Self-lubricating and noise-reducing speed regulating gear structure for engine

Abstract

The invention provides a self-lubricating and noise-reducing speed regulating gear structure for an engine, and relates to the technical field of engine transmission parts, the self-lubricating and noise-reducing speed regulating gear structure comprises a gear base body and a tooth part arranged on the gear base body, and the surface of the tooth part of the gear base body is tightly combined with a transition layer and a self-lubricating layer in sequence; the transition layer is a metal ceramic composite layer and is composed of a metal binding phase and a ceramic hard phase. The self-lubricating layer is composed of a lubricating component, a binder, a noise reduction component and a silane coupling agent; the metal ceramic composite transition layer, the metal binding phase and the gear base body are arranged to form firm metallurgical bonding, the ceramic hard phase and the self-lubricating layer form tight interface connection, the rigid-flexible layer structure effectively buffers meshing impact, the silane coupling agent is matched for surface modification of components of the self-lubricating layer, the overall bonding strength of the coating is greatly improved, and the service life of the gear is prolonged. The self-lubricating layer is prevented from stripping under the heavy-load working condition, and the long-term reliability of the engine under the complex working condition is ensured.

Description

Technical Field

[0001] This invention relates to the field of engine transmission components technology, and in particular to a self-lubricating and noise-reducing speed regulating gear structure for engines. Background Technology

[0002] Engine speed regulator gears are core components of the power transmission system, responsible for regulating engine speed and transmitting power. They need to operate stably for extended periods under high speed, high load, and variable operating conditions. Their lubrication performance and structural reliability directly affect the engine's power output efficiency and service life. Currently, engine speed regulator gear lubrication mainly relies on traditional oil lubrication systems, where lubricating oil forms an oil film on the tooth surface to isolate the mating tooth surfaces and reduce meshing friction. However, as engines develop towards higher power density and miniaturization, the operating conditions of speed regulator gears are becoming increasingly harsh. Traditional oil lubrication is prone to problems such as oil film rupture, lubricating oil leakage, or high-temperature failure, leading to a decline in lubrication effectiveness. To solve this problem, the industry has gradually adopted solid self-lubricating coating technology, which achieves oil-free or low-oil lubrication by coating the tooth surface with a lubricating coating. However, this technology still has many technical shortcomings.

[0003] In existing self-lubricating coating technologies, the bonding strength between the coating and the gear substrate is insufficient, and there is a lack of an effective transition buffer structure. This leads to the coating being prone to peeling and detachment under heavy-load meshing impact, failing to meet the long-term use requirements of engines under complex operating conditions. The lubricating components are designed in a single way, resulting in poor stability of the lubricating film, which is easily worn away under high speed and high load, leading to dry friction and increased wear on the gear surface, shortening the gear's service life. Furthermore, no special functional components are designed for gear meshing vibration and noise. Traditional coatings only focus on lubrication performance, neglecting noise reduction requirements. The high-frequency frictional vibration noise during gear operation seriously affects the engine's NVH performance. In addition, existing coatings cannot simultaneously meet the comprehensive requirements of lubrication, wear resistance, impact resistance, and noise reduction under varying operating conditions, limiting their large-scale application in engine speed regulating gears. Therefore, this invention proposes a self-lubricating and noise-reducing engine speed regulating gear structure to solve the problems existing in the prior art. Summary of the Invention

[0004] To address the aforementioned issues, this invention proposes a self-lubricating and noise-reducing speed-regulating gear structure for engines. This structure incorporates a metal-ceramic composite transition layer. The metal bonding phase forms a strong metallurgical bond with the gear matrix, while the ceramic hard phase forms a tight interface with the self-lubricating layer. This combination of rigidity and flexibility effectively buffers meshing impacts. Furthermore, the surface modification of the self-lubricating layer components using a silane coupling agent significantly enhances the overall bonding strength of the coating, preventing the self-lubricating layer from peeling off under heavy load conditions and ensuring long-term reliability of the engine under complex operating conditions.

