Shaft sealing structure and air valve thereof

Abstract

The utility model relates to the technical field of shaft sealing, in particular to a shaft sealing structure and an air valve thereof. The shaft sealing structure comprises a bearing seat, a sealing gasket, a bearing cover and a bearing, the bearing seat is provided with an inner side used for being connected with a to-be-sealed body, the bearing seat is provided with a first through hole allowing a rotating shaft to penetrate through, the sealing gasket is connected to the outer side of the bearing seat, a boss is arranged on the sealing gasket in the direction towards the inner side of the bearing seat in a protruding mode, and the boss extends into the first through hole. The peripheral wall of the boss abuts against the inner wall of the first through hole in the circumferential direction. The bearing cover covers the side, back to the bearing seat, of the sealing gasket, tightly presses the sealing gasket and is connected with the bearing seat, and a containing groove is formed in the side, facing the bearing seat, of the bearing cover; the end, away from the bearing seat, of the bearing seat abuts against the groove bottom of the containing groove, and the other end of the bearing seat abuts against the sealing gasket. The sealing gasket has the advantage that the sealing performance between the sealing gasket and the bearing seat is improved by abutting the boss against the inner wall of the first through hole in the bearing seat.

Description

Technical Field

[0001] The utility model relates to the technical field of shaft seals, in particular to a shaft seal structure and a damper valve thereof. Background Art

[0002] The damper valve is applied to a pipeline system and can cut off the flow of gas medium to realize the on-off of the pipeline. Therefore, high requirements are imposed on the sealing performance between various components of the damper valve.

[0003] The existing damper valve has a shaft seal structure, which generally includes a bearing seat, a sealing gasket and a bearing cover. The sealing gasket is installed between the bearing seat and the bearing cover, and the bearing seat and the bearing cover are connected and compress the sealing gasket. However, when the shaft seal structure is used for a long time, the problem of medium leakage is still likely to occur. Summary of the Utility Model

[0004] Based on this, in view of the above technical problems, the utility model provides a shaft seal structure.

[0005] A shaft seal structure includes: a bearing seat having an inner side for connecting with a body to be sealed, a first through hole being formed in the bearing seat, and a rotating shaft passing through the first through hole; a sealing gasket connected to the outer side of the bearing seat, and a boss protruding from the sealing gasket toward the inner side of the bearing seat, the boss extending into the first through hole, an outer peripheral wall of the boss being circumferentially abutted against an inner wall of the first through hole, and an inner peripheral wall of the boss being in interference fit with an outer peripheral side of the rotating shaft; a bearing cover covering a side of the sealing gasket facing away from the bearing seat, the sealing gasket being compressed between the bearing cover and the bearing seat, the bearing cover being connected to the bearing seat, and a receiving groove being formed in a side of the bearing cover facing the bearing seat.

[0006] With such a setting, the sealing gasket is compressed by the bearing seat and the bearing cover, so as to seal the installation gap between the bearing seat and the bearing cover. Moreover, the sealing gasket further has a boss extending into the first through hole, and the outer peripheral wall of the boss is abutted against the inner peripheral wall of the first through hole. Therefore, the sealing gasket not only abuts against the outer side surface of the bearing seat facing away from the body to be sealed, but also can be abutted against the inner wall of the first through hole through the boss. Thus, the contact area between the sealing gasket and the bearing seat is enlarged. Generally speaking, gas is most likely to leak out along the first through hole for the rotating shaft to pass through and the installation gap between the bearing cover and the bearing seat. Therefore, in this application, the sealing gasket forms a seal along the path where gas is likely to leak, improving the airtightness of the shaft seal structure.

[0007] In one embodiment, the boss includes a diameter section and a reduced-diameter section, the reduced-diameter section being connected to a radially inner side of the diameter section, and along a direction radially inward of the boss, a thickness of the diameter section remains unchanged, and a thickness of the reduced-diameter section gradually decreases.

[0008] In one embodiment, the bearing housing includes a first section and a second section connected to each other. The outer diameter of the first section is smaller than that of the second section to form a first step; a circumferential edge on the side of the bearing cover facing the bearing housing has a flange. At least a part of the first section is located in the cavity formed by the flange, and the radially inner side of the flange abuts against the outer peripheral side of the first section.

