EP4274979A1

EP4274979A1 - Seal assembly and joint bushing

Info

Publication number: EP4274979A1
Application number: EP21844341.4A
Authority: EP
Inventors: Theodor Wüst
Original assignee: Swiss Tech Innovation Ag
Current assignee: Swiss Tech Innovation Ag
Priority date: 2021-01-06
Filing date: 2021-12-23
Publication date: 2023-11-15
Also published as: WO2022148671A1; JP2024504871A; CA3201389A1; KR20230125796A; US20240151334A1; CH718244A1

Abstract

The invention relates to a seal assembly (10) for producing a sealing function in a pipe joint, in particular a static pipe joint, in particular between a fluid-conducting pipe (11) and a joint bushing (12). The seal assembly (10) comprises a ring seal (20) arranged in a circumferential groove (121), a seal seat (30), and a clamping element (40) for clamping the ring seal (20). The seal assembly (10) has a pressure side. The seal seat (30) is arranged in the circumferential groove (121) on the pressure side and has overflow openings (31) so that the ring seal (20) is exposed to the pressure of the fluid on the pressure side. Additionally or alternatively, the seal seat (30) is arranged in the circumferential groove (121) and tapers conically towards the pressure side, so that clamping of the ring seal (20) causes same to be compressed in a radial direction while the circumferential groove (121) remains accessible on the pressure side.

Description

Sealing assembly and connecting sleeve

The present invention relates to a sealing arrangement for generating a sealing function in a pipe connection, in particular a static one, and a connecting sleeve comprising a sealing arrangement according to the preamble of the independent patent claims.

For the connection of pipelines, in particular plastic pipelines, sockets are often used, in which the end sections of the pipelines to be connected are introduced from two opposite sides and then are sealingly fi xed therein. Alternatively, the sockets can also be formed at the end of a pipeline.

In a widespread type of such plug-in sockets, the fixation is carried out by means of ring seals made of elastomeric material, which also ensure the required tightness of the connection at the same time. The ring seals are located in circumferential ring grooves of the plug-in socket and when inserting the end sections of the pipe or pipes to be connected are radially squeezed between an inner wall of the ring groove and an outer surface of the respective end sections, so that they lie tightly against the outer surfaces of the end sections and the Hold the end sections of the pipes with a friction fit.

The production of such connections with sockets requires a relatively large amount of force in order to insert the end sections of the pipes to be connected into the socket, since the necessary strong squeezing of the ring seals of the introduction tion of the end sections provides considerable resistance. There is also the risk that the corresponding ring seal will be damaged when slipped over the end section of the pipe. In order to avoid this, the respective end sections in particular must be additionally processed, for example deburred. With EP 3120 064 Bl a connector with a ring seal has become known, which eliminates at least some of these disadvantages. EP 3120 064 Bl discloses a plug-in connection with an annular seal which is deformed by means of a clamping element. By tensioning the tensioning element, which is designed as a toggle lever, the width of an annular groove into which the ring seal is inserted is reduced, so that the ring seal is squeezed on both sides. The ring seal rests with an outer circumference in the base of the ring groove, so that an inner diameter of the ring seal is reduced by the deformation and it thus comes into contact with the pipe to be connected. With this arrangement, a pipe end can be tightly connected with a corre sponding plug connection. However, such a connection is not very suitable for connecting pressurized lines, since the ring seal is impacted by internal pressure in the tube precisely in the area of its contact with the tube end, and as a result tends to lift off.

It is therefore an object of the invention to eliminate at least one or more disadvantages of the prior art. In particular, a sealing arrangement and a connecting sleeve are to be made available that make it possible to use all the essential structural properties of a ring seal. Preferably, an additional processing step for deburring a pipe end should be prevented or at least the effort involved in deburring should be reduced.

