Patents Assigned to NSK Ltd.
  • Patent number: 11892060
    Abstract: A frictional roller reducer having a sun roller; a ring roller; a plurality of intermediate rollers having rolling surfaces coming in rolling contact with the sun roller and the ring roller; the sun roller or the ring roller having a pair of roller elements including inclined surface portions on a circumferential surface coming in rolling with rolling surfaces, the inclined surface portions inclined in directions going toward the intermediate rollers in a radial direction as going away from each other in the axial direction; a pressing device pressing the pair of roller elements in directions going closer to each other, and an elastic member arranged between the pair of roller elements, the elastic member urging the pair of roller elements in directions going away from the rolling surface of the intermediate rollers.
    Type: Grant
    Filed: December 3, 2021
    Date of Patent: February 6, 2024
    Assignee: NSK LTD.
    Inventors: Hiroshi Kawahara, Hiroki Hashiguchi, Hirofumi Itagaki, Azusa Hidaka, Hiroki Nishida, Naofumi Fujita, Hikari Yoshimi, Naohiro Hitomi, Masahiro Kita
  • Publication number: 20240039453
    Abstract: A motor control device includes temperature detection elements that are mounted on a circuit board on which a first power conversion circuit and a second power conversion circuit are mounted and are arranged at a position between the first power conversion circuit and the second power conversion circuit.
    Type: Application
    Filed: March 3, 2023
    Publication date: February 1, 2024
    Applicant: NSK LTD.
    Inventor: Akio MARUHASHI
  • Publication number: 20240035528
    Abstract: In a predetermined first state, a distance (D1) in a second direction between a contact portion (Pin) between a input-side engaging part (9) and an input-side engaging part (17) and a rotation center (O) is larger than a distance (D2) in the second direction between a contact portion (Pout) between an output-side engaging part (12) and an output-side engaged part (14) and the rotation center (O). In a locked state or a semi-locked state, a contact portion (C1) between the output-side engaging part (12) and the output-side engaged part (14) is located closer to the rotation center (O) of the output member (4) in a first direction than an imaginary straight line (L) connecting a contact portion (C2) between one pressing surface (13) of the pair of pressing surfaces (13) and a pressed surface (6) to the rotation center (O) of the output member (4).
    Type: Application
    Filed: November 11, 2022
    Publication date: February 1, 2024
    Applicant: NSK Ltd.
    Inventors: Nagao DOHI, Shohei KANEKO
  • Publication number: 20240035906
    Abstract: This load estimating device for a rolling bearing comprises: a vibration sensor for measuring vibrations of the rolling bearing during rotation; a rotational speed sensor for measuring the rotational speed of the rolling bearing during rotation; a deriving means for deriving a vibration value for a predetermined vibration frequency, using vibration information measured by the vibration sensor; and an estimating means for estimating a load acting on the rolling bearing, said load corresponding to the rotational speed measured by the rotational speed sensor and the vibration value derived by the deriving means, using a table defining a correspondence relationship between the load acting on the rolling bearing, the vibration value for the predetermined vibration frequency, and the rotational speed.
    Type: Application
    Filed: June 8, 2022
    Publication date: February 1, 2024
    Applicant: NSK Ltd.
    Inventor: Kinji YUKAWA
  • Patent number: 11884318
    Abstract: A steering device including a steering column supporting a steering shaft to be coupled to a steering wheel. The steering column is sandwiched between a bracket including a first support plate and a second support plate with a tightening shaft penetrating the first support plate and the second support plate and including a male thread at an end of the tightening shaft on a side close to the second support plate having a nut attached thereon. An operation lever is disposed between the nut and the second support plate and penetrated by the tightening shaft. A case including a bottom surface facing an end surface of the tightening shaft is attached to the operation lever, and a coil spring coming into contact with the bottom surface and the tightening shaft.
    Type: Grant
    Filed: November 5, 2020
    Date of Patent: January 30, 2024
    Assignee: NSK LTD.