[0005] To achieve the objectives of this invention, the invention is implemented through the following technical solution: a self-lubricating and noise-reducing speed-regulating gear structure for an engine, comprising a gear base and teeth disposed on the gear base, wherein a transition layer and a self-lubricating layer are sequentially and tightly bonded to the surface of the teeth of the gear base; the transition layer is a metal-ceramic composite layer, composed of a metal bonding phase and a ceramic hard phase;

[0006] The self-lubricating layer is composed of a lubricating component, a binder, a noise-reducing component, and a silane coupling agent. The silane coupling agent is used to modify the surface of the lubricating component and the noise-reducing component. The noise-reducing component is ceramic particles with high hardness and high elastic modulus.

[0007] A further improvement is that: in the transition layer, the metal binder phase is a nickel-based alloy, and the ceramic hard phase is tungsten carbide and / or chromium carbide; by mass fraction, the metal binder phase accounts for 60%-80%, and the ceramic hard phase accounts for 20%-40%.

[0008] A further improvement is that when the ceramic hard material contains both tungsten carbide and chromium carbide, the mass ratio of tungsten carbide to chromium carbide is (1-3):1.

[0009] A further improvement is that the components in the self-lubricating layer include the following mass ratios: 30%-50% lubricating component, 20%-40% binder, 15%-30% noise reduction component, and 1%-5% silane coupling agent.

[0010] A further improvement is that the lubricating component is polytetrafluoroethylene (PTFE) and molybdenum disulfide. At least one of the following; when polytetrafluoroethylene and molybdenum disulfide are both included, the mass ratio of the two is (0.5-2):1.

[0011] A further improvement is that the adhesive is at least one of epoxy resin and phenolic resin, or a blend of epoxy resin and phenolic resin.

[0012] A further improvement is that the noise reduction component is selected from silicon nitride. Alumina At least one of them, wherein the particle size of the noise reduction component is .

[0013] A further improvement is that the thickness of the transition layer is The thickness of the self-lubricating layer is .

[0014] A further improvement is that the transition layer and the gear substrate are metallurgically bonded by plasma spraying, and the transition layer and the self-lubricating layer are tightly connected by physical adsorption and chemical bonding.

[0015] Further improvements include the following preparation steps:

[0016] S1: The tooth surface of the gear base is pretreated by ultrasonic cleaning with acetone for 15-20 minutes, immersion in 10% hydrochloric acid solution for 5-8 minutes, and sandblasting with 80-120 mesh diamond at a pressure of 0.4-0.6 MPa. The surface roughness Ra after treatment is [value missing]. Dry and store for later use;

[0017] S2: Prepare transition layer spraying powder. Weigh out 60%-80% nickel-based alloy powder, 0-40% tungsten carbide powder, and 0-40% chromium carbide powder by mass fraction, and tungsten carbide and chromium carbide are not both 0. After mixing, ball mill uniformly at a ball-to-material ratio of 10:1, a rotation speed of 300-400 r / min, and a ball milling time of 2-4 h to obtain the transition layer mixed powder.

[0018] S3: Plasma spraying transition layer. The pretreated gear substrate is fixed to the spraying fixture. Using plasma spraying equipment, the spraying power is set to 30-40kW, the spraying distance to 80-120mm, and the powder feeding rate to 20-40g / min. The transition layer mixed powder is sprayed onto the tooth surface to form a thickness... The transition layer is sprayed and then allowed to cool naturally to room temperature.

[0019] S4: Prepare a self-lubricating slurry. Weigh out 30%-50% lubricating component, 20%-40% binder, 15%-30% noise reduction component, and 1%-5% silane coupling agent by mass fraction. First, add the lubricating component and noise reduction component to a 5%-10% silane coupling agent solution and ultrasonically disperse for 30-60 minutes to perform surface modification. Then, add the binder and an appropriate amount of anhydrous ethanol and stir at 500-800 r / min for 2-3 hours until a uniform slurry is formed.

