Belarus 1523, Operating Manual

Page: 119 / 312

BELARUS-1523/1523 В /1523.3 /1523В.3 Construction and Operation
114
FDA Drive Operation
When the tractor is running straight
ahead without any slipping, the shaft (6)
(see Figure “FDA drive”) connected with
the FDA wheels rotates at the speed ex-
ceeding that of the gear (1) and the drum
(3) rotates relatively to the shaft. The cams
of the drum (3) move the semi-clutch (4)
over the shaft splines in axial direction;
thus, forcing the spring (5) to contract.
When it will be done, the contacts of the
switch (14) of the drive automatic en-
gagement sensor are open and the elec-
tromagnet of the hydraulic distributor (12)
is de-energized; there is no pressure in
the friction clutch booster .
When the rear wheels start to skid in ex-
cess of a certain setting, the rotational
speed of the shaft (6) drops so that the
drum (3) turns through in the opposite di-
rection and the spring (5) returns the
semi-clutch (4) to its initial position. The
semi-clutch moves the pusher (13) by its
tapered part; the switch (14) closes the
circuit of the electromagnet of the dis-
tributor (12). Oil under pressure is fed to
the clutch booster and forces the piston
(2) to move. Due to this, the pack of disks
is compressed and locks the gear (1) with
the drum (3) to provide for direct transfer
of the torque.
In case of forced engagement of the FDA,
oil is fed to the clutch booster regardless
of the rear wheel skidding. When the FDA
is disengaged, the distributor shuts off the
pressure channel and oil from the clutch
booster is directed to drainage pipeline.
A general idea on design and operation
modes of the FDA drive control system is
described as a whole below.
To check pressure in the drive clutch
booster, a diagnostic opening is provided
which is stopped with a plug (15). The
switch (14) and the electrohydraulic dis-
tributor (12) are protected with cramp (10)
and shield (11) .
Universal-Joint Shaft
1, 3 – universal joints; 2 – universal-joint shaft tube; 4 – edge-joint packing; 5 – collar; 6 – needle bearing; 7
– retaining ring.
The universal-joint shaft is intended for
transmitting the torque from the GB to the
FDA.
The universal-joint shaft consists of a
tube (2) and two universal joints (1), (3)
with the universal-joint trunnions running
in needle bearings (6). The needle bear-
ing cages are locked with retaining rings
(7); the bearing journals of the trunnion
cross are provided with edge-joint pack-
ings (4) and self-tightening collars (5).
The universal-joint shaft in assembly is
dynamically balanced.
To ensure against winding of straw-
stemmed crops on the universal-joint