A test device and method for fatigue life test of harmonic reducer

Abstract

The present application relates to the field of fatigue life test of harmonic reducer, and in particular to a test equipment and method for fatigue life test of harmonic reducer, which includes a test bench, on which a rotating part is provided, for driving the input end of the harmonic reducer to rotate, and also includes: a vacuum-sealed box, which is provided on the test bench, and inside which a fixing component for fixing the harmonic reducer is provided; a load part, which is provided on the side of the vacuum-sealed box away from the rotating part, for providing an output load for the test process; an exhaust part, which is connected to the vacuum-sealed box, and extracts the air inside the vacuum-sealed box to create a low vacuum environment; a vibration measuring part, which is installed in the vacuum-sealed box, for collecting the vibration signal of the harmonic reducer. The present application has the effect of improving the accuracy of fatigue life prediction of harmonic reducer.

Description

Technical Field

[0001] The present application relates to the field of fatigue life testing of harmonic reducers, and in particular to a test device and method for fatigue life testing of harmonic reducers. Background Art

[0002] The harmonic gear reducer is a special gear transmission reducer. Different from the traditional gear transmission structure, the harmonic reducer is mainly composed of three components: the flexible wheel, the rigid wheel and the wave generator. The outer gear ring of the flexible wheel meshes with the inner gear ring of the rigid wheel. The wave generator is a non-standard disc and meshes with the inner ring of the flexible wheel. In the process of reduction transmission, the wave generator is connected to the output shaft of the motor. As the input end of the harmonic reducer, it rotates synchronously with the output shaft of the motor, forcing the flexible wheel to undergo elastic deformation and intermittently mesh with the rigid gear.

[0003] As a high-performance, precise and reliable reduction transmission equipment, harmonic reducers are widely used in aerospace, CNC machine tools and other places with high precision transmission requirements. However, during long-term operation, the internal gear surface of the harmonic reducer is subject to wear, which can easily lead to faults or even failure. Therefore, fatigue life testing of harmonic reducers is of great significance.

[0004] The purpose of the fatigue life test project is to predict the service life of the harmonic reducer, evaluate the reliability of the harmonic reducer, and take corresponding follow-up measures to extend its life. At present, the fatigue life test technology of the harmonic reducer is relatively mature, and the detection equipment is relatively advanced, but the measurement methods and measurement indicators of almost all fatigue life test equipment are centered around operating temperature and transmission efficiency. The operating temperature and transmission efficiency of the harmonic reducer are a direct reflection of the operating performance of the harmonic reducer.

[0005] In view of the above-mentioned related technologies, the traditional test items can be expanded and improved, and the measurement of other test indicators that can reflect the fatigue life of the harmonic reducer can be added to more accurately predict the fatigue life of the harmonic reducer. Summary of the invention

[0006] In order to improve the accuracy of the prediction of the fatigue life of a harmonic reducer, the present application provides a test device and method for testing the fatigue life of a harmonic reducer.

[0007] On the one hand, the present application provides a test device for fatigue life test of harmonic reducer, which adopts the following technical solution:

[0008] A test device for fatigue life test of harmonic reducer, comprising a test bench, wherein a rotating member is arranged on the test bench, and is used to drive the input end of the harmonic reducer to rotate, and further comprising:

[0009] A vacuum sealed box is arranged on the test bench, and a fixing assembly for fixing the harmonic reducer is arranged inside the vacuum sealed box;

[0010] A load member, disposed on a side of the vacuum enclosure away from the rotating member, for providing an output load during a test;

[0011] An air extraction component, connected to the vacuum sealed box, extracting air from the vacuum sealed box to create a low vacuum environment;

[0012] The vibration measuring device is installed in the vacuum sealed box and is used to collect the vibration signal of the harmonic reducer.

