Patents by Inventor Isao Hirai

Isao Hirai 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: 11155161
    Abstract: An automobile-motor driving device equipped with speed reducer which has improved supply of lubrication oil to inside of the rolling bearings without sacrificing the function of the bearings, to reduce deformation in the rolling bearing outer ring. A parallel shaft gear speed reducer provides an automobile-motor driving device equipped with speed reducer. The parallel shaft gear speed reducer includes a plurality of gear shafts having two ends supported via rolling bearings fitted into bearing fitting holes in a speed reducer casing which houses the parallel shaft gear speed reducer. A groove in an inner circumferential surface of the bearing fitting hole into which the rolling bearing is fitted communicates between a space that houses the speed reducer and an inside space of the bearing fitting hole, at a location not crossed by the line of action of a load acting upon the rolling bearing due to the meshing of the gears.
    Type: Grant
    Filed: April 14, 2016
    Date of Patent: October 26, 2021
    Assignee: NTN CORPORATION
    Inventors: Tomoaki Makino, Isao Hirai, Yusuke Shibuya
  • Patent number: 10207572
    Abstract: Helical gears in gear trains of speed reducers generate thrust forces in directions not to separate a speed reducer casing which has an axial three-piece structure, whereby leakage of lubricant oil from between separated surfaces in the speed reducer casing is prevented. Output gear which generates large thrust force on the final stage in each gear train of the speed reducers both generated inward forces, so that the center casing does not receive forces in directions in which the left and the right casings is separated therefrom.
    Type: Grant
    Filed: April 18, 2016
    Date of Patent: February 19, 2019
    Assignee: NTN CORPORATION
    Inventors: Tomoaki Makino, Ryou Yukishima, Hidenori Karasawa, Isao Hirai
  • Publication number: 20180339583
    Abstract: In an electric vehicle in which front wheels are drive wheels, this invention is to provide an electric vehicle capable of endowing the front wheels with sufficient traction and obtain excellent travel performance. The electric vehicle has a sub-frame (56) that fixes a two-motor electric drive device (A) that drives the front wheels (51), at the front of a vehicle body. The two-motor electric drive device (A) that is fixed to the sub-frame (56) has two electric motors (1L, 1R) and two speed reducers (2L, 2R). The two speed reducers (2L, 2R) are integrally housed in a housing (20). The two speed reducers (2L, 2R) are sandwiched by the two electric motors (1L, 1R) and thereby integrated with each other. The lower part of the two-motor electric drive device (A) is fixed to the sub-frame (56) so as to be approximately the same height as the undersurface of the vehicle body.
    Type: Application
    Filed: August 25, 2016
    Publication date: November 29, 2018
    Inventor: Isao HIRAI
  • Publication number: 20180141423
    Abstract: Helical gears in gear trains of speed reducers 2L, 2R generate thrust forces in directions not to separate a speed reducer casing 20 which has an axial three-piece structure, whereby leakage of lubricant oil from between separated surfaces in the speed reducer casing 20 is prevented. Output gears 25L, 25R which generates large thrust force on the final stage in each gear train of the speed reducers 2L, 2R both generates inward forces, so that the center casing 20a does not receive forces in directions in which the left and the right casings 20bL, 20bR is separated therefrom.
    Type: Application
    Filed: April 18, 2016
    Publication date: May 24, 2018
    Applicant: NTN CORPORATION
    Inventors: Tomoaki MAKINO, Ryou YUKISHIMA, Hidenori KARASAWA, Isao HIRAI
  • Publication number: 20180118023
    Abstract: An automobile-motor driving device equipped with speed reducer which has improved supply of lubrication oil to inside of the rolling bearings without sacrificing the function of the bearings, to reduce deformation in the rolling bearing outer ring. A parallel shaft gear speed reducer provides an automobile-motor driving device equipped with speed reducer. The parallel shaft gear speed reducer includes a plurality of gear shafts having two ends supported via rolling bearings fitted into bearing fitting holes in a speed reducer casing which houses the parallel shaft gear speed reducer. A groove in an inner circumferential surface of the bearing fitting hole into which the rolling bearing is fitted communicates between a space that houses the speed reducer and an inside space of the bearing fitting hole, at a location not crossed by the line of action of a load acting upon the rolling bearing due to the meshing of the gears.
