Frequency Converter Controlled Cable Reeling Drums
The drive unit is a squirrel cage motor, the torque is adjusted based on the crane speed, this is controlled by the PLC in the drive system which keeps the constant tension on the cable.
Torque Motorized Cable Reeling Drum
This type of cable reeling drum can handle long lengths of cable, the torque motor can operate continuously in the stalled position and can be rotated in the opposite direction and still maintain a constant tension on the cable.
Magnetic Coupler Motor Driven Cable Reeling Drum
This drive system is normally a standard squirrel cage motor, the magnetic coupler has a air gap between the driven shaft and the output
magnet, the output torque can be altered by adjustment of the air gap, the magnet are permanent magnet and do not require external power.