VDR Series Variable Vane Pump | VDR-1B VDR-11B | Nachi Style High Pressure Pump

Chengyuan Hydraulic presents the VDR Series variable displacement vane pumps (including VDR-1B, VDR-11B, and VDR-11A), engineered for high-efficiency energy-saving in industrial automation and machine tool hydraulic systems. Developed in strict accordance with Nachi technical specifications, this series focuses on delivering high-speed response while minimizing system heat generation. Our VDR series undergoes 100% Simulation Load Testing to ensure precise flow control during the pressure compensation phase. Chengyuan guarantees 100% Drop-in Interchangeability for flange mounting (JIS/SAE compliant), shaft dimensions, and port layouts, making it the perfect cost-effective alternative for the original VDR series.

Technical Specifications 

• Model Identification: VDR-1B-1A1-U-1133K / VDR-11B-1A3-1A3-U-22

• Displacement (VDR-1B): 22 cm³/rev

• Displacement (VDR-11B): 22+22 cm³/rev (Double pump configuration)

• Rated Operating Pressure: 7 MPa (70 Bar)

• Max Operating Pressure: 8 MPa (80 Bar)

• Speed Range: 800 – 1800 r/min

• Pressure Adjustment Ranges: 1A1 (0.8-1.4 MPa) / 1A2 (1.0-3.5 MPa) / 1A3 (2.0-7.0 MPa)

• Control Type: Pressure Compensation

• Shaft Specification: Straight keyed shaft (U/K types)

Key Technical Advantages:

• High-Response Variable Mechanism: Utilizing an optimized stator shifting mechanism, the response time is minimized when system pressure reaches the setpoint. This significantly reduces overflow losses and suppresses oil temperature rise.

• Hydrostatic Balance Precision: The side plates are precision-ground with a hydrostatic balance design, minimizing friction between the rotor and plates. This enhances mechanical efficiency and ensures ultra-low noise levels (below 65dB) across the full pressure range.

• Floating Side Plate Design: Features automatic axial clearance compensation. This engineering ensures that the pump maintains a volumetric efficiency of over 90% even after extended service, compensating for internal wear.

• High-Strength Wear Surfaces: Critical components like the stator and vanes are made of high-quality alloy steel with deep carburizing (HRC 60+). This provides exceptional wear resistance and extends service life under high-frequency switching conditions.

Application Areas:

• Metal Cutting Machine Tools: Clamping and auxiliary circuits for CNC lathes and machining centers.

• Automated Production Lines: Handling equipment, hydraulic lift tables, and robot power sources.

• Plastic Machinery: Auxiliary circuits for compact injection molding machines.

• Woodworking Machinery: Power control for presses and automated feeding systems.

Expert Maintenance Tips:

• Pressure Adjustment Protocol: When adjusting the pressure compensation screw, always monitor the system pressure gauge. Avoid running the pump above 8 MPa for prolonged periods to prevent premature vane fatigue.

• Inlet Environment Requirements: Variable vane pumps are sensitive to cavitation. Maintain inlet flow velocity between 0.5-1.5 m/s and use a 100-mesh suction strainer.

• Initial Bleeding: Before first startup, fill the pump housing with oil via the drain port and rotate the shaft manually. Use the “jogging” method during startup to evacuate all internal air, preventing damage to the stator curve.