Nsk Corporation

Tetsu Takehara

Hiroyasu Yoshioka

Daisuke Gunji

Yasuyuki Matsuda

Kinji Yukawa

Kazutaka Tanaka

Tomoharu Saito

Masafumi Hikida

Yuka Kaneko

Yasunori Suzuki

Hiroaki Ishikawa

Yuji Nakano

Yuji Shimomura

Yukio Sato

Yoshio Shoda

Shoji Noguchi

Shinichi Natsumeda

Hiroshi Kawahara

Katsuhiro Konno

Kiyotaka Hirata

Tomoharu Sugiman

Taketoshi Chifu

Seiji Ijuin

Tohru Ueda

Tooru Ueda

Narihito Otake

Shouji Horike

Tetsuo Wakabayashi

Hirohisa Mihara

Kiyohito Matsubayashi

Kenichi Shibazaki

A rotation transmission device having a high torque measurement resolution is provided. The rotation transmission device is provided with: a rotary-shaft unit () having a first and second rotary shaft () combined so as to be coaxial and such that the end sections thereof can rotate relative to each other and a torsion bar () that is provided on the inner-diameter side of the first and second rotary shafts so as to be coaxial therewith, has one end section connected to the first rotary shaft (), and has the other end section connected to the second rotary shaft (); a first gear () fastened to the outer peripheral surface of the first rotary shaft (); a second gear () fastened to the outer peripheral surface of the second rotary shaft (); a coupling shaft () provided on the inner-diameter side of the torsion bar () so as to be coaxial therewith, having one end section connected to one rotary shaft (), and having the other end section protruding from an end of the torsion bar () in the axial direction; a first encoder disposed and fixed on the other end of the coupling shaft () so as to be coaxial with the first rotary shaft () and having a first detected section (); a second encoder fastened on the other end of the second rotary shaft () so as to be close to the first encoder and having a second detected section (); and a sensor unit having at least one sensor () that faces the first and second detected sections ().

Rotation transmission device

A friction roller-type reduction gear includes a sun roller concentric with an input shaft, a ring roller having a stationary ring roller element and a moveable ring roller element, intermediate rollers in rolling contact with an outer peripheral surface of the sun roller and an inner peripheral surface of the ring roller, a coupling part coupling the ring roller and the output shaft, and a loading cam mechanism having a cam ring for changing contact surface pressure of each rolling contact surface. The outer surface of the sun roller is a concave curved surface of which a shape of an outer edge in an axial cross-section is a single circular arc-shaped concave curve, and an outer surface of the intermediate roller is a convex curved surface of which a shape of an outer edge in an axial cross-section is a single circular arc-shaped convex curve.

Friction roller-type reduction gear

In order to implement a structure capable of improving the resolution of torque measurement while preventing the plastic deformation of a torsion bar (), an input-side stopper () having an uneven shape (gear shape) in the circumferential direction is provided in a portion of an input-side rotating body () that includes an input shaft () and an input gear (), and an output-side stopper () having an uneven shape (gear shape) in the circumferential direction is provided in a portion of an output-side rotating body () that includes an output shaft () and an output gear (). The input-side stopper () and the output-side stopper () are combined so as to be engaged to be able to transmit torque only when the torsional angle within the elastic range of the torsion bar () reaches a predetermined amount.

Torque measurement device-equipped rotation transmission apparatus

To realize a manufacturing method for a wheel-supporting rolling bearing unit that can establish sufficient parallelism between a rotating side installation surfacefor fastening to and supporting a disk of a disk brake and a stationary side installation surfacefor fastening a caliper or support, in the present invention, while rotating a hubcomprising the rotating side installation surfacewith respect to an outer race comprising the stationary side installation surface, a finishing process such as turning is performed on the rotating side installation surfaceor both side surfaces in the axial direction of the disk which is fastened and supported to and by the rotating side installation surface, with the stationary side installation surfaceas a reference surface.

