Patent ID: 9616862
Date: 2017-04-11
CPC Classifications: B60T,F16D

Claim:
1. An actuator for an electric parking brake system, comprising: an outer housing; a planetary gear train and an electric motor received in the outer housing; and at least one gear connected between the planetary gear train and the electric motor, the electric motor being arranged to drive the planetary gear train through the at least one gear; wherein the planetary gear train comprises a multi-stage planetary gear mechanism, an output driven by the planetary gear mechanism, a gear housing for receiving the planetary gear mechanism, and a gear cover connected to one end of the gear housing, wherein the planetary gear mechanism has a first stage through to a Nth stage that are sequentially meshed from one end to the other end of the planetary gear train, N is an integer greater than 1, each stage of planetary gear mechanism comprises a sun gear, a ring gear, a plurality of planet gears meshed with the sun gear and ring gear, and a planet carrier supporting the planet gears, and the output is fixed to the planet carrier of the Nth stage; and wherein the planetary gear train further comprises a centering pin extending through the planetary gear mechanism, such that stages of the planetary gear mechanism rotate about the centering pin; and wherein the centering pin is fixed to the sun gear of the first stage of the planetary gear mechanism or one of the output and the planet carrier of the Nth stage.