| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure capable of increasing the generation of braking force and shortening the time required to generate braking force.SOLUTION: A piston 11a is pressed out toward a rotor by an electric actuator which is driven by an electric motor 8a as a driving source. The electric actuator is constituted by arranging a gear-type speed reducer 10a, a ball speed reducer 19, and a feed screw device 12a in series in the power transmitting direction. Each ball 24 constituting the ball speed reducer 19 is pressurized by a compression coil spring 43 to give resistance to functioning of the ball speed reducer 19. As the ball speed reducer 19 is not actuated immediately after start of braking, the time necessary for pressing a lining of each pad against a side face of the rotor can be shortened. After the pressing, the ball speed reducer 19 is actuated to strongly press the lining against the side face of the rotor. |
