Sealing assembly, shaft sealing structure and shaft transmission device

Abstract

The utility model relates to the technical field of shaft transmission sealing, and discloses a sealing assembly, a shaft sealing structure and a shaft transmission device.The sealing assembly comprises a first sealing piece, a second sealing piece and a third sealing piece, and the first sealing piece is suitable for being fixedly arranged on the peripheral side of a shaft body in a sleeving mode; the second sealing element is movably arranged on the peripheral side of the first sealing element in a sleeving mode, the second sealing element is suitable for being connected and matched with the shell, a liquid passing channel and a liquid returning channel are formed between the first sealing element and the second sealing element, and the liquid returning channel communicates with the interior of the liquid passing channel and the interior of the shell; a liquid blocking piece is further arranged on the peripheral wall of the side, close to the interior of the shell, of the first sealing piece and at least partially shields the liquid return channel in the axial direction of the first sealing piece. Therefore, the liquid in the liquid return channel is blocked by the liquid blocking piece, and the liquid in the liquid return channel flows along the radial direction of the shaft body to flow back into the shell, so that compared with the prior art, the flow rate of the liquid discharged from the liquid return channel can be slowed down, the collision disturbance between the liquid and the liquid in the shell can be reduced, and the working stability of the shaft transmission device can be improved.

Description

Technical Field

[0001] This application relates to the field of shaft drive sealing technology, and in particular to a sealing component, a shaft sealing structure, and a shaft drive device. Background Technology

[0002] Shaft drives (such as steam generators or gearboxes) have a shaft and a housing. Since the shaft can rotate relative to the housing, when a rubber ring is used to seal the gap between the shaft and the housing, the rubber ring will impede the relative movement between the shaft and the housing. Therefore, shaft drives use labyrinth seal assemblies for sealing.

[0003] In related technologies, labyrinth seal assemblies include a first seal sleeved on the outer periphery of the shaft and a second seal sleeved on the outer periphery of the first seal. The first and second seals are rotatable relative to each other, and alternating sealing teeth and liquid passages are provided between them. The sealing teeth and liquid passages cooperate to restrict the flow of liquid from the inside of the housing to the outside. Furthermore, existing labyrinth seal assemblies also include a return liquid passage between the first and second seals, which communicates with the liquid passage to accelerate the return of liquid from the liquid passage to the housing. However, in the direction from the outside to the inside of the housing, the return liquid passage is usually inclined downwards. The liquid gradually accelerates in the return liquid passage. When the liquid flows back into the housing from the return liquid passage, the collision disturbance between the accelerated liquid and the liquid on the outer periphery of the shaft increases, thereby affecting the working stability of the shaft drive device. Utility Model Content

[0004] The purpose of this application is to reduce the collision between the liquid discharged from the return channel and the liquid inside the housing, thereby reducing the turbulence generated inside the housing and improving the working stability of the shaft drive device.

[0005] To achieve the above objectives, this application provides a sealing assembly.

[0006] This application further discloses a shaft seal structure.

[0007] This application further discloses a shaft drive device.

[0008] According to the sealing assembly of this application, for a shaft drive device, the sealing assembly includes: a first sealing member, the first sealing member being adapted to be fixedly sleeved on the outer peripheral side of a shaft, the outer peripheral wall of the first sealing member being provided with a first sealing tooth; a second sealing member, the second sealing member being movably sleeved on the outer peripheral side of the first sealing member, the second sealing member being adapted to connect and cooperate with a housing, the inner peripheral wall of the second sealing member being provided with a second sealing tooth, the second sealing tooth being arranged opposite to the first sealing tooth and forming a sealing tooth group, a liquid passage being formed between any two adjacent sealing tooth groups, and a return liquid channel extending toward the housing being provided between the first sealing member and the second sealing member, the return liquid channel connecting the liquid passage and the housing; wherein, a liquid-blocking member is provided on the outer peripheral wall of the first sealing member near the housing, the liquid-blocking member at least partially blocking the return liquid channel along the axial direction of the first sealing member, a drain port communicating with the return liquid channel being formed between the liquid-blocking member and the second sealing member, the drain port being adapted to allow liquid in the return liquid channel to be discharged radially from the return liquid channel along the shaft.

