POWER STEERING MECHANISM WITH MAGNETOELASTIC TORSION BAR

摘要

A power steering mechanism (10) for turning steerable wheels of a vehicle comprises a rotatable input member (22), a rotatable output member (26), and a torsion bar (28) connecting the input member and the output member. The torsion bar (28) is fixedly connected to the output member (26) and twists upon relative rotation between the input member (22) and the output member. The torsion bar (28) is made of a magnetoelastic material and has a defined surface area (90) which carries a magnetic field, which magnetic field varies upon twisting of the torsion bar. Magnetic field detector (94) is located to sense variance in the magnetic field. The input member (22) is interposed between the torsion bar (28) and the magnetic field detector (94) and is made of a non-magnetic material.