    Type: Application
    Filed: April 14, 2016
    Publication date: May 3, 2018
    Inventors: Tomoaki MAKINO, Isao HIRAI, Yusuke SHIBUYA
  • Patent number: 9797453
    Abstract: A wheel bearing apparatus has an outer member, an inner member, at least one inner ring fit onto the inner member. Double row rolling elements are rollably arranged between the outer and inner raceway surfaces, via cages. A seal is mounted on one end of the outer member. The seal has side lips adapted to be in sliding contact with the wheel hub. The seal has three inclined side lips each extending radially outward from the seal body. The lips are adapted to be in sliding contact with the base of the wheel mounting flange. Interference of the side lips against the base of the wheel mounting flange is set so that the radially inner side lip has a smaller interference than that of the radially outer side lips, in order.
    Type: Grant
    Filed: October 3, 2006
    Date of Patent: October 24, 2017
    Assignee: NTN Corporation
    Inventors: Takayuki Norimatsu, Hiroaki Itakura, Hironori Imanaka, Syougo Suzuki, Isao Hirai, Hiroya Kato, Akira Fujimura, Kikuo Fukada
  • Patent number: 9534635
    Abstract: A wheel bearing apparatus has an outer member, an inner member, at least one inner ring fit onto the inner member. Double row rolling elements are rollably arranged between the outer and inner raceway surfaces, via cages. A seal is mounted on one end of the outer member. The seal has side lips adapted to be in sliding contact with the wheel hub. The seal has three inclined side lips each extending radially outward from the seal body. The lips are adapted to be in sliding contact with the base of the wheel mounting flange. Interference of the side lips against the base of the wheel mounting flange is set so that the radially inner side lip has a smaller interference than that of the radially outer side lips, in order.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: January 3, 2017
    Assignee: NTN Corporation
    Inventors: Takayuki Norimatsu, Hiroaki Itakura, Hironori Imanaka, Syougo Suzuki, Isao Hirai, Hiroya Kato, Akira Fujimura, Kikuo Fukada
  • Patent number: 9168818
    Abstract: An electric vehicle includes: a body that includes a body frame; a driving module that includes a sub-frame detachable from the body frame, driving wheels, a driving device provided with a motor mounted on the sub-frame and applying driving force to the driving wheels to start or accelerate the electric vehicle, a driving-wheel suspension device attached to the sub-frame, a driving-wheel brake device stopping or decelerating the electric vehicle, and some other components; a connection unit that maintains the relative position relationship between the body and driving module upon attachment of the sub-frame to the body frame and connects the body to the driving module with signal lines; and a control unit that controls the driving module under an input signal input from the body side through the signal lines connected with the connection unit.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: October 27, 2015
    Assignee: NTN CORPORATION
    Inventors: Isao Hirai, Tetsuya Yamamoto, Wataru Yamada
  • Publication number: 20150027795
    Abstract: An electric vehicle includes: a body that includes a body frame; a driving module that includes a sub-frame detachable from the body frame, driving wheels, a driving device provided with a motor mounted on the sub-frame and applying driving force to the driving wheels to start or accelerate the electric vehicle, a driving-wheel suspension device attached to the sub-frame, a driving-wheel brake device stopping or decelerating the electric vehicle, and some other components; a connection unit that maintains the relative position relationship between the body and driving module upon attachment of the sub-frame to the body frame and connects the body to the driving module with signal lines; and a control unit that controls the driving module under an input signal input from the body side through the signal lines connected with the connection unit.
