Method for designing and manufacturing a polyamide-imide composite-coated gear

Abstract

The application discloses a design and manufacturing method of a polyamide-imide composite coating gear, and comprises the following steps: S1, collecting customer requirements, sorting the priority of the customer requirements, and establishing a quality house based on a quality function deployment method; S2, formulating a design project according to the priority of the customer requirements; S3, preliminarily evaluating the feasibility of the design project through a probability evaluation and risk analysis tool; S4, obtaining key quality characteristics and clearly defining a tolerance limit range; S5, establishing a parameter-driven input-output model based on a multi-objective optimization processing parameter reverse adjustment method; S6, inputting the key quality characteristics into the input-output model to obtain a design scheme; S7, inputting the design scheme into a multi-objective optimization model to obtain optimized key quality characteristics; S8, planning a manufacturing process based on the customer requirements and the optimized key quality characteristics; and S9, manufacturing a composite coating gear sample, testing the composite coating gear sample, and verifying the service performance of the composite coating gear sample.

Description

Technical Field

[0001] This invention relates to the field of design and manufacturing of composite coated gears, specifically to a method for designing and manufacturing polyamide-imide composite coated gears. Background Technology

[0002] Employing advanced design methodologies and manufacturing processes to optimize product characteristics and production flows is a key strategy for modern manufacturing enterprises to improve product quality, reduce costs, and enhance market competitiveness. However, product performance and quality are often determined during the design phase and early in the product development cycle.

[0003] Gears are core components in mechanical transmissions, and their performance directly affects the operating efficiency and reliability of equipment. Under special operating conditions, traditional metal gears, due to their high surface friction coefficient, poor wear resistance, and insufficient corrosion resistance, are unable to meet the demands of complex working conditions. Therefore, gear performance needs to be designed during the design phase and product development cycle. Summary of the Invention

[0004] The purpose of this invention is to provide a method for designing and manufacturing gears with a polyamide-imide composite coating, comprising the following steps:

[0005] S1. Collect customer requirements and functional requirements, prioritize customer requirements, and establish a house of quality based on the quality function deployment method.

[0006] S2. Develop design projects based on the priority of customer needs;

[0007] S3. Using probability assessment and risk analysis tools, conduct a preliminary assessment of the feasibility of the design project. If the design is feasible, proceed to step S4; otherwise, return to step S1.

[0008] S4. Based on the house of quality and functional requirements, obtain key quality characteristics and clarify the tolerance range of the amount of polyamide-imide composite coating reinforcement material added.

[0009] The key quality characteristics include the coating's wear rate, decomposition temperature, vibration reduction amplitude, noise reduction amplitude, friction coefficient, and service life.

[0010] S5. Based on the multi-objective optimization processing parameter back-adjustment method, establish a parameter-driven input-output model;

[0011] S6. Input the key quality characteristics into the input-output model to obtain the design scheme of the polyamide-imide composite coated gear; the design scheme includes the thickness, material composition and ratio of the polyamide-imide composite coating reinforcement material;

[0012] S7. Input the design scheme into the multi-objective optimization model to obtain the optimized key quality characteristics;

[0013] S8. Based on customer needs and optimized key quality characteristics, plan the manufacturing process, which includes thinning of the gear substrate, gear coating spraying, and gear coating processing.

[0014] S9. Fabricate polyamide-imide composite coated gear samples and conduct wear resistance, heat resistance, vibration reduction and noise reduction effect, friction coefficient and service life tests, as well as reliability tests on the polyamide-imide composite coated gear samples to verify the service performance of the composite coated gear samples; the reliability test is to detect the mean time between failures of the composite coated gear samples.

[0015] If the verification results do not meet the key quality characteristics requirements and tolerance limits, return to step S5; otherwise, deliver the polyamide-imide composite coated gear sample.

[0016] Furthermore, in step S1), the customer requirements include the wear resistance, heat resistance, vibration reduction and noise reduction, friction coefficient, and service life performance requirements of the gears.

[0017] The functional requirements include the optimal ratio of each component in the coating material and the maximum error limit between the actual coating thickness and the designed coating thickness.

[0018] In step S4), the coating material comprises polyamide imide, reinforcing material, additives, and coating solvent.

[0019] The additives include dispersants, leveling agents, and defoamers.

[0020] The components of the reinforcing material need to undergo interface modification treatment.

[0021] The reinforcing material comprises at least one of the following: graphene, boron nitride (BN), alumina (Al2O3), zirconium oxide (ZrO2), and polytetrafluoroethylene (PTFE) microparticles.

[0022] When the reinforcing material is graphene, the amount of graphene used is 0.5-3.0% of the total mass of the coating.

[0023] When the reinforcing material is boron nitride (BN), the amount of boron nitride (BN) used is 1-5% of the total mass of the coating.

[0024] When the reinforcing material is aluminum oxide (Al2O3), the amount of aluminum oxide (Al2O3) used is 5-10% of the total mass of the coating.

[0025] When the reinforcing material is zirconium oxide (ZrO2), the amount of zirconium oxide (ZrO2) used is 5-10% of the total mass of the coating.

