Sealing ring and its use

Abstract

The invention relates to a sealing ring, which is configured substantially in the shape of a 7 when viewed in cross section, comprising an axial leg (1) and a sealing leg (2) with a sealing lip (3), the sealing leg (2) being connected to a first end side (5) of the axial leg (1) by means of a hinge (4), and further comprising a tensioning element (6) for stabilizing the sealing leg (2) in the radial direction (7). The tensioning element (6) is configured in the shape of a ring and, when viewed in cross section, is formed by a spring (8) configured in the shape of a disc spring, the spring (8) being connected to the sealing leg (2).

Description

Technical Field

[0001] The present invention relates to a sealing ring and its application, the sealing ring being configured in a figure-7 shape when viewed in cross-section, the sealing ring including an axial support leg and a sealing support leg having a sealing lip, the sealing support leg being connected to a first end side of the axial support leg by a hinge, and the sealing ring having a tensioning element for stabilizing the sealing support leg in the radial direction. Background Technology

[0002] A sealing ring for sealing grease is known from EP 2 988 035 A1. The sealing ring includes a tensioning element disposed in a mounting groove within the sealing ring. The mounting groove is located on a side of the sealing leg radially away from the sealing lip, wherein the mounting groove has a mounting opening for the tensioning element on the radially opposite side of the sealing lip, the mounting opening being defined by two guide strips spaced apart and adjacent to each other in the axial direction. A hinge, viewed radially and in the manufacturing state of the sealing ring, is located at the center of the sealing ring. Also radially at the center of the sealing ring, a hinge space, axially open on one side and substantially C-shaped, is provided in the hinge region. This hinge space is configured such that the medium to be sealed located within the hinge space is discharged from the hinge space. Since no medium to be sealed remains in the hinge space, undesirable hardening of the sealing ring is prevented, and the sealing leg can follow the highly dynamic offset movement of the machine component to be sealed, while the clamping force of the sealing lip for sealingly contacting the machine component to be sealed does not change significantly.

[0003] Another type of sealing ring of the above type is known from DE 10 2009 053 558 A1. The sealing ring is constructed in a figure-7 shape, including a thicker axial leg in the radial direction and a sealing leg with a sealing lip, the sealing leg being connected to the first end of the axial leg via a hinge. In contrast, no separately manufactured tensioning element is provided for stabilizing the sealing leg in the radial direction. The hinge, viewed radially, is located at the center of the sealing ring in its manufactured state. The two end sides of the axial leg are constructed with protrusions, and these protrusions are supported in the mounting space of the sealing device, preventing the sealing ring from twisting / tilting in the mounting space during normal use. The protrusions can be designed as closed ridges surrounding the periphery, through which a particularly good clamping effect on the axial leg can be obtained in the mounting space.

[0004] Another sealing ring and its application are known from DE 10 2016 011 448 A1.

[0005] The sealing ring has a tensioning element for stabilizing the sealing leg in the radial direction. The tensioning element is constructed in a ring shape and, when viewed in cross-section, is formed by a spring configured in a figure-7 shape. The tensioning element has a second axial leg and a stabilizing leg, the second axial leg being connected to the axial leg, and the stabilizing leg being connected to the sealing leg.

[0006] Regardless of the diameter to be sealed, the aforementioned sealing ring exhibits improved performance characteristics over extended periods of use. Regardless of the sealing ring's mounting configuration, the sealing lip maintains a constant radial preload in sealing contact with the surface of the machine component to be sealed throughout extended use. Due to the tensioning element, it is not important whether the sealing legs, along with their sealing lips, are radially positioned inside or outside the sealing ring for optimal performance. Summary of the Invention

[0007] The object of this invention is to improve the sealing ring of the type described above, so that the sealing ring has improved performance characteristics substantially independent of the diameter to be sealed during long-term use, and in particular, that the sealing lip maintains a constant radial preload in sealing contact with the surface to be sealed of the machine component, regardless of the installation state of the sealing ring, during long-term use. The sealing ring should be simple and economical to manufacture. Furthermore, it should be found that the sealing ring according to the invention is particularly suitable for certain applications.

[0008] According to the present invention, the objective is achieved by the sealing ring according to the present invention and its application.

