Sealed structure

Abstract

The embodiment of the present application provides a sealing structure. The sealing structure includes: a first member, a sealing head and a sealing ring; the first member is cylindrical, and the end of the first member includes an inner side surface, a connecting surface and a first end surface connected in sequence; the connecting surface is arranged around the central axis of the first member and is at a designed angle with the central axis of the first member, and the designed angle is greater than 0 degrees and less than 90 degrees; the sealing head includes a cylindrical main body and a first extension portion arranged on the outer side of the main body; the main body includes a connecting portion located on one side of the first extension portion and configured to extend into the first member; the first extension portion is configured to abut against the first end surface, and the portion of the connecting portion away from the first extension portion is configured to abut against the inner side surface. The sealing ring is configured to be sandwiched between the connecting surface and the portion of the connecting portion close to the first extension portion. The sealing structure provided by the embodiment of the present application can facilitate both manual docking and manual removal.

Description

Technical Field

[0001] The present application relates to the field of liquid rocket technology, and more specifically, to a sealing structure. Background Art

[0002] The fuel of liquid rockets is kerosene, which is a propellant at room temperature and is stable. Therefore, the fuel of liquid rockets can usually be filled and removed in advance. During the refueling process, the fuel tank is docked with the fixed end of the liquid rocket. Generally, a sealing ring (such as an O-ring) is used to seal the docking surface to form a sealing structure, and manual docking and manual removal are used.

[0003] At present, the sealing structure is usually end face sealing or radial sealing. Among them, end face sealing is difficult to achieve manual docking, and the sealing ring is easy to fall off. The radial seal requires a large pull-out force and is difficult to achieve manual pull-out. Summary of the invention

[0004] In view of the shortcomings of the related art, the present application proposes a sealing structure to solve the technical problems of the related art that it is difficult to manually connect and disconnect.

[0005] In a first aspect, an embodiment of the present application provides a sealing structure, including:

[0006] The first member is cylindrical, and the end of the first member includes an inner side surface, a connecting surface and a first end surface which are connected in sequence; the connecting surface is arranged around the central axis of the first member and forms a design angle with the central axis of the first member, and the design angle is greater than 0 degrees and less than 90 degrees;

[0007] A sealing head, comprising a cylindrical main body and a first extension portion arranged outside the main body; the main body comprises a connecting portion located on one side of the first extension portion and configured to extend into the first member; the first extension portion is configured to abut against the first end surface, and a portion of the connecting portion away from the first extension portion is configured to abut against the inner side surface;

[0008] The sealing ring is configured to be sandwiched between the connecting surface and a portion of the connecting portion close to the first extending portion.

[0009] In a possible implementation, a groove is provided on the outer side of the connecting portion and close to the first extending portion, and the sealing ring is partially provided in the groove;

[0010] In the connected state, the connecting portion is located inside the first component, and the sealing ring abuts against the connecting surface.

[0011] In a possible implementation, the connecting surface extends from the inner side surface to the first end surface in a direction away from the center axis of the first component.

[0012] In a possible implementation manner, the connecting surface is a conical surface arranged around the central axis of the first component.

[0013] In a possible implementation, the design angle is greater than 0 degrees and less than 45 degrees.

[0014] In a possible implementation, the cross section of the sealing ring in a free state is rectangular;

[0015] Alternatively, the cross section of the sealing ring in a free state is a right-angled trapezoid.

[0016] In a possible implementation, the sealing structure further includes a second extension portion that bends and extends from the first extension portion away from one side of the main body portion, and a receiving space is formed between the second extension portion and the connecting portion;

[0017] In the connected state, the first component portion is located in the accommodating space.

[0018] In a possible implementation, the sealing structure further includes a cylindrical shell, wherein the shell includes a first inner wall surface, a first connecting surface, a second inner wall surface, a second connecting surface, and a third inner wall surface which are sequentially connected and formed into a step shape;

[0019] The sealing structure further comprises at least one of the following:

[0020] The first inner wall surface is located outside the first member and the second extension portion;

[0021] The main body also includes a second portion located at the other side of the first extension portion, and the second inner wall surface is located outside the second portion;

[0022] The sealing structure further includes an elastic member, and the elastic member is sandwiched between the second connecting surface and the second portion.

