External gear pumps are among the most commonly used positive displacement pumps in various industries. Due to their simple design, high reliability, and efficiency, they are frequently used to pump liquids of varying viscosities. This article describes the components and functions of an external gear pump .
Introduction: What is an external gear pump?
An external gear pump is a hydraulic pump that uses two meshing gears to move fluids. These pumps are widely used in hydraulic systems, the oil and gas industry, the automotive industry, and chemical pipelines. Understanding their design contributes to performance optimization and proper maintenance.
Main components of an external gear pump
External gear pumps consist of several components, each of which plays a crucial role in the overall performance of the pump. The most important components include:
1. Outer gear (pinion)
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Drive wheel : connected to the input shaft and driven by the internal combustion engine or electric motor.
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Secondary gears : They are driven by the drive gears and move in the opposite direction.
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Materials for the gears : Typically made of steel, cast iron or corrosion-resistant materials.
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Function : The rotation of the gears creates a relative vacuum on the suction side, which directs the liquid to the outlet.
2. Living
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Function : A housing that contains gears and other components and prevents the leakage of fluid.
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Housing material : Typically made of cast iron, steel, or aluminum.
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Internal structure : It has an inlet and an outlet to direct the fluid in the correct direction.
3rd axis
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Transmission shaft: transmits the torque from the engine to the transmission.
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Drive shaft : Some models have a second shaft used to move the gears.
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Nuts and washers : are used to securely fasten shafts to gears.
4th camp
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Function : Reduces friction and protects the shaft from radial and axial loads.
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Bearing type : Ball or plain bearing (depending on the pump design).
5. Print
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Mechanical seal : prevents fluid leakage.
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O-rings : Used to seal solid components .
6. Side walls
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The task is to close both sides of the gear to form a closed sleeve.
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Materials : Usually made of steel or copper .
7. Pressure relief valve
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Application : To prevent overpressure in the system and to protect the pump from damage.
8. Entrance and Exit
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Inlet : Liquid is drawn into the pump through this section.
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Outlet : In this section, the pressurized liquid is drained.
The operating principle of an external gear pump
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Intake phase : The rotation of the gears increases the distance between them on the inlet side, and the liquid is drawn in.
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Fluid transport : The fluid is held between the fins and the housing and transported to the outlet.
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Outlet : On the outlet side, the gearbox reduces the distance between the gears, and the fluid is expelled under pressure.
Advantages and disadvantages of external gear pumps
Advantages:
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The design is simple and the manufacturing costs are low.
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Can pump viscous liquids (oil and chemicals).
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High efficiency at moderate pressure.
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Compared to piston pumps, the pulsating flow rate is lower.
Shortage:
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Long-term wear and tear of the equipment.
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Sensitive to solid particles in liquids.
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Its limits are reached at extremely high pressures.
Application of the external gear pump
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Hydraulics industry : Pumps of hydraulic oil.
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Food industry : Production of edible and drinking oils.
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Oil and gas : Transport of industrial oil and petroleum fuels.
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Automobiles : Lubrication and fluid supply systems.
In conclusion
External gear pumps are leaders in this field due to their simple design and reliability. Understanding the key components of these pumps – from the gears and casing to the bearings and sealing systems – helps optimize their operation and extend their service life. Selecting the right materials and performing regular maintenance are crucial for optimal pump performance.
If you are planning to buy or repair a gear pump, you should definitely check the quality of the internal components and their suitability for the intended fluid.