Bosch Rexroth A2FO23/61R-NZB05 fixed-displacement axial-piston pump

Bosch Rexroth A2FO23/61R-NZB05 (material number R902024598) is a series 61 A2FO fixed-displacement bent-axis axial-piston pump for open hydraulic circuits. Nominal size 23 has a geometric displacement of 22.9 cm³/rev. The seal execution is NBR with FKM shaft seal. It rotates clockwise when viewed at the drive shaft, delivering from S to B.

The execution has Splined shaft, DIN 5480, code Z and an ISO four-hole flange, code B. The pressure flange is 1/2 inch high-pressure-series SAE and the rear suction flange 3/4 inch standard-pressure-series SAE, with metric fastening threads. These flange sizes do not denote pipe threads.

The archived shaft-specific outlet values are 400 bar nominal and 450 bar peak, referenced to DIN 24312. Peak pressure is not a continuous rating; this edition does not establish a numerical peak-pressure duty duration. For shaft Z with radial-load drives, the source reduces nominal pressure to 315 bar; no radial-drive peak rating is inferred. The 2500 rpm reference maximum requires mineral oil, 1 bar absolute pressure at suction port S and recommended viscosity 16–36 mm²/s. The 4750 rpm limiting speed requires increased inlet pressure according to the source speed-ratio/inlet-pressure curve and compliance with the shaft-seal limit.

Case pressure must be at least the external pressure at the shaft seal; the size/speed-dependent seal-loading curve governs the permitted load, and a case-pressure maximum is not a continuous operating allowance. 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 September 2000. Representative manufacturer A2FO series 6 photograph; the illustrated shaft, size, rotation and ports may differ from this material-number execution.