| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric actuator capable of recovering a brake fluid scraped out by piston slide movement, preventing the infiltration of the brake fluid into a ball screw mechanism, and ensuring a desired service life in a structure in which a screw shaft of the ball screw mechanism abuts on a piston of a hydraulic cylinder and directly deforms integrally with the piston.SOLUTION: An electric actuator is configured so that a through-hole 11 and a bag hole 12 are formed for accommodating a screw shaft 10 in a housing 2a, a hydraulic cylinder 21 is fitted and inserted into the through-hole 11, a reservoir groove 24 is formed in a bottom of an inner circumferential surface of the through-hole 11 along an axial direction to range from an opening portion of the through-hole 11 beyond a fitted and inserted portion of the hydraulic cylinder 21 so as to recover a brake fluid, and an oil absorption material 25 formed of a polymeric material having high oil absorption properties is buried in this reservoir groove 24. It is, therefore, possible for the brake fluid scraped out from the hydraulic cylinder 21 to flow along the inner circumferential surface of the through-hole 11 to be recovered in the reservoir groove 24, and thereby prevents the infiltration of the brake fluid into a ball screw mechanism 8. |
