Belarus 1523, Operating Manual

Page: 158 / 312

BELARUS-1523/1523 В /1523.3 /1523В.3 Construction and Operation
149
The oil pump of the hydraulic system
is of gear type with clockwise rotation.
The pump drive can be disengaged. It is
independent on the clutch and installed
on the left-hand side of the clutch hous-
ing.
The drive consists of housing (1), gear
(2) splined onto the shaft (3); the latter is
supported in two ball bearings. The balls
(4) placed into holes in the shaft (3) lock
or unlock the shaft with splined bushings
(5, 7) by means of the race (6). The race
is controlled by a fork through the tetra-
hedron of the shifter axle (7).
1 – drive housing; 2 – drive gear; 3 – shaft; 4 – balls; 5 – pump shaft bushing; 6 – race; 7 – shifter axle; 8
– lock plate; 9 – bolt; 10 – pump.
The gear (2) is in constant mesh with the
PTO drive gear. When in the disengaged
position (refer to the engagement dia-
gram), the race (6) is displaced to its
rightmost position. Under the centrifugal
force, the balls (4) come out of engage-
ment with the bushing (5), and the shaft
(3) together with the gear (2) are freely
riding in the bearings. When engaged
(the race is shifted to its leftmost posi-
tion), the balls (4) enter the indentations
of the bushing (5) forced by the tapered
edge of the race (6) and the rotation of
gear (2) is transmitted to the pump shaft
through the shaft (3) and splined bushing
(5). The drive maintains the rotational
speed of the shaft of the pump (11) of
1980 rpm at the engine rated speed, and
the ball coupling (3, 4, 5, 6) makes it
possible to engage and disengage the
pump with the engine running at the
minimum idling speed.
To engage/disengage the pump:
a) loosen the bolt (9) by 1.5…2.0 revolu-
tions;
b) turn the tetrahedron of the shifter axle
(7) clockwise/counter-clockwise, re-
spectively, up to a stop;
c) tighten up the bolt (9).