Type：It is a swash plate type axial piston variable displacement pump, mainly used for closed-circuit hydrostatic transmission23.
Performance Parameters
Displacement：The displacement range is wide, typically from 28 cm³/rev to 250 cm³/rev, such as A4VG28, A4VG40, A4VG56, A4VG71, A4VG90, A4VG125, A4VG180, A4VG250 and so on 2.
Pressure
Nominal Pressure：Usually 400 bar (40 MPa), which is the normal working pressure under which the pump can operate continuously and stably23.
Peak Pressure：The maximum pressure that the pump can withstand for a short time is 450 bar (45 MPa) 23.
Speed
Maximum Rated Speed：Varies with different displacements. For example, for A4VG28, the maximum speed at nominal displacement is 4250 rpm; for A4VG125, it is 2850 rpm .
Intermittent Maximum Speed：Also varies by model. For instance, the A4VG28 can reach 5000 rpm intermittently, while the A4VG125 can reach 3450 rpm intermittently .
Flow Rate：At the nominal displacement and rated speed, the flow rate is proportional to the displacement and speed. For example, the flow rate of A4VG125 at the nominal displacement and rated speed is 356 L/min .
Power and Torque：The power and torque also vary with different displacements and working conditions. For example, at the nominal pressure of 400 bar and the flow rate corresponding to the nominal displacement and rated speed, the power of A4VG125 is 238 kW, and the torque is 796 Nm
