94
I II
III IV
I
- wedge mechanism;
II - toothed mechanism;
III - automatic adjustment initial stage;
IV - automatic adjustment final stage.
1-release spring; 2-toothed ring; 3-adjusting nut; 4-pin; 5-piston; 6-roller; 7-cleat wedge; 8-adjusting bolt;
А
-spiral groove;
В
-toothed coupling
Fig. 70 – Wedge mechanism automatic adjustment
At the increased clearance due to the brake linings wear, the cleat wedge 7 is pressed fur-
ther downwards and the pistons 5 stroke increases. When the toothed ring 2 turn through exceeds
the toothed coupling «
В
» tooth pitch between the toothed ring 2 and adjusting nut 3, the automatic
adjustment is carried out: the toothed coupling jumps over one tooth, and adjusting nut 3 and bolt
8 do not turn through.
At the brake release, the bolt 8, adjusting nut 3, toothed ring 2 and pistons 5 are forced
inwards. As the pin 4 thrusts into the
spiral groove
«
А
»,
adjusting nut
3 and
toothed ring
2 turn
through by one pitch of the
toothed coupling
. The
adjusting nut
3 by means of the thread, shifts the
bolt 8 out, thus reducing the backlash formed as a result of the brake lining wear.
By means of the toothed connection «
В
», the adjustment is carried out with a very short
stroke, evenly, the stroke is being 0,03 mm.
