Patent Application
20250172417
The present application is related to and claims the priority benefit of German Patent Application No. 10 2023 133 004.7, filed Nov. 27, 2023, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a form seal for sealing a gap between a component and a part surrounding the component on the outside and on all sides, to a device including the form seal, the component and the part, and to a method for using at least one form seal in the device.
There are a variety of devices in which a component is inserted into a recess in a part surrounding the component on the outside and on all sides, such as a housing or a fitting.
Examples of this include sensors, measuring devices, measuring arrangements, and measuring systems for metrological detection of a measured variable of a medium, which usually include a component in contact with the medium during measuring operation, such as a window, a membrane or a measuring element. For example, sensors such as optical sensors, photometers and spectrometers generally have windows that are transparent to electromagnetic radiation, through which electromagnetic radiation used for measuring the measured variable passes. Examples thereof are calorimetric sensors, turbidity sensors, sensors for measuring a spectral absorption coefficient, as well as sensors for measuring a concentration of an analyte contained in the medium, such as, for example, sensors for measuring a nitrite content, a nitrate content or an ammonium content. Another example are sensors, such as conductivity sensors, whose components comprise electrode surfaces in contact with the medium during measurement, as well as sensors whose components comprise a membrane in contact with the medium during measurement operation.
These components are usually inserted into a part, such as a housing or a fitting, such that the part surrounds the component on all sides, at least in portions.
In particular, in conjunction with components that are in contact with a medium, e.g., a process medium or a measuring medium, it is generally necessary to ensure reliable sealing of a gap existing between the component and the part. Depending on the location, this seal may also have to meet special hygiene requirements.
The gap can be sealed, for example, by gluing, soldering or a press fit. However, if the component and the part are made of materials with different thermal expansion coefficients, these sealing forms can cause thermomechanical stresses depending on the temperature. An example of this is glass windows inserted into metal housings. In order to avoid damage to the seal and/or the component caused by thermomechanical stresses, it is usually necessary to limit the temperature range in which devices sealed in this way are used.
An alternative form of sealing that can be used is to insert the component into the part with the interposition of a seal, e.g., an O-ring.
In applications where there are high demands on hygiene and cleanability, the component is routinely inserted into the part with the interposition of the seal such that a small partial region of the clamped seal protrudes outward. This avoids undercuts into which medium could penetrate and which could not be easily removed again by cleaning from the outside. The disadvantage, however, is that the protruding partial region may affect the flow behavior of the medium along the outside of the component. The latter is particularly undesirable for sensors and measuring devices with components that are flush with the front of their housing, such as windows or measuring elements, where flow shadows and/or turbulence caused by the protruding partial region can have a detrimental effect on the measuring properties.
A further disadvantage of this form of sealing is that in order to achieve a front-side sealing of the gap between the component and part, it is periodically necessary to insert the seal together with the component into the part through a rear opening of the part opposite the front side.
For example, DE 10 2016 103 750 A1 describes a sensor cap that comprises a component designed as an insertable component, the end face of which has a membrane that is in contact with a medium during measuring operation. The insertable component is inserted flush with the front of a sleeve-shaped part with the interposition of a seal, e.g., an O-ring. The sealing of the end region of the gap facing the medium between the insertable component and the sleeve-shaped part is achieved by inserting the seal into an annular groove of the insertable component arranged on the outside at the front. The insertable component is then inserted together with the seal into the sleeve-shaped part through a rear opening of the sleeve-shaped part and fastened there.
However, the front sealing of the gap by a seal and the associated requirement to the component together with the seal through the rear opening of the part inevitably means that any necessary replacement of the seal must also be carried out through the rear opening of the part. For this purpose, the rear opening of the part must be made accessible. However, this requirement is not always easy to fulfill. For example, if we consider a sensor with a component that is flush with the front of a sensor housing with a seal in between, such as a window or a measuring element, replacing the seal requires opening the sensor housing. This not only involves a lot of effort but can possibly also result in other components in the sensor housing, such as electronic components, being affected and/or being exposed to unfavorable environmental conditions, such as high humidity.
