BELARUS-1221.2/1221
В
.2/1221.3 Description and operation
109
their ends. The valve of the coupling
heads prevents the exit of air when the
pneumatic drive is used with no trailer at-
tached (for example, when inflating tyres)
and in case of emergence detachment of
the trailer. On coupling the duct of the
tractor with that of the trailer, the coupling
head valve opens to ensure the passage
of compressed air from the tractor’s
pneumatic drive to the trailer. The con-
necting ducts should be couple together at
zero pressure in the tractor air bottle (4).
The air pressure in the bottle (4) is
monitored by the air pressure indicator (6)
and red indicator lamp of air emergency
pressure (5) (installed in the dashboard),
air pressure sensors (7) and air emer-
gence pressure sensor (8).
The air bottle (4) is provided with
the cock (9) for draining condensate. To
drain condensate move the pusher ring
aside and upwards.
The air intake from the pneumatic
actuator (for inflating the tyres, etc.) is per-
formed through the air bleeder valve (3) of
the pressure regulator (2).
Rear PTO
The rear PTO is provided with the two-
speed independent (540 and 1,000 rpm)
and synchronous (4.18 revolutions per
metre en route) drives.
The
independent drive
is provided from
the bearing disk of the clutch via a two-
speed PTO drive reduction gear, inner GB
shaft (18) (Fig. E-14), drive shifting clutch
(27) (Fig. E-22) onto the crown gear shaft
(26) of the PTO epicyclical reduction gear.
The
synchronous drive
is provided via
the shift clutch (27) which couples the epi-
cyclical reduction gear shaft (26) with GB
pinion.
The epicyclical PTO reduction gear is lo-
cated in the rear axle housing and con-
sists of the crown gear (22) coupled with
shaft (26), three satellites (23) on axles
(21), cage (25) and sun gear (24).
The sun gear (24) is connected with the
engagement drum (17) through a spline
joint. The drum is connected to shaft (20)
and forms, together with the brake band
(16), an engagement band brake.
The cage (25) is made integral with the
brake drum (19) connected with the shaft
(2) and forms, together with the brake
band (18), an engagement band brake.
The inner bore of the shaft (20) houses
replacement PTO end-pieces (10) – 8
spline (540 rpm) or 21 spline (1000 rpm).
The roller (3) of movable ends of the
brake band has an eccentric with lever (5)
to effect adjustment of the clearance in the
band brakes from outside, by simple rota-
tion of the roller (3).
The rear axle casing houses two adjusting
screws (11). These are connected to the
control roller (6) and levers (4), (5).
The
PTO is engaged
when the brake
band (16) is tensioned and the brake band
(18) is released. In this case, the en-
gagement drum (17) and the sun gear
(24) connected thereto are brought to rest.
Rotational motion is transferred from the
crown gear (22) to the cage (25) and PTO
shaft (20) through satellites (23) running
about the stopped sun gear (24).
The PTO is disengaged
when the brake
band (18) is tensioned and the brake band
(16) is released. In this case the PTO re-
placement end-piece is brought to stand-
still (10).
Summary of Contents for 1221.2
Page 1: ...BELARUS 1221 2 1221В 2 1221 3 1221 0000010РЭ OPERATORS MANUAL 2009 ...
Page 290: ...BELARUS 1221 2 1221В 2 1221 3 Supplement 293 Electrical scheme of tractor connections ...
Page 291: ...BELARUS 1221 2 1221В 2 1221 3 Supplement 294 Variants of tractor connections ...
Page 293: ...BELARUS 1221 2 1221В 2 1221 3 Supplement 290 826 3805010 instrument board scheme ...