Patent ID: 8317646

Claim:
A multi-mode hybrid drive train for selective operation in any one of series, parallel, and power split modes, the multi-mode hybrid drive train comprising: a first planetary gear train having a power input for receiving power from a first motor/generator unit, the first planetary gear train having a first sun gear, first carrier and first ring gear and a second planetary gear train having a power input for receiving power from a second motor/generator unit, the second planetary gear train having a second sun gear, a second carrier connected to a final drive, and a second ring gear; a first clutch for selectively clutching the first carrier to the second carrier and a second clutch for selectively clutching the first sun gear to the second ring gear; a first brake for selectively braking the first carrier, a second brake for selectively braking the first sun gear, and a third brake for selectively braking the second ring gear; and the first motor/generator unit linked to the first sun gear and the second motor/generator linked to the second sun gear such that activation of the clutches, brakes, and motors in a first combination causes the multi-mode hybrid drive train to be in a series mode of operation, activation of the clutches, brakes, and motors in a second combination causes the multi-mode hybrid drive train to be in a parallel mode of operation, and activation of the clutches, brakes, and motors in a third combination causes the multi-mode hybrid drive train to be in a power split mode of operation.