DE2726033A1 - SEAL, IN PARTICULAR FOR CHAIN PIN ON TRACKED TRUCKS OR DGL. - Google Patents

Description

Patent attorneys Dipl-Ing. H. Weickmann, Dipl.-Phys. Dr. K. Fincke

Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Huber

SAHA g MUNICH »6 DEN

PO Box 860820 MÖHLSTRASSE 22, CALL NUMBER 98 3921/22

Chicago Rawhide Manufacturing Co., 900 North State Street, Elgin, Illinois, V.St.A. 60120

Seal, especially for chain pins on crawler tractors

or the like.

The invention relates to a seal as set out in the preamble of the first claim. Such seals are particularly suitable for applications under harsh operating conditions.

One area of application for which numerous seals have already been proposed is that of the chain pins on crawler tractors. Crawler tractors usually have two caterpillars and each caterpillar consists of an inner and an outer chain of caterpillar links. A large number of such links, typically 30 to 40 pails, are joined together to form an endless chain and two such chains are then over the front idler wheel and the rear drive wheel, as well as over several hanging rollers and rollers. The inner and outer links in each chain are held together by chain pins and bushings, which extend through openings at both ends of the chain links. Multi-wall sheets extend in the transverse direction between the relevant links of the inner and outer chain. These plates form the support surface that rests on the ground sits down and ultimately carries the vehicle and moves it forward. You have right and left caterpillars of the vehicle so in each case several web plates and these flats, which are between the links of the inner chain and the links of the

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Extending the outer chain, connect these links together.

Since tracked vehicles are particularly suitable for use under harsh operating conditions, namely mud, sand, egg, ice and snow, rocky terrain, etc., and because the caterpillar is the part of the vehicle that is most immediate and frequent Coming into contact with these difficult terrain, the chain pins and their sockets are subject to rapid wear subject.

An efficient chain pin seal must for a relatively large fluctuation in the axial dimension and a high hatred of possible wear and tear. Such Sighting must have an axial spring rate that is moderate and creates an initial axial force sufficient to insure that the seal will successfully water and gravel and holds back lubricating oil, even with minimal load.

To achieve this, the seal according to the invention has a essentially annular help seal and a pressure wielding Element of characteristic shape, as well as a main sealing ring made of a rigid, elastomeric material. Of the Main ring has a generally L-shaped seat for receiving of the help element and an axially aligned end face part which is to rest against a part of the chain pin mechanism to be sealed is determined, as well as a plurality of channels which extend between the axial ends of the main sealing ring and through which lubricant can flow.

The seal of the present invention offers all or almost all of the benefits previously known, more expensive seals, and this at low initial costs. The seal uses constructions and materials that are different from the prior art and offer new functional properties and advantages.

Further details of the invention emerge from the following

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following description of exemplary embodiments based on attached drawing. Show in it:

Fig.1 is a vertical sectional view, partially broken, the the chain pin seal according to the invention in use position shows;

Pig.2 is a fragmentary vertical sectional view of the invention Seal before installation, in which the axial lubrication channels on the inner diameter of the main sealing ring you can see}

Fig. 3 is an enlarged, fragmentary front view of a Part of the seal shown in Figure 2 along the line 3-3 of these figures;

4 shows an even more enlarged front view of the seal of Figure 1 along the line 4-4 of this Figure;

5a shows a vertical sectional view of a seal with a modified one Cross-sectional shape;

Fig. 5b is a vertical sectional view with yet another Cross-sectional shape;

Fig. 5c shows a vertical section with yet another Cross-sectional shape;

Fig. 6 is a fragmentary vertical sectional view of another Embodiment of the gasket according to the invention, the shows the gasket in its normal installed position of use;

FIG. 7 is a fragmentary vertical sectional view of the FIG Fig. 6 illustrated embodiment, which illustrates the seal shortly before the complete installation of the same;

8 shows a vertical sectional view of the seal according to the invention, with the gasket installed and shown in a slightly compressed condition during use is;

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-Λ -

Pig.9 is a vertical sectional view of that shown in Figures 6-8 Seal shown fully compressed.

In Figure 1, the seal 10 according to the invention is in a caterpillar link structure 12 shown installed.

A cylindrical chain pin 14 has an end cap 16 which attached along the interface 18 between the inner diameter of the cap 16 and the outer diameter of the chain pin 14 is. These parts do not move relative to one another. The end cap 16 is typically the leading one Part of the chain link, while the trailing part of the same link is forced into a press fit over a bushing, which is freely rotatable on the following chain pin.

