles of each magnet (2) facing the stator (3). Close to a magnetic pole of the end of the group, the material (4) that orientates the magnetic field protrudes towards the stator (3). This configuration enables to vary the field of each magnetic pole of the rotor which is projected to the stator; in this way, one end of the group of magnets (2) concentrates a very close magnetic pole in order to interact with the stator (3) and the opposite magnetic pole moves away gradually in order to decrease the interaction with the stator (3). The application is for magnetic motors.
    Type: Application
    Filed: April 23, 2013
    Publication date: September 12, 2013
    Inventor: Ramon FREIXAS VILA
  • Patent number: 8513849
    Abstract: A Halbach array is radially disposed in an environment optimized for efficiency and controlled for efficient generation and use of power in order to generate, establish, and maintain a desired level of rotational energy with enhanced efficiency and in order to make the most efficient use of electromotive forces and magnetic fields which are either intentionally created for the operation of the apparatus or which result from the operation of the apparatus.
    Type: Grant
    Filed: November 13, 2011
    Date of Patent: August 20, 2013
    Inventors: Martin Epstein, Jon Eric Harms
  • Patent number: 8497613
    Abstract: A manufacturing method for a permanent magnet includes the steps of a) producing a permanent magnet (1), b) fracturing the permanent magnet (1) to obtain two or more separate pieces (13), and c) restoring the permanent magnet (1) by fitting the fracture surfaces of adjacent separate pieces (13) together.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: July 30, 2013
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenji Nakamura, Shigeto Takeuchi, Keiu Kanada, Masafumi Suzuki, Tomonari Kogure
  • Patent number: 8493062
    Abstract: According to the present invention, a method for determining coercivity of a coercivity distribution magnet, whereby coercivity of each portion in the coercivity distribution magnet can be determined with good accuracy without, for example, cutting the coercivity distribution magnet into pieces and thus quality assurance can be achieved with good accuracy, is provided.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: July 23, 2013
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Tomonari Kogure, Mayumi Nakanishi
  • Patent number: 8456043
    Abstract: A permanent magnet rotor of a brushless direct current (BLDC) motor, in which cogging torque ripple and electromagnetic vibration noise transferred to the permanent magnet rotor can be blocked and a motor's power-to-weight ratio can be improved. A conventional BLDC motor has to use an electric steel sheet core so as to maintain the maximum magnetic flux density of the permanent magnet rotor and to minimize a rotating electric field loss. As a result, cogging torque vibration is unavoidably transferred to a load side through the motor rotary shaft. However, the rotor can enable stable driving of the BLDC motor by innovatively blocking the cogging torque vibration and the electromagnetic vibration noise and can greatly reduce the motor's weight by using a plastic or non-magnetic material instead of an electric steel sheet core.
    Type: Grant
    Filed: May 17, 2010
    Date of Patent: June 4, 2013
    Inventor: Young-Chun Jeung
  • Publication number: 20130127285
    Abstract: Provided is a means for mitigating strict constraints between a virtual polyhedron inscribed in a rotor and a virtual polyhedron inscribed in a stator of a spherical stepping motor and a spherical AC servo motor and drastically increasing the degree of freedom in design. The above problem is solved by disposing permanent magnets at points of division of the sides of the virtual polyhedron inscribed in the rotor and electromagnets at points of division of the sides of the virtual polyhedron inscribed in the stator.
    Type: Application
    Filed: July 11, 2011
    Publication date: May 23, 2013
    Inventor: Tomoaki Yano
  • Patent number: 8446054
    Abstract: A periodic magnetic field generation device is provided with a field pole of a Halbach array structure in which main pole permanent magnets magnetized in a direction of a generated field and sub pole permanent magnets magnetized in a direction opposite to the direction of magnetic poles of the main pole permanent magnets are alternately disposed linearly or circularly so as to be adjacent to each other. A part of each of the main pole permanent magnets on a side on which the magnetic field is generated is replaced by a soft magnetic member, and a relation between a length A of the soft magnetic member on the side of the generated field along a moving direction and a length B of each main pole permanent magnet on a side of a back yoke along the moving direction is A<B.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: May 21, 2013
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Akihito Toyota, Toru Shikayama, Masanobu Kakihara
  • Publication number: 20130119808
    Abstract: A rotary unit of a motor includes a shaft, a ring-shaped plate, a rotor core defined by a plurality of core pieces, and a plurality of magnets arranged along the circumferential direction. The core pieces and the magnets are alternately arranged in the circumferential direction. The ring-shaped plate and the respective core pieces are fixed to each other by combining the recesses provided in one of the ring-shaped plate and the respective core pieces and the protrusions provided in the other of the ring-shaped plate and the respective core pieces or combining a first through-hole provided in the ring-shaped plate and a protrusion provided in each of the core pieces. The core pieces are fixed to the ring-shaped plate without having to provide a through-hole in each of the core pieces. This reduces a magnetic resistance of each of the core pieces.