It is an object of the present disclosure to provide a seal for sealing a gap between a component and a part surrounding the component on the outside on all sides, which overcomes the aforementioned disadvantages of the prior art.
In this respect, it is, in particular, an object of the present disclosure to provide a seal that meets stringent requirements for hygiene and/or cleanability, which allows flush installation of the seal and/or the component, with which a high-quality seal can be achieved without sealing regions protruding outwards, and/or that is replaceable without a rear opening of the part having to be accessible for this purpose.
For this purpose, the present disclosure comprises a form seal for sealing a gap between a component that can be inserted or is inserted into a recess of a part that is open to the environment on the front side and has a groove arranged on the outside, and the part that delimits the recess on all sides on the outside, wherein the form seal:
The form seal has the advantage that it can be inserted into the recess from the outside together with the component and the component is held in the recess by the form seal. A further advantage is that the form seal can be replaced from the outside if necessary, without having to access an opening on the rear of the part.
In addition, the form seal has the advantage that it can be mounted flush with the front and thus meet high requirements for hygiene and/or cleanability. In contrast to O-rings known from the prior art, the form seal can achieve a high-quality seal of the gap without any sealing region of the form seal protruding outward.
In at least one embodiment, the first sealing region comprises, on the side of the front region facing away from the front side of the form seal, a rear region to which the second sealing region adjoins on the inside and whose radial width corresponds to a maximum radial width of the front region of the first sealing region.
According to a first development, the second sealing region has a projection formed on its inner edge and protruding in a direction facing away from the front side of the form seal.
According to a second development, the third sealing region has outer dimensions over its entire axial height in the radial direction that are smaller than the outer dimensions of the first sealing region.
A third development is that the third sealing region:
According to a fourth development, the form seal has an annular circumferential groove with a rounded cross-sectional geometry on the inside in a transition region adjoining the second sealing region between the first sealing region and the third sealing region.
In a fifth development, the form seal is designed such that its front side is planar, and/or the dimensions of which are dimensioned such that the front side of the form seal facing the environment in the assembled state of the form seal is planar, is flush with a front side of the component facing the environment, and/or is flush with an outer surface of the part that surrounds the front side of the form seal on all sides.
Furthermore, the present disclosure comprises a device with a form seal according to the present disclosure, a component with a groove arranged on the outside, and a part with a recess open to the environment, into which the component is inserted with the interposition of the form seal surrounding the component on all sides on the outside.
A first further development of the device is that the recess comprises a region facing the environment, the dimensions or diameter of which decreases in the direction facing the environment.
A second further development of the device is that:
A third further development of the device provides that a first cavity surrounding the third sealing region on the outside adjoins the third sealing region in the recess, and/or a second cavity surrounded on the outside by the third sealing region adjoins the third sealing region.
A further development of the device is that:
A fifth further development of the device provides that the device is a sensor, a measuring instrument, a measuring device, a measuring arrangement or a measuring system for the metrological detection of a measured variable of a medium,
Further, the present disclosure comprises a method for using at least one form seal according to the present disclosure in a device according to the present disclosure, wherein the method of use comprises an assembly method in which:
A further development of the method comprises a method in which:
According to a further development of the method, the form seal is replaced at least once with an identical replacement seal by removing the form seal from the recess using a tool or a hook, and the replacement seal is mounted in the recess together with the component or an identical replacement component by means of the assembly method.
The present disclosure and its advantages will now be explained in detail using the figures in the drawing, which show several examples of embodiments. The same elements are indicated by the same reference numbers in the figures.
The present disclosure relates to a form seal 1 for sealing a gap between a component 5 that can be inserted or is inserted into a recess 3 of a part 7 that is open to the environment on the front side and the part 7 that delimits the recess 3 on all sides on the outside. An exemplary embodiment of the form seal 1 is shown in
The form seal 1 described here can be used in devices 100 of the most varied types, such as sensors, measuring instruments, measuring devices, measuring arrangements and measuring systems for the metrological detection of a measured variable of a medium, each of which has a part 7, such as a housing or a fitting, with a recess 3 open to the environment and a component 5, such as a probe, a membrane, a measuring element or a window, inserted at least partially into the recess 3 with the form seal 1 interposed.
