Electrically-actuated power steering system

摘要

In one embodiment of the present invention, an electric assist power steering system includes steerable wheels and a polyphase induction motor mechanically coupled to provide assistance in steering the wheels. Additionally, the system includes a DC power source such as a vehicle battery or an alternator. The system also includes an inverter to convert the output voltage of the DC power source into AC phase voltages for the induction motor, the AC phase voltages having line-to-line amplitudes less than or equal to the output voltage of the DC power source. Another embodiment of the present invention includes an induction motor designed to have rotor back iron thinner than stator back iron. Such a motor will have a rotor of reduced diameter, minimizing the rotational inertia of the rotor. The present invention enables a practical electric assisted power steering system and the numerous advantages derived from an electric assisted system.