Through shaft assembly and dual axle drive system

Abstract

The application relates to a through shaft assembly, which comprises a shaft body and an oil seal seat, the shaft body is provided with a sealing shaft shoulder, the oil seal seat is provided with an oil seal opening, the shaft body is inserted into the oil seal opening, the oil seal opening is provided with a stepped inner wall, the sealing shaft shoulder is provided with a shaft shoulder outer wall, an oil seal cavity is formed between the stepped inner wall and the shaft shoulder outer wall, an oil seal piece is arranged in the oil seal opening, the oil seal piece is arranged at one end of the oil seal cavity, the other end of the oil seal cavity is in abutment with the sealing shaft shoulder, and the oil seal cavity is sealed through the oil seal piece and the sealing shaft shoulder. The other end of the through shaft is sealed through the sealing shaft shoulder, thereby replacing a dust cover in the prior art, avoiding the problem of oil seal failure caused by dust cover failure, reducing the possibility of dust and particulate matter directly entering the oil seal of the through shaft, increasing the effectiveness of the oil seal, and reducing the possibility of wear failure of the through shaft.

Description

Technical Field

[0001] This application relates to the field of commercial vehicle drive structure technology, and in particular to through-shaft assemblies and dual-axle drive systems. Background Technology

[0002] Commercial vehicles are mainly driven by single-axle drive and dual-axle drive. Currently, dual-axle drive commercial vehicles typically have a through shaft installed inside the middle drive axle of the twin-axle system, connecting to the rear axle. The torque from the engine input shaft is transmitted to the rear axle through the through shaft, thereby providing stable and reliable power to both rear axles and ensuring the driving stability of the commercial vehicle.

[0003] Currently, due to the harsh working environment of commercial vehicle engines, dust and particulate matter from cylinder combustion are easily generated after long-term use. Existing through shafts are usually equipped with dust covers. By installing the dust cover between the oil seal seat and the through shaft, the possibility of dust and particulate matter entering the oil seal of the through shaft is reduced.

[0004] However, existing dust covers often fail in actual use due to assembly errors, the fragility of the dust cover material itself, and damage caused by bumps during transportation. This results in dust and particles directly entering the oil seal of the through shaft, causing the oil seal to fail, and in severe cases, even causing the through shaft to wear or fail. Summary of the Invention

[0005] Therefore, it is necessary to provide a through-shaft assembly and a dual-axle drive system to address the problem that dust covers are prone to failure during use.

[0006] This application provides a through-shaft assembly, including:

[0007] Shaft body, the shaft body being provided with a sealing shoulder

[0008] An oil seal seat is provided with an oil seal opening inside. The shaft body is inserted into the oil seal opening. The oil seal opening is provided with a stepped inner wall. The sealing shaft shoulder is provided with a shoulder outer wall. An oil seal cavity is formed between the stepped inner wall and the shoulder outer wall. An oil seal element is provided inside the oil seal opening. The oil seal element is provided at one end of the oil seal cavity.

[0009] The other end of the oil seal cavity abuts against the sealing shoulder, and the oil seal cavity is sealed by the oil seal and the sealing shoulder.

[0010] In one embodiment, the oil seal opening includes a first step and a second step arranged along the opening direction, the inner wall of the step is disposed on the second step, and the shaft body also includes an auxiliary shaft shoulder;

[0011] When there is a gap at the contact point between the oil seal cavity and the sealing shoulder, a first oil passage is formed between the auxiliary shoulder and the first step. One end of the first oil passage is connected to the oil seal cavity through the gap, and the other end of the first oil passage abuts against the auxiliary shoulder to seal the first oil passage.

[0012] In one embodiment, the sealing shoulder is provided with a first groove, and the oil seal opening is provided with a first protrusion. The first groove and the first protrusion fit together to separate the oil seal cavity from the first oil passage.

[0013] In one embodiment, a second groove is provided in the oil seal opening, and multiple first protrusions are provided. The number of first grooves is the same as the number of first protrusions, and several first protrusions are arranged in the second groove along the radial direction of the shaft body.

