Abstract: A fast braking device for a grinding machine installed in a grinding machine with a spindle comprises: an electromagnet element closely neighbors an inner braking disc; the electromagnet element and the inner braking disc are jointly fixed on the grinding machine. An outer braking disc is separated from the electromagnet element by a lining plate and axially slidably installed on the electromagnet element. Elastic elements are arranged in between the inner braking disc and the outer braking disc. The lining plate rotates synchronously with the spindle. When the user intends to stop the operation of the grinding machine, the electromagnet element provides magnetic force to make the inner and the outer braking discs clamp the lining plate to fast brake the spindle of the grinding machine. Then, the elastic elements separate the outer braking disc from the inner braking disc, and the spindle of the grinding machine can rotate again.

Abstract: The present invention discloses a dust collector blade structure. In the present invention, the blades are uniformly and radiately arranged on a rotation disc. The blades are vertical to the rotation disc and form an air entrance at the center of the rotation disc. One end of each blade is exactly at the border of the rotation disc, and the other end of each blade has a wind-guiding bevel. The rotation disc is arranged inside a blower housing. The blower housing has an air outlet and a cover. The cover has an air inlet corresponding to the air entrance. The air outlet is arranged in the tangential direction of the rotation disc. The shape of the blades can reduce the air friction on the blades and thus can promote the blower performance and reduce the energy consumption.