[0026] When the reinforcing material is composed of polytetrafluoroethylene (PTFE) microparticles, the amount of PTFE microparticles is 2-8% of the total mass of the coating.

[0027] Further, in step S4), the coating thickness t is calculated using the following formula:

[0028]

[0029] In the formula: F load Indicates the maximum working load on the gear surface;

[0030] σ coating This indicates the maximum allowable stress of the coating.

[0031] Furthermore, in step S5), the multi-objective function of the multi-objective optimization processing parameter back-adjustment method is expressed as:

[0032]

[0033] Customer needs are quantified, and the resulting multi-objective function is shown below:

[0034]

[0035] In the formula: κ i Represents the weighting factors, i = 1, 2, ..., N;

[0036] ω i The coefficients representing the design objectives, i = 1, 2, ..., N;

[0037] N is the number of targets;

[0038] R represents the range of values ​​for the design variable;

[0039] X represents the design factor, X = {W, T, V, N, μ, L};

[0040] W represents the wear rate, W MAX The maximum wear rate is T; T is the decomposition temperature. MIN V is the lowest decomposition temperature; V is the vibration reduction amplitude. MIN N is the minimum vibration reduction amplitude; N is the noise reduction amplitude. MIN Minimum noise reduction amplitude; μ is the coefficient of friction, μ MAX L is the maximum coefficient of friction; L is the service life. MIN For the increase in minimum service life

[0041] Furthermore, in step S5), the regression formula for the input-output model is as follows:

[0042]

[0043] In the formula: t is the coating thickness;

[0044] x graphene ,x hBN , x PTFE These represent the proportions of graphene, boron nitride, alumina, zirconium oxide, and PTFE particles, respectively.

[0045] Furthermore, in step S7), the objective function of the multi-objective optimization model is as follows:

[0046] f=a1W+a2T+a3V+a4N+a5μ+a6L(5)

[0047] In the formula, a1, a2, a3, a4, a5, and a6 are the weighting coefficients of W, T, V, N, μ, and L.

[0048] Furthermore, in step S8), the method for thinning the gear substrate includes the following steps:

[0049] 1) Calculate the target value Ra of tooth surface roughness.

[0050]

[0051] In the formula: k represents the proportionality coefficient;

[0052] γ represents the surface tension between the coating and air;

[0053] θ represents the contact angle of the coating on the gear substrate;

[0054] σ represents the target bonding strength between the coating and the gear substrate;

[0055] 2) The gear base is thinned by using a gear hobbing process;

[0056] During gear hobbing, the gear base is thinned by controlling the displacement coefficient to achieve negative displacement. The formula for calculating the negative displacement coefficient x is as follows:

[0057]

[0058] In the formula: Δt represents the service thickness of the coating; m represents the module of the gear.

[0059] 3) Determine whether the surface roughness of the thinned tooth reaches the target value. If it does, the thinning of the gear base is complete; otherwise, sandblasting is required.

[0060] Furthermore, in step S8), the gear coating spraying method includes the following steps:

[0061] 1) Thoroughly clean the surface of the gears;

[0062] 2) Preheat the gear base;

[0063] 3) Use automated spray gun equipment to perform air spraying on the gear substrate;

[0064] 4) Place the gears in an oven for curing;

[0065] 5) After curing, use a gear micrometer to check the coating thickness to determine if the coating thickness meets the requirements. If it does, the gear coating spraying is complete; otherwise, return to step 3.

[0066] Furthermore, in step S8), whether gear coating processing is required is determined by the following method: judging whether the surface accuracy of the coating after spraying meets the requirements. If it meets the requirements, the gear can be put into use directly after spraying. Otherwise, a processing allowance should be prepared when spraying the gear, and the coating should be thinned after spraying and curing to make its surface accuracy meet the requirements.

[0067] 1. This invention adopts the IDDOV model of the Design for Six Sigma (DFSS) framework to develop a design method for polyamide-imide composite coated gears. Through precise coating composition design, coating thickness optimization design, substrate tooth thickness reduction treatment and automated spraying and curing process, the service performance and service life of the gears are significantly improved.

[0068] 2. This invention is the first to propose using polyamide-imide (PAI) as a coating material for gears, which significantly improves the wear resistance, vibration damping performance and fatigue resistance of gears. Attached Figure Description

[0069] Figure 1 This is the roadmap for implementing Six Sigma design using the IDDOV framework as described in Example 11;

[0070] Figure 2 This is a flowchart illustrating the design phases of the polyamide-imide composite coated gear described in Example 11.

[0071] Figure 3 This is a flowchart illustrating the usage stages of the polyamide-imide composite coated gear described in Example 11. Detailed Implementation

[0072] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0073] Example 1:

[0074] The design and manufacturing method of polyamide-imide composite coated gears includes the following steps:

[0075] S1. Collect customer requirements and functional requirements, prioritize customer requirements, and establish a house of quality based on the quality function deployment method.

[0076] S2. Develop design projects based on the priority of customer needs;

[0077] S3. Using probability assessment and risk analysis tools, conduct a preliminary assessment of the feasibility of the design project. If the design is feasible, proceed to step S4; otherwise, return to step S1.

