2205Q2JE-HO-S6-N_2020.01.
Chapter 7 Related Documents
SCV-series Screw Compressor 7.3 Tightening Torques for Bolts and Nuts
7-28
7.3.4 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.
2. Specified tightening torque and tightening method
Specified
tightening
torque (%)
Tightening torque at each STEP (N・m)
1
First, tighten all bolts by
①
②
③
④
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
3
Next, tighten uniformly
diagonally with 50 % x
specified torque.
①
②
③
④
50 % 20 25 30 60
4
Next, tighten uniformly
diagonally with 50 % x
specified torque.
①
②
③
④
100 % 40 50 60 120
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.