Patent ID: 6962545

Claim:
A power transmission apparatus comprising: an input rotational coupling to which power can be applied from a prime mover and an output rotational coupling by which power can be applied to a load; at least two electric machines, one of the electric machines connectable to one of the input rotational coupling and the output rotational coupling by independently controllable clutch devices, each of the electric machines being independently operable as a motor and as a generator; an electric energy storage device coupled to the electric machines through a controller and operable to store and release electric energy; first and second planetary gear sets respectively coupled to the electric machines; a third planetary gear set having at least two sun gears, coupled to the output rotational coupling; wherein the controller is coupled to operate the clutch devices and the electric machines in coordination so to obtain a plurality of operational ranges, the ranges differing by routing different subsets of input mechanical and electric power from the prime mover and the energy storage device into charging of the energy storage device and application of power to the output rotational coupling, and one of the two sun gears of the third planetary gear set is coupleable a respective one of the independently controllable clutch devices to a planetary gear carrier of the first and second planetary gear sets.