A method and apparatus for testing the performance of an insulating bearing coating

Abstract

The application provides an insulating bearing coating performance test method and a test device, and belongs to the technical field of insulating bearing coating detection, wherein the insulating bearing coating performance test method comprises the following steps: installing a to-be-detected insulating bearing sample on a bearing fixture; automatically stopping the number of impacts by controlling the detection insulation value set by an analysis unit; judging whether the insulating bearing sample is insulation failure due to damage to the insulating coating organizational structure; and testing the influence of the damage to the coating organizational structure of the insulating bearing sample at the impact damage point on the insulation performance of the insulating bearing sample. The insulating bearing coating performance test method provided by the application can obtain the evolution law of the influence of internal organizational structure defects on the insulation performance of the insulating bearing coating by damage detection and insulation performance detection under different degrees of impact at the same impact position, and can truly reflect the relationship between the insulation life of the insulating bearing and the degree of impact.

Description

Technical Field

[0001] This invention relates to the field of insulating bearing coating testing technology, specifically to a method and apparatus for testing the performance of insulating bearing coatings. Background Technology

[0002] Rolling elements in bearings are crucial core components in mechanical equipment, often referred to as the "joints" of these systems. With the rapid development of variable frequency drive technology, AC variable frequency motors are increasingly used in mechanical equipment. However, for high-power, high-voltage, explosion-proof variable frequency motors, high-speed train traction motors, and thermal, wind, and hydroelectric generators, the electrolytic corrosion of their internal bearings remains a long-standing and critical technical challenge hindering the operation and safety of these large-scale equipment. Applying an insulating coating to the inner or outer ring surface of the bearing is one of the most economical and effective methods to solve the electrolytic corrosion problem of traction motor bearings.

[0003] Typically, thermal spraying technology is used to prepare an alumina coating on the surface of motor bearings to improve their insulation performance. However, during the installation and use of insulated bearings, drops and impacts are inevitable, which can damage the internal structure of the coating and create internal defects. In actual operation, environmental changes and fluctuations in process parameters can also damage the internal structure of the bearing surface coating, creating internal defects and severely affecting the insulation performance of the insulated bearing.

[0004] To improve the safety and reliability of insulated bearings, it is necessary to explore the internal correlation mechanism between internal defects in the insulating coating and its insulating performance, and to develop methods and testing systems for evaluating the insulating performance of insulated bearing coatings after structural damage. Currently available testing methods are conventional methods for testing the insulating performance of coatings, and do not address the impact of damage to the internal structure of the coating on its insulating properties.

[0005] For example, the application document with publication number CN114062388A, publication date February 18, 2022, entitled "A Device and Method for Detecting Defects in Ceramic Coatings of Insulating Bearings," proposes using multiple receivers and photodetectors to simultaneously detect the intensity of scattered light from the defective surface, achieving a complete scan and detection of the ceramic coating of the insulating bearing. The final detection signals are all transmitted to a control terminal for analysis and to generate detection results. This device and method are used to detect various defects in the ceramic coating of insulating bearings, such as cracks, holes, and pitting in porous areas, but they cannot reflect the impact of the degree of damage to the coating's microstructure on the bearing's insulation performance. Summary of the Invention

[0006] Therefore, the present invention provides a method and testing device for testing the performance of insulating bearing coatings.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for testing the performance of insulating bearing coatings, comprising the following steps:

[0008] The insulated bearing sample to be tested is mounted on the bearing clamp, and the bearing clamp is rotated to the position where impact damage is expected;

[0009] The impact ball is adjusted to a preset height and falls freely to impact the insulating bearing sample. The insulating bearing sample is then rotated counterclockwise by the first angle so that the damaged area of ​​the insulating bearing coating corresponds to the test probe of the damage tester. The microstructure of the damaged area of ​​the insulating bearing coating is tested, and the microstructure of the coating damage acquired by the damage tester is transmitted to the control and analysis unit through the data acquisition unit.

[0010] The insulating bearing sample is rotated to a second angle so that the damaged area of ​​the insulating bearing coating structure corresponds to the insulation performance tester. The resistance, capacitance or breakdown voltage data of the damaged area of ​​the insulating bearing coating structure are tested, and the test data are transmitted to the control and analysis unit.