    Type: Application
    Filed: October 22, 2012
    Publication date: May 16, 2013
    Applicant: NIDEC CORPORATION
    Inventor: Nidec Corporation
  • Publication number: 20130119790
    Abstract: An electric motor has a wound stator and a permanent magnet rotor. The rotor has a plurality of rotor core portions and a plurality of permanent magnets, the rotor core portions and the permanent magnets being arranged alternately in a circumferential direction of the rotor. The permanent magnets are made of material containing ferric oxide and polarized generally in the circumferential direction of the rotor. The motor may be used in a power tool or a lawn mower.
    Type: Application
    Filed: November 9, 2012
    Publication date: May 16, 2013
    Applicant: JOHNSON ELECTRIC S.A.
    Inventor: Johnson Electric S.A.
  • Publication number: 20130119809
    Abstract: A direct-drive brushless DC motorization apparatus comprises an outer rotor with poles constructed with segments of permanent magnet material alternatively magnetized north and south. The outer rotor is adapted to be part of a wheel and rotating with the wheel about an axis thereof. A stator core of ferromagnetic material is spaced inwardly of said rotor to define a clearance gap with the rotor such that the rotor is rotatable about the stator core. The stator core has forty-two slots and defines teeth therebetween. A three-phase winding with coils of insulated wire is wound around the teeth of the stator core. The three-phase winding is divided in two sets of consecutive teeth for each of the three phases, with each of the two sets of a same phase being diametrically opposed in the stator core.
    Type: Application
    Filed: July 20, 2011
    Publication date: May 16, 2013
    Applicant: BIONX INTERNATIONAL INC
    Inventors: Daniel Levesque, Jerome Cros
  • Patent number: 8432080
    Abstract: This invention provides a rotating electrical machine including a rotor that has an even number of first permanent magnets aligned in a circumferential direction of the rotor, second permanent magnets of a number equal to that of the first permanent magnets, provided respectively between the stator and circumferential ends of the first permanent magnets adjacent to each other in the circumferential direction, and core pieces of a number equal to that of the first permanent magnets, provided respectively between the second permanent magnets adjacent to each other in the circumferential direction.
    Type: Grant
    Filed: August 10, 2010
    Date of Patent: April 30, 2013
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Souji Murakami, Motomichi Ohto, Haruki Yahara, Shinichi Nishi
  • Patent number: 8421293
    Abstract: Improvement of torque densities, miniaturization and weight saving for outer rotor type motors or permanent-magnet-field-type DC motors can be efficiently achieved by high-energy densification of a magnet. However, torque pulsation or armature reaction gives negative influences thereto. Further, in application of a slotless (coreless) structure eliminating the torque pulsation or the armature reaction, the magnetic resistance of motor magnetic circuits will be enhanced. For solving the above problems, there is provided an annular magnet that is opened in a reverse direction relative to the opening direction of a U-shaped segment fabricated in constantly-directed magnetic fields, the annular magnet having an anisotropic distribution where angles relative to inner peripheral tangent lines can be continuously changed in the range of approximately 0 to 90 degrees, and having energy density (BH)max of 160 to 186 kJ/m3.
    Type: Grant
    Filed: July 16, 2008
    Date of Patent: April 16, 2013
    Assignee: Minebea Co., Ltd.
    Inventor: Fumitoshi Yamashita
  • Patent number: 8421292
    Abstract: A permanent magnet motor includes: a rotor and a stator; and a plurality of permanent magnets placed on either the rotor or the stator. Each permanent magnet is an R—Fe—B based rare-earth sintered magnet including a light rare-earth element RL (at least one of Nd and Pr) as a major rare-earth element R, and partially includes a high coercivity portion in which a heavy rare-earth element RH (at least one element selected from the group consisting of Dy, Ho and Tb) is diffused in a relatively higher concentration than in the other portion.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: April 16, 2013
    Assignee: Hitachi Metals, Ltd.
