(under subclass 9) Subject matter wherein said transmission includes first and second surfaces facing each other and having a common rotational axis, said first surface having a semicircular concave portion spaced from its rotational axis, and said second surface having a semicircular concave portion spaced from its rotational axis and facing said concave portion of said first surface so that said concave surface portions of said first and second surface together define a doughnut-shaped cavity surrounding said rotational axis; and said transmission further includes an idler member rotatable about its own axis and positioned in said cavity to transfer rotary motion from said first to said second surface. [figure] [caption] A friction transmission comprising a driving member and a driven member mounted for rotation about a common axis. The members having oppositely facing annular arcuate surfaces and at least one roller contacts said surfaces. The roller is supported in the roller carrier by resilient means with the axis thereof intersecting the common axis of said members. The periphery of the roller has a generally conical configuration. The annular surfaces of the driving and driven members have a configuration such that lines tangent to the periphery of the roller and the races converge at the intersection of the axes of rotation of the roller and the common axis of the members at all positions of the roller giving a true rolling action in the manner of cones with a common apex. Hydraulic means apply a force to the roller in the direction of the roller axis proportional to the driving load. The roller and roller carrier are
supported by a trunnion which is in turn supported by opposed resilient means. The true rolling action without lubrication of the traction surfaces reduces the required contact pressure and permits the use of conventional thrust bearings of reasonable size.
