Gear fretting wear test device and test method

Abstract

The invention relates to the technical field of gear fretting wear, in particular to a gear fretting wear test device and method, the test device comprises a base, a gear transmission mechanism and a load applying mechanism, the gear transmission mechanism comprises a gear box and a locking seat, the gear box is provided with an input shaft and an output shaft, and the output shaft is connected with the locking seat; the load applying mechanism comprises a balance lever frame, the balance lever frame is installed on an input shaft of the gearbox, a balance weight piece and a vibration excitation source are arranged at the two ends of the balance lever frame respectively, and the vibration excitation source and the balance weight piece are matched in a coordinated mode and can apply time-varying torque to the input shaft. The test method is realized by adopting the device. According to the technical scheme, the complex contact form between gear meshing teeth in the gear locking state can be simulated, specifically, the time-varying torque is adjusted by changing the frequency and amplitude of the excitation force provided by the excitation source, and finally the grinding trace amount is calculated through meshing tooth surface morphology data obtained in two times. And simulation and quantification of the fretting wear state of the gear in the locked state are realized.

Description

Technical Field

[0001] The invention relates to the technical field of gear fretting wear, in particular to a gear fretting wear testing device and a testing method. Background Art

[0002] In recent years, wind power, as a key component of clean energy, has experienced rapid growth amidst the global energy transition. China leads the world with an installed capacity exceeding 300 gigawatts, accounting for over one-third of the global total. China's wind power industry, burgeoning in the 1990s, has, after years of development, established a comprehensive industrial chain encompassing wind turbine manufacturing, wind farm construction, operation, and maintenance. Technological advancements continue, with a domestic production rate exceeding 90%. Driven by policies, technologies, and markets, the wind power industry is experiencing unprecedented growth opportunities and is poised to become a key force in driving the global energy transition.

[0003] In modern mechanical engineering, gears, as core components of power transmission, are widely used in the field of wind turbine transmission. They are also the components with the highest failure rate in wind turbines. To ensure the long-term and stable operation of wind turbines, the wind power industry adopts a regular operation and maintenance strategy for wind turbines. During the shutdown inspection and operation and maintenance process, considering the complex and changeable working environment, the blades produce tiny vibrations under the action of random wind loads, causing key parts such as gears and bearings to bear alternating loads, and the gear tooth contact surface to produce tiny reciprocating motions. The gear meshing is under a heavy load and poor lubrication state, making it difficult to form an effective lubricating oil film on the contact surface. Once the meshing tooth surfaces undergo a slight relative sliding, the gear tooth surfaces are prone to micro-wear. The micro-wear generated during the operation and maintenance process will not only reduce the transmission accuracy and strength of the gears, but may even cause pitting, peeling, or even fracture of the gears, greatly affecting the performance and service life of the wind turbine.

[0004] Existing research on fretting wear mainly focuses on parts such as bearings, materials and splines, and there is relatively little research on fretting wear of gears. Some gear fretting wear research is based on the ball-plane contact model, simulating micro-vibrations through a mechanical drive system, and combining a normal load application device to realize tooth surface fretting wear testing; considering that the gear tooth contact process is very complex, simple simulated contact cannot accurately carry out gear fretting wear testing, and it is difficult to effectively solve the problem of fretting wear of wind turbine gears in the locked state; for this type of problem encountered in the shutdown operation and maintenance of wind turbines, there is still a lack of gear fretting wear test methods simulating such working conditions. According to the current status of technological innovation and actual needs, there is an urgent need for a convenient, practical and feasible technical solution for gear fretting wear testing under the shutdown operation and maintenance state of wind turbine transmission systems. Summary of the Invention

[0005] The purpose of the present invention is to provide a gear fretting wear test device and test method, which can simulate the gear fretting wear state under the shutdown operation and maintenance state of the wind turbine transmission system, and solve the gap in the existing technology in the gear fretting wear detection under the shutdown operation and maintenance condition of the wind turbine.

