Abstract: Two magnetic field generators are located symmetrically to each other in a first plane perpendicular to a shaft, and two magnetic field detectors are immobilized in a second plane perpendicular to the shaft. The magnetic field detectors provide a signal proportional to the torsional moment as a result of angular shift of the magnetic field generators with respect to the magnetic field detectors. The magnetic field generators have a magnetized structure with antiparallel magnetization directions and are supported by a first disk mounted on the shaft and are placed at the end of a first hub which surrounds the shaft. The first hub supports a bearing for mounting a second hub and second disk, which is axially shifted and to which the magnetic field detectors are rigidly attached.

Abstract: Two magnetic circuits are separated by an air gap and are made up respectively of a series of permanent magnets which are attached and rigidly held together by flux return yokes. One side of the magnetic circuits is turned towards the air gap. The directions of magnetization of the opposing magnets and of the attached magnets are antiparallel and the length of each magnet is approximately two times larger than the width of the air gap.