Patent attributes
A power transmission apparatus of a hybrid electric vehicle may include a first shaft fixedly connected to an engine, a second shaft selectively connectable to the first shaft and fixedly connected to a motor-generator, a third shaft disposed on a same axis with the first shaft and selectively connectable to the second shaft, a fourth shaft disposed coaxially with the third shaft without rotational interference therebetween, a fifth shaft disposed in parallel with the third and fourth shafts and externally gear-meshed with the third and fourth shafts, a planetary gear set having three elements, one element being fixedly connected to the second shaft, another element being selectively connectable to a transmission housing, and a remaining element being fixedly connected to the fourth shaft, and four gear sets forming gear engagements between the first shaft, the second shaft, the third shaft, the fourth shaft and the fifth shaft.