[0009] To achieve the aforementioned purpose, the tensioning element is configured as annular and, when viewed in cross-section, is formed by a spring configured as a disc spring, and the spring is connected to a sealing leg.

[0010] Because the spring is only located on the sealing foot, the axial foot can be designed to be thinner. This results in a smaller heat concentration, which also negatively impacts the clamping force on the sealing lip.

[0011] The tensioning element, with its disc spring-like design, enables the sealing ring to achieve advantageous usage characteristics regardless of how it is installed. The sealing ring can be used omnidirectionally. The sealing legs, along with their sealing lips, can be radially positioned inside or outside the sealing ring, or axially positioned for sealing.

[0012] Unlike springs that are shaped like a figure 7 and correspond to the overall shape of the sealing ring, disc springs are simpler and more economical to manufacture. No complex production processes are required to manufacture these springs. Furthermore, it is even simpler to connect such springs to the sealing legs of the sealing ring.

[0013] The sealing ring in EP 2 988 035 A1 mentioned earlier is primarily designed for systems that provide radial internal sealing. Sealing feet and sealing lips are radially positioned inside the sealing ring, and the sealing lips, with radial preload, sealably surround the machine component to be sealed, such as the surface of a shaft.

[0014] For radially externally sealed systems, annular helical springs, configured as tensioning elements, are disadvantageous when the axial support is radially positioned inward and the sealing support, along with its sealing lip, extends radially outward from the axial support. Annular helical springs are currently used as tension springs for internally sealed systems. For externally sealed systems, such springs must be designed as compression springs. This is feasible in principle, but typically makes installation and reliable positioning of the spring within the mounting space difficult. The risk of ejection from the mounting space is much higher compared to tension springs.

[0015] In contrast, in the sealing ring according to the invention, a spring configured as a disc spring serves as a tensioning element. An advantage of this sealing ring is that it can also be well used in external sealing systems, i.e., in systems where the sealing leg with the sealing lip extends radially outward and, for example, seals against the wall defining the housing bore.

[0016] The sealing ring according to the invention maintains good performance regardless of whether the sealing lip is radially positioned inside or outside the sealing ring. With the spring configuration described above, the radial spring force originates from the radial movement of the spring. Here, it is not important whether the system is an external or internal seal. The sealing lip is pressed against the surface to be sealed due to the elastic preload of the spring relative to the surface to be sealed of the machine component in the sealing system, and this pressing can therefore be achieved regardless of the diameter. The performance characteristics of the spring remain virtually unchanged throughout the entire service life of the sealing ring. The spring is permanently elastic.

[0017] By constructing a disc spring, large radial offset movements of the machine components to be sealed can be well compensated, while the clamping force of the sealing lip, which is used to seal the surface to be sealed under elastic preload, does not change significantly.

[0018] Furthermore, it is advantageous that springs constructed in the shape of disc springs can be manufactured simply and economically. Such springs can also be integrated into sealing rings without problems and with reliable processes.

[0019] In the manufacturing process of the sealing ring, the spring can have a straight extension from the radial interior to the radial exterior. Advantageously, such a spring can be manufactured particularly simply and economically. It can also be easily connected to a sealing leg supported by the spring during normal use of the sealing ring.

[0020] The outer radial edge of the spring extends from the sealing foot into the elastic material of the axial foot. The amount by which the spring protrudes radially from the sealing foot into the axial foot is preferably at least 10% of the straight extension of the spring, more preferably at least 20%. Therefore, throughout the entire service life of the sealing ring, the spring provides sufficient leverage to press the sealing foot against the surface of the machine component to be sealed with appropriate radial clamping force.

[0021] Furthermore, it is advantageous to additionally fix the spring in the axial support leg, and the spring can thus be better supported in the sealing ring.

[0022] In the manufacturing-induced state of the sealing ring, the spring can form a first angle of 65° to 80° with the axis of symmetry of the sealing ring. This manufacturing-induced first angle is significantly steeper than in normal use. This is necessary to allow the sealing lip of the sealing ring to apply a sufficiently large clamping force to the surface to be sealed during normal use of the sealing ring.

[0023] During normal use of the sealing ring, the spring can form a second angle of 30° to 60° with the axis of symmetry of the sealing ring. During installation of the sealing ring, the spring elastically deforms from its rather steep first angle after the sealing ring is manufactured to the flatter second angle described above. Thus, under an elastic radial preload, the sealing lip remains on the surface of the machine component to be sealed.