[0013] By adopting the above technical scheme, a vacuum sealed box and a vibration measuring device are added to the traditional test scheme. The exhaust device on the vacuum sealed box draws out the air inside the vacuum sealed box, which can create a low vacuum environment during the performance test of the harmonic reducer, test the operating performance of the harmonic reducer under low vacuum conditions, and provide a qualified inspection process for the harmonic reducer that can be used in the aerospace field; during the performance test of the harmonic reducer, the load device provides load torque to simulate the real operation process of the harmonic reducer; the above technical scheme is also provided with a vibration measuring device for collecting vibration signals during the operation process of the harmonic reducer, and the vibration measuring device is placed in the working position of the harmonic reducer, and the vibration signal of the harmonic reducer is measured when the rotating part provides rotational power. The tester can understand the vibration characteristics of the harmonic reducer by analyzing the frequency spectrum of the vibration signal, thereby the tester can further evaluate the performance and health of the harmonic reducer.

[0014] Optionally, it also includes;

[0015] The noise detection component is arranged in the vacuum sealed box and is used to detect the noise data of the harmonic reducer.

[0016] By adopting the above technical scheme, the noise detection component can collect the noise data of the harmonic reducer in the reduction transmission process in real time, and can timely discover the abnormal situation of the harmonic reducer through noise monitoring and analysis. The main reason is that through noise monitoring, noises of different frequencies and amplitudes can be detected, so as to roughly judge the specific fault location and fault type, and noise monitoring and data analysis are performed on a large number of harmonic reducers under different torques and speeds collected to predict the laws and characteristics of their fatigue behavior. Therefore, it is of great significance to add a noise detection process in the above scheme.

[0017] Optionally, it also includes;

[0018] The temperature measuring component is arranged in the vacuum sealed box and is used to measure the working temperature of the harmonic reducer.

[0019] By adopting the above technical scheme, since the harmonic reducer generates heat inside the harmonic reducer due to friction and mechanical energy loss when performing forward and reverse acceleration and deceleration movements, the temperature rises, which is easy to cause damage to the internal structure of the harmonic reducer. Therefore, a temperature measuring device is set in the above scheme to perform dynamic temperature rise monitoring of the harmonic reducer. The tester can timely discover the temperature abnormality of the harmonic reducer by observing the amplitude and efficiency of the temperature change of the harmonic reducer. When the temperature changes too much or too fast, it means that the internal structure of the harmonic reducer cannot engage normally, and there is a risk of transmission failure. Temperature detection can be used as one of the detection indicators to judge whether the harmonic reducer can work normally.

[0020] Optionally, it also includes;

[0021] The torque measuring pieces are arranged opposite to each other on both sides of the vacuum sealed box. The two torque measuring pieces are respectively connected to the rotating piece and the load piece, and are used to measure the input torque and output torque of the harmonic reducer.

[0022] By adopting the above technical scheme, the torque, that is, the operating load at both ends of the harmonic reducer, can reflect the transmission efficiency of the harmonic reducer, and is a more intuitive reflection of the transmission performance of the harmonic reducer. First, the measurement of input torque and output torque can intuitively evaluate the transmission accuracy and stability of the harmonic reducer, and the tester can determine whether there is a stability problem based on the transmission efficiency of the harmonic reducer. Secondly, by comparing the measured values ​​of input torque and output torque of different harmonic reducers under the same model, the operating performance of the harmonic reducer can be more accurately evaluated, providing a more accurate basis for the prediction of fatigue life. There will be no sudden changes in the torque measurement process. If a sudden change occurs, it means that the internal transmission mechanism of the harmonic reducer must be damaged.

[0023] Optionally, it also includes;

[0024] The speed measuring parts are arranged opposite to each other on both sides of the vacuum sealed box. The two speed measuring parts are respectively connected to the rotating part and the load part, and are used to measure the input speed and output speed of the harmonic reducer.

