SEAL AND ROTATING SYSTEM

Abstract

A seal for a rotating system with two sealing units which are arranged one behind the other along a main axis H, the sealing units each having a through-hole for a shaft and being in interlocking engagement with each other in the circumferential direction and at least one axial compression spring element being arranged between the sealing units. O

Claims

1. A seal for a rotating system, comprising two sealing units, which are arranged one behind the other along a main axis H, wherein the sealing units each have a through-hole for a shaft and are in interlocking engagement with each other in the circumferential direction and wherein at least one axial compression spring element is arranged between the sealing units.

2. The seal according to claim 1, wherein at least one of the sealing units has a first sealing ring and a second sealing ring, the sealing rings being arranged axially adjacent to a sealing unit.

3. The seal according to claim 2, wherein the first sealing ring is high in friction and the second sealing ring is low in friction.

4. The seal according to claim 2, wherein the sealing rings each have a through-hole, which together form the through-hole for the shaft.

5. The seal according to one of claims 2, wherein the sealing rings of a sealing unit are in interlocking engagement with each other in the circumferential direction.

6. The seal according to claim 2, wherein the second sealing ring has a recess in the axial direction and the first sealing ring has a projection in the axial direction that is complementary to the recess, wherein the recess and the projection connect the sealing rings in interlocking engagement with each other.

7. The seal according to claim 6, wherein the recess and the projection each have the shape of a Reuleaux triangle in cross-section.

8. The seal according to claim 1, wherein the sealing units are structurally identical but arranged in a mirrored fashion.

9. The seal according to claim 2, wherein the first sealing ring on an axial end face has at least one recess and one protrusion lying behind the recess in the circumferential direction.

10. The seal according to claim 2, wherein the first sealing ring has at least one axial blind hole, the axial pressure spring element being arranged in the axial blind hole.

11. The seal according to claim 2, wherein the first sealing ring is in one piece.

12. The seal according to claim 2, wherein the first sealing ring is interrupted in the circumferential direction and has two ends, wherein at each end a connecting means for joint closing of the sealing ring in the circumferential direction is provided.

13. The seal according to claim 12, wherein the connecting means interlocks positively in the circumferential direction.

14. The seal according to claim 2, wherein the second sealing ring is subdivided into at least two interconnectable segments in the circumferential direction.

15. The seal according to claim 14, wherein adjacent segments can be connected in interlocking engagement with each other.

16. A rotating system with one shaft rotating about a main axis H, at least one surface that is static to the shaft and one seal arranged on the shaft and remaining in contact with the surface according to claim 1.

17. The rotating system according to claim 16, wherein the seal is arranged in a housing, wherein the housing has two static surfaces with which the seal is in contact.

18. The rotating system according to claim 16, wherein the housing has a gas supply opening.

19. The seal according to claim 3, wherein the sealing rings each have a through-hole, which together form the through-hole for the shaft, wherein the sealing rings of a sealing unit are in interlocking engagement with each other in the circumferential direction, wherein the second sealing ring has a recess in the axial direction and the first sealing ring has a projection in the axial direction that is complementary to the recess, wherein the recess and the projection connect the sealing rings in interlocking engagement with each other, wherein the recess and the projection each have the shape of a Reuleaux triangle in cross-section, and wherein the sealing units are structurally identical but arranged in a mirrored fashion.

20. The seal according to claim 19, wherein the first sealing ring on an axial end face has at least one recess and one protrusion lying behind the recess in the circumferential direction, wherein the first sealing ring has at least one axial blind hole, the axial pressure spring element being arranged in the axial blind hole, wherein the first sealing ring is in one piece, wherein the first sealing ring is interrupted in the circumferential direction and has two ends, wherein at each end a connecting means for joint closing of the sealing ring in the circumferential direction is provided, wherein the connecting means interlocks positively in the circumferential direction, wherein the second sealing ring is subdivided into at least two interconnectable segments in the circumferential direction, and wherein adjacent segments can be connected in interlocking engagement with each other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention is illustrated and explained in the following by way of example with reference to the drawings. The figures show the following:

[0027] FIG. 1a shows a partial section of a rotating system;

