P A4CSG 500 EPG /30R-VZH85F994ME

The P A4CSG 500 EPG /30R-VZH85F994ME pump is produced by Bosch Rexroth within the A4CSG Axial Piston Pumps series. This variable-displacement unit supplies hydraulic power to mobile or industrial transmissions. A geometric displacement of 500 cm³ per revolution defines the swept volume of its rotating group, so each shaft rotation moves a half-liter of fluid into the circuit. At rated conditions the pump can deliver a maximum flow of 900 l/min, supporting high-demand actuators such as large swing drives. It maintains continuous operation down to 800 rpm, allowing low-speed engine coupling without flow collapse. System pressure capability reaches 400 bar, and a nominal working limit of 350 bar provides a safety margin for fatigue life. At that 350 bar setting the shaft transmits 525 kW, giving designers a clear power requirement for prime movers, while generated torque reaches 2783 N·m to match heavy-duty splined couplings. A minimum boost pressure of 16 bar is required at the inlet to prevent cavitation during full displacement strokes.

For ancillary functions the integrated boost stage displaces 98 cm³ per revolution, sustaining charge flow when the main circuit pressure drops during swash transitions. A dedicated flushing flow of 20 l/min removes heat and contaminants from the case oil, prolonging bearing life. The internal housing holds 14 liters, so the case volume damps pulsations and stabilizes temperature. Rapid control loops benefit from a permitted angular acceleration of 540 rad/s², letting the pump follow engine speed changes without overshoot. Case pressure must remain below 4 bar absolute, which guides drain line routing back to tank. Control valves can impose pilot pressures up to 350 bar on the port without risking spool damage. The rotating assembly exhibits an inertia of 0.3325 kg·m², a value useful for torsional vibration analysis when coupling the pump to diesel engines.