[0009] In one embodiment, the diameter of the sealing gasket is the same as the outer diameter of the first section, and the outer peripheral side of the sealing gasket abuts against the radially inner side of the flange.

[0010] In one embodiment, along the axial direction of the bearing housing, the thickness of the first section is X1, the thickness of the flange is X2, and the thickness of the sealing gasket is D, satisfying: X2 < X1 + D.

[0011] In one embodiment, the shaft sealing structure includes a bearing. The bearing is located in the accommodation groove, and one end of the bearing housing away from the bearing housing abuts against the bottom of the accommodation groove, and the other end abuts against the sealing gasket; the bearing includes an outer ring, an inner ring and rolling balls, and the rolling balls are located between the outer ring and the inner ring; a first avoidance groove is formed on the side of the sealing gasket facing the bearing. The notch of the first avoidance groove is circular, and the notch diameter of the first avoidance groove is larger than the inner diameter of the outer ring and smaller than the outer diameter of the outer ring.

[0012] In one embodiment, a second avoidance groove is formed at the bottom of the accommodation groove. The notch diameter of the second avoidance groove is larger than the inner diameter of the outer ring and smaller than the outer diameter of the outer ring; the first avoidance groove and the second avoidance groove are located on both sides of the bearing axially.

[0013] A wind valve includes the shaft sealing structure and a valve body as described above. The shaft sealing structure is connected to the valve body. The rotating shaft extends into the shaft sealing structure and is connected to the bearing. The bearing housing, the sealing gasket, the bearing cover, the bearing and the rotating shaft are all coaxially arranged.

[0014] In one embodiment, the rotating shaft includes a first shaft and a second shaft. The first shaft and the second shaft are connected. The outer diameter of the second shaft is larger than that of the first shaft to form a second step. The bearing is sleeved and connected to the outer peripheral side of the first shaft, and one side of the bearing close to the bearing housing abuts against the second step.

[0015] In one embodiment, a second through hole for the rotating shaft to pass through is formed in the sealing gasket, and the diameter of the second shaft is larger than the diameter of the second through hole.

[0016] Compared with the prior art, the utility model improves the sealing performance between the gasket and the bearing housing by providing a boss on the gasket and making the boss abut against the inner wall of the first through hole in the bearing housing. Moreover, through the cooperation between the bearing housing and the bearing cover, the assembly clearance path between the bearing housing and the bearing cover is bent into a shape like the Chinese character 'ji', increasing the difficulty of gas leakage, which in turn improves the sealing performance of the shaft sealing structure. The dimensional relationships among the bearing housing, the bearing cover, the gasket and the rotating shaft are also reasonably set, and proper interference fit is adopted to ensure good airtightness of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a cross-sectional view of one embodiment of the shaft sealing structure provided by the utility model;

[0018] Figure 2 FIG. is a schematic cross-sectional structure view of one embodiment of the shaft sealing structure provided by the utility model;

[0019] Figure 3 FIG. is a schematic structure view of one embodiment of the gasket of the shaft sealing structure provided by the utility model;

[0020] Figure 4 FIG. is a schematic structure view of one embodiment of the gasket from another angle provided by the utility model;

[0021] Figure 5 FIG. is a cross-sectional view of one embodiment of the gasket provided by the utility model;

[0022] Figure 6 FIG. is a schematic structure view of one embodiment of the bearing cover provided by the utility model;

[0023] Figure 7 FIG. is a cross-sectional view of one embodiment of the bearing cover provided by the utility model.

[0024] The meanings of the symbols in the figures are as follows:

[0025] 100, shaft sealing structure; 10, bearing housing; 11, first through hole; 12, first section; 13, second section; 14, first step; 15, connection hole; 20, gasket; 21, boss; 211, diameter section; 212, reduced diameter section; 22, first relief groove; 23, second through hole; 30, bearing cover; 31, accommodation groove; 32, second relief groove; 33, flange; 40, bearing; 41, outer ring; 42, inner ring; 43, ball; 50, valve body; 60, rotating shaft; 61, first shaft; 62, second shaft; 63, second step; 70, connecting piece. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the above objects, features, and advantages of the present application more obvious and understandable, the following describes the specific embodiments of the present application in detail with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0027] It should be noted that when an assembly is referred to as being "fixed to" or "disposed on" another assembly, it can be directly on the other assembly or there can also be an intermediate assembly. When an assembly is considered to be "connected" to another assembly, it can be directly connected to the other assembly or there may be an intermediate assembly at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of the present application are only for illustrative purposes and do not represent the only implementation manner.