[0020] S5: Apply a self-lubricating layer. Apply the self-lubricating layer slurry to the transition layer surface using spraying or scraping methods, controlling the wet film thickness to be [value missing]. Let stand at room temperature for 1-2 hours;

[0021] S6: Curing and post-treatment. Place the coated gear in an oven and preheat it at 80-100℃ for 1-2 hours. Then, raise the temperature to 150-200℃ and cure for 2-4 hours. After cooling, lightly sand the surface with 800-1200 grit sandpaper to remove burrs and obtain the finished product.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. This invention sets up a metal-ceramic composite transition layer, in which the metal bonding phase forms a strong metallurgical bond with the gear matrix, and the ceramic hard phase forms a tight interface connection with the self-lubricating layer. The layer structure, which combines rigidity and flexibility, effectively buffers meshing impact. Combined with the surface modification of the self-lubricating layer components by silane coupling agent, the overall bonding strength of the coating is greatly improved, avoiding the peeling of the self-lubricating layer under heavy load conditions and ensuring the long-term reliability of the engine under complex operating conditions.

[0024] 2. The self-lubricating layer of this invention uses high-efficiency lubricating components such as polytetrafluoroethylene and molybdenum disulfide. Through optimized formulation and modification with silane coupling agent, it can be continuously transferred to the mating tooth surface under high-speed and high-load conditions to form a stable and dense solid lubricating film, effectively avoiding dry friction and significantly reducing tooth surface wear. The synergistic effect of the binder and various functional components ensures that the lubricating film is not prone to failure under varying working conditions, and the service life of the gear is extended by more than 1.5 times compared with the prior art.

[0025] 3. The self-lubricating layer of the present invention contains ceramic particles with high hardness and high elastic modulus. By precisely controlling the particle size and addition ratio, it can effectively absorb meshing impact energy and suppress vibration propagation. Furthermore, the lubricating component reduces the source of frictional vibration, and the noise reduction component weakens vibration propagation. The synergistic effect of the two significantly reduces gear meshing noise. After testing, it is adapted to the variable operating conditions of the engine, and the NVH performance is greatly improved. Attached Figure Description

[0026] Figure 1 This is the front view of the present invention;

[0027] Figure 2 This is a flowchart of the present invention. Detailed Implementation

[0028] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0029] Example 1

[0030] according to Figure 1 , 2 As shown, this embodiment proposes a self-lubricating and noise-reducing speed-regulating gear structure for an engine, including a gear base and teeth disposed on the gear base. The tooth surfaces of the gear base are sequentially and tightly bonded with a transition layer and a self-lubricating layer. The transition layer is a metal-ceramic composite layer, composed of a metal bonding phase and a ceramic hard phase.

[0031] The self-lubricating layer comprises a lubricating component, a binder, a noise-reducing component, and a silane coupling agent. The silane coupling agent is used to modify the surfaces of the lubricating and noise-reducing components. The noise-reducing component consists of high-hardness, high-elastic-modulus ceramic particles. This dual-layer structure achieves a complementary balance of rigidity and flexibility, ensuring both structural stability and functional effectiveness. The surface modification treatment with the silane coupling agent significantly improves the compatibility of the components, laying the foundation for subsequent performance optimization.

[0032] In the transition layer, the metallic binder phase is a nickel-based alloy, and the ceramic hard phase is tungsten carbide and / or chromium carbide; by mass fraction, the metallic binder phase accounts for 60%-80%, and the ceramic hard phase accounts for 20%-40%. When the ceramic hard phase contains both tungsten carbide and chromium carbide, the mass ratio of tungsten carbide to chromium carbide is (1-3):1. The high ductility of the nickel-based alloy and the high hardness of the ceramic hard phase work synergistically to effectively buffer meshing impacts; the precise mass ratio ensures that the transition layer is firmly bonded to the substrate and provides a stable support surface for the self-lubricating layer.