    Inventors: Mitsutoshi Natsumeda, Yoshinori Takayama, Motoharu Shimizu
  • Patent number: 8405342
    Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: March 26, 2013
    Assignee: Asmo Co., Ltd.
    Inventors: Yoji Yamada, Shinji Santo, Seiya Yokoyama, Yoko Tateishi, Yoshiaki Takemoto, Shigemasa Kato
  • Patent number: 8400038
    Abstract: Numerous arrangements for permanent magnets are disclosed that can focus the flux produced by the magnets. Depending on the particular application in which the disclosed designs and techniques are used, efficiency and reliability may be increased by minimizing flux leakage, increasing peak flux density, and shaping the flux fields to improve the effective coercivity of the flux focusing permanent magnet arrangement when loaded, and to achieve customized voltage and current waveforms. The disclosed magnet assemblies may be incorporated into a machine, such as a motor/generator, having windings and may be disposed for movement relative to the windings. The magnet assembly may be mounted on a support formed of one or more ferromagnetic materials, such as a back iron The disclosed flux focusing magnet assemblies may be formed using a variety of manufacturing methods.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: March 19, 2013
    Assignee: Boulder Wind Power, Inc.
    Inventors: James S. Smith, Robert Pillsbury, Brian Sullivan
  • Publication number: 20130062985
    Abstract: A brushless DC motor including a rotor capable of minimizing demagnetization of a magnet even when a short-circuit brake operation is performed by short-circuiting motor coils includes two kinds magnets differing in coercive force from each other which are alternately arranged into an annular shape along a circumferential direction. A magnet having a high coercive force is arranged in the portion where a diamagnetic flux is strongly generated. The portion where a diamagnetic flux is generated is the salient pole portion of a stator. A counter electromotive force becomes greatest when the center of the salient pole portion of the stator comes closer to the border of an N-pole and an S-pole of the magnet. Since the diamagnetic flux has a maximum value in that position, the magnet having a high coercive force is arranged near the border of an N-pole and an S-pole.
    Type: Application
    Filed: August 21, 2012
    Publication date: March 14, 2013
    Applicant: NIDEC SERVO CORPORATION
    Inventors: Motoi JIN, Takaya KATO, Osamu SEKIGUCHI, Shoji OIWA
  • Publication number: 20130049513
    Abstract: A permanent magnet machine includes a stator having a stator core, a plurality of stator teeth and plurality of stator windings coupled to the stator core. The stator is configured to generate a stator magnetic rotating field when the stator windings are excited with an electric current. The stator magnetic rotating field includes both synchronous sub-harmonic and super-harmonic components. The permanent magnet machine also includes a rotor that is disposed within the stator. The rotor includes a rotor core and a plurality of rotor magnets that are coupled to the rotor core. The rotor magnets are further configured to have a predefined orientation profile such that when the stator windings are excited with an electric current, sub-harmonic and super-harmonic magnetic rotating fields are generated in the rotor magnetic field.
    Type: Application
    Filed: August 30, 2011
    Publication date: February 28, 2013
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Ayman Mohamed Fawzi EL-Refaie, James Pellegrino Alexander, Patel Bhageerath Reddy, Manoj Ramprasad Shah
  • Patent number: 8373848
    Abstract: A lithographic apparatus includes an actuator for producing a force in a first direction between a first and a second part including a first magnet assembly and a second magnet assembly each attached opposite to each other to the first part of the apparatus, the first magnet assembly including a first main magnet system and a first subsidiary magnet system, and the second magnet assembly including a second main magnet system and a second subsidiary magnet system, the first and second main magnet system defining a space between them in a second direction perpendicular to the first direction. The actuator includes a coil attached to the second part. The distance between at least a part of the first subsidiary magnet system and at least a part of the second subsidiary magnet system is smaller than the minimum distance between the first main magnet system and the second main magnet system.
    Type: Grant
    Filed: October 6, 2009
    Date of Patent: February 12, 2013
    Assignee: ASML Netherlands B.V.
