Common apex double cone variable speed mechanical transmission

摘要

This invention relates to a variable speed mechanical transmission of friction drive type comprising a pair of coaxially disposed stepped conical friction drive surfaces providing a series of conical frustum shell spaces disposed in a stepwise arrangement therebetween. The extensions of the inner and outer conical surfaces constituting each conical frustum shell space have common apex point. Each conical frustum shell space includes a plurality of conical frustum rollers rotatably secured in axisymmetrically distributed positions therewithin wherein the extension of the conical surface of each conical frustum roller has the same apex point as that of the inner and outer conical surfaces confining thereof when said conical frustum rollers are under line contact with both of the inner and outer conical surfaces confining thereof. Each set of the plurality of conical frustum rollers disposed in each conical frustum shell space has means for pulling away from and pushing toward the common apex point over a small distance relative to the inner and outer conical surface constituting each conical frustum shell space which means establishes and relieves the line contact between the conical frustum rollers and the inner as well as the outer conical surfaces confining those conical frustum rollers. A transmission speed selector establishes a frictional contact between the conical frustum rollers and the inner and outer conical surfaces confining thereof for only one combination comprising a set of conical frustum rollers and the inner and outer conical surfaces at one time and, consequently, provides a stepwisely variable speed transmission between the inner cone and the outer cone including the series of stepped inner and outer conical surfaces, respectively. The transmission speed selector also includes means for relieving the frictional contact between the set of conical frustum rollers and inner and outer conical surfaces confining thereof for all combinations and, consequently, provides a built-in clutch for the stepwise variable speed mechanical transmission of the present invention.