| 摘要 |
<p>A spring return valve actuator is provided to allow forcedly operating a brake and opening or closing the valve by rotating a handle even though the valve is returned by a spring. A spring return valve actuator includes a first planetary gear(P1), a secondary sun gear shaft(27), a secondary planetary gear(P2), and a spring(40). The first planetary gear is installed at a brake to transmit power from a first worm shaft(25-1) to a first worm wheel(25). The secondary sun gear shaft is coupled to a first ring gear(17) of the first planetary gear to be rotated therewith and fix a second sun gear(18-2). The secondary planetary gear transmits power of the first planetary gear to a second worm shaft, and sequentially transmits the power to a second worm shaft(30) through a handle worm shaft(23), a handle worn wheel(28), a second planetary gear carrier(14), a second planetary gear(19-2), a second ring gear(17-2), and a second ring gear shaft(13). The spring is coupled to an outer end of the second worm shaft.</p> |
