Slide ring and slide ring seal arrangement

Abstract

The invention relates to the slide ring of a slide ring seal, comprising an annular main body (30) with a sliding surface (3a) directed in the axial direction (X-X) of the slide ring, a plurality of conveying grooves (5) formed in the sliding surface (3a), wherein the conveying grooves (5) have a groove beginning (51) and a groove end (52), wherein the groove end (52) is spaced apart from an outer edge (32) of the slide ring, and a connection groove (6) which is arranged in the sliding surface (3a) and connects at least two groove ends (52) of the conveying grooves (5) with one another such that, at the connection groove (6), it is possible to distribute pressure fields (7) at the groove ends (52) of the conveying grooves (5) during operation of the slide ring.

Description

[0001] Mechanical ring and mechanical seal arrangement

[0002] Description

[0003] The present invention relates to a sliding ring of a mechanical seal, as well as a mechanical seal arrangement, which has reduced leakage during operation and an increased service life of the sliding rings.

[0004] Mechanical seal assemblies are known in various designs from the prior art. To increase the pressure in the sealing gap between the sliding surfaces of the seal rings during operation, grooves are introduced into at least one of the sliding surfaces. The grooves are often V-shaped, which provide a conveying effect of barrier fluid in the sealing gap during operation. It has been found that pressure fields or pressure peaks of the barrier fluid can occur, particularly at the V-shaped end of the grooves, which can lead to waviness in the seal rings. This results in undesirable increased leakage or, in extreme cases, even contact between the wavy sliding surfaces, which can significantly reduce the service life of the seal rings.

[0005] It is therefore an object of the present invention to provide a sliding ring and a mechanical seal arrangement with a sliding ring, which, with a simple design and simple, cost-effective manufacture, have reduced waviness during operation and thus reduced leakage and an increased service life.

[0006] This object is achieved by a sliding ring having the features of claim 1 and a mechanical seal arrangement having the features of claim 13. The subclaims each show preferred developments of the invention.

[0007] The inventive slide ring of a mechanical seal arrangement with the features of claim 1 has the advantage that waviness on the sliding surfaces of the slide rings can be significantly reduced during operation. This results in significantly reduced leakage and also a significantly reduced risk of contact between the sliding surfaces during operation. This reduces wear on the sliding surfaces, thereby extending the service life of the slide rings. This allows for longer maintenance intervals, and operators of mechanical seal arrangements can significantly reduce their operating costs. This is achieved according to the invention in that the slide ring of a mechanical seal has an annular base body with a sliding surface directed in the axial direction of the slide ring. A plurality of conveying grooves is formed in the sliding surface.The conveying grooves have a groove beginning and a groove end, with the groove end being spaced from an outer edge of the sliding ring. In particular, the conveying grooves begin at the inner edge of the sliding ring and are spaced from the outer edge of the sliding ring. Thus, the conveying grooves in the sliding surface of the sliding ring are not continuous from the inner edge to the outer edge. Furthermore, the sliding ring comprises a connecting groove in the sliding surface, which connects at least two groove ends of the conveying grooves to one another, such that, during operation of the sliding ring, the connecting groove enables a distribution of pressure fields at the groove ends of the conveying grooves.

[0008] This prevents the formation of pressure fields or pressure peaks at the groove ends of the conveying grooves, which are distributed by the additional connecting groove in the area of ​​the groove ends.

[0009] Preferably, the connecting groove is designed such that the connecting groove is at least partially arcuate, and in particular extends in the circumferential direction. This enables a particularly simple distribution of the pressure fields in the circumferential direction. Particularly preferably, the connecting groove has arcuate regions and straight regions. The straight regions are preferably arranged at or near the ends of the conveying grooves.

[0010] The connecting groove is preferably designed concentrically to the edge of the seal ring. This allows the pressure fields to be distributed concentrically to the inner edge in the sealing gap. This enables a symmetrical distribution of the pressure fields and improved performance of the mechanical seal.