    Inventors: Shin Mihara, Osamu Kurihara
  • Publication number: 20240026959
    Abstract: The nut has a first fitting surface provided with a first retaining ring groove on an end portion on the other side in the axial direction; the fitting cylinder, at an end portion on the one side in the axial direction, has a second fitting surface provided with a second retaining ring groove in a portion facing the first retaining ring groove with regard to a radial direction; and the retaining ring is engaged so as to span between the first retaining ring groove and the second retaining ring groove.
    Type: Application
    Filed: August 3, 2022
    Publication date: January 25, 2024
    Applicant: NSK LTD.
    Inventors: Yasumi WATANABE, Ryo SEGAWA, Tomoko MIYAMORI
  • Publication number: 20240026927
    Abstract: The present invention provides a grease composition which makes it possible to prevent deterioration in sealing properties even when base oil having a kinetic viscosity of as low as, for example, 5-40 mm2/s is used and which makes it possible to realize both sealing properties and a decrease in torque. The present invention also provides a rolling device. A sealing member (12a) comprises a plurality of sealing lips (114), (115), (116) each of which is made of an elastic material. A grease composition is sealed in void parts (121), (122) that are each located between a sliding surface of a slinger (106), on which the plurality of sealing lips slide, and two adjacent sealing lips. This grease composition contains base oil and a polar polymer. The polar polymer has a weight-average molecular weight of 5,000-140,000.
    Type: Application
    Filed: November 19, 2021
    Publication date: January 25, 2024
    Applicant: NSK LTD.
    Inventors: Azuma ITO, Tomoaki MATSUMOTO, Haruhisa ASHIDA
  • Patent number: 11877899
    Abstract: The rolling bearing includes: an outer ring having an outer ring raceway surface on an inner peripheral surface; an inner ring having an inner ring raceway surface on an outer peripheral surface; rolling elements rotatably arranged between the outer ring raceway surface and the inner ring raceway surface; and a seal member that is fixed to a seal attachment groove formed in an axially end portion of the outer ring by a snap ring and seals an axially end portion of a bearing internal space between the outer ring and the inner ring, in which an outer diameter of the seal member is larger than an outer diameter of the snap ring in the seal attachment groove, and in which a radially outer end portion of the seal member is sandwiched between an inner peripheral surface of the seal attachment groove and an outer peripheral surface of the snap ring.
    Type: Grant
    Filed: March 11, 2020
    Date of Patent: January 23, 2024
    Assignee: NSK LTD.
    Inventors: Takuya Oyama, Hironori Suzuki
  • Patent number: 11873031
    Abstract: The rack housing has an engaging concave section having a bottom surface configured by a bottom inclined surface that is inclined in a direction outward in the radial direction toward the opening side of the rack housing, and the rack bush comprises an engaging convex section having a top surface configured by a top inclined surface that is inclined in a direction outward in the radial direction toward the opening side of the rack housing. The top inclined surface is pressed against the bottom inclined surface toward outside in the radial direction, and the outside surface of the engaging convex section facing the opening side of the rack housing is pressed against the inner side surface of the engaging concave section facing the inner side of the rack housing.
    Type: Grant
    Filed: August 1, 2019
    Date of Patent: January 16, 2024
    Assignee: NSK LTD.
    Inventor: Tatsuya Ishii
  • Patent number: 11872693
    Abstract: A robot mechanism is provided with a parallel link including a first output base, a first parallel link mechanism disposed on a first side of the first output base, and a second parallel link mechanism and an end effector disposed on a second side of the first output base. The first parallel link mechanism includes a first driver that generates a linear motion output and a second driver that generates a linear motion output. A tilting link mechanism including a mass body that generates a second moment load in a direction to reduce a first moment load exerted on the first parallel link mechanism by the weight of the second parallel link mechanism and the end effector is connected to the first driver and the second driver.
    Type: Grant
    Filed: December 2, 2021
    Date of Patent: January 16, 2024
    Assignee: NSK LTD.
