Waterproof sealing element and sealing device of intermediate shaft of automobile steering device

Abstract

The invention discloses a waterproof sealing piece and a sealing device of an intermediate shaft of an automobile steering gear, the waterproof sealing piece comprises a framework and an elastic body, the elastic body comprises a base body and a sealing part, the base body is integrally formed on the inner circumferential side of the framework, the sealing part is arranged on the inner circumferential side of the base body, and the two axial sides of the base body are an air side and a sealing side respectively; the sealing part comprises a first sealing lip, a second sealing lip and a third sealing lip which are arranged at intervals in the axial direction, the first sealing lip is arranged close to the air side, the third sealing lip is arranged close to the sealing side, and the second sealing lip is arranged between the first sealing lip and the third sealing lip; after the waterproof sealing piece is arranged at the preset position of the shaft in a sleeving mode, the first sealing lip, the second sealing lip and the third sealing lip are all in interference fit with the shaft, the interference magnitude of the first sealing lip and the shaft is larger than that of the second sealing lip and the shaft, and the interference magnitude of the second sealing lip and the shaft is larger than that of the third sealing lip and the shaft. The waterproof sealing element adopts a three-seal combined design, and the waterproof sealing effect is good.

Description

Technical Field

[0001] This invention relates to the field of sealing technology, and in particular to a waterproof seal and a sealing device for the intermediate shaft of an automotive steering gear. Background Technology

[0002] In the passenger car and commercial vehicle industries, both new energy and traditional energy vehicle manufacturers have raised higher requirements for the waterproofing capabilities of automobiles; for the steering gear intermediate shaft guard assembly, water must not enter the driver's cabin when the vehicle is wading through water.

[0003] The existing waterproof structure of the intermediate shaft of automotive steering systems usually adopts a sealing structure with a K-type sealing ring and a retaining ring. Because the interference of the K-type sealing ring is small, it has been confirmed by tests that water leakage occurs after one hour of operation in a water-immersed state, indicating poor waterproof performance. Summary of the Invention

[0004] The purpose of this invention is to provide a waterproof seal to solve the problem of poor waterproof performance in existing waterproof sealing structures for intermediate shafts of automotive steering systems; another purpose of this invention is to provide a sealing device for the intermediate shaft of an automotive steering system that includes the waterproof seal.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention proposes a waterproof sealant comprising a skeleton and an elastomer, both of which are annular structures, wherein: The elastomer includes a matrix and a sealing part. The matrix is ​​integrally formed on the inner circumferential side of the skeleton, and the sealing part is disposed on the inner circumferential side of the matrix. The first side of the matrix in the axial direction is the air side, and the second side of the matrix in the axial direction is the sealing side. The sealing part includes a first sealing lip, a second sealing lip and a third sealing lip that are spaced apart along the axial direction. The first sealing lip is disposed near the air side, the third sealing lip is disposed near the sealing side, and the second sealing lip is disposed between the first sealing lip and the third sealing lip. After the waterproof seal is installed on the shaft, the first sealing lip, the second sealing lip, and the third sealing lip are all interference fit with the shaft. The interference between the first sealing lip and the shaft is greater than that between the second sealing lip and the shaft, and the interference between the second sealing lip and the shaft is greater than that between the third sealing lip and the shaft.

[0006] Optionally, the first sealing lip includes a first lip waist, a first bevel, and a second bevel, wherein: The first lip waist is annular, and the outer peripheral end of the first lip waist is an integral structure with the second sealing lip. The inner peripheral end of the first lip waist extends toward the air side and is inclined near the center of the elastomer. The first and second inclined surfaces are located at the inner periphery of the first lip waist. Both the first and second inclined surfaces are annular. The outer periphery of the first and second inclined surfaces intersect to form the first lip tip.

[0007] Optionally, the second sealing lip includes a second lip waist, a third bevel, and a fourth bevel, wherein: The second lip waist is annular, and the outer peripheral end of the second lip waist is an integral structure with the substrate. The inner peripheral end of the second lip waist extends toward the first sealing lip and is inclined near the center of the elastomer. The inner peripheral end of the second lip waist and the outer peripheral end of the first lip waist are an integral structure. The third and fourth inclined surfaces are located at the inner circumferential end of the second lip waist. Both the third and fourth inclined surfaces are annular, and the outer circumferential ends of the third and fourth inclined surfaces intersect to form the second lip tip. The length of the first lip waist is greater than the length of the second lip waist, and the width of the first lip waist is less than the width of the second lip waist.

