A10VSO pump adjustment

First, Pre-adjustment Preparation of A10VSO pump

1. Safety lockout-tagout; drain pressure, disconnect load, and verify zero pressure.

2. Oil: Recommended grade, clean (NAS 8 class or better), temp 45±5°C (optimal for adjustment).

3. Tools: Pressure gauge (0–40 MPa), flow meter, torque wrench, hex keys, feeler gauge.

4. Documentation: Record original settings (adjustment screw positions, pressure/flow values) before modification.

Second, Core Adjustment Procedures (By Control Type)

Adjust regulator valves to set pressure/flow limits, then calibrate swashplate angle via servo pressure, achieving desired control curves (pressure-compensated, flow-limited, power-limited).

1. DFR/DFR1 (Pressure+Flow Control) – Most Common for Mobile Hydraulics

Flow Limit Adjustment (Maximum Flow Qmax):

Locate flow adjustment screw (on regulator, marked Qmax/Qlim).

Run pump at rated speed, no load (min pressure).

Loosen lock nut; turn screw clockwise (CW) to increase flow, counter-clockwise (CCW) to decrease.

Verify with flow meter; set to rated flow, retighten lock nut.

Pressure Compensation Adjustment (Set Pressure Pcomp):

Locate pressure compensation screw (marked Pcomp/Max P).

Close flow line (or use test bench load valve), run at rated speed.

Loosen lock nut; turn CW to raise set pressure, CCW to lower.

Adjust to system rated pressure (max 280 bar; do not exceed 350 bar peak).

Check pressure stability; retighten lock nut.

Standby Pressure Adjustment (Pstandby):

For DFR1 (proportional control), adjust via proportional valve current or auxiliary screw.

Set to lowest possible pressure for energy saving when unloaded.

2. DFLR (Pressure+Flow+Power Control)

Complete Qmax and Pcomp adjustments first.

Locate power limit adjustment screw (marked Power/HP lim).

Apply load, run at rated speed; adjust screw to set power curve (P×Q=constant).

Verify that pressure rises as flow drops (and vice versa) to prevent engine overload.

3. DR/DRG (Pressure Control Only – Constant Pressure)

Locate main pressure adjustment screw (DR) or remote pressure adjustment port (DRG).

Run pump at rated speed, close load valve.

Adjust to system constant pressure (e.g., for accumulator charging).

DRG: Use remote pressure gauge to set pressure via remote valve, avoiding pump disassembly.

4. ED/ER (Electro-hydraulic Control)

Complete mechanical pre-adjustment first (Qmax, Pcomp).

Connect controller (PLC/ECU); set current/voltage range (e.g., 0–20 mA, 0–10 V).

Calibrate zero point (no current → swashplate angle 0 → no flow) and full stroke (max current → Qmax).

Test step response and control accuracy; optimize PID parameters if needed.

Third, Critical Adjustment Checks & Troubleshooting

1.Pressure stability: No pressure drift under constant load.

2.Flow linearity: Flow changes smoothly with control signal (mechanical/electrical).

3.No abnormal noise/vibration/temperature rise.

4. Leakage check: No external leakage; internal leakage within allowable range.

Rexroth a10vso manual pdf

Bosch a10vso manual