Forward tooth surface design method and apparatus oriented to meshing performance requirements, and medium

Abstract

Disclosed in the present invention are a forward tooth surface design method and apparatus oriented to meshing performance requirements, and a medium. The method comprises the following steps: calculating a mathematical expression for gear meshing performance requirements; calculating an allowable limit deviation during a manufacturing process, and incorporating the allowable limit deviation into the mathematical expression for the gear meshing performance requirements; performing tooth surface solving in a given actual meshing state, so as to obtain an initial designed tooth surface; performing performance checking in a desired meshing state, so as to obtain an advanced designed tooth surface; and correcting the advanced designed tooth surface on the basis of manufacturing conditions and process requirements, so as to obtain an improved design result. In the present invention, in terms of usage performance, a relationship between the usage performance and gear meshing performance is established; under the comprehensive consideration of deviation conditions of machined gears, a method for solving tooth surface geometry on the basis of actual tooth surface meshing performance is defined; and on this basis, machining and manufacturing conditions of gears are taken into comprehensive consideration, and a design result is converted into parameters of a machinable tooth surface.

Description

A tooth surface forward design method, device and medium oriented to meshing performance requirements Technical Field

[0001] The present invention relates to the field of gear transmission design and manufacturing technology. Specifically, the present invention is applied to the field of tooth surface geometry forward design, and in particular to a tooth surface forward design method, device and medium oriented to meshing performance requirements. Background Art

[0002] Gears are an important component of transmission design and are widely used in various transmission mechanisms. Currently, the design method of gears mainly involves macro-parameter design based on the actual use conditions of the gears. On this basis, the tooth surface modification and optimization are performed according to the gear processing and manufacturing conditions. Finally, a set of feasible tooth surface micro-parameters is obtained to determine the tooth surface geometry of the gear in actual operation.

[0003] The traditional gear modification optimization method to obtain tooth surface geometry is essentially an iterative optimization with performance as the goal, without theoretical analysis. There is a disconnect between tooth surface geometry and product performance indicators, so the tooth surface geometry obtained by traditional methods may not be the optimal tooth surface geometry required by the product. In actual engineering, product performance is heavily dependent on the experience of engineering technicians.

[0004] Tooth surface geometry is an important factor in determining gear transmission performance. As an important component of the product, gear transmission performance will directly affect the final performance of the product. With the improvement of living standards, people's performance requirements for products are getting higher and higher. Traditional gear design methods can no longer meet the increasing performance requirements of products. Summary of the Invention

[0005] The purpose of the present invention is to provide a tooth surface forward design method, device and medium for meshing performance requirements in response to the above-mentioned problems in the prior art, thereby solving the problem in the prior art that there is a disconnect between the tooth surface geometry and product performance indicators, and that the tooth surface geometry may not fully meet the use requirements; and changing the current situation where the tooth surface geometry design can only be obtained by modification and optimization based on the experience of engineers, and the results are not unique.

[0006] In order to solve the above technical problems, the specific technical solutions of the present invention are as follows:

[0007] In one aspect, the present invention provides a method for forward design of tooth surfaces oriented to meshing performance requirements, comprising the following steps:

[0008] Calculate the mathematical expression of gear mesh performance requirements;

[0009] Calculate the allowable limit deviations during the manufacturing process and take them into account in the mathematical expression of the gear mesh performance requirements;

[0010] Based on the mathematical expression of the gear meshing performance requirements, the tooth surface is solved under a given actual meshing state to obtain an initial design tooth surface;

[0011] Based on the initial designed tooth surface, a performance check is performed under a desired meshing state to obtain an advanced designed tooth surface;

[0012] The advanced designed tooth surface is modified according to manufacturing conditions and process requirements to obtain a perfect design result.

[0013] As an improved solution, the mathematical expression of the calculation of gear meshing performance requirements includes: obtaining gear macro parameters, product design performance indicators, actual operating conditions of the gear pair, gear materials and heat treatment conditions, and theoretical tooth surfaces of large and small wheels, and converting them into gear meshing performance through calculation, and characterizing them mathematically to obtain the mathematical expression of the gear meshing performance requirements.

[0014] As an improved solution, the mathematical expression for calculating the gear meshing performance requirements further includes: conversion of indicators directly realized by gear transmission; conversion of boundary conditions required for gear operation; conversion of the influence of actual gear operating conditions; and conversion of the conditions of the gear teeth themselves.

[0015] As an improved solution, the calculation of the limit deviation allowed in the manufacturing process and the inclusion of the mathematical expression of the gear meshing performance requirements include: calculating the limit deviation value of the gear teeth and associating it with the deviation type, and converting the limit deviation value and deviation type into input boundary conditions for calculating the gear meshing performance.

[0016] As an improved solution, the mathematical expression based on the gear meshing performance requirement is used to solve the tooth surface under a given actual meshing state to obtain the initial design tooth surface, including: matching the gear meshing performance that is consistent with the given actual meshing state in the gear meshing performance requirement, introducing the limit deviation allowed in the manufacturing process, and on this basis, using the gear meshing principle and taking the theoretical tooth surface of the large wheel as the basis to solve the design tooth surface of the small wheel.