[0025] By adopting the above technical solution, the measurement of input speed and output speed is one of the important data to assist testers in understanding the transmission performance of the harmonic reducer. Testers can observe the stability of the ratio of output speed to input speed to determine whether there is excessive transmission damage. If the transmission structure connection inside the harmonic reducer is unstable, a stable speed ratio cannot be obtained during the measurement of input speed and output speed; in addition, if the speed ratio differs from the rated speed ratio too much, it means that there is a fault inside the harmonic reducer and needs to be inspected or repaired.

[0026] On the one hand, the present application provides a test method for fatigue life testing of a harmonic reducer, comprising the following steps:

[0027] A test method for fatigue life test of harmonic reducer, comprising:

[0028] Open the vacuum sealed box and install the harmonic reducer. The input end of the harmonic reducer is connected to the rotating part, and the output end of the harmonic reducer is connected to the load part.

[0029] Set the load component so that the load torque at the output end of the harmonic reducer is 50N;

[0030] Turn on the torque measuring device and the speed measuring device;

[0031] Open the rotating part;

[0032] Set the initial output speed of the rotating part to 100 rpm, observe and record the torque measurement value and actual speed measurement value at the input and output ends of the harmonic reducer at the initial speed;

[0033] Slowly increase the speed to the rated input speed Z of the harmonic reducer of this model, calculate and record the torque change and actual transmission ratio of the input and output ends of the harmonic reducer during the speed increase, and fit the torque curve and transmission ratio change curve;

[0034] Continue to slowly increase the speed to 1.5Z, calculate and record the torque change and actual transmission ratio at the input and output ends of the harmonic reducer during the increase of input speed, and fit the torque curve and transmission ratio change curve.

[0035] Optionally, the following steps are also included:

[0036] Before the speed of the harmonic reducer is slowly increased from the rated speed Z to 1.5Z, turn on the temperature measuring device and the noise detection device;

[0037] Record the noise data of the harmonic reducer during the increase of input speed, bring the curve into the noise model after fitting, and compare and judge after obtaining the measurement results;

[0038] Record the operating temperature of the harmonic reducer at rated speed as the initial temperature;

[0039] Open the vacuum pump until the air pressure in the vacuum box is less than 0.0015Pa. Observe the change trend of the harmonic reducer transmission efficiency ratio and the temperature during the change of air pressure, and fit the change curve.

[0040] Optionally, the following steps are also included:

[0041] Before the environment in the vacuum sealed box reaches a low vacuum environment with an air pressure less than 0.0015Pa, turn on the vibration measuring piece;

[0042] When the speed of the harmonic reducer is slowly increased from the rated speed Z to 1.5Z:

[0043] 1. Perform spectrum analysis on the vibration signal collected by the vibration measuring device, decompose the components of different vibration frequencies, and compare them with the known vibration characteristic frequencies of the harmonic reducer;

[0044] 2. Analyze the temperature data collected by the temperature measuring device, fit the curve of temperature change over time, and evaluate the trend and law of temperature change with the increase of speed.

[0045] By adopting the above steps, the harmonic reducer is installed in a vacuum-sealed box. During the performance test, the vacuum-sealed box provides environmental variables, which can simulate the vacuum environment in the aerospace application field of the harmonic reducer, making the test results more accurate. The specific test process uses the input speed of the harmonic reducer as a variable. Before the input speed reaches the rated speed, only the transmission efficiency and transmission accuracy of the harmonic reducer are tested. The two are the basic performances of the harmonic reducer. Only under the premise that the basic performance is qualified, the noise detection, temperature measurement and vibration detection in the subsequent overspeed test are meaningful. After the input speed of the harmonic reducer reaches the rated speed, the speed is slowly increased, and the noise data, vibration spectrum and temperature rise efficiency after overspeeding are detected. According to the noise data, vibration data and temperature rise speed data, the bearing capacity of the harmonic reducer under the overspeed test is reasonably estimated, and then its fatigue life is reasonably estimated.

