Hollow transmission shaft end metal sealing structure and assembling method

Abstract

The invention belongs to the technical field of shaft end sealing, and provides a hollow transmission shaft end metal sealing structure and an assembling method.The hollow transmission shaft end metal sealing structure comprises a metal sealing blanking cap which is an annular groove and comprises a ring body and a cover plate which are integrally connected, and the outer wall of the ring body is sequentially provided with a first conical surface, a first plane, an outer arc-shaped surface and a second plane from an opening to the bottom; the shaft end of the hollow transmission shaft is provided with a second conical surface, the inner wall of the hollow transmission shaft is provided with an arc-shaped groove, the metal sealing plug cover is arranged in the shaft end of the hollow transmission shaft, the cover plate is arranged inwards, the first plane and the second plane are in interference fit with the inner wall of the hollow transmission shaft respectively, and the first conical surface and the second conical surface are coplanar. And the outer arc-shaped surface is matched with the arc-shaped groove. The situation that the interior of the hollow transmission shaft is maintained by disassembling the hollow transmission shaft in a complex mechanical system is effectively avoided, meanwhile, the situation that impurities enter the hollow transmission shaft to increase the unbalance value of dynamic balance is avoided, and the safety and reliability of the system are improved.

Description

Technical Field

[0001] This invention belongs to the field of shaft end sealing technology, specifically relating to a metal sealing structure and assembly method for the shaft end of a hollow drive shaft. Background Technology

[0002] As a crucial component in mechanical transmission systems for transmitting torque, the driveshaft has evolved to reduce system mass and rotational inertia. Hollow driveshafts have emerged as a design solution, and the quality of their internal and external surfaces significantly impacts their service life. Damage to the plating and paint film on the inner and outer surfaces of the driveshaft can lead to corrosion. While the external paint film can be prevented from rusting through periodic spraying or brushing, protecting the internal shaft is more challenging, requiring separate inspection and maintenance during disassembly and reassembly within the mechanical system. Therefore, a hollow driveshaft end metal seal structure is urgently needed to protect its internal components while avoiding disassembly and reassembly. Currently, most shaft end seals are concentrated on solid driveshafts, using rubber ring seals to control radial clearance with the driveshaft.

[0003] For example, CN221221432U discloses a drive shaft sealing ring and a drive shaft sealing structure with the same, proposing an NBR rubber sealing ring with a raised lip. The advantage is that the pre-pressure of the interference fit between the drive shaft and the rubber sealing ring ensures the sealing effect. The disadvantage is that rubber is a low-life component and its hardness is lower than that of metal, making it more prone to aging cracks and scratches that reduce the sealing effect. CN208024944U discloses a drive shaft seal for an ash discharge valve, proposing a three-stage seal on the drive housing: a filling seal, a labyrinth seal, and a dry oil seal. The advantage is that it can seal fine dust particles in high-dust environments to prevent bearing damage. The disadvantage is that the structure is complex, and damage to one of the seals will affect the overall sealing effect. The present invention, CN111779835A, discloses a transmission shaft sealing structure and a reaction device, which proposes a sealing structure in which a sealing ring is set between an adjusting ring and a pressure plate. The advantage is that the gap between the sealing ring and the shaft can be flexibly changed by adjusting the compression of the sealing ring by the adjusting ring. The disadvantage is that when the shaft is subjected to radial force, the sealing ring and the adjusting ring will have different degrees of contact with the shaft, resulting in wear on the contact surface and affecting the sealing effect.

[0004] In summary, existing shaft end seals all use rubber sealing rings. Rubber, being a lifespan component, requires regular inspection and replacement to prevent aging and failure, thus avoiding the need to disassemble the drive shaft for maintenance within complex mechanical systems. Furthermore, existing drive shaft seal structures are complex, generating significant vibration and noise, and cannot guarantee safety and reliability. Summary of the Invention

[0005] To overcome the limitations of existing technologies, this invention provides a metal sealing structure and assembly method for the shaft end of a hollow drive shaft. This device effectively avoids the need to disassemble the hollow drive shaft for internal maintenance in complex mechanical systems, while also preventing foreign objects from entering the hollow drive shaft and increasing the imbalance value of the dynamic balance, thereby improving the safety and reliability of the system.

[0006] A hollow drive shaft end metal sealing structure includes a metal sealing plug, which is an annular groove, comprising an integrally connected ring body and a cover plate. The outer wall of the ring body is sequentially configured from the opening to the bottom as a first conical surface, a first flat surface, an outer arcuate surface, and a second flat surface. The shaft end of the hollow drive shaft has a second conical surface, and the inner wall of the hollow drive shaft has an arcuate groove. The metal sealing plug is disposed inside the shaft end of the hollow drive shaft, with the cover plate facing inward. The first flat surface and the second flat surface are respectively interference-fitted with the inner wall of the hollow drive shaft. The first conical surface and the second conical surface are coplanar, and the outer arcuate surface and the arcuate groove are fitted together.

