| 摘要 |
An electric hoist comprising an electric motor and a sheave driven by the electric motor via a reduction gear. The reduction gear comprises a pair of helical gears meshing with each other. One of the helical gears is axially movably arranged on a shaft and is moved in the axial direction thereof when there is a load on the load chain supported by the sheave, and when the axial movement of the movable helical gear is detected by a sensor, the speed of rotation of the electric motor is automatically changed from a higher speed to a lower speed. |
