Hydac PGI Series Internal Gear Pump | PGI103 PGI101 | High Pressure

The PGI Series high-pressure internal gear pumps manufactured by Chengyuan Hydraulic are high-fidelity fluid power components engineered to strictly align with German Hydac technical benchmarks. This series is optimized for high-performance industrial power units, injection molding machines, and energy-saving servo-drive closed-loop control systems. Focusing on the high-demand configurations PGI103-5-064-RA23-10 and PGI101-1-032-RK23, Chengyuan guarantees 100% original-place interchangeable compatibility in geometric mounting profiles and hydrodynamic performance. Every pump undergoes 100% simulated operational load testing and servo dynamic response mapping before dispatch, delivering exceptional volumetric efficiency and whisper-quiet performance under continuous peak working pressues.

Technical Specifications :

• Brand Compatibility: Hydac PGI Series Matrix

• Target Model Configurations: PGI103-5-064-RA23-10, PGI101-1-032-RK23

• Displacement Class Options:

  • 032 (32.0 $cm^3/rev$)

  • 064 (64.0 $cm^3/rev$)

• Continuous Rated Pressure: 300 bar (4350 psi)

• Maximum Peak Pressure Limit: 330 bar (4785 psi)

• Max. Continuous Rotational Speed: 2500 rpm – 3000 rpm (Supports instantaneous servo motor overloads)

• Minimum Rotational Speed Limit: 100 rpm – 200 rpm (Maintains steady high pressure during servo pressure holding)

• Direction of Rotation: R (Right-hand / Clockwise looking from shaft end)

• Shaft & Flange Configurations: A23 (SAE 2-bolt flange with straight keyed shaft) / K23 (Involute splined shaft)

• Fluid Media Requirements: Mineral-based hydraulic oils per DIN 51524; Viscosity range: 10 to 300 $mm^2/s$

Key Technical Advantages:

• Hydrostatic Radial & Axial Pressure Compensation: Floating side plates and radial sealing segments are dynamically energized by the pump’s internal discharge pressure. This allows clearance tolerances to automatically adjust to system pressure variations, forcing volumetric efficiency to remain above 95% at a continuous 300 bar while drastically mitigating internal thermal-leakage slippage.

• Dual-Involute Intermeshing Geometry for Low Ripple: The internal gear and pinion feature a highly optimized, non-symmetrical profile. The smooth transition of fluid entrapment volumes eliminates the trapped-oil pressure spikes common in external gear alternatives. This reduces pressure ripple to within $\pm 1\%$, dampening system acoustic vibrations and pipeline harmonics.

• Hydrodynamic Journal Bearing Optimization: The main driving shaft is supported by premium nitrided journal bearings embedded with a Teflon composite layer. This structure generates a highly resilient hydrodynamic lubricant film under rotation, effectively absorbing heavy radial forces and ensuring long fatigue cycles during rapid servo start-stop switching.

• High-Tensile Ductile Iron Housing: The solid pump body is CNC-machined from premium ductile iron castings to withstand intermittent shock loads up to 330 bar. Following precision thermal stress relief, micro-deformation under intense temperature fluctuations is eliminated, preserving micron-level running clearances.

Application Areas:

• Servo Energy-Saving Systems: Injection molding machinery, rubber extruders, and electro-hydraulic servo press brakes.

• Machine Tools & Production Lines: Heavy-duty CNC metal shearing machines, hydraulic press lines, and automated industrial stamping stations.

• Heavy Industry & Metallurgy: Constant-pressure lubrication loops for rolling mills and heavy-duty material handling equipment.

Expert Maintenance Tips:

• Execute Strict Pump Priming Prior to Commissioning: Internal gear pumps must never be started dry. Upon completing installation, fill the pump housing completely with clean hydraulic fluid through the inlet or dedicated priming port, and manually rotate the shaft by hand for several revolutions to coat internal contact faces before powering on.

• Secure Absolute Suction Sealing to Prevent Cavitation: The PGI series is vulnerable to cavitation damage. Ensure all intake suction flanges and joints are hermetically sealed against air ingress. Keep suction line fluid velocity below 0.5 – 1.0 m/s and avoid over-filtering at the suction port, which creates excessive intake resistance and vacuum-induced howling.

• Manage Thermal Limits During Servo Pressure Holding: In servo circuits, the pump regularly operates under a “low speed, high pressure” zero-flow state, which reduces natural oil cooling. Ensure the system fluid stays below 60°C. If long pressure-holding sequences are required, program a small-volume bleed-off cycle to keep fluid from overheating inside the pump body and scratching the gear faces.