Patent ID: 8277352

Claim:
A power split transmission capable of energy recovery, the power split transmission comprising: a mechanical transmission system comprising a rotatable input shaft and at least a first planetary gear train; the first planetary gear train comprising a sun gear coupled to the input shaft, a carrier directly coupled to a rotatable output shaft [ 178 ], and a ring gear directly coupled to a rotatable third shaft[ 186 ], the first planetary gear train being adapted for mechanically transmitting mechanical power between the third shaft, the input shaft and the output shaft [ 178 ]; a hydraulic transmission system [ 152 ] containing a fluid adapted for hydraulically transmitting hydraulic power to and from the input shaft and the third shaft [ 186 ], the hydraulic transmission system [ 152 ] being continuously operatively coupled by the third shaft to the first planetary gear train; and at least one of the mechanical and hydraulic transmission systems [ 154 , 152 ]; [ 154 , 152 ] comprising means for storing and releasing energy within the power split transmission, the energy storing and releasing means comprising a flywheel or an accumulator or a combination thereof; wherein the mechanical transmission system [ 154 , 158 ] and the hydraulic transmission system [ 152 ] are coupled to the input and output shafts [ 168 , 178 ] so that the power split transmission is operable to recirculate power that is selectively received by the hydraulic transmission system [ 152 ] from the output shaft [ 178 ] through the first planetary gear train and the third shaft [ 186 ], and then delivered by the hydraulic transmission system [ 152 ] through the input shaft to the first planetary gear train.