Danfoss MMF044DAFHABNNN Hydraulic Piston Motor
1. Product Overview
MMF044DAFHABNNN is a fixed-displacement axial piston motor from Danfoss Sauer 40 Series (commonly referred to as a hydraulic piston pump in commercial scenarios). With a displacement of 44cc/rev, it serves as a core actuator for mobile machinery hydraulic systems. It is widely applied in roller vibration systems, loaders, mini excavators, road construction equipment, mining drills and more, compatible with closed hydrostatic circuits. The original unit delivers outstanding durability, and mature alternative domestic versions are available for maintenance replacement.
2. Model Code Breakdown (MMF044DAFHABNNN)
1. MMF : Fixed-displacement axial piston motor of the 40 Series (differentiated from MPV variable pumps)
2. 044 : Base displacement of 44mL/r
3. D : Platform for 35/44cc specifications
4. A : Standard shaft seal configuration
5. F : End cover with flushing circuit and axial port layout
6. H : Standard housing structure
7. A : Standard cylinder block assembly
8. B : Standard mounting flange
9. NNN : General base configuration without custom modifications
3. Key Technical Parameters
Parameter Specification
Rated Displacement 44 mL/r
Continuous Working Pressure 310 bar (31 MPa)
Peak Pressure 350 bar (35 MPa)
Maximum Permissible Speed 3600 rpm; typical operating speed 2000‑2500 rpm
Approx. Weight 16 kg
Recommended Fluid ISO VG46 anti‑wear hydraulic oil
Operating Temperature -20℃~90℃
Shaft Type Spline output shaft
4. Working Principle
Pressurized hydraulic oil enters the motor chamber and pushes axial pistons to reciprocate along the fixed swashplate, rotating the cylinder block and output shaft to convert hydraulic energy into mechanical power. The dedicated built‑in flushing circuit drains hot internal oil for stable temperature control. As a fixed‑displacement unit, its output speed changes linearly with inlet flow, suiting constant‑torque applications such as roller vibration and fan drive.
5. Core Advantages
1. High power density and compact footprint for tight installation spaces, supporting tandem pump layouts.
2. Heavy‑duty wear‑resistant seals withstand dust, vibration and temperature swings on construction sites.
3. Integrated flushing loop slows oil degradation and extends the service life of internal friction pairs.
4. Standardized flange and shaft dimensions enable direct drop‑in replacement of original or compatible aftermarket units, ideal for vibration system maintenance of models like XS122E road rollers.
5. Stable full‑range efficiency and fast start‑stop response for cyclic heavy‑duty road and mining operations.
6. Typical Applications
- Road machinery: Roller vibration drives, pavers, milling machine travel units
- Construction machinery: Mini excavators, wheel loaders, forklifts, sweepers
- Agricultural & mining equipment: Drilling rigs, small bulldozers, forestry machinery and fan‑drive hydraulic systems