[0009] According to the shaft seal structure of this application, by blocking the liquid in the return channel with the liquid baffle and allowing the liquid in the return channel to flow radially along the shaft body back into the housing, compared with the prior art, the flow rate of the liquid discharged in the return channel can be slowed down, and the collision disturbance between the liquid in the return channel and the liquid in the housing can be reduced, thereby improving the working stability of the shaft transmission device.

[0010] In some examples of this application, the liquid-blocking component includes a radial liquid-blocking portion, one end of which is fixedly connected to the outer peripheral wall of the first seal, and the other end extends radially along the first seal. The radial liquid-blocking portion has a liquid-blocking surface, which is disposed opposite to the return liquid channel to adjust the flow direction of the liquid in the return liquid channel.

[0011] In some examples of this application, the liquid-blocking component further includes an axial liquid-blocking portion, one end of which is connected and engaged with the side of the radial liquid-blocking portion away from the first seal, and the other end of which extends along the axial direction of the first seal toward the second seal, and the other end of which is spaced apart from the second seal to form the drain port.

[0012] In some examples of this application, the liquid-blocking element and the first sealing element are constructed as an integral molded part.

[0013] In some examples of this application, the sealing assembly further includes a dust cover, which is sleeved on the outer periphery of the first seal and covers the outer side of the second seal, with a gap between the dust cover and the second seal.

[0014] In some examples of this application, the axial end of the housing is provided with a bearing cap, and the second seal is located between the bearing cap and the dust cover; the dust cover includes a cover body and a dustproof edge, the cover body is sleeved on the outer periphery of the first seal and extends radially along the first seal, the dustproof edge is provided on the side of the cover body away from the first seal and extends axially towards the bearing cap along the first seal, the bearing cap is provided with a dustproof groove, and the dustproof edge is inserted into the dustproof groove.

[0015] In some examples of this application, the bearing cap is further provided with a guide slope opposite to the drain port, and the guide slope is inclined downward in the direction from the outside to the inside of the housing.

[0016] In some examples of this application, the sealing assembly further includes: a stop spring, the stop spring being sleeved on the outer periphery of the first sealing member, and the stop spring being located on the side of the dust cover away from the second sealing member, the stop spring being in a stop-fitting engagement with the side wall of the dust cover away from the second sealing member; the outer periphery of the first sealing member is provided with a stop surface, the stop surface being in a stop-fitting engagement with the side wall of the dust cover near the second sealing member.

[0017] The shaft sealing structure according to this application includes: a shaft and a housing, wherein the outer wall of the housing is provided with a clearance hole, the shaft extends into the housing through the clearance hole, and the shaft is adapted to rotate relative to the housing; and the aforementioned sealing assembly, wherein the sealing assembly is sleeved on the outer periphery of the shaft and covers the outside of the clearance hole to seal the clearance hole.

[0018] According to the shaft seal structure of this application, the shaft seal structure is provided with a sealing component. The liquid blocking element of the sealing component blocks the liquid in the return channel and causes the liquid in the return channel to flow radially along the shaft body to flow back into the housing. Compared with the prior art, it can slow down the flow rate of the liquid discharged in the return channel and reduce the collision and disturbance between the liquid in the return channel and the liquid in the housing, thereby improving the working stability of the shaft transmission device.

[0019] The shaft drive device according to this application includes the aforementioned shaft sealing structure.

[0020] According to the shaft transmission device of this application, the shaft transmission device is provided with a shaft sealing structure, and the shaft sealing structure is provided with a sealing component. The liquid blocking element of the sealing component blocks the liquid in the return channel and causes the liquid in the return channel to flow radially along the shaft body to flow back into the housing. Compared with the prior art, it can slow down the flow rate of the liquid discharged in the return channel and reduce the collision disturbance between the liquid in the return channel and the liquid in the housing, thereby improving the working stability of the shaft transmission device. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the shaft seal structure according to an embodiment of this application;

[0022] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0023] Figure 3 This is a schematic diagram of the first sealing element and the second sealing element after being connected and fitted according to an embodiment of this application;

[0024] Figure 4 This is a cross-sectional view of the first and second sealing elements after they are connected and fitted together according to an embodiment of this application.