[0008] Optionally, the third sealing lip includes a fifth bevel and a sixth bevel, wherein: The fifth and sixth bevels are located at the inner circumferential ends of the second lip waist. Both the fifth and sixth bevels are annular, and their outer circumferential ends intersect to form the third lip tip.

[0009] Optionally, the axial distance between the first lip tip and the second lip tip is greater than the axial distance between the second lip tip and the third lip tip.

[0010] Optionally, a ring of protrusions is provided on the outer peripheral surface of the second lip waist, a ring of first recesses is provided on the outer peripheral surface of the second lip waist on the side of the protrusions near the air side, and a ring of second recesses is provided on the outer peripheral surface of the second lip waist on the side of the protrusions near the sealing side.

[0011] Optionally, the contact surface between the first sealing lip and the shaft is pear-shaped using a grinding tool.

[0012] Optionally, both the substrate and the sealing part are made of EPDM rubber material and are integrally molded by compression molding.

[0013] Optionally, the cross-section of the skeleton is "L" shaped, the elastomer completely or partially covers the skeleton, a first chamfer is provided at the outer peripheral end of the elastomer near the air side, and a second chamfer is provided at the outer peripheral end of the elastomer near the sealing side.

[0014] Secondly, the present invention also provides a sealing device for the intermediate shaft of an automotive steering gear, comprising a dustproof sleeve and two of the aforementioned waterproof seals, wherein: The dust cover is fitted around the shaft, which is the intermediate shaft of the car steering system; The dustproof cylinder has two rings of mounting steps spaced apart inside. A waterproof seal is pressed onto each mounting step, and the elastic body of the two waterproof seals is oriented in the same direction along the axial direction.

[0015] The waterproof seal and the sealing device for the intermediate shaft of an automotive steering gear provided by this invention have the following advantages: 1) It adopts a three-seal combination design. The outermost first sealing lip has a large interference fit and plays the main sealing role. The second and third sealing lips play an auxiliary sealing role. It has a good waterproof sealing effect. After testing, it has been confirmed that it does not leak water after 1000 hours of operation in a submerged state.

[0016] 2) The first sealing lip has a slender structure, which makes the contact area with the shaft wider and can effectively prevent mud and water from entering. The contact surface between the first sealing lip and the shaft is treated with a pear-shaped surface, which makes the durable sealing performance of the first sealing lip more stable, while reducing the lip torque and avoiding potential problems such as difficulty in rotation and abnormal noise.

[0017] 3) The interference of the third sealing lip is small, which not only prevents mud and water from entering, but also mainly supports the second sealing lip. This allows the second sealing lip to make more stable contact with the shaft in cases of eccentricity or tilt, thus ensuring the sealing stability of the second sealing lip.

[0018] 4) The design of the protrusion, the first recess and the second recess can improve the follow-up of the second sealing lip and the third sealing lip, reduce the clamping force of the second sealing lip and the third sealing lip on the shaft, and thus reduce the lip torque.

[0019] 5) Both the base and the sealing part are made of EPDM rubber material, which improves the sealing part's resistance to mud and water and further enhances the waterproof effect. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of the waterproof seal provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the sealing device for the intermediate shaft of an automotive steering gear provided in an embodiment of the present invention.

[0021] Figure 1 and Figure 2 The following reference numerals are included: Waterproof seal 10; Skeleton 20; Elastomer 30: Matrix 31, sealing part 32, first sealing lip 33, first lip waist 330, first inclined surface 331, second inclined surface 332, first lip tip 333, second sealing lip 34, second lip waist 340, third inclined surface 341, fourth inclined surface 342, second lip tip 343, third sealing lip 35, fifth inclined surface 350, sixth inclined surface 351, third lip tip 352; Shaft 40; Protrusion 50, first recess 51, second recess 52, first chamfer 53, second chamfer 54; Dustproof casing 60, installation step surface 61. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In the passenger car and commercial vehicle industries, both new energy and traditional energy vehicle manufacturers have raised higher requirements for the waterproofing capabilities of automobiles; for the steering gear intermediate shaft guard assembly, water must not enter the driver's cabin when the vehicle is wading through water.

