TRACTOR

PROBLEM TO BE SOLVED: To easily enhance vehicle speed detection accuracy by accurately detecting a vehicle speed based on the detected rotations of a gear in correspondence to a vehicle speed transmitted to an input shaft 44 after auxiliary transmission. SOLUTION: In this tractor, the output of a hydraulic straight forward running transmission mechanism 45 is transmitted to running crawlers 9 through right and left planetary speed reduction mechanisms 42 to run a machine body straight forward. The output of a hydraulic turning transmission mechanism 45 is transmitted to the running crawlers 9 through the right and left planetary speed reduction mechanisms 42 to turn the machine body. A rotational speed detection gear 98 is installed on a straight forward run input shaft 44 for inputting the output of the hydraulic straight forward running transmission mechanism 45 into the right and left planetary speed reduction mechanisms 42. Also, a universal coupling shaft 43 for transmitting the output of the hydraulic straight forward running transmission mechanism 45 to the straight forward running input shaft 44 through a universal joint 88 is installed, and the rotational speed detection gear 98 is installed on the spline part 44a of the straight forward running input shaft 44 connected to the universal joint 88.