Lock Nuts - mycom UD Series Instruction Manual

7.4

Lock Nuts

Table 7-14 Lock Nut Used and Each Tightening Torque
Location
P/N
39 Thrust Bearing
Standard/Maximum
69 Unloader Piston
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.
Rotor groove (slot)
where stopper tongue of
the lock washer fits
Figure 7-8 Position where mark is put
UD-series Screw Compressor
Nominal Designation of Lock Nut（Qty）
Tightening Torque N･m
125 160
AN09(2) AN12 (2)
206/258 408/510
AN05(2) AN05 (1)
28/35 80
Table 7-15 Tightening Angles Specified
Marking
7-36
Chapter 7 Related Documents
200 250
AN13 (2) AN17 (2)
522/653 1186/1483 2259/2824
AN07 (1) AN08 (1)
120 140
for Lock Nuts of Rotor
Model
125** - 400**
Angle gauge (example)
320 400
AN21 (2) AN28(2)
5347/6683
AN10 (1) AN10(2)
180 180
Angle range
15° to 30°
7.4 Lock Nuts