Gear transmission error fast calculation method

Abstract

The application discloses a kind of gear transmission error fast calculation methods, comprising: obtaining the angle signal of each transmission shaft in transmission system;Convert angle signal into radian;Calculate the arc length corresponding to driving gear and driven gear;The arc length difference of driving gear and driven gear is calculated as overall transmission error;After the FFT analysis of overall transmission error, the corresponding transmission error of driving gear and driven gear is extracted.The gear transmission error fast calculation method of the application combines transmission error theory, realizes equivalent analysis micro transmission error from macroscopic angle, which widens transmission error calculation method, and has very strong engineering application value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gear transmission error calculation, and particularly relates to a gear transmission error rapid calculation method. BACKGROUND

[0002] As one of the most common transmission forms, gear transmission is widely used in various fields. Due to the existence of factors such as manufacturing error, assembly error and elastic deformation of gear meshing, transmission error exists in the process of gear meshing. Transmission error has always been one of the important indicators for characterizing the dynamic excitation of the gear transmission system. The definition of transmission error is the difference between the actual angle of the driven gear and the theoretical angle when the driving gear rotates through a certain angle. The so-called theoretical angle refers to the angle of the ideal gear without error when the elastic deformation is not considered.

[0003] At present, the calculation methods of gear transmission error mainly include two types: one is to build a CAE model and then perform simulation analysis; the other is to build a transmission error test bench in the laboratory, to arrange pulse encoders at the input and output ends of the gear to read the rotation speed, and then to perform static transmission error test under the test conditions of low speed and stable load, which is relatively harsh. SUMMARY

[0004] The application provides a gear transmission error rapid calculation method to solve the above technical problems, and specifically adopts the following technical scheme:

[0005] A gear transmission error rapid calculation method, comprising the following steps:

[0006] Obtaining the angle signal of each transmission shaft in the transmission system;

[0007] Converting the angle signal into radian;

[0008] Calculating the corresponding arc length of the driving gear and the driven gear;

[0009] Calculating the arc length difference of the driving gear and the driven gear as the overall transmission error;

[0010] After FFT analysis of the overall transmission error, the corresponding transmission error of the driving gear and the driven gear is extracted.

[0011] Further, the specific method for obtaining the angle signal of each transmission shaft in the transmission system is as follows:

[0012] A corresponding high-precision rotation speed sensor is configured for each transmission shaft in the transmission system;

[0013] In the test process, the voltage signal of each high-precision rotation speed sensor is obtained;

[0014] convert the voltage signal into the angle signal.

[0015] Further, the specific method for obtaining the angle signal of each transmission shaft in the power train is:

[0016] A corresponding high-precision rotational speed sensor is configured for part of the transmission shafts in the power train;

[0017] During the test, the voltage signal of each high-precision rotational speed sensor is obtained;

[0018] convert the voltage signal into the angle signal;

[0019] The angle signal of the transmission shaft without the high-precision rotational speed sensor is obtained by speed ratio conversion.

[0020] Further, the specific method for obtaining the voltage signal of each high-precision rotational speed sensor during the test is:

[0021] Make the power train work in light load, medium load, high load and reverse drag conditions respectively to collect voltage signals, and select accurate original signals from the collected data.

[0022] Further, the light load, the medium load and the high load are 20% load, 50% load and 100% load respectively.

[0023] Further, the power train is a vehicle reducer, the reducer is respectively engaged in each gear, and the vehicle under each gear is respectively accelerated by 20% throttle, 50% throttle and full throttle, and reverse drag test is performed, each test condition is tested multiple times, and the voltage pulse signal of each transmission shaft is collected, and accurate original signals are selected from the collected data.

[0024] Further, during the conversion of the angle signal into radian, the angle signal is first high-pass filtered.

[0025] Further, the angle signal is high-pass filtered at 5Hz.

[0026] Further, after the total transmission error is subjected to FFT analysis and the corresponding transmission error of the driving gear and the driven gear is extracted, the gear transmission error rapid calculation method further comprises:

[0027] The transmission error of each pair of driving gear and driven gear is calculated by the foregoing steps.

[0028] The application has the advantages that the gear transmission error rapid calculation method provided combines the transmission error theory, realizes equivalent analysis of micro transmission error from a macro perspective, widens the transmission error calculation method, and has strong engineering application value. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic diagram of a gear transmission error rapid calculation method of the application. DETAILED DESCRIPTION

[0030] The application will be specifically introduced below in combination with the drawings and specific embodiments.

[0031] As Figure 1 shown is a gear transmission error rapid calculation method of the application, which comprises the following steps: S1: obtaining the angle signal of each transmission shaft in the transmission system. S2: converting the angle signal into radian. S3: calculating the arc length corresponding to the driving gear and the driven gear. S4: calculating the arc length difference of the driving gear and the driven gear as the overall transmission error. S5: extracting the corresponding transmission error of the driving gear and the driven gear after FFT analysis of the overall transmission error. The gear transmission error rapid calculation method of the application combines the transmission error theory, realizes equivalent analysis of micro transmission error from a macro perspective, widens the transmission error calculation method, and has strong engineering application value.