    Inventors: Fidelus Adrianus Boon, Hendrikus Pascal Gerardus Johannes Van Agtmaal
  • Patent number: 8354766
    Abstract: A permanent magnet motor includes a rotor and a stator, a plurality of permanent magnets forming a plurality of magnetic poles in a core of the rotor and magnetic pole teeth located so as to correspond to phase windings of the stator. The permanent magnets include a plurality of types of permanent magnets having different coercive forces and arranged substantially into an annular shape so that one type of the permanent magnet constitutes each magnetic pole. The permanent magnets each having a relatively smaller coercive force are arranged at a first interval in the rotor, and the magnetic pole teeth corresponding to the same phase windings are arranged at a second interval differing from the first interval in the stator.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: January 15, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Sari Maekawa
  • Publication number: 20120293033
    Abstract: A rotor includes a rotor core with a circumferential surface facing a stator and permanent magnets each received in a corresponding slot of the rotor core. Each of the permanent magnets has a first corner portion positioned closest to the circumferential surface of the rotor core and a first side surface that intersects an imaginary line, faces toward the stator side and makes up part of the first corner portion. The imaginary line extends in the magnetization direction of the permanent magnet through the center of the permanent magnet. Between the first side surface of the permanent magnet and the inner surface of the corresponding slot, there are formed a first gap, a second gap and an abutment area from the first corner portion side in this order. The first gap has a smaller width than the second gap in a direction perpendicular to the first side surface.
    Type: Application
    Filed: May 18, 2012
    Publication date: November 22, 2012
    Applicant: DENSO CORPORATION
    Inventor: Tomokazu HISADA
  • Patent number: 8304949
    Abstract: A magnet pole portion 31 is made up of an integral magnet 44 into which are integrated a main permanent magnet piece 41 which is magnetized in the direction of a rotational axis, a pair of auxiliary permanent magnet pieces 42, 42 which are disposed at circumferential sides on one side of the main permanent magnet piece 41 with respect to the direction of the rotational axis, which are each magnetized in the direction of the rotational axis and a direction which is at right angles to a radial direction and on which magnetic poles face each other which are the same as a magnetic pole on the one side of the main permanent magnet piece 41 with respect to the direction of the rotational axis, and a pair of auxiliary magnet pieces 43, 43 which are disposed at circumferential sides on the other side of the main permanent magnet piece 41 with respect to the direction of the rotational axis, which are each magnetized in the direction of the rotational axis and a direction which is at right angles to a radial direction
    Type: Grant
    Filed: November 20, 2009
    Date of Patent: November 6, 2012
    Assignee: Honda Motor Co., Ltd.
    Inventor: Keiichi Yamamoto
  • Patent number: 8299672
    Abstract: A flux-focused, shaped permanent magnet includes a body of magnetic material having multiple surface contouring to form a reduced flux side with convex surfaces and an increased flux side with concave surfaces. The surfaces develop high and low resistance external flux paths creating focused asymmetric flux fields. A magnetic unit having the shaped permanent magnet and a magnetic flux attracter or two shaped permanent magnets interconnected by two segmented permanent magnets and a kinetic device having a stationary stator ring, a rotor disc rotating within the stator ring and a multiplicity of the magnetic units on the stator ring and the rotor disc, are also provided.
    Type: Grant
    Filed: June 24, 2011
    Date of Patent: October 30, 2012
    Inventor: W. Thomas McClellan
  • Patent number: 8294316
    Abstract: An electrical power generation apparatus is embedded in a contra-rotating propulsion system that includes overlapping first and second shafts operatively connected for counter-rotation about a common axis. The electrical power generation apparatus includes a winding mounted to one of the shafts and a field array mounted to the other of the shafts adjacent to the winding. Relative rotation of the winding and the field array induces electrical current in the winding.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: October 23, 2012
    Assignee: Rolls-Royce North American Technologies, Inc.
    Inventors: Mark J. Blackwelder, John Timothy Alt, Steven Gagne, Daniel Kent Vetters
  • Patent number: 8288908
    Abstract: A reconfigurable electric motor includes a rotor containing rotatable permanent magnets or non-magnetically conducting shunting pieces. The magnets and/or shunting pieces have a first position producing a weak magnetic field for asynchronous induction motor operation at startup and a second position producing a strong magnetic field for efficient synchronous operation. The motor includes a squirrel cage for induction motor operation at startup with the permanent magnets and/or shunting pieces positioned to product the weak magnetic field to not interfere with the startup. When the motor approaches or reaches synchronous RPM, the permanent magnets and/or shunting pieces rotate to produce a strong magnetic field for high efficiency synchronous operation.
