Patents Assigned to NSK Ltd.
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Publication number: 20080199112Abstract: A linear guide apparatus includes a plurality of a rolling elements which circulates within a rolling element circulation path at predetermined intervals, spacers disposed between the respective rolling elements and a rolling elements accommodation belt which accommodates the rolling elements, connects each of the spacers and has ends thereof. At least one rolling element is disposed between the ends of the rolling elements accommodation belt, a cantilever-shaped elastically deformable projection is provided on an end face of the spacer situated at the end of the rolling elements accommodation belt, the projection projects from an inner circumferential side towards an outer circumferential side of the rolling element circulation path and the projection is inclined relative to an external end face of the spacer at the end of the rolling elements accommodation belt.Type: ApplicationFiled: February 6, 2008Publication date: August 21, 2008Applicant: NSK LTD.Inventors: Yoshinori MIZUMURA, Wei XU
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Publication number: 20080201041Abstract: A control device for an electric power steering apparatus includes a control unit which controls a motor giving steering assist force to a steering system according to a current command value computed based on steering toque and vehicle speed in a vector control manner and an advance angle map for compensating for a phase lag occurring in a motor current relative to the current command value. Advance angle compensation is made for the current command value based on the advance angle map.Type: ApplicationFiled: February 6, 2008Publication date: August 21, 2008Applicant: NSK LTD.Inventor: ChunHao JIANG
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Publication number: 20080199118Abstract: The magnetic encoder is constituted by integrally bonding a magnet portion obtainable by forming a magnetic material containing a magnetic powder and a binder for the magnetic powder in a circular ring shape to a slinger. The binder contains at least a thermoplastic resin and an impact resistance-improving agent.Type: ApplicationFiled: May 9, 2006Publication date: August 21, 2008Applicant: NSK LTD.Inventors: Toshikazu Yabe, Takeshi Murakami, Nariaki Aihara
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Patent number: 7413051Abstract: Since a nut 45 is provided with paths for connecting rolling paths 23b, 45f and circulating paths 45c, that is, return paths 45d at end caps 45b, 45b attached to both ends of a main body 45a, a receiving portion for receiving power transmitted from an electric motor 35, that is, a driven gear portions 45e is provided at a center of an outer peripheral face on outer sides in a radius direction of the rolling paths and therefore, when power is transmitted from the electric motor 35 to the driven gear portion 45e, smooth operation can be carried out by restraining the nut 45 from being twisted.Type: GrantFiled: March 21, 2005Date of Patent: August 19, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventor: Jun Okada
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Patent number: 7413222Abstract: A vehicular steering column system includes an outer column and an inner column which fits slidably in the outer column, whereby a relative position between the inner column and the outer column is adjusted by expanding and contracting the diameter of an inner circumferential surface of the outer column. An iron bush is provided between the inner circumferential surface of the outer column and an outer circumferential surface of the inner column in such a manner as to fit in or on at least the inner circumferential surface of the outer column or the outer circumferential surface of the inner column.Type: GrantFiled: August 31, 2004Date of Patent: August 19, 2008Assignee: NSK Ltd.Inventors: Kiyoharu Higashino, Kiyoshi Sadakata
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Patent number: 7412911Abstract: A steering column apparatus includes: a stationary column member; a movable column member whose one end is supported on the stationary column member nonrotatably about a center axis and movably along the center axis; a column head disposed on the other end of the movable column member; a wheel shaft supported rotatably on the column head; a column clamp for clamping and unclamping the movable column member with respect to the stationary column member at two or more points which are spaced along the center axis of the movable column member; and a control lever whose operation lever end is positioned in the vicinity of a steering wheel and which is capable of operating the column clamp.Type: GrantFiled: September 16, 2004Date of Patent: August 19, 2008Assignees: NSK, Ltd., NSK Steering Systems Co., Ltd.Inventors: Masaki Nishioka, Naoki Sawada
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Patent number: 7410190Abstract: In a motor-driven steering wheel position adjustment apparatus, a nut 17 being a driven member is mounted such that it can be detached from an inner column of a steering column, based on a shock load applied at the time of a secondary collision, and therefore a threaded rod of a feed screw mechanism does not have resistance with respect to displacement of the inner column in the forward direction at that time. Improvement in the protection of a driver at the time of a collision can thus be achieved, and, since an integrated member can be used for the threaded rod, silence during the position adjustment of a steering wheel by the feed screw mechanism can be ensured.Type: GrantFiled: February 17, 2006Date of Patent: August 12, 2008Assignee: NSK Ltd.Inventors: Naoki Sawada, Masato Iwakawa, Akihiro Shoda, Takeshi Fujiwara
