KOHTECT BT-77, Руководство по эксплуатации

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KOHTECT BT-77
1. Good bearing generates mainly shocks in the interface between the loaded rolling
element and the raceway. These shocks create normal background level with low
carpet value (dB
c
< 10) and random strikes with maximum value dB
m
< 20 dB.
2. When the defects occur on the outer raceway of a bearing or a bearing element, the
general background features peak signals with Max ��alue dB
m
> 40 dB. The collisions
happens randomly, quite often their carpet values stand within the limits dB
c
< 20 dB.
Though when the bearing failure occurs, the carpet value can be decreased. As a rule,
a great difference between dB
m
and dB
c
values occurs.
3. When there is no lubrication supply or tight (loose) roller bearing fit, the Carpet ��alue
will reflect this by increasing (dB
c
> 10), even there are not any defects on the outer
raceway of a the bearing. The Max ��alue and the Carpet ��alue are relatively close (dB
m
= 30, dB
c
= 20).
4. Under pump cavitation both backgrounds feature high magnitude value. Shock
pulse standards on pump cavitation are published. The measurements are taken on
the pump case. Be aware that the curved surfaces damp shock pulses out of cavitation.
The difference between the Max ��alue and the Carpet ��alue is quite small (for example,
dB
m
= 38dB, dB
c
= 30 dB).
5. Mechanical contact between the rotating and stationary parts of the mechanism next
to the bearing create rhythmic (periodic) a high amplitude burst of Shock Pulse waves.
6. If the bearing undergoes the shock load, for example, as the result of piston stroke
in the compression pump, the shock pulses will be rhythmic (periodic) with respect to
the operating mode of the machine, so the Carpet ��alue (dB
c
) and the Max ��alue (dB
m
)
are easily defined.
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