Harmonic Drive Systems Inc.

Shunichi Tezuka

Yoshihide Kiyosawa

Junji Koyama

Kunio Miyashita

Toshimi Yamagishi

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

A magnetic absolute sensor for a geared motor comprises a dipole magnet and hall elements. The dipole magnet is fixed to a hollow portion of a hollow rotor shaft. A bracket attached to an end plate of a motor housing is coaxially inserted from the rear end side of the hollow portion. The dipole magnet is inserted from the front side in a cylindrical portion of the bracket. The hall elements are arranged at an interval of 90 degree on the circular inner periphery surface of the cylindrical portion. The hall elements face the circular outer periphery surface of the dipole magnet with a fixed gap therebetween. It is not necessary to increase a motor shaft length in order to incorporate the magnetic absolute sensor. The flux of a motor driven magnet is blocked by the hollow rotor shaft and the hall elements are not adversely affected.

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Azumino, Japan

Shunichi Tezuka