Patent ID: 8746082
Filing Date: 2014-06-10
Classification: G01L

Abstract:
1. A torque sensor which detects a deflection angle between an input shaft and an output shaft, the input shaft and output shaft being aligned with a shaft axis, said sensor comprising: an annular sine ring, annular cosine ring and annular flux return ring coaxially disposed around the shaft axis, said sine ring, cosine ring and flux return ring being constructed of a ferromagnetic material and fixed against rotation relative to the input and output shafts, a sine spoke secured to one of said input and output shafts and having an outer periphery closely adjacent said sine ring, a cosine spoke secured to said one of said input and output shafts and having an outer periphery closely adjacent said cosine ring, said cosine spoke being angularly offset from said cosine spoke by a predetermined angle, a pair of flux return spokes, one flux return spoke being connected at one end to said one of said input and output shafts and diametrically opposed from said sine ring, said one flux return spoke having an outer periphery closely adjacent said flux return ring, the other flux return spoke being connected at one end to said one of said input and output shafts and diametrically opposed from said cosine ring, said one flux return spoke having an outer periphery closely adjacent said flux return ring, all of said spokes being constructed of a ferromagnetic material, a sine magnetic flux bridge formed between said sine ring and said flux return ring and a cosine magnetic flux bridge formed between said cosine ring and said flux return ring, a pair of flux sensors, one flux sensor positioned to measure the magnitude of flux passing through each bridge, a magnet attached to the other of said input and output shafts, said magnet having a pole positioned angularly between both said sine spoke and said cosine spoke, and a circuit which receives the signals from the flux sensors and generates an output signal representative of the angular deflection between the input shaft and output shaft.