MMF044DAF1ABNNN Sauer Danfoss Motor 44cc 380 bar

Product Overview

The MMF044DAF1ABNNN is a swashplate-type axial piston fixed displacement motor built on the Sauer Danfoss (now Danfoss) Series 40 platform, in the MMF044 displacement size (44 cm³/rev). The motor features a swashplate design with parallel arrangement of axial pistons and slippers, specifically engineered for medium-power applications in closed-circuit hydrostatic transmission systems. The Series 40 MMF044 fixed motor offers a nominal pressure of 380 bar (5,511 psi), maximum pressure of 415 bar (6,019 psi), rated speed of 3,300 rpm, maximum speed of 4,100 rpm, and a weight of approximately 11 kg.

The MMF044 series is the mid-size specification in the Sauer Danfoss Series 40 hydraulic motor family, alongside the MMF025 (25 cc/rev), MMF035 (35 cc/rev), and MMF046 (46 cc/rev) sizes. These fixed displacement motors feature a compact, high power density design that can be used alone or combined with other products in a system for transmitting and controlling hydraulic power. MMF044 hydraulic motors are widely used in agriculture, construction, road building, material handling, forestry, and lawn care applications, and are particularly common in road roller vibratory drive applications.

The model code MMF044DAF1ABNNN decodes as follows: MMF designates the fixed motor series (Series 40), 044 is the displacement size (44 cm³/rev), D is the design code, A is the control type code (fixed displacement), F is the mounting flange code (SAE B two-bolt flange), 1 is the shaft type code, A is the port configuration code, B is the seal material code, and NNN is the standard configuration code. The motor’s fixed displacement design eliminates the need for variable adjustment mechanisms, offering simple construction, straightforward control logic, and low maintenance requirements.

Engineered as a form-fit-function replacement for original Sauer Danfoss MMF044 series motors, this model maintains identical mounting flange dimensions (SAE B two-bolt flange), 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 

• Model: MMF044DAF1ABNNN

• Series: Sauer Danfoss Series 40 MMF Fixed Motor Series

• Motor Type: Swashplate-type axial piston fixed displacement motor

• Design Feature: Swashplate configuration, parallel axial piston/slipper arrangement, fixed displacement

• Displacement: 44 cm³/rev (2.65 in³/rev)

• Nominal Pressure: 380 bar (38 MPa / 5,511 psi)

• Maximum Pressure: 415 bar (41.5 MPa / 6,019 psi)

• Rated Speed (max displacement): 3,300 rpm

• Maximum Speed (max displacement): 4,100 rpm

• Rated Speed (min displacement): 3,900 rpm

• Maximum Speed (min displacement): 4,850 rpm

• Case Pressure (continuous): 1.7 bar (25 psi)

• Case Pressure (maximum): 5.2 bar (75 psi)

• Mounting: SAE B two-bolt flange

• Shaft Type: Splined / Tapered / Straight key (optional)

• Port Connections: Side / Twin / Axial (optional)

• Rotation: Bi-directional

• Weight (approx.): 11 kg (24.3 lb)

• Mass Moment of Inertia: 0.0032 kg·m²

• Loop Flushing: Optional

• Hydraulic Fluid: Standard hydraulic oil (ISO VG46 anti-wear recommended)

Key Technical Advantages

1. Swashplate Axial Piston Design with High Power Density

The MMF044DAF1ABNNN employs the classic swashplate design of the Sauer Danfoss Series 40 platform, with axial pistons and slippers arranged in parallel, changing piston stroke through a tiltable swashplate. Series 40 pumps/motors feature a compact, high power density design, achieving a displacement of 44 cm³/rev and a nominal pressure of 380 bar at a weight of 11 kg. The swashplate configuration provides a compact axial dimension, suitable for mobile hydraulic systems with limited installation space. The parallel piston/slipper arrangement ensures dynamic balance of the rotating group, reducing vibration and noise levels at high speeds.

