160GR Natural Gas Booster Instruction Manual
Mayekawa all rights reserved. Subject to change without notice. Lat revised in October 2007
p.28
Figure 18 Hexagon socket head screw
Figure 19 Removing Spring Retainer
7.4.5.2 Inspection
a) Check the spring (83) for any defects. If there is, replace the part.
7.4.6 Balance Piston, Balance Piston Sleeve
Compared with the F rotor, on the screw compressor, the M rotor receives the larger
thrust load by the gas load from the discharge to the suction. In order to reduce the load
on the M rotor, a piston is located on the suction end of the M rotor which puts the oil
pressure to the discharge side in order to balance out the thrust load, which results in a
longer life span of the bearing. This piston is the balance piston.
On the F rotor side, however, the gas load towards in the thrust direction is smaller than
on the M rotor, and the number of rotations is smaller as well. Therefore, the F rotor does
not need a balance piston to assure a long life span of the thrust bearing.
The balance piston sleeve is structured to keep the gap between the sleeve and the
balance piston small so that the oil pressure can be maintained.
7.4.6.1 Disassembly
a
）
Remove the stop ring (32) that fixes the balance piston (30) on the shaft by using the
stop ring pliers.
Screw the eyebolts in the balance piston (30) and pull them in a parallel to remove
the balance piston.
Though the balance piston key (31) will remain on the rotor shaft, it does not need to
be pulled out.
b
）
Pull out the balance piston sleeve (33).
