Slip ring seal assembly
By introducing a torque device of multiple transmission elements into the slip ring seal assembly, the problem of high torque during start-up is solved, effective torque sharing and stress reduction are achieved, and the service life and sealing effect of the slip ring seal assembly are improved.
Patent Information
- Application Number
- CN202380074419.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-11-29
- Filing Date
- 2023-10-26
- Publication Date
- 2025-06-03
AI Technical Summary
The existing slip ring seal assembly will have high torque problems when starting from the stop state, especially in high pressure environments, which can easily lead to cracks and shortened service life of the slip ring material.
By introducing a torque device of multiple transmission elements into the slip ring seal assembly, the total torque is distributed to the multiple independent transmission elements, and the torque is transmitted between the slip ring support and the slip ring through the rolling element, reducing the magnitude of torque and stress concentration.
The torque transmission between the slip ring support part and the slip ring or the slip ring and the slip ring support part is significantly improved, and the slip ring damage caused by excessive torque is avoided, and the additional stop seal is required, which improves the service life of the seal assembly.
Smart Images
Figure CN120092145A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a slip ring seal assembly having a significant improvement possibility in torque transmission from and to a slip ring, in particular a ceramic slip ring. Background Art
[0002] Slip ring seal assemblies are known from different designs of the prior art. Here, a series of problems occur when starting from a stopped state under high pressure of the medium to be sealed off. When the slip ring seal assembly is stopped, the slip rings are usually pressed against each other by means of elastic means and the pressure of the medium to ensure a sealing-off effect as much as possible at the sealing gap between the sliding surfaces of the slip rings. Generally speaking, the greater the axial preloading force applied to the slip rings, the better the sealing-off effect. However, this in turn leads to problems when starting the slip ring seal assembly from a stopped state, because very high torques are transmitted from the starting shaft via, for example, the slip ring support to the rotating slip ring. In the same way, due to the contact during stopping, very high torques also occur at the stationary slip ring when starting the slip ring seal assembly, and this stationary slip ring is held in a position-invariant manner by the stationary slip ring support or the housing. This problem also occurs in the case of slip ring seals for sealing off a medium, especially in high-pressure applications such as pump or agitator seals, because the slip rings additionally bear high pressure and are pressed against each other in the stopped state. For example, press-fitted pins are used to transmit torque between the slip ring support and the slip ring. However, this is not possible in the case of ceramic slip rings due to the brittleness of the slip ring material. A shrink fit connection is also known between the slip ring support and the slip ring, but this may introduce undesired high stresses into the slip ring, which may lead to cracks in the slip ring material and perhaps an undesired short service life of the slip ring. Especially in agitator seals, so-called stop seals usually have to be additionally used to ensure the sealing of the slip ring seal assembly when stopped. Summary of the Invention
[0003] Therefore, the object of the present invention is to provide a slip ring seal assembly which has a simple structure and can be manufactured in a simple and low-cost manner, and which enables an improvement in the torque transmission between the slip ring and the slip ring support in the case of a rotating slip ring and a stationary slip ring.
[0004] This object is achieved by a slip ring seal assembly having the features of the following technical solutions. The following technical solutions show preferred improvement schemes of the present invention.
[0005] In contrast, the slip ring seal assembly according to the present invention having the features of the following technical solutions has the following advantages, namely, the transmission of torque between the slip ring support portion and the slip ring or between the slip rings can be significantly improved. In particular, damage to the slip ring caused by excessive torque can be avoided. In addition, no additional stop seal is required. In addition, according to the present invention, a very protective torque introduction between the components for torque transmission can be achieved. In addition, the force introduction point K can be selectively selected, and in particular, the direction of the force and / or the strength of the introduced force can be defined.
