Patents by Inventor Mitsuhiro Takemoto

Mitsuhiro Takemoto 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: 11949293
    Abstract: A rotor used in an outer rotor motor includes a rotor holder in a tubular shape extending along a center axis, a rotor core in a tubular shape extending in an axial direction and being fixed to a surface of the rotor holder, directed radially inward, and permanent magnets bonded to an inner circumferential surface of the rotor core and side by side in a circumferential direction. The rotor core includes projection portions projecting radially inward from the inner circumferential surface of the rotor core. One or more of the projection portions are in a gap between the permanent magnets adjacent to each other in the circumferential direction. Each of the projection portions has an axial length shorter than an axial length of each of the permanent magnets.
    Type: Grant
    Filed: September 26, 2019
    Date of Patent: April 2, 2024
    Assignee: NIDEC CORPORATION
    Inventors: Shinji Takemoto, Tomoya Ueda, Mitsuhiro Takemoto, Yusuke Isogai
  • Publication number: 20220399773
    Abstract: A motor includes: a rotor including a shaft rotatable about an axis extending in a vertical direction; a bearing rotatably supporting the shaft; a stationary portion including a stator; and a lead wire electrically connected to the stator. The stationary portion includes a housing located radially outward of the bearing and radially inward of the stator, and supporting the bearing and the stator, a base portion which is located axially below the stator and to which the housing is fixed, and a fixing member fixed to the base portion. The fixing member includes a cover portion covering a shaft lower end portion located at an axially lower end of the shaft when viewed from axially below. The cover portion has an opening portion that opens in an axial direction. The opening portion is located radially more inside than an inner peripheral surface of the shaft when viewed from axially below.
    Type: Application
    Filed: June 14, 2022
    Publication date: December 15, 2022
    Inventors: Mitsuhiro TAKEMOTO, Shinji TAKEMOTO
  • Patent number: 11469633
    Abstract: A motor includes a rotor with one or more magnets, a rotor core holding the one or more magnets, a spacer that contacts the one or more magnets, and a rotor holder. The rotor holder includes a holder lid portion and a holder tubular portion in a tubular shape extending to one side in the axial direction from a radially outer edge of the holder lid portion. The holder lid portion includes a holder first surface that extends radially inward from an inner surface of the holder tubular portion, a holder second surface that extends radially and is radially inward of the holder first surface and on the other side in the axial direction, and a connecting surface connecting the holder first surface and the holder second surface.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: October 11, 2022
    Assignee: NIDEC CORPORATION
    Inventors: Mitsuhiro Takemoto, Sho Fukuhara, Shinji Takemoto
  • Patent number: 11381141
    Abstract: A motor includes a rotor rotatable about a center axis extending vertically, a stator radially opposing the rotor, a bracket holding the stator, a circuit board including an upper surface with a first wiring pattern and a lower surface with a second wiring pattern, and a first fixing portion having conductivity and fixing the circuit board to the stator. The stator includes a stator core having conductivity. The first fixing portion includes a board holding portion holding the circuit board, and a stator fixed portion fixed to a portion of the stator core. The board holding portion is in contact with the first wiring pattern and the second wiring pattern.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: July 5, 2022
    Assignee: NIDEC CORPORATION
    Inventors: Mitsuhiro Takemoto, Sho Fukuhara, Shinji Takemoto
  • Publication number: 20220006341
    Abstract: A rotor used in an outer rotor motor includes a rotor holder in a tubular shape extending along a center axis, a rotor core in a tubular shape extending in an axial direction and being fixed to a surface of the rotor holder, directed radially inward, and permanent magnets bonded to an inner circumferential surface of the rotor core and side by side in a circumferential direction. The rotor core includes projection portions projecting radially inward from the inner circumferential surface of the rotor core. One or more of the projection portions are in a gap between the permanent magnets adjacent to each other in the circumferential direction. Each of the projection portions has an axial length shorter than an axial length of each of the permanent magnets.
    Type: Application
    Filed: September 26, 2019
    Publication date: January 6, 2022
    Inventors: Shinji TAKEMOTO, Tomoya UEDA, Mitsuhiro TAKEMOTO, Yusuke ISOGAI
  • Publication number: 20210036584
    Abstract: A motor includes a rotor rotatable about a center axis extending vertically, a stator radially opposing the rotor, a bracket holding the stator, a circuit board including an upper surface with a first wiring pattern and a lower surface with a second wiring pattern, and a first fixing portion having conductivity and fixing the circuit board to the stator. The stator includes a stator core having conductivity. The first fixing portion includes a board holding portion holding the circuit board, and a stator fixed portion fixed to a portion of the stator core. The board holding portion is in contact with the first wiring pattern and the second wiring pattern.