[0023] In a possible implementation, the first component includes a first outer wall surface and a second outer wall surface in a stepped shape;

[0024] The first inner wall surface is located outside the second extending portion and abuts against the second outer wall surface; the inner wall of the second extending portion abuts against the first outer wall surface.

[0025] In a possible implementation, the first component further includes a second end surface connected to the inner side surface, and the connecting portion is located in a recess formed by the inner side surface and the second end surface.

[0026] The beneficial technical effects brought about by the technical solution provided by the embodiment of the present application include:

[0027] Since the sealing ring is arranged on the connecting surface between the inner side surface of the first component and the first end surface, a sealing structure between the end surface sealing and the radial sealing is formed. Compared with the end surface sealing structure, the inclined connecting surface can amplify the smaller axial force into a larger normal force. The normal force provides a sealing pressure ratio, that is, a larger sealing pressure ratio can be achieved with a smaller axial force. The smaller axial force is conducive to manual docking, and the sealing ring is not easy to fall off after being pulled out. Compared with the radial sealing structure, the internal and external pressure difference of the sealing structure is on the connecting surface between the inner side surface and the first end surface. The pulling out is not affected by the internal and external pressure difference, and there is no risk of jamming during the pulling out, which is conducive to manual pulling out. In summary, the sealing structure provided in the embodiment of the present application can facilitate both manual docking and manual pulling out.

[0028] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0030] Figure 1 A cross-sectional schematic diagram of a sealing structure provided in an embodiment of the present application;

[0031] Figure 2 An exploded view of a sealing structure provided in an embodiment of the present application;

[0032] Figure 3 A cross-sectional schematic diagram of a first component in a sealing structure provided in an embodiment of the present application;

[0033] Figure 4 A schematic cross-sectional view of a sealing head in a sealing structure provided in an embodiment of the present application;

[0034] Figure 5 A schematic cross-sectional view of a housing in a sealing structure provided in an embodiment of the present application;

[0035] Figure 6 A force diagram of a connection surface of a sealing structure provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 100-sealing structure;

[0038] 11- first component;

[0039] 111 - inner side surface; 112 - connection surface; 113 - first end surface; 114 - second end surface; 115 - first outer wall surface; 116 - second outer wall surface;

[0040] 12-sealing head;

[0041] 121-main body; 121a-connecting part; 121b-second part;

[0042] 122- first extension portion;

[0043] 123- second extension;

[0044] 13- sealing ring;

[0045] 14- housing;

[0046] 141 - first inner wall surface; 142 - first connecting surface; 143 - second inner wall surface; 144 - second connecting surface; 145 - third inner wall surface;

[0047] 15- elastic member;

[0048] 20-Grooves. DETAILED DESCRIPTION

[0049] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0050] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the implementation of other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the technical field. The term "and / or" used herein refers to at least one of the items defined by the term, for example, "A and / or B" may be implemented as "A", or as "B", or as "A and B".

[0051] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0052] During the refueling process, the fuel tank is docked with the fixed end of the liquid rocket. Generally, a sealing ring (such as an O-ring) is used on the docking surface to form a sealing structure, and manual docking and manual removal are used.

[0053] At present, the sealing structure is usually end face sealing or radial sealing. Among them, end face sealing requires a large axial force to achieve the sealing pressure ratio. The large axial force leads to a large docking force, which is difficult to achieve manual docking, and the sealing ring is easy to fall off. During the removal process of radial sealing, there is a large pressure difference between the inside and outside of the sealing ring, and the required removal force is large, which is difficult to achieve manual removal.

[0054] The sealing structure provided in this application is intended to solve the above technical problems in related technologies.

[0055] The following is a detailed description of the technical solution of the present application and how the technical solution of the present application solves the above technical problems with specific embodiments. It should be noted that the following implementations can refer to, draw on or combine with each other, and the same terms, similar features and similar implementation steps in different implementations will not be described repeatedly.

