Patent ID: 9026378
Filing Date: 2015-05-05
Classification: G01D,G01L

Abstract:
1. A device for detecting a twist angle of a shaft and/or a torque occurring on the shaft, the device comprising: at least one first passive encoder associated with at least a part of the circumference of the shaft, influencing at least one first coil parameter, and having at least one first encoder track having at least one period per revolution of the shaft, at least one first inductive proximity sensor for scanning the at least one first passive encoder and providing a first rotational angle of the shaft within the period, at least one second passive encoder also associated with at least a part of the circumference of the shaft, influencing at least one second coil parameter, being provided at a predefined spacing to the at least one first passive encoder, and having at least one second encoder track having at least one period per revolution of the shaft, at least one second inductive proximity sensor for scanning the at least one second passive encoder and also providing a second sensor signal reflecting at least one measure for a second rotational angle of the shaft within the period, and a difference ascertainment unit ascertaining and providing the twist angle of the shaft as an angle difference of the first rotational angles detected by the at least one first inductive proximity sensors and the second rotational angle detected by the at least one second inductive proximity sensor; wherein the at least one first encoder track extends without pitch only in the circumferential direction of the shaft and contains a plurality of repeating periods; wherein the at least one first inductive proximity sensor comprises a first first inductive proximity sensor and a second first inductive proximity sensor; wherein the first first inductive proximity sensor and the second first inductive proximity sensor are associated with the at least one first encoder track; wherein the first first inductive proximity sensor and the second first inductive proximity sensor are positioned in relation to the periods of the at least one first encoder track such that the first first inductive proximity sensor provides a first first sensor signal phase-shifted by at least approximately 90°in relation to a second first sensor signal provided by the second first inductive proximity sensor; wherein the at least one first encoder track comprises a first first encoder track and a second first encoder track directly adjacent to the first first encoder track; wherein the first first encoder track contains a first predefined number greater than one of repeating periods; wherein the second first encoder track has a second predefined number of repeating periods; and wherein the second predefined number deviates by at least one from the first predefined number.