A method, system and device for measuring dynamic stress of a bevel gear with small size

Abstract

The application discloses a small-size bevel gear dynamic stress measurement method, system and equipment, belongs to the technical field of stress testing, and the small-size bevel gear dynamic stress measurement method comprises the following steps: determining the geometric size similarity ratio of a bevel gear; determining the similarity ratio of each parameter of the bevel gear according to the dynamic similarity theory and the geometric size similarity ratio, and obtaining a bevel gear model; determining the patch position of a strain gauge based on the bevel gear model; and performing dynamic stress measurement on the bevel gear model. The application adopts the dynamic similarity theory, constructs a geometrically similar bevel gear model, verifies the dynamic similarity relationship through finite element calculation, and provides a theoretical basis for dynamic characteristic test of a small-size, high-speed bevel gear.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of stress testing, and particularly relates to a small-size bevel gear dynamic stress measurement method, system and device. BACKGROUND

[0002] The bevel gear is also commonly known as a bevel gear, and is commonly used in industrial transmission fields such as vehicles, ships and aerospace, and has the characteristics of long service life, light weight, low cost, strong load capacity and shock and noise reduction. With the development of gear transmission towards high speed and heavy load, the problem of vibration and noise of bevel gears is becoming increasingly serious, and the failure of bevel gears caused by resonance is also becoming more and more serious, so it is more and more important to reasonably avoid resonance or take corresponding measures to reduce vibration and noise within the working speed range of the bevel gear. The vibration design and analysis of the bevel gear is the basis for the design, optimization and development of the bevel gear, and provides protection for high-precision transmission of the bevel gear.

[0003] The bevel gear often has a pitch diameter resonance danger within the working speed range, and the vibration failure of the gear is also becoming more and more serious, and the measurement of the dynamic stress of the gear by attaching a strain gauge is an effective method to judge whether the gear has a failure caused by resonance. Although the dynamic stress measurement technology has become mature, but due to the small size of some bevel gears, the strain gauge cannot be directly attached for measurement, and how to measure the dynamic stress of such gears to evaluate their high-cycle fatigue resistance has not been solved. SUMMARY

[0004] In view of the above problems, the application discloses a small-size bevel gear dynamic stress measurement method, comprising the following steps:

[0005] Determine the geometric size similarity ratio of the bevel gear;

[0006] According to the dynamic similarity theory and the geometric size similarity ratio, determine the similarity ratio of each parameter of the bevel gear, and obtain a bevel gear model;

[0007] Based on the bevel gear model, determine the attachment position of the strain gauge;

[0008] Measure the dynamic stress of the bevel gear model.

[0009] Further, the step of determining the similarity ratio of each parameter of the bevel gear according to the dynamic similarity theory and the geometric size similarity ratio to obtain the bevel gear model comprises the following steps:

[0010] Determine the similarity criterion based on the equation analysis method and the dynamic similarity theory;

[0011] Determine the similarity ratio of each parameter of the bevel gear based on the similarity criterion and the geometric size similarity ratio;

[0012] Determine the bevel gear model based on the similarity ratio of each parameter.

[0013] Further, the similarity ratios of the respective parameters include a mass similarity ratio, a damping similarity ratio, a stiffness similarity ratio, a force similarity ratio, a displacement similarity ratio, a time similarity ratio, a density similarity ratio, an elastic modulus similarity ratio, an excitation frequency similarity ratio, a natural frequency similarity ratio, a velocity similarity ratio, an acceleration similarity ratio, a rotational speed similarity ratio, and a stress similarity ratio.

[0014] Further, the similarity criterion is determined by the following equation:

[0015]

[0016] wherein A C is a damping similarity ratio; A F is a force similarity ratio; A t is a time similarity ratio; A l is a geometric dimension similarity ratio; A ρ is a density similarity ratio; A E is an elastic modulus similarity ratio.

