New energy automobile motor shaft damage detection method

Abstract

The invention discloses a new energy automobile motor shaft damage detection method, and relates to the technical field of mechanical part tests.The new energy automobile motor shaft damage detection system comprises an eddy current detection module, an ultrasonic detection module and a track setting module, and the eddy current detection module sweeps a motor shaft through an eddy current detection method; the estimation module is used for estimating approximate distribution of distortion cracks and fatigue cracks, the ultrasonic detection module is used for scanning axial areas of the distortion cracks and the fatigue cracks by adopting a spiral scanning method and a circumferential stepping scanning method, and the track setting module is used for setting a scanning track according to the axial distribution of the fatigue cracks and the distortion cracks. The eddy current detection module comprises an eddy current sensor, a signal processing unit and a data acquisition module, the signal processing unit is electrically connected with the eddy current sensor, and the data acquisition module is electrically connected with the signal processing unit.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic detection technology, and in particular to a method for detecting damage to a motor shaft of a new energy vehicle. Background Art

[0002] New energy vehicles offer improved acceleration performance, especially at starting and low speeds, requiring the motor shaft to possess strong torsional resistance. The motor generates a high instantaneous torque during starting, and the motor shaft must be able to effectively withstand and transmit this torque to prevent deformation or fracture. To detect torsional damage on the motor shaft, an ultrasonic probe is used to probe the interior. During crack testing for torsional damage, cracks in the motor shaft are primarily divided into torsional cracks that develop in an axial direction due to an inability to withstand torsional deformation, and fatigue cracks that extend radially around the axis due to long-term repetitive loads.

[0003] There are two main methods for scanning the trajectory of a motor shaft: spiral scanning and circumferential stepping scanning. With spiral scanning, the ultrasonic probe moves in the axial direction of the motor shaft as it rotates. With circumferential stepping scanning, the ultrasonic probe circles the shaft once, then moves forward a certain distance, repeating this process when the motor shaft is stationary. Another method is eddy current testing, which utilizes the principle of electromagnetic induction to generate eddy currents by applying an alternating current to the surface of a conductive material. Cracks or defects within the material affect the flow of the eddy currents, causing changes in the detection signal. However, this method can only determine the approximate distribution of cracks and cannot provide detailed image information.

[0004] Existing scanning methods use either spiral scanning or circumferential stepping scanning. However, the spiral scanning method suffers from axial deflection errors due to slight torsional deformation of the motor shaft, and the continuous lateral movement makes the error difficult to correct. The circumferential stepping scanning method can miss some cracks due to excessively large stepping feed widths. This is especially true for small or slow-growing cracks, where too small a step width can reduce detection efficiency. Therefore, it is imperative to design a precise and efficient method for detecting motor shaft damage in new energy vehicles. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for detecting damage to a motor shaft of a new energy vehicle to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a new energy vehicle motor shaft damage detection system, the system including an eddy current detection module, an ultrasonic detection module, and a trajectory setting module. The eddy current detection module uses the eddy current detection method to scan the motor shaft and estimate the approximate distribution of torsional cracks and fatigue cracks. The ultrasonic detection module is used to scan the axial areas of torsional cracks and fatigue cracks using a spiral scanning method and a circumferential step scanning method. The trajectory setting module is used to set the scanning trajectory according to the axial distribution of fatigue cracks and torsional cracks.

[0007] According to the above technical solution, the eddy current detection module includes an eddy current sensor, a signal processing unit, and a data acquisition module. The signal processing unit is electrically connected to the eddy current sensor, and the data acquisition module is electrically connected to the signal processing unit. The eddy current sensor is used to generate an alternating current and detect eddy current signals to estimate the crack distribution in the motor shaft. The signal processing unit is used to analyze the changes in the eddy current signal and determine the presence and location of the crack. The data acquisition module is used to collect real-time data of eddy current detection and transmit it to the control system.

[0008] The ultrasonic detection module includes an ultrasonic transmitter, an ultrasonic receiver, a scanning control module, and a scanning image generation module. The ultrasonic receiver is electrically connected to the scanning image generation module, and the scanning control module is electrically connected to the ultrasonic transmitter. The ultrasonic transmitter is used to generate high-frequency sound waves and send them to the motor shaft for crack scanning. The ultrasonic receiver is used to receive the reflected sound wave signal and analyze its characteristics to identify the crack. The scanning control module is responsible for controlling the execution of the spiral scanning method and the circumferential stepping scanning method to ensure coverage of the entire detection area. The scanning image generation module is used to convert the ultrasonic signal into an image signal and generate it on the screen.

[0009] The trajectory setting module includes an area planning module and a parameter setting module. The area planning module is electrically connected to the data acquisition module, and the parameter setting module is electrically connected to the area planning module. The area planning module is used to set the axial areas of the shaft in which the spiral scanning method and the circumferential step scanning method are specifically applied. The parameter setting module is used to set the step feed scanning parameters of the circumferential step scanning method.