[0028] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0029] In the present application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be that the first feature is in direct contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature has a lower horizontal height than the second feature.

[0030] Unless otherwise defined, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the specification of the present application includes any and all combinations of one or more of the related listed items.

[0031] The present utility model provides a shaft seal structure 100, which improves the structure of the gasket 20 to provide a better sealing effect.

[0032] Please refer toFigures 1 - 2 , the shaft seal structure 100 includes a bearing housing 10, a gasket 20, a bearing cover 30 and a bearing 40. The bearing housing 10 has an inner side for connecting with the body to be sealed. A first through hole 11 is formed in the bearing housing 10, and a rotating shaft 60 passes through the first through hole 11. The gasket 20 is connected to the outer side of the bearing housing 10 (i.e., the other side of the bearing housing 10 away from the above-mentioned inner side), and a boss 21 protrudes from the gasket 20 towards the inner side of the bearing housing 10. The boss 21 extends into the first through hole 11, and the outer peripheral wall of the boss 21 is circumferentially abutted against the inner wall of the first through hole 11. The inner peripheral wall of the boss 21 is in interference fit with the outer peripheral wall of the rotating shaft 60. The bearing cover 30 is covered on the side of the gasket 20 facing away from the bearing housing 10. The gasket 20 is pressed between the bearing cover 30 and the bearing housing 10. The bearing cover 30 is connected to the bearing housing 10. A receiving groove 31 is formed on the side of the bearing cover 30 facing the bearing housing 10. The bearing 40 is located in the receiving groove 31. One end of the bearing housing 10 away from the bearing housing 10 abuts against the bottom of the receiving groove 31, and the other end abuts against the gasket 20. In this way, the bearing 40 rotates in the bearing cover 30, the rotating shaft 60 penetrates into the bearing 40 through the first through hole 11, and freely rotates in the shaft seal structure 100 by means of the bearing 40. The gasket 20 is pressed by the bearing housing 10 and the bearing cover 30, so as to seal the installation gap between the bearing housing 10 and the bearing cover 30. Moreover, the gasket 20 further has a boss 21 extending into the first through hole 11, and the outer peripheral wall of the boss 21 abuts against the inner peripheral wall of the first through hole 11. Therefore, it can be said that the gasket 20 not only abuts against the outer side of the bearing housing 10 facing away from the valve body 50, but also can abut against the inner wall of the first through hole 11 through the boss 21. Thus, the contact area between the gasket 20 and the bearing housing 10 is enlarged. Generally speaking, gas is most likely to leak out along the first through hole 11 for the rotating shaft 60 to pass through and the installation gap between the bearing cover 30 and the bearing housing 10. Therefore, the gasket 20 in the present application forms a seal along the path where gas is likely to leak, improving the airtightness of the shaft seal structure 100.

[0033] It should be noted that in this embodiment, the body to be sealed is the valve body 50. In other embodiments, the body to be sealed may also be other structures such as a housing that requires shaft sealing.

[0034] The connection between the bearing housing 10 and the valve body 50 is welded. Full welding is adopted at the position where the inner wall edge of the bearing housing 10 contacts the valve body 50, and intermittent welding is adopted at the outer wall edge of the bearing housing 10, so as to block the escape of gas from between the valve body 50 and the bearing housing 10.

[0035] Please refer to Figures 3 - 5, Further, the boss 21 includes a diameter section 211 and a reduced-diameter section 212. The reduced-diameter section 212 is connected to the radially inner side of the diameter section 211. Along the direction radially inward of the boss 21, the thickness of the diameter section 211 remains unchanged, and the thickness of the reduced-diameter section 212 gradually decreases. In this way, the diameter section 211 can improve the structural strength of the boss 21. When the rotating shaft 60 extends into the shaft seal structure 100 and contacts the gasket 20, since the rotating shaft 60 is located at the radial center position of the gasket 20, and the thickness of the reduced-diameter section 212 becomes thinner along the radially inward direction, the thickness at the contact portion between the reduced-diameter section 212 and the rotating shaft 60 is already very small. Therefore, the contact area between the rotating shaft 60 and the reduced-diameter section 212 can be reduced, and the frictional torque of the rotating shaft 60 and the wear of the reduced-diameter section 212 can be decreased. Moreover, the thickness of the reduced-diameter section 212 gradually decreases, rather than having a sudden change in thickness (a sudden change in thickness means suddenly reducing a lot along the radial direction, forming a fault, rather than a linear decrease). Therefore, the strength of the gasket 20 can be ensured. And the gradually decreasing thickness of the reduced-diameter section 212 can form an inclined surface to block the entry of foreign objects.

