Patents by Inventor Tomoaki Oikawa

Tomoaki Oikawa 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).

  • Patent number: 10396690
    Abstract: An electric motor includes a stator, a rotor provided to be rotatable with respect to the stator, and a driving circuit board including a power IC applying a driving voltage to the stator, a Hall IC detecting a rotation position of the rotor, and a control IC adjusting a phase of the driving voltage in accordance with a magnetic-pole-position signal from the Hall IC and rotation speed information calculated on the basis of the magnetic-pole-position signal. The Hall IC is provided at a position at which an advance angle is larger than zero when a rotation speed of the rotor is zero.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: August 27, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Junichiro Oya, Tomoaki Oikawa, Mineo Yamamoto, Hiroyuki Ishii, Hiroki Aso, Yuto Urabe, Kazunori Hatakeyama, Takuya Shimomugi
  • Patent number: 10389215
    Abstract: A motor including a rotor, and a stator having a plurality of coils wound around slots, wherein at least any one of the coils includes a single aluminum wire, a single copper wire joined to the aluminum wire, a stranded wire (lead wire) joined to the copper wire, a cold-pressure-welded joint portion (joint portion) joined between the aluminum wire and the copper wire by cold pressure welding, and a non-pressure welded joint portion (joint portion) provided between the copper wire and the stranded wire (lead wire). A burr covered by an insulation member (insulation tube) is provided in the cold-pressure-welded joint portion (joint portion). A thickness of the insulation member (insulation tube) is larger than a height of the burr.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: August 20, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Koji Yabe, Kazuhiko Baba, Takahiro Tsutsumi, Tomoaki Oikawa
  • Publication number: 20190199149
    Abstract: A consequent-pole-type rotor includes a first rotor core having a first insertion hole, and a second rotor core having a second insertion hole, the second rotor core being stacked on the first rotor core such that the first insertion hole and the second insertion hole together form a space accommodating a permanent magnet. The first insertion hole has an opening at a first circumferential position of the first rotor core, and the second insertion hole is occluded at least at a second circumferential position of the second rotor core. The second circumferential position corresponds to the first circumferential position.
    Type: Application
    Filed: June 22, 2016
    Publication date: June 27, 2019
    Inventors: Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE
  • Publication number: 20190181712
    Abstract: A motor includes a stator, and includes a first substrate and a second substrate mounted on the stator. The stator has a stator core in a ring shape and a first coil of a first phase and a second coil of a second phase wound around the stator core. The first substrate includes a first power supply wiring to supply electric power to the first coil. The second substrate has a second power supply wiring to supply electric power to the second coil.
    Type: Application
    Filed: August 4, 2016
    Publication date: June 13, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroki ASO, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Junichiro OYA, Yuto URABE
  • Publication number: 20190157951
    Abstract: A rotor includes a yoke that is formed annularly and a resin magnet integrated with the yoke. The yoke includes a first inner circumferential surface, a second inner circumferential surface, and a third inner circumferential surface. The second inner circumferential surface is adjacent to the first inner circumferential surface, and has a radius larger than a radius of the first inner circumferential surface. The third inner circumferential surface is adjacent to the second inner circumferential surface, and has a radius larger than both of the radius of the first inner circumferential surface and the radius of the second inner circumferential surface.
    Type: Application
    Filed: July 1, 2016
    Publication date: May 23, 2019
    Inventors: Mineo YAMAMOTO, Tomoaki OIKAWA, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE
  • Publication number: 20190115798
    Abstract: A motor includes a rotor having a shaft, a stator provided so as to surround the rotor, a first bearing and a second bearing rotatably supporting the shaft and disposed at a distance from each other in an axial direction of the shaft, a molded resin part covering the stator and having a bearing support part supporting the first bearing, a bracket attached to the molded resin part, supporting the second bearing, and having conductivity, and a conductive member provided in contact with both of the bearing support and the bracket.
    Type: Application
    Filed: July 4, 2016
    Publication date: April 18, 2019
    Inventors: Hiroyuki ISHII, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroki ASO, Junichiro OYA, Yuto URABE
  • Publication number: 20190044399
    Abstract: The rotor of the electric motor includes a rotor magnet. The rotor magnet includes a yoke, and a resin magnet part formed of a resin material containing rare-earth magnetic powder, which is disposed outside the yoke. Multiple pedestals and multiple connecting portions are formed on an end surface of the yoke. The connecting portion joins together the adjacent pedestals. The connecting portions are disposed in a middle position of the end surface in the radial direction. The connecting portions each have a height less than the height of the pedestals. The present invention gains advantage in that the amount of rare-earth magnetic powder used in the rotor magnet can be reduced.
