GRR090RPC21NNNN3S1B2A1NCAANNNN Sauer Danfoss Piston Pump 90cc

Product Overview

The GRR090RPC21NNNN3S1B2A1NCAANNNN is a Sauer Danfoss (now Danfoss) Series 45 Frame G open-circuit variable displacement axial piston pump with a nominal displacement of 90 cm³ (5.49 in³), continuous operating pressure of 310 bar (4495 psi), peak pressure of 400 bar (5800 psi), maximum speed of 2400 rpm, minimum speed of 500 rpm, and weight of approximately 33.5 kg. The pump employs a swashplate-type axial piston variable mechanism, specifically designed for open-circuit hydraulic systems in mobile machinery, delivering output flow proportional to drive speed and displacement, with stepless displacement variation via swashplate angle adjustment.

Series 45 Frame G pumps offer two control options: load sensing with pressure compensator (LS+PC) or pressure compensator only (PC). The “RPC” in the GRR090RPC21NNNN3S1B2A1NCAANNNN model code corresponds to load sensing with pressure compensator combined control, achieving intelligent on-demand flow supply and constant pressure holding through coordinated pressure feedback and flow demand control. The pump features an SAE-C2 two-bolt mounting flange and SAE-C 14-tooth splined shaft (shaft diameter 31.2 mm), with FKM (Viton®) shaft seals rated for a wide temperature range of -40 ℃ to +104 ℃.

Series 45 GRR/GRL pumps are widely deployed in Claas combine harvesters, Liebherr truck-mounted and boom cranes, telehandlers, backhoe loaders, asphalt pavers, and mining equipment. The series is also compatible with John Deere tractor hydraulic systems.

The GRR090RPC21NNNN3S1B2A1NCAANNNN features mounting flange (SAE-C2 two-bolt, 180 mm hole circle), SAE-C 14-tooth splined shaft, and port layouts conforming to Sauer Danfoss Series 45 Frame G standards, enabling drop-in interchangeability with same-series GRR074, GRL074, and GRL090 models.

Every GRR090RPC21NNNN3S1B2A1NCAANNNN undergoes 100% simulated duty-cycle testing prior to shipment — covering pressure holding, flow output, control response, and internal leakage — ensuring complete drop-in interchangeability with original Sauer Danfoss pumps without installation or plumbing modifications.

Technical Specifications

• Model: GRR090RPC21NNNN3S1B2A1NCAANNNN

• Brand: Sauer Danfoss (now Danfoss)

• Series: Series 45 Frame G

• Pump Type: Open-circuit swashplate axial piston variable displacement pump

• Nominal Displacement: 90 cm³/rev (5.49 in³/rev)

• Continuous Operating Pressure: 310 bar (4495 psi)

• Peak Pressure: 400 bar (5800 psi)

• Maximum Speed (at peak pressure): 2200 rpm

• Maximum Speed (continuous): 2400 rpm

• Minimum Speed: 500 rpm

• Control Type: LS+PC (load sensing + pressure compensator)

• Direction of Rotation: Right (clockwise, viewed from shaft end)

• Mounting Flange: SAE-C2 two-bolt flange (hole circle 180 mm, recess 127.0 mm)

• Shaft Type: SAE-C 14-tooth splined shaft (12/24 DP), shaft diameter 31.2 mm

• Shaft Seal Material: FKM/FPM (Viton®)

• Housing Material: Cast iron

• Weight: Approx. 33.5 kg

• Oil Viscosity Range: 9–110 cSt (recommended)

• Fluid Cleanliness Requirement: ISO 4406 22/18/13

• Operating Temperature Range: -40 to +104 ℃

• Fluid Compatibility: Mineral-based hydraulic oil

• OEM Reference Numbers: 90623 (90R180+GRR090C), 90693 (90R180+GRR090C)

Series 45 Frame G Same-Family Displacement Reference:

• GRR074 / GRL074: 74 cm³/rev (4.52 in³/rev), 310 bar nominal, 400 bar peak, min 500 rpm, max approx. 2400 rpm

• GRR090 / GRL090: 90 cm³/rev (5.49 in³/rev), 310 bar nominal, 400 bar peak, min 500 rpm, max approx. 2400 rpm

• FRR074: 74 cm³/rev, 310 bar nominal, 400 bar peak, max 2400 rpm

• FRR090: 90 cm³/rev, 310 bar nominal, 400 bar peak, max 2400 rpm

Key Technical Advantages

1. LS+PC Load Sensing + Pressure Compensator Control — Intelligent Flow Matching and Energy Savings

The GRR090RPC21NNNN3S1B2A1NCAANNNN features load sensing with pressure compensator (LS+PC) combined control, one of the two standard control options for Series 45 Frame G pumps. Load sensing precisely matches pump output flow to actual system demand, eliminating relief losses; pressure compensation automatically reduces displacement to only leakage flow when system pressure reaches the set point. Combined, these functions deliver significant energy savings under variable load conditions while reducing system oil temperature and extending fluid and component life. The LS control acts as the pump’s flow regulator, coordinating pump working volume with system consumption based on differential pressure, improving system dynamic characteristics and maintaining high drive efficiency.

