| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deterioration of responsivity of an actuator due to swaying of a rotary portion.SOLUTION: An actuator 10 includes: a nut 14; a planetary shaft 16; a rotor 22; and a sun shaft 15 reciprocating with rotations of a rotary portion 24 such as an inner ring 31 of a bearing 30. The nut 14 is supported by the single-ball type bearing 30. The bearing 30 is fixed to a housing 11 at an outer ring 32 and fixed to the nut 14 at the inner ring 31. In an axial direction of the sun shaft 15, a contact portion P of a ball 33 and the inner ring 31 of the bearing 30, and a gravity center position C of the whole of the rotary portion 24 match with each other. |
