Tools motor are mostly series - excited attack motor, internal brush.The motor has the characteristics of small size, large power and high speed.But not for long hours.Most motor speed control of power tools is the same motor speed, through the output of mechanical deceleration mechanism to speed.Speed regulating motor by the driving wheel with taper and the pressure plate is pressed by a set of disc spring, the input shaft and the driving wheel with a key connection, near and composed of pressing the active device.A set of planetary friction wheel with taper inside clamped between the driving wheel and the pressure plate, the outside clamped between the fixed ring with taper and the speed regulating CAM, near and form a friction pair;When the active device is running, the friction wheel will do pure rolling, because the fixed ring and speed regulating CAM do not move, therefore, the friction wheel in the rotation of the revolution at the same time, through the central shaft of the planetary friction wheel and the slider bearing and drive the planetary frame rotation.
Rotating the handwheel drives the speed regulating CAM to change the angular position at the same time, the end curve of the speed regulating CAM through the action of the plane pin clip and the end curve of the fixed CAM, so that the speed regulating CAM produces axial movement, so as to evenly change the interval between the speed regulating CAM and the fixed ring, so that the taper planetary friction wheel produces radial movement.Finally, the working radius of the friction between the planetary friction wheel and the driving wheel, the pressure plate and the fixed ring, and the speed-regulating CAM are uniformly changed to achieve stable stepless variable speed.
