A10VSO28DR/31R-PPA12N00 A10VSO28DG/31L-PPA12N00 German Rexroth Engineering Systems Mechanical Equipment Genuine Original Imported Hydraulic Pump

A11: Volumetric efficiency reduction (normal ≥95%) is mainly caused by internal or external leakage:

• Internal leakage causes:
  • Piston-cylinder pair wear (clearance >0.03mm)--replace with genuine pairs
  • Valve plate and cylinder block contact surface damage (scratches ≥0.02mm)--lap with abrasive paper (400-grit then 800-grit) until the contact area reaches ≥90%
  • Swashplate seal ring damage--replace the O-ring (FKM material)
• External leakage causes: Pressure port seal damage or hose aging--replace seals and hoses
• Restoration steps: After replacing worn parts, assemble the pump and perform a volumetric efficiency test: run at 1500 rpm and 280 bar, measure flow (should be ≥64 L/min for 45 cm³/r pump); if efficiency is still low, recheck the valve plate lapping quality
• Preventive measures: Maintain oil cleanliness (NAS 9 class) and replace oil every 6 months to reduce wear

A12: Early warning signs and monitoring methods:

• Abnormal temperature rise: Case drain temperature increases by 10-15°C compared to normal operation--monitor with a contact thermometer (check daily)
• Pressure fluctuations: Pressure gauge shows ±10 bar fluctuations during stable operation--install a pressure recorder (Rexroth R901023456) to track changes
• Oil contamination: Oil turns black or has metal particles--use a magnetic plug in the tank to collect debris (check weekly)
• Noise change: Noise increases by 5-8 dB--use a sound level meter to measure (record monthly)
• Flow reduction: System execution speed slows down--measure flow with a bucket and stopwatch (check biweekly)

Establish a "baseline database" of normal operating parameters (temperature, pressure, noise, flow) during pump commissioning, and compare with real-time data to detect early failures.