Patent ID: 8092332
Filing Date: 2012-01-10
Classification: F16H

Abstract:
1. A friction drive, comprising: a carrier having a center axis; a sun shaft rotatably supported by the carrier and positioned along the center axis, the sun shaft having a first raceway; a outer ring member having a second raceway concentric to the first raceway and positioned along the center axis, the outer ring having a ring shaft positioned along the center axis; a plurality of planet assemblies pivotally mounted to the carrier to frictionally engage with the first raceway and the second raceway in a wedged engagement for transferring power between the sun shaft and the outer ring member; wherein the plurality of planet assemblies frictionally engage the first raceway and second raceway to satisfy the equations tan (α1)≦μ and tan (α2)≦μ; wherein μ is the friction coefficient at the friction contact points; wherein α2 is a first wedge angle associated with the planet assemblies and the first raceway; and wherein α1 is a second wedge angle associated with the planet assemblies and the second raceway.