Contact Seal Maintenance (Open-Drive Machines); Seal Disassembly; Seal Reassembly - Carrier 17 Start Up & Operation Manual

Fig. 35 — Electronic Vane Actuator Linkage
Contact Seal Maintenance (Open-Drive Ma-
chines) (Refer to Fig. 36) —
tion, a few drops of oil per minute normally seeps through
the space between the contact sleeve (Item 16) and the shaft
locknut (Item 8). This oil slowly accumulates in an atmo-
spheric oil chamber and is automatically returned to the sys-
tem by a seal oil return pump.
Oil should never leak between the contact sleeve and the
packing gland (Item 14). If oil is found in this area, the O-ring
(Item 12) should be checked and replaced.
The oil passing through the shaft seal carries with it some
absorbed refrigerant. As the oil reaches the atmosphere, the
absorbed refrigerant flashes to gas because of the reduction
in pressure. For this reason, a detector will indicate the pres-
ence of a slight amount of refrigerant around the compressor
shaft whenever the machine is running.
During machine shutdown, however, no refrigerant should
be detected nor should there be any oil seepage. If oil flow
or the presence of refrigerant is noted while the machine is
shut down, a seal defect is indicated. Arrange for a seal-
assembly inspection by a qualified serviceman to determine
the cause of the leakage and make the necessary repairs.
SEAL DISASSEMBLY (Fig. 36) — Contact seal disassem-
bly and repair should be performed only by well qualified
compressor maintenance personnel. These disassembly in-
structions are included only as a convenient reference for
the authorized serviceman.
For ease of disassembly, refer to Fig. 36 while following
these instructions.
1. Remove refrigerant.
2. Remove shaft coupling and spacer (if any).
3. Remove screws holding windage baffle (Item 4) and re-
move baffle.
During machine opera-
68
4. Remove shaft-end labyrinth (Item 7), gasket (Item 5)
and necessary piping.
5. Remove snap ring (Item 11) from shaft-end baffle and
assemble to contact sleeve (Item 16).
6. Remove seal housing cover (Item 2). The contact sleeve,
spring (Item 15) and packing gland (Item 14) will come
out with the cover.
7. Place assembly on bench with contact sleeve assembly
face down on a soft cloth or clean cardboard. Protect
seal faces at all times.
8. Press down on seal housing cover to compress the con-
tact sleeve spring.
9. Maintain pressure and remove snap ring.
10. Slowly release pressure on cover. Spring tension will
force contact sleeve out of housing. For further inspec-
tion, remove packing gland and O-ring (Item 12).
11. Place contact sleeve in a protected area to avoid damage
to lapped face.
12. Remove outer carbon ring (Item 17). Handle carefully.
13. Remove spray header (Item 3).
14. Use a spanner wrench to remove shaft nut (Item 8).
15. Remove shaft sleeve (Item 9) and contact ring key
(Item 18).
16. Carefully remove contact ring (Item 19), avoiding a jammed
or cocked position. If binding occurs, reinstall shaft sleeve
and nut to free the ring.
17. Replace O-ring (Item 10) if damaged or deformed.
18. Remove inner carbon ring key (Item 27) and retaining
ring (Item 21). Screws must be loosened evenly against
guide-ring spring pressure.
19. Remove guide ring assembly consisting of inner carbon
ring (Item 20), diaphragm (Item 24) and guide ring
(Item 25). Protect seal faces of ring.
20. Remove guide-ring spring (Item 26).
Clean all parts to be reused with solvent, coat with oil and
place in a protected area until needed.
NOTE: Items 22, 23, and 28 are not part of the seal disas-
sembly process. They are removed only if the journal bear-
ing is removed.
SEAL REASSEMBLY (Fig. 36) — Be sure that all gasket
surfaces are clean and that all holes, including oil holes, are
properly aligned between gasket and mating flange. Coat gas-
ket with oil-graphite mixture to prevent sticking.
1. Assembly guide-ring spring (Item 26) and guide-ring as-
sembly (Items 20, 24 and 25). Check that travel of inner
carbon seal ring (Item 20) is .06 in. minimum in each
direction.
2. Install retaining ring (Item 21) and inner carbon ring key
(Item 27). Tighten screws evenly against spring
pressure.
3. Replace O-ring (Item 10) in shaft shoulder groove.
4. Install spray header gasket (Item 29) and spray header
(Item 3).
5. Install contact ring (Item 19), contact ring key (Item 18),
shaft sleeve (Item 9) and shaft nut (Item 8).
6. Carefully install outer carbon ring (Item 17).