An internal gear pump operates on the same principle but the. The liquid is forced out the discharge port by the meshing of the gears. 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. These sideported pumps have the option to bolt saedin flanges onto them ensuring maximum flexibility on the porting arrangements. External gear pump overview michael smith engineers. 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.
Designs are available to provide the same direction of flow regardless of the direction of shaft rotation. Working mechanism of a centrifugal pump a centrifugal pump is one of the simplest pieces of equipment in any process plant. The spaces between the gear teeth transport the fluid on either side of a crescent to the discharge side, and. Pdf format this file type includes high resolution graphics and schematics when applicable. In this paper, the flow ripple equation is derived to analyze the effect of working condition on pressure pulsations of an internal gear pump. This fine clearance is the main object of concern in this pump. This is a function of the fluid viscosity, clearance between internal components, friction between mating components, and other variables.
Gear pump working principle animation video a gear pump is a rotary type of positive displacement pump. As the gears come out of mesh on the inlet side of the pump, they create an expanded volume. The normal gerotor type, sometimes called gerolor, shown in figure 2, and the spur gear type pump which uses a different type of gears. Inlet and outlet points are made in pump casing for proper fluid transfer. The rotor is a larger gear and also an inner gear, and it has the teeth projecting inside. The internal design is seen as being reliable, easy to operate and maintain due to only two moving parts being present. 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 is a hydraulic machine which converts mechanical energy into. Theyre also birotational, meaning that the same pump can be used to load and unload vessels. The internal design is seen as being reliable, easy to operate and maintain due to only two. Precise by design, they deliver accurate and repeatable performance, a smooth flow and a pressure up to 18 bar 260 psi.
The modules listed in the overview are linked to the corresponding pages. The internal gear pump is nonpulsing, selfpriming, and can run dry for short periods. Internal gear pump design for high viscosity fluids. In internal gear pumps, a gear with internal teeth meshes with a gear with external teeth figure 2. The blue pump curve represents either of these options. 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.
An internal gear pump works on a similar principle except the two linking gears sizes are different with one revolving within the other. The pump features a casing in which a dual gear an outer rotor gear and an internal idler gear and crescent assembly is housed. Operates a gear within a gear principle, whereby one gear the idler is positioned inside another gear the rotor. The working principle of the external gear pump is illustrated in figure 1. Gear pump working, construction, maintenance marinersgalaxy.
Typically, gear pumps have efficiencies around 85%. The impeller has a uniform blade length, b, of 2 in. Internal gerotor gear pump figure 1 shows the inside view of a basic gerotor gear pump. Text headings in each module are linked to and f\ rom the table of contents for that module.
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 pumping capacity of the internal gear pump is less in comparison to the external fear pumps. External gear pumps can come in single or double two sets of gears pump configurations with spur shown, helical, and herringbone gears. External gear pump free download as powerpoint presentation. Each gear is supported by a shaft with bearings on both sides of the gear. As the rotor gear begins to turn, the idler gear rotates with the teeth beginning to mesh accordingly. 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. Its output flow tends to vary little with respect to the pressure at the pump outlet, because the moving. 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. Liquid enters the suction port between the rotor large exterior gear and idler small interior gear teeth. While they are often used on thin liquids such as solvents and fuel oil, they excel at efficiently pumping thick liquids such as asphalt, chocolate, and adhesives. This pumping principle produces a pulsating flow, rather than a smooth flow. Internal gear pumps generate flow using a gear with externallycut teeth contained in and meshed with a gear with internallycut teeth. A directdrive gerotor motor consists of an innerouter gear set and an output shaft fig.
Tandem and multiple pumps are available worldwide in more than variants. 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. The arrows indicate the direction of the pump and liquid. The gear pump is a precision machine with extremely tight fits and tolerances, and is capable of working against high differential pressures. This pump type is incredibly versatile and can efficiently handle high viscosity fluids at. 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. Liquid at discharge line shall be accelerated from low velocity to higher velocity. All types of hydraulic motors have common design features. These pumps may come with or without a crescentshaped partition.
