摘要 |
A magnetic transducer fits over and encompasses a rotatable shaft and has a primary or excitation magnetic assembly having a winding arrangement that is energized to provide a-c excitation for producing an alternating magnetic flux or field, adjacent to and within the shaft, which is modified as the shaft is torsionally stressed when torque is applied thereto. This stressing causes compression and tension in the shaft which alter the shaft permeability and thus vary the magnetic flux pattern in the shaft. The resulting or modified magnetic field is also a function of the shaft speed due to the shaft's armature reaction, eddy currents being generated in the shaft which develop a counter magnetic field that opposes and distorts the field produced by the primary winding arrangement. A pair of secondary or pick-up magnetic assemblies, having secondary windings, respond to the modified magnetic field and provide information signals relative to the torque and speed characteristics of the rotating shaft. The size, weignt, cost and complexity of the transducer are substantially reduced by constructing the three magnetic assemblies so that the primary and secondary windings are effectively wrapped around the shaft with the winding turns and the shaft sharing the same axis, the magnetic field thereby being parallel to the shaft. Relatively short poles extend radially inwardly from the magnetic assemblies toward the shaft to control the magnetic flux paths and maximize the amount of flux passing through the shaft.
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