Connection structure and engine
By using zirconia ceramic bolts and nuts and alumina ceramic gaskets, the problem of poor sealing between flanges under high temperature conditions was solved, achieving a low-cost, high-strength sealing connection and improving the sealing performance and connection strength of the flange assembly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-07-21
AI Technical Summary
The sealing effect between flanges is not good under high temperature conditions. Existing high temperature alloy bolts are expensive and will experience stress relaxation over time, resulting in a decrease in sealing effect.
Zirconia ceramic parts are used as connectors and fasteners, designed as bolts and nuts, combined with alumina ceramic gaskets to achieve a fixed connection of the flange. The sealing performance and connection strength are improved by matching the coefficient of thermal expansion and dimensional design.
It reduces costs, improves the sealing performance and connection strength of flange assemblies, avoids fastening failure caused by thermal decay of alloy materials, and enhances the sealing effect in high-temperature environments.
Smart Images
Figure CN224533746U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of engine technology, specifically relating to a connection structure and an engine. Background Technology
[0002] Some components of engineering equipment, such as burners and heat exchangers, are prone to high-temperature environments (above 800°C). In order to ensure system efficiency, flange cooling measures are not designed, which poses a severe challenge to the sealing of high-temperature gas between flanges. The common fastening solution between flanges is to connect them with high-temperature alloy bolts and seal the flanges. However, alloy bolts are expensive and will experience stress relaxation and loss of fastening effect over time, thereby reducing the sealing effect between flanges. Utility Model Content
[0003] The purpose of this invention is to at least solve the problem of poor fastening performance of existing alloy bolts in high-temperature environments. This purpose is achieved through the following technical solution:
[0004] The first aspect of this utility model provides a connection structure, comprising:
[0005] A flange assembly includes a first flange and a second flange. The first flange is disposed on one side of the second flange. The first flange has a first connecting hole along its own axial direction, and the second flange has a second connecting hole along its own axial direction. The first connecting hole and the second connecting hole are coaxially arranged and connected.
[0006] A connecting assembly includes a connector and a fastener. One end of the connector is sequentially provided with a first connecting hole and a second connecting hole. The fastener is engaged with the other end of the connector to connect and secure the first flange and the second flange. Both the connector and the fastener are zirconia ceramic parts.
[0007] By using the connection structure in this technical solution, the connector can pass through the first connection hole and the second connection hole and be connected with the fastener, thereby realizing the fixation between the first flange and the second flange. Since the bolts and nuts are all zirconia ceramic parts, the cost is low, and they have higher strength and better creep resistance. Compared with existing high temperature alloy bolts, the problem of fastening connection failure caused by thermal decay of alloy materials is avoided, while improving the sealing performance and connection strength of the flange assembly.
[0008] In addition, the connection structure of this utility model may also have the following additional technical features:
[0009] In some embodiments of this utility model, the connector includes a bolt, the fastener includes a nut, and the connection structure further includes a first washer, which is sleeved on the outer periphery of the bolt thread and located between the head of the bolt and the first flange.
[0010] In some embodiments of this utility model, the connecting structure further includes a second washer, which is sleeved on the outer periphery of the bolt thread and located between the nut and the second flange.
[0011] In some embodiments of this utility model, the first gasket and / or the second gasket are alumina ceramic parts.
[0012] In some embodiments of this utility model, the thermal expansion coefficients of the first flange and the second flange are both α1, the thermal expansion coefficients of the bolt and the nut are both α2, and the thermal expansion coefficients of the first washer and the second washer are both α3, wherein α1 > α2 > α3.
[0013] In some embodiments of this utility model, the first flange (11) has a dimension d1 along its own axial direction, the second flange has a dimension d2 along its own axial direction, the first gasket has a dimension d3 along its own axial direction, and the second gasket has a dimension d4 along its own axial direction, wherein (d1+d2)*α1+(d3+d4)*α3=(d1+d2+d3+d4)*α2.
[0014] In some embodiments of this utility model, both the first flange and the second flange are stainless steel parts.
[0015] In some embodiments of this utility model, the connection structure further includes an annular sealing gasket, which is disposed between the first flange and the second flange, and the opposite sides of the annular sealing gasket along its own axial direction abut against the first flange and the second flange respectively.
[0016] In some embodiments of this utility model, the flange assembly has a through hole, the through hole is coaxially arranged with the flange assembly, and the through hole penetrates the first flange and the second flange;
[0017] The flange assembly has multiple first connecting holes and multiple second connecting holes, which are connected in a one-to-one manner. The multiple first connecting holes and multiple second connecting holes are respectively arranged at intervals along the circumference of the flange assembly, and are also arranged at intervals from the through hole along the radial direction of the flange assembly.
