Rexroth A2F Series Bent Axis Hydraulic Pump & Motor A2F28 A2F45 A2FO107 A2FO125

The heavy-duty A2F Series Bent Axis High-Pressure Hydraulic Axial Piston Pumps & Motors (encompassing global standard designations A2FO107, A2FO125, A2F45W1Z1, A2F45W1Z2, A2F28W2Z1, and A2F28W3Z1), engineered by Chengyuan Hydraulic, represent premium fluid power solutions configured for 100% direct drop-in interchangeability across open and closed hydrostatic circuits. Fabricated in complete mechanical conformity with original Bosch Rexroth A2F and A2FO technical guidelines, this portfolio perfectly matches factory mounting pilots, shaft extensions (including DIN/SAE splines or keyed drives), and rear port geometries. Global B2B industrial procurement networks and heavy plant maintenance facilities can execute instant on-site unit swap-outs with zero modifications to legacy machine chassis brackets or high-pressure rigid lines.

Utilizing a time-tested 40° bent-axis geometric topology, the A2F series operates alternately as a fixed-displacement pump (e.g., A2FO sub-series) or a high-speed fixed motor (e.g., A2F sub-series), outputting exceptional power-to-weight ratios compared to traditional flat swashplate configurations. This structural configuration delivers superior self-priming velocities, higher maximum continuous rotations, and superior resilience against line shocks. At Chengyuan, all operational risks are eliminated through our 100% rigorous dynamic simulation test bench criteria. Every pump and motor completing assembly is tested under a continuous 350 bar load and up to 400 bar peak pressure to verify volumetric efficiency at high thermal ranges, track case drain leakage bounds, monitor spherical valve plate oil-film stability, and measure acoustic noise signatures before factory sign-off.

Technical Specifications

• Product Series Classification: A2F / A2FO Bent Axis Fixed Displacement Hydraulic Pump & Motor Series

• Structural Profile: 40° Bent axis layout (Decoupled cylinder barrel and drive shaft architecture)

• Nominal Continuous Operating Pressure: 350 bar (35 MPa)

• Maximum Permissible Peak Pressure: 400 bar (40 MPa extreme shock-load threshold)

• Fluid Routing Control: Fixed displacement (Configured via open or closed-loop specific port plates)

• Recommended Fluid Cleanliness Class: Premium anti-wear mineral oils matching ISO 4406 19/16/13 minimum benchmarks

• Model-Specific Nomenclature & Engineering Metrics (Catalog Verified):

  • High-Capacity Output Models: A2FO107 / A2FO125

  • Geometric Displacement Scale: 107 cc/rev or 125 cc/rev ($cm^3/rev$)

  • Maximum Continuous Speed (Self-Priming / Open Circuit): 2150 rpm (Size 107) / 2000 rpm (Size 125)

  • Maximum Intermittent Speed (Closed Circuit Boosted / Motor Duty): 3500 rpm / 3150 rpm

  • Theoretical Fluid Delivery at 1500 rpm: Approx 160 L/min (Size 107) / 187.5 L/min (Size 125)

  • Net Weight Envelope: Approx 42.0 kg to 51.0 kg

  • Mid-Scale Specialized Trims: A2F45W1Z1 / A2F45W1Z2

  • Geometric Displacement Scale: 45 cc/rev ($cm^3/rev$)

  • Hardware Suffix Configuration W1Z1 / W1Z2: Denotes upgraded Viton dynamic seals for high thermal resistance, localized port configurations (SAE split-flange vs. metric straight threads), and dedicated shaft taper specifications or standard DIN involute profiles.

  • Maximum Rated Shifting Velocity (Motor Mode): 4750 rpm

  • Maximum Permissible Output Torque at 350 bar: Approx 250 Nm

  • Net Weight: Approx 18.0 kg

  • Compact High-Speed Units: A2F28W2Z1 / A2F28W3Z1

  • Geometric Displacement Scale: 28 cc/rev ($cm^3/rev$)

  • Hardware Suffix Configuration W2Z1 / W3Z1: Denotes customized radial or axial positioning of the case drain ports alongside an augmented heavy-duty bearing group tailored for high-frequency rotational reversals.

