A gear pump uses the meshing of gears to pump fluid by displacement. The chamber of the pump is divided into a set of control volumes cvs, whose effective volumes change along with the rotation of the gears. This seal forces the liquid out of the discharge port. Sep 07, 2019 liquid ring vacuum pump working principle. These pumps are positive displacement pumps and anything drawn into them will be forced out. An internal gear pump operates on the same principle but the two interlocking. The qxv unit is an internal gear pump for lowviscosity flu. External gear pump overview michael smith engineers. All content contained herein is subject to change at the companys discretion without notice. As the gears come out of mesh on the inlet side of the pump, they create an expanded volume. Thus, the pump has only two moving parts, the rotor and the idler gear. The internal gear pump is nonpulsing, selfpriming, and can run dry for short periods. It has more than two internal gears which create vacuum pressure to push the fluid in the pump. Jul 18, 20 the arrows indicate the direction of the pump and liquid, 2.
Displacement d the displacement of a rotary gear pump is the volume displaced during one complete. The fluidotech ig series positive displacement gear pump has been designed to handle viscous fluids with impurities in suspension and temperatures up to 200 c 392 f whilst delivering a smooth flow. Screw pumps also falls in the category of rotary pumps and have the same mechanism and principle. Rotor and idler teeth mesh completely to form a seal equidistant from the discharge and suction ports.
A three screw pump operates on the same principle of intermeshing screws as the two screw pump, and can be configured as a double suction pump technically, a six screw pump. They typically consist of a northern heavy duty gear pump, electric motor, shaft coupling, and coupling guard, mounted on a unit base. The straightforward and rugged construction guarantees long service life without the need for extensive maintenance. The positivedisplacement principle is well illustrated in the reciprocating type. We model the whole working process of an external gear pump. The three screw design utilizes a centrallylocated primary screw, or power rotor, which intermeshes with two secondary screws, or idler rotors. Annual tests at least once a year, test the pumper to determine if it is capable of meeting the. Roots pumps, screw pumps, claw pumps or at the pumps high pressure.
The working of the gear pump starts from receiving of fluid at the inlet. Advances in the manufacturing process have made it poss. Design and per formance of gear pumps with a noninvolute tooth pro file. Useful information on gear pumps what is a gear pump. Internal gear pump design for automotive oil pumps. When using a gear pump a pressure relief valve must be fitted to protect the pump if deadheaded against a closed valve or blockage. The term positive displacement for gear pumps describes the fixed amount of fluid they move for each revolution. Gear pumps make good chemical additive dosing pumps provided material compatibility issues are addressed. Gear pumps are compact, high pressure pumps which provide a steady and pulseless fluid. Two identical gears positioned side by side, rotating into one another. Centrifugal fire pump principles of operation, inspection tests and troubleshooting guide. One rotor of internally cut gear teeth will mesh with one externally cut gear. Gear pumps are positive displacement rotary pumps that transport liquids using rotating gears.
As the rotor gear begins to turn, the idler gear rotates with the. Some internal gear pumps have an additional, crescentshaped seal shown above, right. As the gears come out of mesh, they create expanding volume on the inlet side of the pump. Hi guys, this is an animation video on the working of crescent type pump or called as internal gear pump, charging pump etc. Liquid ring vacuum pump working principle and pumping system. A screw pump is a positivedisplacement pd pump that use one or several. Basics concepts of operation, maintenance, and troubleshooting, part i. Above figure shows construction exploded view of a typical flat plate type vacuum pump.
Internal gear pumps can be used up to a continuous pressure of 315 bar 4550 psi depending on the frame size. The arrows indicate the direction of the pump and liquid. A drive gear that is driven by a motor rotates an idler gear in the opposite direction. Rexroths complete line of hydraulic pumps serve virtually every industry in manufacturing and technology applications such as railway engineering, chemical process plants, power and environmental engineering, automotive engineering, plastics processing machinery, paper industry, presses, test rigs and simulation systems, marineoffshore. Gear pumps use toothed gears turning inside a close tolerance housing to drawin liquid and then squeezing it out ahead of them. Most pd pumps can be adapted to handle a wide range of applications, but some types are better suited than. Hydraulicspneumatics com sites hydraulicspneumatics com files uploads 2015 02. The theoretical flow ripple of an external gear pump. The pump features a casing in which a dual gear an outer rotor gear and an internal idler gear and crescent assembly is housed.
They come in many different sizes and designs and a firefighter needs to know how to operate the pump efficiently at all times. Liquid travels through the pump between the teeth of the gear withina gear principle. The gear pump is a precision machine with extremely tight fits and tolerances, and is capable of working against high differential pressures. Gear pumps galtech group 2 start pumps 12 tooth gears and consequent decrease in noise levels. Gear pump manual original instructions albany pumps. Gear pump working principle animation video a gear pump is a rotary type of positive displacement pump. Many external gear pumps use journal bearings to support the rotating shafts.
