BISOPE series
91- Vibration Problem of Rolling Bearing - 4 - Cause of Defect Frequency----------------------------------------------------
Rolling bearings have their own defect
frequency calculation formula. This defect frequency always occurs even if it
is small, but it is not exactly a natural frequency because the frequency is
constant and unique, so it is not called a ‘defect’ frequency
but a ‘natural’ frequency of the bearing.
This is because the natural frequency actually exists somewhere else.
Therefore, it seems a better expression to change the name of this defect
frequency to the ‘rotational characteristic frequency’ of the rolling bearing.
However, there are times when I get questions about this rolling bearing defect
frequency not matching the formula. After a long period of operation and
disassembly, the bearing defect is correct, but the frequency is close to it,
but it is not accurate. Therefore, it is only a correct formula if the outer
ring is defective (scratched) and assembled and turned right away. Since the
characteristics change slightly due to thermal expansion and tapping when
assembling the bearing, there is bound to be a slight error. Moreover, as time
passes, the tolerance of the bearing increases and becomes looser, and the
frequency also fluctuates. So how do you check for bearing
defects?
Fault frequency mechanism of cloud bearings
Bearing
defects are checked by the frequency or time waveform pattern. If the pattern
(harmonic, sidebands) is checked, and the bearing information is not accurate
and there is an error of less than 10Hz,
Keywords:
Bearing vibration, rolling bearing, bearing defect, spectrum, BPFI, BPFO, inner
ring defect, outer ring defect, bearing defect frequency, bearing natural
frequencyMeasurement Location
