A11VLO260LG1S/11R-NZD12K02-S Rexroth Pump 260cc 350bar LG1S

Product Overview

The A11VLO260LG1S/11R-NZD12K02-S is a Bosch Rexroth A11VLO Series size 260 swashplate-type axial piston variable pump, Series 11, with a nominal displacement of 260 cm³/rev, nominal pressure of 350 bar, and maximum pressure of 400 bar. The pump is designed for open circuit hydrostatic drives, with output flow proportional to drive speed and displacement and stepless flow adjustment achieved by changing the swashplate angle.

The “L” in A11VLO indicates the pump is equipped with a built-in charge pump (impeller pump), enabling self-priming operation and higher allowable speeds. The pump body supports 100% through drive, suitable for tandem mounting of gear pumps and axial piston pumps of the same size, providing flexible expansion for multi-circuit systems. The series covers displacements from 40 to 260 cm³/rev, serving as Rexroth’s all-purpose high-pressure pump platform for mobile machinery.

The model code A11VLO260LG1S/11R-NZD12K02-S contains comprehensive configuration information: 260 for nominal size (260 cm³/rev displacement); LG1S for pilot-pressure related power control override, which overrides the power controller setting via external pilot pressure signal acting on the power regulator adjustment spring through port Z; the “S” suffix indicates pressure cut-off function; 11 for series designation (Series 11); R for clockwise rotation (viewed from shaft end); NZD12K02 for shaft, port, and mounting option codes. Material number is R902233799.

Manufactured to exact Rexroth OEM specifications, all mounting dimensions, flange interfaces, and port layouts are fully consistent with the original pump for true drop-in interchangeability. Every unit undergoes 100% simulated operating condition testing before shipment.

Technical Specifications 

• Model: A11VLO260LG1S/11R-NZD12K02-S

• Material Number: R902233799 (also R902233800)

• Series: Rexroth A11VLO Series 11

• Pump Type: Swashplate axial piston variable pump, open circuit

• Nominal Displacement (Vg max): 260 cm³/rev

• Displacement Range: 0 – 260 cm³/rev (stepless variable)

• Nominal Pressure (pnom): 350 bar (5,100 psi)

• Maximum Pressure (pmax): 400 bar (5,800 psi)

• Maximum Speed (at Vg max): 1,800 rpm

• Maximum Speed (at Vg ≤ Vg max): 2,300 rpm

• Theoretical Flow at 1800 rpm (Vg max): 468 L/min

• Maximum Power (at Δp = 350 bar): 273 kW (366 hp)

• Maximum Torque (at Δp = 350 bar): 1,448 N·m (1,068 lb-ft)

• Control Type: LG1S — Pilot-pressure related power control override with pressure cut-off

• Rotation Direction: Clockwise (R — viewed from shaft end)

• Mounting Type: Flange mounting

• Charge Pump: Integrated impeller pump (L configuration)

• Through Drive: 100% through drive

• Weight (approx.): 138 kg

• Rotary Group Moment of Inertia: 0.0878 kg·m²

• Maximum Angular Acceleration: 4,800 rad/s²

• Recommended Hydraulic Fluid: HL / HLP mineral oil per DIN 51524

• Fluid Viscosity Range: 10–1,000 cSt

Key Technical Advantages

1. LG1S Pilot-Pressure Related Power Control for Remote Power Adjustment: The LG1S control is the defining technical feature of this model. The power control regulates pump displacement depending on operating pressure to ensure a given drive power is not exceeded at constant drive speed. In the pilot-pressure related override, an external pilot pressure signal acts on the power regulator adjustment spring via port Z, enabling remote override adjustment of the power setting. The “S” suffix adds pressure cut-off functionality that rapidly reduces displacement to zero when system pressure reaches the set value, providing system safety protection. This control type enables operators or machine control systems to remotely switch power curves based on operating conditions (e.g., fine-operation mode vs. high-efficiency mode) for optimal power matching.

2. Integrated Charge Pump (Impeller Pump) with High-Speed Capability: The “L” designation in A11VLO indicates an integrated built-in charge pump (impeller pump). This charge pump enables self-priming operation and achieves significantly higher allowable speeds — up to 1,800 rpm at Vg max and 2,300 rpm at Vg ≤ Vg max, substantially exceeding the A11VO version without charge pump. The integrated charge pump supplies replenishing and cooling oil flow without external charge pump piping, simplifying machine hydraulic plumbing.