[0014] In one embodiment, the through shaft assembly further includes a bridge housing surrounding the oil seal seat, and the bridge housing and the oil seal seat are fixedly connected.

[0015] In one embodiment, the oil seal seat forms an oil leakage gap after being connected to the bridge housing. The oil seal seat is provided with a third groove, and a sealing element is provided in the third groove. The sealing element abuts against the third groove and the bridge housing respectively to seal the oil leakage gap.

[0016] In one embodiment, the axle housing is further provided with a bearing, a locking nut, and a limiting washer. The bearing, the locking nut, and the limiting washer are all sleeved on the shaft body. The bearing abuts against the third shaft shoulder. The limiting washer is disposed between the bearing and the locking nut. One end of the limiting washer abuts against the bearing, and the other end of the limiting washer abuts against the locking nut.

[0017] In one embodiment, the bridge housing is provided with a first mounting hole, the oil seal seat is provided with a second mounting hole, the first mounting hole is provided with a first bolt, and the first mounting hole and the second mounting hole are threadedly connected by the first bolt.

[0018] In one embodiment, the shaft body has a stepped opening inside to reduce the weight of the shaft body.

[0019] This application also provides a dual-axle drive system, including the aforementioned through-shaft assembly.

[0020] In use, the aforementioned through-shaft assembly involves inserting the shaft body into the oil seal cavity. The oil seal is then installed by placing the oil seal component inside the oil seal cavity. Finally, a sealing shoulder is placed over the oil seal opening, replacing the dust cover in traditional technology. This avoids the problem of oil seal failure caused by dust cover failure, reduces the possibility of dust and particles directly entering the through-shaft oil seal, increases the effectiveness of the oil seal, and reduces the possibility of through-shaft wear failure. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the shaft body according to an embodiment of this application.

[0022] Figure 2 This is a partial cross-sectional view of a through shaft assembly according to an embodiment of this application.

[0023] Figure 3 for Figure 2 A partial sectional view of the through shaft assembly.

[0024] Figure 4 This is a partial cross-sectional view of an oil seal seat according to an embodiment of this application.

[0025] Figure 5 This is a front view of an oil seal seat according to an embodiment of this application.

[0026] Icon labels:

[0027] 10. Shaft body; 11. Sealing shoulder; 111. Shoulder outer wall; 112. First groove; 12. Auxiliary shoulder; 13. Stepped opening; 14. Input end; 20. Oil seal seat; 21. Oil seal opening; 211. First step; 2111. Step inner wall; 212. Second step; 213. First protrusion; 22. Oil seal; 23. Oil seal cavity; 24. First oil passage; 25. Second groove; 26. Third groove; 261. Seal; 27. Second mounting hole; 28. Sealing edge; 29. ​​First bolt; 30. Bridge housing; 31. Bearing; 32. Locking nut; 33. Limiting washer; 34. First mounting hole. Detailed Implementation

[0028] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0029] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0034] A drive axle typically consists of a final drive, differential, wheel transmission, and drive axle housing. Steering drive axles also include constant velocity joints. Furthermore, the drive axle must withstand vertical, longitudinal, and lateral forces acting between the road surface and the vehicle frame or body, as well as braking torque and reaction forces. Commercial vehicles primarily use single-axle drive and dual-axle drive systems. Current dual-axle drive commercial vehicles typically employ a through-shaft within the middle drive axle of a twin-axle configuration, connecting to the rear axles. This through-shaft transmits the engine input shaft torque to the rear axles, providing stable and reliable power to both rear axles and ensuring the vehicle's driving stability.

[0035] However, the applicant discovered that current through-shaft output end structures all use separate dust cover structures, with the dust covers exposed. These dust covers are easily damaged during transportation and during assembly, leading to misalignment and damage. This negatively impacts the dust cover's dustproof function, weakening its dustproof capability and further causing lubricant contamination and abnormal wear of transmission components.