[0024] According to an advantageous design, the spring can be embedded in the sealing leg. Advantageously, the spring forms an integral part of the sealing leg of the sealing ring. Thus, undesirable loss of the spring can be reliably prevented both when storing the sealing ring before use and during normal use in the installed state.

[0025] The spring can be at least substantially surrounded by the sealing feet. Advantageously, the positioning of the spring within the sealing feet of the sealing ring is particularly reliable and durable. Thus, despite the use of a spring, the sealing ring is practically integral, resulting in lower assembly costs. The risk of assembly errors is also minimized.

[0026] According to an advantageous design, the spring is completely surrounded by the sealing material of the sealed legs. This effectively protects the spring from external influences.

[0027] The performance characteristics of the sealing ring, especially the oscillation of the sealing leg with sealing lip around the hinge, depend primarily on the performance characteristics of the spring. Even when the machine component to be sealed has a large radial offset movement throughout the entire working area of ​​the sealing ring, and the sealing leg with sealing lip oscillates around the hinge accordingly, the sealing material positioned at the acute angle between the axial leg and the sealing leg will not cause undesirable hardening of the sealing ring. The sealing material may be undesirably compressed during the oscillation of the sealing leg around the hinge, which may adversely alter the performance characteristics of the sealing ring.

[0028] The spring can be made of spring steel. Advantageously, the spring will not loosen during the long-term use of the sealing ring, and the sealing ring thus maintains its good performance characteristics over extended periods. Other materials that can be used for the spring include, for example, polymer materials, which possess sufficiently good elastic performance characteristics during long-term use.

[0029] The axial support and sealing support, more preferably, the axial support, sealing support, and hinge can be constructed as a single, seamless unit made of a uniform material and the same sealing material. Due to this simple structure and the small number of parts, the sealing ring can be manufactured simply and economically. The sealing material can be an elastomer or polyurethane, preferably having a Shore A hardness of 60 to 98. This material achieves excellent sealing performance over long-term use.

[0030] According to an advantageous design, the axial support leg can be configured with a lateral recess on its radially facing side towards the sealing leg, the recess extending axially from the second end of the axial support leg toward the first end and the hinge. Generally, it is advantageous for the sealing ring of a system with radially external sealing characteristics, particularly for such systems, that the hinge is positioned radially away from the sealing lip between the axial support leg and the sealing leg. Thus, even when the radial offset movement of the machine component to be sealed is large, the sealing leg can follow the radial offset movement well. The magnitude of the radial offset movement depends on the diameter to be sealed. For example, the diameter to be sealed in wind power equipment could be, for example, 4 meters, and in a tunnel boring machine, it could be, for example, 18 meters. Because the hinge is positioned radially away from the sealing lip as much as possible, and thus the sealing leg achieves good elastic yieldability throughout the entire working area of ​​the sealing ring, the sealing lip, even in this case, contacts the surface to be sealed with a constant and good radial clamping force and thus a good sealing effect throughout the entire circumference.

[0031] Viewed radially and in the manufacturing state of the sealing ring, the hinge is located in the third of the sealing ring furthest from the sealing lip, thereby contributing to the aforementioned advantageous performance characteristics of the sealing ring.

[0032] When the eccentricity is high and the diameter to be sealed is large, the compensation capability is significantly lower for the hinge when viewed radially and for the sealing ring which is approximately set at the center of the sealing ring in the manufacturing state, compared to the previously described design.

[0033] As mentioned above, the sealing lip can be positioned radially inside or outside the sealing ring. Surprisingly, it has been shown that the sealing ring exhibits consistently good performance characteristics regardless of whether the sealing lip is radially positioned inside or outside the sealing ring. A surface to be sealed radially outside can be sealed by the sealing ring with the same reliability as a surface to be sealed radially inside.