2. 310 bar High-Pressure Capability — Industry-Leading Power Density

The GRR090 delivers a continuous operating pressure of 310 bar and peak pressure of 400 bar, with power density leading among comparable open-circuit piston pumps. The 90 cm³/rev displacement combined with 2400 rpm maximum speed provides robust hydraulic power output within a compact installation envelope, meeting the demands of heavy-duty mobile machinery. The swashplate axial piston design with optimized rotary group and valve plate flow passages, along with reinforced housing construction, maintains stable volumetric efficiency and long service life at 310 bar continuous working pressure.

3. Compact Lightweight Design — 33.5 kg Class-Leading Power-to-Weight Ratio

The GRR090 weighs only approximately 33.5 kg at 90 cm³/rev displacement, featuring compact, lightweight design with power-to-weight ratio leading among comparable products. The Series 45 Frame G is renowned for its compact structure and high power density, suitable for the limited installation space of mobile machinery. The pump features SAE-C2 standard mounting flange and SAE-C 14-tooth splined shaft for simple installation and direct connection to mobile machinery drive systems.

4. Wide Temperature Range and Excellent Media Compatibility

The GRR090 features FKM (Viton®) shaft seals rated for a wide temperature range of -40 ℃ to +104 ℃, meeting the demands of cold climate and high-temperature operating conditions. The pump is compatible with mineral-based hydraulic oil, with recommended oil viscosity of 9–110 cSt and fluid cleanliness requirement of ISO 4406 22/18/13. The wide viscosity and temperature ranges enable the pump to adapt to various outdoor working environments from cold winters to hot summers.

5. Exceptional Field Interchangeability and Broad Compatibility

The GRR090RPC21NNNN3S1B2A1NCAANNNN features SAE-C2 two-bolt mounting flange, SAE-C 14-tooth splined shaft, and port layouts conforming to Sauer Danfoss Series 45 Frame G standards, enabling drop-in interchangeability with same-series GRR074, GRL074, GRL090, FRR074, and FRR090 models. The pump is widely deployed in Claas combine harvesters, Liebherr cranes, telehandlers, backhoe loaders, asphalt pavers, mining equipment, and John Deere tractors, installing directly without modifying mounting interfaces or plumbing layouts.

Application Areas

• Agricultural Machinery: Claas Lexion combine harvester hydraulic systems, John Deere tractor hydraulic hitch and auxiliary systems

• Lifting Machinery: Liebherr truck-mounted and boom crane hydraulic swing and hoist systems

• Construction Machinery: Telehandler, backhoe loader, and mini excavator hydraulic systems

• Road Machinery: Asphalt paver travel drive and working device hydraulic systems

• Mining Equipment: Mining machinery hydraulic power systems

• Dozers: Crawler dozer hydraulic drive systems

The GRR090RPC21NNNN3S1B2A1NCAANNNN is ideally suited for mobile machinery open-circuit hydraulic systems requiring 310 bar continuous working pressure and displacements in the 90 cm³/rev range — the classic configuration for combine harvester and crane hydraulic systems.

Expert Maintenance Tips

1. Shaft Alignment and Coupling Requirements

Maintain concentricity between the pump shaft and drive shaft within 0.05 mm. Flexible couplings are strongly recommended to accommodate minor angular misalignment. The GRR090RPC21NNNN3S1B2A1NCAANNNN weighs approximately 33.5 kg — use appropriate lifting equipment during installation and never strike the shaft end. Tighten SAE-C2 two-bolt mounting flange bolts in diagonal sequence to the specified torque. The SAE-C 14-tooth splined shaft (12/24 DP) engagement with the drive coupling should ensure sufficient spline engagement length.

2. Pre-Start Priming Procedure

Before initial startup, the pump must be slowly filled through the case drain port with clean hydraulic oil to ensure adequate lubrication, cooling, and sealing during startup. Start the pump in jog mode until the pump and piping are sufficiently filled and vented. After complete venting, run at low pressure for 5–10 minutes, check piping and component tightness, then gradually increase to rated pressure.

3. LS+PC Controller Commissioning

Commission the LS+PC load sensing + pressure compensator controller ensuring coordination between load sensing differential and pressure compensation setting. The pressure compensation setting should be at least 10–15 bar below the system relief valve setting. The load sensing differential should be adjusted according to actual system requirements. During commissioning, first turn the control setting screw to the lowest pressure position, then gradually increase to the target pressure. Adjustment must be performed with the pump at full displacement and low operating pressure to avoid system pressure oscillation.

4. Fluid Cleanliness and Filtration

The GRR090RPC requires fluid cleanliness of ISO 4406 22/18/13. Use pressure line filters with a filtration ratio β10 ≥ 75 (per ISO 4572). Avoid suction filters, which increase suction resistance and cavitation risk. Recommended oil viscosity range is 9–110 cSt. Install a breather filter with filtration accuracy ≤10 μm on the reservoir and regularly check oil level and fluid condition.

5. Restart Procedure After Extended Shutdown

If the pump has been idle for more than 30 days, manually rotate the shaft several turns to verify free rotation before restarting. Check for abnormal leakage at the case drain port. After startup, operate at low pressure for 10–15 minutes until oil temperature reaches normal operating range before applying full load. Regularly inspect the splined shaft and drive coupling engagement during operation, ensuring sufficient spline engagement length.