MEASUREMENT OF VERY LOW TORQUE VALUES

摘要

A tangential force sensor is used instead of a coaxial strain gauge to measure the torque required to produce the rotation of a part. The force sensor is coupled tangentially to the rotating part through a non-slip contact produced by a force applied radially on the part. A progressively increasing tangential force produced by translating the force sensor in a direction normal to the axis of rotation of the part is then applied to initiate and maintain its rotation. The radial force applied to the part is judiciously selected and measured such that the part is engaged with enough friction to ensure a non-slip condition. By measuring the tangential force applied to the part, the torque characteristics of the rotatable part are determined. By sensing and controlling the radial force applied to the part, damage to the part or the mechanism supporting it is avoided.

主权项

1. A method of measuring a torque applied to a rotatable object, the method comprising the following steps:
providing a sensor assembly with a flat surface adapted for translation in orthogonal directions, said assembly including a force sensor: contacting a cylindrical surface of the object with said flat surface through the application of a radial force sufficient for frictional engagement of the object; applying a tangential force to said cylindrical surface of the object by translating the sensor assembly in a direction normal to an axis of rotation of the object, thereby causing the rotation of the object; measuring said tangential force with the force sensor during said step of applying the tangential force; and utilizing tangential-force values produced by the measuring step to determine torque characteristics of the rotatable object.