DE102004034208A1 - tempered sealing component for machine shaft as hollow component of optional cross section has one or two sealing lips, sealing edges, or sealing faces, with inner contour and outer contour having no common center - Google Patents

Abstract

The tempered sealing component as a hollow component of optional cross section has one or two sealing lips, sealing edges, or sealing faces. The sealing component has one or two support components. The inner contour of the sealing component in the region of the sealing lip, sealing edge, or sealing face follows the outer contour. The inner contour and outer contour have no common center as an intersecting point of the two axes.

Description

State of technology

Of the Mechanical engineering calls for ever lower weights, higher moments higher speeds. This results in ever higher Peripheral speeds at the sealing points, in particular the shaft seals. This makes shaft seals extremely important components with guarantees for reliability, quality and lifetime.

The rapid development to ever higher performance create for Subcontracting under conditions to which these components are gaskets have grown.

Increases in performance inevitably lead to higher Temperatures, pressures, Shaft peripheral speeds, changes of direction, accelerations and delays.

At The sealing point meets these boundary conditions together with the lubricant. Together with additives a complex field of different Conditions. Biodegradable lubricants are also included. Extremely important are the material and the microgeometric surface of the rotating Component. Disturbances such as eccentricities, tilted installation (run out), and vibrations for better Stresses.

The loads on the sealing points today lead to running loads of 330 Wat / cm ² . This is many times more like a hotplate with 8-10Watt / cm ".

These Temperature affected the lifespan is crucial. And these amounts of heat have to be dissipated. These high temperatures also subject to the lubricant. This causes premature aging of the lubricant due to oxidation. It is not uncommon to experience cracking temperatures on, where the lubricant breaks down. Blue sanding marks on waves are not rare today. Help with spring-loaded seals The fitters with the approval of the designers, that the spring is removed from these seals, the seal manufacturer use highest Attention and means to the development goal "Reduction of the sealing edge or sealing surface temperature.

this Temperatures are also subject to the sealing materials, as a rule Chemical materials. Pointing high temperatures destroy as well punctually the seal. Attention is paid to the sealing edge geometry, Material issues, in particular The resistance to abrasion, thermal conductivity and the lubricity.

The Sealing offer is extensive. Tie types and designs are included the sizes of the individual Constructor hard to miss. First are two groups to distinguish. Seals with a shape and those made from profiles.

For big and very size Shaft diameters are common no forms available. This is where the area of special begins Seal manufacturer. These produce frequently or regularly without form and finished seals by machining from full material. To reach sufficient repeatability; -spring quality, is more appropriate Effort required. With the tolerances arise immediately other conditions at the sealing edge, with other temperatures and other wear.

in the The area of the molded sealing rings is complete mounted seal with lip, race, grease filled for worldwide Availability on consistently high quality level the state of the art.

this Getting up there and keeping it up is a challenge that everyone faces Manufacturer must ask. The developer has to contribute the appropriate.

task

Design a temperable Sealing system.

• - Variable in the choice of the material at the sealing edge
• - Temperable with a liquid or gaseous medium
• - Contact pressure the sealing lip adjustable.
• - Built up from profiles, if possible commercially available for Minimize the price.
• - easy Assembly,
• - Customizable to different shaft diameter, in particular very large shaft diameter
• - Heatable with direct heating

Solution of task

The Seal a shaft always has a line touch or cylindrical contact the shaft with short jacket length. Only a pipe or hose can follow this geometric shape and at the same time a flowing one or streaming To transport the medium to all points of the shaft circumference. As well alone a Schaluch or pipe can be acted upon so that an inner Pressure arises. (Image 1).

According to Figure 1, the circular shaped tube (pipe) is clipped into a support ring. By This support ring is fed to the sealing hose, the tempering medium. (Picture 3). This support ring is preferably made of elastic material. Thus, the back of the support ring on the profiles according to detail A is sealed. Held and supported by the surrounding housing and connecting parts (Figure 13), the force acting in the reaction chamber of the tempering medium. and / or constructed or supported in the active space of the secondary medium force.