[0006] This is achieved according to the present invention in such a way that the slip ring seal assembly includes a slip ring seal, which includes a rotating slip ring having a first sliding surface and a stationary slip ring having a second sliding surface, wherein a sealing gap is defined between the sliding surfaces. In addition, the slip ring seal assembly includes a torque device for introducing torque into at least one of the slip rings and / or for introducing torque from at least one of the slip rings. The torque device here has a plurality of transmission elements, which transmit torque between the slip ring support portion and the slip ring. The torque can be transmitted in both directions here, that is, from the slip ring support portion to the slip ring or from the slip ring to the slip ring support portion. The torque transmission is achieved in such a way that the total torque is distributed over a plurality of independent transmission elements. The slip ring support portion here has a first receiving opening, which has an arcuate cross-section in a cross-sectional view. The slip ring has a second receiving opening, which has an arcuate cross-section in a cross-sectional view. The first receiving opening and the second receiving opening are preferably semi-circular in a cross-sectional view. In addition, the transmission elements are simultaneously arranged in the first receiving opening and the second receiving opening and are in contact with the slip ring support portion and the slip ring. Here, an interference fit is not formed between the transmission elements and the first receiving opening and the second receiving opening. Since there are a plurality of transmission elements and all the transmission elements share the torque transmission, the corresponding magnitude of the transmitted torque is significantly reduced in a manner corresponding to the number of transmission elements in the case of the given maximum torque. The stress at the contact area of the torque device can also be reduced.
[0007] Particularly preferably, the transmission element is a rolling element which is configured to perform a rolling process (Abrollvorgang) between the slip ring support portion and the slip ring during torque transmission. The rolling process is relatively small during operation and is only performed via a small rotation angle, which is preferably less than 2°, particularly less than 1°.
[0008] The rolling elements are preferably cylindrical bodies. Further preferably, all the rolling elements are constructed in the same manner. The cylindrical bodies are arranged such that their cylindrical axes are parallel to the central axis of the slip ring seal. Thereby, a rolling motion in the circumferential direction of the slip ring can be achieved, which realizes a variant of the force introduction point K between the torque transmission members. By means of the rolling elements, in particular, the force introduction point can be moved away from the outer diameter of the slip ring and thus away from the weak edges at the receiving openings provided at the outer circumference of the slip ring. Thereby, possible stress concentrations can be avoided, which may lead to flaking of the material of the slip ring, especially in the region of the edges of the receiving openings. This is particularly advantageous when using ceramic slip rings.
[0009] Further preferably, the first radius R1 of the rolling element is smaller than the second radius R2 of the first receiving opening in the slip ring support and / or the first radius R1 of the rolling element is smaller than the third radius R3 of the second receiving opening in the slip ring. That is to say, in the contact points, the first radius R1 is always smaller than or equal to the second radius R2 and / or the third radius R3. Thereby, the force direction can be adjusted, which acts when transmitting the torque to the torque-receiving member. In particular, the force introduction point K can be moved away from the outer circumference of the slip ring, at which the edge of the second receiving opening is located. In addition, when starting from a stopped state of the slip ring seal assembly, it is feasible that, by selecting different radii of the rolling elements and the receiving openings, a transient sliding surface deformation occurs in the region between adjacent rolling elements during startup. This can be achieved especially under high pressure, and the medium to be sealed and isolated under pressure briefly flows into this sliding surface deformation and supports the lifting of the slip ring. Therefore, by selecting the force introduction point K, a certain waviness can be achieved specifically for the startup process of the slip ring seal assembly, especially at the sliding surface of the outer circumference of the slip ring, especially on the pressure-bearing side, which causes a retracted trough in the region of the rolling elements and a protruding bulge in the region between the rolling elements in the axial direction at the sliding surface, so that the medium can flow into the sealing gap briefly and support the lifting of the sliding surface during the startup process.
[0010] Preferably, the radius R2 of the second receiving opening is equal in size to the radius R3 of the third receiving opening.
[0011] Further preferably, in an alternative design of the present invention, the transmission element includes a first body and a second body, which are connected to each other by a connecting device. The first body has an arcuate first contact surface for contacting the first receiving opening in the slip ring support, and the second body has an arcuate second contact surface for contacting the second receiving opening in the slip ring.
