Winch with overload safety - has drum driven by three=phase motor via gearbox with two hydraulically operated clutches

摘要

The winch has a winch drum driven by a stepped electric motor, especially a reversible three-phase motor, via a gearbox. The gearbox has two clutches, which are hydraulically operated alternately via a hydraulic pump controlled from a pneumatic valve. The two clutches are used to select the slow and fast speeds and one of them can be closed under spring pressure. The pneumatic valve is operated to change over from the slow to fast speed or vice versa.