Thk Co., Ltd.

Takashi Sakuyama

Soshi Miyahara

Masahiko Yoshino

Tsutomu Togashi

Lina Teng

Hiroaki Mochizuki

Tetsuhiro Nishide

Akimasa Yoshida

Kentaro Nishimura

Hiroshi Kaneshige

Tetsuya Miura

Toshiaki Kadono

Yusuke Todoroki

Kazuhiro Tani

Sho Taniguchi

Hideo Saito

Yuki Hayashi

Takeki Shirai

Hidekazu Michioka

Katsuya Iida

Toshiyuki Aso

Tomozumi Murata

Satoshi Hirata

Tomoyuki Aida

Futoshi Nakamura

Yuji Tachikake

Sho Iwashiro

Eri Kameda

Takashi Oshida

An actuator whose total length can be reduced is provided. An actuator () includes: a casing (); a hollow shaft () rotatably supported by the casing () via a bearing (), the hollow shaft () including a bottom portion (); a screw shaft () coupled to the bottom portion () of the hollow shaft (), the screw shaft () sharing a common center line with the hollow shaft (); and a nut () threadedly connected to the screw shaft (). The nut () is capable of moving in an axial direction of the screw shaft () to enter between the hollow shaft () and the screw shaft ().

Actuator or suspension

A suspension is provided which can not only generate a damping force between sprung mass and unsprung mass but also steer a wheel. A suspension includes: a shaft coupled to sprung mass of a vehicle, the shaft having a screw groove and a spline groove formed thereon; a ball screw nut assembled to the shaft via a ball; a ball spline nut assembled to the shaft via a ball; a ball screw-specific motor connected to the ball screw nut; a ball spline-specific motor connected to the ball spline nut; and a case coupled to unsprung mass of the vehicle, the case being configured to hold the ball screw-specific motor and the ball spline-specific motor. The ball spline-specific motor rotates the ball spline nut and the shaft relative to the case.

Suspension

In a bearing for vertical axis windmill configured to rotatably support a vertical axis of a vertical axis windmill, the bearing includes a ball (), a diameter of the ball and a curvature of a rolling groove of the bearing are set to satisfy a predetermined starting torque and a load rating. For example, the curvature of the rolling groove of the bearing is 54% or more and 100% or less, and the diameter of the ball has a ratio of 20% or less with respect to a vertical shaft ().

Bearing for vertical axis windmill and vertical axis wind power generator

There is provided a roller screw in which a twisted amount of an unloaded return path is reduced. The roller screw has a screw shafthaving a spiral roller-rolling surfaceon an outer peripheral surface thereof; a nuthaving a spiral loaded roller-rolling surfaceon an inner peripheral surface thereof, the spiral loaded roller-rolling surface being opposed to the roller-rolling surfaceof the screw shaft; a circulation memberarranged in the nutand formed to have an unloaded return pathconnecting one end and the other end of the loaded roller-rolling surface, whose turn number is less than one, of the nut; and a plurality of rollersarranged in a one-turn roller circulation path composed by a loaded roller-rolling pathand the unloaded return path. The circulation memberguides the rollers which have moved and arrived at the one end of the loaded roller-rolling pathhaving less than one turn, to the unloaded return path, and then returns the rollers to the other end of the loaded roller-rolling pathhaving less than one turn. The number of turns of the loaded roller-rolling pathis set to be less than one turn, whereby the rollerswhich have arrived at one end of the loaded roller-rolling pathcan be transferred to the other end of the loaded roller-rolling pathwithout changing their attitudes.

Roller screw and method of circulating rollers in roller screw

A rolling-element screw device includes: a large number of rolling elements; a screw shaft having an outer periphery on which a rolling groove for the large number of rolling elements is helically formed; a nut member which has a through-hole through which the screw shaft is passed and which is threadedly engaged with the screw shaft through intermediation of the large number of rolling elements; a lubricant supply hole formed through the nut member from an outer peripheral surface of the nut member to an inner peripheral surface of the nut member; a lubricant tank mounted to the outer peripheral surface of the nut member and comprising an accommodating chamber for lubricant; and a lubricant applying body standing from the lubricant tank, and inserted into the lubricant supply hole along with amounting operation of the lubricant tank with respect to the nut member.