[0032] If the gears are in ideal state, the meshing line length of the driving gear and the driven gear is always equal, and considering the objective existence of error, the actual rotation angle of the driven gear is:

[0033] θ2' = θ2 + Δθ2

[0034] wherein θ2' is the actual rotation angle of the driven gear, θ2 is the theoretical rotation angle of the driven gear, and Δθ2 is the angle deviation caused by the transmission error.

[0035] Based on the above analysis, the transmission error caused by the gear meshing process can be equivalent evaluated by analyzing the arc length turned by Δθ2 in the test process, therefore, the transmission error can be expressed as:

[0036] TE = r2 * ω2 - r1 * ω1

[0037] wherein r1 and r2 are the pitch circle radii of the driving gear and the driven gear respectively, and ω1 and ω2 are the angular velocities of the driving gear and the driven gear respectively. The arc length turned by Δθ2 is subjected to FFT analysis, and then the order energy corresponding to the gear meshing is extracted, so that the final transmission error result is obtained.

[0038] The above steps will be specifically introduced below.

[0039] For step S1: obtaining the angle signal of each drive shaft in the drive train.

[0040] As a preferred embodiment, the specific method of obtaining the angle signal of each drive shaft in the drive train is as follows:

[0041] A corresponding high-precision speed sensor is configured for each drive shaft in the drive train. First, the state of the high-precision speed sensor inside the drive train is confirmed. If a drive shaft does not have a high-precision speed sensor, an external high-precision speed sensor is needed.

[0042] During the test, the voltage signal of each high-precision speed sensor is obtained. The voltage pulse signal generated by the rotation of each shaft is directly obtained by using the speed special channel on the professional vibration noise data acquisition equipment. According to the sampling theorem, the sampling frequency needs to be greater than or equal to 2.56 times the analysis frequency.

[0043] Specifically, the voltage signal is collected under the conditions of light load, medium load, high load and reverse drag of the drive train, and the accurate original signal is selected from the collected data. Optionally, the light load, medium load and high load are 20% load, 50% load and 100% load respectively.

[0044] Taking the drive train as a vehicle reducer as an example, the reducer is respectively engaged in each gear, and the vehicle under each gear is respectively accelerated by 20% throttle, 50% throttle and full throttle, and reverse drag test is performed. Each kind of test condition is tested for multiple times, and the voltage pulse signal of each drive shaft is collected, and the accurate original signal is selected from the collected data. The working condition of each gear is defined in order to comprehensively evaluate the transmission error of each pair of gears inside the reducer. The 20% throttle, 50% throttle and 100% throttle acceleration respectively represent small throttle acceleration, medium throttle acceleration and full throttle acceleration, which correspond to three different working scenes of light load, medium load and high load of the reducer. Each tooth of the gear has two tooth surfaces, and the acceleration test and the reverse drag test correspond to different working tooth surfaces. Preferably, the voltage pulse signals of multiple sets of drive shafts are obtained. The purpose of recording multiple sets of data is to obtain more accurate original signals.

[0045] Finally, the voltage signal is converted into an angle signal.

[0046] Specifically, the voltage signal is first converted into a speed signal, and the speed signal is further converted into an angle signal.

[0047] In the above embodiment, a high-precision speed sensor is configured for each drive shaft.

[0048] As an optional embodiment, the specific method of obtaining the angle signal of each drive shaft in the drive train is as follows:

[0049] A corresponding high-precision rotation speed sensor is configured for each transmission shaft in the transmission system. The voltage signal of each high-precision rotation speed sensor is obtained during the test. The voltage signal is converted into an angle signal. The angle signal of the transmission shaft without the high-precision rotation speed sensor is obtained through the speed ratio conversion.

[0050] It can be understood that, unlike the previous embodiment, in the present embodiment, a high-precision rotation speed sensor is not configured for each transmission shaft, and the angle signal of the transmission shaft without the high-precision rotation speed sensor can be indirectly obtained through the angle signal of other transmission shafts through the speed ratio relationship.

[0051] For step S2: converting the angle signal into radian.

[0052] As a preferred embodiment, in the process of converting the angle signal into radian, the angle signal is first subjected to 5Hz high-pass filtering. Then, the radian is obtained through the following conversion formula of radian and angle.

[0053] ω = θ x π / 180

[0054] Wherein, ω is radian, and θ is angle.

[0055] For step S3: calculating the corresponding arc length of the driving gear and the driven gear.

[0056] A transmission system includes a plurality of pairs of driving gears and driven gears meshing with each other. One pair of driving gear and driven gear is selected, and the corresponding arc length of the driving gear and the driven gear is calculated through the following calculation method.

[0057] l = ω x r

[0058] Wherein, l is arc length, ω is radian, and r is pitch circle radius.