    Type: Grant
    Filed: October 15, 2010
    Date of Patent: October 16, 2012
    Inventors: Louis J. Finkle, Andrea Furia
  • Patent number: 8278794
    Abstract: The rotor 11 of an axial gap type motor 10 is provided with a plurality of main magnets 41 respectively magnetized in an axial direction of a rotational axis and disposed at predetermined intervals in a peripheral direction, a plurality of yokes 42 structured by a laminated member 71 produced by winding a tape-shaped electromagnetic steel plate 60 and respectively disposed on both sides of the main magnets 41 in the axial direction, and a rotor frame 30 made of a die-cast alloy and including a plurality of ribs 31 respectively interposed between the main magnets 41 adjoining each other in the peripheral direction and extending in the radial direction, and an inner cylindrical portion 32 and an outer cylindrical portion 33 respectively formed on the radially inner side of the ribs 31 and on the radially outer side of the ribs 31.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: October 2, 2012
    Assignee: Honda Motor Co., Ltd.
    Inventors: Satoshi Ishikawa, Keiichi Yamamoto, Shoei Abe
  • Patent number: 8269390
    Abstract: A permanent-magnet-type rotating electrical machine capable of realizing variable-speed operation in a wide range from low speed to high speed at high output and improving, in a wide operating range, efficiency, reliability, and productivity. The rotating electrical machine includes a first permanent magnet whose product of coercive force and magnetizing direction thickness is small and a second permanent magnet whose product of coercive force and magnetizing direction thickness is large, to form a magnetic pole. The product of coercive force and magnetizing direction thickness of the first permanent magnet is equal to or larger than the product of magnetic field strength and magnetizing direction thickness of the second permanent magnet at a no-load operating point. At the magnetic pole, a magnetic field created by a current of an armature coil magnetizes the first permanent magnet, irreversibly changing a flux amount of the first permanent magnet.
    Type: Grant
    Filed: February 16, 2009
    Date of Patent: September 18, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuto Sakai, Kazuaki Yuuki
  • Patent number: 8258782
    Abstract: An angle detecting apparatus includes a rotor fixed to a rotating shaft, a pair of magnetic sensors arranged close to the outer periphery of the rotor so as to have a difference in angle (?/2) with respect to the center of rotation of the rotor, a differential operational circuit performing differential operation on detection signals output by the magnetic sensors to output a differential signal, and the angle calculating circuit calculating the angle of rotation of the rotating shaft based on the differential signal. The planar shape of the rotor is such that the sum of the distances between the center of rotation and the respective two points where two straight lines crossing at the center of rotation at a crossing angle of (?/2) cross the outer periphery of the rotor is constant, and the planar shape is symmetric with respect to a straight line passing through the center of rotation.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: September 4, 2012
    Assignee: TDK Corporation
    Inventors: Yoshio Kaita, Hirokazu Miyamoto, Toshinao Kido, Junya Fukuda
  • Publication number: 20120200189
    Abstract: A rotating electrical machine includes a rotor core, a stator core, and at least one permanent magnet. The rotor core has an inner circumference portion and an outer circumference portion. The stator core is opposed to the outer circumference portion of the rotor core. The at least one permanent magnet radially extends inside the rotor core. The at least one permanent magnet has an incremental circumferential width in a direction from the inner circumference portion to the outer circumference portion of the rotor core.
    Type: Application
    Filed: November 8, 2011
    Publication date: August 9, 2012
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventors: Sohji MURAKAMI, Haruki Yahara, Mitsunori Kamo, Motomichi Ohto
  • Patent number: 8227951
    Abstract: In a three-phase permanent-magnet synchronous machine, a pole gap and a skew of permanent magnets on the rotor are designed such that oscillating torques which are caused by the fifth and seventh harmonics of the stator field and of the rotor field are mutually reduced. In particular, the skew can be chosen as a function of the pole gap, such that the majority of the respective oscillating torques is neutralized. This results in minimal torque ripple.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: July 24, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Udo Grossmann, Rolf Vollmer, Michael Zastrow
  • Patent number: 8222787
    Abstract: An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.
    Type: Grant
    Filed: April 1, 2009
    Date of Patent: July 17, 2012
    Assignee: General Electric Company
    Inventors: Ayman Mohamed Fawzi El-Refaie, Patel Bhageerath Reddy
  • Publication number: 20120153763
    Abstract: A synchronous motor which causes decrease in iron loss without increase in copper loss due to increase in q-axis current, and increases efficiency. The synchronous motor includes a rotor, the number of magnetic poles of which is changeable. The magnetic poles of the rotor include permanent magnets and electromagnets having changeable polarity, and the number of the magnetic poles of the rotor is changed by changing a current flow direction of the electromagnets.
