TORQUE SENSOR

PROBLEM TO BE SOLVED: To provide a torque sensor accurately detecting a small displacement between an input shaft and an output shaft caused by torsion of a torsion bar by enlarging it and to improve the reliability by eliminating the poor contacting. SOLUTION: A piston pipe 7 having long holes 6 for fitting a pair of sliding elements 5 diagonally provided in its inner circumferential face is coaxially arranged with the sliding elements 5 oppositely projecting across an axial core in the outer circumferential face of the other end 4a of an outer pipe having the torsion bar 3 internally fitted therein. The piston pipe 7 is set movable only axially relative to the output shaft 2 and a detection bar 11 swinging corresponding to the moving change in the piston pipe 7 is pivoted to the inner face 9a of an outer case 9, and the detecting element 12 of a direct-moving potentiometer 13 is connected to its tip 11a in such a state as freely appearing and disappearing.