Method for testing and identifying co-vibration stress of spiral bevel gear radial plate

Abstract

The invention discloses a spiral bevel gear wheel disk co-vibration stress test identification method, and relates to the technical field of bevel gear wheel disk resonance stress identification. And the resonance rotating speed, the resonance frequency and the radial plate co-vibration stress in the working rotating speed interval can be determined, so that subsequent vibration reduction optimization treatment is facilitated. Comprising the following steps: step 1, information acquisition; step 2, constructing a radial plate dynamic stress test bed; step 3, carrying out a constant-speed acceleration frequency sweeping test; 4, according to the relation graph of the strain and the rotating speed obtained in the step 3, obtaining a resonance rotating speed interval and a traveling wave resonance rotating speed point when pitch diameter type resonance occurs; step 5, carrying out a rotating speed retention test; step 6, data analysis; and 7, processing a result. According to the scheme, a vibration reduction design scheme of the bevel gear can be accurately and rapidly formulated, and lightweight vibration reduction design of the bevel gear is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of bevel gear spoke plate resonance stress identification, and in particular to a method for testing a test resonance frequency and a spoke plate resonance stress of a bevel gear when traveling wave resonance occurs. Background Art

[0002] The speed in the gear transmission system of an aircraft engine is high, the working conditions are complex, and the vibration problem is prominent. Among them, bevel gears are often set as thin spoke plates to meet the requirements of lightweight design. The increased structural flexibility will cause multiple resonant speed points to appear in the working speed range. The large resonant stress will cause high-cycle fatigue of the gear spoke plate, and even cause the spoke plate to break, affecting the life of the entire transmission system, and thus posing a hidden danger to aviation flight safety.

[0003] The resonance stress generated by each resonance speed point of the bevel gear is different in magnitude. Not all resonance stresses will affect the safety of the gear. Some resonance speed points within the working speed range can be adjusted away by structural frequency modulation, but there are still resonance speed points. Therefore, identifying the resonance stress of the spoke plate at the resonance speed point has great engineering significance for whether to perform passive vibration reduction in the future.

[0004] At present, there is still a lack of a complete and effective test and identification method for the resonance stress of the spoke plate within the working speed range in China. It is impossible to obtain the resonance speed, resonance frequency and resonance stress of the accurate resonance speed point, so it is impossible to accurately and quickly formulate the vibration reduction design plan of the bevel gear, which restricts the lightweight vibration reduction design of the bevel gear. Summary of the invention

[0005] In view of the above problems, the present invention proposes a method for testing and identifying the resonant vibration stress of the spoke plate of a spiral bevel gear, which can determine the resonant speed, resonant frequency and resonant vibration stress of the spoke plate within the working speed range for subsequent vibration reduction optimization processing.

[0006] The technical solution of the present invention is as follows: Step 1: Information collection; Conduct prestressed modal analysis and traveling wave resonance analysis of the spiral bevel gear pair using the Campbell diagram to obtain the modal frequency, modal displacement and modal stress of the radial plate pitch vibration, and obtain the strain gauge distribution diagram; Step 2: Build a radial plate dynamic stress test bench; According to the modal stress results and the strain gauge layout diagram, the strain gauge is arranged at the position where the modal stress of the test spiral bevel gear spoke is the largest, and the acceleration sensor is arranged on the test gearbox; the strain value is obtained through the strain gauge, and the vibration acceleration data finally transmitted from the spiral bevel gear to the test gearbox is obtained through the acceleration sensor; Step 3, perform a uniform speed increase frequency sweep test; The spiral bevel gear is rotated to increase the speed uniformly from the lower limit of the working speed range to the upper limit of the working speed range, and the spoke strain signal within the working speed range is extracted; Step 4: According to step 3, a relationship diagram between strain and rotation speed is obtained, thereby obtaining a resonance rotation speed range and a traveling wave resonance rotation speed point when a pitch-diameter resonance occurs; Step 5, perform a speed dwell test; Taking the traveling wave resonance speed point n obtained in step 4 as the reference, 5 speed points are taken before and after the speed point, namely (n-40), (n-20), n, (n+20), (n+40) speed points, and the speed point residence time is determined as t And the acceleration time between each speed point; Carry out the speed dwell test according to the set speed dwell time and dwell interval; Extract the speed variation diagram of the process; Extract the data of the strain gauge in the process and obtain the strain signal diagram of the spoke; Extract the vibration acceleration signal of the box during the process and obtain an acceleration signal graph; Step 6: Data analysis; Perform time-frequency analysis of acceleration signals and strain gauge signals to obtain the resonant speed, resonant frequency and radial plate dynamic stress at the resonance point; Step 7: Result processing; When the number of traveling wave resonance speed points obtained in step 4 is greater than 1, return to step 5 to carry out speed dwell tests on all traveling wave resonance speed points to obtain multiple spoke plate resonant vibration stress values. Combined with the Goodman curve and SN curve of the gear, it is determined whether the above multiple spoke plate resonant vibration stress values ​​exceed the allowable dynamic stress range. If they exceed the range, active or passive vibration reduction optimization processing is performed.