[0024] The existing waterproof structure of the intermediate shaft of automotive steering systems usually adopts a sealing structure with a K-type sealing ring and a retaining ring. Because the interference of the K-type sealing ring is small, it has been confirmed by tests that water leakage occurs after one hour of operation in a water-immersed state, indicating poor waterproof performance.

[0025] Therefore, in a first aspect, the present invention provides a waterproof seal, see [link to relevant documentation]. Figure 1 and Figure 2 As shown, the waterproof seal 10 proposed in this embodiment of the invention includes a skeleton 20 and an elastomer 30. Both the skeleton 20 and the elastomer 30 are annular structures. The elastomer 30 includes a base 31 and a sealing part 32. The base 31 is integrally formed on the inner circumferential side of the skeleton 20, and the sealing part 32 is disposed on the inner circumferential side of the base 31. The base 31 is axially ( Figure 1 The first side of the X direction is the air side (in the X direction). Figure 1 (As shown on side A), the substrate 31 is a sealing side on the second axial side ( Figure 1 (Side B shown); the sealing part 32 includes a first sealing lip 33, a second sealing lip 34 and a third sealing lip 35 arranged axially at intervals. The first sealing lip 33 is disposed near the air side, the third sealing lip 35 is disposed near the sealing side, and the second sealing lip 34 is disposed between the first sealing lip 33 and the third sealing lip 35. After the waterproof seal 10 is fitted onto the shaft 40, the first sealing lip 33, the second sealing lip 34 and the third sealing lip 35 are all interference-fitted with the shaft 40. The interference amount between the first sealing lip 33 and the shaft 40 is greater than the interference amount between the second sealing lip 34 and the shaft 40, and the interference amount between the second sealing lip 34 and the shaft 40 is greater than the interference amount between the third sealing lip 35 and the shaft 40.

[0026] The waterproof seal 10 proposed in this invention adopts a three-seal combination design. The outermost first sealing lip 33 has the largest interference with the shaft 40 and plays the main sealing role; the second sealing lip 34 plays an auxiliary sealing role and can better delay the intrusion time of mud and water; the innermost third sealing lip 35 has the smallest interference with the shaft 40 and plays an auxiliary sealing role; the overall waterproof sealing effect is good.

[0027] In one embodiment, the first sealing lip 33 includes a first lip waist 330, a first inclined surface 331, and a second inclined surface 332. The first lip waist 330 is annular, and the outer peripheral end of the first lip waist 330 is integrally formed with the second sealing lip 34. The inner peripheral end of the first lip waist 330 extends toward the air side and is inclined near the center of the elastomer 30. The first inclined surface 331 and the second inclined surface 332 are disposed at the inner peripheral end of the first lip waist 330. Both the first inclined surface 331 and the second inclined surface 332 are annular, and the outer peripheral ends of the first inclined surface 331 and the second inclined surface 332 intersect to form a first lip tip 333.

[0028] It can be seen that by setting the first sealing lip 33, a first sealing lip 33 with a simple structure, easy implementation, and good sealing effect is provided.

[0029] In one embodiment, the second sealing lip 34 includes a second lip waist 340, a third inclined surface 341, and a fourth inclined surface 342. The second lip waist 340 is annular, and its outer peripheral end is integral with the substrate 31. The inner peripheral end of the second lip waist 340 extends toward the first sealing lip 33 and is inclined near the center of the elastomer 30. The inner peripheral end of the second lip waist 340 is integral with the outer peripheral end of the first lip waist 330. The third inclined surface 341 and the fourth inclined surface 342 are disposed at the inner peripheral end of the second lip waist 340. Both the third inclined surface 341 and the fourth inclined surface 342 are annular, and their outer peripheral ends intersect to form a second lip tip 343. The length of the first lip waist 330 is greater than the length of the second lip waist 340, and the width of the first lip waist 330 is less than the width of the second lip waist 340.

[0030] It can be seen that by setting the second sealing lip 34, a reasonable design, easy implementation, and good sealing effect are provided; at the same time, by setting the first lip waist 330 and the second lip waist 340, the first sealing lip 33 is made into a slender structure, which makes its contact zone with the shaft 40 wider, effectively blocking mud and water intrusion and increasing the follow-up of the first sealing lip 33.

