An expandable and retractable wheel assembly in accordance with one or more embodiments includes a hub structure having a circular periphery and a rim expandable in circumference from a retracted circular position to one or more expanded circular positions. The rim engages and is supported by the circular periphery of the hub structure when in the retracted position. A plurality of linear actuators is attached to and supported by the hub structure. Each linear actuator includes a piston rod and a drive system for moving the piston rod from a retracted position to one or more extended positions, wherein a distal end of the piston rod engages and moves the rim when the piston rod is extended and also supports the rim in the one or more expanded rim positions.

An expandable and retractable wheel assembly in accordance with one or more embodiments includes a hub structure having a circular periphery and a rim expandable in circumference from a retracted circular position to one or more expanded circular positions. The rim engages and is supported by the circular periphery of the hub structure when in the retracted position. A plurality of linear actuators is attached to and supported by the hub structure. Each linear actuator includes a piston rod and a drive system for moving the piston rod from a retracted position to one or more extended positions, wherein a distal end of the piston rod engages and moves the rim when the piston rod is extended and also supports the rim in the one or more expanded rim positions.

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.

A stepless transmission transmits a driving force by an endless transmission member (5) wound around a V-groove (6) of an input pulley (1). The input pulley (1) has moving parts (9) which are fastened by threaded engagement so as to be axially movable with respect to a transmission case (3) and have ring gears (10), to which rotation can be input from the outer periphery sides, and pulley half discs (13) which are relatively rotatable with respect to the moving parts (9), which axially move integrally with the moving parts (9) and which are contactable with an endless transmission member (5). The pulley half discs (13) and an input shaft 2, which is disposed at the center of the pulley half discs (13), rotate together as one piece. The ring gears (10) are each rotationally driven from a drive source of the same drive member.

A stepless transmission transmits a driving force by an endless transmission member (5) wound around a V-groove (6) of an input pulley (1). The input pulley (1) has moving parts (9) which are fastened by threaded engagement so as to be axially movable with respect to a transmission case (3) and have ring gears (10), to which rotation can be input from the outer periphery sides, and pulley half discs (13) which are relatively rotatable with respect to the moving parts (9), which axially move integrally with the moving parts (9) and which are contactable with an endless transmission member (5). The pulley half discs (13) and an input shaft 2, which is disposed at the center of the pulley half discs (13), rotate together as one piece. The ring gears (10) are each rotationally driven from a drive source of the same drive member.

A segmented pulley transmission with an actuator system is disclosed. The actuator system comprises: an engaging deflector radially movable between first active and idle positions: a disengaging deflector radially movable between second active and idle positions: and a motivator assembly for moving the engaging and disengaging deflectors between the active and idle positions. In the first active position, the engaging deflector is configured to move a plurality of pulley segments of the segmented pulley transmission from a disengaged region to an engaged region during rotational operation of the segmented pulley transmission. In the second active position, the disengaging deflector is configured to move the plurality of pulley segments from the engaged region to the disengaged region during rotational operation. In the first and second idle positions respectively, the engaging deflector and the disengaging deflector do not move the plurality of pulley segments during rotational operation of the segmented pulley transmission.

A segmented pulley transmission with an actuator system is disclosed. The actuator system comprises: an engaging deflector radially movable between first active and idle positions: a disengaging deflector radially movable between second active and idle positions: and a motivator assembly for moving the engaging and disengaging deflectors between the active and idle positions. In the first active position, the engaging deflector is configured to move a plurality of pulley segments of the segmented pulley transmission from a disengaged region to an engaged region during rotational operation of the segmented pulley transmission. In the second active position, the disengaging deflector is configured to move the plurality of pulley segments from the engaged region to the disengaged region during rotational operation. In the first and second idle positions respectively, the engaging deflector and the disengaging deflector do not move the plurality of pulley segments during rotational operation of the segmented pulley transmission.

The transmission comprises a chainring (12) rotatable around an axis of rotation (x), at least one sprocket (13) and a chain (14) for transmitting to said at least one sprocket (13) the rotary motion of the chainring (12) around the axis of rotation (x). The chainring (12) comprises a disc (16) and a plurality of meshing devices (22; 122) which are mounted in radially movable manner on the disc (16) and are arranged to enable engagement of the disc (16) with the chain (14) for transmitting motion from the chainring (12) to the at least one sprocket (13) by means of the chain (14). The transmission further comprises shifting means (18, 60) for varying the radial position of the meshing devices (22; 122) in order to change the transmission ratio with which the chainring (12) transmits motion to the at least one sprocket (13). Each meshing device (22; 122) comprises a support body (24; 124) and a tilting fork (28; 128) which is supported on the respective support body (24; 124) for tilting around a first tilting axis (x) parallel to the axis of rotation (x) of the chainring (12), and comprises at least one tooth (28a; 128a) for engaging a link (14a) of the chain (14). Each meshing device (22; 122) further comprises braking means (32, 38, 40; 132, 138, 140, 178) for preventing the respective tilting fork (28; 128) from tilting around the first tilting axis (x).

A drive pulley for a CVT has a fixed sheave, a fixed sheave shaft fixedly connected to the fixed sheave, a movable sheave, a movable sheave shaft fixedly connected to the movable sheave, a spider and at least one centrifugal actuator. The fixed sheave shaft is disposed at least in part inside the movable sheave shaft. The movable sheave is disposed axially between the spider and the fixed sheave. A biasing member biases the movable sheave axially away from the fixed sheave. A torque transfer assembly is operatively connected to at least one of the fixed sheave and the movable sheave. The torque transfer assembly transfers torque between the fixed sheave and the movable sheave. The biasing member, the at least one centrifugal actuator and the torque transfer assembly are disposed radially outward of the fixed and movable sheave shafts.

A drive pulley for a CVT has a fixed sheave, a fixed sheave shaft fixedly connected to the fixed sheave, a movable sheave, a movable sheave shaft fixedly connected to the movable sheave, a spider and at least one centrifugal actuator. The fixed sheave shaft is disposed at least in part inside the movable sheave shaft. The movable sheave is disposed axially between the spider and the fixed sheave. A biasing member biases the movable sheave axially away from the fixed sheave. A torque transfer assembly is operatively connected to at least one of the fixed sheave and the movable sheave. The torque transfer assembly transfers torque between the fixed sheave and the movable sheave. The biasing member, the at least one centrifugal actuator and the torque transfer assembly are disposed radially outward of the fixed and movable sheave shafts.