What is Gear Pump? Its Application, Diagram, And How It Works
Gear pumps are mostly utilized for high-viscosity materials with lubricating qualities. They can produce high pressures at low flow rates and are often utilized for hydrocarbon samples, including the heaviest fuel oils and diesel oil.
These pumps are simple and compact, but they can be noisy if poorly designed. The simplest type is the gear pump. As the gears rotate, the fluid is trapped in the spaces between the gear teeth and the housing, and the flow volume is controlled by adjusting the drive gear’s speed.
In this article, we will explore what a Gear Pump is, it’s application, diagram, types, it features, and how it works. We also discussed its advantages and disadvantages
Let’s drive in!
What is a Gear Pump?
A gear pump pumps fluid through positive displacement by means of gear meshing. They are among the most popular kinds of pumps used in hydraulic fluid power systems. Around 1600, Johannes Kepler created the gear pump.
In chemical plants, gear pumps are also frequently used to move extremely viscous liquids. Internal gear pumps, which use an external and internal spur gear, and external gear pumps, which use two external spur gears, are the two primary variations.
A gear pump in which is used for small volume lubricating oil services and particularly viscous liquids (such as asphalt, polyethylene, etc.). The fluid is conveyed between the teeth of two external gears and displaced when they mesh.
Gear pumps pump a fixed volume of fluid with each revolution because they are positive displacement (also known as fixed displacement) pumps. Certain gear pumps are made to work as both a pump and a motor.
Gear pumps are rotary pumps that generate pumping motion by meshing two or more gears. Typically, one gear can drive the other gears. The gerotor pump is the most basic kind of this kind of rotary pump.
These pumps are frequently employed in applications with tiny volume capacities and constrained space. These gear pumps can be used to lubricate vital moving machine parts with oil on a rotating shaft, such as a crankshaft.
Application of Gear Pump
Gear pumps are frequently used to pump high-viscosity fluids like oil, paints, resins, or foodstuffs. They are preferred in any application where precise dosing or high-pressure output is needed.
Known for its high accuracy, repeatability, and reliability, the gear pump is used in a variety of industries where precise metering is necessary to ensure product quality and process control. It is a mechanical delivery device used for precise and controlled metering of liquids or viscous materials.
It is made up of two intermeshing gears that rotate in a housing, in which the material to be conveyed is trapped between the teeth and transported from the inlet side to the outlet side.
They are used as oil pumps in engines for cooling and lubricating oil supply; they are also used in automatic gearbox systems, semi-automatic clutches, power steering and propulsion systems; they are used in the food industry to transfer oils, butter, vegetable fats and other similarly viscous
Petrochemicals include bitumen, pitch, diesel oil, crude oil, and lubricating oil. Chemicals include sodium silicate, acids, polymers, and mixed chemicals. Paint and ink, resins, adhesives, and pulp and paper contain acid, soap, lye, black liquor, kaolin, lime, latex, and sludge.
Diagram
What are the different types of gear pumps?
Various types of gear pumps can be distinguished based on their design and intended use. The primary categories of gear pumps are as follows:
Internal gear pumps: The internal gear, or input gear, of an internal gear pump engages with the external gear, or output gear, which is housed inside the casing. Applications involving high viscosity frequently use these pumps.
External gear pumps: The input and output gears of external gear pumps are located outside the casing. The material is pumped by the gears rotating on the same axis.
Internal Gear Metering Pumps: These pumps are made especially for applications involving dispensing and metering. They offer accurate fluid metering and frequently employ two intermeshing internal gears.
External gear metering pumps: Similar to internal gear pumps, external gear metering pumps are employed only for metering and dispensing purposes. Their metering accuracy is well-known.
Gear pumps with internal and exterior gears: To satisfy certain needs, such as high viscosity or high pressures, some gear pumps are designed with both internal and external gears.
Multiple gear pumps: To improve metering performance, these pumps have several pairs of gears that work together. They are frequently employed in industrial settings where substantial liquid volumes are needed.
Gear pumps (gerotor pumps): Gerotor pumps, often referred to as gear pumps, employ an exterior gear with unique geometry in addition to an internal gear. They offer a good combination of performance and compactness.
Twin-screw pumps: These pumps use two intermeshing helical gears to move fluids. They are used in high-flow and low-viscosity applications.
Gear pumps for high-pressure applications: Specially designed gear pumps can produce very high pressures and are used in applications such as high-pressure cleaners and water jet cutting machines.
Choosing the right gear pump depends on the specific requirements of an application, including the type of material being pumped, metering accuracy, pressure and temperature range, and other factors. Each type of pump has its own benefits and limitations and is better suited for various jobs.
What are the main features of a gear Pump
Gear pumps have few moving components and are small and straightforward. They provide greater pressures and throughputs than vane or lobe pumps, but they cannot equal the pressure produced by reciprocating pumps or the flow rates of centrifugal pumps.
For pumping oils and other highly viscous fluids, gear pumps are especially well-suited. Because of the tighter tolerances and more sturdy shaft support, external gear pumps can withstand higher pressures (up to 3000 psi) and flow rates than the other type.
Although internal gear pumps have a usable working range of 1cP to over 1,000,000cP, they are superior at suction and work best with high viscosity fluids. Gear pumps are frequently employed for mixing and metering tasks since their output is directly related to their rotating speed.
Aggressive liquids can be handled using gear pumps. New alloys and composites enable the pumps to handle corrosive liquids including sulphuric acid, sodium hypochlorite, ferric chloride, and sodium hydroxide, despite their typical construction from cast iron or stainless steel.