[0006] To achieve the above objectives, this paper provides the following technical solutions:

[0007] A gear micro-wear testing device: comprises a base, on which a gear transmission mechanism and a load applying mechanism are provided, the gear transmission mechanism comprises a gear box and a locking seat, the gear box has an input shaft and an output shaft extending outward, wherein the output shaft is connected to the locking seat; the load applying mechanism comprises a balancing lever frame, the middle position of the balancing lever frame is installed on the input shaft of the gear box, and a counterweight and an excitation source are respectively provided at the left and right ends of the balancing lever frame, the excitation source and the counterweight cooperate to apply time-varying torque to the input shaft.

[0008] As a preferred solution of the present application: the excitation source includes a drive motor, an eccentric mass block and a controller, the drive motor is fixed at the end of the balance lever frame, and its transmission shaft is connected to the eccentric mass block, the controller is electrically connected to the drive motor and can adjust the speed of the drive motor.

[0009] As a preferred solution of the present application: the eccentric mass block includes a rotating body and an eccentric shaft, and the eccentric shaft is provided with multiple groups of mounting holes equidistantly along its length direction. By adjusting the positions of the mounting holes, the center of mass of the eccentric mass block can be adjusted.

[0010] As a preferred solution of the present application: a gear set consisting of a large gear and a small gear meshing with each other is provided in the gearbox, the transmission shaft of the small gear is connected to the input shaft, and the transmission shaft of the large gear is connected to the output shaft.

[0011] As a preferred solution of the present application: bearings and shaft seals are respectively provided on both sides of the pinion and the gear. The bearings are used to support the input shaft and the output shaft and bear radial and axial loads. The shaft seals are used to prevent the leakage of lubricant inside the gearbox and the entry of external contaminants.

[0012] As a preferred solution of the present application: the locking seat is provided with an axial hole and a keyway adapted to the output shaft, the output shaft is inserted into the axial hole and is locked in axial rotation by the keyway.

[0013] As a preferred solution of the present application: it also includes a meshing tooth surface morphology data acquisition unit, which is used to measure and obtain the meshing tooth surface morphology data before and after the test in the gearbox.

[0014] The present application also provides a gear fretting wear test method, which uses the gear fretting wear test device described above. The method specifically includes the following steps:

[0015] Step S1: measuring and obtaining the initial morphology data of the meshing tooth surface in the gearbox;

[0016] Step S2: adjusting the counterweight and the excitation source so that the balance lever frame is in a horizontal balance state, starting the excitation source to provide a periodically changing time-varying torque to the balance lever frame, and measuring and acquiring the wear morphology data of the meshing tooth surfaces in the gearbox again after rotating for a required period;

[0017] Step S3: Calculate the wear trace amount based on the meshing tooth surface topography data obtained twice in step S1 and step S2. Specifically, the wear amount V is obtained using the following algorithm: s :

[0018]

[0019] Where Ω is the tooth surface topography field, V i is the i-th wear volume, i = {1, 2, 3, ···, n}.

[0020] As a preferred solution of the present application: when testing the micro-wear state of the gear under different torques of the input shaft, the distance between the center of mass of the excitation source and the center of rotation can be adjusted, and the counterweight can be adjusted to make the balance lever frame in a static equilibrium state again before executing steps S2 and S3, and the center of rotation is the connection point between the excitation source and the balance lever frame.

[0021] As a preferred solution of the present application: the distance between the center of mass of the excitation source and the center of rotation is adjusted by adjusting the position of the mounting hole of the eccentric mass block. The specific algorithm for obtaining the time-varying torque T borne by the input shaft is:

[0022] T=(lc±i·e)·sin(ω+Ψ)·Mg

[0023] Where lc is the distance between the center of mass and the center of rotation of the excitation source;

[0024] i is the number of mounting holes on the eccentric mass block;

[0025] e is the center distance between adjacent mounting holes;

[0026] ω is the angular velocity of the eccentric mass;

[0027] Ψ is the initial phase, which is zero in this experiment;

[0028] g is the acceleration due to gravity;

[0029] M is the mass of the eccentric mass.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The gear fretting wear test device of this scheme has a simple structure and can simulate the complex contact form between the gear meshing teeth when the gear is in a locked state under heavy load and poor lubrication conditions. Specifically, the time-varying torque is adjusted by changing the frequency and amplitude of the excitation force provided by the excitation source, and then the frequency, amplitude and rotation angle of the micro-displacement rotation of the meshing teeth in the gear box are adjusted. Finally, the wear mark amount is calculated by using the meshing tooth surface morphology data obtained twice before and after, thereby realizing the simulation and quantification of the gear fretting wear state in the locked state. It can be seen that the gear fretting wear test device and test method of this scheme are not only easy to use, but also repeatable, providing new tools and means for the study of gear fretting wear in the locked state. At the same time, when changing the frequency and amplitude of the excitation force output by the excitation source, the time-varying torque can be amplified by different multiples in combination with the counterweight and the balance lever frame, which is suitable for testing requirements of various gears and different time-varying torques, thereby improving the wide range of use.

