5. assembly – Duff-Norton SK6905-200 User Manual

Page 7

NOTE

Disassembly should be accomplished on a clean cloth.

lating tube (50) wall. Do not drive pins against OD
of screw (46). Remove nut (48) with screw (46) from
translating tube (50).

16. Remove screw (46) from nut (48).

17. Remove pins (49) from nut (48) by driving pins (49)

remaining distance into ID of nut (48).

18. Remove stop pin (47) from screw (46).

19. If worm (44) or pin (45) must be replaced, remove

worm (44) from pin (45) by closing pliers loosely
around pin (45) behind worm and lightly tap up with
a plastic or wood hammer. To remove pin (45) from
screw (46) clamp pin (45) in vise and rotate and
pull on screw (46). Pin will come out.

20. Drive pin (25) from motor (23) shaft and remove

coupling (24).

NOTE

If coupling is not damaged, it need not be
removed.

21. If bushing (36) in housing (22) is worn, remove it.

22. If bushing (33) in housing (22) clevis is worn, press

bushing (33) out.

NOTE

If switches (16), switch gear cam (13), switch
cam (11), or gear cam shaft (10) do not have
to be replaced, do not remove. Disassembly
of actuator is complete. If these parts must
be removed, proceed as follows:

23. Remove set screws (14) from switch gear cam (13)

and set screw (12) from switch cam (11). With a

" diameter punch and hammer, tap on bearing (9)

driving bearings and gear cam shaft (10) out. (Bear-
ings (9) will be damaged and must be replaced.)

24. Remove screws (15) (potentiometer bracket (6) if

actuator has potentiometer unit), switches (16) with
terminal wires (17, 18, 19 and 20) and insulation (8
and 21) from housing (22). Remove terminal wires
(17, 18, 19 and 20) from switches (16).

25. If gear (5) on potentiometer is damaged, it must be

replaced. Remove gear (5) from potentiometer (7)
shaft. Take care to prevent damage to potentiom-
eter. Disassembly is now complete.

4-5. Assembly

Assemble drive coupling (24) on motor (23) shaft.
Align hole in coupling (24) with hole in motor (23)
shaft and install pin (25).

Assemble bearing (31) on pinion (32) and install
retaining ring (30) on pinion (32).

Apply Loctite retaining compound grade AV (or

Clamp actuator housing (22) in vise (use soft jaws).
Unit should be in horizontal position with switch
cover (2) up.

Remove screws (1) from cover (2) housing (22),
limit switch box and remove switch cover (2) and
gasket (3).

If unit has potentiometer, loosen nut (7a) and re-
move potentiometer (7) from potentiometer bracket
(6).

Loosen screws (back end of motor (23)) from
motor adapter (29) (do not remove screws from
motor).

II.

Remove motor (23) from motor adapter (29)
(use screwdriver to separate motor end from
adaptor). Taking care that motor end bells do
not separate from motor shell.

III. Remove brake springs (27) from motor adap-

tor (29) and brake cam (26) from pinion (32).

Remove screws (28) from housing (22) and remove
motor adapter (29).

Remove pinion (32) and bearing (31) from housing
(22).

Remove retaining ring (30) from pinion (32) and re-
move bearing (31) from pinion (32).

Clamp housing (22) clevis end in vise (use soft
jaws), remove set screw (35) from housing (22).

Unscrew outer tube (41) from housing (22) and re-
move translating tube (50) screw (46), gear (37)
and outer tube (41) from housing (22).

10. Remove translating tube (50) from outer tube (41)

by slipping outer tube (41) over translating tube (50)
towards clevis end.

11. Remove seal (43) from outer tube (41) and press

guide bushing (42) from outer tube (41). Seal and
guide bushing need not be removed unless dam-
aged.

12. Support screw (46) end taking care not to damage

gear (37) teeth. With a

" diameter punch, drive

pin (38) from screw (46) and remove gear (37), bear-
ing (39) and washer (40) from screw.

13. Thread screw (46) part way out of nut (48) and check

screw (46) and nut (48) for wear. There should not
be excessive play between screw and nut thread. If
screw or nut are not excessively worn, the disas-
sembly of screw (46), nut (48) and translating tube
(50) will not be necessary.

14. Pins (49) should be approximately

" above trans-

lating tube (50) OD. Grind pins (49) flush with OD of
translating tube (50).

15. Using

" diameter punch, drive pins (49) far

enough into the lifting nut (48) to just clear the trans-