METAL SEAL FOR A FLAP VALVE

Abstract

A metal seal for a flap valve, is disclosed which has a valve housing with a flow channel, in the flow cross-section of which a valve disk is disposed such that it can be swiveled around a swivel axis between an open position and a shutoff position. The seal has sealing elements, which can be pressed against one another, and which are disposed on the outer circumference of the valve disk and on the inner circumference of the valve housing, and they have at least one annular metal sealing lip, which in the shutoff position bears with elastic preload on an oppositely situated, likewise annular metal mating sealing face. To prevent damage to outer components, the metal sealing lip is produced in an additive method from metal materials having shape, cross-sectional geometry and/or alloy adapted to the different circumferential regions of the metal sealing lip.

Claims

1. A metal seal for a flap valve (1), which has a valve housing (2) with a flow channel (3), in the flow cross-section of which a valve disk (4) is disposed such that it can be swiveled around a swivel axis (5) between an open position and a shutoff position, wherein sealing elements (7, 7a, 7b, 9), which can be pressed against one another, are disposed on the outer circumference of the valve disk (4) and on the inner circumference of the valve housing, and they have at least one annular metal sealing lip (7, 7a, 7b), which in the shutoff position bears with elastic preload on an oppositely situated, likewise annular metal mating sealing face (9), wherein either the metal sealing lip (7, 7a, 7b) is disposed on the outer circumference of the valve disk (4) and the mating sealing face (9) is disposed on the inner circumference of the valve housing (2) or the mating sealing face (9) is disposed on the outer circumference of the valve disk (4) and the metal sealing lip (7, 7a, 7b) is disposed on the inner circumference of the valve housing (2), wherein the metal sealing lip (7, 7a, 7b) is produced in an additive method from metal materials having shape, cross-sectional geometry and/or alloy adapted to the different circumferential regions of the metal sealing lip (7, 7a, 7b).

2. The metal seal according to claim 1, wherein the metal sealing lip (7, 7a, 7b) has circumferential portions wherein the flexural strength is different as a function of the distance of these circumferential portions relative to the swivel axis (5) of the valve disk (4).

3. The metal seal according to claim 2, wherein the circumferential portions of the metal sealing lip (7, 7a, 7b) disposed with largest distance to the swivel axis (5) of the valve disk (4) have a higher flexural strength than the circumferential portions of the metal sealing lip (7, 7a, 7b) disposed with smallest distance to this swivel axis (5).

4. The metal seal according to claim 3, wherein the cross-sectional areas of the metal sealing lip (7, 7a, 7b) in the circumferential portions with largest distance to the swivel axis (5) of the valve disk (4) have higher area moments of inertia than the cross-sectional areas of the metal sealing lip (7, 7a, 7b) in circumferential portions with smallest distance to the swivel axis (5) of the valve disk (4).

5. The metal seal according to claim 2, wherein the circumferential portions of the metal sealing lip (7, 7a, 7b) largest distance to the swivel axis (5) of the valve disk (4) have a higher degree of damping than circumferential portions with smallest distance to the swivel axis (5) of the valve disk (4).

6. The metal seal according to claim 2, wherein the circumferential portions of the metal sealing lip (7, 7a, 7b) with largest distance to the swivel axis (5) of the valve disk (4) consist of a metal alloy having stiffness greater than the stiffness of the metal alloy of which the circumferential portions of the metal sealing lip (7, 7a, 7b) consists that have the smallest distance to the swivel axis (5) of the valve disk (4).

7. The metal seal according to claim 2, wherein the differently formed circumferential portions of the metal sealing lip (7, 7a, 7b) transition gradually into one another in circumferential direction of the metal sealing lip (7, 7a, 7b).

8. The metal seal according to claim 1, wherein the surface regions of the metal sealing lip (7, 7a, 7b) coming into contact with the mating sealing face (9) are coated with a soft-sealing metal layer (10).

9. The metal seal according to claim 1, wherein a second metal sealing lip (7b) is associated with the metal sealing lip (7a) and, in the flow direction of the flap valve (1), has a distance to the first metal sealing lip (7a) such that the two metal sealing lips (7a, 7b) together enclose an annular hollow space (8) in the shutoff position of the flap valve (1) while bearing on the mating sealing face (9), and such that the cross-sectional areas of the two metal sealing lips (7a, 7b) extend in inclined and/or bent-off manner in the direction of the interior of this annular hollow space (8).

Description

[0032] An exemplary embodiment of the invention will be explained in more detail in the following on the basis of the drawing, wherein

[0033] FIG. 1: schematically shows the frontal view of a flap valve looking in flow direction;

[0034] FIG. 2: shows a section along the line A-A in FIG. 1;

[0035] FIG. 3: shows an enlargement of the details B and C from FIG. 2, i.e. the metal seal according to the invention in the circumferential regions with the largest distance to the swivel axis;

[0036] FIG. 4: shows a section along the line D-D in FIG. 1;

[0037] FIG. 5: shows an enlargement of the details D and E from FIG. 4, i.e. the metal seal according to the invention in the circumferential regions with the smallest distance to the swivel axis;

[0038] FIGS. 6, 7,8 and 9: show various possible cross sections of the metal sealing lip in different circumferential regions of the metal seal;

[0039] FIG. 10: shows the cross section through a metal sealing lip for a metal seal with only one single metal sealing lip.

