| 摘要 |
PURPOSE:To make main transmission control ever so easy, by making a main transmission into a planetary gearing system which changes gears in a way of locking and controlling plural gears selectively, while situating the main transmission at the higher driving side than that of an auxiliary transmission in front of a transmission case. CONSTITUTION:A planetary gearing type main transmission 10 is installed in the front end part of a transmission case 3. An auxiliary transmission 12 is connected to this main transmission 10 via a speed increaser 16, and then a differential mechanism 11 for rear wheel use is connected to the auxiliary transmission 12. The main transmission 10 is made up of the following formation that engages each of first to fourth sun gears 34-37 with the first to third planetary gears 27, 28 and 29 separately engaging each of first to third driving gears 24, 25 and 26 and a fifth planetary gear 33 engaging a fourth gear 32, respectively. A gearshift valve 43 is controlled for shift selection and each of first to fourth hydraulic cylinders 39-42 is driven separately whereby each of sun gears 34-37 is forcibly pressed and locked to a case 38 individually. |
