Gearbox cost reduction and efficiency improvement process based on plastic hardware hybrid architecture

Abstract

The application discloses a gear box cost-reducing and efficiency-improving process based on a plastic hardware mixed architecture, and relates to the technical field of gear boxes.The application adopts a mixed architecture design in which high-load gears are made of hardware materials and low-load gears are made of polyformal plastic materials, and high-load hardware gears are prepared through a powder metallurgy process.The preparation process comprises the following steps: material preparation, mixing treatment, high-pressure pressing, precise sintering, precision machining, strengthening heat treatment, quality detection, surface treatment and assembly forming, and realizes precise matching of materials and load working conditions.The process effectively improves the structural strength, wear resistance and operation stability of the gear box, reduces production noise and manufacturing cost, takes into account production efficiency and product quality, and is suitable for manufacturing various gear boxes, especially for transmission scenes with double requirements of reliability and cost.

Description

Technical Field

[0001] This invention relates to the field of gearbox technology, specifically to a gearbox efficiency-enhancing and cost-reducing process based on a plastic-metal hybrid architecture. Background Technology

[0002] As a core component of mechanical transmission systems, the gearbox's performance stability, service life, and manufacturing cost directly affect the market competitiveness of end products. In resistance adjustment devices for fitness equipment, the gearbox needs to withstand cyclic loads for extended periods, placing particularly stringent requirements on wear resistance and structural reliability. Currently, most gears inside gearboxes are manufactured using either all-plastic (POM) or a composite process of plastic and copper. All-plastic gears are widely used due to their ease of molding and lower cost, while the plastic-copper process attempts to enhance local strength through copper teeth.

[0003] However, traditional all-plastic gears are susceptible to defects in the production process due to the lack of expertise of machine operators, often resulting in defects such as missing tooth profiles, dimensional deviations, and large roundness deviations. This not only leads to high noise levels during gearbox operation but also poses significant reliability risks. After approximately 10,000 cycles under a load of around 8 kg, there is a high probability of tooth stripping or breakage. On the other hand, the plastic-copper process requires pre-inserting copper teeth into the injection molding machine before injection bonding, resulting in low production efficiency. Furthermore, the high cost of copper materials further exacerbates the overall high manufacturing cost of gearboxes. It is difficult to balance production efficiency, product quality, and cost control, which has become a key issue restricting the technological upgrading and market promotion of this type of gearbox.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] The purpose of this invention is to provide a gearbox efficiency-enhancing and cost-reducing process based on a plastic-metal hybrid architecture, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides a gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure, comprising a gearbox adopting a plastic-metal hybrid structure, high-load gears being made of metal materials, and low-load gears being made of polyoxymethylene plastic materials. The metal materials are powder metallurgy materials. The preparation of the high-load gears includes the following steps: S1 Material Preparation: Select metal powder suitable for high-load working conditions as raw material. The metal powder is selected from at least one of iron-based powder, alloy steel powder, and copper-based powder. According to the gear's preset load-bearing strength and wear resistance requirements, determine the particle size and composition ratio of the metal powder to ensure that the performance of the raw material meets the requirements of subsequent working conditions. S2 Mixing Process: The metal powder selected in S1 is homogenized and mixed with functional additives, including lubricants and reinforcing agents. The mixing process controls the stirring rate and time to ensure that the additives are evenly dispersed in the metal powder system, thereby improving the flowability and density of the powder during the forming stage and ensuring that the finished product has a uniform and dense texture. S3 High Pressure Pressing: The uniformly mixed metal powder is fed into a customized mold and pressed into shape by applying a preset pressure. The pressure parameters are set according to the gear size and structural strength requirements, so that the metal powder particles are tightly combined to form a stable blank that matches the target gear structure. S4 Precision Sintering: The pressed metal powder blank is placed in a controllable high-temperature sintering furnace. The sintering temperature and holding time are set according to the type of metal powder. Through chemical reaction and physical fusion between particles, a dense gear blank is formed to ensure that the mechanical properties of the blank meet the standards. S5 Precision Machining: The sintered gear blank is precision machined using a combination of milling, grinding and turning processes. The machining accuracy is strictly controlled so that the gear tooth profile and dimensional tolerances meet the preset standards, ensuring the stability of gear meshing transmission. S6 Enhanced Heat Treatment: The precision-machined gears are subjected to at least one of the heat treatment processes, namely quenching and carburizing, to make the surface hardness of the gears reach HRC30-40°, thereby improving the wear resistance and load-bearing capacity of the gears. S7 Quality Inspection: Professional measuring instruments are used to comprehensively inspect the dimensional accuracy, tooth profile accuracy, hardness value, and density of gears, and unqualified products are rejected to ensure the consistency of gear quality leaving the factory; S8 Surface Treatment: Depending on the requirements of the usage environment, at least one of the following surface treatments, namely plating, coating, and polishing, is applied to qualified gears to improve the surface quality and corrosion resistance of the gears; S9 Assembly and Molding: The high-load metal gears produced in the above steps are assembled with low-load polyoxymethylene (POM) plastic gears to form a gearbox with a hybrid plastic-metal structure. The high-load metal gears are specifically designed to withstand high-load conditions of the main drive torque. Through the hybrid structure design of high-load metal gears and low-load POM plastic gears, combined with powder metallurgy preparation technology, the problems of easy stripping and tooth breakage and short service life of traditional all-plastic gears are solved, while avoiding the defects of high cost and low production efficiency of all-metal gears or plastic plus copper processes. The precise control of raw material properties, molding quality and processing accuracy in each step ensures stable transmission under high-load conditions, while taking into account both production efficiency and product quality, achieving the dual goals of increasing efficiency and reducing costs.

