mycom UD Series User Manual

Chapter 7 Related Documents
UD-series Screw Compressor 7.5 Thrust Bearing Gland
7-37
7.5 Thrust Bearing Gland
Standard tightening torque of thrust bearing gland bolt and its tightening method
1. Introduction
Thrust bearing gland bolts for screw compressors are a very important task in assembling precision
thrust bearings.
In this work, excessive tightening or partial tightening exceeding the specified torque may affect the
bearing life, so be sure to use the specified torque and tightening method below.
Table 7-16 Specified tightening torque and tightening method
STEP
Working procedure
Specified
tightening
torque (%)
Tightening torque at each STEP (N
･
m)
160
200
250
320
400
4-M10
4-M12
4-M16
4-M20
6-M20
1
First, tighten all bolts by
hand. (
①
→
②
→
③
→
④
)
0 0 0 0 0 0
2
Next, temporarily tighten
diagonally and uniformly
with a snug torque (25 % x
specified torque).
(
①
→
②
→
③
→
④
)
25 10 13 15 30 23
3
Next, tighten uniformly
diagonally with 50 % x
specified torque.
(
①
→
②
→
③
→
④
)
50 20 25 30 60 45
4
Next, tighten uniformly
diagonally with 50 % x
specified torque.
(
①
→
②
→
③
→
④
)
100 40 50 60 120 90
Note 1) STEP1 and STEP2 in this procedure are intended to ensure that the bolt seating surface is
securely and uniformly contacted with the object to be fastened without any gaps, thereby
preventing one-sided tightening.
Note 2) STEP3 and STEP4 in this procedure are intended to fix the outer ring of the bearing, which is
the object to be fastened, with uniform tightening.
Note 3) When tightening bolts, always use a torque wrench. If using a ratchet type torque wrench, be
careful not to overtighten.
1
2
3
4

mycom UD Series Specifications

General

Brand	mycom
Model	UD Series
Category	Air Compressor
Language	English