The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 10, 1990
Filed:
Jul. 21, 1988
Robert D Klauber, Fairfield, IA (US);
Erik B Vigmostad, Fairfield, IA (US);
SensorTech, L. P., Fairfield, IA (US);
Abstract
A noncontacting method for sensing torque based on the principle of magnetostriction comprises inducing a primary magnetic flux in a shaft (20) via such means as a primary excitation core/coil(30/32), keeping primary path flux amplitude constant via such means as an auxiliary core/coil (48/50) and appropriate feedback circuitry, and obtaining a torque dependent signal which is a function of a secondary flux via such means as a secondary core/coil(34/36). Signal dependence on RPM, temperature, and material property inhomogeneities is eliminated or minimized, instantaneous torque measurement is possible, and mass production is made feasible. A second embodiment utilizes modified signal processing circuitry to eliminate spurious signal components. A third embodiment comprises a single core/coil(58/60) placed close to a shaft (20) which detects torque by means of voltage or current changes in the coil (60). Embodiment four comprises two single core/coils(58/60 and 59/61) such as those of embodiment three and signal processing circuitry which produces a signal minimally affected by RPM, temperature, and material property inhomogeneities. A fifth embodiment employs a plurality of sensors (66A/66B) strategically located around the shaft (20) to eliminate spurious signals which are due to bending stress and shaft misalignment.