[0007] Furthermore, in S1, the particle size range of the metal powder is 50-200μm, and the content of alloying elements in the composition is adjusted according to the gear load requirements. The carbon content in the iron-based powder does not exceed 0.8%, and the copper purity in the copper-based powder is not less than 99.5%. By clearly defining the particle size and composition parameters of the metal powder, the performance of gears with different load requirements can be matched in a targeted manner. Controlling the carbon content of the iron-based powder and ensuring the high purity of the copper-based powder can ensure the strength and wear resistance of the gears, and avoid molding defects caused by improper composition, thereby further improving the product yield and stability.

[0008] Furthermore, in S3, the pressing pressure is 500-1500MPa, and the pressing process adopts a bidirectional pressing mode to ensure uniform density in all parts of the blank. By limiting the specific pressing pressure range and adopting a bidirectional pressing mode, the metal powder particles can be tightly and uniformly combined, avoiding the problems of local looseness and uneven density in the blank, improving the structural strength of the gear blank, laying a good foundation for subsequent sintering and finishing, and reducing the scrap rate in subsequent processing.

[0009] Furthermore, in step S4, the sintering temperature is 800-1200℃, the holding time is 1-4 hours, and the sintering atmosphere is an inert gas protective atmosphere to avoid oxidation of the blank. Precise control of the sintering temperature, holding time, and protective atmosphere can not only promote the full fusion between metal powder particles to form a dense gear blank, but also effectively prevent the blank from oxidizing and deteriorating at high temperatures, ensuring the mechanical properties and service life of the gear, while avoiding product performance fluctuations caused by improper sintering parameters.

[0010] Furthermore, in S7, dimensional accuracy is measured using a coordinate measuring machine, tooth profile accuracy is measured using a gear measuring center, and hardness is measured using a Rockwell hardness tester. The test results must meet the relevant requirements of GB / T 3077-2015. By clearly defining the testing instruments and standards, the key performance indicators of the gears can be precisely controlled, ensuring that the dimensional accuracy, tooth profile accuracy, and hardness of the gears leaving the factory meet industry standards. This reduces after-sales problems caused by substandard product quality and improves product market acceptance and user experience.

[0011] Furthermore, in step S2, the lubricant is selected from at least one of zinc stearate and paraffin wax, and the amount added is 0.5%-2% of the total mass of the metal powder; the reinforcing agent is selected from at least one of silicon carbide and alumina powder, and the amount added is 1%-5% of the total mass of the metal powder. By limiting the types and amounts of additives, the structural strength and wear resistance of the gear can be improved by the reinforcing agent while ensuring the fluidity and formability of the metal powder. This avoids molding defects or insufficient performance caused by excessive or insufficient additives, and achieves an optimal balance between raw material cost and product performance.

