DIFFERENTIAL AND BEVEL GEAR
DIFFERENTIAL
SYSTEMS OPERATION
TM 5-3805-263-14&P-2
DIFFERENTIAL
The differential is used to send power from the
transmission,
through the final drives, to the
wheels. When the rear wheels on one side are
turning slower than the rear wheels on the other
side (as in a turn) the differential lets the inside
wheels stop or turn slower in relation to the
outside wheels.
The output flange of the transmission turns the
shaft for the bevel gear pinion (6). The bevel
pinion (6) turns the bevel gear (4) which is
fastened to the differential housing. The differen-
tial has four pinions (7), a spider (5) for the
pinions,
and two side gears (8) and (9). The
connection between the four pinions (7) and the
two side gears is at right angles through a gear
mesh. Splines make the connection between the
side gears and the shafts to the final drives.
When the machine is moving straight in a
forward direction and the differential is in the
UNLOCK position, the same amount of traction is
under the wheels on each side. The same amount
of torque that is sent to each shaft for the final
drive stops pinions (7) so they can not turn on
spider (5). This gives the same effect as if both
tandem drives were driven by the same shaft. When
the force that is sent to the shaft is not the same
(as in a turn) forces that are not the same are put
on opposite sides of the differential. This action
makes pinions (7) turn. The rotation of pinions (7)
lets the inside two wheels go slower or stop in
relation to the two outside wheels. This moves the
machine through the turn under full power.
The housing for the differential runs on tapered
roller bearings. Pinions (7) turn on hardened steel
bearings. Pinions (7) and side gears (8) and (9) turn
against thrust washers which take the end thrust
against the differential housing.
The differential gets lubrication from oil thrown
about inside the bevel gear housing. A flat surface
on each shaft of the spider (5) lets lubrication go
to pinions (7) and to the thrust washers.
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