Brother RH-9820 Service Manual page 96

6. ASSEMBLY
B
Belt (upper shaft - lower shaft) installation and belt tension adjustment
lower
<If the belt ( shaft – upper shaft motor) is not installed (if installing the upper shaft motor later)>
0935B
0936B
0937B
87
Measurement position
RH-9820
1) Place the timing belt (24) (for lower shaft –
upper shaft motor) into the groove (C) in lower
shaft tension pulley B (7).
2) Loosen the socket bolt (23) of the tension
pulley assembly (a).
3) Place the timing belt (25) (for upper shaft -
lower shaft) onto the upper shaft timing pulley
(b), idler pulley (16), lower shaft tension pulley
B (7) and tension pulley assembly (a).
4) Use a spanner to turn the hexagonal part (c) of
the eccentric shaft of the tension pulley
assembly (a) in the direction of the arrow to
adjust the belt tension to within the ranges
given below, and then tighten the socket bolt
(23).
・ When using a new belt: 170 - 190 N
・ When reusing an old belt: 140 - 170 N
* Be sure to use a belt tension gauge to measure
the belt tension, and measure at the position
shown in the illustration.
* The belt tension gauge should be set to
measure a unit weight of 0.04 kg/m, a belt width
of 15 mm and a span length of 198 mm.
NOTE:
If you do not have a belt tension gauge, adjust so
that the amount of deflection is approximately 2
mm when a pressure of 5N is applied to the middle
of the span (the measurement position shown in
the illustration).