[0032] Figures in the specification

[0033] Figure 1 This is a schematic diagram of the overall structure of the gear fretting wear testing device provided by the present invention.

[0034] Figure 2 This is a schematic diagram of the internal structure of the gearbox provided by the present invention.

[0035] Figure 3 Schematic diagram of the torque analysis applied to the input shaft provided by the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 10 is the base; 20 is the gearbox; 21 is the locking seat; 22 is the input shaft; 23 is the output shaft; 24 is the large gear; 25 is the small gear; 26 is the angular contact ball bearing; 27 is the oil shield; 28 is the felt ring; 29 is the bearing end cover; 30 is the balance lever frame; 31 is the counterweight; 32 is the excitation source; 321 is the drive motor; 322 is the eccentric mass block; 323 is the controller; 324 is the threaded hole; 325 is the mounting hole; 33 is the annular boss; 34 is the data cable; 35 is the set screw; 4 is the key. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with specific implementation methods and with reference to the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present invention and its application.

[0038] This embodiment provides a gear fretting wear test device, such as Figure 1As shown, the device includes a base 10, which serves as a supporting structure and an operating platform, and is provided with a gear transmission mechanism and a load applying mechanism. The gear transmission mechanism includes a gear box 20 and a locking seat 21. The gear box 20 includes a tooth seat and a tooth cover. It can be understood that a gear set should be provided in the gear box 20. The gear box 20 is also provided with an input shaft 22 and an output shaft 23 connected to the gear set and extending outward. The input shaft 22 is connected to the load applying mechanism, and the output shaft 23 is coaxially arranged with the locking seat 21 and fixed by the locking seat 21. In this embodiment, the output shaft 23 is fixed by the locking seat 21 to simulate the locking state of the gear set, thereby providing a basis for the micro-wear of the gear; the load applying mechanism includes a balancing lever frame 30, the middle position of which is installed on the input shaft 22 of the gear box 20, and the axial displacement is limited by a set screw 35 (the set screw 35 is axially perpendicular to the input shaft 22). It can be understood that the balance The lever frame 30 should be suspended with the input shaft 22 as the support point. The left and right ends of the balancing lever frame 30 are respectively provided with a counterweight 31 and an excitation source 32. The excitation source 32 and the counterweight 31 cooperate to apply a time-varying torque to the input shaft 22. Specifically, the counterweight 31 is placed on the left side of the balancing lever frame 30. The counterweight 31 includes a counterweight block and a small tray. The small tray is fixed on the balancing lever frame 30, and the counterweight block is placed on the small tray. The balance degree of the left and right sides of the balancing lever frame 30 can be adjusted by adding or subtracting the counterweight block. On the one hand, the counterweight 31 is used to adjust the static equilibrium state of the balancing lever frame 30 at the initial time, and on the other hand, it is used to offset part of the dynamic force of the excitation source 32 when it is in action to reduce vibration. The excitation source 32 is placed on the right side of the balancing lever frame 30 to provide a stable vibration frequency and amplitude, thereby providing a periodically changing alternating torque to the input shaft 22. The alternating torque will drive the input shaft 22 to rotate synchronously, thereby providing power for the gear micro-motion.

[0039] In order to facilitate the acquisition of wear data, the device in this embodiment also includes a meshing tooth surface morphology data acquisition unit, which is used to measure and obtain the meshing tooth surface morphology data before and after the test in the gear box 20, and calculate the micro-wear of the meshing tooth surface based on the data. In this embodiment, the meshing tooth surface morphology data acquisition unit is preferably an existing three-dimensional profilometer.