[0034] According to an advantageous design, the sealing leg has a contamination lip on its axially facing side towards the first end. The contamination lip has at least one sealing edge and a radially inward first boundary surface and a radially outward second boundary surface. By providing the contamination lip on the side of the sealing lip facing the surrounding environment of the sealing ring, the sealing lip is effectively protected against contamination. Especially when using the sealing ring in heavily polluted environments, functionally tandemly arranging the upstream contamination lip towards the surrounding environment has a significant advantage. The contamination lip prevents contaminants from entering the sealing lip. Thus, the sealing lip protected by the contamination lip maintains the same excellent performance during long-term use.

[0035] The anti-fouling lip can be hinged to the sealing leg via a second hinge. Advantageously, the sealing leg and the anti-fouling lip are functionally coupled. If, during normal use of the sealing ring, the sealing leg moves radially outward or inward within its working area, the anti-fouling lip will follow accordingly, since it is hinged to the sealing leg via the second hinge. Because the anti-fouling lip is hinged to the sealing leg, it automatically follows the sealing leg across its entire radial working area without adversely affecting the function of the sealing lip on the sealing leg.

[0036] The second hinge may have a hinge radius that is radially inward and a hinge radius that is radially outward, and the anti-fouling lip is configured to transition into the sealing leg through the hinge radius.

[0037] The internal and external hinge radii can be approximately the same size. In this case, the ratio of the internal hinge radius to the external hinge radius is approximately 1.

[0038] This hinge radius design allows each hinge element to be independently adapted to its respective application. The radially inward hinge radius primarily affects the contact force required for the anti-fouling lip to fit snugly around the machine component to be sealed during normal use of the sealing ring. Conversely, the radially outward hinge radius affects the radial flexibility of the anti-fouling lip.

[0039] In the manufacturing process of the sealing ring, the sealing feet and the anti-fouling lip can be defined at substantially right angles radially inward and radially outward. This design achieves a good trade-off between a good seal for dirt sealing and the anti-fouling lip operating with minimal friction loss on the machine component to be sealed.

[0040] This is also aided by observing that the sealing lip has a first diameter and the sealing edge has a second diameter, respectively, in the manufacturing state of the sealing ring, wherein the first diameter is smaller than the second diameter. During normal use of the sealing ring, i.e., when the sealing ring is installed in the sealing system, the sealing lip surrounds the machine component to be sealed with a radial preload greater than that of the sealing edge.

[0041] The first boundary surface defining the right angle radially inside the anti-fouling lip has a first length, while the third boundary surface of the sealing leg has a third length different from the first length, wherein the first length is greater than the third length, thereby further facilitating the realization of the advantageous usage characteristics described above.

[0042] The sealing feet and anti-fouling lip are preferably constructed as a single, seamless unit made of a rubber-elastic sealing material. Advantageously, the sealing ring has a simple structure with few parts, enabling simple and economical manufacturing. Furthermore, due to the integrated structure, assembly is particularly simple; thus, the risk of assembly errors during sealing ring installation is minimized.

[0043] According to an advantageous design, the second boundary surface can be configured to be convex along its extension. The convex geometry of the second boundary surface of the anti-fouling lip is necessary to achieve a defined line contact with the sealing edge of the anti-fouling lip. Here, the radius of curvature of the convex boundary surface is chosen such that surface contact between the anti-fouling lip and the component to be sealed is reliably avoided during normal use of the sealing ring, and the resulting deterioration of performance is reliably prevented.

[0044] The spring is located on the side of the sealing leg that is axially opposite to the anti-fouling lip, so as to stabilize the sealing leg in the radial direction.

[0045] According to an advantageous design, the sealing lip, when viewed in cross-section, is substantially parabolic in shape on its axially distant side from the space to be sealed, such that the parabola and the surface to be sealed define a substantially constant sealing angle over the entire radial working area of ​​the sealing lip. Due to this parabolic shape, the sealing lip is also particularly suitable for sealing oily media. Oily media can also be reliably sealed with negligible leakage.