[0012] Preferably, the connecting device between the first body and the second body includes one or more rods. Thereby, the first body and the second body are connected to each other only in some areas, so that the transmission element designed in this way has a certain elasticity. Particularly preferably, the rod and / or the first body and the second body are made of a material having an elasticity greater than that of the slip ring and the slip ring support. Further preferably, the connecting device includes a truss-shaped connecting portion that is rigid particularly in the radial direction.
[0013] The first body and / or the second body are preferably rod-shaped members, particularly having an elliptical cross-section. Alternatively, it is also feasible that the first body and the second body are configured as cylinders preferably having different diameters.
[0014] Further preferably, the first body and the second body have different cross-sectional shapes.
[0015] Further preferably, the first receiving opening and the second receiving opening are arranged in an N-sided polygon, where N is an integer. Particularly preferably, N = 6, and the positions for torque introduction are arranged in a circumferentially uniform distribution along the circumference of the slip ring. Preferably, the transmission of torque from and to the slip ring is achieved at the outer circumference of the slip ring.
[0016] Further preferably, torque devices for torque transmission are provided both at the rotating slip ring and the stationary slip ring. The torque devices at the rotating slip ring and the stationary slip ring preferably have the same geometric design.
[0017] Further preferably, the torque device is arranged at the first receiving portion and the second receiving portion such that the force introduction point K does not lie on the circumferential diameter (Manteldurchmesser) of the slip ring and the slip ring support.
[0018] The slip ring seal assembly preferably includes a ceramic slip ring, particularly made of SiC or WC. Description of the Drawings
[0019] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings:
[0020] Figure 1 A schematic cross-sectional view of a slip ring seal according to a first embodiment of the present invention is shown,
[0021] Figure 2 A schematic cross-sectional view along Figure 1 line II-II is shown,
[0022] Figure 3 A schematic cross-sectional view of a slip ring seal assembly having a torque device according to a second embodiment of the present invention is shown, and
[0023] Figure 4Shows a schematic cross-sectional view of a slip ring seal assembly according to a second embodiment. Detailed Description of the Invention
[0024] The following will refer to Figure 1 and Figure 2 to describe in detail a slip ring seal assembly 1 according to a first preferred embodiment of the present invention.
[0025] Figure 1 A cross-sectional view of a slip ring seal assembly 1 having a slip ring seal 2 is shown. The slip ring seal 2 includes a rotating slip ring 3 and a stationary slip ring 4. The rotating slip ring 3 has a first sliding surface 30 and the stationary slip ring 4 has a second sliding surface 40. A sealing gap 5 is defined between the two sliding surfaces 30, 40.
[0026] The slip ring seal assembly 1 seals and isolates the product area 11 from the atmosphere area 12 at the shaft 10.
[0027] The rotating slip ring 3 is connected by means of a first slip ring support 31, which is firmly connected to the shaft 10. The stationary slip ring 4 is connected to a stationary member, such as a second slip ring support 41 or a housing part.
[0028] To transfer the torque M1 from the first slip ring support 31 to the rotating slip ring 3, the slip ring seal assembly 1 includes a torque device 6. By means of the torque device 6, torque can be introduced into the rotating slip ring.
[0029] In addition, especially when starting the machine and thus when the shaft begins to rotate, a support torque M2 is obtained between the stationary slip ring 4 and the second slip ring support 41, which also has to be transferred between these two members by means of the torque device 6.
[0030] As can be seen in detail from Figure 1 and Figure 2 the torque device 6 between the rotating slip ring 3 and the first slip ring support 31. The torque device 6 includes a plurality of transmission elements 60, which are cylindrical rolling elements in the present embodiment. As can be seen from FIG. 6, there are a total of six rolling elements arranged between the rotating slip ring 3 and the first slip ring support 31 in a circumferentially uniform distribution.
[0031] The transmission elements 6 are configured to transfer torque between the first slip ring support 31 and the rotating slip ring 3. Here, the total torque M1 is distributed to a plurality of independent transmission elements 61 of the same size.
[0032] As can be seen from Figure 1 and Figure 2It can be further seen that a first receiving opening 61 is configured in the first slip ring support portion 31, and the first receiving opening has an arcuate cross-section in a cross-sectional view. A second receiving opening 62 is configured in the rotary slip ring 3, and the second receiving opening has an arcuate cross-section in a cross-sectional view. Therefore, the transmission element 60 is arranged in the first receiving opening 61 and the second receiving opening 62 here.