3. 100% Through Drive with Multi-Pump Tandem Flexibility: The A11VLO260 supports 100% through drive, suitable for tandem mounting of gear pumps and axial piston pumps of the same size, with combined drive torque not exceeding the front pump shaft’s load capacity. This feature enables equipment manufacturers to integrate multiple hydraulic pumps on a single drive interface, providing flexible expansion for multi-circuit hydraulic systems while reducing piping connections and installation space. The LRC cross-sensing control feature also enables constant total power for two same-size power-controlled pumps.

4. High-Pressure Large-Flow Output with High Power Density: The A11VLO260 delivers 350 bar nominal pressure and 273 kW maximum power output at 260 cm³/rev displacement, with theoretical flow up to 468 L/min and maximum torque of 1,448 N·m. The compact swashplate design weighs approximately 138 kg, delivering an excellent power-to-weight ratio in its displacement class. High-strength cast iron housing and wear-resistant alloy steel rotating components ensure long-term stable operation at 400 bar peak pressure.

5. A11VLO Series Drop-In Interchangeability with Complete Series Coverage: The A11VLO series covers displacements from 40 to 260 cm³/rev, with high consistency in mounting flanges, shaft ends, and ports across sizes within the series. The A11VLO260LG1S/11R-NZD12K02-S’s mounting dimensions are fully consistent with the original pump, enabling drop-in replacement without piping or coupling modification — dramatically reducing equipment downtime. The pump is compatible with the complete A11VLO260 product line, widely used in excavators, concrete pump trucks, cranes, hydraulic drilling rigs, roadheaders, and shield machines.

Application Areas

• Construction Machinery: Excavators (including 30-ton class and above), wheel loaders, cranes — main hydraulic pumps

• Concrete Pumping Machinery: Concrete pump trucks, concrete wet spray machines — hydraulic drive systems

• Mining and Tunneling Equipment: Hydraulic drilling rigs, roadheaders, shield machines

• Piling Machinery: Rotary drilling rigs, static pile drivers

• Marine Hydraulics: Ship deck machinery, steering gear hydraulic power sources

• Industrial Hydraulics: Large hydraulic presses, test stand hydraulic power units

Expert Maintenance Tips

1. Shaft Alignment and Flange Connection: Concentricity deviation between the pump and drive shaft must be less than 0.05 mm, with angular deviation less than 0.25°. The A11VLO260 weighs approximately 138 kg — use appropriate lifting equipment during installation. Tighten flange bolts in diagonal sequence for even loading and check the locating step for integrity.

2. Initial Start-Up Filling and Bleeding: Pre-fill the pump with clean HL/HLP mineral oil through the case drain port before installation. The A11VLO model features an integrated charge pump — during initial start-up, also verify proper operation of the charge pump circuit. Start at the lowest drive speed and observe a steady oil flow from the case drain port free of bubbles.

3. LG1S Control Setting Verification: The LG1S control power setting and pilot pressure override range are factory-calibrated to standard specifications. After pump replacement, verify settings match the original system using calibrated pressure gauges and confirm proper response of the pilot pressure signal (port Z). The pressure cut-off setting must be verified separately. Record original settings before adjustment for restoration.

4. Rotation Direction Verification: This model is clockwise rotation (R — viewed from shaft end). Driving it counter-clockwise is strictly prohibited — incorrect drive direction will reverse the suction and pressure sides, causing severe rotating group damage within a short period.

5. Fluid Cleanliness and Viscosity Management: Use HL / HLP mineral oil with a viscosity range of 10–1,000 cSt. System filtration should achieve β10 ≥ 75. The integrated charge pump requires high fluid cleanliness. Replace filter elements after the first 500 operating hours, then every 1,000 hours or annually thereafter.

6. Through Drive Application Notes: When using through drive for tandem mounting of multiple pumps, ensure proper coupling alignment between pumps and verify that the combined drive torque does not exceed the front pump shaft’s load capacity. Consult factory technical support for combination configuration confirmation.