[0012] Furthermore, the gearbox contains two high-load metal gears and three low-load polyoxymethylene (POM) plastic gears. The two high-load metal gears correspond to the core transmission position that bears the main transmission torque, while the three low-load plastic gears correspond to the auxiliary transmission position. By limiting the specific number and corresponding transmission positions of the high-load metal gears and low-load plastic gears, precise matching and reasonable allocation of gear materials are achieved. This ensures the high load-bearing capacity of the core transmission parts while maximizing the control of the proportion of plastic materials used, further reducing production costs. At the same time, fixing the number and position relationship of gears ensures the stability and assembly efficiency of the gearbox transmission structure, avoiding transmission failures caused by improper number or position.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. By adopting a hybrid architecture design that uses high-load gears as hardware materials and low-load gears as polyoxymethylene plastic materials, a precise match between materials and load conditions is achieved. This not only solves the problems of short service life and easy stripping and breakage of traditional all-plastic gears, but also avoids the defects of high cost and low production efficiency of all-metal gears or plastic plus copper processes, effectively controlling manufacturing costs while ensuring product performance.

[0014] 2. High-load hardware gears are manufactured using powder metallurgy technology. Combined with targeted mixing treatment, high-pressure pressing, precision sintering and enhanced heat treatment, the structural strength, wear resistance and dimensional stability of the gears are significantly improved. This reduces defects such as missing tooth profiles and dimensional deviations caused by material characteristics in the production process, thereby reducing noise during product operation and improving overall operational stability and durability.

[0015] 3. This invention does not require major modifications to the overall structure of the gearbox. By optimizing the materials and upgrading the processes of the core transmission components, a leapfrog improvement in product quality can be achieved. The production process is simple and controllable, taking into account both production efficiency and quality consistency. It provides a technical solution for gearbox manufacturing that is both economical and reliable, and has broad application prospects. Attached Figure Description

[0016] Figure 1 A flowchart illustrating the efficiency improvement and cost reduction process for gearboxes based on a plastic-metal hybrid architecture; Figure 2 This is a schematic diagram showing the installation positions of the high-load metal gear and the low-load polyoxymethylene plastic gear in the gearbox of this embodiment. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figures 1 to 2 This invention provides a technical solution: a gearbox efficiency-enhancing and cost-reducing process based on a plastic-metal hybrid architecture. This process is applicable to gearbox manufacturing. The gearbox adopts a hybrid architecture of high-load metal gears and low-load polyoxymethylene plastic gears, wherein there are two high-load metal gears, corresponding to the core transmission position of the gearbox, used to bear the main transmission torque, such as... Figure 2 The gears are No. 3 and No. 4; there are three low-load polyoxymethylene plastic gears, corresponding to the auxiliary transmission positions, which reduces the overall manufacturing cost while ensuring transmission performance. Figure 2 Tooth No. 1, Tooth No. 2 and Tooth No. 5.

[0019] This invention sets up five embodiments, changing only the core single variable in the preparation of high-load hardware gears (metal powder type, pressing pressure, sintering temperature, additive ratio, and surface treatment process), while keeping all other process parameters the same, in order to verify the optimal technical solution.

[0020] Example 1: S1 Material Preparation: 1. Selection of raw materials for high-load hardware gears: Iron-based alloy steel powder is selected as the core raw material. The powder has a carbon content of 0.4% and a particle size of 100μm. The alloying elements manganese content is 1.2% and chromium content is 0.8%, which ensures that the gears have good strength and wear resistance and are suitable for the transmission requirements under an 8kg load.

[0021] 2. Selection of raw materials for low-load plastic gears: Polyoxymethylene plastic granules, model POM M90, are used. They have stable mechanical properties and good molding fluidity, which meets the low-load requirements of auxiliary transmission positions.

[0022] 3. Raw material testing: The composition and particle size of the iron-based alloy steel powder are tested to ensure that the composition ratio and particle size meet the preset standards; the melt flow index of the polyoxymethylene plastic granules is tested to ensure that their molding performance meets the standards.