In Figure 1, a complementary end piece 22 is a leading one Chain link shown and this end piece has a radially inwardly directed wall 24 which has an opening for receiving the outer diameter 26 of a chain pin bushing 28 forms. Between the inner diameter 32 of the chain pin bushing 28 and the outlet An operating gap 30 is present in diameter 34 of the chain pin 14, the central axis of which is indicated at 20.

The link 22 and sleeve 28 are compressed and therefore move as a unit relative to the chain pin 14. Die The end cap 16 of the leading link is on the chain pin 14 attached so that the chain pin 14 can move back and forth with respect to one end of the chain link.

The seal is received in a cavity 36 which is partially delimited by a mating surface 38 which extends in a radial direction Direction extending and looking in the axial direction end face of the socket 28 is. The outward-facing surface 40 of a spacer ring 42, the end wall 44 which extends in the radial direction and which extends in the axial direction

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Kende wall 46 also delimit the cavity 36, the Walls 44, 46 delimit a depression in the end cap 16. The cavity 36 accepts an annular main seal ring 48 which has a slightly inclined end face 50 which ends at an edge 52. The band 54 running radially inward from the edge 52 forms the actual sealing surface which abuts the mating surface 38 of the bushing 28 to provide the main seal. The inner peripheral surface of the main seal ring 48 is provided with a plurality of teeth 56 (Fig.3 »4), the with their inner surfaces 58 fit snugly against the outer circumferential surface 40 of the spacer ring 42. On the main sealing ring 48, a seat for receiving an auxiliary sealing element 60 is formed by an axial and a radial hanging surface 62 and 64 ·

The auxiliary elastomeric sealing element 60 has a cross-sectionally approximately parallelogram-shaped body, which is a radially inner one and a radially outer surface 66, 68 extending in the axial direction, and an inclined front surface 70 and a inclined rear surface 72 forms. The surfaces 66, 68 and 70, 72 are approximately in pairs in the unloaded state of the seal parallel to each other. Around the outside in the radial direction Leading edge of the body of the auxiliary sealing member 60 is formed an outwardly and upwardly extending flange 74 of small cross-section. This flange 74 is when the Seal is installed (see Fig. 1) pressed down in the radial direction and deformed.

The auxiliary sealing element 60, also known as the auxiliary sealing ring is preferably made of a relatively soft synthetic rubber such as a nitrile rubber ("Buna H"), which withstands temperature fluctuations well and has a Shore hardness "A" of about 50-60. Other rubber compositions are also suitable.

The main sealing ring 48 preferably consists of a hard

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ten abrasion-resistant elastomer such as a polyurethane rubber, i.e. a material with a Shore A hardness of 90-95. An example for such a mass is a rubber, which as a reaction product of a polyether glycol, such as dep poly (1,4-oxbutylene) glycols, with an etoichiometric excess of a mixture of the 2,4- and 2,6-isomers of toluene diisocyanate, which is a prepolymer having a molecular weight between about 1500 and about 3000. This prepolymer is then cured with a reactive diamine such as methylene-bis-orthochloroaniline. The cured elastomer has a Shore hardness A of 90-95 and a spec. Weight of about 1.16. Other compositions can also be used.

During installation, the ring 60 is slipped over the ring 48, with the mutually facing surfaces 62, 66 on the main ring and on the auxiliary ring bear against each other with moderate pressure, including the auxiliary ring 60 needs to be stretched a little. Then these two parts are placed in the cavity 36, the teeth 56, the axial Forming grooves 76, either a very small distance from the outer circumferential surface 40 of the spacer ring 42 or slightly concern about this. The flange 74 rests against the surface 46 at the start of installation around the auxiliary sealing ring 60 to hold in the recess 46 in the correct position; the auxiliary ring 60 is then pushed completely into the recess, until the radially outer edge of the surface 72 meets the end wall 44 of the cavity 36.

A rounded portion 78 of the helper ring 60 rests against a groove 80 in the end cap 16. When there is no load in In the axial direction, the surface 68 on the outer circumferential surface of the auxiliary ring 60 is at a small distance from the mating surface 46 of the depression, or can also lightly touch this surface; the flange 74 centers the auxiliary ring 60 in the cavity.

