Patents by Inventor Yoji Unoki

Yoji Unoki 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: 8823232
    Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: September 2, 2014
    Assignee: Nidec Servo Corporation
    Inventors: Shigeaki Terashita, Yoji Unoki
  • Publication number: 20140152142
    Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.
    Type: Application
    Filed: February 6, 2014
    Publication date: June 5, 2014
    Applicant: NIDEC SERVO CORPORATION
    Inventors: Shigeaki TERASHITA, Yoji UNOKI
  • Patent number: 8704412
    Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: April 22, 2014
    Assignee: Nidec Servo Corporation
    Inventors: Shigeaki Terashita, Yoji Unoki
  • Patent number: 8138641
    Abstract: A permanent-magnet rotary electric machine preferably includes a stator and a rotor opposed thereto via an air gap. The stator includes a stator core having 4m (m is an integer equal to or larger than 2) main poles each having inductor teeth at a tip thereof. The rotor includes two rotor units adjacent to each other in the axial direction. Each rotor unit includes a pair of rotor magnetic poles and a permanent magnet arranged therebetween. The permanent magnets in the rotor are axially magnetized in opposite directions to each other. Each rotor magnetic pole has magnetic teeth on its outer periphery at a regular pitch. The rotor magnetic poles in each rotor unit are arranged such that the magnetic teeth of one rotor magnetic plate are offset by half a pitch from those of the other rotor magnetic pole, and the magnetic teeth of adjacent rotor magnetic poles are aligned with each other in the axial direction.
    Type: Grant
    Filed: December 1, 2009
    Date of Patent: March 20, 2012
    Assignee: Nidec Servo Corporation
    Inventors: Masafumi Sakamoto, Yoji Unoki, Toru Kobayashi
  • Publication number: 20110304225
    Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.
    Type: Application
    Filed: June 10, 2011
    Publication date: December 15, 2011
    Applicant: NIDEC SERVO CORPORATION
    Inventors: Shigeaki TERASHITA, Yoji UNOKI
  • Patent number: 7939976
    Abstract: A hybrid type stepper motor preferably includes a two-phase eight-main-pole stator and a rotor defined by two rotor units each having a pair of rotor magnetic poles with a permanent magnet interposed therebetween. Each rotor magnetic pole has fine teeth at a regular pitch. The permanent magnets are magnetized in opposite directions to each other. The adjacent rotor magnetic poles of the rotor units are arranged with their fine teeth aligned with each other in the axial direction. Each main pole has six inductor teeth including: a pair of innermost inductor teeth arranged at the first pitch in the central portion of the main pole; a pair of intermediate teeth on the outside of the innermost inductor teeth at the second pitch therefrom; and a pair of outermost inductor teeth on the outside of the intermediate inductor teeth at the third pitch therefrom. The first, second, and third pitches are all different from the pitch of the fine teeth of the rotor magnetic pole.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: May 10, 2011
    Assignee: Nidec Servo Corporation
    Inventors: Masafumi Sakamoto, Yoji Unoki
  • Publication number: 20100133929
    Abstract: A permanent-magnet rotary electric machine preferably includes a stator and a rotor opposed thereto via an air gap. The stator includes a stator core having 4m (m is an integer equal to or larger than 2) main poles each having inductor teeth at a tip thereof. The rotor includes two rotor units adjacent to each other in the axial direction. Each rotor unit includes a pair of rotor magnetic poles and a permanent magnet arranged therebetween. The permanent magnets in the rotor are axially magnetized in opposite directions to each other. Each rotor magnetic pole has magnetic teeth on its outer periphery at a regular pitch. The rotor magnetic poles in each rotor unit are arranged such that the magnetic teeth of one rotor magnetic plate are offset by half a pitch from those of the other rotor magnetic pole, and the magnetic teeth of adjacent rotor magnetic poles are aligned with each other in the axial direction.
    Type: Application
    Filed: December 1, 2009
    Publication date: June 3, 2010
    Applicant: NIDEC SERVO CORPORATION
    Inventors: Masafumi SAKAMOTO, Yoji UNOKI, Toru KOBAYASHI
  • Publication number: 20100066184
    Abstract: A hybrid type stepper motor preferably includes a two-phase eight-main-pole stator and a rotor defined by two rotor units each having a pair of rotor magnetic poles with a permanent magnet interposed therebetween. Each rotor magnetic pole has fine teeth at a regular pitch. The permanent magnets are magnetized in opposite directions to each other. The adjacent rotor magnetic poles of the rotor units are arranged with their fine teeth aligned with each other in the axial direction. Each main pole has six inductor teeth including: a pair of innermost inductor teeth arranged at the first pitch in the central portion of the main pole; a pair of intermediate teeth on the outside of the innermost inductor teeth at the second pitch therefrom; and a pair of outermost inductor teeth on the outside of the intermediate inductor teeth at the third pitch therefrom. The first, second, and third pitches are all different from the pitch of the fine teeth of the rotor magnetic pole.
    Type: Application
    Filed: November 24, 2009
    Publication date: March 18, 2010
    Applicant: Nidec Servo Corporation
    Inventors: Masafumi SAKAMOTO, Yoji UNOKI
  • Patent number: 6674187
    Abstract: Disclosed is an inner rotor or outer rotor hybrid stepping motor of 6-phase/6 m-pole type or 10-phase/10 m-pole type. The motor includes a stator that has 6 m or 10 m pieces of magnetic poles and a rotor that is rotatably supported by the stator. Excitation windings are wound around the stator magnetic poles. The stator magnetic pole is divided into two halves in the axial direction, one half has pole teeth being line-symmetric and the other half has pole teeth being asymmetric and deviated from the symmetric pole teeth by ¼ pitch. The positions of the symmetric half and the asymmetric half are inverted between the adjacent magnetic poles. The rotor has a first and second rotor units each of which includes a permanent magnet and first and second rotor magnetic poles around which pole teeth are formed with deviation of ½ pitch.
    Type: Grant
    Filed: December 31, 2001
    Date of Patent: January 6, 2004
    Assignee: Japan Servo Co., Ltd.
    Inventors: Kouki Isozaki, Yoji Unoki, Noriyoshi Kikuchi
  • Publication number: 20020089243
    Abstract: Disclosed is an inner rotor or outer rotor hybrid stepping motor of 6-phase/6 m-pole type or 10-phase/10 m-pole type. The motor includes a stator that has 6 m or 10 m pieces of magnetic poles and a rotor that is rotatably supported by the stator. Excitation windings are wound around the stator magnetic poles. The stator magnetic pole is divided into two halves in the axial direction, one half has pole teeth being line-symmetric and the other half has pole teeth being asymmetric and deviated from the symmetric pole teeth by ¼ pitch. The positions of the symmetric half and the asymmetric half are inverted between the adjacent magnetic poles. The rotor has a first and second rotor units each of which includes a permanent magnet and first and second rotor magnetic poles around which pole teeth are formed with deviation of ½ pitch.
    Type: Application
    Filed: December 31, 2001
    Publication date: July 11, 2002
    Applicant: JAPAN SERVO CO., LTD.
    Inventors: Kouki Isozaki, Yoji Unoki, Noriyoshi Kikuchi
  • Patent number: D694186
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: November 26, 2013
    Assignee: Nidec Servo Corporation
    Inventors: Shigeaki Terashita, Yoji Unoki