Ebike Systems Ltd

Nexxtdrive Limited

Linan Gong

David Taitt

A drive system for a cycle has an input that receives drive from a pedal. An output rotates to drive a wheel via an electrical machine that provides motor drive. A drive train transmits drive to the output. The drive train includes first and second epicyclic gear sets EP-1, EP-2, which each include a sun gear, a planet carrier, a plurality of planet gears, and an annulus gear. Both annulus gears are connected to the output. Both sun gears are driven by the electrical machine. The first epicyclic gear set transmits drive from its sun gear to its annulus gear with its planet carrier in a fixed position. The second epicyclic gear set transmits drive from a pedal to its annulus gear via its planet carrier. Electrical assistance may be provided when the cyclist is pedalling and not pedalling.

Electrically-assisted pedal cycles

There is provided a method of controlling a pedal cycle and a pedal cycle incorporating the same. The pedal cycle has an electro-mechanical drive arrangement including a continuously variable ratio transmission system having an input which is mounted to rotate about the axis and an output connected to rotate with a hub member, the transmission system comprising an epicyclic gear set including a sun gear in mesh with a plurality of planet gears mounted to rotate about respective planet shafts carried by a common carrier, which is mounted to rotate with the input about the axis, the planet gears being in mesh with an annulus gear, which is connected to rotate with the hub member. Only the sun gear may be connected to rotate a rotor of an electrical machine or an additional machine may be provided. The electrical connections of the stator of the electrical machine are connected to a controller; the method may include the step of applying a time division multiplexed control algorithm to the electrical machine, wherein the time division multiplexed control algorithm alternates between a first control mode in which current generated by the electrical machine is monitored to infer torque applied to the crank arms of the cycle and a second control mode in which the current in the input electrical machine is controlled using the inferred torque.

Method of controlling an electromechanical drive mechanism

There is provided a method of operating a pedal cycle and a pedal cycle incorporating the same. The pedal cycle has an electro-mechanical drive arrangement including a continuously variable ratio transmission system having an input which is mounted to rotate about the axis and an output connected to rotate with a hub member, the transmission system comprising an epicyclic gear set including a sun gear in mesh with a plurality of planet gears mounted to rotate about respective planet shafts carried by a common carrier, which is mounted to rotate with the input about the axis, the planet gears being in mesh with an annulus gear, which is connected to rotate with the hub member. Only the sun gear may be connected to rotate a rotor of an electrical machine or an additional machine may be provided. The electrical connections of the stator of the electrical machine are connected to a controller; the method may include the step of applying a time division multiplexed control algorithm to the electrical machine, wherein the time division multiplexed control algorithm alternates between a first control mode in which current generated by the electrical machine is monitored to infer torque applied to the crank arms of the cycle and a second control mode in which the current in the input electrical machine is controlled using the inferred torque.

Method of operating a pedal cycle having an electro-mechanical drive arrangement

A hub comprises a cylindrical, hollow hub member which is mounted to rotate about its axis and accommodated in whose interior is a continuously variable ratio transmission system having an input, which is mounted to rotate about the axis, and an output mounted to rotate with the hub member. The transmission system comprises a single epicyclic gearset including a sun gear in mesh with a plurality of planet gears mounted to rotate about respective planet shafts carried by a common carrier, which is mounted to rotate with the input about the axis. The planet gears are in mesh with an annulus gear, which is connected to rotate with the rotors of first and second electric motor/generators, respectively. The electrical connections of the stators of the two motor/generators are connected by a controller arranged to control the transmission of power from one motor/generator to the other. The hub further includes a one-way clutch, which includes a drive member, which is constituted by the common carrier and a driven member, which is connected to rotate with the hub member. The one-way clutch is arranged to connect the hub member to rotate with the carrier as soon as the carrier rotates faster than the hub member.

Growing community of inventors

London, United Kingdom

Linan Gong