ELECTRONIC PARKING BRAKE ACTUATOR

A parking brake actuator is provided. The parking brake actuator includes a motor, a power transfer unit connected to an output shaft of the motor, a planetary gear set including a linear gear connected to the power transfer unit, a planetary gear engaged with the linear gear, and a ring gear engaged with the planetary gear and including an insertion protrusion formed on a bottom, and a housing including a motor accommodating portion in which the motor is accommodated and a ring gear accommodating portion in which the ring gear is accommodated, in which the ring gear accommodating portion includes an insertion groove formed on a bottom surface into which the insertion protrusion is forcibly inserted. The parking brake actuator provides may prevent a gap between the ring gear of the planetary gear set and the housing. A configuration described above increases the degree of freedom in a tolerance design with respect to the ring gear accommodating portion of the housing, thereby increasing the quality of products.