This design does have more mechanical sealing faces that would normally result in increased losses however, the products tend to be higher priced that external gear pumps with the extra cost going to the higher quality manufacturing required. Operates a gear within a gear principle, whereby one gear the idler is positioned inside another gear the rotor. A typical application of this is in the supply of hydraulic oil in power steering systems. External gear pump working animation with detail explanation. Design analysis and testing of a gear pump research inventy. Multiport gear pump design based on virtual prototyping technology xiaoyang yu school of mechanical engineering dalian jiaotong university, dalian, p. Proceedings of the bathasme 2020 symposium on fluid power and motion control. Parker gear pumps power dense design produces an energy savings and provides oems a marketable advantage to improve revenues. A design procedure for multistage external gear pumps. The pump is so named because it has two gears that are sidebyside or externalto each other. Rotary pumps use a variety of means to generate flow. There is no doubt that the gear type pump is the most widely used design in hydraulic systems.
Positive displacement pumps allow liquid to flow into an open cavity trap the liquid in the pump transport liquid from the suction to discharge port mechanically force liquid out of the pump. Figure 2 shows one kind of external gear pump structure here n3. In addition to imposing limits on the operational speed, in many cases, the bearings determine the maximum pressure the pump can operate at. Their objective is to start the engine, to provide take off flow at the required pressure and to prime a fuel system. Fluid, drawn into the pump, is enclosed within the cavities of its rotating gears and transferred to the discharge. Pdf an investigation of external gear pump efficiency. China email protected abstract in this paper, the familiar structures of multiport gear pump are analyzed, and designed based on. Gear pumps are the most popular type of positive displacement pump. Purdue university activities on gear pumps motors project 1.
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. To investigate the fluid flow phenomena that occur in external gear pumps, one of the commercial cfd software packages was selected. The external gear pump is a positive displacement pd type of pump generally used for the transfer and metering of liquids. Apr, 2019 as a result, the pump overall performance increases with smoother outflow. Design parameter simulation parameter pump layout window cadfem interface september 2011 14 pump. In this study, a mathematical modeling of gear pairs is deduced based on the meshing theory and a complete set of mathematical equa. Gear pumps are often used in pumping relatively viscous liquids, such as some viscous liquid hydrocarbons, liquid fuels, lubrication oil pumping in machinery packages, hydraulic units and fluid power transfer units. This work is focused on the optimization of the pump design with particular.
It may be calculated from the physical dimensions of the gears, or it. You immediately receive a project drawing pdf format if. Failures of the front pump are, in fact, limited to just a few specific modes such as overheating, overpressurization, shaft. External gear pumps with spur gears are classified as low. Design of a hydraulic pump for construction with additive. Centrifugal pumps develop pressure by increasing the velocity of the liquid liquid is literally flung out of the cutwater. Nasgp external gear pump nasgp 300 a 8 a 9 h 2 r e10 model code how to order port type.
China email protected li sun school of mechanical engineering dalian jiaotong university, dalian, p. Thus the discharge per unit revolution is a function of the size of the gears and the number of teeth. High pressures high viscosity fluids are able to be pumped over long distances using external gear pumps, thanks to their ability to handle high pressure applications selfpriming capabilities gear pumps benefit from excelling selfpriming capabilities thanks to their rotating gears evacuating any air in the suction line, and forcing the liquid into the pump inlet. They can manage low viscosity liquids like alcohols, solvents or liquid gases as well as medium and high viscosity liquids like polymer melts, gumbase or rubber. Also, the effect of gear teeth radiusteeth tip length on the pump performance has been studied in various working pressures within a case study. Construction the external gear pump consists essentially of a pair of. External gear pump overview michael smith engineers. Small gear pumps usually operate at a speed between 1,700 rpm and 4,500 rpm, and larger models most often. Internal gear pumps use a gear within a gear design. 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. Further configuration variants are given by different flanges, shafts, valve arrangements and multiple pump combinations. Our design gear pump generate noise level between 90db to 100db. In addition to imposing limits on the operational speed, in many cases, the bearings determine the maximum pressure the pump.
In these pumps water enters axially and is discharged by the rotor into a discharge pipe. Gear pump manual original instructions albany pumps. For 35 years, viking sg series external gear pumps have followed in that proud tradition, with the advantages of higher developed pressures and higher speeds. Gear pumps d series and xd series gear pumps technical. First, the internal gear pump without crescent is described below. Many external gear pumps use journal bearings to support the rotating shafts. Jul 18, 20 external gear pumps work external gear pumps are similar in pumping action to internal gear pumps in that two gears come into and out of mesh to produce flow. The external gear pump consists essentially of a pair of gears supported in bearing. In this last case the authors have also tested a new boundary condition for maintaining a good.
External gear pump design, advantages and disadvantages. Heisler et al 2 used the computational fluid dynamics cfd to better analyze the effect of modifying the design of an existing external gear pump. 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. Investigation of leakage within an external gear pump with. Two identical gears positioned side by side, rotating into one another. Because seal leakage is the most frequent cause of pump downtime, the sg series minimizes shaft. This design does have more mechanical sealing faces that would normally result in increased losses however, the products tend to be higher priced that external gear pumps with the extra cost going to. Scribd is the worlds largest social reading and publishing site.
