| 摘要 |
PURPOSE:To prevent occurrence of rattling by providing a counter shaft with the first switching mechanism which is moved to connect and disconnect an extremely low speed shaft to and from a main shaft and the second switching mechanism which mutually changes over the forward and backward low speed gear trains of an extremely low speed gear mechanism. CONSTITUTION:A main shaft 14 and an extremely low speed shaft 84 are joined to or disjoined from each other by the first switching mechanism 118 which has the first switching sleeve 116 axially moved so as to be engaged with and disengaged from a main shaft spline 112 formed on the end of a shaft 14 and engaged with an extremely low speed shaft spline 114 formed on the end of a shaft 84. On a counter shaft 16 between an advancing low speed driven gear 102 and a retreating low speed driven gear 108, is provided the second switching mechanism 126 which has the second switching sleeve 124 axially moved by a hub unit 122 fixed on the shaft 16. When the sleeve 124 is moved so as to be engaged with the gear 102, the gear 102 and the shaft 16 are connected together, and when the sleeve 124 is located in an approximately middle position between the gear 102, 108, a neutral condition of impeding power transmission to the shaft 16 occurs. |
