Rotational component torque measurement and monitoring system

• US 8,079,274 B2
• Filed: 05/21/2009
• Issued: 12/20/2011
• Est. Priority Date: 05/22/2008
• Status: Active Grant

• Current Assignee: IEM Limited
• Original Assignee: IEM Limited
• Inventors: Mian, Zahid, Peabody, William, Salon, Sheppard
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US12/453,749
• Publication Number:
  US 20100031756A1
• Time in Patent Office: 943 Days
• Field of Search: 73862331-862335
• US Class Current: 73/862.335
• CPC Class Codes: G01L 3/104 involving permanent magnets
• CPC Class Codes: G01L 3/109 involving measuring phase difference of two signals or pulse trains

Abstract

A system and method for measuring torque on a rotating component, comprising of signal-producing components which are applied to the rotating component, and a means for obtaining the signals produced by said signal producing components, in which at least two signal producing components are applied to the rotating component with some linear separation between the two signal producing components and their corresponding devices for obtaining signals produced, such that torque applied to the rotating component will cause a change in phase between the signals received from each of the signal-producing components and thus permit the measurement of torque based on this change in phase; one embodiment of this invention comprising two magnetic rings, one at either end of a driveshaft, with sensor coils placed near to each magnetic ring such that an alternating electrical current is produced, the comparative phase between these currents permitting measurement of torque on the driveshaft.

Claims

1. A system for measuring torque on a rotating component, the method comprising:

At least two signal-producing components which are magnet rings comprising at least one North and one South magnetic pole along the circumference of said magnet ring applied to the rotating component with some separating distance between the magnet rings and affixed in a manner which prevents the magnet rings from moving with respect to each other due to the movement of the rotating component;

A means for obtaining a signal from the magnetic field emanating from the magnet rings, said means affixed to a non-rotating structure partially or wholly surrounding the rotating component;

A means for determining torque from the signals obtained from the magnet rings, comprising hardware or software means of comparing the waveforms created by the magnet rings'"'"' movement and thereby determining a twist in the rotating component based on the comparison of the waveforms.

2. The system of claim 1, in which the means for obtaining signals comprises one or more sensing coils for each magnet ring, separated from the rings.

3. The system of claim 2, in which said sensing coils are spaced such that a number of sensing coils may be placed around the rotating component, the number of possible sensing coils being equal to the total number of magnetic poles on the magnet rings.

4. The system of claim 3, further comprising hardware or software means for amplifying the signal from said sensing coils as the magnet ring rotates on the rotating component.

5. The system of claim 4, further comprising hardware or software means for filtering or removing noise.

6. The system of claim 5, further comprising hardware or software means of determining torque on the rotating component from the twist.

7. The system of claim 6, further comprising means of storing and retrieving measurements of torque and other data obtained by the system of claim 6 during operation.

8. The system of claim 7, further comprising a means of determining rotating component remaining lifetime based on the stored torque history.

9. The system of claim 8, further comprising means of estimating other component lifetimes based on transmitted torque estimates.

10. The system of claim 7, further comprising a means for transmitting a torque measurement from the torque measurement system to another separate system such as a data-processing system which performs storage, retrieval, and/or analysis of the torque data for various purposes.

11. The system of claim 1, where the rotating component is a driveshaft.

12. The system of claim 1, where the rotating component is a bearing or sleeve around a stationary shaft and the signal obtaining components may be either inside or outside the bearing or sleeve.

13. The system of claim 1, where the magnet rings are installed on the non-rotating structure partially or wholly surrounding the rotating component and the means for obtaining a signal from the magnet rings are applied to the rotating component with some separating distance between individual instances of the means for obtaining signals from the magnetic rings.

14. The system of claim 13, further comprising a set of electronics for acquiring and wirelessly transferring the data from the means for obtaining signals to another system exterior to the sensing system.

15. The system of claim 14, further comprising a set of components for harvesting power from the environment.

16. The system of claim 15, where the power to be harvested is generated by the action of the invention through the interaction of the signal-producing components with the means for obtaining signals.

17. A method of determining torque comprising:

Removably or permanently applying at least two magnet rings to an existing rotating component, said magnet rings separated by some distance and said magnet rings being permanent magnets of at least one North and one South magnetic pole about the ring'"'"'s circumference;

Removably or permanently installing sensing coils corresponding to each installed magnet ring on a non-rotating structure such that the sensing coils are at an appropriate distance from the magnet rings;

Obtaining a waveform generated by a magnet ring on a rotating component rotating past sensing coils

Obtaining at least one other such waveform generated by another magnet ring on the same rotating component, said other ring separated from the first by some linear distance along the rotating component

Comparing the relative phases of these two (or more) waveforms to determine the twist of the rotating component relative to a known non-torque relative phase difference

Calculating the torque based on a known relationship between torque and twist of the rotating component.

18. A method of determining torque comprising:

Removably or permanently applying at least two sensing coils to an existing rotating component, said sensing coils separated by some distance;

Removably or permanently installing magnet rings corresponding to each installed magnet ring on a non-rotating structure such that the magnet rings are at an appropriate distance from the sensing coils, and said magnet rings being permanent magnets of at least one North and one South magnetic pole about the ring'"'"'s circumference;

Obtaining a waveform generated by sensing coils on a rotating component rotating past a fixed magnet ring

Obtaining at least one other such waveform generated by another set of sensing coils on the same rotating component paired with another fixed magnet ring, said other ring and coil pair or pairs separated from the first by some linear distance along the rotating component

Comparing the relative phases of these two (or more) waveforms to determine the twist of the rotating component relative to a known non-torque relative phase difference

Calculating the torque based on a known relationship between torque and twist of the rotating component.