Rexroth A2FM16 Fixed Displacement Axial Piston Hydraulic Motor

The A2FM series is defined by its bent-axis principle. Unlike swashplate designs, the cylinder block and drive shaft form an angle (bent axis). This allows pistons to move linearly within cylinders, creating extremely high starting torque and smooth low-speed operation.

The A2FM16 specifically refers to a motor with 16 cm³ per revolution displacement. It is a fixed displacement unit, meaning it moves a constant volume of fluid per rotation. You cannot change its output speed without changing input flow.

Engineering Highlights of the Rexroth A2FM16

1.Bent-Axis Design for High Starting Torque

Swashplate motors can struggle under initial load (stick-slip). The A2FM16’s bent-axis design ensures starting torque efficiency >90% of theoretical value. In practice, this means you can crack open a valve at 50 bar, and the shaft will rotate immediately—no hesitation.

2.Compact Power Density

At only 5.5 kg, the A2FM16 delivers up to 56 kW (75 hp) of mechanical output at 400 bar and 4,000 rpm. Compare that to an electric motor of similar power (which would weigh ~40 kg), and you understand why hydraulic drives dominate in weight-sensitive applications.

3.Robust Tapered Roller Bearings

The shaft is supported by heavy-duty tapered roller bearings designed for both radial and axial loads. You can mount a pulley or sprocket directly on the shaft without external bearings—common in agricultural balers and concrete mixer drives.

4.Long Service Life with High Pressure

Rexroth rates the A2FM16 for continuous operation at 400 bar (5,800 psi). The cylinder block is made from case-hardened steel, and the pistons feature a bronze sliding layer to resist galling. Field data show average rebuild intervals above 10,000 hours in clean oil (ISO 18/15/13 or better).

Common Applications (With Real-World Examples)

Example 1 – Track Tensioning on Compact Track Loaders

Many CTL manufacturers use the A2FM16 as the auxiliary track tensioning motor. Low flow, high torque, and sealed housing allow it to operate submerged in final drive gear oil. The fixed displacement ensures the tensioner extends at a predictable rate, preventing track derailment.

Example 2 – Centrifugal Separator Drive in Marine Fuel Systems

On ships, fuel oil purifiers need constant, high-speed rotation (4,000+ rpm). The A2FM16 runs directly coupled to a centrifuge bowl. Its bent-axis design minimizes vibration, and the 16 cc displacement matches typical flow rates from a 25 kW hydraulic power unit.

Example 3 – Sweeper Broom Drive for Municipal Trucks

Street sweepers use multiple hydraulic motors. The A2FM16 often drives the side gutter broom. It must reverse direction quickly to clear obstructions. The fixed displacement motor—paired with a 4/3-way valve—reverses instantly because there is no variable mechanism to delay response.

Installation, Maintenance, and Common Pitfalls

Mounting Requirements

Use the designated ISO 3019-2 flange (two-hole or four-hole).

Shaft couplings must be aligned to within 0.2 mm to avoid bearing overload.

Case drain port must be unrestricted and routed to tank (maximum case pressure 2 bar absolute).

Fluid Recommendations

Viscosity range: 10 to 800 mm²/s (optimal 25–36 mm²/s)

Recommended fluids: HL, HLP (DIN 51524), or biodegradable HEES

Filtration: β10 ≥ 100 (ISO 4406 code 18/15/13 or better)

Most Common Failure Mode

Shaft seal leakage from excessive case pressure. This happens when users plug the case drain or use undersized return lines. Always pipe the case drain separately to the tank, not into a pressurized return manifold.

For more information on the A2FM16 hydraulic motor, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: Is the A2FM16 reversible?

A1:Yes. It operates identically in both rotating directions. Just reverse the supply and return ports. No internal modifications needed.

Q2:Can I use this motor in a closed-loop hydrostatic system?

A2:Absolutely. The A2FM16 is often paired with a Rexroth A4VG variable pump. However, ensure the closed-loop charge pump supplies at least 10 bar of case pressure to prevent cavitation.

Q3:What is the price and delivery time of the A2FM16 hydraulic motor?

A3: The specific price and delivery time will be provided based on the specific model you provide.

Q4:How to purchase an A2FM16 hydraulic motor?

A4:You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.