Attitude and drilling-direction control device

摘要

An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such that it is supportedly contacted with the inner surfaces of the eccentric hollow portions. In operation, the eccentric hollow portions are rotated relative to each other, whereby the member to be driven is controllably oriented to a desired direction. The attitude control device can be employed as a drilling-direction control device wherein a rotational drill shaft is supported by inner surfaces of eccentric hollow portions of first and second rotational members. These rotational members are rotated by first and second harmonic drive mechanisms. By rotating the eccentric hollow portions, the rotational drilling shaft is changed in orientation from the vertical direction.