Patents Assigned to Koyo Seiko Co., Ltd.
  • Patent number: 8336412
    Abstract: An electric power steering apparatus in which steering assistance is achieved by transmitting a rotary motion of an electric motor for steering assistance to a steering shaft on which a worm wheel is mounted through a worm shaft on which a worm is mounted, wherein the worm shaft is deflectable toward the worm wheel and equipped with a biasing member biasing the worm shaft in the deflective direction thereof, or alternatively, the worm wheel is deflectable toward the worm shaft and equipped with a biasing member biasing the worm wheel in the deflective direction thereof.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: December 25, 2012
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Yasuhiro Ishii, Osamu Sano, Hirokazu Arai
  • Patent number: 7763124
    Abstract: Provided are a steel having excellent rolling contact fatigue life and the manufacturing method thereof. The steel consists essentially of 0.7 to 1.1% C, 0.2 to 2.0% Si, 0.4 to 2.5% Mn, 1.6 to 4.0% Cr, 0.1% or more and less than 0.5% Mo, 0.010 to 0.050% Al, bymass, and balance of Fe and inevitable impurities, is treated by quenching and tempering, has residual cementite grain sizes ranging from 0.05 to 1.5 ?m, and has prior-austenite grain sizes of 30 ?m or smaller. When the steel is used to bearing steel, the bearing life extends even under service in more severe environments.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: July 27, 2010
    Assignees: JFE Steel Corporation, Koyo Seiko Co., Ltd.
    Inventors: Takashi Iwamoto, Akihiro Matsuzaki, Kazuhiko Ohno, Masao Goto, Hisashi Harada, Hisato Nishisaka
  • Patent number: 7709427
    Abstract: Disclosed are a lubricant composition to which is added as buffer particles to a lubricant polyurethane resin particles obtained by reacting and synthesizing long-chain polyol having a number-average molecular weight of not less than 500, a crosslinking agent having three or more active hydrogen groups in one molecule, and polyisocyanate as buffer particles, a speed reduction gear filled with the lubricant composition, and an electric power steering apparatus having the speed reduction gear incorporated therein, wherein noise produced by the speed reduction gear can be made lower than ever before irrespective of the magnitude of backlash in a case where a worm and a worm wheel are combined with each other and without complicating the configuration of the speed reduction gear by the buffer action of the buffer particles added to the lubricant composition, thereby making it possible to reduce noise produced in an automobile due to the electric power steering apparatus at low cost.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: May 4, 2010
    Assignees: Koyo Seiko Co., Ltd., Nippon Polyurethane Industry Co., Ltd.
    Inventors: Kouji Kitahata, Naoki Uchida, Mitsuo Yoneda, Masahiro Hayashi
  • Patent number: 7690846
    Abstract: A bearing device is provided with a bearing ring and a shaft body that is made of carbon steel including pearlite having a cementite layer structure, and has an end portion caulked onto the bearing ring, and in this device, at least in the end portion of the shaft body, the layer gap of the cementite in the pearlite is made greater.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: April 6, 2010
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Kazutoshi Toda, Shinichirou Kashiwagi, Daisaku Tomita
  • Patent number: 7662245
    Abstract: A steel bar for a steering rack that contains 0.50 to 0.60% by mass of C, 0.05 to 0.5% by mass of Si, 0.2 to 1.5% by mass of Mn, 0.0005 to 0.003% by mass of B, 0.005 to 0.05% by mass of Ti, 0.0005 to 0.1% by mass of Al, and 0.002 to 0.02% by mass of N is provided. Given D as a diameter of the steel bar, then the steel bar is adjusted in such a manner that quenched and tempered structures in a portion of the steel bar at a depth of D/4 from a surface satisfy conditions I), II), and III) as follows: I) a sum of a tempered bainitic structure and a tempered martensitic structure accounts for 30 to 100% in area percentage; II) a regenerated perlite structure accounts for 0 to 50% in area percentage; and III) a sum of the tempered bainitic structure, the tempered martensitic structure, and the regenerated perlite structure accounts for 50 to 100% in area percentage.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: February 16, 2010
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Atsuhiko Ohta, Makoto Kamei, Kazuhiro Watanabe, Yukinori Kanaike, Osamu Tsukamoto, Masakazu Ikeda, Gorou Anan, Hiroshi Itoziri
  • Patent number: 7612556
