Preparation method for self-lubricating composite material coating wound on shaft surface

Abstract

The invention relates to a preparation method for winding a self-lubricating composite material coating on a shaft surface, which comprises the following steps: by taking epoxy resin and a curing agent as base materials, further adding an antifriction agent and an anti-wear agent filler, and twisting industrial long cellosilk through a wet winding process, thereby obtaining the self-lubricating composite material coating on the shaft surface. The self-lubricating composite material is uniformly wound on the surface of a shaft with a rough surface according to a certain winding angle under a certain tension condition, a self-lubricating composite material coating is further formed on the surface of the shaft through curing molding and surface processing, the self-lubricating composite material coating is firmly combined with the surface of the shaft, the shaft has a transmission function and a surface self-lubricating performance, the shaft is better protected, and the service life of the shaft is prolonged. The friction of the shaft surface is reduced; and meanwhile, the requirement for antifriction and wear resistance of the inner surface of the friction pair sliding bearing is lowered.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material coatings, and more particularly, to a method for preparing a self-lubricating composite material coating wound on the surface of a shaft. Background Art

[0002] In a mechanical transmission system, shaft components are key components for transmitting power and motion. However, under long-term and high-load operating conditions, the surface of the shaft is prone to wear, resulting in performance degradation or even failure. Traditional repair and protection methods, such as surfacing and thermal spraying, have disadvantages such as large thermal stress and easy peeling of the coating. Therefore, it is of great significance to develop a composite material coating with excellent self-lubricating performance and capable of firmly adhering to the shaft surface.

[0003] As key components in mechanical transmission, sliding bearings and rolling bearings both bear the important tasks of supporting and reducing friction, but they have significant differences in structure, performance, and applicable scenarios. Rolling bearings are designed specifically for the shafts and shaft seats in mechanical operations, and their friction type is rolling friction. In contrast, sliding bearings rely on sliding friction to work and support the rotating shaft through the smooth inner surface of the sliding bearing. Therefore, higher requirements are placed on the anti-friction and wear-resistant performance of the inner surface of the sliding bearing. When the performance requirements for drive shafts and sliding bearings are both high, it undoubtedly increases the manufacturing cost and maintenance cost.

[0004] Currently, there are coatings with anti-friction and wear-resistant performance on the inner surface of sliding bearings, but there are problems such as complex manufacturing processes, high difficulty, insufficient mechanical strength, and low anti-friction and wear-resistant performance.

[0005] For example, the Chinese patent application with publication number CN 119465057 A discloses a method for preparing a wear-resistant coating on the surface of a planetary ball screw, which specifically includes the following steps: S1, cleaning of the substrate; S2, installation of the substrate; S3, ion cleaning: sequentially performing glow cleaning process and high-energy ion cleaning process for cleaning; S4, preparation of a Ti bonding layer; S5, preparation of a TiN transition layer; S6, preparation of a TiAlSiN nanocoating; S7, sampling: taking samples 60 - 90 minutes after the coating preparation is completed; this wear-resistant coating has the characteristics of high strength and toughness integration, and the prepared coating has high uniformity, and the coating process is flexibly adjustable. In addition, the coating prepared by this method on the inner wall of the pipe has a fast deposition rate, simple operation, low cost, and is suitable for mass production. However, the coating prepared by this preparation method is not firmly bonded to the surface of the screw. Summary of the Invention

[0006] To solve the above-mentioned technical deficiencies existing in the prior art, the object of the present invention is to provide a method for preparing a self-lubricating composite material coating wound on the surface of a shaft. By designing a coating with anti-friction and wear-resistant functions on the surface of the transmission shaft, it replaces the self-lubricating coating manufactured on the inner surface of the sliding bearing, has a firm bond with the shaft surface, and enables the shaft to have surface self-lubricating performance while having a transmission function, better protecting the shaft and reducing the friction on the shaft surface. At the same time, it also reduces the requirements for the anti-friction and wear-resistant performance of the inner surface of the mating sliding bearing.

[0007] The method for preparing a self-lubricating composite material coating wound on the surface of the shaft of the present invention uses epoxy resin and curing agent as matrix materials, further adds anti-friction agent and wear-resistant agent fillers, and uses twisted industrial long fiber filaments to be evenly wound on the surface of the shaft with a rough surface under certain tension conditions according to a certain winding angle through a wet winding process. Further through curing and forming and surface machining, a self-lubricating composite material coating is formed on the shaft surface, which has a firm bond with the shaft surface, and enables the shaft to have surface self-lubricating performance while having a transmission function, better protecting the shaft and reducing the friction on the shaft surface.

