ROTATION POSITION SENSOR

PROBLEM TO BE SOLVED: To improve capability of insertion and contact to an object shaft by press-contacting the plane of the object shaft to a pressing part provided to the inner diameter part of rotor and supporting the shaft with a support piece pushed inside by a snap ring. SOLUTION: When a sensor is assembled, a whole case 97 is pushed to a shaft 88 side in the state the plane part 89 of the object shaft 88 and the position of a pressing part 90 of a rotor 84 match, the rotor 84 is fitted in the tip end of the shaft 88 and combined against the rotation direction and the case 97 is fixed to a throttle body with machine screws and the like. At this moment, since the plane part 89 of the shaft 88 is pressed to the pressed part 50 of the rotor 84, contact is improved. As a support piece 91 supporting the shaft 88 is pushed up inside with a snap ring 92 provided outside the rotor 84, the support piece 91 freely elastically distorts outward when inserting the shaft 88, and so insertion capability is improved. Furthermore, excess inclination of the rotor 84 due to shaft 88 insertion is prevented as an inclination prevention part 95 touches the bottom of a cover 101.