    Abstract: The rolling bearing apparatus of the present invention comprises a rolling element, a non-rolling element disposed concentrically with the rolling element, and a rotation detector for outputting an input exciting voltage by converting it to an induced voltage according to the relative rotation state of the rolling element and the non-rolling element. The rotation detector comprises a rotor provided in the rolling element, a stator provided in the non-rolling element, and an exciting winding and output windings being wound to the stator. The output windings induce a voltage according to the gap permeance between the rotor and the stator in response to the exciting voltage inputted to the exciting winding.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: November 3, 2009
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Masahiro Inoue
  • Patent number: 7540569
    Abstract: A flange face portion located radially outwardly of boltholes of a flange is formed as a tilting face so that a maximum oppositely-spaced distance ? of the flange face portion from a disc rotor is preferably 10 ?m. Thereby, minimization is implemented for convex deformation of an outer circumferential end portion of the flange when bolts are press-inserted into boltholes, when nuts are tightened onto bolts, tightening forces compress the disc rotor and the flange to be in close contact and to be fixed-via planar surfaces thereof without clearance being formed therebetween. Consequently, the accuracy of side run-out with surface of the flange can be prevented from being deteriorated.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: June 2, 2009
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Shunji Morimoto, Nobuyoshi Murakami, Koichi Nate
  • Patent number: 7524238
    Abstract: A method of processing an antifriction bearing unit for a wheel, the antifriction bearing unit including an outer race, an inner race, a plurality of rolling elements and a flange portion for directly or indirectly mounting a brake disk provided to one of the outer and inner races, the method includes: assembling the outer and inner races and the rolling element together; after assembling, placing the one of the outer and inner race in position incapably of circumferential rotation; grinding the flange portion by bring the flange portion into contact with a grindstone which is rotated while the other of the outer and inner race is left free.
    Type: Grant
    Filed: April 5, 2007
    Date of Patent: April 28, 2009
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Takeshi Fukao, Toshihiro Nakano
  • Patent number: 7512468
    Abstract: In an electric power steering apparatus which comprises a motor for generating steering assist force, it is judged whether or not the vehicle is in a state of straight forward motion. A mean reference steering angle is determined by dividing total of relative steering angles which are determined when the vehicle is judged to be in a state of straight forward motion by the number of judgments that the vehicle is in a state of straight forward motion. A steering angle is determined by subtracting a steering angle midpoint from a relative steering angle with taking the mean reference steering angle as the steering angle midpoint. The output of the motor for generating steering assist force is corrected in accordance with an output correction value determined on the basis of the determined steering angle. This output correction value is altered so as to have a positive correlation with the number of judgments that the vehicle is in a state of straight forward motion.
    Type: Grant
    Filed: October 19, 2005
    Date of Patent: March 31, 2009
    Assignees: Favess Co., Ltd., Koyo Seiko Co., Ltd., Toyoda Koki Kabushiki Kaisha
    Inventors: Terutaka Tamaizumi, Yuji Kariatsumari
  • Patent number: 7508148
    Abstract: A current sensor 8a detects a motor current of a steering motor 5 which supplies a steering mechanism 1 with steering force corresponding to the steering amount applied to a steering wheel 2. A main controller 4 extracts component within a predetermined frequency range out of a motor current detected by the current sensor 8a, amplifies the extracted component and drives a reaction force motor 3 in a controlled manner so as to supply the steering wheel 2 with steering reaction force corresponding to the steering amount applied to the steering wheel 2 and steering reaction force corresponding to a current of the component, which has been extracted and amplified. The vehicle steering apparatus constructed as above can supply steering means with steering reaction force corresponding to component within a predetermined frequency range of a motor current of the steering motor.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: March 24, 2009
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Koji Kanda
  • Patent number: 7488270
