A4VSO260LR2 Rexroth Axial Piston Pump 260cc 350 bar LR2

Product Overview

The A4VSO260LR2/30R-PPB25N00 is the 260 cc-class core model within the Bosch Rexroth A4VSO series of open-circuit axial piston variable displacement pumps. The A4VSO series features a swashplate design where pump flow is proportional to input drive speed and displacement, with output flow infinitely variable via swashplate angle adjustment. Flow direction changes smoothly when the swashplate is tilted across the neutral position.

Model Code Breakdown (for procurement and engineering reference):

• A4VSO: Rexroth open-circuit swashplate axial piston variable pump

• 260: Nominal size (NG), geometric displacement 260 cm³/rev

• LR2: Power controller with hyperbolic characteristic curve for perfect power utilization at constant rotational speed

• /30R: Series 30, clockwise rotation (viewed from shaft end)

• PPB25N00: PB = mounting flange and port code; 25 = port configuration (B and S ports are SAE side flanges at 90° to each other, metric threaded connections); N00 = additional configuration code

Drop-in Replacement Advantage: Manufactured to exact Rexroth OEM specifications, this pump achieves complete drop-in interchangeability with the original A4VSO series for ISO 3019-2 metric 4-hole mounting flange, shaft dimensions, port layout, and LR2 control module interface. Every pump undergoes 100% simulated load testing prior to shipment, validating 350 bar pressure loading, LR2 power control response, and volumetric efficiency under conditions replicating real-world duty cycles.

Technical Specifications 

Model A4VSO260LR2/30R-PPB25N00:

• Model Code: A4VSO260LR2/30R-PPB25N00

• Series: Rexroth A4VSO Series 30 (Open Circuit, Swashplate Design)

• Nominal Size: NG 260 (corresponding to standard size 250)

• Geometric Displacement: 260 cm³/rev (enhanced version of the 250 cm³/rev nominal size)

• Nominal Pressure: 350 bar (continuous)

• Peak Pressure: 400 bar (intermittent)

• Maximum Speed (at Vg max): 1500 rpm

• Maximum Flow (at Vg max and n nom): 375 L/min

• Maximum Power (at Δp = 350 bar): Approx. 219 kW

• Maximum Theoretical Torque (at Δp = 350 bar): Approx. 1391 N·m

• Control Type: LR2 — Power controller with hyperbolic characteristic curve, mechanically adjustable control start point

• Rotation: Clockwise (viewed from shaft end, /30R code)

• Mounting Flange: ISO 3019-2 metric, 4-hole, Ø224 mm

• Shaft: Cylindrical keyed shaft per DIN 6885 (code P)

• Main Ports: SAE side flanges, B and S ports at 90° to each other, metric threaded connections; second delivery port B1 on opposite side

• Housing Material: High-strength cast iron

• Seal Material: NBR, suitable for mineral oil-based hydraulic fluid

• Fluid Cleanliness: ISO 4406 18/15/12 or better

• Weight: Approx. 184–186 kg (without working fluid)

• Operating Temperature: 30–90°C

• Through Drive Capability: Supports mounting of subsequent pumps of same or smaller size

A4VSO Series Displacement Size Reference:

• A4VSO40: 40 cm³/rev, max speed 2600 rpm

• A4VSO71: 71 cm³/rev, max speed 2200 rpm

• A4VSO125: 125 cm³/rev, max speed 1800 rpm

• A4VSO180: 180 cm³/rev, max speed 1800 rpm

• A4VSO250/260: 250/260 cm³/rev, max speed 1500 rpm

• A4VSO355: 355 cm³/rev, max speed 1500 rpm

• A4VSO500: 500 cm³/rev, max speed 1320 rpm

• A4VSO750: 750 cm³/rev, max speed 1200 rpm

• A4VSO1000: 1000 cm³/rev, max speed 1000 rpm

Key Technical Advantages

1. LR2 Constant Power Control with Hyperbolic Characteristic
The A4VSO260LR2/30R-PPB25N00 is equipped with an LR2 power controller, whose core is precise control based on a hyperbolic characteristic curve. At constant drive speed, the LR2 controller automatically adjusts pump displacement according to system pressure, ensuring that hydraulic system power output always matches the available power of the engine (or electric motor). The control start point is mechanically adjustable for precise calibration to the actual prime mover characteristics. This control method is particularly suitable for industrial hydraulic systems requiring protection against prime mover overload under variable load conditions, effectively preventing stalling or lock-up.

