21-06-2012, 01:39 PM
LIMITED SLIP DIFFERENTIAL (LSD)
02. Limited Slip Differential (LSD) (Viscous Coupling Type).pdf (Size: 138.05 KB / Downloads: 97)
Limited Slip Differential (LSD) (Viscous Coupling Type)
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.
CONSTRUCTION
The V/C (viscous coupling) type LSD has outer plates and inner plates arranged alternately. Each
outer plate is splined to the inside of the differential case at its outer periphery and each inner plate
is splined to the outer circumference of the left side gear at its inner periphery.
The outer plates are held in position by spacer rings while the inner plates can slide in the axial direction
along the spline teeth.
The space between the differential case and the left side gear is filled with a mixture of high viscosity
silicone oil and air and hermetically sealed with X-rings.
WHEN RIGHT AND LEFT WHEELS ROTATE AT DIFFERENT SPEEDS
When a speed difference occurs between the right and left wheels, the differential case and the left
side gear do not rotate at the same speed any more. The speed difference between them corresponds
to that between both the wheels. Because of the shear force caused in the silicone oil, a
differential torque is then generated, which limits differential action.
For example, if the left wheel spins due to small road resistance, a speed difference occurs between
the right and left wheels. Since there is the V/C between the differential case and left side gear, a
differential torque corresponding to the speed difference is generated in the V/C. This differential
torque is transferred from the left wheel to the right wheel. As a result, a greater driving torque is
distributed to the right wheel which is rotating at a lower speed.
When the right wheel spins, the differential torque is transferred from the right wheel to the left
wheel. Also in this case, a torque greater by the differential torque than the torque to the spinning
wheel is transmitted to the wheel rotating at the lower speed.