[0023] S2 Mixed Processing: 1. Additive selection: Zinc stearate is selected as the lubricant, and the addition amount is 1.2% of the total mass of the metal powder; silicon carbide powder is selected as the reinforcing agent, and the addition amount is 3% of the total mass of the metal powder.

[0024] 2. Mixing equipment and parameters: A double cone mixer is used for homogenization mixing. The mixing speed is set to 30 r / min and the mixing time is 40 min to ensure that zinc stearate and silicon carbide powder are uniformly dispersed in the iron-based alloy steel powder system, thereby improving the fluidity and density in the subsequent molding stage.

[0025] 3. Post-mixing testing: Take a mixed powder sample and observe the dispersion of additives using a scanning electron microscope to ensure that there is no agglomeration and that the powder has a uniform overall texture.

[0026] S3 high-pressure compression: 1. Mold Preparation: Based on the structural dimensions of the high-load gear, a precision mold is customized. The surface roughness of the mold cavity Ra ≤ 0.8 μm ensures the surface quality of the gear blank after pressing. The structural dimensions of the high-load gear are: module 2.0, number of teeth 25, and tooth width 15 mm.

[0027] 2. Pressing equipment and parameters: A four-column hydraulic press is used for pressing and forming. The pressing pressure is set to 1000MPa. A bidirectional pressing mode is adopted, with the upper and lower die pressing rates both at 5MPa / s. The holding time is 15s, which makes the metal powder particles tightly bonded to form a stable gear blank.

[0028] 3. Blank Inspection: After pressing, the gear blank is inspected for size and density to ensure that the dimensional deviation is ≤ ±0.1mm and the density is ≥ 6.8g / cm³. 3 It has no defects such as cracks or missing materials.

[0029] S4 Precision Sintering: 1. Sintering equipment: A bell-type sintering furnace is adopted, equipped with an inert gas protection system, and argon is selected as the protective gas to prevent the green body from oxidizing at high temperature.

[0030] 2. Sintering parameter settings: sintering temperature is 1050℃, heating rate is 5℃ / min, holding time is 2.5 hours, cooling rate is 3℃ / min, until the furnace temperature drops to room temperature and then the furnace is removed.

[0031] 3. Post-sintering inspection: The sintered gear blank undergoes visual inspection and compressive strength testing to ensure a compressive strength ≥ 800 MPa, meeting the requirements of high-load transmission. Visual inspection must ensure the blank is free of oxidation spots, deformation, and other defects.

[0032] S5 Precision Machining: 1. Processing equipment and technology: CNC milling machine is used for rough machining of the tooth profile to remove excess material from the surface of the blank; forming gear grinding machine is used for fine machining of the tooth profile to ensure the accuracy of the tooth profile; CNC lathe is used for end face and inner hole machining to ensure installation accuracy.

[0033] 2. Machining accuracy control: Tooth profile tolerance is set to grade 6 according to GB / T 10095.1-2008 standard, dimensional tolerance is set to grade IT7, and surface roughness Ra≤0.4μm.

[0034] 3. Post-machining inspection: A coordinate measuring machine is used to inspect the tooth profile, pitch, and dimensional accuracy of the gears to ensure they meet the preset standards and guarantee the stability of gear meshing transmission.

[0035] S6 Enhanced Heat Treatment: 1. Heat treatment process: The precision-machined gears are subjected to a combined heat treatment of carburizing and quenching. The carburizing temperature is 930℃ and the carburizing time is 3 hours. The quenching medium is oil cooling and the quenching temperature is 850℃. The tempering temperature is 200℃ and the tempering time is 2 hours.

[0036] 2. Performance testing after heat treatment: The surface hardness of the gears was tested using a Rockwell hardness tester to ensure that the hardness reached HRC35; the impact toughness of the gears was tested using an impact testing machine to ensure that the impact toughness was ≥45J / cm. 2 This improves the wear resistance and load-bearing capacity of gears.

[0037] S7 Quality Inspection: 1. Inspection items and equipment: Dimensional accuracy is inspected using a coordinate measuring machine, tooth profile accuracy is inspected using a gear measuring center, hardness is inspected using a Rockwell hardness tester, density is inspected using an ultrasonic flaw detector, and surface defects are inspected using a magnetic particle flaw detector.

