Drive Center Member Installation And Alignment; Table 5-5. Hub Clamp Bolt And Set Screw Torque Specifications; Table 5-6. Disc Pack Installation Torque Specifications - Emerson Vilter VSS Installation, Operation & Maintenance Manual

Section 5 • Maintenance/Service

Table 5-5. Hub Clamp Bolt and Set Screw Torque Specifications

Coupling
Series/Size
BH38U
BH41U
BH47U
BH54U
BH56U
DP42
15. Tighten bolt and draw hub up shaft to a stop.
16. If locking tab is being used, bend locking tabs in
gap towards shaft and around bolt.
17. Install set screw in hub cap to secure key in keyway
of shaft.
18. Tighten set screw, see Table 5-5.
Drive Center Member Installation and
Alignment
Always adjust motor to the compressor. The
compressor is aligned to the frame.
19. Adjust motor position as needed to obtain a dis-
tance of 5" between both hub faces.
20. Soft Foot. The motor must sit flat on its base
(+/- 0.002"). Any soft foot must be corrected prior
to center member installation.
Figure 5-17. Hub Distance (Axial Spacing)
VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
Clamping Bolt
# Bolts Size-Pitch
4 1/4-28
4 5/16-24
4 3/8-24
4 7/16-20
4 1/2-20
4 1/2-20
NOTE
Set Screw
Torque
Size
ft-lbs (Nm)
12 (16) 3/8
23 (31) 3/8
49 (66) 1/2
78 (106) 1/2
120 (163) 5/8
120 (163) 1/2
If the driver or driven equipment alignment
specification is tighter than these recommendations,
the specification should be used. Also, be sure
to compensate for thermal movement in the
equipment. The coupling is capable of approximately
four time the above shaft alignment tolerances.
However, close alignment at installation will provide
longer service with smoother operation. The flex
disc pack is designed to an optimal thickness and is
not to be used for axial adjustments.
21. Axial Spacing. The axial spacing of the shafts should
be positioned so that the flex disc packs are flat
when the equipment is running under normal op-
erating conditions. This means there is a minimal
amount of waviness in the flex disc pack when
viewed from the side. This will result in a flex disc
pack that is centered and parallel to its mating
flange faces. Move the motor to obtain the correct
axial spacing, see Table 5-6 and Figure 5-17.
Table 5-6. Disc Pack Installation Torque
Coupling
Size
BP38U
BP41U
BP47U
BP54U
BP56U
Torque
ft-lbs (Nm)
10 (13)
10 (13)
20 (27)
20 (27)
40 (54)
20 (27)
NOTE
Specifications
Tightening
Lock Nut
Torque
Size
ft-lbs (Nm)
5/16-24 22 (30)
7/16-20 55 (75)
9/16-18 120 (163)
9/16-18 120 (163)
9/16-18 120 (163)
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