A4VG71DA1D7/32R-NZF02F021SH Rexroth Pump 71cc 400bar Closed Circuit

Product Overview (Model 1: A4VG71DA1D7/32R-NZF02F021SH)

The A4VG71DA1D7/32R-NZF02F021SH (Material Number: R902055346) is a member of the Bosch Rexroth A4VG Series 32 swashplate-type axial piston variable displacement pump family. With a geometric displacement of 71 cm³/rev, this pump is specifically designed for closed-circuit hydrostatic transmission applications.

The A4VG Series represents Rexroth’s high-performance axial piston pump platform for closed-circuit hydrostatic drives, with displacement sizes ranging from 28 to 250 cm³/rev, widely deployed in mobile machinery and industrial equipment hydrostatic drive systems. This model is equipped with DA1 electronic-hydraulic proportional control, enabling stepless displacement adjustment and flow direction reversal via electrical signals—making it an ideal choice for modern electronically controlled hydrostatic drive systems.

Engineered as a premium drop-in replacement for Bosch Rexroth original hydraulic pumps, this unit strictly adheres to Rexroth A4VG Series 32 design standards and manufacturing specifications, ensuring complete interchangeability — mounting flange interfaces, port configurations, and control logic are fully compatible with the original OEM model, requiring zero field modification for direct replacement.

Every unit undergoes 100% simulated duty-cycle testing — full performance curve validation under rated pressure (400 bar), rated speed, and expected operating temperature ranges — guaranteeing volumetric efficiency, response characteristics, and noise levels that meet or exceed Rexroth factory specifications.

Technical Specifications (Model 1)

• Model Code: A4VG71DA1D7/32R-NZF02F021SH

• Material Number: R902055346

• Series: Bosch Rexroth A4VG Series 32, Swashplate Axial Piston Variable Pump

• Maximum Geometric Displacement (Vg max): 71 cm³/rev

• Rated Operating Pressure (Continuous): 400 bar

• Peak Pressure (Intermittent): 450 bar

• Maximum Flow Rate: 234 L/min

• Maximum Speed: 3300 rpm

• Control Type: DA1 — Electronic-Hydraulic Proportional Control

• Design Series: Series 32

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

• Shaft Type: Z — Splined Shaft DIN 5480

• Mounting Flange: F — SAE J744 2+4 Hole Flange

• Port Configuration: 02 — SAE Working Ports A and B (top and bottom), Suction Port S (bottom)

• Charge Pump: Integrated charge pump for feed and control oil supply

• Circuit Type: Closed Circuit

• Weight: Approx. 50–56 kg

Product Overview (Model 2: A4VG71HD1DM3R/32L-NZF02F001D)

The A4VG71HD1DM3R/32L-NZF02F001D is a member of the Bosch Rexroth A4VG Series 32 swashplate-type axial piston variable displacement pump family. With a geometric displacement of 71 cm³/rev, this pump is specifically designed for closed-circuit hydrostatic transmission applications.

This model is equipped with HD1 hydraulic control, enabling stepless displacement adjustment and flow direction reversal via hydraulic pilot signals—making it an ideal choice for traditional hydraulic pilot-controlled hydrostatic drive systems. HD1 control offers fast response and excellent disturbance rejection, particularly suited for mobile machinery applications with extreme reliability requirements.

Engineered as a premium drop-in replacement for Bosch Rexroth original hydraulic pumps, this unit strictly adheres to Rexroth A4VG Series 32 design standards and manufacturing specifications, ensuring complete interchangeability — mounting flange interfaces, port configurations, and control logic are fully compatible with the original OEM model, requiring zero field modification for direct replacement.

Every unit undergoes 100% simulated duty-cycle testing — full performance curve validation under rated pressure (400 bar), rated speed, and expected operating temperature ranges — guaranteeing volumetric efficiency, response characteristics, and noise levels that meet or exceed Rexroth factory specifications.

Technical Specifications (Model 2)

• Model Code: A4VG71HD1DM3R/32L-NZF02F001D

• Series: Bosch Rexroth A4VG Series 32, Swashplate Axial Piston Variable Pump

• Maximum Geometric Displacement (Vg max): 71 cm³/rev

• Rated Operating Pressure (Continuous): 400 bar

• Peak Pressure (Intermittent): 450 bar

• Maximum Flow Rate: 234 L/min

• Maximum Speed: 3300 rpm

• Control Type: HD1 — Hydraulic Control

• Design Series: Series 32

• Rotation Direction: L — Counterclockwise (viewed from shaft end)

• Shaft Type: Z — Splined Shaft DIN 5480

• Mounting Flange: F — SAE J744 2+4 Hole Flange

• Port Configuration: 02 — SAE Working Ports A and B, Suction Port S

• Charge Pump: Integrated charge pump for feed and control oil supply

• Circuit Type: Closed Circuit

• Weight: Approx. 50–56 kg

Key Technical Advantages (Applicable to Both Models)

1. Swashplate Variable Design & Closed-Circuit Optimized Architecture

The proven swashplate axial piston design enables stepless displacement adjustment by varying the swashplate angle. Flow direction reversal is achieved smoothly as the swashplate passes through the zero position, eliminating the need for directional valves in actuator reversal control. Internally optimized fluid passages specifically for closed-circuit applications ensure stable charge pressure and heat dissipation under high-pressure, high-speed operating conditions.

