Patent ID: 8840498

Claim:
A transmission for a hybrid electric vehicle, comprising: an input element where a rotation power is inputted and an output element from which the rotation power is outputted; a first motor generator and a second motor generator; a first planetary gear set to which the input element, the output element, and the first motor generator are connected; a second planetary gear set that is a multiple planetary gear set to which the output element and the second motor generator are connected and that includes at least four or more rotary elements; a first clutch and a second clutch, wherein a first rotary element of the first planetary gear set and a first rotary element of the second planetary gear set are kept connected with the output element, a second rotary element and a third rotary element of the first planetary gear set are connected with the input element and the first motor generator, respectively, a second rotary element of the second planetary gear set is connected with the second motor generator, a third rotary element of the second planetary gear set is switched to be rotatable by the first clutch, and the second rotary element of the first planetary gear set and a fourth rotary element of the second planetary gear set are switched to be selectively connected by the second clutch; and a third clutch that switches one rotary element to be rotatable, which is not connected with the output element, the first clutch, and the second clutch, in the at least four or more rotary elements of the second planetary gear set, in order to make a fixed gear stage when the second clutch operates.