Normally closed electromechanical disc brake

The utility model discloses a normally closed electromechanical disc brake, which relates to the field of electromechanical braking and mine hoist braking, and adopts the working principle that a torque motor is used as a power source, speed reduction and torque increase are realized through a planetary reducer, rotary motion is converted into linear motion through a ball screw pair, and a ball nut drives a piston to compress a belleville spring. The belleville spring serves as an energy accumulator to store energy for the brake. The brake execution module sequentially comprises a brake shell, a belleville spring and a ball screw from outside to inside, an end cover is installed on one side of the brake shell, a brake shoe, a brake shoe supporting piece, a ball nut, a piston and the belleville spring are sequentially installed on the other side of the brake shell from outside to inside along the axis, and the ball screw serves as an execution module input shaft and receives rotation motion and torque of the p