[0046] In summary, the present application includes at least one of the following beneficial technical effects:

[0047] 1. Use a vacuum sealed box to simulate the real application environment of the harmonic reducer to make the test results more accurate;

[0048] 2. Add noise, vibration and temperature rise test processes to the traditional test process to more accurately estimate the fatigue life of the harmonic reducer through multi-faceted data. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the structure of the harmonic reducer in the embodiment of the present application.

[0050] Figure 2 It is a schematic diagram of the overall structure of an embodiment of the present application.

[0051] Figure 3 It is a structural diagram for highlighting the servo motor in the embodiment of the present application.

[0052] Figure 4 It is a structural diagram designed to highlight the load motor in the embodiment of the present application.

[0053] Figure 5 It is a cross-sectional view made in the embodiment of the present application to highlight the internal structure of the vacuum sealed box.

[0054] Explanation of the reference numerals: 1. harmonic reducer; 11. rigid wheel; 12. flexible wheel; 13. wave generator; 2. test bench; 21. vacuum sealed box; 211. mounting plate; 212. noise sensor; 213. temperature sensor; 214. vibration sensor; 22. vacuum pump; 221. exhaust pipe; 23. servo motor; 24. load motor; 25. torque measuring device; 251. torque sensor; 26. speed measuring device; 261. grating sensor; 27. slide rail; 271. bottom plate; 28. input shaft; 29. ​​output shaft. DETAILED DESCRIPTION

[0055] The following is combined with Figure 1-5 This application is described in further detail.

[0056] On the one hand, the present application embodiment discloses a harmonic reducer, referring to Figure 1 A harmonic reducer includes a rigid wheel 11 and a flexible wheel 12. The rigid wheel 11 is annular, and a gear portion is circumferentially provided on the inner ring side of the rigid wheel 11. The flexible wheel 12 is cylindrical, and a gear is circumferentially provided on the outer wall of one end of the cylinder of the flexible wheel 12. The outer gear of the flexible wheel 12 meshes with the inner gear of the rigid wheel 11, and the other end of the flexible wheel 12 is the output end of the harmonic reducer 1; the inner wall of one end of the flexible wheel 12 with a gear meshes with a wave generator 13, and the center part of the wave generator 13 is provided with a hole for plugging in the output shaft of the motor. Therefore, the wave generator 13 is the input end of the harmonic reducer 1, and the end of the flexible wheel 12 facing away from the gear portion is the output end of the harmonic reducer 1. During the reduction transmission process of the harmonic reducer 1, the rigid wheel 11 is fixed to the motor housing and is a stationary part. The harmonic reducer 1 is a prior art, and the specific transmission principle is not described in detail.

[0057] On the one hand, the present application embodiment discloses a test device for fatigue life test of harmonic reducer. Figure 2 A test equipment for fatigue life test of harmonic reducer includes a test bench 2, which is the main part of the test equipment in this embodiment; a vacuum sealed box 21 is fixedly arranged at the center of the table top of the test bench 2, and a fixed installation area for the harmonic reducer 1 is arranged in the vacuum sealed box 21, and the opposite side walls of the vacuum sealed box 21 are the input end and output end of the harmonic reducer 1, and the side walls of the vacuum sealed box 21 corresponding to the input end and output end of the harmonic reducer 1 are rotatably connected to a shaft respectively. For the convenience of distinction, the shaft on one side of the vacuum sealed box 21 corresponding to the input end of the harmonic reducer 1 is the input shaft 28, and the other shaft is the output shaft 29, and the input shaft 28 and the output shaft 29 are coaxial.

[0058] In this embodiment, a side wall of the vacuum sealed box 21 on which the input shaft 28 is disposed is an open side, and a tester can remove the side wall to open the vacuum sealed box 21 .