[0036] The bearing 40 includes an outer ring 41, an inner ring 42, and rolling balls 43. The rolling balls 43 are located between the outer ring 41 and the inner ring 42. A first relief groove 22 is formed on one side of the gasket 20 facing the bearing 40. The opening of the first relief groove 22 is circular, and the diameter of the opening of the first relief groove 22 is larger than the inner diameter of the outer ring 41 and smaller than the outer diameter of the outer ring 41. In this way, the opening of the first relief groove 22 can abut between the inner diameter and the outer diameter of the outer ring 41. Therefore, during the rotation of the bearing 40, it can be ensured that the rotation of the rolling balls 43 will only occur in the first relief groove 22 and will not contact the gasket 20. Therefore, the frictional torque of rolling friction and the wear of the gasket 20 caused by friction are avoided, the service life of the device is prolonged, and the leakage of bearing grease can also be prevented from contaminating other components of the shaft seal structure 100, as well as the rotating shaft 60 and the valve body 50.

[0037] Meanwhile, please refer to Figures 6 - 7 , a second relief groove 32 is formed at the bottom of the receiving groove 31. The diameter of the opening of the second relief groove 32 is larger than the inner diameter of the outer ring 41 and smaller than the outer diameter of the outer ring 41. The first relief groove 22 and the second relief groove 32 are located on both axial sides of the bearing 40. Similar to the above, the second relief groove 32 is arranged in this way to ensure that the rolling balls 43 will not contact the bottom of the receiving groove 31 during rotation, thereby avoiding the frictional torque and wear generated by the rolling balls 43 in the bearing 40 contacting the bearing cover 30. It can also prevent the leakage of bearing grease from contaminating other components of the shaft seal structure 100, as well as the rotating shaft 60 and the valve body 50.

[0038] Please refer to Figure 1, Further, the bearing housing 10 includes a first section 12 and a second section 13 that are connected to each other. The outer diameter of the first section 12 is smaller than the outer diameter of the second section 13 to form a first step 14. The circumferential edge of the side of the bearing cover 30 facing the bearing housing 10 has a flange 33, and the radially inner side of the flange 33 abuts against the outer peripheral side of the first section 12. In this way, the presence of the flange 33 makes the contact surface between the bearing housing 10 and the bearing cover 30 not a single plane, but also has a contact surface that forms a circumferential abutment in the axial direction (that is, the abutment between the radially inner side of the above-mentioned flange 33 and the outer peripheral side of the first section 12). Therefore, it further prevents the difficulty of gas leakage, and thus improves the airtightness of the device.

[0039] Further, the diameter of the gasket 20 is the same as the outer diameter of the first section 12, and the outer peripheral side of the gasket 20 abuts against the radially inner side of the flange 33. In this way, the installation stability of the gasket 20 is improved. After its outer peripheral side abuts against the flange 33, it is not easy to move in position.

[0040] In other embodiments, the outer peripheral side of the gasket 20 can also be bent to form a structure similar to the above-mentioned flange 33 and extend between the flange 33 and the first section 12. In this way, while the bearing cover 30 and the bearing housing 10 are pressed and sealed, the contact surfaces in the circumferential direction of the two can also be sealed by the gasket 20, which further improves the sealing performance of the shaft sealing structure 100.

[0041] Along the axial direction of the bearing housing 10, the thickness of the first section 12 is X1, the thickness of the flange 33 is X2, and the thickness of the gasket 20 is D, satisfying: X2 < X1 + D. In this way, that is to say, if the flange 33 abuts completely against the first step 14, then the gap formed between the bearing cover 30 and the bearing housing 10 is smaller than the thickness D of the gasket 20. Therefore, when the bearing cover 30 and the bearing housing 10 are completely connected (referring to the two approaching each other to the limit position and being locked at this limit position), the gasket 20 will be press-fitted with interference, which improves the contact tightness between the gasket 20, the bearing cover 30 and the bearing housing 10, thereby improving the sealing performance and preventing dust particles from passing through.

