by Michelle EauClaire on February 17, 2011

Traction devices transfer torque across a thin layer of fluid between two metal rolling elements. The systems tend to use expensive, non-standard parts that can be difficult to manufacture.

Fallbrook’s NuVinci CVP is a traction drive, but uses a common part shape: the ball-bearing. “People know how to make the parts that make up our device,” says Smithson. The spheres are made of standard bearing steel. “We’re not using any exotic materials or material processes.” This results in a simplified manufacturing process, lowering part production costs and allowing for easier part replacement.

“For the kind of torque capacity we have, other CVT geometries would be heavier. It comes back to our basic geometry. The two rings, the array of balls and the idler give you the capability to transfer a lot of torque through a very compact package,” says Smithson.

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