[0007] An assembly method for a hollow drive shaft end metal seal structure includes:

[0008] S1. Before assembling the sealing plug, clean and dry the inside of the hollow drive shaft.

[0009] S2. Apply primer and topcoat to the inside of the hollow drive shaft;

[0010] S3. Apply sealant to the mating surface between the hollow drive shaft and the sealing plug;

[0011] S4. Install the sealing plug into the hollow drive shaft until the first conical surface and the second conical surface are engaged, and enlarge the hole on the inner arc surface until the outer arc surface fits into the arc groove of the hollow drive shaft;

[0012] S5. After enlarging the hole, use a portable magnetic particle detector to perform magnetic particle inspection on the sealing plug. Defects are not allowed on the surface of the sealing plug. After inspection, demagnetize and complete the assembly.

[0013] The advantages of this invention compared to the prior art are:

[0014] 1. This invention can effectively avoid the need to disassemble the hollow drive shaft for internal maintenance in complex mechanical systems, and at the same time avoids the entry of foreign objects into the hollow drive shaft, which would increase the imbalance value of the dynamic balance, thus improving the safety and reliability of the system.

[0015] 2. The sealing plug used in this invention is made of metal, and is mass-produced from hot-rolled stainless steel plates, which has a simple structure and low cost.

[0016] 3. Unlike rubber sealing rings, metal sealing plugs do not have aging cracks or scratches that reduce sealing performance.

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments: Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a metal seal structure at the end of a hollow drive shaft.

[0019] Figure 2 This is a partial view at point I.

[0020] In the diagram, 1 is the hollow drive shaft, 11 is the second conical surface; 2 is the metal sealing plug, 21 is the first conical surface, and 221 is the first conical surface.

[0021] 222, second plane, 23, outer arc surface, 24, inner arc surface, 25, cover plate. Detailed Implementation

[0022] The embodiments of the technical solutions of this application will now be described in detail with reference to the accompanying drawings. Unless otherwise stated, the technical or scientific terms used in this application have the ordinary meanings understood by those skilled in the art.

[0023] Example 1, Reference Figure 1 and Figure 2 The hollow drive shaft end metal sealing structure of this embodiment includes: a metal sealing plug 2, which is an annular groove, comprising an integrally connected ring body and a cover plate 25. The outer wall of the ring body is sequentially configured from the opening to the bottom as a first conical surface 21, a first plane 221, an outer arc-shaped surface 23, and a second plane 222. The shaft end of the hollow drive shaft 1 has a second conical surface 11, and the inner wall of the hollow drive shaft 1 has an arc-shaped groove. The two metal sealing plugs 2 are symmetrically arranged inside the two shaft ends of the hollow drive shaft 1. The cover plate 25 is arranged inward, that is, away from the shaft end of the hollow drive shaft. The first plane 221 and the second plane 222 are respectively interference-fitted with the inner wall of the hollow drive shaft 2. The first conical surface 21 and the second conical surface 11 are coplanar. The outer arc-shaped surface 23 fits with the arc-shaped groove. The inner wall of the ring body has an inwardly concave inner arc-shaped surface 24. An adhesive layer is applied between the interference-fitted surface and the conical surface.

[0024] Interference fits and cover plates can prevent corrosion caused by water, oil and debris entering the shaft, as well as increase the imbalance, which can lead to increased vibration and noise in the mechanical system.

[0025] The advantages of this embodiment are: The provided hollow drive shaft end metal seal structure and assembly method avoid the problem of disassembling the hollow drive shaft for maintenance in complex mechanical systems. Furthermore, the shaft end seal of the hollow drive shaft 1 effectively prevents water, oil, and debris from entering, avoiding the problem of increased dynamic imbalance due to internal debris, which could lead to greater vibration and noise in the mechanical system, thus improving the safety and reliability of the system.

[0026] The design concept of this implementation scheme is as follows: First, the outer diameter of the sealing plug 2 is determined according to the inner diameter of the hollow drive shaft 1 to ensure a certain interference fit; second, the angle of the second conical surface 11 and the first conical surface 21 (both are conical surfaces) is designed to be consistent to minimize the radial thickness of the sealing plug 2 and ensure its rigidity so as to allow for expansion deformation after installation; finally, the sealing plug is formed by pressing a common material of a certain thickness, which is low in cost and easy to replace.

[0027] Example 2, Reference Figure 2 Taking the inner diameter of the drive shaft as φ150+0.040 as an example, the outer diameter of the sealing plug is designed to be φ150.1+0.05-0.05, ensuring an interference fit of 1~15.

[0028] An adhesive layer is applied to both the interference fit surface and the conical surface.

[0029] Furthermore, the cone angle θ of the first cone surface 21 or the second cone surface 11 is 25°-35°.

