Abstract: A continuously variable transmission has a number of tiltable ball-leg assemblies configured angularly about a longitudinal axis. Each ball-leg assembly is in contact with, and guided through a tilting motion by an axially translating shift cam having a convex shape. The convex shape of the shift cam can have a profile defined by a set of parametric equations. The profile of the shift cam can vary according to the location of the contact point between an idler and the ball-leg assembly as well as the amount of relative axial motion between the ball-leg assembly and the idler. The profile of the shift cam can be configured to control the axial translation of the idler relative to the change in tilt angle of the ball-leg assembly. A roll-slide factor can be used to characterize the axial translation of the idler relative to the tilt angle of the ball-leg assembly.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Abstract: A continuously variable transmission (CVT) having a number of tiltable ball-leg assemblies configured angularly about a longitudinal axis. Each ball-leg assembly is in contact with, and guided through a tilting motion by an axially translating shift cam having a convex shape. The convex shape of the shift cam can have a profile defined by a set of parametric equations. In one embodiment, the profile of the shift cam vary according to the location of the contact point between an idler and the ball-leg assembly as well as the amount of relative axial motion between the ball-leg assembly and the idler. In some embodiments, the profile of the shift cam can be configured to control the axial translation of the idler relative to the change in tilt angle of the ball-leg assembly. In other embodiments, a roll-slide factor can be used to characterize the axial translation of the idler relative to the tilt angle of the ball-leg assembly.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: Traction planets and traction rings can be operationally coupled to a planetary gearset to provide a continuously variable transmission (CVT). The CVT can be used in a bicycle. In one embodiment, the CVT is mounted on the frame of the bicycle at a location forward of the rear wheel hub of the bicycle. In one embodiment, the CVT is mounted on and supported by members of the bicycle frame such that the CVT is coaxial with the crankshaft of the bicycle. The crankshaft is configured to drive elements of the planetary gearset, which are configured to operationally drive the traction rings and the traction planets. Inventive component and subassemblies for such a CVT are disclosed. A shifting mechanism includes a plurality of pivot arms arranged to pivot about the centers of the traction planets as a shift pin hub moves axially.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A continuously variable transmission (CVT) having a torsion disc for a CVT. The torsion disc includes a splined bore about its central axis, an annular recess formed in the disc for receiving the race of a bearing, and a raised surface for supporting a torsion spring. In one embodiment, the torsion disc includes a number of holes for receiving dowels that support a torsion spring. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Abstract: A continuously variable planetary gear set is described having a generally tubular idler, a plurality of balls distributed radially about the idler, each ball having a tiltable axis about which it rotates, a rotatable input disc positioned adjacent to the balls and in contact with each of the balls, a rotatable output disc positioned adjacent to the balls opposite the input disc and in contact with each of the balls such that each of the balls makes three-point contact with the input disc, the output disc and the idler, and a rotatable cage adapted to maintain the axial and radial position of each of the balls, wherein the axes of the balls are oriented by the axial position of the idler.

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Abstract: A continuously variable planetary gear set is described having a generally tubular idler, a plurality of balls distributed radially about the idler, each ball having a tiltable axis about which it rotates, a rotatable input disc positioned adjacent to the balls and in contact with each of the balls, a rotatable output disc positioned adjacent to the balls opposite the input disc and in contact with each of the balls such that each of the balls makes three-point contact with the input disc, the output disc and the idler, and a rotatable cage adapted to maintain the axial and radial position of each of the balls, wherein the axes of the balls are oriented by the axial position of the idler.

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.