Heavy Duty Balanced Opposed Compressors - Ariel Corporation

FOR MODELS: JGZ AND JGU SECTION 5 - MAINTENANCE
cap screws to Table 1-11 on Page 1-18 in an alternating (criss-cross) pattern,
following the sequence numbers stamped on the cap, in 25% increments for
each cap to the recommended pre-torque value. The separately purchased
hydraulic connecting rod/main bearing-caps cap screw torquing tool (see Figure
7-12 on Page 7-7), is used to achieve the cap screws final turn degrees. This
tool reacts against the opposite diagonal cap screw. Be sure that the hydraulic
tool is configured for tightening the main bearing-caps cap screws. Set the turn
indicator to the reference mark on the tool, so that the recessed area will indicate
the additional turn degrees. Tighten the cap screws to the additional turn
degrees to Table 1-11 on Page 1-18 in an alternating (criss-cross) pattern, following
the sequence numbers stamped on the cap. Bearing caps are matchmarked
to their position, correspond with the spacer bar and spacer bar bosses
on the frame.
17. Repeat the above procedure to replace each main bearing one at a time.
18. Reinstall the main bearing spacer bars. Reinstall the spacer bars so that the
match marks are up and next to the spacer bar boss with the same marking.
Tighten all spacer-bar cap screws to value in Table 1-11 on Page 1-18.
19. Check crankshaft main bearing jack and thrust clearances to values in Table 1-4
on Page 1-13. See “Checking Main Bearing Clearances” on Page 5-17. Record
readings on a copy of form on page 5-68.
20. If readings are not within tolerance after installing new bearings, contact your
packager or Ariel before proceeding.
21. Reinstall the RTD’s/thermocouples in the main bearing caps.
22. Reinstall the top-cover spacer-bars if removed. Utilize the Ariel furnished topcover
spacer bar alignment tools (A-11987). Tighten spacer bar fasteners to
Table 1-11 on Page 1-18.
23. Operate pre-lube pump and visually confirm lube oil flow at each bearing position.
24. Account for all tools, measuring and lifting equipment, supplies, replaced parts,
etc. to be sure they have all been removed from inside the crankcase. Be sure
that the chain oiling system is properly installed. Inspect top-cover gaskets. If
there is any doubt that they are not in a good usable condition, replace with new
gaskets. Before installing a gasket, apply a light coat of anti-seize lubricant to
both sides or to the metal seating surfaces. This will help to hold the gasket in
place during assembly and aid in ease of future removal. Install gaskets and top
covers. Tighten cover cap screws hand wrench tight.
25. Reinstall coupling center member to packager’s recommendations or remove
lockout.
26. After replacing bearings, thoroughly pre-lube compressor to be sure that bearings
are lubricated and to help remove foreign materials from the lube system.
27. After replacing bearings it is important to check the bearing break-in temperatures.
When starting the compressor after the first 10 minutes of run time, after
one hour and after 4 hours, shutdown compressor and remove the frame top
covers. Immediately (within 5 minutes after shutdown), check the bearing cap
temperatures using a temperature probe (hand held thermocouple probe or
infrared thermometer), record on a copy of form on page 5-68. If a variation
more than 8°F (4.5°C) is measured between any two main or connecting rod
bearings, contact Ariel.
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