Patent ID: 8807260

Claim:
A magnetostrictive torque sensor comprising: a magnetostrictive portion formed on a rotational shaft; a bobbin surrounding an outer circumference of the magnetostrictive portion; a coil wound on the bobbin for detecting a change in magnetic property of the magnetostrictive portion; a case covering the bobbin with a clearance defined between the case and an outer peripheral surface of the bobbin; and a terminal extending from the bobbin through the case in a direction perpendicular to an axis of the rotational shaft for energizing the coil, wherein the bobbin fits over the magnetostrictive portion in contact with the magnetostrictive portion in such a manner as to allow rotation of the magnetostrictive portion relative to the bobbin, wherein the bobbin is supported by the rotational shaft, wherein the bobbin is slidably in contact with the magnetostrictive portion such that when the rotational shaft is subjected to a load tending to twist the rotational shaft, the bobbin follows the twisting of the rotational shaft, wherein the terminal extending through the case serves to prevent the bobbin from rotating together with the rotational shaft due to contact with the magnetostrictive portion, and wherein the clearance provides an air layer acting as a thermal insulating layer to make it difficult for the coils to be affected by a change in temperature outside the case.