Brake of tubular dynamo

The utility model relates to a brake of tubular dynamo which is arranged in an axle housing of the roller-blind door matching with the rolling motor for application. The utility model is formed by the fitting of a magnet core connected with a spring and a brake disc fixed on the rolling motor axis and having the capacity of brake with a elastic brake disc and installed in the axle housing; an excitation winding is connected with the magnet core, and the excitation winding and the rolling dynamo powers on and off at the same time. When the rolling dynamo powers on and rolls, the excitation winding powers on and generates a magnetic field, and then makes the elastic brake disc be away from the brake disc through suction, finally the rolling dynamo runs normally. If no suction existed after power failure, the elastic brake disc is made to cling with the brake disc through a spring load, and brake is performed immediately. The utility model is characterized in quick braking speed, good braking effect, large suction, high sensibility and long service life; and the utility model is convenient for installation, easy to maintain and transpose for the brake is arranged in the outside of the rolling dynamo.