Snowmobile Clutch

Advanced Simulation Software Services

Shown to the right is a centrifugal clutch on a snowmobile. As the clutch spins up, the pulley cones move closer or farther apart, changing the pulley ratio in the transmission. The idea is to have the clutch operate so that the motor produces the most power no matter what the vehicle speed or snow load is.

In this case, a successful clutch design was later used in a larger, more powerful snowmobile. This is very common. To save time and money, a company will often take a part that works well in one design and use it in a different design. Sometimes the move is successful; sometimes it is not.

This clutch was not strong enough to transmit the power generated in the larger more powerful snowmobile and began suffering low cycle fatigue (LCF) failures. When the clutch fails, the snowmobile becomes immobile, potentially miles from anywhere. Clearly this failure was a major problem.

The load in the clutch plates is determined by the centrifugal mass and the distance from the axis of spin. At different powers with different pulley loads, the clutch spins in significantly different states with significantly different internal loads. This requires a sophisticated nonlinear analysis.