[0059] Reference Figure 1 and Figure 2 A servo motor 23 is provided on one side edge of the test bench 2 near the input shaft 28 of the vacuum sealed box 21. The output shaft of the servo motor 23 faces the vacuum sealed box 21 and is coaxial with the input shaft 28. The servo motor 23 serves as a rotating part of the harmonic reducer 1 in this embodiment. Its output shaft is connected to the input end of the harmonic reducer 1 to drive the wave generator 13 of the harmonic reducer 1 to rotate.

[0060] Reference Figure 2 and Figure 3 A load motor 24 is provided on one side edge of the test bench 2 near the output shaft 29 of the vacuum sealed box 21. The output shaft of the load motor 24 faces the vacuum sealed box 21 and is coaxial with the output shaft 29. In this embodiment, the load motor 24 and the servo motor 23 are arranged opposite to each other. The load motor 24 serves as a load part of the harmonic reducer 1, and its output shaft is connected to the output end of the harmonic reducer 1 to provide a transmission load for the harmonic reducer 1.

[0061] Reference Figure 3 and Figure 4 A speed measuring device 26 is provided between the vacuum sealed box 21 and the servo motor 23, and between the vacuum sealed box 21 and the load motor 24. The two speed measuring devices 26 are arranged opposite to each other on both sides of the vacuum sealed box 21, and are used to measure the speed of the input end and the output end of the harmonic reducer 1 respectively. The real-time transmission ratio of the harmonic reducer 1 can be calculated through the specific measured values ​​of the input speed and the output speed. In this embodiment, the speed measuring device 26 adopts a grating sensor 261. The grating scale of the grating sensor 261 is disc-shaped. The grating scale of the grating sensor 261 is coaxial with the servo motor 23 and the load motor 24. The central parts of the grating scales of the two grating sensors 261 are respectively plugged into the input shaft 28 and the output shaft 29, and rotate synchronously with the input shaft 28 and the output shaft 29. The detector of the grating sensor 261 is arranged directly below the grating scale to measure the diffraction fringe frequency on the grating scale in real time. Since the grating sensor 261 belongs to the prior art, the specific principle is not described in detail. The tester obtains the real-time rotation speed of the input and output ends of the harmonic reducer 1 through the grating sensor 261, and observes and records the real-time transmission ratio.

[0062] Reference Figure 3 and Figure 4A torque measuring device 25 is also provided between the vacuum sealed box 21 and the servo motor 23, and between the vacuum sealed box 21 and the load motor 24. The two torque measuring devices 25 are arranged opposite to each other, and are used to measure the torque at the input end and the output end of the harmonic reducer 1, respectively, so as to determine the real-time transmission efficiency of the harmonic reducer 1. In this embodiment, the torque measuring device 25 adopts a torque sensor 251. The test shaft of the torque sensor 251 on the input side of the harmonic reducer 1 is connected to the servo motor 23 and the input shaft 28 through a spline, and the test shaft of the torque sensor 251 on the output side of the harmonic reducer 1 is connected to the load motor 24 and the output shaft 29 through a spline. Therefore, in this embodiment, the basic transmission performance of the harmonic reducer 1 is tested by the torque sensor 251 and the speed sensor.

[0063] Reference Figure 2 and Figure 5 , a mounting assembly for mounting the harmonic reducer 1 is arranged in the vacuum sealed box 21, which mainly includes a mounting plate 211, the mounting plate 211 is arranged vertically, the mounting plate 211 is fixed to the bottom wall of the vacuum sealed box 21, the input shaft 28 is passed through the center part of the harmonic reducer 1 and is connected to the wave generator 13 of the harmonic reducer 1 through a spline, so that the input end of the harmonic reducer 1 rotates synchronously with the output shaft of the servo motor 23; a mounting groove adapted to the output part of the harmonic reducer 1 is provided on the side of the mounting plate 211 close to the harmonic reducer 1, and the output end of the harmonic reducer 1 is snapped into the mounting groove. Therefore, when the tester installs the harmonic reducer 1 into the vacuum sealed box 21, he first docks the wave generator 13 of the harmonic reducer 1 with the input shaft 28, snaps one side of the output end of the harmonic reducer 1 into the mounting groove, and docks the output shaft 29.