[0011] Particularly preferably, the connecting groove is designed as a completely closed ring around its circumference, connecting all groove ends of all conveying grooves to one another. This ensures a reliable distribution of the pressure fields at the ends of the conveying grooves during operation. In the optimal case, this results in a pressure field that is continuous in the circumferential direction with a reduced volume, with particularly reduced leakage.

[0012] According to an alternative embodiment of the invention, the connecting groove has a plurality of partial connecting grooves, each partial connecting groove connecting at least two groove ends, in particular three groove ends, of conveying grooves. This also enables a distribution of pressure fields at the groove ends. According to a further preferred embodiment of the invention, at least one of the conveying grooves has its groove beginning at an inner edge of the sliding ring. In other words, the conveying groove begins at the inner circumference of the sliding ring. Particularly preferably, all conveying grooves begin at the inner edge of the sliding ring.

[0013] According to an alternative embodiment of the invention, the conveying grooves are designed such that, in the circumferential direction, the groove ends alternately begin at the inner edge of the sliding ring and are arranged at a distance from the inner edge. Thus, conveying grooves are provided in the circumferential direction, alternating from the inner edge and beginning at a distance from the inner edge. The formation of pressure fields can be influenced by appropriately selecting the distance between the groove ends, which are arranged at a distance from the inner edge.

[0014] The connecting groove preferably has a groove base that alternates between deep and raised areas in the circumferential direction. The deep areas are further away from the sliding surface than the raised areas.

[0015] Particularly preferably, the groove base of the connecting groove is designed such that the deep regions of the groove base are located at the mouths of the groove ends on the connecting groove. Thus, the deep regions of the connecting groove create an enlarged space at the mouths of the groove ends, which facilitates pressure distribution of the pressure fields at the groove ends.

[0016] The pressure fields are three-dimensional areas in which the barrier fluid is present under an increased pressure compared to the pressure of the barrier fluid in other areas in the sealing gap.

[0017] Particularly preferably, the groove base of the connecting groove is formed in a wave-like manner, with deep regions and raised regions arranged alternately in the circumferential direction. Particularly preferably, the groove base is formed with sinusoidal waves in cross-section. This allows a uniform design of the groove base to be achieved, with one wavelength of a sinusoidal wave of the groove base corresponding to a distance in the circumferential direction between the groove ends.

[0018] According to an alternative embodiment of the invention, the groove base of the connecting groove is designed like a sawtooth. As a result, the groove base has a sawtooth shape in cross-section. A circumferential spacing between adjacent sawtooths of the groove base is preferably equal to a circumferential spacing between adjacent groove ends of two conveying grooves. The tips of the sawtooths are preferably rounded to improve the flow behavior of the barrier fluid in the connecting groove. Further preferably, a transition between the conveying grooves and the connecting groove at the mouth of the conveying grooves in the connecting groove is designed to be edge-free.

[0019] Particularly preferably, the connecting groove is designed with a constant groove width in the radial direction. This offers manufacturing advantages and allows for a sufficient volume of the connecting groove to absorb barrier fluid from the pressure fields at the ends of the conveying grooves.

[0020] Further preferably, the conveying grooves also have a constant groove width.

[0021] According to a further preferred embodiment of the invention, all conveying grooves have a geometrically identical cross-section. In particular, all conveying grooves have a constant depth or a constant width. The conveying grooves are preferably formed spirally in the sliding surface.

[0022] Further preferably, a distance of an outer edge of the connecting groove to the outer edge of the sliding ring is smaller than a distance of the inner edge of the connecting groove to the inner edge of the sliding ring.

[0023] Furthermore, the present invention relates to a mechanical seal assembly with a seal ring according to the invention. The seal ring according to the invention of the mechanical seal assembly is preferably the rotating seal ring. It should be noted that it is also possible for a corresponding design of conveying grooves and connecting grooves as described above to be provided in both the rotating and stationary seal rings. Preferably, the design of the conveying grooves and connecting grooves in the rotating and stationary seal rings is geometrically identical.