[0010] According to the above technical solution, it also includes a main frame, the bottom of the main frame is fixedly connected to a displacement motor by welding, the top of the displacement motor is provided with a screw slide, the slide part of the screw slide is connected to a shaft support, a rotary motor is installed on one side of the top of the main frame, the output end of the rotary motor is connected to a rotary gear through a coupling, sliding support seats are correspondingly installed on both sides of the main frame, a rotary gear disk is rotatably installed between the two sliding support seats, the rotary gear disk and the rotary gear are meshed with each other, and a clamping device is installed on the inner wall of the rotary gear disk.

[0011] According to the above technical solution, the clamping device includes a connecting shell, a wall-attaching wheel is rotatably installed between the inner walls on both sides of the connecting shell, a number of electromagnets are evenly installed on the outer walls of the wall-attaching wheel, and permanent magnets are fixedly installed on the inner walls on both sides of the connecting shell, and the permanent magnets and electromagnets are magnetically attracted to each other.

[0012] According to the above technical solution, an inner hole is opened inside the wall-adhering wheel, and a main air pipe is fixedly installed between the two end faces of the inner hole, one end of the main air pipe extends out of the side wall of the wall-adhering wheel, and an air pump is fixedly installed on the outer wall of one side of the connecting shell, and the output end of the air pump is interconnected with the main air pipe, and bronchi are evenly installed on the main air pipe, and an electromagnetic valve is installed on the bronchi, and the side walls of the inner hole are evenly extended outward to open an installation groove, and a fixed tube is fixedly installed inside the installation groove, and the external sliding sleeve of the fixed tube is connected with a clamping block, and the external sleeve of the fixed tube is provided with a spring, and one end of the spring is connected to the clamping block.

[0013] A method for detecting damage to a motor shaft of a new energy vehicle comprises the following steps:

[0014] S1. Perform a preliminary scan of the motor shaft using the eddy current detection method. The eddy current sensor generates an alternating current and detects the eddy current signal to estimate the approximate distribution of torsional cracks and fatigue cracks in the shaft, and set the step-feed scanning parameters of the circumferential step-scan method.

[0015] S2. Different scanning trajectories are set according to the respective characteristics of torsion cracks and fatigue cracks. A circumferential step-by-step scanning method with a large feed step is used for the axial region of the torsion crack, a spiral scanning method is used for the axial region of the fatigue crack, and a circumferential step-by-step scanning method with a small feed step is used for the region where the two cracks overlap.

[0016] S3. After clamping one end of the motor shaft using a clamping device, the rotary gear rotates and drives the motor shaft to rotate. An ultrasonic transmitter generates high-frequency sound waves to scan the motor shaft for cracks. After rotating the motor shaft one circle in the axial region using the circumferential step scanning method, the ultrasonic transmitter and ultrasonic receiver are driven to move laterally for ultrasonic testing. In the axial region using the spiral scanning method, ultrasonic testing is performed by rotating the motor shaft while moving the ultrasonic transmitter and ultrasonic receiver laterally, and the clamping point is continuously updated.

[0017] S4. The ultrasonic receiver receives the reflected signal and analyzes its characteristics to identify the crack, transmits the signal received by the ultrasonic wave to the scanning image generation module, converts the detection result into an image signal and generates it on the display screen.

[0018] According to the above technical solution, the specific process of detecting eddy current signals in S1 is as follows: fix the eddy current sensor on the surface of the motor shaft to ensure that it is in good contact with the shaft surface, start the power supply of the eddy current sensor, and generate an alternating current through the internal circuit. This alternating current will generate an alternating magnetic field in the sensor coil. When the alternating magnetic field acts on the motor shaft, eddy currents will be generated on its surface. At this time:

[0019] S1-1. When the eddy current sensor detects a twisted crack, it will cause uneven eddy current flow, resulting in phase change, displacement and distortion on the waveform;

[0020] S1-2. When the eddy current sensor detects a fatigue crack, the signal strength is significantly reduced, the frequency in the signal changes, and additional noise appears;

[0021] S1-3. When setting the step-feed scanning parameters of the circumferential step-scanning method, the more severe the waveform displacement is, the smaller the step-feed distance k is. The axial area is divided into several sections, which are recorded as {l1, l2...l n}, n is the paragraph number, and the coordinates are {o1~o2, o2~o3, ..., o n―1 ~o n}, the displacement deviation of the normal eddy current signal at time zero is recorded as F α0 , the displacement deviation of the current paragraph at time zero is recorded as F αi , where i∈1 ～ n, then the relative size of the waveform displacement is The distance of the step feed of the current paragraph Where k0 is the default stepping distance, and γ is the waveform displacement conversion coefficient.

