Keister's KHG internal gear pumps represent a breakthrough in hydraulic technology, engineered specifically for demanding industrial applications where precision, reliability, and high-pressure performance are non-negotiable. As a leading hydraulic gear pump manufacturer, we deliver solutions that combine advanced meshing gears technology with exceptional volumetric efficiency across diverse operating conditions—from injection molding to die casting and automated press systems.
Product Range & Applications
Our KHG series encompasses displacement capacities from 8.2 mL/r to 162.8 mL/r, meeting the varied demands of industrial hydraulics. The KHG H0-25 model has become the industry benchmark for automated presses, while our KHG H1-40 variant excels in plastic processing machines where consistent flow and minimal pulsation are critical. These positive displacement gear pumps serve foundry equipment, metal processing machinery, and packaging systems with proven reliability.
Technical Advantages & Performance
Superior Pressure Capability: Unlike conventional external gear pump designs, our internal gear pumps achieve maximum operating pressures up to 35 MPa (5,075 psi) through precision-engineered gears, optimized porting geometry, and reinforced side plates. This high-pressure design eliminates the need for oversized components in space-constrained installations.
Ultra-Low Pulsation Technology: The specialized tooth profile and balanced radial/axial pressure distribution deliver exceptionally smooth flow characteristics even at speeds ranging from 200 to 3,000 rpm. This makes our pumps ideal for integration with servo systems and variable-frequency drives where flow stability directly impacts product quality.
Extended Service Life: High-strength cast iron construction combined with contamination-resistant internal architecture ensures durability in harsh industrial environments. The gear pump maintenance requirements remain minimal due to the pump's tolerance of particulate matter that would compromise competitive designs.
Whisper-Quiet Operation: Proprietary acoustic dampening features integrated into the housing design significantly reduce operational noise levels compared to standard gear pump solutions, supporting modern workplace safety standards.
Material & Fluid Compatibility
Our internal gear pumps handle a wide viscosity range, from low-viscosity hydraulic oils to high-viscosity lubricating oils and synthetic fluids. The robust construction accommodates temperatures from -20°C to +80°C, making these pumps suitable for chemical additives, resins, and petroleum-based media across petrochemical, food processing, and general manufacturing sectors.
Frequently Asked Questions
What distinguishes internal gear pumps from external gear pump designs?
Internal gear pumps feature an external rotor (outer gear) and internal rotor (inner gear) configuration that provides smoother flow, lower noise levels, and higher contamination resistance compared to external designs. The meshing gears create progressive cavities that minimize pressure pulsation—critical for precision hydraulic systems and servo applications.
How do I calculate the required displacement for my application?
Displacement selection depends on your flow rate requirements and operating speed. Use the formula: Flow (L/min) = Displacement (mL/r) × Speed (rpm) ÷ 1000. Our engineering team provides comprehensive selection guides and can recommend optimal models based on your system pressure, fluid viscosity, and duty cycle. The KHG H2-80 series offers versatile displacement options for diverse packaging machinery requirements.
Can KHG pumps integrate with modern servo-controlled systems?
Absolutely. Our pumps are specifically designed for servo and variable-frequency drive compatibility, offering stable performance across the full 200-3000 rpm speed range. The balanced pressure design and low flow pulsation make them ideal for applications requiring precise flow control and rapid response to speed changes.
What maintenance intervals are recommended for internal hydraulic gear pumps?
Due to the contamination-resistant design and robust construction, KHG pumps typically require only routine fluid analysis and filter changes per your system's maintenance schedule. The simple internal architecture minimizes wear points, with many installations achieving 10,000+ operating hours between major services under normal industrial conditions.
Partner with a Trusted Hydraulic Gear Pump Supplier
Keister Hydraulics brings decades of precision engineering expertise to every internal gear pump we manufacture. Whether you need a compact hydraulic pump for space-limited installations or a high-displacement solution for heavy-duty industrial machinery, our technical team delivers customized recommendations backed by comprehensive application support. Explore our complete range of vane pumps and external gear pumps for complementary hydraulic solutions, or contact our specialists to discuss your specific requirements and receive expert selection guidance tailored to your operating parameters.
