Contactless measurer for torque and/or rotary angle - uses two concentric pieces fixed to shaft concerned to form air gap strengthening or weakening magnetic field

摘要

Two pieces (1, 2) have end regions fixed to the stationary or rotating shaft (3). The pieces can be rotated w.r.t. each other. An associated measuring system derives the torque and/or rotation angle transmitted from the shaft to the pieces so that their relative positions change. The pieces are concentric cylinders with a tooth profile at the ends facing each other. They are fixed to the shaft at such a distance that an air gap of constant width is created between the inclined tooth flanks in the direction of the circumference. This width changes by relative rotation of the pieces, weakening or strengthening an externally applied magnetic field. Alternatively, the gap can be measured optically. ADVANTAGE - Continuous precise measurement. Interference for a.c. voltages of measuring system can be prevented.