[0007] The spoke plate dynamic stress test bench constructed in step 2 includes a motor 1, a coupling 2, a speed increasing gearbox 3, a torque meter 4, a test gearbox 5, a speed reducing gearbox 9 and an eddy current brake 10 which are connected in sequence; The spiral bevel gear pair to be tested is installed in the test gear box 5, and is respectively connected to the torque meter 4 and the reduction gear box 9. The motor 1 provides power to the spiral bevel gear pair to be tested, and the eddy current brake 10 provides torque to the spiral bevel gear pair to be tested. The radial plate dynamic stress test bench constructed in step 2 also includes a strain gauge, an acceleration sensor 6, a slip ring 7, a data acquisition instrument 8, and a computer 11 connected to the data acquisition instrument 8; A number of strain gauges are also installed on the spiral bevel gear. According to the modal stress result and the strain gauge distribution diagram, the strain gauges are arranged at the position where the modal stress of the test spiral bevel gear web is the largest; the strain gauges are connected to the data acquisition instrument 8 via the slip ring 7; An acceleration sensor 6 is also fixedly mounted on the housing of the test gear box 5 , and the acceleration sensor 6 is also connected to a data acquisition device 8 .

[0008] In step 6, the strain gauge signal and acceleration signal at each dwell speed are analyzed in the time domain and frequency domain: If the frequency of the dynamic strain signal at the same speed n f d The frequency of the acceleration signal f e The following relationship exists: f e = f d ±mn / 60 Where: m is the number of node diameters, that is, the number of node lines of node diameter type vibration, which is an integer; like f e = f d +mn / 60, then the m-node diameter forward wave resonance occurs, and the resonance speed is n F ;like f e = f d -mn / 60, at this time, the m-diameter rear traveling wave resonance occurs, and the resonance speed is n B ; The dynamic stress magnitude that meets the traveling wave resonance is obtained and is used as the radial plate dynamic stress at the resonance point.

[0009] Compared with the prior art, the present invention forms a complete and effective radial plate dynamic stress test and identification method, which combines the strain gauge signal and the acceleration signal to accurately obtain the resonant speed, resonant frequency and resonant vibration stress of the resonant speed point, thereby helping to accurately and quickly formulate a vibration reduction design plan for the bevel gear, which is beneficial to the lightweight vibration reduction design of the bevel gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a flow chart of an embodiment of the present invention, Figure 2 The experimental principle diagram of the present invention is shown in FIG. Figure 3 This is a diagram showing the arrangement of gear strain gauges according to an embodiment of the present invention. Figure 4 This is the lead diagram of the gear strain gauge of the embodiment of the present invention. Figure 5 is the rising speed strain gauge signal of the embodiment of the present invention, Figure 6 is the time domain signal of the dwell test speed of the embodiment of the present invention, Figure 7 is the time domain signal of the dwell test strain gauge of an embodiment of the present invention, Figure 8 It is the acceleration time domain signal of the dwell test according to the embodiment of the present invention. DETAILED DESCRIPTION

[0011] In order to clearly illustrate the technical features of this patent, this patent is elaborated in detail below through a specific implementation method and in combination with its accompanying drawings.

[0012] like Figure 1-Figure 6 As shown, this embodiment provides a method for testing and identifying the resonant vibration stress of a spiral bevel gear spoke, comprising the following steps: Step 1: Figure 1 As shown, firstly, the prestressed modal analysis and the traveling wave resonance analysis of the spiral bevel gear pair are carried out by using the Campbell diagram, and the modal frequency, modal displacement and modal stress of the radial plate pitch vibration are obtained, and the strain gauge distribution diagram is obtained; Step 2: Build a radial plate dynamic stress test bench, including a drive motor, a test gearbox, a slip ring, a torque meter, an acceleration sensor, and an eddy current brake. The schematic diagram is as follows: Figure 2 As shown in the figure, the motor 1 provides power to the spiral bevel gear pair to be tested, and the eddy current brake 10 provides torque to the spiral bevel gear pair to be tested; according to the modal stress results and the strain gauge layout diagram, the strain gauge is arranged at the position where the modal stress of the test spiral bevel gear web is the largest, and at least 4 strain gauges are arranged along the circumference to eliminate the accidental error of the test. The layout position is as follows: Figure 3 As shown; the slip ring rotor end is connected to the test gear shaft, the strain gauge lead passes through the shaft hole and connects to the rotor end lead, and the stator end lead is connected to the data acquisition instrument; the acceleration sensor is arranged on the test gear box, its position is close to the bearing of the test gear, and is connected to the data acquisition instrument, as shown Figure 4 The strain value is obtained through the strain gauge, and the vibration acceleration data finally transmitted from the spiral bevel gear to the test gearbox is obtained through the acceleration sensor.

