Rotor spring

The rotor spring in Bulgarian T and MT series hoists is a crucial part of the electric motor's braking system. It is responsible for stopping and holding the mechanism when the power is disconnected.

When the motor is not running, the spring presses the brake disc with its friction lining (the "ferodo") against the motor housing. This locks the rotor's rotation, and the hoist securely holds the load.

When voltage is applied, a magnetic field is created in the motor, which draws the rotor into the stator. The spring compresses, the brake disc is released from the housing, and the motor begins to rotate.

When the power is disconnected, the magnetic field disappears, the spring returns the rotor to its original position and presses the brake disc again, instantly stopping the mechanism.