Rolling
bearings are widely used in the equipment. The condition of the rolling
bearing is directly related to the running condition of the rotating
equipment. Especially in large continuous production companies, many of
them are used in important parts of large rotating equipment. Therefore,
the rolling bearing condition monitoring and Oil-free bearing bush diagnosis is to do a good job of equipment repair and handling an important part. Through a long time internship and exploration, we have accumulated
some useful tips for the diagnosis of practical problems of rolling
bearing.
First, the diagnosis of rolling bearing defects approach and the key
Rolling bearing condition monitoring and diagnosis of self-lubricating steel sleeve useful method is oscillation analysis.
Useful Need to pay attention to the location of the measurement point selection and collection methods. To
accurately reflect the rolling bearing vibration bronze-based shaft
bearing condition, it is necessary to pay attention to the precise
collection of the signal, and therefore to the local tissue from the
bearing near the measuring point, the motor usually at the free end of
the rear fan cover, the measuring point selected in the fan Cover set screws have better monitoring results. {TodayHot}
It is also necessary to pay attention to the collection and analysis of
the oscillation signal, summarized for comparison. Ability to be precise conclusion.
Second, the normal operation of the characteristics of rolling bearings and useful diagnostic tips
We
monitor the status of production in a long time found that rolling
bearings in the course of its use showed a strong regularity and
repeatability is very good. Normal high-quality bearings in the beginning of use, the oscillation
and noise are small, but some scattered spectrum, the amplitude is
small, may be due to some of the shortcomings in the production process,
such as appearance caused by burrs.
After
a period of exercise, the oscillation and noise are kept at a certain
level, the spectrum is very simple, showing only one and two times the
frequency. Fewer than three times the frequency spectrum presented above, the bearing condition is very stable, into a stable job period.
Continued
operation into the later stage of application, bearing vibration and
noise began to increase, sometimes showing abnormal noise, but changes
in oscillation more slowly, at this moment, the bearing kurtosis value
suddenly reached a certain value. We think, at the moment bearing performance for the pre-fault.
At this time, the bearing on the need for close monitoring, pay close attention to its changes. After
that, the bearing kurtosis began to decrease rapidly and approached the
normal value, while the oscillation and noise started to increase
obviously. The fluctuation began to accelerate. When the vibration
surpassed the oscillation standard (such as ISO2372), the bearing
kurtosis Also began to grow rapidly, when both surpass the oscillation norms,
and kurtosis values also exceed the normal value (available kurtosis
relative to the norms), {HotTag} we think the bearings have entered the
late defects, the need for timely maintenance of equipment, replace the
rolling bearings.
Bearings
show the characteristics of advanced disease to present a serious
problem (usually bearing damage such as axial, burns, sand rack
spalling, raceway, bead wear, etc.) most of the time does not exceed a
week, the greater the capacity of the device, the faster the speed of
its The shorter the interval. Thus, in the practice of rolling bearing diagnosis, once found the
characteristics of late problems should be judged to determine the
existence of bearing defects, and quickly organize maintenance.
Third, the unusual characteristics of rolling bearings and diagnosed tricks
Now
because of fake and shoddy bearings will inevitably enter the company
and equipment, and these activities bearing the serious problems are
usually sudden and catastrophic. Such
as the bearing cage ruptures suddenly, the inner and outer rings
suddenly cracked, these problems will form the rotor shaft, which led to
heavy rotor or equipment void. In recent years we often encounter such situations in the internship. Therefore,
in internship monitoring and diagnosis, it is necessary to quickly
diagnose the condition of the rolling bearing is good and bad, and
timely replacement of inferior bearings to prevent major episodes. We
have also accumulated some useful tips on many of these issues, that
is, such bearings in the pre-operation of the device to monitor the
oscillation, and conduct spectrum analysis. We
found that bearings in the pre-operation, the spectrum has its own
common characteristics, namely, equipment, power frequency usually does
not account for the primary ingredient. However, the total value of the oscillation is not large, with the
oscillation specification (such as ISO2372 specification) to determine
the oscillation is acceptable.
At
the moment, we should cause alertness, which is the performance of the
bearing components such as the existence of shortcomings, the failure is
usually very fast and very rude. In the above example, after measuring this figure two hours after the rotor shaft.
In the diagnosis of these problems of fake and shoddy bearings, we
should pay attention to the multi-stack set of normal high-frequency
bearings in the normal operation of the equipment on the spectrum and
oscillation time domain conditions, in order to facilitate the
identification of such anomalous spectrum in time to identify bearing
defects and prevent equipment problems.
Fourth, the useful diagnostic accuracy of rolling bearings trick
We
internship monitoring, usually only to determine the quality of rolling
bearings can be used for a long time, and detailed analysis and
diagnosis of a diagnosis of a certain part of the bearing is usually not
useful. Useful
in the fine diagnosis because of the factors such as working
conditions, often can not find the corresponding characteristics of the
rolling bearing frequency. Although
the wavelet analysis developed in recent years has a precise contrast
with the rapid resonance resonance demodulation and analysis skills, the
required equipment is more invested and needs more analysis. The fault
diagnosis personnel in the field usually use less. We
useful in the diagnosis of dimension parameters and dimensionless
parameters to determine the bearing speed diagnosis of disease, that is,
the frequency spectrum analysis of frequency oscillation speed, contact
bearing kurtosis value induction diagnosis. When the two conditions are beyond the standard, we distinguish the bearing defects.
This
method of identification through three years of internship, confirmed
the diagnosis of rolling bearing defects is very useful. Discriminate rapid, accurate, accurate rate of more than 90%. The bearings diagnosed are basically in the late period of illness, with very good economic benefits.
In addition, when it is detected that the low-frequency oscillation of
the rolling bearing is very large, excluding the unit is not aligned,
unbalanced, loose structure, structural elements of the fundamental
resonance, even without the characteristic frequency of the rolling
bearing should be judged to determine the failure of the rolling bearing
for maintenance.
Fifth, the useful rolling bearing spectrum analysis and diagnosis tips
The use of data collectors is now more common. But pay attention to useful tips. On
the oscillation is not big, bearing kurtosis is not large, the spectrum
of chaotic oscillation signal, difficult to identify in the field with
no problems, we will collect the oscillation signal back to the computer
for detailed analysis. At
the moment, first routine analysis to see the oscillation speed
spectrum and bearing kurtosis is not close to the specification, and
then use the power spectrum to investigate whether the oscillation
energy is over-expenditure, if the power spectrum is not large, the
frequency spectrum of the investigation of various ingredients. If
the spectral line corresponds to the frequency of frequency doubled,
you should focus on the search engine unit structure problems; if the
frequency fractional frequency, showing more decimal places, you should
focus on finding the frequency of bearing, if so, the existence of the
bearing Problems, if not, ruled out other problems after components need to be vigilant and strengthen monitoring. Internship found that many oscillations do not overspend, and bearing cases of bearing defects. Once
the bearing characteristic frequency or close to the bearing
characteristic frequency spectrum should be identified bearing defects,
and then according to the magnitude of the size can be used for trend
analysis or organization and maintenance.
CATEGORIES
Latest news
- Ferrofluid Vacuum Feedthrough Seals us
- Which one is wear-resistant, steel sle
- Bimetal Flange Bush Bearing
- Selection standard for dimension refer
- Red color ptfe bushing
- Pipe-Mounted Ball Transfer
Contact us
- ADD: No.503,Hunan International Commerce Center, Jintai Square,Changsha 410001,Hunan.
- TEL: +86 731 84770165
- FAX: +86 731 84770163
- E-mail: sales1@slide-bearing.com
> Industry news