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Service
SHAFT SEAL REPLACEMENT
(REFER TO FIG, 11)
During operation, a small amount of oil dripping past
the seal surfaces is normal. The rate is dependent on
speed, pressure, and size. Oil leakage to the atmospheric
side of the shaft seal is collected in the drain trap. If it
becomes necessary to drain the drain trap daily, the shaft
seal should be replaced.
Seal parts "wear in" to each other during operation and
it is difficult to determine the exact location of leaks. It
is recommended that the complete seal assembly (seal
ring, seal collar and O-rings) be replaced if excessive
shaft seal leakage occurs. The springs may be reused if
not visibly damaged.
If a shaft seal failure occurs, the thrust bearing clear-
ance, alignment, and coupling spacing should be
checked. A thrust bearing failure may have caused the
seal failure.
If it becomes necessary to replace the shaft seal, refer
to Figs. 11 - 15 and proceed as follows:
Removing the Shaft Seal
If sump is vented to atmosphere, the
shaft seal can be changed with oil in
the main compressor sump. The shaft
seal reservoir will have to be drained.
Follow safety guidelines to isolate ma-
chine from operating.
1. To facilitate shaft seal replacement with minimum
loss of gas and oil, the unit should be pumped down
to remove refrigerant (See Preparation for Servic-
ing) and drain oil from the compressor.
2. Remove the coupling guard. (See Table 8)
3. Remove the driven coupling disk (Refer to Fig. 9).
Only the driven coupling disk needs to be removed
for seal and suction end journal bearing replacement.
4. Remove the coupling guard/bearing housing cover
plate, if equipped (see Fig. 14B, Item 14)
40
FIG. 15 – ASSEMBLING SHAFT SEAL COLLAR
FIG. 16 – SEAL RING ASSEMBLY
TABLE 11 – TYPICAL SHAFT SEAL
INSTALLATION "HEIGHT" DIMENSION
DRIVE SHAFT
INSTALLATION
AND
HEIGHT
COUPLING
OF SEAL
THREAD SIZE
(INCHES)
(INCHES)
1-1/2
1-25/32
1-7/8
2-13/32
2-1/2
2-13/16
3
3-1/32
3-3/4
3-11/32
FORM 220.11-NM2 (602)
LD07329
LD07330
LD07331
DRIVE END
MAIN BEARING
DIAMETRAL
CLEARANCE
(SMALL END)
(INCHES)
.002 - .004
.0025 - .0055
.003 - .005
.004 - .006
.006 - .008
YORK INTERNATIONAL
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