Brother NV4000D Service Manual page 138

Main unit
5
Needle-presser module and upper shaft assembly connection
1. Face the shaft 1 and the upper shaft D-cut 2 of the needle-presser
module to the front.
2. Slide the fixed joint 3 to the left, and then insert it into the shaft 1 of the
needle-presser module.
3. Align the 2 screw holes on the fixed joint 3 with the D-cut face, and
tighten the screw 1 in the left screw hole by hand.
*Key point
• Move the fixed joint to the left to adjust the clearance between
the retaining ring 4 on the needle-presser module side and
the fixed joint to 0.5 mm.
4. Move the upper shaft assembly to the left, and tighten the screw 1 in the
right screw hole on the fixed joint 3 by hand.
5. Fully tighten the 2 screws 1 on the fixed joint 3.
6. Rotate the upper shaft half a turn, and tighten the 2 screws 2 in the 2
screw holes on the fixed joint 3.
*Key point
• Tighten the screws 2 in the following order: 2-2 and then 2-1.
• Be sure to tighten the 4 screws 2 after fully tightening the 2
screws 1 on the fixed joint.
• If the needle-presser module and the upper shaft assembly
are assembly properly, the base line 6 of the pulley 5 is
positioned at the top.
NOTE
Check the upper shaft rotation torque before the timing belt is
attached.
If the rotation torque is heavy, perform the following adjustment.
• Drop a brass bar of approx. 1 kg from a height of 50 mm onto
the oil hole on bushing presser A.
• Tighten the screw, and apply 1 or 2 drops of Turbine Oil #100
to the oil hole on bushing presser A.
Start movie clip (CD-ROM version only)
1
2
3 - 6
Needle-presser unit, needle threader unit, upper shaft unit
Set Screw, Socket (FT)
M5X5
Color; Black
Set Screw, Socket (CP)
M4X4
Color; Black
Torque
·
1.37 – 1.79 N m
Torque
·
0.78 – 1.18 N m
1 2
4 3
1
0.5 mm
3
2-1 2-2
6
5