[0046] Especially for sealing rings with large diameters, such as those used in tunnel boring machines or wind power equipment, it is essential to compensate well for the large radial offset movements of the machine components to be sealed, while still maintaining a good seal. This is not achievable using the practically sharp-edged sealing lip used in radial shaft sealing rings. Radial shaft sealing rings are designed to seal oil-containing media and are based on a hydrodynamic design with two opposing angles. The steeper angle towards the oil side forms a 40° to 50° angle with the axis of symmetry of the radial shaft sealing ring, while the flatter angle towards the ambient side forms a 20° to 30° angle with the same axis of symmetry. These angles are fixed in relation to each other, maintaining this relationship even if the positions of the machine components to be sealed change radially. However, as a result, undesirable changes occur in the angle towards the machine component to be sealed in this case. Radial shaft sealing rings are not well-suited for large offset movements and for achieving good functioning in the large radial working area of ​​the sealing ring. Due to the sealing feet tilted at significantly different degrees relative to the axis of symmetry of the sealing ring during normal use, the sealing effect of the sealing ring is limited, and undesirable leaks may occur. Because of the parabolic shape of the sealing foot on its side facing the machine component to be sealed, the sealing angle of the sealing lip remains constant throughout the entire radial working area of ​​the sealing lip during normal use of the sealing ring, thereby achieving the same good sealing effect all the time.

[0047] An approximate parabola can be described by the following function:

[0048] F(x) = a1*x^2+a2*sin(f1*x)

[0049] A1: First compression factor

[0050] A2: Second compression factor

[0051] f1: Frequency

[0052] X: Axial direction

[0053] The sealing lip extends in a generally parabolic shape, but is constructed in a distinctly asymmetrical manner. Both the axial profile of the sealing lip towards the space to be sealed and its profile towards the environment are convex curves. However, the trajectory of these two convexities differs from a classic parabola. This is achieved by incorporating a sine term into the parabolic shape.

[0054] Starting from the point X-axis = 0, the parabola and sine extend in opposite directions along the negative axis in the X direction (towards the space to be sealed) in their radial Y values. This initially flattens the parabola. Once the sine reaches its low point, it increases the curvature of the parabola, and the resulting function value rises more steeply.

[0055] Conversely, in the positive X direction, the sine initially rises faster than the parabola and dominates the profile. Once the sine reaches its maximum value and declines, it begins to weaken the time-dominant parabola.

[0056] By appropriately selecting the coefficients a1 and a2 of the parabola, the sine f1 forms a profile with a constant positive slope near x=0, connecting to a steep convex profile in the negative direction and a relatively flat convex profile in the positive x-direction. Surprisingly, with appropriate selection of the corresponding coefficients, it is possible to achieve a common flat angle towards the surrounding environment when the machine component to be sealed has a small offset relative to the sealing ring, depending on the installation and usage. As the offset increases, the increasingly steep profile counteracts the further flattening. This results in a defined sealing surface. Friction and heat input are minimized.

[0057] The minimum value of this function corresponds to the zero position of the seal edge during installation, depending on the usage. Conversely, the profile of the sealing lip towards the medium to be sealed is designed in normal use to create a steep angle. In the zero position, there is a normal angle on the side facing the medium to be sealed. This angle becomes steeper when offset upwards (the sealing lip is compressed). However, due to the convex profile described above unfolding along the positive X direction, a gradually flattening profile is formed. The flattening profile offsets the steep position caused by the offset. With negative radial offset, the situation is exactly the opposite. The continuously flattening angle towards the medium to be sealed, such as the oil side, is compensated by the continuously steepening profile. This essentially maintains the normal steep position.

[0058] The sealing ring described above can be used in tunnel boring machines, wind power equipment, or other radial applications. Attached Figure Description

[0059] The following reference Figures 1 to 4 Two embodiments of the sealing ring according to the present invention are described in detail.

[0060] The following diagrams are provided:

[0061] Figure 1 A first embodiment of the sealing ring according to the invention is shown in the form of a sealing ring caused by manufacturing processes.

[0062] Figure 2 Show Figure 1 In the first embodiment, the sealing ring is shown during its normal use in the sealing system.

[0063] Figure 3 A second embodiment of the sealing ring according to the invention is shown in the form of a sealing ring caused by manufacturing processes, the sealing ring having a contamination-resistant lip disposed adjacent to the sealing leg.

[0064] Figure 4 Show Figure 3 In the second embodiment, the sealing ring is shown during its normal use in the sealing system, and

[0065] Figure 5 Show Figure 3 and 4 Details of the free end of the sealing lip. Detailed Implementation

[0066] exist Figure 1 and 2 The diagram illustrates a first embodiment of a sealing ring according to the invention. The sealing ring is configured in a figure-7 shape and has a spring 8 as a tensioning element 6, the spring forming an integral part of the sealing ring and being completely surrounded by the sealing material of the sealing ring. The spring 8 is configured as annular and, when viewed in cross-section, as a disc spring.