A section of an exemplary embodiment of the device 100 comprising the form seal 1, the recess 3 of the part 7 and the component 5 is shown in
Depending on the type of device 100, the component 5 is, for example, a sensor element, such as a membrane, e.g., an analyte-sensitive membrane of a sensor, e.g., an optochemical sensor, or a sensor element comprising at least one electrode, such as a sensor element comprising at least one measuring electrode of a conductivity sensor.
In conjunction with devices 100 designed as optical measuring devices or as optical sensors, the component 5 is, for example, a window through which, by means of the correspondingly designed devices 100, transmission radiation is sent into a medium adjoining the outside of the window and/or through which measurement radiation is received. In this case, the device 100, which is only partially shown in
Depending on the type of device 100, the part 7 is, for example, a fitting or a housing with at least one recess 3 for receiving a component 5.
As shown in
The form (e.g., molded) seal 1, or the first sealing region 11, the second sealing region 13 and/or the third sealing region 15 each consist of a sealing material, e.g., an elastomer, a plastic, such as polytetrafluoroethylene (PFTE), polyetheretherketone (PEEK) or polypropylene (PP) or another sealing material.
The first sealing region 11 is designed to seal a front region of the gap facing the environment and located in the recess 3. Accordingly, the dimensions of the first sealing region 11 are preferably dimensioned such that the first sealing region 11, when mounted in the device 100, is clamped in the front region of the gap in the radial direction between an inner surface area 17 of the part 7, which delimits the recess 3 on all sides on the outside, and an outer surface area of the component 5.
Optionally, a front side 19 of the first sealing region 11 facing the environment in the assembled state of the form seal 1 has, for example, a planar shape. Alternatively or additionally, the dimensions of the form seal 1 are optionally dimensioned, for example, such that the front side 19 of the first sealing region 11 is substantially flush with a front side 21 of the component 5 facing the environment, and/or is substantially flush with an outer surface 23 of the part 7 surrounding the front side 19 of the form seal 1 on all sides.
This avoids undercuts into which medium could penetrate that could not be easily removed again by cleaning from the outside. In contrast to O-rings known from the prior art, which routinely have to be clamped such that a partial region of the O-ring protrudes from the gap to be sealed in order to avoid undercuts, the dimensions of the form seal 1 described here are optionally dimensioned, for example, such that the front side 19 of the first sealing region 11 is substantially planar in the assembled state of the form seal 1. This avoids the disadvantages previously described in connection protruding partial regions of O-rings. The latter is advantageous in particular in devices 100 for the metrological detection of a measured variable of a medium, in which protruding partial regions can have a detrimental effect on the measuring properties.
The first sealing region 11 has, at least in a front region 11a adjoining its front side 19, decreasing external dimensions in the axial direction extending in the direction of the front side 19.
In this respect, the recess 3 of the part 7 of the device 100 preferably has decreasing dimensions in the axial direction towards the environment, at least in its region 3a facing the environment.
This shape, which is actually disadvantageous with regard to the insertion of the form seal 1 from the outside through an opening 49 of the recess 3 facing the environment, offers the advantage that the inner surface area 17 of the part 7, which delimits the recess 3 on the outside, forms a counter bearing for the form seal 1 inserted into the recess 3, on which the outer surface area 25 of the first sealing region 11 rests in the inserted state. This causes a fixation of the form seal 1 in the recess 3 in addition to the radial clamping of the first sealing region 11 in the front region of the gap, which prevents the form seal 1 clamped in the gap from emerging from the recess 3 in the direction facing the environment.
In order to achieve this fixation acting in the axial direction, the first sealing region is optionally designed, for example, in such a way that it has decreasing external dimensions over its entire axial height in the axial direction running towards the front side. In this case, the front region is identical to the first sealing region.
