| 摘要 |
PURPOSE:To permit a worm-wheel to revolve at a moment, following the normal and reverse revolution of a worm by constituting the worm-wheel rotatably screwed with the worm which can revolve in the normal and reverse directions so that the center of gravity is positioned at eccentric position from the revolution shaft of the worm-wheel. CONSTITUTION:An imbalance mass 6 is installed onto a worm-wheel 2 so that a center of gravity is positioned at the position eccentric from the shaft of revolution of the worm-wheel, and the teeth part 3 of a worm 1 is allowed to always contact with the teeth part 4 of the worm-wheel 2 independently of the direction of normal and reverse revolutions of the worm 1. When the worm 1 revolves in A direction, the worm-wheel 2 is revolved in C direction along the teeth part 3 of the worm 1 by the turning moment of the imbalance mass 6. While, when the revolution of the worm 1 is switched to B direction, the turning moment of the worm 1 is transmitted to the worm-wheel 2 at a moment, and the worm-wheel 2 revolves in D direction against the turning moment of the imbalance mass 6. |