The end cap 16, the chain pin 14 and the abetander ring 42

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are joined together so that the chain pin 14 is received in the socket 28. You edge 52 of the main ring 48 is calibrated then against the end wall or mating surface 38 of the socket 28, wherein the edge 54 of the Hauptdiohtungsringes 48 is slightly deformed is, so that a sealing tape 54 of measurable radial Width forms. The extent to which the sleeve 28 can move to exert axial pressure on the seal becomes determined by the axial width of the spacer ring 42. When the end face 82 of the spacer ring on the mating surface 38 of the If Buchee 28 is present, the assembly is complete.

An axial compression of the seal becomes the elastic Auxiliary sealing ring 60 deformed. When the auxiliary diaphragm ring 60 is compressed in the axial direction, it tends to bulge on its side walls 70, 72 (? ig.1) and become more flat and to assume a less conical shape, i.e. its axial dimension is shortened and its cone angle is flattened. Through this takes the radial compression load on the main sealing ring 48 essential to what causes the main seal ring to be tight is detected by the help ring 60. The auxiliary ring 60 is then able to transmit considerable rotational forces.

In some respects, the puncture of this seal is similar to that of the seal described in ÜS-PS 3 241 843. With such previous seals, however, the main seal was ring Constructed from a stiff, thick metal material that was capable of very high radial deformation without significant deformation Withstanding compression forces · With the seal according to the invention The main sealing ring 48 is made of a much harder, stiffer material than the auxiliary ring 60, but it is still made of an elastomer and can in its free, unsupported State no compression loads of the required order of magnitude absorb without being bent inward to an undesirably great extent. Therefore, according to the invention the inner peripheral surface of the Hauptdiohtungsringee 48 the Teeth 56, which look against a metal surface, namely-

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borrowed against the spacer ring 42. This becomes the main sealing ring 48 supported against impermissible radial bending.

Before installation, the teeth 56 can be pointed (see FIG. 3), but the radial compression forces deform the teeth in the manner shown in Fig.4. Nevertheless, the channels remain open and a considerable volume of oil can be in the seal area be held. The total volume occupied by the channels 76 and the volume in the cavity 84 can be Ul and this can also be the gap 30.

The main sealing ring made of a solid rubber receives its radial support from the spacer ring 42. The channels 76 allow all of the oil trapped in the assembly to be used. The auxiliary sealing ring 60 is soft and has a low axial spring rate, so that the main seal ring 48 can move without excessive or to develop insufficient axial forces. If the spring rate is too high, the seal wears out very quickly; if the forces are too small, the seal does not seal.

The rubber materials described above provide suitable spring rates, but other rubbers can also be used.

The sealing ring 60 is a conical ring with an approximately parallelogram-shaped cross section. However, other equivalent shapes can also work well, see Figures 5a and 5b. When fully enclosed, rubber is essentially incompressible. The auxiliary ring 60 deforms during operation under load so that it has both a sealing pressure in the axial direction and a compression pressure in the radial direction on the Main sealing ring 48 exerts.

The mounting flange 74, which is also called a barb, is useful for the installation, but not absolutely necessary.

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-JS-

According to the invention, the main sealing ring 48 is stiff, but elastomeric; therefore should be the part of the auxiliary ring 60, the one behind the intended area of the viewing tape 54 is to be in contact with a rounded or wedge-shaped rubber piece of the auxiliary ring 60, even if the Auxiliary ring 60 is relaxed. In accordance with the invention, two pairs of rings 48, 60 can also be used in a single sealing cavity facing each other or used in so-called mirror image form. See US Pat. No. 3,241,845. In operation the spacer ring 42 limits the movement of the bushing 28 axially inward, while a spacer ring 42 attached as a counterpart at the other end of the chain pin is an impermissible axial Prevents shifting in the other direction. You radial force establishes a solid mechanical connection between the Bndkappe 16 and the main sealing ring 48 forth. The ring 48 is supported by the lubricated surface 40 of the spacer 42.

The end face 50 of the main sealing ring 48 is slightly angled, so that not all of the surface is in contact with surface 38.

5a shows a sighting ring 28a with an inclined, radial outward and rearward-facing seat surface 100. The auxiliary ring 60a has an O-ring configuration in the relaxed state and is a little toroidal or somewhat flattened in operation. On the end cap 16a is one directed radially inward and forward Seat 102 is formed. You two facing seat surfaces 100, 102 form conical ramps on which the auxiliary seal ring 60a can move when radial and attack axial forces on the ring. You sighting elements 48a, 60a function essentially in the same way as their corresponding ones Parts in Figures 1-4 and the materials these parts are made of are also the same.

