Emerson VSG, VSSG manual Drive Center Member Installation and Alignment, Maintenance/Service

Section 5 • Maintenance/Service

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 5-4.

Drive Center Member Installation and Alignment

NOTE

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.

NOTE

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 5-3 and Figure 5-8.

22.Angular Alignment. Rigidly mount a dial indicator on one hub or shaft, reading the face of the other hub flange. Rotate both shafts together, making sure the shaft axial spacing remains constant. Adjust the motor by shimming and/or moving so that the indi- cator reading is within 0.002” per inch of coupling flange, see Figure 5-9.

23.Parallel Offset. Rigidly mount a dial indicator on one hub or shaft, reading the other hub flange outside diameter. Indicator set-up sag must be compen- sated for. Rotate both shafts together. Adjust the equipment by shimming and/or moving so that the indicator reading is within 0.002” per inch of the axial length between flex disc packs, see Figure 5-9.

With the coupling in good alignment the bolts will fit through the holes in the flanges and the disc packs more easily.

NOTE

All bolt threads should be lubricated. A clean motor oil is recommended. On size 226 and larger, a link must be put on bolt first. Remove the disc pack alignment bolt. Proceed to mount the second disc pack to the other hub in the same way.

Ensure that the beveled part of the washer is against

Hub Distance

Figure 5-8. Hub Distance (Axial Spacing)

VSG/VSSG • Installation, Operation and Maintenance Manual •Vilter/Emerson • 35391SSG 5 – 11