They operate on the principle of positive clearance and do not rub on shafts or housing. Isotech of illinois inc, usa a labyrinth seal that is designed to allow for radial, axial and angular misalignment of the shaft is described. The effects of two seal design parameters, namely blade tooth thickness and blade profile, on labyrinth seal leakage, as well as the effect of operating a seal in an offcenter position, were. Align the drain port at 6 oclock position and slide the seal onto the shaft uniformly pressing both stator and rotor in the equipment. In short, the integrated lip seal contacts the shaft at lower speeds, and. Aircraft cabin air and engine oil an engineering view pdf speech. Analysis of labyrinth seal flow patterns to improve bulk. Therefore, this paper uses the quaternionquadratic regression orthogonal 12 implementation method and determines the variation range of four control parameters on the basis of the general principles of labyrinth seal design.
Labyrinth seals and clearance seals specifications. The steel inner ring is first surrounded with molded aluminum. Of course the cf labyrinth seal also provides all general advantages of a non. The labyrinth seal consists of one or more sharpedged ridges machined on the outside diameter of a rotating shaft or on the inside diameter of a sealing passage as shown in fig. Engineered polymer seals installation instructions polymer. The design is noncontacting and does not wear the machinery shaft. The implementation of brush seals as an alternative to labyrinth seals in a gas turbine engine is outlined in this article. If your design requires looser fitting of the seal due to ease of mounting you might use the tolerance h7.
Mounting instructions for labyrinth seals gmn bearing usa. Pdf the influence of labyrinth seal structure parameters and their interaction on the characteristics of leakage amount are numerically investigated. Find out how your company can benefit from plm built on salesforce. Using a tortuous path, labyrinth seals reduce leakage by dissipating the fluids kinetic energy through viscous forces caused by the formation of vortices in each seal groove. Morrison annular seals are devices used in turbomachinery to avoid flow losses which reduce efficiency. Apr 08, 2020 in fact, movement can make the labyrinth seal even more effective, depending on the design.
This noncontact seal has no wearing parts and eliminates fretting caused by conventional lip seals. The hybrid labyrinth seal incorporates a plain contact seal component to solve some standard labyrinth seal limitations. Geometry of a labyrinth seal with a smooth land, case 2. Intuitively, they do this by taking advantage of the resistance to fluid flow depending on not just the p. Labyrinth seal calculations mechanical seal engineering. Incorporates a gas type seal that effectively seals around the shaft to protect against static and dynamic liquid leakage. Labyrinth seal design optimization based on quadratic. Another form of labyrinth and clearance seals is a laminar sealing ring, which uses a series of flat metal washerlike rings of varying diameters to create a labyrinth seal. In this white paper, learn how you can configure freely without requiring any custom development, and quickly update configurations as your needs evolve. Specifically, im looking for calculations that give me leakage rates given a. Brush seals and labyrinth seals in gas turbine applications. Labyrinth seals, formerly named leidenfrost seals or mini mace, have a very specific manufacturing process that guarantees the identity of the inner and outer ring profiles to ensure they remain inseparable here are the steps taken to produce a labyrinth seal. The paper introduces a variety of carefully thoughtout labyrinth systems for practical application and the designer is supplied with detailed design directives.
When choosing labyrinth seals and clearance seals, the operating speed and temperature must be considered. Labyrinth seal geometries linear seal with more chambers a, stepped design b and seal in application to gas turbines c, 2. In these applications, it is the long and difficult path and the formation of controlled fluid vortices plus some limited contactsealing action that creates the seal. Most fillers are stable up to 400 c, so they do not restrict use in high temperatures. For a more complete description of dry gas seal principles of operation, see shah 1988. These types of seals are used in a variety of settings, and can be used on objects which rotate and otherwise move. Labyrinth seals lip seal alternative an effective alternative to lip seals, chesterton offers a unique polymerbased labyrinth seal design for use in splash applications for protection of pumps, gearboxes and other rotating equipment. Predicting leakage flow in labyrinth seals dates back to egli. Advanced labyrinth seal design performance for high pressure. Cavity pressures, velocity and leakage computation in straight through or stepped labyrinth seals.