[0017] Further, the geometric dimension similarity ratio A l = λ;

[0018] The mass similarity ratio A M = λ 3 ;

[0019] The damping similarity ratio A C = λ 2 ;

[0020] The stiffness similarity ratio A K = λ;

[0021] The force similarity ratio A F = λ 2 ;

[0022] The displacement similarity ratio A X = λ;

[0023] The time similarity ratio A t = λ;

[0024] The density similarity ratio A ρ = 1;

[0025] The elastic modulus similarity ratio A E = 1;

[0026] The excitation frequency similarity ratio A f = 1 / λ;

[0027] The natural frequency similarity ratio A ω = 1 / λ;

[0028] The velocity similarity ratio A v = 1;

[0029] Acceleration similarity ratio A a =1 / λ;

[0030] similarity ratio of rotational speed A Ω =1 / λ;

[0031] Stress similarity ratio A σ =1;

[0032] Where λ is the magnification factor of the bevel gear.

[0033] Furthermore, the requirements for the placement of the strain gauge are as follows:

[0034] The ratio of the patch position coordinates of the strain gauge in the bevel gear model to the patch position coordinates of the original bevel gear strain gauge is the geometric similarity ratio, and the strain gauge patching directions are consistent.

[0035] Furthermore, the patch position sensitivity of the strain gauge is determined by the following formula:

[0036]

[0037] Among them, (σ i ) cs The stress in the patch direction; σ eqv σ1 is the equivalent stress; σ2 is the maximum principal stress; σ3 is the minimum principal stress.

[0038] This invention also discloses a dynamic stress measurement system for small-sized bevel gears, comprising:

[0039] Geometric similarity ratio unit, used to determine the geometric similarity ratio of bevel gears;

[0040] The bevel gear model unit is used to determine the similarity ratio of each parameter of the bevel gear based on the dynamic similarity theory and the geometric similarity ratio, so as to obtain the bevel gear model;

[0041] The patch position unit is used to determine the patch position of the strain gauge based on the bevel gear model;

[0042] The measuring unit is used to measure the dynamic stress of the bevel gear model.

[0043] Furthermore, the bevel gear model unit is specifically used for:

[0044] Based on equation analysis and dynamic similarity theory, similarity criteria are determined;

[0045] Based on similarity criteria and geometric similarity ratios, the similarity ratios of various parameters of the bevel gear are determined;

[0046] The bevel gear model is determined based on the similarity ratio of each parameter.

[0047] The present invention also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for measuring the dynamic stress of small-sized bevel gears.

[0048] Compared with the prior art, the embodiments of the present invention have at least the following advantages: a dynamic stress measurement method for small-sized bevel gears is proposed, and since the dynamic stress distribution on the bevel gear has a gradient change, after the bevel gear model is enlarged, the stress gradient change on the same area is smaller than the stress gradient change of the original bevel gear. Therefore, the measured dynamic stress data is more accurate, and the dynamic stress data can be used for high-cycle fatigue life assessment of bevel gears; a geometrically similar bevel gear model is constructed using a dynamic similarity method, and its dynamic similarity relationship is verified by finite element calculation. The results provide a theoretical basis for dynamic characteristic tests of small-sized, high-speed bevel gears.

[0049] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 A flowchart of a method for measuring the dynamic stress of small-sized bevel gears according to an embodiment of the present invention is shown;

[0052] Figure 2 A Campbell's diagram of a bevel gear according to an embodiment of the present invention is shown;

[0053] Figure 3 A Campbell diagram of a bevel gear model according to an embodiment of the present invention is shown;

[0054] Figure 4 The diagram shows the dynamic stress contour plot of a 7-section diameter according to an embodiment of the present invention;

[0055] Figure 5 A schematic diagram of the patch position with a 7-section diameter is shown according to an embodiment of the present invention;

[0056] Figure 6 A schematic diagram of a small-sized bevel gear dynamic stress measurement system according to an embodiment of the present invention is shown. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Figure 1 A flowchart illustrating a method for measuring the dynamic stress of small-sized bevel gears according to an embodiment of the present invention is shown. Figure 1 As shown, the present invention proposes a method for measuring the dynamic stress of small-sized bevel gears, comprising the following steps:

[0059] Step 1: Based on the vibration characteristic analysis results of the bevel gear, the rotational speed that the drive equipment can handle, the transmission relationship of the bevel gear pair, the requirements for dynamic stress test patches, and the dynamic similarity theory, determine the geometric amplification factor of the bevel gear, i.e., the geometric similarity ratio A. l :

[0060] To perform dynamic stress measurement on the bevel gear and meet the patching requirements, the bevel gear needs to be enlarged. Based on the dynamic similarity theory, the magnification factor of the bevel gear, i.e., the geometric similarity ratio A, needs to be determined. l =λ, λ>1. The geometric dimensions of the bevel gear model to be tested are λ times the geometric dimensions of the original bevel gear.