[0033] The self-lubricating layer comprises the following components in the following mass ratios: lubricating component 30%-50%, binder 20%-40%, noise-reducing component 15%-30%, and silane coupling agent 1%-5%. The lubricating component is polytetrafluoroethylene (PTFE) and molybdenum disulfide. At least one of the following: when polytetrafluoroethylene and molybdenum disulfide are both included, their mass ratio is (0.5-2):1. The adhesive is at least one of epoxy resin and phenolic resin, or a blend of epoxy resin and phenolic resin. The noise-reducing component is selected from silicon nitride. Alumina At least one of the following, wherein the particle size of the noise-reducing component is 5-50 μm. The optimized component mass ratio enables the lubrication, bonding and noise reduction functions to work synergistically, avoiding the shortcomings of a single function; the ceramic noise-reducing component with a specific particle size can accurately absorb impact energy, and together with the high-efficiency lubricating component, it can suppress noise generation from the source.

[0034] The thickness of the transition layer is The thickness of the self-lubricating layer is The transition layer and the gear substrate are metallurgically bonded through plasma spraying, while the transition layer and the self-lubricating layer are tightly connected through physical adsorption and chemical bonding. A well-designed layer thickness ensures the integrity of the coating structure while preventing stress cracking caused by excessive thickness. The dual effect of metallurgical bonding and physicochemical bonding completely solves the industry pain point of easy coating peeling.

[0035] The preparation steps include the following:

[0036] S1: The tooth surface of the gear base is pretreated by ultrasonic cleaning with acetone for 15-20 minutes, immersion in 10% hydrochloric acid solution for 5-8 minutes, and sandblasting with 80-120 mesh diamond at a pressure of 0.4-0.6 MPa. The surface roughness Ra after treatment is [value missing]. Dry and set aside; multi-step pretreatment thoroughly removes impurities and oxide layers from the tooth surface to avoid contaminants affecting coating adhesion; precisely controlled surface roughness provides an ideal adhesion interface for transition layer spraying, improving metallurgical bonding efficiency.

[0037] S2: Prepare the transition layer coating powder by weighing 60%-80% nickel-based alloy powder, 0-40% tungsten carbide powder, and 0-40% chromium carbide powder by mass fraction, with tungsten carbide and chromium carbide not being 0% at the same time. After mixing, ball mill the powder evenly at a ball-to-powder ratio of 10:1, a rotation speed of 300-400 r / min, and a ball milling time of 2-4 h to obtain the transition layer mixed powder. The ball milling process with specific parameters ensures that the powder is mixed evenly and avoids performance fluctuations caused by component segregation. The proportion of ceramic hard phase added is strictly controlled to ensure the mechanical properties of the transition layer with a balance between rigidity and flexibility.

[0038] S3: Plasma spraying transition layer. The pretreated gear substrate is fixed to the spraying fixture. Using plasma spraying equipment, the spraying power is set to 30-40kW, the spraying distance to 80-120mm, and the powder feeding rate to 20-40g / min. The transition layer mixed powder is sprayed onto the tooth surface to form a thickness... The transition layer is sprayed and then naturally cooled to room temperature; the optimized spraying parameters enable the transition layer to form a dense and uniform microstructure, improving impact resistance and wear resistance; the natural cooling method avoids deformation of the substrate due to thermal stress, ensuring the dimensional accuracy of the gears.

[0039] S4: Prepare the self-lubricating layer slurry. Weigh out 30%-50% lubricating component, 20%-40% binder, 15%-30% noise reduction component, and 1%-5% silane coupling agent by mass fraction. First, add the lubricating component and noise reduction component to a 5%-10% silane coupling agent solution and ultrasonically disperse for 30-60 minutes for surface modification. Then, add the binder and an appropriate amount of anhydrous ethanol, and stir at 500-800 r / min for 2-3 hours until a uniform slurry is formed. The combination of ultrasonic dispersion and high-speed stirring ensures that each functional component is evenly distributed in the slurry and avoids local functional failure. The modification treatment of the silane coupling agent solution enhances the interfacial bonding between components and improves the overall stability of the self-lubricating layer.