[0031] In one embodiment, the third sealing lip 35 includes a fifth inclined surface 350 and a sixth inclined surface 351, which are disposed at the inner peripheral end of the second lip waist 340. Both the fifth inclined surface 350 and the sixth inclined surface 351 are annular, and their outer peripheral ends intersect to form a third lip tip 352.

[0032] It is evident that the design of the third sealing lip 35 provides a reasonable, easy-to-implement, and effective sealing solution. Furthermore, the small interference fit of the third sealing lip 35 effectively prevents mud and water intrusion while primarily supporting the second sealing lip 34. This allows the second sealing lip 34 to maintain more stable contact with the shaft in eccentric or tilted situations, ensuring the sealing stability of the second sealing lip 34.

[0033] In one implementation, the axial distance between the first lip tip 333 and the second lip tip 343 is greater than the axial distance between the second lip tip 343 and the third lip tip 352, further improving the contact zone between the first sealing lip 33 and the shaft 40.

[0034] In one embodiment, a ring of protrusions 50 is provided on the outer peripheral surface of the second lip waist 340, a ring of first recesses 51 is provided on the outer peripheral surface of the second lip waist 340 on the side of the protrusions 50 near the air side, and a ring of second recesses 52 is provided on the outer peripheral surface of the second lip waist 340 on the side of the protrusions 50 near the sealing side.

[0035] Specifically, the protrusion 50, the first recess 51, and the second recess 52 all adopt a smooth arc transition design.

[0036] It can be seen that the design of the protrusion 50, the first recess 51 and the second recess 52 can improve the follow-up of the second sealing lip 34 and the third sealing lip 35, reduce the clamping force of the second sealing lip 34 and the third sealing lip 35 on the shaft 40, and thus reduce the lip torque.

[0037] As one implementation method, the contact surface between the first sealing lip 33 and the shaft 40 is pear-shaped using a grinding tool.

[0038] It can be seen that by using a pear-shaped surface treatment on the contact surface between the first sealing lip 33 and the shaft 40, the durable sealing performance of the first sealing lip 33 is made more stable, while the lip torque is reduced, avoiding potential problems such as difficulty in rotation and abnormal noise.

[0039] In one embodiment, both the substrate 31 and the sealing part 32 are made of EPDM rubber material and integrally molded by compression molding. This provides a processing method for the elastomer 30 that is easy to process, implement, and cost-effective.

[0040] In one embodiment, the cross-section of the skeleton 20 is "L" shaped, the elastomer 30 completely or partially covers the skeleton 31, a first chamfer 53 is provided at the outer peripheral end of the elastomer 30 near the air side, and a second chamfer 54 is provided at the outer peripheral end of the elastomer 30 near the sealing side.

[0041] Specifically, the frame 20 is made of metal. It can be seen that by setting the skeleton 20, a skeleton 20 with simple structure and high reliability is provided; by setting the first chamfer 53 and the second chamfer 54 on the elastomer 30, the installation of the sealing device is facilitated, so that there is a certain gap between the elastomer 30 and the mounting groove, which can make room for the deformation of the elastomer 30.

[0042] It should be noted that, depending on the actual needs, the cross-section of the skeleton 20 can be set to a straight line, a wave shape, etc.

[0043] Secondly, this invention proposes a sealing device for the intermediate shaft of an automotive steering gear; please refer again to [the relevant documentation]. Figure 1 and Figure 2 As shown, the sealing device for the intermediate shaft of the automobile steering gear proposed in this embodiment of the invention includes a dustproof sleeve 60 and two waterproof seals 10 as described above. The dustproof sleeve 60 is fitted around the shaft 40, which is the intermediate shaft of the automobile steering gear. Two rings of mounting steps 61 are provided at intervals inside the dustproof sleeve 60. A waterproof seal 10 is pressed on each mounting step 61. The elastic bodies 30 of the two waterproof seals 10 have the same axial orientation.

[0044] The sealing device for the intermediate shaft of the automotive steering gear proposed in this invention can meet the waterproof requirements of the intermediate shaft cover assembly of the automotive steering gear when the vehicle is wading through water. After testing, it was confirmed that it does not leak water after 1000 hours of operation in a submerged state.

[0045] Of course, it should be noted that the waterproof seal and sealing device proposed in the embodiments of the present invention can also be applied to the waterproof sealing of shaft parts in other similar working environments.

