End Clearance Measurement - mycom i125S Instruction Manual

5.5.6.1 End Clearance Measurement

At this point (i.e., after the thrust bearing block has been fully assembled), measure the clearance
between the bearing head end face and the rotor end face on the discharge side. This clearance is
called as the end clearance.
In particular, this measurement must be made when the thrust bearing has been replaced. Even if the
same bearing is used, the measurement should be made for verification.
If the measured clearance does not satisfy the range specified in Table 5-15, proper adjustment must
be made.
Photo 024 Attaching Dial Gauge to
Rotor Shaft End
a) Push the rotor from the suction side (bearing cover side) to the discharge side while the thrust
bearing inner race is secured to the rotor shaft, by using a tool (such as the handle edge of a soft
hammer).
Alternatively, by using a chamfered part of the lock nut, pull out the rotor with the edge of a flat blade
screwdriver.
b) When the rotor has been pushed to the discharge side, prepare to install the thrust bearing gland.
Attach a dial gauge on the bearing cover side axial end of the rotor, and match the needle to 0
(Photo 024).
c) Secure bearing glands [43-1] [43-2] by tightening the four bolts [45] evenly and gradually to the
specified torque as shown in Table 5-15. Tightening each bolt to the specified torque at once will
lead to uneven tightening. Tighten bolts in turn and in several steps.
d) Then, read the dial gauge measurement. This value is the actual end clearance.
If the end clearance is outside the specified value, perform the adjustment work described in the
next section. If the end clearance is within the specified value, turn the M rotor shaft by hand and
confirm the smooth turning without uneven tightening. And then perform the measurement of the
run-out of the rotor shaft described in next section (3).
Table 5-16 Tightening Torques for Thrust Bearing Glands
Tightening torque
Screw Compressor i-series
Table 5-15 End Clearance
End clearance mm
kgf·cm
i125* i160*
0.03 to 0.05 0.07 to 0.13
Photo 025 Tightening Thrust Bearing Gland
i125*
N·m 30
300
5-26
2203M4JE-MY-iS2-N_2017.04.
Chapter 5 Maintenance
i160*
40
390
5.5 Reassembly