[0033] As can be seen from Figure 2 It can be further seen that the columnar transmission element 60 has a first radius R1, the first receiving opening 61 in the first slip ring support portion 31 has a second radius R2, and the second receiving opening 62 in the rotary slip ring 3 has a third radius R3. Here, the first radius R1 is smaller than the second radius R2 and smaller than the third radius R3. In addition, the second radius R2 and the third radius R3 are of equal size.
[0034] As can be seen from Figure 1 It can be seen that when the slip ring seal assembly is started from the stationary position, a rolling cutting motion of the transmission element 60 in the first receiving opening 61 and the second receiving opening 62 is obtained by selecting the three radii R1, R2, and R3. By selecting the sizes of the radii R1, R2, and R3, the force introduction point K can be defined here. Since the first radius R1 is smaller than the two radii R2 and R3, the force introduction point K located at a distance A from the edge of the second receiving opening 62 in the rotary slip ring 3 is obtained. Therefore, it can be prevented that the force F, especially during the starting process of the slip ring seal assembly, is located at the edge of the second receiving opening 62, so that spalling or crack formation at this sensitive area of the slip ring can be avoided. Therefore, the force introduction point K can be placed away from the outer circumference of the slip ring, and thus stress concentration that may cause spalling at the slip ring can be avoided.
[0035] The fact that the transmission element 60 is configured as a rolling element also ensures that a short rolling process of the transmission element 60 occurs from the stationary position during the starting process, so that the torque is introduced from the first slip ring support portion 31 onto the rotary slip ring 3 in a uniformly distributed and thus smooth manner.
[0036] In addition, by adjusting the force direction of the force F to be at an angle α with respect to the tangent T during the starting process due to the torque M1, an additional radial force can be provided at each first receiving opening 61. Thereby, a short-term torque-activated sliding surface deformation of the sliding surface 30 of the rotary slip ring can be provided specifically at the outer circumference of the rotary slip ring (drehmomentaktive ), resulting in a certain degree of waviness during the start-up process of the sliding surface 30. Thus, it can prompt the medium to penetrate into the sealing gap 5 from the product area 11 in the short term under high pressure, which, in addition to the starting torque, also helps the sliding surfaces to start from the stationary state relative to each other, so as to form the sealing gap 5 between the sliding surfaces 30 and 40 as quickly as possible. Since this process only occurs in a very short period, usually no medium passes through the formed sealing gap 5 from the pressure area 11 towards the atmosphere area 12. After overcoming the starting torque, the torque between the first slip ring support 31 and the rotating slip ring 3 immediately decreases, so that the sliding surface becomes smooth again immediately.
[0037] Since the same sliding surface deformation occurs at the second sliding surface 40 of the stationary slip ring 4 during the start-up process to overcome the starting torque, short-term waviness will appear at both sliding surfaces and disappear immediately after overcoming the starting torque. Therefore, this design of the slip ring seal assembly has great advantages especially when there is a very high pressure in the product area 11.
[0038] In addition, the transmission element 60 of the torque device 6 between the stationary slip ring 4 and the second slip ring support 41 at the stationary slip ring 4 has the same structure as that at the rotating slip ring. Here, the corresponding counter-torque M2 acts between the stationary slip ring 4 and the second slip ring support 41 during the start-up process because the rotating slip ring 3 in contact with the stationary slip ring 4 during the start-up process tries to rotate the stationary slip ring 4. Then, the stationary slip ring 4 is supported at the second slip ring support 41 via the transmission element 60, and a counter-torque M2 is generated at the stationary slip ring 4.
[0039] The number of the transmission elements 60 at the rotating slip ring 3 and the stationary slip ring 4 is preferably equal.
