SB-7-621 Page 29
3. Assemble gear headplate (18) and mounting foot (17) to the impeller case with cap screws (21) and where the
mounting foot is secured to the headplate use capscrews (16). The two positioning dowel pins (19) will
ensure proper alignment of the headplate and impeller case. Also secure lifting lugs using capscrews (21)
(see exploded assembly drawing on page 35. Refer to Figure 7-8, page 34, for torque specifications.
Seals are delicate; use extreme care when installing impeller shafts in the headplate bores. A piece
of light shim stock wrapped around the shaft keyway will prevent cutting the seal lip.
4. Apply a light oil or grease on the shaft seal areas and the bearing areas. Insert impellers into the gear
headplate using the same headplate bores as used in the original assembly.
5. Position blower so that impellers are vertical, with the drive end on top. It will be necessary to use blocks in
order for the unit to set level. Measure the total end clearance using a depth micrometer (see Figure 7-2).
NOTICE
If more than .007” shim is required, put .007” on the drive end and the remaining on the gear end.
If total clearance is not within the limits specified in Figure 7-4, page 30, it may be necessary to shim the case
to obtain the proper total end clearance. The shim should be placed between the drive headplate and
impeller case.
6. Assemble drive headplate (24) to impeller case as in step 3 with the gear headplate. If shims were required,
place shims between drive headplate and impeller case.
MECHANICAL SEALS ONLY
A. Refer to Figure 7-1, page 28. Lightly coat the impeller shaft (H) and the inside diameter of the mating
ring (B) with assembly lubricant.
B. Install the mating ring (B) on the shaft only far enough to get the bearing (E) started on the shaft.
Do not drive the mating ring down to the mechanical seal, as this can damage the seal.
C. Lightly lubricate the bearing inner race (E) with a light oil or grease.
D. Using a press, install the bearing on the shaft with the bearing driver shown on page 24.
FIGURE 7-2
FIGURE 7-3
