Winches are devices used for traction, and are mainly used to rescue vehicles in harsh environments. When the vehicle is trapped in muddy or rough terrain and not the wheels are on the ground, the winch can be used to drag the vehicle out by using another object as a fulcrum. The winch can also be used to drag large-size obstacles such as logs. Existing electrical winches are mainly comprised of a motor, a driving shaft, a gear reduction box and a winding drum. The gear reduction box transmits the driving power from the motor to the winding drum so that a substantial traction force can be induced on a steel wire wound around the winding drum for functions of the winch.
Winches are mainly prepared for emergencies so they have to work under various hostile environments. Unexpected failures may frequently happen during use of winches. The structures of existing winches need improvement in ease of maintenance and operation to deal with unexpected failures rapidly. Besides, mechanical components of a winch are subject to water damage in water or rainy weather.