[0042] The bearing cover 30 and the bearing housing 10 are connected by a connecting member 70. In this embodiment, the bearing cover 30 and the bearing housing 10 are provided with corresponding connecting holes 15, and the connecting member 70 passes through the connecting holes 15 to connect the bearing cover 30 and the bearing housing 10.

[0043] The connecting member 70 is preferably a bolt. The connecting hole 15 is provided with an internal thread, and the cooperation between the bolt and the connecting hole 15 connects the bearing cover 30 and the bearing housing 10 together, and is convenient for disassembly and assembly.

[0044] The present utility model further provides a wind valve, which includes the shaft sealing structure 100 as described above, a rotating shaft 60, and a valve body 50. The shaft sealing structure 100 is connected to the valve body 50. The rotating shaft 60 extends into the shaft sealing structure 100 and is connected to a bearing 40. The bearing seat 10, the sealing gasket 20, the bearing cover 30, the bearing 40, and the rotating shaft 60 are all coaxially arranged. In this way, the bearing seat 10, the bearing cover 30, and the sealing gasket 20 are all fixedly connected to the valve body 50, and their positions are stabilized by the valve body 50. Moreover, the rotating shaft 60 is spaced from both the bearing seat 10 and the bearing cover 30, so that the rotating shaft 60 can avoid contacting the bearing seat 10 and the bearing cover 30 during rotation. At the same time, the inner ring 42 of the bearing 40 is connected to the rotating shaft 60 and rotates synchronously with the rotating shaft 60, while the outer ring 41 is connected to the bearing cover 30 to keep its position fixed. The balls 43 are connected between the inner ring 42 and the outer ring 41, reducing the friction of relative rotation between the two.

[0045] The rotating shaft 60 includes a first shaft 61 and a second shaft 62. The first shaft 61 and the second shaft 62 are connected. The outer diameter of the second shaft 62 is larger than that of the first shaft 61, forming a second step 63. The bearing 40 is sleeved and connected to the outer peripheral side of the first shaft 61, and one side of the bearing 40 close to the bearing seat 10 abuts against the second step 63. In this way, the second step 63 can abut against the bearing 40 to fix the position of the bearing 40 and prevent the bearing 40 from falling off.

[0046] The sealing gasket 20 is provided with a second through hole 23 for the rotating shaft 60 to pass through, and the diameter of the second shaft 62 is larger than that of the second through hole 23. In this way, an interference fit is formed between the sealing gasket 20 and the second shaft 62, making the abutment between the sealing gasket 20 and the rotating shaft 60 closer, and also improving the airtightness.

[0047] Preferably, the diameter of the second shaft 62 is 0.5 mm - 1 mm larger than the diameter of the second through hole 23. In this way, it can not only ensure the tightness of the interference fit between the two, avoid gas leakage easily occurring between the second shaft 62 and the sealing gasket 20, but also prevent the sealing gasket 20 from being easily deformed and damaged after the interference amount is too large.

[0048] Compared with the prior art, the present utility model improves the sealing performance between the sealing gasket 20 and the bearing seat 10 by providing a boss 21 on the sealing gasket 20 and abutting the boss 21 against the inner wall of the first through hole 11 in the bearing seat 10. And through the cooperation between the bearing seat 10 and the bearing cover 30, the assembly clearance path between the bearing seat 10 and the bearing cover 30 is bent into a zigzag shape, increasing the difficulty of gas leakage, which also improves the sealing performance of the shaft sealing structure 100 in effect. The dimensional relationships among the bearing seat 10, the bearing cover 30, the sealing gasket 20, and the rotating shaft 60 are also reasonably set, ensuring good airtightness of the device through appropriate interference fit.

[0049] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0050] The above-described embodiments merely represent several implementation manners of the present utility model. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the present utility model patent shall be subject to the appended claims.