[0036] Based on the above considerations, the applicant proposed a through-shaft assembly, which forms a first layer of seal by fitting the stepped inner wall and the outer wall of the shaft shoulder together, and then forms a second layer of seal by fitting the auxiliary shaft shoulder and the oil seal seat together. By replacing the dust cover in the traditional technology with a double-layer seal, the possibility of dust and particulate matter directly entering the oil seal of the through-shaft is reduced, the effectiveness of the oil seal is increased, and the possibility of wear failure of the through-shaft is reduced.

[0037] Please see Figures 1 to 5 , Figure 1 This is a three-dimensional structural diagram of the shaft body 10 according to an embodiment of this application. Figure 2 This is a partial cross-sectional view of a through shaft assembly according to an embodiment of this application. Figure 3 for Figure 2 A partial sectional view of the through shaft assembly. Figure 4 This is a partial cross-sectional view of an oil seal seat 20 according to an embodiment of this application. Figure 5 This is a front view of an oil seal seat 20 according to an embodiment of this application.

[0038] Please refer to it again. Figure 1 and Figure 2This application provides a dual-bridge drive system, mainly including a through shaft assembly. The through shaft assembly includes a shaft body 10 and an oil seal seat 20. The shaft body 10 is provided with a sealing shoulder 11. The oil seal seat 20 is provided with an oil seal opening 21. The shaft body 10 is inserted into the oil seal opening 21. The oil seal opening 21 is provided with a stepped inner wall 2111. The sealing shoulder 11 is provided with a shoulder outer wall 111. An oil seal cavity 23 is formed between the stepped inner wall 2111 and the shoulder outer wall 111. An oil seal element 22 is provided in the oil seal opening 21. The oil seal element 22 is provided at one end of the oil seal cavity 23. The other end of the oil seal cavity 23 abuts against the sealing shoulder 11. The oil seal cavity 23 is sealed by the oil seal element 22 and the sealing shoulder 11.

[0039] In use, the shaft body 10 is inserted into the oil seal opening 21. An oil seal cavity 23 is formed between the outer wall 111 of the shaft shoulder and the inner wall 2111 of the stepped shaft. An oil seal component 22 is provided at one end of the oil seal cavity 23 to complete the oil seal setting of the through shaft. Then, the other end of the through shaft is sealed by the sealing shaft shoulder 11, thereby replacing the dust cover in the traditional technology. This avoids the problem of oil seal failure caused by dust cover failure, reduces the possibility of dust and particulate matter directly entering the oil seal of the through shaft, increases the effectiveness of the oil seal, and reduces the possibility of wear failure of the through shaft.

[0040] Optionally, in some embodiments, the oil seal 22 includes a rubber-plastic sealing element, a rotary shaft lip seal, and other sealing elements that can reduce lubricant leakage. The specific sealing element selected as the oil seal 22 can be chosen according to actual usage requirements, and this application does not limit this. In some embodiments, such as Figure 2 As shown, the outer diameter of the auxiliary shoulder 12 is larger than the outer diameter of the sealing shoulder 11. By limiting the size of the outer diameter of the shoulder, on the one hand, the outer wall 111 of the shoulder can be tightly attached to the inner wall 2111 of the step; on the other hand, it can also reduce the process and reduce the weight of the through shaft, thereby making the shaft body and the overall weight of the through shaft lower and easier to carry.

[0041] In some specific embodiments, the oil seal opening 21 includes a first step 211 and a second step 212 arranged along the opening direction. The inner wall 2111 of the step is arranged on the second step 212. The shaft body 10 also includes an auxiliary shoulder 12. When there is a gap at the abutment of the oil seal cavity 23 and the sealing shoulder 11, a first oil passage 24 is formed between the auxiliary shoulder 12 and the first step 211. One end of the first oil passage 24 is connected to the oil seal cavity 23 through the gap, and the other end of the first oil passage 24 abuts against the auxiliary shoulder 12 to seal the first oil passage 24.