[0078] S4. Based on the house of quality and functional requirements, obtain the key quality characteristics and clarify the tolerance range of the amount of polyamide-imide composite coating reinforcement material added (for specific requirements and parameters, see GB / T 10095.1-2022 and GB / T 10095.2-2023);

[0079] The key quality characteristics include the coating's wear rate, decomposition temperature, vibration reduction amplitude, noise reduction amplitude, friction coefficient, and service life.

[0080] S5. Based on the multi-objective optimization processing parameter back-adjustment method, establish a parameter-driven input-output model;

[0081] S6. Input the key quality characteristics into the input-output model to obtain the design scheme of the polyamide-imide composite coated gear; the design scheme includes the thickness, material composition and ratio of the polyamide-imide composite coating reinforcement material;

[0082] S7. Input the design scheme into the multi-objective optimization model to obtain the optimized key quality characteristics;

[0083] S8. Based on customer needs and optimized key quality characteristics, plan the manufacturing process, which includes thinning of the gear substrate, gear coating spraying, and gear coating processing.

[0084] S9. Fabricate polyamide-imide composite coated gear samples and conduct wear resistance, heat resistance, vibration reduction and noise reduction effect, friction coefficient and service life tests, as well as reliability tests on the polyamide-imide composite coated gear samples to verify the service performance of the composite coated gear samples; the reliability test is to detect the mean time between failures of the composite coated gear samples.

[0085] If the verification results do not meet the key quality characteristics requirements and tolerance limits, return to step S5; otherwise, deliver the polyamide-imide composite coated gear sample.

[0086] Example 2:

[0087] The main structure of this embodiment is the same as that of embodiment 1. Furthermore, in step S1), the customer requirements include the wear resistance, heat resistance, vibration reduction and noise reduction, friction coefficient and service life performance requirements of the gear.

[0088] The functional requirements include the optimal ratio of each component in the coating material and the maximum error limit between the actual coating thickness and the designed coating thickness.

[0089] Example 3:

[0090] The main structure of this embodiment is the same as any one of embodiments 1 to 2. Further, in step S4), the coating material of the coating includes polyamide imide, reinforcing material, additives and coating solvent.

[0091] The additives include dispersants, leveling agents, and defoamers.

[0092] The components of the reinforcing material need to undergo interface modification treatment.

[0093] The reinforcing material comprises at least one of the following: graphene, boron nitride (BN), alumina (Al2O3), zirconium oxide (ZrO2), and polytetrafluoroethylene (PTFE) microparticles.

[0094] When the reinforcing material is graphene, the amount of graphene used is 0.5-3.0% of the total mass of the coating.

[0095] When the reinforcing material is boron nitride (BN), the amount of boron nitride (BN) used is 1-5% of the total mass of the coating.

[0096] When the reinforcing material is aluminum oxide (Al2O3), the amount of aluminum oxide (Al2O3) used is 5-10% of the total mass of the coating.

[0097] When the reinforcing material is zirconium oxide (ZrO2), the amount of zirconium oxide (ZrO2) used is 5-10% of the total mass of the coating.

[0098] When the reinforcing material is composed of polytetrafluoroethylene (PTFE) microparticles, the amount of PTFE microparticles is 2-8% of the total mass of the coating.

[0099] When reinforcing materials are made of two-component or multi-component composites, the dosage can be reduced based on the recommended amount.

[0100] Example 4:

[0101] The main structure of this embodiment is the same as any one of embodiments 1 to 3. Further, in step S4), the coating thickness t is calculated using the following formula:

[0102]

[0103] In the formula: F load Indicates the maximum working load on the gear surface;

[0104] σ coating This indicates the maximum allowable stress of the coating.

[0105] Example 5:

[0106] The main structure of this embodiment is the same as any one of embodiments 1 to 4. Further, in step S5), the multi-objective function of the multi-objective optimization processing parameter back-adjustment method is expressed as:

[0107]

[0108] Customer needs are quantified, and the resulting multi-objective function is shown below:

[0109]

[0110] In the formula: κ i Representing the weighting factors, o = 1, 2, ..., N;

[0111] ω i The coefficients representing design objectives indicate the contribution of different design objectives (wear resistance, heat resistance, etc.) to the final product performance, i = 1, 2, ..., N;

[0112] N is the number of targets;

[0113] R represents the range of values ​​for the design variables, which is the set of all possible design parameters and defines the range of variables that can be adjusted during the design process.

[0114] X represents the design factor, X = {W, T, V, N, μ, L};

[0115] W represents the wear rate, W MAX The maximum wear rate is T; T is the decomposition temperature. MIN V is the lowest decomposition temperature; V is the vibration reduction amplitude. mIN N is the minimum vibration reduction amplitude; N is the noise reduction amplitude. MIN Minimum noise reduction amplitude; μ is the coefficient of friction, μ MAX L is the maximum coefficient of friction; L is the service life. MIN This represents the increase in minimum service life.

[0116] Example 6:

[0117] The main structure of this embodiment is the same as any one of embodiments 1 to 5. Further, in step S5), the regression formula of the input-output model is as follows:

[0118]

[0119] In the formula: t is the coating thickness;

[0120] x graphene ,x hBN , x PTFE These represent the proportions of graphene, boron nitride, alumina, zirconium oxide, and PTFE particles, respectively.

