Rexroth AA2FM90 Fixed Displacement Axial Piston Motor for Mining Machinery Industrial Drives

Product Overview:
The AA2FM90 is a high-performance bent-axis design axial piston motor from the renowned Rexroth A2FM series. Designed for both open and closed circuit hydrostatic drives, this fixed motor delivers exceptional power density, reliable operation, and high efficiency under demanding conditions . With a displacement of 90 cm³/rev and a compact, robust design, it provides consistent torque and speed for a wide range of mobile and industrial applications. This all-purpose high-pressure motor features a large variety of available nominal sizes, ensuring precise adjustment to specific application requirements . This unit is a direct, high-quality replacement solution for original Rexroth equipment.

Technical Specifications:

• Model: AA2FM90

• Type: Bent-axis design, fixed axial piston motor

• Displacement: 90 cm³/rev (geometric, per revolution) 

• Nominal Pressure: 400 bar (continuous operation) 

• Maximum Pressure: 450 bar (peak) 

• Maximum Speed: Up to 4000 rpm at Vg max 

• Torque: Approximately 572 in-lbs (rated) 

• Design: For open and closed circuit hydrostatic drives 

• Mounting Flange: SAE / ISO 3019-1 standard, with working ports SAE flange or thread options for US market compatibility 

• Weight: Approximately 32 kg 

• Material: Robust cast iron construction with one-piece tapered piston with piston rings for sealing

• Temperature Range: -20°C to +90°C (continuous operation)

Core Features:

• Bent-Axis Design: The robust angled shaft and axial tapered piston rotary group ensure high starting efficiency, excellent total efficiency, and resilience against shock loads . The drive shaft can withstand radial loads .

• Fixed Displacement Motor: Output speed is dependent on the flow of the pump and the displacement of the motor, with output torque increasing with the pressure differential between high and low pressure sides .

• High Power Density: Delivers impressive power within small dimensions, providing excellent power-to-weight ratio in a compact design .

• Very High Total Efficiency: Maintains exceptional efficiency even at high starting conditions, minimizing energy loss and reducing operating costs .

• High Pressure Capability: Up to 400 bar continuous and 450 bar peak pressure for demanding applications .

• Flexible Installation Options: Available with working ports SAE flange or thread, catering to various market requirements .

• Optional Integrated Valves: Can be equipped with integrated pressure relief valve for overpressure protection, or mounted additional valves such as counterbalance valve (BVD/BVE), flushing and boost-pressure valve for enhanced functionality .

• Finely Graduated Sizes: Wide variety of nominal sizes allows precise adaptation to specific application requirements .

• Durability: Robust bearing system and high-quality cast iron materials ensure long service life in demanding continuous operation .

• Versatile Applications: Suitable for use as motor in both open and closed circuits; also suitable for use as pump in closed circuits .

Main Applications (Suitable Equipment):
The AA2FM90 is widely recognized as the specialized fixed motor for machinery requiring consistent, high-torque hydraulic power. It is extensively used in:

1. Concrete Mixer Trucks (Primary Application):

• Concrete mixer drum drives for 8m³ to 12m³ concrete mixer trucks 

• Yunba, Zoomlion, and SANY concrete mixer trucks - standard motor configuration 

• XCMG concrete mixer truck drum drives 

• Concrete agitator drives and transport mixers

2. Mining & Drilling Machinery:

• Mining machinery and coal mining equipment - conveyor drives and auxiliary functions 

• Rock drilling rigs and foundation equipment 

• Terex Reedrill drilling equipment - OEM applications 

• Rotary drilling rigs  - auxiliary functions 

3. Construction & Earthmoving Machinery:

• Crawler excavators - track drives and swing drives 

• Wheel loaders and material handlers

• Road rollers and compaction equipment 

4. Industrial Machinery:

• Machine tools and industrial drives

• Conveyor systems and material handling equipment

• General industrial hydraulic systems requiring fixed-speed drives

• Robotic arms and automation equipment 

5. Marine & Offshore Applications:

• Marine hydraulic systems - winch drives and deck machinery 

• Navy shipboard material handling equipment - military applications 

• Anchor winches, cargo cranes, and steering gear

6. Specialty Applications:

• Mobile and stationary hydrostatic drives

• Winch drives and hoisting equipment

• Agricultural machinery - tractors, combine harvesters 

• Pile machinery and foundation equipment