A2FM80/61W-VBB010 Rexroth Motor | 450 Bar Bent Axis

Product Overview

The A2FM80/61W-VBB010 is an 80 cm³/rev displacement model from Bosch Rexroth’s A2FM series of bent-axis fixed displacement axial piston motors. The A2FM series employs a bent-axis design suitable for hydrostatic drives in both open and closed circuits, offering high power density, compact dimensions, high overall efficiency and favorable starting efficiency. Motor output speed depends on pump flow and motor displacement, with output torque increasing as the pressure differential between high and low pressure sides increases.

The model code breaks down as follows: A2FM identifies the A2F series fixed displacement axial piston motor (bent-axis, fixed displacement); 80 denotes the nominal displacement of 80 cm³/rev; 61 indicates series 61 (6th generation high-pressure version); W is the rotation direction and seal configuration code; V denotes the shaft seal type (FKM fluoro-rubber seal); B is the mounting flange type; B is the working port configuration; 010 is the additional option combination code.

The A2FM series offers finely graduated frame sizes from 5 to 1000 cm³/rev with nominal pressure ratings of 315–400 bar, enabling flexible adaptation to various drive requirements. The A2FM80 is a mid-range frame size balancing torque output and flow demand, delivering up to approximately 510 N·m maximum torque at 400 bar. It is widely deployed in construction machinery travel drives, concrete mixer trucks, road rollers and mining equipment.

Every A2FM80/61W-VBB010 unit undergoes 100% simulated operating-condition bench testing prior to shipment. Mounting flange, shaft end and port dimensions comply with SAE/DIN standards and are identical to the original Rexroth A2FM80, ensuring true drop-in interchangeability with zero modification required.

Technical Specifications

A2FM Series Frame Size Specifications (Partial):

• A2FM5: Displacement 5 cm³/rev, nominal pressure 315 bar, max pressure 350 bar

• A2FM10: Displacement 10 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM12: Displacement 12 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM16: Displacement 16 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM23: Displacement 23 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM28: Displacement 28 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM32: Displacement 32 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM45: Displacement 45 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM56: Displacement 56 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM63: Displacement 63 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM80 (This Model): Displacement 80 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM90: Displacement 90 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM107: Displacement 107 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM125: Displacement 125 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM160: Displacement 160 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM180: Displacement 180 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM200: Displacement 200 cm³/rev, nominal pressure 400 bar, max pressure 450 bar

• A2FM250: Displacement 250 cm³/rev, nominal pressure 350 bar, max pressure 400 bar

• A2FM500: Displacement 500 cm³/rev, nominal pressure 350 bar, max pressure 400 bar

• A2FM1000: Displacement 1000 cm³/rev, nominal pressure 350 bar, max pressure 400 bar

A2FM80/61W-VBB010 Additional Specifications:

• Model Code: A2FM80/61W-VBB010

• Type: Bent-axis axial piston fixed displacement motor

• Displacement: 80 cm³/rev (4.88 in³/rev), fixed and non-adjustable

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

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

• Rated Speed: 2,500 rpm

• Maximum Speed: 3,000 rpm

• Maximum Torque (at 400 bar): ~510 N·m

• Rotation: Bidirectional (reversible)

• Shaft Seal Material: FKM fluoro-rubber, temperature range -20°C to +90°C

• Mounting Flange: SAE standard flange

• Shaft Type: Parallel keyed shaft or splined shaft (varies by configuration)

• Port Connections: SAE flange ports

• Circuit Compatibility: Open circuit / closed circuit universal

• Hydraulic Fluid: Mineral oil (ISO VG46/68), water glycol, synthetic oil

• Overall Efficiency: ~92%

• Weight: ~38 kg

• Noise Level: ~70 dB

Key Technical Advantages

1. Bent-Axis Fixed Displacement Design for High Starting Torque and High Power Density

The A2FM80/61W-VBB010 employs a bent-axis axial piston design with the cylinder block angled relative to the output shaft, transmitting torque through pistons acting on a thrust plate. This architecture delivers high torque at startup with favorable starting efficiency. Compared to swashplate designs, bent-axis motors offer superior performance under high-speed heavy-load conditions, with maximum torque reaching approximately 510 N·m at 400 bar. The compact construction and weight of only about 38 kg deliver class-leading power density.

2. High Pressure Capability — 400 Bar Continuous, 450 Bar Peak

The A2FM80’s 10–200 cm³/rev frame size range supports 400 bar nominal pressure and 450 bar maximum pressure, enabling adaptation to high power-density open and closed circuit hydraulic systems. This pressure rating offers significant advantages in travel drive and tool drive applications requiring high torque density. The 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 Low Pulsation Operation

The A2FM80/61W-VBB010 achieves a rated speed of 2,500 rpm and maximum speed of 3,000 rpm, representing excellent speed capability among comparable bent-axis motors. Combined with the inherent balance characteristics of the bent-axis design, the motor maintains low pulsation and low noise (~70 dB) at high speeds, suitable for continuous high-speed operation such as cooling fan drives and mixer truck drives.

4. FKM Seals and Wide Temperature Adaptability

This model is configured with FKM fluoro-rubber shaft seals rated for -20°C to +90°C, suitable for mineral oil and synthetic oil systems. FKM seal material offers excellent oil resistance and temperature resistance, maintaining low leakage risk under harsh operating conditions, suitable for outdoor operations and applications with large temperature variations.

5. 100% Simulated Load Testing & Drop-In Interchangeability

Each A2FM80/61W-VBB010 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 SAE/DIN standards, matching the original Rexroth A2FM80 exactly, enabling direct replacement without pipework or interface modification.

Application Areas

The A2FM80/61W-VBB010 is deployed across demanding applications:

• Construction: 15–25 ton excavator fan drives and auxiliary drives, road roller travel motors, asphalt paver drives

• Concrete Machinery: concrete mixer truck closed-circuit drives (fixed displacement, high torque, uniform mixing, continuous operation)

• Mining: mining drill drives, belt conveyor drives

• Marine: deck machinery (winches, anchor windlasses) with salt spray resistance and high reliability

• Industrial: metallurgical roller table drives, industrial conveying systems (fixed displacement, stable speed, dust resistance)

• Off-Road Winches: high torque, reliable braking, flexible bidirectional rotation

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. FKM seals are rated for -20°C to +90°C—system temperature must not exceed this range at any point. Replace hydraulic oil and filter after the first 500 hours, then follow a 2,000-hour or annual replacement cycle.

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 A2FM80 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 A2FM80’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 original specification parts when replacing piston groups to ensure fit accuracy.