This object is achieved by the devices defined in the independent patent claims. Further embodiments emerge from the dependent patent claims

A sealing arrangement according to the invention for generating a sealing function in a, in particular static, pipe connection, in particular between a fluid-carrying pipe and a connection socket, comprises a sealing arrangement arranged in a circumferential groove ring seal. The sealing arrangement comprises a sealing seat and a tensioning element for tensioning the ring seal, it being possible or being brought into contact with the fluid-carrying pipe by tensioning the ring seal. This also makes it possible for a ring seal to be used which has an inner diameter which is larger than an outer diameter of the pipe end to be sealed. Correspondingly, the ring seal does not have to be slipped or pulled over an edge of the pipe end, but rather can be slipped over the pipe end without interfering with it because of its larger diameter. The sealing system has a pressure side.

The pressure side of the sealing arrangement is that side which, in the operational state, is subjected to pressure from the pipe to be connected.

The seal seat is located in the circumferential groove on the pressure side and has overflow openings so that the pressure of the fluid is applied to the ring seal on the pressure side.

Additionally or alternatively, the seal seat can be arranged in the circumferential groove in such a way that it tapers conically in the direction of the pressure side, so that tensioning the ring seal compresses it in the radial direction, in particular shifts it, with the circumferential groove becoming accessible on the pressure side remains.

In other words, this means that the circumferential groove can be subjected to pressure on its pressure side, in particular at the bottom of the groove.

Directional designations are defined here by the sealing arrangement in generic use. An axial direction thus essentially corresponds to the direction of the longitudinal axis of a pipe to be connected, and correspondingly a radial direction corresponds to the direction of a pipe ray extending perpendicularly from this axis. A jam analysis in the radial direction thus corresponds to a displacement of an element or a surface in the direction of the longitudinal axis of the pipe.

Because the circumferential groove is accessible on the pressure side and can be pressurized accordingly, the ring seal can also be pressurized. Existing compression on the ring seal is additionally increased by this pressure application. In other words, with the increase in pressure within the pipe connection, the pressure on the ring seal is increased and the sealing function is accordingly increased.

It can be provided that the overflow openings are designed as radially extending grooves. On the one hand, this permits simple and cost-effective production, on the other hand, for example, a visual check of the condition of the overflow openings before or during installation is easily possible.

Alternatively, the overflow openings can be designed as radially extending bores. By designing it as a bore, the seal seat can be provided with a circumferential and uninterrupted surface and thus provide a correspondingly large contact surface for the ring seal.

A combination of these two embodiments is also possible.

The seal seat can have a bearing surface for bearing the ring seal. This bearing surface is preferably spaced apart from a bottom of the circumferential groove by a recess. It can be provided in particular that the recess is designed as a radially inwardly offset surface of the seal seat. Such a design of the seal seat with a recess ensures that the ring seal can also be subjected to pressure in the area of its largest diameter, in particular in the area of the bottom of the groove. In other words, with such a configuration, essentially the entire surface of the ring seal arranged on the pressure side of the sealing arrangement can be subjected to pressure evenly.

The sealing seat is preferably ring-shaped. It can thus be manufactured easily and with a high level of accuracy.

In the case in which the seal seat is designed to taper conically in the direction of the pressure side, this can be at an angle of 5° to 20°, in particular from 7° to 15°, preferably in an angle of 7° to 12°, in particular in an Angle of 10 ° be tapered.

These minimum angles and maximum angles ensure that there is a corresponding reduction in an inner diameter of the ring seal, but this is not forced so quickly that the ring seal is damaged. It can be seen that the flatter the angle, the further the clamping element has to be moved in order to achieve a correspondingly desired narrowing of the inside diameter. An angle of 10° has proven particularly advantageous here.

The seal seat can be made of plastic. This he allows a simple and inexpensive production.

The seal seat is preferably formed as a separate element, but alternatively it may be formed as an integral part of the coupling sleeve. An integral production is particularly advantageous if the seal seat is designed to run conically. The ring seal can be designed as an O-ring. O-rings are easy to manufacture, inexpensive and available in different standard sizes. In addition, they can be easily replaced and have extremely homogeneous properties.

