Brakes; Service Brakes And Service Brakes Control - Belarus 80.1 Operation Manual

3.7 Brakes

3.7.1 Service brakes and service brakes control

Tractors "BELARUS-80.1/82.1/820" are equipped with two-disc service brakes with
foot pedal control.
The service brakes are mounted on shafts of drive gears of hub drives. The service
brakes type is dry.
Left and right service brakes are controlled for simultaneous braking of both wheels
by interlocked pedals or separately for braking of the left or right wheel. Separate braking
is used when performing a number of operations, when increased maneuvering perfor-
mance with minimum steering radii of the tractor or the tractor machine is required by
means of partial braking of the inner wheel.
The composition of the service brakes and the service brakes control is shown in
figure 3.7.1.
1 – bolt; 2 – locknut; 3 – cotter; 4 – left brake lever; 5 – ball washer; 6 – link bolt;
7 – roller; 8 – pullback spring; 9 – left pedal with lever; 10 – plank; 11 – right pedal with
lever; 12 – shell; 13 – brake discs; 14 – spring; 15 – ball; 16 – cup; 17 – pressure discs;
18 – link; 19 – fork; 20 – pin; 21 – screw.
Figure 3.7.1 – Composition of the service brakes and service brakes control
Operation principle of the service brakes is as follows:
When pressing brakes pedals the force is transmitted from fork 5 (figure 3.7.2) through
pins 4, of link 6 to pressure plates 8 and 9, rotating them towards each other. Pressure discs
8 and 9, rolling around with inclined surfaces of the profile grooves A over balls 11, move
apart, choosing gaps between the friction surfaces of the discs and body parts and brake fric-
tion discs 1 and drive gear shafts 10 of the hub drives connected to them. At the same time
pressure discs 8, 9 are rotated by the friction force in the direction of friction discs 1, rotation
of pressure disc 8 is limited by stop 2. In this case the second pressure disc 9 can rotate ad-
ditionally at some angle relative to pressure disc 8, and rolling around with inclined surfaces
of profile grooves A over balls 11, creates additional pressure on the friction surface, enhanc-
ing the braking effect of pressure discs 8, 9 and tractor as a whole.
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80-0000010B OM