Transmission for four wheel drive vehicle

A center differential of a twin shaft transmission for a four wheel drive vehicle, said transmission having an input shaft driveably connected with an engine, a hollow counter shaft arranged in parallel with said input shaft, shift gear trains provided between said input shaft and said counter shaft in a meshing relationship with each other, one of front and rear drive shafts coaxially provided in said counter shaft, said center differential comprising:

• a hollow center differential input shaft connected coaxially with said counter shaft for inputting power to said center differential;
• a first sun gear mounted on said center differential input shaft;
• a second sun gear provided coaxially with said first sun gear for outputting power to the other of said front and rear drive shafts;
• a first pinion meshing with said first sun gear and provided around said center differential input shaft;
• a second pinion formed integrally with said first pinion and meshing with said second sun gear;
• a carrier rotatably holding said first and second pinions and enclosing said first and second sun gears and said first and second pinions therein for outputting power to one of said front and rear drive shafts;
• and
• a hub secured to the inside of said carrier and extending through a space between said first and second sun gears to the inside of said center differential input shaft and connected with one of said front and rear drive shafts.