In hydraulic power applications, such as those used in automobiles, lifting equipment, and mobile plant equipment, external gear pumps can also be employed. A hydraulic motor is produced by driving a gear pump in reverse while using oil that has been pumped from another part of the system, usually by an engine tandem pump.
In places where electrical equipment is large, expensive, or cumbersome, this is very helpful for supplying electricity. For instance, the services of tractors are powered by external gear pumps that are operated by engines.
How do gear pumps work?
Gear pumps move fluids by means of revolving cogs or gears. At the pump inlet, the rotating element generates suction and forms a liquid seal with the pump casing. After being drawn into the pump, the fluid is moved to the discharge through the cavities of its revolving gears.
A gear pump in measuring technology operates by rotating two intermeshing gears. The pump chamber is filled with material at the beginning of the pumping cycle, with the inlet valve open.
As the gears rotate, gaps between teeth on the material inlet side fill with material, while material is displaced from the pump on the outlet side through engagement of teeth in the other gear’s tooth gaps.
The displaced material is then conveyed into the metering area with the outlet valve opening and discharged into the metering system.
By trapping fluid between the teeth of two or three rotating gears, gear pumps function. Because they are frequently magnetically driven, they require fewer “wetted” materials for improved chemical compatibility. Instead of reciprocating, gear pumps rotate a cavity.
These pumps don’t pulse nearly as frequently as diaphragm pumps because they move a lot of tiny cavities with each revolution. The main drawback of gear pumps is that their flow rate does decrease as the backpressure rises.
When pumping against steady backpressure, they perform at their best. Gear pumps are ideal for applications where fluid shearing or particle contamination from gear wear is not an issue because they work by moving fluid between the teeth of two or three rotating gears.
These pumps are frequently used for hydraulic fluid power applications, such as in tractors and garbage trucks, and with heavier viscosity fluids, like oil, that are not compressible. They also function well in high-system pressure applications.
True positive displacement is a feature of gear pumps, which deliver a precise volume with each revolution. The flow rate is almost pulseless because each fluid pocket that moves through the chamber is tiny, and there are a lot of pockets that move through in a given amount of time.
Advantages of a Gear Pump
Gear pumps provide several benefits in a variety of applications, particularly where accurate metering or dependable fluid delivery are needed. Below are list of some benefits of gear pumps:
High accuracy: Because the gears mesh finely and provide a precisely defined volume per revolution, gear pumps provide accurate metering of liquids or viscous solids.
Low pulsation: In applications requiring delicate instruments or equipment, gear pumps usually generate a consistent and low amount of pulsation in the fluid flow.
Versatility: They work with a variety of fluids and viscous substances, such as paints, adhesives, lubricants, chemicals, and oils.
Reliability: Generally speaking, gear pumps are dependable and long-lasting. They have little downtime and require minimal maintenance.
Easy maintenance: Due to its accessibility and reduced number of moving components, gear pumps are frequently simple to maintain.
Efficiency: Gear pumps often achieve high metering rates with minimal energy usage, making them energy efficient.
Good self-priming: In some applications, their ability to prime fluids from low levels or against a little vacuum is advantageous.
inexpensive maintenance expenses: Long-term maintenance costs are frequently inexpensive due to their dependability and minimal requirement for spare components.
Adaptability: They may be modified for a range of settings and uses, such as high-pressure and high-temperature applications.
Compact design: Gear pumps may frequently be fitted in small spaces due to their compact design.
The particular needs of an application determine which pump is best. Gear pumps are a common option where minimal pulsation and accurate metering are crucial. They are employed in many different sectors, including the production of chemicals, food, oil and gas, and pharmaceuticals, among many others.
Disadvantages of a Gear Pump
After wear, repairs are difficult: It is difficult to replace the gear pump after wear since the parts are not easily interchangeable. The complete gear pump is quite hard to replace if the parts are worn, even though the repair procedure is straightforward.
A lot of noise: The gear pump produces an extremely loud noise because to its enormous flow artery and radial force imbalance. The gear pump will interfere with other people’s work or relaxation if it is in a location where noise levels are required for the surrounding environment or if it is utilised in the middle of the night. The bearings’ service life will also be somewhat impacted by the presence of imbalanced radial forces.
displacement without adjustment: The gear pump’s displacement cannot be changed and it can only be used as a dosing pump since the end cap and gear’s inter-tooth groove creates a number of permanent sealed working chambers. If you wish to raise the pump’s displacement, this is not feasible.
FAQs
What is the advantage of a gear pump?
In fluid transfer, gear pumps are renowned for their accuracy and efficiency. Their distinctive shape contributes to a steady and efficient fluid flow, reducing waste and increasing efficiency. Because they typically only contain two gears, gear pumps are simple to operate and maintain.
Can a gear pump pump water?
Pumping water, light oils, chemical additives, resins, or solvents is a popular application for external gear pumps. When precise dosage or high pressure output are needed, they are the recommended option. High pressures can be maintained using external gear pumps.
What is the difference between a gear pump and a centrifugal pump?
The gear pump has quantitative capability and less capacity fluctuation as pressure increases than the centrifugal pump. By altering the rotation speed, the capacity may be easily controlled. As a result, an inverter or speed variator may be attached to regulate the flow rate.
What are the 2 types of gear pump?
The two primary categories are internal and exterior. Two similar gears that interlock and are supported by different shafts make up an external gear pump. Two interlocking gears of varying diameters, one of which rotates within the other, make up an internal gear pump.
How long do gear pumps last?
Generally speaking, the following is true: Gear pump: 10,000–15,000 hours, or around five to seven years of operation 12,000 to 18,000 hours of vane pump operation, or around 6 to 9 years of use Piston pump: 20,000+ hours, or around ten years of operation.
