Product Overview
The FRR074BLS2520NNN3S1B2A1NNNNNNNNNN is a Sauer Danfoss Series 45 Frame F variable displacement axial piston pump with a displacement of 74 cc/rev, specifically engineered for open-circuit hydraulic systems. This pump features a swashplate-type displacement mechanism with load sensing (LS) and pressure compensator (PC) combined control, delivering precise flow and pressure matching across medium-to-high pressure operating conditions.
Every FRR074 pump undergoes 100% simulated-condition bench testing, covering rated pressure, peak pressure, and flow characterization. The product is designed for drop-in interchangeability—mounting flange, shaft, and port dimensions are fully matched to original Sauer Danfoss specifications, enabling direct replacement without modification to piping or couplings.
The Series 45 Frame F platform covers displacements from 25 to 147 cm³/rev, with maximum speeds up to 2,800 rpm and continuous operating pressures up to 310 bar. FRR074 shares the Frame F platform with FRL074, FRR090, and FRL090—FRR models are clockwise (CW) rotation, while FRL models are counter-clockwise (CCW).
Technical Specifications
Full Model Code: FRR074BLS2520NNN3S1B2A1NNNNNNNNNN
Series: Sauer Danfoss Series 45, Frame F
Pump Type: Variable displacement axial piston, open circuit
Displacement: 74 cm³/rev (4.52 in³/rev)
Continuous Pressure: 310 bar (4,495 psi)
Peak Pressure: 400 bar (5,800 psi)
Minimum Speed: 500 rpm
Rated Speed: 2,400 rpm
Maximum Speed: 2,800 rpm
Control Type: LS (Load Sensing) + PC (Pressure Compensator), factory setting PC 250 bar, LS stand-by 20 bar
Mounting Flange: SAE-C 4-Bolt
Rotation: Right hand (clockwise, viewed from shaft end)
Shaft Style: Straight keyed, 1.25 in
Shaft Seal: Viton (FKM)
Weight: Approx. 33 kg (Frame F reference)
Model Code Breakdown: FRR = Frame F, clockwise, open-circuit variable pump; 074 = displacement designation (74 cc); B = Frame F size; LS = load sensing control; 25 = pressure compensator setting (250 bar); 20 = LS stand-by pressure (20 bar); NN = no torque limiter; N3 = standard orifice configuration; S1B2 = shaft and port configuration; A1N = shaft seal and mounting flange options; subsequent fields define displacement limiter, special hardware, and paint options.
Key Technical Advantages
1. Dual Servo Piston Swashplate Support Design
Frame F pumps feature a dual servo piston design with the swashplate mounted on polymer-coated journal bearings, effectively reducing friction and vibration during swashplate movement. Compared to single servo piston designs, the dual servo configuration delivers faster response and more stable flow output under sudden load changes.
2. Bi-Metal Valve Plate with High Volumetric Efficiency
The cylinder block rides on a bi-metal valve plate optimized for high volumetric efficiency and low noise. At 310 bar continuous operating pressure, volumetric efficiency remains above 92%. Cylinder bores undergo precision lapping to achieve micron-level clearance with pistons.
3. Load Sensing + Pressure Compensator Combined Control
The LS control valve continuously monitors the pressure differential between system load and pump outlet, automatically adjusting swashplate angle to match actuator flow demand. When system pressure reaches the PC setting (factory 250 bar), pressure compensation activates automatically to limit maximum pressure and protect system components. LS stand-by pressure is set at 20 bar, maintaining only standby pressure during neutral conditions for energy-efficient operation.
4. Heavy-Duty Bearings with Through-Drive Capability
Tapered roller bearings handle combined axial and radial loads, supporting the input shaft and absorbing external shaft loads. The pump features standard through-drive capability, supporting tandem-mounted auxiliary pumps for multi-circuit hydraulic systems, reducing overall installation costs. L10 bearing life exceeds 10,000 hours under rated conditions.
5. Integrated Gauge Port and Gasket-Free Connections
The pump body integrates a gauge port for operating condition monitoring, facilitating on-site fault diagnosis and pressure verification. Hydraulic connections use gasket-free fittings, reducing potential leak points and improving system reliability.
Application Areas
Combine Harvesters: Claas Lexion series, John Deere S series, Case IH series
Tractors & Agricultural Machinery: Hydraulic hitch systems, steering systems, auxiliary output circuits
Wheel Loaders: Volvo L series, Cat 966 series
Excavators: Medium-to-large tracked and wheeled excavator hydraulic systems
Lifting Equipment: Truck cranes, knuckle-boom cranes hydraulic circuits
Industrial Hydraulics: Injection molding machines, die-casting machines, machine tool hydraulic power units
Expert Maintenance Tips
Pre-Installation Check: Verify shaft-to-drive alignment within 0.05 mm tolerance. Use flexible couplings to compensate for minor angular misalignment. Tighten SAE-C 4-Bolt flange bolts in diagonal sequence to specified torque, preventing housing distortion that could alter internal clearances.
First Start-Up: Fill the pump housing with clean hydraulic fluid to the overflow port level before starting—dry running is strictly prohibited. Run at no-load for 3–5 minutes during initial start-up, checking suction line sealing and case drain line flow. Use rigid tubing or high-pressure hose for LS control lines to prevent cavitation.
LS & PC Setting Adjustment: FRR074BLS is factory-set to PC 250 bar and LS stand-by 20 bar. If system adjustment is required, first adjust LS stand-by pressure, then adjust PC setting. After adjustment, bench verification is required to ensure pressure-flow characteristics meet system requirements.
Hydraulic Fluid Maintenance: ISO VG 46 anti-wear hydraulic fluid is recommended, with cleanliness level not lower than ISO 4406 18/16/13. Check fluid cleanliness every 500 hours; replace filter elements when differential pressure exceeds 3 bar. Investigate cooling system if oil temperature consistently exceeds 82°C.
Storage Requirements: During storage, the pump interior should remain filled with rust-preventive oil, with all ports sealed. Storage temperature range: -20°C to +60°C, avoiding direct sunlight and humid environments. After 12 months of storage, re-bench testing is recommended.