[0040] In this embodiment, a stable and periodically changing alternating torque is provided to the input shaft 22 of the gear box 20 by a load applying mechanism, and the output shaft 23 of the gear seat is fixed by the locking seat 21, so that the state of the wind turbine gear in the locked state can be effectively simulated. In addition, the time-varying torque can be adjusted by changing the frequency and amplitude of the excitation force provided by the excitation source 32, and then the frequency, amplitude and rotation angle of the micro-displacement rotation of the meshing teeth in the gear box 20 can be adjusted, that is, the micro-motion external force of different torques is provided to the gear to form micro-motion friction between the meshing teeth. Finally, by The wear traces were calculated using the meshing tooth surface morphology data obtained in the last two times, which realized the simulation and quantification of the gear fretting wear state in the locked state. It can be seen that the gear fretting wear test device of this scheme is not only easy to use, but also repeatable, and provides new tools and means for the study of gear fretting wear in the locked state. At the same time, when the frequency and amplitude of the excitation force output by the excitation source 32 are changed, the time-varying torque can be amplified by different multiples in combination with the counterweight 31 and the balance lever frame 30, which is applicable to the test requirements of various gears and different time-varying torques, thereby improving the wide range of use.

[0041] It can be understood that after completing a static balancing of the balancing lever frame 30 , a complete dynamic wear test is performed.

[0042] The excitation source 32 includes a driving motor 321, an eccentric mass block 322 and a controller 323. The driving motor 321 is preferably a stepper motor. The stepper motor has four threaded holes 324, which are fixed to one end of the balance lever frame 30 by the cooperation of bolts and threaded holes 324. Its transmission shaft is connected to the eccentric mass block 322 through a key 4, driving the eccentric mass block 322 to rotate at a uniform speed, and then providing a time-varying torque to the balance lever frame 30 through the eccentric mass block 322. In this embodiment, an annular boss 33 is provided between the eccentric mass block 322 and the balance lever frame 30 to prevent the eccentric mass block 322 from colliding with the bolts; the controller 323 is fixed on the base 10, and is connected to the stepper motor through a data line 34 to control the start and stop and speed of the stepper motor.

[0043] The eccentric mass block 322 includes a rotating body and an eccentric shaft. The rotating body is a rectangular block. The eccentric shaft and the rotating body are integrally formed, and a plurality of mounting holes 325 are equidistantly provided on the eccentric shaft along its length. By adjusting the position of the mounting holes 325, the center of mass of the eccentric mass block 322 can be adjusted. Adjusting the center of mass of the eccentric mass block 322 can adjust the eccentricity and centrifugal force, thereby affecting the time-varying torque exerted on the input shaft 22. In this embodiment, in order to ensure the stability of the installation of the eccentric mass block 322, it is preferred that threaded holes 324 corresponding to the number and position of the mounting holes 325 are further provided on the eccentric shaft. The setting direction of the threaded holes 324 is perpendicular to the axial direction of the mounting holes 325 at the corresponding position. After the eccentric mass block 322 is installed on the transmission shaft of the stepper motor through the mounting holes 325, the axial displacement of the eccentric mass block 322 is limited by the cooperation between the bolts and the threaded holes 324, thereby improving the stability of the installation of the eccentric mass block 322.

[0044] The specific principle of adjusting the center of mass of the eccentric mass 322 to adjust the magnitude of the time-varying torque on the input shaft 22 is as follows:

[0045] The two ends of the balance lever are respectively acted upon by the torque of the counterweight 31 and the eccentric mass block 322. When the eccentric mass block 322 rotates, centrifugal force will be generated due to the deviation of the center of mass, and then a periodic dynamic load will be generated through the centrifugal force. Since the torque actually borne by the input shaft 22 is the superposition of the counterweight 31 and the eccentric mass block 322, and the direction of the centrifugal force of the eccentric mass block 322 changes periodically, this will cause the actual torque borne by the input shaft 22 to fluctuate over time. By adjusting the position of its center of mass (eccentricity) and rotational speed, the magnitude and frequency of the time-varying torque borne by the input shaft 22 can be precisely controlled to ensure that the time-varying torque is completely generated by the dynamic component of the centrifugal force, thereby avoiding static eccentric loading.