[0056] The present application embodiment provides a sealing structure 100, such as Figures 1 to 5 As shown, it includes: a first component 11, a sealing head 12 and a sealing ring 13.

[0057] The first component 11 is cylindrical, and the end of the first component 11 includes an inner side surface 111, a connecting surface 112 and a first end surface 113 connected in sequence; the connecting surface 112 is arranged around the central axis OO' of the first component 11 and forms a design angle α with the central axis OO' of the first component 11, and the design angle α is greater than 0 degree and less than 90 degrees.

[0058] The sealing head 12 includes a cylindrical main body 121 and a first extension portion 122 arranged on the outside of the main body 121; the main body 121 includes a connecting portion 121a located on one side of the first extension portion 122 and configured to extend into the first component 11; the first extension portion 122 is configured to abut against the first end face 113, and the portion of the connecting portion 121a away from the first extension portion 122 is configured to abut against the inner side surface 111.

[0059] The sealing ring 13 is configured to be sandwiched between the connecting surface 112 and a portion of the connecting portion 121 a close to the first extending portion 122 .

[0060] Since the sealing ring 13 provided in the embodiment of the present application is arranged on the connecting surface 112 between the inner side surface 111 and the first end surface 113 of the first component 11, a sealing structure 100 between the end face seal and the radial seal is formed. Compared with the end face seal structure 100, the inclined connecting surface 112 can amplify the smaller axial force into a larger normal force, and the normal force provides a sealing pressure ratio, that is, a larger sealing pressure ratio can be achieved with a smaller axial force, and the smaller axial force is conducive to manual docking, and the sealing ring 13 is not easy to fall off after being pulled out; compared with the radial sealing structure 100, the internal and external pressure difference of the sealing structure 100 is on the connecting surface 112 between the inner side surface 111 and the first end surface 113, and the pulling out is not affected by the internal and external pressure difference, and there is no risk of jamming during pulling out, which is conducive to manual pulling out. In short, the sealing structure 100 provided in the embodiment of the present application can be convenient for both manual docking and manual pulling out.

[0061] See also Figure 1 , Figure 2 and Figure 4 Optionally, in some embodiments, a groove 20 is provided on the outer side of the connecting portion 121 a and close to the first extending portion 122 , and a portion of the sealing ring 13 is provided in the groove 20 .

[0062] In the connected state, the connecting portion 121 a is located inside the first component 11 , and the sealing ring 13 abuts against the connecting surface 112 .

[0063] That is to say, the groove 20 of the connecting portion 121a of the sealing head 12 is flush with the first extension portion 122, a portion of the sealing ring 13 is located in the groove 20 of the connecting portion 121a of the sealing head 12, and the other portion is located outside the groove 20 of the connecting portion 121a of the sealing head 12. Therefore, under the premise that the sealing ring 13 is abutted against the connecting surface 112, it is ensured that the first end face 113 of the first component 11 is abutted against the first extension portion 122 of the sealing head 12, thereby improving the sealing between the first component 11 and the sealing head 12.

[0064] See also Figure 1 , Figure 2 and Figure 3 Optionally, in some embodiments, the connecting surface 112 extends from the inner side surface 111 to the first end surface 113 in a direction away from the center axis OO′ of the first component 11 .

[0065] That is, the connection surface 112 is arranged toward the outside of the first component 11, rather than facing the first component 11. In other words, when viewed from the direction facing the first end surface 113 toward the inside of the first component 11, the connection surface 112 of the first component 11 is open, so that there is no risk of jamming during removal, which is conducive to manual removal.

[0066] See also Figure 1 , Figure 2 and Figure 3 Optionally, in some embodiments, the connecting surface 112 is a conical surface arranged around the central axis OO' of the first component 11. Such an arrangement facilitates the processing and manufacturing of the first component 11 and can reduce the manufacturing cost.

[0067] It is understandable that when the connection surface 112 extends from the inner side surface 111 to the first end surface 113 in a direction away from the central axis OO′ of the first component 11 , the connection surface 112 may also be stepped, wavy, or the like.