[0064] It should be noted that in actual applications, the wave generator 13 of different models of harmonic reducers 1 has different sizes of the mounting parts used to connect to the motor. The part of the input shaft 28 in the vacuum sealed box 21 should be mounted to adapt to the size of the mounting part of the wave generator 13 of the harmonic reducer 1 to be tested.

[0065] Replay Figure 2 According to the installation process of the harmonic reducer 1, in this embodiment, a slide rail 27 is laid on the input side of the test bench 2 corresponding to the harmonic reducer 1, and a bottom plate 271 is slidably connected to the slide rail 27. A slider adapted to the slide rail 27 is fixed at the bottom end of the bottom plate 271. The servo motor 23, the grating sensor 261 and the torque sensor 251 are fixed to the bottom plate 271. Therefore, the overall sliding of the input slide rail 27 of the vacuum sealed box 21 is realized by the sliding of the bottom plate 271 along the slide rail 27, so as to achieve docking.

[0066] Reference Figure 5The mounting plate 211 is used to mount a noise sensor on both the top and bottom edges of one side of the harmonic reducer 1. The noise sensor is used to collect noise data of the harmonic reducer 1. It is the noise detection component of the harmonic reducer 1 in this embodiment. The detection head ends of the two noise sensors are facing the harmonic reducer 1; the mounting plate 211 is used to mount a temperature sensor 213 on both the opposite sides of one side of the harmonic detector. It is used to monitor the temperature change of the harmonic reducer 1 in real time. It is the temperature measurement component of the harmonic reducer 1 in this embodiment; after the harmonic reducer 1 is installed in the vacuum sealed box 21, a vibration sensor 214 is installed on the rigid wheel 11 of the harmonic reducer 1 to monitor the vibration frequency and vibration amplitude of the harmonic reducer 1 during the transmission process. In this embodiment, the temperature sensor 213, the noise sensor and the vibration sensor 214 on the side wall of the vacuum sealed box 21 close to the mounting plate 211 are all provided with a wireless transmission module for wirelessly sending the test data of the sensor to the control end.

[0067] Replay Figure 2 The test bench 2 is provided with an exhaust pipe 221 connected to the vacuum sealed box 21. One end of the exhaust pipe 221 is connected to the vacuum pump 22. When the vacuum pump 22 is operated, the air in the vacuum sealed box 21 is extracted to create a low vacuum test environment.

[0068] The implementation principle of the test equipment for fatigue life test of a harmonic reducer in an embodiment of the present application is as follows: a noise sensor 212, a vibration sensor 214 and a temperature sensor 213 are arranged in a vacuum sealed box 21 to detect the noise data, vibration frequency and amplitude and temperature rise of the harmonic reducer 1 in real time during operation, and the fatigue life of the harmonic reducer 1 is reasonably evaluated based on the real-time data.

[0069] The main principle is that when fatigue damage occurs in the harmonic reducer 1 during operation, there will be certain noise changes when the flexible wheel 12 and the rigid wheel 11 or the flexible wheel 12 and the wave generator 13 are kneaded. By analyzing the noise detection box, the abnormality can be discovered in time, and the specific fault type and fault location can be determined; when the rigid wheel 11 and the flexible wheel 12 of the harmonic reducer 1 are meshed, as the meshing gear surface wears, the amplitude and vibration frequency of the flexible wheel 12 and the rigid wheel 11 increase. Therefore, according to the vibration spectrum detection, the corresponding fault part of the unqualified harmonic reducer 1 can be predicted in advance, and the meshing vibration trend of the rigid wheel 11 and the flexible wheel 12 can be predicted in advance, so as to make a reasonable prediction of the fatigue life of the meshing part; the temperature fluctuation reflects the internal loss of the harmonic reducer 1 in real time, and the collision and friction of the meshing part of the flexible wheel 12 and the rigid wheel 11 generate heat, which causes the temperature rise of the harmonic reducer 1 over a long period of time. Therefore, during normal transmission, the temperature of the harmonic reducer 1 is also an important factor affecting the fatigue life of the harmonic reducer 1. Therefore, reasonable test items such as vibration test and noise test which can indirectly reflect the fatigue life of the harmonic reducer 1 are added to the basic tests of transmission efficiency, transmission accuracy and working temperature, so that the fatigue life prediction result of the harmonic reducer 1 is more accurate.