[0013] Step 3: Perform a uniform speed increase sweep test. First, uniformly increase the motor speed to the lower limit of the working speed range, such as 1000r / min, and then uniformly increase the speed at 50r / min / s until the upper limit of the working speed range is 4300r / min; extract the radial plate strain signal within the working speed range, such as Figure 5 shown.

[0014] Step 4: According to step 3, a relationship diagram between strain and rotation speed is obtained, thereby obtaining the resonance rotation speed range and the traveling wave resonance rotation speed point when the pitch-diameter resonance occurs. Specifically: By analyzing the strain gauge signal, it was found that there were three traveling wave resonance speed points in the working speed range, namely 2796r / min, 3012r / min, and 3896r / min.

[0015] Step 5, perform a speed dwell test; Taking the first resonance point as an example, the resonance speed range is determined to be 2750r / min~2830r / min. Five speed points are taken before and after this speed, and the vehicle stays at 2750r / min, 2770r / min, 2790r / min, 2810r / min, and 2830r / min respectively. The dwell time is 4s, and the acceleration time between each speed point is 2s to carry out the speed dwell test.

[0016] According to the set speed dwell time and dwell interval, a speed dwell test is performed to extract the speed change diagram of the process, such as Figure 6 As shown in the figure, the shaded part is the dwell speed. The data of the strain gauge in this process is extracted to obtain the strain signal diagram of the spoke plate, as shown in Figure 7 As shown, the vibration acceleration signal of the box during this process is extracted to obtain the acceleration signal diagram, such as Figure 8 shown.

[0017] Step 6: Perform time domain and frequency domain analysis on the acceleration signal and strain gauge signal. It is found that when the speed stays near 2790r / min, the amplitude of the strain gauge signal and the acceleration signal increases. According to the frequency domain analysis, when the speed is 2789r / min, the first-order meshing frequency of the acceleration signal is f e is 2754Hz, and the strain gauge signal is f d The strain amplitude at 2849Hz is the largest, reaching 196με. According to the formula: f e = f d ±mn / 60 At this time, the pitch diameter m is calculated to be 2.04, which satisfies f e = f d -mn / 60, that is, the two-node diameter rear traveling wave resonance occurs at this time (on the contrary, if it satisfies f e = f d+mn / 60, it is considered that the two-node forward wave resonance occurs), the resonant speed is 2789r / min, the resonant frequency is 2849Hz, and the resonant vibration stress of the spoke is 40.37MPa.

[0018] Step 7: Similarly, a speed dwell test is performed on the other two traveling wave resonance speed points, and finally three spoke plate resonant vibration stress values ​​are obtained. Combined with the Goodman curve and SN curve of the gear, it is determined whether the above three values ​​exceed the allowable dynamic stress range. If they exceed the range, active or passive vibration reduction optimization processing is performed.

[0019] This embodiment proposes a method for testing and identifying the resonant vibration stress of the spoke plate of an arc bevel gear. This method considers that excessive resonant vibration stress of the spoke plate in the working speed range will cause fatigue fracture failure of the gear spoke plate, thereby measuring the dynamic stress when traveling wave resonance occurs. First, the prestressed modal analysis and traveling wave resonance analysis of the arc bevel gear pair are carried out to obtain the resonance point in the working speed range; a spoke plate dynamic stress test bench is built, strain gauges are pasted on the spoke plate, and acceleration sensors are arranged at the bearing position of the test gear box; a uniform speed increase sweep frequency experiment is carried out to obtain strain and acceleration signals, and the speed dwell range, dwell interval and dwell time are set according to the results; taking the two-pitch diameter rear traveling wave as an example, a speed dwell experiment is carried out to obtain the dynamic stress of the spoke plate when the two-pitch diameter rear traveling wave resonance occurs. According to this dynamic stress test and identification method, the traveling wave resonance point existing in the working speed range can be quickly and accurately identified, and its resonant speed, resonant frequency, and pitch diameter number, i.e., the resonant spoke plate dynamic stress, can be identified, so as to quickly and accurately propose a vibration reduction plan for the excessively large resonant speed point.

