| 摘要 |
<p>The invention relates to a hydraulically driven forestry hoist, mainly meant to equip tractors working in the filed of forestry exploitations, being also used in other activities for hauling and lifting loads, when adequately placed on vehicles destined to these operations. According to the invention, the hoist uses for driving some reversible rotary hydraulic engines (), with some radial pistons, directly coupled with some cable carrying drums (), by means of a shaft () and of a driving bushing (), the drums () being supported by a central shaft () by means of a bearing () and by a side plate () by means of another bearing (), and the working fluid supply to the rotary hydraulic engines () is performed by its own supply circuit or from the hydraulic installation of the vehicle gearing it is mounted on, the braking and load blocking in the conveying position being made by some multiple disk brakes (), upon receiving the command to couple the rotary hydraulic engines (), to the effect of winding or unwinding the cable from the drums (), the pressure in the supply circuit increases, the brakes are released allowing the rotary rotation thereof, so that at the moment of cancelling the command, the fluid supply to the engines ceases, the pressure in the circuit decreases and the multiple disk brakes () are driven by the elastic force developed by a tray spring (), there being achieved the braking and blocking of the rotary movement of the cable carrying drums (), and the position of the multiple disk brakes () is normally closed.</p> |
