A conductive self-lubricating bearing based on a metal mesh extension structure and a preparation method thereof

Abstract

A conductive self-lubricating bearing based on a metal mesh extension structure and a preparation method thereof, the conductive self-lubricating bearing based on a metal mesh extension structure includes a body and a through hole. The body includes a low-friction layer and a conductive mesh. The conductive mesh has a plurality of mesh holes arranged in an array. The conductive mesh is embedded in the low-friction layer and part of the conductive mesh is evenly exposed on one end face of the low-friction layer. The exposed part is a conductive contact and is used to contact an external workpiece. The low-friction layer is provided with an end face that exposes the conductive mesh as a conductive surface, and the other end face of the low-friction layer is a non-conductive surface. The through hole is formed by punching out the conductive surface. During punching, the conductive mesh located in the through hole is extended to the non-conductive surface, allowing the internal and external workpieces of the body to pass current, thereby realizing the integrated processing of the through hole and the metal mesh extension, eliminating the secondary processing step of the notch.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive bearings, in particular to a conductive self-lubricating bearing based on an extended metal mesh structure and a preparation method thereof. Background Art

[0002] As a key transmission component in the fields of automobiles, home appliances, industrial equipment, etc., self-lubricating bearings must meet the requirements of low friction and conductivity at the same time. Especially in the field of automobile manufacturing, the surface of the bearing needs to form a uniform anti-corrosion coating through an electrophoretic coating process, and conductivity is the core prerequisite for ensuring the quality of the coating. The conductive design scheme of traditional self-lubricating bearings, such as CN202080079836.9, mainly achieves conductivity by machining deformed notches on the side walls or flanges of the bearings, removing low-friction materials to expose the metal substrate. The conductive deformed notches of the bearings in the prior art require secondary processing to remove the low-friction material, which increases manufacturing costs, and the notches will cause stress concentration under mechanical vibrations such as bumps during car driving. Summary of the Invention

[0003] In view of this, the present invention provides a conductive self-lubricating bearing based on an extended metal mesh structure and a preparation method thereof to solve the above technical problems.

[0004] A conductive self-lubricating bearing based on an extended metal mesh structure comprises a body and at least one through-hole arranged on the body, the body comprising a low-friction layer and a conductive mesh arranged on the low-friction layer, the conductive mesh having a plurality of mesh holes arranged in an array, the conductive mesh being embedded in the low-friction layer and a portion of the conductive mesh being uniformly exposed from one end face of the low-friction layer, the low-friction layer being provided with an end face exposing the conductive mesh as a conductive surface, and the other end face of the low-friction layer being a non-conductive surface, the through-hole being formed by punching out the conductive surface, and the conductive mesh located in the through-hole being extended to the non-conductive surface during punching.

[0005] Furthermore, the low friction layer is a PTFE polytetrafluoroethylene composite material.

[0006] Furthermore, the mesh holes are in the shape of diamonds, square holes, polygons, and elliptical holes, and the conductive mesh is formed by weaving in a warp and weft interlaced manner or by direct stamping.

[0007] Furthermore, the exposed area of ​​the conductive mesh accounts for more than 8% of the area of ​​the conductive mesh.

[0008] Furthermore, the conductive mesh is made of a high-ductility copper alloy mesh with an elongation of ≥15%.

[0009] Furthermore, the through hole covers at least three metal wires of the conductive mesh. When the mesh is a diamond-shaped hole, the lower limit of the through hole diameter is:

[0010] d> ,

[0011] Wherein, a and b represent the distances between the two centers of the diamond holes, that is, the straight-line distance between the centers of two adjacent diamond holes, and t represents the diameter of the metal wire used to make the conductive mesh.

[0012] Furthermore, after the body is rolled and flanged, the body forms a sleeve with a hollow cylindrical structure and a flange arranged at one end of the sleeve, the conductive surface is located on the inner wall of the sleeve, and the non-conductive surface is located on the outer wall of the sleeve.

[0013] A method for preparing a conductive self-lubricating bearing based on an extended metal mesh structure comprises the following steps:

[0014] Step S1: providing a body, the body comprising a low-friction layer and a conductive mesh disposed in the low-friction layer, wherein a portion of the conductive mesh is uniformly exposed on one end surface of the low-friction layer, the low-friction layer is configured such that the end surface exposed by the conductive mesh is a conductive surface, and the other end surface of the low-friction layer is a non-conductive surface;

[0015] Step S2: providing a punching tool, punching from one side of the conductive surface toward the side of the non-conductive surface through a punching die to form a through hole, so that the conductive mesh in the through hole extends to the non-conductive surface;

[0016] Step S3: rolling and flanging the punched body to form a sleeve and a flanging.

[0017] Furthermore, in the above step S2, the punch speed is controlled to be greater than or equal to 20 mm / s.