[0046] As a preferred solution of this embodiment, a gear set consisting of a large gear 24 and a small gear 25 is provided in the gear box 20. The transmission shaft of the small gear 25 is connected to the input shaft 22 through a key 4, and the small gear 25 rotates alternately clockwise and counterclockwise under the drive of the input shaft 22; the transmission shaft of the large gear 24 is connected to the output shaft 23 through a key 4, and the large gear 24 is locked by the locking seat 21 through the output shaft 23. When the small gear 25 rotates, micro-friction occurs between the meshing teeth of the two.

[0047] Bearings and shaft seals are respectively provided on both sides of the small gear 25 and the large gear 24. The bearings are used to support the input shaft 22 and the output shaft 23 and bear radial and axial loads. The shaft seals are used to prevent the lubricant inside the gear box 20 from leaking and external contaminants from entering. In this embodiment, the bearings are preferably angular contact ball bearings 26, and the shaft seals preferably include at least one of an oil baffle 27, a felt ring 28 and a bearing end cover 29. In this embodiment, oil baffles 27 and angular contact ball bearings 26 are preferably installed on both sides of the small gear 25, and felt rings 28 and angular contact ball bearings 26 are respectively installed on both sides of the large gear 24. At the same time, oil baffles 27 are provided at the ports extending from the output shaft 23 and the input shaft 22. The oil baffles 27 prevent the lubricant inside the gear box 20 from leaking and block the entry of external contaminants.

[0048] As a preferred solution of this embodiment, the locking seat 21 is fixed to the base 10 by bolts. The locking seat 21 is provided with an axial hole and a keyway adapted for the output shaft 23. The output shaft 23 is inserted into the axial hole and is locked in axial rotation by the keyway; that is, the output shaft 23 is locked by the locking seat 21 so that it cannot rotate, thereby simulating the locked state of the wind turbine gear.

[0049] The present application also provides a gear fretting wear test method, which uses the gear fretting wear test device in the above embodiment and specifically includes the following steps:

[0050] Step S1: measuring and acquiring initial morphological data of the meshing tooth surface in the gearbox 20;

[0051] In this step, the initial topography data of the meshing tooth surface can be obtained by opening the gear cover of the gear box 20 or after the gear set is assembled. The specific choice depends on the specific situation. The acquisition of the initial topography data of the meshing tooth surface provides a reference basis for the subsequent calculation of micro-wear.

[0052] Step S2: Adjust the counterweight 31 and the excitation source 32 so that the balance lever frame 30 is in a horizontal balance state, start the excitation source 32 to provide a periodically changing time-varying torque to the balance lever frame 30, and after rotating for a required period, measure and obtain the wear morphology data of the meshing tooth surfaces in the gearbox 20 again;

[0053] The excitation source 32 includes a drive motor 321, an eccentric mass block 322, and a controller 323. The connection relationship between the three is described in the above-mentioned device embodiment and will not be repeated here. In this step, the counterweight 31 and the excitation source 32 are adjusted to bring the balancing lever frame 30 into a balanced and stable state. The main method is to first adjust the center of mass of the eccentric mass block 322, and then achieve a static equilibrium state of the balancing lever frame 30 by increasing or decreasing the number of counterweight blocks on the small tray.

[0054] After the static balance adjustment is completed, the drive motor 321 (stepper motor) is started to drive the eccentric mass block 322 to rotate. Since the two ends of the balance lever are respectively subjected to the torque of the counterweight 31 and the eccentric mass block 322, the deviation of the center of mass during the rotation of the eccentric mass block 322 will generate centrifugal force, which in turn generates a periodic dynamic load through the centrifugal force, ensuring that a stable and periodically changing time-varying torque is provided to the end of the input shaft 22. The time-varying torque is generated by the dynamic component of the centrifugal force of the eccentric mass block 322. The dynamically changing torque is transmitted to the pinion 25 by the input shaft 22, driving the pinion 25 to rotate alternately clockwise and counterclockwise. Since the large gear 24 is fixed by the locking seat 21, micro-friction will be generated between the meshing teeth of the pinion 25 and the large gear 24 during this process.