    Type: Application
    Filed: January 24, 2013
    Publication date: January 29, 2015
    Inventors: Isao Hirai, Tetsuya Yamamoto, Wataru Yamada
  • Patent number: 8714829
    Abstract: A wheel support bearing assembly includes an outer member and an inner member, each having a raceway surface. The inner member is made up of a combination of a rotatable ring, having its outer periphery formed with a vehicle body fitting flange, and a separate member. Each of the outer member and the flanged rotatable ring has a surface region representing a thermally refined structure formed by means of martensite hardening and high temperature tempering and also has a core region representing an as-forged structure made up of ferrite and pearlite.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: May 6, 2014
    Assignee: NTN Corporation
    Inventor: Isao Hirai
  • Patent number: 8393974
    Abstract: A driving wheel bearing apparatus has an inner ring 5 secured to a wheel hub 1 by a caulked portion 13. An outer joint member 14 of a constant velocity universal joint 3 has a shoulder portion 19 and a cylindrical shaft portion. Face splines 19a and 13a are formed at the end faces of the shoulder portion 19 and the caulked portion 13. Face splines 19a and 13a are supported with pressure by a fastening bolt 21 that abuts the outer side end face of the wheel hub 1 and is threadedly connected to an internal thread 20a of the shaft portion 20. Compressive remaining stress is placed on the surfaces of the face splines 19a and 13a as a result of surface modification, by shot peening. The surface hardness is set at 300 Hv or more.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: March 12, 2013
    Assignee: NTN Corporation
    Inventors: Isao Hirai, Kiyotake Shibata
  • Patent number: 8302309
    Abstract: A method is directed to a production of a bearing device for a wheel including an inner member and an outer member rotatable relative to each other through a plurality of rolling elements, in which a component part forming one of the inner member and the outer member is a hot forged product. In the practice of this method, during or at the end of a hot forging step for hot forging the component part, a portion of the component part is cooled by spraying a coolant or by controlling an atmospheric temperature, to thereby render a matrix of the component part to represent a standard structure and render a surface portion of the component part to represent a non-standard structure.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: November 6, 2012
    Assignees: NTN Corporation, JFE Steel Corporation
    Inventors: Isao Hirai, Kohei Yoshino, Takayasu Takubo, Kazuhiko Yoshida, Kazukuni Hase, Hideto Kimura, Kiyoshi Uwai, Takaaki Toyooka
  • Patent number: 8240922
    Abstract: A wheel support bearing assembly, which enables an increase in the strength and the fatigue strength of its wheel mounting flange or vehicle body fitting flange against high stress and repeated stress and the suppression of the increase of the number of processes, includes an inner member and an outer member rotatable relative to each other through rolling elements. The flange is formed on the inner member or the outer member. A component part having the flange is a hot-forged product of steel in which a matrix portion is formed as a standard structure and the non-standard structural portion is formed on the surface of the flange. The non-standard structure is formed of either of a fine ferrite/pearlite structure, an upper bainite structure, a lower bainite structure, and a tempered martensite structure, or mixture of two or more of these structures.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: August 14, 2012
    Assignee: NTN Corporation
    Inventors: Isao Hirai, Kohei Yoshino, Takayasu Takubo, Akira Fujimura, Takuya Obata
  • Patent number: 8215846
    Abstract: A wheel support bearing assembly includes an outer member (1), which serves as a stationary member and has an inner periphery formed with a plurality of rows of raceway surfaces (3), an inner member (2), which serves as a rotatable member and has an outer periphery formed with respective raceway surfaces (4) opposed to the previously described raceway surfaces (3), and a plurality of rows of rolling elements (5) interposed between the respective opposed raceway surfaces (3, 4). The outer member (1) is thermally refined by means of a quenching and a high temperature tempering process so that a layer of at least 2 mm in depth from a surface of the outer member is rendered to have a micro-pearlite structure.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: July 10, 2012
    Assignee: NTN Corporation
    Inventor: Isao Hirai
  • Publication number: 20120083344
    Abstract: A driving wheel bearing apparatus has an inner ring 5 secured to a wheel hub 1 by a caulked portion 13. An outer joint member 14 of a constant velocity universal joint 3 has a shoulder portion 19 and a cylindrical shaft portion. Face splines 19a and 13a are formed at the end faces of the shoulder portion 19 and the caulked portion 13. Face splines 19a and 13a are supported with pressure by a fastening bolt 21 that abuts the outer side end face of the wheel hub 1 and is threadedly connected to an internal thread 20a of the shaft portion 20. Compressive remaining stress is placed on the surfaces of the face splines 19a and 13a as a result of surface modification, by shot peening. The surface hardness is set at 300 Hv or more.