[0018] Furthermore, in the above step S2, the blanking clearance is controlled to be 10%-20% of the bearing thickness.

[0019] Compared with the prior art, the present invention provides a preparation method for a conductive self-lubricating bearing based on a metal mesh extension structure, which forms the through hole by punching the conductive surface. During punching, the conductive mesh located in the through hole is extended to the non-conductive surface, so that the inner side of the sleeve also has a conductive contact, thereby allowing the inner and outer workpieces of the body sleeve to pass current, thereby realizing the integrated processing of the through hole and the metal mesh extension, eliminating the secondary processing step of the notch. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural schematic diagram of a conductive self-lubricating bearing based on an extended metal mesh structure provided by the present invention.

[0021] Figure 2 for Figure 1 FIG. 1 is a cross-sectional view of a body 10 of a conductive self-lubricating bearing based on an extended metal mesh structure.

[0022] Figure 3 for Figure 1 Schematic diagram of the structure of the conductive mesh of the conductive self-lubricating bearing based on the metal mesh extended structure.

[0023] Figure 4 for Figure 1 Schematic diagram of the structure of the diamond-shaped holes of the conductive mesh of the conductive self-lubricating bearing based on the metal mesh extended structure. DETAILED DESCRIPTION

[0024] The following is a further detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0025] like Figures 1 to 4 , which is a schematic structural diagram of a conductive self-lubricating bearing based on an extended metal mesh structure provided by the present invention. The conductive self-lubricating bearing based on an extended metal mesh structure includes a body 10 and at least one through-hole 20 provided in the body 10. It is conceivable that the conductive self-lubricating bearing based on an extended metal mesh structure may also include other functional structures, such as an anti-corrosion layer and a lubricating layer, etc. These are well known to those skilled in the art and will not be further described here.

[0026] The body 10 is a multi-layer composite structure, and includes a low-friction layer 11 and a conductive mesh 12 disposed in the low-friction layer 11 .

[0027] The low friction layer 11 can be made of a composite material with PTFE (polytetrafluoroethylene) as the main material or other low friction materials, so as to have a lower friction coefficient and adapt to the high-speed rotation or reciprocating motion of the sleeve.

[0028] The conductive mesh 12 has a plurality of meshes 121 arranged in an array. In this embodiment, the meshes 121 are diamond-shaped, but can also be square, polygonal, elliptical, etc., and can be arranged according to actual needs. The conductive mesh 12 can be woven by interlacing warp and weft or directly punched and stretched.

[0029] The conductive mesh 12 is embedded in the low-friction layer 11, with a portion of the conductive mesh 12 uniformly exposed on one end surface of the low-friction layer 11. This provides the low-friction layer 11 with a conductive surface 13 on one end surface where the conductive mesh 12 is exposed. The exposed portion of the conductive mesh 12 serves as a conductive contact point and is used to make electrical contact with an external workpiece. The exposed area of ​​the conductive mesh 12 accounts for at least 8% of the area of ​​the conductive mesh 12, forming a continuous and stable conductive network. The other end surface of the low-friction layer 11 is a non-conductive surface 14.

[0030] The through hole 20 is formed by punching out the conductive surface 13. During punching, the conductive mesh 12 located within the through hole 20 extends to the non-conductive surface 14, providing conductive contacts on the inner side of the sleeve, thereby allowing current to flow through the inner and outer workpieces of the body 10. When punching from the conductive surface 13 toward the non-conductive surface 14, the low-friction layer 11 is cut by the punch, and the conductive mesh 12 undergoes plastic deformation due to compression. The metal wires of the conductive mesh 12 extend along the inner sidewall of the through hole 20 to the non-conductive surface 14, thereby forming a conductive channel connecting the inside and outside of the body 10. This can be achieved in a single process. The conductive mesh 12 is made of a high-ductility copper alloy mesh with an elongation of ≥15% to ensure that the punched metal wires have sufficient mechanical strength and ductility when extending to the non-conductive surface 14 of the low-friction layer 11. Ensure that the extended length of the punched metal wire is greater than the depth of the through hole 20 , that is, the thickness of the body 10 , so as to ensure that the punched metal wire extends out of the through hole 20 .

[0031] In order to ensure that the conductive mesh 12 is fully exposed and extends into the non-conductive surface 14 to form a continuous conductive network, the through hole 20 covers at least three metal wires of the conductive mesh 12, ensuring that at least three metal wires are punched out of the inner wall of the through hole 20. Specifically, it is necessary to first limit the diameter of the through hole 20 to ensure that the metal wires can be punched out at any position. The punching position of the through hole 20 may occur in three positions, such as Figure 3As shown, the first position 100 is the position where three metal wires are punched out, namely, one end of two metal wires and one end where the two metal wires intersect. The second position 200 is the position where four metal wires are punched out, namely, both ends of two metal wires. The third position 300 is the position where the four sides of the diamond hole are just punched out and are at the adjacent boundary. If the diameter of the through hole 20 is smaller than the third position 300, it is possible that the metal wires cannot be punched out, namely, the through hole 20 is just located in the diamond hole and is spaced from the four sides of the diamond hole. The critical position where the metal wires can be punched out is when the circumference of the through hole is tangent to the four sides of the inner edge of the diamond hole. Therefore, it is necessary to ensure that the diameter of the through hole 20 is larger than the size of the through hole diameter at the critical position. In this way, there is no need to control the position of the through hole and the diamond hole during punching, and the metal wires can be punched out and extended at any position.

