NORD brake motors are equipped with DC-excited spring pressure brakes. The brakes prevent accidental rotation of machines (as holding brakes) or bring rotation of the machine to a standstill (as a service brake or for emergency stop).

The brake linings are asbestos-free and the braking action is activated on interruption of the current (idling current principle). The brake can no longer be released if the brake linings are worn.Idling current principle The brake disc is located between the brake bearing cover and the rotor plate. The brake disc has a brake lining on both sides. The brake disc transfers the braking torque to the motor shaft by means of the coupling. The brake disc can be moved in an axial direction on the coupling. The rotor plate presses the brake disc against the brake cover plate by means of spring pressure. The friction between the rotor plate and the brake lining and between the brake bearing cover and the brake lining produces the braking torque. The brake is released by an electromagnet (magnetic component).

After the current is switched on, the electromagnet pulls the rotor plate back from the brake lining by several tenths of a millimetre against the pressure of the spring. This allows the brake disc to rotate freely. Interruption of the current causes the magnetic force to collapse, so that the spring pressure predominates. Therefore the brake is automatically activated.
Brake activated Brake released
Power-to-apply principle Brakes which are activated by the force of an electromagnet are designated as power-to-apply brakes. (