| 摘要 |
<p>A variable speed engine (10) drives a tractive effort drive train (12) and fixed and variable displacement pumps, (14 and 16) arranged to supply fluid pressure to a hydraulic work system (24). The displacement of the variable pump (16) is determined by a control ram (42) and a conduit (44, 53, 74) interconnects the variable pump output and the control ram (42). An engine speed control valve (60) and a system pressure compensator valve (46) interposed in series in said conduit (44, 53, 74). The two valves (60 and 46) maintain the variable pump (16) at full output except when low engine speed and high system pressure exists simultaneously.</p> |