[0038] 2. Inspection Standards: All inspection items must meet the relevant requirements of GB / T 3077-2015 "Alloy Structural Steel" and GB / T10095.1-2008 "Spiral Gear Accuracy System Part 1: Definition and Permissible Values ​​of Tooth Surface Deviation on the Same Side of Gears". Unqualified products will be directly rejected to ensure the consistency of gear quality leaving the factory.

[0039] S8 surface treatment: The surface treatment process employs galvanizing followed by passivation. The specific steps are as follows: First, the gears undergo degreasing, pickling, and activation treatment; then, galvanizing is performed; finally, passivation is applied. Degreasing is done using an alkaline degreasing solution at 50℃ for 15 minutes; pickling is done using a hydrochloric acid solution at 25℃ for 5 minutes; the galvanizing solution temperature is 45℃, and the current density is 2 A / dm³. 2 The electroplating time is 20 minutes; the passivation solution temperature is 25℃, and the time is 10 minutes. This surface treatment improves the corrosion resistance of the gear surface, ensuring a service life of ≥5 years in humid environments.

[0040] S9 assembly: 1. Assembly preparation: Clean the two high-load metal gears made in the above steps and the three injection-molded low-load polyoxymethylene plastic gears to remove surface oil and impurities.

[0041] 2. Assembly process: According to the gearbox transmission logic, install the metal gears and polyoxymethylene plastic gears in sequence to the preset shaft positions on the gearbox housing, ensuring that the gear meshing clearance is 0.05-0.1mm. After installation, manually rotate the gear shaft to ensure smooth rotation without jamming or abnormal noise.

[0042] 3. Post-assembly testing: Load testing, speed testing, and noise testing were conducted on the assembled gearbox. Test results showed that after 30,000 cycles of pulling and releasing under an 8kg load, the gearbox exhibited no broken or stripped teeth. The motor input speed was 3000 rpm, the output speed was 2 revolutions per minute, and the noise level at a distance of one meter was 62 dB, meeting the design requirements.

[0043] Example 2: The only difference between this embodiment and Embodiment 1 is the type of metal powder; all other process steps and parameters are exactly the same. The raw material for high-load hardware gears has been replaced with pure iron powder, which has a carbon content of 0.1% and a particle size of 100μm, with no additional alloying elements added.

[0044] Example 3: The only difference between this embodiment and Embodiment 1 is the pressing pressure; all other process steps and parameters are exactly the same. The pressing pressure in the high-pressure pressing stage is adjusted to 800MPa. The pressurization mode remains bidirectional, with the upper and lower mold pressurization rates at 5MPa / s and the holding time at 15s.

[0045] Example 4: The only difference between this embodiment and Embodiment 1 is the sintering temperature; all other process steps and parameters are exactly the same. The sintering temperature in the precision sintering process was adjusted to 950℃, with a heating rate of 5℃ / min, a holding time of 2.5 hours, a cooling rate of 3℃ / min, and the sintering atmosphere was still argon protection.

[0046] Example 5: The only difference between this embodiment and Embodiment 1 is the surface treatment process; all other process steps and parameters are exactly the same. The surface treatment was changed to a single polishing process, eliminating the steps of degreasing, pickling, zinc plating and passivation, and only improving the smoothness of the gear surface through polishing equipment.

[0047] Comparison table of variables and performance test results for each embodiment:

[0048] Verification of process effect: The plastic-metal hybrid gearbox manufactured using the process described in this embodiment exhibits the following effects after actual testing and comparative experiments: 1. Cost advantage: Compared with all-metal gearboxes, the manufacturing cost is reduced by 30%; compared with plastic and copper gearboxes, the manufacturing cost is reduced by 25%, while the production efficiency is increased by 40%.

[0049] 2. Performance advantages: The yield rate of Example 1 reaches 95%, which is 15 percentage points higher than the traditional process; the noise is as low as 62dB, which is 7dB lower than the traditional all-plastic gearbox; the durability is improved by more than 3 times, and it can work stably for more than 30,000 cycles under an 8kg load, which solves the problem of easy stripping and tooth breakage of traditional all-plastic gears.

