Hydraulic transmission system for agricultural tractor - has separate hydraulic motors for road wheels and for power take-off

摘要

An agricultural tractor has a hydraulic transmission system consisting of an engine driving a hydraulic pump. The accelerator pedal which controls the engine also controls a by-pass valve which by-passes the excess flow to the pump inlet. The road wheels are driven by hydraulic motors and the power take-off shaft is driven by the hydraulic motor. The direction of rotation of these motors is controlled by a slide valve and the individual motors are controlled by the valves. A safety valve opens the by-pass valve fully in the event of an excessive pressure rise.