[0055] The rotation period of the eccentric mass block 322 can be selected according to actual test needs. It is understandable that one rotation of the eccentric mass block 322 is one period. After reaching the required period, the drive motor 321 is turned off to stop the rotation of the eccentric mass block 322, and then the gear cover of the gear box 20 is opened to measure again and obtain the wear morphology data of the meshing tooth surface of the gear box 20;

[0056] Step S3: Calculate the wear trace amount based on the meshing tooth surface topography data obtained twice in step S1 and step S2. Specifically, the wear amount V is obtained using the following algorithm: s :

[0057]

[0058] Where Ω is the tooth surface topography field, V i is the i-th wear volume, i = {1, 2, 3, ···, n};

[0059] In this step, the maximum meshing area of the gear is used as the tooth surface topography field. The wear area during the wear process is obtained by subtracting the initial meshing tooth surface topography data from the acquired meshing tooth surface wear topography data. Because normalization is used, multiplying by 1 is its wear volume, also known as wear amount. Then, by integrating and summing, the wear volumes of different units are accumulated to obtain the wear amount in the entire tooth width direction.

[0060] In this embodiment, the specific calculation method of the wear amount can be calculated by the developed software, or it can be calculated using existing instruments. In this embodiment, the existing three-dimensional profilometer is preferably used to obtain the meshing tooth surface morphology data and perform the calculation.

[0061] In this embodiment, a static leveling is a wear measurement under a specific torque. In order to simulate the wear conditions under different torques or different frequencies, the distance between the center of mass of the excitation source 32 and the center of rotation, that is, the eccentricity, can be adjusted, and the counterweight 31 can be adjusted to make the balance lever frame 30 in a static equilibrium state again before executing steps S2 and S3. The center of rotation is the connection point between the excitation source 32 and the balance lever frame 30. It can be understood that in this embodiment, the center of mass of the excitation source 32 is the center of mass of the eccentric mass block 322. Figure 3 It can be seen that the distance Lc between the center of mass c of the eccentric mass block 322 and the center of rotation g can be adjusted through the mounting hole 325 on the eccentric mass block 322, that is, by adjusting the position of the mounting hole 325, the change in the length of the distance Lc between the center of mass c of the eccentric mass block 322 and the center of rotation g can change the frequency and amplitude of the excitation force output by the excitation source 32 (that is, the time-varying torque of the input shaft 22), and then the frequency, amplitude and rotation angle of the micro-displacement rotation of the meshing teeth in the gear box 20 can be adjusted, and finally the measurement of the micro-wear of the gears under different time-varying torques can be realized.

[0062] In this embodiment, the specific algorithm for obtaining the time-varying torque T borne by the input shaft 22 is:

[0063] T=(lc±i·e)·sin(ω+Ψ)·Mg

[0064] Wherein, lc is the distance between the center of mass and the center of rotation of the excitation source 32;

[0065] i is the number of mounting holes 325 on the eccentric mass block 322;

[0066] e is the center distance between adjacent mounting holes 325;

[0067] ω is the rotational angular velocity of the eccentric mass 322;

[0068] Ψ is the initial phase, which is zero in this experiment;

[0069] g is the acceleration due to gravity;

[0070] M is the mass of the eccentric mass 322;

[0071] It can be understood that in this algorithm, the rotational angular velocity ω of the eccentric mass block 322 can be achieved by adjusting the rotational speed n of the stepper motor. Specifically, The mass of the eccentric mass block 322 can be obtained by a high-precision scale.

[0072] In this algorithm, it is preferred to use a “-” sign (minus sign) when the current mounting hole 325 is close to the center of mass of the eccentric mass block 322 , and a “+” sign (positive sign) when it is far from the center of mass of the eccentric mass block 322 .

[0073] It is understandable that, when necessary, the mass of the gear meshing surface before and after wear can be directly obtained, specifically the mass of the meshing surface of the pinion 25 before and after wear, and the mass difference is calculated. The mass difference is compared with the wear amount obtained by the three-dimensional profiler to verify whether the result is accurate and to realize the calibration of the three-dimensional profiler wear amount algorithm.

[0074] This algorithm can be used to calculate the actual dynamic torque currently borne by the input shaft 22 based on the position of the mounting hole 325 where the eccentric mass block 322 is installed, forming a corresponding relationship with the wear amount obtained subsequently, providing data support for subsequent wear research.

