0510425025 AZPF-1X-008RQR20MB German original Rexroth gear pump

The geometric displacement is 8.0 cm³/rev.

The maximum continuous working pressure is 250 bar, the maximum intermittent pressure is 280 bar, and the peak pressure is 300 bar.

Clockwise rotation when viewed from the shaft end.

This model (RQR) features a straight shaft with a keyway, unlike the tapered shafts common in other AZPF models.

• Shaft Alignment: The pump shaft and motor shaft must be connected via a flexible coupling. The radial runout should be less than 0.1 mm, and the angular error should be less than 1 degree. Rigid connections are strictly prohibited.
• Suction Conditions: The inlet line should be short and straight. The absolute pressure at the pump inlet must not fall below 0.7 bar. A flooded suction or boost pump is recommended for high-speed operation.
• Priming: The pump housing must be filled with clean hydraulic oil before the first start. Never run the pump dry.

The case drain line must be connected directly, without restriction, and without a filter, back to the reservoir. The connection point should be below the fluid level but above the pump centerline. The backpressure in the drain line must not exceed 1 bar.

Noise is usually caused by cavitation (whining) or aeration (crackling).

• Cavitation: Check for clogged inlet filters, oil viscosity that is too high, or a low oil level.
• Aeration: Check for air leaks in the suction line.
• Mechanical Noise: Check for misalignment or damaged bearings.

Theoretical flow = 8.0 (cm³/rev) × Speed (rpm) / 1000. Actual flow will be 5-10% lower due to internal leakage (slip). If the flow drops more than 15%, the pump is likely worn.

Possible causes include:

1. Internal Pump Wear: Increased clearance between the gear set and side plates.
2. System Leakage: Check other valves and actuators.
3. Low Motor Speed or incorrect relief valve setting.

The use of ISO VG 32/46/68 mineral-based hydraulic oils (HL, HLP) is recommended. Other fluids (HFC, HFD, etc.) are permissible, but seal material compatibility must be verified.

A cleanliness level of NAS Class 9 or cleaner is mandatory. This is critical for ensuring the long service life of the precision sliding bearings.

It is not recommended for critical applications. While seal replacement is possible, the installation of the sliding bearings and pressure-compensated side plates requires special tools and pressure testing. For most users, an exchange unit is safer.