Product Overview
The HG0 series (HG0-8 / HG0-10 / HG0-13 / HG0-16 / HG0-29), HG1 series (HG1-25 / HG1-32 / HG1-40 / HG1-50 / HG1-63), and HG2 series (HG2-80 / HG2-100 / HG2-125 / HG2-160) are internal gear pumps from the HYTEK HG series. The HG0 series covers displacements from 8 to 29 cm³/rev; the HG1 series from 25 to 63 cm³/rev; and the HG2 series from 80 to 160 cm³/rev.
The HG series is based on the internal gear principle—the internal gear drives the external gear in the same direction, creating negative pressure at the inlet to draw fluid in, and compressing fluid at the outlet through gear meshing. The unique “crescent” plate separates the suction and pressure chambers. Featuring axial and radial pressure compensation technology, the pump maintains high volumetric efficiency even at low speeds and low viscosities. The HG series is fully interchangeable with the Rexroth PGH series.
Every unit is manufactured to original equipment specifications, ensuring 100% drop-in interchangeability. Each pump undergoes rigorous 100% simulated duty-cycle testing to validate pressure-flow-efficiency performance curves.
Brand Disclaimer: This product is a high-quality compatible replacement engineered for full interchangeability with HYTEK original equipment. All HYTEK brand names and model codes are referenced solely to indicate compatibility and interchangeability. This product is manufactured by an independent producer and is not an original HYTEK product.
Technical Specifications
HG Series General Specifications
Brand Series: HYTEK HG Series Internal Gear Pump
Product Type: Fixed Displacement Internal Gear Pump
Rated Pressure: 315 bar (31.5 MPa)
Peak Pressure: 350 bar (35 MPa)
Maximum Speed: 3,000 r/min
Minimum Speed: 600 r/min
Pressure Compensation: Axial + Radial pressure compensation
Noise Level: Ultra-low noise design (silent pumps)
Housing Material: High-strength cast iron
Hydraulic Fluid: Mineral oil
Operating Temperature: -10°C to +80°C
Multi-Pump: Single and double pump configurations available (HG0, HG1, HG2 series)
HG0 Series (Group 0)
Frame Size: HG0 (Group 0)
Displacement Range: 5 – 29 cm³/rev
Rated Pressure: 315 bar (31.5 MPa)
Peak Pressure: 350 bar (35 MPa)
Speed Range: 600 – 3,000 r/min
Weight: Approx. 4.4 – 4.6 kg
Model Displacements:
HG0-8: 8 cm³/rev
HG0-10: 10 cm³/rev
HG0-13: 13 cm³/rev
HG0-16: 16 cm³/rev
HG0-29: 29 cm³/rev
HG1 Series (Group 1)
Frame Size: HG1 (Group 1)
Displacement Range: 25 – 63 cm³/rev
Rated Pressure: 315 bar (31.5 MPa)
Peak Pressure: 350 bar (35 MPa)
Speed Range: 600 – 3,000 r/min
Housing Material: Cast Iron
Model Displacements:
HG1-25: 25 cm³/rev
HG1-32: 32 cm³/rev
HG1-40: 40 cm³/rev
HG1-50: 50 cm³/rev
HG1-63: 63 cm³/rev
HG2 Series (Group 2)
Frame Size: HG2 (Group 2)
Displacement Range: 63 – 160 cm³/rev
Rated Pressure: 315 bar (31.5 MPa)
Peak Pressure: 350 bar (35 MPa)
Speed Range: 600 – 3,000 r/min
Housing Material: Cast Iron
Model Displacements:
HG2-80: 80 cm³/rev
HG2-100: 100 cm³/rev
HG2-125: 125 cm³/rev
HG2-160: 160 cm³/rev
Key Technical Advantages
1. Axial & Radial Pressure Compensation – High Efficiency
Innovative axial and radial pressure compensation technology maintains high volumetric efficiency even at low speeds and low viscosities. The compensation mechanism automatically adjusts gear end and radial clearances, ensuring stable flow output across the full pressure range.
2. Ultra-Low Noise Design – Silent Operation
High-strength cast iron with internal sound-dampening design，combined with modified involute, short-tooth internal gear geometry，delivers ultra-low noise operation. Ideal for noise-sensitive injection molding workshops and indoor industrial equipment.
3. High-Pressure Rating – Industrial-Grade Durability
Rated pressure of 315 bar (31.5 MPa) and peak pressure of 350 bar (35 MPa) . The high-strength cast iron housing with precision pressure compensation ensures long-term reliability under high-pressure, high-frequency, continuous-duty operations.
4. Full Interchangeability with Rexroth PGH Series
The HG series is fully interchangeable with the Rexroth PGH series. Direct replacement with zero system modifications—significantly reducing maintenance costs and downtime.
5. Broad Speed Range
Supports a wide speed range of 600 – 3,000 r/min. Maintains stable flow characteristics from low-speed precision control to high-speed continuous duty.
6. Wide Industrial Application Versatility
Specifically developed for demanding industrial hydraulic applications. Can replace piston pumps, vane pumps, and external gear pumps—suitable for all industrial hydraulic systems.
7. 100% Simulated Duty-Cycle Testing
Every pump is 100% tested on dedicated hydraulic test benches under simulated real-world operating conditions—validating pressure-flow characteristics and efficiency curves at rated pressure (315 bar), peak pressure (350 bar), and full speed range—ensuring zero-defect, plug-and-play performance upon installation.
Application Areas
Injection Molding Machines: Servo hydraulic systems, energy-efficient oil pump systems
Die Casting Machines: High-pressure hydraulic systems
Shearing & Bending Machines: Hydraulic systems
Cranes: Hydraulic systems
Sanitation Vehicles: Hydraulic systems
Industrial Hydraulic Systems: Fixed hydraulic systems requiring low noise, high pressure, and high reliability
Expert Maintenance Tips
1. Fluid Cleanliness Control
Internal gear pumps have relatively low sensitivity to contamination, but maintain system fluid cleanliness to ISO 4406 19/17/14 or better as good practice. Install a ≤10 μm absolute filtration filter upstream of the inlet port.
2. Inlet Line Requirements
Keep suction lines short and straight with adequate diameter—not less than the port size. Inlet pressure must be maintained between 0.8 – 2.0 bar (absolute) to prevent cavitation that could damage the internal ring gear and crescent plate assembly.
3. Coupling Alignment Precision
Ensure pump shaft-to-drive shaft coaxiality deviation ≤0.05 mm and angular deviation ≤0.5° during installation. Flexible couplings are strongly recommended.
4. First-Start Priming Procedure
Before initial startup, thoroughly bleed air through the drain port or a loosened outlet fitting. Perform 2–3 jog starts under no-load conditions (outlet open) until oil fills the pump cavity without air bubbles, then connect the load circuit for full operation.
5. Speed & Temperature Monitoring
Speed range: 600 – 3,000 r/min. Operating temperature range: -10°C to +80°C. During cold starts when viscosity is high, ensure adequate suction conditions or preheat the fluid.
6. Rotation Direction Confirmation
“R” indicates right-hand (clockwise) rotation; “L” indicates left-hand (counterclockwise) . Always verify that the drive motor/engine rotation matches the pump before installation.
