| 摘要 |
A door hoist includes a bracket, drive sprocket, ring gear, hub assembly, set of planetary gears, and governor shaft. The drive sprocket has a drive sprocket axis. The ring gear is fastened to the drive sprocket. The ring gear has a ring gear axis that is in alignment with the drive sprocket axis. The hub assembly includes a connector to receive a door drive shaft and secure the door drive shaft in a fixed rotational alignment with the hub assembly. The set of planetary gears is rotationally mounted to the hub assembly. The set of planetary gears is configured to mate with the ring gear. The governor shaft includes a sun gear, brake assembly, and link. The sun gear is configured to mate with the set of planetary gears. The brake assembly has an engaged position and a disengaged position. The sun gear is rotationally fixed relative to the bracket in response to the brake assembly being in the engaged position. In response to the brake assembly being in the disengaged position, rotation of the sun gear is unfixed relative to the bracket. The link secures the brake assembly in the engaged position. The link is configured to melt in response to an ambient temperature exceeding a predetermined temperature. |