As already explained, the ring seal can have a diameter that is larger than the outside diameter of the pipe to be sealed. This enables the sealing arrangement to be joined to a corresponding pipe end without the use of force, without the ring seal touching the pipe end.

It can be provided in particular that an inner diameter of the ring seal is larger than an inner diameter of the groove. The inner diameter of the groove is defined by the surfaces adjacent to the groove.

In other words, the ring seal is set back from the elements adjacent to the ring seal and is therefore protected.

The clamping element is preferably arranged so that it can move axially and can therefore be moved in the axial direction, ie along the tube. This allows the width of the circumferential groove to be changed easily so that the ring seal can be easily clamped.

Preferably, the circumferential groove is limited on one side by the clamping element. In other words, the circumferential groove has a fixed and a movable side wall, with the side wall being movable being formed as part of the clamping element. The ring seal can thus be tightened easily.

A further aspect of the invention relates to a connecting sleeve comprising a sealing arrangement as described here. This makes it possible to provide a compact unit for connecting tube ends.

The tensioning element can be designed as a sleeve that can be screwed into the connecting sleeve.

The ring seal can be pretensioned by simply twisting or screwing the tensioning element into the connecting socket.

Alternatively, the tensioning element can be designed as an end section of an arrangement of a plurality of tensioning elements which can be moved into a stable position via a dead center.

As a result, the ring seal can be precisely preloaded by simply snapping the clamping elements over. The tendons can be formed in particular as described in EP 3120 064 B1.

Alternatively, the clamping element can be designed as a clamping ring with clamping screws, the clamping ring being displaceable in the direction of the ring seal by means of the clamping screws.

In particular, this makes it possible to provide relatively large connecting sleeves and to bring about relatively high prestressing forces.

The connecting sleeve as described here can be designed in such a way that it has a second sealing arrangement as described here, which is arranged in particular opposite the first sealing arrangement.

With such a connecting sleeve, two pipe ends can be easily and securely connected to one another. The two pipes can preferably be pushed into the connecting sleeve from opposite directions and each clamped and sealed with the appropriate sealing arrangement. Several possible embodiments of the sealing arrangement are explained using schematic figures. It shows:

Figure 1 shows a prior art coupling sleeve in the open position;

FIG. 2: the connecting sleeve according to FIG. 1 in the tensioned position;

FIG. 3: the functional principle of a conventional 0-ring;

FIG. 4: a first embodiment of a sealing seat; FIG. 5: a detailed view of a cross section through the sealing seat according to FIG. 4;

FIG. 6: a detailed view of a cross section of a sealing arrangement in the installed state in the open position;

FIG. 7: the detailed view according to FIG. 6 in the clamped position;

FIG. 8: a second embodiment of a sealing seat;

FIG. 9: a detailed view of a cross section through the sealing seat according to FIG. 8;

FIG. 10: a detailed view of a cross section of a sealing arrangement in the installed state in the open position;

FIG. 11: the detailed view according to FIG. 10 in the clamped position;

FIG. 12: a sealing arrangement with an alternative design of a tensioning element. FIG. 1 shows a prior art coupling sleeve 12 in the open position. A sealing arrangement 10 is arranged in the connecting sleeve 12 . The sealing arrangement 10 has an annular seal 20 which forms out in the present case as an O-ring.

The sealing arrangement 10 also has a tensioning element 40 . The tensioning element 40 is axially movable and displaceable with tensioning elements, not designated in any more detail, which are designed as toggle levers. The clamping element 40 is present as an Endab cut countries an integral part of the arrangement of clamping members. The ring seal 20 is arranged in the connecting sleeve 12 in a circumferential groove 121 ei. The basic structure of the connecting sleeve 12 corresponds to the structure disclosed in EP 3120 064 Bl. The structure, arrangement and mode of operation of the tendons also correspond to those in EP 3120 064 Bl.