    Type: Application
    Filed: April 27, 2016
    Publication date: February 7, 2019
    Inventors: Mineo YAMAMOTO, Tomoaki OIKAWA, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE
  • Publication number: 20190036385
    Abstract: An electric motor includes an annular stator and a consequent-pole-type rotor including an annular rotor core disposed on the inner side of the stator and a plurality of permanent magnets disposed inside the rotor core and arrayed in a circumferential direction of the rotor core, in which the stator is covered with an unsaturated polyester resin.
    Type: Application
    Filed: April 21, 2016
    Publication date: January 31, 2019
    Inventors: Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE
  • Publication number: 20190028009
    Abstract: A permanent-magnet synchronous motor includes: an annular stator core; a cylindrical rotor disposed inside the stator core, and having a first end face in an axial direction of the stator core and a second end face in the axial direction; a disk-shaped sensor magnet having a plurality of magnetic poles disposed circumferentially, and having a third end face and a fourth end face; and a magnetic sensor disposed so as to be opposed to the fourth end face in the axial direction, and detecting a rotating position of the sensor magnet. When a first thickness means the axial thickness at the center of each of the magnetic poles and a second thickness means the axial thickness of an inter-magnetic-pole portion between adjacent magnetic poles of the magnetic poles, the second thickness is greater than the first thickness.
    Type: Application
    Filed: September 18, 2015
    Publication date: January 24, 2019
    Inventors: Takaya SHIMOKAWA, Kazuhiko BABA, Koji YABE, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Junichiro OYA, Hiroki ASO, Yuto URABE
  • Patent number: 10141811
    Abstract: A stator for an electric motor includes: an annular lead wiring part attached to one axial end of the stator and routing a power lead to a winding of the stator; and a lead-out part provided on the radially outer side of the annular lead wiring part and leading out the power lead to the radial outside of the lead wiring part. The lead wiring part is formed such that the curvature of the inner diameter is different near the lead-out part compared with the remaining portion, and the radius of the inner diameter of the lead wiring part is largest at a portion other than near the lead-out part.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: November 27, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuto Urabe, Tomoaki Oikawa, Mineo Yamamoto, Hiroyuki Ishii, Hiroki Aso, Junichiro Oya, Takaya Shimokawa
  • Patent number: 10135307
    Abstract: An end of each of slits of a rotor on a magnet insertion hole side has a triangular shape. A slit inner-side line of each of the slits includes an apex and a pair of side ends. An interval between each of the pair of side ends and the magnet insertion hole is larger than an interval between the apex and the magnet insertion hole, and an interval between the apex and the magnet insertion hole is larger than a plate thickness of each of steel plates forming a rotor core.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: November 20, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kazuchika Tsuchida, Tomoaki Oikawa, Masahiro Nigo, Naohiro Oketani
  • Publication number: 20180254682
    Abstract: The stator includes a stator core having a first tooth and a second tooth adjacent to each other, a coil having a first winding portion wound around the first tooth and a second winding portion wound around the second tooth, a resin chip disposed in in a gap between the first winding portion and the second winding portion, and a molding resin covering the stator core, the coil, and the resin chip.
    Type: Application
    Filed: December 16, 2015
    Publication date: September 6, 2018
    Inventors: Hiroki ASO, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Junichiro OYA, Yuto URABE
  • Publication number: 20180219438
    Abstract: An electric motor includes a stator and a consequent-pole-type rotor including an annular rotor core disposed on an inner side of the stator and a plurality of permanent magnets disposed inside the rotor core and arrayed in a circumferential direction of the rotor core. The rotor core includes at least one slit provided inside the rotor core and disposed on an outer side of each of the permanent magnets in a radial direction of the rotor core, and at least one slit provided on an outer circumferential surface of the rotor core and disposed between the permanent magnets adjacent to each other.
    Type: Application
    Filed: November 18, 2015
    Publication date: August 2, 2018
    Inventors: Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE, Takaya SHIMOKAWA, Koji YABE
  • Publication number: 20180212480
    Abstract: A stator includes a plurality of winding sections circumferentially disposed at an equal interval; a spacer inserted into a space between the winding sections; and a resin section filling the space into which the spacer is inserted.