[0121] When a certain component is not included in the design combination, the proportion of the combination is 0.

[0122] Example 7:

[0123] The main structure of this embodiment is the same as any one of embodiments 1 to 6. Further, in step S7), the optimization objective function of the multi-objective optimization model is as follows:

[0124] f=a1W+a2T+a3V+a4N+a5μ+a6L(5)

[0125] In the formula, a1, a2, a3, a4, a5, and a6 are the weighting coefficients of W, T, V, N, μ, and L.

[0126] Example 8:

[0127] The main structure of this embodiment is the same as any one of embodiments 1 to 7. Further, in step S8), the method for thinning the gear base includes the following steps:

[0128] 1) Calculate the target value Ra of tooth surface roughness.

[0129] Method 1: Determine the target value of tooth surface roughness (Ra range is 2-8μm) based on the particle size and adhesion performance requirements of PAI coatings and composite reinforcing materials.

[0130] Method 2: Based on the principle of coating mechanical bonding, calculate the target value of tooth surface roughness. The calculation formula is as follows:

[0131]

[0132] In the formula: k represents the proportionality coefficient, which is determined through empirical values ​​or regression fitting in preliminary experiments;

[0133] γ represents the surface tension between the coating and air;

[0134] θ represents the contact angle of the coating on the gear substrate;

[0135] σ represents the target bonding strength between the coating and the gear substrate;

[0136] 2) The gear base is thinned by using a gear hobbing process;

[0137] During the processing, the amount of tooth thickness reduction must be strictly controlled, and its tolerance range should be less than ±0.001mm to ensure accurate matching of the subsequent coating thickness.

[0138] During gear hobbing, the gear base is thinned by controlling the displacement coefficient to achieve negative displacement. The formula for calculating the negative displacement coefficient x is as follows:

[0139]

[0140] In the formula: Δt represents the service thickness of the coating; m represents the module of the gear.

[0141] 3) Determine whether the surface roughness of the thinned tooth reaches the target value. If it does, the thinning of the gear base is complete; otherwise, sandblasting is required.

[0142] Sandblasting process parameters include:

[0143] Sandblasting particle size: 40-60μm;

[0144] Spray angle: 30°-45°;

[0145] Injection pressure: 0.6-0.8MPa.

[0146] After sandblasting, the surface should be cleaned to ensure that there are no residual particles or oil stains on the tooth surface.

[0147] Example 9:

[0148] The main structure of this embodiment is the same as any one of embodiments 1 to 8. Further, in step S8), the gear coating spraying method includes the following steps:

[0149] 1) Thoroughly clean the gear surface to remove oil, oxides and other impurities to ensure good adhesion between the coating and the substrate;

[0150] 2) Preheat the gear substrate to a temperature range of 100-130℃ for 10-15 minutes to enhance the adhesion and uniformity of the coating.

[0151] 3) Use automated spray gun equipment to perform air spraying on the gear substrate;

[0152] During the spraying process, the spraying speed is controlled at 10-15 mm / s to ensure uniform coating distribution, and the deviation of the spraying thickness is controlled within ±0.02 mm.

[0153] 4) Place the gears in an oven for curing at a temperature of 210-280℃ for 0.5-1 hour.

[0154] 5) After curing, use a gear micrometer to check the coating thickness to determine if the coating thickness meets the requirements. If it does, the gear coating spraying is complete; otherwise, return to step 3.

[0155] The required thickness during the spraying stage is as follows:

[0156] The deviation of the coating thickness is controlled within ±0.02mm.

[0157] Method for determining coating thickness:

[0158] If the precision of the tooth surface coating after spraying meets the requirements, the spraying thickness = the service thickness of the coating.

[0159] If the precision of the tooth surface coating after spraying does not meet the requirements, the spraying thickness = coating service thickness + coating machining allowance.

[0160] The sprayed coating includes PAI material and reinforcing material.

[0161] During the preparation of the PAI coating matrix, each component of the reinforcing material needs to be added gradually, and the reinforcing material is dispersed by ultrasonic dispersion, mechanical stirring or high-energy ball milling.

[0162] Example 10:

[0163] The main structure of this embodiment is the same as any one of embodiments 1 to 9. Further, in step S8), whether gear coating processing is required is determined by the following method: judging whether the surface accuracy of the coating after spraying meets the requirements. If it meets the requirements, the gear can be put into use directly after spraying. Otherwise, a processing allowance should be prepared when spraying the gear. After the coating is cured, the coating is thinned to make its surface accuracy meet the requirements.

[0164] For specific requirements and parameters, please refer to GB / T 10095.1-2022 and GB / T 10095.2-2023.

[0165] Example 11:

[0166] The main structure of this embodiment is the same as any one of embodiments 1-10. Furthermore, using the IDDOV (Design for Six Sigma) framework (DFSS), a design method for polyamide-imide composite coated gears is developed. Through precise substrate tooth thickness reduction, coating thickness optimization design, and automated spraying and curing processes, the service performance and lifespan of the gears are significantly improved. The process is mainly divided into design and manufacturing / application stages.

