Product Overview
The A2FM series bent-axis fixed displacement piston motors are a flagship product line within the Bosch Rexroth hydraulic transmission platform, classified as all-purpose high-pressure motors. Featuring a bent-axis design with axial tapered piston rotary groups, these motors are specifically engineered for hydrostatic drives in both open and closed circuits. Designed to fully comply with Rexroth A2FM Series 61 mounting and interface standards, these motors offer 100% direct interchangeability with original Rexroth units—enabling plug-and-play replacement without any管路 modifications or adapter plates, significantly minimizing downtime and retrofit costs.
The A2FM series covers an ultra-wide displacement range from 5 to 1000 cc/rev. The A2FM10 delivers 10.3 cc/rev, the A2FM16 delivers 16 cc/rev, and the A2FM28 delivers 28.1 cc/rev—all compact yet powerful members of the family. Sizes 10–200 are rated at 400 bar nominal pressure with 450 bar peak pressure.
Every unit undergoes 100% factory testing under simulated real-world working conditions, validating pressure, flow, and sealing performance before shipment—ensuring reliable operation from the very first start.
Model Code Interpretation:
A2FM10/61W-VBB030 (Part No.: 9610656)
A2FM – Series code: Bent-axis fixed displacement piston motor
10 – Displacement size: 10.3 cm³/rev
61 – Series number: Series 61
W – Rotation: Bidirectional (viewed on drive shaft)
VBB030 – Specific configuration code (shaft end, mounting flange, port options)
A2FM16/61W-VAB030 (Part No.: 9411111)
A2FM – Series code: Bent-axis fixed displacement piston motor
16 – Displacement size: 16 cm³/rev
61 – Series number: Series 61
W – Rotation: Bidirectional
VAB030 – Specific configuration code
A2FM28/61W-VPB020 (Part No.: R902193783)
A2FM – Series code: Bent-axis fixed displacement piston motor
28 – Displacement size: 28.1 cm³/rev
61 – Series number: Series 61
W – Rotation: Bidirectional
VPB020 – Specific configuration code (SAE working ports A and B at side, opposite)
Technical Specifications
A2FM10/61W-VBB030
Model: A2FM10/61W-VBB030
Part Number: 9610656
Type: Bent-axis fixed displacement piston motor (Series 61)
Geometric Displacement: 10.3 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed: 6300 r/min
Medium: Mineral oil and synthetic hydraulic oil (HFB/HFC)
Seal Material: FKM (fluoroelastomer)
Rotation: Bidirectional (viewed on drive shaft)
A2FM16/61W-VAB030
Model: A2FM16/61W-VAB030
Part Number: 9411111
Type: Bent-axis fixed displacement piston motor (Series 61)
Geometric Displacement: 16 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed: 4600 r/min
Medium: Mineral oil and synthetic hydraulic oil
Seal Material: FKM (fluoroelastomer)
Rotation: Bidirectional (viewed on drive shaft)
A2FM28/61W-VPB020
Model: A2FM28/61W-VPB020
Part Number: R902193783
Type: Bent-axis fixed displacement piston motor (Series 61)
Geometric Displacement: 28.1 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed: 6300 r/min
Net Weight: 9.5 kg
Mounting Flange: ISO 3019-2 100B4 HW
Port Configuration: SAE working ports A and B at side, opposite
Medium: Mineral oil and synthetic hydraulic oil
Seal Material: FKM (fluoroelastomer)
Rotation: Bidirectional (viewed on drive shaft)
A2FM Series General Parameters :
Displacement Range: 5–1000 cm³/rev
Sizes 10–200: Nominal pressure 400 bar / Peak pressure 450 bar
Size 5: Nominal pressure 315 bar / Peak pressure 350 bar
Sizes 250–1000: Nominal pressure 350 bar / Peak pressure 400 bar
Circuits: Open and closed circuits
Design: Bent-axis, axial tapered piston design
Key Technical Advantages
1. 100% Direct Interchangeability – Zero Modification Required
The A2FM series is engineered to exact Rexroth A2FM Series 61 mounting and interface specifications, with identical dimensions, port locations, and shaft end configurations. End users can replace original units directly without any管路 modifications or adapter plates—transforming unplanned downtime into scheduled, rapid maintenance while significantly reducing spare parts procurement costs and equipment downtime losses.