[0040] The present invention provides a solution that occurs especially at the moment of the start of rotation, especially at the moment of starting the machine, in the slip ring seal. In particular, the present invention enables ceramic slip rings to be used as rotating slip rings and stationary slip rings in an unrestricted manner. In the prior art, to date, considerable efforts have been made through shrinkage valve seats, hubs or slip ring materials with low brittleness to alleviate this dangerous situation when starting the slip ring seal. In addition, the slip ring seal of the present invention can also achieve the following design of the slip ring seal assembly, that is, when the slip ring seal stops, there is no critical operating state with residual leakage defined by the minimum gap between the slip rings, so as to keep the starting torque as small as possible.
[0041] Furthermore, the present invention enables the use of ceramic materials for stationary slip rings and rotating slip rings without a coating, because the starting torque of the slip ring sealing assembly according to the present invention can be significantly reduced. In the prior art, a diamond coating is usually used to achieve the service life of the slip ring under frequent start-stop conditions with a relatively high torque during startup. The present invention makes it possible to dispense with such an expensive diamond coating and the like.
[0042] Therefore, the slip ring seal 1 can significantly reduce the starting torque of the slip ring seal 2 during the starting process. The cylindrical transmission element 60 is preferably made of metal here, and the rotating slip ring 3 and the stationary slip ring 4 are made of ceramic material, especially SiC.
[0043] Figure 3 and Figure 4 shows a slip ring sealing assembly 1 according to a second embodiment of the present invention. Identical or functionally identical components are labeled with the same reference numerals as in the first embodiment.
[0044] The second embodiment basically corresponds to the first embodiment, wherein the difference between the second embodiment and the first embodiment is that the transmission element 70 is constructed in a different way. In the second embodiment, the transmission element 70 is constructed such that the transmission element 70 has a first body 71 and a second body 72 and a connecting device 73. The first body 71 has a curved first contact surface 71a for contacting a first receiving opening 61 in the first slip ring support portion 31. The second body 72 has a second arcuate contact surface 72a for contacting a second receiving opening 62 in the rotating slip ring 3.
[0045] As can be seen from Figure 3 , the first body 71 has a smaller cross-section than the second body 72. Here, the first body 71 has an elliptical cross-section, and the second body 72 also has an elliptical cross-section. The connecting device 73 includes a plurality of rods (see Figure 4 ), which establish a connection between the first body 71 and the second body 72. The rods of the connecting device 73 have a greater elasticity than the first body 71 and the second body 72. Thereby, a smooth torque introduction from the first slip ring support portion 31 to the rotating slip ring 3 is achieved during the starting process of the slip ring sealing assembly. The first body 71 and the second body 72 are rod-shaped members that extend along the axial direction X-X of the slip ring seal. The connecting device 73 having a plurality of rods extends in the radial direction of the slip ring sealing assembly.
[0046] As can be further seen from Figure 3It can be seen that the radius R2 of the first receiving opening 61 is smaller than the radius R3 of the second receiving opening 62. The cross-sections of the elliptical first body 71 and second body 72 are adapted to the radii R2 and R3 here. Therefore, during the startup process, a rolling process between the contact surfaces of the receiving openings 61, 62 and the first body 71 and second body 72 is achieved via a small rotation angle (preferably less than 5°). As in the first embodiment, a plurality of transmission elements 70 are arranged along the circumference of the rotary slip ring 3, and they are preferably all constructed in the same manner. Such transmission elements 70 can of course also be arranged in the same manner between the stationary slip ring 4 and the second slip ring support portion 41. In other respects, this embodiment corresponds to the first embodiment, so the description given there can be referred to.