[0070] Furthermore, the vacuum sealed box 21 can maintain a low vacuum environment after evacuation to detect the transmission performance of the harmonic reducer 1 under vacuum.

[0071] On the one hand, based on the above-mentioned test equipment for fatigue life test of harmonic reducer, the embodiment of the present application discloses a test method for fatigue life test of harmonic reducer, comprising the following steps:

[0072] The tester opens the vacuum sealed box 21 and installs the harmonic reducer 1. The input end of the harmonic reducer 1 is connected to the input shaft 28, and the output end of the harmonic reducer 1 is connected to the output shaft 29.

[0073] The torque of the load motor 24 is set so that the load torque at the output end of the harmonic reducer 1 is 50N;

[0074] Turn on the torque sensor 251 and the grating sensor 261;

[0075] Turn on the servo motor 23, set the initial output speed of the servo motor 23 to 100 rpm, observe and record the torque measurement value and the actual speed measurement value at the input and output ends of the harmonic reducer 1 at the initial speed;

[0076] Slowly increase the output speed of the servo motor 23 to the rated input speed Z of the harmonic reducer 1 of this model, calculate and record the torque change and actual transmission ratio of the input and output ends of the harmonic reducer 1 during the speed increase process, and fit the torque curve and the transmission ratio change curve;

[0077] The output speed of the servo motor 23 is maintained at Z, the temperature sensor 213, the noise sensor 212 and the vibration sensor 214 are turned on, and the noise data, the noise data and the vibration data when the input speed of the harmonic reducer 1 is Z are recorded as the initial value;

[0078] Continue to slowly increase the speed to 1.5Z, calculate and record the torque change at the input and output ends of harmonic reducer 1 and the actual transmission ratio during the increase of input speed, and fit the torque curve and transmission ratio change curve;

[0079] Record the noise data of harmonic reducer 1 during the process of increasing input speed, bring the noise model into the curve after curve fitting, and compare and judge after obtaining the measurement results;

[0080] Record the amplitude and vibration frequency during the increase of input speed, perform spectrum analysis on the vibration signal, decompose the components of different vibration frequencies, and compare them with the known vibration characteristic frequencies of harmonic reducer 1;

[0081] Record temperature data, fit a graph of temperature changes over time, and evaluate the trend and law of temperature changes with increasing speed;

[0082] After the test is completed, the servo motor 23 stops operating, and after being stationary for a preset period of time, the torque of the load motor 24 is adjusted to 100N, 150N and 200N in turn, and the above process is repeated under each different load torque output by the harmonic reducer 1;

[0083] When the output load of the harmonic reducer 1 is 150N and 200N, it is considered overloaded. The tester should pay attention to the test data of the harmonic reducer 1 under overload;

[0084] After the test is completed, the servo motor 23 stops operating and remains stationary for a preset period of time;

[0085] Turn off the noise sensor 212;

[0086] Open the vacuum pump until the air pressure in the vacuum sealed box 21 is less than 0.0015 Pa, and maintain this air pressure condition to keep the vacuum sealed box 21 in a low vacuum state;

[0087] The above steps are repeated to test the performance of the harmonic reducer 1 under each load torque, and the test data of the harmonic reducer 1 under vacuum conditions are obtained.

