Bearings - Proper Care & Pinpointing Failure

Nate Brim

A little effort goes a long way, and that's just as true for bearings inspection and maintenance as it is for anything else worth doing. Here are a couple of notes to keep in mind when you're reviewing the wear on your bearings, as well as simple storage reminders.

The following content has been selected from Big Rock Mountain partner SKF:

Rolling bearing defect frequency analysis

Every bearing generates a low frequency signal. Every time a bearing defect is over-rolled, a high frequency signal is generated, which causes a peak in the amplitude of the signal. The rate of these peaks is a function of speed as well as the position of the defect on the bearing and the internal geometry of the bearing.

To monitor the condition of a bearing, a technique called enveloped acceleration or enveloping is used. Enveloping isolates the high frequency signal generated by the defect from other naturally occurring rotational or structural frequencies in the machine. In cases where it is difficult or time consuming to gain access to the bearings for inspection, an Endoscope can be a valuable tool. An endoscope, available on Big Rock Mountain soon in the field, is a good tool. It should have a small diameter insertion tube, an LCD display and a picture recording function.

Storage

Storage time is the period that a bearing can remain in storage in order to avoid adverse effects on operational performance of the bearing. Bearings are coated with a high-quality preservative oil to protect them from corrosion. Long storage times can be attained by storing bearings in their original, unopened and undamaged, packaging. The storage time of bearings also depends on their storage environment conditions. To maintain the potential operating performance of a bearing, it is recommended that  a "first in, first out" inventory policy be developed.

Storage time for open bearings

Typical storage times for open (unsealed) and not lubricated bearings are listed in table 1:

table 1 - Storage time for open (unsealed) and not lubricated bearings

 

Storage environment conditions

Storage time

Relative air humidity

Ambient temperature

%

°C

°F

years

65

20 to 25

70 to 75

10

75

20 to 25

70 to 75

5

75

35 to 40

95 to 105

3

Uncontrolled tropical conditions1)

1

 

Storage time for capped bearings

Capped bearings (bearings with seals or shields) should be stored for a maximum of three years to avoid deterioration of their grease fill.

Additional storage-related factors

To avoid deterioration of your bearings while in storage, consider these factors:

  • Store indoors, in a frost- and condensation-free environment, at a maximum ambient temperature of 40 °C (105 °F), avoiding air flow.
  • Store in vibration-free conditions. Vibration can cause damage to raceways.
  • Store horizontally, preferably, to avoid damage that could be caused by the bearing falling over.
  • Do not open or damage the original packaging.

If you're unsure about whether or not your bearings merely require cleaning and relubrication, if they're misaligned or damaged and in need of replacement, you can always contact our team at sales@bigrockmountain.com at your convenience. 

Find the right bearings by clicking here.

Big Rock Mountain's line of lubricants and cleaning products to service bearings can be found here.

 

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