Sensor for measurement of the torque acting on a rotating shaft

US4941363A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Guenter Doemens · Holzkirchen, DE
• Markus Gilch · Moosburg an der Isar, DE

Key dates

• Filing date: Jul 26, 1989
• Grant date: Jul 17, 1990
• Expiry date: Jul 26, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L3/106
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor for measuring the torque acting on a rotating shaft has two electrode structures which are respectively mechanically coupled to two axially spaced points on the shaft to be measured so that a relative movement between the two electrode structures occurs due to the torque. The electrode structures each have a number of parallel, spaced electrodes and are asymmetrically mounted in a plane so that a number of capacitors are formed by electrode pairs each having an electrode from each electrode structure. Because of the asymmetrical arrangement, the electrodes in a pair are spaced a relatively large distance away from the next closest electrode, so that a capacitive decoupling between the pairs is achieved. Changes in the spacing between the points on the shaft due to torsion of the shaft caused by the torque will change the spacing between the electrodes in each pair, thereby resulting in a total capacitance change which is proportional to the torque. To compensate for the influence of transverse forces or bending moments acting on the shaft, a further capacitor arrangement identical to the first arrangement is arranged at an angle of 180.degree. with respect to the first arr…