A method for designing a continuously variable transmission assembly for a corn harvester and products thereof

Abstract

This invention discloses a design method and product for a continuously variable transmission (CVT) assembly for a corn harvester. The invention defines the transmission design boundaries for a 100kW high-power corn harvester by defining operating parameters, employing a metal belt CVT and a two-stage reduction composite transmission scheme to precisely match the transmission ratio range. It specifically optimizes the CVT cone angle and metal belt structure parameters, selects high-strength materials for the shaft system and reduction gear parameter design and strength and stiffness verification, and incorporates a composite sealed housing structure. Finally, finite element simulation verifies the overall machine's mechanical performance. The transmission system designed in this invention achieves a total transmission ratio of 4.8–30, a maximum output torque ≥20640 N·m, sufficient strength and stiffness redundancy in the shaft system and gear structure, and excellent sealing performance. It enables continuously variable and smooth speed adjustment across all operating conditions, including heavy-duty harvesting in the field and high-speed road transport, solving the problems of poor adaptability, weak load-bearing capacity, and low reliability of traditional transmissions. The design scheme is systematic and the parameters are precise, making it suitable for mass production applications of high-power corn harvester transmissions.

Description

Technical Field

[0001] This invention relates to the field of computer-aided design technology, belonging to the application of emerging software and new information technology services, and more specifically, to a design method for a continuously variable transmission (CVT) assembly for a corn harvester and its product. Background Technology

[0002] Currently, gearboxes in the agricultural machinery field are mainly divided into two categories: stepped gearboxes (TGTs) and continuously variable transmissions (CVTs). TGTs are simple in structure and low in cost, but power interruptions occur during gear shifts, leading to reduced operating efficiency. CVTs, on the other hand, can achieve smooth gear shifts and maintain continuous power output. Among CVTs, the metal belt CVT has gradually become a research hotspot in the agricultural machinery field due to its compact structure and high transmission efficiency.

[0003] In the prior art, CN104358849A discloses an electronically controlled continuously variable transmission (CVT) for fuel-powered vehicles, which adopts a structure of a fixed cone disc and a movable cone disc for the drive wheel. Gear shifting is achieved by adjusting the cone disc spacing through an electric speed-regulating drive device, meeting the performance requirements of vehicles at high speeds and low speeds while climbing hills. CN105697700A proposes a metal belt CVT with mechanical transmission speed regulation controlled by a motor. This CVT employs a pressurized speed regulation mechanism with dual-motor controlled mechanical transmission, reducing hydraulic components, lowering maintenance difficulty, and improving transmission efficiency.

[0004] Regarding dedicated transmission systems for agricultural machinery, CN217011824U discloses a part-time four-wheel drive continuously variable transmission (CVT) chassis and a corn harvester. This chassis adopts a part-time four-wheel drive structure and is equipped with a CVT assembly, enabling it to adapt to the four-wheel drive operation requirements under various complex road conditions such as climbing slopes or muddy conditions. CN113357323A proposes a centrifugal moving gear CVT, which transmits power through a purely mechanical means, achieving high efficiency and large torque transmission, and enabling smooth gear changes with uninterrupted power flow throughout the entire process.

[0005] However, the existing gearboxes still have some problems in practical applications: First, the traditional friction continuously variable transmission is prone to slippage under high torque conditions, which affects transmission efficiency and service life; Second, the existing gearboxes have insufficient sealing performance, and dust and moisture are easy to enter in the harsh environment of frequent operation of agricultural machinery, which leads to accelerated wear of internal parts; Third, the transmission ratio range of the gearbox is limited, which is difficult to meet the needs of corn harvesters under different working conditions; Fourth, the friction coefficient of the existing continuously variable transmission decreases significantly in wet and slippery environments, which affects the stability and reliability of speed change[5]. In addition, the existing gearboxes have complex structures, high maintenance costs, and insufficient reliability under high load conditions, which makes it difficult to meet the needs of corn harvesters for long-term continuous operation.

[0006] Therefore, there is an urgent need to develop a metal belt continuously variable transmission assembly suitable for corn harvesters to solve the problems of poor adaptability to complex working conditions, low transmission efficiency, and insufficient high torque load in existing technologies, so as to improve the operating efficiency of corn harvesters, reduce energy consumption, and enhance reliability in harsh environments. Summary of the Invention

[0007] 1. The problem to be solved To address the technical problems existing in the prior art, this invention provides a molding die for left and right side decorative brackets of automobiles and its manufacturing method, which solves the problems of uneven cavity filling, uneven cooling, long molding cycle, difficult demolding, and insufficient structural stability in the prior art.

