JUKI AMB-289, Engineer'S Manual

Page: 45 / 177

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Disassembling of the main shaft
1. Remove needle, rear cover
, arm cover and face plate
“refer to (2) Disassembling and assembling of the face plate”.
2. When timing belt is not replaced, put marking with white paint or
the like on main shaft sprocket , main motor shaft sprocket ,
looper shaft sprocket and timing belt .
3. Loosen two setscrews in idler pulley installing plate , and re-
move timing belt .
4. Remove with two setscrews relay circuit board installing plate
. Connector does not have to be removed. However, remove it if
it is hard to perform the work.)
5. Remove frame support and needle bar rocking shaft, and remove
needle bar rocking base. “Refer to (3) Disassembling and assem-
bling of the needle bar rocking base and the needle bar crank rod.”
At this time, be careful not to lose the needle bar connecting rod
and the square block.
6. When timing belt is not replaced, put marking with white paint or
the like on main shaft sprocket and sprocket bush A .
7. Loosen setscrew and remove main shaft sprocket .
8. Loosen two setscrews in sprocket bush A . (Screw No. 1 is set
to the flat section of the shaft.)
9. Enter the hand from the section of relay circuit board installing plate
which has been removed, and loosen two setscrews in main
shaft bearing . (Screw No. 1 is set to the flat section of the shaft.)
10. Loosen two setscrews in gear A from the top surface of ma-
chine arm.
11. Make the lacked part of counter weight below, and draw out
main shaft together with needle bar crank rod . Be careful not
to lose main shaft spacer .
12. Loosen setscrew in counter weight , remove taper screw
(screw No. 1), and draw out main shaft .
Procedures of disassembling / assembling Caution in disassembling / assembling
o At the time of assembling, timing
adjustment of main motor shaft,
main shaft and looper shaft does
not have to be performed if the
components are adjusted to the
positions where marking has been
put.
o At the time of assembling, timing
adjustment of the main shaft does
not have to be performed if the
components are adjusted to the
positions where marking has been
put.