Claims

1. A shaft sealing structure, characterized in that: include: A bearing seat (10) having an inner side for connecting with a body to be sealed, a first through hole (11) being formed on the bearing seat (10), and a rotating shaft (60) passing through the first through hole (11); A sealing gasket (20) is connected to the outer side of the bearing seat (10), and the sealing gasket (20) is provided with a boss (21) protruding toward the inner side of the bearing seat (10), the boss (21) extends into the first through hole (11), and the outer peripheral wall of the boss (21) is circumferentially abutted against the inner wall of the first through hole (11), and the inner peripheral wall of the boss (21) is interference fit with the outer peripheral side of the rotating shaft (60); A bearing cover (30) is arranged on a side of the sealing gasket (20) facing away from the bearing seat (10), the sealing gasket (20) is pressed between the bearing cover (30) and the bearing seat (10), the bearing cover (30) is connected to the bearing seat (10), and a receiving groove (31) is provided on a side of the bearing cover (30) facing the bearing seat (10).

2. The shaft sealing structure according to claim 1, characterized in that: The boss (21) comprises a diameter section (211) and a reduced diameter section (212), wherein the reduced diameter section (212) is connected to the radial inner side of the diameter section (211), and along the radial inward direction of the boss (21), the thickness of the diameter section (211) remains unchanged, while the thickness of the reduced diameter section (212) gradually decreases.

3. The shaft sealing structure according to claim 1, characterized in that: The bearing seat (10) comprises a first section (12) and a second section (13) connected to each other, wherein the outer diameter of the first section (12) is smaller than the outer diameter of the second section (13) to form a first step (14); The bearing cover (30) has a flange (33) on its circumferential edge facing the bearing seat (10), the first section (12) is at least partially located in a cavity formed by the flange (33), and the radial inner side of the flange (33) abuts against the outer circumferential side of the first section (12).

4. The shaft sealing structure according to claim 3, characterized in that: The diameter of the sealing gasket (20) is the same as the outer diameter of the first section (12), and the outer peripheral side of the sealing gasket (20) abuts against the radial inner side of the flange (33).

5. The shaft sealing structure according to claim 4, characterized in that: Along the axial direction of the bearing seat (10), the thickness of the first section (12) is X1, the thickness of the flange (33) is X2, and the thickness of the sealing gasket (20) is D, satisfying: X2<X1+D.

6. The shaft sealing structure according to any one of claims 2 to 5, characterized in that: The shaft sealing structure comprises a bearing (40), wherein the bearing (40) is located in the receiving groove (31), and one end of the bearing seat (10) away from the bearing seat (10) abuts against the bottom of the receiving groove (31), and the other end abuts against the sealing gasket (20); the bearing (40) comprises an outer ring (41), an inner ring (42) and a ball (43), and the ball (43) is located between the outer ring (41) and the inner ring (42); A first avoidance groove (22) is provided on one side of the sealing gasket (20) facing the bearing (40); the opening of the first avoidance groove (22) is circular, and the opening diameter of the first avoidance groove (22) is larger than the inner diameter of the outer ring (41) and smaller than the outer diameter of the outer ring (41).

7. The shaft sealing structure according to claim 6, characterized in that: A second avoidance groove (32) is provided at the bottom of the accommodating groove (31); a groove opening diameter of the second avoidance groove (32) is larger than an inner diameter of the outer ring (41) and smaller than an outer diameter of the outer ring (41); and the first avoidance groove (22) and the second avoidance groove (32) are located on both sides of the axial direction of the bearing (40).

8. A damper, characterized in that: It comprises the shaft sealing structure and the valve body (50) as claimed in claim 7, wherein the shaft sealing structure is connected to the valve body (50), the rotating shaft (60) extends into the shaft sealing structure and is connected to the bearing (40), and the bearing seat (10), the sealing gasket (20), the bearing cover (30), the bearing (40) and the rotating shaft (60) are all coaxially arranged.

9. The air valve according to claim 8, characterized in that: The rotating shaft (60) comprises a first shaft (61) and a second shaft (62), the first shaft (61) and the second shaft (62) are connected, the outer diameter of the second shaft (62) is larger than that of the first shaft (61) and forms a second step (63), the bearing (40) is sleeved and connected to the outer peripheral side of the first shaft (61), and the side of the bearing (40) close to the bearing seat (10) is in contact with the second step (63).

10. The air valve according to claim 9, characterized in that: The sealing gasket (20) is provided with a second through hole (23) for the rotating shaft (60) to pass through, and the diameter of the second shaft (62) is greater than the diameter of the second through hole (23).

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