The second sealing region 13 is designed as a spring that, when the form seal 1 is pushed onto the component 5, engages in a complementary outer groove 27 of the component 5. This creates a positive connection between the form seal 1 and the component 5. This offers the advantage that by pushing the form seal 1 onto the component 5, an assembly is formed that can then be inserted into the recess 3 from the outside. A further advantage is that the component 5 is held in the recess 3 by the form seal 1 clamped in the part 7 and the tongue and groove connection.
An optional embodiment is that the second sealing region 13 has a projection 29 formed on its inner edge and protruding in the direction facing away from the front side 19 of the form seal 1. In conjunction with this optional design, the component 5 has, for example, a recess 31 adjoining the groove 27. As shown in
The third sealing region 15 adjoins the first sealing region 11 on a side of the first sealing region 11 facing away from the front side 19 of the form seal 1. The third sealing region 15 is designed as a rear support of the form seal 1. In this respect, the third sealing region 15 in the device 100 adjoins, for example, a stop surface 33 of the device 100, in particular of the part 7, which stop surface delimits at least one outer edge region of the recess 3 facing away from the environment. This limits the insertion depth to which the form seal 1 can be inserted into the recess 3 both during its assembly and in the installed state.
In order to achieve the rear support, the form seal 1 has, in its radial region comprising the third sealing region 15, an axial height h in the axial direction which is adapted to a depth of the radial region of the recess 3 delimited at the rear by the stop surface 33.
As shown in
This method of use comprises an assembly method shown in
Subsequently, the form seal 1 mounted on the component 5 is compressed in the radial direction. For this purpose, for example, the component 5, together with the form seal 1 pushed thereon, is pushed in the axial direction into a sleeve 35 whose cross-sectional area decreases in the axial direction. The smallest cross-sectional area of the sleeve 35 present at one end of the sleeve 35 is less than or equal to, preferably substantially equal to, the cross-sectional area of the opening 49 of the recess 3 adjoining the environment.
The component 5 is then inserted from the outside into the recess 3 of the part 7 together with the form seal 1 compressed in the radial direction. This step is carried out, for example, such that the component 5 together with the compressed form seal 1 is inserted into the recess 3 of the part 7 through the sleeve 35 positioned accordingly in front of the recess 3. The insertion depth of the form seal 1 in the recess 3 is limited by the stop of the third sealing region 15 on the stop surface 33 of the device 100.
Depending on the type of device 100 and/or component 5, the stop surface 33 also serves as stop surface 33 for the component 5. In this case, the stop surface 33 of the part 7 extends radially inwardly such that at least one outer edge of the component 5 of the device 100 rests against the stop surface 33. Alternatively, the device 100 may also have a stop surface of the part 7 or of another component of the device 100, which stop surface is separate from the stop surface 33 and against which the component 5 in the device 100 rests.
Both the pushing in of the assembly formed by the component 5 and the form seal 1 pushed thereon as well as the pushing of this assembly through the sleeve 35 into the recess 3 can be done, depending on the axial length of the sleeve 35, for example, by hand or by means of a suitably shaped tool. As an example,
The inner surface 41 preferably has a shape adapted to the shape of the front side 21 of the component 5 facing the environment. As shown in
Irrespective of the design of the punch 37, 37′, 37″ adapted to the geometry of the component 5, 5′, 5″, the edge surface 43 of the punch surface 39 of the punch 37, 37′, 37″ has a shape adapted to the shape of the front side 19 of the form seal 1.
A further advantage is that the form seal 1 is compressed in the axial direction by the protruding edge surface 43 during installation and assumes the clamped shape intended for it after the removal of the punch 37, 37′. This also ensures that the form seal 1, in the assembled state, is supported on the rear side on the stop surface 33 and/or is clamped between the stop surface 33 and the inner surface 17 of the part 7.
Alternatively or additionally to the shaping of the punch surface 39 shown in
For this purpose, an embodiment of the form seal is first considered, the dimensions of which are dimensioned such that the form seal inserted into the recess completely or at least almost completely fills a partial space of the recess located on the side of the first sealing region facing away from the environment. In this embodiment, the first sealing region and the third sealing region must be compressed radially over their entire axial height during assembly to such an extent that they can be introduced into the recess through the front opening of the recess. During this process, compression forces are exerted on all sealing regions with external dimensions exceeding the cross-sectional area of the opening, which compression forces are greater the larger the external dimensions are in comparison to the cross-sectional area of the opening.
