3520VQ38A4 3520VQ38A5 3520VQ38A6 3520VQ38A7 Eaton Vickers VQ Vane Pump

Product Overview

The 3520VQ38A4, 3520VQ38A5, 3520VQ38A6 and 3520VQ38A7 (and the broader 2520VQ, 3520VQ, 3525VQ series) are Eaton Vickers VQ high-performance tandem fixed-displacement vane pumps engineered for demanding applications such as injection molding machines and machine tools. Featuring the 10-vane Intra-Vane cartridge design, they deliver independent dual-circuit flow from the shaft-end and cover-end sections. These pumps offer excellent drop-in interchangeability with genuine Eaton/Vickers units, matching flange, shaft and port dimensions exactly. Every unit undergoes 100% simulated operating condition testing to verify volumetric efficiency, pressure stability and durability.

Technical Specifications 

• Models: 3520VQ38A4, 3520VQ38A5, 3520VQ38A6, 3520VQ38A7 (series includes 2520VQ, 3520VQ, 3525VQ)
• Series: Eaton Vickers VQ tandem fixed-displacement vane pump
• Shaft-end geometric displacement: code 38 ≈ 121.6 cm³/r (7.42 in³/r)
• Cover-end geometric displacement: code 5 ≈ 18.0 cm³/r (1.10 in³/r); A4/A6/A7 are similar small-displacement or flow-control variants
• Continuous rated pressure: up to 210 bar (3000 psi) with anti-wear mineral oil
• Peak pressure: approx. 228 bar (3300 psi) intermittent
• Maximum speed: shaft-end (code 38) up to approx. 2400 r/min; cover-end up to approx. 2500 r/min (based on 0 bar inlet pressure)
• Minimum speed: approx. 600 r/min
• Control type: Fixed displacement (Intra-Vane cartridge design; some models with optional flow-control cover)
• Rotation: Standard clockwise (viewed from shaft end); counterclockwise optional
• Port configuration: Primarily A (SAE 4-bolt flange)
• Shaft options: Keyed or splined
• Approximate weight: 34 kg
• Recommended fluid: Anti-wear mineral oil (e.g. SAE 10W)

Key Technical Advantages

• Intra-Vane precision cartridge design: The 10-vane configuration with floating side plates automatically compensates end-face clearance, maintaining high volumetric efficiency and low internal leakage under high pressure.
• High-speed and high-pressure capability: Continuous pressure reaches 210 bar with maximum speeds of 2400 r/min and above, supporting rapid cycles in injection molding and machine tools.
• Superior interchangeability and serviceability: Cartridge construction allows rapid replacement of rotor, vanes and cam ring; mounting dimensions fully match original Eaton/Vickers pumps for direct drop-in replacement.
• Low noise and extended service life: Hydraulically balanced vane design reduces radial forces and vibration; quality bearings and wear-resistant materials, validated by 100% simulated testing, ensure reliable continuous operation.

Application Areas

Injection molding machine main hydraulic systems (injection and clamping circuits), machine tool feed and clamping systems, die-casting machines, hydraulic presses, construction machinery dual-circuit systems, and fixed or mobile hydraulic power units requiring high-speed, high-pressure tandem vane pumps.

Expert Maintenance Tips

Maintain proper shaft alignment between the pump and motor/drive to avoid additional radial or axial loads. Keep inlet pressure between 0–0.34 bar gauge (maximum 1.38 bar); inlet depression should not exceed 0.17 bar. Use anti-wear mineral oil and maintain cleanliness (recommended filtration ≤10–25 μm). Periodically inspect cartridge components for wear and replace vanes/cam ring with genuine or equivalent-precision parts. Fully purge air before initial start-up and avoid dry running. Do not exceed rated pressure or speed limits, and control oil temperature within the recommended range to maximize seal and bearing life.