23-06-2012, 10:59 AM
FRONT DIFFERENTIAL (APTRAC TYPE LIMITED SLIP DIFFERENTIAL)
FRONT DIFFERENTIAL.pdf (Size: 61.36 KB / Downloads: 79)
Front Differential (APTRAC Type Limited Slip Differential)
A: GENERAL
The limited slip differential (LSD) automatically limits the differential action and distributes torque to
the left and right wheels adequately to enhance driving stability when the left and right wheels are
rotating at speeds different from each other during driving on a slippery road (muddy, snow-covered
or slushy road) or cornering.
B: CONSTRUCTION
In the APTRAC differential, there is a set of hexagonally-shaped cam followers placed between and
kept in contact with the left and right face cams (which correspond to the side gears in a conventional
differential).
The cam followers engage at their outer ends with the slots that are cut on the inner surface of the
cage in the axial direction, so they can slide laterally in the slots but must rotate together with the
cage. Since the cam followers push the face cams as the cage rotates, the input torque to the cage
is transmitted to the axle shafts.
There are a needle bearing and thrust washer pair between the face cam on each side and cage.
Moreover, there is a Belleville spring between one of the needle bearing and thrust washer pairs to
give preloading, thus ensuring proper initial friction between the cam followers and face cams.
C: OPERATION
WHEN RIGHT AND LEFT WHEELS ROTATE AT DIFFERENT SPEEDS
If the left and right wheels move relative to each other in the direction of arrow Z and in the direction
of arrow Y, respectively, the cam follower A is pushed by the slope B of the left face cam, moving to
the right. Then the cam follower A is pushed by the slope C of the right face cam, now moving to the
left.
Likewise, all the other cam followers also repeat rightward and leftward movements as long as the
right and left wheels continue rotating at different speeds, so the vehicle can turn a corner smoothly.