2. Bent-Axis Compact Design – High Power Density and Superior Efficiency
The bent-axis compact design delivers exceptional power density within a compact footprint. The bent-axis axial tapered piston rotary group ensures minimal friction losses. Durable one-piece pistons with piston rings provide long service life and robust performance.
3. High-Pressure Capability with Wide Displacement Selection
Sizes 10–200 are rated at 400 bar nominal pressure with 450 bar peak pressure, maintaining superior performance under high-load conditions. The A2FM series offers an ultra-wide displacement selection from 5 to 1000 cc/rev, allowing precise matching to specific application requirements.
4. High-Speed Capability with Bidirectional Rotation
Maximum speed reaches 6300 r/min, approved for high-speed operation. Bidirectional rotation design (viewed on drive shaft) enables adaptation to various system requirements without the need for model changes based on rotation direction.
5. Spherical Port Plate Technology – Self-Centering with High Efficiency
The cylinder block and port plate employ a spherical port plate design that automatically self-centers during rotation, reducing peripheral speed and friction losses for exceptional efficiency. The drive shaft is capable of supporting radial loads, making it suitable for applications such as belt drives where radial loads are present.
6. 100% Factory Testing Under Simulated Working Conditions
Every A2FM series unit undergoes rigorous factory testing under simulated real-world conditions, validating pressure, flow, volumetric efficiency, and sealing performance across the full operating range. Test media match actual operating conditions, ensuring each unit is ready for immediate installation and reliable operation upon delivery—eliminating the risk of “dead on arrival” components.
Application Areas
The A2FM series fixed displacement motors are widely deployed across the following industries and equipment types:
Construction Machinery: Small excavator travel/swing drives
Road Construction Equipment: Roller travel drives, asphalt pavers
Crane Machinery: Crane hoisting mechanisms, swing mechanisms
Mining Equipment: Mining machinery, rock drilling rigs
Agricultural Machinery: Tractor hydraulic outputs
Industrial Equipment: Injection molding machines, conveyors
Specific model applications include:
A2FM10/61W-VBB030: Small agricultural implement hydraulic drives, light-duty industrial equipment
A2FM16/61W-VAB030: Medium/small construction machinery auxiliary drives
A2FM28/61W-VPB020: Radiator fan drives, small travel machinery
Expert Maintenance Tips
1. Hydraulic Fluid Cleanliness Management
The A2FM series utilizes bent-axis piston designs with minimal clearances between pistons and cylinder bores, making them highly sensitive to fluid contamination. It is recommended to install filters with ≤10μm filtration rating, maintaining fluid cleanliness to ISO 4406 19/17/14 or better. Mineral oil and synthetic hydraulic oil are recommended. Never use degraded or substandard hydraulic fluids.
2. Case Drain and Backpressure Control
Ensure the case drain line is unrestricted with no flow restrictions. For sizes 10–200, continuous case backpressure must not exceed 10 bar. Excessive case backpressure will cause shaft seal damage and premature bearing failure. The drain line should return directly to the reservoir, not in parallel with the return line.
3. Air Bleeding and Pre-filling Before Start-up
Always bleed air from the motor housing via the highest vent port before initial start-up or after extended shutdown periods to prevent cavitation damage. Ensure the motor housing is completely filled with hydraulic fluid prior to starting.
4. Coupling Alignment Requirements
Maintain shaft alignment within 0.05 mm concentricity and 0.5° angular deviation between the drive shaft and the load shaft. Excessive misalignment will lead to premature bearing wear and shaft seal leakage. The use of flexible couplings is recommended to compensate for minor installation deviations.
5. Rotation Direction Confirmation
The A2FM series features bidirectional rotation as viewed on the drive shaft. Verify that the system circuit direction matches the required rotation direction before installation—reversing fluid flow will reverse the motor‘s direction of rotation.
6. Periodic Inspection and Maintenance
Inspect shaft seals for leakage and listen for abnormal operating noise every 1,000 operating hours or every 6 months (whichever comes first). If reduced volumetric efficiency or insufficient output torque is observed, timely overhaul of the piston assembly and valve plate is recommended.
