| 摘要 |
<p>A rotary diverter valve assembly having a low voltage low current drive motor driving the rotating valve shaft through a differential planetary gear train. The motor drives the sun gear which engages a first pitch diameter set of teeth on the carrier mounted orbiting planetary gears, the first set of planetary gear teeth also is engaged by a fixed outer ring gear. A second lesser pitch diameter set of coaxial teeth are provided on the planetary gears which engage an output ring gear attached to the rotary valve shaft. A torsion spring has one end attached to the planetary carrier and is wound up by the relative rotation of the carrier with respect to the sun gear during motor operation. In the event of motor failure during operation, the stored energy of the wound spring applies a torque to back rotate the carrier and effect rotation of the valve member to its initial position.</p> |
