Patent ID: 7913582

Claim:
A transmission for a tractor comprising a main transmission part between a forward/reverse transmission part and a sub transmission part, the main transmission part comprises: a driving shaft including a main driving gear connected to an output side of the forward/reverse transmission part to transmit power to the main transmission part; a first sub shaft parallel with the driving shaft and having a driven gear engaged with the main driving gear of the driving shaft to thereby rotate; a second sub shaft parallel with the first sub shaft and the driving shaft disposed therebetween and having a driven gear engaged with the main driving gear of the driving shaft to thereby rotate; an output shaft arranged between the first sub shaft and the second sub shaft parallel with them to thereby transmit power from the first sub shaft and the second sub shaft to the sub transmission part; first and second driving gears rotatably installed spaced to a distance from each other on the first sub shaft and having different teeth in number from each other; third and fourth driving gears rotatably installed spaced to a distance from each other on the second sub shaft and having different teeth in number from each other; a first output gear installed on the output shaft to rotate together with the same while being continuously engaged with the first driving gear of the first sub shaft and the third driving gear of the second sub shaft; a second output gear installed on the output shaft to rotate together with the same while being continuously engaged with the second driving gear of the first sub shaft and the fourth driving gear of the second sub shaft; a first clutch arranged between the first driving gear and the second driving gear of the first sub shaft to selectively operate in a state of being connected to the first driving gear, a neutral state, or a state of being connected to the second driving gear; and a second clutch arranged between the third driving gear and the fourth driving gear of the second sub shaft to selectively operate in a state of being connected to the third driving gear, a neutral state, or a state of being connected to the fourth driving gear.