Fig.5b shows a main sealing ring 48b and an auxiliary seal

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OFHGiNAL INSPECTED

processing ring 60b, which differs somewhat from ring 60 in Pig.1 and 2. A plurality of deformable mounting hooks 108 are provided in order to bring the auxiliary ring 60b into the correct position right from the start. The cross-section deforms during operation of the auxiliary ring 60b a little and the ring 60b works practically in the same way as the ring 60 in the Pig.1-4 ·

Pig.5o shows a ring 60c, which has a small foot 110 and 112, respectively, at its inner and outer radial ends having. Between the ends of the TUQs 110, 112 and the rest Ring 60c, narrow grooves 114, 116 appear when ring 60c is unloaded. As soon as a load is applied, it deforms the ring 60c in such a way that most of the grooves 114, 116 or even all of the grooves close and the feet 110, 112 fit snugly against the ring 60c.

The seal shown in Fig.5c works as well as the gasket of Fig.1-4 and the materials are the same

6-9 show a modified embodiment of an inventive Poetry. Fig.6 shows the seal installed at a typical "operating altitude"} Fig.7 shows the seal in the Submission submitted shortly before completion of the installation; Flg. 8 shows the seal at its maximum "operating height" and FIG. 9 shows the seal at minimum "operating height" or under maximum compression.

Chain pin seals and similar seals have - so says man - an "operating height" indicating the extent to which the seal is axially compressed. The maximum operating altitude occurs when the bottom of the indentation is axially the greatest distance from the part of the main sealing ring which forms the sealing tape 54. The lowest operating height is when the one forming the sealing tape Part of the main sealing ring is closest to the bottom of the recess. A typical operating level is between these

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two extreme values and is the height that should be present in practice, but is not always. You fluctuations in the operating altitude occur because of the need for the operation of the machine required working margins and the need for reasonable manufacturing tolerances. You sighting equals changes the operating height primarily through a compression of the auxiliary ring or spring element 60 and to a much lesser extent Measure by bending or compressing parts of the main sealing element 48 from.

If a sighting with one above the maximum operating altitude If working at a lying level, the seal may fail because the sighting is not compressed enough to form the sighting tape to be loaded in the axial direction. If the sighting is compressed beyond the minimum allowable operating altitude, the Auxiliary sealing ring compressed to the maximum and such a compression creates forces that squeeze out the lubricating film between the parts, and the sifting is very rapid due to excessive Friction and high temperatures are unusable.

You Fig.6-9 show a further embodiment of the sighting with a spacer ring 42d, a bushing 28d with a barrel surface 38d on the end face and with a recess which has a radial wall 44d and an axial wall 46d. Ser cavity 36d for the sighting is of these three surfaces and of the radially outwardly directed surface 40d of the spacer ring 42d limited.

When the sighting 10d is installed in the cavity 36d, the main sealing ring 48d and the auxiliary sealing ring 60d in the cavity 36d in FIG Position brought. The radially outward facing surface 68d and the radially inward facing surface 66d are parallel to each other, but through a gap Z and Y, respectively, from the surface 46d of the depression and the surface directed radially near the outside 62d of the main sealing ring 48d spaced apart.

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These distances X and Y are usually a few hundredths of a millimeter. In one case the gap Y is practically zero or a pest fit, while the gap X measures 0.5 to 1.5 mm. In this Pail allows an interference fit between surfaces 66d and 62d to handle the rings 48d and 6Od as a unit. When the gasket takes this position, the molded rubber parts 6Od and 48d relaxed and the end face 38d is at a distance from the sealing tape part or the edge 52d of the main sealing ring 48d. In this state, the conical extension of the auxiliary sealing ring 6Od forms with a radial plane an angle Θ. This angle θ can be, for example, 30 °.

When assembled, the bushing 28d and the part 22d of the chain link pushed towards the cap I6d, see Fig. 8. The bush 28d slides along on the chain pin 14d. If the Edge 52d of ring 48d comes to rest on surface 38d of bushing 28d and is then displaced by this in the axial direction is, the help sealing ring 6Od is up to the full system shifted, its part 78d rests against part 80d of the recess 36d. With further compression, compression deformation of the auxiliary sealing ring 6Od creates a sealing pressure in Axis direction generated, the angle θ is slightly reduced, for example to 20 ° to 25 °.

When the auxiliary ring 6Od is in the position of Fig. 8, the surfaces 70d, 72d are inclined at the angle θ, but parallel to one another and not noticeably bulged or deformed.