[0067] The sealing ring includes an axial support leg 1 and a sealing support leg 2 with a sealing lip 3. Depending on the application, the sealing support leg 2 and the sealing lip 3 are located radially inside or radially outside the sealing ring. The sealing ring can be used omnidirectionally.

[0068] The sealing leg 2 is hinged to the first end side 5 of the axial leg 1 by means of a hinge 4, which is positioned as far away from the sealing lip 3 as possible in the radial direction 7, so as to also compensate for the large eccentricity of the machine component 37. This large eccentricity mainly occurs when the diameter to be sealed is large, for example, about 2 meters or more. The working area of ​​the sealing ring is indicated by reference numeral 34. The hinge 4 is constructed to transition integrally with the axial leg 1 and the sealing leg 2 and is made of the same material. Viewed in the radial direction 7, and in the manufacturing state of the sealing ring, the hinge 4 is positioned in the third 16 of the sealing ring furthest from the sealing lip 3. To further improve the swingability of the sealing leg 2 relative to the axial leg 1 about the hinge 4 in the working area 34, the axial leg 1 has a side recess 13 on its radially facing side towards the sealing leg 2, which extends in the axial direction 14 from the second end side 15 of the axial leg 1 to the first end side 5 and the hinge 4.

[0069] In the first embodiment, the sealing lip 3 is configured with sharp edges along its axial direction away from the side of the space 31 to be sealed. This sealing lip 3 is particularly suitable for sealing grease.

[0070] The hinge space 36 is defined by the axial support leg 1 and the sealing support leg 2 facing each other. The spring 8 is disposed substantially directly below the surface of the sealing support leg 2. The spring 8 extends substantially parallel to the sealing support leg 2. The spring 8 ensures that the sealing support leg 2, and thus the sealing lip 3, is provided with a consistently consistent circumferential clamping force to the machine element to be sealed during long-term use, where the sealing lip 3 makes sealing contact with the surface of the machine element to be sealed.

[0071] Spring 8 extends radially outward into axial support 1. The disc-spring-shaped spring 8 effectively compensates for the eccentricity of the machine components 37 and 38 to be sealed throughout the entire working area 34. Throughout the working area, the sealing support contacts the machine component 37 to be sealed with substantially the same radial preload. The first machine component 37 to be sealed has a radial spacing that matches the machine component 38 to be sealed. Spring 8 extends linearly from radially inward to radially outward. This spring 8 can be manufactured particularly simply and economically. Connection to the sealing support 2, supported by spring 8, can also be easily established during normal use of the sealing ring.

[0072] In the illustrated embodiment, the spring 8 extends radially from the sealing leg into the elastic material of the axial leg 1. 10% of the radial length of the spring 8 is surrounded by the elastic material of the axial leg 1. If the sealing leg 2 extends from its... Figure 1 The elastic deformation of the shape caused by manufacturing, as shown in the figure, is in Figure 2As shown in the figure, during normal use, the spring 8 holds the sealing leg 2 to the surface of the machine element 37 to be sealed by lever action with appropriate radial clamping force. In its manufacturing state, the spring 8 forms a first angle 11 with the axis of symmetry 10 extending circumferentially from the sealing ring, which is approximately 75° in the illustrated embodiment. Conversely, during normal use, a second angle 12 is approximately 45° in the illustrated embodiment.

[0073] The machine components 37 and 38 to be sealed can be formed radially inwardly by the shaft to be sealed, or radially outwardly and in a sealing manner by the wall portion to be sealed that defines the housing bore.

[0074] The sealing ring according to the invention maintains its excellent performance regardless of whether the sealing lip 3 is radially disposed inside or outside the sealing ring 3. The distance from the sealing lip 3 to the surface to be sealed is achieved by the elastic bending of the spring 8 and is therefore independent of the diameter.

[0075] exist Figure 3 and 4 The image shows a second embodiment of the sealing ring according to the invention. Viewed in cross-section, the sealing ring is constructed in a figure-7 shape and includes an axial support leg 1 and a sealing support leg 2 with a sealing lip 3. The sealing support leg 2 is hinged to the first end side 5 of the axial support leg 1 via a hinge 4.

