A4VG125EP2DM1/32R-NZF02N00XEH-S Rexroth Piston Pump 125cc 400bar

Product Overview

The A4VG125EP2DM1/32R-NZF02N00XEH-S is a Bosch Rexroth A4VG Series swashplate-type axial piston variable displacement pump. The A4VG Series is Rexroth’s high-pressure pump line for closed-circuit hydrostatic drive applications, covering displacements from 28 to 250 cm³/rev. The A4VG125 delivers a maximum displacement of 125 cm³/rev.

This model features EP2D control—Electro-hydraulic proportional displacement control, enabling remote, precise displacement adjustment via electrical signals for stepless flow regulation. 32R denotes the Series 32 design platform with Right-hand rotation configuration. NZF02N00XEH-S is the shaft, mounting flange, and port configuration code. The corresponding Rexroth material number (Artikelnummer) is R902061001.

As a direct OEM-equivalent replacement solution for the Bosch Rexroth A4VG Series, this product offers complete in-situ interchangeability, strictly adhering to Rexroth’s original design specifications and mounting interface standards. Every unit undergoes 100% simulated duty-cycle testing, ensuring that key performance metrics—including volumetric efficiency, pressure-flow characteristics, and case drain flow at rated pressure and full displacement—meet or exceed original factory specifications.

Technical Specifications 

• Model Number: A4VG125EP2DM1/32R-NZF02N00XEH-S

• Rexroth Material Number (Artikelnummer): R902061001

• Brand Series: Bosch Rexroth A4VG Series (Series 32)

• Pump Type: Swashplate Axial Piston Variable Displacement Pump (Closed Circuit)

• Maximum Displacement: 125 cm³/rev (125 ml/r)

• Nominal Pressure: 400 bar

• Maximum Pressure (Peak): 450 bar

• Rated Speed: 1500 rpm

• Control Type: EP2D – Electro-hydraulic Proportional Displacement Control

• Rotation Direction: R – Right-hand (clockwise from shaft end)

• Design Series: Series 32

• Charge Pump: Integral built-in charge pump (for boost and pilot oil supply)

• Mounting Type: Flange Mounting

• Housing Material: Cast Iron

• Weight: Approx. 85–95 kg (configuration dependent)

• Hydraulic Fluid: Mineral Oil

• Operating Temperature Range: 30–90°C

• Nominal Pressure (MPa): 32 MPa

Key Technical Advantages

1. Closed-Circuit Dedicated Design with High System Integration
The A4VG Series is specifically designed for closed-circuit hydrostatic applications, featuring an integral built-in charge pump that provides system replenishing oil, cooling flow, and control pilot pressure. This design eliminates the need for an external charge pump, significantly simplifying system layout. Flow direction changes when the swashplate is moved through the neutral position, enabling seamless forward/reverse transitions in mobile machinery.

2. 400 bar Nominal Pressure with 450 bar Peak Capacity – Industry Leading
The A4VG125 delivers a nominal pressure of 400 bar with peak pressures up to 450 bar. At 125 cm³/rev displacement, this pressure rating provides substantial power reserves for closed-circuit hydrostatic drives, enabling the pump to withstand extreme pressure shocks encountered in excavators, pavers, and other mobile equipment under heavy-load conditions.

3. EP2D Electro-Hydraulic Proportional Control for Remote Precision Displacement Adjustment
The EP2D control configuration enables remote displacement regulation via electrical signals, delivering stepless flow adjustment from 0 to 125 cm³/rev. With a response speed of ≤20 ms, it dynamically matches complex operating conditions and load demands. This control approach is particularly suited for modern mobile equipment requiring integration with electronic control systems (ECU, PLC).

4. High Power Density with Compact Design
The A4VG Series employs a swashplate axial piston design that delivers exceptionally high power density within a compact footprint. The Series 32 design platform further optimizes rotating group components while maintaining high reliability, enhancing overall efficiency. The A4VG125 outputs substantial hydraulic power at 400 bar, providing ample power reserves for mobile equipment.

5. Excellent Low-Noise Performance with Long Service Life
The A4VG Series is renowned for its low noise level, short response times, and favorable power-to-weight ratio. The optimized swashplate and piston/slipper friction pair design, combined with precision manufacturing processes, ensures reliable and stable performance over long-term continuous operation. High-precision friction pairs and long-life bearings together form the technical foundation that makes this series a benchmark in closed-circuit applications.

Application Areas

• Excavators: Closed-circuit travel drive pump providing high-pressure hydraulic power for travel motors

• Pavers: Core power element for hydrostatic travel drive systems

• Rollers: Closed-circuit vibration and travel drives

• Concrete Mixer Trucks: Hydrostatic drive for mixer drum rotation

• Agricultural Machinery: Hydrostatic drive systems for large combine harvesters and tractors

• Material Handling Equipment: Travel drives for reach stackers and heavy forklifts

Expert Maintenance Tips

1. Model Confirmation & Pre-Installation Inspection: Prior to installation, confirm the complete model code as A4VG125EP2DM1/32R-NZF02N00XEH-S with Rexroth material number R902061001. This is a Series 32 right-hand rotation configuration. Verify that the SAE flange mounting specification and splined shaft type match the host machine PTO interface. Manually rotate the shaft before installation to confirm smooth, obstruction-free rotation.

2. Closed-Circuit Air Purge & Charge: The A4VG Series is a closed-circuit design—ensure thorough system air purge before first start-up. Air in the closed circuit can cause cavitation, noise, and performance degradation. After start-up, run at low speed with repeated direction changes to purge air from both high and low pressure circuits.

3. Fluid Cleanliness Control: Closed circuits have stringent fluid cleanliness requirements. A minimum filtration rating of ISO 18/15 is recommended. Complete system flushing is mandatory before initial start-up. Rexroth A4VG Series recommends using high-quality mineral hydraulic fluid meeting specifications.

4. EP2D Electro-Hydraulic Proportional Controller Tuning: The EP2D control configuration regulates displacement via electrical signals. Commissioning requires coordination with a proportional amplifier or PLC controller for parameter setting. Verify that the linear relationship between electrical signal and displacement output meets specifications. Perform initial settings under no-load conditions, then gradually increase load to target operating conditions with fine adjustments.

5. Charge Pressure Verification: The A4VG Series features an integral built-in charge pump. After first start-up, verify charge pressure is within specification range. Low charge pressure causes sluggish control response and inadequate piston/slipper lubrication; excessive charge pressure may cause system overheating.

6. Case Drain Port Positioning & Pressure Monitoring: During installation, ensure the drain port is positioned higher than the pump body to prevent oil starvation in the pump chamber after shutdown. Case pressure must not exceed 1.5 bar (absolute) . Install a pressure gauge on the case drain line for real-time monitoring.