[0050] 3. Determination of the best implementation method: As can be seen from the comparison table data, Implementation Method 1 is superior to other implementation methods in terms of core performance indicators such as yield rate, number of load stabilization cycles, and noise control. It has the best overall performance and is the best technical solution.

Claims

1. A gearbox efficiency-enhancing and cost-reducing process based on a plastic-metal hybrid architecture, characterized by: The gearbox adopts a plastic-metal hybrid structure. The high-load gears are made of metal materials, while the low-load gears are made of polyoxymethylene plastic materials. The metal materials are powder metallurgy materials. The preparation of the high-load gears includes the following steps: S1 Material Preparation: Select metal powder suitable for high load conditions as raw material. The metal powder is selected from at least one of iron-based powder, alloy steel powder, and copper-based powder. The particle size and composition ratio of the metal powder are determined according to the preset load-bearing strength and wear resistance requirements of the gear. S2 Mixing Process: The metal powder selected in S1 is homogenized and mixed with functional additives, including lubricants and reinforcing agents. The mixing process controls the stirring rate and time to ensure that the additives are uniformly dispersed in the metal powder system. S3 High Pressure Pressing: The uniformly mixed metal powder is fed into a customized mold and pressed into shape by applying a preset pressure. The pressure parameters are set according to the gear size and structural strength requirements, so that the metal powder particles are tightly combined to form a stable blank that matches the target gear structure. S4 Precision Sintering: The pressed metal powder blank is placed in a controllable high-temperature sintering furnace. The sintering temperature and holding time are set according to the type of metal powder. Through chemical reaction and physical fusion between particles, a dense gear blank is formed. S5 Precision Machining: The sintered gear blank is precision machined using a combination of milling, grinding, and turning processes, with strict control over machining accuracy to ensure that the gear tooth profile and dimensional tolerances meet the preset standards. S6 Enhanced Heat Treatment: The precision-machined gears are subjected to at least one of the heat treatment processes, namely quenching and carburizing, to make the surface hardness of the gears reach HRC30-40°. S7 Quality Inspection: Professional measuring instruments are used to inspect the dimensional accuracy, tooth profile accuracy, hardness value, and density of the gears; S8 Surface Treatment: Depending on the requirements of the usage environment, at least one of the following surface treatments is applied to the qualified gears: plating, coating, and polishing. S9 Assembly: The high-load metal gears made in the above steps are assembled with the low-load polyoxymethylene plastic gears to form a gearbox with a plastic-metal hybrid structure. The high-load metal gears are specifically designed to withstand high-load conditions of the main drive torque.

2. The gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure as described in claim 1, characterized in that: In S1, the particle size of the metal powder ranges from 50 to 200 μm, and the content of alloying elements in the composition is adjusted according to the gear load requirements. The carbon content in the iron-based powder does not exceed 0.8%, and the copper purity in the copper-based powder is not less than 99.5%.

3. The gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure as described in claim 1, characterized in that: In step S3, the pressing pressure is 500-1500MPa, and the pressing process adopts a bidirectional pressing mode to ensure uniform density in all parts of the billet.

4. The gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure as described in claim 1, characterized in that: In step S4, the sintering temperature is 800-1200℃, the holding time is 1-4 hours, and the sintering atmosphere is an inert gas protective atmosphere to avoid oxidation of the green body.

5. The gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure as described in claim 1, characterized in that: In S7, dimensional accuracy is measured using a coordinate measuring machine, tooth profile accuracy is measured using a gear measuring center, and hardness is measured using a Rockwell hardness tester.

6. The gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure as described in claim 1, characterized in that: In S2, the lubricant is selected from at least one of zinc stearate and paraffin wax, and the amount added is 0.5%-2% of the total mass of the metal powder; the reinforcing agent is selected from at least one of silicon carbide and alumina powder, and the amount added is 1%-5% of the total mass of the metal powder.

7. The gearbox efficiency improvement and cost reduction process based on a plastic-metal hybrid structure as described in claim 1, characterized in that: The gearbox contains two high-load metal gears and three low-load polyoxymethylene plastic gears. The two high-load metal gears correspond to the core transmission position that bears the main transmission torque, and the three low-load plastic gears correspond to the auxiliary transmission position.

Images