[0076] On the axial side of the sealing leg 2 facing the first end side 5, a contamination lip 17 is provided in a radially inward region of the sealing leg 2. The contamination lip includes a sealing edge 18. The contamination lip 17 has a first boundary surface 19 radially inward and a second boundary surface 20 radially outward. The first boundary surface 19 is configured to be substantially flat, while the second boundary surface 20 is configured to be convex.

[0077] The sealing foot 2 and the anti-fouling lip 17 are constructed as a single, integrated unit with uniform material, and are made of a rubber-elastic material. They are elastically and yieldably connected to each other via a second hinge 21. The second hinge 21 is formed by a hinge radius 22 along the radial interior and a hinge radius 23 along the radial exterior, and these two hinge radii are constructed to be substantially the same in the example shown.

[0078] exist Figure 3 The image shows its state due to manufacturing defects, i.e., not installed as in Figure 4 The sealing ring in the sealing system shown. As shown here, the anti-fouling lip 17 extends substantially vertically from the sealing leg 2, and the first diameter 26 of the sealing lip 3 is smaller than the second diameter 27 of the sealing edge 18. The sealing leg 2 and the anti-fouling lip 17 substantially define right angles 24 and 25.

[0079] A first boundary surface 19, defining a right angle 24 radially inside the anti-fouling lip 17, has a first length 28. A third boundary surface 29 of the sealing leg 2 has a third length 30, which differs from the first length 28. The first length 28 is greater than the third length 30. Through the geometry of the anti-fouling lip 17 radially inside the second hinge 21, the geometry of the sealing leg 2, and the hinge of the anti-fouling lip 17 on the sealing leg 2, the anti-fouling lip 17 forms an integral part of the sealing ring and moves radially with the sealing leg 2 in the working area. During normal use of the sealing ring, the anti-fouling lip 17 protects the sealing lip 3 of the sealing leg 2 from contamination from the surrounding environment. The anti-fouling lip 17 functions throughout the entire working area 34 of the sealing ring without adversely affecting the function of the sealing lip 3.

[0080] Tensioning element 6 is disposed on the side of sealing leg 2 facing away from anti-fouling lip 17 along the axial direction. Tensioning element 6 is configured to stabilize sealing leg 2 radially. Tensioning element 6 is formed by spring 8, which in the embodiment shown here is composed of permanently elastic spring steel.

[0081] In the second embodiment, the sealing lip 3 is formed by a parabola 32 axially away from the side of the space 31 to be sealed. The parabola 32 contacts the surface 33 of the machine element 37 to be sealed at a substantially constant sealing angle 35 throughout the entire radial working area 34 of the sealing lip 3. This substantially parabolic geometry is particularly suitable for sealing dilute liquid media, such as oil.

[0082] Because the sealing ring according to the invention exhibits good performance characteristics even when the sealing ring is radially externally sealed, it is also particularly well suited for use in tunnel boring machines or wind power equipment.

[0083] exist Figure 5 Show in detail Figure 3 and 4 The free end of the sealing lip 3 in the middle.

[0084] The sealing edge geometry 39 essentially conforms to the geometry of parabola 40. The sealing edge geometry 39 conforms to the following function:

[0085] F(x) = a1*x^2+a2*sin(f1*x).

[0086] The sine curve is labeled 41 in the attached diagram.

Claims

1. A sealing ring, viewed in cross-section, is constructed to be substantially figure-7 shaped, comprising an axial support (1) and a sealing support (2) with a sealing lip (3), the sealing support (2) being connected to a first end side (5) of the axial support (1) via a hinge (4), and the sealing ring further comprising a tensioning element (6) for stabilizing the sealing support (2) in the radial direction (7), wherein, The tensioning element (6) is constructed in an annular shape. In cross-section, the tensioning element is formed by a spring (8) constructed in the shape of a disc spring. The spring (8) has a radially outer edge forming a protrusion. The spring (8) extends radially outward from the sealing leg (2) into the axial leg (1) by the protrusion, and the spring (8) is connected to the sealing leg (2). The sealing leg (2) is characterized by having a lip (17) on its axially facing side towards the first end (5). The lip has at least one sealing edge (18) and a radially inward... The first boundary surface (19) and the second boundary surface (20) along the radial exterior, respectively, in the manufacturing state of the sealing ring, the sealing lip (3) has a first diameter (26) and the sealing edge (18) has a second diameter (27), and the first diameter (26) is smaller than the second diameter (27), the first boundary surface (19) that defines a right angle in the interior of the anti-fouling lip (17) along the radial direction has a first length (28), and the third boundary surface (29) of the sealing leg (2) has a third length (30) that is different from the first length (28), and the first length (28) is greater than the third length (30).