[0061] Based on the theory of dynamic similarity, a gear that meshes with a bevel gear in actual operation is enlarged to resemble the bevel gear. The enlargement ratio is the same as that of the bevel gear, and its geometric similarity ratio is A. l =λ, λ>1. Only the web and gear teeth are required to be enlarged similarly to simulate gear meshing and web load transmission. The gear shaft can adopt a universal design to facilitate installation and drive equipment rotation and power input.

[0062] The enlarged bevel gear pair has the same meshing relationship as the original bevel gear pair, and they have the same transmission ratio. According to the theory of dynamic similarity, the speed similarity ratio A... Ω = 1 / λ. The rotational speed of the bevel gear model to be tested is 1 / λ times the rotational speed of the original bevel gear. The test bevel gear and the bevel gear model to be tested have the same rotational speed similarity ratio. That is, the larger the model magnification, the smaller the required rotational speed of the drive equipment. Therefore, the geometric similarity ratio also needs to be determined according to the rotational speed that the drive equipment can handle.

[0063] Step 2: Based on vibration characteristic analysis, dynamic similarity theory, geometric similarity ratio, material selection, etc., determine the similarity ratio of other parameters of the bevel gear to obtain the bevel gear model;

[0064] The enlarged bevel gear model to be tested is made of the same material as the original bevel gear; therefore, the similarity ratios of material density and elastic modulus are A. ρ =1 and A E =1. The mechanical property parameters of the bevel gear model to be tested are consistent with the mechanical property parameters of the original bevel gear material.

[0065] The enlarged test bevel gear has no material requirements and can use similar low-cost materials.

[0066] According to the dynamic similarity theory, the natural frequency similarity ratio A ω = 1 / λ. The natural frequency of the bevel gear model to be tested is 1 / λ times the natural frequency of the original bevel gear.

[0067] According to the theory of dynamic similarity, the similarity ratio of resonant rotational speeds is the same as the similarity ratio A of gear rotational speeds. Ω = 1 / λ. The resonant speed of the bevel gear model to be tested is 1 / λ times the resonant speed of the original bevel gear.

[0068] According to the dynamic similarity theory, the stress similarity ratio A σ =1. The stress distribution of the bevel gear model to be tested is consistent with the stress distribution of the original bevel gear, and the stress magnitudes at the corresponding positions are the same.

[0069] Dynamic similarity is a method for predicting the dynamic characteristics of a prototype using similar models. Dimensional analysis or equation analysis is typically used to determine similarity criteria. Dimensional analysis uses basic units of measurement to express the derived units of measurement. This method examines the dimensions of each physical quantity during the study of similarity problems, and its theoretical basis is the theory of dimensional homogeneous equations. Equation analysis, on the other hand, uses consistent differential equations, integral equations, or physical equations to solve for similarity criteria when the mathematical equations of the physical model are known. This invention uses equation analysis to theoretically derive similarity criteria, thereby obtaining the similarity relationships between various physical quantities.

[0070] The differential equation of motion of a multi-degree-of-freedom system under the action of an external force F(t) is:

[0071]

[0072] Where M is mass; t is time; C is damping; K is stiffness; X is displacement; and F is force.

[0073] Now, let n denote the original bevel gear and m denote the bevel gear model. The kinematic differential equations for the original bevel gear and the bevel gear model are:

[0074]

[0075] Now let's use A respectivelyM A C A K A F A X A t A l A ρ A E A f A ω These represent the mass similarity ratio, damping similarity ratio, stiffness similarity ratio, force similarity ratio, displacement similarity ratio, time similarity ratio, geometric dimension similarity ratio, density similarity ratio, elastic modulus similarity ratio, excitation frequency similarity ratio, and natural frequency similarity ratio, respectively. A v A a A Ω A σ Let represent the velocity similarity ratio, acceleration similarity ratio, rotational speed similarity ratio, and stress similarity ratio, respectively. Then we have:

[0076]

[0077] Based on the relationships between the various physical quantities:

[0078] M = ρV, then we have

[0079] A X =A l ;

[0080] F = KX = ES, then A F =A K A X =A E A S =A E A l 2 .