[0018] The second aspect of this utility model provides an engine having the above-described connection structure. Attached Figure Description
[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0020] Figure 1 A schematic diagram of the connection structure according to an embodiment of the present invention is shown.
[0021] Figure 2 for Figure 1 A cross-sectional schematic diagram of the central connecting structure;
[0022] Figure 3 The diagram schematically illustrates the thermal decay curves of the connection structure according to the present invention and the alloy bolts in the prior art.
[0023] The labels in the attached diagram are as follows:
[0024] 11. First flange; 111. First annular groove; 12. Second flange; 13. Through hole;
[0025] 21. Bolt; 211. Head; 212. Connecting part; 22. Nut;
[0026] 30. First washer ring;
[0027] 40. Second washer ring;
[0028] 50. Annular sealing gasket. Detailed Implementation
[0029] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0030] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.
[0031] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.
[0032] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.
[0033] In engineering projects, some burners, heat exchangers, and other components are prone to high-temperature environments (above 800℃). To ensure system efficiency, certain specialized equipment does not have flange cooling measures. This poses a severe challenge to high-temperature gas sealing. Two common fastening solutions are welding and high-temperature alloy bolt sealing. One solution involves directly welding the flanges at both ends. This method offers good sealing performance and high reliability, but it prevents disassembly, increasing component manufacturing and maintenance costs. The other solution is high-temperature alloy (nickel-based) bolt fastening. While this method maintains flexibility in assembly and disassembly, it cannot address the issue of high-temperature stress relaxation in the bolts, leading to a gradual loss of sealing capability between the flanges over time. Furthermore, larger flanges require more bolts and gaskets, increasing costs and hindering structural assembly and disassembly.
[0034] Figure 1 A schematic diagram of the connection structure according to an embodiment of the present invention is shown. Figure 2 for Figure 1 A cross-sectional structural diagram of the connecting structure. (See diagram below.) Figure 1 and 2 As shown, this utility model proposes a connection structure and an engine. The connection structure of this utility model includes a flange assembly and a connecting assembly. The flange assembly includes a first flange 11 and a second flange 12. The first flange 11 is disposed on one side of the second flange 12. The first flange 11 has a first connecting hole along its own axial direction, and the second flange 12 has a second connecting hole along its own axial direction. The first connecting hole and the second connecting hole are coaxially arranged. The connecting assembly includes a bolt 21 and a nut 22. One end of the bolt 21 passes through the first connecting hole and the second connecting hole in sequence and is connected to the nut 22 to fix the first flange 11 and the second flange 12. Both the bolt 21 and the nut 22 are zirconia ceramic parts.
[0035] By using the connection structure in this technical solution, the bolt 21 can pass through the first connection hole and the second connection hole and be connected with the nut 22, thereby achieving the fixation between the first flange 11 and the second flange 12. Since both the bolt 21 and the nut 22 are zirconia ceramic parts, the cost is low, and they have higher strength and better creep resistance. Compared with the existing high-temperature alloy bolt 21, the problem of fastening connection failure caused by the thermal decay of alloy materials is avoided, while improving the sealing performance and connection strength of the flange assembly.
[0036] Specifically, in this embodiment, the outer surface of one end of the bolt 21 has an external thread structure, and the inner surface of the nut 22 has an internal thread structure. Through the threaded engagement of the external thread structure and the internal thread structure, the bolt 21 and the nut 22 can be fastened, thereby achieving the fastening between the first flange 11 and the second flange 12, and ensuring the connection between the first flange 11 and the second flange 12.
[0037] Specifically, in this embodiment, the first flange 11 is connected to the first pipe body on the side opposite to the second flange 12, and the second flange 12 is connected to the second pipe body on the side opposite to the first flange 11. The first pipe body and the second pipe body are connected through the first flange 11 and the second flange 12, thereby enabling gas communication between the first pipe body and the second pipe body. In this embodiment, the bolts 21 and nuts 22 made of zirconia ceramic are used. Compared with nickel-based alloy (or high-temperature alloy) bolts 21, they have higher strength, higher operating temperature, better creep resistance, and better batch cost. They also avoid the problem of fastening connection failure caused by thermal decay of alloy materials, thereby improving the sealing performance when high-temperature gas flows between the first pipe body and the second pipe body.
[0038] Furthermore, in other embodiments of this utility model, the connecting assembly further includes a double-ended stud and two nuts 22. The outer surfaces of both ends of the double-ended stud are respectively provided with external threads. The double-ended stud passes through the first connecting hole and the second connecting hole. The external thread on the outer surface of one end of the double-ended stud is connected to the internal thread of one nut 22, and the external thread on the outer surface of the other end of the double-ended stud is connected to the internal thread of the other nut 22. This also enables the connecting assembly to fix the first flange 11 and the second flange 12.