[0025] Figure 5 This is a schematic diagram of the first sealing element according to an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the second sealing element according to an embodiment of this application.

[0027] In the diagram, 100 represents the shaft seal structure.

[0028] 10. Sealing assembly; 20. Shaft body; 30. Housing; 40. Bearing cap; 401. Dustproof groove; 50. Bearing; 60. Limiting ring;

[0029] 1. First sealing element; 11. First sealing tooth; 12. Stop surface; 13. Limiting recess;

[0030] 2. Second seal; 21. Second sealing tooth;

[0031] 3. Liquid passage; 4. Liquid return passage;

[0032] 5. Liquid-blocking component; 51. Liquid outlet; 52. Radial liquid-blocking part; 521. Liquid-blocking surface; 53. Axial liquid-blocking part;

[0033] 6. Dust cover; 61. Cover body; 62. Dustproof edge; 63. Dust exhaust notch;

[0034] 7. Stop spring. Detailed Implementation

[0035] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0036] like Figures 1-6As shown in the illustration, a sealing assembly 10 according to an embodiment of this application is used for sealing a shaft drive device. The sealing assembly 10 can be a labyrinth seal assembly, and the shaft drive device can be a device that uses a shaft 20 (e.g., a drive shaft) to transmit power, such as a steam generator or a gearbox. The sealing assembly 10 according to an embodiment of this application includes: a first seal 1 and a second seal 2.

[0037] The first sealing element 1 is adapted to be fixedly sleeved on the outer periphery of the shaft 20. That is, when the shaft 20 rotates around its central axis, the shaft 20 can drive the first sealing element 1 to rotate around its central axis. The outer peripheral wall of the first sealing element 1 is provided with first sealing teeth 11, which extend radially along the first sealing element 1. In some specific embodiments, such as… Figure 1 , Figure 2 , Figure 5 As shown, the outer peripheral wall of the first sealing element 1 may be provided with a plurality of first sealing teeth 11, which are arranged sequentially at intervals along the axial direction of the first sealing element 1. A first fluid passage groove is formed between any two adjacent first sealing teeth 11.

[0038] The second seal 2 is movably fitted onto the outer periphery of the first seal 1. That is, when the first seal 1 is driven to rotate by the shaft 20, the second seal 2 does not rotate with the first seal 1. Furthermore, to ensure the second seal 2 can be smoothly fitted onto the outer periphery of the first seal 1, the second seal 2 can be composed of multiple second sub-seals connected end-to-end. The second seal 2 is suitable for connection and mating with the housing 30. Specifically, the second seal 2 can be fixedly connected to the housing 30 by welding or other methods, or the second seal 2 can be detachably connected to the housing 30 by screwing or other methods, or the first seal 1 can be integrally molded with the housing 30.

[0039] The inner peripheral wall of the second seal 2 is provided with second sealing teeth 21, which extend radially along the second seal 2. In some specific embodiments, such as... Figure 1 , Figure 2 , Figure 6As shown, the outer peripheral wall of the second seal 2 can be provided with multiple second sealing teeth 21, each corresponding to a plurality of first sealing teeth 11, and the multiple second sealing teeth 21 are arranged sequentially at intervals along the axial direction of the second seal 2. A second liquid passage groove is formed between any two adjacent second sealing teeth 21. The second sealing teeth 21 are arranged opposite to the first sealing teeth 11, and each second sealing tooth 21 and its corresponding first sealing tooth 11 form a sealing tooth group. The first liquid passage groove and the second liquid passage groove are arranged opposite to each other. The first liquid passage groove and the second liquid passage groove are combined to form an annular liquid passage channel 3, and the liquid passage channel 3 is located between two adjacent sealing tooth groups. When liquid (e.g., lubricating oil or water) flows from inside the housing 30 to outside the housing 30, the liquid needs to flow sequentially through a tortuous path formed by multiple tooth gaps and the liquid passage channel 3 connected in series. Each tooth gap can throttle the liquid, and each liquid passage channel 3 provides expansion space for the liquid, thereby gradually blocking the liquid from flowing into the sealing assembly 10.