[0040] In the drawing, the flap valve is denoted in its entirety with the reference numeral 1. The flap valve 1, which may be built into a pipeline, for example, has a valve housing 2, which is equipped with a circular flow channel 3, in the flow direction of which a valve disk 4 is disposed that can be turned in the flow channel 3 around a swivel axis 5. A swivel drive 6 fastened externally on the valve housing 2 is used for movement of the valve disk 4 around the swivel axis 5. In the drawing, the valve disk 4 is situated in the shutoff position, in which it completely shuts off the flow channel 3 of the valve housing 2.

[0041] Two annular metal sealing lips 7a and 7b, which are disposed at a short distance from one another in flow direction of the flow channel 3 and leave an annular hollow space 8 between them, are fastened to the inner circumference of the flow channel 3. The cross sections of these two metal sealing lips 7a and 7b extend in the direction of the interior of this hollow space 8 in inclined or bent-off manner.

[0042] The valve disk 4 of the flap valve 1 is equipped on its outer circumference with an annular mating sealing face 9, which in the illustrated shutoff position of the valve disk 4 bears on the annular metal sealing lips 7a and 7b. In the illustrated shutoff position, these two metal sealing lips 7a and 7b are subjected to elastic preload and thus form, together with the mating sealing face 9 of the valve disk 4, a more secure metal seal.

[0043] In contrast to the illustrated exemplary embodiment, it is also possible - inversely - to dispose the metal sealing lips on the outer circumference of the valve disk 4 and the mating sealing face on the inner circumference of the flow channel 3 of the valve housing 2. Furthermore, it is also possible to provide only one single metal sealing lip instead of two metal sealing lips 7a and 7b. As explained in the introduction, however, such a metal seal with only one metal sealing lip then acts in self-reinforcing manner only in one flow direction.

[0044] According to the teaching of the invention, the metal sealing lips 7a and 7b are produced in an additive method from metal materials with shape, elasticity and hardness adapted to the local requirements and have various flexural strengths distributed over their circumference.

[0045] This special feature will be explained in the following on the basis of a comparison of FIGS. 3 and 5. FIG. 3 shows enlarged cross sections through the metal sealing lips 7a and 7b in the circumferential regions with the largest distance from the swivel axis 5, i.e. the details B and C from FIG. 2. A comparison of these details B and C shows that the metal sealing lips 7a and 7b clearly differ from one another both in the geometric shape and in the cross-sectional area in these two circumferential regions. The differences in the geometric shape serve first of all for better adaptation to the different relative movements that occur during the opening and closing process between the metal sealing lips 7a and 7b on the one hand and the mating sealing face 9 on the other hand. The different cross-sectional areas of the metal sealing lips 7a and 7b match their flexural strength and mass to the special requirements in these circumferential regions. The correctly matched elasticity and distribution of masses in these circumferential regions is of great importance here for counteracting the particularly intensively occurring resonance vibrations caused by the Bernoulli effect in these circumferential regions during the opening and closing process.

[0046] In contrast, the sealing conditions in the circumferential regions with the smallest distance to the swivel axis 5 are much simpler, as is illustrated in FIGS. 4 and 5 on the basis of details E and F. In these circumferential regions, the metal sealing lips 7a and 7b may then be constructed as equal to one another in shape and cross section as well as advantageously thin, because the relative movements with respect to the mating sealing face 9 permit this and resonance phenomena are less to be feared. A further advantage consists in the fact that smaller closing and breakaway torques are needed because of the smaller friction between metal sealing lips 7a and 7b and mating sealing face 9.

[0047] Finally, it is further important for the functional capability of the new metal seal that the differently constructed circumferential portions (compare the details B and C explained above on the one hand and E and F on the other hand) transition continuously into one another in circumferential direction, which is possible without problems in an additive manufacturing. It is only by such a gradual transition that it can be ensured that the metal sealing lips 7a and 7b bear uniformly all around on the mating sealing face 9.

[0048] FIGS. 6, 7 and 8 show various exemplary embodiments of possible cross-sectional shapes of metal sealing lips 7a and 7b produced in the additive production method and capable of being used in the different circumferential regions. FIG. 9 shows metal sealing lips 7a and 7b in cross section, in which the surface regions coming into contact with the mating sealing face 9 are coated with a soft-sealing metal layer 10.

[0049] Finally, FIG. 10 shows the cross-sectional configuration of a metal sealing lip 7 to be used alone for a metal seal, which is equipped with only one single metal sealing lip.