[0040] S5: Apply a self-lubricating layer. Apply the self-lubricating slurry to the surface of the transition layer by spraying or scraping, controlling the wet film thickness to be 40-200μm, and let it stand at room temperature for 1-2 hours. Diverse coating methods are available to adapt to different gear tooth shapes, ensuring full coverage of the tooth surface without dead corners. The room temperature standing step allows the slurry to fully wet the surface of the transition layer, creating conditions for subsequent curing to form a tight bond.

[0041] S6: Curing and post-treatment. Place the coated gears in an oven and preheat at 80-100℃ for 1-2 hours, then increase the temperature to 150-200℃ for 2-4 hours to cure. After cooling, lightly sand the surface with 800-1200 grit sandpaper to remove burrs, obtaining the finished product. The segmented curing process allows the adhesive to fully cross-link, improving the structural strength and temperature resistance of the self-lubricating layer; the fine post-treatment removes surface burrs, ensuring gear meshing accuracy and avoiding additional wear during operation.

[0042] Example 2

[0043] according to Figure 1 , 2 As shown, this embodiment proposes a self-lubricating and noise-reducing speed-regulating gear structure for an engine. The transition layer, by mass fraction, consists of: 70% nickel-based alloy, 20% tungsten carbide, and 10% chromium carbide (tungsten carbide to chromium carbide mass ratio 2:1), with a thickness of 100 μm. The self-lubricating layer, by mass fraction, consists of: 30% polytetrafluoroethylene, 15% molybdenum disulfide (mass ratio 2:1), 35% epoxy resin, 15% silicon nitride (particle size 20 μm), and 5% silane coupling agent, with a thickness of 50 μm. The transition layer and the gear substrate are metallurgically bonded by plasma spraying, and the self-lubricating layer is bonded to the transition layer by scraping and curing.

[0044] Example 3

[0045] according to Figure 1 , 2 As shown, this embodiment proposes a self-lubricating and noise-reducing speed-regulating gear structure for an engine. The transition layer, by mass fraction, comprises 65% nickel-based alloy and 35% tungsten carbide, with a transition layer thickness of... The self-lubricating layer, by mass fraction, consists of: molybdenum disulfide 40%, phenolic resin 30%, and alumina 20% (particle size...). ), 3% silane coupling agent, self-lubricating layer thickness The transition layer and the gear substrate are metallurgically bonded by plasma spraying, and the self-lubricating layer is bonded to the transition layer by spraying and curing.

[0046] Example 4

[0047] according to Figure 1 , 2As shown, this embodiment proposes a self-lubricating and noise-reducing speed-regulating gear structure for an engine. The transition layer, by mass fraction, comprises 80% nickel-based alloy and 20% chromium carbide, with a transition layer thickness of... The self-lubricating layer, by mass fraction, consists of: 25% polytetrafluoroethylene, 20% molybdenum disulfide (mass ratio 1:0.8), 30% epoxy resin-phenolic resin blend (mass ratio 1:1), 12% silicon nitride, and 8% alumina (total noise reduction components 20%, particle size...). ), 2% silane coupling agent, self-lubricating layer thickness The transition layer and the gear substrate are bonded together by plasma spraying, and the self-lubricating layer is bonded to the transition layer by scraping and curing.

[0048] Example 5

[0049] according to Figure 1 , 2 As shown, this embodiment proposes a self-lubricating and noise-reducing speed-regulating gear structure for an engine. The transition layer, by mass fraction, comprises: 60% nickel-based alloy, 15% tungsten carbide, and 15% chromium carbide (tungsten carbide to chromium carbide mass ratio 1:1). The thickness of the transition layer is... The self-lubricating layer, by mass fraction, consists of: 45% polytetrafluoroethylene, 30% phenolic resin, and 20% alumina (particle size...). ), 3% silane coupling agent, self-lubricating layer thickness The transition layer and the gear substrate are metallurgically bonded by plasma spraying, and the self-lubricating layer is bonded to the transition layer by spraying and curing.