[0030] Furthermore, the thickness of the metal sealing plug 2 is 1.0-2.0 mm.

[0031] Taking the second conical surface 11 of the hollow drive shaft 1 as an example with an angle of 30°, the first conical surface 21 of the sealing plug 2 is also designed to have an angle of 30°.

[0032] Furthermore, 06Cr19Ni10 hot-rolled stainless steel plates, with a thickness of 1.5mm, were selected and batch-formed into sealing plugs 2.

[0033] Example 3, Reference Figure 1 and Figure 2 Based on any of the above embodiments, an assembly method for a hollow drive shaft end metal seal structure is provided, the method comprising:

[0034] S1. Before assembling the sealing plug 2, clean and dry the inside of the hollow drive shaft 1.

[0035] S2. Spray epoxy zinc-rich primer and polyurethane topcoat inside the hollow drive shaft 1.

[0036] Epoxy zinc-rich primer is the core primer type for high corrosion resistance scenarios of metal substrates (especially steel). Its core advantage is that it uses the "sacrificial anode protection" principle of zinc powder to achieve a rust prevention effect far exceeding that of ordinary epoxy primer.

[0037] Polyurethane topcoat is a high-performance topcoat that uses polyurethane resin as the film-forming substance. Its core advantage is that it combines excellent weather resistance and decorative properties, providing long-term outdoor protection and aesthetic effects for metal substrates. It is a type of topcoat widely used in industrial and civilian applications.

[0038] S3. Apply 515 sealant to the mating surface between the hollow drive shaft 1 and the sealing plug 2.

[0039] S4. Install the sealing plug 2 into the hollow drive shaft 1 until the first conical surface 21 and the second conical surface 11 are combined, and expand the hole in the inner arc surface 24 until the outer arc surface 23 fits into the arc groove of the hollow drive shaft 1.

[0040] S5. After enlarging the hole, use a portable magnetic particle detector to perform magnetic particle inspection on the sealing plug. Defects are not allowed on the surface of the sealing plug. After inspection, demagnetize and complete the assembly.

[0041] This assembly method effectively avoids the need to disassemble the hollow drive shaft for internal maintenance in complex mechanical systems, ensuring the reliability of the seal and improving the safety and reliability of the system.

[0042] This application has been disclosed above with preferred embodiments, but it is not intended to limit this application. Any person skilled in the art can make some changes or modifications to the above-disclosed structure and technical content to create equivalent embodiments without departing from the scope of the technical solution of this application, and all such modifications and modifications are within the scope of the technical solution of this application.

Claims

1. A metal sealing structure at the end of a hollow drive shaft, characterized in that: Include: The metal sealing plug is an annular groove comprising an integrally connected ring and a cover plate. The outer wall of the ring is sequentially configured from the opening to the bottom as a first conical surface, a first flat surface, an outer arcuate surface, and a second flat surface. The shaft end of the hollow drive shaft has a second conical surface, and the inner wall of the hollow drive shaft has an arcuate groove. The metal sealing plug is disposed inside the shaft end of the hollow drive shaft, with the cover plate facing inward. The first flat surface and the second flat surface are respectively interference-fitted with the inner wall of the hollow drive shaft. The first conical surface and the second conical surface are coplanar, and the outer arcuate surface fits the arcuate groove.

2. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: The interference fit between the sealing plug and the hollow drive shaft is 1 to 15.

3. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: The cone angle of the first or second cone surface is 25°-35°.

4. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: The metal sealing plug is made of stainless steel.

5. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: The metal sealing plug is made of 06Cr19Ni10.

6. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: The thickness of the metal sealing plug is 1.0-2.0 mm.

7. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: The inner wall of the ring has an inwardly concave arc-shaped surface.

8. The hollow drive shaft end metal sealing structure according to claim 1, characterized in that: An adhesive layer is applied to both the interference fit surface and the conical surface.

9. A method for assembling the hollow drive shaft end metal seal structure according to any one of claims 1-8, characterized in that: The method includes: S1. Before assembling the sealing plug, clean and dry the inside of the hollow drive shaft. S2. Spray primer and topcoat inside the hollow drive shaft; S3. Apply sealant to the mating surface between the hollow drive shaft and the sealing plug; S4. Install the sealing plug into the hollow drive shaft until the first conical surface and the second conical surface are engaged, and enlarge the hole on the inner arc surface until the outer arc surface fits into the arc groove of the hollow drive shaft; S5. After enlarging the hole, use a portable magnetic particle detector to perform magnetic particle inspection on the sealing plug. Defects are not allowed on the surface of the sealing plug. After inspection, demagnetize and complete the assembly.

10. The assembly method of the hollow drive shaft end metal seal structure according to claim 9, characterized in that: The primer in step S2 is made of epoxy zinc-rich material, and the topcoat is made of polyurethane.

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