    Inventors: Kohei Shirahama, Sumio Sugita, Satoshi Inagaki
  • Patent number: 11873039
    Abstract: A motor control device includes a third harmonic calculation unit configured to calculate a first third harmonic on a basis of an average value between a voltage command value of a maximum phase with a maximum duty ratio and a voltage command value of a minimum phase with a minimum duty ratio among three-phase voltage command values; an amplitude calculation unit configured to calculate an amplitude of the three-phase voltage command values; a third harmonic conversion unit configured to convert the first third harmonic into a second third harmonic on a basis of the first third harmonic and the amplitude; a correction unit configured to correct the three-phase voltage command values by subtracting the second third harmonic from the three-phase voltage command values.
    Type: Grant
    Filed: October 2, 2020
    Date of Patent: January 16, 2024
    Assignee: NSK LTD.
    Inventors: Yasutoshi Miki, Masahiro Maeda
  • Patent number: 11867264
    Abstract: A ball screw device comprising: a screw shaft, a nut, balls arranged between the shaft-side ball thread groove and the nut-side ball thread groove, a stopper including: a boss portion fitted to the fitting shaft portion of the screw shaft, and a second engaging portion protruding in the radial direction from the boss portion and engageable with a first engaging portion of the nut in the circumferential direction, and a holding member arranged adjacent to one side in the axial direction of the stopper, such that an axial load can be transmitted between the screw portion of the screw shaft and the holding member through the stopper without applying a moment to the stopper.
    Type: Grant
    Filed: April 11, 2022
    Date of Patent: January 9, 2024
    Assignee: NSK LTD.
    Inventor: Ryo Segawa
  • Patent number: 11867242
    Abstract: A power transmission path switching device has a friction engaging device; a rotation transmission state switching device comprising a first member and a second member arranged coaxial with each other and having: a free mode and/or a one-way clutch mode allowing rotation of the first member with respect to the second member, and a lock mode preventing rotation of the first member with respect to the second member; and a control device that, when connecting the friction engaging device and setting the rotation transmission state switching device to the lock mode, has a function of connecting the friction engaging device, and then while maintaining the friction engaging device in a connected state, switches the rotation transmission state switching device to the lock mode.
    Type: Grant
    Filed: June 29, 2021
    Date of Patent: January 9, 2024
    Assignee: NSK LTD.
    Inventors: Akihiro Yamamoto, Hirotaka Kishida
  • Patent number: 11867262
    Abstract: The frictional roller reducer has an input shaft, an output shaft, a pair of annular roller elements, a plurality of planetary rollers, a carrier, a pressing device, and a controller. The pressing device rotationally drives a cam disk by a pressing force adjusting motor, which causes an annular roller element of the pair of annular roller elements to displace in the axial direction. The controller, by adjusting the rotational drive of the pressing force adjusting motor, adjusts the surface pressure at the traction portions between rolling surfaces of the planetary rollers and an inner-diameter side rolling contact surface of the input shaft and outer-diameter side rolling contact surfaces of the pair of annular roller elements to a target value.
    Type: Grant
    Filed: January 10, 2020
    Date of Patent: January 9, 2024
    Assignee: NSK, LTD.
    Inventors: Hiroshi Kawahara, Hirofumi Itagaki
  • Patent number: 11858142
    Abstract: Provided are a manipulation system and a driving method of the manipulation system capable of performing manipulation efficiently and suitably while suppressing damage to a minute object at the time of manipulation regardless of the degree of skill and technique of an operator. A sample stage configured such that a minute object is placed thereon, a first manipulator including a first pipette for holding the minute object, a second manipulator including a second pipette for operating the minute object that is held on the first pipette, an imaging unit for imaging the minute object, and a controller that controls the sample stage, the first pipette, the second pipette, and the imaging unit are provided.
    Type: Grant
    Filed: May 27, 2019
    Date of Patent: January 2, 2024
    Assignee: NSK LTD.
