MEASURING APPARATUS OF MINUTE TORQUE

PURPOSE:To obtain a measuring apparatus of a minute torque which reduces nonuniformity in a loaded torque and lessens measuring errors. CONSTITUTION:This apparatus is equipped with a torsion bar 2 of which one end is fixed to a support part 11, a motor fitting plate 13 which fixes the stator side M1 of a motor M to the other end of the torsion bar 2 concentrically with the torsion bar 2, a noncontact type brake 5 which makes a braking force act in a noncontact manner on the rotor side M2 of the motor M, an electrode fitting plate 12 which is opposed to the motor fitting plate 13 with a gap between them and fixed to the support part 11, a fixed electrode 3 and a rotary electrode 4 which are provided on the opposite surfaces of the electrode fitting plate 12 and the motor fitting plate 13, respectively and composed of a plurality of electrodes extending radially, a capacitance detector 8 which detects a capacitance between the fixed electrode 3 and the rotary electrode 4 changing in accordance with a rotational angle of the rotor side M2, and a torque computing unit 9 which computes a generated torque of the motor M from a change in an output of the capacitance detector 8.