SLIDING RING SEAL ARRANGEMENT WITH IMPROVED AXIAL FORCE SUPPORT

Description

[0001] The present invention relates to a mechanical seal arrangement for sealing between a high-pressure area and a low-pressure area on a shaft with improved support of axial forces which can act on the mechanical seal arrangement during operation.

[0002] Mechanical seal assemblies are known in various designs from the prior art. Particularly in gas seals, very high axial forces can act on the components of the mechanical seal assembly in high-pressure applications with pressures above 200 x 10 5 Pa. To absorb these high forces, it is known to use a so-called split ring, which is composed of several circumferential segments, to transfer the axial force to a shaft or the like. Deformations of this split ring can cause circumferential waviness, which in extreme cases can penetrate through to the sliding surfaces of the seal rings due to elastic deformation. Waviness on the sliding surfaces, however, must be avoided at all costs to avoid unnecessarily limiting the performance of the mechanical seal.To reduce the potential ripple transfer from the split ring to the sliding surfaces, the state of the art uses elastic secondary sealing elements between the split ring and the mechanical seal. These can be elastically deformed when axial forces occur, thus reducing the risk of unwanted ripple transfer to the sliding surfaces of the mechanical seal. In high-pressure applications and in sealing tasks where the medium to be sealed is at high temperatures, elastic secondary sealing elements are not suitable or only suitable to a limited extent.

[0003] EP 3 450 805 A1 discloses a mechanical seal assembly, according to the preamble of claim 1, comprising a mechanical seal and a mechanical seal carrier, which connects the rotating mechanical seal to a rotating component in a rotationally fixed manner. The mechanical seal carrier is constructed in several parts and connected by means of screws. Flexible packings are provided on the multi-part mechanical seal carrier for sealing. An axial force acting on the mechanical seal assembly is supported by screwing the sleeve to a shaft. Furthermore, US Pat. No. 4,997,191 A discloses a mechanical seal assembly with a slotted ring with a radial slot.

[0004] It is therefore an object of the present invention to provide a mechanical seal arrangement which, with a simple structure and simple, cost-effective manufacture, can prevent the transmission of waviness of a split ring to the sliding surfaces of the mechanical seal arrangement and is particularly suitable for high-pressure applications and high-temperature applications.

[0005] This object is achieved by a mechanical seal arrangement having the features of claim 1. The subclaims show preferred developments of the invention.

[0006] The mechanical seal assembly according to the invention with the features of claim 1 has the advantage that axial forces acting on the mechanical seal assembly can be absorbed much better and transmitted to a rotating component. In particular, waviness can be prevented from being imparted to the sliding surfaces of the mechanical seal assembly when axial forces occur. This is achieved according to the invention in that the mechanical seal assembly has a mechanical seal for sealing between a high-pressure region and a low-pressure region on a shaft or the like, which has a rotating sliding ring with a first sliding surface and a stationary sliding ring with a second sliding surface, wherein a sealing gap is defined between the sliding surfaces of the sliding rings.Furthermore, a slide ring carrier is provided for the rotating slide ring, which is designed for a rotationally fixed connection to the rotating component, in particular a shaft. The slide ring carrier has a sleeve region. Furthermore, the mechanical seal arrangement comprises a force support arrangement, which is designed to support an axial force acting on the mechanical seal arrangement. The force support arrangement is arranged on an end face of the sleeve region of the slide ring carrier. The force support arrangement comprises a clamping sleeve, a conical sleeve, and a split ring with at least two segments. The split ring is divided in the radial direction of the mechanical seal arrangement into several circumferential segments, which are connected to one another in the assembled state on a rotating component. Furthermore, a conical connection is formed between the clamping sleeve and the conical sleeve.The clamping sleeve rests on the end face of the sleeve area of ​​the slide ring carrier and the tapered sleeve rests on a side surface of the split ring.

[0007] Thus, when an axial force acts on the mechanical seal assembly, the force is transmitted from the mechanical seal carrier to the adapter sleeve, from the adapter sleeve to the tapered sleeve, from the tapered sleeve to the split ring, and from the split ring to the rotating component. Thus, the axial force is transmitted via four connecting surfaces: a first connecting surface between the sleeve area and the adapter sleeve, a second connecting surface at the tapered connection between the adapter sleeve and the tapered sleeve, a third connecting surface between the tapered sleeve and the split ring, and a fourth connecting surface between the split ring and the rotating component.

[0008] A particular advantage of the inventive design is that, by using the tapered connection between the adapter sleeve and the tapered sleeve, a portion of the axial force can be transmitted radially via an inner circumference of the tapered sleeve directly to the rotating component. This significantly reduces the axial force ultimately remaining at the fourth connection surface for transmission to the rotating component. This prevents the separation points of the split ring from imprinting on the sliding surfaces of the mechanical seal assembly.

