37-1-614 Page 52
FIGURE 7-30 – SETTING THE INTERLOBE
CLEARANCE
FIGURE 7-31 – HOLD GEAR & SHAFT FROM
TURNING TIGHTEN FIVE GEAR TO HUB
31.
SETTING THE INTERLOBE CLEARANCE
– (FIGURE 7-31 page 52). The interlobe clearance
is divided with 2/3 on the discharge side and 1/3 on the suction side. Hold the gear from turning.
Move the shaft counterclockwise with a wrench just enough to obtain 1/3 of the indicator reading
obtained is Step 29.
EXAMPLE: The minimum plus reading in Step 29 is +.024; move the rotor until the indicator
reads +.016. This divides the interlobe clearance with 2/3 on the discharge and 1/3 on the
suction side.
32. Hold the gear and shaft from turning and evenly tighten four gear to hub “Nylok” screws (49)
(FIGURE 7-32). Be sure the indicator reading does not change while tightening the screws. The
rotors are held in time by the clamping action of the screws and distortion of the flat washers into
the gear holes. Tighten screws securely. Check interlobe clearance to make sure the 2/3
indicator reading is on the discharge side.
Discharge side clearance is checked with a feeler gauge through the discharge opening in the
housing. Rotate the blower several times to be sure timing has not slipped. Recheck the
discharge side interlobe clearance and discharge end clearance. When timing is completed
remove the indicator, button bracket and gear hub retainer plate. Install the hub retainer plate
(13) with pilot in the hub bore with three “Nylok’ type screws (60). Install gasket (24) and carrier
cover plate (15). Install breathers (38) on bearing carriers (4, 5).
Referring to “Lubrication,” page 25, fill the carriers with proper oil. Cover all openings to prevent
dirt entering the blower during transportation and installation.
If the blower is to be stored, refer to “Storage”, page 9.
FIGURE 7-32 – FASTENER TORQUE VALUES
