A4VG71 Rexroth Variable Piston Pump 400bar Closed Circuit

Product Overview

The A4VG series from Bosch Rexroth comprises closed-circuit variable-displacement axial piston pumps of swash-plate design, covering sizes A4VG40, A4VG56, A4VG71, A4VG90, A4VG125 and specific codes such as A4VG71DA2D2/32R-NZF02F001SQ. Flow is proportional to drive speed and displacement and is infinitely variable in both directions. Features an integrated boost pump, high-pressure relief valves and standard adjustable pressure cut-off. Manufactured to exact OEM dimensions and interfaces for 100% drop-in interchangeability. Every unit undergoes 100% simulated operating-condition testing to verify pressure, flow and sealing integrity under demanding mobile closed-circuit applications.

Technical Specifications

• Models: A4VG40 / A4VG56 / A4VG71 / A4VG90 / A4VG125 (example: A4VG71DA2D2/32R-NZF02F001SQ)
• Pump Type: Variable displacement axial piston pump (closed circuit, swash-plate)
• Geometric displacement: 40 cm³/rev (40), 56 cm³/rev (56), 71 cm³/rev (71), 90 cm³/rev (90), 125 cm³/rev (125)
• Nominal pressure: 400 bar
• Peak pressure: 450 bar
• Continuous maximum speed: 3300 rpm for A4VG71 (2500–4000 rpm depending on size)
• Control methods: DA (speed-related automatic), HD (hydraulic pilot), HW (mechanical servo), EP (electric proportional), etc.
• Weight: approx. 31–80 kg (A4VG71 approx. 50 kg)
• Other: Integrated boost pump, through-drive capability

(Data sourced from official Bosch Rexroth A4VG series technical documentation.)

Key Technical Advantages

• High-precision swash plate and piston-shoe design: Precision machining and wear-resistant materials deliver high volumetric efficiency and low internal leakage with smooth bidirectional flow reversal.
• Integrated boost and protection functions: Built-in boost pump, high-pressure relief valves and pressure cut-off simplify the system while enhancing reliability.
• Versatile control options and fast response: DA speed-related control, electric proportional and hydraulic pilot options adapt to complex closed-circuit transmission demands.
• 100% drop-in interchangeability and simulated testing: Mounting interfaces match OEM exactly; full duty-cycle validation before shipment ensures sealing integrity and minimizes downtime.

Application Areas

Travel and swing systems in construction machinery (excavators, loaders, cranes), agricultural equipment, forestry machines, material-handling vehicles and any application requiring high-pressure closed-circuit hydrostatic transmissions.

Expert Maintenance Tips

Clean ports and drive shaft thoroughly before installation. Use recommended hydraulic oil and verify system cleanliness. Pre-fill the case with oil before start-up. After replacement, run at low speed under no load, then gradually increase load while checking for noise or leakage. Regularly monitor boost pressure and filters; avoid prolonged over-pressure or cavitation. Perform pressure and flow verification tests according to the official Rexroth manual.