FIG. 2 shows the connecting sleeve 12 according to FIG. 1 in the tensioned position. The annular seal 20 was compressed by the radial pressing in of the toggle levers, which hold the tensioning element 40 . Their shape has thus changed from an essentially round shape (see FIG. 1) to an essentially oval shape. The ring seal 20 rests on the base of the circumferential groove 121, on the side walls of the groove 121, one of these side walls being formed by the clamping element 40, and on an outer surface of the pipe end of the pipe 11. The ring seal 20 is thus in contact with a counterpart on four sides. Only an area of the ring seal 20 in the area of its contact with the tube 11 is accessible from the inside of the tube 11 and can be pressurized. The application of pressure at this point results in the ring seal 20 being pushed open and its contact with the pipe 11 being reduced and the connecting sleeve 12 thus becoming leaky. FIG. 3 shows the functional principle of a ring seal 20 which is designed as a conventional O-ring. The O-ring is in an unspecified groove of a connecting sleeve 12. A tube 11 to be sealed is pressed in the direction of the arrow into the connec tion sleeve 12. As can easily be seen, the tube 11 must have a chamfer in the area of initial contact with the O-ring in order to avoid damaging the O-ring. During the sliding process (transition from the first to the middle illustration), the O-ring is compressed radially. This then exerts a certain contact pressure on the base of the groove and on the outer wall of the pipe 11 . In the third representation according to FIG. 3, the situation is now shown when an interior of the tube 11 is subjected to pressure. The 0-ring is correspondingly pressed against a side wall of the circumferential groove facing away from the pressure side. In addition, the pressure of the O-ring increases in the radial direction and in the opposite direction to the radial direction. In other words, the contact pressure of the O-ring in the circumferential groove and on the outside of a tube 11 increases with increasing pressure acting on the O-ring on the pressure side.

It is immediately apparent that with a connecting sleeve according to the prior art (Figures 1 and 2), it is not possible to apply pressure to the O-ring on one side, since this is compressed laterally by a radial prestress, as in the middle illustration of the Figure 3 is shown to reach it.

FIG. 4 shows a first embodiment of a sealing seat 30. The sealing seat 30 is essentially ring-shaped and has a large number of overflow openings 31. For the sake of clarity, only one of the overflow openings 31 is provided with a reference symbol. The seal seat 30 also has a bearing surface 32 for bearing a ring seal. As can be seen from FIG. 4, this bearing surface 32 divided by the overflow openings 31 in meh eral sections. The overflow openings 31 are formed before lying as radially extending grooves. A recess 33 is arranged on the periphery of the sealing seat 30 so that the contact surface 32 is spaced apart from a circumferential groove in which the sealing seat 30 is arranged or can be arranged. The overflow openings 31 create a connection from an area of the circumferential groove directed towards the center of a pipe to an area at the base of the groove, so that pressure can be equalized via these overflow openings 31 or the recess 33 can be pressurized .

5 shows a detailed view of a cross section through the seal seat 30 according to FIG spaced in generic use to a base of a circumferential groove.

FIG. 6 shows a detailed view of a cross section of a sealing arrangement 10 in the installed state in the open position. The sealing arrangement 10 includes a sealing seat 30 as described for FIG. The cross section shown here corresponds to that from FIG. 5. The sealing arrangement 10 is shown in the open position in the present case. It can be seen that the ring seal 20 is slightly spaced from an outer surface of the tube 11 . However, the ring seal 20 touches the bearing surface 32 of the seal seat 30 on one side and a surface of the clamping element 40 on the opposite side. In the position shown here, the pipe 11 can be inserted without colliding with the ring seal 20 in be moved into or removed from the seal assembly 10.