An external gear pump consists of two identical, interlocking gears supported by separate shafts. The speed of the pump can be reduced or the existing impeller can be trimmed or new lower size impeller. 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. There are several gear pump pdf books available in market. One gear is driven by the motor and in turn moves the other gear. An internal gear pump operates on the same principle but the two interlocking gears are of different sizes with one rotating inside the other. The useful viscosity range of an internal gear pump is from 1cps to over 1,000,000cp 14. 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. A drive gear that is driven by a motor rotates an idler gear in. This process will effect in pressure loss, where reciprocating pump has higher pressure loss compared with continuous flow in each circle of crankshaft rotation, see figure 12. Review different pump types commonly used understand the difference between centrifugal pumps and positive displacement pumps understand the working principle of the tuthill. So the fluid is contained internally between the ring gear and the driven gear. Many external gear pumps use journal bearings to support the rotating shafts. As the gears come out of mesh on the inlet side, liquid is drawn into the pump.
Download the file data into the pump memory disconnect the pump from the pc carry out your application on the spot, using the pump as a standalone unit unique. The pumps are ideal for use with variable speed drives over a very wide speed range and for operation in reverse mode. The series is based on the proven internal gear principal and is enhanced in response from our oem customers for a pump that offers advanced features which make installation easier. The gears themselves are lubricated by the fluid, which is of a lubricating nature.
The casing of the pump is as important as the gear. This article describes internal gear pumps in more detail. A gear pump uses two meshing, toothed cogs to force water from the inlet of the pump through to the outlet. Fundamentals of fluid mechanics chapter 12 pumps and turbines.
Liquid travels through the pump between the teeth of the gear withina gear principle. What we now need is a new pump which will operate with its best efficiency point at c. An internal rotary gear pump employs a positive displacement principle. These pumps can handle small suspended particulate in abrasive applications, but. Abstract the paper comprises research results of the gear pump typical failures and their connection with symptoms observed during the pump working. 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. The operating pressure at the pump outlet side is specified also for fireresistant and environmen tallyfriendly fluids hfc. The straightforward and rugged construction guarantees long service life without the need for extensive maintenance. An internal gear pump uses internal and external gears figure 2, below.
Scribd is the worlds largest social reading and publishing site. Two identical gears positioned side by side, rotating into one another. Because internal gear pumps have only two moving parts, they are reliable, simple to operate, and easy to maintain. I mean because of the close clearance between the casing and the teeth of the gears, pressure is developed and we get the pressurized fluid at the end. The useful viscosity range of an internal gear pump is from 1cps to over 1,000,000cp. 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. Internal gear pumps operate by drawing fluid into the pump inlet between the rotor large exterior gear and idler small interior gear teeth, operating with a gearwithinagear principle. But there are other simpler options rather than replacing the pump. It is a hydraulic machine which converts mechanical energy into hydraulic energy. Internal gear pumps are made to close tolerances and are damaged when pumping large solids. The main characteristics are valid for hydraulic oils din 51524 with a viscosity of 20 to 50 mm2s. Based on its design a gear pump can be of external or internal gear type. A gear pump contains two or more rotating gears inside a casing with high tolerance in between casing and the gears.
Keep this manual carefully at hand so that it can be consulted at anytime when operating, inspecting or maintaining the pump. Introduction internal gear pumps used in relatively low pressure conditions have been widely used for automatic. They work with just one gear stage, and thanks to their. Reciprocating pump has uncontinous flow to deliver the liquid. In a positivedisplacement pd pump, a discrete amount of fluid is trapped, forced through the pump, and discharged. The theoretical flow ripple of an external gear pump. Worked out criteria and their boundary values allowed the defect classes creation and the defectsymptom diagnostics relation. This portable document format \ pdf \ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. Jul 18, 20 internal gear pumps internal gear pumps are exceptionally versatile. 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. Internal gear pumps internal gear pumps are exceptionally versatile.
Internal gear pump working animation with detail explanation. Aug 30, 2014 the internal gear pump is nonpulsing, selfpriming, and can run dry for short periods. There are three stages in an internal gear pump s working cycle. Internal gear pumps operating principles angelfire. This pump type is incredibly versatile and can efficiently handle high viscosity fluids at moderate speeds. As the gears come out of mesh, they create expanding volume on the inlet side of the pump. Calculation of theoretical torque and displacement in an.
409 882 948 1095 480 841 952 202 371 1396 1156 1228 548 1439 1482 1037 451 548 19 674 459 379 98 270 1447 539 826 1150 410 1481 428 52 366 317 1228 1399 545 1189 183 878 1446 869 1089 1151 1463