ELECTRIC BRAKE ACTUATOR, AND BRAKE SYSTEM FOR VEHICLE

A motor cylinder device (16) is configured with a cylinder mechanism (76) provided with first and second slave pistons that are displaced along a hydraulic pressure chamber; an electric motor (72) for driving first and second slave pistons; and an actuator housing (75) formed separable from the cylinder mechanism (76), wherein the actuator housing houses a gear mechanism for transmitting a rotational driving force of the electric motor (72), and a conversion mechanism for converting the rotational driving force transmitted through the gear mechanism, into a linear movement and transmitting the linear movement to the piston.