A control device for controlling a transmission ratio between a traction means and a sprocket set rotatable about an axle may include at least two sprockets alternatively wrapped around by the traction means. At least one of the sprockets may include several independently adjustable rim segments. Adjustment of the rim segments in relation to a fixed plane may be effected by a control device in a direction substantially transverse to the plane. The control device includes at least one electrically actuatable control element, e.g., a servomotor. The at least one control element is configured to rotate with the sprockets.

A control device for controlling a transmission ratio between a traction means and a sprocket set rotatable about an axle may include at least two sprockets alternatively wrapped around by the traction means. At least one of the sprockets may include several independently adjustable rim segments. Adjustment of the rim segments in relation to a fixed plane may be effected by a control device in a direction substantially transverse to the plane. The control device includes at least one electrically actuatable control element, e.g., a servomotor. The at least one control element is configured to rotate with the sprockets.

A transmission element for a transmission such as a continuously variable transmission, including an elongate flexible endless carrier element provided with a number of receiving spaces with an opening and with a passage extending through the number of receiving spaces in the longitudinal direction of the carrier element, a number of engaging elements which are each received in a receiving space for movement between an active position and a passive position and which in the active position protrude further inward than in the passive position and at least out of the opening of this receiving space so as to be able to engage in the active position with a pulley of the transmission, and a spring element for providing resistance for each of the number of engaging elements during movement from the active position in the direction of the passive position.

A transmission mechanism has a set of two composite sprockets, each having pinion sprockets (210) supported movably in a radial direction with respect to a rotation shaft 1 that inputs or outputs power and a movement mechanism radially moving the pinion sprockets (210) in synchronization with each other while maintaining equidistance of the pinion sprocket (210) from a shaft center (C.sub.1) of the rotation shaft 1, and a chain wound around the two composite sprockets. Transmission ratio is changed by changing a circumcircle radius that is a radius of a circle encircling and circumscribing all the pinion sprockets (210). The pinion sprocket (210) is formed into a sector gear shape having a teeth portion (212) that is arranged along a circumference of a minimum radius circumcircle (A.sub.1) and meshes with the chain. With this configuration, torque can surely be transmitted.

A transmission mechanism has a set of two composite sprockets, each having pinion sprockets (210) supported movably in a radial direction with respect to a rotation shaft 1 that inputs or outputs power and a movement mechanism radially moving the pinion sprockets (210) in synchronization with each other while maintaining equidistance of the pinion sprocket (210) from a shaft center (C.sub.1) of the rotation shaft 1, and a chain wound around the two composite sprockets. Transmission ratio is changed by changing a circumcircle radius that is a radius of a circle encircling and circumscribing all the pinion sprockets (210). The pinion sprocket (210) is formed into a sector gear shape having a teeth portion (212) that is arranged along a circumference of a minimum radius circumcircle (A.sub.1) and meshes with the chain. With this configuration, torque can surely be transmitted.

Transmission mechanism has set of two composite sprockets (5, 5), each having pinion sprockets (20) supported movably in radial direction with respect to rotation shaft (1) inputting or outputting power and movement mechanism radially moving pinion sprockets (20) in synchronization with each other while maintaining equidistance of pinion sprocket (20) from shaft center (C.sub.1) of rotation shaft (1), and chain (6) wound around two composite sprockets. Transmission ratio is changed by changing circumcircle radius that is radius of circle encircling and circumscribing all the pinion sprockets (20). Each guide rod (29) has first guide rod (291) guiding chain (6) all the time regardless of circumcircle radius size, and second guide rod (292) guiding chain (6) at least when circumcircle radius is a maximum and positioned at radial direction inner side with respect to first guide rod (291) when circumcircle radius is a minimum. With this, ratio coverage can be expanded.

The control device is for controlling a transmission ratio between a traction means and a wheel set rotatable about a wheel axle and including at least two wheel blades alternatively wrapped around by the traction means. At least one of the wheel blades is composed of several independently adjustable wheel rim segments. The adjustment of the wheel rim segments in relation to a fixed plane (“plane of alignment”) in which the traction means wraps around the wheel set is effected by the control device in a direction substantially transverse to the plane of alignment. The control device includes at least one electrically actuatable control element, in particular a servomotor, provided that the at least one control element is arranged to rotate with the at least two wheel blades.

Disclosed is a continuously variable transmission which can simplify a structure and contribute to miniaturization of a device. A continuously variable transmission including a first disk unit with a first guide slot, a second disk unit with a second guide slot which the first guide slot crosses, and a guide member provided to move along the first guide slot and the second guide slot in response to relative rotation of the second disk unit to the first disk unit, includes: a rotation driving unit rotating any one of the first disk unit and the second disk unit with respect to the other one, wherein the rotation driving unit includes a barrel cam member, a linear movement member linearly moving in response to rotation of the barrel cam member, a driving cam member linearly moving together with the linear movement member, and a driven cam member rotatably connected integrally with any one of the first disk unit and the second disk unit and selectively rotating in response to the linear movement of the driving cam member.

Example gear systems and methods for use are provided herein. An example gear system may include (a) an expandable gear that defines a plurality of circular sectors, (b) a hub disposed in the gear, where the hub includes an expandable portion, and (c) an expander, where the expandable gear has an expanded position when the expander is disposed within the hub and the expandable gear has an unexpanded position when the expander is disposed outside of the hub.

Example gear systems and methods for use are provided herein. An example gear system may include (a) an expandable gear that defines a plurality of circular sectors, (b) a hub disposed in the gear, where the hub includes an expandable portion, and (c) an expander, where the expandable gear has an expanded position when the expander is disposed within the hub and the expandable gear has an unexpanded position when the expander is disposed outside of the hub.