Belarus 1523, Operating Manual

Page: 118 / 312

BELARUS-1523/1523 В /1523.3 /1523В.3 Construction and Operation
113
FDA drive
1 – gear; 2 – piston; 3 – drum; 4 – jaw semi-clutch; 5 – spring; 6 – shaft; 7 – splined bushing; 8 – torsion
bar; 9 – universal-joint fork; 10 – cramp; 11 – protective shield; 12 – electrohydraulic distributor; 13 –
pusher; 14 – switch; 15 – plug.
The FDA drive is intended for transmit-
ting the torque from the gearbox secon-
dary shaft to the front driving axle
through synchronous PTO drive gear,
multidisk hydraulically-controlled friction
clutch, torsion bar and universal-joint
shaft.
The FDA drive is engaged (disengaged)
with the help of a hydraulic compression
clutch, on a signal from the sensor. The
latter is acted upon by a free-wheeling
mechanism, depending on slipping of the
rear wheels.
The FDA drive is located in the gearbox
housing, on the right-hand side (as seen
in the direction of tractor forward travel);
the torsion bar passes through the clutch
housing. The universal-shaft sliding fork
support is installed in the clutch housing .
The drive consists of the following main
units and parts. The shaft (6) is sup-
ported on the ball bearings in the GB
housing. The gear (1) is free to rotate
(when the clutch is disengaged) on the
shaft and is in constant mesh with the
synchronous FDA drive gear; when the
clutch is engaged, the gear comes in
mesh with drum (3) of the hydraulic
compression clutch through a pack of
friction disks. The disks are cramped by
the piston (2) under the action of oil
pressure. The drum and the jaw semi-
clutch (4) of the free-wheeling mecha-
nism are splined on the shaft (6); the
joint allows the drum to pivot through 45
degrees relative to the shaft. The semi-
clutch is constantly pressed against the
drum cams by spring (5) and are free to
be displaced in the axial direction, thus,
activating the pusher (13) of the drive
automatic engagement sensor . The tor-
sion bar (8) connects the shaft (6) to the
universal-joint shaft sliding fork (9)
through a splined bushing (7) .