0510225006 AZPF-1X-004RCB20KB German Rexroth hydraulic gear pump

Frequently Asked Questions (FAQ)

1. Product & Selection

Q: What does the model code "AZPF-1X-004RCB20KB" mean?

A: It decodes as follows:

• AZPF: Series code for high-pressure external gear pumps.

• 1X: Frame size / bearing specification.

• 004: Geometric displacement (4.0 cm³/rev).

• R: Clockwise rotation.

• C: Tapered shaft 1:5.

• B20: Port and flange configuration (Square flange per ISO 8434-1).

• KB: Variant code for seals and covers.

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

A: Yes. The AZPF series is designed for heavy-duty use. This model can handle continuous pressures up to 250 bar​ and intermittent peaks up to 280 bar, making it ideal for industrial machinery and mobile hydraulics.

Q: Can I get this pump in counter-clockwise rotation?

A: Yes. Rexroth typically offers a left-hand rotation version (denoted by an 'L' in the suffix, e.g., ...LCB...). Always verify the rotation direction before installation.

2. Installation & Operation

Q: What is the recommended operating viscosity?

A: Operate within 10 to 300 mm²/s. For optimal efficiency and service life, maintain viscosity between 20 and 100 mm²/s. Avoid prolonged operation below 10 mm²/s to prevent internal wear.

Q: What is the minimum speed at maximum pressure?

A: To ensure adequate lubrication of the sliding bearings, the minimum speed should be 1200 rpm​ when operating at the maximum continuous pressure (250 bar). Running slower than this under high load can cause premature failure.

Q: How do I calculate the flow output?

A: Use the formula:

Flow (L/min) = Displacement (4.0 cm³/rev) × Speed (rpm) / 1000

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

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 (FKM), 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. Always refer to the official RE 10 250​ datasheet for your specific application and safety guidelines.