[0011] Continue rotating the insulating bearing sample by a third angle until it returns to its initial position. Repeat the above steps. The automatic number of impacts is cut off by controlling the insulation value set by the analysis unit to determine whether the insulating bearing sample has failed due to damage to the insulating coating structure. At the same time, the impact of the coating structure damage at the impact damage point on the insulation performance of the insulating bearing sample is tested.

[0012] Optionally, it also includes a step of online analysis of the microstructure characteristics of coating damage.

[0013] Optionally, the method also includes the step of rotating the insulated bearing sample to a new location to be subjected to impact damage and repeating the test.

[0014] Optionally, the insulated bearing sample has at least five impact damage locations.

[0015] Optionally, the preset height of the impact ball is 0-3m.

[0016] Optionally, the first angle is 90 degrees, the second angle is 180 degrees, and the third angle is 90 degrees.

[0017] The testing device is also provided, including: a base, on which a ball drop support is provided, wherein an impact ball is adapted to be mounted;

[0018] An electric motor is mounted on the base, and an insulating bearing sample is mounted on the drive shaft of the motor, with the position of the insulating bearing sample mounted on the drive shaft corresponding to the landing point of the impact ball in the ball drop bracket.

[0019] The damage testing instrument is suitable for detecting the microstructure morphology of damaged areas in the coating of insulating bearings.

[0020] Insulation performance tester is suitable for testing the resistance, capacitance or breakdown voltage source data at the damaged area of ​​the coating structure of insulating bearings;

[0021] The data acquisition unit is electrically connected to the damage tester and the insulation performance tester;

[0022] The control and analysis unit, together with the data acquisition unit, is adapted to analyze the data transmitted by the data acquisition unit.

[0023] Optionally, the ball drop support includes a frame, on which a track is provided, the extension direction of which is perpendicular to the plane where the base is located;

[0024] The mounting base is slidably mounted on the track, the mounting base is adapted to hold the impact ball, and the mounting base is provided with a gate adapted to prevent the impact ball from falling.

[0025] Optionally, a linear motor is installed on the frame, and the drive end of the linear motor forms the track.

[0026] Optionally, it also includes a bearing clamp disposed on the drive shaft of the motor, and the insulating bearing sample is adapted to be installed in the bearing clamp.

[0027] The technical solution of this invention has the following advantages:

[0028] 1. The insulating bearing coating performance testing method provided by the present invention can obtain the evolution law of the influence of internal structural defects on the insulation performance of the insulating bearing coating by detecting damage and insulation performance under different degrees of impact at the same impact location, and can truly reflect the relationship between the insulation life of the insulating bearing and the degree of impact.

[0029] 2. The method for testing the performance of insulating bearing coatings provided by this invention has at least five impact damage locations on the bearing sample. Multiple tests can be performed using one insulating bearing, resulting in high testing efficiency and high integration. It is suitable for rapid testing of the insulation performance of insulating bearing coatings. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the test device provided in Embodiment 2 of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Motor; 2. Drive shaft; 3. Bearing clamp; 4. Bearing sample; 5. Impact ball; 6. Damage tester; 7. Insulation performance tester; 8. Control and analysis unit; 9. Data acquisition unit; 10. Ball drop support; 11. Gate; 12. Ball drop channel. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] Example 1

[0039] This embodiment provides a specific implementation method for testing the performance of insulating bearing coatings, such as... Figure 1As shown, the process includes the following steps: The insulating bearing sample 4 to be tested is mounted on the bearing clamp 3, and the bearing clamp 3 is rotated to the location of the impact damage; the impact ball 5 is adjusted to a preset height, and after the impact ball 5 falls freely and impacts the insulating bearing sample 4, the insulating bearing sample 4 is rotated counterclockwise by a first angle, so that the damaged area of ​​the insulating bearing coating structure corresponds to the test probe of the damage tester 6, the microstructure morphology of the damaged area of ​​the insulating bearing coating structure is tested, and the microstructure morphology data of the coating structure damage acquired from the damage tester 6 is transmitted to the control and analysis unit 8 through the data acquisition unit 9; the insulating bearing sample 4 is then rotated by a second angle. The insulation performance tester 7 is used to test the resistance, capacitance, or breakdown voltage data of the damaged area of ​​the insulation bearing coating structure, and the test data is transmitted to the control and analysis unit 8. The insulation bearing sample 4 is rotated by a third angle to return it to the initial position. The above steps are repeated. The number of impacts is automatically cut off according to the detection insulation value set by the control and analysis unit 8. It is determined whether the insulation of the insulation bearing sample 4 has failed due to the damage of the insulation coating structure. At the same time, the influence of the coating structure damage at the impact damage point on the insulation performance of the insulation bearing sample 4 is tested.

