Gearbox; General Information; Speed Unit - Belarus 3522.5 Operator's Manual

3.4 Gearbox

3.4.1 General information

The gearbox is mechanical with constant-mesh gears of a range type, it provides
twenty four speeds for the front motion and twelve speeds for the reverse, continuous PTO
and FDA drives. The ranges are shifted by means of gear clutches with use of the coupling
clutch, and the speeds are shifted by means of electro-hydraulically operated friction
clutches without use of the coupling clutch.

3.4.2 Speed unit

The speed unit, presented in figure 3.4.1, provides speed switching within the
range. The speed unit is located in the coupling clutch body 20 and consists of a primary
shaft 35, a shaft of even speeds 30, a shaft of odd speeds 37, an output shaft 44. The roll-
ing-contact blocks of the shafts are located in the clutch body 20 from the one side, and in
a plate 42 from the other one.
On the primary shaft 35 a gear 33 is mounted, which is responsible for torque trans-
fer from the engine to the shaft of even speeds 30 and to the shaft of odd speeds 37. One
of the rolling-contact blocks is two tapered bearings 32, mounted in a cage 31. The play in
the taper bearings 32 is adjusted by means of an adjusting sleeve 36. The primary shaft
35 is hollow-bored, inside there is a PTO drive shaft 34. A needle bearing 8, which serves
as a support for the PTO drive shaft 34, is mounted in the primary shaft 35. The primary
shaft 35 is connected with the driven disks of the main coupling clutch 1 (figure 3.3.2) by
means of a shaft 6 (figure 3.4.1)
A twin friction clutch 21 and a single friction clutch 25, gears 17, 24, 27 and 29 are
mounted on the shaft of even speeds 30. The gear 29 is rigid-mounted on the shaft and
participates in torque transfer from the primary shaft 35. The friction clutches 21 and 25
are mounted on the shaft rigidly. The gears 17, 24 and 27 rotate on the shaft on needle
bearings 18, 23 and 26.
The needle bearings 18, 23 and 26 are lubricated forcedly through the channels,
made in shafts 30 and 37. A lengthwise channel is located on the center line of the shafts
executed 30 and 37, and radial channels are located in places of sleeves 19, 22, 28 instal-
lation for the needle bearings 18, 23 and 26. The sleeves 19, 22 and 28 also have holes
for lubrication.
Forced oil supply to cool the friction disks is also executed through a lengthwise and
radial channels, made in the shafts 30 and 37.
Oil supply to boosters of the friction clutches 21 and 25 is executed through three
channels, which are shut with plugs 13 at the shaft end. Eight sealing rings 15 to deliver oil
to the channels are mounted on the shaft journal at places of radial drillings. Oil delivery to
the shaft radial channels is executed through channels, made in the cages 14, 2 and in the
coupling clutch body 20.
The shaft of odd speeds 37 is designed by analogy with the shaft of even speeds 30.
The shafts of even speeds 30 and odd speeds 37 differ from each other in gears 29 and 38.
The meshing of gears 33 and 38 transfers torque from the primary shaft 35 to the shaft of
odd speeds 37, and the meshing of gears 33 and 29 transfers torque to the shaft of even
speeds 30.
Gears 17, 24 and 27 on the shaft of even gears 30 are the gears of the fourth, the
sixth and the second speeds, and gears 46, 45 and 43 on the odd shaft 37 are the gears of
the third, the fifth and the first speeds, respectively.
The output shaft 44 transfers torque from the shaft of even speeds 30 and from the
shaft of odd speeds 37 to the input shaft 12 (figure 3.4.3) of the gearbox by means of
sleeves 39 and 40 (figure 3.4.1). Gears 47 and 41 are rigidly mounted on the output shaft
44.
Leak-proofness of a dry section of the coupling clutch is provided by collars 7 and 10,
mounted to the shaft 6 and the bracket 9, by rubber rings 3, 5, 12 and 48, mounted to
grooves of the bracket 9 and covers 4, 11 and 49, by paronite packings 1 and 16, mounted
between the cages 2 and 14 and the coupling clutch body 20 with use of sealant.
The friction clutches 21 and 25 are intended to provide gear engagement without us-
ing the coupling clutch.
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