[0088] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A test method for fatigue life test of harmonic reducer, characterized in that: A test device for fatigue life testing of a harmonic reducer, the test device comprising a test bench (2), the test bench (2) being provided with a rotating part for driving the input end of the harmonic reducer (1) to rotate; The test equipment also includes: A vacuum sealed box (21) is arranged on the test bench (2), and a fixing component for fixing the harmonic reducer (1) is arranged inside the vacuum sealed box; A load member, arranged on a side of the vacuum sealed box (21) away from the rotating member, and used to provide an output load during a test process; An air extraction component connected to the vacuum sealed box (21) to extract the air inside the vacuum sealed box (21) to create a low vacuum environment; A vibration measuring device installed in the vacuum sealed box (21) and used for collecting vibration signals of the harmonic reducer (1); A noise detection component, arranged in the vacuum sealed box (21), for detecting noise data of the harmonic reducer (1); A temperature measuring device, arranged in the vacuum sealed box (21), for measuring the operating temperature of the harmonic reducer (1); Torque measuring parts (25) are arranged opposite to each other on both sides of the vacuum sealed box (21), and the two torque measuring parts (25) are respectively connected to the rotating part and the load part, and are used to measure the input torque and output torque of the harmonic reducer (1); A rotation speed measuring member (26) is disposed opposite to each other on both sides of the vacuum sealed box (21), and the two rotation speed measuring members (26) are respectively connected to the rotating member and the load member, and are used to measure the input rotation speed and the output rotation speed of the harmonic reducer (1); The test method comprises the following steps: Open the vacuum sealed box (21), install the harmonic reducer (1), connect the input end of the harmonic reducer (1) to the rotating part, and connect the output end of the harmonic reducer (1) to the load part; The load component is set so that the load torque at the output end of the harmonic reducer (1) is 50N; Open the torque measuring component (25) and the rotation speed measuring component (26); Open the rotating part; The initial output speed of the rotating part is set to 100 rpm, and the torque measurement values ​​and the actual speed measurement values ​​at the input and output ends of the harmonic reducer (1) at the initial speed are observed and recorded; Slowly increase the speed to the rated input speed Z of the harmonic reducer (1), calculate and record the torque change and actual transmission ratio of the input and output ends of the harmonic reducer (1) during the speed increase process, and fit the torque curve and the transmission ratio change curve; Continue to slowly increase the speed to 1.5Z, calculate and record the torque change at the input and output ends of the harmonic reducer (1) and the actual transmission ratio during the increase of the input speed, and fit the torque curve and the transmission ratio change curve; The test method also includes the following steps: Before the speed of the harmonic reducer (1) is slowly increased from the rated speed Z to 1.5Z, the temperature measuring component and the noise detecting component are turned on; Record the noise data of the harmonic reducer (1) during the process of increasing the input speed, bring the noise model into the curve after curve fitting, and compare and judge after obtaining the measurement results; Record the operating temperature of the harmonic reducer (1) at the rated speed at this time as the initial temperature; Open the vacuum part until the air pressure in the vacuum sealed box (21) is less than 0.0015 Pa, observe the change trend of the transmission ratio of the harmonic reducer (1) and the change trend of the temperature during the change of the air pressure, and fit the change curve; The test method also includes the following steps: Before the environment in the vacuum sealed box (21) becomes a low vacuum environment with an air pressure less than 0.0015 Pa, the vibration measuring component is turned on; When the speed of the harmonic reducer (1) is slowly increased from the rated speed Z to 1.5Z: Performing spectrum analysis on the vibration signal collected by the vibration measuring device to decompose the components of different vibration frequencies and compare them with the known vibration characteristic frequencies of the harmonic reducer (1); Analyze the temperature data collected by the temperature measuring device, fit the temperature change curve over time, and evaluate the trend and law of temperature change with the increase of speed.

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