SYSTEM AND METHOD FOR MONITORING THE CONDITION OF A GEAR ASSEMBLY

• US 20100198534A1
• Filed: 01/30/2009
• Published: 08/05/2010
• Est. Priority Date: 01/30/2009
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: General Electric Company
• Inventors: Hatch, Charles T., Weiss, Adam, Hala, Roger, Maalouf, Mel, Kalb, Matthew, Hadley, Steven
• Granted Patent: US 7,970,556 B2
• Time in Patent Office: Days
• US Class Current: 702/56
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis

Abstract

A system and method for monitoring the condition of a gear assembly analyzes a signal output by a vibration detector that is attached to the gear assembly. Each time that an amplitude of the signal output from the vibration detector exceeds a threshold value, the system assumes that a debris particle has passed between meshing parts of the gear assembly. The number of times that this occurs, and possibly the amplitude of the vibrations are analyzed to determine a condition of the gear assembly, and possibly a damage index. This system and method are particularly applicable to planetary gear arrangements where the vibration detector can be mounted on a fixed ring gear of the gear assembly, or a structure upon which the fixed ring gear is mounted.

Claims

1. A method of monitoring a condition of a gear assembly, comprising:

receiving a signal from a vibration detector attached to a portion of the gear assembly; and

analyzing the vibration detector signal to determine when debris particles pass between meshing parts of the gear assembly.

2. The method of claim 1, wherein the analyzing step comprises:

periodically comparing an amplitude of the vibration detector signal to a threshold value;

determining that a debris particle has passed between meshing parts of the gear assembly each time that the amplitude of the vibration detector signal exceeds the threshold value.

3. The method of claim 2, wherein the amplitude of the vibration detector signal is compared to a predetermined default threshold.

4. The method of claim 2, wherein the amplitude of the vibration detector signal is compared to an adaptive threshold that varies over time.

5. The method of claim 2, wherein the amplitude of the vibration detector signal is compared to an adaptive threshold that gradually increases over time.

6. The method of claim 2, further comprising counting the number of times that a debris particle passes between meshing parts of the gear assembly over a predetermined period of time to generate an event count.

7. The method of claim 6, further comprising calculating a damage index which is based on a rate of change of the event count.

8. The method of claim 2, further comprising determining the maximum amplitude of the vibration detector signal each time that it is determined that a debris particle has passed through meshing parts of the gear assembly.

9. The method of claim 8, further comprising calculating a damage index that is based on a number of times that a debris particle passes through the gear assembly per unit of time, and the maximum amplitude of the vibration detector signal each time that a debris particle passes through meshing parts of the gear assembly.

10. The method of claim 8, further comprising calculating a damage index which is based on a number of times that a debris particle passes through the gear assembly per unit of time, and an average of the maximum amplitude of the vibration detector signal each time that a debris particle passes through meshing parts of the gear assembly per unit of time.

11. A method of calculating a damage index for a gear assembly, comprising:

receiving a signal from a vibration detector attached to a portion of the gear assembly;

determining that a debris particle has passed between meshing parts of the gear assembly each time that an amplitude of the vibration detector signal exceeds a threshold value;

counting the number of times that a debris particle passes between meshing parts of the gear assembly over a predetermined period of time to generate an event count; and

calculating a damage index for the gear assembly based on the event count.

12. The method of claim 11, wherein the damage index is also based on how the event count changes over time.

13. The method of claim 11, further comprising determining the maximum amplitude of the vibration detector signal each time that it is determined that a debris particle has passed between meshing parts of the gear assembly, wherein the damage index is also based on the recorded maximum amplitudes.

14. The method of claim 13, wherein the damage index is based on an average of the maximum amplitudes of the vibration detector signal for a predetermined period of time.

15. The method of claim 13, further comprising calculating how the damage index changes over time.

16. A system for detecting conditions in a gear assembly, comprising:

a vibration detector that is attached to a portion of the gear assembly;

a processor that compares an amplitude of a signal from the vibration detector to a threshold value and that determines that a debris particle has passed between meshing parts of the gear assembly when the vibration detector signal exceeds the threshold value.

17. The system of claim 16, wherein the vibration detector is attached to one of a fixed gear of the gear assembly and a mounting structure to which a fixed gear of the gear assembly is attached.

18. The system of claim 16, wherein the processor also determines the maximum amplitude of the vibration detector signal each time that a debris particle passes between meshing parts of a gear assembly.

19. The system of claim 16, further comprising a data analyzing unit that calculates a damage index for the gear assembly based on changes in a number of times that a debris particle passes between meshing parts of the gear assembly per unit time.

20. The system of claim 19, wherein the damage index is also based on an average of the maximum amplitudes of the vibration detector signal each time that a debris particle passes between meshing parts of a gear assembly per unit time.