Heavy Duty Balanced Opposed Compressors - Ariel Corporation

FOR MODELS: JGZ AND JGU SECTION 5 - MAINTENANCE
8. Remove the cap screws from the main (journal) bearing caps. The separately
purchased hydraulic connecting rod/main bearing-caps cap screw torquing tool
and appropriate electric or pneumatic pump (see Figure 7-12 on Page 7-7), is
used to loosen the cap screws. This tool reacts against the opposite diagonal
cap screw head. Be sure that hydraulic tool is configured for loosening the main
bearing cap screws.
9. Pull the caps straight up to prevent damage to the dowel fit. If the cap is tight,
use a Bearing Cap Puller as illustrated in Figure 5-14 on Page 5-20.
10. Before removing the crankshaft from the crankcase, wooden saddles with sides
high enough to prevent the webs or oil slinger from touching bottom should be
prepared in order to hold the crankshaft during maintenance - even though it
may be out for only a short time. In addition, the crankshaft should be adequately
protected from above so that dropped tools or equipment cannot mar
the surface of pins and journals.
11. Manually rotate the crankshaft so that sling lifting points are above the center of
gravity of the shaft, so that it does not want to rotate when lifted. Lift straight up
keeping the crankshaft bearing journals parallel to the frame. Two to three people
will be needed to safely remove the crankshaft as well as a crane or lift due
to the weight of the crankshaft, see Table 1-1 on Page 1-2 to approximate bare
crankshaft weights. Appropriate sized nylon slings should be used during this
operation so as not to mar the bearing surfaces of the crankshaft. Great care
must be taken during this operation since the crankshaft could bind and become
damaged.
NOTE: THE LOWER BEARING HALF SHELLS SOMETIMES HAVE A TENDENCY TO
STICK TO THE CRANKSHAFT JOURNALS BECAUSE OF THE CLOSE FITTING
OILY SURFACES OF THE TWO PARTS. THEREFORE, WHEN THE SHAFT HAS
BEEN LIFTED CLEAR OF THE SADDLES (APPROXIMATELY 1/4 INCHES OR
6 mm) CHECK TO MAKE SURE THAT THE LOWER BEARING HALF SHELLS
HAVE NOT COME OUT WITH THE CRANKSHAFT. IF SO, THE BEARING
SHELLS SHOULD BE TAPPED BACK ONTO THE SADDLES BEFORE LIFTING
THE CRANKSHAFT ANY FURTHER.
12. While one person operates the crane, raising it very slowly, the second (and
third) person(s) must grasp the crankshaft at the drive end (or both ends) with
one hand on the counterweight or one of the throws and the other hand on the
end of the shaft to keep the crankshaft level. Wear gloves to avoid being cut by
the slinger and to achieve a good grip. The gloves should be clean to avoid marring
the running surface. As the shaft is being slowly raised, the drive and auxiliary
ends should be lifted at the same rate. Care must be taken to avoid marring
the crankshaft surfaces by carefully guiding the crankshaft.
Crankshaft - Oil Slinger
OIL SLINGER REMOVAL:
Although the slinger should last indefinitely with proper care, it can become nicked (reference
Figure 5-13 on Page 5-20). Should it need replacement, suspend the crankshaft on an
appropriately sized, clean sling with the auxiliary end up, and heat the slinger to approximately
400°F (204°C). It will attain a yellow glow at this temperature. When it has expanded
it should fall off by itself. Do not over heat.
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