Koyo Seiko Company, Ltd.

Showa Tool Co., Ltd.

Showa Seiki Kabushiki Kaisha

Eiichi Katayama

Kouichi Ueda

Kazuo Rokkaku

Hiroaki Takebayashi

Shinji Yasuhara

Toshiaki Oku

A traction drive tool adapter, has a rotary portion provided at its front half section with planetary roller-inserting bores extending radially from the outer circumferential surface of the rotary portion into a central bore therein, each of the roller-inserting bores having planetary rollers driving shaft member-setting grooves continuing from two ends of the roller-inserting bore that are opposed to each other in the axial direction of the central bore. Each driving shaft member which supports a relative planetary roller is set in the front half section of the rotary portion by inserting the planetary roller from the side of the outer circumferential surface of the front half section in the radial direction of the rotary portion into the roller-inserting bore, and the end sections of the shaft member into the shaft member-setting grooves, and the outer circumferential section of each planetary roll is engaged with an annular fixed track in a fixed portion of the adapter and the outer circumferential section of a sun roller in a tool mount portion of the adapter. A thread is provided in a through bore extending from the rear end of the rotary portion to the central bore in the axial direction thereof, and a male screw is engaged with the thread. Labyrinth seals are provided at the outer ends of the relative rotary regions between the fixed, rotary and tool must portions, and elastic contact lip-carrying rings are fitted on the inner side of the labyrinth seals.

Traction drive tool adapter

A speed-up spindle unit including a non-rotative housing having a fixed ring, a sun roller secured to a high speed spindle rotatably carried in the housing and a plurality of planetary rollers rotatably carried in such a manner as to be in contact with the fixed ring at one peripheral end and the sun roller at the opposite peripheral end so that the planetary rollers individually rotate about their own axes while they revolve about the sun roller, thereby transmitting a torque from the planetary rollers to the high speed spindle through the sun roller.

Speed-up spindle unit

A traction drive spindle device includes an input shaft connectable to a drive main shaft for rotation therewith. A hollow holder shaft is connected to an output end of the input shaft in coaxial relation thereto, the hollow holder shaft having a plurality of planetary rollers mounted thereon intermediate opposite ends of the holder shaft. A high-speed spindle is rotatably received in a bore of the hollow holder shaft, the high-speed spindle having an inner end portion which is received in the bore and serves as a sun shaft disposed in rolling contact with the planetary rollers. A housing is mounted on the outer periphery of the holder shaft through a first ball-and-roller bearing so as to be rotatable relative to the holder shaft, the housing having a fixed ring fixed to an inner periphery thereof. The planetary rollers are disposed in rolling contact with the fixed ring. A second ball-and-roller bearing is interposed between the holder shaft and the high-speed spindle. Only the balls and both the balls and the rollers of the second ball-and-roller bearing are made of ceramics.

Traction drive spindle device

Growing community of inventors

Osaka, Japan

Eiichi Katayama