[0046] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above examples. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waterproof sealant, characterized in that, The waterproof seal includes a skeleton and an elastomer, both of which are annular structures, wherein: The elastomer includes a matrix and a sealing portion. The matrix is ​​integrally formed on the inner circumferential side of the skeleton, and the sealing portion is disposed on the inner circumferential side of the matrix. The matrix is ​​an air side on a first axial side and a sealing side on a second axial side. The sealing portion includes a first sealing lip, a second sealing lip, and a third sealing lip that are spaced apart along the axial direction. The first sealing lip is disposed near the air side, the third sealing lip is disposed near the sealing side, and the second sealing lip is disposed between the first sealing lip and the third sealing lip. After the waterproof seal is fitted onto the shaft, the first sealing lip, the second sealing lip, and the third sealing lip are all interference-fitted with the shaft. The interference between the first sealing lip and the shaft is greater than the interference between the second sealing lip and the shaft, and the interference between the second sealing lip and the shaft is greater than the interference between the third sealing lip and the shaft.

2. The waterproof sealant according to claim 1, characterized in that, The first sealing lip includes a first lip waist, a first inclined surface, and a second inclined surface, wherein: The first lip waist is annular, and the outer peripheral end of the first lip waist is integral with the second sealing lip. The inner peripheral end of the first lip waist extends toward the air side and is inclined near the center of the elastomer. The first and second inclined surfaces are disposed at the inner peripheral end of the first lip waist. Both the first and second inclined surfaces are annular. The outer peripheral ends of the first and second inclined surfaces intersect to form the first lip tip.

3. The waterproof sealant according to claim 2, characterized in that, The second sealing lip includes a second lip waist, a third bevel, and a fourth bevel, wherein: The second lip waist is annular, and the outer peripheral end of the second lip waist is an integral structure with the substrate. The inner peripheral end of the second lip waist extends toward the first sealing lip and is inclined near the center of the elastomer. The inner peripheral end of the second lip waist and the outer peripheral end of the first lip waist are an integral structure. The third and fourth inclined surfaces are disposed at the inner peripheral end of the second lip waist. Both the third and fourth inclined surfaces are annular, and the outer peripheral ends of the third and fourth inclined surfaces intersect to form the second lip tip. The length of the first lip waist is greater than the length of the second lip waist, and the width of the first lip waist is less than the width of the second lip waist.

4. The waterproof sealant according to claim 3, characterized in that, The third sealing lip includes a fifth bevel and a sixth bevel, wherein: The fifth and sixth inclined surfaces are disposed at the inner peripheral end of the second lip waist. Both the fifth and sixth inclined surfaces are annular, and their outer peripheral ends intersect to form the third lip tip.

5. The waterproof sealant according to claim 4, characterized in that, The distance between the first lip tip and the second lip tip in the axial direction is greater than the distance between the second lip tip and the third lip tip in the axial direction.

6. The waterproof sealant according to claim 4, characterized in that, A ring of protrusions is provided on the outer peripheral surface of the second lip waist. A ring of first recesses is provided on the outer peripheral surface of the second lip waist on the side of the protrusions near the air side. A ring of second recesses is provided on the outer peripheral surface of the second lip waist on the side of the protrusions near the sealing side.

7. The waterproof sealant according to claim 1, characterized in that, The contact surface between the first sealing lip and the shaft is treated with a grinding tool to create a pear-shaped surface.

8. The waterproof sealant according to claim 1, characterized in that, Both the substrate and the sealing part are made of EPDM rubber material and are integrally molded by compression molding.

9. The waterproof sealant according to claim 1, characterized in that, The cross-section of the skeleton is "L" shaped, and the elastomer completely or partially covers the skeleton. The outer peripheral end of the elastomer has a first chamfer near the air side, and the outer peripheral end of the elastomer has a second chamfer near the sealing side.

10. A sealing device for the intermediate shaft of an automobile steering gear, characterized in that, The sealing device for the intermediate shaft of the automotive steering gear includes a dustproof sleeve and two waterproof seals as described in any one of claims 1-9, wherein: The dustproof sleeve is fitted around the shaft, which is the intermediate shaft of the automobile steering gear; The dustproof cylinder has two rings of mounting steps spaced apart inside, and a waterproof seal is pressed onto each mounting step to provide two layers of waterproof sealing for the shaft. The elastic bodies of the two waterproof seals are oriented in the same direction along the axial direction.

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