    Abstract: In a toroidal continuously variable transmission, rolling contact portions of an input disc 4, an output disc 7, and roller 13 are formed of bearing steel, which contains C: 0.8-1.5 wt %; Si: 0.5-2.5 wt %; Mn: 0.3-2.0 wt %; Cr: 1.9-2.5 wt %; Mo: 0.3-1.0 wt %; and a total of 1.0 wt % or more of Si and Mo; with the balance being iron and unavoidable impurities. A residual austenite in a range of depth Z=1.0L, where L is the major axis of a contact ellipse of the traction contact portion, from the surface of the rolling contact portion is 15 wt % or less, and the hardness of the range is HRC 58-62 by tempering a blank with a predetermined shape at a temperature of 250° C. or more after quenching the blank.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: February 10, 2009
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Hisashi Harada, Yoshihiro Ono
  • Patent number: 7484890
    Abstract: There is provided a rolling slide member coming in contact with a mating member in a rolling or sliding manner, wherein a plurality of grooves having an inclination of 0 to 30 degree and a groove depth of 0.5 to 15 ?m are formed in a circumferential direction at the time of grinding a contact surface with the mating member. In the contact surface, the axial surface waviness is set to 0.1 or more in the filtered centerline waviness (WCA) and the axial surface roughness is set to 0.7 or more in the ten-point height of roughness profile (Rz) by the grooves 26.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: February 3, 2009
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Takaaki Ikeda, Yoshiaki Sakaki, Kazuyoshi Kurihara, Yoshitaka Waseda, Masanori Setsuda, Kenichi Watanabe
  • Patent number: 7484760
    Abstract: A column hole cover is interposed between a circumferential portion of an aperture of a column hole of an instrument panel and a steering gear box capable of being displaced in a predetermined direction. The column hole cover includes a cylindrical main body extended in the predetermined direction. The main body includes a first annular end portion directly or indirectly fixed to the steering gear box, and a second annular end portion. The second end portion is provided with an annular seal. An intermediate portion between the first and second end portions is provided with a expandable/contractible portion capable of being elastically expanded or contracted in the predetermined direction. Irrespective of the displacement of the steering gear box, the annular seal is maintained in an elastic pressure contact against the circumferential portion of the aperture of the instrument panel by a reaction force of the compressed expandable/contractible portion.
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: February 3, 2009
    Assignees: Koyo Seiko Co., Ltd., Marugo Rubber Industries, Ltd.
    Inventors: Hirohisa Suzuki, Seizou Furukawa, Noboru Yamamoto, Teruya Fujiwara
  • Publication number: 20080309322
    Abstract: A wheel speed detector for detecting a relative rotating speed between an outer ring and an inner ring by means of a magnetic sensor in association with a magnetic ring. A stationary seal member is fixed to the stationary ring and a rotatable seal member is fixed to the rotatable ring. The seal members engage to seal a gap between the inner ring and the outer ring. The magnetic sensor is fixed to a radial inner surface of the stationary seal member and the magnetic ring is fixed to a radial outer or a radial inner surface of the rotatable seal member and surfaces of the magnetic ring other than that fixed to the radial inner surface of the rotatable seal member are covered with a seal lip.
    Type: Application
    Filed: August 27, 2007
    Publication date: December 18, 2008
    Applicant: KOYO SEIKO CO., LTD.
    Inventors: Minoru Sentoku, Motoshi Kawamura, Kazutoshi Toda, Nobuyuki Seo, Naoki Morimura, Tomohiro Ishii, Kanichi Kouda, Yoshifumi Shige, Fujio Harumi
  • Patent number: 7438740
    Abstract: With the object of effective utilization of a fine powder generated during comminution of a crude material for iron manufacture, a briquette is provided which comprises a porous brittle molded body with a bulk specific gravity of 1.5 or more which is obtained by compression molding a molding composition comprising a fine powder generated during comminution of a crude material for iron manufacture and a reinforcing portion for reinforcing the brittle molded body. Further, with the object of effective reuse of used alumina grinding stones, a briquette is provided which comprises a porous brittle molded body obtained by compression molding a molding composition comprising a comminuted powder of a used alumina grinding stone and a cotton-like aggregate comprising a grinding powder of a ferrous metal and a grinding liquid, and a reinforcing portion for reinforcing the brittle molded body.
    Type: Grant
    Filed: March 8, 2004
    Date of Patent: October 21, 2008
    Assignee: Koyo Seiko Co. Ltd.