[0040] A return channel 4 extending toward the interior of the housing is also provided between the first seal 1 and the second seal 2. Specifically, the outer peripheral wall of the first seal 1 and / or the inner peripheral wall of the second seal 2 are provided with a return groove extending axially along the first seal 1. The return groove forms the return channel 4, which passes through multiple sealing teeth in sequence. The return channel 4 connects the liquid channel 3 and the interior of the housing 30. Figure 1 As shown, when the shaft 20 extends horizontally, the return channel 4 is located near the bottom end of the sealing assembly 10 in the height direction of the sealing assembly 10. The height direction of the sealing assembly 10 can be defined as... Figure 1 In the vertical direction and from the outside to the inside of the housing 30, the return channel 4 is inclined downwards, so that the liquid in the liquid channel 3 can flow back into the housing 30 more quickly.

[0041] Among them, the outer peripheral wall of the first sealing member 1 near the inside of the housing 30 is also provided with a liquid-blocking member 5, and the inward and outward directions of the housing 30 are as follows: Figure 1 As shown. The liquid-blocking member 5 at least partially blocks the return liquid channel 4 along the axial direction of the first seal 1. A drain port 51 communicating with the return liquid channel 4 is formed between the liquid-blocking member 5 and the second seal 2. The drain port 51 is adapted to allow liquid in the return liquid channel 4 to be discharged radially from the shaft 20 into the return liquid channel 4. In some embodiments, such as Figure 6 As shown, the drain port 51 is located on the outer peripheral wall of the second sealing member 2.

[0042] The liquid-blocking component 5 has a liquid-blocking surface 521 formed on the side wall near the liquid return channel 4. The liquid-blocking surface 521 has an angle with the flow direction of the liquid in the liquid return channel 4. When the liquid in the liquid return channel 4 flows to the liquid-blocking component 5, the liquid-blocking surface 521 can prevent the liquid in the liquid return channel 4 from continuing to flow along the axial direction of the shaft 20 into the housing 30. It can also change the flow direction of the liquid in the liquid return channel 4 and make it flow towards the drain port 51. Then the liquid in the liquid return channel 4 can flow back into the housing 30 from the drain port 51 along the radial direction of the shaft 20, thus realizing the liquid return effect of the liquid return channel 4.

[0043] Therefore, by blocking the liquid in the return channel 4 with the liquid baffle 5 and allowing the liquid in the return channel 4 to flow radially along the shaft 20 back into the housing 30, compared with the prior art, the flow rate of the liquid discharged in the return channel 4 can be slowed down, the collision disturbance between the liquid in the return channel 4 and the liquid in the housing 30 can be reduced, and the working stability of the shaft transmission device can be improved.

[0044] like Figure 1 , Figure 4 , Figure 5 As shown, in some embodiments of this application, the liquid-blocking member 5 includes a radial liquid-blocking portion 52. One end of the radial liquid-blocking portion 52 is fixedly connected to the outer peripheral wall of the first sealing member 1, and the other end extends radially along the first sealing member 1. The radial liquid-blocking portion 52 has the aforementioned liquid-blocking surface 521, which is disposed opposite to the return liquid channel 4 to adjust the flow direction of the liquid in the return liquid channel 4. The radial liquid-blocking portion 52 can block the flow path between the return liquid channel 4 and the housing 30, thereby achieving the technical effect that the liquid in the return liquid channel 4 of the liquid-blocking member 5 is discharged into the housing 30 along the axial direction of the shaft 20.

