We have been rewinding and repairing Demag brake motors, crane motors and chain hoists as a factory authorized service station since Demag was introduced to the United States.
We follow Demag Service and E.A.S.A guidelines for inspection, rewind and repair. All airgap and brake adjustments are made as per factory specifications. Rewinds are made with factory supplied winding data.
Our experience is based on more than 30 years of rewinding new motors for Demag used in special OEM applications and 30 years of warranty experience.
Q: What is different about the Demag motor?
A: The Demag squirrel-cage self-braking motor operates on the sliding rotor principal. The rotor and spring-loaded brake are located on a single shaft which can slide in the stator housing. The rotor and stator bore have a tapered profile.
Q: How does the Demag brake motor work?
A: At rest, the motor is braked by spring pressure. As the motor is energized and stator produces a magnetic field that overcomes the braking spring, it pulls in the axially offset rotor and releases the brake. As the motor is switched off, the magnetic force collapses and the motor is mechanically braked to a standstill by the return force of the brake spring.
Q: Since the rotor and the stator bore have a tapered profile, is the gap between them important?
A: Its critical! The gap or airgap is preset at the factory for optimum performance.
One of the most often seen root cause of failure is damage caused by the rotor rubbing the stator bore.