Patent ID: 8070169

Claim:
An actuator for an active roll control system that connects a stabilizer bar with a lower arm and actively improves roll of a vehicle by changing torsional rigidity of the stabilizer bar according to a driving condition of the vehicle, the actuator comprising: a screw housing having a space formed therein; a power transmitter slidably mounted in an upper interior circumference of the screw housing, and having an upper end portion connected to one end of the stabilizer bar by a joint and a lower end portion slidably movable in the space of the screw housing, wherein the lower end portion of the power transmitter includes a screw groove therein and a screw thread is formed at an interior circumference of an inlet portion thereof; a lead screw being inserted in the screw groove of the power transmitter and threaded to the screw thread of the inlet portion and having a screw rotation shaft integrally connected to a lower end thereof; a drive motor mounted at a lower portion of the screw housing and having a rotation shaft connected to the screw rotation shaft; an annular damper for absorbing impact to an interior surface of the space in the screw housing provided at a lower end portion of the space in the screw housing; and an impact absorbing unit disposed between the screw rotation shaft and the screw housing for absorbing and dispersing impact, wherein the impact absorbing unit comprises: a metal bush mounted in the screw housing in a state of being inserted on the screw rotation shaft; a thrust disk disposed under the metal bush and insertedly mounted on the screw rotation shaft; upper and lower thrust bearings inserted on the screw rotation shaft,and mounted corresponding respectively to upper and lower surfaces of the thrust disk; and bearing plates mounted respectively at an upper surface of the upper thrust bearing and lower surface of the lower thrust bearing.