[0045] like Figure 1 , Figure 4 , Figure 5 As shown, in some embodiments of this application, the liquid-blocking member 5 further includes an axial liquid-blocking portion 53. One end of the axial liquid-blocking portion 53 is connected and engaged with the side of the radial liquid-blocking portion 52 away from the first seal member 1, and the other end of the axial liquid-blocking portion 53 extends along the axial direction of the first seal member 1 toward the second seal member 2, that is, the other end of the axial liquid-blocking portion 53 extends toward... Figure 1 The middle housing 30 extends to the front side, and the other end of the axial liquid-blocking part 53 is spaced apart from the second seal 2 to form a drain port 51. By using the radial liquid-blocking part 52 to block the liquid in the return channel 4, the radial liquid-blocking part 52 can further adjust the liquid flow direction in the return channel 4. At the same time, the radial liquid-blocking part 52 can guide the liquid in the return channel 4 to drain into the housing 30 from near the front end of the housing 30, thereby further slowing down the flow rate of the liquid in the return channel 4 into the housing 30.

[0046] In some embodiments of this application, the liquid-blocking component 5 and the first sealing component 1 are constructed as a single integral part. It can also be understood that the liquid-blocking component 5 and the first sealing component 1 can be manufactured in a single integral manner, such as by casting or machining. This reduces the number of parts in the sealing assembly 10 and lowers the production cost of the sealing assembly 10.

[0047] like Figure 1 As shown, in some embodiments of this application, the sealing assembly 10 may further include: a dust cover 6, which is sleeved on the outer periphery of the first sealing member 1 and covers the outer side of the second sealing member 2. The dust cover 6 is used to prevent dust from entering between the first sealing members 1 and hindering the movement of the first sealing member 1 relative to the second sealing member 2. The dust cover 6 is also used to prevent dust from entering the housing 30 from the gap between the first sealing member 1 and the second sealing member 2, thereby preventing the liquid inside the housing 30 from being contaminated.

[0048] Furthermore, a gap is formed between the dust cover 6 and the second seal 2. When the shaft 20 drives the first seal 1 to rotate the dust cover 6, the gap between the dust cover 6 and the second seal 2 can prevent the dust cover 6 and the second seal 2 from contacting each other, thereby preventing the second seal 2 from obstructing the rotation of the shaft 20 through the dust cover 6.

[0049] like Figure 1 As shown, in some embodiments of this application, a bearing cap 40 may be provided at the axial end of the housing 30. It should be noted that when the shaft 20 rotates relative to the housing 30, in order to reduce the friction between the shaft 20 and the housing 30, a bearing 50 is also provided between the shaft 20 and the housing 30. The bearing 50 is located close to the outer wall of the housing 30. The bearing cap 40 is located on the housing 30 and is used to limit the bearing 50. The bearing cap 40 is sleeved on the outer periphery of the shaft 20 and fixedly connected to the housing 30. In some preferred embodiments, a limiting ring 60 may also be provided between the bearing cap 40 and the bearing 50. The limiting ring 60 is in a stop-fitting engagement with the inner ring of the bearing 50, which can prevent the bearing cap 40 from contacting the outer ring of the bearing 50 and causing the bearing 50 to jam.

[0050] The second seal 2 is located between the bearing cap 40 and the dust cover 6. The dust cover 6 includes a cover body 61 and a dustproof edge 62. The cover body 61 is sleeved on the outer periphery of the first seal 1 and extends radially along the first seal 1. The cover body 61 can block dust moving toward the second seal 2 along the axial direction of the shaft 20.

[0051] A dustproof baffle 62 is disposed on the side of the cover body 61 away from the first seal 1, and extends axially toward the bearing cap 40 along the first seal 1. The dustproof baffle 62 can block dust moving radially toward the second seal 2 along the shaft 20. The bearing cap 40 is provided with a dustproof groove 401, which is located on the side wall of the bearing cap 40 near the outer side of the housing 30. The dustproof baffle 62 is inserted into the dustproof groove 401. By cooperating with the dustproof groove 401, the difficulty of dust entering between the first seal 1 and the second seal 2 from the dust cover 6 and the bearing cap 40 can be increased, thereby further improving the dustproof effect of the sealing assembly 10.

