Internal Low-pressure Hydraulic Gear Pump - Compact, Efficient, and Reliable Hydraulic Solution
Fairy Deer Benefits Of Internal Below 16 MPa Low-pressure Hydraulic Gear Pump
Compact and Lightweight Design: The internal gear pump’s compact size and light weight enable easy integration into hydraulic systems with limited space.
Low Noise and Smooth Operation: Designed with internal gear meshing, these pumps operate quietly with minimal vibration, improving working environment and equipment longevity.
High Efficiency at Low Pressure: Optimized for pressures below 16 MPa, they maintain stable flow and pressure output even at low speeds, ensuring energy-efficient performance.
Durability and Low Maintenance: Fewer moving parts and robust construction reduce wear and maintenance costs, enhancing system reliability and uptime.
Wide Application Range: Suitable for lubrication, fuel supply, and hydraulic circuits in engineering machinery, forklifts, and industrial automation systems.
COMPARISON
Compact Structure and Weight:
Internal low-pressure gear pumps feature a compact, lightweight design ideal for integration into space-constrained hydraulic systems. High-pressure pumps, designed for greater pressures, are generally larger and heavier, limiting their use in compact equipment.
Smooth Operation and Noise Level:
Low-pressure internal gear pumps operate quietly with minimal flow pulsation due to internal gear meshing, enhancing working conditions and equipment lifespan. High-pressure pumps, while capable of withstanding higher pressures, tend to have more noise and pressure fluctuations, requiring more complex manufacturing.
Volumetric Efficiency and Application:
Low-pressure pumps maintain high volumetric efficiency at high speeds and are well-suited for medium and low-pressure systems, especially as charge pumps in closed-loop circuits. High-pressure pumps suffer from lower efficiency and higher pulsation at low speeds and high pressures, making them less ideal for smooth flow requirements.
Manufacturing Complexity and Cost:
While internal gear pumps have complex tooth profiles and higher manufacturing difficulty, low-pressure variants are simpler and more cost-effective to produce and maintain. High-pressure pumps demand tougher materials and precision, raising costs and maintenance efforts.
Recommendation:
For customers seeking quiet, stable, compact, and cost-effective hydraulic solutions in medium to low-pressure applications, internal low-pressure (below 16 MPa) gear pumps offer superior performance, reliability, and economy compared to high-pressure alternatives.
Compactness and Weight：
Internal low-pressure gear pumps are renowned for their compact structure, small size, and light weight, enabling flexible installation in space-constrained hydraulic systems and improving equipment integration. Medium-pressure internal gear pumps, designed for higher pressures, tend to be bulkier and heavier, limiting their use in compact equipment.
Flow Pulsation and Noise Control：
Low-pressure internal gear pumps feature low flow pulsation and noise due to the same-direction rotation of internal and external gears, ensuring smooth operation and extended equipment life. Medium-pressure pumps, although capable of higher pressures, often experience increased pulsation and noise, requiring additional noise reduction measures and increasing system complexity.
Volumetric Efficiency and Application：
Low-pressure internal gear pumps maintain high volumetric efficiency below 16 MPa, ideal for closed-loop systems as charge pumps or pilot oil sources, delivering stable flow and responsive control with energy savings. Medium-pressure pumps (16-25 MPa) see efficiency drops and higher leakage and wear risks at increased pressures, affecting system stability and maintenance costs.
Manufacturing Complexity and Cost：
While internal gear pumps require complex tooth profiles and high manufacturing precision, low-pressure versions have relatively lower machining difficulty and material demands, offering better cost-effectiveness and lower maintenance expenses. Medium-pressure pumps require higher-grade materials and stricter processes to ensure durability under pressure, raising costs and upkeep.
Recommendation：
For customers with system pressures below 16 MPa, internal low-pressure hydraulic gear pumps provide an optimal balance of compactness, quiet operation, stable flow, and cost efficiency, enhancing overall system performance and reducing operational expenses. Medium-pressure pumps suit higher pressure needs but involve trade-offs in noise, cost, and maintenance.
Smooth Operation and Noise Reduction:
Internal helical tooth gear pumps feature angled teeth that mesh more smoothly, resulting in significantly lower flow pulsation and quieter operation compared to internal straight tooth gear pumps. This reduces mechanical vibration and extends equipment lifespan, improving workplace comfort. In contrast, straight tooth pumps have higher noise and pulsation due to perpendicular tooth engagement.
Volumetric Efficiency and Flow Stability:
Helical gear pumps provide more continuous fluid delivery and maintain higher volumetric efficiency at medium to high speeds, making them ideal for hydraulic systems requiring stable flow. Straight tooth pumps, while simpler and stable at low speeds, exhibit greater flow fluctuations and reduced efficiency at higher speeds.
Manufacturing Complexity and Cost:
Straight tooth gear pumps are easier and cheaper to manufacture, suitable for cost-sensitive applications with less stringent noise requirements. Helical gear pumps involve more complex machining and higher costs, but their superior performance and noise reduction translate into lower maintenance and energy expenses over time, enhancing overall cost-effectiveness.
Application Suitability:
Internal helical gear pumps are preferred in noise-sensitive, precision machinery, environmental equipment, and advanced hydraulic systems demanding smooth flow. Internal straight tooth gear pumps fit well in general industrial applications and basic hydraulic equipment where cost and simplicity are prioritized.
