Double clutch transmission

A double clutch transmission comprising:

• a main input shaft for receiving an engine torque;
• a first input shaft rotating coaxially with the main input shaft;
• a second input shaft rotating coaxially with the main input shaft and along an exterior circumference of the first input shaft;
• first and second clutches for selectively transmitting a torque of the main input shaft to the first and second input shafts;
• first and third drive gears formed on one input shaft among the first and second input shafts;
• second and fourth drive gears formed on another input shaft among the first and second input shafts, said another input shaft being different from said one input shaft;
• a first output device for selectively changing torques of the first, second, third, and fourth drive gears and for outputting the changed torque;
• a second output device for selectively changing torques of the first, second, third, and fourth drive gears and for outputting the changed torque;
• and
• a differential gear commonly connected to the first output device and the second output device.