[0167] I. Design Stage of Composite Coated Gears

[0168] 1. Design of composite coated gears

[0169] A design methodology for polyamide-imide composite coated gears was developed using the IDDOV pattern-based Design for Six Sigma (DFSS) framework, comprising the following stages:

[0170] (S1) Identification Phase (I: Identify)

[0171] Objective: To identify the project's customer needs (VOC) and clarify the design challenges and priorities.

[0172] Design process:

[0173] 1. Identify the project to be implemented: Optimization of gear design for polyamide-imide composite coating.

[0174] 2. Identify customer needs and functional requirements

[0175] Customer requirements: high wear resistance, high heat resistance, vibration reduction and noise reduction, low coefficient of friction, and long service life.

[0176] Functional requirements: Optimal ratio of coating materials and reinforcing components, and precise control of coating thickness.

[0177] 3. Priority sorting

[0178] Use QFD (Quality Function Deployment) to build a House of Quality (HOQ), prioritizing performance metrics and ranking customer requirements.

[0179] 4. Conduct DFSS project feasibility study

[0180] Using probability assessment and risk analysis tools, a preliminary feasibility assessment of the design was conducted.

[0181] (S2) Definition Phase (D: Define)

[0182] Objective: Define critical quality characteristics (CTQs), select a conceptual design scheme, and transform VOCs into CTQs.

[0183] To address the large volume, fuzzy, uncertain, and even contradictory VOCs in the market, optimization and screening are first required. Through precise processing and fuzzy optimization methods, these VOCs are transformed into important, accurate, and useful information. Subsequently, QFD (Quality-Determining Facility) is used to refine the VOCs layer by layer, clarifying the design, process flow, and production requirements of the composite gear, and extracting CTQs (Comprehensive Quality Qualifications). Finally, by accurately identifying and quantifying customer needs, the product design and process requirements of the composite gear are determined. Combining the comprehensive analysis of VOCs and CTQs, the geometric and physical properties of the gear are used as design factors for co-optimization and integrated into the design scheme. It is worth emphasizing that an evaluation criterion for optimal CTQs items is proposed to determine the final performance evaluation items. These evaluation items can be expressed as functions of input machining parameters and are applied throughout the entire product development process. Therefore, the CTQs-based design scheme is novel and challenging in composite gear design, and also represents an advanced improvement method for process and performance optimization.

[0184] Design process

[0185] 1. Determine technical requirements (CTQ variables and tolerance limits)

[0186] Design benchmarks:

[0187] Based on the service requirements of composite coated gears, select the appropriate reinforcing material according to the table below:

[0188]

[0189]

[0190] Design variables: Coating thickness S, graphene ratio x graphene Boron nitride ratio x hBN Alumina ratio x Al2O3 Zirconia ratio x ZrO2 PTFE particulate ratio x PTFE .

[0191] Tolerance range: Control the error of each variable to meet the design objectives.

[0192] 2. Selection, simulation, and review of conceptual designs

[0193] Different design schemes were simulated and evaluated using TRIZ (Theory of Inventive Problem Solving) and fuzzy information processing to select the optimal concept. Based on the specific description of composite coated gears in HOQ (House of Questions), the research objectives and design purpose were clarified, and customer needs were clearly defined. A multi-objective optimization (MOO) machining parameter back-adjustment method that integrates customer needs was proposed as the core solution of the collaborative optimization system. Based on this, the multi-objective function of the design factor X was expressed as:

[0194]

[0195] In the formula, κ i (i = 1, 2, ..., N) represents the weighting factor, which is generally set to ±1.

[0196] When setting the HOQ, it should be based on customer needs and material properties, taking into account customer requirements (maximum wear rate W). MAX Minimum decomposition temperature T MIN Small vibration reduction amplitude V MIN Minimum noise reduction amplitude N MIN Maximum friction coefficient μ MAX Minimum service life increase L MIN Quantifying these, we have:

[0197]

[0198] stW MAX ≤5;

[0199] 200℃≤T MIN

[0200] 20%≤V MIN

[0201] 20%≤N MIN

[0202] μ MAX ≤0.2

[0203] 30%≤L MIN

[0204] The amount of reinforcing material added can be optimized according to process requirements to ensure a balance between the mechanical properties and process performance of the coating.

[0205] To achieve synergistic optimization of multiple properties, composite reinforced materials are designed using the following methods:

[0206] a. Two-component composites: such as graphene + boron nitride combination, which takes into account both lubricity and heat resistance.

[0207] b. Multi-component composites: such as a combination of alumina + graphene + PTFE microparticles, which have the properties of wear resistance, corrosion resistance and low friction.

[0208] c. Interface modification treatment: Chemical or physical modification (such as acidification, coupling agent treatment) is performed on the surface of the reinforcing material to improve its bonding strength and dispersibility with PAI coating.

[0209] Order of addition: Reinforcing materials should be added gradually during the preparation of the PAI coating matrix to avoid agglomeration.

[0210] Dispersion technology: Ultrasonic dispersion, mechanical stirring or high-energy ball milling processes are used to ensure that the reinforcing material is evenly distributed in the coating.

[0211] (S3) Development Phase (D: Develop)

[0212] Objective: To identify design parameters, establish input-output models, and formulate manufacturing plans.

