Patent attributes
A torque detecting apparatus having a permanent magnet fixed to an input shaft, magnetic yokes fixed to an output shaft coaxially connected to the input shaft via a torsion bar and disposed within a magnetic field of the permanent magnet to form a magnetic circuit, and a Hall IC for detecting a magnetic flux induced by the magnetic yokes. The permanent magnet is of a truncated conical shape, and the bevel circumference surface thereof is magnetized by magnetic poles alternately in a reverse polarities along circumference direction, so as to oppose the magnetic yokes. A torque applied to the input shaft or the output shaft can be detected through detection by the Hall IC of the magnetic flux generated between the magnetic yokes. The configuration allows reducing the length in an axial direction of the input shaft.