In addition the new cf labyrinth seal is also offered in a different design for standard ball bearings made from aluminum. Air compressors generally will always use a labyrinth seal. Straight through triangular labyrinth seals are one of the most commonly used. Labyrinth seals and clearance seals selection guide. The labtecta product range is an advanced labyrinth design that offers ingress protection of ip66 as standard and up to ip69k with the labtecta op. Pdf labyrinth seal design optimization based on quadratic. Keywords machine tool labyrinth seal spindle bearing shaft seal precision machine tool. The two pieces interlock to effectively seal out the majority of contaminants while holding in the lubricant. Capable of excluding contamination as effectively as contact or lip seals, skf noncontact labyrinth seals also operate with little or no friction.
Analysis of labyrinth seal flow patterns to improve bulk flow. Standard labyrinthstyle airgas and oil seals used with atmospheric air and lowpressure gases effectively confine air in the stage casings and. The influence of labyrinth seal structure parameters and their interaction on the characteristics of leakage amount are numerically investigated by conducting a quadratic regression orthogonal. A labyrinth seal is a seal which creates a complicated path for liquids to pass through, making it challenging for liquids to cross the barrier created by the seal because they have difficulty making their way all the way through the labyrinth. Volume iii analytical and experimental development of a design model for labyrinth seals. An example of such a seal is sometimes found within an axles bearing to help prevent the leakage of the oil lubricating the bearing a labyrinth seal may be composed of many grooves that press tightly inside another axle, or inside a hole, so that the fluid has to pass through a. The dynamic stability of the machine is also improved by the seal. They consist of a stationary and a rotating ring and are made of engineering plastic. Inboard of the dry gas seal is an inner labyrinth seal, which separates the process gas from the gas seal. The advance labyrinth design allows the bearing housing to breath out when the shaft is rotating but seals when the shaft stops. Labyrinth seals lip seal alternative page intro an effective alternative to lip seals, chesterton offers a unique polymerbased labyrinth seal design for use in splash applications for protection of pumps, gearboxes and other rotating equipment. Labyrinth seal calculations labyrinth seal calculations iainuts mechanical op 8 jan 07 11. A labyrinth seal is a type of mechanical seal that provides a tortuous path to help prevent leakage. Therefore, an investigation was undertaken to design, fabricate and test several unique labyrinth seal concepts intended to decrease leakage through higher efficiency.
Advanced labyrinth seal design performance for high. Made from chestertons proprietary polymer material technology, the chesterton, patentpending polymer labyrinth seal pls is a noncontact bearing seal designed to provide protection for pumps, motors, gearboxes, and other rotating equipment in splash applications. The aluminum seal is offered in all sizes according to ball bearing row 62. The seal is mounted in a ball joint assembly that is also free to move. I have attached a copy of their analysis and results within this report. Shape optimization of a labyrinth seal applying the simulated. Labyrinth seal preprocessor and postprocessor design and parametric study by rumeet pradeep mehta thesis submitted to the faculty of the virginia polytechnic institute and state university in. The labyrinth seal is a controlled leakage seal used to prevent highpressure gas leaking out of the case to the atmosphere and minimizes internal leakage. Engineered polymer seals installation instructions 1 3 2 4 seal orientation and parts. Standard labyrinthstyle airgas and oil seals used with atmospheric air and lowpressure gases. Similarly, if the labyrinth chambers are correctly designed, any liquid that has escaped the main chamber becomes entrapped in a labyrinth chamber, where it. Engineering a better noncontact seal machine design.
Various groups of labyrinth seals based on their design and arrangement on the blades tips and on the rotor, are discussed in 3, 4, 6. Maintaining an accurate clearance during nominal and transient operation and providing effective damping is of key importance for seal designers. C geometry of three canted knives with a smooth land case 3. Users may specify a labyrinth seal because of favorable operating experience, cost, or a dislike of mechanical seals. Apr 30, 2015 therefore, an investigation was undertaken to design, fabricate and test several unique labyrinth seal concepts intended to decrease leakage through higher efficiency. The company reserves the right to change designs and specifications at any time. Labyrinth seals have been designed in the past in a variety of different shapes with different leakage mass flow rates. A typical type of noncontacting seal is the labyrinth seal, where circumferential grooves are cut into the rotor, stator or both. Skf noncontact labyrinth seals provide an ideal solution. These seals are more info not designed to seal pressure differentials or to seal against high fluid levels. The approach used in the unique designs for improving the efficiency of labyrinth seals involved increasing the internal cavity turbulence of the seal.