[0039] In some embodiments of this utility model, such as Figure 2 As shown, the bolt 21 includes a connected head 211 and a connecting portion 212. The head 211 is located on the side of the first flange 11 opposite to the second flange 12. The end of the connecting portion 212 opposite to the head 211 passes through a first connecting hole and a second connecting hole in sequence, and is connected to the nut 22. The connection structure also includes a first washer 30, which is sleeved on the connecting portion 212, and the opposite sides of the first washer 30 abut against the head 211 and the first flange 11 respectively along its own axial direction. In this embodiment, a first washer 30 is provided between the head 211 and the first flange 11. The first washer 30 can fill the gap at the connection between the head 211 of the bolt 21 and the first flange 11, preventing gas leakage between the first flange 11 and the second flange 12, and improving the sealing performance.
[0040] In some embodiments of this utility model, such as Figure 2 As shown, the connection structure also includes a second washer 40, which is sleeved on the outside of the connecting portion 212, and the two opposite sides of the second washer 40 abut against the nut 22 and the second flange 12 respectively along its own axial direction. In this embodiment, the second washer 40 is provided between the nut 22 and the second flange 12. The second washer 40 can fill the gap at the connection between the nut 22 and the second flange 12, preventing gas leakage between the first flange 11 and the second flange 12, and further improving the sealing performance.
[0041] In some embodiments of this utility model, the first gasket 30 and the second gasket 40 are both alumina ceramic parts. In this embodiment, the gasket material is alumina ceramic. By adding the first gasket 30 and the second gasket 40, the sealing force is transferred to the flange assembly by the first gasket 30 and the second gasket 40 respectively. At this time, the compressive stress is dispersed, the force on the flange assembly is reduced, the creep deformation of the flange assembly is reduced, and the material requirements of the flange assembly can be further reduced.
[0042] In some embodiments of this utility model, the coefficients of thermal expansion of the first flange 11 and the second flange 12 are both α1, the coefficients of thermal expansion of the bolt 21 and the nut 22 are α2, and the coefficients of thermal expansion of the first gasket 30 and the second gasket 40 are both α3, wherein α1 > α2 > α3. In this embodiment, the above arrangement can achieve thermal expansion matching of the first flange 11, the second flange 12, the bolt 21, the nut 22, the first gasket 30, and the second gasket 40 at high temperatures, ensuring the sealing effect between the flange assemblies.
[0043] In some embodiments of this utility model, the first flange 11 has an axial dimension of d1, the second flange 12 has an axial dimension of d2, the first gasket 30 has an axial dimension of d3, and the second gasket 40 has an axial dimension of d4, wherein (d1+d2)*α1+(d3+d4)*α3=(d1+d2+d3+d4)*α2. In this embodiment, the thermal expansion coefficients of ceramics and metals differ significantly. Through the above-mentioned design of dimensions and thermal expansion coefficients, thermal expansion matching at high temperatures can be achieved, ensuring a seal.
[0044] In some embodiments of this utility model, both the first flange 11 and the second flange 12 are made of stainless steel. In this embodiment, the stainless steel flanges described above can maintain stable performance under high-temperature conditions, meeting the requirements of the operating conditions.
[0045] In some embodiments of this utility model, such as Figure 2 As shown, the connection structure also includes an annular sealing gasket 50, which is disposed between the first flange 11 and the second flange 12. The annular sealing gasket 50 abuts against the first flange 11 and the second flange 12 on opposite sides along its own axial direction. In this embodiment, a first annular groove 111 is provided on the side of the first flange 11 facing the second flange 12. At least a portion of the annular sealing gasket 50 is disposed within the first annular groove 111, and the opposite sides of the annular sealing gasket 50 abut against the bottom surface of the first annular groove 111 and the second flange 12, respectively. This seals the high-temperature gas between the first flange 11 and the second flange 12, further improving the sealing performance.
[0046] Specifically, in other embodiments of this utility model, a second annular groove is provided on the side of the second flange 12 facing the first flange 11, at least a portion of the annular sealing gasket 50 is disposed in the second annular groove, and the opposite sides of the annular sealing gasket 50 abut against the bottom surface of the second annular groove and the first flange 11, respectively.
[0047] Specifically, in other embodiments of this utility model, a third annular groove is provided on the side of the first flange 11 facing the second flange 12, and a fourth annular groove is provided on the side of the second flange 12 facing the first flange 11. The annular sealing gasket 50 is respectively disposed in the third annular groove and the fourth annular groove, and the opposite sides of the annular sealing gasket 50 abut against the bottom surface of the third annular groove and the bottom surface of the fourth annular groove, respectively.