[0008] To solve the above technical problems, the solution adopted by the present invention is as follows:

[0009] The present invention provides a method for preparing a self-lubricating composite material coating wound on the surface of a shaft, which includes,

[0010] Step 1, preparation of coating slurry: Mix epoxy resin matrix, curing agent, lubricant, additive and fiber evenly in proportion to form coating slurry;

[0011] Step 2, pre-treatment of shaft surface: First, clean the shaft surface to remove impurities such as oil stains and rust, add extension shafts to both ends of the connecting shaft, and the extension shafts are connected to the connecting shaft by screws; then rough the shaft surface, such as machining, sandblasting, grinding, etc., to increase the bonding force between the coating and the shaft surface;

[0012] Step 3, coating winding: Wind the fiber evenly on the shaft through the wet winding method to form a continuous coating; Wind the fiber tightly on the pre-treated shaft surface to ensure that the coating evenly covers and has no obvious bubbles and defects;

[0013] Step 4, curing: Heat and cure the wound shaft at a certain temperature to form a firm physical chemical bond between the coating and the shaft surface;

[0014] Step 5, post-treatment: After curing, perform grinding and polishing post-treatment on the coating surface to improve its surface finish; Finally, remove the screws connecting the connecting shaft and the extension shaft, and cut along the joint of the connecting shaft and the extension shaft to form the final shaft with a wound coating on the surface.

[0015] Preferably, an appropriate amount of absolute ethanol and acetone can be added as solvents in the first step to adjust the viscosity and fluidity of the slurry.

[0016] In any of the above - mentioned solutions, preferably, the mass percentage of the epoxy resin matrix in the first step is 36 - 44%; the lubricant includes molybdenum disulfide and graphite, wherein the mass percentage of molybdenum disulfide is 10 - 15%, and the mass percentage of graphite is 10 - 25%; the additive is SiO2 with a wear - resistant function, and its mass percentage is 3 - 5%; the fiber is selected from polyester fiber, carbon fiber or Kevlar fiber, and the twist is 200 - 300 turns / meter.

[0017] In any of the above - mentioned solutions, preferably, the range of the surface roughness of the shaft in the second step is: Ra6.3 - Ra15, Rz40 - 80.

[0018] In any of the above - mentioned solutions, preferably, the temperature in the fourth step is 100 - 200 °C.

[0019] In any of the above - mentioned solutions, preferably, the number of layers of the winding layer in the third step is 2 - 10 layers, the winding angle between the fiber and the shaft is 30 - 75°, and the winding tension is 5 - 15 N.

[0020] In summary, the method for preparing the self - lubricating composite material coating by winding on the shaft surface of the present invention has the following advantages: The self - lubricating composite material coating prepared by the present invention has a low friction coefficient and high wear resistance, which can significantly reduce the friction loss and energy consumption of the shaft during operation; the coating is firmly bonded to the shaft surface and is not easy to peel off, improving the service life and reliability of the shaft; the graphite - epoxy resin fiber composite material coating wound on the shaft surface can be applied to dry friction conditions, as well as water lubrication, oil lubrication and even corrosive environments, and maintains a low friction coefficient and a low wear amount; the preparation method is simple and easy to operate, is applicable to the surface treatment of various shaft parts, and has a wide application prospect. Description of the Drawings

[0021] Figure 1 It is a working flowchart of a preferred embodiment of the method for preparing the self - lubricating composite material coating by winding on the shaft surface according to the present invention.

[0022] Figure 2 It is a finished product drawing of the shaft coated with the method for preparing the self - lubricating composite material coating by winding on the shaft surface according to the present invention. Detailed Embodiments

[0023] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application or use. The following further explains the detailed embodiments of the method for preparing the self - lubricating composite material coating by winding on the shaft surface of the present invention with reference to the accompanying drawings of the specification.

[0024] As Figure 1 shown in the flowchart of a preferred embodiment of the method for preparing a self-lubricating composite material coating wound on the shaft surface according to the present invention. The method for preparing a self-lubricating composite material coating wound on the shaft surface of the present invention includes,

[0025] Step 1, preparation of coating slurry: Mix epoxy resin matrix, curing agent, lubricant, additive and fiber evenly in proportion to form coating slurry;

[0026] Step 2, pre-treatment of shaft surface: First, clean the shaft surface to remove impurities such as oil stains and rust. Add extension shafts 3 to both ends of the connecting shaft 1, and the extension shafts 3 are connected to the connecting shaft 1 by screws 4; then roughen the shaft surface, such as machining, sandblasting, grinding, etc., to increase the bonding force between the coating and the shaft surface;

[0027] Step 3, coating winding: By means of wet winding, wind polyester fiber or carbon fiber or Kevlar fiber evenly on the shaft to form a continuous coating; wind the polyester fiber tightly on the pre-treated shaft surface to ensure that the coating evenly covers and there are no obvious bubbles and defects;

[0028] Step 4, curing: Heat and cure the wound shaft at a certain temperature to form a firm physical chemical bond between the coating and the shaft surface;

[0029] Step 5, post-treatment: After curing, perform grinding and polishing post-treatment on the coating surface to improve its surface finish; finally remove the screws 4 connecting the connecting shaft 1 and the extension shaft 3, and cut along the joint of the connecting shaft 1 and the extension shaft 3 to form the final shaft with the wound coating 2 on the surface (see Figure 2 shown).

