mycom 3225MSC User Manual

2202MYJE-MY-C8-N_2018.02.
Chapter 5 Maintenance and Inspection
Compound 2-stage Screw Compressor 3225**C 5.4 Disassembly and Inspection
5-33
5.4.12.2 Disassembly of Low-stage Thrust Bearing Block
Figure 5-12 Low-stage Thrust Bearing Block
Photo 041
Unlike the high-stage, the low-stage thrust bearing block of 3225**C is using an oil supply spacer for
the combined surface. This is to facilitate lubrication of the ball bearing because as the rotor diameter
becomes larger, the rotor shaft diameter become larger. Thus, a larger thrust bearing is required and
the ball rotation speed increases accordingly. Furthermore, as with the high-stage, the low-stage thrust
bearing block of 3225**C has no spacer for the thrust bearing outer race.
a) Remove the lock nut [39-1] that has been loosened. Then, remove the torsional slip washer [237-1],
lock washer [40-1], and thrust washer [250-1].
b) Similarly to the case of the high-stage, remove the thrust bearing [38-1] and the thrust bearing
alignment spacer [42-1].
5.4.12.3 Inspection (High-stage and Low-stage)
a) The thrust bearing is normal if the bearing balls are found fully glossy after the thrust bearing has
been fully washed and cleaned. It is abnormal if the ball surface has tarnish streaky pattern.
b) Support the inner race with your hand and rotate the outer race. If you feel abnormal vibration on the
hand, the rolling contact surface of the inner or outer race or some balls may be in an abnormal
condition. So, carefully check the conditions. You could feel some irregular click even with a small
foreign matter that has entered during the removal process. In such a case, it should return to the
normal condition when high pressure air is used to blow out the foreign matters after washing and
cleaning the unit. If the bearing is determined to be defective, it must be replaced with new ones.
c) If the inner race and outer race can be easily separated, the wear is considered excessive. If so, you
cannot reuse the bearing.
d) After washing the bearing, you should be able to hear a clattering sound when the bearing is rotated
by hand. Such a sound is due to the motion of the ball within the backlash or play, or the gap
between the retainer and the ball. Such a sound will not be heard if the bearing is held horizontal
and turned. If some lubricating oil is applied after washing the bearing, the sound should not be
heard when the bearing is turned. If you can still hear the sound, the bearing is abnormal.
e) If any abnormality is seen in the thrust bearing in the above inspection, replace with new ones.
In addition, carefully check the reason whether due to mere aging or any problem with the operating
condition and/or lubricating mechanism.
f the compressor has been operated for more than 20,000 hours without replacing the thrust bearing,
it is recommended to replace the bearing with a new one for safely continuing the operation until the
next overhaul, even if no abnormality is found in the above described inspection.
 As the bearing used for the compressor is a specially designed combined-type bearing, the
accuracy and material are different from normal ones of the same part number that may be
found in the catalogue of a bearing manufacturer. Be sure to use only genuine
parts for replacement. Otherwise, it will not be covered by the warranty.

mycom 3225MSC Specifications

General

Brand	mycom
Model	3225MSC
Category	Compressor
Language	English