Torque sensor

摘要

764,724. Torque measuring apparatus. BENDIX AVIATION CORPORATION. Feb. 14, 1955 [Feb. 18, 1954], No. 4337/55. Class 40 (1). A device for measuring the torque of a shaft comprises multiple air gaps at the shaft ends and electromagnetic means responsive to variation in said air gaps in accordance with torque. Each multiple air gap is an assembly comprising a component rigid with the near-by end of the shaft and a component extending from the further end of the shaft. In Fig. 1, an inner rotor 47 comprises a magnetic sleeve 48 integral with torque rings 49, 50 and secured only to shaft hub 44 whilst an outer rotor 34 comprises a non-magnetic sleeve 39 carrying torque rings 35, 36 and secured only to shaft hub 43 whereby hub 43 is related to complementary torque ring pairs 35, 49 having axial fingers 40, 51 to form multiple air gaps 105 (see Fig. 2) and hub 44 is related to complementary torque ring pairs 36, 50 similarly having axial fingers 7, 52 to form multiple air gaps 106. The surrounding stator 10 has a magnetic shell 12 and comprises A.C. fed primary coils 24, 241 and series-opposition secondary coils 25, 251 (see Fig. 5) and there are two magnetic circuits through half portions of magnetic shell 12 and rotor sleeve 48 and via complementary stator and rotor central flanges 15, 53 and when shaft 9 is under torsional strain such that each air gap 105 increases then each air gap 106 will decrease and the opposite changes in reluctance of the two magnetic circuits produces an increase in voltage from one secondary coil and a decreased voltage from the other and the nett output voltage indicated on meter 122 serves as a measure of torque on the gauge shaft 9. The Specification includes, Fig. 6 (not shown), a detailed drawing of the two magnetic circuits. A modification, Figs. 3 and 4 (not shown), comprises torque rings having radial finger laminations to provide the multiple air gaps.