[0081] Where ρ is density; V is volume; E is elastic modulus; S is area; A S This represents the area similarity ratio.

[0082] Simplifying equation (4), we get:

[0083]

[0084] Based on equations (3) and (5), in order to make the models similar, the following similarity criteria can be obtained:

[0085]

[0086] Typically, bevel gear models are made of the same material as the original bevel gear, so there is A. E =A ρ=1, this paper assumes that the geometric similarity ratio A of the bevel gears is 1. l =λ, we can get:

[0087] A l =λ, A t =λ, A c =λ 2 (7)

[0088] System speed similarity ratio A v Similarity ratio with acceleration A a The following relationship must be satisfied:

[0089] A v =1,

[0090] Furthermore, based on the relationship between stress and load, and the relationship between rotational speed and velocity, the stress similarity ratio A can be determined. σ Similarity ratio with rotational speed A Ω The following relationship must be satisfied:

[0091] A σ =1, A Ω =1 / λ(9)

[0092] In summary, the similarity ratios of each physical quantity in the dynamic similarity design can be obtained, as shown in Table 1, thus obtaining the bevel gear model.

[0093] A geometrically similar bevel gear model was constructed using a dynamic similarity method, and its dynamic similarity relationship was verified by finite element calculation. The results provide a theoretical basis for dynamic characteristic tests of small-sized, high-speed bevel gears.

[0094] Thus, the inherent characteristics and response of the structure designed based on the above similarity ratios should satisfy the similarity relationships given in Table 1.

[0095] Table 1 Parameter Similarity Ratio

[0096]

[0097] Where λ is the magnification factor of the bevel gear.

[0098] Step 3: Based on vibration characteristic analysis, dynamic similarity theory, and bevel gear model, determine the strain gauge placement location and perform sensitivity analysis;

[0099] According to the theory of dynamic similarity, the ratio of the strain gauge patch position coordinates of the bevel gear model to the original bevel gear strain gauge patch position coordinates is the geometric similarity ratio λ, and the strain gauge patching directions are consistent.

[0100] According to the theory of dynamic similarity, the sensitivity of the dynamic stress test patch position of the bevel gear model to be tested is consistent with the sensitivity of the dynamic stress measurement patch position of the original bevel gear.

[0101] The sensitivity of the strain gauge patch position is determined by the following formula:

[0102]

[0103] Among them, (σ i ) cs The stress in the patch direction; σ eqv σ1 is the equivalent stress; σ2 is the maximum principal stress; σ3 is the minimum principal stress.

[0104] According to the theory of dynamic similarity, the maximum dynamic stress of the bevel gear model under test is the same as the maximum dynamic stress of the original bevel gear.

[0105] Since the strain gauges are of a fixed size, the stress gradient change on the same area of ​​the bevel gear model under test is smaller than that of the original bevel gear, thus the measured dynamic stress data are more accurate.

[0106] Step 4: Perform dynamic stress measurement on the bevel gear model;

[0107] The dynamic stress measurement test is carried out by a drive device that drives a transmission shaft, which in turn drives the test bevel gear to rotate. This drives the bevel gear model to be tested through meshing. A patch is attached to the bevel gear model to be tested, and the dynamic stress test system is connected to measure the dynamic stress. Based on the sensitivity of the patch position, the maximum dynamic stress is calculated and the resonance pitch diameter order is determined.

[0108] The maximum dynamic stress and resonance pitch diameter order obtained from the actual measurement of the bevel gear model to be tested are the same as the maximum dynamic stress and resonance pitch diameter order of the original bevel gear.

[0109] The test results can be used to assess the high-cycle fatigue life of bevel gears.

[0110] like Figure 6 As shown, based on the above-described method for measuring the dynamic stress of small-sized bevel gears, this embodiment proposes a dynamic stress measurement system for small-sized bevel gears, comprising:

[0111] Geometric similarity ratio unit, used to determine the geometric similarity ratio of bevel gears;

[0112] The bevel gear model unit is used to determine the similarity ratio of each parameter of the bevel gear based on the dynamic similarity theory and the geometric similarity ratio, so as to obtain the bevel gear model;

[0113] The patch position unit is used to determine the patch position of the strain gauge based on the bevel gear model;

[0114] The measuring unit is used to measure the dynamic stress of the bevel gear model.

