| 摘要 |
A head assembly for a manipulator has a rear segment rotatable about an inner axis fixed relative to the manipulator and extending through the rear segment, an intermediate segment supported on the rear segment for rotation about an intermediate axis defined by the rear segment and intersecting the inner axis at an acute intermediate angle open away from the rear segment, and a front segment having a holder adapted to carry a tool and suppported on the intermediate segment for rotation about an outer axis fixed relative to the intermediate segment, extending through the front segment, and intersecting the intermediate axis at an acute outer angle open away from the intermediate segment. A drive rotates the intermediate and outer segments on the inner and intermediate segments about the respective intermediate and outer axes. The drive has an intermediate shaft extending along the intermediate axis, an outer shaft extending along the outer axis, angle gearing interconnecting the intermediate and outer shafts for joint synchronous rotation, an intermediate stepdown transmission with a high stepdown ratio of N:1 connected between the intermediate shaft and the intermediate segment for relatively slowly rotating the intermediate segment relative to the intermediate shaft, and an outer stepdown transmission with a high stepdown ratio of (N+/-1):1 connected between the outer shaft and the front segment for relatively slowly rotating the intermediate segment relative to the intermediate shaft. The factor N is a whole number of revolutions. |
