What is Internal Gear Pump | Principle, Construction, Working and more

• When motor shaft rotates, it will rotate the internal gear and it drives the external gear.

• It effects a fluid fight seal at the meshing point of the teeth. The teeth wich are unmeshing at the inlet port creates partial vaccum and suction of oil occurs.

• Oil is get trapped between internal and external gear teeth and both side of the crescent shaped spacer.

• Meshing of gear teeth reduces the volume in the high pressure cavity near the outlet port and discharge high pressure oil from the outlet port.

• The internal gear pumps are very efficient and produces less noise.

• The volumetric efficiency is about 95% and overall efficiency 85-90% .

Advantages and Disadvantages

Internal gear pumps are widely used in various industries for fluid transfer and pumping applications. Like any other technology, they have their own set of advantages and disadvantages. Here are some advantages and disadvantages of internal gear pumps:

Advantages:

1. High Efficiency: Internal gear pumps are known for their high volumetric efficiency, meaning they can move a large volume of fluid with minimal energy losses. This makes them energy-efficient and cost-effective in the long run.
2. Wide Range of Viscosity: Internal gear pumps can handle a wide range of fluid viscosities, from low-viscosity liquids to highly viscous fluids. This versatility makes them suitable for pumping different types of liquids, including thin oils, fuels, chemicals, and even adhesives.
3. Self-Priming: Internal gear pumps are self-priming, which means they can draw fluid into the pump and create suction without the need for external priming assistance. This feature simplifies the installation and operation of the pump.
4. Low Noise and Vibration: Internal gear pumps operate with minimal noise and vibration levels, making them suitable for applications where quiet operation is required, such as in medical equipment or in noise-sensitive environments.
5. Reversible Flow: Internal gear pumps can provide reversible flow by changing the direction of rotation. This feature allows for versatility in applications that require bidirectional pumping.

Disadvantages:

1. Limited Solids Handling: Internal gear pumps are not designed for handling fluids with high solid content. They are more suitable for pumping clean or slightly contaminated fluids. Solids or abrasive particles in the fluid can cause wear and damage to the pump’s internal components.
2. Sensitivity to Fluid Viscosity Changes: While internal gear pumps can handle a wide range of viscosities, they may experience a decrease in performance when there are significant changes in fluid viscosity. Viscosity changes can affect the pump’s volumetric efficiency and overall pumping capability.
3. Limited Pressure Capability: Internal gear pumps are typically limited in their maximum pressure capability compared to other pump types, such as centrifugal pumps. If high-pressure pumping is required, additional stages or a different pump design might be necessary.
4. Internal Leakage: Internal gear pumps can experience internal leakage due to the close tolerances between the gears and the pump casing. This internal leakage can reduce the overall efficiency and require regular maintenance and monitoring to prevent issues.
5. Complex Design: The internal gear pump design consists of multiple internal components, such as gears, bushings, and shafts. This complexity can make the pump more difficult to manufacture, assemble, and maintain compared to simpler pump designs.

It’s important to consider these advantages and disadvantages when evaluating the suitability of an internal gear pump for a specific application. The specific requirements and characteristics of the application should be carefully assessed to determine if an internal gear pump is the right choice.

Application

nternal gear pumps find application in various industries and sectors due to their versatile pumping capabilities. Some common applications of internal gear pumps include:

1. Lubrication Systems: Internal gear pumps are extensively used in machinery and equipment lubrication systems. They can efficiently pump lubricating oils or fluids to ensure smooth operation and minimize wear and friction between moving parts.
2. Chemical Processing: Internal gear pumps are suitable for handling various chemicals and corrosive fluids. They are used in chemical processing plants for transferring and circulating chemicals, acids, solvents, and other corrosive substances.
3. Fuel Transfer: Internal gear pumps are commonly employed in fuel transfer applications, such as refueling systems, fuel oil delivery, and bulk fuel transfer. They can handle a wide range of fuels, including gasoline, diesel, biodiesel, and aviation fuel.
4. Pharmaceuticals and Cosmetics: Internal gear pumps are used in the pharmaceutical and cosmetic industries for precise and controlled pumping of liquids, creams, lotions, and other cosmetic products. Their ability to handle a wide range of viscosities makes them suitable for these applications.
5. Food and Beverage: Internal gear pumps are employed in the food and beverage industry for pumping various liquids, including fruit juices, sauces, chocolate, syrups, and food additives. They are designed to meet sanitary standards and can handle both viscous and non-viscous food products.
6. Polymer and Plastics: Internal gear pumps are used in polymer processing and plastics manufacturing for pumping polymers, resins, and molten plastics. They provide consistent and reliable flow control, which is crucial for maintaining quality and precision in these processes.
7. Hydraulic Systems: Internal gear pumps are utilized in hydraulic power units and systems for generating hydraulic pressure. They can provide the necessary flow and pressure for operating hydraulic cylinders, actuators, and motors in various industrial machinery and equipment.
8. Marine and Offshore Applications: Internal gear pumps are employed in marine and offshore industries for applications such as ballasting, bilge pumping, fuel transfer, and hydraulic power units. They are chosen for their compact size, reliability, and ability to handle marine fuels and fluids.

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