CN-122020892-A - Noise prediction method and system for gear transmission system

CN122020892ACN 122020892 ACN122020892 ACN 122020892ACN-122020892-A

Abstract

The invention discloses a noise prediction method, a system, equipment and a medium of a gear transmission system, and relates to the technical field of vehicle NVH. The method aims at solving the problems that in the prior art, the gear noise prediction model is complex in calculation and difficult to quantitatively evaluate the influence of microscopic modification and dislocation quantity. The method comprises the steps of determining meshing stiffness of the bevel gear pair by utilizing a straight gear stiffness model integration based on a slicing method, determining vibration displacement by utilizing a vibration displacement model considering tooth direction drum shape quantity, tooth form drum shape quantity, tooth top trimming quantity and dislocation quantity, and finally calculating an overall noise value based on a noise prediction model comprising macroscopic parameters, power and vibration displacement. According to the invention, through theoretical deduction and combined test correction, the quick and accurate prediction of the noise of the helical gear of the electric drive assembly is realized, and the gear shape correction design can be effectively guided.

Inventors

QIAO MENG
XU CHENG
Zhang Feibing
HAN TAO

Assignees

智新科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260121

Claims (10)

1. A method of noise prediction for a gear train, comprising: determining the meshing stiffness of the bevel gear pair along a contact line integral based on a discretization slicing principle by using a spur gear meshing stiffness model with unit tooth width; Determining vibration displacement by utilizing a vibration displacement model based on deformation quantity, microcosmic modification parameters and dislocation quantity of the gear pair at the index circle under load, wherein the vibration displacement represents the difference between the actual meshing position and the ideal meshing position of the gear pair after correction; substituting the vibration displacement amount, the geometric parameters of the gear pair and the working condition parameters into a gear noise prediction model to obtain the overall noise value of the gear transmission system, wherein the gear noise prediction model comprises a macroscopic parameter contribution part, a power contribution part and a vibration displacement contribution part.
2. The method of claim 1, wherein the spur gear engagement stiffness model per unit tooth width is expressed as: Wherein, C th is the rigidity value of the unit tooth width, C is the rigidity reference value of the unit tooth width, K f is the end amplification factor, X pos is the non-dimensionalized meshing position coordinate, and the value range is 0 to 1.
3. The noise prediction method of a gear transmission system according to claim 2, wherein the meshing stiffness of the helical gear pair is obtained by equally dividing the gear pair into N sheets in the tooth width direction, regarding each sheet as a spur gear, and integrating by using the line of contact of the spur gear meshing stiffness model and a helical gear; The calculation formula of the meshing rigidity of the bevel gear pair is as follows: wherein K total is the meshing rigidity of the bevel gear pair, L t is the contact line length of the bevel gear pair, W is the width of the gear, and beta is the helix angle.
4. The method of claim 1, wherein the parameters in the vibration displacement model satisfy the following relationship: Wherein CP is the comprehensive deformation quantity of the reference circle, X is the vibration displacement quantity, namely the pre-shaping variable, C β is the tooth direction drum quantity, e is the dislocation quantity, T p is the tooth crest trimming quantity, and C α is the tooth shape drum quantity.
5. The method for predicting noise in a gear train according to claim 4, wherein the process of determining the vibration displacement amount specifically includes: establishing a coordinate system, wherein an X axis is along an axial direction, and a Y axis is along a pressure angle direction; approximating the bevel gear to N straight gear slices with the same end surface parameters; calculating the comprehensive deformation CP of each spur gear slice at the reference circle, and further obtaining the deformation of the helical gear at the contact position; and correcting the deformation amount until the deformation amount is equal by comparing the sum of the deformation amounts and the rigidity product and the load of the bevel gear, so as to determine the vibration displacement amount X.
6. The method of claim 1, wherein the specific formula of the gear noise prediction model is: Wherein L is the total noise value, K is the speed coefficient, beta is the helix angle, mu is the speed ratio, epsilon α is the end face overlap ratio, P is the input power, X max is the maximum value of vibration displacement amplitude distributed on the meshing line, and W corr is the correction coefficient.
7. The method according to claim 6, wherein the correction factor W corr is a constant value determined by experiment according to the inherent characteristics of different gear box structures, and the speed factor K is a factor related to the rotational speed derived by experiment.
8. The method of claim 1 to 7, wherein the gear pair is a reduction gear bevel gear pair in an electric drive assembly of an electric vehicle.
9. A noise prediction system for a gear train, comprising: the rigidity calculation module is used for determining the meshing rigidity of the bevel gear pair along a contact line integral based on a discretization slicing principle by utilizing a spur gear meshing rigidity model with unit tooth width; The displacement calculation module is used for determining the vibration displacement by utilizing a vibration displacement model based on the deformation quantity, the microcosmic modification parameter and the dislocation quantity of the gear pair at the index circle under load, and the vibration displacement represents the difference value between the actual meshing position and the ideal meshing position of the gear pair after modification; And the noise prediction module is used for substituting the vibration displacement quantity, the geometric parameters of the gear pair and the working condition parameters into a gear noise prediction model to obtain the total noise value of the gear transmission system, wherein the gear noise prediction model comprises a macroscopic parameter contribution part, a power contribution part and a vibration displacement contribution part.
10. The noise prediction system of a gear train of claim 9 wherein the noise prediction module employs a noise prediction model formula of: Wherein L is the total noise value, K is the speed coefficient, beta is the helix angle, mu is the speed ratio, epsilon α is the end face overlap ratio, P is the input power, X max is the maximum value of vibration displacement amplitude distributed on the meshing line, and W corr is the correction coefficient.

