| 摘要 |
PROBLEM TO BE SOLVED: To suppress function deterioration of a linear solenoid due to inflow of grease into a pin guide gap and a plunger guide gap, in an electrically-driven linear motion actuator having a parking brake function.SOLUTION: An electrically-driven linear motion actuator has: an electric motor 30; and an electric lock mechanism 70 incorporated in a gear speed reduction mechanism 40 for decelerating the rotation of a rotor shaft 33a of the electric motor 30, and holding the gear speed reduction mechanism 40 in a lock state by electric conduction. The electric lock mechanism 70 moves forward a lock pin 72 which is movable forward and backward to/from an engaging recessed part 71 of one gear 43 of the gear speed reduction mechanism 40 by the electric conduction with respect to a linear solenoid 73. A vent hole is provided in a casing 74 in the linear solenoid 73, so that even when the volume inside the casing 74 changes due to the forward/backward movement of a plunger 79, a pressure inside the casing 74 does not change. |