[0017] As an improved solution, the mathematical expression based on the gear meshing performance requirements is used to solve the tooth surface under a given actual meshing state to obtain the initial design tooth surface, which further includes: determining the performance indicators and working conditions for tooth surface design; analyzing the actual meshing performance indicators of the gear teeth; solving the comprehensive stiffness of the gear teeth; defining the gear motion law; solving the small wheel design tooth surface, based on the theoretical tooth surface of the large wheel, the gear motion law, the calculation conditions corresponding to the gear motion law, and the tooth thickness thinning amount, using the meshing principle to solve the small wheel design tooth surface.

[0018] As an improved solution, the performance is checked based on the initial design tooth surface under the expected meshing state to obtain the advanced design tooth surface, including: using the large wheel theoretical tooth surface and the small wheel design tooth surface to check the gear meshing performance under the expected meshing state. If there is any situation that does not meet the product requirements, iterative calculation is performed by modifying the gear motion law and tooth thickness thinning amount until it meets the product requirements.

[0019] As an improved solution, the advanced designed tooth surface is modified according to manufacturing conditions and process requirements to obtain a perfect design result, including:

[0020] Select the processing conditions and technology of the designed gear; based on the principle that the instantaneous meshing characteristics of the tooth surface remain unchanged, the tooth thickness reduction amount of each meshing phase is distributed between large and small according to the selected processing conditions and technology;

[0021] Based on the selected processing conditions and processes, determine the limit deviation of the tooth surface geometry during the manufacturing process, and use the tooth surface geometry containing the limit deviation to verify and calculate the performance indicators; if the requirements are not met, reselect the processing conditions or processes; if they can meet the requirements, specify the allowable limit deviation of the tooth surface geometry;

[0022] Integrate the tooth surface geometry, limit deviations, corresponding processing conditions and process requirements to obtain and output the perfect design results.

[0023] On the other hand, the present invention also provides a tooth surface forward design device oriented to meshing performance requirements, comprising: a mathematical expression calculation unit for calculating the mathematical expression of the gear meshing performance requirements;

[0024] A limit deviation conversion unit for calculating the limit deviations allowed during the manufacturing process and taking them into account in the mathematical expression of the gear meshing performance requirements;

[0025] A tooth surface geometry solving unit is used to solve the tooth surface under a given actual meshing state based on the mathematical expression of the gear meshing performance requirements to obtain an initial design tooth surface;

[0026] A tooth surface geometry verification unit is used to perform a performance verification under a desired meshing state based on the initial design tooth surface to obtain an advanced design tooth surface;

[0027] The tooth surface geometry output unit is used to modify the advanced design tooth surface according to manufacturing conditions and process requirements to obtain a perfect design result.

[0028] On the other hand, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the tooth surface forward design method oriented to meshing performance requirements.

[0029] The beneficial effects of the technical solution of the present invention are:

[0030] 1. The tooth surface forward design method for meshing performance requirements described in the present invention starts from the product performance, establishes the relationship between product performance and gear meshing performance, and defines a method for calculating tooth surface geometry based on the actual meshing performance of the tooth surface under the overall consideration of the deviation of the processed gear; on this basis, the processing and manufacturing conditions of the gear are comprehensively considered, and the design results are converted into machinable tooth surface parameters; the application of this method lays the foundation for the realization of forward design of tooth surface geometry, changes the separation between tooth surface geometry and product performance indicators, and the current situation that tooth surface geometry may not fully meet the use requirements; solves the problem that tooth surface geometry design can only rely on engineers' experience for modification and optimization, and the results are not unique; under the same conditions, the meshing performance is further improved through tooth surface geometry design, and it also provides a theoretical and implementation basis for the design of high-performance gear transmission devices, has great practical value, and makes up for the shortcomings of the existing technology.

[0031] 2. The tooth surface forward design device for meshing performance requirements described in the present invention can achieve the goal of starting from product performance through the mutual cooperation of a mathematical expression calculation unit, a limit deviation conversion unit, a tooth surface geometry solution unit, a tooth surface geometry verification unit, and a tooth surface geometry output unit. By establishing the relationship between product performance and gear meshing performance, and taking into account the deviation conditions of the processed gear, a method for calculating the tooth surface geometry based on the actual meshing performance of the tooth surface is defined; on this basis, taking into account the processing and manufacturing conditions of the gear, the design results are converted into machinable tooth surface parameters, laying the foundation for realizing the forward design of the tooth surface geometry.

[0032] 3. The computer-readable storage medium described in the present invention can guide the coordination of the mathematical expression calculation unit, the limit deviation conversion unit, the tooth surface geometry solution unit, the tooth surface geometry verification unit, and the tooth surface geometry output unit. Then, starting from the product performance requirements, the product requirements are converted into the actual gear meshing performance requirements. Then, the tooth surface geometry is designed according to the actual meshing performance requirements using forward theories such as meshing principles and elastic mechanics. The basic idea from tooth surface geometry to processing and manufacturing is provided, which provides a theoretical basis for high-performance gear transmission design, solves the current situation where tooth surface geometry design relies on the experience of engineering and technical personnel, and at the same time, provides a feasible method and approach for improving gear transmission performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] FIG1 is a flow chart of a method for forward design of tooth surfaces oriented to meshing performance requirements according to Example 1 of the present invention;

[0035] FIG2 is a schematic diagram showing the expression of a single tooth pitch in a gear motion diagram in the tooth surface forward design method oriented to meshing performance requirements according to Example 2 of the present invention;

[0036] 3 is a schematic diagram of the definition of the internal contact geometry of the meshing surface in the tooth surface forward design method oriented to meshing performance requirements according to Example 2 of the present invention;

