© Brüel & Kjær Vibro
● C106834.002 / V06 ●
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Brüel & Kjær Vibro
│
Instruction VC-1800 Series
Installation and Operation of VIBROCONTROL
18xx
EN
UNRESTRICTED DOCUMENT
Once the manufacturer and the bearing model have been selected, a number of parameters that
are proprietary for this particular bearing will be calculated and displayed:
-
d/D:
d/D is the ratio between the diameter of the balls (d) and the diameter of the circle formed by
the center-points of the balls in the bearing.
-
Z:
Z is the total number of balls or rollers in the bearing.
-
Angle:
Angle is the contact angle.
List of predominant critical frequencies in rolling element bearings:
-
~ BFPO:
B
all-
P
ass
F
requency -
O
uter = rollover frequency of outer ring
-
~ BPFI:
B
all-
P
ass
F
requency -
I
nner = rollover frequency of inner ring
-
~ FTF:
F
undamental
T
rain
F
requency
– cage rotation frequency
-
~ BSF:
B
earing
S
pin
F
requency - rollover frequency of the rolling element
Several parameters are needed to evaluate the damage frequencies:
- Inner ring or outer ring rotation:
"
R
olling
E
lement
B
earings
REB
" typically consists of two circular rings (outer and inner ring),
between which there are balls or other types of rolling elements.
Please determine whether it is the inner ring or the outer ring of the bearing that is rotating. Indicate
the correct movement by marking either "Inner ring rotation" or "Outer ring rotation" in the
Frequency Calculator setup menu.
- Rotation speed:
Next enter the rotation speed (ROT) of the bearing (= shaft). The value entered must be in either
revolutions per minute (RPM) or revolutions per second (Hz).
Bearing damage frequencies:
Critical frequencies are the bearing specific vibration frequencies that will be induced on the whole
machine as the result of damage in the ball bearing.
~ Harmonics of the bearing damage frequencies
Under "Harmonics," the number of harmonics that must be taken into consideration for the
calculation of the limit frequencies can be entered.
The number of harmonics considered should not exceed the number of balls in the ball bearing.
The number of harmonics can be an integer number between 1 and 10. The default value is 1.
When all parameters related to the critical frequencies have been selected/entered, a list of the
calculated critical frequencies will appear in the top left corner of the Bearing Frequency Calculator
window.
~ Sidebands
Under "Sidebands," the number of side bands that must be taken into consideration for the
calculation of the limit frequencies can be entered.
The number of side bands can be between 0 and 10. The default value is 1.
When all parameters related to the critical frequencies have been selected/entered, a list of the
calculated critical frequencies will appear in the top left corner of the Bearing Frequency Calculator
window.