Excavator main pump ZX250LC-5 9191165 9195236 HPV118JX-25A hitachi hydraulic pump assembly

Excavator hydraulic pumps are mostly high-pressure variable displacement pumps. In principle, the output flow is adjusted in real time through a variable mechanism (such as an electric proportional valve, hydraulic feedback valve): when the excavator performs heavy-load actions (such as digging hard rock), the variable mechanism reduces the flow to increase the system pressure, ensuring sufficient digging force; when performing light-load actions (such as rapid boom lifting), it increases the flow to speed up the action, realizing dynamic matching of "pressure-flow". In terms of function, its high-pressure characteristic (usually working pressure up to 30-40MPa) can meet the high-intensity operation needs of excavators such as crushing and heavy-load digging. At the same time, through adaptive flow adjustment, it reduces engine energy consumption, reduces heat generation of the hydraulic system, and extends the service life of the entire machine.