A two-stage log splitter uses a high-pressure/low-flow pump and a low-pressure/high-flow pump to provide fast cylinder extension under low load and high splitting force under high load, with automatic unloading of the low-pressure pump.
Read the decisions behind it.
Use separate positive displacement pumps for high and low pressure stages with individual check valves on each discharge.
Add a pressure transmitter and controller loop to unload the low-pressure pump once system pressure reaches the high-pressure setpoint.
Include a pressure relief valve on the high-pressure supply and a return filter before the reservoir.
Reuse this pattern for hydraulic systems that require high flow at low pressure and high pressure at low flow, such as presses, compactors, and injection molding machines.