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Patent number: 7410028Abstract: A steering control apparatus in which a steering shaft coupled to a steering wheel is mechanically separated from a turning mechanism to turn a turning wheel, a steering angle of the steering wheel is detected, and the turning mechanism turns the turning wheel by a turning angle corresponding to the steering angle, includes a hypercycloidal mechanism including an external tooth gear revolving in a housing according to rotation of the steering wheel, an Oldham coupling mechanism to extract only a self-rotating movement in a rotation movement of the external tooth gear as a self-rotating movement of a rotation disk, and a rotation regulating mechanism by engagement between a groove formed in the rotation disk and a projection projecting from the housing.Type: GrantFiled: December 24, 2003Date of Patent: August 12, 2008Assignee: NSK Ltd.Inventor: Kazuo Chikaraishi
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Publication number: 20080187261Abstract: A ball bearing has an inner ring fitted on a rotational shaft and including an inner ring raceway on an outer circumferential surface thereof, an outer ring including an outer ring raceway on an inner circumferential surface thereof, a plurality of balls rotatably provided between the inner ring raceway and the outer ring raceway and a crown resin cage for retaining the balls at equal intervals in a circumferential direction. A bore diameter of the inner ring is 100 mm or more, and a radial clearance resulting in a state that the inner ring is assembled to the rotational shaft is 20 ?n or more.Type: ApplicationFiled: January 29, 2008Publication date: August 7, 2008Applicant: NSK Ltd.Inventors: Susumu TANAKA, Yoshiaki SAKAJIRI, Yuuki TSUCHIDA
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Patent number: 7404768Abstract: A telescopic shaft for vehicle steering has first and second torque transferring members. The first torque transferring member is interposed, with an elastic body in between, between axial grooves formed in an outer peripheral surface of a male shaft and an inner peripheral surface of a female shaft. The second torque transferring member is interposed between other axial grooves formed in the outer peripheral surface of the male shaft and in the inner peripheral surface of the female shaft. The elastic body has transferring-member-side contact portions contacting the first torque transferring member, shaft-side contact portions contacting groove surfaces of the axial groove of the male shaft or the female shaft, and a biasing portion for elastically urging the transferring-member-side contact portions and the shaft-side contact portions away from each other. Rigidity of the transferring-member-side contact portions is different from that of the shaft-side contact portions.Type: GrantFiled: June 11, 2004Date of Patent: July 29, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventor: Yasuhisa Yamada
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Patent number: 7404675Abstract: A retainer for a ball bearing formed in a generally annular shape and having a plurality of pockets arranged in a circumferential direction, respectively, to rollably hold a plurality of balls along a pitch circle, respectively, the pockets each having an inner peripheral surface comprising a radially inner section which is located inward of the pitch circle of the balls in the radial direction of the retainer, and has an inner diameter larger than the diameter of the balls, such that the gap between the radially inner section of the inner peripheral surface of the pockets and the rolling surface of the balls gradually increases toward the opening of the pockets on the inner side in the radial direction of the retainer, and that the maximum inscribing circle of the opening of the pockets on the outer side in the radial direction of the retainer has a diameter smaller than the diameter of the balls.Type: GrantFiled: December 29, 2003Date of Patent: July 29, 2008Assignee: NSK Ltd.Inventor: Fusasuke Gotoh
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Patent number: 7401813Abstract: In a steering apparatus for a vehicle in which an inner column is supported to be movable in the axial direction by an outer jacket supported by a body-side bracket and a steering shaft is fixed to an adjustment position by clamping the inner column by the use of telescopic clamping means through the outer jacket, the outer jacket is provided with a slit entirely along the axial direction thereof.Type: GrantFiled: March 17, 2004Date of Patent: July 22, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: Naoki Sawada, Yuichi Tomaru
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Patent number: 7402550Abstract: A rolling bearing holding two or more rolling elements 13 between inner ring 10 and outer ring 11 in such a way that these rolling elements can freely roll, and packed with a grease is described, wherein the grease is a mixture of at least one of metal complex soap-based grease and urea-based grease, each incorporated with 8 to 35% by mass of thickening agent, and fluorine-based grease comprising perfluoropolyether oil as a base oil incorporated with 15 to 42.5% by mass of polytetrafluoroethylene as a thickening agent, ratio of said at least one of the metal complex soap-based grease and urea-based grease versus said fluorine-based grease being 40 to 80:60 to 20 by mass, and total content of the thickening agents being 20 to 30% by mass.Type: GrantFiled: July 28, 2004Date of Patent: July 22, 2008Assignee: NSK Ltd.Inventor: Kenichi Iso
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Patent number: 7401978Abstract: A linear guiding device where noise characteristics are improved by reducing traveling noise and operability of a slider body is smoothed, and where movement braking can be improved by reducing rolling body passage vibration. Crowning 24 with a curved surface having a predetermined curvature radius R is provided on an end section of a rolling body raceway groove 11 of a bearing block 24. A crowning amount C of the crowning 24 is set to a value C>Hmax greater that the value of a maximum elastic deformation amount Hmax of a rolling body B elastically deformed in a rolling body rolling path 14 by a preload or an external load. By this, even when a large load acts on a bearing block 2A or a large installation error occurs by skewing etc., the rolling body B smoothly rolls without an elastic deformation amount of the rolling body B rolling on the end section side of the rolling body raceway groove 11 becoming greater than the crowning amount C.Type: GrantFiled: August 24, 2004Date of Patent: July 22, 2008Assignees: NSK Ltd., NSK Precision Co., Ltd.Inventors: Kenta Nakano, Ryoichi Sato, Hiroki Yamaguchi
