Mechanical seal device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- EAGLEBURGMANN GERMANY GMBH &CO KG
- Filing Date
- 2024-07-09
- Publication Date
- 2026-06-16
Smart Images
Figure 2026519480000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a mechanical seal device with significantly improved leakage stability.
Background Art
[0002] Mechanical seal devices are known in various embodiments according to the prior art. Essentially, due to the sealing gap between the sliding surfaces of the sliding rings, a certain amount of leakage may occur during operation in a mechanical seal device. To prevent or minimize this leakage, sometimes significant technical efforts are made. Different interference forces can act on the mechanical seal during operation. These interference forces are particularly amplified in the case of, for example, high pressures exceeding 100×10 5 Pa and high temperatures above, for example, 100°C. The sliding ring of the mechanical seal is often inserted into a metal sliding ring carrier. In this case, the sliding ring is supported by the sliding ring carrier on its rear side at the axial mounting surface. The contact force is transmitted through that mounting surface. When there is expansion of the radial components of the sliding ring and / or the sliding ring carrier, which may have thermal and / or mechanical factors, a radial frictional force occurs at the mounting surface between the rear side of the sliding ring and the sliding ring carrier. Depending on the direction of the frictional force, i.e., whether it is radially outward or radially inward, the frictional force can reverse its acting direction. Thereby, what is known as an inversion torque occurs and acts on the sliding ring. And the inversion torque on the sliding ring leads to a change in the shape in the sealing gap, which leads to a change in the leakage behavior of the mechanical seal.
Summary of the Invention
Problems to be Solved by the Invention
[0003] Therefore, an object of the present invention is to provide a mechanical seal device that has a simple design, is simple to manufacture and cost-effective, and prevents the inversion torque applied to the sliding ring. [Means for solving the problem]
[0004] This objective is achieved by a mechanical seal device having the features of claim 1. Dependent claims disclose preferred developments of the present invention.
[0005] In contrast, the mechanical seal device according to the present invention, having the features of claim 1, has the advantage that, during operation, there is no change in the shape of the sealing gap of the mechanical seal, or the change is significantly reduced. This results in significantly improved stability of leakage during operation. Consequently, countermeasures against excessive leakage during operation can be implemented very effectively and at reduced cost.
[0006] This is realized by the present invention, in which the mechanical seal device comprises a mechanical seal having a rotating sliding ring and a stationary sliding ring. A sealing gap is defined between the sliding surfaces of the rotating sliding ring and the stationary sliding ring, and leakage may occur through this sealing gap. Furthermore, a component is provided located on the rear side of at least one of the sliding rings. The sliding rings can be a rotating sliding ring or a stationary sliding ring. One of the sliding rings has a radial contact surface on its rear side that directly contacts the surface of the component facing the rear side of the sliding ring to form a radial contact region. In this case, the torque-neutral point of the cross section of one of the sliding rings and the radial contact region on the rear side of the sliding ring are selected so that they are located in a common plane. The plane is perpendicular to the central axis of the mechanical seal. The torque-neutral point of the cross section is the point at which the force acting on that point does not apply torque to the sliding ring. In a three-dimensional annular sliding ring, the torque-neutral point forms the torque-neutral line. In cross-section, the torque-neutral point can also be the center of mass of the region of the cross-section.
[0007] This means that the axial contact force acting from the component on the sliding ring does not add inversion torque to the sliding ring. The point where the contact force is applied is located in the plane where the torque-neutral point of the sliding ring's cross-section is also located. As a result, the contact force does not add torque to the sliding ring, and therefore, the absence of torque from the contact force prevents undesirable inversion of the sliding ring around the torque-neutral point during operation. This allows the operation and shape of the sealing gap, as constructed in the calculations for the mechanical seal, to be maintained, and the possible leakage can be kept approximately constant even with changes in temperature and / or mechanical stress. This makes it possible to effectively select possible countermeasures against excessive leakage during operation.
[0008] The component positioned behind one of the sliding rings is preferably a sliding ring carrier. The sliding ring carrier is particularly preferably made of a metallic material.
[0009] Alternatively, the component positioned behind the sliding ring is a pressure ring, particularly preloaded in the axial direction. The pressure ring is also preferably made of a metallic material.
