Smart foil journal bearing with piezoelectric actuators

摘要

A foil journal bearing utilizes a plurality of piezoelectric actuators to increase the load carrying capacity of the bearing. The foil journal bearing is provided at an interior surface of its bearing housing with a plurality of foils or a top foil for supporting a rotating shaft The foil journal bearing includes a plurality of piezoelectric actuator devices embedded in an inside portion of the bearing housing while coming into contact with and supporting the foils or foil to increase stiffness and damping coefficient of the bearing at critical speeds of the rotating shaft. Each of the piezoelectric actuator devices is comprised of a piezoelectric actuator inserted into one of dimples formed on the interior surface of the bearing housing and provided with at least a piezoelectric actuating element and an elastic spring interposed between a bottom of the piezoelectric actuator and a bottom of the dimple, so as to increase stiffness and damping coefficient of the bearing by application of voltage to the piezoelectric actuator.