Blower Repair & Maintenance Manual #34-05198-6 v1.2 11.2014
11
DETERMINING PROPER IMPELLER CLEARANCE
The timing of a blower is the setting of one impeller with respect to the other so they do not touch during
operation. The clearances between the impellers are measured at points o-o and c-c when the impellers
are in the positions shown in the Fig. 12 below. Note that the impellers are shown viewed from the drive
end of the blower; always face the drive shaft end when determining clearance.
Table 2
CLEARANCES FOR IMPELLERS INCHES
GUELPH
SERIES
TIMING
CLEARANCE
TIP CLEARANCE
END CLEARANCE -
SHAFT END
END CLEARANCE
–
GEAR END
510
.009 MIN.
TOP: .008 MIN.
MID: .005 MIN.
BOT: .004 MIN.
.009 MIN.
.005 MIN.
614
.011 MIN.
TOP: .013 MIN.
MID: .008 MIN.
BOT: .005 MIN.
.012 MIN.
.005 MIN.
Denoted
Below
D
TOP:
A
MID:
B
BOT:
C
F
G
Attention:
The timing and tip clearances are very important. Maintaining proper clearances will prevent
damage to the impellers and will ensure maximum performance.
Fig. 12
Impeller Clearances