In maintenance and failure situations, a specific bearing may be the problem. These bearing cursors overlay your data to help you identify faults present in bearings in your equipment. The data in Figure 1 was taken from a machine which had a faulty bearing. We can clearly see a number of harmonics present in the data, but there is no clear indication of what the specific fault might be.
This data can be analyzed with a "Bearing Cursor" to help identify the fault in the bearing by right clicking on the plot. Right click on the plot to bring up the menu, select "Add Cursor," then select "Bearing" as the type of cursor you wish to add. The dialog box will be displayed. Notice the radio buttons marked "Geometry," "Estimator," and "Orders." You need to input the best information that you have. The geometry or order information is typically available from the bearing supplier, for the "Estimator" you need only count the number of balls or rollers. Click the appropriate button and input information.
A "Bearing Cursor" consists of a "speed cursor" and five individual cursors which display the following information:
The cursors automatically appear on the plot, and when you hover the mouse pointer over a specific cursor, its name will appear in a pop up frame. Select the Speed cursor and place on the first order if your plot has orders on the x axis, or on the shaft speed if your x axis is frequency. The other five cursors automatically line up as seen in Figure 3. We can very quickly see a large amplitude response at order 15.74. This indicates a fault on the bearing outer races. There is also a smaller response at the inner race (Order 18.218).
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