[0024] Preferred embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing:

[0025] Fig. 1 is a schematic sectional view of a mechanical seal arrangement with a sliding ring according to a first preferred embodiment of the invention,

[0026] Fig. 2 is a schematic plan view of a sliding surface of the rotating seal ring of the mechanical seal arrangement of Fig. 1,

[0027] Fig. 3 is a schematic sectional view along the line III - III of Fig. 2,

[0028] Fig. 4 is a schematic partial view of the sliding ring of the mechanical seal arrangement of Fig. 1 with a schematically illustrated pressure field,

[0029] Fig. 5 is a partial view of the sliding ring of the mechanical seal arrangement with a distributed pressure field, Fig. 6 is a schematic sectional view corresponding to the sectional view of Fig. 3 of a sliding ring according to a second embodiment,

[0030] Fig. 7 is a schematic plan view of a sliding ring of a mechanical seal according to a third embodiment of the invention,

[0031] Fig. 8 is a schematic plan view of a sliding ring of a mechanical seal according to a fourth embodiment of the invention, and

[0032] Fig. 9 is a schematic plan view of a sliding ring of a mechanical seal according to a fifth embodiment of the invention.

[0033] In the following, with reference to Figures 1 to 5, a mechanical seal arrangement

[0034] 1 described in detail.

[0035] As can be seen from Fig.1, the mechanical seal arrangement 1 comprises a mechanical seal

[0036] 2 with a rotating seal ring 3 and a stationary seal ring 4. The rotating seal ring

[0037] 3 has a first sliding surface 3a, and the stationary seal ring 4 has a second sliding surface 4a. A sealing gap 2a is formed between the two sliding surfaces 3a, 4a. The mechanical seal 2 seals a product chamber 11 and an atmosphere chamber 12.

[0038] The rotating seal ring 3 is connected to a shaft 17 by means of a seal ring carrier 13. The stationary seal ring 4 is preloaded against the rotating seal ring 3 by means of a preloading device 14, which is located on a rear side 41 of the stationary seal ring 4 and preloads the latter in the axial direction XX. The stationary seal ring 4 is axially movable on a sleeve 16. Reference numeral 15 denotes a housing.

[0039] The rotating seal ring 3 can be seen in detail in Figures 2 and 3. Figure 2 shows a plan view of the sliding surface 3a of the rotating seal ring 3.

[0040] As shown in Fig. 2, a plurality of conveying grooves 5 are formed in the sliding surface 3a of the rotating seal ring 3. The conveying grooves 5 enable the conveyance of barrier fluid within the sealing gap 2a during operation of the mechanical seal 2.

[0041] The conveying grooves 5 are all geometrically identical and have a groove beginning 51 and a groove end 52. The groove beginning 51 is located on an inner circumference 31 of the rotating seal ring. The groove end is arranged at a radial distance from an outer circumference 32 of the rotating seal ring 3.

[0042] As can be seen from Fig. 2, a connecting groove 6 is also provided, which connects all groove ends 52 of the conveying groove 5. The connecting groove 6 is annular and arranged concentrically to the inner circumference 31 and the outer circumference 32. In the radial direction, the connecting groove 6 is provided closer to the outer circumference 32 than to the inner circumference 31.

[0043] The connecting groove 6 has a constant groove width.

[0044] The conveying grooves 5 begin at the inner circumference 31 and open into the connecting groove 6. An edge-free transition is provided between the groove ends 52 and the connecting groove 6.

[0045] The conveying grooves 5 and the connecting groove 6 are formed in the base body 30 of the rotating slide ring 3.

[0046] Fig. 3 shows a sectional view of the connecting groove 6 along the line III-III of Fig. 2. From the cross-section of the connecting groove 6 in Fig. 3, it is clearly visible that the connecting groove 6 has a groove bottom 65 which is wave-shaped. In this exemplary embodiment, the groove bottom 65 is sinusoidal. The groove bottom 65 has deep regions 61 and raised regions 62. As can be seen from Fig. 3, the raised regions 62 are somewhat spaced from the sliding surface 3a of the sliding ring 3, so that the connecting groove 6 is completely annular in the circumferential direction.

