Bosch Rexroth A2F fixed displacement hydraulic piston pump

The A2F is a bent-axis, fixed displacement axial piston pump built by Bosch Rexroth, one of the most established names in industrial and mobile hydraulics. Unlike variable displacement pumps that adjust flow output on the fly, the A2F delivers a constant flow rate for a given shaft speed — the displacement (cc per revolution) is fixed at the factory and doesn't change during operation.

How the Bent-Axis Piston Design Works

Where a swash-plate pump tilts a plate to stroke the pistons, the A2F uses a bent-axis configuration: the cylinder barrel and drive shaft are set at a fixed angle relative to one another. As the shaft rotates, the pistons are drawn in and out of the barrel bores by that angular offset, drawing fluid in on one side and forcing it out under pressure on the other.

A few things fall out of this geometry that matter in practice:

Higher Pressure Tolerance

Bent-axis pumps generally handle higher operating pressures than comparable swash-plate designs because the piston side-loading is lower. Most A2F series pumps are rated for a nominal pressure around 350–400 bar, with peak pressures up to 450 bar, depending on series and frame size.

Compact, Rugged Package

The fixed bend angle (typically around 25–40 degrees depending on the model) gives the A2F a shorter, stiffer housing than a swash-plate unit of similar displacement — a real advantage in mobile equipment where mounting space is tight, and vibration loads are constant.

Broad Displacement Range

Across the A2F/A2FO family, geometric displacements run from roughly 5 cm³/rev up to 1000 cc/rev, covering everything from small auxiliary circuits to primary drive pumps on large mobile machines.

Common Applications

The A2F's combination of ruggedness and constant flow makes it a natural fit anywhere the system doesn't need on-the-fly flow adjustment:

Cooling fan drives on off-highway equipment, where a steady flow to a fixed fan motor is exactly what's wanted

Auxiliary and charge pump duty feeding a larger variable pump's control circuit or replenishing a closed loop

Steering circuits on construction and agricultural machinery

Press and injection molding auxiliary circuits, where a constant-flow secondary pump handles clamping or ejector functions

Industrial power units supplying a fixed-flow branch alongside a variable main pump

How to Identify the Right A2F for Replacement

If you're sourcing a replacement rather than specifying a new design, don't just match the frame size — pull the full type code and material number (R9xxxxxxxx) off the nameplate. The type code encodes displacement, series, rotation direction, shaft type, port configuration, and control/valve options, and getting even one character wrong (say, ordering the wrong rotation direction) means the pump won't bolt in or work correctly. When the nameplate is worn or missing, cross-reference the original equipment's service manual or contact an authorized Rexroth distributor with the machine's serial number.

For more information on the A2F hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: Can an A2F pump run in reverse rotation?

A1: No, not without ordering the correct rotation-direction variant. A2F pumps are built for either clockwise or counter-clockwise rotation (viewed from the shaft end), and running the wrong direction can starve suction and damage the unit. Always match rotation direction to the original type code.

Q2: What does "fixed displacement" mean on a hydraulic pump?

A2: It means the pump moves a constant volume of fluid per shaft revolution, set by its internal geometry at the time of manufacture. Output flow changes only with shaft speed, not with any internal adjustment — unlike a variable displacement pump, which can change its own stroke to vary flow at a constant speed.

Q3:How to purchase an A2F hydraulic pump?

A3: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.

Q4:What is the price and delivery time of the A2F hydraulic pump?

A4: The specific price and delivery time will be provided based on the model you specify.