Patents by Inventor Kenji Tomohara
Kenji Tomohara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9231514Abstract: A winding switching signal generator is configured to obtain information indicating a degree of field weakening from at least one of a current command calculator and a constant output controller, and to generate a winding switching signal for switching from a low speed rotation state to a high speed rotation state when the degree of the field weakening exceeds a predetermined condition in the low speed rotation state.Type: GrantFiled: May 16, 2013Date of Patent: January 5, 2016Assignee: KABUSHIKI KAISHA YASKAWA DENKIInventors: Zhenning Chen, Tomohiro Kawachi, Kenji Tomohara, Koji Higashikawa, Masashi Takenouchi
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Patent number: 9166513Abstract: Provided is an inverter apparatus 20 configured to switch a current winding to an optimal winding when a rotation speed of a rotor of an AC electric motor 40 is within a hysteresis region defined by first and second switch timings for switching a state of an armature winding between a first winding and a second winding and when the current winding differs from the optimal winding.Type: GrantFiled: May 16, 2013Date of Patent: October 20, 2015Assignee: KABUSHIKI KAISHA YASKAWA DENKIInventors: Masashi Takenouchi, Tomohiro Kawachi, Kenji Tomohara, Koji Higashikawa
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Patent number: 9041268Abstract: A rotary electric machine includes a rotor core in which first magnetic pole portions having permanent magnets and second magnetic pole portions having no permanent magnets are alternately arranged in a circumferential direction; and a stator core which is arranged to face an outer periphery of the rotor core. The rotor core is configured such that an average gap length between the stator core and the second magnetic pole portions is larger than an average gap length between the stator core and the first magnetic pole portions.Type: GrantFiled: February 13, 2013Date of Patent: May 26, 2015Assignee: KABUSHIKI KAISHA YASKAWA DENKIInventors: Kenji Tomohara, Akihiko Maemura
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Publication number: 20140285055Abstract: A wound member for manufacturing a coil is a wound member for manufacturing a coil for manufacturing a coil wound around a slot of a stator core. The wound member for manufacturing a coil includes: a first side to be an end side at one side of a coil end disposed at an inner peripheral side of the stator core; a second side disposed opposite to the first side, the second side being to be an end side at another side of a coil end disposed at an outer peripheral side of the stator core; and a third side and a fourth side that respectively couple the first side and the second side. The first side has a length shorter than a length of the second side.Type: ApplicationFiled: March 17, 2014Publication date: September 25, 2014Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Kenji TOMOHARA, Akihiko MAEMURA, Takeshi INOUE, Norimasa ADACHI, Junichi YASUKAWA
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Publication number: 20140285056Abstract: A wound member for manufacturing a coil for manufacturing a coil wound around a slot of a stator core, the wound member for manufacturing a coil includes: a first side and a second side disposed opposite one another so as to be end sides of coil ends; and a third side and a fourth side that respectively couple the first side and the second side, wherein at least one of the first side and the second side is wrapped such that a side end at an outer peripheral side is shifted to an outer peripheral side to form a side end at an outer peripheral side to be an approximately flat surface when the first side and the second side become end sides of the coil ends.Type: ApplicationFiled: March 17, 2014Publication date: September 25, 2014Applicant: Kabushiki Kaisha Yaskawa DenkiInventors: Kenji TOMOHARA, Akihiko MAEMURA, Takeshi INOUE, Norimasa ADACHI, Junichi YASUKAWA
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Publication number: 20140285052Abstract: A coil includes: a coil main body in which one coil end in an axial direction is bent to an inner peripheral side of a stator core including a tooth having an protrusion preventing portion configured to prevent the coil from protruding to the inner peripheral side of the stator core; and a relief portion provided for a portion of the coil main body that is bent to the inner peripheral side of the stator core. The relief portion is configured to release the protrusion preventing portion of the tooth when the coil main body is inserted into a slot of the stator core in the axial direction from one coil end in the axial direction that is bent to the inner peripheral side of the stator core.Type: ApplicationFiled: March 19, 2014Publication date: September 25, 2014Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Kenji TOMOHARA, Akihiko MAEMURA, Takeshi INOUE, Norimasa ADACHI, Junichi YASUKAWA
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Publication number: 20140210397Abstract: Provided is an inverter apparatus 20 configured to switch a current winding to an optimal winding when a rotation speed of a rotor of an AC electric motor 40 is within a hysteresis region defined by first and second switch timings for switching a state of an armature winding between a first winding and a second winding and when the current winding differs from the optimal winding.Type: ApplicationFiled: May 16, 2013Publication date: July 31, 2014Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Masashi TAKENOUCHI, Tomohiro KAWACHI, Kenji TOMOHARA, Koji HIGASHIKAWA
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Publication number: 20140197771Abstract: A winding switching signal generator is configured to obtain information indicating a degree of field weakening from at least one of a current command calculator and a constant output controller, and to generate a winding switching signal for switching from a low speed rotation state to a high speed rotation state when the degree of the field weakening exceeds a predetermined condition in the low speed rotation state.Type: ApplicationFiled: May 16, 2013Publication date: July 17, 2014Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Zhenning CHEN, Tomohiro KAWACHI, Kenji TOMOHARA, Koji HIGASHIKAWA, Masashi TAKENOUCHI