    Type: Application
    Filed: July 21, 2020
    Publication date: February 4, 2021
    Inventors: Mitsuhiro TAKEMOTO, Sho FUKUHARA, Shinji TAKEMOTO
  • Publication number: 20210036563
    Abstract: A motor includes a rotor with one or more magnets, a rotor core holding the one or more magnets, a spacer that contacts the one or more magnets, and a rotor holder. The rotor holder includes a holder lid portion and a holder tubular portion in a tubular shape extending to one side in the axial direction from a radially outer edge of the holder lid portion. The holder lid portion includes a holder first surface that extends radially inward from an inner surface of the holder tubular portion, a holder second surface that extends radially and is radially inward of the holder first surface and on the other side in the axial direction, and a connecting surface connecting the holder first surface and the holder second surface.
    Type: Application
    Filed: July 21, 2020
    Publication date: February 4, 2021
    Inventors: Mitsuhiro TAKEMOTO, Sho FUKUHARA, Shinji TAKEMOTO
  • Patent number: 10530217
    Abstract: A rotating portion includes a hollow shaft extending along a central axis. The hollow shaft includes a through hole passing therethrough in an axial direction. The rotating portion includes an upper screw to close an upper opening that is an opening at an upper end portion of the through hole. The rotating portion includes a lower screw to close a lower opening that is an opening at a lower end portion of the through hole. The hollow shaft includes an upper groove portion into which the upper screw is screwed at the upper opening. The hollow shaft includes a lower groove portion into which the lower screw is screwed at the lower opening. A lubricating oil is in contact with the lower screw. The lower groove portion is shorter in axial length than the upper groove portion, and the lower screw is smaller in axial pitch than the upper screw.
    Type: Grant
    Filed: October 30, 2018
    Date of Patent: January 7, 2020
    Assignee: NIDEC CORPORATION
    Inventors: Seiji Maruoka, Mitsuhiro Takemoto
  • Publication number: 20190165644
    Abstract: A rotating portion includes a hollow shaft extending along a central axis. The hollow shaft includes a through hole passing therethrough in an axial direction. The rotating portion includes an upper screw to close an upper opening that is an opening at an upper end portion of the through hole. The rotating portion includes a lower screw to close a lower opening that is an opening at a lower end portion of the through hole. The hollow shaft includes an upper groove portion into which the upper screw is screwed at the upper opening. The hollow shaft includes a lower groove portion into which the lower screw is screwed at the lower opening. A lubricating oil is in contact with the lower screw. The lower groove portion is shorter in axial length than the upper groove portion, and the lower screw is smaller in axial pitch than the upper screw.
    Type: Application
    Filed: October 30, 2018
    Publication date: May 30, 2019
    Inventors: Seiji MARUOKA, Mitsuhiro TAKEMOTO
  • Patent number: 9837113
    Abstract: A stationary portion of a spindle motor includes a stator portion and an outside surface. The stator portion includes a stator core and coils. The outside surface extends in an axial direction parallel or substantially parallel to a central axis, and is centered on the central axis. The spindle motor includes a fixing portion at which an inside surface of the stator core and the outside surface are fixed to each other. The fixing portion includes a first press fit portion, a second press fit portion, and a gap arranged therein. The gap is located between the first press fit portion and the second press fit portion. The second press fit portion is located above the first press fit portion. At least a portion of the second press fit portion is located above a middle of the stator core in the axial direction.
    Type: Grant
    Filed: April 20, 2015
    Date of Patent: December 5, 2017
    Assignee: NIDEC CORPORATION
    Inventors: Mitsuhiro Takemoto, Tsuchitsugu Watanabe, Hiroyuki Abe
  • Publication number: 20160190875
    Abstract: A stationary portion of a spindle motor includes a stator portion and an outside surface. The stator portion includes a stator core and coils. The outside surface extends in an axial direction parallel or substantially parallel to a central axis, and is centered on the central axis. The spindle motor includes a fixing portion at which an inside surface of the stator core and the outside surface are fixed to each other. The fixing portion includes a first press fit portion, a second press fit portion, and a gap arranged therein. The gap is located between the first press fit portion and the second press fit portion. The second press fit portion is located above the first press fit portion. At least a portion of the second press fit portion is located above a middle of the stator core in the axial direction.