[0032] The lower limit of the diameter of the through hole 20 is:

[0033] d> ,

[0034] Where a and b represent the distances between the two centers of the diamond holes, that is, the straight-line distances between the centers of two adjacent diamond holes. The above formula can be derived by the equal-area method, but the metal wire used to make the conductive mesh 12 has a certain diameter. Therefore, the effective aperture of the diamond hole needs to be subtracted from the wire diameter of the metal wire. t represents the diameter of the metal wire used to make the conductive mesh 12, which will be the effective aperture in the diamond hole. A diamond can be regarded as being made up of four congruent right triangles. Therefore, only one of the right triangles needs to be calculated. The two right-angled sides of this right triangle correspond to half of the diagonal of the diamond, respectively. The two right-angled sides of the right triangle can be represented by (at) / 2 and (bt) / 2, respectively. The area of ​​the triangle S1 is the product of the opposite side and the adjacent side divided by 2, which can be expressed as follows:

[0035] S1= .

[0036] Another method is used to calculate the area of ​​the right triangle. At the third position of 300, the through hole 20 is inscribed in this right triangle. At this time, the area of ​​the right triangle can also be regarded as the area of ​​a triangle with the hypotenuse as the base and the radius d / 2 of the through hole 20 as the height. The hypotenuse obtained by the Pythagorean theorem is multiplied by the diameter of the through hole 20 at the third position of 300 and then divided by 2. The formula is expressed as:

[0037] S2= .

[0038] Regardless of the calculation method, the areas of the same right triangle are equal, so S1 equals S2. After simplification, the diameter d of the through hole 20 at the third position 300 is obtained. Preferably, the upper limit of the diameter of the through hole 20 is less than or equal to twice the center distance of the diamond holes to prevent the through hole 20 from being too large and thus reducing the bearing's load capacity. However, it is not essential. A larger through hole will result in more metal wire being punched, but the load capacity will be correspondingly reduced. The upper limit can be set according to the application.

[0039] Secondly, when punching, the blanking gap should also be 20%-40% of the thickness of the main body 10. The blanking gap refers to the horizontal distance between the outer wall of the punch and the inner wall of the die. This blanking gap can ensure that there is a certain gap between the punch and the die after entering the die to ensure the extension effect of the metal wire. During blanking, the metal wire needs to extend to the non-conductive surface 14 along the blanking direction. If the gap between the outer wall of the punch and the inner wall of the die is too small, the blanking force will be too large, which may easily cause the metal mesh wire to break, resulting in insufficient extension length of the metal wire and inability to extend to the non-conductive surface 14. If the gap is too large, the extension direction of the metal wire will be dispersed, and a stable conductive path cannot be formed.

[0040] Finally, the punching speed is controlled to be greater than or equal to 20 mm / s. If the speed is too slow, the processing efficiency is too low and stable batch production cannot be achieved. At the same time, when the punching speed is insufficient, the contact time between the cutting edge and the low-friction layer is prolonged, and the material is prone to viscoelastic creep rather than instantaneous brittle separation, which directly leads to the formation of fibrous burrs on the edge of the cut surface of the low-friction layer, affecting the extension of the metal wire to form a stable conductive path.

[0041] After punching out the through hole 20, the body 10 can be rolled or flanged to form a hollow cylindrical sleeve 15 and a flange 16 at one end of the sleeve 15. The conductive surface 13 is located on the outer side wall of the sleeve 15, and the non-conductive surface 14 is located on the inner side wall of the sleeve 15.

[0042] The present invention also provides a method for preparing a conductive self-lubricating bearing based on a metal mesh extended structure, which comprises the following steps:

[0043] Step S1: providing a body 10, the body 10 comprising a low-friction layer 11, and a conductive mesh 12 disposed in the low-friction layer 11, wherein a portion of the conductive mesh 12 is uniformly exposed from one end surface of the low-friction layer 11, the low-friction layer 11 being provided with a conductive surface 13 on one end surface exposed from the conductive mesh 12, and a non-conductive surface 14 on the other end surface of the low-friction layer 11;

[0044] Step S2: providing a punching die, punching from one side of the conductive surface 13 toward one side of the non-conductive surface 14 to form a through hole 20, wherein the lower limit of the diameter of the through hole 20 is:

[0045] d> ,

[0046] To ensure that the conductive mesh 12 located in the through hole 20 extends to the non-conductive surface 14, wherein d is the diameter of the through hole 20, a and b represent the two center distances of the diamond holes, that is, the straight-line distances between the centers of two adjacent diamond holes, and t represents the diameter of the metal wire used to make the conductive mesh 12. At the same time, the blanking gap is controlled to be 20%-40% of the thickness of the body 10, and the punch speed is controlled to be greater than or equal to 20 mm / s.