Rolling element screw device

Provided is a roller screw capable of preventing rollers moving from an unloaded return path to a loaded roller rolling path from coming into collision with a scooping portion. The roller screw has: a screw shafthaving a spiral roller rolling surfaceformed on an outer peripheral surface thereof; a nuthaving a loaded roller rolling surfaceformed in an inner peripheral surface thereof; a circulation memberhaving an unloaded return path connecting one end of the loaded roller rolling surfaceof the nutto an opposite end thereof; and a plurality of rollersarranged in a loaded roller rolling pathand the unloaded return path. In the circulation member, as a scooping portion that juts toward the screw shaftand provided for scooping the rollersmoving in the loaded roller rolling pathup into the unloaded return path, a pair of diagonal corresponding partsis provided which are in contact with diagonal partsof a rectangular side surface of each rollerand a width between which is gradually narrower as they are deeper in the unloaded return path in such a manner that a cross section of the unloaded return path is closer to a rectangle.

Roller screw

Provided is a roller screw having an unloaded roller return path of new shape capable of moving rollers smoothly. The roller circulation path of the roller screw has the unloaded roller return path and a loaded roller rolling path. The unloaded roller return pathis twisted so that while each rollermoves in the unloaded roller return pathits central axis is inclined. In a cross sectional shape of the twisted part of the unloaded roller return path, each of paired side surface corresponding partsandfacing respective side surfaces of the rolleris convex toward the inside of the unloaded roller return path

Roller screw and method of designing unloaded roller return path thereof

There is provided a new rolling body screw device manufactured with cheap cost without degrading quality in comparison with a conventional device even for a device having any large dimension in an end-cap type rolling body screw device. The rolling body screw device includes the direction changing passageseach including: a scoop-up portionscooping a ball rolling in a loaded rolling body passage as a loaded area of the endless track so as to hand over the balls to the direction changing passageas a non-loaded area of the endless track; and a route pathforming a circulation path of the ball scooped by the scoop-up portion. Each of the return pieces is composed, in combination, of a metal partformed of a metal material including the scoop-up portion, and non-metal partsformed of a non-metal material including the route path

Rolling body screw device

A ball screw device having a novel ball circulation structure suitable for a screw shaft with a large lead, optimum for downsizing and weight saving of a nut member, capable of being manufactured at low cost, and capable of exhibiting high reliability even under severe use conditions. In a ball screw device where a screw shaft and a nut member are screwed to each other through an intermediation of a large number of balls, a no-load ball path which forms an infinite circulation path for the balls is constituted by a no-load ball groove spirally formed in an inner peripheral surface of a through-hole of the nut member and by a pair of direction change grooves which communicatively couple a load rolling groove and the no-load ball groove to each other so as to complete the infinite circulation path as a closed loop.

Ball screw device

Provided is a motion guide device having a scooping portion that is not damaged even when a moving member is moved at high speed. When seen in an axial direction of a track shaft, a direction change pathis inclined relative to a contact angle line L(line connecting a center C of a balland a bottom Pof a ball rolling groove). The direction change pathincluding a scooping portionhas a cross section of Gothic arch groove shape formed of two arcs Rin such a manner that the ballis in contact with the direction change pathat two points. The direction change pathis twisted in such a manner that a locusof the top of the Gothic arch groove shape approaches the contact angle line Lat the scooping portion

Motion guide device

A motion guide device having a novel scoop section structure whose scoop section is not likely to break even if a movement member is moved at high speed. A scoop section () of a movement block () scoops balls () that roll in a ball rolling groove () of a raceway rail () and introduces them into no-load ball return paths (). The scoop section () is formed in a Gothic arch groove shape in which the scoop section () is in two-point contact with a ball (). In a cross-section orthogonal to the advance direction of the balls (), an angle (contact angle &#x3b1;) formed by a line Lthat connects a point P at which the scoop section () and a ball () are in contact and the center C of the ball () and a line Lthat connects the center of the ball () and a bottom () of the Gothic arch groove-shaped scoop section () exceeds 30 degrees and is not more than an angle &#x3b3; formed by a line Lthat connects the center C of the ball () rolling in the ball rolling groove () of the raceway rail () and an edge () of the ball rolling groove () of the raceway rail () and the line Lthat connects the center C of the ball () and the bottom of the ball rolling groove ().

Growing community of inventors

Tokyo, Japan

Takashi Sakuyama