[0040] Specifically, the first angle is 90 degrees, the second angle is 180 degrees, and the third angle is 90 degrees.

[0041] In this embodiment, the damage test and the insulation performance test are not ordered; either one can be tested first.

[0042] In this embodiment, the method also includes a step of online analysis of the microscopic morphological characteristics of coating damage, such as crack length, number of cracks, area of ​​spalling, and depth of spalling.

[0043] In this embodiment, the method further includes rotating the insulating bearing sample 4 to a new impact damage location for repeated testing. Specifically, the insulating bearing sample 4 has at least five impact damage locations. By performing damage testing and insulation performance testing on each impact damage location, the influence of the damaged microstructure on the insulation performance can be analyzed.

[0044] Case 1: The insulation performance of an insulating bearing with an deposited alumina coating was tested using the insulating bearing coating performance test method described in Example 1. The specific steps are as follows:

[0045] Step 1: Install the insulated bearing with the deposited alumina coating on the bearing clamp 3, start the motor 1, rotate the insulated bearing to the position to be impacted and damaged, and adjust the impact ball 5 to the 1m position;

[0046] Step Two: Open gate 11, impact ball 5 falls, striking the insulating bearing with the deposited alumina coating; start motor 1, rotate the insulating bearing with the deposited alumina coating 90 degrees counterclockwise, so that the damaged area of ​​the coating structure is facing the objective lens of the fiber optic microscope, and use an electric push rod to push the optical microscope towards the insulating bearing. Use the automatic focusing function of the optical microscope to test the surface morphology of the damaged area of ​​the alumina coating structure. The surface morphology data of the coating structure damage (such as cracks, spalling, and other defect morphology) acquired from the optical microscope is transmitted to the control and analysis unit 8 through data acquisition unit 9. Start motor 1 again, continue to rotate the insulating bearing 180 degrees, so that the damaged area of ​​the coating structure is facing the resistance tester, and use an electric push rod to push the resistance tester towards the insulating bearing, so that the probe of the resistance tester contacts the damaged area of ​​the alumina coating structure. Apply voltage (0-10000V) to the damaged area of ​​the alumina coating structure through the test probe, test the insulation resistance data of the alumina coating, and transmit the obtained insulation resistance value to the control and analysis unit 8. The surface morphology of alumina coating damage (such as crack length, crack number, and spall area) was analyzed online, the trend of insulation resistance value of alumina coating was recorded, and the insulation resistance value of alumina coating under what morphological characteristics of coating damage caused a sudden change, the relationship between the two was analyzed, and finally the test results were formed.

[0047] Step 3: Restart motor 1 and rotate the insulating bearing to the initial position. Repeat step 2. Automatically cut off the number of impacts by controlling the insulation value (insulation resistance less than 50 megohms) set by the control analysis unit 8. Determine whether the insulating bearing with the deposited alumina coating has failed due to damage to the alumina coating structure. Test the effect of the coating structure damage at the impact damage point on the insulation performance of the insulating bearing sample 4.

[0048] Step 4: Restart motor 1 and rotate the insulated bearing with the aluminum oxide coating to the new impact damage position. Repeat steps 2 and 3 again.

[0049] Step 5: Test at least five locations of structural damage on the insulated bearing to ultimately evaluate the impact of structural damage to the alumina coating on the evolution of the bearing's insulation performance.

[0050] Case 2: The insulation performance of an insulating bearing with a deposited silica coating was tested using the insulating bearing coating performance testing method of Example 1. The specific steps are as follows:

[0051] Step 1: Install the insulated bearing with the silica coating onto the bearing clamp 3, start the motor 1, rotate the insulated bearing to the position to be impacted and damaged, and adjust the impact ball 5 to 1m.

