Lower Shaft Mechanism - Brother LK3-B430E Mark II Service Manual

5. ASSEMBLY

5-9. Lower shaft mechanism

!2
w
e
!4
!2
!3
!2
1. Tilt the machine head until it stops.
2. Insert the rock gear shaft q from the rear of the machine, pass the rock gear w, the set screw collar e over
the shaft, bring them close together without any clearance, and tighten the set screw r.
3. Insert the lower shaft t from the rear of the machine, pass the set screw collar y over it, and engage the
lower shaft gear with the rock gear w.
NOTE:
When inserting the lower shaft t from the rear into the machine, lower the needle bar to its lowest position, and
position the screw flat of the lower shaft so that it faces down. Also, apply grease to the shuttle race base and the
lower shaft bush u at this time.
4. Sandwich the lower shaft bush u between the lower shaft gear and the set screw collar y without any
clearance, and tighten the set screw i.
*Apply grease to the portion between the lower shaft bush u and the set screw collar y.
5. Fit the retaining ring o on the lower shaft t, press the driver !0 against the retaining ring o, and tighten
the screw ! 1 .
6. Return the machine head to its original position.
7. Fit the crank rod !2 over the crank of the upper shaft !3 , align the matching mark of the crank rod !2 with
that of the upper shaft ! 3 , and tighten the screw ! 4 .
* Apply grease to the engagement portion between the upper shaft crank and the crank rod.
8. Tilt the machine head until it stops.
9. Turn the pulley ! 5 to move the rock gear w right and left until the pulley rotates easily. Turn the rock gear
shaft q to allow 0.05 - 0.12 mm play of the driver !0 .
10. Pass the wick ! 7 through the rock gear shaft q, and knot it on the end.
11. Return the machine head to its original position.
35
q
r
o
!0
!1
Matching
marks
!5
LK3-B430E Mark II
w
!7
0.05 - 0.12 mm
t
Lower
u
shaft gear
Screw flat
y
i
q
!6
!0