    Type: Application
    Filed: December 5, 2011
    Publication date: June 21, 2012
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Kitajima KENJI
  • Patent number: 8198774
    Abstract: A motor includes: a stator (12) having coils; a rotor (11), which is disposed inside the stator and has a plurality of magnets; and a magnetic path switching part (18), which is provided in the rotor (11) and switches a magnetic path of the rotor (11) to select intense field control as a forward salient-pole structure or weak field control as an inverse salient-pole structure. The magnetic path switching part (18) is formed by use of a member having magnetic anisotropy, which is arranged on a magnetic path connecting magnets (13) of the same pole and a magnetic path connecting magnets (13) of different poles in the rotor (11). By changing the magnetic anisotropy of the member, the forward salient-pole structure and the inverse salient-pole structure are switched therebetween.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: June 12, 2012
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Hiroshi Takashima, Yuki Nakajima
  • Patent number: 8183731
    Abstract: A Halbach array is radially disposed in an environment optimized for efficiency and controlled for efficient generation and use of power in order to generate, establish, and maintain a desired level of rotational energy with enhanced efficiency.
    Type: Grant
    Filed: July 16, 2009
    Date of Patent: May 22, 2012
    Inventors: Martin Epstein, Jon Eric Harms
  • Patent number: 8183732
    Abstract: To improve tranquility and controllability of an iron core-equipped permanent magnet motor with an improved maximum energy product (BH)max by improving shape compatibility of a radial anisotropic magnet, there is provided a radial anisotropic magnet manufacturing method of fixing magnet powder in a net shape so as to maintain a magnetic anisotropic (C-axis) angle of a magnet with respect to a tangential line and for performing a deformation with a flow so as to have a predetermined circular arc shape or a predetermined annular shape. Particularly, by performing a deformation with a viscous flow or an extension flow, a deformability of the magnet is improved, and thus shape compatibility with respect to a thickness is. improved. A C-axis angle ? with respect to a tangential direction is controlled at an arbitrary position and an arbitrary angle so as to reduce cogging torque without separating a magnetic pole into segments.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: May 22, 2012
    Assignee: Panasonic Corporation
    Inventors: Fumitoshi Yamashita, Hiroshi Murakami, Kiyomi Kawamura
  • Patent number: 8179009
    Abstract: A rotor for an electrical machine includes a rotor hub and a plurality of permanent magnet segments affixed around a perimeter of the rotor hub. A first plurality of the permanent magnet segments have a substantially uniform arcuate span and are formed of a single unitary piece of material. A multi-piece permanent magnet segment includes at least two pieces, each having a smaller arcuate span than the first plurality of segments. The magnetization direction vector of one piece different than the magnetization direction vector of at least one other piece in each multi-piece segment.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: May 15, 2012
    Assignee: Direct Drive Systems, Inc.
    Inventor: Daniel M. Saban
  • Publication number: 20120091848
    Abstract: An increase of the magnetization current can be prevented 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), a variable magnetic force magnet (3) and a fixed magnetic force magnet (4). A variable magnetic force magnet (3) and a fixed magnetic force magnet (4a) are overlapped in the magnetization direction thereof to form a series of magnets. The series of magnets is located within the rotor core at a position where the magnetization direction is in the direction of a d-axis. On either side of the series of magnets of the variable magnetic force magnet (3) and the fixed magnetic force magnet (4a), fixed magnetic force magnets (4b, 4b) are located at a position where the magnetization direction is in the direction of the d-axis.
    Type: Application
    Filed: November 19, 2009
    Publication date: April 19, 2012
    Applicant: Kabushkiki Kaisha Toshiba
    Inventors: Kazuto Sakai, Yutaka Hashiba, Norio Takahashi, Kazuaki Yuuki
  • Publication number: 20120080972
    Abstract: There is provided a sintered magnet that is capable of, as compared to conventional divided magnets, significantly reducing eddy loss, flexibly accommodating diverse shape and dimensional variations, and significantly lowering productions costs while maintaining the desired coercivity, as well as a method of producing same. It is a sintered magnet 10 in which one kind of base magnet 1 of an identical shape or a plurality kinds of base magnets 1 . . . with varying shapes that is/are in the shape of a rectangular cuboid or cube whose edges are each in the range of 1 to 10 mm in length are plurally provided side by side in each of a longitudinal direction and transverse direction forming a plane and a height direction that is orthogonal to this plane, and the magnetic force between at least adjacent base magnets 1, 1 maintains the joint between the base magnets 1, 1.
