Patent ID: 8210974

Claim:
A hub comprising a substantially cylindrical, hollow hub member, which is mounted to rotate about its axis and accommodated in whose interior is a transmission system having an input, which is mounted to rotate about the axis, and an output connected to rotate with the hub member, the transmission system comprising first and second epicyclic gearsets, the first gearset comprising a first sun gear which is mounted to rotate about the axis and is in mesh with a plurality of first planet gears mounted to rotate about respective planet shafts carried by a first common carrier, which is mounted to rotate about the axis, the first planet gears being in mesh with a further gear element, the second gearset comprising a second sun gear, which is mounted to rotate about the axis and is in mesh with a plurality of second planet gears mounted to rotate about respective planets shafts carried by a second common carrier, the second planet gears being in mesh with a second annulus gear, the first planet gears or the first common carrier being connected to rotate in synchronism with the second planet gears or the second common carrier, the first and second sun gears being connected to the rotors of first and second reversible machines, respectively, arranged to produce power or to act as motors, the power connections of the two stators being connected via a controller arranged to control the transmission of power from one machine to the other.