[0213] Design process

[0214] 1. Use FMEA (Failure Mode and Effects Analysis) to identify potential defects.

[0215] Analyze the potential failure modes of each design variable (coating thickness and material ratio) and formulate risk avoidance measures.

[0216] Based on the gear's working load, speed, and tribological characteristics, the service thickness of the coating is determined through theoretical calculation formulas, and the thickness design is optimized in combination with actual working conditions to ensure that the gear's strength, transmission accuracy, and lubrication requirements are met.

[0217] The service thickness of the coating is calculated using the following formula:

[0218]

[0219] Among them, F load Indicates the maximum working load on the gear surface; σ coating The maximum allowable stress of the coating.

[0220] 2. Identify design parameters using engineering analysis methods.

[0221] Experimental design (DOE) was used to generate an experimental matrix and collect data on the impact of design variables on performance indicators (wear resistance, heat resistance, vibration reduction and noise reduction effect, friction coefficient, and service life).

[0222] 3. Establish an input-output model

[0223] Regression modeling:

[0224]

[0225] Objectives: High wear resistance, high heat resistance, vibration reduction and noise reduction, low coefficient of friction, and long service life.

[0226] 4. Determine the manufacturing plan

[0227] Planning the manufacturing process includes spraying technology, coating curing, testing, and precision control.

[0228] (S4) Optimization Phase (O: Optimize)

[0229] Objective: To optimize design parameters, ensure design robustness, and reduce process fluctuations.

[0230] Design process

[0231] 1. Ability to judge the process

[0232] Determine whether the design parameters (coating thickness, material ratio) meet the CTQ requirements and tolerance limits.

[0233] 2. Optimize design

[0234] Using multi-objective optimization (Monte Carlo method, robust design):

[0235] Maximize wear resistance, maximize heat resistance, maximize vibration reduction and noise reduction, minimize the coefficient of friction, and maximize service life.

[0236] Optimize the objective function:

[0237] In step S7), the objective function of the multi-objective optimization model is as follows:

[0238] f=a1W+a2T+a3V+a4N+a5μ+a6L(5)

[0239] 3. Robust Design

[0240] To improve the robustness of the design, noise factors (coating thickness deviation) should be considered.

[0241] 4. Statistical tolerance optimization

[0242] Optimize the standard deviation to reduce manufacturing costs and precision requirements.

[0243] (S5) Verification Phase (V: Verify)

[0244] Objective: To verify the design results and ensure that the design meets Six Sigma quality standards.

[0245] Design process

[0246] 1. Prototype Testing and Verification

[0247] Composite coated gear samples were manufactured and tested for friction coefficient, wear resistance and service life.

[0248] 2. Evaluate design performance

[0249] Reliability Testing: Mean Time Between Failures (MTBF)

[0250] Life testing and failure mode analysis.

[0251] 3. Repetitive design

[0252] If the verification results do not meet the CTQ requirements, return to the optimization phase to readjust the design parameters.

[0253] 4. Final Review

[0254] Conduct a comprehensive review, complete the design delivery, and summarize the project.

[0255] 2. Thinning of the gear base

[0256] (1) Determination of tooth surface roughness requirements

[0257] Based on the particle size and adhesion performance requirements of PAI coatings and composite reinforcing materials, the target value for tooth surface roughness (Ra range of 2-8 μm) is determined.

[0258] Based on the principle of coating mechanics, the target value of tooth surface roughness is calculated using the following formula:

[0259]

[0260] Where k represents the proportionality coefficient, which is determined through empirical values ​​or regression fitting from pre-experiments;

[0261] γ represents the surface tension between the coating and air;

[0262] θ represents the contact angle of the coating on the gear substrate;

[0263] σ represents the target bonding strength between the coating and the gear substrate;

[0264] (2) Selection of matrix thinning process

[0265] The gear base is thinned using a gear hobbing process. During this process, the amount of tooth thickness reduction must be strictly controlled, with a tolerance range of less than ±0.001 mm, to ensure precise matching of the subsequent coating thickness. During gear hobbing, negative displacement is used to thin the gear base by controlling the displacement coefficient. The negative displacement coefficient is determined by the following formula:

[0266]

[0267] In the formula, x represents the negative displacement coefficient; Δt represents the coating service thickness; and m represents the module of the composite gear.

[0268] (3) Sandblasting

[0269] If the surface roughness after thinning still does not meet the design requirements, sandblasting is required. Sandblasting process parameters include:

[0270] Sandblasting particle size: 40-60μm;

[0271] Spray angle: 30°-45°;

[0272] Injection pressure: 0.6-0.8MPa.

[0273] After sandblasting, the surface should be cleaned to ensure that there are no residual particles or oil stains on the tooth surface.

[0274] 3. Gear coating spraying

[0275] (1) Cleaning pretreatment

[0276] Thoroughly clean the gear surface using chemical or physical methods to remove oil, oxides, and other impurities to ensure good adhesion between the coating and the substrate.

[0277] (2) Preheating of the substrate

[0278] Based on the characteristics of PAI coatings and composite reinforcing materials, the substrate preheating process was optimized. The preheating temperature range was 100-130℃, and the preheating time was 10-15 minutes to enhance the adhesion and uniformity of the coating.