FIG. 7 shows the detailed view according to FIG. 6 in the clamped position. The clamping element 40 was moved in the direction of the arrow towards the ring seal 20 so that the ring seal 20 was clamped between the seal seat 30 and the clamping element 40 and was deformed accordingly. Due to the deformation, an inner diameter of the ring seal 20 has been reduced, so that the ring seal 20 now rests with its inner periphery on an outer circumference of the tube 11 . As can be seen in FIG. 7, an annular space formed by the recess 33 in the groove 121 is accessible to a fluid. This can flow along the outer surface of the pipe 11 and flow through the overflow openings 31 in the sealing seat 30 into this recess 33 . The ring seal 20 can thus be subjected to pressure both in the area of the seal or its contact with the pipe 11 and in the area of its seal or its contact with the bottom of the groove 121 . In other words, the ring seal 20 can be subjected to the pressure of a fluid located in the pipe 11 on its pressure side. With this arrangement, an increase in the pressure in the radial direction and opposite to the radial direction can be achieved by the ring seal 20 . With increasing pressure, the ring seal 20 is deformed in such a way that it lifts off the support surface 32 .

FIG. 8 shows a second embodiment of a sealing seat 30. The sealing seat 30 is essentially ring-shaped and has a large number of overflow openings 31. For the sake of clarity, only one of the overflow openings 31 is provided with a reference symbol.

The seal seat 30 also has a bearing surface 32 for position on a ring seal. As can be seen from FIG. 4, this bearing surface 32 is designed to be continuous. the Overflow openings 31 are presently formed as radially extending bores. At the periphery of the sealing seat 30 a recess 33 is arranged, into which these holes open. The bearing surface 32 is at a distance from a circumferential groove in which the sealing seat 30 is arranged. The overflow openings 31 create a connection from an area of the circumferential groove directed towards the center of a pipe to an area at the base of the groove, so that pressure equalization can be created via these overflow openings 31, or the recess 33 with pressure can be charged.

FIG. 9 shows a detailed view of a cross section through the seal seat 12 according to FIG spaced in generic use to a base of a circumferential groove.

The embodiment of the sealing seat according to FIGS. 8 and 9 is fully compatible with the sealing arrangement according to FIGS. 6 and 7 and can be exchanged with the sealing seat 30 illustrated therein.

FIG. 10 shows a detailed view of a cross section of an alternative sealing arrangement 10 in the installed state in the open position. In this sealing arrangement 10 of the device seat 30 is formed as an integral part of a circumferential groove 121 of a connecting sleeve 12 . In the present case, the sealing seat 30 is designed as a surface that tapers conically in the direction of a pressure side. It can also be seen here that the ring seal 20 has an inner diameter which is larger than the outer diameter of a pipe 11. In the state shown here, the ring seal 20 lies on the surface of the Seal seat 30 and on a surface of the clamping element 40.

FIG. 11 shows the detailed view according to FIG. 10 in the tensioned position. The clamping element 40 was actuated and moved in the axial direction illustrated by an arrow. Accordingly, the ring seal 20 was moved along the tapered surface of the seal seat 30 tapering toward the pressure side of the pipe joint. As can be seen, the ring seal 20 has been deformed and radially displaced and/or upset towards the center of the tube. It can be seen that the ring seal is now in contact with an outer surface of the pipe 11, with the surface of the seal seat 30 and with the clamping element 40. It can be seen immediately that the pressure side of the ring seal can be fully pressurized and on this ring seal 20 a state occurs, as is described for the third illustration from FIG. The application of pressure thus increases the sealing of the pipe 11 on the one hand and the clamping of the pipe by the ring seal 20 on the other hand.

FIG. 12 shows a sealing arrangement 10 with an alternative design of the tensioning element 40. This embodiment is compatible with all of the embodiments described and the function of the ring seal 20 and the sealing seat 30 corresponds to that of the exemplary embodiments already described, which is why it is not repeated again becomes. In other words, the tensioning element 40 can be configured as described here, for example as an end section of an arrangement of toggle levers, which is moved axially by the tensioning of the toggle levers.

The clamping element 40 is constructed in several parts and has a pressure ring 41 , a clamping ring 42 and a conical ring 43 . The pressure ring 41 is in contact with the ring seal 20 and with the Cone ring 43 or can be brought into contact. Arranged centrally within the cone ring 43 is a clamping ring 42. The cone ring 43 and the clamping ring 42 are slidably mounted on one another on conical surfaces. The cone on the cone ring 43 widens in the direction of the joining direction, so that a movement of the cone ring 43 in the direction of the ring seal 20 compresses the clamping ring 42 radially. The clamping ring 42 is pressed onto the pipe 11 by this radial pressure, so that this is held by an additional radial force.