Displacement d the displacement of a rotary gear pump is the volume displaced during one complete. Liquids containing solids are not really suitable for gearpumps unless the particles are really small. Sg series pumps were designed to ensure reliability in industrial process applications. Gear pumps spa industrial pumps star pump alliance. The simulation tool hygesim a entire simulation of external gear machines pumps motors considering main physical phenomena tool versatile, useful for verification design purposes main features of the hygesim hydraulic gear machines simulator. One gear is driven by the motor and in turn moves the other gear.
Gear pumps are less expensive but limited to pressures below 140 bar. Grp operating principle delivery port cover plate mid plate base plate inner rotor outer rotor. External gear pumps can be divided into external and internal gear types. A design procedure for multistage external gear pumps fluid.
External gear pump free download as powerpoint presentation. Internal gear pump design for automotive oil pumps. Pdf in this work, the authors have developed a mathematical model that simulates the run in of external gear pumps, as an useful tool in the. The design principles and the performance of hydrostatically loaded wear end plates in three highpressure external gear pumps were examined experimentally while the pumps were running under.
The pump is composed of a driving gear an external tooth gear placed inside and a driven gear an internal tooth gear placed outside. Hydraulic gear pump and motor failure analysis and repair. Rexroth external gear pumps are available as standard performance gear pumps in the series w. Power group of the university of parma has implemented a numerical code for the simulation of external gear pumps and motors. To get the best from the pump, carefully read and understand this manual before installation and startup. External gear pump the external gear pump consists of externally meshed two gears housed in a pump case as shown in figure. Pdf flow characteristics of external gear pumps considering. It is simple in construction, reliable in operation and the most costeffective way of. Calculation of theoretical torque and displacement in an. Nov 11, 2020 the paper presents a cfd model of an external gear pump. Internal gear pumps internal gear pumps are exceptionally versatile. Design parameter simulation parameter pump layout window cadfem interface september 2011 14 pump library geometry import geometry export result. The fixed displacement gear pumps utilized by alamo industrial are of a proven design and will easily provide exceptional service for the life of the machine. 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 displacements are graded by different gear widths. Sae oring nachi america external gear pump design number max pump capacity ccrev nominal. Gerotor pumps for automotive drivetrain applications. One of the gears is coupled with a prime mover and is called as driving gear and another is called as driven gear. A vast knowledge of magnet, pump, and motor technology is utilized in the design, manufacturing, and application of our magnetically coupled pumps. External gear pump design for hydraulic power applications. The results show that the curve of trapped volume is similar to a parabola and the pump designed with a large number of teeth, module, and pressure angle easily. Internal gear crescent internal gear pump design for high viscosity fluids. The outer gear of this pump rotates concentrically in the casing and is coupled to the driver. Pdf cfd model of an external gear pump researchgate. What should we consider technically if we have to run our external gear pump for soft water with inject dye liquid. In order for these bearings to work, a minimum speed is required depends upon pressure of the pump. The rotating gear carries the fluid from the tank to the outlet pipe. Installation, operation, maintenance user instructions user instructions 71569246 2167be1.
Rotary pumps are usually classified according to the type of element that transmits the liquid, so that we speak of a gear, lobe, vane, or pistontype rotary pump. Usually, these pumps are designed to work over a wide range of speeds and high delivery pressures as positive displacement units in hydraulic. Gears permco pumps are cut in our own plant to extremely close tolerances. The external gear pump belongs to the class of rotating postive displacement pumps. Useful information on gear pumps michael smith engineers. External gear pumps can come in single or double two sets of gears pump configurations with spur shown, helical, and herringbone gears. The useful viscosity range of an internal gear pump is from 1cps to over 1,000,000cp. It is noisy in operation than either vane or piston pumps. Failures of the front pump are, in fact, limited to just a few specific modes such as overheating, overpressurization, shaft failures, contamination and cavitation. 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. They have an impeller which rotates in a casing of a special shape. Highquality, heattreated alloy steel integral gears and shaft 2. 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.
This nomenclature differentiates it from an internalgear pump, which has one gear positioned inside the other. You can interact with actual flash animation at the link given above. Gear pumps with integral valves in order to reduce external pipework it is possible to incorporate a flowcontrol valve or pressurerelief valve in the rear cover of the gear pump. Apr 20, 2016 external gear pumps under the following two cases. In this video we are going to see how external gear pump works. This investigation can be an essential and simple tool to design high performance gear pumps. External gear pump gd5 series eaton hydraulics pdf. Hydraulic gear pump and motor failure analysis and repair guide. To prevent leakage caused by the common crowning effect, permco shapes gears rather than hobbing and shaving them. Gear pumps are invariably of fixed displacement type, which means that the amount of fluid displaced for each revolution of the drive shaft is theoretically.
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