6 shows the seal in an exemplary position of use in which the surfaces 70d, 72d are somewhat bulged. Fig. 9 shows the seal at the lowest operating height, in which the front and rear surfaces 70d and 72d are noticeably bulged. The entire front edge, which in the embodiment of Fig.6-9 is a two-part surface consisting of a radially inner, substantially planar part 200 and a radially outer, consists essentially of conical part 202 is after

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inclined at the rear and radially outwards. The inner, normally planar surface 202 is radially outward and toward the bottom of the Inclined depression, while the conical surface part 200, which ends at the sealing edge 52, is inclined somewhat less to the front is than it would be under less axial pressure.

The axial dimensions or heights H ₁ , Hg >> H, and H, in Figures 6-9 illustrate the meaning of the expressions just used relating to the operating height. The dimension H ₁ from the edge 52d of the main sealing ring 48d to the rear edge 78d of the auxiliary ring 6Od is the greatest height (FIG. 7). This is the height when the unit is established. H ₂ shows the maximum installation height, which is slightly smaller than the production height. H, is a typical example of the operating altitude under moderate load, the intended working pressure. H * is the smallest installation height or operating height that is reached under the maximum permissible load.

The angled or two-part surface 200, 202 on the edge of the radial flange of the main seal element 48d is in the Proven use to be beneficial. This construction allows a slightly larger effective angle between surface 202 and the area 38d than can be achieved between the corresponding areas 50 and 38 in the example of FIGS. 1-5. Self when the seal operates within a range of small operating heights, including that shown in Figure 9 the frustoconical part 202 that the angle between of surface 200 and end surface 38d of bushing 28d is pointed enough to create a good seal.

The seals according to the invention offer a very long useful life and a high level of operational reliability compared to their low cost and can operate under harsh environmental conditions can be used, for example as a seal for chain pins, in order to provide a longer service life for the sealed parts and a much quieter caterpillar track than before

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was available. Some preferred embodiments of the seal according to the invention have been described in detail. Other equivalent designs of such a seal are included within the scope of the invention.

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Claims (12)