2. The sealing ring according to claim 1, characterized in that, In the manufacturing state of the sealing ring, the spring (8) has a straight extension (9) from the radial interior to the radial exterior.

3. The sealing ring according to claim 1 or 2, characterized in that, In the state caused by the manufacturing of the sealing ring, the spring (8) forms a first angle (11) with the axis of symmetry (10) of the sealing ring, the first angle being 65° to 80°.

4. The sealing ring according to claim 1 or 2, characterized in that, During normal use of the sealing ring, the spring (8) forms a second angle (12) with the axis of symmetry (10) of the sealing ring, the second angle being 30° to 60°.

5. The sealing ring according to claim 1 or 2, characterized in that, The spring (8) is embedded in the sealing support (2).

6. The sealing ring according to claim 1 or 2, characterized in that, The spring (8) is at least partially surrounded by the sealing leg (2).

7. The sealing ring according to claim 1 or 2, characterized in that, The spring (8) is made of spring steel.

8. The sealing ring according to claim 1 or 2, characterized in that, The axial support (1) and the sealing support (2) are constructed as a single, mutually transitional unit made of a single material and are made of a sealing material.

9. The sealing ring according to claim 1 or 2, characterized in that, The axial support (1), sealing support (2) and hinge (4) are constructed as a single, mutually transitional unit made of a single material and are made of a sealing material.

10. The sealing ring according to claim 1 or 2, characterized in that, The axial support (1) has a side recess (13) on its side facing the sealing support (2) in the radial direction, the side recess extending in the axial direction (14) from the second end side (15) of the axial support (1) toward the first end side (5) and the hinge (4).

11. The sealing ring according to claim 1 or 2, characterized in that, Observed in the radial direction (7) and in the state caused by the manufacturing of the sealing ring, the hinge (4) is located in the third (16) of the sealing ring furthest away from the sealing lip (3).

12. The sealing ring according to claim 1 or 2, characterized in that, The sealing lip (3) is disposed inside or outside the sealing ring in the radial direction (7).

13. The sealing ring according to claim 1 or 2, characterized in that, The anti-fouling lip (17) is hinged to the sealing leg (2) by means of a second hinge (21).

14. The sealing ring according to claim 13, characterized in that, The second hinge (21) has a hinge radius (22) along the radial interior and a hinge radius (23) along the radial exterior, through which the anti-fouling lip (17) is configured to transition into the sealing foot (2).

15. The sealing ring according to claim 1 or 2, characterized in that, In the manufacturing state of the sealing ring, the sealing foot (2) and the anti-fouling lip (17) are substantially right angles defined radially inward and radially outward.

16. The sealing ring according to claim 1 or 2, characterized in that, The sealing foot (2) and the anti-fouling lip (17) are constructed as a single unit that transitions between each other and is made of a rubber-elastic sealing material.

17. The sealing ring according to claim 1, characterized in that, The second boundary surface (20) is convex along its extension direction.

18. The sealing ring according to claim 1 or 2, characterized in that, On the side of the sealing foot (2) away from the anti-fouling lip (17) along the axial direction, the spring (8) is provided from the sealing foot (2) to the axial foot (1) to stabilize the sealing foot (2) in the radial direction.

19. The sealing ring according to claim 1 or 2, characterized in that, In the cross-sectional view, the sealing lip (3) is formed by a parabola (32) on its side axially away from the space (31) to be sealed, such that the parabola (32) and the surface to be sealed (33) define a substantially constant sealing angle (35) over the entire radial working area (34) of the sealing lip (3).

20. The application of the sealing ring according to any one of claims 1 to 19 in a tunnel boring machine or wind power equipment.

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