IMPROVEMENTS IN ELECTRIC ACTUATORS FOR VEHICLE SYSTEMS

摘要

An electric actuator (14) is disclosed which comprises an electric motor (28) and a sensing means is provided which is adapted for detecting the angular position, and hence speed, of the rotor assembly (27) of the motor (20) by sensing the passing of a magnetic means which forms part of the rotor assembly. In one embodiment, the sensing means is adapted to measure the passing of an end face or an overhanging portion of the rotor magnet of the motor. The sensing means may comprise Hall effect or magneto-resistive sensing elements (62) and a shielding assembly (65) is also disclosed which both protects the sensing elements (62) from unwanted magnetic fields and increases the flux linked between the magnetic means and the sensing elements.