[0008] 2. Technical Solution To solve the above problems, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a design method for a continuously variable transmission (CVT) assembly for a corn harvester, comprising the following steps: 1) Operating conditions and parameter definitions: The maximum power of the engine is determined to be 100kW, the rated speed is 2500r / min, the travel speed is 3–12km / h, the diameter of the travel wheel is 1.2m, and the total transmission ratio requirement of the system is calculated to be 12.5–50. 2) Determine the transmission scheme: A composite transmission of metal belt CVT mechanism and two-stage reduction mechanism is adopted. The CVT transmission ratio range is set to 0.4–2.5. The first stage transmission ratio of the two-stage reduction mechanism is 3 and the second stage transmission ratio is 4, with a total reduction ratio of 12, so that the total transmission ratio of the system reaches 4.8–30. 3) Shaft system design and verification: 40Cr quenched and tempered material is selected. The diameter of the driving shaft is ≥135mm and the diameter of the driven shaft is ≥180mm according to the torsional strength formula. The safety factor K=1.8 is taken, and the stiffness of the shaft is verified to ensure that the deflection meets the usage requirements. 4) CVT core component design: The theoretical upper limit of the cone disc half cone angle is calculated based on the oil lubrication friction coefficient μ=0.12. Combined with the metal strip meshing force transmission effect, the cone disc half cone angle is determined to be 12°. The metal strip contact radius is calculated and rounded to be 25mm based on the input torque, allowable stress of the metal strip and friction coefficient. 5) Reduction gear design and verification: The gears are made of 20CrMnTi material with a machining accuracy of grade 7. The standard module is calculated and selected according to the bending strength formula. The module of the first gear is 3mm and the number of teeth is 20 / 60. The module of the second gear is 4mm and the number of teeth is 20 / 80. The tooth surface contact fatigue strength and tooth root bending fatigue strength are verified. 6) Housing and sealing design: The housing size is determined to be 510mm×532mm×280mm based on the center distance of the transmission components, the maximum gear diameter and the shaft installation height. A double-lip skeleton oil seal is used at the shaft extension, and the housing mating surface is sealed with a composite seal of silicone oil-resistant sealant and nitrile rubber gasket. 7) Finite element verification: Establish a three-dimensional model of the gear, apply rated load and boundary conditions, perform stress, displacement and strain analysis, and confirm that the strength and stiffness meet the requirements of heavy load conditions.

[0009] According to any embodiment of the first aspect of the present invention, in the metal belt CVT mechanism, the metal belt assembly is composed of more than 200 metal sheets with a thickness of 2 mm and two sets of metal rings, with a belt width of 40 mm. The metal rings are made of 9-12 high-strength steel strips of 0.20 mm stacked together, and the friction material is a mixture of polyester and ceramic fiber.

[0010] According to any embodiment of the first aspect of the present invention, the center distance between the two conical disc shafts of the CVT mechanism is determined by the equivalent radius of the conical disc plus the installation allowance, and is taken as 300mm.

[0011] According to any embodiment of the first aspect of the present invention, in the shaft stiffness check, the allowable deflection is set to 0.175 mm, and the calculated deflection is ≤0.035 mm, which meets the stiffness requirements.

[0012] According to any embodiment of the first aspect of the present invention, in the gear verification, the tooth surface contact stress is controlled within 1900–2000 MPa, and the maximum equivalent stress in finite element analysis is 61.33 MPa, which meets the strength requirements.

[0013] According to any embodiment of the first aspect of the invention, the gearbox ultimately outputs a maximum torque ≥ 20640 N. m, suitable for heavy-duty field and road transport conditions of corn harvesters.

[0014] The second aspect of the present invention provides a continuously variable transmission (CVT) assembly for a corn harvester, which is obtained by the optimization design method described in the first aspect.