[0068] See also Figure 1 , Figure 2 and Figure 3 Optionally, in some embodiments, the design angle α is greater than 0 degrees and less than 45 degrees. This arrangement can avoid the problem of requiring a large sealing force to achieve the required sealing pressure ratio, and is further conducive to manual docking.

[0069] It can be understood that the design angle α can be any angle greater than 0 degrees and less than 90 degrees, for example, 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees, etc., which can facilitate both manual docking and manual disconnection.

[0070] In this embodiment, the sealing ring 13 may be an O-ring.

[0071] See also Figure 1 and Figure 2 Optionally, in some embodiments, the cross-section of the sealing ring 13 in a free state is rectangular; or, the cross-section of the sealing ring 13 in a free state is a right-angled trapezoid.

[0072] See also Figure 1 , Figure 2 and Figure 4 The cross section of the groove 20 of the connection part 121a of the sealing head 12 can be rectangular, the connection surface 112 is a conical surface arranged around the central axis OO' of the first component 11, and the cross section of the sealing ring 13 in the docking state is a right-angled trapezoid. The inner wall surface of the groove 20 of the connection part 121a of the sealing head 12, the partial surface of the first extension part 122 of the sealing head 12 and the conical surface of the first component 11 enclose a first space, and the cross section of the first space is a right-angled trapezoid. The sealing ring is arranged in the first space in the docking state.

[0073] When a sealing ring 13 having a right-angle trapezoidal cross section in a free state is used, since the shape of the sealing ring 13 in a free state matches the shape of the first space, only a small axial force is required to achieve docking, which is conducive to manual docking.

[0074] When the sealing ring 13 with a rectangular cross section in a free state is used, the sealing ring 13 can be squeezed into a right-angled trapezoid under the action of the butt joint force, thereby reducing the manufacturing cost of the sealing ring 13 while ensuring the sealing performance.

[0075] It is understandable that the cross-section of the sealing ring 13 in the free state may also be circular, elliptical, etc. Under the action of the docking force, the shape of the sealing ring 13 can be squeezed into a shape that is compatible with the first space to ensure the sealing performance of the sealing structure 100.

[0076] See also Figure 1 , Figure 2 and Figure 3 Optionally, in some embodiments, the first component 11 further includes a second end surface 114 connected to the inner side surface 111 , and the connecting portion 121 a is located in a recess formed by the inner side surface 111 and the second end surface 114 .

[0077] See also Figure 1 , Figure 2 and Figure 4 Optionally, in some embodiments, the sealing structure 100 may further include a second extension portion 123 extending from the first extension portion 122 away from the main body portion 121, and a receiving space is formed between the second extension portion 123 and the connecting portion 121a; in the connected state, the first component 11 is partially located in the receiving space.

[0078] In other words, the connecting portion 121a is clamped on the inner side surface 111 of the first member 11, the first extending portion 122 is in contact with the first end surface 113 of the first member 11, and the second extending portion 123 is clamped on the outer side surface of the first member 11 opposite to the inner side surface 111. Figure 1 From the perspective of the cross section, the connecting portion 121a, the first extension portion 122 and the second extension portion 123 form a U-shaped structure, and one end of the first member 11 is clamped in the U-shaped structure. From the perspective of the three-dimensional structure, the connecting portion 121a and the second extension portion 123 can be concentric cylinders, and one end of the first member 11 is clamped between the connecting portion 121a and the second extension portion 123.

[0079] By clamping one end of the first component 11 between the connecting portion 121 a of the concentric cylinder and the second extending portion 123 , the connection between the first component 11 and the sealing head 12 is made more stable.

[0080] See also Figure 1 , Figure 2 and Figure 5 Optionally, in some embodiments, the sealing structure 100 may further include a cylindrical 14, which includes a first inner wall surface 141, a first connecting surface 142, a second inner wall surface 143, a second connecting surface 144 and a third inner wall surface 145 which are sequentially connected and form a step shape.

[0081] The sealing structure 100 further includes at least one of the following:

[0082] The first inner wall surface 141 is located outside the first member 11 and the second extending portion 123 .

