AUTOMATIC BALANCING APPARATUS MOTOR

PROBLEM TO BE SOLVED: To provide a small-sized thin automatic balancing apparatus of a motor, wherein unstable rotational fluctuations are not generated when it is rotated at high speed. SOLUTION: Formed concentricity with a turntable 30, etc., of a motor a storage portion 36 comprising an annular space, first and second rings 37, 38 are stored in the storage portion 36. The diameter of the first ring 37 is made larger than the outer diameter of the inner peripheral wall of an annular recess 35 but smaller than the inner diameter of the outer peripheral wall of the annular recess 35 for making the outer peripheral surface of the first ring 37 abut against the outer peripheral wall surface of the annular recess 35. The diameter of the second ring 38 is made larger than the outer diameter of the inner peripheral wall of the annular recess 35 but smaller than the first ring 37 for making the inner peripheral surface of the second ring 38 abut against the inner peripheral wall surface of the annular recess 35. When rotating the motor, both the rings 37, 38 are moved to the opposite side to a positions, where to the weight balance of the motor deviates from its center of rotation, to correct the deviation thereof. Further, around the center of gravity of the rotational portion of the motor, making mutually reverse the directions of the frictional forces of both the rings 37, 38 caused by their abuttings, the variations in the gravity position of the rotational portion of the motor will not occur by virtue of their frictional forces to prevent the rotational fluctuations.