Bosch Rexroth A2FO56/61L-PZB05 fixed-displacement axial-piston pump

Bosch Rexroth A2FO56/61L-PZB05 (material number R902018374) is a series 61 A2FO fixed-displacement bent-axis axial-piston pump for an open hydraulic circuit. Nominal size 56 has a geometric displacement of 56.1 cm³/rev. This execution has NBR seals and rotates counter-clockwise when viewed at the shaft end, delivering from S to A.

The shaft is Splined shaft, DIN 5480 W30 x 2 x 14 x 9g. It uses a four-hole ISO 3019-2 flange. The side pressure connection has 3/4 inch SAE J518 high-pressure-series flange dimensions and the rear suction connection 1 inch SAE J518 standard-pressure-series dimensions. The flange fasteners use metric threads; the inch flange sizes are not pipe threads.

The 350 bar nominal and 400 bar peak outlet values are the archived shaft-specific limits, referenced to DIN 24312; peak pressure is not a continuous rating. For shaft Z with radial-load drives such as pinions or V-belts, the source reduces these limits to 315 bar nominal and 350 bar peak. The 2000 rpm reference maximum requires mineral oil, 1 bar absolute inlet pressure at S and the recommended 16–36 mm²/s viscosity range. Reaching the 3750 rpm limiting speed requires increased inlet pressure according to the manufacturer inlet-pressure/speed curve and compliance with the shaft-seal pressure limit.

NBR shaft seals have 33% lower permissible case pressure than the published FKM shaft-seal curve. Case pressure must be at least the external pressure at the shaft seal. A suction-port pressure allowance does not override this case/seal limit. Keep the case filled, bleed air before loading, and route the highest case-drain port to the tank as specified for the installation position; left-hand rotation uses the port plate rotated 180° from the clockwise drawing.

The applicable technical reference is the original manufacturer publication RE91401, March 2008, which documents this NBR execution and its shaft-specific limits. Representative manufacturer A2FO series 6 photograph; the illustrated shaft, size, rotation and ports may differ from this material-number execution.