[0015] 3. Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention adopts a metal belt CVT and a two-stage fixed reduction composite transmission scheme to accurately match the working parameters of a 100kW high-power corn harvester, and controls the total transmission ratio of the system at 4.8–30, effectively covering the harvester’s full travel speed range of 3–12km / h. This solves the problems of narrow speed range and poor working condition adaptability of traditional gearboxes, and can realize stepless smooth speed adjustment for low-speed high-torque harvesting in the field and high-speed smooth transfer on the road, greatly improving the adaptability of operation. (2) The present invention optimizes the core structural parameters of CVT in a targeted manner. By accurately matching the friction coefficient and force transmission characteristics, the half cone angle of the 12° cone disk and the contact radius of the 25mm metal belt are determined. Combined with the polyester ceramic fiber mixed friction material and the multi-layer stacked high-strength metal ring structure, the force transmission efficiency and anti-slip ability of the CVT mechanism under oil lubrication conditions are greatly improved, the running stability under heavy load conditions is significantly improved, and the wear life is greatly extended. (3) The present invention adopts a material matching scheme of 40Cr quenched and tempered shaft system and 20CrMnTi high-precision reduction gear, combined with high strength and high stiffness parameter design and strict strength and stiffness verification. The shaft system deflection is far below the allowable value, the gear contact stress is controllable, the structural strength redundancy is sufficient, and it can withstand heavy alternating loads for a long time, eliminating failures such as deformation and fatigue damage. (4) The present invention adopts a composite sealing structure with a special box size design to completely solve the problems of oil seepage, oil leakage and dust ingress of traditional gearboxes, and improve the overall sealing performance and environmental adaptability of the gearbox; the structural mechanical performance is verified by finite element simulation in the whole domain, the design has high reliability, and the final output of the assembly has a maximum torque ≥20640N·m, which perfectly matches the heavy-duty operation requirements of high-power corn harvesters. Attached Figure Description

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless specifically indicated, these drawings are intended only to conceptually illustrate the structural construction described herein and are not necessarily drawn to scale.

[0017] Figure 1 Material selection diagram for gear static stress analysis of this invention; Figure 2 This is a stress analysis diagram of the gears in this invention; Figure 3 This is a gear displacement analysis diagram of the present invention; Figure 4 This is a gear strain analysis diagram of the present invention; Detailed Implementation The following detailed description of exemplary embodiments of the invention is taken with reference to the accompanying drawings, which form part of the description and illustrate exemplary embodiments in which the invention may be practiced. While these exemplary embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and various changes may be made to the invention without departing from the spirit and scope thereof. The more detailed description of embodiments of the invention below is not intended to limit the scope of the claimed invention, but is merely illustrative and not restrictive of the description of the features and characteristics of the invention, to suggest the best mode for carrying out the invention, and is sufficient to enable those skilled in the art to practice the invention. Therefore, the scope of the invention is defined only by the appended claims.

[0018] The following detailed description and exemplary embodiments of the invention can be better understood in conjunction with the accompanying drawings, wherein the elements and features of the invention are identified by reference numerals.

[0019] The metal belt continuously variable transmission mechanism in this embodiment contains a metal drive belt, a driving pulley, and a driven pulley. The metal drive belt consists of over 200 metal sheets, each 2mm thick, with a width of 40mm, and is assembled with two sets of stacked metal rings. Each set of metal rings consists of 9 or 12 0.20mm thick belt loops, which not only provide preload to the drive belt but also guide the movement of the metal sheets during power transmission, sharing some of the torque. Under the pressure of the driving and driven pulleys, the metal sheets become the key carrier for transmitting power.

[0020] The design method of the continuously variable transmission (CVT) assembly for a corn harvester in this embodiment includes the following steps:

Operating Conditions and Parameter Definitions

[0021] [Determine the transmission scheme] This embodiment uses a composite transmission of a metal belt CVT mechanism and a two-stage reduction mechanism. The speed ratio range of the metal belt CVT is about 0.4–2.5. In order to make the transmission ratio range of the entire transmission system meet the working requirements of the corn harvester, the total transmission ratio of the intermediate reduction mechanism is designed to be between 4 and 30.

[0022] For intermediate reduction mechanisms employing a two-stage transmission, the first-stage transmission ratio is set between 2 and 5, and the second-stage transmission ratio is set between 2 and 6. If the first-stage transmission ratio is set to 3 and the second-stage transmission ratio is set to 4, then the total transmission ratio of the intermediate reduction mechanism is: (3-1) When the continuously variable transmission (CVT) is at its minimum gear ratio of 0.4: (3-2) When the continuously variable transmission (CVT) is at its maximum transmission ratio of 2.5: (3-3) Wheel diameter Set the walking speed to 1.2m. (3-4) Since the walking speed is designed to be 3-12 km / h, it can be calculated from equation (3-4) The approximate speed range is 50–200 r / min.

