Product Overview
The M6F3N1D3 is a heavy-duty fixed-displacement axial piston motor from the Parker Denison Gold Cup series, Series 6 specification. With a displacement of 98.3 cm³/rev, it delivers continuous working pressure of 350 bar and peak pressure up to 420 bar, with a maximum continuous speed of 3000 rpm, theoretical flow of approximately 295 L/min, and theoretical torque gradient of 1.56 N·m/bar. The model code decodes as: “M6” = Series 6, “F” = Fixed displacement, “3” = Standard SAE D spline shaft (13 teeth), “N” = Buna N seals, “1” = Bi-directional rotation, “D” = Rear SAE Code 62 flange ports, “3” = Control/design series code.
The motor features the Gold Cup series’ signature barrel bearing design, in which the rotating group operates on a hydrodynamic oil film, eliminating metal-to-metal contact and delivering exceptional durability and resistance to shock loads. This design enables the M6F series to operate at speeds up to 3600 rpm at 5000 psi continuous pressure or 6000 psi intermittent pressure.
The M6F3N1D3 offers complete interchangeability: mounting dimensions, SAE D 4-bolt flange, SAE D splined shaft (13 teeth), and SAE Code 62 rear ports are identical to the original Parker Denison specification, enabling drop-in replacement without hose or bracket modification. Every unit undergoes 100% simulated duty-cycle testing before shipment, covering full-load pressure cycling, thermal balance verification, and shock-load validation.
The Gold Cup series spans M6F/M6G (fixed, with/without oil change valve), M6H/M6V (variable, with/without oil change valve), and the larger M7/M7G/M7F/M7H/M7V range. The M7 series offers 118.8 cm³/rev displacement with the same 420 bar maximum pressure and 3600 rpm maximum speed.
Technical Specifications
Model: M6F3N1D3
Brand Series: Parker Denison Gold Cup Series 6
Motor Type: Axial piston, fixed displacement, heavy-duty
Displacement: 98.3 cm³/rev (6.00 in³/rev)
Continuous Working Pressure: 350 bar (5000 psi)
Peak Pressure: 420 bar (6000 psi)
Maximum Speed (Continuous): 3000 rpm
Maximum Speed (Intermittent): 3600 rpm
Theoretical Flow at 3000 rpm: ~295 L/min
Theoretical Torque Gradient: ~1.56 N·m/bar
Mounting Flange: SAE D 4-bolt
Shaft Type: SAE D splined shaft, 13 teeth
Port Connections: SAE Code 62 flange ports (rear)
Rotation: Bi-directional
Seal Material: Buna N (Nitrile)
Weight: Approximately 45 kg (99 lbs)
Fluid Compatibility: Mineral oil, biodegradable fluids, fire-resistant fluids
Key Technical Advantages
① Barrel Bearing Design — Elimination of Metal Contact and Superior Shock Resistance
The Gold Cup series’ patented barrel bearing allows the rotating group to run on a hydrodynamic oil film, completely eliminating metal-to-metal contact between pistons and cylinder bore. In high-shock applications such as shredders and drill rigs, this design distributes impact loads uniformly through the oil film, preventing localized stress concentration and premature failure. This architecture enables the M6F series to operate at 3000 rpm at 5000 psi continuous pressure and withstand 3600 rpm transient conditions at 6000 psi intermittent pressure.
② Low Moment of Inertia Rotating Group — Rapid Response and Precise Control
The low-inertia rotating group enables fast speed and direction changes in bi-directional circuits. For applications requiring frequent start-stop or reversing cycles (hydraulic test stands, winch control), this characteristic significantly reduces response time and improves system control accuracy and operational efficiency.
③ High Volumetric Efficiency — Low Internal Leakage, Maximum Power Transfer
The precision-matched running surfaces between the cylinder block and valve plate maintain extremely low internal leakage across a wide speed and pressure range, maximizing volumetric efficiency. This means greater effective torque output for a given input flow, reduced system heat generation, and improved overall energy efficiency.
④ Broad Fluid Compatibility — Adaptable to Demanding Conditions and Environmental Requirements
The M6F3N1D3 is compatible with mineral oil, biodegradable hydraulic fluids, and fire-resistant fluids (including water-glycol). In mining, steel, and marine applications with strict fire-safety or environmental requirements, the motor can be adapted to the appropriate fluid without replacement, reducing system modification complexity and cost.
⑤ Modular Series Architecture — Broad Displacement Coverage and Mounting Compatibility
The Gold Cup series offers a complete displacement range from M6 (98.3 cc) to M30 (501.5 cc), with maximum pressure coverage of 345–420 bar. The M6F3N1D3’s SAE D 4-bolt flange and 13-tooth splined shaft are compatible with the M7 series (118.8 cc) mounting interface, providing users with a flexible displacement upgrade path.
Application Areas
Marine: Winches, steering gears, thrusters
Mining: Blast hole drills, excavators, underground LHDs
Industrial: Shredders, hydraulic presses, test stands
Oil & Gas: Top drives, mud pump drives
Steel & Metallurgy: Rolling mill auxiliary drives, continuous casting equipment
Heavy Mobile Machinery: Compactors, large telehandler drive systems
Alternative Fluid Systems: Hydraulic transmissions using biodegradable or fire-resistant fluids
Expert Maintenance Tips
Pre-Installation Inspection: Verify flatness and cleanliness of the SAE D 4-bolt flange mating surface; remove burrs and residual sealant. The spline shaft-to-coupling fit must conform to SAE D standards; avoid interference fits that could damage the spline. Tighten port flange bolts in a diagonal sequence to the specified torque.
First Commissioning: The motor casing must be filled with clean hydraulic oil before initial start-up. Fill through the highest casing port until oil overflows from the level port. Dry starting causes the barrel bearing to run without an oil film, resulting in metal-to-metal contact and irreversible damage — the most common cause of premature failure in Gold Cup series motors.
Fluid Cleanliness: Maintain system oil cleanliness at NAS 8 (ISO 4406 18/16/13) or better. The barrel bearing oil film is highly sensitive to particulate contamination; excessive contamination accelerates bearing wear and scoring of the valve plate surface, significantly reducing service life.
Scheduled Inspection: Check casing drain flow every 500 operating hours. Under normal conditions, drain flow should stabilize at 2–5 L/min depending on oil temperature and speed. A sustained increase in drain flow indicates accelerated wear of the barrel bearing or valve plate, and preventive maintenance should be scheduled. Inspect the spline shaft area for oil seepage; replace seals at the first sign of degradation.
Long-Term Storage Protection: If the motor will be idle for more than 3 months, fill the casing with rust-preventive hydraulic oil and manually rotate the shaft several turns monthly to prevent corrosion or adhesion on bearing and valve plate surfaces.