[0075] The above is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A gear fretting wear test device, characterized by: It comprises a base, on which a gear transmission mechanism and a load applying mechanism are provided, the gear transmission mechanism comprises a gear box and a locking seat, the gear box has an input shaft and an output shaft extending outward, wherein the output shaft is connected to the locking seat; the load applying mechanism comprises a balancing lever frame, the middle position of the balancing lever frame is installed on the input shaft of the gear box, and a counterweight and an excitation source are respectively provided at the left and right ends of the balancing lever frame, the excitation source and the counterweight cooperate to apply time-varying torque to the input shaft.

2. The gear fretting wear testing device according to claim 1, characterized in that: The excitation source includes a drive motor, an eccentric mass block and a controller. The drive motor is fixed to the end of the balance lever frame, and its transmission shaft is connected to the eccentric mass block. The controller is electrically connected to the drive motor and can adjust the speed of the drive motor.

3. The gear fretting wear testing device according to claim 2, characterized in that: The eccentric mass block comprises a rotating body and an eccentric shaft. The eccentric shaft is provided with a plurality of mounting holes at equal intervals along its length. By adjusting the positions of the mounting holes, the center of mass of the eccentric mass block can be adjusted.

4. The gear fretting wear testing device according to claim 1, characterized in that: The gear box is provided with a gear set consisting of a large gear and a small gear meshing with each other. The transmission shaft of the small gear is connected to the input shaft, and the transmission shaft of the large gear is connected to the output shaft.

5. The gear fretting wear testing device according to claim 4, characterized in that: Bearings and shaft seals are provided on both sides of the pinion and gear respectively. The bearings are used to support the input shaft and output shaft and bear radial and axial loads. The shaft seals are used to prevent lubricant leakage inside the gearbox and external contaminants from entering.

6. The gear fretting wear testing device according to claim 1, characterized in that: The locking seat is provided with an axial hole and a keyway adapted to the output shaft. The output shaft is inserted into the axial hole and is locked in axial rotation by the keyway.

7. The gear fretting wear testing method according to claim 1, characterized in that: It also includes a meshing tooth surface topography data acquisition unit, which is used to measure and obtain meshing tooth surface topography data before and after the test in the gear box.

8. A gear fretting wear test method, using the gear fretting wear test device according to any one of claims 1 to 7, characterized in that: The method specifically comprises the following steps: Step S1: measuring and obtaining the initial morphology data of the meshing tooth surface in the gearbox; Step S2: adjusting the counterweight and the excitation source so that the balance lever frame is in a horizontal balance state, starting the excitation source to provide a periodically changing time-varying torque to the balance lever frame, and measuring and acquiring the wear morphology data of the meshing tooth surfaces in the gearbox again after rotating for a required period; Step S3: Calculate the wear trace amount based on the meshing tooth surface topography data obtained twice in step S1 and step S2. Specifically, the wear amount V is obtained using the following algorithm: s : Where Ω is the tooth surface topography field, V i is the i-th wear volume, i = {1, 2, 3, ···, n}.

9. The gear fretting wear testing method according to claim 8, characterized in that: When testing the micro-wear state of the gear under different torques on the input shaft, the distance between the center of mass of the excitation source and the center of rotation can be adjusted, and the counterweight can be adjusted so that the balance lever frame is in a static equilibrium state again before executing steps S2 and S3. The center of rotation is the connection point between the excitation source and the balance lever frame.

10. The gear fretting wear testing method according to claim 9, characterized in that: The distance between the center of mass of the excitation source and the center of rotation is adjusted by adjusting the position of the mounting hole of the eccentric mass block. The specific algorithm for obtaining the time-varying torque T borne by the input shaft is: T=(lc±i·e)·sin(ω+Ψ)·Mg Where, lc is the distance between the center of mass and the center of rotation of the excitation source; i is the number of mounting holes on the eccentric mass block; e is the center distance between adjacent mounting holes; ω is the angular velocity of the eccentric mass; Ψ is the initial phase, which is zero in this experiment; g is the acceleration due to gravity; M is the mass of the eccentric mass.

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