What is the principle of motor brake?

- Nov 07, 2018 -

What is the principle of motor brake?

 

AC Garage Door Opener.jpgWhen the motor is connected to the power supply, the electromagnetic brake coil is also energized, and the armature is pulled in. The brake force of the brake is separated from the brake wheel by the tension of the spring, and the motor is normally operated. When the switch or contactor is disconnected, the motor loses power, and the electromagnetic brake coil is also de-energized. The armature is separated from the iron core by the tension of the spring, and the brake shoe is tightly clamped to the brake wheel, and the motor is braked and stopped. turn.


After the motor cuts off the AC power, the rotor continues to rotate due to inertia, and DC current is immediately applied to the two-phase stator winding, and a static magnetic field is generated in the stator. The guide bars in the rotor cut the static magnetic field to generate an induced current, which is subjected to electromagnetic force in the static magnetic field. The force generated by this force is opposite to the direction of inertia rotation of the rotor, called the braking torque, which forces the rotor speed to drop. When the rotor speed drops to zero, the rotor no longer cuts the magnetic field, the motor stops and the braking ends. This method uses the energy of the rotor to cut the magnetic flux to generate the braking torque. In essence, the kinetic energy of the rotor is consumed in the resistance of the rotor circuit, so it is called energy braking.