[0047] Description of Reference Numerals
[0048] 1 Slip Ring Seal Assembly
[0049] 2 Slip Ring Seal
[0050] 3 Rotary Slip Ring
[0051] 4 Stationary Slip Ring
[0052] 5 Sealing Gap
[0053] 6 Torque Device
[0054] 10 Shaft
[0055] 11 Product Area
[0056] 12 Atmosphere Area
[0057] 30 Sliding Surface
[0058] 31 First Slip Ring Support Portion
[0059] 40 Sliding Surface
[0060] 41 Second Slip Ring Support Portion
[0061] 60 Transmission Element / Roller
[0062] 61 First Receiving Opening in Slip Ring Support Portion
[0063] 62 Second Receiving Opening in Slip Ring
[0064] 70 Transmission Element
[0065] 71 First Body
[0066] 71a First Contact Surface
[0067] 72 Second Body
[0068] 72a Second Contact Surface
[0069] 73 Connecting device / rod
[0070] A Distance
[0071] F Force
[0072] K Force introduction point
[0073] M1 Torque at the rotating slip ring
[0074] M2 Reaction torque at the stationary slip ring
[0075] R1 First radius of the rolling element
[0076] R2 Second radius of the first receiving opening
[0077] R3 Third radius of the second receiving opening
[0078] T Tangent
[0079] α Angle
Claims
1. A slip ring seal assembly, comprising: - a slip ring seal (2), the slip ring seal comprising a rotating slip ring (3) having a first sliding surface (30) and a stationary slip ring (4) having a second sliding surface (40), wherein a sealing gap (5) is defined between the sliding surfaces (30, 40), - a torque device (6) for transmitting torque between one of the slip rings and slip ring supports (31, 41), - wherein the torque device (6) has a plurality of transmission elements (60, 70), the transmission elements being configured to transmit torque between the slip ring supports (31, 41) and the slip rings in such a way that the total torque is distributed over the plurality of transmission elements (60, 70), - wherein the slip ring supports (31, 41) have a first receiving opening (61) which has an arcuate cross-section in a sectional view, and the slip rings have a second receiving opening (62) which has an arcuate cross-section in a sectional view, and - wherein the transmission elements (60, 70) are arranged in the first receiving opening (61) and the second receiving opening (62).
2. The slip ring seal assembly according to claim 1, wherein the transmission element (60) is a rolling body which is configured to perform a rolling process between the slip ring support (31, 41) and the slip ring during torque transmission.
3. The slip ring seal assembly according to claim 2, wherein the rolling body is a cylinder.
4. The slip ring seal assembly according to claim 2 or 3, wherein a first radius R1 of the cylinder is smaller than a second radius R2 of the first receiving opening (61) in the slip ring support and / or wherein the first radius R1 of the cylinder is smaller than a third radius R3 of the second receiving opening (62) in the slip ring.
5. The slip ring seal assembly according to claim 4, wherein the second radius R2 and the third radius R3 are of equal size.
6. The slip ring seal assembly according to claim 1, wherein the transmission element (70) comprises a first body (71), a second body (72) and a connecting device (73) which connects the first body (71) to the second body (72), wherein the first body (71) has an arcuate first contact surface for contacting the first receiving opening (61) in the slip ring support (31, 41), and the second body (72) has an arcuate second contact surface for contacting the second receiving opening (62) in the slip ring.
7. The slip ring seal assembly according to claim 6, wherein the connecting device comprises one or more rods (73) extending substantially in a radial direction and / or a truss-like connecting part.
8. The slip ring seal assembly according to claim 6 or 7, wherein the connecting device has a greater elasticity than the first body (71) and the second body (72).
9. The slip ring sealing assembly according to any one of claims 6 to 8, wherein the first body (71) and / or the second body (72) is a rod-shaped member having an elliptical cross-section.
10. The slip ring sealing assembly according to any one of the preceding claims, wherein torque devices (6) are arranged at the rotating slip ring (3) and the stationary slip ring (4) for transferring torque from the slip rings to the slip ring supports (31, 41).
11. The slip ring sealing assembly according to any one of the preceding claims, wherein the torque devices (6) are arranged in the first receiving opening (61) and the second receiving opening (62) such that the force introduction point K is at a distance A from the edges of the first receiving opening (61) and the second receiving opening (62).
12. The slip ring sealing assembly according to any one of the preceding claims, wherein the rotating slip ring (3) and / or the stationary slip ring (4) is made of ceramic material and / or wherein the rotating slip ring and the stationary slip ring (4) do not have a coating at the sliding surfaces (30, 40).
13. The slip ring sealing assembly according to any one of the preceding claims, - wherein there is a line contact between the transmission elements (60, 70) and the first receiving opening (61) and the second receiving opening (62).