[0048] In some embodiments of this utility model, such as Figure 1 As shown, the flange assembly has a through hole 13, which penetrates the first flange 11 and the second flange 12. The through hole 13 is spaced apart from and parallel to the first connecting hole. In this embodiment, the through hole 13 is connected to the first pipe body (which may be a part of the burner) and the second pipe body (which may be a part of the heat exchanger), thereby realizing the connection between the first pipe body and the second pipe body.
[0049] Furthermore, the connection structure in this embodiment has been verified through simulation, with the axial force variation curve of M10 bolt 21 at 800℃ as shown in the figure. Figure 3 As shown in the figure (the horizontal axis represents time, and the vertical axis represents the axial tensile stress of bolt 21), it can be seen that under high temperature conditions, the axial tensile stress of bolt 21 of GH4141 decreases rapidly over time. After 80,000 hours, the axial tensile stress has decreased to about 5 MPa, which is much lower than the axial tensile stress of 550 MPa of zirconia ceramic bolt 21 at this time.
[0050] Furthermore, the bolts 21 of the zirconia ceramic component in the connection structure of this invention have significantly different coefficients of thermal expansion compared to existing alloy bolts 21. Through reasonable dimensional design, thermal expansion matching at high temperatures can be achieved, ensuring a tight seal. Secondly, the stress relaxation resistance and high-temperature strength of zirconia ceramics are far superior to those of alloy metals, preventing seal failure due to material thermal decay. Simultaneously, the use of alumina ceramic first gasket 30 and second gasket 40 indirectly applies compressive stress, dispersing the compressive stress on the flange assembly and solving the surface creep problem of the flange assembly. In addition, the batch cost of zirconia ceramics and alumina ceramics is far lower than that of high-temperature metals such as nickel-based alloys.
[0051] This utility model also proposes an engine having the above-described connection structure.
[0052] By using the connection structure in this technical solution, the bolt 21 can pass through the first connection hole and the second connection hole and be connected with the nut 22, thereby achieving the fixation between the first flange 11 and the second flange 12. Since both the bolt 21 and the nut 22 are zirconia ceramic parts, the cost is low, and they have higher strength and better creep resistance. Compared with the existing high-temperature alloy bolt 21, the problem of fastening connection failure caused by the thermal decay of alloy materials is avoided, while improving the sealing performance and connection strength of the flange assembly.
[0053] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A connection structure, characterized in that, include: A flange assembly includes a first flange and a second flange. The first flange is disposed on one side of the second flange. The first flange has a first connecting hole along its own axial direction, and the second flange has a second connecting hole along its own axial direction. The first connecting hole and the second connecting hole are coaxially arranged and connected. A connecting assembly includes a connector and a fastener. One end of the connector is sequentially provided with a first connecting hole and a second connecting hole. The fastener is engaged with the other end of the connector to connect and secure the first flange and the second flange. Both the connector and the fastener are zirconia ceramic parts.
2. The connection structure according to claim 1, characterized in that, The connector includes a bolt, the fastener includes a nut, and the connection structure further includes a first washer, which is sleeved on the outer periphery of the bolt thread and located between the bolt head and the first flange.
3. The connection structure according to claim 2, characterized in that, The connection structure further includes a second washer, which is sleeved on the outer periphery of the bolt thread and located between the nut and the second flange.
4. The connection structure according to claim 3, characterized in that, The first gasket and / or the second gasket are alumina ceramic parts.
5. The connection structure according to claim 3, characterized in that, The coefficient of thermal expansion of the first flange and the second flange is α1, the coefficient of thermal expansion of the bolt and the nut is α2, and the coefficient of thermal expansion of the first washer and the second washer is α3, wherein α1 > α2 > α3.
6. The connection structure according to claim 5, characterized in that, The first flange has a dimension d1 along its own axis, the second flange has a dimension d2 along its own axis, the first gasket has a dimension d3 along its own axis, and the second gasket has a dimension d4 along its own axis, wherein (d1+d2)*α1+(d3+d4)*α3=(d1+d2+d3+d4)*α2.
7. The connection structure according to any one of claims 1-6, characterized in that, Both the first flange and the second flange are made of stainless steel.
8. The connection structure according to any one of claims 1-6, characterized in that, The connection structure further includes an annular sealing gasket, which is disposed between the first flange and the second flange, and the annular sealing gasket abuts against the first flange and the second flange on opposite sides along its own axial direction.
9. The connection structure according to any one of claims 1-6, characterized in that, The flange assembly has a through hole, which is coaxially arranged with the flange assembly and passes through the first flange and the second flange; The flange assembly has multiple first connecting holes and multiple second connecting holes, which are connected in a one-to-one manner. The multiple first connecting holes and multiple second connecting holes are respectively arranged at intervals along the circumference of the flange assembly, and are also arranged at intervals from the through hole along the radial direction of the flange assembly.
10. An engine, characterized in that, It has a connection structure according to any one of claims 1-9.