[0052] Step 2: Start the drive chain, causing the ball tray on it to move upwards carrying the 0.15Kg impact ball 5. After moving upwards to the ball recovery channel, the impact ball 5 enters the ball drop channel 12 of the ball drop module along the ball recovery channel. Start the drive chain again, and stop the drive chain after the ball tray on the drive chain reaches the gate 11. Open the gate 11, and the impact ball 5 falls, hitting the insulating bearing with a silica coating. After hitting the insulating bearing, it rolls into the collection gate through the inclined collection plate and stops on the ball tray. Start the motor 1 and rotate the insulating bearing sample with a silica coating 490° counterclockwise, so that the damaged area of ​​the coating structure is facing the test probe of the optical 3D surface profilometer. Use an electric push rod to push the optical 3D surface profilometer towards the insulating bearing sample 4. Use the automatic focusing function of the optical 3D surface profilometer to test the three-dimensional morphology of the damaged area of ​​the silica coating structure. The surface morphology data of coating structure damage (such as cracks, spalling, and other defect morphology) acquired by the optical 3D surface profilometer is transmitted from the data acquisition unit 9 to the control and analysis unit 8. The motor 1 is restarted, and the insulating bearing sample 4 is rotated 180° to align the damaged area of ​​the coating structure with the high-voltage breakdown tester. An electric push rod is used to push the high-voltage breakdown tester towards the insulating bearing sample 4, bringing the test probe of the high-voltage breakdown tester into contact with the damaged area of ​​the silica coating structure. A voltage (0–10000V) is applied to the damaged area of ​​the silica coating through the test probe, and the breakdown voltage data of the silica coating is measured. The obtained breakdown voltage value is then transmitted to the control and analysis unit 8. Online analysis of the surface morphology of silica coating damage (such as crack length, number of cracks, area and depth of spalling) is performed, the trend of the breakdown voltage of the silica coating is recorded, and the morphological characteristics of the coating damage are investigated to find the abrupt change in the breakdown voltage of the silica coating. The relationship between the two is analyzed, and the test results are finally formed. The combined use of an optical 3D surface profilometer and a high-voltage breakdown tester can analyze the breakdown morphology of the silica coating after it is completely broken down, which is crater-shaped along the cracks / weak points of the coating. This can be used to analyze the relationship between the coating damage and the breakdown voltage.

[0053] Step 3: Restart motor 1, rotate the insulating bearing to the initial position, repeat step 2, and automatically stop the number of impacts by controlling the insulation value (breakdown voltage less than 1000V) set by the control analysis unit 8 to determine whether the insulating bearing sample 4 with silica coating deposited on the surface has failed due to damage to the silica coating structure. Test the effect of coating structure damage at the impact damage point on the insulation performance of the insulating bearing sample 4.

[0054] Step 4: Restart motor 1 and rotate the insulated bearing with the silicon dioxide coating to the new impact damage position. Repeat steps 2 and 3 again.

[0055] Step 5: Test at least five locations of structural damage in the insulated bearing to ultimately evaluate the impact of structural damage to the silica coating on the evolution of bearing insulation performance.

[0056] Example 2

[0057] This embodiment provides a specific implementation of the testing device, such as... Figure 1 As shown, the device includes a base, on which a ball drop support 10 is mounted, on which an impact ball 5 can be placed; a motor 1 is mounted on the base, and an insulating bearing sample 4 can be mounted on the drive shaft 2 of the motor 1, with the position of the insulating bearing sample 4 on the drive shaft 2 of the motor 1 corresponding to the landing point of the impact ball 5 in the ball drop support 10; a damage tester 6 is mounted on the ball drop support 10, and an insulation performance tester 7 is mounted on the base; it also includes a data acquisition unit 9 and a control and analysis unit 8.

[0058] Specifically, the data acquisition unit 9 is electrically connected to the damage tester 6, the data acquisition unit 9 is electrically connected to the insulation performance tester 7, and the control and analysis unit 8 is electrically connected to the data acquisition unit 9.

[0059] In this embodiment, the ball drop support 10 includes a frame with a track on it. The track extends perpendicularly to the plane of the base. A mounting seat and a support rod are slidably mounted on the track. The mounting seat is rotatably mounted on the support rod. The mounting seat is shaped like a scoop. In its natural state, the mounting seat is tilted and can accommodate the impact ball 5. After receiving the impact ball 5, the mounting seat slides upward. When the mounting seat touches the ball drop channel 12, the mounting seat rotates around the support rod until the bearing surface of the mounting seat bearing the impact ball 5 is parallel to the ball drop channel 12, so that the impact ball 5 can enter the ball drop channel 12. The mounting seat can hold the impact ball 5. The ball drop channel 12 is also provided with a gate 11 suitable for blocking the impact ball 5 from falling. When the gate 11 is open, the impact ball 5 can fall freely. When the gate 11 is closed, the impact ball 5 stays on the gate 11.