[0037] FIG4 is a schematic diagram of the change in torsional stiffness of a single tooth in the forward tooth surface design method oriented to meshing performance requirements described in Example 2 of the present invention. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0039] In the description of the present invention, it should be noted that the embodiments described in the present invention are only part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

[0040] The terms "initial," "advanced," "complete," and the like in the specification and claims herein and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0041] In this invention, starting from the performance requirements of product usage, a method for forward design of tooth surface geometry from the actual performance requirements of gear meshing is provided. At the same time, the basic idea of ​​processing and manufacturing the designed tooth surface is proposed, laying the foundation for the design and manufacture of high-performance gear transmission. Example 1

[0042] This embodiment provides a tooth surface forward design method oriented to meshing performance requirements, as shown in FIG1 , comprising the following steps:

[0043] S100, calculate the mathematical expression of gear meshing performance requirements;

[0044] The mathematical expression of the gear meshing performance requirements is based on the determined gear macro design and the theoretical tooth surfaces of the large and small gears. According to the product performance requirements and the actual working conditions of the gear pair, such as misalignment and temperature, the product performance is converted into gear meshing performance through calculation and characterized by mathematical methods.

[0045] Specifically, the product performance requirements for gear transmission devices are mainly manifested in: smaller size, lighter weight, lower noise, longer service life, and greater reliability; the product performance requirements are reflected in the gear meshing performance, mainly in: the load-bearing capacity and transmission error of the gear teeth under conditions such as misalignment and temperature.

[0046] Since the corresponding relationship between the performance requirements of different products and the gear meshing performance is complex, in order to achieve the transformation of product performance requirements, this step requires analysis and specific work from the following aspects:

[0047] S101, conversion of indicators directly realized by gear transmission;

[0048] Product performance indicators such as volume requirements, weight requirements, life requirements, reliability requirements, noise requirements, etc. are converted into corresponding gear meshing performance indicators such as load capacity, transmission error, etc.

[0049] S102, conversion of boundary conditions required for gear operation;

[0050] The boundary conditions required for gear operation, such as operating speed, torque, ambient temperature, lubrication conditions, etc., are converted into calculation conditions for gear meshing performance, such as load spectrum, thermal equilibrium conditions, and lubricant (grease) viscosity;

[0051] S103, conversion of the influence of actual gear operating conditions;

[0052] The actual operating conditions of the gears, such as system deformation caused by external loads, deformation caused by centrifugal force, heat dissipation and cooling, are converted into calculation conditions for gear meshing performance, such as tooth misalignment and thermal deformation.

[0053] S104, conversion of gear tooth conditions;

[0054] The conditions of the gear teeth themselves include: material heat treatment conditions, macroscopic parameters of the gear, theoretical tooth surface, single tooth stiffness of the gear teeth, theoretical meshing trajectory, etc.

[0055] S200, calculating the allowable limit deviation during the manufacturing process and taking it into account in the mathematical expression of the gear meshing performance requirement;

[0056] The allowable limit deviation and conversion in the manufacturing process refers to the allowable limit deviation value of the gear tooth in actual processing according to the use conditions and design experience of the designed tooth surface, and is converted into the input boundary conditions required for the forward design of the tooth surface according to the impact on the gear meshing performance and the deviation type;

[0057] Specifically, the errors generated during the manufacturing and assembly process can be divided into two parts: one is the error caused by the manufacturing and assembly of the gear itself, and the other is the error caused by the manufacturing of the gear.

[0058] S201, conversion of errors caused by manufacturing and assembly of the gear teeth themselves;

[0059] The errors generated during the product manufacturing and assembly process mainly change the actual working boundaries and working conditions of the gear teeth in terms of gear meshing performance, such as the deviation of the support shaft hole, the non-concentric deviation of the support shaft, the clearance of the bearing, the fit of various support parts, etc. In actual calculations, they can be directly converted into the boundaries and working conditions required for meshing performance calculations.

[0060] S202, conversion of errors caused by gear tooth manufacturing;

[0061] The error effects caused by the gear manufacturing process can be divided into three categories: First, the tooth surface geometry design will not change the impact caused by the error, such as the dynamic response caused by radial runout. This type of deviation needs to be comprehensively considered when converting performance indicators, and is defined as the first type of error in this document; second, the tooth surface geometry design can improve the impact caused by the error, such as the meshing impact caused by a single tooth pitch. This type of deviation needs to be comprehensively considered as an input condition when designing the tooth surface geometry, and is defined as the second type of error in this document; third, the manufacturing error of the tooth surface geometry itself, such as errors in tooth shape, tooth direction, tooth surface topology, etc. For this type of error, it is necessary to give a limit deviation value that meets the requirements when outputting the tooth surface design results based on the analysis of its impact. This is defined as the third type of error in this document.

[0062] S300, based on the mathematical expression of the gear meshing performance requirement, performing tooth surface calculation under a given actual meshing state to obtain an initial design tooth surface;

[0063] The tooth surface solution under a given actual meshing state is based on the product performance requirements. Among all the actual meshing performance requirements of the gears, the gear meshing performance under a unique and certain condition is given, and the limit deviation of the manufacturing process is introduced. On this basis, the gear meshing principle is adopted and the theoretical tooth surface of the large wheel is used as the basis to solve the small wheel tooth surface.