[0083] The main body 121 further includes a second portion 121 b located at the other side of the first extension portion 122 , and the second inner wall surface 143 is located outside the second portion 121 b .

[0084] The sealing structure 100 further includes an elastic member 15 , and the elastic member 15 is sandwiched between the second connecting surface 144 and the second portion 121 b .

[0085] The elastic member 15 may be a wave spring, or a spring sheet or other elastic structure.

[0086] Since the first inner wall surface is located outside the first component 11 and the second extension portion 123 , the sealing performance of the connection between the first component 11 and the sealing head 12 can be improved, thereby avoiding fuel leakage during the fuel filling process.

[0087] Since the first inner wall surface is located on the outside of the first component 11 and the second extension portion 123, and the second inner wall surface is located on the outside of the second portion 121b of the main body 121, that is, the stepped 14 is clamped on the sealing head 12 and extends to the outside of the first component 11, it can not only achieve the connection between 14 and the first component 11, but also avoid relative movement between 14 and the first component 11.

[0088] Since the elastic member 15 is sandwiched between the second connecting surface 144 of the sealing member 14 and the second portion 121 b of the sealing head 12 , it is possible to prevent the sealing performance of the sealing structure 100 from being damaged by external forces such as vibration during the process of fuel filling.

[0089] See also Figure 1 , Figure 2 and Figure 3 Optionally, in some embodiments, the first component 11 includes a first outer wall surface 115 and a second outer wall surface 116 that are stepped.

[0090] The first inner wall surface 141 is located outside the second extending portion 123 and abuts against the second outer wall surface 116 ; the inner wall of the second extending portion 123 abuts against the first outer wall surface 115 .

[0091] Optionally, in practical applications, the first component 11 further includes a third connecting surface connecting the first outer wall surface 115 and the second outer wall surface 116 .

[0092] Such arrangement enables the second outer wall surface of the first component 11 to be flush with the outer side of the second extension portion 123 of the sealing head 12, so that 14 can be clamped on the outer sides of the first component 11 and the sealing head 12 under the premise of ensuring that one end of the first component 11 is clamped in the U-shaped structure formed by the connecting portion 121a and the second extension portion 123 of the sealing head 12, which is convenient for the installation of the first component 11, the sealing head 12 and 14.

[0093] Optionally, in actual applications, the first component 11 can be used as a fixed end, and the fixed end can be fixed to the body of the liquid rocket by bolts; the elastic member 15, the sealing head 12, and the sealing ring 13 are all installed on 14, and the elastic member 15, the sealing head 12, the sealing ring 13 and 14 together constitute a movable end, and the movable end is connected to the fuel tank.

[0094] The sealing head 12 can compress the elastic member 15, so that the sealing structure 100 has a certain amount of movement in the axial direction. By manually pushing the movable end to resist the axial force provided by the elastic member 15, the movable end and the fixed end are manually docked, so that the elastic member 15 provides an axial sealing force, and the sealing ring 13 forms a conical surface seal on the conical surface to ensure that the medium (such as fuel) is not easy to leak when it circulates, so as to realize the refueling of the liquid rocket.

[0095] See also Figure 6 , Figure 6 It is a force diagram when the connecting surface 112 is a conical surface.

[0096] Figure 6 In the figure, F is the axial force applied by the elastic member 15 on the conical surface, Fn is the normal sealing force, α is the angle between the connecting surface 112 and the central axis OO' of the first member 11 (i.e., the design angle), B is the distance between the outer edge and the inner edge of the conical surface, and D is the diameter of the circle formed by the center points of the outer edge and the inner edge of the conical surface.

[0097] It can be seen that the axial force F is converted into the normal sealing force Fn through the conical surface, Fn = F / sinα, the force area of ​​the conical surface S = 3.14 × D × B, and the sealing specific pressure p generated on the conical surface = Fn / S. Therefore, a relatively small axial force F can be used to obtain a larger sealing specific pressure p, which is beneficial for both manual docking and manual removal.