Sep 11, 2014 internal gear pump overview internal gear pumps are very versatile, with the ability to pump many different types of fluids at a wide range of viscosities and temperatures. Liquid enters the suction port between the rotor large exterior gear and idler small interior gear. We will also learn how is the working of screw pump different from that of other types of pumps. Jan 02, 2017 external gear pump flow through stephen stott. Some manufacturers produce gear pumps with higher working pressures and speeds but these types of pumps tend to be noisy and special precautions may have to be made. As the rotor gear begins to turn, the idler gear rotates with the teeth beginning to mesh accordingly. Pg330 pg331 tutorial01 cast iron gear pump salami spa duration. Abstract the paper comprises research results of the gear pump typical failures and their connection with symptoms observed during the pump working. A directdrive gerotor motor consists of an innerouter gear set and an output shaft fig. What is a double chamber vane pump and why you need it. I am sure that this book will serve the needs of electrical engineers working in the field of general services. Information on gear pumps including how gear pumps work, the main features.
Tandem and multiple pumps are available worldwide in more than variants. Operates a gear within a gear principle, whereby one gear the idler is positioned inside another gear the rotor. 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. Internal gear pump with detail explaination and animation in this video, you will learn about an internal gear pump working process. Each gear is supported by a shaft with bearings on both sides of the gear. One gear is driven by the motor and in turn moves the other gear. Each individual pump is preset for rear connection to one or more pumps by interposition of the appropriate coupling flange. 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. Theyre also birotational, meaning that the same pump can be used to load and unload vessels.
The prv can be piped back to the suction side of the pump or into the supply tank. Flange and cover in aluminium or on request, cast iron. A pump may be driven by hand, by an electric motor, by an internal combustion engine, or by hydraulic or pneumatic means. Typically, gear pumps have efficiencies around 85%. Flat plate type vacuum pumps have a port plate configuration rather than a cone, but the working principle is the same. Numerous improvements have been made to the straightforward and robust design. The qx pumps are the 5th generation of bucher internal gear pumps, which have proven themselves in thirty years of service around the world. Useful information on internal gear pumps what is an internal gear pump. Internal gear pump fluidotech ig series positive displacement internal gear pumps are designed to work in harsh environments, with unfiltered, abrasive fluids and in a wide temperature and viscosity range. Worked out criteria and their boundary values allowed the defect classes creation and the defectsymptom diagnostics relation. The qxv unit is an internal gear pump for lowviscosity flu ids. Gear pumps use the actions of rotating cogs or gears to transfer fluids. Precise by design, they deliver accurate and repeatable performance, a smooth flow and a pressure up to 18 bar 260 psi. For double chamber vane pumps, the process of filling the chambers suction and emptying is in principle the same as for single chamber vane pumps.
An internal rotary gear pump employs a positive displacement principle. Externalgear pumps can be divided into external and internalgear types. Viking pump pump innovations in liquid handling since 1911. Gear pump is straight forward and simple in their working. Useful information on gear pumps michael smith engineers. When the impeller rotates at high speed, the impeller drive a rotation of the liquid between the blades, due to centrifugal force, the liquid thrown from the center of the impeller outer edge of the impeller flow rate can be increased to 15 25m s, the kinetic. The fluid is been trapped in between the gap if the gear teeth and the casing and gets carried to the outlet and not through the engaging portion. A gear pump is a type of positive displacement pd pump. 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. This is a function of the fluid viscosity, clearance between internal components, friction between mating components, and other variables. The fluid travel through the pump between the the teeth of the gearwithinagear principle. Scribd is the worlds largest social reading and publishing site. The vacuum is created in the vacuum pump by using a liquid seal,the most commonly used liquid sealant is water.
S volumetric efficiency up to 98% by multistage principle. Indicating lights check to make sure they are working properly. This pump principle features a compact design with particularly high energy density. An internal rotary gear pump is typically specified for viscous fluids such as oils, bitumen, fats, syrups, chocolate and resins as the more viscous the product is, the more efficient the displacement aspect of the working principle becomes. External gear pump overview 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 close tolerance between the gears acts as a seal between the suction and discharge ports. Internal gear gerotor pump design for high viscosity fluids. This pumping principle produces a pulsating flow, rather than a smooth flow. When using equivalent pump speeds, gear pumps have comparable shear imparted compared to progressive cavity pumps. What is the most important application for internal gear pumps. Liquid flows into the cavities and is trapped by the gear teeth as the gears continue to rotate against the pump casing and partition. The pump head is now nearly flooded, just prior to forcing the liquid out of the discharge port. Each screw pump operates on the same basic principal. Working mechanism of a centrifugal pump a centrifugal pump is one of the simplest pieces of equipment in any process.
Note that if fluid slippage is substantial, the pump is not operating properly and. Selection of a positive displacement pd rotary pump is not always an easy choice. External gear pump free download as powerpoint presentation. In a radial flow pump, the liquid enters at the center of the impeller and is directed out along the impeller blades in a direction at right angles to the pump shaft. External gear pumps can come in single or double two sets of gears pump configurations with spur shown, helical, and herringbone gears. The trapped fluid is moved from the inlet, to the discharge, around the casing. Experts in internal and external gear pumps, general pumps, and liquid handling. Learn more about viking pump industry leader and innovator since 1911. 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. Liquid travels through the pump between the teeth of the gear withinagear principle. An external precision gear pump is usually limited to a maximum working. A pump is a machine, powered by an external source, which imparts energy to a fluid or gas. Centrifugal fire pump principles of operation, inspection.