[0028] FIG. 1b shows a further partial section of the rotating system according to FIG. 1a;

[0029] FIG. 2a shows a first perspective view of a first sealing ring of the rotating system according to FIG. 1a;

[0030] FIG. 2b shows a second perspective view of a first sealing ring of the rotating system according to FIG. 1a;

[0031] FIG. 2c shows the entirety of two first sealing rings of the rotating system according to FIG. 1a;

[0032] FIG. 3a shows a perspective view of a second sealing ring of the rotating system according to FIG. 1a;

[0033] FIG. 3b shows a plan view of a second sealing ring of the rotating system according to FIG. 1a;

DETAILED DESCRIPTION OF THE INVENTION

[0034] The rotating system 100 shown in FIG. 1a, 1b comprises a shaft 102 rotating about a main axis H and a seal 10 arranged on the shaft 102 (see FIG. 1a). The seal 10 is arranged in a housing 110. When used as intended, the housing 110 does not rotate with the shaft 102. Rather, the housing 110 is static and includes two static surfaces 112a, 112b, which each run perpendicular to the main axis H (see FIG. 1b). The seal 10 is arranged between the surfaces 112a, 112b and remains in contact in the axial direction with both static surfaces 112a, 112b.

[0035] The seal 10 comprises two sealing units 20a, 20b, which are arranged one behind the other along the main axis H. Each sealing unit 20a, 20b comprises a through-hole 22, the shaft 102 running through the through-holes 22. The sealing units 20a, 20b are structurally identical, but mirrored and rotated relative to one another on the shaft 102.

[0036] The sealing units 20a, 20b each include a first sealing ring 30a, 30b 5 and a second sealing ring 50a, 50b.

[0037] The first sealing rings 30a, 30b shown in FIGS. 2a, 2b each have two axial end faces 41, 42 and an axial through-hole 31. On the first end face 41, two recesses 45 and two protrusions 46 are arranged (see FIG. 2a). The recesses 45 and protrusions 46 alternate in the circumferential direction and merge into one another. Each recess 45 and each protrusion 46 forms a plateau 47, 48. In total, there are four plateaus 47, 48. An axial blind hole 39 is arranged in the area of each plateau. The blind holes 39 extend parallel to the through-hole 31.

[0038] The first sealing rings 30a, 30b consist of an elastomer and are in one piece. However, the first sealing rings 30a, 30b are each interrupted in the circumferential direction and have two ends 34, 35. At each of the ends 34, 35, a connecting means 36, 37 is provided. The connecting means 36, 37 form a puzzle connection and, when used as intended, engage with one another in a form-fitting manner in the circumferential direction, as a result of which they close the respective sealing ring 30a, 30b in the circumferential direction by means of a form-fit connection.

[0039] The first sealing rings 30a, 30b each have a projection 32 on the second end face 42 (see FIG. 2b). The projection 32 is arranged centrally on the second end face 42 and has the shape of a Reuleaux triangle with rounded corners in cross section.

[0040] The structurally identical sealing units 20a, 20b are, as mentioned, mirrored and arranged rotated with respect to one another. In this way, the axial first end surfaces 41 of the first sealing rings 30a, 30b face one another in such a way that the protrusions 46 of the first sealing rings 30a, 30b each lie in the recesses 45 of the other first sealing ring 30a, 30b. As a result, the first sealing rings 30a, 30b are positively engaged with one another (see FIG. 2c). Consequently, the sealing units 20a, 20b as a whole are also in positive engagement with one another in the circumferential direction (see FIG. 1a).

[0041] The second sealing rings 50a, 50b shown in FIGS. 3a, 3b consist of a PTFE compound. In other embodiments, the sealing rings 50a, 50b can consist of other wear-resistant plastics. In this way, the second sealing rings 50a, 50b have lower friction than the first sealing rings 30a, 30b.

[0042] The second sealing rings 50a, 50b each have a through-hole 51 which, together with the through-hole 31 of the associated first sealing ring 30a, 30b, form the through-hole 22 for the shaft 102 (see FIG. 1a).