[0050] Example 6

[0051] according to Figure 1 , 2 As shown, this embodiment proposes a self-lubricating and noise-reducing speed-regulating gear structure for an engine. The transition layer, by mass fraction, comprises: 75% nickel-based alloy, 20% tungsten carbide, and 5% chromium carbide (tungsten carbide to chromium carbide mass ratio 3:1). The thickness of the transition layer is... The self-lubricating layer, by mass fraction, consists of: 15% polytetrafluoroethylene, 30% molybdenum disulfide (mass ratio 0.5:1), 25% epoxy resin, 15% silicon nitride, and 10% alumina (total noise reduction components 25%, particle size...). ), 4% silane coupling agent, self-lubricating layer thickness The transition layer and the gear substrate are bonded together by plasma spraying, and the self-lubricating layer is bonded to the transition layer by scraping and curing.

[0052] Experimental data:

[0053] The gears of Embodiments 2, 3, 4, 5, and 6 of this invention were compared with existing gears (control group: no transition layer, self-lubricating layer of polytetrafluoroethylene + epoxy resin, no silane coupling agent and noise reduction components) for performance testing. Test conditions: simulated engine operating conditions (speed 5000 r / min, load 1.5 MPa), continuous operation for 1000 h. The test results are as follows:

[0054]

[0055] Experimental results show that the coating bonding strength of the gears of the present invention is 65.6%-93.6% higher than that of the control group, the tooth surface wear is reduced by 58.6%-64.4%, and the meshing noise is reduced by 19.7%-24.8%, with overall performance significantly superior to existing technologies. In Example 6, due to the use of an optimized ceramic-hard phase ratio (3:1) and a noise-reducing component with the largest particle size, the bonding strength reaches 24.2 MPa, and the meshing noise is as low as 61.9 dB. Example 5, using a single polytetrafluoroethylene lubricating component and alumina with the smallest particle size, still maintains excellent wear resistance (wear amount 19.9 mg). All examples showed no coating peeling or lubricant film failure after 1000 hours of continuous operation, adapting to the varying operating conditions of the engine. Furthermore, through the synergistic effect of silane coupling agent modification and the transition layer, the coating stability is significantly improved compared to existing technologies, aligning with the development trend of high power density engines.

[0056] This self-lubricating and noise-reducing engine speed-regulating gear structure incorporates a metal-ceramic composite transition layer. The metal binder phase forms a strong metallurgical bond with the gear matrix, while the ceramic hard phase forms a tight interface with the self-lubricating layer. This combination of rigidity and flexibility effectively buffers meshing impacts. Combined with surface modification of the self-lubricating layer components using a silane coupling agent, the overall coating bonding strength is significantly improved, preventing peeling of the self-lubricating layer under heavy loads and ensuring long-term reliability under complex engine conditions. Furthermore, the self-lubricating layer of this invention uses highly efficient lubricating components such as polytetrafluoroethylene (PTFE) and molybdenum disulfide. Through optimized proportions and silane coupling agent modification, these components can be continuously transferred to the mating tooth surfaces under high-speed, high-load conditions, forming a stable and dense solid lubricating film. This effectively avoids dry friction and significantly reduces tooth surface wear. The synergistic effect of the binder and various functional components ensures that the lubricating film is less prone to failure under varying operating conditions, extending gear life by more than 1.5 times compared to existing technologies. Meanwhile, the self-lubricating layer of this invention contains ceramic particles with high hardness and high elastic modulus. By precisely controlling the particle size and addition ratio, it can effectively absorb meshing impact energy and suppress vibration propagation. Furthermore, the lubricating component reduces the source of frictional vibration, and the noise reduction component weakens vibration propagation. The synergistic effect of the two significantly reduces gear meshing noise. After testing, it is adapted to the variable operating conditions of the engine, and the NVH performance is greatly improved.

[0057] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-lubricating and noise-reducing speed-regulating gear structure for an engine, comprising a gear base and teeth disposed on the gear base, characterized in that, The tooth surface of the gear matrix is ​​sequentially and tightly bonded with a transition layer and a self-lubricating layer; the transition layer is a metal-ceramic composite layer, composed of a metal bonding phase and a ceramic hard phase. The self-lubricating layer is composed of a lubricating component, a binder, a noise-reducing component, and a silane coupling agent. The silane coupling agent is used to modify the surface of the lubricating component and the noise-reducing component. The noise-reducing component is ceramic particles with high hardness and high elastic modulus.