    Inventors: Mitsuma Matsuda, Masafumi Sedou
  • Patent number: 7435008
    Abstract: There are provided tapered roller bearings which support a pinion shaft. Inner races have large rib faces each having a recessed surface shape on which large-diameter end faces of tapered rollers slide. The surface roughness of the large-diameter end face is ?1 [?mRa] is 0.025 or more. In addition, assuming the surface roughness of the large rib face is ?2 [?mRa], (?12+?22)1/2 is 0.17 [?mRa] or less. The sliding portion of the large-diameter end face and the sliding portion of the large rib face are made of a carburized steel, and the carbon content in a matrix phase in a surface layer portion of each of the sliding portions to a depth of 50 ?m from a surface is 0.8 wt % or more, the surface hardness thereof is in the range of Rockwell C63 to 67, and a surface retained austenite amount is set to be 20% or more and 25% or less.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: October 14, 2008
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Toshihiro Kawaguchi
  • Patent number: 7431511
    Abstract: A rolling bearing includes: outer and inner rings, at lease one of which is made of a ceramics; a plurality of rolling elements interposed between the outer and inner rings; a seal groove, a sectional shape in an axial direction of which is formed by substantially a partial circular arc, and which is formed on a shoulder portion of a raceway of one of the outer and inner rings; and a resin seal member including a peripheral edge portion fitted to the seal groove.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: October 7, 2008
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Kazuhisa Kitamura, Tomoya Hattori, Kazunori Hayashida, Kenichi Kouduki, Kazuyoshi Yamakawa
  • Patent number: 7413704
    Abstract: A case hardening bearing steel having an excellent rolling contact fatigue life in intermediate temperature, in addition, excellent toughness at room temperature is provided. Specific means for solving the problems are as follows. The composition contains, by mass percent, C of 0.15 to 0.30 mass percent, Si of 0.5 to 2.0 mass percent, Mn of 0.3 to 2.0 mass percent, Cr of 1.3 to 2.5 mass percent, Mo of 0.3 to 1.0 mass percent, and O of not more than 0.0012 mass percent in a range where (Si+Mo)?1.0 mass percent is satisfied, and contains iron and inevitable impurities as remnant; the maximum size of oxide nonmetallic inclusion is not more than 12.5 ?m when examined area is 320 mm2; number of the oxide nonmetallic inclusion having a diameter of equivalent circle of 3 ?m or more is not more than 250 when the examined area is 320 mm2; in addition, C density of an outer layer is adjusted to be in a range from 0.7 to 1.2 mass percent by carburization.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: August 19, 2008
    Assignees: JFE Steel Corporation, Koyo Seiko Co., Ltd.
    Inventors: Akihiro Matsuzaki, Takashi Iwamoto, Masao Goto, Katsuhiko Kizawa
  • Patent number: 7402006
    Abstract: This method includes: a supporting process of supporting a worm wheel in a first supporting section of a supporting body; an engaging process of engaging a jig gear which corresponds to a worm with the worm wheel; a measuring process of measuring a distance between the centers of the worm wheel and the jig gear; a gear processing process of processing the worm based on the measured distance between the centers; and a supporting process of supporting the worm in a second supporting section of the supporting body after releasing the engagement between the worm wheel and the jig gear.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: July 22, 2008
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Hiroshi Yoshikawa
  • Patent number: 7387034
    Abstract: A torque detecting apparatus having a permanent magnet fixed to an input shaft, magnetic yokes fixed to an output shaft coaxially connected to the input shaft via a torsion bar and disposed within a magnetic field of the permanent magnet to form a magnetic circuit, and a Hall IC for detecting a magnetic flux induced by the magnetic yokes. The permanent magnet is of a truncated conical shape, and the bevel circumference surface thereof is magnetized by magnetic poles alternately in a reverse polarities along circumference direction, so as to oppose the magnetic yokes. A torque applied to the input shaft or the output shaft can be detected through detection by the Hall IC of the magnetic flux generated between the magnetic yokes. The configuration allows reducing the length in an axial direction of the input shaft.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: June 17, 2008
    Assignees: Koyo Seiko Co., Ltd., Favess Co., Ltd., Denso Corporation
    Inventors: Toshiharu Ishihara, Taisuke Tsujimoto, Naoki Nakane