[0043] The second sealing rings 50a, 50b are each subdivided in the circumferential direction into at least two segments 54, 55 that can be connected to one another (see FIG. 3a). The segments 54, 55 each have complementary connecting means of two puzzle connections 57 and can be connected to one another in this way.

[0044] The second sealing rings 50a, 50b have a recess 52 on an axial first end face 61. The recess 52 is arranged centrally on the end face 61 and has the shape of a Reuleaux triangle with rounded corners in cross section. The recess 52 is complementary to the projection 32 of the associated first sealing ring 30a, 30b. When used as intended, the projection 32 sits in the recess 52, whereby the sealing rings 30a, 50a of the sealing unit 20a and the sealing rings 30b, 50b of the sealing unit 20b are each in positive engagement with one another in the circumferential direction.

[0045] The second axial end face 62 of the second sealing rings 50a, 50b acts, when used as intended, as a sliding surface opposite the static surface 112a, 112b.

[0046] A plurality of axial compression spring elements 12 are arranged between the sealing units 20a, 20b (see FIG. 1a). The compression spring elements 12 are arranged in the blind holes 39 of the first sealing rings 30a, 30b and have the effect that the sealing units 20a, 20b are pretensioned against one another in the axial direction, that is to say are pressed apart in opposite axial directions. In this way, the second axial end faces 62 of the second sealing rings 50a, 50b, when used as intended, are pressed against the static areas 112a, 112b of the housing 110 and there seal an interior 111 of the housing 110 relative to the environment 120. In this way, the entry of gas from the environment 120 into the interior 111 of the housing 110 is prevented or reduced. The second sealing rings 50a, 50b continue to be pressed against the static surfaces 112a, 112b even when wear occurs, so that the sealing effect is also ensured in the long term.

[0047] The housing 110 comprises two gas supply openings 114, each in the form of a through-hole (see FIG. 1b). A flushing or sealing gas (such as nitrogen) can be introduced through the gas supply openings 114 when used as intended. The pressure of the sealing gas is higher than the pressure in the environment 120. The sealing gas increases the pretension between the sealing units 20a, 20b. At the same time, the higher pressure means that in the event of a leak in the area of the seal, sealing gas is released into the environment 120. This also prevents or reduces the entry of gas from the environment 120 into the interior 111 of the housing 110.

[0048] Overall, the seal 10 is thus held securely on the shaft 102 by the first sealing rings 30a, 30b due to their high friction. The interlocking connection of the first sealing rings 30a, 30b with one another leads to the blind holes 39 being aligned with one another. The compression spring elements 12 bring about an axial prestress between the sealing units 20a, 20b. The prestress is increased by the sealing gas. The second sealing rings 50a, 50b, due to their form-fitting connection, are moved as well by the first sealing rings 30a, 30b and form a seal against the static surfaces 112a, 112b. Since the friction between the shaft 102 and the first sealing rings 30a, 30b is greater than the friction between the second sealing rings 50a, 50b and the static surfaces 112a, 112b, it is ensured that the seal 10 rotates with the shaft 102.

LIST OF REFERENCE SYMBOLS

[0049] 10 seal

[0050] 12 compression spring element

[0051] 20a sealing unit

[0052] 20b sealing unit

[0053] 22 through-hole

[0054] 30a first sealing ring

[0055] 30b first sealing ring

[0056] 31 through-hole

[0057] 32 projection

[0058] 34 end

[0059] 35 end

[0060] 36 connecting means

[0061] 37 connecting means

[0062] 39 blind hole

[0063] 41 first end face

[0064] 42 second end face

[0065] 45 recess

[0066] 46 protrusion

[0067] 47 plateau

[0068] 48 plateau

[0069] 50a second sealing ring

[0070] 50b second sealing ring

[0071] 51 through-hole

[0072] 52 recess

[0073] 54 segment

[0074] 55 segment

[0075] 57 puzzle connection

[0076] 61 first end face

[0077] 62 second end face

[0078] 100 rotating system

[0079] 102 wave

[0080] 110 housing

[0081] 111 interior

[0082] 112a area

[0083] 112b area

[0084] 114 gas supply opening

[0085] 120 environment

[0086] H main axis