    Type: Application
    Filed: June 24, 2009
    Publication date: April 5, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Keiu Kanada
  • Patent number: 8148865
    Abstract: Movement of magnets due to centrifugal force is restricted. In a permanent magnet rotating electrical machine 100 having a stator 1 and a rotor core 5 provided with a plurality of permanent magnets 3 inserted in an outer circumferential portion of the rotor 5, each permanent magnet 3 has inclined surfaces on the outer circumferential side of the rotor 2 and the thinnest portions of the inclined surfaces are adjacent to permanent magnets of the opposite polarity. Further, each magnet 3 has a convex-shaped cross section and is divided into two magnet segments 3, 3. A magnetic pole bridge 15 is formed at the boundary of the permanent magnet segments 3, 3. Thus, movement of the permanent magnet segments 3, 3 due to centrifugal force is firmly restricted, and the peeling off of the rotor core 5 and the permanent magnet segments 3, 3 from each other is prevented.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: April 3, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Kimura, Daisuke Kori, Hiroyuki Mikami, Seikichi Masuda, Masayasu Fujieda
  • Publication number: 20120038236
    Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.
    Type: Application
    Filed: October 24, 2011
    Publication date: February 16, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Masashi Kitamura, Noriaki Hino, Takashi Kobayashi, Shigeru Kakugawa, Takashi Yasuhara
  • Patent number: 8102090
    Abstract: A first member (40a) has a magnet assembly (20) that includes a plurality of permanent magnets (10) held with their homopoles contacting one another. A second member (50a) includes magnet coils (30), and is designed to be changeable in position relative to the first member. The magnet assembly (20) generates the strongest magnetic field in a magnetic field direction lying in the homopolar contact plane at which the homopoles contact one another, the magnetic field direction being oriented outward from the magnet assembly (20) along the magnetic field direction.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: January 24, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Kesatoshi Takeuchi
  • Patent number: 8097993
    Abstract: Apparatus and method for tuning the magnetic field of brushless motors and alternators to obtain efficient operation over a broad RPM range. The motor or alternator includes fixed windings (or stator) around a rotating rotor carrying permanent magnets. The permanent magnets are cylindrical and have North (N) and South (S) poles formed longitudinally in the cylindrical magnets. The magnets reside in magnetic conducing pole pieces (for example, low carbon or soft steel, and/or laminated insulated layers, of non-magnetizable material). Rotating the cylindrical permanent magnets inside the pole pieces either strengthens or weakens the resulting magnetic field to adjust the motor or alternator for low RPM torque or for efficient high RPM efficiency. Varying the rotor magnetic field adjusts the voltage output of the alternators allowing, for example, a windmill generator, to maintain a fixed voltage output. Other material used in the rotor is generally non-magnetic, for example, stainless steel.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: January 17, 2012
    Inventors: Louis J. Finkle, Andrea Furia
  • Patent number: 8084910
    Abstract: The object of the invention is a rotor for a permanent-magnet synchronous machine in which a pole structure is fitted onto the surface of the rotor body structure facing the air gap. Each of the rotor's pole structures comprises at least one permanent magnet and a shell structure fitted on top of it. According to the invention, an intermediate layer made of magnetic composite is fitted between the permanent magnet and the shell structure.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: December 27, 2011
    Assignee: ABB Oy
    Inventor: Eino Silander
  • Patent number: 8080915
    Abstract: In an embedded magnet motor, radial magnets and first inclined magnets form north poles. The radial magnets and second inclined magnets form south poles. Core sheets each include preformed radial accommodating slots the number of which is expressed by P/2. Some of the preformed radial accommodating slots are short slots and the rest are long slots. The short slots are located at some parts of each radial accommodating slot along the axial direction. Radially inner ends of the short slots restrict the radial magnets from moving radially inward.
    Type: Grant
    Filed: December 7, 2010
    Date of Patent: December 20, 2011
    Assignee: Asmo Co., Ltd.
