Nachi PZ Series Hydraulic Piston Pump | PZ-4B-100E2A-10 PZ-6B-180E2A-20 | Variable Displacement Pump

The PZ Series Variable Displacement Piston Pumps, manufactured by Chengyuan Hydraulic, are high-end hydraulic components engineered as premium replacements for Nachi industrial standards. Covering a wide spectrum from the PZ-2B-35 to the high-capacity PZ-6B-180E, these pumps are renowned for their unique semi-cylindrical swashplate design, which provides rapid power response and quiet operation. Chengyuan guarantees 100% Drop-in Interchangeability with original Nachi units, matching all mounting flanges, shaft ends, and pressure/flow control logic. Every pump is subjected to 100% simulation load testing on our digital benches to ensure peak efficiency and stability under complex load variations.

Technical Specifications 

• Compatible Brand: Nachi

• Core Model Designations: PZ-4B-100E2A-10, PZ-6B-180E2A-20, PZ-5B-130E1A-10, PZ-2B-35-E1A-11

• Displacement Sizes: 35cc, 100cc, 130cc, 180cc per revolution

• Rated Operating Pressure: 25 MPa (250 Bar)

• Peak Pressure: 28 MPa (280 Bar)

• Control Options: E1A (Pressure Compensation), E2A (Load Sensing / Dual Pressure-Flow Control)

• Max. Operating Speed: 1800 r/min – 2200 r/min

• Housing Material: High-strength ductile iron (superior pressure and shock resistance)

• Port Connections: Flanged (SAE or JIS standard compliant)

Key Technical Advantages:

• Semi-Cylindrical Swashplate Support: This specialized structure reduces frictional resistance during swashplate movement, enabling lightning-fast variable response. This design enhances control precision while significantly dampening vibration and high-frequency noise.

• Load Sensing Control Logic: Specifically for E2A models, the pump automatically adjusts flow output based on real-time actuator demands. By minimizing reactive power loss, system heat generation is reduced by over 30%, optimizing overall energy efficiency.

• Dual Side-Plate Balance Design: Incorporates a pressure-balanced structure on both side plates to neutralize lateral forces from piston movement. This protects the cylinder block and extends the lifespan of rotating components during continuous 25 MPa operation.

• Low Pulsation Output: The 9-piston configuration ensures ultra-smooth pressure delivery. This is critical for applications demanding high stability, such as precision injection molding and advanced CNC machining.

Application Areas:

• Injection Molding Machines: Acting as the primary pump for precise flow distribution and pressure regulation.

• Forging & Construction Equipment: Ideal for mid-to-large scale bending machines, presses, and aerial work platforms.

• Industrial Automation: Used in hydraulic power units where fast response and low noise levels are strictly required.

• Marine Hydraulics: Reliable power source for steering gear control or deck machinery.

Expert Maintenance Tips:

• Drain Port Backpressure: The PZ series is highly sensitive to case pressure. Ensure the drain line goes directly to the tank below the oil level. Backpressure must not exceed 0.1 MPa to prevent shaft seal failure or swashplate sticking.

• Case Priming: Before initial startup or after filter changes, the pump casing MUST be filled with clean hydraulic oil through the highest drain port. Never allow a “Dry Run,” as the piston shoes will seize within seconds.

• Temperature Management: Maintain operating oil temperatures between 20°C and 60°C (68°F – 140°F). Temperatures exceeding 80°C (176°F) will cause oil viscosity to drop, leading to lubrication film failure and rapid internal wear.