To Figure 3 shows that the entire circumference of a seal is divided into sections. Outstanding Grooves in the housing, in which the seal is installed or in the support ring itself allow üner radial Drilling the distribution of the tempering medium (Fig. 15). The sealing hose is therefore often in the right place for this purpose shut off. Naturally in the absence of subdivision, can interrupt the sealing tube only between inflow and outflow take place. (Picture 3 + 4).

The flowing through Medium can be pressurized. Then the sealing hose expands and thus the pressure in the sealing line or sealing surface is built up or increased. Contexts between pressure and expansion of the sealing tube or between pressure and contact pressure is the material of the sealing tube and its Geometry dependent.

Of the Sealing hose is executed according to picture 2 with elliptical cross-section. in the Comparison with the circular cross section according to Figure 1 becomes clear that the elliptical Cross section less stiff than the elliptical cross section. Therefore, the contact forces set different fine and adapt to the sealing purpose. The same contact pressure of the sealing tube is elliptical To achieve cross-section with lower pressure of the tempering medium.

Next These two sealing profiles - elliptical and circular - are some other forms can be used. Under internal pressure they each show a different behavior. In addition, the simple geometric Cross section through sealing strips and sealing lips is to vary.

Within a profile are also designed to different wall thicknesses the conversion of the sealing tube internal pressure in

contact pressure the sealing lip or sealing edge implement. The elliptical hollow body seal This is clearly shown in Figures 2 and 19. In the area of the sealing line the wall thickness is significantly thinner as at the contact surface in the support ring. The smooth transition from the sealing line to the bearing surface on the support ring causes an equally increasing number Contact force due to deformation of the sealing tube.

Sealing tube variants from picture 12 and 19 in connection with pictures 6; 7; 11; 12; 13 Figures 19a and 20a-c show. In all pictures is the different Wall thickness characterized by the center offset of both axes of the the profile forming ellipses.

The featured profiles, circular or elliptical, shaped as a ring, affect the sealing on the shaft. As a result of wear, the Wall thinner. Out the line touch becomes surface contact. The life span is finished with breakage of the sealing jacket. The lifespan is to extend with sealing edges and sealing lips. (Pictures 6a-c; 7a-c; 9a-c; 10a-c; 19a; 20a-c).

The Number of possible Variants is not exhausted. From the large number of variants, applications are quite special Kind of to realize the most diverse tasks.

outgoing Picture 7b shows the profile as shown in picture 12. The profile is inside the hose with openings Mistake. At the same time, according to the pictures 3 + 4, the inner Channel completed.

The Temperature control medium is now led directly to the sealing point. Of the Disadvantage of a sealing lip, that the tempering through this lip or sealing edge is removed from the sealing point is with it fixed. In the special case of cooling the sealing point passes the cooling Medium directly to the sealing lip, but also directly to the heated point the shaft to be sealed. This cooling is optimal, because the Waves to be sealed are regularly made of metal with good thermal conductivity. For other materials such as chemical materials is the Aufziehen a shaft protection ring (Figure 21). This distributes the Heat faster.

Generally is the sealing tube, however provided with sealing edges or Sealing lips made of chemical materials, preferably of PTFE, whose sliding properties are to be supplemented by additives advantageous. Tables 1 + 2 contain the industrially practicable information for such Compounds. Common are materials with two or three additives, so that an optimal material for this Art seals can be put together.

Sealing tube profiles, which wet the shaft are not pressable with coolant pressure on the wave.

Bislange has been initially spoken solely by the sealing profile and not by the wider function of the Stützrings.im Dichtungssys tem, as shown in pictures 1 + 2.

This support ring is first made of metallic material. For large shaft diameters is a metal ring with reasonable accuracy not inexpensive to manufacture. Made of chemical materials, extruded, there are more advantageous functional possibilities.

At first are inexpensive seals can be produced for very large shaft diameters. For these diameters PTFE seals with sliding speeds up to 12m / sec. from worked out a full material. That's good for so long like there is no better solution gives.

The Clip the sealing tube into the support ring profile when in use of chemical materials easy. Metal support rings can be made in two parts be, e.g. made of aluminium. These profiles are also easy to produce. (Picture 14). For both parts require only one press pad. Shaped into a ring and with clipped sealing hose according to pictures 1; 2; 13; 15 is in the support ring introduced pressurized medium.

