Product Overview
The A2FM32/61W-PAB02 is a 32 cm³/rev displacement model from Bosch Rexroth’s A2FM series 61 generation of bent-axis fixed displacement axial piston motors. The A2FM series employs a bent-axis design where pistons are arranged at an angle to the drive shaft and rest directly on the drive shaft, generating torque depending on pressure—suitable for hydrostatic drives in both open and closed circuits. The series features high power density, very high total efficiency, high starting efficiency and robust 40° bent-axis technology, with displacements ranging from 5 to 1000 cm³/rev, nominal pressure up to 400 bar and peak pressure up to 450 bar.
The output speed of A2FM series motors depends on pump flow and motor displacement, with output torque increasing with the pressure differential between high and low pressure sides. The series is widely deployed in construction machinery travel drives, concrete mixer trucks, road rollers and mining equipment.
The model code breaks down as follows: A2FM identifies the A2F series fixed displacement axial piston motor (bent-axis, fixed displacement); 32 denotes the nominal displacement of 32 cm³/rev; 61 indicates series 61 (6th generation high-pressure version); W is the rotation direction and seal configuration code; PAB02 is the mounting flange, port configuration and additional option combination code.
Every A2FM32/61W-PAB02 unit undergoes 100% simulated operating-condition bench testing prior to shipment. Mounting flange, shaft end and port dimensions comply with ISO/SAE standards and are identical to the original Rexroth A2FM32, ensuring true drop-in interchangeability with zero modification required.
Technical Specifications
A2FM Series Frame Size Specifications:
A2FM10: Displacement 10.3 cm³/rev, max speed 8000 rpm, max flow 82 L/min
A2FM12: Displacement 12 cm³/rev, max speed 8000 rpm, max flow 96 L/min
A2FM16: Displacement 16 cm³/rev, max speed 8000 rpm, max flow 128 L/min
A2FM23: Displacement 22.9 cm³/rev, max speed 6300 rpm, max flow 144 L/min
A2FM28: Displacement 28.1 cm³/rev, max speed 6300 rpm, max flow 176 L/min
A2FM32 (This Model): Displacement 32 cm³/rev, max speed 6300 rpm, max flow 201 L/min
A2FM45: Displacement 45.6 cm³/rev, max speed 5600 rpm, max flow 255 L/min
A2FM56: Displacement 56.1 cm³/rev, max speed 5000 rpm, max flow 280 L/min
A2FM63: Displacement 63 cm³/rev, max speed 5000 rpm, max flow 315 L/min
A2FM80: Displacement 80.4 cm³/rev, max speed 4500 rpm, max flow 360 L/min
A2FM107: Displacement 107 cm³/rev, max speed 4000 rpm
A2FM125: Displacement 125 cm³/rev, max speed 3750 rpm
A2FM160: Displacement 160 cm³/rev, max speed 3600 rpm
A2FM355: Displacement 355 cm³/rev, max speed 2240 rpm, max flow 795 L/min, weight ~110 kg
A2FM32/61W-PAB02 Additional Specifications:
Model Code: A2FM32/61W-PAB02
Type: Bent-axis axial piston fixed displacement motor, 40° bent-axis angle
Displacement: 32 cm³/rev, fixed and non-adjustable
Nominal Pressure (Continuous): 400 bar (5,800 psi)
Peak Pressure (Intermittent): 450 bar (6,525 psi)
Rated Speed: 5600 rpm
Maximum Speed: 6300 rpm
Limit Speed: 6900 rpm
Rated Torque (Δp=400 bar): 204 N·m
Rated Torque (Δp=350 bar): 178 N·m
Maximum Flow: 201 L/min
Rotation: Bidirectional
Mounting Flange: ISO 3019-2 standard flange
Shaft Type: Splined shaft (DIN 5480)
Port Connections: SAE flange ports
Shaft Seal Material: FKM fluoro-rubber
Circuit Compatibility: Open circuit / closed circuit universal
Operating Temperature Range: -40°C to +115°C
Weight: ~9.5–12 kg
Key Technical Advantages
1. 40° Bent-Axis Design for High Power Density and Total Efficiency
The A2FM32 employs Bosch Rexroth’s signature 40° bent-axis design, with pistons arranged at an angle to the drive shaft and resting directly on the shaft, generating torque depending on pressure. This architecture delivers a compact envelope at equivalent displacement with a weight of only about 9.5–12 kg, delivering class-leading power density. The bent-axis design produces high torque at startup with favorable starting efficiency.