[0098] The beneficial technical effects brought about by the technical solution provided by the embodiment of the present application include:

[0099] Since the sealing ring 13 is arranged on the connecting surface 112 between the inner side surface 111 and the first end surface 113 of the first component 11, a sealing structure 100 between the end face seal and the radial seal is formed. Compared with the end face seal structure 100, the inclined connecting surface 112 can amplify the smaller axial force into a larger normal force, and the normal force provides a sealing pressure ratio, that is, a larger sealing pressure ratio can be achieved with a smaller axial force, and the smaller axial force is conducive to manual docking, and the sealing ring 13 is not easy to fall off after being pulled out; compared with the radial sealing structure 100, the internal and external pressure difference of the sealing structure 100 is on the connecting surface 112 between the inner side surface 111 and the first end surface 113, and the pulling out is not affected by the internal and external pressure difference, and there is no risk of jamming during pulling out, which is conducive to manual pulling out. In summary, the sealing structure 100 provided in the embodiment of the present application can be convenient for both manual docking and manual pulling out.

[0100] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, changed, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be alternated, changed, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the related art that are similar to those disclosed in this application may also be alternated, changed, rearranged, decomposed, combined, or deleted.

[0101] In the description of the present application, the directions or positional relationships indicated by words such as "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the exemplary directions or positional relationships shown in the accompanying drawings. They are for the convenience of describing or simplifying the description of the embodiments of the present application, and do not indicate or imply that the referred device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0102] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0103] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0104] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0105] The above is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the scheme of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.

Claims

1. A sealing structure, characterized in that: include: The first member is cylindrical, and the end of the first member includes an inner side surface, a connecting surface and a first end surface which are connected in sequence; the connecting surface is arranged around the central axis of the first member and forms a design angle with the central axis of the first member, and the design angle is greater than 0 degrees and less than 90 degrees; A sealing head, comprising a cylindrical main body, a first extension portion arranged on the outside of the main body, and a second extension portion bent and extended from the first extension portion away from the main body; the main body comprises a connecting portion located at one side of the first extension portion and configured to extend into the first member; the first extension portion is configured to abut against the first end surface, a portion of the connecting portion away from the first extension portion is configured to abut against the inner side surface, an accommodation space is formed between the second extension portion and the connecting portion, and in a connected state, a portion of the first member is located in the accommodation space; A sealing ring is configured to be sandwiched between the connecting surface and a portion of the connecting portion close to the first extending portion, a groove is provided on the outer side of the connecting portion close to the first extending portion, and the sealing ring is partially disposed in the groove; A cylindrical shell, the shell comprising a first inner wall surface, a first connecting surface, a second inner wall surface, a second connecting surface and a third inner wall surface which are sequentially connected and formed into a step shape; The sealing structure further comprises at least one of the following: The first inner wall surface is located outside the first member and the second extension portion; The main body also includes a second portion located at the other side of the first extension portion, and the second inner wall surface is located outside the second portion; The sealing structure further includes an elastic member, and the elastic member is sandwiched between the second connecting surface and the second portion.

2. The sealing structure according to claim 1, characterized in that: In the connected state, the connecting portion is located inside the first component, and the sealing ring abuts against the connecting surface.

3. The sealing structure according to claim 1, characterized in that: The connecting surface extends from the inner side surface to the first end surface in a direction away from the central axis of the first component.

4. The sealing structure according to claim 3, characterized in that: The connecting surface is a conical surface arranged around the central axis of the first component.

5. The sealing structure according to any one of claims 1 to 4, characterized in that: The design angle is greater than 0 degree and less than 45 degrees.

6. The sealing structure according to claim 1, characterized in that: The cross section of the sealing ring in a free state is rectangular; Alternatively, the cross section of the sealing ring in a free state is a right-angled trapezoid.

7. The sealing structure according to claim 1, characterized in that: The first component includes a first outer wall surface and a second outer wall surface in a stepped shape; The first inner wall surface is located outside the second extending portion and abuts against the second outer wall surface; the inner wall of the second extending portion abuts against the first outer wall surface.

8. The sealing structure according to claim 1, characterized in that: The first component also includes a second end surface connected to the inner side surface, and the connecting portion is located in a recess formed by the inner side surface and the second end surface.

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