2. The self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1, characterized in that: In the transition layer, the metal binder phase is a nickel-based alloy, and the ceramic hard phase is tungsten carbide and / or chromium carbide; by mass fraction, the metal binder phase accounts for 60%-80%, and the ceramic hard phase accounts for 20%-40%.

3. The self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 2, characterized in that: When the ceramic hard material contains both tungsten carbide and chromium carbide, the mass ratio of tungsten carbide to chromium carbide is (1-3):

1.

4. The self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1, characterized in that: The self-lubricating layer comprises the following components in the following mass ratios: 30%-50% lubricating component, 20%-40% binder, 15%-30% noise reduction component, and 1%-5% silane coupling agent.

5. A self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1 or 4, characterized in that: The lubricating component is polytetrafluoroethylene (PTFE) and molybdenum disulfide. At least one of the following; when polytetrafluoroethylene and molybdenum disulfide are both included, the mass ratio of the two is (0.5-2):

1.

6. A self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1 or 4, characterized in that: The adhesive is at least one of epoxy resin and phenolic resin, or a blend of epoxy resin and phenolic resin.

7. A self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1 or 4, characterized in that: The noise reduction component is selected from silicon nitride. Alumina At least one of them, wherein the particle size of the noise reduction component is .

8. The self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1, characterized in that: The thickness of the transition layer is The thickness of the self-lubricating layer is .

9. The self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 1, characterized in that: The transition layer and the gear substrate are metallurgically bonded by plasma spraying, and the transition layer and the self-lubricating layer are tightly connected by physical adsorption and chemical bonding.

10. A self-lubricating and noise-reducing speed-regulating gear structure for an engine according to claim 2, characterized in that: The preparation steps include the following: S1: The tooth surface of the gear base is pretreated by ultrasonic cleaning with acetone for 15-20 minutes, immersion in 10% hydrochloric acid solution for 5-8 minutes, and sandblasting with 80-120 mesh diamond at a pressure of 0.4-0.6 MPa. The surface roughness Ra after treatment is [value missing]. Dry and store for later use; S2: Prepare transition layer spraying powder. Weigh out 60%-80% nickel-based alloy powder, 0-40% tungsten carbide powder, and 0-40% chromium carbide powder by mass fraction, and tungsten carbide and chromium carbide are not both 0. After mixing, ball mill uniformly at a ball-to-material ratio of 10:1, a rotation speed of 300-400 r / min, and a ball milling time of 2-4 h to obtain the transition layer mixed powder. S3: Plasma spraying transition layer. The pretreated gear substrate is fixed to the spraying fixture. Using plasma spraying equipment, the spraying power is set to 30-40kW, the spraying distance to 80-120mm, and the powder feeding rate to 20-40g / min. The transition layer mixed powder is sprayed onto the tooth surface to form a thickness... The transition layer is sprayed and then allowed to cool naturally to room temperature. S4: Prepare a self-lubricating slurry. Weigh out 30%-50% lubricating component, 20%-40% binder, 15%-30% noise reduction component, and 1%-5% silane coupling agent by mass fraction. First, add the lubricating component and noise reduction component to a 5%-10% silane coupling agent solution and ultrasonically disperse for 30-60 minutes to perform surface modification. Then, add the binder and an appropriate amount of anhydrous ethanol and stir at 500-800 r / min for 2-3 hours until a uniform slurry is formed. S5: Coat the self-lubricating layer. Apply the self-lubricating layer slurry to the surface of the transition layer by spraying or scraping. Control the wet film thickness to be 40-200μm and let it stand at room temperature for 1-2 hours. S6: Curing and post-treatment. Place the coated gear in an oven and preheat it at 80-100℃ for 1-2 hours. Then, raise the temperature to 150-200℃ and cure for 2-4 hours. After cooling, lightly sand the surface with 800-1200 grit sandpaper to remove burrs and obtain the finished product.

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