Traction roller transmission

A planetary type traction roller transmission comprising a housing having coaxial input and output shafts supported therein rotatably about a central transmission axis and disposed in said housing traction elements including a sun associated with one of said shafts, a traction ring concentric with, but spaced from, said sun and being mounted on the other of said shafts and motion transmitting planetary type traction rollers rotatably supported in the space between said sun and said traction ring, said sun, said traction rollers and said traction ring all having, with respect to their axes, somewhat conical traction surfaces and also being so disposed in said housing that the tangential axial lines of all said traction surfaces intersect in a point on the axis of said transmission, and said traction rollers being supported on an axially movable carrier having engaging means associated therewith for forcing it toward the other traction elements to provide for engagement forces with the traction elements for the transmission of motion therebetween, said engagement means having adjustable members associated therewith for limiting the engagement forces to a predetermined value corresponding to the largest torque to be transmitted through the transmission.