Description

Noise prediction method and system for gear transmission system Technical Field The invention relates to the technical field of vehicle engineering and NVH (noise, vibration and harshness), in particular to a noise prediction method and a system of an electric drive assembly gear transmission system. Background Electric automobiles are the main stream of development in the automotive industry. Because of the trend of light weight and power density improvement of the electric drive system, the NVH problem of the gears becomes particularly important, and becomes a key factor for restricting the power density and the rotation speed improvement of the electric automobile drive system. Vibration of the gear system is mainly caused by transmission errors caused by time-varying rigidity of gear tooth engagement, machining errors, installation errors, deformation of a box body and the like, and the factors cause periodic fluctuation of impact and speed load of gear tooth engagement and gear tooth engagement, so that excitation vibration is formed. If a pair of involute gears of ideal shape and infinite stiffness are engaged, the rotation angle of the driven gear will be kept consistent with the rotation angle of the driving gear strictly according to the ratio of the two gears, and the noise will tend to be small. However, in fact, due to errors such as gear manufacturing errors, assembly errors, load deformations of the reducer system, and load deformations of the gears, the passive gear angle will lead or lag its theoretical angle position at different moments, which becomes a gear transmission error. The larger the amplitude of the gear transmission error is used as an internal excitation source of the gear system, the larger the vibration and noise are. In the prior art, the following methods and defects of the gear noise prediction mainly exist: 1. The finite element method and the boundary element method can solve the vibration and noise of a single-stage straight gear box to obtain a sound field of the gear box, but the method is mainly limited to straight gears, has very complex modeling process and large calculation amount, and is difficult to be rapidly applied to a helical gear transmission system with a more complex structure. 2. A simple empirical formula is that a model is used for connecting the noise intensity with the tooth width and the meshing frequency only, and the vibration amplitude is regarded as dynamic transmission error. The other is to establish a linear regression equation through experiments. These methods have difficulty finding a simple and accurate predictive model because gear noise is affected by various factors such as tooth profile deviation, transmitted power, etc. 3. The existing empirical formula based on the genetic algorithm usually only depends on gear machining errors, and is insufficient to cover the noise level of the whole transmission system. The influence of other core parameters of the gear, such as the contact ratio, the tooth top coefficient and the like, on noise is not fully mentioned, and the influence of the dislocation amount of the gear transmission system is not considered, so that the whole noise model cannot reflect the real situation. In summary, most of the current researches are based on the conventional gear meshing theory, when analyzing the influence of the transmission error, only the error is processed into a complex integrated error, specific researches and analyses are not performed on each component error (such as tooth shape, tooth direction modification, dislocation amount, etc.), and meanwhile, the quantitative relation between the transmission error and the gear meshing transmission is not studied deeply. Therefore, there is a need for a gear noise prediction method that combines macroscopic and microscopic parameters, takes into account the offset effects, and is computationally efficient. Disclosure of Invention The invention provides a noise prediction method, a system, equipment and a medium for a gear transmission system, aiming at solving the technical problems that a gear noise prediction model in the prior art is complex in calculation, micro-modification parameters and offset cannot be quantitatively evaluated to influence noise, and prediction accuracy is insufficient. To solve the above technical problem, in a first aspect, the present invention provides a noise prediction method of a gear transmission system, including: determining the meshing stiffness of the bevel gear pair along a contact line integral based on a discretization slicing principle by using a spur gear meshing stiffness model with unit tooth width; Determining vibration displacement by utilizing a vibration displacement model based on deformation quantity, microcosmic modification parameters and dislocation quantity of the gear pair at the index circle under load, wherein the vibration displacement represents the difference between the actual meshing position an