Nsk Corporation

Kyodo Yushi Co., Ltd.

Takeshi Yamamoto

Haruhiko Kiyota

Seiichi Moriyama

Fumiaki Mitsuhashi

Toru Segawa

Kaname Yasuda

Kazuki Hotta

Tomohiro Arai

Junichi Takano

Toru Ishii

Hiroshi Shibazaki

Kazuhiko Kojima

Tatsuya Ishii

Masahiro Maeda

Ryou Oosawa

Iwaki Hirooka

Michita Hokao

Katsuhiko Sawa

Ryota Sugihara

Toshiyuki Aizawa

Tomoaki Ebuchi

Akihide Fujita

Kentaro Ogi

A torque transmission joint to suppress occurrence of noise when reversing the direction of rotation of a drive shaft. A first transmission member fixed to an output shaft (the drive shaft) is engaged with a first elastic member such that a first gap in a circumferential direction is interposed, as well as with an intermediate transmission member such that a larger gap in the circumferential direction is interposed. A second transmission member fixed to an end portion of a worm is engaged with a second elastic member such that a second gap in the circumferential direction is interposed, as well as with the intermediate transmission member such that a larger gap in the circumferential direction is interposed. First and second annular convex portions are fitted to, respectively, first and second concave portions to prevent separation of the first and second elastic members with respect to the intermediate transmission member.

Torque transmission joint and electric-powered power steering apparatus

An inner wheel element () is embedded in an outer wheel element (), such that a continuous range from an inner diameter side circumferential surface configuring an inner surface of a first annular concave part (), through an outer circumferential surface of the inner wheel element (), to an inner diameter side circumferential surface configuring an inner surface of a second annular concave part () in a surface of the inner wheel element () is covered over the entire circumference. Accordingly, a structure is achieved which easily secures a holding power of the synthetic resin outer wheel element with respect to the inner wheel element.

Worm wheel, worm reduction gear, and method for producing worm wheel

A first concave-convex part is formed in an outer diameter side circumferential surface of a first annular concave part provided in an axial one-side surface of an inner wheel element, and a second concave-convex part is formed in a bottom surface of a second annular concave part provided in the axial other-side surface of the inner wheel element. An outer circumferential part of the inner wheel element is embedded in an outer wheel element, and synthetic resin forming the outer wheel element partially enters into a plurality of concave parts constituting the first concave-convex part and the second concave-convex part. Thus, a configuration is achieved in which the holding power of a synthetic resin outer wheel can be secured from the metal inner wheel element, and the manufacturing error can be suppressed in the worm wheel tooth part provided in the outer circumferential surface of the outer wheel.

Worm wheel, worm decelerator, and method for producing worm wheel

An outer wheel element () formed in an annular shape with a synthetic resin and having a worm wheel tooth part () on an outer circumferential surface thereof embeds a radially outer end part of an inner wheel element () formed in an annular shape with a metal. An outer circumferential surface of the inner wheel element (), which is radially superimposed with an engaging part between the worm tooth part () and a the worm wheel tooth part serves as a cylindrical surface part (). This realizes a structure capable of suppressing manufacturing error of the worm wheel tooth part engaging with the worm tooth part.

Worm wheel and worm speed reducer

The invention provides a grease composition for lubricating resins which contains a base oil, a diurea compound represented by formula (I) as a thickener: R&#x2014;NHCONH&#x2014;R&#x2014;NHCONH&#x2014;R(I) (wherein Rrepresents a bivalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and Rand Reach independently represent a straight-chain or branched alkyl group having 8 to 22 carbon atoms), and a chained hydrocarbon polymer having a weight-average molecular weight of 20,000 to 300,000.

Grease composition for lubricating resins and electric power steering device

An electric power steering apparatus has a first rolling bearing and a second rolling bearing rotatably supporting an output shaft. The first rolling bearing is provided between an inner peripheral surface of a through-hole of a gear housing and an outer peripheral surface of the output shaft. The second rolling bearing is provided between an inner peripheral surface of an intermediate plate and the outer peripheral surface of the output shaft. The intermediate plate has an outer peripheral portion supported and fixed in an opening portion of the gear housing.

Electric power steering apparatus

A torque transmission joint has a shock-absorbing member between a drive shaft and a driven shaft. When the drive shaft is rotated in one direction, forces due to torque transmitted from the drive shaft to the driven shaft act inward in a radial direction of the shock-absorbing member on held sections that are held between one side surfaces in the circumferential direction of drive-side arm sections that are positioned in the front side in the one direction of rotation of the drive shaft, and side surfaces in the circumferential direction of driven-side arm sections that are positioned on the rear side in the one direction of rotation of the drive shaft.

