Because internal gear pumps have only two moving parts, they are reliable, simple to operate, and easy to maintain. The working of the gear pump starts from receiving of fluid at the inlet. The rotating part extends the seal of liquid by the pump case to create suction at the inlet of the pump. The gear pump is simple in its operating principle. External gear pump free download as powerpoint presentation. An external precision gear pump is usually limited to a maximum working pressure of 210. The internal gear pumping principle was invented by jens nielsen it uses two rotating gears which unmesh at the suction side of the pump to create voids which allow atmospheric pressure to force fluid into the pump. The fluid travel through the pump between the the teeth of the gearwithinagear principle. The working principle of gear pump the structure of the gear pump is very simple, that is, it is the most basic form of two dimensions of the same gear in a tight fit the shell body of a mesh with each other in the rotation, the shell of internal similar 8 glyph, two gear installed inside, outside diameter of gear on both sides and the shell and tight fit. The shoes of the pump are fixed onto the rotor of the pump, which press the fluid through the pump. It may be calculated from the physical dimensions of the gears, or it. External gear pumps use straight spur type gears or helical type gears for their working.
The gear pump working animation video below describes the working principle of the spur type gear pump, which is more common. The working pistons extend in a radial direction symmetrically around the drive shaft, in contrast to the axial piston pump. However, the external gear pump uses two identical gears rotating against each other one gear is driven by a motor and it in turn drives the other gear. Gear pump working, construction, maintenance marinersgalaxy. A drive gear that is driven by a motor rotates an idler gear in the opposite direction. In this video we are going to see how external gear pump works. As the process fluids i was dealing with were of high viscosity, the most common pumping system i came across was the gear pump. The straightforward and rugged construction guarantees long service life without the need for extensive maintenance. Lobe contact is prevented by external timing gears located in the gearbox. All 29 digits of the code must be present to release a new product number. The working principle is similar to how our body pumps blood, nutrition and. An external gear pump uses two external gears figure 1, below that displace nonlubricating fluids gears are oil lubricated. A pump is a device or an apparatus used for conveying a fluid from one point to other, usually through a pipe. Review different pump types commonly used understand the difference between centrifugal pumps and positive displacement pumps understand the working principle of the tuthill.
Gear pump is straight forward and simple in their working. Pdf this paper presents an experimental study of external gear. Experimental study of the flow in an external gear pump by. The gear pump working principle is, it uses the gears actions otherwise rotating actions to move liquids. The pump features a casing in which a dual gear an outer rotor gear and an internal idler gear and crescent assembly is housed. Its purpose is to convert energy of a prime mover a electric motor or turbine first into velocity or kinetic energy and then into pressure energy of a fluid that is being pumped. In an internal gear pump fluid enters int the suction port between the rotor and idler it is a small interior gear teeth. The main benefits of using these pumps are superior like it can drive high thickness fluids, easy to use, operate and also maintain.
In an internal gear pump, the rotor supports on one or two bearing and the design of the pump is bulky that makes it inefficient to work on high specification models. It has more than two internal gears which create vacuum pressure to push the fluid in the pump. Working mechanism of a centrifugal pump a centrifugal pump is one of the simplest pieces of equipment in any process plant. Each gear is supported by a shaft with bearings on both sides of the gear. A gear pump is basically a positive displacement rotary pump, it has more than two internal gears that generate vacuum pressure through the mechanical movement of the gears, aiming to propel the movement of the fluid in the pump. An external gearpump can be built with two gears namely interlocking and identical where interlocking gear is held up with. Gear pump working principle animation video a gear pump is a rotary type of positive displacement pump. This is a function of the fluid viscosity, clearance between internal components, friction between mating components, and other variables.
Largecapacity external gear pumps typically use helical or herringbone. This nomenclature differentiates it from an internal gear pump, which has one gear positioned inside the other. In this study, the flow phenomena of an external gear pump. Three factors are involved in the regulation of flow. Apr 27, 2017 external gear pump body base mounted motor. The term positive displacement for gear pumps describes the fixed amount of fluid they move for each revolution. External gear pumps are used in industrial and mobile e.
Internal gear pumps are rotary positive displacement pumps which move the same amount of fluid with each revolution of the shaft. Though the gear pump is extremely simple in its operating principle, the. Internal gear typical internal gear or gearwithinagear technology was invented in 1902 by the founder of viking pump, which is the worldleading provider of internal gear process pumps. The gear pump is a precision machine with extremely tight fits and tolerances, and is capable of working against high differential pressures. Use this model code to specify a pump with the desired features. External gear pumps external gear pumps are a popular pumping principle and are often used as lubrication pumps in machine tools, in fluid power transfer units, and as oil pumps in engines. In this lecture the working principle, flow ripple and relevant characteristics of an involute gear pump are discussed. A typical representation of an external spur type gear pump is shown above. The qx pumps are the 5th generation of bucher internal gear pumps, which have proven themselves in thirty years of service around the world. The mechanism is usually driven by one of the toothed gears, which in turn drives the other. The working principle of external gear pumps is very simple. External gear pumps are a popular pumping principle. Liquid enters the suction port between the rotor large.
