Power transmission apparatus for a vehicle

A power transmission apparatus for a vehicle, the power transmission apparatus comprising:

• a planetary gear set for outputting a reduced speed or a same speed as a rotation speed of an engine, the planetary gear seat including a sun gear, a planetary carrier, and a ring gear, wherein the sun gear is fixedly connected to an engine output shaft, the planetary carrier is selectively connected with the engine output shaft, and the ring gear is selectively connected with a transmission housing;
• a first input shaft selectively connected with the engine output shaft through a first clutch, wherein a first and a third drive gear are disposed on the outer circumference of the first input shaft and selectively connected to the first input shaft;
• a second input shaft disposed on the outer circumference of the first input shaft without rotational interference and selectively connected with the engine output shaft through a second clutch, wherein a first power delivery gear is fixed to the second input shaft;
• a third input shaft disposed in parallel with the first input shaft, wherein a second and a fourth drive gear are disposed on the outer circumference of the third input shaft and selectively connected to the third input shaft, and wherein a second power delivery gear is fixed to the third input shaft;
• an output shaft disposed in parallel with the first input shaft wherein first, second, and third driven gears and an output gear are fixed to the output shaft;
• an idle shaft disposed in parallel with the first input shaft, wherein a reverse drive gear is disposed on the outer circumference of the idle shaft, and wherein an idle gear is fixed to the idle shaft;
• and
• a fixed transmission comprising:
• a first speed gear train including a first drive gear, a second drive gear, and a first driven gear externally geared to the first drive gear and the second drive gear;
• a second speed gear train including a reverse drive gear and a second driven externally geared to the reverse drive gear;
• a third speed gear train including a third drive gear, a fourth drive gear, and a third driven gear externally geared to the third drive gear and the fourth drive gear;
• and a fourth speed gear train including a first power delivery gear, a second power delivery gear, and an idle gear externally geared to the first power delivery gear and the second power delivery gear.