[0060] Specifically, a linear motor 1 is installed on the frame, and the drive end of the linear motor 1 forms a track.

[0061] Specifically, a bearing clamp 3 is provided on the drive shaft 2 of the motor 1, and the insulated bearing sample 4 is installed in the bearing clamp 3 to prevent the insulated bearing sample 4 from shifting during the testing process.

[0062] In this embodiment, a ball-carrying tray is also installed on the base, located on one side of the insulating bearing sample 4, and a transmission chain is provided on the bracket. The transmission chain can drive the ball-carrying tray to move upward to the ball-dropping channel 12 of the mounting seat, so that the impact ball 5 enters the mounting seat and is located at the gate 11.

[0063] Specifically, the impact ball 5 is a stainless steel ball.

[0064] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for testing the performance of an insulating bearing coating, characterized in that, Includes the following steps: The insulated bearing sample to be tested is mounted on the bearing clamp, and the bearing clamp is rotated to the position where impact damage is expected; The impact ball is adjusted to a preset height and falls freely to impact the insulating bearing sample. The insulating bearing sample is then rotated counterclockwise by the first angle so that the damaged area of ​​the insulating bearing coating corresponds to the test probe of the damage tester. The microstructure of the damaged area of ​​the insulating bearing coating is tested, and the microstructure of the coating damage acquired by the damage tester is transmitted to the control and analysis unit through the data acquisition unit. The insulating bearing sample is rotated to a second angle so that the damaged area of ​​the insulating bearing coating structure corresponds to the insulation performance tester. The resistance, capacitance or breakdown voltage data of the damaged area of ​​the insulating bearing coating structure are tested, and the test data are transmitted to the control and analysis unit. Continue rotating the insulating bearing sample to a third angle until it returns to the initial impact damage position. Repeat the above steps. Automatically cut off the number of impacts by controlling the insulation value set by the analysis unit to determine whether the insulating bearing sample has failed due to damage to the insulating coating structure. At the same time, test the effect of the coating structure damage at the impact damage point on the insulation performance of the insulating bearing sample.

2. The method for testing the performance of insulating bearing coatings according to claim 1, characterized in that, It also includes a step of online analysis of the microstructure characteristics of coating damage.

3. The method for testing the performance of insulating bearing coatings according to claim 2, characterized in that, It also includes the step of rotating the insulated bearing sample to a new location to be subjected to impact damage and repeating the test.

4. The method for testing the performance of insulating bearing coatings according to claim 3, characterized in that, The insulating bearing sample has at least five locations to be impacted and damaged.

5. The method for testing the performance of insulating bearing coatings according to claim 1, characterized in that, The preset height of the impact ball is 0-3m.

6. The method for testing the performance of insulating bearing coatings according to claim 1, characterized in that, The first angle is 90 degrees, the second angle is 180 degrees, and the third angle is 90 degrees.

7. A testing apparatus, applied to the method for testing the performance of insulating bearing coatings as described in any one of claims 1 to 6, characterized in that, include: A base, on which a ball drop bracket is provided, wherein an impact ball is adapted to be installed; An electric motor is mounted on the base, and an insulating bearing sample is mounted on the drive shaft of the motor, with the position of the insulating bearing sample mounted on the drive shaft corresponding to the landing point of the impact ball in the ball drop bracket. The damage testing instrument is suitable for detecting the microstructure morphology of damaged areas in the coating of insulating bearings. Insulation performance tester is suitable for testing the resistance, capacitance or breakdown voltage source data at the damaged area of ​​the coating structure of insulating bearings; The data acquisition unit is electrically connected to the damage tester and the insulation performance tester; The control and analysis unit, together with the data acquisition unit, is adapted to analyze the data transmitted by the data acquisition unit.

8. The testing apparatus according to claim 7, characterized in that, The ball drop support includes a frame, on which a track is provided, the extension direction of which is perpendicular to the plane where the base is located; The mounting base is slidably mounted on the track, the mounting base is adapted to hold the impact ball, and the mounting base is provided with a gate adapted to prevent the impact ball from falling.

9. The testing apparatus according to claim 8, characterized in that, A linear motor is installed on the frame, and the drive end of the linear motor forms the track.

10. The testing apparatus according to claim 7, characterized in that, It also includes a bearing clamp disposed on the drive shaft of the motor, and the insulating bearing sample is adapted to be installed in the bearing clamp.

Images