    Type: Application
    Filed: April 20, 2015
    Publication date: June 30, 2016
    Inventors: Mitsuhiro TAKEMOTO, Tsuchitsugu WATANABE, Hiroyuki ABE
  • Patent number: 9001460
    Abstract: A spindle motor includes a stationary portion and a rotating portion. The stationary portion includes a shaft, a first cup portion. The first cup portion includes a circular plate member and an annular member. The rotating portion includes an annular concave portion that accommodates at least a lower end portion of the annular member. A lubricant is interposed in a gap between a surface of a stationary portion and a surface of the rotating portion. The shaft, the rotating portion, and the lubricant define a fluid dynamic pressure bearing. A connection gap that reaches an inner side of the first cup portion from an outer circumferential surface of the first cup portion is configured between the circular plate member and the annular member. At least a portion of the connection gap is filled with an adhesive.
    Type: Grant
    Filed: July 14, 2014
    Date of Patent: April 7, 2015
    Assignee: Nidec Corporation
    Inventors: Hironori Ando, Mitsuhiro Takemoto
  • Publication number: 20150055247
    Abstract: A spindle motor includes a stationary portion and a rotating portion. The stationary portion includes a shaft, a first cup portion. The first cup portion includes a circular plate member and an annular member. The rotating portion includes an annular concave portion that accommodates at least a lower end portion of the annular member. A lubricant is interposed in a gap between a surface of a stationary portion and a surface of the rotating portion. The shaft, the rotating portion, and the lubricant define a fluid dynamic pressure bearing. A connection gap that reaches an inner side of the first cup portion from an outer circumferential surface of the first cup portion is configured between the circular plate member and the annular member. At least a portion of the connection gap is filled with an adhesive.
    Type: Application
    Filed: July 14, 2014
    Publication date: February 26, 2015
    Inventors: Hironori ANDO, Mitsuhiro TAKEMOTO
  • Patent number: 8675304
    Abstract: A motor includes a stationary portion and a rotating portion. The rotating portion includes a sleeve portion including one communicating hole arranged to extend completely there through from an upper surface to a lower surface thereof, and a cover portion including a hole portion. The axial extension range of the hole portion is arranged to overlap with the axial extension range of the communicating hole in a radial direction. A center of the hole portion is arranged on a plane including a central axis and a center of the communicating hole. The communicating hole and the hole portion are arranged on opposite sides of the central axis. The following inequality is satisfied: V2<(?1/?2)·V1, where ?1 is the density of the sleeve portion, V1 is the volume of the communicating hole, ?2 is the density of the cover portion, and V2 is the volume of the hole portion.
    Type: Grant
    Filed: January 19, 2012
    Date of Patent: March 18, 2014
    Assignee: Nidec Corporation
    Inventors: Takehito Tamaoka, Kazushi Miura, Mitsuhiro Takemoto
  • Patent number: 8567067
    Abstract: A method of manufacturing a bearing mechanism of a motor includes steps a)-e). In step a), a bearing assembly is assembled. In step b), an upper seal gap between an upper thrust portion and an upper hub annular portion is arranged to face downward to increase the width of a gap between an outer tubular portion and a flange portion, or a lower seal gap between the outer tubular portion and a lower hub annular portion is arranged to face downward to increase the width of a gap between the upper thrust portion and the flange portion. In step c), pressure in all gaps is reduced. In step d), lubricating oil is injected into the upper or lower seal gap which faces upward, and a predetermined time or longer is allowed to pass. In step e), pressure is returned to atmospheric pressure.