[0047] As can be further seen from Fig. 3, the deep regions 61 are arranged at the mouth regions of the conveying grooves 5 into the connecting groove 6. Between two adjacent groove ends 52, exactly one raised region 62 is provided (see Fig. 2).

[0048] The wave-shaped groove bottom 65 is provided in such a way that, starting from a first deep region 61 at a first conveying groove 5, the groove bottom 65 has a wave which extends to an adjacent further conveying groove 5 (cf. Fig. 3).

[0049] During operation of the mechanical seal 2, when the rotating seal ring 3 rotates in the direction of rotation A, pressure fields 7 form in the sealing gap between the sliding surfaces 3a, 4a of the seal rings at the groove ends 52 of the conveying grooves 5. This is illustrated schematically in Fig. 4. A pressure field 7 is a three-dimensional spatial structure without a defined shape in which an enlarged volume of barrier fluid can be located under high pressure. Such pressure fields 7 can cause waviness on the sliding surfaces of the seal rings during operation.

[0050] The inventive measure of connecting groove ends 52 of the conveying grooves 5 by means of the connecting groove 6 now results in a distribution of existing pressure fields 7, as schematically shown in Fig. 5. The distributed pressure field is designated by the reference numeral 7'. The connecting groove 6 thus allows the barrier fluid accumulated at the groove ends 5 to be distributed circumferentially, so that the height of the pressure field between the sliding surfaces is reduced and thus the risk of wave formation on the sliding surfaces is significantly reduced.

[0051] Since the connecting groove 6 runs concentrically to the inner and outer circumference in the circumferential direction, the pressure field 7 is also distributed in the circumferential direction. Depending on the rotational speed and / or the distance between adjacent groove ends 52 of the conveying grooves, a coherent, distributed pressure field 7' can be created during operation, since the pressure fields are distributed at each groove end 52. This can create an additional pressure barrier within the sealing gap 2a against leakage of medium from the product chamber 11 toward the atmospheric chamber 12.

[0052] Thus, the groove arrangement comprising the conveying grooves 5 and the connecting groove 6 in the sliding surface 3a of the rotating seal ring 3 prevents the formation of ripples on the sliding surfaces. This results in significantly reduced leakage during operation and a significantly extended service life, as contact on the sliding surfaces is minimized due to the reduced waviness on the sliding surfaces, thus minimizing wear on the seal rings.

[0053] Fig. 6 shows a sectional view of a sliding ring of a mechanical seal assembly according to a second exemplary embodiment of the invention. Identical or functionally identical parts are designated by the same reference numerals as in the first exemplary embodiment.

[0054] As can be seen from Fig. 6, in the second embodiment the groove bottom 65 of the connecting groove 6 is designed differently. In the second embodiment the groove bottom 65 is sawtooth-shaped. The groove bottom 65 has raised regions 62 in the form of peaks and deep regions 61 in the form of valleys. The deep regions are arranged directly adjacent to the raised regions 62. Starting from a deep region 61, a ramp 63 is provided which runs from the deep region 61 to the raised region 62. The ramp 63 is preferably provided with a constant gradient. As can be seen from Fig. 6, the conveying grooves 5 end directly at the deep region 61 of the sawtooth-shaped groove bottom 65. The distribution of the pressure fields at the groove ends in the second embodiment is correspondingly as described in the first embodiment, so that reference can be made to the description given there.