[0052] like Figure 1 As shown, in some embodiments of this application, the outer peripheral wall of the dustproof baffle 62 may also be provided with a dust discharge notch 63. The dust discharge notch 63 is recessed radially inward along the dustproof cover 6 and has an annular structure. The dust discharge notch 63 communicates with the external environment and can store dust, thereby preventing dust from further entering the housing 30 through the gap between the dustproof cover 6 and the bearing cap 40. Furthermore, the inner wall of the exhaust notch can be arc-shaped. When the dust in the exhaust notch rotates with the dustproof cover 6 to near the lower end of the sealing assembly 10, the inner wall of the dust discharge notch 63 allows the dust to be more easily discharged from the dust discharge notch 63 to the external environment, thereby further restricting dust from entering the housing 30.

[0053] like Figure 1 As shown, in some embodiments of this application, the bearing cap 40 is also provided with a guide slope opposite to the drain port 51. The guide slope is inclined downwards in the direction from the outside to the inside of the housing 30. The guide slope can further guide the liquid discharged from the drain port 51, so that the liquid can flow back into the housing 30 more quickly along the guide slope, reducing the accumulation of liquid near the outside of the housing 30.

[0054] like Figure 1 As shown, in some embodiments of this application, the sealing assembly 10 may further include: a stop spring 7, which is sleeved on the outer periphery of the first sealing member 1. In some preferred embodiments, such as... Figure 3 As shown, the outer periphery of the first sealing member 1 is provided with a limiting groove that cooperates with the stop spring 7, and the stop spring 7 extends into the limiting recess 13.

[0055] Furthermore, the stop spring 7 is located on the side of the dust cover 6 away from the second seal 2. The stop spring 7 abuts against the side wall of the dust cover 6 away from the second seal 2. The outer peripheral wall of the first seal 1 is provided with a stop surface 12, which abuts against the side wall of the dust cover 6 near the second seal 2. By cooperating with the stop spring 7, the dust cover 6 can be confined between the stop surface 12 and the stop spring 7, thereby preventing the dust cover 6 from loosening when rotating with the shaft 20, thus reducing the runout of the shaft 20 and improving the working stability of the shaft transmission device.

[0056] Based on this, this application further discloses a shaft sealing structure 100. According to an embodiment of this application, the shaft sealing structure 100 includes: a shaft body 20, a housing 30, and a sealing assembly 10. The outer wall of the housing 30 is provided with a clearance hole. The shaft body 20 extends into the housing 30 through the clearance hole and is adapted to rotate relative to the housing 30. The sealing assembly 10 is the same as the sealing assembly 10 described in the above embodiment. The sealing assembly 10 is sleeved on the outer periphery of the shaft body 20 and covers the outside of the clearance hole to seal it.

[0057] By using a shaft seal structure 100 within the shaft drive device, the outflow of liquid from the housing 30 to the outside of the housing 30 can be restricted, thereby achieving a good sealing effect within the housing 30. According to an embodiment of this application, the shaft seal structure 100 is provided with a sealing component 10. By having the liquid-blocking member 5 of the sealing component 10 block the liquid in the return channel 4, and by allowing the liquid in the return channel 4 to flow radially along the shaft 20 back into the housing 30, compared to the prior art, the flow rate of the liquid discharged from the return channel 4 can be slowed down, reducing the collision and disturbance between the liquid in the return channel 4 and the liquid in the housing 30, thereby improving the operational stability of the shaft drive device.

[0058] Based on this, this application further discloses a shaft drive device. According to an embodiment of this application, the shaft drive device includes the shaft sealing structure 100 described above. The shaft drive device can be a power transmission device for a steam generator, in which case the liquid inside the housing 30 is water droplets generated by the condensation of water vapor. Alternatively, the shaft drive device can also be a gearbox, in which case the liquid inside the gearbox housing 30 is lubricating oil or the like.

[0059] According to the shaft transmission device of the present application embodiment, the shaft transmission device has a shaft sealing structure 100, and the shaft sealing structure 100 is provided with a sealing component 10. By blocking the liquid in the return channel 4 with the liquid baffle 5 of the sealing component 10, and causing the liquid in the return channel 4 to flow radially along the shaft body 20 to flow back into the housing 30, compared with the prior art, the flow rate of the liquid discharged in the return channel 4 can be slowed down, the collision and disturbance between the liquid in the return channel 4 and the liquid in the housing 30 can be reduced, thereby preventing turbulence from occurring in the housing 30, and thus improving the working stability of the shaft transmission device.