[0042] Specifically, such as Figure 2As shown, the first oil passage 24 is sealed by the auxiliary shaft shoulder 12, so that the auxiliary shaft shoulder 12 and the first step can form a second layer of seal outside the oil seal cavity 23, which further enhances the sealing effect of the through shaft assembly; in some specific embodiments, the projected area of ​​the oil seal opening 21 on the auxiliary shaft shoulder 12 along the axial direction of the shaft body 10 is smaller than the projected area of ​​the auxiliary shaft shoulder 12 along the axial direction of the shaft body 10.

[0043] Optionally, the oil seal seat 20 only needs to abut against the auxiliary shaft shoulder 12 to enable the auxiliary shaft shoulder 12 to have a sealing effect. Specifically, in some embodiments, the size of the contact surface between the oil seal seat 20 and the auxiliary shaft shoulder 12 also affects the sealing performance and sealing effect of the auxiliary shaft shoulder 12. By limiting the projected area of ​​the oil seal opening 21 along the axial direction of the shaft body 10 on the auxiliary shaft shoulder 12 to be smaller than the projected area of ​​the auxiliary shaft shoulder 12 along the axial direction of the shaft body 10, the auxiliary shaft shoulder 12 can cover the entire oil seal opening 21 while fitting against the oil seal seat 20, thereby further improving the sealing performance and sealing effect of the auxiliary shaft shoulder 12.

[0044] Please refer to it again. Figure 2 and Figure 3 In some specific embodiments, the sealing shoulder 11 is provided with a first groove 112, and the oil seal opening 21 is provided with a first protrusion 213. The first protrusion 213 surrounds the oil seal 22, and the first groove 112 and the first protrusion 213 fit together to separate the oil seal 22 from the stepped inner wall 2111.

[0045] Specifically, by setting the first protrusion 213 and the first groove 112, on the one hand, the first protrusion 213 and the first groove 112 can play a positioning role during installation, reducing the leakage of the oil seal opening 21 due to installation errors; on the other hand, by fitting the first protrusion 213 and the first groove 112 together, the oil seal 22 and the stepped inner wall 2111 are separated, providing a third layer of sealing protection for the oil seal opening 21, reducing the possibility of oil seal leakage from the oil seal 22 to the stepped inner wall 2111, further reducing the possibility of oil seal leakage to the outside, and also reducing the possibility of external dust entering the oil seal.

[0046] Please refer to it again. Figure 3 and Figure 5 In some specific embodiments, a second groove 25 is provided in the oil seal opening 21, and multiple first protrusions 213 are provided, with several first protrusions 213 arranged in the second groove 25 along the radial direction of the shaft body 10.

[0047] Alternatively, a groove can be provided on the oil seal opening 21, and a protrusion can be provided on the sealing shoulder 11 to form a sealing edge 28 to separate the oil seal and the stepped inner wall; a groove and a protrusion can also be provided at the abutment of the stepped inner wall 2111 and the shoulder outer wall 111, or a protrusion can be provided instead of a protrusion to complete the seal. In short, as long as the oil seal 22 and the stepped inner wall 2111 can be separated, the specific setting can be set according to the actual use requirements.

[0048] Specifically, by setting a second groove 25 inside the oil seal opening 21 and setting a number of first protrusions 213 inside the second groove 25, on the one hand, setting a number of first protrusions 213 can reduce the overall weight of the oil seal seat 20 compared to setting a whole protruding edge; on the other hand, by setting the second groove 25, the weight of the oil seal seat 20 can be further reduced, and the portability of the oil seal seat 20 can be improved.

[0049] Please refer to it again. Figure 1 and Figure 2 In some specific embodiments, a stepped opening 13 is provided inside the shaft body 10 to reduce the weight of the shaft body 10. Specifically, by providing the stepped opening 13, on the one hand, the stepped shape of the stepped opening 13 fits the shape of the auxiliary shaft shoulder 12, the sealing shaft shoulder 11 and the shaft body 10. Compared with directly providing a through opening or a straight opening, the stepped opening 13 can better ensure the strength of the auxiliary shaft shoulder 12, the sealing shaft shoulder 11 and the shaft body 10, and reduce the possibility of breakage of the auxiliary shaft shoulder 12, the sealing shaft shoulder 11 and the shaft body 10. On the other hand, the volume of the stepped opening 13, compared with other opening methods, can further reduce the weight of the shaft body 10 and improve the portability of the shaft body 10.