    Type: Grant
    Filed: January 19, 2012
    Date of Patent: October 29, 2013
    Assignee: Nidec Corporation
    Inventors: Katsuki Yamaguchi, Shigeki Horiki, Yoshitsugu Hideshima, Akio Tatsumi, Akinobu Sumiji, Takehito Tamaoka, Kazushi Miura, Mitsuhiro Takemoto
  • Patent number: 8553355
    Abstract: A motor includes a stationary portion and a rotating portion. The stationary portion includes a shaft portion and an upper thrust portion. The upper thrust portion includes a tubular first outer circumferential surface arranged radially outside the upper thrust portion, and a tubular second outer circumferential surface arranged above the first outer circumferential surface. The rotating portion includes a sleeve portion, a tubular portion, and an annular cover portion. The annular cover portion includes a plate portion and an inner annular projecting portion arranged to project upward or downward. An inner circumferential surface of the inner annular projecting portion is arranged above an inner circumferential surface of the tubular portion. An upper seal portion includes a surface of a lubricating oil located therein.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: October 8, 2013
    Assignee: Nidec Corporation
    Inventors: Junya Mizukami, Takayuki Oe, Yoichi Sekii, Naoki Sabashi, Takehito Tamaoka, Takashi Yamamoto, Shigeki Horiki, Kazushi Miura, Mitsuhiro Takemoto, Kazuhiro Sato
  • Patent number: 8542459
    Abstract: A motor includes a seal cap and a tubular portion. The seal cap includes a first seal cap lower surface which is an annular surface facing axially downward, and a second seal cap lower surface which is an annular surface facing axially downward and arranged radially outward of the first seal cap lower surface. The tubular portion includes a first tubular portion upper surface which is an annular surface arranged axially opposite to the first seal cap lower surface, and a second tubular portion upper surface which is an annular surface arranged radially outward of the first tubular portion upper surface and in contact with the second seal cap lower surface. The first tubular portion upper surface includes an oil-repellent film region covered with an oil-repellent film. A substantially annular radially extending gap is defined between the first tubular portion upper surface and the first seal cap lower surface.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: September 24, 2013
    Assignee: Nidec Corporation
    Inventors: Junya Mizukami, Takayuki Oe, Yoichi Sekii, Naoki Sabashi, Takehito Tamaoka, Takashi Yamamoto, Shigeki Horiki, Kazushi Miura, Mitsuhiro Takemoto, Hironori Ando, Katsuya Takahashi
  • Patent number: 8385017
    Abstract: In a motor, an annular radially extending gap is defined between an outer annular surface and a lower surface of an annular cover portion. The radially extending gap has an axial width smaller than a maximum width of an upper seal portion defined between an outer circumferential surface of an upper thrust portion and an inner circumferential surface of a tubular portion. An annular axially extending gap is defined between an inner cylindrical surface and a radially inner edge of the annular cover portion. The axially extending gap has a radial width smaller than the maximum width of the upper seal portion.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: February 26, 2013
    Assignee: Nidec Corporation
    Inventors: Junya Mizukami, Takayuki Oe, Yoichi Sekii, Naoki Sabashi, Takehito Tamaoka, Takashi Yamamoto, Shigeki Horiki, Kazushi Miura, Mitsuhiro Takemoto
  • Publication number: 20120327534
    Abstract: A method of manufacturing a bearing mechanism of a motor includes steps a)-e). In step a), a bearing assembly is assembled. In step b), an upper seal gap between an upper thrust portion and an upper hub annular portion is arranged to face downward to increase the width of a gap between an outer tubular portion and a flange portion, or a lower seal gap between the outer tubular portion and a lower hub annular portion is arranged to face downward to increase the width of a gap between the upper thrust portion and the flange portion. In step c), pressure in all gaps is reduced. In step d), lubricating oil is injected into the upper or lower seal gap which faces upward, and a predetermined time or longer is allowed to pass. In step e), pressure is returned to atmospheric pressure.
    Type: Application
    Filed: January 19, 2012
    Publication date: December 27, 2012
    Applicant: NIDEC CORPORATION
    Inventors: Katsuki YAMAGUCHI, Shigeki HORIKI, Yoshitsugu HIDESHIMA, Akio TATSUMI, Akinobu SUMIJI, Takehito TAMAOKA, Kazushi MIURA, Mitsuhiro TAKEMOTO
  • Publication number: 20120250183
    Abstract: A motor includes a stationary portion and a rotating portion. The rotating portion includes a sleeve portion including one communicating hole arranged to extend completely there through from an upper surface to a lower surface thereof, and a cover portion including a hole portion. The axial extension range of the hole portion is arranged to overlap with the axial extension range of the communicating hole in a radial direction. A center of the hole portion is arranged on a plane including a central axis and a center of the communicating hole. The communicating hole and the hole portion are arranged on opposite sides of the central axis. The following inequality is satisfied: V2<(?1/?2)·V1, where ?1 is the density of the sleeve portion, V1 is the volume of the communicating hole, ?2 is the density of the cover portion, and V2 is the volume of the hole portion.
    Type: Application
    Filed: January 19, 2012
    Publication date: October 4, 2012
    Applicant: NIDEC CORPORATION
    Inventors: Takehito TAMAOKA, Kazushi MIURA, Mitsuhiro TAKEMOTO