Recommended Internal Low-pressure Gear Pump
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Internal Low-pressure Hydraulic Gear Pumps: Enjoy Smooth, Low-noise Hydraulic Performance
Discover internal low-pressure (below 16 MPa) hydraulic gear pumps, engineered for diverse industrial applications. Experience compact design, quiet operation, high efficiency, and reliable fluid transfer tailored for manufacturing, construction, automotive, and chemical processing industries.
Agricultural Machinery - Combine Harvester
Drive grain bin unloading systems and header height adjustment to meet the needs of low-pressure, high-flow field operations.
Industrial Equipment - Conveyor Belt Drive
Control material transmission speed, suitable for light-load assembly line scenarios.
Automotive Manufacturing - Automatic Transmission
Provide low-pressure hydraulic oil in the shift control module to assist the precise engagement of the clutch and gear.
Automotive Manufacturing - Suspension Test Rig
Simulate vehicle load conditions and adjust test parameters through low-pressure hydraulic system.
Food & Pharmaceutical - Liquid Filling Machine
Transport low-viscosity liquids (such as juice and dairy products), meet hygiene standards and are corrosion-resistant.
Food & Pharmaceutical - Pharmaceutical Mixing Tank
Circulate liquid medicine or detergent to ensure pollution-free transmission in a low-pressure environment.
Medical Equipment - Blood Analyzer
Precisely control the quantitative delivery of reagents and samples to avoid high pressure damage to biological component.
Medical Equipment - Dialysis Machine
Drive the dialysate circulation system to ensure the safety and stability of the patient's treatment process.
Marine & Port Equipment - Ship Hatch Control
Operate hatch opening and closing, low-pressure system is suitable for corrosion protection and space-constrained environments.
Marine & Port Equipment - Passenger Boarding Bridge
Adjust the height of the boarding bridge, low-pressure hydraulics ensure smooth lifting and low noise.
Proper Maintenance Tips for Internal Low-Pressure Hydraulic Gear Pumps (<16MPa)
Maintaining internal low-pressure (below 16 MPa) hydraulic gear pumps properly is critical for extending service life, reducing downtime, and ensuring consistent hydraulic system performance in industries such as manufacturing, construction, automotive, and chemical processing. Below are key maintenance practices supported by industry data and best practices:
1. Regular Inspections
Conduct routine visual and operational inspections every 500 operating hours or quarterly, whichever comes first. Check for signs of wear such as increased internal leakage, abnormal noise, vibration, or temperature rise above 80°C. Inspect pump housing, shaft seals, and gear teeth for cracks, scoring, or corrosion. Early detection of wear can prevent catastrophic failures and extend pump life by up to 30%.
2. Proper Fluid Management
Use hydraulic fluids with ISO cleanliness level of at least 16/14/11 or better to minimize contamination-related wear. Monitor fluid viscosity and replace fluid every 2,000 operating hours or annually, whichever occurs first. Contaminated or degraded fluid can increase wear rates by 40% and reduce volumetric efficiency by 15-20%. Employ filters with micron ratings of 3-5 µm to protect internal components.
3. Controlled Operating Conditions
Avoid operating the pump continuously at pressures near the 16 MPa limit. Maintaining operating pressure at 70-85% of maximum rated pressure improves volumetric efficiency by 5-10% and reduces mechanical stress. Also, prevent excessive shaft misalignment and ensure proper coupling to reduce bearing and gear wear.
4. Scheduled Bedding-in and Break-in Procedures
For new or rebuilt pumps, perform a controlled break-in by running the pump at 50% load and 60-80% rated speed for the first 10 hours. This allows gear teeth and housing surfaces to mate properly, reducing initial wear and improving sealing. Proper break-in can extend pump service intervals by 20%.
5. Clean System Components
Regularly clean or replace hydraulic filters and maintain reservoir cleanliness to prevent abrasive particles from damaging pump internals. Flush the hydraulic system during major maintenance or fluid changes to remove sludge and deposits that can impair pump efficiency.
FAQs
Internal meshing gear pumps are more compact, quieter, and have strong self-priming capabilities, making them suitable for scenarios with limited space and low noise requirements (such as medical equipment and food processing); external meshing pumps are lower in cost but have larger flow pulsations, and are mostly used in general industrial equipment.
Yes, by optimizing gear materials (such as powder metallurgy or surface hardening) and sealing technology, the service life can reach more than 10,000 hours, and regular replacement of filters and hydraulic oil can further extend the service life.
The system flow demand (L/min) and working pressure curve need to be calculated, the recommended displacement range is 5-50 cm³/rev, and viscosity compatibility is considered (such as food-grade hydraulic oil requires special sealing materials).
Yes, pumps with fluororubber (FKM) or polytetrafluoroethylene (PTFE) seals are compatible with environmentally friendly oils, but custom designs are required to avoid corrosion and leakage risks.
It provides 316 stainless steel housings, polished flow channels without dead ends, FDA-certified seals, and is designed with CIP (cleaning in place) to meet EHEDG and 3-A hygiene standards.
Yes, its low inertia design and wear-resistant coating can withstand high-frequency start-stop, and is suitable for short-cycle operation scenarios such as logistics sorting machines and automated production lines.
Leakage is mostly caused by seal aging or shaft wear. It is recommended to check the seals every 2000 hours. When the flow rate decreases, it is necessary to check the filter blockage or oil contamination first.
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