[0009] To achieve the most compact design possible and ensure reliable force transmission from the clamping sleeve to the tapered sleeve, the clamping sleeve preferably has a receiving space for accommodating the tapered sleeve. The tapered sleeve can preferably be arranged largely, in particular more than 80% of its axial extension, in the receiving space of the clamping sleeve.

[0010] Preferably, the receiving space of the clamping sleeve has a first inner conical surface, and the conical sleeve has a second outer conical surface. The two conical surfaces form the conical connection between the clamping sleeve and the conical sleeve.

[0011] The conical connection is preferably arranged at an angle α of 35° ± 8°, especially 35° ± 3°, to the center axis XX of the mechanical seal. Depending on the choice of angle α < 45°, a greater force can be achieved by radial force introduction into the rotating component via the conical sleeve than by axial force introduction in the direction of the split ring.

[0012] Particularly preferably, the average diameter of the split ring is larger than the inner diameter of the tapered sleeve. This results in a favorable force transfer from the tapered sleeve to the split ring. In particular, the inherent deformation of the split ring is reduced in this contact area of ​​the split ring.

[0013] Particularly preferably, the adapter sleeve, the split ring, the slide ring carrier, and the conical sleeve are made of metal material, in particular of the same metal material. Steel is preferably used as the metal material. This allows the mechanical seal arrangement to be used in particular in high-temperature applications where the use of elastic sealing elements is not possible due to the destruction of elastic sealing elements caused by the high temperatures, as well as in high-pressure applications where the use of split rings carries a high probability of waviness being imprinted on the sliding surfaces of the slide rings. When using different materials for the adapter sleeve, the split ring, the slide ring carrier, and the conical sleeve, the different materials preferably have the same or very similar (± 10%) coefficient of thermal expansion.

[0014] Particularly preferably, the split ring is arranged in a groove in the rotating component, in particular in a groove in a shaft.

[0015] Further preferably, an axial gap is provided on the inner circumferential region between the adapter sleeve and the tapered sleeve. This provides the force-supporting arrangement with at least certain damping properties when an axial force is applied. The axial force can thus be reliably transmitted via the force introduction path from the sleeve area of ​​the slide ring carrier to the rotating component.

[0016] To further improve the transmission of the axial force, a screw connection is preferably formed between the sleeve area of ​​the slide ring carrier and the adapter sleeve. The screw connection preferably comprises a plurality of screw bolts arranged along the circumference, which are guided through the adapter sleeve and screwed into the end face of the sleeve area.

[0017] More preferably, the mechanical seal arrangement is a gas seal for sealing a gaseous medium. The gaseous medium is particularly preferably under a high pressure, preferably greater than 200 x 10 5 Pa, and a high temperature, in particular greater than 400°C.

[0018] An embodiment of the invention is described in detail below with reference to the accompanying drawing. In the drawing: Fig. 1 is a schematic sectional view of a mechanical seal arrangement according to a preferred embodiment of the invention, Fig. 2 is a schematic sectional view along the line II-II of Fig. 1 , Fig. 3 a schematic, enlarged partial sectional view of the mechanical seal arrangement of Fig. 1 , Fig. 4 a schematic sectional view of a clamping sleeve of the mechanical seal arrangement of Fig. 1 and Fig. 5 a schematic sectional view of a conical sleeve of the mechanical seal arrangement of Fig. 1 .

[0019] The following is based on the Fig. 1 bis 5 a mechanical seal arrangement 1 according to a preferred embodiment of the invention is described in detail.

[0020] As from Fig. 1 As can be seen, the mechanical seal assembly 1 comprises a mechanical seal 2 with a rotating seal ring 3 and a stationary seal ring 4. The rotating seal ring 3 has a first sliding surface 30 and the stationary seal ring 4 has a second sliding surface 40. A sealing gap 5 is defined between the two sliding surfaces 30, 40 of the seal rings 3, 4.

[0021] How to continue Fig. 1 As can be seen, the mechanical seal arrangement 1 on a shaft 7 seals off a high-pressure region 8 from a low-pressure region 9. In the high-pressure region 8, a gas under high pressure, in particular greater than 200 x 10 5< Pa, is preferably present as the medium to be sealed.

[0022] The rotating seal ring 3 is connected to the shaft 7 in a rotationally fixed manner by means of a seal ring carrier 31. The seal ring carrier 31 comprises a sleeve region 32 arranged on the shaft 7 and a holding region 33 that partially encloses the rotating seal ring 3. Thus, when the shaft 7 rotates, power is transmitted from the shaft 7 to the seal ring carrier 31 and from there to the rotating seal ring 3.