[0023] The range of the total transmission ratio of the system is: (3-5) From equation (3-5), we know that the total transmission ratio is 12.5 to 50, which can meet the needs of low speed and high torque (field operation) as well as the needs of high speed transfer (road driving).

[0024] [Shaft System Design and Verification] 40Cr quenched and tempered material was selected. The diameter of the driving shaft was ≥135mm and the diameter of the driven shaft was ≥180mm according to the torsional strength formula. The safety factor K=1.8 was taken, and the shaft stiffness was checked to ensure that the deflection met the usage requirements.

[0025] Pulley radius R, running angle Corner The relationship between them is shown in equation (3-10).

[0026] (3-10) The formula for the maximum operating angle is shown in equation (3-11), where... ; according to It increases with the increase of A, and decreases with the increase of A.

[0027] (3-11) (3-12) According to Table 2-1, if the engine power of a corn harvester is designed to be P=100kW (approximately 136 horsepower), then the engine output torque is: (3-13) Table 2-1 Harvester Engine Parameters

[0028] Considering the harsh working conditions of agricultural machinery, a safety factor of K = 1.8 is adopted, then the design torque is: (3-14) Torque after the first-stage reducer (CVT input): (3-15) CVT output torque range (gear ratio 0.4~2.5): (3-16) Maximum torque after the two-stage reducer (final output): (3-17) Material selection for metal belt pulley shaft: 40Cr alloy steel (quenched and tempered, allowable shear stress […]) =45MPa), preliminary calculation of shaft diameter (torsional strength): (calculated according to the torsional strength formula) (3-18) Drive pulley shaft diameter (CVT input shaft): (3-19) Driven pulley shaft diameter (CVT output shaft): (considering maximum torque) ) (3-20) Because rounding is the standard value, take... =135mm, =180mm.

[0029] If the shaft span L = 350 mm, then the allowable deflection is: Thus, the stiffness of the driven shaft is calculated: Deflection of a diameter of 180mm under maximum torque: (3-21) in, elastic modulus .

[0030] Calculated from equation (3-21): (3-22) (3-23) (3-24) [CVT Core Component Design] The theoretical upper limit of the cone disc half-cone angle is calculated based on the oil lubrication friction coefficient μ=0.12. Combined with the metal strip meshing force transmission effect, the cone disc half-cone angle is determined to be 12°. The metal strip contact radius is calculated and rounded to be 25mm based on the input torque, allowable stress of the metal strip and friction coefficient.

[0031] Calculations are based on the specifications of the metal belt drive designed above: The tensile strength of the metal strip depends on the number of metal ring layers, therefore the tensile strength of a single ring is... =1000MPa (high-strength steel strip), then: × Single ring cross-sectional area × Total number of pieces (3-24) According to formula (3-24), the result is obtained as follows: =192kN Normal pressure between the metal strip and the cone disc With axial force The relationship is: (3-25) Where F is the tension of the metal strip (take the maximum tension). ).

[0032] Friction conditions: (3-26) (Oil lubrication condition), calculated according to formula (3-26) (3-27) According to equation (3-27), we get

[0033] Since the semi-cone angle cannot rely on pure friction for transmission, it is necessary to use the meshing effect of metal plates to assist in force transmission. .

[0034]

[0035] In this embodiment, the tension of the metal strip must be much smaller than the allowable value (safety factor n=2-3), so here... .

[0036] Input torque calculation: (3-28) The allowable tensile stress of the metal strip is For metal strips, usually take In this embodiment, in order to ensure that the material has sufficient safety margin during use and to avoid plastic deformation or fracture due to overload, [σ] = 200MPa is taken.

[0037] Total thickness of the transmission belt: Effective cross-sectional area of ​​the transmission belt , Maximum tension =54400N.

[0038] The input torque of a CVT is transmitted by the friction of the drive belt, that is: (3-29) (Both conical discs provide friction, so multiply by 2).

