| 摘要 |
<p>The gearbox consists of a main gear and a two-branch group gear that can be changed by a pressure-operated control motor or cylinder. The gear is selected by a shaft that moves axially to select a gear branch and rotates to engage a gear within the branch. The shaft carries a component that has cam tracks corresponding to the gear branches. Near each of the cam tracks, the housing has a three-part two-position valve, to regulate the pressure fluid supply to the control motor in response to movement of the cams. The shapes, dimensions and positions of the cams are such that, with the shaft at the limit of its rotary motion, all the valves are closed, and only the valve that corresponds to the axial position of the shaft can be opened.</p> |