[0064] Specifically, the solution of the tooth surface under the actual meshing state can be carried out in the following steps:

[0065] S301. Determine the performance indicators and working conditions for tooth surface design;

[0066] In actual engineering, whether it is the product's performance indicators or working conditions, they are usually not uniquely determined, but have a certain range of values. On the other hand, the tooth surface geometry that realizes power and motion transmission is uniquely determined.

[0067] In view of the above situation, the factors such as the effects of different meshing performance on product performance indicators, product performance indicator requirements, and the degree of redundancy of different meshing performance indicators are comprehensively considered, and the determination conditions for solving the tooth surface geometry are defined based on experience.

[0068] S302, analysis of actual gear tooth meshing performance indicators;

[0069] Actual gear tooth meshing performance indicators include: tooth contact stress, tooth bending stress, motion pattern, tooth normal force distribution, tooth relative velocity distribution, tooth power loss, tooth temperature, and so on. The essence of high-performance gear transmission is that all of the above indicators can meet the application requirements with minimal redundancy under certain conditions.

[0070] Meshing performance index analysis is the process of determining the required meshing performance index for a tooth surface under defined calculation conditions and based on the product's performance requirements. Typically, the index with the least redundancy is used as the input variable for forward tooth geometry design. Simultaneously, the index is modified by comprehensively considering the impact of first-order error, and other meshing performance indicators are then verified or iterated under these conditions.

[0071] S303, solve the comprehensive stiffness of gear teeth;

[0072] Define the calculation reference point: Usually, select the point where the middle section of the large gear tooth width falls on the instantaneous axis surface (the curved surface formed by the instantaneous sliding axis of the gear pair around their respective rotation centers). You can also select other tooth surface points on the large gear tooth surface based on actual conditions.

[0073] Define the meshing trajectory: Starting from the reference point, while satisfying the meshing principle, taking into account the meshing performance and the requirements of the designed tooth surface conjugation, define the meshing trajectory. Usually, the theoretical meshing trajectory can be used.

[0074] Single tooth stiffness solution: along the defined meshing trajectory, calculate the single tooth stiffness of the large and small wheels at each meshing phase (if there are no other calculation conditions, the theoretical contact length can be used).

[0075] Solution of single tooth comprehensive stiffness: Calculate the single tooth comprehensive stiffness of the gear pair at each meshing phase point along the defined meshing trajectory. If necessary, draw a relationship curve between the gear working phase or meshing trajectory and the single tooth comprehensive stiffness.

[0076] S304, defining the gear motion law;

[0077] Define the no-load motion law function of the gear teeth under calculation conditions: based on the uniform speed motion of the small wheel, define the functional relationship between the difference between the actual angular displacement and the theoretical angular displacement of the large wheel in each meshing phase and the undetermined coefficient between the meshing phase, such as a polynomial relationship.

[0078] Calculation of inter-tooth load distribution: Taking into account constraints such as the second-order error, gear contact ratio, and the no-load motion law of the gear teeth (if this is the first iteration, the initial value is given based on experience), starting from the reference point, the external load is converted into a concentrated load along the meshing trajectory. Then, based on load balance, deformation coordination, and Hooke's law, a gear tooth load distribution calculation equation is constructed. The equation is solved to obtain the concentrated load on the gear teeth converted to the fitting trajectory at each meshing phase and the macroscopic deformation of the gear teeth in that phase.

[0079] Calculate the geometric characteristic parameters of each point on the meshing trajectory according to the meshing characteristics: along the defined meshing trajectory, at each meshing phase point, calculate the tooth surface geometric contact characteristic parameters according to the meshing characteristic requirements, such as the curvature radius in the direction of the meshing trajectory and the curvature radius perpendicular to the meshing trajectory.

[0080] Determine the motion law: Using the macroscopic deformation of the gear teeth, the radius of curvature perpendicular to the meshing trajectory, and phase continuity as constraints, iterate the above steps to solve the unknown coefficients of the motion law function and obtain the motion law under these calculation conditions.

[0081] S305, solving the pinion tooth surface;

[0082] Definition of the tooth thickness reduction function perpendicular to the meshing trajectory: Starting from the reference point, along the meshing trajectory, based on the calculated geometric characteristic parameters of each point on the meshing trajectory and the meshing performance requirements of each point on the trajectory, define the tooth thickness reduction function perpendicular to the trajectory direction for each point on the trajectory.

[0083] Tooth surface meshing EASEOFF surface check: Based on the obtained motion law and tooth thickness reduction function, the tooth surface meshing EASEOFF surface function is defined, and the EASEOFF surface within the meshing boundary is checked for continuity and convexity. If the motion law or tooth thickness reduction is not satisfied, the modified motion law or tooth thickness reduction is applied.

[0084] Solution of small gear tooth surface: Based on the theoretical tooth surface of the large gear, the motion law, the calculation conditions corresponding to the motion law (such as misalignment), the tooth thickness reduction, etc., the meshing principle is used to solve the small gear tooth surface.

[0085] S306, analysis of calculation results;

[0086] During the initial design process, the tooth stiffness is calculated using the theoretical tooth surface and theoretical contact state. To further improve the calculation accuracy, the obtained tooth surface can be used to repeat the iterative calculation S303 to S305.

[0087] S400, based on the initial designed tooth surface, performing a performance check in a desired meshing state to obtain an advanced designed tooth surface;

[0088] The expected meshing state refers to other actual meshing states except the given actual meshing state. The performance verification under the other actual meshing states is carried out based on the actual meshing requirements of the gears and the manufacturing limit deviation conditions, and the meshing performance under all conditions is verified and calculated using the theoretical tooth surface of the large wheel and the designed tooth surface of the small wheel. If there is a situation that does not meet the product requirements, the process returns to step S400, and the calculation conditions required for step S400 are appropriately corrected and the small wheel tooth surface is redesigned until the requirements are met.