    Type: Application
    Filed: December 7, 2011
    Publication date: April 5, 2012
    Applicant: NTN Corporation
    Inventors: Isao Hirai, Kiyotake Shibata
  • Patent number: 8100775
    Abstract: A driving wheel bearing apparatus has an inner ring 5 secured to a wheel hub 1 by a caulked portion 13. An outer joint member 14 of a constant velocity universal joint 3 has a shoulder portion 19 and a cylindrical shaft portion. Face splines 19a and 13a are formed at the end faces of the shoulder portion 19 and the caulked portion 13. Face splines 19a and 13a are supported with pressure by a fastening bolt 21 that abuts the outer side end face of the wheel hub 1 and is threadedly connected to an internal thread 20a of the shaft portion 20. Compressive remaining stress is placed on the surfaces of the face splines 19a and 13a as a result of surface modification, by shot peening. The surface hardness is set at 300 Hv or more.
    Type: Grant
    Filed: December 3, 2010
    Date of Patent: January 24, 2012
    Assignee: NTN Corporation
    Inventors: Isao Hirai, Kiyotake Shibata
  • Publication number: 20110304197
    Abstract: A wheel bearing apparatus has an outer member formed with double row outer raceway surfaces on its inner circumferential surface. An inner member includes a wheel hub with a wheel mounting flange integrally formed at one end and a cylindrical portion axially extending from the wheel mounting flange. At least one inner ring is fit onto the cylindrical portion of the wheel hub. The inner ring is formed with double row inner raceway surfaces on its outer circumferential surface. The double row inner raceway surfaces are arranged opposite to the double row outer raceway surfaces. Double row rolling elements are rollably arranged between the outer and inner raceway surfaces, via cages. A seal is mounted on one end of the outer member. The seal has integrally formed side lips adapted to be in sliding contact with the wheel hub. The base of the wheel mounting flange is formed to have a curved surface, in cross-section, of a circular arc.
    Type: Application
    Filed: August 22, 2011
    Publication date: December 15, 2011
    Applicant: NTN Corporation
    Inventors: Takayuki Norimatsu, Hiroaki Itakura, Hironori Imanaka, Syougo Suzuki, Isao Hirai, Hiroya Kato, Akira Fujimura, Kikuo Fukada
  • Patent number: 8021054
    Abstract: A vehicle wheel bearing apparatus has an outer member with a body mounting flange, an inner member and double row rolling elements freely rollably contained between the inner and outer raceway surfaces of the inner and outer members. The body mounting flange is formed with a plurality of screw apertures. An inner side flange surface of the body mounting flange is formed by machining to have a flat vertical surface relative to a longitudinal axis of a wheel hub. An outer side flange surface of the body mounting flange is formed by forging to have a tapered surface of a predetermined inclined angle. Thus, the thickness of the body mounting flange is gradually reduced radially outward.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: September 20, 2011
    Assignee: NTN Corporation
    Inventors: Isao Hirai, Takayasu Takubo, Kiyotake Shibata, Syougo Suzuki
  • Publication number: 20110135240
    Abstract: A wheel support bearing assembly includes an outer member (1) and an inner member (2), each having a raceway surface (3, 4). The inner member (2) is made up of a combination of a rotatable ring (9), having its outer periphery formed with a vehicle body fitting flange (9a), and a separate member (10). Each of the outer member (1) and the flanged rotatable ring (9) has a surface region representing a thermally refined structure formed by means of martensite hardening and high temperature tempering and also has a core region representing an as-forged structure made up of ferrite and pearlite.
    Type: Application
    Filed: August 18, 2009
    Publication date: June 9, 2011
    Inventor: Isao Hirai
  • Patent number: 7950858
    Abstract: A vehicle wheel bearing apparatus has an outer member formed with a body mounting flange on its outer circumferential surface. The body mounting flange is to be mounted on a knuckle of the vehicle. The outer member inner circumference includes double row outer raceway surfaces. An inner member includes a wheel hub with a wheel mounting flange formed on one end. A cylindrical portion extends from the wheel mounting flange. At least one inner ring is press-fit onto the cylindrical portion of the wheel hub. The inner ring outer circumference is formed with an inner raceway surface arranged opposite to the double row outer raceway surfaces. Double row rolling elements are freely rollably contained between the outer raceway surfaces and inner raceway surfaces of the outer member and the inner members. Seals are mounted within annular openings formed between the outer member and the inner member. The inner ring is axially secured relative to the wheel hub by a caulked portion.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: May 31, 2011
    Assignee: NTN Corporation
    Inventors: Takayuki Norimatsu, Akira Fujimura, Isao Hirai, Shinji Morita