[0050] Please refer to it again. Figure 2 and Figure 3 In some specific embodiments, the through-shaft assembly also includes an axle housing 30, which surrounds the oil seal seat 20, and the axle housing 30 and the oil seal seat 20 are fixedly connected. Specifically, in some embodiments, the main reducer, differential, and half-shaft can also be installed inside the axle housing 30. Whether to select the main reducer, differential, and half-shaft can be set according to actual usage requirements. In one embodiment, the axle housing 30 can be connected to the frame or carriage via a longitudinally arranged leaf spring. By setting the axle housing 30, the axle body 10 and the oil seal seat 20 can be supported and protected, reducing the possibility of failure of the axle body 10 and the oil seal seat 20 due to collision with the longitudinally arranged leaf spring, the frame, and the carriage.

[0051] Please refer to it again. Figure 3 and Figure 4In some specific embodiments, the oil seal seat 20 is provided with a third groove 26, and a sealing element 261 is provided in the third groove 26. One end of the sealing element 261 abuts against the third groove 26, and the other end of the sealing element 261 abuts against the bridge housing 30. Specifically, in some embodiments, such as Figure 4 As shown, the third groove 26 can be set on the mating surface of the oil seal seat 20 and the bridge housing 30. By setting the sealing element 261, one end of the sealing element 261 is attached to the third groove 26, and the other end is attached to the inner wall of the bridge housing 30, the problem of oil leakage at the mating surface of the oil seal seat 20 and the bridge housing 30 is solved, and the possibility of oil leakage at the mating surface of the oil seal seat 20 and the bridge housing 30 is reduced.

[0052] Please refer to it again. Figure 2 and Figure 3 In some specific embodiments, the bridge housing 30 is further provided with a bearing 31, a locking nut 32 and a limiting washer 33. The bearing 31, the locking nut 32 and the limiting washer 33 are all sleeved on the shaft body 10. The bearing 31 and the shaft body 10 abut against each other. The limiting washer 33 is disposed between the bearing 31 and the locking nut 32. One end of the limiting washer 33 abuts against the bearing 31 and the other end of the limiting washer 33 abuts against the locking nut 32.

[0053] Specifically, the contact between the shaft body 10 and the bearing 31 can serve as a limiting action, reducing the possibility of the shaft body 10 shaking; the locking nut 32 is used to fix the bearing 31 and the shaft body 10, reducing the movement or offset of the shaft body 10 and the bearing 31 along the axial direction of the shaft body 10; the limiting washer 33 is used to limit the locking nut 32 and the bearing 31, reducing the movement of the locking nut 32 and the bearing 31. The locking nut 32, the bearing 31 and the limiting washer 33 form a limiting action on the shaft body 10, reducing the possibility of the shaft body 10 shaking and moving along the axial direction, thus increasing the reliability of the shaft body 10.

[0054] Please refer to it again. Figure 2 and Figure 3 In some specific embodiments, the axle housing 30 is provided with a first mounting hole 34, and the oil seal seat 20 is provided with a second mounting hole 27. A first bolt 29 is provided in the first mounting hole 34, and the first mounting hole 34 and the second mounting hole 27 are connected by the first bolt 29. Specifically, the oil seal seat 20 and the axle housing 30 are connected by the first bolt 29, which not only makes the connection between the oil seal seat 20 and the axle housing 30 tight and reliable, but also allows the oil seal seat 20 and the axle housing 30 to be installed or disassembled separately according to the actual use scenario, further improving the versatility of the axle housing 30 and the oil seal seat 20.