Method of manufacturing a rolling bearing unit for supporting a wheel

A hub unit for wheel is described, with an outer ring having two bearing tracks on its inner circumferential surface, and a hub having a wheel mount flange on the outer end side and an end portion on the axially vehicle center side. The hub has a first bearing track corresponding to the axially vehicle outer end side bearing track of the outer ring, and an inner ring element fitted on the end portion side of the hub. The inner ring element has on its outer circumference a second bearing track opposed to the axially vehicle center side bearing track of the outer ring, and is fixed on the end portion by plastically deforming the end portion of the hub radially outwardly. Rolling members are provided between the two bearing tracks of the outer ring and the first and second bearing tracks.

Hub unit for wheel

It is intended that the rotation resistance is decreased while the durability and seal performance are kept in the rolling bearing unit with seal ring. The most thin wall-thickness portionis provided in the vicinity of the base end of the seal lipprojecting laterally in sliding contact with the mating surface. The most thick wall thickness portionis provided adjacent to the most thin wall thickness portionon the tip end side. The thickness is gradually decreased from the most thick wall thickness portionto the tip end. Further, the ratios of thickness in the respective portionsare properly controlled.

Seal ring and rolling bearing unit with seal ring

An amount of undulation by which the inner surface of a large-diameter-side flange portion formed in an inner ring is undulated is defined as an axial deflection &dgr;. And, the composite roughness of a contact portion between the inner surface and the head portion of a tapered roller is expressed as &sgr;. A tapered roller bearing is structured in such a manner that &dgr;&lE;8 &mgr;m and &sgr;&lE;0.22 &mgr;mRMS, or, &dgr;&lE;12 &mgr;m and &sgr;&lE;0.18 &mgr;, or, &dgr;&lE;16 &mgr;m and &sgr;&lE;0.13 &mgr;mRMS can be satisfied.

Roller bearing

In the roller bearing, between an outer ring ( ) and an inner ring ( ), there are interposed a plurality of tapered rollers ( ) in a freely rollable manner. A flange portion ( ) is formed in the side portion of the inner ring ( ). The undercut allowance ratios of a contact ellipse formed due to mutual contact between the flange portion ( ) and the end face of the roller ( ) is set in the range of &minus;0.6&lE;(h&minus;b&minus;c)/b&lE;2, where a grinding undercut dimension on the flange portion ( ) is expressed as c, a contact point height between the flange portion ( ) and the end face of the roller ( ) is expressed as h, and the minor radius of a contact ellipse formed due to contact between the flange portion ( ) and the end face of the roller ( ) is expressed as b.

Rolling bearing

An inner ring of a tapered roller bearing is provided with an groove-like recess formed between an outer race surface and a large rib surface. A Chamfer is provided between a large-diameter-side end surface and a rolling surface in each tapered roller. (1) The height from the outer race surface of the inner ring to a contact position where the inner ring large rib surface contacts with the large-diameter-side end surface of each roller is set to be 6 to 9.5% of the diameter of the roller large-diameter-side end surface. (2) The chamfer of the large-diameter-side end surface of each roller is set to be 30 to 60% of the contact position height. In addition, (3) the size of the recess in the large rib surface side of the inner ring is set to be not larger than 75% of the chamfer of the large-diameter-side end surface of each roller.

Tapered roller bearing

A roller bearing comprising an outer ring having an outer ring raceway, an inner ring having an inner ring raceway, the inner peripheral surface at the end portion of the outer ring and/or the outer peripheral surface at the end portion of the inner ring formed with a flange portion, and a plurality of rollers having a rolling surface in contact with the outer and inner ring raceways, a sliding contact face in sliding contact with the inner face of the flange portion, and a chamfered portion provided between the sliding contact face and the rolling face, the sliding contact face smoothly connected to the chamfered portion in a curved surface the radius of curvature of which is at least 0.08 mm, and provided that the center line average height roughness of the sliding contact surface is .delta..sub.1 while the center line average height roughness of the inner face in contact with the sliding surface is .delta..sub.2, the composite roughness represented by the formula (.delta..sub.1.sup.2 +.delta..sub.2.sup.2).sup.1/2 is up to 0.09 .mu.mRa.

Growing community of inventors

Fujisawa, Japan

Tetsu Takehara