    Inventors: Hiroki Ueda, Manabu Kishida, Nobuaki Tanaka
  • Patent number: 11858136
    Abstract: A parallel link mechanism includes three or more link mechanisms that couple a fixed base and an end-effector base. The end-effector base has a facing surface facing the fixed base. The link mechanisms each include a proximal-end joint, a proximal link, an intermediate joint, a distal link, and a distal-end joint. The proximal-end joint is rotatably coupled to the fixed base. The proximal link is coupled to the proximal-end joint. The intermediate joint is provided to the proximal link. The distal link is rotatably coupled to the proximal link via the intermediate joint. The distal-end joint rotatably couples the distal link to the end-effector base. The point of intersection at which the extensions of the axes of rotation of the proximal-end joints, the extensions of the axes of rotation of the intermediate joints, and the extensions of the axes of rotation of the distal-end joints intersect is the center of rotation of the end-effector base.
    Type: Grant
    Filed: June 7, 2022
    Date of Patent: January 2, 2024
    Assignee: NSK LTD.
    Inventors: Haruaki Chiba, Seiichi Teshigawara
  • Patent number: 11852198
    Abstract: An amount of decrease ?C in an axial clearance of a hub unit bearing is found based on an amount of expansion ?D of an inner ring of the hub unit bearing, which is the difference between the outer-diameter dimension D1 of the inner ring after the inner ring is externally fitted with a tubular fitting portion of a hub spindle of the hub unit bearing and after formation of a swaged portion of the hub spindle, the inner ring being held between the swaged portion and a stepped surface of the hub spindle, and an outer-diameter dimension D0 of the inner ring before the inner ring is externally fitted with the tubular fitting portion.
    Type: Grant
    Filed: September 7, 2020
    Date of Patent: December 26, 2023
    Assignee: NSK, LTD.
    Inventors: Takashi Sakaguchi, Eisho Watanabe
  • Patent number: 11852228
    Abstract: A differential device includes: an input member; a case member arranged coaxially with the input member; a one-way clutch arranged between the input member and the case member and transmitting torque therebetween only when the input member attempts to rotate in a normal rotation direction; a pinion gear supported by the case member to rotate about the axis perpendicular to the center axis of the case member; and a pair of side gears supported coaxially with the input member to rotate relative to the input member and the case member and meshing with the pinion gear.
    Type: Grant
    Filed: March 14, 2022
    Date of Patent: December 26, 2023
    Assignee: NSK LTD.
    Inventors: Akihiro Yamamoto, Eiji Inoue
  • Publication number: 20230408435
    Abstract: There is provided a state detection method for detecting an oil film state according to a lubricant in a device configured to lubricate a plurality of parts with the lubricant, the method including: a measurement step of measuring impedance and a phase angle of an electric circuit by applying an AC voltage to the electric circuit configured with the plurality of parts while changing a frequency; and a derivation step of deriving an oil film thickness according to the lubricant and a parameter indicating an electrical characteristic according to the oil film thickness, based on a relative dielectric constant at a high frequency limit of the lubricant defined based on a composition of the lubricant, and the impedance and the phase angle measured in the measurement step.
    Type: Application
    Filed: September 24, 2021
    Publication date: December 21, 2023
    Applicant: NSK LTD.
    Inventors: Shunsuke IWASE, Taisuke MARUYAMA
  • Publication number: 20230406394
    Abstract: Provided is a screw shaft in which shape accuracy of a male threaded portion is sufficiently secured. A screw shaft includes a large-diameter shaft portion, medium-diameter shaft portions and small-diameter shaft portions. The large-diameter shaft portion has a male threaded portion along its entire axial length on its outer peripheral surface. The medium-diameter shaft portions are arranged axially adjacent to the large-diameter shaft portion and have an outer diameter smaller than an outer diameter of the large-diameter shaft portion. The small-diameter shaft portions are axially arranged adjacent to the medium-diameter shaft portions on sides opposite to the large-diameter shaft portion, have an outer diameter smaller than the outer diameter of each of the medium-diameter shaft portions, and do not have rolling traces having a helical shape on their outer peripheral surfaces.
    Type: Application
    Filed: October 11, 2021
    Publication date: December 21, 2023
    Applicant: NSK Ltd.
    Inventor: Takeshi SAITO