Cleveland Motion Controls ULTRA SERIES UNDER PILLOW BLOCK TRANSDUCER UPB1 REV AA - Manual (Page 6)

U LTRA S ERIES U NDER P ILLOW B LOCK T RANSDUCER MAN-70254 R EV . AA
P AGE 6 OF 18
Disassembly by improperly trained personnel may result in additional damage to these units. Should repairs
be required or for warranty repairs, contact the Customer Service Department for a return authorization
number before returning the units.
1.3 R ECEIVING AND U NPACKING
After receiving the Ultra Under Pillow Block Transducer you should:
•
Carefully, unpack and inspect the equipment
•
Compare the received shipment with the packing list
•
Report any damage to the carrier and your CMC representative
•
Store equipment that will not be used in a clean, dry location
•
Take appropriate precautions to prevent moisture, dust and dirt from accumulating in storage and
installation areas
1.4 P RE -I NSTALLATION P RECAUTIONS
1.4.1 S HIPPING
Shock and the vibration transmitted to the transducers by the sensing roll during transportation can damage the
transducers. It is essential that you remove the sensing roll when the machine is shipped with the transducers
mounted.
1.4.2 R OLL B ALANCE
The sensing roll should be adequately balanced. Understand that the balance of the sensing roll will be more
demanding than that typically needed in general rotating machinery. The goal goes beyond just limiting the force to
which bearings will be subjected, but rather to minimize the generation of an unintended noise component in the
transducer tension signal. The centrifugal force caused by imbalance can be estimated using the following formula:
F = (1.77 x 10
-6
) x W x R x (RPM)
2
Where:
F = centrifugal force (in units of lb-f)
W = weight imbalance (in units of ounces)
R = radius of displacement, distance of imbalance weight from roll axis of rotation (in inches)
RPM = Revolution per minute
The force increase is equal to the square of the RPM, or in other words, doubling the RPM causes four times the
imbalance force. Because rolls tend to have a high length-to-diameter ratio, two-plane (dynamic) balancing is
recommended. Balancing is particularly needed where higher RPMs and lower web forces are involved.
To illustrate how much imbalance induced “noise” could be generated, the following table shows the force
disturbance for various ISO balance grades for an illustrative case of a 20 pound roll (4” diameter x 36” long,
aluminum ) rotating at 1500 RPM.
Balance Grade
(ISO 1940/1)
Residual Imbalance
Resultant Force due to
Residual Imbalance
G16 1.25 oz-in +/- 5 lb-f at 25 Hz
G6.3 0.5 oz-in +/- 2 lb-f at 25 Hz
G2.5 0.2 oz-in +/- 0.8 lb-f at 25 Hz
G1 0.08 oz-in +/- 0.3 lb-f at 25 Hz