- y- M.J Radial surface seal, especially for harsh operating conditions, marked duroh a main sealing ring (48) having a substantially axial Planechteil and a substantially radial Planschteil comprises, of which the axial Plansch an inner circumferential surface and an outer circumferential surface (62) and the radial plano has a front surface (50) and a back surface (64) extending substantially radially, and wherein a part (52) is provided on the Yorderfläohe (50) of the radial flange which is to rest against a mating surface (38) can be brought, so that a full flat surface seal is created in between when this part (52) in the axial direction is pressed onto the mating surface, and an auxiliary sealing element (60) of approximately ring shape, the approximately axially extending inner and outer peripheral surfaces (66, 68), and a front surface (70) and has a rear surface (72) which are inclined forwardly and inwardly such that the auxiliary sealing element (60) in the unloaded State has an approximately parallelogram-shaped cross-section, wherein the inner peripheral surface of the auxiliary sealing member (60) in use of the seal on the outer circumference of the axial flange of the main sealing ring (48) so received Is that at least a part of the front surface (70) of the auxiliary sealing element (60) against at least a part the rear surface (64) of the Hauptdiohtungsringee (48), and in that the main sealing ring (48) is made from a relatively stiff but resilient first elastomeric Material is and the auxiliary sealing element (60) from a second elastic elastomeric material, which is substantially less is stiffer than the first material, and wherein the axial flange of the main sealing ring (48) on its inner circumference in use of the seal of one 709852/0816 ORIGINAL INSPECTED Part of an element to be sealed by the sighting (42) is supported. ' 2. Sighting according to claim 1, characterized in that the the substantially radially extending front surface (50) of the radial plane hinge in its outward extension is inclined slightly forward. 3 · sifting according to claim 1 or 2, characterized in that in the unloaded state of the sifting a radially inner Part of the front surface (70) of the auxiliary sealing element (60) extends further forward than the remaining front surface and is practically parallel to the back surface (64) of the radial flange of the main sealing ring (48). 4 · Sighting according to one of the preceding claims, characterized characterized in that on the inner circumference of the main sealing ring (48) means (56) are provided which at least partially Oil channels (76) form, which extend axially from the front surface (50) of the radial Planeehe8 to the rear end of the axial Extend flange " 5. Sifting according to one of the preceding claims, characterized characterized in that the inner periphery of the axial flange has a plurality of radially inwardly directed supporting Has projections (56) spaced on the circumference have inner ends (58) which, during operation, bear against part of the element to be sealed (42), whereby the Inner circumference is supported against movement radially inward, and wherein the gaps between the supporting projections (56) form oil channels during operation, which extend in the axial direction between the front surface (50) of the radial flange and the rear surface of the axial flange. 6. A sighting according to claim 5, characterized in that the supporting projections (56) have the shape of grooves, whose 709852/0816 2/26033 inner ends are axially extending teeth and that these inner ends can be flattened with the application of a radial compressive force on the main sealing ring (48) through the auxiliary sealing element (Si,) to a substantially circumferential contact with the part of the element to be sealed. 7. Seal according to one of the preceding claims, characterized in that the first elastomeric material is a Urethane elastomer is 8. Seal according to one of the preceding claims, characterized characterized in that the second elastomeric material is a nitrile rubber. 9 · Seal according to one of the preceding claims, characterized characterized in that the auxiliary sealing element (60) under the application of an axial load to the seal in such a way is deformable that its front and back surfaces (70, 72) bulge outwards and the parallelogram-shaped Cross-section is deformed so that its inner peripheral surface and its outer peripheral surface is shifted toward a radially aligned position. 10. Chain pin arrangement with a seal, characterized in that that the chain pin arrangement has a chain pin (14), a part of a first chain link (16) fastened to the chain pin and a part of a second chain link (22) which reciprocates with respect to the chain pin is movable, comprises, and a bushing (28) which surrounds a part of the chain pin (14) and in the part (22) of the second chain link is added and the one extending in the radial direction, looking in the axial direction End face (38) has as a mating surface, as well as a recess in the first chain link (16) for receiving the seal, and a spacer ring (42) that holds the chain 709852/0816 bolt (H) surrounds and calibrates in the axial direction between one End face (44) of the recess and the end face V38) the beech (28) extends and its outer peripheral surface together with the end face (38) of the bushing and the recess forms a cavity (36) for receiving the seal, and that in the cavity (36) inserted a radial surface seal having a main sealing ring (48) which a substantially axial flange with an inner circumference surface and an outer circumferential surface (62), as well comprises a radial flange with a substantially radially extending front surface (50) and rear surface (64), wherein the front surface (50) of the radial flange has a part (52) with which it is against the front surface (38) the socket (28) creates a tight seal when the radial flange is pressed against the end face in the axial direction will, and an auxiliary sealing element (60) of approximately ring shape having a substantially axially extending inner peripheral surface (66) and outer peripheral surface (68) and a Front surface (70) and a rear surface (72) which inclines in such a way forward and inward in the unloaded state of the sighting are that the auxiliary sealing element (60) has an approximately parallelogram-shaped cross section, the inner Peripheral surface of the auxiliary sealing element on the outer peripheral surface of the axial flange of the main sealing ring (48) is added in such a way that βloh at least one Part of the front surface (70) of the auxiliary roofing element (60) against at least part of the rear surface (64) of the main diaphragm ring (48) creates, the main seal ring (48) from a relatively is rigid but elastic first elastomeric material and the Hllfsdiohtungeelement (60) from a second elastic elastomeric material, which is much less rigid than the first material, and wherein the axial Flange of the main ring (48) on its inner circumference 709852/0816 _ 5 - catch surface (58) on the outer circumferential surface (40) of the spacer ring (42) is added and supported. ' 11 · Arrangement according to claim 10, characterized in that, when the end face of the bushing (38) rests against the spacer ring (42), the auxiliary sealing element (60) under one of the Face of the bushing exerted on the main sealing ring (48) axial pressure is deformed such that the front surface (70) and rear surface (72) of the auxiliary sealing element (60) bulge outwards and deform the parallelogram-shaped cross section of the auxiliary sealing ring in this way will move its inner peripheral surface and its outer peripheral surface toward a radially aligned position will. 12. Seal according to claim 1, characterized in that the Front surface of the radial flange of the main sealing ring (48d) comprising a first surface (202) and a second surface (200), of which the first surface (202) is a substantially planar, radially extending surface and the second surface (200) adjoins the first surface along a common edge and is frustoconical Has shape and is inclined radially outward and towards the mating surface (38). (Fig. 6-9) 13 · Seal according to claim 12, characterized in that the Angle between the first and the second surface (202, 200), measured on the outside of the surfaces, between approximately 140 ° and is about 165 °. 709852/0816