[0030] In this embodiment, an appropriate amount of anhydrous ethanol and acetone can be added as solvents in Step 1 to adjust the viscosity and fluidity of the slurry.

[0031] In this embodiment, the mass percentage of the epoxy resin matrix in Step 1 is 40%; the lubricant includes molybdenum disulfide and graphite, wherein the mass percentage of molybdenum disulfide is 12% and the mass percentage of graphite is 12%; the additive is SiO2 with wear-resistant effect, and its mass percentage is 4%; the rest is alcohol solvent; the fiber is polyester fiber with a twist of 200 - 300 turns / meter.

[0032] In this embodiment, the range of the surface roughness of the shaft in Step 2 is: Ra8, Rz60.

[0033] In this embodiment, the temperature in Step 4 is 120 °C.

[0034] In this embodiment, the number of layers of the winding layer in the third step is 4, the winding angle between the polyester fiber and the shaft is 60°, and the winding tension is 10 N.

[0035] The friction coefficient of the sample was tested by a sliding bearing testing machine. The diameter of the shaft with the coating was 24 mm, the counter friction pair was a bearing steel bushing, the load was gradually increased from 200 to 10,000 N, reciprocating dry friction was applied, the frequency was 30 times / min, the temperature was room temperature, and the friction coefficient was less than 0.12.

[0036] It is not difficult for those skilled in the art to understand that the method for preparing the self-lubricating composite material coating wound on the surface of the shaft of the present invention includes any combination of the various parts in this specification. Limited by space and for the sake of making the specification concise, these combinations are not introduced in detail one by one here. However, after reading this specification, the scope of the present invention constituted by any combination of the various parts constituted by this specification is self-evident.

Claims

1. A preparation method of a self-lubricating composite material coating wound on the surface of a shaft, characterized in that including Step 1, preparation of coating slurry: uniformly mix an epoxy resin matrix, a curing agent, a lubricant, an additive, and fibers in proportion to form a coating slurry; Step 2, pre-treatment of the shaft surface: First, clean the shaft surface to remove impurities such as oil stains and rust. Add extension shafts (3) to both ends of the connecting shaft (1), and the extension shafts (3) are connected to the connecting shaft (1) by screws (4); then roughen the shaft surface, such as by machining, sandblasting, or grinding; Step 3, coating winding: uniformly wind polyester fibers, carbon fibers, or Kevlar fibers on the shaft by wet winding to form a continuous coating; Step 4, curing: heat and cure the wound shaft at a certain temperature to form a firm physical chemical bond between the coating and the shaft surface; Step 5, post-treatment: After curing, polish and buff the coating surface to improve its surface finish; finally, remove the screws (4) connecting the connecting shaft (1) and the extension shaft (3), and cut along the joint of the connecting shaft (1) and the extension shaft (3) to form a shaft with a wound coating (2) on the final surface.

2. The detection method for the preparation method of the self-lubricating composite material coating wound on the shaft surface according to claim 1, characterized in that: In Step 1, an appropriate amount of absolute ethanol and acetone can be added as solvents according to needs to adjust the viscosity and fluidity of the slurry.

3. The detection method of the preparation method of the self-lubricating composite material coating wound on the shaft surface according to claim 1, characterized in that: In Step 1, the mass percentage of the epoxy resin matrix is 36-44%; the lubricant includes molybdenum disulfide and graphite, where the mass percentage of molybdenum disulfide is 10-15%, and the mass percentage of graphite is 10-25%; the additive is SiO2 with a wear-resistant effect, and its mass percentage is 3-5%; the fiber is selected from polyester fibers, carbon fibers, or Kevlar fibers, and the twist is 200-300 turns / meter.

4. The detection method of the preparation method of the self-lubricating composite material coating wound on the shaft surface according to claim 1, characterized in that: In Step 2, the range of the shaft surface roughness is: Ra6.3-Ra15, Rz40-80.

5. The detection method of the preparation method of the self-lubricating composite material coating wound on the shaft surface according to claim 1, characterized in that: The temperature in Step 4 is 100-200°C.

6. The detection method of the preparation method of the self-lubricating composite material coating wound on the shaft surface according to claim 1, characterized in that: In Step 3, the number of winding layers of the winding layer is 2-10 layers, the winding angle between the fiber and the shaft is 30-75°, and the winding tension is 5-15N.

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