Page 233 - Machinery Component Maintenance

Muchiner! Alignment 215

Having found the vertical corrections, we now proceed to the horizon-
tal readings, as shown earlier in Figure 5-28.
Albegraic difference side to side:

-.008 - (+.010) = -.008 - .010 = b.018

- .018
Half of this: ~ = -.009 in.
2
This tells us that the south face distance is 0.009 in. wider.
Looking at the rim readings, we see that the motor shaft centerline is

-- - -.007 in. or .007 in. north of the pump centerline exten-
2 sion, at the plane of measurement.

The plotting board allows us to solve for corrections as shown in Fig-
ure 5-30:

Move inboard feet .026 in. south.
Move outboard feet .090 in. south.

These corrections will handle horizontal angular and parallel align-
ment at the same time.
After making corrections and tightening motor hold-down bolts, a final
check should be made. If final alignment is not within acceptable toler-
ances, the alignment procedure should be repeated until it is.

Aligning Close-Coupled Machinery

The motor shown in Figure 5-3 1 is close-coupled to a gearbox; that is,
it has no coupling spacer. The motor can be rotated, but the gearbox is
impossible to rotate. We can determine alignment corrections by using
the data and method illustrated in Figures 5-32 and 5-33, which indicate
vertical and horizontal alignment conditions, respectively.
Here, we obviously need setup 3, as shown earlier in Figure 5-5. For
face readings, we will use taper gauge, feeler gauge, dial caliper, or
small hole gauge and micrometer. We might also be able to mount an in-
dicator on the motor coupling, and use a tip extender to contact the gear
coupling face. For rim readings, we can either mount an indicator on the
motor and let the tip ride on the gearbox, or use a straightedge and feeler
gauge.