Torque transmission joint and electric power steering apparatus

A shock-absorbing member comprises held sections located at a plurality of locations in a circumferential direction and comprising paired held sections and non-paired held sections, and is constructed to have a non-circular cylindrical shape in cross-section. Portions where outer-diameter side end sections of held sections that are adjacent to each other in the circumferential direction are made continuous by way of outer-diameter side cover sections, and portions where inner-diameter side end sections of held sections that are adjacent to each other in the circumferential direction are made continuous directly or by way of inner-diameter side cover sections, in an alternating sequence in the circumferential direction. Drive-side arm sections are placed between the non-paired held sections, driven-side arm sections are placed between the paired held sections, and the outer circumferential surfaces of the drive-side arm sections are covered by the outer-diameter side cover sections.

Worm wheel construction that is able to sufficiently increase the strength of the connecting portion between a huband a gear portion, and to maintain sufficient durability even when applied to an electric power steering apparatus that applies a large auxiliary torque, is achieved. A synthetic resin gear portionis molded and formed in the end portion on the outer-diameter side of a metal hub. A first annular concave portionis provided on one surface side in the axial direction of the hub, and a second annular concave portionis provided on the other surface side in the axial direction thereof. Part of the synthetic resin of the gear portionis fed into the portions near the outer diameter of the first annular concave portionand the second annular concave portionto form a first restraining portionand a second restraining portion. These restraining portionstightly hold the end portion on the outer-diameter side of the hub, and improve the strength and rigidity of the connecting portion between the huband the gear portion

Worm wheel and electric power steering apparatus

A core of a worm wheel has an axial end surface formed with a first annular recess, another axial end surface formed with a second annular recess, and a third annular recess formed in a radially outer region of the first annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess, a second inner circumferential portion fixed to the second annular recess, and a protrusion engaged with the third annular recess.

A core of a worm wheel has an axial end surface formed with a first annular recess nad and another axial end surface formed with a second annular recess. An outer circumferential wall surface of a radially outer region of the second annular recess has a tapered surface extending from a bottom surface of the second annular recess to form an obtuse angle relative to the bottom surface, and a third annular recess formed radially outside the tapered surface. A cross-section of the third annular recess is a right-angled triangle having, as two sides, a surface parallel to the bottom surface of the second annular recess and a surface perpendicular to the bottom surface of the second annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess and a second inner circumferential portion fixed to the second annular recess.

A core of a worm wheel has an axial end surface formed with a first annular recess and another axial end surface formed with a second annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess and a second inner circumferential portion fixed to the second annular recess. An outer circumferential wall surface of the second annular recess extends from a bottom surface of the second annular recess so as to be perpendicular to the bottom surface. A depth of the second annular recess is at least 0.1 mm but not deeper than half of a gate thickness.

An electric power steering apparatus has a first rolling bearing and a second rolling bearing rotatably supporting an output shaft. The first rolling bearing is provided between an inner peripheral surface of a through-hole of a gear housing and an outer peripheral surface of the output shaft. The second rolling bearing is provided between an inner peripheral surface of an intermediate plate press-fitted and fixed in an opening portion of the gear housing and the outer peripheral surface of the output shaft. An outer peripheral portion of the intermediate plate has alternately arranged large diameter portions and small diameter portions, and the large diameter portions are press-fitted in the gear housing.

Construction of an electric power-steering apparatus is achieved that, by stably suppressing backlash of an output shaftof an electric motorover a long period of time, is able to stably reduce vibration and strange noise that occurs during operation. The front end section of the output shaftand the base end section of a wormare connected such that torque can be transmitted and such that relative displacement in the axial direction is possible. An elastic memberhaving an elastic force in a direction that separates the output shaftand wormis provided in the connecting section between the output shaftand the worm. Due to the elastic force of the elastic member, together with the tandem arrangement contact angles, the preload is applied to a pair of ball bearingsthat support the output shaftwith respect to the motor casesuch that the output shaftcan rotate freely.

Electronic power-steering apparatus

An electric power steering apparatus including a steering system into which steering torque is inputted, an electric motor for imparting steering assist force to the steering system, a controller for controlling a energizing state of the electric motor according to the steering torque, a terminal board electrically connected to the electric motor, and a control unit provided with a connector, wherein a mounting face of the electric motor with respect to the control unit, a mounting face of the terminal board with respect to the control unit, and a mounting face of the connector with respect to the control unit are arranged on a same plane.

Growing community of inventors

Maebashi, Japan

Takeshi Yamamoto