2. High Pressure Capability — 400 Bar Continuous, 450 Bar Peak
The A2FM32 supports 400 bar nominal pressure and 450 bar peak pressure, enabling adaptation to high power-density open and closed circuit hydraulic systems. At Δp=400 bar pressure differential, rated torque reaches 204 N·m. One-piece conical pistons with piston ring seals effectively minimize internal leakage, maintaining high volumetric efficiency across the full speed and pressure range.
3. High Speed Capability and Wide Operating Range
The A2FM32 achieves rated speed of 5600 rpm, maximum speed of 6300 rpm and limit speed up to 6900 rpm, representing excellent speed capability among comparable bent-axis motors. The inherent balance characteristics of the bent-axis design ensure low pulsation and low noise at high speeds. Maximum flow reaches 201 L/min with ample flow reserve.
4. Bidirectional Rotation and Open/Closed Circuit Compatibility
The A2FM32 supports bidirectional rotation for hydrostatic drives in both open and closed circuits. FKM fluoro-rubber shaft seals offer excellent oil resistance and temperature resistance with a range of -40°C to +115°C, suitable for outdoor operations and applications with large temperature variations. Optional counterbalance valves (BVD/BVE), flushing valves and boost pressure valves are available for different system configurations.
5. 100% Simulated Load Testing & Drop-In Interchangeability
Each A2FM32/61W-PAB02 unit is bench-tested under simulated operating conditions prior to dispatch, covering pressure cycling, speed stepping and torque output. Mounting flange, shaft end and port dimensions comply with ISO/SAE standards, matching the original Rexroth A2FM32 exactly, enabling direct replacement without any interface modification.
Application Areas
The A2FM32 is deployed across demanding applications:
Construction: excavator fan drives and auxiliary drives, road roller travel motors, asphalt paver drives
Concrete Machinery: concrete mixer truck closed-circuit drives
Mining: mining drill drives, belt conveyor drives
Marine: deck machinery, winch drives
Industrial: metallurgical roller table drives, industrial conveying systems
Specialty Vehicles: street sweepers, snow removal equipment drives
Material Handling: forklift hydraulic systems, aerial work platform drives
Expert Maintenance Tips
1. Installation Position and Housing Priming: Pump/motor installation is recommended with the control at the top or side. The housing must always be filled with hydraulic fluid; fill with clean hydraulic oil before first startup. Ensure coupling alignment deviation does not exceed 0.05 mm to prevent abnormal bearing wear and shaft seal leakage.
2. Oil Cleanliness and Temperature Control: Maintain system oil cleanliness at ISO 4406 18/16/13 or better. Operating oil temperature should be kept below 80°C—system temperature must not exceed 115°C at any point. FKM seals are rated for -40°C to +115°C. Replace hydraulic oil and filter after the first 500 hours, then follow a 2,000-hour or annual replacement cycle. VG 46 is recommended at 60°C operating temperature.
3. Drain Line Management: The drain port must return to the reservoir independently—housing back pressure must not exceed 2 bar. The drain line end must remain submerged to prevent air ingestion. After extended shutdown, fill the housing with clean hydraulic oil before restarting.
4. Open/Closed Circuit Compatibility Maintenance: The A2FM32 is suitable for both open and closed circuits. In closed-circuit applications, ensure the loop flushing valve operates correctly—periodically inspect flushing flow and pressure settings. In open-circuit applications, monitor reservoir level and return filter condition.
5. Periodic Piston Group and Bearing Inspection: The A2FM32’s piston rings and bent-axis bearings are primary wear components. Inspect piston ring wear, cylinder bore clearance and bent-axis bearing clearance every 2,000 hours. Abnormal efficiency loss, noise or vibration requires immediate shutdown and service. Use Rexroth original specification parts when replacing piston groups to ensure fit accuracy.
