Proximity sensor to sense rotating shaft position and velocity
AssigneeHamilton Sundstrand Corporation
InventorsGordon Elliott Winer, Shihab T. A. Muhammed
Life of this patent
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Abstract
A shaft monitoring system includes a rotatable shaft having a target element coupled thereto that rotates along with the shaft. A proximity sensor is located adjacent to the target element. The proximity sensor measures an inductance of the target element based on one or both of a volume of the target element and a distance between the target element and the proximity sensor, and generates a proximity sensor output signal based on the measured inductance. A signal processing system determines at least one of a position of the shaft, a rotational speed of the shaft, and a rotational direction of the shaft based on the proximity sensor output signal.
Claims18
A shaft monitoring system comprising:
- a rotatable shaft including a target element coupled thereto that rotates along with the shaft, the target element including a series of individual target sections arranged sequentially one after another;
- a proximity sensor located adjacent to the target element, the proximity sensor configured to measure an inductance of the target element based on one or both of the volume of the target element indicated by the individual target section sensed by the proximity sensor and a distance between the individual target section of the target element and the proximity sensor, and to generate a proximity sensor output signal based on the measured inductance;
- and
- a signal processing system in signal communication with the proximity sensor, the signal processing system configured to determine at least one of a position of the shaft, a rotational speed of the shaft, and a rotational direction of the shaft based on the proximity sensor output signal,
- wherein the individual target sections directly contact one another such that each of the different measured inductances corresponds to a respective rotational position of the shaft, and wherein the different measured inductances increase according to a positive constant slope defined as a change in the inductance of the target elements with respect to a change in the rotational position of the shaft in response to rotating the shaft in a first direction, and wherein the different measured inductances decrease according to a negative constant slope defined as a change in the inductance of the target elements with respect to a change in the rotational position of the shaft in response to rotating the shaft in a second direction opposite the first direction.
A method of monitoring a rotatable shaft, the method comprising:
- positioning a target element coupled to the rotatable shaft a distance away from a proximity sensor, the target element including a series of individual target sections arranged sequentially one after another;
- measuring, via the proximity sensor, an inductance based on one or both of a volume of the target element indicated by the individual target section sensed by the proximity sensor and a distance between the individual target section of the target element and the proximity sensor;
- generating a proximity sensor output signal based on the measured inductance;
- determining, via a signal processing system in signal communication with the proximity sensor, at least one of a position of the shaft, a rotational speed of the shaft, and a rotational direction of the shaft based on the proximity sensor output signal;
- determining a respective rotational position of the shaft based on a respective different measured inductance,
- wherein the individual target sections directly contact one another such that each of the different measured inductances corresponds to a respective rotational position of the shaft, and wherein the different measured inductances increase according to a positive constant slope defined as a change in the inductance of the target elements with respect to a change in the rotational position of the shaft in response to rotating the shaft in a first direction, and wherein the different measured inductances decrease according to a negative constant slope defined as a change in the inductance of the target elements with respect to a change in the rotational position of the shaft in response to rotating the shaft in a second direction opposite the first direction.
Dependencies are inferred from the claim text.