Method and arrangement for determining and monitoring the state of a rolling bearing

• US 8,438,925 B2
• Filed: 07/24/2008
• Issued: 05/14/2013
• Est. Priority Date: 07/24/2008
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Zinecker, Mike, Mller, Klaus-Dieter, Klos, Hans-Henning, Scherer, Stefan
• Primary Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US13/055,677
• Publication Number:
  US 20110219880A1
• Time in Patent Office: 1,755 Days
• Field of Search: 735/87, 735/93, 736/60
• US Class Current: 73/587
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis

Abstract

An arrangement and method for determining and monitoring the state of a rolling bearing, wherein a first sensor signal is captured in the form of a sound emission signal in a first frequency band in the ultrasonic range during operation of the rolling bearing, a second sensor signal is captured in a second frequency band of lower frequency in the ultrasonic range, a first characteristic value for recently occurred damage is determined from the shape of the first sensor signal, a second characteristic value for recently occurred damage is determined from the shape of the second sensor signal, and the state of the rolling bearing is determined by comparing the first characteristic value to a reference value dependent on the speed of the rolling bearing and dependent on the second characteristic value to at least one second reference value dependent on the speed of the rolling bearing.

Claims

1. A method for determining and monitoring a state of a rolling bearing during operation of the rolling bearing, the method comprising:

capturing a first sensor signal comprising an acoustic emission signal in a first frequency band in an ultrasonic range;

capturing a second sensor signal in a second frequency band at a lower frequency in the ultrasonic range;

determining at least one first characteristic value for ongoing damage to the rolling bearing from a signal shape of the first sensor signal;

determining at least one second characteristic value for damage that has already occurred to the rolling bearing from a signal shape of the second sensor signal; and

comparing the at least one first characteristic value with at least one first reference value dependent on a speed of the rolling bearing and comprising the at least one second characteristic value with at least one second reference value dependent on the speed of the rolling bearing to determine the state of the rolling bearing;

wherein, for a steel rolling bearing, the first sensor signal is captured at a resonant frequency of between 100 kHz and 120 kHz and the second sensor signal is captured at a second resonant frequency in a frequency range of between 25 kHz and 50 kHz.

2. The method as claimed in claim 1, wherein the at least one first characteristic value is compared with at least one first reference value also dependent on at least one of a material, size, mass and type of the rolling bearing.

3. The method as claimed in claim 1, wherein the at least one second characteristic value is compared with at least one second reference value also dependent on at least one of a material, size, mass and type of the rolling bearing.

4. The method as claimed in claim 2, wherein the at least one second characteristic value is compared with at least one second reference value also dependent on the at least one of the material, size, mass and type of the rolling bearing.

5. The method as claimed in claim 4, wherein the second sensor signal is captured independently of the at least one of the material, size and speed of the rolling bearing by a second mechanically oscillatory system with a second resonant frequency.

6. The method as claimed in one claim 1, wherein the first sensor signal is captured by a first mechanically oscillatory system at a first resonant frequency dependent on a material of the rolling bearing and independent of a size and speed of the rolling bearing.

7. The method as claimed in one claim 1, wherein the first sensor signal is captured in a first frequency band with a bandwidth of 4 kHz to 8 kHz.

8. The method as claimed in claim 1, wherein the second sensor signal is captured in a second frequency band with a bandwidth of 3 kHz to 7 kHz.

9. The method as claimed in claim 8, wherein an alarm signal is output if at least one of the at least one first characteristic value and the at least one second characteristic value deviate from the a respective one of the at least one first and second reference values over a defined time period.

10. The method as claimed in claim 1, wherein a product of a maximum value and an RMS value of a respective one of the first and second sensor signals is determined to determine the first characteristic value and the second characteristic value.

11. An arrangement for determining and monitoring a state of a rolling bearing during operation, comprising:

a first sensor device for capturing a first sensor signal comprising an acoustic emission signal in a first frequency band in the ultrasonic range, the first sensor device being configured to capture the first sensor signal at a first resonant frequency between 100 kHz and 120 kHz to determine the state of a steel rolling bearing;

a second sensor device for capturing a second sensor signal in a second frequency band of lower frequency in a frequency range between 25 kHz and 50 kHz;

a first signal processing device for determining, from a signal shape of the first sensor signal, at least one first characteristic value for ongoing damage to the rolling bearing;

a second signal processing device for determining, from a signal shape of the second sensor signal, at least one second characteristic value for damage that has already occurred to the rolling bearing; and

an evaluation device for determining the state of the rolling bearing by comparing the at least one first characteristic value with at least one reference value dependent on the speed of the rolling bearing and comprising the at least one second characteristic value to at least one second reference value dependent on a speed of the rolling bearing.

12. The arrangement as claimed in claim 11, wherein the evaluation device is configured to compare the at least one first characteristic value with at least one first reference value also dependent on at least one of a material, size, mass and type of the rolling bearing.

13. The arrangement as claimed in claim 12, wherein the evaluation device is configured to compare the at least one second characteristic value with at least one second reference value also dependent on the at least one of the material, size, mass and type of the rolling bearing.

14. The arrangement as claimed in claim 13, wherein the second sensor device has a second mechanically oscillatory system for capturing the second sensor signal independently of the material, size and speed of the rolling bearing.

15. The arrangement as claimed in claim 11, wherein the evaluation device is configured to compare the at least one second characteristic value with at least one second reference value also dependent on at least one of a material, size, mass and type of the rolling bearing.

16. The arrangement as claimed in claim 11, wherein the first sensor device has a first mechanically oscillatory system with a first resonant frequency for capturing the first sensor signal dependently on the material of the rolling bearing and independently of the size and speed of the rolling bearing.

17. The arrangement as claimed in claim 11, wherein the first sensor device is configured to capture the first sensor signal in a first frequency band with a bandwidth of 4 kHz to 8 kHz.

18. The arrangement as claimed in claim 11, wherein the second sensor device is configured to capture the second sensor signal in a second frequency band with a bandwidth of 3 kHz to 7 kHz.

19. The arrangement as claimed in claim 11, wherein the first and second signal processing device are configured to determine a product of a maximum and an RMS value of a respective one of the first and second sensor signals to determine the first and second characteristic values, respectively.

20. The arrangement as claimed in claim 11, wherein the evaluation device is configured to output an alarm signal if at least one of the at least one first characteristic value and the at least one second characteristic value deviates from a respective one of the first and second reference values over a defined period of time.

21. The arrangement as claimed in claim 11, wherein the first and the second sensor devices comprise a common micromechanical system.

22. The arrangement as claimed in claim 11, wherein at least one of the first and the second sensor devices are implemented as one of piezoelectric, piezoresistive, capacitive and inductive sensor units.

23. The arrangement as claimed in claim 11, wherein the first signal processing device, the second signal processing device and the evaluation device are combined in an integrated electrical circuit.

24. The arrangement as claimed in claim 11, wherein the first and the second sensor devices are combined in an integrated electrical circuit.

25. The arrangement as claimed in one of claim 11, further comprising:

an amplifier unit for amplifying at least one of the first and the second sensor signals;

wherein the evaluation device is configured to adjust a gain of the amplifier unit.