Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT). In one embodiment, a main axle is adapted to receive a shift rod that cooperates with a shift rod nut to actuate a ratio change in a CVT. In another embodiment, an axial force generating mechanism can include a torsion spring, a traction ring adapted to receive the torsion spring, and a roller cage retainer configured to cooperate with the traction ring to house the torsion spring. Various inventive idler-and-shift-cam assemblies can be used to facilitate shifting the ratio of a CVT. Embodiments of a hub shell and a hub cover are adapted to house components of a CVT and, in some embodiments, to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Among other things, shift control interfaces and braking features for a CVT are disclosed.

Provided is a pressing device for a toroidal continuously variable transmission that is capable of sufficiently supplying lubrication oil to all rollers inside a pocket, and is capable of suppressing the occurrence of fretting wear on the rolling surfaces of the rollers, a first cam surface and a second cam surface. An oil passage 28 is provided for supplying lubrication oil to the inside of each pocket 25 in the inside portion in the radial direction of a retainer 14 that holds a plurality of more than one roller 13 arranged in a row in the radial direction. The center axis O.sub.29 of a discharge port 29 that is provided on an end portion on the downstream side of the oil passage 28 and that opens to the inside surface in the radial direction of the pocket 25 is inclined toward the front side in the rotational direction of the retainer 14 with respect to the center axis of the pocket 25.

A stepless speed changer applied to a CVT gearbox is provided which comprises a speed changing mechanism, a clamping mechanism, and a speed regulating mechanism, and the speed changing mechanism is mounted on a shaft body and connected with a power input mechanism and a power output mechanism respectively along both sides of the shaft body; the clamping mechanism is distributed along an axial direction of the shaft body and located at both sides of the speed changing mechanism, and the clamping mechanism guarantees the speed changing mechanism transmits a torque normally by use of pressurization of a first hydraulic system; the speed regulating mechanism is located at a radial end of the shaft body and combined with the speed changing mechanism, and the speed regulating mechanism achieves speed change of the speed changing mechanism by use of acceleration and deceleration control of a second hydraulic system, which solves the structural problems of the existing CVT gearbox, for instance, low input torque, limited speed-change range, high cost and the like. With a steel-ring friction pair replacing a chain-steel belt drive friction pair, both cost and manufacture difficulty are greatly lowered.

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT). In one embodiment, a main axle is adapted to receive a shift rod that cooperates with a shift rod nut to actuate a ratio change in a CVT. In another embodiment, an axial force generating mechanism can include a torsion spring, a traction ring adapted to receive the torsion spring, and a roller cage retainer configured to cooperate with the traction ring to house the torsion spring. Various inventive idler-and-shift-cam assemblies can be used to facilitate shifting the ratio of a CVT. Embodiments of a hub shell and a hub cover are adapted to house components of a CVT and, in some embodiments, to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Among other things, shift control interfaces and braking features for a CVT are disclosed.

An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

A pressing device for a toroidal continuously variable transmission, comprises: a disk having a toroidal curved surface and a first cam surface; a cam plate having a cylindrical portion, and an outward facing flange portion having a second cam surface; and a plurality of rolling bodies. The cylindrical portion has a cylinder portion, a projection projecting inward in the radial direction in one axial end portion of the cylinder portion and having a step surface, and an oil supply passage. At least a part of a radial inside opening of the oil supply passage opens to a portion of the cylinder portion positioned further on the other side in the axial direction than the step surface. The oil supply passage has an oil-passage hole penetrating the cylinder portion and an oil-passage groove continuous with the oil-passage hole and recessed from the step surface.

An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

A variator for a mechanical transmission system is disclosed. Transfer means are in rolling contact with input and output members of the variator to transfer rotary motion between them. The input member is coupled to the variator input through a first biasing device arranged to exert a first biasing force on the variator according to a first, input gain which relates input torque acting on the input member and the first biasing force. The output member is coupled to the variator output through a second biasing device arranged to exert a second biasing force on the variator according to a second, output gain which relates output torque acting on the output member and the second biasing force. The first and second biasing forces clamp the variator to provide traction. The first, input gain and second, output gain are different, which, at least in specific variator applications, optimises the traction coefficient.

A skew limiter for a toric-drive CVT is described herein. The skew limiter proposes a shaped piece that limits the skew angle to a known angle notwithstanding the tilt angle of the rollers.

A pressing device for a toroidal continuously variable transmission, comprises: a disk having a toroidal curved surface and a first cam surface; a cam plate having a cylindrical portion, and an outward facing flange portion having a second cam surface; and a plurality of rolling bodies. The cylindrical portion has a cylinder portion, a projection projecting inward in the radial direction in one axial end portion of the cylinder portion and having a step surface, and an oil supply passage. At least a part of a radial inside opening of the oil supply passage opens to a portion of the cylinder portion positioned further on the other side in the axial direction than the step surface. The oil supply passage has an oil-passage hole penetrating the cylinder portion and an oil-passage groove continuous with the oil-passage hole and recessed from the step surface.