In conjunction with this embodiment of the third sealing region 15, the recess 3 of the device 100, as shown in
Alternatively or additionally, the third sealing region 15 is optionally dimensioned, for example, such that a second cavity 53 surrounded on the outside by the third sealing region 15 adjoins the third sealing region 15 in the device 100.
The first cavity 51 as well as the second cavity 53 each offer the advantage that they are available as a swelling space into which sealing material of the form seal 1 can expand as needed, in particular, when the ambient temperature changes. As a result, the form seal 1 is protected from damage, in particular, also at very high temperatures and also during large temperature fluctuations, and is held in its position within the recess 3. The latter is, in particular, advantageous when the component 5 and the part 7 consist of materials with different thermal expansion coefficients, which may, among other things, result in temperature-dependent changes in the gap width of the gap sealed by the form seal 1. The swelling spaces offer the advantage that reliable sealing of the gap by the form seal 1 is ensured in an even larger temperature range without sealing material protruding outwards. In addition, the expansion of sealing material into the swelling spaces reduces thermomechanical stresses that may occur depending on the temperature and that could otherwise have a detrimental effect on the form seal 1 and/or the component 5.
The previously described optional designs of the third sealing region 15 can be achieved by different shapes of the cross-sectional area of the third sealing region 15.
The cross-sectional geometry is optionally designed, for example, such that the third sealing region 15, in its region facing away from the first sealing region 11 and corresponding to one of the three vertices of the triangle, has a rounded or flattened rear side 55, which is advantageous, in particular, with regard to the rear support of the form seal 1 in the recess 3.
Alternatively or additionally, the third sealing region 15 is designed, for example, such that in its region facing the first sealing region 11 it has a radially inwardly facing inner surface area 57 that runs parallel to a radially inwardly facing inner surface area 59 of the front region 11a of the first sealing region 11.
An optional embodiment is that the inner surface area 57 of the third sealing region 15 extends radially outwardly offset relative to the inner surface area 59 of the front region 11a of the first sealing region 11 in the radial direction by a predetermined distance d, e.g., a distance d of 0.05 mm to 0.20 mm. The distance d is dimensioned such that the inner surface area 57 of the third sealing region 15 only rests against the component 5 when the form seal 1 surrounding the component 5 on all sides is compressed in the radial direction and/or clamped in the recess 3.
A further optional design is that the form seal 1 has an annular circumferential groove 61 with a rounded cross-sectional geometry on the inside in a transition region adjoining the second sealing region 13 between the first sealing region 11 and the third sealing region 15. The groove 61 designed in this way as a stress relief groove offers the advantage that it facilitates the deformation of the form seal 1 during assembly and thereby reduces stress peaks occurring within the form seal 1.
Irrespective of the shape of the third sealing region 15, the installation of the form seal 1 in the recess 3 that is open to the environment and thus easily accessible from the outside offers the advantage that no access is required to a region of the device 100 located on the side of the recess 3 facing away from the environment. This offers the advantage that the form seal 1 can be replaced if necessary without having to open the device 100.
In this respect, an optional design of the previously described method of use comprises, for example, a further method step in which the form seal 1 mounted in the recess 3 of the device 100 in the manner described above is replaced at least once, when required or at predetermined times.
In this case, the process is carried out in such a way that the form seal 1 is removed from the recess 3 by means of a tool, such as a hook. For this purpose, O-ring hooks known from the prior art for removing O-rings can be used. The form seal 1 is then replaced by an identical replacement seal, which is mounted in the recess 3 together with the component 5 or an identical replacement component using the assembly method described above.
Just like the installation of the form seal 1 in the recess 3 that is open to the environment and thus easily accessible from the outside, the replacement of the form seal 1 also offers the advantage that no access to a region of the device 100 located on the side of the recess 3 facing away from the environment is required. This offers the advantage that the device 100 does not have to be opened or at least partially dismantled for replacement.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 133 004.7 | Nov 2023 | DE | national |
