Chapter 5 Maintenance and Inspection
UD-series Screw Compressor
5.4 Disassembly and Inspection
5-38
d
）
Once the suction cover has been separated, for 320 and 400, remove the hexagon socket
head cap screws (part number 166) at the section where the unloader push rod was
incorporated and remove the "O" ring retainer (part number 326). Replace the “O” ring inside
the “O” ring retainer and the “O” ring (part number 9, 325) inside the suction cover.
e
）
Remove the stop ring (part number 29) to remove the side bearings (part number 28).
Then
push the side bearings out from the rotor side.
If the fitting is hard, do not hit the bearing
directly, but use a copper, aluminum or plastic wire.
The side bearings have clearance fits due
to machining tolerances.
Replace the "O" ring (part number 433) on the outer circumference of
the bearing.
Removing of Retaining Ring for Side Bearing
Unloader push rod “O” ring retainer
Inspection
a
）
Inspect the unloader push rod (part number 67).
Replace the rod if it is deformed or the sliding
part on the outer circumference is abnormal.
Be sure to replace the “O” ring (part number 73)
on the unloader piston fitting.
b
）
Check if foreign matter is embedded in the inner sliding surface of the side bearings and the
dimensional accuracy.
Judging from the result of the inspection, replace the side bearing if
necessary.
5.4.12 Rotor and Rotor Casing
Disassembly
The rotor is a heavy object, so use a crane or chain block while working with care.
a
）
Hook the hemp rope or nylon belt at the position where the rotor was pulled out halfway
through the casing, and then lift the rotor while pulling it out.
Avoid using wire rope as it will
damage the rotor.
You can pull out from either the M rotor or the F rotor.
When pulling out from the F rotor, turn
the rotor counterclockwise and it will come out from the rotor casing.
When about two-thirds
out, hang a belt around the outer circumference, make it feel like lift up, and pull out the rest.
Be careful not to scratch the inner diameter of the rotor casing with the tip of the shaft when
pulling it out.
b
）
Please support the shaft by V block (wooden) etc. so that the outer circumference of the rotor
