Patent ID: 8836458
Filing Date: 2014-09-16
Classification: G01L,Y10T

Abstract:
1. A method of manufacturing a magnetic torque sensing device comprising the steps of: providing a generally disk-shaped member having opposite generally circular spaced apart surfaces and a central axis of rotation, wherein the disk-shaped member includes at least a portion that is both ferromagnetic and magnetorestrictive, wherein said portion is capable of producing a magnetic field that varies with a torque applied to the disk-shaped member, and wherein said portion possesses sufficient magnetic anisotropy to return the magnetization in said portion to an initial state when the torque applied to the disk-shaped member is reduced to zero; positioning a pair of oppositely polarized permanent magnets with no radial gap therebetween proximate to the surface of the disk-shaped member at a first distance from a surface of the disk-shaped member; and rotating the disk-shaped member about its central axis to form two annular, oppositely polarized, magnetically conditioned regions with no radial gap therebetween.