    Inventors: Takahiro Nakayama, Hirotaka Itoh, Yoshiyuki Takabe
  • Patent number: 8069552
    Abstract: A method of manufacturing a rotor magnet for a micro rotary electric machine is provided which includes steps of: a process in which a plurality of thick films, each of which is made of nanocomposite texture composed of ?Fe and R-TM-B where R is either 10 to 20 atomic % Nd or 10 to 20 atomic % Pr, B is 5 to 20 atomic % and TM is either Fe or partly Co-substituted Fe with 0 to 16 atomic %, are formed into a laminated magnet including isotropic nano-crystalline texture which contains ?Fe and R2TM14B and which has a remanence, Mr, of 0.95 T or more; and a process where the laminated magnet is multi-polar magnetized in-plane of the thick films.
    Type: Grant
    Filed: August 13, 2009
    Date of Patent: December 6, 2011
    Assignee: Minebea Co., Ltd.
    Inventor: Fumitoshi Yamashita
  • Patent number: 8072109
    Abstract: To improve tranquility and controllability of an iron core-equipped permanent magnet motor with an improved maximum energy product (BH)max by improving shape compatibility of a radial anisotropic magnet, there is provided a radial anisotropic magnet manufacturing method of fixing magnet powder in a net shape so as to maintain a magnetic anisotropic (C-axis) angle of a magnet with respect to a tangential line and for performing a deformation with a flow so as to have a predetermined circular arc shape or a predetermined annular shape. Particularly, by performing a deformation with a viscous flow or an extension flow, a deformability of the magnet is improved, and thus shape compatibility with respect to a thickness is improved. A C-axis angle ? with respect to a tangential direction is controlled at an arbitrary position and an arbitrary angle so as to reduce cogging torque without separating a magnetic pole into segments.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: December 6, 2011
    Assignee: Panasonic Corporation
    Inventors: Fumitoshi Yamashita, Hiroshi Murakami, Kiyomi Kawamura
  • Publication number: 20110266894
    Abstract: There is provided the manufacturing method of a laminated magnet film, including the steps of: a first step of preparing a magnet film, 40 ?m to 300 ?m in thickness, provided with a nanocrystalline structure magnetically isotropic; a second step of applying a self-bonding resin composition with film formability on the magnet film preparing a self-bonding magnet film composed of the magnet film and a self-bonding layer; a third step of mechanically processing the self-bonding magnet film being solid or hollow; a fourth step of preparing the laminated magnet film by laminating the self-bonding magnet films; a fifth step of melting the self-bonding layer of the laminated magnet film and then cooling and solidifying the self-bonding layer to integrally rigidify the laminated magnet film; and a sixth step of magnetizing the rigidified laminated magnet film.
    Type: Application
    Filed: April 21, 2011
    Publication date: November 3, 2011
    Applicant: MINEBEA CO., LTD.
    Inventors: Fumitoshi YAMASHITA, Shinsaku NISHIMURA, Noboru MENJO
  • Patent number: 8047816
    Abstract: An electric pump for use with an engine in a vehicle is provided. The electric pump has an impeller having a plurality of blades for moving coolant. A working surface of each blade is formed to be a flat plane which extends generally straight in both an axial direction and a radial direction. The electric pump is formed by a centrifugal pump. When the electric pump is not operating and is used as a portion of a coolant passage, flowing resistance can be reduced as compared with a case where the working surface of each blade is curved.
    Type: Grant
    Filed: September 25, 2007
    Date of Patent: November 1, 2011
    Assignee: Nidec Corporation
    Inventors: Yoshio Fujii, Kenichiro Hamagishi, Toshinobu Shinohara
  • Publication number: 20110260568
    Abstract: Rotor formed by groups of materials (4) that orientate the magnetic field and magnets (2) in spiral lines, with the two magnetic poles of each magnet (2) facing the stator (3). Close to a magnetic pole of the end of the group, the material (4) that orientates the magnetic field protrudes towards the stator (3). This configuration enables to vary the field of each magnetic pole of the rotor which is projected to the stator; in this way, one end of the group of magnets (2) concentrates a very close magnetic pole in order to interact with the stator (3) and the opposite magnetic pole moves away gradually in order to decrease the interaction with the stator (3). The application is for magnetic motors.
    Type: Application
    Filed: July 1, 2011
    Publication date: October 27, 2011
    Inventor: Ramon Freixas Vila