KYB KFZ Series Gear Pump | KFZ4-14CPSB KFZ4-17CPSB KFZ4-19CPSB | High Pressure

The KFZ4 Series high-pressure axial-compensated gear pumps from Chengyuan Hydraulic are heavy-duty power components fully compatible with KYB industrial standards. Specifically engineered for mobile equipment requiring low noise and high pressure stability, the KFZ4 series is widely utilized in forklift hydraulic circuits (e.g., Heli, Hangcha brands). Utilizing a floating side-plate structure, these pumps automatically adjust internal clearances based on pressure. As a flagship product from Chengyuan, every KFZ4 unit (including KFZ4-14CPSB, KFZ4-19CPSB) undergoes 100% simulated full-load testing to ensure superior volumetric efficiency at high speeds, guaranteeing 100% original-place interchangeability.

Technical Specifications :

• Core Model Series: KFZ4-14, KFZ4-17, KFZ4-19, KFZ4-23, KFZ4-25, KFZ4-30

• Displacement Range: 14.0 mL/r to 30.0 mL/r

• Nominal Pressure: 25 MPa (250 bar)

• Peak Pressure: 28 MPa (280 bar)

• Allowable Speed Range: 500 – 3000 rpm

• Mounting Interface: CPSB (Diamond flange/Standardized spline or keyed)

• Rotation: Clockwise (R) or Counter-clockwise (L)

• Fluid Compatibility: Mineral-based hydraulic oils (ISO VG32/46/68)

Key Technical Advantages:

• Automatic Axial Clearance Compensation: Features specialized floating side plates that utilize hydraulic feedback to press against the gear faces. This balanced design ensures volumetric efficiency remains above 92% across the entire 25MPa pressure range.

• Low-Noise Gear Profile Technology: Gears are CNC-ground to micron-level precision. The unique unloading groove design eliminates vibration and sharp noise caused by “trapped oil” phenomena, keeping noise levels significantly lower than standard industrial pumps.

• Enhanced Aluminum Alloy Body: The shell is gravity-cast from high-density aluminum alloy with high tensile strength, offering excellent heat dissipation and deformation resistance. This maintains the geometric stability of internal components even under high temperature rise.

• Multi-Layer Composite DU Bearings: High-load composite bearings provide superior dry-friction protection during cold starts (when oil film is not yet established), greatly extending the life of the shaft seals and gear shafts.

Application Areas:

• Material Handling: Forklifts (Lift & Steering), electric stackers, and pallet trucks.

• Construction Machinery: Steering systems for road rollers and auxiliary circuits for compact loaders.

• Sanitation Equipment: Lift circuits for refuse compactors and control systems for street sweepers.

Expert Maintenance Tips:

• No-load Run-in & Bleeding: After installation, run the pump at 500-800 rpm without load for 10 minutes. Ensure all air is bled to prevent cavitation from damaging the floating sleeves.

• Seal Integrity Checks: Due to frequent vibration in forklifts, periodically check the bolt torque and seal condition at the CPSB flange. Any air ingestion will lead to oil emulsification and increased noise.

• Preventative Oil Changes: It is recommended to change hydraulic oil every 1500 working hours. For high-cycle operations, maintain filtration accuracy within 15μm to protect the precision gear surfaces.