[0055] In the above-mentioned dual-bridge drive system, the shaft body 10 is inserted into the oil seal seat 20 with the input end 14 as the head. The first layer of seal is formed by the step inner wall 2111 and the outer wall 111 of the shaft shoulder. The second layer of seal is formed by the auxiliary shaft shoulder 12 and the oil seal seat 20. Finally, the third layer of seal is formed by the first groove 112 and the first protrusion 213. The three-layer seal replaces the dust cover in the traditional technology, reducing the possibility of dust and particles directly entering the oil seal of the through shaft, increasing the effectiveness of the oil seal, and reducing the possibility of wear failure of the through shaft.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A through-shaft assembly, characterized in that, The through shaft assembly includes: Shaft body (10), wherein the shaft body (10) is provided with a sealing shoulder (11); Oil seal seat (20), the oil seal seat (20) is provided with an oil seal cavity (23), the shaft body (10) is inserted into the oil seal cavity (23), and an oil seal component (22) is provided in the oil seal cavity (23); The oil seal cavity (23) is provided with an oil seal opening (21), and the sealing shoulder (11) covers the oil seal opening (21); The oil seal cavity (23) includes a continuous first step (211) and a second step (212), and the oil seal opening (21) is located at the first step (211); The shaft body (10) is provided with an auxiliary shaft shoulder (12), one end of which is connected to the sealing shaft shoulder (11). The sealing shaft shoulder (11) is provided with a shaft shoulder outer wall (111), and the first step (211) is provided with a step inner wall (2111). When there is a gap at the connection between the oil seal cavity (23) and the sealing shoulder (11), a first oil passage (24) is formed between the outer wall (111) of the shoulder and the inner wall (2111) of the step. One end of the first oil passage (24) is connected to the oil seal cavity (23) through the gap, and the other end of the auxiliary shoulder (12) is covered on the first oil passage (24) to seal the first oil passage (24).

2. The through-shaft assembly according to claim 1, characterized in that, The sealing shoulder (11) is provided with a first groove (112), and the oil seal opening (21) is provided with a first protrusion (213). The first groove (112) and the first protrusion (213) fit together to separate the oil seal cavity (23) and the first oil passage (24).

3. The through-shaft assembly according to claim 2, characterized in that, The oil seal opening (21) is provided with a second groove (25), and a plurality of first protrusions (213) are provided. The number of first grooves (112) is the same as the number of first protrusions (213). A plurality of first protrusions (213) are arranged in the second groove (25) along the radial direction of the shaft body (10).

4. The through-shaft assembly according to claim 1, characterized in that, The through shaft assembly also includes a bridge housing (30), which surrounds the oil seal seat (20), and the bridge housing (30) and the oil seal seat (20) are fixedly connected.

5. The through-shaft assembly according to claim 4, characterized in that, After the oil seal seat (20) is connected to the bridge housing (30), an oil leakage gap is formed. The oil seal seat (20) is provided with a third groove (26). A sealing element (261) is provided in the third groove (26). The sealing element (261) abuts against the third groove (26) and the bridge housing (30) respectively, and is used to seal the oil leakage gap.

6. The through-shaft assembly according to claim 5, characterized in that, The third groove (26) is disposed on the mating surface between the oil seal seat (20) and the bridge housing (30).

7. The through-shaft assembly according to claim 4, characterized in that, The bridge housing (30) is also provided with a bearing (31), a locking nut (32) and a limiting washer (33). The bearing (31), the locking nut (32) and the limiting washer (33) are all sleeved on the shaft body (10). The bearing (31) and the shaft body (10) abut against each other. The limiting washer (33) is disposed between the bearing (31) and the locking nut (32). One end of the limiting washer (33) abuts against the bearing (31) and the other end of the limiting washer (33) abuts against the locking nut (32).

8. The through-shaft assembly according to claim 4, characterized in that, The bridge housing (30) is provided with a first mounting hole (34), the oil seal seat (20) is provided with a second mounting hole (27), the first mounting hole (34) is provided with a first bolt (29), and the first mounting hole (34) and the second mounting hole (27) are threadedly connected by the first bolt (29).

9. The through-shaft assembly according to claim 1, characterized in that, The shaft body (10) has a stepped opening (13) inside, which is used to reduce the weight of the shaft body (10).

10. A dual-axle drive system, characterized in that, Includes the through shaft assembly as described in any one of claims 1-9.

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