0510525311 AZPF-11-011LCB20MB German made Rexroth gear pump

Frequently Asked Questions (FAQ)

1. Product & Selection

Q: What is the key difference between this model (LCB) and the common RCB version?

A: The "L"​ in the model code indicates Counter-Clockwise (Left-Hand) rotation​ when viewed from the shaft end. The RCB version is Clockwise (Right-Hand). This is critical for system plumbing and motor direction compatibility.

Q: Is this pump suitable for high-pressure applications?

A: Yes. As part of the AZPF-F platform, this model is designed for heavy-duty use with a maximum continuous pressure of 250 bar​ and intermittent peaks up to 280 bar.

Q: What does the "11" in AZPF-11 stand for?

A: It denotes the frame size and bearing specification for the 11 cm³/rev displacement variant within the AZPF series.

2. Installation & Operation

Q: What is the recommended operating viscosity?

A: Operate within 12 to 800 mm²/s. For optimal efficiency and service life, maintain viscosity between 20 and 100 mm²/s. Avoid prolonged operation below 12 mm²/s to prevent internal wear.

Q: What is the maximum allowable speed?

A: The absolute maximum speed is 3500 rpm. However, the recommended continuous operating range is 1000 to 3000 rpm. Exceeding 3000 rpm may require special suction conditions (e.g., pressurized inlet) to avoid cavitation.

Q: How do I calculate the theoretical flow output?

A: Use the formula:

Flow (L/min) = Displacement (11.0 cm³/rev) × Speed (rpm) / 1000

Actual flow will be slightly less (typically 90-95% efficiency) due to volumetric losses.

3. Maintenance & Troubleshooting

Q: What are common failure signs?

A: Watch for:

• Noise:​ High-pitched whining indicates cavitation (check inlet suction); knocking suggests bearing wear.

• Reduced Flow:​ Often caused by worn gears or side plates due to contamination.

• External Leakage:​ Usually from the shaft seal (NBR), often due to age or excessive shaft play.

Q: Can this pump be repaired in the field?

A: While Rexroth provides seal kits, the AZPF pump uses precision sliding bearings and pressure-compensated side plates. Replacing seals is possible, but rebuilding the internal gear set requires specialized tools and pressure testing. For critical applications, an exchange unit is often recommended.

Q: What is the #1 cause of premature failure?

A: Oil contamination. This pump requires very clean oil (NAS Class 9-10). Always use a pressure filter with a beta ratio (β₁₀) ≥ 100. Running with a clogged suction filter or low oil level can cause cavitation and catastrophic damage.

Disclaimer:​ This data is based on standard Rexroth documentation for the AZPF series (RE 10 250). Always refer to the official datasheet for your specific application and safety guidelines.