This Medium is either static or it flows through as well as the medium the sealing hose picture 2 in connection with picture 15 and pictures 3 and 4. Optionally both rings acted upon by a common or separate pressure sources be. flows the medium through the support ring, and If this is made of metal, then this ring also promotes that Cool of the sealing tube.

Sensitive rules the pressures causes a fine concern of the sealing lips and sealing edges on the to be sealed shaft. That applies to the sealing tube and for the support ring. Exactly dimensioned is a seal as described only with the sealing element abutting the shaft to be sealed when pressure is applied. Either on the cooling medium or in the print medium for the support ring. Both rings also have to be pressurized with different pressure. That increases the contact pressure of the sealing elements on the shaft to be sealed.

at two-fold arrangement of such a sealing system (Figure 15) forms between two sealing tubes another sealed room. Also this channel can picture 23 be flooded and cool the shaft with the circulating medium contained therein. It is connected to the 1st sealing system. It also works on the 2nd sealing system be connected. According to Figure 24, this room is independently flooded with a separate system for Circulation and pressure of the medium.

above are described practicable ways To cool a seal and its environment with the goal of higher sliding speeds preferably To achieve minimal contact pressure of the sealing elements.

In special applications, e.g. in extreme minus temperatures can it is necessary be, icy or cold-prone Seals on operating heat preheat. The principle, this with the featured seals To realize the pictures 16 and 17. In the shock of Dichtschlauchprofiles a connector is inserted and glued. This connector leads the Ends of the previously introduced heating conductor out of the sealing tube. For better transfer of heat to the Sealing point can be the support ring be pressurized. All medium filled cavities are oil or antifreeze filled.

For the purpose When heating a seal, the sealing tube profile can also be made Metal be made to better transfer the heat. Of the Push is soldered or welded.

in the Continuing the inventive concept of sealing compilation After the pictures 15 and 7c, the double sealing tube was created Picture 21. The circular shape is in principle. Other geometric Shapes are usable as set forth in the previous text. This Double hose profile is in the area of the sealing lip over the entire Length open. For evenly distributing the Temperiermediums are circumferential grooves in the housing with factually corresponding subdivisions into sectors, according to pictures 3 + fourth

The Subdividing also happens with inserted hose or pipe pieces, the at the sealing lips at intervals openings to have. Distributing the tempering media is also sensible outside of the installation housing according to the usual rules of the technique. See Figure 22. This seal assembly carries the Temperingmedien directly over the sealing lips and the shaft to be sealed. The distance between Shaft and seal affected doing the rinse effect insofar that at a very small gap an adherent layer of the tempering does not arise. This layer impeded the removal of upcoming ones Warmth. That must be yes away from the area of seals.

It is said that seals, which allow the temperature control medium to wet the shaft, by the temperature control medium do not allow contact pressure of the sealing lip on the shaft. Alone, and without support ring in the machine housing built-in contact pressure is created solely by excess of the shaft.

Figure 24 shows the version "double seal with wave sinks" with a common support ring for internal pressure build-up. In different Profile sizes for double sealing hose and support ring can be sealed over a wide range of diameters.

All Profiles in engineering materials, including the Chemical materials in general and PTFE materials in particular are known as Profiles can be produced. These materials are invariably glued connect to. On the rules of technology to be respected not received here.