2. Ultra-High Pressure Capability & Extended Service Life

Rated operating pressure reaches 400 bar (40 MPa) with peak pressure capability of 450 bar (45 MPa). High-strength nodular cast iron housings and precision-machined rotating assemblies, combined with hardened piston-slipper friction pairs and long-life tapered roller bearings, maintain minimal wear rates and long-term reliable operation under continuous high-pressure duty.

3. Integrated Charge Pump & Comprehensive Safety Protection

An integrated charge pump is standard equipment, providing continuous charge and cooling flow to the closed circuit, ensuring adequate low-side pressure under all operating conditions. Integrated high-pressure relief valves with feed function protect the pump and actuators during system overload events. Adjustable pressure cut-off is standard, effectively preventing system overpressure.

4. Low Noise & Low Pulsation Operation

The nine-piston design, combined with optimized port plate timing, effectively reduces output flow pulsation and pressure fluctuations. Continuous stepless swashplate angle adjustment enables smooth flow transition from zero to maximum, ensuring precise synchronization between actuator speed and command input for impact-free, low-noise operation.

5. Thru-Drive Capability & Modular Design

Full-power thru-drive capability supports tandem mounting of additional pumps of the same or smaller nominal size without additional power input. Modular design supports flexible configuration of multiple control options (DA1, HD1, HD3, HW, DG, EP3, EP4, EZ1, EZ2, etc.) to meet diverse application control requirements.

6. Complete Drop-In Interchangeability & Standardized Interfaces

Strictly manufactured to original Rexroth A4VG Series 32 micro-metric factory blueprints. SAE standard mounting flanges and port configurations align flawlessly with original factory specifications. Field replacement requires zero piping modifications or control logic changes, dramatically minimizing equipment downtime.

Application Areas

• Hydrostatic Travel Drives — Wheel loaders, telescopic handlers, mining trucks

• Crawler Travel Drives — Crawler excavators, bulldozers, pavers

• Concrete Mixer Drum Drives

• Agricultural Machinery Hydrostatics — Combine harvesters, forage harvesters

• Industrial Hydrostatic Transmissions

• Road Construction Machinery — Rollers, milling machines

Expert Maintenance Tips

1. Case Fill & Air Bleeding Before Start-up

Prior to first start-up, fill the pump housing with clean hydraulic fluid through the highest case drain port to ensure complete pre-lubrication of all bearings and rotating components. For closed-circuit systems, ensure charge pump has established adequate charge pressure (typically no less than 20 bar) before start-up. Run at low speed without load for at least 2-3 minutes after start-up, and only apply load after the system is fully purged of air.

2. Fluid Cleanliness Management

A4VG Series pumps are ultra-high-pressure precision hydraulic components highly sensitive to fluid contamination. Maintain system fluid cleanliness at or above the recommended ISO 18/16/13 level. Use full-flow return filters with minimum 10μm absolute rating (β₁₀≥100) and conduct regular fluid sampling analysis (recommended every 500 operating hours).

3. DA1 Electronic Control Setting & Calibration (Model 1)

DA1 electronic-hydraulic proportional control settings should be adjusted after the pump reaches operating temperature and the system is fully purged. The relationship between control current and displacement output should be calibrated per Rexroth standard characteristic curves. Use a current source and pressure sensor with accuracy class 0.5 or better for setting verification. Adjust control current slowly while observing system response to avoid abrupt impacts.

4. HD1 Hydraulic Control Setting & Calibration (Model 2)

HD1 hydraulic control pilot pressure settings should be adjusted after the pump reaches operating temperature. The relationship between pilot pressure and displacement output should be calibrated per Rexroth technical manual specifications. The pilot oil circuit should use independent filtration to ensure pilot oil cleanliness meets or exceeds system oil requirements.

5. Charge Pressure & System Temperature Monitoring

Charge pressure is a critical parameter for proper pump operation in closed-circuit systems. Regularly verify charge pump outlet pressure (typically set at 20–25 bar) remains within specification. Install continuous oil temperature monitoring to ensure fluid temperature does not exceed 80°C. Charge filters should be replaced periodically to prevent insufficient charge flow due to filter clogging.

6. Scheduled Inspection & Seal Replacement

Perform comprehensive performance testing every 2000 operating hours or annually (whichever comes first), including volumetric efficiency testing, control response time verification, and case drain leakage assessment. Always use genuine Rexroth service kits (material numbers beginning with R902/R909/R910) when replacing seals, and verify that seal material options are compatible with the system fluid type.