Nachi PVD Series Gear Pump | PVD-00B PVD-0B PVD-1B PVD-2B Hydraulic Pump

The PVD Series high-pressure gear pumps (covering PVD-00B, 0B, 1B, 2B, and 3B) by Chengyuan Hydraulic are precision-engineered fluid power units fully compatible with Nachi (Fujikoshi) industrial standards. These pumps are predominantly utilized as pilot pumps, cooling fan drives, or third pumps in mini-excavator hydraulic systems (e.g., Kubota, Yanmar, Takeuchi). For specific OEM configurations like PVD-2B-44P-12G-5198A, we utilize high-precision gear grinding and reinforced aluminum housings to ensure performance stability under high back-pressure conditions. Every PVD gear pump undergoes 100% simulated operational load testing at full rated pressure before delivery, ensuring all technical metrics align with original specifications for guaranteed 100% original-place interchangeability.

Technical Specifications :

• Product Series: Nachi PVD Series High-Pressure Gear Pump

• Supported Models: PVD-00B / PVD-0B / PVD-1B / PVD-2B / PVD-3B

• Specific Reference Support: PVD-2B-44P-12G-5198A (and other OEM variants)

• Displacement Range: 1.1 cm3/rev to 12.0 cm3/rev (model dependent)

• Rated Operating Pressure: 21 MPa (210 bar)

• Peak Pressure Limit: 25 MPa (250 bar)

• Maximum Rated Speed: 3000 – 4000 rpm

• Minimum Stable Speed: 600 rpm

• Body Material: High-Strength Extruded Aluminum Alloy

• Volumetric Efficiency: $\ge 91\%$ (at rated pressure)

• Mechanical Efficiency: $\ge 88\%$

Key Technical Advantages:

• Automatic Axial Clearance Compensation: Utilizing a flexible side-plate pressure compensation mechanism. As system pressure rises, hydraulic force pushes the side plates against the gear faces, effectively sealing internal leakage and maintaining high volumetric efficiency even at 21 MPa.

• Special Involute Low-Pulsation Gears: The gear sets undergo a secondary honing process to optimize the contact ratio. This significantly reduces pressure ripples caused by fluid trapping, resulting in smoother operation and a noise reduction of 5-10 dB(A) compared to standard gear pumps.

• High-Load DU Composite Bushings: Equipped with high-performance DU sliding bearings. These bushings offer superior self-lubrication and shock resistance, capable of absorbing the radial forces generated during high-load directional shifts, thereby extending the pump’s fatigue life.

• Superior Thermal Stability: Combined with high-performance FKM seals and precision clearances, the pump maintains seal integrity in the high-temperature environment of mini-excavator engine compartments (up to 90∘C) without performance degradation.

Application Areas:

• Mini/Compact Excavators: Often stacked behind the main piston pump (e.g., PVD-22L) to provide pilot pressure or drive cooling fans.

• Mobile Machinery: Used in steering circuits for agricultural equipment or auxiliary hydraulic loops for construction machinery.

• Attachment Control: Providing pilot pressure for the activation of breakers, grapples, and other hydraulic attachments.

Expert Maintenance Tips:

• Inlet Port Sealing Integrity: The PVD series is highly sensitive to cavitation due to its high operational speeds. Ensure all inlet clamps are tightened to prevent air ingress, which causes high-frequency noise and rapid erosion of the side plates.

• Case Back-Pressure Limits: Ensure that return or drain lines remain unobstructed. Instantaneous back-pressure should not exceed 0.5 MPa to prevent damage to the shaft seal.

• Fluid Cleanliness Standard: Maintain a hydraulic fluid cleanliness of ISO 4406 18/16/13. For pilot systems, micro-particulates can lead to joystick sticking or premature gear pump wear