Belarus 1221.2, Operator'S Manual

Page: 99 / 295

BELARUS-1221.2/1221 В .2/1221.3 Description and operation
98
Final Drive
The final drive of a bevel circular-arc teeth
type consists of a final-drive bevel pinion
(20), which is integral with the transmis-
sion gearbox secondary shaft, and a final
drive gear (21), the latter being bolted to
the differential case (22).
Differential
The differential of the closed lockable
bevel-pinion type consists of the case (22)
and cover (16) fastened together by
means of the bolts (32), four differential
pinions (17) together with spherical wash-
ers (19) and two thrust washers (14). The
differential case is installed as an assem-
bly in the rear-axle housing in two roller
bearings (23). To lock the differential, the
hydraulically-controlled friction multiple-
disk clutch (Fig. E-17) which interlocks the
cross and the differential pinions with the
left-hand half-axle gear of the differential.
Hub Drives
The hub drives consist of two pairs of
straight spur pinions and gears (13, 2) and
(25, 33) (Fig. E-16).
The hub-drive pinions (13, 25) are
mounted in the splines of shafts (10, 26)
which are running in roller bearing bodies.
The differential is locked axially by means
of the bearings (23).
The shafts (10) and (26) link the half-axle
gears (15) with the hub-drive pinions and
the brake disks through their spline joints.
The hub-drive gears (2, 33) are mounted
on splined bushings (5) which are
mounted on ball bearings.
The adjusting shims (34) with the thick-
ness of 0.2 mm and 0.5 mm are inserted
between the flanges of the bearing bodies
(9, 27) and the rear axle housing for ad-
justment of the axial clearance in the
bevel roller bearings (23) and backlask in
the final drive pinion-to-gear (20), (21)
pair. The bevel roller bearings shall be so
adjusted that the torque needed for turn-
ing the differential would be 5 to 8 N-m.
The backlash in the final drive shall be
within the range 0.20…0.55 mm.
Wheel Transmissions
The wheel transmissions are made up of
two straight-spur planetary trains, located
in the half-axle housings (3, 42), torsion
bars (6) made with splines which link the
hub-drive gears (2, 33) with the above-
mentioned planetary trains through
splined bushings (5).
The planetary train consists of a fixed
crown gear (35) mounted on the boss (36)
and bolted to the housing (42); carrier
(37); sun gear (38) seated on the splines
of torsion bar (6) and four differential pin-
ions (50) running on the rollers (48) of the
axles (49).
The half-axle bearings (39, 40) are ad-
justed by formation of stocks of shims (44)
with the thickness of 0.2-mm and 0.5 mm.