| 摘要 |
A magnetoelastic torque sensor for providing an output signal indicative of the torque transmitted between radially separated locations of a disk-shaped member includes a magnetoelastically active, ferromagnetic, magnetostrictive region which is magnetically polarized in a single circumferential direction and possesses sufficient magnetic anisotropy to return the magnetization in the region, following the application of torque to the member, to the single circumferential direction when the applied force is reduced to zero. First and second torque transmitting elements are directly attached to or form a part of the member at its central axis of rotation and its periphery in such a manner that torque is proportionally transmitted between the member and the transmitting elements. Magnetic field sensor means are mounted proximate to the member to sense the magnitude of the magnetic field produced by the member in response to the torque which is radially transmitted through the member between the first and second transmitting elements. The member is preferably formed of a polycrystalline material wherein at least 50% of the distribution of local magnetizations lie within a 90° quadrant symmetrically disposed around the single circular direction and has a coercivity sufficiently high that the field arising from the member does not magnetize proximate regions of the member to give rise to parasitic magnetic fields which are of sufficient strength to destroy the usefulness, for force sensing purposes, of the net magnetic field seen by the magnetic field sensor means. |