[0010] According to a more preferred embodiment of the present invention, the sliding ring for preventing inversion torque has a stepped rear side having a first radial rear surface and a second radial rear surface. In this case, the first rear surface is the radial contact surface of the sliding ring. Although this increases the manufacturing cost of the sliding ring due to its stepped rear side, the stepped rear side ensures relatively simple torque neutrality of the cross-section of the sliding ring and that the radial contact region located between the radial contact surface of the sliding ring and the surface of the component is located in a common plane.
[0011] More preferably, a secondary sealing element for sealing the rear side of the sliding ring and a component located behind the sliding ring, particularly a sliding ring carrier, is located on a second radial rear surface of the rear side of the sliding ring. The secondary sealing element is preferably an elastomer sealing element, such as an O-ring.
[0012] Particularly preferably, the secondary sealing element is positioned near the inner or outer circumference of the stepped rear side surface of the secondary sealing element. Alternatively, the secondary sealing element is preferably positioned precisely on the radially inner edge of the rear side of the sliding ring.
[0013] The sliding ring can be either a rotating sliding ring or a stationary sliding ring, or both the torque-neutral point and the radial contact area on the rear side of the sliding ring are located in a common plane.
[0014] More preferably, the component located behind the sliding ring is made of a metallic material, particularly steel, and / or the sliding ring is preferably made of a ceramic material, particularly SiC or WC. This combination of materials is proven in principle, and the concept of the present invention makes it possible to reliably prevent undesirable inversion torque during operation.
[0015] The mechanical seal device is preferably, in particular, about 100 x 10 5 It is provided for sealing products used under high pressure of Pa and especially at high temperatures exceeding 100°C.
[0016] Embodiments of the present invention will be described in detail below with reference to the attached drawings. [Brief explanation of the drawing]
[0017] [Figure 1] Figure 1 is a schematic cross-sectional view of a mechanical seal device according to the first embodiment of the present invention. [Figure 2] Figure 2 is a schematic enlarged partial cross-sectional view of the mechanical seal device from Figure 1. [Figure 3] Figure 3 is a graph showing the leakage behavior of the mechanical seal device of the first embodiment according to the pressure and rotational speed over time. [Figure 4] Figure 4 is a graph showing the leakage behavior of the mechanical seal device according to the prior art. [Figure 5] Figure 5 is a schematic cross-sectional view of the mechanical seal device according to the second embodiment.
Mode for Carrying Out the Invention
[0018] Hereinafter, referring to FIGS. 1 to 5, two embodiments of the present invention will be described in detail.
[0019] FIGS. 1 to 3 show the first embodiment of the present invention.
[0020] As can be seen from FIG. 1, the mechanical seal device 1 includes a mechanical seal 2 having a rotating sliding ring 3 and a fixed sliding ring 4. A sealing gap 5 is defined between the sliding surfaces of the rotating sliding ring and the fixed sliding ring facing each other.
[0021] The mechanical seal device 1 seals the product area 16 from the atmosphere area 17 or other areas of the shaft 18.
[0022] The rotating sliding ring carrier 3 is connected to the rotating shaft 18 via the sliding ring carrier 8 so that torque transmission occurs from the shaft to the rotating sliding ring 3 via the sliding ring carrier 8.
[0023] The fixed sliding ring 4 is disposed on the housing 19. A pretensioning device including a pretensioning element 15 and a pressure ring 9 on the rear side 40 of the fixed sliding ring 4 preloads the fixed sliding ring 4 in the axial direction X-X with respect to the rotating sliding ring 3.
[0024] A secondary sealing element 10, such as an O-ring, is placed on the pressure ring 9.
[0025] In particular, as can be seen from Figure 2, the rotating sliding ring 3 is configured with a stepped shape at its rear side 30. The rear side is divided by the step into a first radial rear surface 31 and a second radial rear surface 32. The edge 33 is formed in the radially inner region of the second radial rear surface 32.
[0026] The secondary sealing element 10 is positioned within the groove of the sliding ring carrier 8 at the edge 33 of the rear side 30 of the rotating sliding ring 3. This positioning of the secondary sealing element 10 at the edge 33 creates a gap 13 between the second rear surface 32 and the sliding ring carrier 8, and approximately the same pressure as that of the product area 16 spreads within this gap. The positioning of the secondary sealing element 10 relative to the edge 33 of the rotating sliding ring 3 ensures that the contact force F acts mainly on the first rear surface 31 of the rear side 30 of the rotating sliding ring 3.
