GPA Series Internal Gear Pump | GPA1 GPA2-10-E-20-R | High Pressure

The GPA Series high-pressure internal gear pumps from Chengyuan Hydraulic are precision-engineered power components designed for industrial hydraulic stations and mobile machinery. This series serves as a premium replacement for global standard specifications (such as GPA1 and GPA2), including models GPA2-10-EK2-20-R and GPA1-4-EK1-20-R. Utilizing radial and axial pressure compensation logic, the GPA series maintains exceptional volumetric efficiency even under high-pressure conditions. Chengyuan ensures 100% Drop-in Interchangeability in mounting dimensions, shaft ends, and port configurations. Backed by our 100% Simulation Load Testing, each GPA pump is verified for pressure pulsation and mechanical efficiency before shipment, with a signature low-noise profile that makes it the ideal choice for indoor hydraulic units.

Technical Specifications 

• Model Examples: GPA2-10-EK2-20-R / GPA1-4-EK1-20-R

• Displacement Range: GPA1 Series (1.25 – 6.3 cm³/rev); GPA2 Series (6.3 – 16 cm³/rev)

• Rated Pressure: 25 MPa (250 Bar)

• Maximum Pressure: 31.5 MPa (315 Bar)

• Rated Speed: 500 – 3000 r/min

• Control Type: Fixed Displacement

• Rotation: Right-hand (R) / Left-hand (L) optional

• Mounting: International standard flange connection (EK/EM interfaces)

• Weight: Approx. 2.5 kg – 5.5 kg (Depending on size)

Key Technical Advantages:

• Ultra-Low Noise Operation: Featuring an internal gear design with high contact ratios, the mechanical impact from trapped oil is significantly reduced. Noise levels are typically maintained below 60-65 dB(A), ensuring a quiet workspace.

• Dual Pressure Compensation: Equipped with internal axial support plates and radial sealing segments that automatically adjust clearances based on working pressure. This engineering ensures over 95% volumetric efficiency even at 25 MPa.

• Superior Flow Stability: Compared to traditional external gear pumps, the GPA series offers extremely low flow pulsation. This helps minimize vibration in system piping, protecting downstream servo valves and sensors.

• High-Grade Materials: Gear sets are crafted from high-quality carburized steel with vacuum quenching. The pump body uses high-strength aluminum alloy or ductile iron, ensuring long-life bearing support under harsh conditions.

Application Areas:

• Plastic Machinery: Auxiliary circuit control for injection molding machines.

• Machine Tool Industry: Lubrication and clamping hydraulic systems for CNC lathes.

• Lifting Platforms: Scissor lifts and small-scale lifting tables.

• Hydraulic Power Units (HPU): Indoor power units with strict environmental noise requirements.

Expert Maintenance Tips:

• Startup Bleeding: After installation, air should be bled through the pump outlet. Conduct an unladen “jog” start to prevent surface damage to the gears caused by cavitation.

• Filtration Standards: To protect the precise internal clearances, ensure the system is equipped with 10-15 micron filtration, maintaining oil cleanliness at NAS Grade 8 or better.

• Viscosity Management: Ensure the hydraulic oil viscosity stays between 20-100 mm²/s. Low viscosity will lead to increased internal leakage and reduced output pressure.