Harmonic Drive Systems Inc.

Toshimi Yamagishi

Yoshihide Kiyosawa

Xin Yue Zhang

Keiji Ueura

Shunichi Tezuka

Yoshio Yamaguchi

Yukio Sawada

A silk hat-type strain wave gear device has a crossed roller bearing for supporting an internal gear and an external gear so as to allow relative rotation. A first gap part between the inner and outer rings of said bearing is sealed by an oil seal and a second gap part thereof is in communication with a gear-side gap part on the outside of the external gear. A bearing seal separates the second gap part from the gear-side gap part. The bearing seal prevents excessive inflow of lubricant from the gear-side gap part into the second gap part. Excess lubricant that has flowed into the bearing can flow back from the second gap part to the gear-side gap part. Excess lubricant in the bearing is prevented from leaking through the oil seal to the outside.

Silk hat-type strain wave gear device

The flexible bearing of the wave generator for a wave gear device is a deep-groove ball bearing in which an outer race and an inner race form an annular flexible bearing ring capable of bending in a radial direction. A ball diameter Da is set to be 5 to 15% greater than that of each model of the currently available product. Dimensions of orbital plane radii ro, ri of the inner and outer races are set so that the ratio ro/Da of the orbital plane radius ro of the inner race and the ball diameter Da, as well as the ratio ri/Da of the orbital plane radius ri of the outer race and the ball diameter Da, are both in the range of 0.51 to 0.52. With this configuration, the service life of the flexible bearing can be extended.

Wave generator for wave gear device

A rotation transmitting device 1 introduces rotation into a vacuum side space 200 via a flexible meshing type gear drive 4 from an atmosphere side space 100. A first spacer 15 is disposed between ball bearings 13 and 14 of a rotation output shaft 5 positioned at the vacuum side, and a magnetic circuit is formed passing from the spacer 15 and through the ball bearing 13, a shaft portion 51 of the rotation output shaft 5 and the ball bearing 14. A magnetic fluid is filled as lubricant for lubricating potions of the ball bearings 13 and 14, which is retained on these portions by magnetic force generated by the magnetic circuit, whereby these portions are always lubricated appropriately. The magnetic fluid retained on these portions captures wear particles or other dust generated from the ball bearings 13 and 14, preventing these particles from leaking out to the vacuum side.

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Azumino, Japan

Toshimi Yamagishi