Transmission mechanism and electronic parking brake

The utility model provides a transmission mechanism which comprises a shell, a motor, a flexible gear, a support and an output shaft. The motor is fixed onto the shell, the flexible gear is positioned in the shell, the support is positioned in the flexible gear, and the output shaft is used for outputting driving force of the transmission mechanism; a through hole is arranged in the middle of the support, the section of the through hole is D-shaped, a motor shaft penetrates through the through hole of the support, the shape of the motor shaft is matched with that of the through hole, a plurality of rollers are movably connected onto the support, and the sum of the revolution radius of each roller along the motor shaft and the radius of the roller is larger than that of the inner wall of the flexible gear; and external teeth are arranged on the outer wall of the flexible gear, internal teeth meshed with the external teeth are arranged on the inner wall of the shell, and the output shaft is fixed onto the flexible gear and penetrates through the shell. The transmission has the advantages of simple structure and stability and reliability in transmission.