Integral torsion sensor

Apparatus for direct measurement of torque comprising:

• a first shaft rotatably mounted in a shaft support and including means for coupling said first shaft for rotation to a first external device;
• a second shaft rotatably mounted in said support coaxial with said first shaft and including means for coupling said second shaft for rotation to a second external device;
• a driver collar coaxially fixed to said first shaft;
• a driven collar fixed to said second shaft and concentric with said driver collar and said first and second shafts;
• resilient means, disposed between said driver and driven collars, for transferring rotary motion between the driver and driven collars in response to rotation of either the first shaft, by the first external device, or, in response to rotation of the second shaft, by the second external device;
• and
• sensor means, disposed between the driver and driven collars, for measuring an angular displacement of the driver collar relative to the driven collar in order to provide a direct measurement of torque, said sensor means being mounted in a rotational plane of the resilient means and in a clearance space not occupied by the resilient means, said sensor means comprising two interacting components, one of the two components being mounted on the driver collar and a second of the two components being mounted on the driven collar.