[0047] Step S3: rolling and flanging the punched body 10 to form a sleeve 15 and a flanging 16 .

[0048] Compared with the prior art, the preparation method of the conductive self-lubricating bearing based on the metal mesh extension structure provided by the present invention forms the through hole 20 by punching the conductive surface 13. During the punching, the conductive mesh 12 located in the through hole 20 is extended to the non-conductive surface 14, so that the inner side of the sleeve also has a conductive contact, thereby allowing the inner and outer workpieces sleeved by the body 10 to pass current, thereby realizing the integrated processing of the through hole 20 and the metal mesh extension, eliminating the secondary processing step of the notch.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements or improvements within the spirit of the present invention are included in the scope of the claims of the present invention.

Claims

1. A conductive self-lubricating bearing based on an extended metal mesh structure, characterized in that: The conductive self-lubricating bearing based on the metal mesh extension structure includes a body and at least one through hole arranged on the body, the body includes a low-friction layer and a conductive mesh arranged on the low-friction layer, the conductive mesh has a plurality of mesh holes arranged in an array, the conductive mesh is embedded in the low-friction layer and part of the conductive mesh is uniformly exposed on one end face of the low-friction layer, the low-friction layer is provided with an end face exposed with the conductive mesh as a conductive surface, and the other end face of the low-friction layer is a non-conductive surface, the through hole is formed by punching the conductive surface, and the conductive mesh located in the through hole is extended to the non-conductive surface during punching.

2. The conductive self-lubricating bearing based on the extended metal mesh structure according to claim 1, characterized in that: The low friction layer is made of PTFE polytetrafluoroethylene composite material.

3. The conductive self-lubricating bearing based on the extended metal mesh structure according to claim 1, characterized in that: The mesh holes are in the shape of diamonds, square holes, polygons, or elliptical holes, and the conductive mesh is formed by weaving in a warp-weft interlaced manner or by directly punching and stretching.

4. The conductive self-lubricating bearing based on the extended metal mesh structure according to claim 1, characterized in that: The exposed area of ​​the conductive mesh accounts for more than 8% of the area of ​​the conductive mesh.

5. The conductive self-lubricating bearing based on the extended metal mesh structure according to claim 1, characterized in that: The conductive mesh is made of a high-ductility copper alloy mesh with an elongation of ≥15%.

6. The conductive self-lubricating bearing based on the extended metal mesh structure according to claim 1, characterized in that: The through hole covers at least three metal wires of the conductive mesh. When the mesh is a diamond hole, the lower limit of the through hole diameter is: d＞ ， Wherein, a and b represent the distances between the two centers of the diamond holes, that is, the straight-line distance between the centers of two adjacent diamond holes, and t represents the diameter of the metal wire used to make the conductive mesh.

7. The conductive self-lubricating bearing based on the extended metal mesh structure according to claim 1, characterized in that: After the body is rolled and flanged, the body forms a sleeve with a hollow cylindrical structure and a flange arranged at one end of the sleeve. The conductive surface is located on the outer wall of the sleeve, and the non-conductive surface is located on the inner wall of the sleeve.

8. A method for preparing the conductive self-lubricating bearing based on the extended metal mesh structure according to any one of claims 1 to 7, comprising the following steps: Step S1: providing a body, the body comprising a low-friction layer and a conductive mesh disposed in the low-friction layer, wherein a portion of the conductive mesh is uniformly exposed on one end surface of the low-friction layer, the low-friction layer is configured such that the end surface exposed by the conductive mesh is a conductive surface, and the other end surface of the low-friction layer is a non-conductive surface; Step S2: providing a blanking tool, and performing blanking from one side of the conductive surface toward one side of the non-conductive surface through a blanking die to form a through hole, and extending the conductive mesh in the through hole to the non-conductive surface; Step S3: rolling and flanging the punched body to form a sleeve and a flanging.

9. The method for preparing a conductive self-lubricating bearing based on an extended metal mesh structure according to claim 8, characterized in that: In the above step S2, the punch speed is controlled to be greater than or equal to 20 mm / s.

10. The method for preparing a conductive self-lubricating bearing based on an extended metal mesh structure according to claim 8, wherein: In the above step S2, the blanking clearance is controlled to be 20%-40% of the bearing thickness.

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