An image can be paired in principle with the next or previous. The gear pump working principle involves the rotary action of two gear toothed rotors which unmeshes at the suction end thus drawing in liquid carries liquid along the gear teeth and meshes at discharge end thus forcing the liquid out against discharge line pressure. A pump may, therefore, be defined as a mechanical device which translates the mechanical energy imparted to it from an external source electric motor, diesel engine or even manual energy into hydraulic energy in the fluid handled by it. A balanced vane pump is a very versatile design that has found widespread use in both industrial and mobile applications. The internal gear pump is nonpulsing, selfpriming, and can run dry for short periods. There are two types of spur gears used in industries i. Similar to the external gear pump, the lobes rotate to create expanding volume at the inlet. External gear pumps are capable of working against high differential pressures. Gear pumps a simple type of rotary pump where the liquid is pushed between two gears. Based upon the work of hersey, this dimensionless group of. In the gear pump, one of the rotors receives drive from an external source and directly transmits the drive to the other rotor. External gear pumps can come in single or double two sets of gears pump configurations with spur shown, helical, and herringbone gears.
The working principle of a peristaltic pump is based on moving a product through a hose, by compressing and decompressing. Internal gear pumps use a gear within a gear design. The pump housing is in stainless steel aisi 316l, while gears and bushings fg200300400 series pumpmotor unit. Types of gear pump internal, external,gerotor, lobe pump. The rotating gears develop a liquid seal with the pump casing and create suction at the pump inlet. It differs from the conventional externalgear pump in the way the gears are driven. Fundamentals of industrial oil hydraulics and pneumatics. External gear pumps are a popular pumping principle and are often used as lubrication pumps in machine tools, in fluid power transfer units, and as oil pumps in engines. The fluidotech fg200300400 series, born from the solid experience in mag drive gear pumps, is a. Internal gear pump with detail explaination and animation in this video, you will learn about an internal gear pump working process. Tandem and multiple pumps are available worldwide in more than variants. Pdf flow characteristics of external gear pumps considering. A gear pump is a type of positive displacement pd pump. Rotary pumps use a variety of means to generate flow.
An external precision gear pump is usually limited to a maximum working pressure of 210 bars 21,000 kpa and a maximum speed of 3,000 rpm. A gear pump uses the meshing of gears to pump fluid by displacement. The spaces between the gear teeth transport the fluid on either side of a crescent to the discharge side, and. An internal rotary gear pump employs a positive displacement principle.
Pdf an investigation of external gear pump efficiency and. Useful information on external gear pumps michael smith engineers. Theyre also birotational, meaning that the same pump can be used to load and unload vessels. The lobe pump is a rotary, externalgear pump, figure 3. Advantages and disadvantages of gear pump hoffwell pump.
Pump efficiency models are based upon the principles of newton, petroff, and poiseuille. As the rotor gear begins to turn, the idler gear rotates with the. The fluidotech fg100 series, born from the solid experience in mag drive gear pumps, is a smart and compact pumpmotor unit. The pumping capacity of the internal gear pump is less in comparison to the external fear pumps. Displacement d the displacement of a rotary gear pump is the volume displaced during one complete. When the fluid moves forward due to the vacuum created behind the teeth of the two gears, it starts getting trapped into the teeth of the gears. Gear pumps use the actions of rotating cogs or gears to transfer fluids. This gear pump uses two external gears with external cut teeth for the displacement of fluids.
This type of pump is very cheap, easy to handle and operate. Lobe pumps work on the similar principle of working as that of external gear pumps. External gear pump principles michael smith engineers. However in lobe pumps, the lobes do not make any contact like external gear pump see figure. A pair of gears with many teeth external to the gear and called an external gear pump in gear pumps or a few lobes in lobe pumps is demonstrated in fig.
The gear pumps are the highpressure pumps which come in small sizes to provide a pulseless as well as stable fluid flows as compared to other pumps like peristaltic and diaphragm pumps. Scribd is the worlds largest social reading and publishing site. A gear pump uses two meshing, toothed cogs to force water from the inlet of the pump through to the outlet. Types of rotary pumps include camandpiston, internalgear, lobular, screw, and vane pumps. Gear pumps are found in home heating systems in which the burners are fired by oil.
Eaton ternal ear pump d series pcc01 december 14 7 model code double pump the following 29digit coding system has been developed to identify standard configuration options for the external double gear pump. Suction and delivery of this type of pump occurs due to. This is an animation video on the working of an internal gear. Useful information on internal gear pumps what is an internal gear pump. Some manufacturers produce gear pumps with higher working pressures and speeds but these types of pumps tend to be. Typically, gear pumps have efficiencies around 85%. Because the pump body weight than the motor, but it and other equipment for the pipeline connected to each other, while other equipment after installation. Peristaltic pumps are not generally used for high pressures. Externalgear pumps are comparatively immune to contaminants in the oil, which will increase wear rates and lower efficiency, but sudden seizure and failure are not likely to occur. What is positive displacement pumps types and advantages. Gear pumps are among the oldest and most commonly used pumps within the industry. What is an external gear pump and why do you need it. The working principle of the external gear pump is illustrated in figure 1. There are three stages in an internal gear pumps working cycle.
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