[0059] For step S4: calculating the arc length difference of the driving gear and the driven gear as the overall transmission error.

[0060] The overall transmission error is the arc length difference of the driving gear and the driven gear,

[0061] Δl = |l 主 -l 从 |

[0062] Wherein, Δl is the overall transmission error, l 主 is the arc length of the driving gear, and l 从 is the arc length of the driven gear.

[0063] For step S5: extracting the corresponding transmission error of the driving gear and the driven gear after the FFT analysis of the overall transmission error.

[0064] It can be understood that the overall transmission error is similar to the vibration time domain signal, and the frequency domain result is obtained through fast Fourier transform (FFT). The transmission error corresponding to each pair of gears is related to the corresponding meshing order, for example, if the gear meshing order is 32 orders, then the transmission error corresponding to the pair of gears includes 32 orders, 64 orders, 96 orders, etc., that is, the orders corresponding to 1 times, 2 times and 3 times frequency. In this way, the transmission errors of the corresponding driving gear and driven gear can be calculated. Through the foregoing steps, the corresponding transmission errors of any driving gear and driven gear in the transmission system can be calculated.

[0065] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the above-mentioned embodiments do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. A method for fast computation of gear transmission error, characterized in that, The method comprises the following steps: obtaining an angle signal of each transmission shaft in a transmission system; converting the angle signal into radian; calculating the arc length corresponding to the driving gear and the driven gear; calculating the arc length difference between the driving gear and the driven gear as the overall transmission error; performing FFT analysis on the overall transmission error to convert the overall transmission error in time domain into a frequency domain spectrum, extracting peak energy corresponding to the meshing order of the driving gear and the driven gear, the meshing order including the base order and integer multiple orders, and taking the peak energy as the corresponding transmission error of the driving gear and the driven gear; the actual rotation angle of the driven gear is: θ2' = θ2 + Δθ2; wherein θ2' is the actual rotation angle of the driven gear, θ2 is the theoretical rotation angle of the driven gear, and Δθ2 is the angle deviation caused by the transmission error; Based on the above analysis, the transmission error generated during the gear meshing process can be equivalent evaluated by analyzing the arc length turned by Δθ2 during the test process. Therefore, the transmission error can be represented as: TE = r2 * w2 - r1 * w1; wherein r1 and r2 are the pitch circle radii of the driving gear and the driven gear, and w1 and w2 are the angular velocities of the driving gear and the driven gear, respectively. The arc length turned by Δθ2 is analyzed by FFT, and then the order energy corresponding to the gear meshing is extracted to obtain the final transmission error result; The overall transmission error is the arc length difference between the driving gear and the driven gear, Δl = |l 主 -l 从 |; wherein Δl is the total transmission error, l 主 is the arc length of the drive gear, l 从 is the arc length of the driven gear.

2. The fast calculation method of gear transmission error according to claim 1, wherein the specific method for obtaining the angle signal of each transmission shaft in the transmission system is: configuring a corresponding high-precision speed sensor for each transmission shaft in the transmission system; obtaining the voltage signal of each high-precision speed sensor during the test process; converting the voltage signal into the angle signal.

3. The fast calculation method of gear transmission error according to claim 1, wherein the specific method for obtaining the angle signal of each transmission shaft in the transmission system is: configuring a corresponding high-precision speed sensor for part of the transmission shafts in the transmission system; obtaining the voltage signal of each high-precision speed sensor during the test process; converting the voltage signal into the angle signal; obtaining the angle signal of the transmission shafts without the high-precision speed sensor through speed ratio conversion.

4. The fast calculation method of gear transmission error according to any one of claims 2 or 3, wherein the specific method for obtaining the voltage signal of each high-precision speed sensor during the test process is: making the transmission system work under light load, medium load, high load and reverse drag conditions to collect voltage signals, and selecting accurate original signals from the collected data.

5. The fast calculation method of gear transmission error according to claim 4, wherein the light load, the medium load and the high load are 20% load, 50% load and 100% load, respectively.

6. The fast calculation method of gear transmission error according to claim 4, wherein The transmission system is a vehicle decelerator, and the decelerator is engaged in each gear position, and the vehicle under each gear position is respectively subjected to 20% throttle, 50% throttle and full throttle acceleration and reverse drag test, each test condition is tested for multiple times, voltage pulse signals of each transmission shaft are collected, and accurate original signals are selected from the collected data.

7. The gear transmission error fast calculation method of claim 1, wherein, In the process of converting the angle signal into radian, the angle signal is first subjected to high-pass filtering.

8. The gear transmission error fast calculation method of claim 7, wherein, The angle signal is subjected to 5Hz high-pass filtering.

9. The gear transmission error fast calculation method of claim 1, wherein, After the total transmission error is subjected to FFT analysis and the corresponding transmission errors of the driving gear and the driven gear are extracted, the gear transmission error fast calculation method further comprises: The transmission error of each pair of the driving gear and the driven gear is calculated through the foregoing steps.

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