[0060] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A sealing assembly for a shaft drive device, characterized in that, The sealing assembly includes: A first sealing element is adapted to be fixedly sleeved on the outer peripheral side of the shaft, and the outer peripheral wall of the first sealing element is provided with first sealing teeth. The second sealing element is movably sleeved on the outer periphery of the first sealing element. The second sealing element is adapted to connect and cooperate with the housing. The inner peripheral wall of the second sealing element is provided with second sealing teeth. The second sealing teeth are arranged opposite to the first sealing teeth and form a sealing tooth group. A liquid passage is formed between any two adjacent sealing tooth groups. A liquid return channel extending toward the inside of the housing is also provided between the first sealing element and the second sealing element. The liquid return channel connects the liquid passage and the inside of the housing. The first seal is provided with a liquid-blocking member on the outer peripheral wall near the housing. The liquid-blocking member at least partially blocks the return liquid channel along the axial direction of the first seal. The liquid-blocking member and the second seal form a drain port communicating with the return liquid channel. The drain port is adapted to allow liquid in the return liquid channel to be discharged radially from the shaft into the return liquid channel.

2. The sealing assembly according to claim 1, characterized in that, The liquid-blocking component includes a radial liquid-blocking portion. One end of the radial liquid-blocking portion is fixedly connected to the outer peripheral wall of the first sealing component, and the other end extends radially along the first sealing component. The radial liquid-blocking portion has a liquid-blocking surface, which is disposed opposite to the return liquid channel to adjust the flow direction of the liquid in the return liquid channel.

3. The sealing assembly according to claim 2, characterized in that, The liquid-blocking component further includes an axial liquid-blocking portion, one end of which is connected and engaged with the side of the radial liquid-blocking portion away from the first seal, and the other end of which extends along the axial direction of the first seal toward the second seal, and the other end of which is spaced apart from the second seal to form the drain port.

4. The sealing assembly according to claim 2, characterized in that, The liquid-blocking component and the first sealing component are constructed as an integral molded part.

5. The sealing assembly according to claim 1, characterized in that, Also includes: A dust cover is fitted around the outer periphery of the first sealing member and covers the outer side of the second sealing member, with a gap between the dust cover and the second sealing member.

6. The sealing assembly according to claim 5, characterized in that, The axial end of the housing is provided with a bearing cover, and the second seal is located between the bearing cover and the dust cover; The dust cover includes a cover body and a dustproof edge. The cover body is sleeved on the outer periphery of the first sealing member and extends radially along the first sealing member. The dustproof edge is located on the side of the cover body away from the first sealing member and extends axially towards the bearing cover along the first sealing member. The bearing cover has a dustproof groove, and the dustproof edge is inserted into the dustproof groove.

7. The sealing assembly according to claim 6, characterized in that, The bearing cap is also provided with a guide slope opposite to the drain port, and the guide slope is inclined downwards in the direction from the outside to the inside of the housing.

8. The sealing assembly according to claim 6, characterized in that, Also includes: A stop spring is sleeved on the outer periphery of the first seal, and the stop spring is located on the side of the dust cover away from the second seal. The stop spring is in a stop-fitting engagement with the side wall of the dust cover away from the second seal. The outer peripheral wall of the first seal is provided with a stop surface, which abuts against the side wall of the dust cover near the second seal.

9. A shaft seal structure, characterized in that, include: A shaft and a housing, wherein the outer wall of the housing is provided with a clearance hole, the shaft extends into the housing through the clearance hole, and the shaft is adapted to rotate relative to the housing; According to any one of claims 1-8, the sealing assembly is sleeved on the outer peripheral side of the shaft body, and the sealing assembly covers the outside of the clearance hole to seal the clearance hole.

10. A shaft transmission device, characterized in that, Includes the shaft seal structure according to claim 9.

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