[0039] Calculated from equation (3-29): (3-30) Bending stress is generated when the metal strip bends around the conical disk. It is necessary to ensure that the total stress does not exceed the allowable value. Bending stress: (3-31) Will Substituting R=0.0292m and t=6.8m into equation (3-31), we get: (3-32) Total stress: (Safety) The contact radius is rounded to 25mm. Verification: MPa, safe.

[0040] [Reduction Gear Design and Verification] The gears are made of 20CrMnTi material with a machining accuracy of grade 7. The standard module is calculated and selected according to the bending strength formula. The module of the first gear is 3mm and the number of teeth is 20 / 60. The module of the second gear is 4mm and the number of teeth is 20 / 80. The tooth surface contact fatigue strength and tooth root bending fatigue strength are checked.

[0041] Specifically, the gear material is 20CrMnTi; machining accuracy is grade 7; hardness is 56-62 HRC. The center distance of the conical disc shaft is determined according to design requirements: (4-1) (

[0042] From equation (4-1) we get mm, rounded to the nearest integer 90 mm.

[0043] The calculation of the pinion requires that the gear module m must meet the bending strength requirement. The formula for the module of a steel gear is as follows: (4-2) (Where K is the load factor, taken as 1.3;) The face width factor is set to 1.0; The pinion has 20 teeth to avoid root cutting; (The allowable bending stress is taken as 70 MPa) First-stage reduction gear: Will Substituting into equation (4-2), we get: (4-3) To ensure its strength, a thickness of 3mm is used.

[0044] Second-stage reduction gear:

[0045] Substituting into equation (4-2), we get: (4-4) To ensure its strength, a thickness of 4mm is used.

[0046] Based on the calculation results and in conjunction with the national standard module series (GB / T 1357-2008), the standard values ​​are selected as shown in Table 4-1.

[0047] Table 4-1 Selection Table for Standard Gear Module

[0048] Tooth number allocation: First-stage transmission ratio 3: pinion large gear .

[0049] Second-stage transmission ratio 4: pinion large gear .

[0050] Tooth width calculation formula: (4-5) The tooth width of each gear is calculated using equation (4-5):

[0051]

[0052]

[0053]

[0054] The above calculation of tooth surface contact strength: rpm rpm 600rpm rpm Tangential force at the pitch circle: (4-6) Calculated from equation (4-6): = N Formula for calculating gear linear velocity: m / s(4-7) The formula for the transmission accuracy coefficient can be found in the literature: (4-8) Calculated from equation (4-8): C=6.518, rounded up to C=7.

[0055] Find the formula for the tooth load distribution factor: = (4-9) Calculated from equation (4-9): =1.1465. According to the formula for calculating tooth surface contact stress: (4-10) The gear verification is calculated using equation (4-10): (Gears 1 and 2) ) Gear 1:

[0056]

[0057] 1880 MPa Gear 2:

[0058] =

[0059] 1785MPa MPa Mpa (Gears 3 and 4) ) Gear 3:

[0060] =

[0061] 1832MPa Gear 4:

[0062] =

[0063] 1839 MPa MPa Mpa Gears 5 and 6

[0064] Gear 5:

[0065] =

[0066] 1861MPa Gear 6:

[0067] =

[0068] 1867MPa MPa; MPa. Verification showed that the contact strength of all three sets of gears met the standard.

[0069]

Enclosure and Sealing Design

[0070] 1) Determining the center distance of transmission components First stage gear (module) ): (5-1) Second stage gear (module) ): (5-2) 2) Center distance of continuously variable transmission Contact radius equivalent cone disk radius: (5-3) Center distance: (Rounded to 300mm) (5-4) Box length calculation: (5-5) 3) Box width and height Width B: Due to the largest gear diameter The allowance on one side is 50mm. (5-6) Height H: Maximum installation height of shaft system: center height of driven wheel shaft: (5-7) oil pool depth Top margin Calculate H: (5-8) The dimensions of the box are as follows: .

[0071] [Finite Element Verification] (1) Model Establishment: Based on the design parameters, open the input axis model in SolidWorks. Select alloy steel as the material. For example... Figure 1 As shown.

[0072] (2) Load and boundary conditions: Calculate the gear torque under rated operating conditions based on the engine's rated power, speed and transmission ratio.