    Type: Application
    Filed: August 13, 2015
    Publication date: July 26, 2018
    Inventors: Hiroki ASO, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Junichiro OYA, Yuto URABE
  • Patent number: 10027192
    Abstract: An interior permanent magnet motor includes: a rotator; a stator; a permanent magnet inserted into a magnet accommodating hole; and a slit formed on a radially outer side of the magnet accommodating hole. A space portion is ensured between a radially outer surface of the permanent magnet and a rotator core in each region opposed to the slit. The permanent magnet is apart from the rotator core via the space portion in the each region opposed to the slit.
    Type: Grant
    Filed: June 12, 2013
    Date of Patent: July 17, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kazuhiko Baba, Koji Yabe, Masahiro Nigo, Tomoaki Oikawa
  • Publication number: 20180198390
    Abstract: An electric motor includes a stator, a rotor provided to be rotatable with respect to the stator, and a driving circuit board including a power IC applying a driving voltage to the stator, a Hall IC detecting a rotation position of the rotor, and a control IC adjusting a phase of the driving voltage in accordance with a magnetic-pole-position signal from the Hall IC and rotation speed information calculated on the basis of the magnetic-pole-position signal. The Hall IC is provided at a position at which an advance angle is larger than zero when a rotation speed of the rotor is zero.
    Type: Application
    Filed: October 30, 2015
    Publication date: July 12, 2018
    Inventors: Junichiro OYA, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Hiroki ASO, Yuto URABE, Kazunori HATAKEYAMA, Takuya SHIMOMUGI
  • Publication number: 20180183282
    Abstract: A stator includes a stator core having a first tooth and a second tooth adjacent to each other, a coil having a first winding portion wound around the first tooth and a second winding portion wound around the second tooth, a spacer inserted into a gap between the first winding portion and the second winding portion, and a molding resin covering the stator core, the coil, and the spacer. The spacer is shaped from a plastic material identical with a plastic material of which the molding resin is composed.
    Type: Application
    Filed: December 16, 2015
    Publication date: June 28, 2018
    Inventors: Hiroki ASO, Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Junichiro OYA, Yuto URABE
  • Publication number: 20180109167
    Abstract: A permanent-magnet electric motor includes: a rotor; and a rotational-position detection sensor configured to detect a rotational position of the rotor. The rotor includes: a rotating shaft; an annular ferrite magnet disposed on an outer circumferential surface of the rotating shaft; and a rare-earth magnet disposed on an outer circumferential surface of the ferrite magnet, and a length from a center of the ferrite magnet in an axial direction of the ferrite magnet to an end face of the ferrite magnet on a side of the rotational-position detection sensor in the axial direction of the ferrite magnet is longer than a length from a center of the rare-earth magnet in an axial direction of the rare-earth magnet to an end face of the rare-earth magnet on a side of the rotational-position detection sensor in the axial direction of the rare-earth magnet.
    Type: Application
    Filed: June 15, 2015
    Publication date: April 19, 2018
    Inventors: Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE, Takaya SHIMOKAWA
  • Publication number: 20180091008
    Abstract: A permanent-magnet electric motor includes an annular stator core, a rotor core, and a rotating-position detection sensor. In each of a plurality of magnet insertion holes formed in the rotor core, a rare-earth magnet and a ferrite magnet are disposed adjacent to each other in an axial direction of the rotor core. The rotor core has an axial length longer than an axial length of the stator core. The rare-earth magnet is disposed in each of the magnet insertion holes to be opposed to the stator core in a radial direction of the stator core. The ferrite magnet disposed in each of the magnet insertion holes is disposed between the rare-earth magnet disposed in the corresponding magnet insertion hole and the rotating-position detection sensor.
    Type: Application
    Filed: June 17, 2015
    Publication date: March 29, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tomoaki OIKAWA, Mineo YAMAMOTO, Hiroyuki ISHII, Hiroki ASO, Junichiro OYA, Yuto URABE, Takaya SHIMOKAWA
  • Patent number: 9876402
    Abstract: An interior permanent magnet motor includes a stator and a rotor. The rotor includes a rotor core formed by laminating a plurality of plate members. The rotor core has a plurality of magnet insertion holes formed therein, into which corresponding permanent magnets are respectively inserted. At least one slit and at least one caulked portion are formed between a rotor outer peripheral surface of the rotor and a radially-outer insertion hole contour surface of the magnet insertion hole. At least a part of the caulked portion is positioned between a pair of width extended lines of the slit.
    Type: Grant
    Filed: September 18, 2014
    Date of Patent: January 23, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kazuchika Tsuchida, Masahiro Nigo, Kazuhiko Baba, Atsushi Ishikawa, Tomoaki Oikawa