ACTUATOR INTEGRAL WITH ELECTRIC MOTOR

摘要

PROBLEM TO BE SOLVED: To provide an actuator integral with an electric motor capable of preventing a cavitation without causing a large size. SOLUTION: This actuator is provided with a hydraulic cylinder 51; a hydraulic pump 54 generating a pressure oil driving the hydraulic cylinder 51; and an electric motor 55 driving the hydraulic pump 54. In the actuator, at least hydraulic pump 54 and the electric motor 55 are integrated. A by-pass passage 53c for communicating a flow-in side 59 or 60 of a pressure oil against the hydraulic cylinder 51 with a flow-out side 60 or 59 and an opening/closing means 52 for opening and closing the by-pass passage 53c are integrally assembled to the hydraulic cylinder 51.