2. High-Speed Capability with Wide Speed Range

The MMF044 achieves a rated speed of 3,300 rpm and a maximum speed of 4,100 rpm at maximum displacement; at minimum displacement, rated speed reaches 3,900 rpm and maximum speed reaches 4,850 rpm. Series 40 motors offer high output speed capability, with speed range covering 3,300 to 5,300 rpm (including variable models), meeting the needs of various high-load and continuous operation conditions. This wide-range speed regulation characteristic makes the MMF044 particularly suitable for applications requiring high-frequency vibration, such as road roller vibratory drives.

3. Fixed Displacement Stable Output with Bi-Directional Rotation

The fixed displacement design provides constant displacement, simple control logic, and stable operating characteristics. When used as a motor, output speed is proportional to input flow and inversely proportional to displacement; output torque is proportional to system pressure and displacement. The motor supports bi-directional rotation, with forward/reverse output shaft switching achieved by changing the swashplate direction (or the pump’s swashplate direction), suitable for travel drive and vibratory drive systems requiring frequent direction changes. The fixed displacement motor eliminates the need for complex variable adjustment mechanisms, reducing system integration complexity and maintenance risk.

4. Compact Structure with Multi-Standard Mounting Compatibility

The Series 40 MMF044 motor features a compact cast iron housing, with an SAE B two-bolt mounting flange conforming to industry standard interfaces. Shaft options include splined, tapered, and straight key configurations; port connections are available in side, twin, and axial configurations to suit different machine mounting requirements. An optional loop flushing valve helps with heat dissipation and smooth hydraulic flow, improving system efficiency under continuous duty conditions. The motor’s mounting dimensions, shaft interface, and port configuration are identical to original Sauer Danfoss MMF044 series motors, enabling direct replacement.

Application Areas

• Road Construction Machinery: Road roller vibratory motors (e.g., Bomag 05817004 vibratory motor, Hyundai TCS122J road roller vibratory motor), road roller travel drives, pavers, continuous soil mixing machines

• Construction Machinery: Skid steer loaders, mini excavators, wheel loaders

• Agricultural Machinery: Combine harvesters, tractor auxiliary drives, sprayers

• Material Handling: Forklift drives, conveyor drives

• Forestry & Lawn Care: Mowers, forestry machinery auxiliary drives

• Concrete Equipment: Concrete mixer truck drives

The MMF044 series has mature applications in road roller vibratory drive applications, with Bomag 05817004 vibratory motors and Hyundai TCS122J road roller vibratory motors utilizing this series.

Expert Maintenance Tips

1. Shaft Alignment Requirements: The motor features SAE B two-bolt flange mounting. During installation, ensure the coaxiality deviation between the motor shaft and drive-end coupling does not exceed 0.05 mm. Although Series 40 motors are equipped with high-capacity roller bearings, excessive radial forces will accelerate bearing wear and shaft seal aging.

2. Case Pressure Control: The MMF044 has a continuous case pressure of 1.7 bar and a maximum case pressure of 5.2 bar. The drain port must be connected separately to the reservoir with back pressure not exceeding the maximum case pressure value; higher back pressure will damage the shaft seal and deform the housing. When used in series systems, ensure the return back pressure from upstream components does not exceed this limit.

3. Hydraulic Fluid Cleanliness and Viscosity Management: ISO VG46 anti-wear hydraulic oil is recommended. Maintain hydraulic fluid cleanliness at 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.

4. Vibratory Duty Special Notes: The MMF044 experiences high-frequency alternating loads in road roller vibratory drive applications. Inspect motor mounting bolt tightness and case drain leakage every 500 operating hours. If vibration amplitude increases abnormally, check the wear condition of piston/slipper pairs and swashplate surfaces.

5. Initial Startup and Extended Storage: Fill the motor housing with clean hydraulic fluid during initial installation to prevent dry friction on piston pairs during startup. For motors stored over 6 months, manually rotate the shaft 2–3 revolutions to confirm free rotation, then run at low pressure under no load for 10 minutes before gradually applying load.