The outside of conical shaped plant wheels is pressed between the two friction ring , inside pressed between the driver and the press ring. The driver and the press ring are pressed by the dish spring. When the motor drives the driver, the planet wheels purely roll. For two friction ring are static, the planet wheel revolves around the carrier while rotating, and drives the carrier through the shaft of the planet wheel and the bushing. Turning of the hand wheel (not illustrated) changes the angle of the speed adjust cam, and through its camber, makes the speed adjust cam move in axial direction. So the space changes between two friction ring, and the planet wheel cam move in radial, resulting in changes of the inside contacts on the planet wheel. When the space gets larger, the planet wheels move outside, and the revolution speed gets slower. When the space gets smaller, the planet wheels move inside, and the revolution speed gets faster. The maximum speed is the minimum speed of 5 times, Thus the objective of variation is obtained. In brevity, turn the hand wheel at certain position, the planet wheels are well distributed at correspondent, and the stable output speed is available on the output shaft. This revolution speed can direct output (190 ~ 950r/min), also can output many kind revolution speeds and torques though reduce with gear, worm and cycloidal etc.