[0089] Specifically, based on the calculated tooth surface geometry, the performance under other actual meshing states is calculated to see if it meets the product requirements. If not, it is iteratively calculated by modifying the motion law and tooth thickness reduction until the requirements are met.

[0090] S500, modifying the advanced designed tooth surface according to manufacturing conditions and process requirements to obtain a perfect design result and obtain a tooth surface geometry design output that can be machined;

[0091] The output of the tooth surface geometry design that can be machined is achieved by first selecting the machining conditions and processes for the designed tooth surface. Then, based on the principle of keeping the instantaneous meshing characteristics of the tooth surface unchanged and the feasibility of the machining conditions and processes, the actual microscopic parameters of the large and small gear tooth surfaces are reallocated to obtain the design of the large and small gear tooth surface morphologies that meet the product requirements.

[0092] Specifically, first determine the manufacturing conditions and processing technology of the designed gear. Based on the specific requirements of the manufacturing conditions and processes, the tooth thickness reduction of each meshing phase is reasonably distributed between large and small to meet the processing requirements.

[0093] Secondly, based on the selected processing conditions and process, the possible limit deviations of the tooth surface geometry during the manufacturing process are determined. The tooth surface geometry containing the limit deviations is then used to verify and calculate various performance indicators. If the requirements are not met, the processing conditions or process are reselected. If they are met, the allowable limit deviations of the tooth surface geometry are determined.

[0094] Finally, the above design results are sorted out to complete the output of tooth surface geometry, limit deviations, and corresponding manufacturing conditions and process requirements. Example 2

[0095] This embodiment is based on the same inventive concept as the tooth surface forward design method for meshing performance requirements described in Example 1, and further provides a tooth surface forward design method for meshing performance requirements, which is applied to a first-stage involute cylindrical gear transmission device whose design indicators for the product are input speed, input torque, working time, and noise, and the tooth surface design process in which the gear macro parameters have been determined; correspondingly, this embodiment 2 further improves the method in Example 1, and further describes the specific implementation of this method in detail.

[0096] Compared with the tooth surface forward design method for meshing performance requirements in Example 1, the tooth surface forward design method for meshing performance requirements in Example 2 has further implementation steps in the specific implementation of steps S100 to S500 according to the conditions of given tooth surface geometric design.

[0097] As shown in FIG2 to FIG4 , the tooth surface forward design method oriented to meshing performance requirements described in this embodiment 2 mainly includes the following steps:

[0098] S100, calculate the mathematical expression of gear meshing performance requirements;

[0099] Obtain and sort out the conditions for a given tooth surface geometry design:

[0100] Input speed: RPM: the working speed of the small wheel;

[0101] Input torque: Nm, the working torque of the small wheel;

[0102] Working hours: Hour;

[0103] noise: decibel;

[0104] Gear macro parameters: number of teeth on small and large wheels ;

[0105] Modulus mm;

[0106] Pressure angle Spend;

[0107] Displacement coefficient ;

[0108] Helix angle Spend;

[0109] Tooth addendum height mm;

[0110] Full tooth height mm;

[0111] Tooth width mm;

[0112] Requirements on gear materials, heat treatment conditions, and machining accuracy levels.

[0113] S101, conversion of indicators directly realized by gear transmission;

[0114] As an implementation of the present invention, in this embodiment 2, step S101 specifically includes:

[0115] Gear ratio: ;

[0116] Carrying capacity (taking contact as an example): , unit MPa,

[0117] Where, is the tooth surface contact stress, which is the product design performance index; The allowable contact stress limit of the tooth surface is calculated based on the gear material, heat treatment conditions, SN curve, and cycle number; is a safety factor defined according to industry needs;

[0118] Transmission error: , unit is μm, the transmission error is the displacement converted to the meshing line;

[0119] The transmission error is obtained by establishing a system dynamics model while considering factors such as gear tooth processing errors and possible vibration responses of the system.

[0120] S102, conversion of boundary conditions required for gear operation;

[0121] As an implementation of the present invention, in this embodiment 2, step S102 specifically includes:

[0122] Normal force of tooth contact: , unit N, is obtained by calculating the working torque T of the small wheel and its macro-geometric parameters;

[0123] Cycle times: , where n is the small wheel speed and H is the working time.

[0124] S103, conversion of the influence of actual gear operating conditions;

[0125] As an implementation of the present invention, in this embodiment 2, step S103 specifically includes:

[0126] Dislocation amount: , unit μm, is obtained by calculating the system deformation calculation model by considering the machining error, bearing clearance, system deformation under working load and other conditions.

[0127] S104, conversion of gear tooth conditions;

[0128] As an implementation of the present invention, in this embodiment 2, step S104 specifically includes:

[0129] Material conditions: , unit MPa, is determined based on material, heat treatment, SN curve and cycle number N;

[0130] Gear macro parameters: number of teeth on small and large wheels ;

[0131] Modulus mm;

[0132] Pressure angle Spend;

[0133] Displacement coefficient ;

[0134] Helix angle Spend;

[0135] Tooth addendum height mm;

[0136] Full tooth height mm;

[0137] Tooth width mm;

[0138] Theoretical tooth surface: Calculate the tooth surface equation of the working area of ​​the tooth surface based on the gear macro parameters and involute equation;

[0139] Single tooth stiffness: Select the single tooth stiffness based on the calculation accuracy requirements Calculation method;

[0140] Theoretical meshing trajectory: perpendicular to the instantaneous contact line within the meshing surface, with an angle of (unit: degrees) of the straight line, is the base circle helix angle.

