Bosch Rexroth A2FO56/61L-VZB05 fixed-displacement axial-piston pump

Bosch Rexroth A2FO56/61L-VZB05 (material number R902024698) is a series 61 A2FO fixed-displacement bent-axis axial-piston pump for open hydraulic circuits. Nominal size 56 has a geometric displacement of 56.1 cm³/rev. The seal execution is FKM. It rotates counter-clockwise when viewed at the drive shaft, delivering from S to A.

The execution has Splined shaft, DIN 5480 W30 x 2 x 14 x 9g and a four-hole ISO 3019-2 flange. The pressure flange is 3/4 inch high-pressure-series SAE and the rear suction flange 1 inch standard-pressure-series SAE, with metric fastening threads. These flange sizes do not denote pipe threads.

The generic series hydraulic table gives 400 bar absolute nominal and 450 bar absolute maximum (10 seconds per period, 300 cumulative hours), but these are not unrestricted ratings for the selected shaft. The NG56 splined-shaft Z row has restricted technical data: an intermittent radial force of 7.8 kN at 18 mm from the shaft collar is paired with permissible torque 294 Nm and pressure differential 330 bar. The applicable shaft/load combination must be checked before using a series hydraulic limit. The 2000 rpm reference maximum requires mineral oil, 1 bar absolute pressure at suction port S and recommended viscosity 16–36 mm²/s. The 3750 rpm limiting speed requires increased inlet pressure according to the source speed-ratio/inlet-pressure curve and compliance with the shaft-seal limit.

The mean case-to-ambient differential pressure must not continuously exceed 2 bar at normal operating temperature; the lower-speed curve governs any higher load. Peaks up to 10 bar last less than 0.1 second. Case pressure must be at least ambient pressure; the suction pressure allowance does not override the case-seal limit. Keep the case filled, bleed air before loading and connect the drain according to installation position. Left-hand rotation uses the port plate rotated 180° from the clockwise view.

The applicable original manufacturer technical reference is RE91401, edition June 2012. Representative manufacturer A2FO series 6 photograph; the illustrated shaft, size, rotation and ports may differ from this material-number execution.