  • Maximum Permissible Motor Shifting Velocity: 5600 rpm

  • Maximum Power Throughput Capacity: Up to 87 kW (At upper limit speed and pressure configurations)

  • Net Weight: Approx 14.5 kg

Key Technical Advantages

• Robust 40° Bent-Axis Rigid Piston Topology: Utilizes tapered pistons equipped with high-tension compression rings linked directly to the drive shaft hub via robust ball-ended rods. By eliminating the sliding slipper-on-swashplate interface, the risks of shoe lift-off or centrifugal breakout are removed, allowing the unit to comfortably sustain continuous velocities (up to 5600 rpm on Size 28) with high mechanical stability.

• Micro-Lapped Spherical Valve Plate Interface: The mating contact between the rotating cylinder barrel and the fixed timing plate is engineered as a precision spherical surface. Polished to micron-level tolerances on multi-axis CNC lapping machines, this self-centering design accommodates slight drive shaft deflection under intense radial loads, keeping volumetric efficiency above 95% over the product’s lifespan.

• Monoblock High-Density Ductile Iron Casting Frame: The main enclosure is cast from high-tensile, low-porosity ductile iron, with structural internal webbing optimized via finite element analysis (FEA). This rigid frame limits structural micro-yielding or expansion under continuous 400 bar impulses, preventing internal cross-port bleeding and eliminating case cracking.

• Oversized Pre-Loaded Tapered Roller Bearings: The primary drive shaft is nested within an oversized, pre-loaded tapered roller bearing assembly. This robust arrangement manages the high axial thrust forces generated by the bent-axis piston linkage as well as radial residual loads from external pulleys or gear meshes, lowering bearing fatigue and extending operation lifetimes in vibrating mobile applications.

Application Areas

Thanks to their high operating pressures, high self-priming limits, and exceptional rotational velocities, the A2F / A2FO series is widely integrated across critical open and closed hydrostatic circuits:

• Mobile Construction Machinery & Heavy Lifting Fleet: Main variable pumps or high-pressure drum drive motors for concrete pump trucks, primary winch hoist and swing motors for crawler cranes/all-terrain trucks, and excavator slewing gearsets (Sizes A2F45/A2F28).

• Marine Engineering & Deck Machinery Equipment: Primary high-pressure piston pumps or drive motors for offshore anchoring windlasses, heavy-duty mooring winches, and commercial marine cargo towlines.

• Industrial Power Stations & Extrusion Machinery: High-pressure hydraulic power packs for scrap metal scrap shears and heavy baling presses, primary cutting-head power grids for tunnel boring machines (TBM), and underground mining headers.

Expert Maintenance Tips

• Mandatory Pre-Commissioning Housing Saturation: The internal bearings and spherical timing pairs of the bent-axis configuration rely entirely on the internal oil bath within the housing for thermal dissipation. Prior to initial commissioning, always remove the highest available case drain plug and pre-fill the pump or motor frame completely with clean, filtered hydraulic fluid, rotating the drive shaft by hand to clear trapped air. Sudden dry ignition will immediately score the cylinder face and valve plate.

• Maintain Low Case Drain Line Back-Pressure Restrictions: Due to the high shear forces generated by high-speed internal rotation, the drain line must be routed directly and without restriction back to the oil reservoir, terminating below the minimum oil level. Never install inline check valves or filters, or merge this path with main control valve return lines. Keep static case pressure beneath $\le 2$ bar to protect the shaft face seals from blowing out or failing.

• Rigidly Audit Fluid Hygiene to Avoid Spherical Surface Scoring: The spherical timing interface and piston ring tolerances are highly sensitive to microscopic abrasive grit. If fluid contamination exceeds ISO 4406 19/16/13 thresholds, hard micro-particles can groove the spherical surfaces under high pressure, causing a surge in internal leakage, elevated temperatures, and a drop in system operating pressure. Install high-pressure inline filters and test oil quality regularly.