[0279] (3) Spraying process

[0280] PAI coatings are applied using an automated spray gun system. The spraying speed is controlled during the process (10-15 mm / s) to ensure uniform coating distribution, with thickness deviations kept within ±0.02 mm.

[0281] Method for determining coating thickness:

[0282] If the precision of the tooth surface coating after spraying meets the requirements, the spraying thickness = the service thickness of the coating.

[0283] If the precision of the tooth surface coating after spraying does not meet the requirements, the spraying thickness = coating service thickness + coating machining allowance.

[0284] (4) Curing process

[0285] After spraying, the gears are placed in an oven for curing. The curing temperature is 210-280℃, and the time is 0.5-1 hour. After curing, ensure that the coating's wear resistance and heat resistance meet the design standards.

[0286] (5) Thickness detection and adjustment

[0287] The coating thickness was measured using a gear micrometer.

[0288] If the thickness does not meet the requirements, adjustments can be made by optimizing the spraying parameters (such as spraying pressure, spraying time, etc.), or by using multiple spraying methods to achieve the required thickness.

[0289] 4. Gear coating processing

[0290] (1) When the accuracy is satisfied:

[0291] If the thickness and precision of the coating after spraying meet the service requirements, it can be put into use directly.

[0292] (2) When the accuracy requirement is not met:

[0293] If the test results after spraying do not meet the accuracy requirements, the coating needs to be thinned. Precision grinding can be used to achieve the required tooth surface accuracy.

[0294] 5. Service data collection

[0295] (1) Tooth thickness monitoring

[0296] During use, gears should be periodically inspected using measuring equipment to determine the degree of coating wear and whether it meets service requirements.

[0297] (2) Data feedback and recoating

[0298] If the coating wears down to the design threshold (thickness reduced to 60% of the original design value), relevant service data is recorded and recoating is performed. Data analysis is used to optimize the recoating process parameters, further extending gear life.

[0299] II. Manufacturing and Application Stages of Composite Coated Gears

[0300] Based on data from the preliminary design phase and service conditions, dynamic monitoring and maintenance management of the gears are implemented throughout their entire lifecycle. Specifically, this includes:

[0301] 1. Gear surface maintenance

[0302] Clean the gear teeth regularly during service to ensure gear performance.

[0303] 2. Coating recoating

[0304] The coating is repainted based on its wear level. The coating thickness is designed based on the remaining service thickness of the coating and the target thickness.

[0305] 3. Determination of substrate scrapping

[0306] If the gear base no longer meets manufacturing standards due to repeated thinning or structural fatigue, it will be terminated from service and disposed of or remanufactured.

[0307] Example 12:

[0308] The main structure of this embodiment is the same as any one of embodiments 1 to 11. Furthermore, this invention relates to a design and manufacturing method for polyamide-imide (PAI) composite coated gears. By employing a Design for Six Sigma (DFSS) framework based on the IDDOV model, and addressing the requirements of high wear resistance, high heat resistance, vibration reduction and noise reduction, low friction coefficient, and long service life in gear service environments, a comprehensive optimization scheme from design to manufacturing has been developed. The design phase includes precise ratio optimization of reinforcing materials (graphene, boron nitride, alumina, etc.), and proposes a coating processing parameter design method based on multi-objective optimization (MOO) by combining QFD and TRIZ methods. The manufacturing phase employs key processes such as substrate thinning, sandblasting, spray curing, and thickness detection to ensure coating uniformity and service performance. During the service phase, dynamic monitoring of coating wear data is used to formulate recoating process plans, achieving full life-cycle management of the gears. This invention significantly improves the service reliability and service life of gears and is suitable for high-performance mechanical transmission components under complex operating conditions.

Claims

1. A method for designing and manufacturing gears with polyamide-imide composite coating, characterized in that, Includes the following steps: S1) Collect customer requirements and functional requirements, prioritize customer requirements, and establish a house of quality based on the quality function deployment method. S2) Develop design projects based on the priority of customer needs; S3) Using probability assessment and risk analysis tools, conduct a preliminary assessment of the feasibility of the design project. If the design is feasible, proceed to step S4; otherwise, return to step S1. S4) Based on the house of quality and functional requirements, obtain key quality characteristics and clarify the tolerance limits for the amount of polyamide-imide composite coating reinforcement material added. The key quality characteristics include the coating's wear rate, decomposition temperature, vibration reduction amplitude, noise reduction amplitude, friction coefficient, and service life. S5) Based on the multi-objective optimization processing parameter back-adjustment method, a parameter-driven input-output model is established; the multi-objective function of the multi-objective optimization processing parameter back-adjustment method is expressed as: Customer needs are quantified, and the resulting multi-objective function is shown below: In the formula: κ i Represents the weighting factors, i = 1, 2, ..., N; ω i The coefficients representing the design objectives, i = 1, 2, ..., N; N is the number of targets; R represents the range of values ​​for the design variable; X represents the design factor, X = {W, T, V, N, μ, L}; W represents the wear rate, W MAX The maximum wear rate is T; T is the decomposition temperature. MIN V is the lowest decomposition temperature; V is the vibration reduction amplitude. MIN N is the minimum vibration reduction amplitude; N is the noise reduction amplitude. MIN Minimum noise reduction amplitude; μ is the coefficient of friction, μ MAX L is the maximum coefficient of friction; L is the service life. MIN This represents the increase in minimum service life. S6) Input the key quality characteristics into the input-output model to obtain the design scheme of the polyamide-imide composite coated gear; the design scheme includes the thickness, material composition and ratio of the polyamide-imide composite coating reinforcement material; S7) Input the design scheme into the multi-objective optimization model to obtain the optimized key quality characteristics; S8) Based on customer needs and optimized key quality characteristics, plan the manufacturing process, which includes thinning of the gear substrate, gear coating spraying, and gear coating processing. S9) Manufacturing polyamide-imide composite coated gear samples, and conducting wear resistance, heat resistance, vibration reduction and noise reduction effect, friction coefficient and service life tests, as well as reliability tests on the polyamide-imide composite coated gear samples to verify the service performance of the composite coated gear samples; the reliability test is to detect the mean time between failures of the composite coated gear samples. If the verification results do not meet the key quality characteristics requirements and tolerance limits, return to step S5; otherwise, deliver the polyamide-imide composite coated gear sample.

2. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 1, characterized in that: In step S1), the customer requirements include the wear resistance, heat resistance, vibration reduction and noise reduction, friction coefficient, and service life performance requirements of the gears. The functional requirements include the optimal ratio of each component in the coating material and the maximum error limit between the actual coating thickness and the designed coating thickness.

3. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 1, characterized in that: In step S4), the coating material comprises polyamide-imide, reinforcing material, additives, and coating solvent; The additives include dispersants, leveling agents, and defoamers; The components of the reinforcing material need to undergo interface modification treatment; The reinforcing material comprises at least one of the following: graphene, boron nitride (BN), alumina (Al2O3), zirconium oxide (ZrO2), and polytetrafluoroethylene (PTFE) microparticles. When the reinforcing material is graphene, the amount of graphene used is 0.5-3.0% of the total mass of the coating; When the reinforcing material is boron nitride (BN), the amount of boron nitride (BN) used is 1-5% of the total mass of the coating. When the reinforcing material is aluminum oxide (Al2O3), the amount of aluminum oxide (Al2O3) used is 5-10% of the total mass of the coating. When the reinforcing material is zirconium oxide (ZrO2), the amount of zirconium oxide (ZrO2) used is 5-10% of the total mass of the coating. When the reinforcing material is composed of polytetrafluoroethylene (PTFE) microparticles, the amount of PTFE microparticles is 2-8% of the total mass of the coating.

4. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 1, characterized in that: In step S4), the coating thickness t is calculated using the following formula: In the formula: F load Indicates the maximum working load on the gear surface; σ coating This indicates the maximum allowable stress of the coating.

5. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 1, characterized in that: In step S5), the regression formula for the input-output model is as follows: In the formula: t is the coating thickness; x graphene ,x hBN , x PTFE These represent the proportions of graphene, boron nitride, alumina, zirconium oxide, and PTFE particles, respectively.

6. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 1, characterized in that: In step S7), the objective function of the multi-objective optimization model is as follows: f=a1W+a2T+a3V+a4N+a5μ+a6L (5) In the formula, a1, a2, a3, a4, a5, and a6 are the weighting coefficients of W, T, V, N, μ, and L.

7. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 1, characterized in that: In step S8), the method for thinning the gear base includes the following steps: 1) Calculate the target value Ra of tooth surface roughness. In the formula: k represents the proportionality coefficient; γ represents the surface tension between the coating and air; θ represents the contact angle of the coating on the gear substrate; σ represents the target bonding strength between the coating and the gear substrate; 2) The gear base is thinned by using a gear hobbing process; During gear hobbing, the gear base is thinned by controlling the displacement coefficient to achieve negative displacement. The formula for calculating the negative displacement coefficient x is as follows: In the formula: Δt represents the service thickness of the coating; m represents the gear module; 3) Determine whether the surface roughness of the thinned tooth reaches the target value. If it does, the thinning of the gear base is complete; otherwise, sandblasting is required.

8. The method for designing and manufacturing polyamide-imide composite coated gears according to claim 1, characterized in that: In step S8), the gear coating spraying method includes the following steps: 1) Thoroughly clean the surface of the gears; 2) Preheat the gear base; 3) Use automated spray gun equipment to perform air spraying on the gear substrate; 4) Place the gears in an oven for curing; 5) After curing, use a gear micrometer to check the coating thickness to determine if the coating thickness meets the requirements. If it does, the gear coating spraying is complete; otherwise, return to step 3.

9. The design and manufacturing method of the polyamide-imide composite coated gear according to claim 8, characterized in that: In step S8), whether gear coating processing is required is determined by the following method: judging whether the surface accuracy of the coating after spraying meets the requirements. If it meets the requirements, the gear can be put into use directly after spraying. Otherwise, a processing allowance should be prepared when spraying the gear, and the coating should be thinned after spraying and curing to make its surface accuracy meet the requirements.

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