[0027] Figures 1 and 2 schematically show the resulting contact force F between the surface 14 of the sliding ring carrier 8 and the first rear surface 31. This creates a radial contact region 6 between the rotating sliding ring 3 and the sliding ring carrier 8, which is located between the first radial rear surface 31 and the surface 14 of the sliding ring carrier 8. Here, if there are thermal and / or mechanical influences, frictional forces F1 and F2 are generated in this radial contact region 6 during operation. As can be seen from Figure 2, the frictional forces F1 and F2 exist in the radial directions opposite to each other, starting from the point where the contact force F is applied.
[0028] As can be further seen from Figures 1 and 2, the torque-neutral point 7 of the cross-section of the outer profile of the rotating sliding ring 3 is located on the first plane 11 where the radial contact region 6 is also located. The resulting frictional forces F1 and F2 can act on the rotating sliding ring 3 in such a way that no inversion torque is applied to it.
[0029] As a result, the shape of the sealing gap 5 of the mechanical seal 2 can maintain stability during operation, even when mechanical and / or thermal changes occur, as well as corresponding expansion of the components of the mechanical seal 2, particularly the rotating sliding ring 3 and / or sliding ring carrier 8. The contact force F does not apply torque around the torque-neutral point 7. This ensures that the sealing gap 5 remains constant and stable during operation, resulting in improved leakage stability of the mechanical seal device during operation.
[0030] Figures 3 and 4 are graphs illustrating the beneficial effect of the present invention on the leakage stability of a mechanical seal device in operation. Figure 3 shows a mechanical seal device 1 according to the present invention, and Figure 4 shows a mechanical seal device according to the prior art. In both graphs, the leakage curve A, pressure curve B, and rotational speed curve C are plotted against time t in each case. Leakage curve A shows the leakage V across the sealing gap 5 at time t. Pressure curve B shows the pressure change of the pressure p in the sealing gap 5 starting from the machine stopping (time t=0), and rotational speed curve C shows the rotational speed n of the rotating sliding ring 3 or shaft 18 at time to.
[0031] As can be seen from Figures 3 and 4, when the machine starts up, the rotational speed n begins to increase rapidly up to approximately 11,200 rpm. After a short initial phase, the rotational speed n remains approximately constant.
[0032] As shown in Figures 3 and 4, the pressure p increases somewhat gradually from the point of stopping up to a certain pressure p.
[0033] Leakage V is plotted by leakage curve A in Figures 3 and 4. As can be directly seen, in the case of the present invention (Figure 3), there is a significant decrease in the amount of leakage after startup compared to the case of the seal according to the prior art (Figure 4). From this, it is clear that the present invention achieves significantly improved leakage stability during operation without jumping. Furthermore, in the embodiments according to the present invention, leakage during operation is also stabilized compared to the prior art, and in particular the amount of leakage is significantly reduced.
[0034] Accordingly, the present invention makes it possible to improve the leakage behavior of a mechanical seal device during operation in terms of both leakage stability and the absolute amount of leakage. Thanks to the more consistent leakage through the sealing gap 5 during operation, the present invention makes it possible to significantly improve the overall leakage compared to the prior art with the corresponding measures.
[0035] Figure 5 shows a second embodiment of the mechanical seal device 1, where identical or functionally identical parts are denoted by the same reference numerals as in the first embodiment.
[0036] The second embodiment substantially corresponds to the first embodiment, and in contrast to the first embodiment, in the second embodiment, the present invention is provided on both the rotating sliding ring 3 and the stationary sliding ring 4. In particular, as can be seen from Figure 5, the stationary sliding ring 4 is also configured in a stepped shape. The first radial rear surface 41 and the second radial rear surface 42 are provided on the rear side 40 of the stationary sliding ring 4. The first secondary sealing element 10 is positioned on the edge 43 of the rear side 40.
[0037] In this case, the first secondary sealing element 10 is positioned in a groove formed therein in the pressure ring 9. A gap 13 exists radially outward of the first secondary sealing element 10 on the rear side of the fixed sliding ring 4, between the fixed sliding ring 4 and the pressure ring 9, and the pressure from the product area 16 spreads substantially within that gap.
[0038] The pressure ring 9 has an inverted T-shape in cross-section. The fixed sliding ring 4 is positioned on the shell-like portion of the pressure ring 9 and is axially movable. For sealing, a second secondary sealing element 10a is provided between the pressure ring 9 and the housing 19 of the mechanical seal device.