[0141] S200, calculating the allowable limit deviation during the manufacturing process and taking it into account in the mathematical expression of the gear meshing performance requirement;

[0142] In step S200, the conversion of errors caused by the manufacturing and assembly of the gear teeth specifically includes:

[0143] S201. Errors generated during the product manufacturing and assembly process include: manufacturing deviation of the housing, bearing clearance, and deviation of the gear teeth relative to the rotation center of the supporting bearing.

[0144] The deviation of the box and the gear teeth relative to the support bearing rotation center is half of the limit deviation value and converted to the support bearing rotation center. On this basis, the rigid body deflection angle is calculated according to the span of the support bearing, and the calculated value is directly linearly superimposed on the gear misalignment.

[0145] The bearing clearance is included in the system deformation calculation model as a clearance displacement of half the clearance value in the bearing load direction, so as to consider the influence of bearing clearance on gear working conditions.

[0146] In step S200, the conversion of errors generated by gear tooth manufacturing specifically includes:

[0147] S202, Type I error: radial runout , which is simplified to have an amplitude of The period is a sine function of the gear rotation shaft frequency, and this is used as the excitation source to convert it into transmission error through the system dynamics model. middle;

[0148] The second type of error: If the small wheel single tooth pitch 、Big wheel single tooth pitch When the small wheel rotates at a constant speed, the large wheel rotation angle error caused by the pitch error is

[0149] Using the formula Perform conversion calculations and express them in the motion law relationship diagram as shown in Figure 2.

[0150] S300, based on the mathematical expression of the gear meshing performance requirement, performing tooth surface calculation under a given actual meshing state to obtain an initial design tooth surface;

[0151] The solution of the tooth surface under the actual meshing state in this step specifically includes:

[0152] S301. Determine the performance indicators and working conditions for tooth surface design;

[0153] As an implementation mode of the present invention, in this embodiment 2, step S301 specifically includes: the calculation condition given by the tooth surface is only a single speed torque, so the working condition is unique, and the calculated gear working conditions and gear meshing performance indicators are all uniquely calculated under this calculation condition; the boundary conditions required for the tooth surface design are as described above and will not be repeated here.

[0154] S302, analysis of actual gear tooth meshing performance indicators;

[0155] As an implementation of the present invention, in this embodiment 2, step S302 specifically includes:

[0156] The performance indicators of tooth surface engagement include contact load capacity and transmission error. The specific mathematical expressions are as follows:

[0157]

[0158] According to the given requirements, the contact load capacity is used as the basis for subsequent tooth surface design, and the transmission error is used as the verification index.

[0159] S303, solve the comprehensive stiffness of gear teeth;

[0160] As an implementation of the present invention, in this embodiment 2, step S303 specifically includes:

[0161] Define the calculation reference point: select the intersection of the middle section of the large gear tooth width and the pitch cylinder as the reference point M. Its position within the meshing surface is shown in Figure 3;

[0162] Define meshing trajectory: In the meshing surface, select the The curve is the meshing line, see Figure 3;

[0163] Single tooth stiffness solution: along the defined meshing trajectory, calculate the single tooth stiffness of the large and small wheels at each meshing phase (if there are no other calculation conditions, the theoretical contact length can be used);

[0164] For three-dimensional gear teeth, the load stiffness of a single tooth can be calculated using the slice method. The stiffness of each slice can be decomposed into bending stiffness, shear stiffness, extrusion stiffness, and contact stiffness. The slice stiffness of the i-th gear tooth is:

[0165]

[0166] At a contact instant, the stiffness of a single tooth is

[0167]

[0168] N is the number of slices participating in meshing at the moment of contact;

[0169] At each meshing phase point, the comprehensive stiffness of a single tooth of the gear pair is:

[0170]

[0171] From this, the comprehensive stiffness curve of a single tooth from engagement to disengagement can be obtained, as shown in FIG4 .

[0172] S304, defining the gear motion law;

[0173] As an implementation of the present invention, in this embodiment 2, step S304 specifically includes:

[0174] Define the no-load motion law function of the gear teeth under calculation conditions and design it using polynomial as an example:

[0175] ;

[0176] in, is the angular error of the large wheel; is the coefficient to be determined; is the large wheel rotation angle phase;

[0177] The inter-tooth load distribution calculation can establish the following inter-tooth load distribution equation:

[0178]

[0179]

[0180] : Large wheel turning angle

[0181] : Large wheel transmits torque

[0182] It should be noted that: in actual calculation, the first calculation is iterated based on the initial values ​​of the unknown coefficients given by experience.

[0183] S305, solving the pinion tooth surface;

[0184] As an implementation of the present invention, in this embodiment 2, step S305 specifically includes:

[0185] Define the tooth thickness reduction function for the vertical meshing trajectory and design it using a polynomial as an example:

[0186]

[0187] : is the coefficient to be determined;

[0188] : Tooth thickness reduction.

[0189] Based on the results of the previous step, the normal force at the contact position can be obtained; based on the thinning amount and the law of motion, the comprehensive curvature of the tooth surface can be calculated; based on the normal force and the comprehensive curvature, the contact stress at the contact position can be calculated using the Hertz contact algorithm; based on the design stress index, the thinning coefficient is iterated to determine the undetermined thinning coefficient.

