Patent ID: 9080623
Filing Date: 2015-07-14
Classification: F16D

Abstract:
1. An electromechanical brake system comprising: a base carrier provided with a pair of pad plates for application of pressure to a disc, the pad plates installed to be movable forward and backward; a caliper housing supported by the base carrier to be movable forward and backward to apply pressure to the pad plates; a pressing member including a ball nut installed at the caliper housing to convert rotational motion into rectilinear motion to apply pressure to the pad plates and a ball screw coupled to the ball nut; a force sensor installed at the ball nut to sense load produced by operation of the ball nut; a motor to produce rotational force to operate the pressing member; and a speed reducer connected to a rotating shaft of the motor to transfer driving force to the pressing member, wherein the speed reducer is adapted to change a reduction ratio depending on presence of the load sensed by the force sensor, wherein the speed reducer comprises: wherein the internal gear unit comprises: wherein the second internal gear moves forward or backward to be engaged with the planetary gears and the carrier to transfer rotational force or to be placed between and engaged with the planetary gears and the first internal gear to amplify the rotational force.