Mastering Internal Eccentric Gear Pump Working Principle and Maintenance

An internal eccentric gear pump is a type of positive displacement pump that is widely used across various industrial applications, from automotive and chemical processing to food and beverage production. Its unique design offers advantages such as high efficiency, robust construction, and low noise operation, making it an indispensable tool in modern industrial processes.

This article aims to provide a comprehensive guide on the working principle of internal eccentric gear pumps and essential maintenance practices. By understanding how these pumps operate and maintaining them correctly, you can ensure optimal performance and extend their lifespan.

What is an Internal Eccentric Gear Pump?

An internal eccentric gear pump is designed to move liquids using rotating gears. The pump consists of two gears: a rotor (inner gear) and an idler (outer gear).

The rotor is mounted on a shaft and is driven by an electric motor. The idler gear is mounted within the rotor and is driven by the rotor gear. This design allows the pump to handle high viscosity fluids with ease and ensures smooth flow.

Key Components of Internal Eccentric Gear Pumps

1. Rotor (Inner Gear)
2. The rotor is the smaller gear with external teeth.

3. It rotates within the larger idler gear, creating a pumping action.

4. Idler (Outer Gear)

5. The idler is the larger gear with internal teeth.

6. It rotates within the rotor, driving fluid through the pump.

7. Crescent Seal

   
   
8. A fixed, crescent-shaped seal is installed between the rotor and idler.
9. It separates the suction and discharge zones, preventing fluid from flowing back.

Working Principle of Internal Eccentric Gear Pumps

Understanding the working principle of an internal eccentric gear pump is crucial for troubleshooting and maintenance. The pump operates by creating and collapsing fluid cavities, which transport the fluid through the pump.

Step-by-Step Operation

1. Cavity Formation (Suction Side)
2. As the rotor rotates, the teeth of both gears disengage on the side opposite where they mesh.

3. This creates an expanding cavity, which draws in fluid from the suction port due to atmospheric pressure.

4. Fluid Transport

5. The fluid is carried around the pump between the gears.

6. The crescent seal prevents backflow from the discharge to suction side.

7. Cavity Collapse (Discharge Side)

8. As the gears approach the meshing point, the cavities shrink.

9. The meshing of the gears forces the fluid through the discharge port.

10. Continuous Rotation

    
    
11. The continuous rotation ensures a steady flow of fluid.
12. The overlapping phases result in smooth, pulse-free flow.

Maintenance Practices for Internal Eccentric Gear Pumps

Proper maintenance is essential to ensure the longevity and efficiency of internal eccentric gear pumps. Here are some best practices:

Regular Inspection Schedule

• Inspection Frequency: Monthly or bi-monthly checks are recommended.
• Components: Check the rotor, idler, seals, and bearings.

Lubrication and Seal Checks

• Lubrication: Regularly check and replace lubricant as needed.
• Seal Condition: Inspect seals for wear and tear. Replace as required.

Cleaning and Sealing Recommendations

• Cleaning: Clean the pump regularly to remove debris and ensure proper operation.
• Re-sealing: Apply proper sealing compounds to maintain tightness.

Common Problems and Troubleshooting

Fixing a Leaking Internal Eccentric Gear Pump

1. Inspection: Identify the source of the leak.

2. Check for worn seals, loose connections, or damaged components.

3. Seal Replacement:

4. Replace worn or damaged seals with new ones.

5. Ensure proper sealing compound is applied during installation.

6. Alignment Check:

7. Ensure proper alignment of the rotor and idler.

8. Misalignment can cause increased wear and higher leakage rates.

9. Pressure Relief Valves:

   
   
10. Check the pressure relief valves to ensure they are functioning correctly.
11. Properly functioning relief valves can prevent excessive pressure build-up and reduce the risk of leakage.

Other Maintenance Tips

• Filters: Use appropriate filters to remove impurities and particulates from the fluid.
• Routine Checks: Perform routine checks on the pump's health and performance.
• Temperature Monitoring: Monitor temperature during operation to prevent overheating.

Table Comparison: Internal vs. External Gear Pumps

Conclusion

Final Thoughts

Regular maintenance and proper operation are key to maximizing the efficiency and longevity of internal eccentric gear pumps. Trustech Technology, as a leading manufacturer, emphasizes the importance of regular inspection, lubrication, and sealing checks to maintain the integrity of these critical components. Implementing these best practices will help you avoid common issues like leaking and ensure your pumps continue to function reliably over time.