mycom UD Series - Lock Nuts

Chapter 7 Related Documents
UD-series Screw Compressor 7.4 Lock Nuts
7-36
7.4 Lock Nuts
Table 7-14 Lock Nut Used and Each Tightening Torque
P/N
Location
Nominal Designation of Lock Nut（Qty）
Tightening Torque N･m
125
160
200
250
320
400
39 Thrust Bearing
Standard/Maximum
AN09(2)
206/258
AN12 (2)
408/510
AN13 (2)
522/653
AN17 (2)
1186/1483
AN21 (2)
2259/2824
AN28(2)
5347/6683
69 Unloader Piston
AN05(2)
28/35
AN05 (1)
80
AN07 (1)
120
AN08 (1)
140
AN10 (1)
180
AN10(2)
180
When tightening a lock nut, if it is difficult to use a torque wrench, manage the tightening torque of the
lock nut controlling the tightening angle range as explained below.
 Distortion correction of slip washers and lock washers
a) Tighten the lock nut by hand.
b) Use a lock nut wrench and tighten until the rotor turns.
c) Use a lock nut wrench and a hammer, hit twice lightly.
d) Use a lock nut wrench and a hammer, loosen the lock nut.
 Tightening Angle Range of Lock Nuts for Rotors
a) After tightening the lock nut by hand, further tighten the lock nut by using a lock nut wrench until the
rotor starts to turn. Take care not to over-tighten.
b) Put a mark on the lock nut at the right side edge of the rotor groove where the stopper tongue of the
lock washer fits in, as shown in Figure 7-8.
c) From this marking position, tighten the lock nut in such a way that rotation can be stopped within the
tightening angle range shown in Table 7-15.
When measuring the angle, use an angle gauge which is set to the diameter of rotor shaft.
Table 7-15 Tightening Angles Specified
for Lock Nuts of Rotor
Model
Angle range
125** - 400** 15° to 30°
Figure 7-8 Position where mark is put
Angle gauge (example)
Marking
Rotor groove (slot)
where stopper tongue of
the lock washer fits