Cleveland Motion Controls ULTRA SERIES CARTRIDGE TRANSDUCER REV AA - Manual (Page 14)

U LTRA S ERIES S TATIONARY S HAFT T RANSDUCER MAN-70251 R EV . AA
P AGE 14 OF 18
3.2 M OUNTING THE S ENSING R OLL
The following steps take into consideration the risk and difficulty of handling large rolls and help to minimize the
number of failed attempts at mounting the roll.
1. Before mounting the sensing roll, confirm that the transducer bodies are securely mounted and that they are “in
line” with each other (coaxial).
2. Measure the roll shaft diameter, the shaft coupling bore diameter and any bushings (if used) to be sure that they
fit properly.
3. If you are using bushings, be sure that they are split on their circumference so that they readily yield to hold the
roll shaft. Refer to Figure 6.
4. Remove the four (4) socket head cap screws and then remove the shaft coupling cap.
5. Measure the overall length of the roll shaft to verify that it fits correctly between the transducer bodies. The
journal must be long enough to fully engage the transducer’s shaft coupling, but not so long that it makes
contact with the bottom of the coupling bore. A clearance of approximately 1/16” (1.6 mm) per side should
ensure against bottoming.
6. Install coupling bushings on the roll shaft (if being used) and place the roll onto the stationary portion of the
shaft coupling. To be sure that the clamping force is properly transmitted to the roll shaft align the bushings so
that the split coincides with the split of the shaft coupling. Refer to Figure 6.
7. Install the coupling cap loosely using the socket head cap screws. Do not completely tighten the screws until
you have performed Preloading steps outlined in section 3.3 of this document.
3.3 P
RELOADING
The design of the gimbaled shaft coupling incorporates a feature to accommodate shaft expansion and contraction.
Temperature changes and material differences can cause the shaft to expand or contract, therefore the coupling
needs to provide a degree of axial “free-play” so that the strain beams in the transducer are not subjected to
excessive force. Performing the preloading steps outlined below lets the transducer accommodate limited amounts
of contraction or expansion. As a point of reference, a 100 degree Fahrenheit rise in temperature can cause an
aluminum shaft to expand by nearly 0.016” per foot of shaft. Steel expands only about 60% as much as aluminum.
To pre-load the transducer:
1. Confirm that there is clearance between the end of the roll shaft and the bottom of the coupling bore (described
above) then, tighten the shaft in the coupling at one transducer by tightening the four (4) socket head cap
screws.
2. Check the remaining transducer to be sure that the shaft is loose in the coupling and then, press the coupling
inward by approximately 1/16” (as if pushing it into the transducer body). Hold the coupling in the pre-loaded
state while tightening the cap screws. When you release the coupling, the free play that you established is
evenly distributed between the transducers (half at each transducer).
Do not defeat the expansion capability by bottoming both transducer couplings while tightening the cap.