Brake system

A brake system comprising:

• an electromagnetic brake device configured to apply a brake to a rotary shaft when current is not applied to the brake system and release the brake on the rotary shaft when current is applied to the brake system;
• and
• a brake release device configured to forcibly release the brake on the rotary shaft when current is not applied to the brake system, wherein
• the electromagnetic brake device includes:
• a brake disc integrated with the rotary shaft;
• a stator disposed facing the brake disc;
• a brake plate positioned opposite to the stator with respect to the brake disc;
• an armature disposed between the brake disc and the stator and cooperating with the brake plate to hold the brake disc between the armature and the brake plate;
• an urging member disposed between the stator and the armature and configured to urge the armature such that the armature is pressed against the brake disc;
• and
• a magnet coil disposed in the stator and configured to be excited when current is applied to the magnet coil, and
• the brake release device includes:
• a guide member having a tube shape;
• a release plate disposed within the guide member and engaged with the armature;
• and
• a transfer unit configured to move the release plate in a direction in which the rotary shaft extends, wherein
• the transfer unit is disposed within the guide member, and includes a bag that is configured to expand and contract in the direction in which the rotary shaft extends and an air supplier that is configured to supply air into the bag.