| 摘要 |
PROBLEM TO BE SOLVED: To make a parking brake function be surely operated at all times by preventing impairing of slidability of a lock pin caused by attachment of grease, in an electric linear actuator having the parking brake function.SOLUTION: A lock mechanism 60 capable of locking and unlocking rotation of a rotor shaft 25 of an electric motor 24 is composed of a locking hole 61 formed at one side of a gear 33 configuring a gear speed reduction mechanism 30, a lock pin 62 for locking the gear by being engaged with the locking hole in forward movement, and a linear solenoid 63 for moving the lock pin forward and backward. A radial groove 70 is formed toward a radial outer part from between locking portions adjacent to a side face of the gear, and adhesion grease moving outward by centrifugal force by rotation of the gear, is guided to the radial outer part by a radial groove to prevent intrusion of the grease into the locking hole. Impairing of slidability of the lock pin caused by attachment of grease is suppressed by preventing the attachment of the grease to an outer periphery of the lock pin from the locking hole. |