[0020] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A method for testing and identifying the resonance stress of a spiral bevel gear spoke, characterized in that: The steps include: Step 1: Information collection; Conduct prestressed modal analysis and traveling wave resonance analysis of the spiral bevel gear pair using the Campbell diagram to obtain the modal frequency, modal displacement and modal stress of the radial plate pitch vibration, and obtain the strain gauge distribution diagram; Step 2: Build a radial plate dynamic stress test bench; According to the modal stress results and the strain gauge layout diagram, the strain gauge is arranged at the position where the modal stress of the test spiral bevel gear spoke is the largest, and the acceleration sensor is arranged on the test gearbox; the strain value is obtained through the strain gauge, and the vibration acceleration data finally transmitted from the spiral bevel gear to the test gearbox is obtained through the acceleration sensor; Step 3, perform a uniform speed increase frequency sweep test; The spiral bevel gear is rotated to increase the speed uniformly from the lower limit of the working speed range to the upper limit of the working speed range, and the strain signal of the spoke plate within the working speed range is extracted; Step 4: According to step 3, a relationship diagram between strain and rotation speed is obtained, thereby obtaining a resonance rotation speed range and a traveling wave resonance rotation speed point when a pitch-diameter resonance occurs; Step 5, perform a speed dwell test; Taking the traveling wave resonance speed point n obtained in step 4 as the reference, 5 speed points are taken before and after the speed point, namely (n-40), (n-20), n, (n+20), (n+40) speed points, and the speed point residence time is determined as t And the acceleration time between each speed point; Carry out the speed dwell test according to the set speed dwell time and dwell interval; Extract the speed variation diagram of the process; Extract the data of the strain gauge in the process and obtain the strain signal diagram of the spoke; Extract the vibration acceleration signal of the box during the process and obtain an acceleration signal graph; Step 6: Data analysis; Perform time-frequency analysis on acceleration signals and strain gauge signals to obtain the resonant speed, resonant frequency and dynamic stress of the radial plate at the resonance point; Step 7: Result processing; When the number of traveling wave resonance speed points obtained in step 4 is greater than 1, return to step 5 to carry out speed dwell tests on all traveling wave resonance speed points to obtain multiple spoke plate resonant vibration stress values. Combined with the Goodman curve and SN curve of the gear, it is determined whether the above multiple spoke plate resonant vibration stress values ​​exceed the allowable dynamic stress range. If they exceed the range, active or passive vibration reduction optimization processing is performed.

2. A method for testing and identifying the resonant vibration stress of a spiral bevel gear web according to claim 1, characterized in that: The radial plate dynamic stress test bench constructed in step 2 comprises a motor (1), a coupling (2), a speed increasing gearbox (3), a torque meter (4), a test gearbox (5), a speed reducing gearbox (9) and an eddy current brake (10) which are connected in sequence; The bevel gear pair to be tested is installed in a test gear box (5) and connected to a torque meter (4) and a reduction gear box (9) respectively; the motor (1) provides power to the bevel gear pair to be tested, and the eddy current brake (10) provides torque to the bevel gear pair to be tested; The radial plate dynamic stress test bench constructed in step 2 also includes a strain gauge, an acceleration sensor (6), a slip ring (7), a data acquisition instrument (8), and a computer (11) connected to the data acquisition instrument (8); A plurality of strain gauges are also installed on the spiral bevel gear. According to the modal stress result and the strain gauge distribution diagram, the strain gauges are arranged at the position where the modal stress of the test spiral bevel gear web is the largest. The strain gauges are connected to a data acquisition instrument (8) via a slip ring (7). An acceleration sensor (6) is also fixedly mounted on the housing of the test gear box (5), and the acceleration sensor (6) is also connected to the data acquisition device (8).

3. The method for testing and identifying the resonant vibration stress of a spiral bevel gear web according to claim 1, characterized in that: In step 6), the strain gauge signal and acceleration signal at each dwell speed are analyzed in the time domain and frequency domain: If the frequency of the dynamic strain signal at the same speed n f d The frequency of the acceleration signal f e The following relationship exists: f e = f d ±mn / 60 Where: m is the number of node diameters, that is, the number of node lines of node diameter type vibration, which is an integer; like f e = f d +mn / 60, then the m-node diameter forward wave resonance occurs, and the resonance speed is n F ;like f e = f d -mn / 60, at this time, the m-diameter rear traveling wave resonance occurs, and the resonance speed is n B ; The dynamic stress magnitude that meets the traveling wave resonance is obtained and is used as the radial plate dynamic stress at the resonance point.

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