[0115] In some embodiments, the bevel gear model unit is specifically used for:

[0116] Based on equation analysis and dynamic similarity theory, similarity criteria are determined;

[0117] Based on similarity criteria and geometric similarity ratios, the similarity ratios of various parameters of the bevel gear are determined;

[0118] The bevel gear model is determined based on the similarity ratio of each parameter.

[0119] The present invention also proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for measuring the dynamic stress of small-sized bevel gears.

[0120] The present invention also proposes a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-described method for measuring the dynamic stress of a small-sized bevel gear.

[0121] The bevel gear of a certain type of aero-engine reduction transmission has the characteristics of small structural size and high speed. Vibration characteristic analysis results show that it has the risk of pitch diameter type resonance within the operating speed range.

[0122] A prototype bevel gear was established, and its geometry was enlarged by a factor of 2.0, resulting in a 2.0 bevel gear model. The vibration characteristics analysis results of the prototype and the 2.0 bevel gear model are shown in Table 2. Furthermore, based on the similarity relationships in Table 1, the rotational speed similarity ratio of the 2.0 bevel gear model is 0.5. The Campbell plots of the two models are shown below. Figure 2 and Figure 3 As can be seen from the figure, the prototype bevel gear and the 2.0 bevel gear model have the same vibration order in terms of pitch diameter, and the frequency and resonant speed satisfy the similarity ratio. The resonant speeds within the operating speed range are shown in Table 3.

[0123] Table 2 Results of Gear Vibration Characteristic Analysis

[0124]

[0125] Table 3 Gear Resonance Speed

[0126]

[0127] Based on the analysis results of the vibration characteristics of the gears and the resonant speed, they all satisfy the similarity relationship, that is, the modes are similar. The frequencies and resonant speeds of the gears in the 2.0 bevel gear model are 0.5 times those of the prototype.

[0128] Bevel gears are susceptible to resonance in their operating speed range. In engineering, dynamic stress is often measured experimentally to assess their resistance to high-cycle fatigue. However, due to the small size of the prototype bevel gear, dynamic stress measurement is inconvenient. This invention uses dynamic similarity theory to enlarge the geometric dimensions of the bevel gear and uses similarity criteria to reflect the dynamic characteristics of the prototype bevel gear model. The dynamic stress cloud diagrams of the 7-pitch diameter bevel gear and bevel gear model in the operating speed range where resonance is a risk are shown below. Figure 4 As shown. Figure 4 (a) is the dynamic stress cloud diagram of the prototype bevel gear with a 7-pitch diameter; Figure 4 (b) is the dynamic stress cloud diagram of the 7 pitch diameter of the bevel gear model.

[0129] like Figure 4 (a) Figure 4 As shown in (b), the dynamic stress cloud diagrams of the pitch diameter of the prototype bevel gear and the 2.0 bevel gear model show that their dynamic stress distributions are completely similar, and the sensitivity at each location is also consistent. According to the stress similarity ratio in Table 1, the measured dynamic stress value at the patch position of the bevel gear model during the dynamic stress measurement test is the dynamic stress at the corresponding position on the prototype bevel gear.

[0130] In addition, since the dynamic stress distribution on the bevel gear has a gradient change, the stress gradient change on the same area after the model is enlarged is smaller than the stress gradient change of the prototype bevel gear, so the measured dynamic stress data is more accurate.

[0131] Figure 5 (a) is a schematic diagram of the patch position for the 7-pitch diameter prototype bevel gear. Figure 5 (b) is a schematic diagram showing the location of the 7-pitch diameter patch on the bevel gear model. For example... Figure 5 (a) and Figure 5 As shown in (b), the strain gauge application direction for both is circumferential. The calculated results of the strain gauge application position sensitivity for the prototype bevel gear and the bevel gear model are shown in Table 4. The strain gauge application ratio for both is the geometric similarity ratio, and their sensitivity is consistent.

[0132] Table 4. Calculation results of patch location sensitivity (taking 7-section diameter as an example)

[0133]

[0134] This invention addresses the issue of the small size of a certain type of engine's bevel gear structure by conducting dynamic similarity design and research. The finite element calculation results show that the dynamic characteristics of the geometrically similar bevel gear model satisfy the corresponding similarity relationship, and the geometrically enlarged bevel gear model can reduce the influence of stress gradient changes on dynamic stress measurement data.