2. Swashplate Design with High Volumetric Efficiency
The A4VSO series employs a swashplate axial piston rotary group design where swashplate inclination angle determines piston stroke and displacement. Pistons and cylinder bores are precision match-ground to micron-level clearances. Valve plate pre-compression and pre-decompression angles are optimized to minimize pressure spikes and flow pulsation. Volumetric efficiency remains above 95% at 350 bar continuous pressure. The swashplate configuration offers compact axial dimensions suitable for space-constrained industrial installations.

3. Long-Life Bearing System with Robust Design
The A4VSO series is renowned for exceptionally long service life, employing long-life, high-precision aviation-grade full roller bearings internally, with bearings selected through system-level load analysis for long-term stable operation at 350 bar continuous pressure and high speeds. The drive shaft is capable of absorbing axial and radial loads, enhancing system design flexibility.

4. Excellent Suction Characteristics with Low Noise Operation
The A4VSO series delivers excellent suction characteristics, with optimized suction flow passages reducing cavitation risk and aeration damage. The housing is precision-cast from high-strength cast iron, with the material’s damping characteristics effectively suppressing structural vibration and fluid-borne noise, achieving industry-leading noise levels.

5. Through Drive and System Expansion Capability
The A4VSO series supports through drive, allowing direct mounting of subsequent pumps of same or smaller size on the rear of the main pump for single-motor multi-pump compound hydraulic systems. This modular design provides flexibility for system expansion and customization without significant modifications to existing mounting foundations. The through-drive shaft specification and torque capacity must be matched to the power requirements of the subsequent pump.

Application Areas

• Metallurgical Equipment: Continuous casting machine hydraulic systems, rolling mill hydraulic screwdown devices, steelmaking furnace hydraulic power sources

• Forging Equipment: Open-die forging presses, closed-die forging press main hydraulic pumps

• Mining & Tunneling: Tunnel boring machine thrust hydraulic systems, mine hoist hydraulic drives

• Cement & Building Materials: Roller press hydraulic systems, vertical mill hydraulic loading devices

• Marine & Offshore: Deck machinery hydraulic systems, large steering gear hydraulic power units

• Test Equipment: Large hydraulic test benches, fatigue testing machine hydraulic power sources

• Power Generation: Turbine bypass system hydraulic actuators, hydro turbine governor hydraulic systems

Expert Maintenance Tips

1. Hydraulic Fluid Cleanliness
The A4VSO series LR2 power control spool operates with extremely tight clearances and is highly sensitive to particulate contamination. System fluid cleanliness must meet ISO 4406 18/15/12 or better. Install a 10 μm absolute-rated filter element at the pump inlet. Replace elements at 500 hours after first commissioning, then every 1,000 operating hours or 6 months, whichever comes first.

2. LR2 Power Controller Setting and Adjustment
The LR2 power controller control start point is mechanically adjustable. During commissioning, first determine the power control curve start point based on the prime mover’s power characteristics, then set the system pressure control value. Mechanical adjustment of the power control start point should be performed with the pump at neutral (zero displacement). The power control setting must ensure that the system does not exceed the prime mover’s available power at maximum working pressure. Notice: The power controller is not a safeguard against pressure overload. A pressure relief valve must be installed in the hydraulic system.

3. Case Drain Line Requirements
The case drain line must return directly to the reservoir. Maximum permissible back pressure is 2 bar (0.2 MPa). The drain outlet must terminate below oil level at all times to prevent air ingestion. The drain line diameter must not be smaller than the pump case drain port size. For 260 cc class large displacement pumps, case drain flow is substantial — drain line design must fully account for flow demand to avoid excessive case pressure from pipe resistance.

4. Pre-Start Priming and Air Bleeding
Before first start, fill the pump housing with clean hydraulic fluid through the case drain port. After installation, turn the drive shaft by hand several revolutions to confirm free rotation without binding. Start at low speed with zero load and run for 5–10 minutes. Verify continuous bubble-free flow from the case drain. Only then apply load.

5. Through Drive End Maintenance
If equipped with through drive, regularly inspect rear pump mounting bolt tightness and spline connection wear. The through-drive end bearing is lubricated by the pump’s internal case drain circuit — no additional maintenance required. However, the rear pump’s power demand must not exceed the through-drive rated torque capacity. Inspect through-drive end bolt torque at 500 hours after first commissioning, then recheck every 2,000 operating hours.