描述

A10VO71 – Open‑Circuit Variable Displacement Pump

The A10VO71 is a swashplate‑type axial‑piston pump with variable displacement, engineered for open hydraulic circuits. The number “71” denotes a nominal displacement of 71 cm³ per revolution. At 1800 rpm, it produces a theoretical flow of roughly 128 L/min (33.8 GPM), which makes it well suited for mid‑size excavators, forklift trucks, and marine steering systems.

Common features across all builds include:

• Through‑drive – allows a second pump to be mounted directly behind the unit.

• Pressure ratings – 280 bar (4060 psi) continuous, 350 bar (5075 psi) peak.

• Control variants – DR (pressure compensation), DFR (load sensing), DRS (combined pressure‑flow), and LR (torque limiting).

Decoding the Variants: AA10VO71 vs. ALA10VO71 vs. APA10VO71

Though these suffixes are sometimes used interchangeably, each denotes specific engineering modifications. Here is what they really mean.

AA10VO71 – The Industrial Baseline

The prefix AA marks the standard, unmodified industrial version. It comes with SAE or ISO mounting flanges (two‑ or four‑bolt), conventional splined or keyed shaft ends, and nitrile or FKM seals rated for mineral oils.

Best suited for – stationary plant equipment like presses, conveyor systems, or test benches, where ambient conditions and fluid quality are stable and predictable.

ALA10VO71 – Optimised for Low Speed & Extended Life

The ALA variant is purpose‑built for low‑speed, high‑torque operation. The “L” generally indicates reinforced bearings or a special cylinder‑block spring arrangement that maintains internal preload even below 500 rpm – a regime where standard pumps risk metal‑to‑metal contact from inadequate centrifugal force.

Real‑world use – steel‑mill crane traverse drives, which often run at just 300 rpm for precise positioning. The ALA version prevents slipper lift‑off and avoids premature wear on the swashplate.

APA10VO71 – Enhanced Tribology & Faster Response

The APA code typically points to improved friction pairs – often steel‑on‑steel interfaces or a bronze‑plated valve plate for better durability. In some Rexroth documentation, APA also indicates a modified pressure‑compensator spool that shortens response time to under 50 ms.

Critical application – hydraulic power units for injection moulding machines, where rapid pressure build‑up and decompression are essential. This variant also reduces cavitation erosion on the valve plate, extending service life.