[0135] The dynamic similarity design results of this invention provide a theoretical basis for the dynamic stress test of the bevel gear. In engineering, dynamic similarity design can be used to accurately predict the dynamic characteristics of the prototype bevel gear, which is highly practical and has a wide range of applications.

[0136] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the dynamic stress of small-sized bevel gears, characterized in that, Includes the following steps: Determine the geometric magnification factor of the bevel gear, i.e., the geometric similarity ratio; Based on the dynamic similarity theory and the geometric similarity ratio, the similarity ratio of each parameter of the bevel gear is determined, and the bevel gear model is obtained. Based on the bevel gear model, the placement position of the strain gauge is determined; Dynamic stress measurement was performed on the bevel gear model; The process of determining the similarity ratio of each parameter of the bevel gear based on dynamic similarity theory and geometric similarity ratio to obtain the bevel gear model includes the following steps: Based on equation analysis and dynamic similarity theory, similarity criteria are determined; Based on similarity criteria and geometric similarity ratios, the similarity ratios of various parameters of the bevel gear are determined; Based on the similarity ratio of each parameter, the bevel gear model is determined; The similarity criterion is determined by the following formula: in, For damping similarity ratio; For force similarity ratio; For time similarity ratio; The geometric similarity ratio; The density similarity ratio; This represents the similarity ratio of elastic modulus.

2. The method for measuring the dynamic stress of small-sized bevel gears according to claim 1, characterized in that, The similarity ratios of the various parameters include mass similarity ratio, damping similarity ratio, stiffness similarity ratio, force similarity ratio, displacement similarity ratio, time similarity ratio, density similarity ratio, elastic modulus similarity ratio, excitation frequency similarity ratio, natural frequency similarity ratio, velocity similarity ratio, acceleration similarity ratio, rotational speed similarity ratio, and stress similarity ratio.

3. The method for measuring the dynamic stress of small-sized bevel gears according to claim 2, characterized in that, The geometric similarity ratio = ; Quality similarity ratio = ; Damping similarity ratio = ; Stiffness similarity ratio = ; Force similarity ratio ; Displacement similarity ratio = ; Time similarity ratio = ; Density similarity ratio =1; Elastic modulus similarity ratio =1; Excitation frequency similarity ratio = ; Natural frequency similarity ratio = ; Speed ​​similarity ratio =1; Acceleration similarity ratio = ; similarity ratio of rotational speed = ; Stress similarity ratio =1; in, This is the magnification factor of the bevel gear.

4. The method for measuring the dynamic stress of small-sized bevel gears according to claim 1, characterized in that, The requirements for the placement of the strain gauges are as follows: The ratio of the patch position coordinates of the strain gauge in the bevel gear model to the patch position coordinates of the original bevel gear strain gauge is the geometric similarity ratio, and the strain gauge patching directions are consistent.

5. The method for measuring the dynamic stress of small-sized bevel gears according to claim 1, characterized in that, The sensitivity of the strain gauge patch position is determined by the following formula: in, This refers to the stress in the patch direction; Equivalent stress; This is the maximum principal stress; It is the minimum principal stress.

6. A dynamic stress measurement system for small-sized bevel gears, characterized in that, include: The geometric similarity ratio unit is used to determine the geometric magnification factor of the bevel gear, i.e., the geometric similarity ratio. The bevel gear model unit is used to determine the similarity ratio of each parameter of the bevel gear based on the dynamic similarity theory and the geometric similarity ratio, so as to obtain the bevel gear model; The patch position unit is used to determine the patch position of the strain gauge based on the bevel gear model; The measurement unit is used to measure the dynamic stress of the bevel gear model. The bevel gear model unit is specifically used for: Based on equation analysis and dynamic similarity theory, similarity criteria are determined; Based on similarity criteria and geometric similarity ratios, the similarity ratios of various parameters of the bevel gear are determined; Based on the similarity ratio of each parameter, the bevel gear model is determined; The similarity criterion is determined by the following formula: in, For damping similarity ratio; For force similarity ratio; For time similarity ratio; The geometric similarity ratio; The density similarity ratio; This represents the similarity ratio of elastic modulus.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for measuring the dynamic stress of small-sized bevel gears as described in any one of claims 1-5.

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