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Patent number: 7402970Abstract: The present invention includes a control part for controlling switching elements on diagonal lines in the upper and lower stage of an H bridge circuit respectively by different duty ratios based on a steering torque exerted on a steering system, and an electric power supply source for supplying an electric power. When the voltage of the electric power supply source is lower than a prescribed voltage, the control part causes the switching element EET 1 or FET2 on the upper-stage side to be driven by a pulse width modulation signal PWM1 or PWM2, the switching element FET 4 or FET3 on the lower-stage side to be turned on, and the frequency of the pulse width modulation signal to be lowered to an audible frequency range.Type: GrantFiled: August 23, 2006Date of Patent: July 22, 2008Assignee: NSK Ltd.Inventors: Hideaki Kawada, Yuho Aoki
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Publication number: 20080168854Abstract: A reduction gear in which an engaging surface of gear teeth is processed so that grease for lubricating the engaging surface is sufficiently supplied over the entire of the engaging surface, thereby reducing the friction caused on the engaging surface, and increasing the durability of the gear teeth is provided. In a reduction gear which includes a worm made of metal and a worm wheel having gear teeth which engage with the worm, wherein at least the gear teeth of the worm wheel are made of synthetic resin, and in which an engaging surface of the gear teeth is lubricated by grease, the engaging surface has over an entire surface a plurality of grease reservoir grooves formed along a sliding line of the engaging surface.Type: ApplicationFiled: July 27, 2005Publication date: July 17, 2008Applicant: NSK LTD.Inventor: Toshiyuki Iwano
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Patent number: 7397210Abstract: In the present invention, only an abnormality of detection of a rotating direction of a motor is detected and therefore, with simple processing and by using a table for judging the abnormality of the detection of a rotating direction of a motor and the rotating direction of the motor, the abnormality of the detection of a rotating direction and the rotating direction of the motor are judged at one time.Type: GrantFiled: October 6, 2004Date of Patent: July 8, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: Kenji Arai, Yuho Aoki
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Publication number: 20080156573Abstract: A rack and pinion steering gear 10 including a pinion shaft 11 coupled to a steering shaft, a rack shaft 12 which meshes with the pinion 11, and a rack guide 14 having provided thereon a metallic roller 16 adapted to roll on a back side of the rack shaft 12 and adapted to support the rack shaft 12 via the metallic roller 16, wherein the metallic roller 16 has an elastic member 32 which is partially secured to a rolling contact surface 29 thereof in a circumferential direction, whereby the metallic roller 16 is brought into contact with the back side of the rack shaft 12 at a metallic portion of the rolling contact surface 29 and the elastic member 32 By this configuration, the generation of abnormal noise can be suppressed, and the increase in driving stability of the vehicle can be realized.Type: ApplicationFiled: April 4, 2006Publication date: July 3, 2008Applicant: NSK LTD.Inventor: Shinya Amada
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Publication number: 20080156138Abstract: When a lower column 3 tilts upwards or downwards, a vehicular front end face 831 of a resin cover 83 having a small friction coefficient tilts slidably along a first guide surface 22A of a left-hand side plate 22 of a vehicle body mounting upper bracket 2. Consequently, since there emerges no situation in which the front end face 831 is caught on the first guide surface 22A of the left-hand side plate of the vehicle body mounting upper bracket 2, a smooth tilt position adjustment can be implemented without any abnormal noise. Further, in secondary collision, the front end face 831 of the resin cover 83 collides with the first guide surface 22A of the left-hand side plate 22 of the vehicle body mounting upper bracket 2, whereby frontward impact force can be transmitted to the vehicle body mounting upper bracket 2 in an ensured fashion.Type: ApplicationFiled: December 18, 2007Publication date: July 3, 2008Applicant: NSK LTD.Inventors: Masaki TOMARU, Kouji NAGAI, Kouhei YONEZAWA
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Patent number: 7394214Abstract: In order to solve a problem that a motor generates a noise so as to deteriorate an environment in a vehicle if a field weakening control is executed to the motor of a electric power steering apparatus, in the case that a vehicle speed is high, the same field weakening control as the conventional one is applied to the motor because a noise generated due to a friction between a tire and a road surface and a wind noise of a vehicle body are large, and in the case that the vehicle speed is low, the field weakening control is weakly applied in comparison with the conventional one because the noise generated by the motor is felt relatively largely. Accordingly, the field weakening control can be executed in response to the vehicle speed in such a manner as to make the motor noise smaller.Type: GrantFiled: November 11, 2004Date of Patent: July 1, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: Shuji Endo, Yuho Aoki