[0055] Fig. 7 shows a slide ring of a mechanical seal arrangement according to a third embodiment of the invention. Identical or functionally equivalent parts are again designated by the same reference numerals as in the previous embodiments. As can be seen from Fig. 7, which shows a plan view of the sliding surface 3a of the rotating slide ring 3, the connecting groove of the third embodiment is designed differently from the previous embodiments. As shown in Fig. 7, a plurality of partial connecting grooves 60 are provided. A partial connecting groove 60 connects exactly two adjacent conveying grooves 5 in the region of the groove ends 52 of the conveying grooves 5. The partial connecting grooves 60 are arranged concentrically to the inner circumference 31 and the outer circumference 32 of the rotating slide ring 3. As can be seen from Fig.7, a partial connecting groove begins before a first groove end of a conveying groove 5 and extends beyond a groove end of an adjacent second conveying groove 5. Between the partial connecting grooves 60, sliding surface regions 64 are provided in the circumferential direction, which form a usual sliding surface region of the sliding surface 3a of the rotating slide ring 3. The partial connecting grooves 60 are in turn sinusoidally formed with deep regions 61 at the groove ends of the conveying grooves 5 and precisely one raised region 62 between two adjacent deep regions 61. Thus, the third exemplary embodiment essentially corresponds to the first exemplary embodiment with the difference that the connecting groove 6 is interrupted and the partial connecting grooves 60 each connect exactly two adjacent conveying grooves 5 to one another.

[0056] Regarding the third embodiment, it should be noted that it is of course also possible for the partial connecting grooves 60 to connect more than two conveying grooves 5, for example, three or four conveying grooves. Otherwise, this embodiment corresponds to the previous embodiment, so reference can be made to the description given there.

[0057] Fig. 8 shows a sliding ring according to a fourth exemplary embodiment of the invention. The fourth exemplary embodiment essentially corresponds to the first exemplary embodiment, wherein, in contrast to the first exemplary embodiment, the conveying grooves 5 are designed differently in the fourth exemplary embodiment. As can be seen from Fig. 8, the conveying grooves 5 are arranged alternately in the circumferential direction such that a conveying groove begins at a groove start 51a on an inner circumference 31 of the sliding ring and an adjacent conveying groove has a groove start 51b which is spaced apart from the inner circumference 31 of the sliding ring. As can be seen from Fig. 8, in this exemplary embodiment all groove starts 51b which are spaced apart from the inner circumference are arranged on a common diameter D1. It should be noted, however, that it is also possible for the groove starts 51b which are spaced apart from the inner circumference 31 to begin at different diameters.Due to the different design of the groove beginnings 51a, 51b in the fourth embodiment, the pressure fields generated during operation can be specifically influenced. Fig. 9 shows a slide ring of a mechanical seal arrangement according to a fifth embodiment of the invention. The fifth embodiment essentially corresponds to the third embodiment, whereby, in contrast to the third embodiment, the partial connecting grooves 60 are designed differently in the fifth embodiment. In the fifth embodiment, the partial connecting grooves 60 have a straight partial region 60a and an arcuate partial region 60b. The partial connecting grooves 60 each connect two adjacent conveying grooves 5. The straight partial region 60a is arranged at a groove end 52 of one of the conveying grooves 5 connected by the connecting groove 6.The arcuate portion 60b is part of a spiral centered on the center axis of the sliding ring. The connecting grooves 60 of the fifth embodiment are each provided with identical geometric configurations.

[0058] In addition to the above written description of the invention, reference is hereby explicitly made to the graphic representation of the invention in the figures for its supplementary disclosure.