Stepped labyrinth seal cavity control volume mass fluxes stepped labyrinth seal cavity control volume shear stress forces stepped labyrinth seal cavity control volume momentum fluxes straight labyrinth seal, teeth on stator notation for leakage, pressure and velocity stepped labyrinth seal, teeth on stator notation for leakage, pressure and. Labyrinth seals are constructed in multiple pieces. Saving fuel, reducing emissions for rail freight applications, the ecoturn seal offers an approximate 20 inchpound 2. Skf the kno wledge engineering company s p e c i f i c a t i o n design and ed velo p ma nuf act ur e a n d t e s t i n s t a. Noncontact labyrinth seal assembly pdf free download. The labyrinth seal has a number of grooves which interlock with other grooves or teeth.
Cavity pressures, velocity and leakage computation in. Labyrinth air seal labyrinth seal design options oil seal ingersoll rand offers a complete range of seal arrangements to meet the specific needs of your application. Labyrinth seal fda seals american high performance seals. Design optimization and verification skf can work with you to optimize current or new designs with proprietary 3d modeling software that can also be used as a virtual test rig to confirm the integrity of the design. Labyrinth seals are also found on pistons, which use them to store oil and seal against high pressure during compression and power strokes, as well as on other nonrotating shafts. The labyrinth is a straight through design and a defined clearance on the shaft. Labyrinth seal air leakage performance in current and advanced high pressure ratio gas turbines is directly related to the limitations of current available sealing. Lowfriction seals with skf wave lip design the seal types crw1, crwh1, crwa1 and crwha1 have an skf wave lip design to reduce friction and heat generation. This catalog reflects the latest design features at the time of printing. Labyrinth seals and clearance seals are minimumleakage seals that protect machine elements from contamination through a noncontact method.
Labyrinth seal pumps acds labyrinth seal design is reliable and provides trouble free centrifugal pump operation eliminating the need for a traditional mechanical seal. Ptfe seals parker hannifin 8 prdifa technology division general information 1 when to use ptfe seals in the 1960s, the addition of fillers was found to improve a number of physical properties, particularly creep and wear rate. Labyrinth seals are intended to prevent fluid liquid or gas flowing from one region to another, while not sealing off the passage entirely. Lip seal alternative to avoid fretting chesterton labyrinth. Labyrinth seals a promising and effective design semantic scholar. An extensive data base was accumulated from published and inhouse experimental results as the foundation for the development of a design model for labyrinth seals. Labyrinth seals alabyrinth seal may be specified where the process to be sealed is at low to moderate pressures and relatively high leakage flows are tolerable. These seals generally do not perform well at low operating speeds. Find labyrinth seals and clearance seals on globalspec by specifications.
Optimizing a helical groove seal with grooves on both the rotor and stator surfaces. The impact of adding a labyrinth surface to an optimal helical seal design. The other piece, called the rotor, is attached to the shaft and rotates with the motion of the system. Labyrinth seals use a noncontact seal design and are specifically designed to protect bearings from splashing water and other contaminants.
Outboard of the dry gas seal is a barrier seal, which separates the gas seal from the compressor shaft bearings fig. Apply a thin film of lubricant to the shaft and bore. Rotor will stretch once installed on the shaft and create interfe. Labyrinth seal design options oil seal ingersoll rand offers a complete range of seal arrangements to meet the specific needs of your application. This differs from most traditional seals, which use a single lip in an attempt to seal an opening. Geometry of a stepped labyrinth seal configuration case 1. A labyrinth seal is a type of mechanical seal that provides a tortuous path to help prevent. When using this fit, it will be necessary to take care for additional fixing of the gmn labyrinth seal to the housing or shaft by using additional gluing. Gmn labyrinth seal cf 60 and cf 619 for spindle bearings. The sinusoidal form of the skf wave lip considerably extends the path on the counter surface and reduces the radial load against the shaft. A second seal element is received within the second groove and the retention of each seal element, within 12 sealing technology a crosssectional view of a noncontact labyrinth seal assembly disposed on a shaft constructed in accordance with a preferred embodiment of patent wo20147963. This is important for the design of high pressure compressors, where labyrinth damping is a. One piece, known as the stator, is affixed to the machine and remains stationary.
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