By using several pump stages connected in series, pressures to 250 bar can be developed with high efficiency at viscosities of around 1 mm2s. A pump is a device that moves fluids liquids or gases, or sometimes slurries, by mechanical action. The working principle of the external gear pump is illustrated in figure 1. They function through the use of two or more internal gears that create vacuum pressure, propelling the fluid media. Screw pumps are the only type of pumps which are different from other rotary displacement pumps because of the axial flow of the fluid through their pumping elements. A magnetic drive pump uses a balanced magnetic field to create the rotation of the fluid impeller.
It is a hydraulic machine which converts mechanical energy into hydraulic energy. An internal gear pump uses two gears to move fluid. 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. Pumps can be classified into three major groups according to the method they use to move the fluid. We frequently build and assemble pump unit assemblies, or skids as they are sometimes called. The teeth are shaped so all of the teeth of the inner gear are in contact with some portion of the outer gear at all times. As the rotor gear begins to turn, the idler gear rotates with the teeth beginning to mesh. Liquid enters the suction port between the rotor large exterior gear and idler small interior gear teeth. Back to basics w hen i left university, i found that i needed addi. Mar 01, 2000 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. In the analysis that follows, the numbers of teeth on each gear will be allowed to vary and therefore, in general, the two gears will not be identical. Gear pump components pump unit assembly northern pump is a full service gear pump manufacturer. Pumps operate on the principle whereby a partial vacuum is created at the pump inlet due to the internal operation.
This is an animation video on the working of an internal gear. The fluid in screw pumps moves between the screw threads and is displaced axially as the screws rotate and mesh. Because internal gear pumps have only two moving parts, they are reliable, simple to operate, and easy to maintain. Hi guys, this is an animation video on the working of an internal gear pump, you can learn its working and the components involved in it just by watching this video.
The gear mounted to this shaft driving gear engages the other gear driven gear fluid on the inlet side flows into and is trapped between the rotating gear teeth and the housing. Tooth profile, external gear pumps, mathematical models, control volume. Types of gear pump internal, external,gerotor, lobe pump. Though the construction, shape and design of gear, vane and globe pumps are a bit different, they fall under the same category of rotary pumps. Installation and service instructions excellence at work. The three screw design utilizes a centrallylocated primary screw, or power rotor.
Fluid shall be carried between gear teeth and shall be displaced when the gear teeth mesh. The arrows indicate the direction of the pump and liquid, 2. Pumps operate by some mechanism typically reciprocating or rotary, and consume energy to perform mechanical work moving the fluid. The rotor is a larger gear and also an inner gear, and it has the teeth projecting inside. The gg series pumps use the internal gear design pumping principle see figure 1 to perform the positivedisplacement pumping action desired. The rotating gears develop a liquid seal with the pump casing and create suction at the pump inlet. An internal gear pump works on a similar principle except the two linking gears sizes are different with one revolving within the other.
Maintenance and service manual selfpriming internal gear. The crescent shape divides the liquid and acts as a seal between the suction and discharge ports. The fluid is carried around the outside of the gears to the outlet side of the pump. We have medium pressure and highpressure pumps in our product portfolio. The pumping capacity of the internal gear pump is less in comparison to the external fear pumps.
It moves a fluid by repeatedly enclosing a fixed volume using interlocking cogs or gears, transferring it mechanically using a cyclic pumping action. Sep 05, 20 centrifugal pumps generally driven by the motor, before starting the pump, the pump and the suction pipe is filled with liquid. A rotor gear on the outside and a smaller, idler gear nested inside. Shipment shortages, checked against the transport documents, should be reported. Modeling and simulation of gear pumps based on modelicamworks. The gear pumps are basically positive displacement rotary pumps which helps you to transfer liquid or fluid by using its gears. The working of all these pumps are based on the same principle, i. Paddle steamers used the same principle of operation. The qxv is being used with great success to pump aviation jet fuel, automotive fuels, paraffin oilkerosene, brake fluids, pentosin and.
Unlike a traditional centrifugal pump which has a direct drive connection between impeller and motor, a magdrive pump eliminates the direct drive mechanism and replaces it with a magnetic field. An internal rotary gear pump can handle fluids with a viscosity of 100,000cst. In an internal gear pump fluid enters int the suction port between the rotor and idler it is a small interior gear teeth. Construction, working, operation and maintenance of liquid. Fixed displacement vane pumps hydraulic pumps and parts. The impeller of a typical radial flow pump and the flow through a radial flow pump are shown in figure 6. It may be calculated from the physical dimensions of the gears, or it. 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. The two important things in liquid ring vacuum pumps are used to create vacuum are liquid sealent and impeller. The positivedisplacement principle is well illustrated in the reciprocatingtype. The gear pump is simple in its operating principle.