Latching brake using permanent magnet

A magnetic brake, comprising:

• a rotatable shaft;
• a brake disc fixedly mounted on the shaft;
• a non-rotating core housing located around the shaft;
• a magnetic armature adjacent to the core housing and capable of movement toward the core housing and toward and into engagement with the brake disc to prevent rotation of the shaft;
• means for urging the armature away from the core housing and into engagement with the brake disc;
• a permanent magnet within the core housing, the permanent magnet capable of holding the magnetic armature toward the core housing in opposition to the urging means;
• and
• bipolar solenoid means adjacent to the permanent magnet in the core housing, the permanent magnet continually producing a magnetic field around the solenoid means, the solenoid means moving the armature toward and away from the core.

A magnetic brake, comprising:

• an outer housing;
• a rotatable shaft mounted for rotation within the outer housing and having an end extending from the outer housing;
• a brake disc fixedly mounted on the shaft within the outer housing, the brake disc rotating with the shaft;
• a non-rotating core housing attached to the outer housing, the core housing extending around the shaft;
• a magnetic armature disc adjacent to the core housing and capable of movement toward the core housing and toward and into engagement with the brake disc to prevent rotation of the shaft;
• spring means for urging the armature disc away from the core housing and into engagement with the brake disc;
• a permanent magnet within the core housing, the permanent magnet capable of holding the magnetic armature disc in engagement with the core housing in opposition to the urging means, the urging means capable of holding the armature disc in engagement with the brake disc in opposition to the permanent magnet;
• and
• bipolar solenoid means adjacent to the permanent magnet in the core housing, the permanent magnet continually producing a magnetic field around the solenoid means, the solenoid means capable of being energized in a first polarity to move the armature disc toward the core housing in opposition to the spring means and capable of being energized in a second polarity to move the armature disc away from the core housing in opposition to the permanent magnet.

An electric motor, comprising:

• a stator;
• a rotor having a rotatable shaft attached thereto;
• and
• brake means for releasably locking the shaft in position, the brake means comprising
• a brake disc mounted on the shaft;
• a non-rotating core housing assembly located around the shaft, the core housing assembly, including
• a permanent magnet and
• bipolar solenoid means adjacent to the permanent magnet, the permanent magnet continually producing a magnetic field around the solenoid means;
• a magnetic armature adjacent to the core housing assembly and capable of movement toward the core housing assembly and toward and into engagement with the brake disc to prevent rotation of the shaft;
• and
• means for urging the armature away from the core housing assembly and into engagement with the brake disc.