NBZ Series Internal Gear Pump | NBZ4-D63F NBZ5-D160F | Low Noise High Pressure

The NBZ Series Internal Gear Pump (including NBZ4 and NBZ5) from LIC Hydraulic is the premier solution for applications requiring high pressure and whisper-quiet operation. Utilizing advanced internal gearing and a compensated “crescent” design, these pumps eliminate the pulsation and noise associated with traditional external gear technology. Models like the NBZ5-D160F are widely used in high-end servo-driven hydraulic systems. We provide 100% drop-in replacements that match original OEM specifications for mounting, shafts, and performance curves.

Technical Highlights

• Frame Sizes: NBZ2, NBZ3, NBZ4, NBZ5.

• Displacement Range: $40\text{ cc/rev}$ (NBZ4) to $160\text{ cc/rev}$ (NBZ5).

• Max Pressure: Continuous duty up to $250\text{ bar}$ ($3625\text{ psi}$); Peak up to $315\text{ bar}$.

• Speed Capability: Optimized for servo motor operation ($400\text{ to }3000\text{ rpm}$).

Core Advantages

• Industry-Leading Noise Reduction: The internal gearing allows for multiple tooth contact, which dampens fluid vibration. This results in a pump that is significantly quieter than piston or external gear pumps of similar displacement.

• Dual Gap Compensation: Our NBZ pumps feature both radial and axial pressure compensation. This ensures that internal clearances are kept to a minimum, maintaining high efficiency even during the low-speed holding cycles of injection molding.

• High Power Density: The compact design of the NBZ5 series provides massive flow capacity in a small footprint, reducing the overall size and weight of the hydraulic power unit (HPU).

• Reliable Under Heavy Duty: Hardened internal components and low-friction bearings ensure that the NBZ4 and NBZ5 series can withstand millions of cycles in high-pressure CNC and pressing applications.

Expert Maintenance Tips

• Oil Cleanliness: Internal gear pumps have tight clearances. Maintain oil cleanliness at ISO 18/16/13 to prevent premature wear of the crescent and gears.

• Servo Tuning: When used with servo motors, ensure the acceleration/deceleration ramps are correctly tuned to prevent cavitation during rapid speed changes.

• Inlet Pressure: Ensure the suction line is appropriately sized to maintain an inlet pressure between $-0.2\text{ to }+0.5\text{ bar}$ for optimal filling and noise control.