[0190] It should be noted that: in actual calculation, the initial value of the thinning coefficient to be determined is given based on experience in the first calculation.

[0191] On this basis, the ease-off surface calculation is completed, and the concavity and convexity of the ease-off surface are determined according to the Gaussian curvature;

[0192]

[0193] K: Gaussian curvature of the surface;

[0194] detⅡ: is the determinant of the second fundamental form of the surface;

[0195] detⅠ: is the determinant of the first fundamental form of the surface.

[0196] Small gear tooth surface solution: Based on the theoretical tooth surface of the large gear, the motion law, the calculation conditions corresponding to the motion law (such as misalignment), the tooth thickness reduction, etc., the meshing principle is used to solve the small gear tooth surface; the solution formula is:

[0197]

[0198] n: normal direction of the contact point, related to the amount of tooth thickness reduction;

[0199] v pw : The relative speed of the large and small wheels at the contact point is related to the laws of motion and calculation conditions.

[0200] S306, analysis of calculation results;

[0201] According to the margin between the calculated stress and the allowable stress and the requirements of the motion law, repeat steps S303 to S305 for iterative calculation.

[0202] S400, based on the initial designed tooth surface, performing a performance check in a desired meshing state to obtain an advanced designed tooth surface;

[0203] As an embodiment of the present invention, the expected meshing state refers to other actual meshing states except the given actual meshing state. In this embodiment 2, only one load condition is involved, and performance verification calculations under other actual meshing states are not involved.

[0204] S500, modifying the advanced designed tooth surface according to manufacturing conditions and process requirements to obtain a perfect design result, and outputting a tooth surface geometry design that can be machined;

[0205] As an implementation of the present invention, in this embodiment 2, step S500 specifically includes:

[0206] S501, determining a comprehensive modification amount for each meshing phase according to the ease-off surface;

[0207] S502. Reasonably distribute the modification amount of the large and small wheels according to the principle error caused by the manufacturing process conditions of the designed gear and the feasible modification methods. ;

[0208] S503. Based on the above selected processing conditions and processes, determine the possible limit deviations of the gear and wheel that may be generated during the manufacturing process. ;

[0209] S504. According to the limit deviation and thinning amount, a set of designed tooth surfaces with different error distributions of large and small wheels are obtained. ;

[0210] S505. Based on the designed tooth surface, calculate the gear meshing performance under different deviation conditions;

[0211] S506: If the conditions are met, the design is completed; if not, the undetermined coefficients of the motion error and the undetermined coefficients of the tooth thickness reduction in step S300 are adjusted and iteratively calculated;

[0212] S507. Organize the above design results and complete the output of the tooth surface geometry, limit deviation, and corresponding manufacturing conditions and process requirements. Example 3

[0213] This embodiment provides a tooth surface forward design device oriented to meshing performance requirements, comprising: a mathematical expression calculation unit for calculating the mathematical expression of the gear meshing performance requirements;

[0214] A limit deviation conversion unit for calculating the limit deviations allowed during the manufacturing process and taking them into account in the mathematical expression of the gear meshing performance requirements;

[0215] A tooth surface geometry solving unit is used to solve the tooth surface under a given actual meshing state based on the mathematical expression of the gear meshing performance requirements to obtain an initial design tooth surface;

[0216] A tooth surface geometry verification unit is used to perform a performance verification under a desired meshing state based on the initial design tooth surface to obtain an advanced design tooth surface;

[0217] The tooth surface geometry output unit is used to modify the advanced design tooth surface according to manufacturing conditions and process requirements to obtain a perfect design result. Example 4

[0218] This embodiment provides a computer-readable storage medium, including:

[0219] The storage medium is used to store computer software instructions used to implement the tooth surface forward design method for meshing performance requirements described in the above-mentioned Example 1 / Example 2, which includes a program for executing the above-mentioned tooth surface forward design method for meshing performance requirements; specifically, the executable program can be built into the tooth surface forward design device for meshing performance requirements described in Example 3, so that the tooth surface forward design device for meshing performance requirements can implement the tooth surface forward design method for meshing performance requirements described in Example 1 / Example 2 by executing the built-in executable program.

[0220] In addition, the computer-readable storage medium of this embodiment may adopt any combination of one or more computer-readable storage media, wherein the computer-readable storage medium includes electrical, optical, electromagnetic, infrared or semiconductor systems, devices or components, or any combination thereof.

[0221] Different from the existing technology, the present application adopts a tooth surface forward design method, device and medium for meshing performance requirements. Starting from the product performance requirements, the product requirements are converted into the actual meshing performance requirements of the gear. Then, forward theories such as meshing principles and elastic mechanics are used to design the tooth surface geometry according to the actual meshing performance requirements. The basic ideas from tooth surface geometry to processing and manufacturing are provided, which provides a theoretical basis for high-performance gear transmission design, solves the current situation that tooth surface geometry design relies on the experience of engineering and technical personnel, and at the same time, provides a feasible method and approach to improve gear transmission performance.

[0222] It should be understood that in the various embodiments of this document, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this document.

[0223] It should also be understood that in the embodiments herein, the term "and / or" merely describes an association between associated objects, indicating that three possible relationships exist. For example, "A and / or B" could represent: A alone, A and B simultaneously, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0224] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the composition and steps of each example according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this document.