[0059] List of reference symbols

[0060] 1 mechanical seal arrangement

[0061] 2 mechanical seals

[0062] 2a Sealing gap

[0063] 3 rotating slide ring

[0064] 3a first sliding surface

[0065] 4 stationary sliding ring

[0066] 4a second sliding surface

[0067] 5 Conveying groove

[0068] 6 connecting groove

[0069] 7 Print field

[0070] 7' distributed pressure field

[0071] 11 Product room

[0072] 12 Atmosphere space

[0073] 13 Slide ring carrier

[0074] 14 Pre-tensioning device

[0075] 15 housings

[0076] 16 sleeve

[0077] 17 Wave

[0078] 30 basic bodies

[0079] 31 inner circumference

[0080] 32 outer circumference

[0081] 41 Back of the stationary sliding ring

[0082] 51 groove start

[0083] 51a Groove start on the inner circumference

[0084] 51b Groove start spaced from the inner circumference

[0085] 52 groove end

[0086] 60 partial connecting groove

[0087] 60a straight section of the partial connecting groove

[0088] 60b arched section

[0089] 61 deep area

[0090] 62 raised area

[0091] 63 Ramp

[0092] 64 sliding surface area

[0093] 65 groove bottom

[0094] A Rotation direction

[0095] D1 Diameter on which the groove beginnings are located, spaced from the inner circumference

[0096] XX Axial direction

Claims

Claims 1. Mechanical ring of a mechanical seal comprising . an annular base body (30) with a sliding surface (3a) directed in the axial direction (XX) of the sliding ring, . a plurality of conveying grooves (5) formed in the sliding surface (3a), . wherein the conveying grooves (5) have a groove beginning (51) and a groove end (52), wherein the groove end (52) is spaced from an outer edge (32) of the sliding ring, and . a connecting groove (6) which is arranged in the sliding surface (3a) and connects at least two groove ends (52) of the conveying grooves (5) to one another, so that during operation of the sliding ring on the connecting groove (6) a distribution of pressure fields (7) at the groove ends (52) of the conveying grooves (5) is made possible.

2. Sliding ring according to claim 1, wherein the connecting groove (6) is at least partially arcuate, in particular in the circumferential direction of the sliding ring.

3. Sliding ring according to claim 2, wherein the connecting groove (6) runs concentrically to the inner and outer edge (31, 32) of the sliding ring.

4. Slide ring according to one of the preceding claims, wherein the connecting groove (6) is formed completely circumferentially and connects all groove ends (52) of the conveying grooves (5) to one another. 5 Slide ring according to one of claims 1 to 3, wherein the connecting groove comprises a plurality of partial connecting grooves (60), each partial connecting groove (60) connecting at least two groove ends (52) of conveying grooves (5) to one another.

6. Sliding ring according to one of the preceding claims, wherein at least one conveying groove (5) has the groove beginning (51) on an inner edge (31) of the sliding ring.

7. Sliding ring according to claim 6, wherein all conveying grooves (5) have the groove beginning at an inner edge (31) of the sliding ring or wherein the conveying grooves (5) alternately have the groove beginnings at the inner edge (31) and at a distance from the inner edge (31) in the circumferential direction.

8. Sliding ring according to one of the preceding claims, wherein the connecting groove (6) has a groove bottom (65) which has alternating deep regions (61) and raised regions (62) in the circumferential direction, wherein a distance of the deep regions (61) to the Sliding surface (3a) is greater than a distance of the raised areas (62) to the sliding surface (3a).

9. Sliding ring according to claim 8, wherein the deep regions (61) of the groove bottom (65) are arranged at mouths of the groove ends (52) on the connecting groove (6).

10. Sliding ring according to claim 8 or 9, wherein the groove bottom (65) is wave-shaped with deep regions (61) and raised regions (62) arranged alternately in the circumferential direction.

11. Sliding ring according to one of claims 8 or 9, wherein the groove bottom (65) is sawtooth-shaped.

12. Slide ring according to one of the preceding claims, wherein an edge-free transition is provided between the conveying grooves (5) and the connecting groove (6) in the region of the groove end (52), or - wherein the connecting groove (6) has a constant groove width, or - wherein the conveying grooves (5) all have a geometrically identical cross-section.

13. Mechanical seal arrangement comprising a mechanical seal (2) with a sliding ring according to one of the preceding claims. 14 Mechanical seal arrangement according to claim 13, wherein the sliding ring is the rotating sliding ring (3).

15. Mechanical seal arrangement according to claim 13 or 14, wherein the mechanical seal (2) is a gas-lubricated mechanical seal.

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