[0023] Further preferably, a metallic seal 34 without an elastic secondary seal is formed between the slide ring carrier 31 and the rotating slide ring 3. This eliminates the need for an elastic secondary sealing element to seal the gap between the slide ring carrier 31 and the rotating slide ring 3, allowing both high-pressure and high-temperature applications to be achieved without any problems.

[0024] The mechanical seal assembly 1 further comprises a force support assembly 6. The force support assembly 6 is shown in detail in Fig. 3 The force support assembly 6 comprises a clamping sleeve 60, a conical sleeve 61, and a split ring 62.

[0025] The split ring 62 is a ring divided into two circumferential segments, wherein in this embodiment, the split ring 62 has a first segment 621 and a second segment 622. The two segments are connected to each other via screw connections 63 (see. Fig. 2 ). Alternatively, the split rings are held in place by means of a sleeve.

[0026] The split ring 62 is arranged in a groove 70 in the shaft 7.

[0027] The clamping sleeve 60 is made in detail from Fig. 4 The clamping sleeve 60 comprises in particular a first conical surface 60a and a receiving space 16. The receiving space 16 is, like the first conical surface 60a, formed on a radial inner side, ie a side of the clamping sleeve 60 directed towards the shaft 7. The receiving space 16 serves to receive the conical sleeve 61, as can be seen from the Fig. 1 and 3 is evident.

[0028] The conical sleeve 61 is made in detail from Fig. 5 The conical sleeve 61 has a second conical surface 61a. Furthermore, the conical sleeve 61 has an inner circumference 61b, with which the conical sleeve 61 is arranged on the shaft 7.

[0029] The force support arrangement 6 is designed to support an axial force F acting on the mechanical seal arrangement 1. Such axial forces F can occur during operation of the mechanical seal arrangement, in particular as a function of a load on a machine to be sealed, and in particular during load changes.

[0030] As can be seen from the Fig. 1 and 3 As can be further seen, a conical connection is formed between the clamping sleeve 60 and the conical sleeve 61, which is provided by the first conical surface 60a of the clamping sleeve 60 and the second conical surface 61a of the conical sleeve 61. The conical sleeve 61 is received in the receiving space 16 of the clamping sleeve 60.

[0031] How further from the Fig. 1 and 3As can be seen, the clamping sleeve 60, in the assembled state, rests against an end face 32a of the sleeve region 32 of the slide ring carrier 31. Furthermore, the conical sleeve 61 rests against a side surface 62a of the split ring 62.

[0032] Furthermore, the conical sleeve 61 has an inner diameter D1 which is smaller than a mean diameter D2 of the split ring 62 (cf. Fig. 1 ). This ensures that force is introduced into a radially inner region of the split ring 62, whereby the axial force is then transmitted from the split ring 62 to the shaft 7 without great leverage.

[0033] The conical connection between the clamping sleeve 60 and the conical sleeve 61 has an angle α to a central axis XX of the mechanical seal arrangement 1 (cf. Fig. 1 ). The angle α is preferably in a range of 35° ± 3°.

[0034] The clamping sleeve 60 is connected to the sleeve portion 32 of the sliding ring support 31 by means of a bolt 15. Preferably, several bolts 15 are arranged at equal distances from one another along the circumferential direction of the clamping sleeve.

[0035] The mechanical seal carrier 31, the adapter sleeve 60, the tapered sleeve 61, and the split ring 62 are all made of a single steel material, preferably the same steel material. This ensures that the mechanical seal assembly 1 can be used for both high-pressure and high-temperature applications.

[0036] How to continue Fig. 3 As can be seen, four connecting surfaces are provided between the slide ring carrier 31 and the shaft 7 for transmitting the axial force F. A first connecting surface 11 is formed between the sleeve region 32 and the clamping sleeve 60. A second connecting surface 12, which establishes the conical connection, is formed between the clamping sleeve 60 and the conical sleeve 61. A third connecting surface 13 is formed between the conical sleeve 61 and a side surface 62a of the split ring 62. A fourth connecting surface 14 is formed between the split ring 62 and the shaft 7 in the region of the groove 70 (cf. Fig. 3 ).

[0037] Thus, when an axial force F acts on the mechanical seal assembly 1 during operation, it is transmitted via the mechanical ring carrier 31 to the force support assembly 6, which is arranged on the shaft 7. By providing the conical second connecting surface 12 between the clamping sleeve 60 and the conical sleeve 61, the force F is thus divided into an axial component F1 and a radial component F2. The radial component F2 is then transmitted directly to the shaft 7 via the inner circumference 61b of the conical sleeve 61. Thus, the remaining force to be transmitted, which must be transferred from the conical sleeve 61 to the split ring 62 and from there via the groove 70 to the shaft 7, is significantly reduced.

[0038] Thus, in particular, load-induced wavinesses, which can occur due to a deformation of the split ring 62 when the axial force F occurs, can be reduced to such an extent that these wavinesses are not impressed on the sliding surfaces 30, 40 of the sliding rings.