economic advantages

• 1) Einbau ohne Vorspannung der Dichtung auf der Welle mit nachträglichem Aufbringen oder Einbringen eines Druckmediums mit der Möglichkeit, den Auflagedruck korrekt einzustellen und zu wiederholen. Dieses Nachstellen kompensiert Verschleiß allein durch gleichmäßig anstehenden Druck.
• 2) Die Dichtungen sind gekühlt; direkt oder indirekt. Direkte Kühlung: Auf einer Seite der Dichtlippe oder Dichtkante steht das Kühlmittel an. Gleichzeitig ist die Welle an der Dichtkante mit Kühlmittel benetzt. Indirekte Kühlung: Das Kühlmittel verläßt den Schlauch durch den es fließt nicht. Im Schlauch wird es so nahe wie möglich an die Dichtkante herangeführt. Die Wärmeenergie muß als durch das Schlauchmaterial hindurch.
• 3) Die Dichtungen sind Temperierbar. Sie können also auch erwärmt werden, insbesondere in Anlaufsituationen. Hierfür sind Temperiergeräte handelsüblich.
• 4) Die Dichtungen sind einfach aus stranggepresstem Material herzustellen, Das ergibt einen günstigen Preis, besonders für Dichtungen mit sehr großem Durchmesser; z.B. 2000mm.
• 5) Jedes der Profile kann zweckdienlich in den erforderlichen Werkstoffen hergestellt werden. Dazu ist nicht zwingend immer ein neues Werkzeug erforderlich.
• 6) Die zu erzielenden Gleitgeschwindigkeiten liegen erheblich höher über dem bisherigen Limit von ca. 15m/sec.
• 7) Einfacher Ein- und Ausbau der Dichtungen bei Dichtungswechsel.
• 8) Mit der nach 6) erzielbaren höheren Gleitgeschwindigkeit sind neue Großmaschinen überhaupt erst realisierbar. Diese Dichtungen mit großem Durchmesser sind vorteilhaft durch preiswertes Herstellen aus hochwertigen Materialien.

With seals according to proposed solutions combine a number of different advantages that do not offer the offers on the market.

• 1) Installation without preloading the seal on the shaft with subsequent application or introduction of a pressure medium with the ability to set the bearing pressure correctly and repeat. This adjustment compensates for wear by uniformly applied pressure.
• 2) The seals are cooled; directly or indirectly. Direct cooling: The coolant is applied to one side of the sealing lip or sealing edge. At the same time, the shaft is wetted with coolant at the sealing edge. Indirect cooling: The coolant leaves the hose through which it does not flow. The tube is brought as close as possible to the sealing edge. The heat energy must pass through the tubing.
• 3) The seals can be tempered. So they can also be heated, especially in start-up situations. For this purpose, temperature control units are commercially available.
• 4) The gaskets are easily made of extruded material, which gives a low price, especially for very large diameter gaskets; eg 2000mm.
• 5) Each of the profiles can be conveniently made in the required materials. This does not always require a new tool.
• 6) The sliding speeds to be achieved are considerably higher than the previous limit of about 15 m / sec.
• 7) Easy installation and removal of gaskets when changing seals.
• 8) With the higher sliding speed achievable according to 6), new large machines can only be realized in the first place. These large diameter seals are advantageous in that they are made inexpensively from high quality materials.

Claims (15)

seal body as a hollow body any cross section Dichungskörper according to claim 1, equipped with one or two sealing lips, Kichtkanten or sealing surfaces. seal body according to claims 1 and 2, equipped with one or two supporting bodies. seal body according to claims 1 to 3, with the feature that the Inner contour in the area of the sealing lip, sealing edge or sealing surface of the outer contour follows. seal body according to claim 1 with the feature that Innenkontor and outer contour do not own a common center. as the intersection of two axes. seal body according to claim 2, wherein between the sealing lips are bores in constructive distance. seal body according to claims 1-5, with the feature that 2 hollow body to a sealing body are united. seal body according to claim 7, with the feature structurally executed holes / openings in the hollow body behind the sealing lip. seal body according to claim 7 with two mutually opposed sealing lips, sealing edges or Sealing surfaces. seal body according to claim 2 and 7 with the feature that both hollow body over the Interspace between the sealing lips and the surface to be sealed correspond. seal body according to claims 6 and 7 with the feature that instead the holes under the sealing lip, sealing edge or sealing surface Gap is located. seal body according to claim 7 to 11, gekennzeich net by a defined Gap between seal to be sealed surface. seal body according to claims 1-12 with one or more connection points radially or axially parallel for and outlet of the tempering medium. seal body according to claims 1 + 2; 9-13 with the feature that the radial Dichtungsduckaxial is generated by delimiting components. Sealing body according to claims 1-14 with the feature that in the hollow body, a heating wire is inserted with thermocouple.