There are several signifi cant
advantages of a smaller
diameter, multiple disc clutch
over a larger diameter single disc unit.
Multi disc clutch advantages:
- Increase the amount of torque able to be transmitted.
- Decrease the pedal effort to operate the clutch.
- Decrease the weight of the clutch
- Decrease the M.O.I. (Moment of Inertia) of the clutch.
The amount of torque that a clutch
transmits is critical to the ultimate
performance of a vehicle.
Multi disc clutches increase the
available torque capacity by 2 for twin
disc and 3 for triple disc.
Torque Capacity is affected by 4
- Decreasing the diameter reduces torque capacity.
- A smaller diameter clutch has a smaller diaphragm, which usually means a lower clamping force
- Adding a second clutch disc doubles the torque capacity.
- Increasing the coeffi cient of friction of the clutch discs increases the torque capacity.
- If the multi disc clutch is correctly designed and engineered, the losses from the smaller diameter and lower clamp force are much less than the gain in coeffi cient of friction and extra disc(s), giving the torque increase.
Smaller diaphragms used in multi
disc clutches will usually require less
pedal effort to disengage the clutch.
This is in direct contrast to a larger
single disc clutch, which has a larger
diaphragm with heavier pedal effort.
The above examples clearly show
the weight relationship between multi
disc and single disc clutches.
M.O.I (Moment of Inertia)
Lower weight means less inertia has
to be overcome to spin the clutch. This
means less engine power is needed to
turn the clutch. The net effect is the
vehicle is able to accelerate faster.
Lower weight also means that the
clutch discs will not continue to spin on
for as long and allow faster shifting. The
net result again is faster acceleration
and less time when there is no power
being transmitted to the wheels.