By the movement of the cone ring 43 in the direction of the ring you device 20 this presses on the pressure ring 41, which in turn moves in the direction of the ring seal 20 and this as described be described here deformed.

The clamping ring 42 has teeth on its inner circumference, which are directed counter to the direction in which the pipe 11 is joined. When the pipe 11 moves counter to the joining direction, the clamping ring 42 is pressed further into the cone and the radial force which holds the pipe 11 is additionally increased.

Claims

patent claims

1. Sealing arrangement (10) for generating a sealing function in a, in particular static, pipe connection, in particular between a fluid-carrying pipe (11) and a connecting sleeve (12), comprising an annular seal (20) arranged in a circumferential groove (121), a seal seat (30) and a clamping element (40) for clamping the ring seal (20), the sealing arrangement (10) having a pressure side, characterized in that the seal seat (30) is arranged in the circumferential groove (121) on the pressure side and has overflow openings (31), so that the ring seal (20) is subjected to the pressure of the fluid on the pressure side and/or that the sealing seat (30) is arranged in the circumferential groove (121) and is designed to taper conically towards the pressure side is, so that when the ring seal (20) is tensioned, it is compressed in a radial direction, with the circumferential groove (121) remaining accessible on the pressure side.

2. Sealing arrangement (10) according to claim 1, characterized in that the overflow openings (31) are designed as radially extending grooves.

3. Sealing arrangement (10) according to claim 1, characterized in that the overflow openings (31) are designed as radially extending bores.

4. Sealing arrangement (10) according to one of Claims 1 to 3, characterized in that the seal seat (30) has a bearing surface (32) for bearing the ring seal (20), this bearing surface (32) being defined by a recess (33) is spaced from a bottom of the circumferential groove (121).

5. Sealing arrangement (10) according to any one of claims 1 to 4, characterized in that the sealing seat (30) is ring-shaped.

6. Sealing arrangement (10) according to claim 1, characterized in that the seal seat at an angle of 5 ° to 20 °, in particular from 7 ° to 15 °, preferably at an angle of 7 ° to 12 °, in particular at an angle of 10°, is designed to taper conically.

7. Sealing arrangement (10) according to any one of claims 1 to 6, characterized in that the sealing seat (30) is made of plastic.

8. Sealing arrangement (10) according to any one of claims 1 to 7, characterized in that the sealing seat (30) is designed as an integral part of the connecting sleeve (12).

9. Sealing arrangement (10) according to any one of claims 1 to 8, characterized in that the ring seal (20) is designed as an 0-ring.

10. Sealing arrangement (10) according to any one of claims 1 to 9, characterized in that the ring seal (20) has an inner diameter which is larger than an outer diameter of the pipe to be sealed.

11. Sealing arrangement (10) according to any one of claims 1 to 10, characterized in that the clamping element (40) is arranged axially movable.

12. Sealing arrangement (10) according to any one of claims 1 to 11, characterized in that the circumferential groove (121) is delimited on one side by the clamping element (40).

13. Connection sleeve (12) comprising a sealing arrangement (10) according to any one of claims 1 to 12.

14. Connecting sleeve (12) according to claim 13, characterized in that the clamping element (40) is designed as a sleeve which can be screwed into the connecting sleeve (12).

15. Connecting sleeve (12) according to claim 13, characterized in that the clamping element (40) is designed as an arrangement of a plurality of clamping members which are movable over a dead point in a stable position.

16. Connecting sleeve (12) according to claim 13, characterized in that the clamping element (40) is designed as a clamping ring with clamping screws, with screws by means of the clamping of the clamping ring in the direction of the ring seal (20) is displaceable.

17. Connecting sleeve (12) according to any one of claims 13 to 16, characterized in that it comprises a second sealing arrangement (10) which is arranged opposite to the first sealing arrangement (20).