MOTOR SHAFT FOR MICROMOTOR, AND MICROMOTOR

摘要

[Problems] A motor shaft for a micromotor where a high reduction ratio can be obtained by a speed-reduction gear mechanism and where high coaxiality between the motor shaft and a pinion can be achieved. [Means for Solving problems] The invention is based on the fact that, because a micromotor has a very small motor torque, even a pinion having a diameter smaller than that of a shaft has sufficient strength for the motor torque. Based on this, the motor shaft of the invention has a pinion integrally formed on the front end side of the shaft and the pinion has an outer diameter equal to or less than that of the shaft. Because the pinion can be sufficiently reduced in diameter, a high reduction ratio can be obtained by a speed-reduction gear mechanism. In addition, since the pinion can be integrally formed on the motor shaft, high coaxiality between the shaft and the pinion can be achieved.