[0073] Table 6-1 Example Results

[0074] (3) As shown in Table 6-1: Figure 2 , Figure 3 and Figure 4 As shown in the stress distribution cloud map of the gear, there is significant stress concentration at the tooth root, with the maximum stress reaching 61.33 MPa. Compared with the allowable stress of the material, the gear strength meets the standard under the current working condition. Deformation analysis shows that the maximum deformation of the tooth surface is approximately 0.0026 mm.

[0075] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A design method for a continuously variable transmission (CVT) assembly for a corn harvester, characterized in that, Includes the following steps: 1) Operating conditions and parameter definitions: The maximum power of the engine is determined to be 100kW, the rated speed is 2500r / min, the travel speed is 3–12km / h, the diameter of the travel wheel is 1.2m, and the total transmission ratio requirement of the system is calculated to be 12.5–50. 2) Determine the transmission scheme: A composite transmission of metal belt CVT mechanism and two-stage reduction mechanism is adopted. The CVT transmission ratio range is set to 0.4–2.

5. The first stage transmission ratio of the two-stage reduction mechanism is 3 and the second stage transmission ratio is 4, with a total reduction ratio of 12, so that the total transmission ratio of the system reaches 4.8–30. 3) Shaft system design and verification: 40Cr quenched and tempered material is selected. The diameter of the driving shaft is ≥135mm and the diameter of the driven shaft is ≥180mm according to the torsional strength formula. The safety factor K=1.8 is taken, and the stiffness of the shaft is verified to ensure that the deflection meets the usage requirements. 4) CVT core component design: The theoretical upper limit of the cone disc half cone angle is calculated based on the oil lubrication friction coefficient μ=0.

12. Combined with the metal strip meshing force transmission effect, the cone disc half cone angle is determined to be 12°. The metal strip contact radius is calculated and rounded to be 25mm based on the input torque, allowable stress of the metal strip and friction coefficient. 5) Reduction gear design and verification: The gears are made of 20CrMnTi material with a machining accuracy of grade 7. The standard module is calculated and selected according to the bending strength formula. The module of the first gear is 3mm and the number of teeth is 20 / 60. The module of the second gear is 4mm and the number of teeth is 20 / 80. The tooth surface contact fatigue strength and tooth root bending fatigue strength are verified. 6) Housing and sealing design: The housing size is determined to be 510mm×532mm×280mm based on the center distance of the transmission components, the maximum gear diameter and the shaft installation height. A double-lip skeleton oil seal is used at the shaft extension, and the housing mating surface is sealed with a composite seal of silicone oil-resistant sealant and nitrile rubber gasket. 7) Finite element verification: Establish a three-dimensional model of the gear, apply rated load and boundary conditions, perform stress, displacement and strain analysis, and confirm that the strength and stiffness meet the requirements of heavy load conditions.

2. The design method for a continuously variable transmission (CVT) assembly for a corn harvester according to claim 1, characterized in that, In the metal belt CVT mechanism, the metal belt assembly consists of more than 200 2mm thick metal sheets and two sets of metal rings, with a belt width of 40mm. The metal rings are made of 9-12 0.20mm high-strength steel strips stacked together, and the friction material is a mixture of polyester and ceramic fiber.

3. The design method for a continuously variable transmission (CVT) assembly for a corn harvester according to claim 1, characterized in that, The center distance between the two cone disc shafts of the CVT mechanism is determined by the equivalent radius of the cone disc plus the installation allowance, and is set to 300mm.

4. The design method for a continuously variable transmission (CVT) assembly for a corn harvester according to claim 1, characterized in that, In the shaft system stiffness check, the allowable deflection is set to 0.175 mm, and the calculated deflection is ≤0.035 mm, which meets the stiffness requirements.

5. The design method for a continuously variable transmission (CVT) assembly for a corn harvester according to claim 1, characterized in that, In the gear verification, the tooth surface contact stress was controlled within 1900–2000 MPa, and the maximum equivalent stress in the finite element analysis was 61.33 MPa, which met the strength requirements.

6. The design method for a continuously variable transmission (CVT) assembly for a corn harvester according to claim 1, characterized in that, The transmission ultimately outputs a maximum torque ≥ 20640N. m, suitable for heavy-duty field and road transport conditions of corn harvesters.

7. A continuously variable transmission (CVT) assembly for a corn harvester obtained by the design method of the CVT assembly for a corn harvester according to any one of claims 1-6.

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