Kit, method and apparatus for monitoring operation of a bearing assembly, method for producing said apparatus, and bearing assembly with a condition monitor

• US 7,843,192 B2
• Filed: 08/16/2007
• Issued: 11/30/2010
• Est. Priority Date: 08/16/2007
• Status: Expired due to Fees

• Current Assignee: National Research Council Canada
• Original Assignee: National Research Council Canada
• Inventors: Galeote, Brian
• Primary Examiner(s): Patidar; Jay M
• Application Number:
  US11/889,811
• Publication Number:
  US 20090046964A1
• Time in Patent Office: 1,202 Days
• Field of Search: None
• US Class Current: 324/234
• CPC Class Codes: F16C 19/52 with devices affected by abnormal or undesired conditions
• CPC Class Codes: F16C 41/008 Identification means, e.g. markings, RFID-tags; Data transfer means
• CPC Class Codes: G01N 3/56 Investigating resistance to wear or abrasion
• CPC Class Codes: G01N 9/36 Analysing materials by measuring the density or specific gravity, e.g. determining quantity of moisture methods of measurement in general G01N9/02 - G01N9/32
• CPC Class Codes: Y10T 29/49636 Process for making bearing or component thereof

Abstract

A technique for determining properties of a bearing assembly in use involves using an eddy current probe for detecting changes in material density within a raceway of the bearing assembly. A field of detection of the eddy current probe enters the bearing raceway intermediate races that define the raceway, and as such the detection is of the bearing elements, and not deflections in a wall that defines the raceway.

Claims

1. An apparatus for monitoring operation of a bearing assembly, the apparatus comprising:

an eddy current probe for detecting a change in material density within a spatial region in front of a tip of the probe; and

a fixture mounting the probe in a stable position with the tip of the probe proximate a raceway of the bearing assembly so that part of the spatial region enters the raceway at a position intermediate opposing races that provide supporting walls of the raceway, whereby the probe is not directed substantially through either supporting wall.

2. The apparatus of claim 1 wherein the fixture is mounted on or adjacent a relatively stationary part of the bearing assembly.

3. The apparatus of claim 1 wherein the bearing assembly is for bearing a principally radial load, and the probe is positioned with the tip substantially intermediate an inner and an outer race above or below the raceway, the probe being directed at least partially in a direction of an axis of rotation of the bearing assembly.

4. The apparatus of claim 3 wherein the probe is directed at least mostly in the direction of the axis of rotation.

5. The apparatus of claim 1 wherein the bearing assembly is for bearing a principally axial load and the probe is positioned with its tip intermediate the races of the raceway, the probe being directed at least partially in a direction radially inwardly or outwardly of an axis of the bearing assembly.

6. The apparatus of claim 5 wherein the probe is directed at least mostly in the radially inwardly or outwardly direction.

7. A bearing assembly with a condition monitor, comprising:

the apparatus of claim 1; and

the bearing assembly comprising a rotating part having a meeting surface defining a first of the races, a supporting part having a complementary surface defining a second of the races, and a plurality of bearing elements, the rotating and supporting parts arranged so that the first and second races face each other to define the raceway for the bearing elements.

8. The bearing assembly of claim 7 wherein the fixture is mounted on or adjacent the stationary part of the bearing assembly.

9. The bearing assembly of claim 7 wherein the bearing assembly is for bearing a principally radial load and the probe is positioned with its tip substantially intermediate the inner and outer race axially above or below the raceway, the probe being directed at least partially in a direction of an axis of rotation of the bearing assembly.

10. The apparatus of claim 8 wherein the probe is directed at least mostly in the direction of the axis of rotation.

11. The bearing assembly of claim 7 wherein the bearing assembly is for bearing a principally axial load, and the probe is positioned with its tip intermediate the inner and outer race, the probe being directed at least partially in a direction radially inwardly or outwardly of the bearing assembly.

12. The apparatus of claim 11 wherein the probe is directed at least mostly in the direction of the axis of rotation.

13. A method for producing an apparatus for monitoring operation of a bearing assembly, the method comprising:

providing an eddy current probe for detecting a change in material density within a spatial region in front of a tip of the probe; and

retaining the probe in a stable position relative to a stationary part of the bearing assembly to position the tip of the probe with at least part of the spatial region crossing a raceway of the bearing assembly at a position intermediate inner and outer races that provide supporting walls of the raceway, whereby the probe is not directed substantially through either supporting walls;

whereby supplying power to the probe and driving the bearing assembly permits detection of bearing elements circuiting the raceway.

19. A kit for monitoring operation of a bearing assembly, the kit comprising:

an eddy current probe for detecting a change in material density within a volume in front of a tip of the probe; and

instructions for effecting the method of claim 13.

14. A method for monitoring operation of a bearing assembly, the method comprising:

providing an eddy current probe for detecting a change in material density within a spatial region in front of a tip of the probe;

retaining the probe in a stable position relative to a stationary part of the bearing assembly to position the tip of the probe with at least part of the spatial region passing into a raceway of the bearing assembly from a position intermediate inner and outer races of the raceway that provide supporting walls of the raceway, whereby the probe is not directed substantially through either supporting walls;

supplying power to the probe from a power supply to activate the probe to detect changes in material density within the raceway at a given sample rate while the bearing assembly is in operation;

capturing data from the probe in a stream of data at a sample rate greater than a cycling rate of a cage of the bearing assembly; and

analyzing the captured data to determine properties of the bearing assembly in use.

15. The method of claim 14 wherein analyzing further comprises determining a ball pass frequency of the bearing assembly.

16. The method of claim 14 wherein analyzing comprises identifying noise and signal patterns within a time domain signal.

17. The method of claim 14 wherein analyzing comprises applying a Fourier transform to the data to identify peak detected frequencies corresponding to a shaft speed, a cage speed and a ball pass frequency.

18. The method of claim 14 wherein analyzing comprises identifying at least one of:

an increase in noise, an increase in number of peaks, a change in relative amplitudes of the peaks, and a change in frequency of the peaks, with respect to one of;

a baseline healthy measurement, a previously established operating regime, and a previous measurement interval.

20. The kit of claim 18 further comprising program instructions for carrying out an analysis of data captured from the eddy current probe to determine properties of the bearing assembly in use.