A2FE32/61W-VAL100 Rexroth Hydraulic Motor 32cc 400 bar

Product Overview

The A2FE32/61W-VAL100 is a bent-axis axial piston fixed displacement plug-in motor built on the Bosch Rexroth A2FE Series 61 platform, in the A2FE32 displacement size (32 cm³/rev). The motor features a bent-axis design with an axial tapered piston rotary group, engineered for hydrostatic drives in both open and closed circuits. It offers a nominal pressure of 400 bar, maximum pressure of 450 bar, maximum speed of 6,300 rpm, maximum flow of approximately 177 L/min, maximum output torque of approximately 155 N·m (Δp=350 bar), and a weight of approximately 10.5 kg.

The defining design feature of the A2FE series is its plug-in structure — the motor’s mounting flange is located at the center of the case, and this recessed center flange design allows the motor to be almost fully integrated into a mechanical gearbox, providing an extremely compact unit. Installation requires simply “plugging” the motor into the gearbox without needing to observe installation tolerances. The A2FE series fixed displacement plug-in motors are equipped with an axial tapered piston rotary group of bent-axis design, featuring one-piece tapered pistons with piston rings for sealing, offering high power density, very high total efficiency, and excellent starting efficiency.

The model code A2FE32/61W-VAL100 decodes as follows: A2FE32 designates the series and displacement size (plug-in fixed motor, 32 cm³/rev), 61 is the series designation (Series 61), W indicates bidirectional rotation, and VAL100 is the port configuration, shaft type, and special option code. The motor’s fixed displacement design eliminates the need for variable adjustment mechanisms, offering simple construction, low failure rate, and low maintenance requirements.

Engineered as a form-fit-function replacement for original Bosch Rexroth A2FE32 series motors, this model maintains identical mounting flange dimensions, shaft specifications, and port locations, enabling drop-in interchangeability without modification to the host machine’s mounting interface or hydraulic circuit. Each unit undergoes 100% simulated load testing prior to shipment, validating output torque and volumetric efficiency against original specifications.

Technical Specifications (Bulleted List)

• Model: A2FE32/61W-VAL100

• Material Number: R902158629 / R902197559

• Series: Bosch Rexroth A2FE Series 61

• Motor Type: Bent-axis axial piston fixed displacement plug-in motor

• Design Feature: Bent-axis configuration, axial tapered piston rotary group, recessed center mounting flange, plug-in design

• Displacement (Vg): 32 cm³/rev (1.95 in³/rev)

• Nominal Pressure (p nom): 400 bar (5,800 psi)

• Maximum Pressure (p max): 450 bar (6,525 psi)

• Maximum Speed (n max): 6,300 rpm

• Maximum Flow (qV max): Approx. 177 L/min (46.8 US gal/min)

• Maximum Output Torque (Δp=350 bar): Approx. 155 N·m (114 lb-ft)

• Power (n=1450 rpm, Δp=40 MPa): Approx. 31 kW (41.6 HP)

• Rotation: Bidirectional (W)

• Mounting: Plug-in (recessed center flange, direct mechanical gearbox insertion)

• Shaft Type: DIN 5480 splined shaft

• Port Connections: SAE flange ports (A/B same side, bottom)

• Seal Material: FKM

• Weight (approx.): 10.5 kg (23.1 lb)

• Circuit: Open circuit / Closed circuit

• Optional Features: Integrated pressure relief valve, counterbalance valve (BVD/BVE), flushing valve, boost-pressure valve, speed sensor

Key Technical Advantages

1. Bent-Axis Tapered Piston Design with High Starting Efficiency

The A2FE32 employs the classic bent-axis design of the Bosch Rexroth A2FE series, with pistons arranged at an angle to the drive shaft, transmitting torque through spherical contact between tapered pistons and the drive plate. The one-piece tapered piston with piston ring sealing design ensures reliable volumetric efficiency with reduced internal leakage. The bent-axis design offers higher mechanical efficiency and excellent starting efficiency compared to swashplate motors, maintaining stable torque output during low-speed starts and heavy-load conditions. The A2FE series offers high power density and very high total efficiency.

2. Plug-In Design with Direct Gearbox Integration

The A2FE32’s mounting flange is located at the center of the case. The recessed center flange design allows the motor to be almost completely inserted into the mechanical gearbox, achieving an extremely space-saving compact installation. The motor can be directly slid into the mechanical gearbox without needing to observe configuration specifications or installation tolerances. This design offers significant advantages in track drive gearbox and travel drive applications: eliminating couplings and external mounting brackets, reducing system component count and potential failure points, while improving drive system rigidity and alignment precision. The A2FE32 is delivered as a complete unit, ready-assembled and tested.

3. High-Speed Capability with Wide-Range Application Adaptability

The A2FE32 achieves a maximum speed of 6,300 rpm at 32 cm³/rev displacement, with a maximum flow of approximately 177 L/min and power output of approximately 31 kW (n=1450 rpm, Δp=40 MPa). The high-speed capability makes this motor suitable for travel drive and auxiliary drive systems requiring high-speed output. Output speed is proportional to pump flow and inversely proportional to displacement, while output torque increases with the pressure differential between high and low-pressure sides.

4. Multi-Standard Mounting Compatibility with Functional Extensibility

The A2FE32 features DIN 5480 splined shaft configuration, SAE flange ports (A/B same side, bottom), and FKM fluorocarbon seals suitable for high-temperature and chemically aggressive media. The motor can be optionally equipped with an integrated pressure relief valve for additional safety protection. Counterbalance valves (BVD/BVE), flushing valves, and boost-pressure valves can also be mounted directly onto the motor, simplifying system piping design and reducing external connection points and leakage risks.

Application Areas

• Track Drive Gearboxes: Excavator, bulldozer, and drilling rig travel drive systems

• Construction Machinery Travel Drives: Wheel loader and road roller travel drives

• Rotary Drilling Rigs: Power head drives and chassis travel devices

• Industrial Hydraulic Transmissions: Industrial drive scenarios requiring compact integration and high efficiency

• Other Mobile Applications: Various mobile hydraulic systems requiring plug-in fixed motors

Expert Maintenance Tips

1. Plug-In Mounting Notes: Before installation, ensure the gearbox input shaft spline and motor output spline are clean and free of damage, with no burrs on mating surfaces. Installation simply requires sliding the motor into the gearbox without needing to observe installation tolerances. Do not strike the coupling or motor shaft end during installation, to avoid damaging internal bearings and rotating components.

2. Case Filling and Venting: Before initial installation or startup after extended idle periods, fill the motor housing with clean hydraulic fluid to prevent dry friction on piston pairs during startup. Ensure the unit is pre-filled/vented, verifying suction conditions and oil viscosity meet OEM specifications.

3. Case Drain Management: The case drain port must be connected separately to the reservoir, with return lines below the minimum oil level. When multiple motors are connected in series, avoid back pressure buildup in shared return lines. Respect maximum allowable case pressure limits.

4. Hydraulic Fluid Cleanliness and Viscosity Management: Recommended optimum viscosity range is 16–36 mm²/s (at operating temperature). Maintain hydraulic fluid cleanliness at ISO 18/15 or NAS Level 9 or better. Replace hydraulic fluid and filter elements every 1,000 operating hours or annually, with filter element filtration accuracy no less than 10 μm.

5. Restart After Extended Storage: For motors stored over 6 months, manually rotate the shaft 2–3 revolutions to confirm free rotation, then run at low pressure (10 MPa) under no load for 10 minutes, confirming normal case temperature and leakage before gradually applying load.