The present invention relates to an energy transfer system, in particular in the form of an energy efficient wheel for use with a vehicle such as a bicycle, which energy transfer system is operable to convert potential energy in the form of the load applied by the weight of the person on the vehicle into kinetic energy in the form of driving torque applied to the wheel, the system including an inner hub and an outer hub eccentrically coupled to the inner hub, in addition to a rim connected to the outer hub via an array of spokes, wherein an actuator comprising a pair of flanges extends radially outwardly from the inner hub and an array of lever arms are hingedly mounted to the outer hub and engaged by the actuator such as to be hingedly displaceable by the actuator in response to relative movement between the inner and outer hubs, and a spring captured between each lever arm and one of the spokes.

A variable stiffness joint and method to alter the stiffness of the joint with multiple stiffness levels is described wherein a plurality of stiffness bits (m) are used for enabling 2 m stiffness level variations for the joint. Each stiffness bit comprises an elastic element in mechanical connection with a clutch (21, 22, 23). The joint revolves with zero stiffness level when all the clutches (21, 22, 23) are disengaged whereas a clutch (21, 22, 23) involves one of the elastic elements which alter the stiffness of the joint. Engaging other clutches (21, 22, 23) involve more elastic elements for altering the joint stiffness and the resultant joint stiffness is determined by adding the stiffness values of all the involved springs (6, 7, 8).

A variable stiffness joint and method to alter the stiffness of the joint with multiple stiffness levels is described wherein a plurality of stiffness bits (m) are used for enabling 2 m stiffness level variations for the joint. Each stiffness bit comprises an elastic element in mechanical connection with a clutch (21, 22, 23). The joint revolves with zero stiffness level when all the clutches (21, 22, 23) are disengaged whereas a clutch (21, 22, 23) involves one of the elastic elements which alter the stiffness of the joint. Engaging other clutches (21, 22, 23) involve more elastic elements for altering the joint stiffness and the resultant joint stiffness is determined by adding the stiffness values of all the involved springs (6, 7, 8).

An actuator includes a casing, an output disc, a transmission component, a cable, a power source, and a tension adjustment assembly. The output disc and the transmission component are rotatably disposed on the casing. The cable is disposed through the transmission component and connected to the output disc. The power source can drive the transmission component. The tension adjustment assembly includes a lever, an elastic component, and a slidable component. The lever has a first end and a second end opposite to each other. The first end is connected to the cable. The elastic component is connected to the casing and the second end of the lever. The slidable component is in contact with a portion of the lever located between the first end and the second end, and is slidable along the lever to change its position to adjust a tension of the cable.

An actuator includes a casing, an output disc, a transmission component, a cable, a power source, and a tension adjustment assembly. The output disc and the transmission component are rotatably disposed on the casing. The cable is disposed through the transmission component and connected to the output disc. The power source can drive the transmission component. The tension adjustment assembly includes a lever, an elastic component, and a slidable component. The lever has a first end and a second end opposite to each other. The first end is connected to the cable. The elastic component is connected to the casing and the second end of the lever. The slidable component is in contact with a portion of the lever located between the first end and the second end, and is slidable along the lever to change its position to adjust a tension of the cable.

An isolator for isolating a device driven by an engine via an endless drive member is described. The isolator comprises a shaft adapter that is connectable with a shaft of the device, defining a shaft adapter axis, a rotary drive member that is rotatable relative to the shaft adapter and has an endless drive member engagement surface that is engageable with the endless drive member, and an isolation spring arrangement positioned to transfer torque between the shaft adapter and the rotary drive member. The isolation spring arrangement has at least one isolation spring that is axially offset from the endless drive member engagement surface. The at least one isolation spring has an outer edge that is radially outside the endless drive member engagement surface.

A transmissive joint has an elastic response for transmitting a torsional load capable of ensuring the transmission in the absence of coaxiality between two actuating and actuated devices, and allowing the internal passage of cabling or possible accessory components along the axis of transmission/torsion.

A transmissive joint has an elastic response for transmitting a torsional load capable of ensuring the transmission in the absence of coaxiality between two actuating and actuated devices, and allowing the internal passage of cabling or possible accessory components along the axis of transmission/torsion.

A torque transmission device includes an inner ring, an outer ring, and at least one pair of receiving bellows. The at least one pair of receiving bellows includes a positive receiving bellows and a negative receiving bellows. The torque transmission device also includes at least one gas pressure spring and an adjusting unit connected to the at least one gas pressure spring. The receiving bellows are arranged between the outer ring and the inner ring such that when the inner ring is rotated in the positive rotational direction, the positive receiving bellows may be compressed, and when the inner ring is rotated in the negative rotational direction, the negative receiving bellows may be compressed. In addition, the receiving bellows are connected to the at least one gas pressure spring in a fluidically conductive manner.

A torque transmission device includes an inner ring, an outer ring, and at least one pair of receiving bellows. The at least one pair of receiving bellows includes a positive receiving bellows and a negative receiving bellows. The torque transmission device also includes at least one gas pressure spring and an adjusting unit connected to the at least one gas pressure spring. The receiving bellows are arranged between the outer ring and the inner ring such that when the inner ring is rotated in the positive rotational direction, the positive receiving bellows may be compressed, and when the inner ring is rotated in the negative rotational direction, the negative receiving bellows may be compressed. In addition, the receiving bellows are connected to the at least one gas pressure spring in a fluidically conductive manner.