Gearbox Control - Belarus 80.1 Operation Manual

3.3.2.2 Gearbox control

GB control consists of fork housing 3 (figure 3.3.1) and GB control cover 15, which
are mounted on the upper plane of GB housing 29 and are secured to it by bolts.
Fork housing 3 consists of fork of the 1
rd
3.3.2), fork of the 3
duction unit carrier 13, sliders of which are installed in the housing groove 1 and have a
possibility of movement along the groove. On the upper planes of the sliders there are
transverse slots, in which spring-loaded locking balls 10 enter, which ensure locking of the
fork sliders and speed reduction unit slider in the required positions as well as prevent self-
disengagement of gears under load.
Gear shifting is carried out by forks 12, 20 and 21, jaws of which enter into the ring
grooves of the corresponding gears. Shifting of the range speed reduction unit stages is
carried out by carrier 13, which is connected to shaft 11 (figure 3.3.1), on which fork 9 is
secured. Fork 9 controls drive gear of the 1
Fork sliders are provided with slots, and range speed reduction unit carrier is pro-
vided with a "pocket", in which gear lever 4 goes (figure 3.3.2), installed on shaft 2 of cover
22 of GB control. As gear shifting is preceded by selection of the corresponding range of
speed reduction unit, the shape of the "pocket" is made in such a way that it provides un-
hindered withdrawal of gear lever 4 from it into fork sliders slots for subsequent gear selec-
tion.
Fork sliders and range speed reduction unit are divided between each other by
three locking planks 11. Planks 11 are installed immovably in housing 1 and exclude sim-
ultaneous shifting by gear lever 4 of several sliders. When gear is engaged locking planks
11 lock gear lever 4 in the fork slider slot of engaged gear.
GB control cover 15 (figure 3.3.1) consists of cover 22 (figure 3.3.2) in the boring of
pipe 5 in which bearing 7 is installed in cantilever fashion. Bearing 7 can swing in longitu-
dinal plane, and its axial movement is blocked by lock 6, which enters the cut slot of the
bearing pipe. Inside bearing 7 shaft 2 is located, on which by means of cotter key and ter-
minal clamp gear lever 4 is secured. Bearing 7 and shaft 2 are connected to each other by
means of splines, which allow shaft 2 with gear shifting lever 4 to swing in longitudinal
plane all in one with bearing 7. At its swinging gear lever 4 affects directly the sliders in
fork housing 1, causing their movement, and accordingly engagement or disengagement
of the selected gear or range in GB. Shaft 2 can have axial movement along bearing pipe
splines 7, which is necessary for selection of the required slider in fork housing 1.
To eliminate excessive swing amplitudes of gear lever 8 (Figure 3.3.1), as well as to
accurately direct its movement, limiting plate 14 is used, which is attached to cover 15 by
means of bolts.
The gearbox is controlled by the operator from the workplace by acting on gearbox
control lever 9 (Figure 3.3.2). In this case swinging of gearbox control lever 9 in transverse
plane through carrier 8 causes axial movement of shaft 2 and selection of the required
slider in fork housing 1 (selection of a gear or range). Swinging movement of GB control
lever 9 in longitudinal plane is carried out together with bearing 7, and causes GB gear or
range engagement.
Design of GB control cover 15 (figure 3.3.1) ensure clear selection of the required
gear due to exact entry of gear shifting lever 8 in each slider of fork housing 3. For this on
gears shaft 2 (figure 3.3.2) there is a flattened surface in which there is spring-loaded ball
3.
th
and 6 gears 21, fork of the 4
st
gear and reverse movement 20 (figure
th th
and 5 gears 12 and range speed re-
st stage of range speed reduction unit 24.
109
80-0000010B OM