[0039] Furthermore, an axial gap 10 is present between the clamping sleeve 60 and the conical sleeve 61 (cf. Fig. 3 ). The axial gap 10 provides a certain damping effect when axial forces F occur, which enables a certain inherent deformation of the components of the force support arrangement 6.

[0040] Since deformation of the steel used as material for the mechanical seal carrier 31, the clamping sleeve 60, the conical sleeve 61 and the split ring 62 is relatively small, an improved design of components of the mechanical seal arrangement 1 can also be realized.

[0041] In particular, by selecting the angle α of the conical connection between the clamping sleeve 60 and the conical sleeve 61, a maximum size of introduction of waviness caused by the split ring 62 onto the sliding surfaces 30, 40 can be achieved. List of reference symbols

[0042] 1 Mechanical seal arrangement 2 Mechanical seal 3 Rotating seal ring 4 Stationary mechanical seal 5 Sealing gap 6 Force support arrangement 7 Shaft / rotating component 8 High-pressure area 9 Low-pressure area 10 Axial gap 11 First connecting surface 12 Second connecting surface 13 Third connecting surface 14 Fourth connecting surface 15 Bolt 16 Receptacle 30 First sliding surface 31 Mechanical ring carrier 32 Sleeve area 32a End face of the sleeve area 33 Retaining area 34 Metallic seal 40 Second sliding surface 60 Clamping sleeve 60a First tapered surface 61 Tapered sleeve 61a Second tapered surface 61b Inner circumference 62 Split ring 62a Side surface of the split ring 63 Screw connection 621 First segment 622 Second segment 70 Groove D1 Inner diameter of the tapered sleeve D2 mean diameter of the split ring FAxial force F1axial force component of the axial force F2radial force component of the axial force X-X center axis α angle

Claims

1. Mechanical seal assembly (1) for sealing between a high-pressure region (8) and a low-pressure region (9) on a rotating component (7), comprising • a mechanical seal (2) with a rotating slide ring (3) with a first slide surface (30) and a stationary slide ring (4) with a second slide surface (40), wherein a sealing gap (5) is defined between the slide surfaces (30, 40), • a slide ring carrier (31) for the rotating slide ring (3), which is configured to connect the rotating slide ring (3) to the rotating component (7) in a rotationally fixed manner, wherein the slide ring carrier (31) comprises a sleeve region (32), and • a force support arrangement (6) which is configured to support an axial force (F) acting on the mechanical seal assembly (1), • wherein the force support arrangement (6) is arranged on an end face (32a) of the sleeve region (32) of the slide ring carrier (31), • wherein the clamping sleeve (60) bears against the end face (32a) of the sleeve region (32) and the conical sleeve (61) bears against a side surface (62a) of the split ring (62), • characterized in that the force support arrangement (6) comprises a clamping sleeve (60), a conical sleeve (61) and a split ring (62) with at least two segments (621, 622), • wherein a conical connection with a first conical surface (60a) on the clamping sleeve (60) and a second conical surface (61a) on the conical sleeve (61) is formed between the clamping sleeve (60) and the conical sleeve (61).

2. Mechanical seal assembly (1) according to claim 1, wherein the clamping sleeve (60) comprises a receiving space (16) for receiving the conical sleeve (61).

3. Mechanical seal assembly (1) according to claim 2, wherein the receiving space (16) of the clamping sleeve (60) comprises a first inner-side conical surface (60a) and the conical sleeve (61) comprises a second outer-side conical surface (61a).

4. Mechanical seal assembly (1) according to any one of the preceding claims, wherein the conical connection has an angle (α) of 35° ± 8° to a central axis (X-X) of the mechanical seal assembly (1).

5. Mechanical seal assembly (1) according to any one of the preceding claims, wherein an average diameter (D2) of the split ring (62) is larger than an inner diameter (D1) of the conical sleeve (61).

6. Mechanical seal assembly (1) according to any one of the preceding claims, wherein the slide ring carrier (31), the clamping sleeve (60), the conical sleeve (61) and the split ring (62) are made of metal material.

7. Mechanical seal assembly according to any one of the preceding claims, wherein the split ring (62) is configured to be received in a groove (70) of the rotating component (7).

8. Mechanical seal assembly (1) according to any one of the preceding claims, wherein an axial gap (10) is formed on the inner circumferential region between the clamping sleeve (60) and the conical sleeve (61).

9. Mechanical seal assembly (1) according to any one of the preceding claims, wherein a screw connection is formed between the clamping sleeve (60) and the slide ring carrier (31).

10. Mechanical seal assembly (1) according to any one of the preceding claims, wherein a metallic seal (34) without elastic secondary sealing elements is formed between the slide ring carrier (31) and the rotating slide ring (3).