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Patent number: 8760026Abstract: A rotor includes first and second permanent magnets provided in each magnetic pole inside a rotor core. The rotor is configured such that when a first end of the first permanent magnet located on the outer circumferential side of the rotor core and the second permanent magnet side is located at a position that faces a first end in the circumferential direction of one of teeth of a stator, a second end of the first permanent magnet located on the axis of rotation side of the rotor core and the second permanent magnet side is located at a position that faces a second end in the circumferential direction of the tooth that faces the first end of the first permanent magnet.Type: GrantFiled: February 29, 2012Date of Patent: June 24, 2014Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Takeo Suzuki, Akihiko Maemura, Yosuke Kawazoe, Yuto Fukuma, Kenji Tomohara
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Patent number: 8427023Abstract: A rotor includes a rotor core; and first and second permanent magnets arranged in the core such that each of the first magnets corresponds to one of the second magnets and, on a cross-sectional plane of the rotor core perpendicular to a rotation axis thereof, a first line passing through the first magnet and a second line passing through the second magnet meet at a point pointing toward the rotation axis. The first and second magnets are arranged such that a straight line interconnecting the rotation axis and the point is interposed therebetween, an angle of the first magnet relative to the straight line being smaller than that of the second magnet relative to the straight line, and a width of the first magnet in the direction parallel to the first line being smaller than that of the second magnet in the direction parallel to the second line.Type: GrantFiled: October 26, 2012Date of Patent: April 23, 2013Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Akihiko Maemura, Kenji Tomohara, Takeo Suzuki
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Patent number: 8319387Abstract: A rotor includes a rotor core; and first permanent magnets and second permanent magnets arranged in the rotor core so that, on a cross-sectional plane of the rotor core perpendicular to the rotation axis thereof, the first and second magnets corresponding to each other define the letter V having an apex pointing toward the rotation axis. The first and second magnets corresponding to each other are arranged so that a straight line interconnecting the rotation axis and the apex of the letter V is interposed therebetween, an angle of the first magnet relative to the straight line being smaller than that of the second magnet relative to the straight line, a width of the first magnet in the direction parallel to the first side of the letter V being smaller than that of the second magnet in the direction parallel to the second side of the letter V.Type: GrantFiled: January 12, 2011Date of Patent: November 27, 2012Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Akihiko Maemura, Kenji Tomohara, Takeo Suzuki
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Publication number: 20120212095Abstract: A rotor includes first and second permanent magnets provided in each magnetic pole inside a rotor core. The rotor is configured such that when a first end of the first permanent magnet located on the outer circumferential side of the rotor core and the second permanent magnet side is located at a position that faces a first end in the circumferential direction of one of teeth of a stator, a second end of the first permanent magnet located on the axis of rotation side of the rotor core and the second permanent magnet side is located at a position that faces a second end in the circumferential direction of the tooth that faces the first end of the first permanent magnet.Type: ApplicationFiled: February 29, 2012Publication date: August 23, 2012Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Takeo SUZUKI, Akihiko MAEMURA, Yosuke KAWAZOE, Yuto FUKUMA, Kenji TOMOHARA
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Patent number: 8102092Abstract: Split cores comprising laminated iron cores each having formed thereon a tooth, and a yoke and a pole piece which are connected to the tooth at both ends thereof, and arranged and connected together into an annular shape to make a stator. Both ends of the yokes and both ends of the pole pieces are displaced in one circumferential direction by laminated iron core from a top laminated layer of the iron cores of the split cores to a bottom laminated layer of the iron cores or split cores.Type: GrantFiled: January 19, 2007Date of Patent: January 24, 2012Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Kenji Tomohara, Seiji Miyazaki, Mitsuhiro Koga, Makoto Matsumoto, Hiroshi Koga, Shinichi Sakamoto
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Publication number: 20110169364Abstract: A rotor includes a rotor core; and first permanent magnets and second permanent magnets arranged in the rotor core so that, on a cross-sectional plane of the rotor core perpendicular to the rotation axis thereof, the first and second magnets corresponding to each other define the letter V having an apex pointing toward the rotation axis. The first and second magnets corresponding to each other are arranged so that a straight line interconnecting the rotation axis and the apex of the letter V is interposed therebetween, an angle of the first magnet relative to the straight line being smaller than that of the second magnet relative to the straight line, a width of the first magnet in the direction parallel to the first side of the letter V being smaller than that of the second magnet in the direction parallel to the second side of the letter V.Type: ApplicationFiled: January 12, 2011Publication date: July 14, 2011Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Akihiko MAEMURA, Kenji Tomohara, Takeo Suzuki
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Publication number: 20090026872Abstract: Although in a conventional permanent magnet type synchronous motor, cogging torque is reduced by displacing permanent magnets of a rotor in a circumferential direction or displacing a stator core in a circumferential direction, since the skew so produced reduces the output of the motor and moreover the winding work of windings cannot be automated to make the resulting motor highly expensive, split cores are provided which solves those problems and enables the winding work of windings to be automated so as to obtain an inexpensive and high-output motor.Type: ApplicationFiled: January 19, 2007Publication date: January 29, 2009Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Kenji Tomohara, Seiji Miyazaki, Mitsuhiro Koga, Makoto Matsumoto, Hiroshi Koga, Shinichi Sakamoto