[0039] As a result, the radial contact region 6 between the fixed sliding ring 4 and the sleeve-shaped region of the pressure ring 9 is located on the second plane 12, where the torque-neutral point 7 of the fixed sliding ring 4 is also located. This prevents contact forces F, which may generate frictional forces F1 and F2 acting radially on the radial contact region 6 during operation due to mechanical and / or thermal changes, from having an effect on generating torque on the fixed sliding ring 4. This also prevents the fixed sliding ring 4 from reversing during operation. The rotating sliding ring 3 is configured similarly to the first embodiment, and therefore the description therein can be referenced.
[0040] In the second embodiment, both sliding rings 3 and 4 have countermeasures against the generation of inversion torque. This leads to further improved leakage stability during operation and, accordingly, to a reduced amount of leakage during operation. In other respects, this embodiment corresponds to the first embodiment, and therefore the description therein can be referred to. [Explanation of Symbols]
[0041] 1. Mechanical seal device 2 Mechanical seals 3 Rotating sliding rings 4 Fixed sliding ring 5. Sealing gap 6 Radial contact area 7. Torque-neutral point of the cross-section of the sliding ring. 8. Sliding ring carrier 9 Pressure ring 10. First secondary sealing element (O-ring) 10a Second secondary sealing element (O-ring) 11 The First Plane 12 The second plane 13 Gap 14. The surface of the component facing the rear side of the sliding ring. 15 Pretension Elements 16 Product Area 17 Atmospheric Region 18 shafts 19 Housing 30 Rear side of the rotating sliding ring 31 First radial rear side 32 Second radial rear side view 33 Edge 40 Rear side of fixed sliding ring 41 First radial rear side view 42 Second radial rear side view 43 Edge A leakage curve B Pressure curve C Rotational speed curve Contact force in the F-axis direction F1 Frictional force in the radial direction F2 is the radial frictional force opposite to the frictional force F1. n rotation speed p pressure t time V leakage XX Axial direction
Claims
1. A mechanical seal (2) having a rotating sliding ring (3) and a fixed sliding ring (4) that define a sealing gap (5) between the sliding surfaces, The component comprises a surface (14) and a component positioned on one rear side (30, 40) of the sliding rings (3, 4), One of the sliding rings (3, 4) has radial contact surfaces (31, 41) on its rear side (30, 40) that directly contact the surface (14) of the component facing the sliding ring to form a radial contact region (6). A mechanical seal device in which the torque-neutral point (7) (cross-section) (7) and the radial contact region (6) of one of the sliding rings (3, 4) are located on a common plane (11, 12), and the plane (11, 12) is perpendicular to the axial X-X of the mechanical seal (2).
2. The mechanical seal device according to claim 1, wherein the component having the surface (14) facing the sliding ring is a sliding ring carrier (8).
3. The mechanical seal device according to claim 1, wherein the component having the surface (14) facing the sliding ring is a pressure ring (9).
4. A mechanical seal device according to any one of claims 1 to 3, wherein one of the sliding rings has a stepped rear side (30, 40) having a first radial rear surface (31, 41) and a second radial rear surface (32, 42), the first radial rear surface (31, 41) rests on the surface (14) of the component, and the radial contact region (6) is formed between the first radial rear surface (31, 41) and the surface (14) of the component.
5. The mechanical seal device according to claim 4, wherein the secondary sealing element (10) is arranged on the second radial rear surface (32, 42).
6. The mechanical seal device according to claim 5, wherein the secondary sealing element (10) is positioned near the inner or outer circumference of the second radial rear surface (32, 42), or the secondary sealing element (10) is positioned precisely on the second radial rear surface (32, 42) at the rear edge (33, 43) of the sliding ring (30, 40).
7. The mechanical seal device according to any one of claims 1 to 6, wherein one of the sliding rings is the rotating sliding ring (3), or the one of the sliding rings is the fixed sliding ring (4).
8. A mechanical seal device according to any one of claims 1 to 7, wherein the rotating sliding ring and the stationary sliding ring (3, 4) each have a stepped rear side (30, 40), the torque-neutral point (7) (7) of the cross-section of the rotating sliding ring and the stationary sliding ring, and the radial contact region (6) (6) located on the rear side (30, 40) of the rotating sliding ring and the stationary sliding ring in each case are located on a common plane (11, 12), and the plane (11, 12) is perpendicular to the axial X-X of the mechanical seal (2).
9. The mechanical seal device according to any one of claims 1 to 8, wherein the component having the surface (14) is manufactured from a metal material.
10. The mechanical seal device according to any one of claims 1 to 9, wherein the rotating sliding ring and / or fixed sliding ring (3, 4) are manufactured from a ceramic material.