[0225] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0226] In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices, or units, or can be an electrical, mechanical, or other form of connection.

[0227] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments herein.

[0228] In addition, the functional units in the various embodiments herein may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0229] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this article is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of this article. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0230] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A tooth surface forward design method for meshing performance requirements, characterized in that: The following steps are involved: Calculate the mathematical expression of gear mesh performance requirements; Calculate the limit deviations allowed during the manufacturing process and take into account the mathematical expression of the gear mesh performance requirements; Based on the mathematical expression of the gear meshing performance requirements, the tooth surface is solved under a given actual meshing state to obtain an initial design tooth surface; Based on the initial designed tooth surface, a performance check is performed under a desired meshing state to obtain an advanced designed tooth surface; The advanced designed tooth surface is modified according to manufacturing conditions and process requirements to obtain a perfect design result.

2. The tooth surface forward design method oriented to meshing performance requirements according to claim 1, characterized in that: The mathematical expression of calculating the gear meshing performance requirements includes: obtaining gear macro parameters, product design performance indicators, actual operating conditions of gear pairs, gear materials and heat treatment conditions, and theoretical tooth surfaces of large and small wheels, and converting them into gear meshing performance through calculation, and characterizing them mathematically to obtain the mathematical expression of the gear meshing performance requirements.

3. The method for forward design of tooth surface oriented to meshing performance requirements according to claim 2, characterized in that: The mathematical expression for calculating the gear meshing performance requirements further includes: conversion of indicators directly realized by gear transmission; conversion of boundary conditions required for gear operation; conversion of the influence of actual gear operating conditions; and conversion of gear tooth conditions themselves.

4. The tooth surface forward design method oriented to meshing performance requirements according to claim 3 is characterized by: The calculation of the limit deviation allowed in the manufacturing process and taking into account the mathematical expression of the gear meshing performance requirements includes: calculating the limit deviation value of the gear teeth and associating it with the deviation type, and converting the limit deviation value and the deviation type into input boundary conditions for calculating the gear meshing performance.

5. The method for forward design of tooth surface oriented to meshing performance requirements according to claim 4, characterized in that: The mathematical expression based on the gear meshing performance requirement is used to solve the tooth surface under a given actual meshing state to obtain the initial design tooth surface, including: matching the gear meshing performance that is consistent with the given actual meshing state in the gear meshing performance requirement, introducing the limit deviation allowed in the manufacturing process, and on this basis, using the gear meshing principle and taking the large wheel theoretical tooth surface as the basis, solving the small wheel design tooth surface.

6. The tooth surface forward design method oriented to meshing performance requirements according to claim 5, characterized in that: The mathematical expression based on the gear meshing performance requirement is used to solve the tooth surface under a given actual meshing state to obtain the initial design tooth surface, which further includes: determining the performance indicators and working conditions for the tooth surface design; analyzing the actual meshing performance indicators of the gear teeth; solving the comprehensive stiffness of the gear teeth; defining the gear motion law; solving the small wheel design tooth surface, based on the large wheel theoretical tooth surface, the gear motion law, the calculation conditions corresponding to the gear motion law, and the tooth thickness thinning amount, using the meshing principle to solve the small wheel design tooth surface.

7. The method for forward design of tooth surface oriented to meshing performance requirements according to claim 6, characterized in that: The performance is checked based on the initial designed tooth surface under the expected meshing state to obtain the advanced designed tooth surface, including: using the large wheel theoretical tooth surface and the small wheel designed tooth surface to check and calculate the gear meshing performance under the expected meshing state; if there is any situation that does not meet the product requirements, iterative calculation is performed by modifying the gear motion law and the tooth thickness reduction amount until it meets the product requirements.

8. The method for forward design of tooth surface oriented to meshing performance requirements according to claim 7, characterized in that: The advanced designed tooth surface is modified according to manufacturing conditions and process requirements to obtain a perfect design result, including: Select the processing conditions and technology of the designed gear; based on the principle that the instantaneous meshing characteristics of the tooth surface remain unchanged, the tooth thickness reduction amount of each meshing phase is distributed between large and small according to the selected processing conditions and technology; According to the selected processing conditions and processes, determine the limit deviation of the tooth surface geometry during the manufacturing process, and use the tooth surface geometry containing the limit deviation to check and calculate the performance index; if it cannot meet the requirements, reselect the processing conditions or processes; if it can meet the requirements, give the allowable limit deviation of the tooth surface geometry; Integrate the tooth surface geometry, limit deviation, corresponding processing conditions and process requirements to obtain and output the perfect design result.

9. A tooth surface forward design device for meshing performance requirements, characterized in that: include: Mathematical expression calculation unit, used to calculate the mathematical expression of gear meshing performance requirements; A limit deviation conversion unit for calculating the limit deviations allowed during the manufacturing process and taking into account the mathematical expression of the gear meshing performance requirements; A tooth surface geometry solving unit, used for solving the tooth surface under a given actual meshing state based on the mathematical expression of the gear meshing performance requirements, to obtain an initial design tooth surface; A tooth surface geometry verification unit, used to perform a performance verification under a desired meshing state based on the initial design tooth surface to obtain an advanced design tooth surface; The tooth surface geometry output unit is used to modify the advanced designed tooth surface according to manufacturing conditions and process requirements to obtain a perfect design result.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the tooth surface forward design method for meshing performance requirements described in any one of claims 1 to 8 are implemented.

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