[0022] According to the above technical solution, in S3, the specific method for updating the clamping point is:

[0023] When using the spiral scanning method to detect a certain axial area, first divide this axial area into multiple clamping sections, each clamping section is l0 long, retract the clamping block, start the screw slide to drive the motor shaft to move horizontally, and use the wall wheel to maintain the position during movement. After reaching the edge of this axial area, the clamping block is expanded and the motor shaft and the rotary gear are fixed. At this time, driving the rotary gear to rotate can drive the motor shaft to rotate to complete the ultrasonic spiral scanning. The axial length passed through each scan is l0. After reaching the length of l0, the clamping block is retracted again. This reciprocating process completes the update of the clamping point.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: when performing crack testing, the present invention first uses the eddy current detection method to scan the motor shaft, and estimates the approximate distribution of torsion cracks and fatigue cracks. When designing the trajectory scanning method, according to the respective characteristics of the two cracks, the axial area of the torsion crack is scanned by a circumferential step scanning method with a large feed step, the axial area of the fatigue crack is scanned by a spiral scanning method, and the overlapping axial area where both cracks exist is scanned by a circumferential step scanning method with a small feed step, thereby avoiding axial deflection errors caused by torsion cracks. At the same time, a larger step feed step can also be set. After setting the scanning trajectory, only one scan is required to complete the shaft damage detection, and the detection efficiency is high.

[0025] At the same time, the clamping components of the motor shaft are specifically designed, and new clamping points are established in the axial area of the spiral scanning method. Before scanning using the spiral scanning method, the motor shaft is clamped at its closest position. This effectively reduces the axial deflection error in the scanning result caused by slight torsional deformation of the motor shaft. This clamping point adjustment method is more suitable for combined scanning methods and does not affect the continuity of the spiral scanning method. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 It is a schematic diagram of the detection principle of the present invention;

[0028] Figure 2 It is a schematic diagram of the clamping principle of the present invention;

[0029] Figure 3 This is a schematic diagram of the installation of the wall-adhering wheel of the present invention;

[0030] Figure 4 Schematic diagram of the internal structure of the wall-adhering wheel of the present invention;

[0031] 1. Main frame; 21. Displacement motor; 22. Shaft support; 23. Screw slide; 31. Rotary motor; 32. Rotary gear; 33. Rotary gear plate; 34. Sliding support seat; 4. Clamping device; 41. Connecting shell; 42. Clamping block; 43. Wall wheel; 44. Air pump; 45. Mounting slot; 46. Permanent magnet; 47. Electromagnet; 431. Inner hole; 432. Main air pipe; 433. Solenoid valve; 434. Bronchus; 451. Fixed pipe; 452. Spring. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] See also Figure 1-Figure 4 The present invention provides a technical solution: a new energy vehicle motor shaft damage detection system, comprising an eddy current detection module, an ultrasonic detection module, and a trajectory setting module. The eddy current detection module uses an eddy current detection method to scan the motor shaft and estimate the approximate distribution of torsion cracks and fatigue cracks. The ultrasonic detection module is used to scan the axial areas of torsion cracks and fatigue cracks using a spiral scanning method and a circumferential step scanning method. The trajectory setting module is used to set the scanning trajectory according to the axial distribution of fatigue cracks and torsion cracks.

[0034] The eddy current detection module includes an eddy current sensor, a signal processing unit, and a data acquisition module. The signal processing unit is electrically connected to the eddy current sensor, and the data acquisition module is electrically connected to the signal processing unit. The eddy current sensor is used to generate an alternating current and detect eddy current signals to estimate the crack distribution in the motor shaft. The signal processing unit is used to analyze the changes in the eddy current signal and determine the existence and location of the crack. The data acquisition module is used to collect real-time data of eddy current detection and transmit it to the control system;

[0035] The ultrasonic detection module includes an ultrasonic transmitter, an ultrasonic receiver, a scanning control module, and a scanning image generation module. The ultrasonic receiver is electrically connected to the scanning image generation module, and the scanning control module is electrically connected to the ultrasonic transmitter. The ultrasonic transmitter is used to generate high-frequency sound waves and send them to the motor shaft for crack scanning. The ultrasonic receiver is used to receive the reflected sound wave signal and analyze its characteristics to identify cracks. The scanning control module is responsible for controlling the execution of the spiral scanning method and the circumferential stepping scanning method to ensure coverage of the entire detection area. The scanning image generation module is used to convert the ultrasonic signal into an image signal and generate it on the screen.

[0036] The trajectory setting module includes a region planning module and a parameter setting module. The region planning module is electrically connected to the data acquisition module, and the parameter setting module is electrically connected to the region planning module. The region planning module is used to set the axial regions of the shaft in which the spiral scanning method and the circumferential step scanning method are specifically applied. The parameter setting module is used to set the step feed scanning parameters of the circumferential step scanning method.

[0037] The main frame 1 also includes a main frame 1, the bottom of the main frame 1 is fixedly connected to a displacement motor 21 by welding, a screw slide 23 is provided on the top of the displacement motor 21, the slide portion of the screw slide 23 is connected to the shaft support 22, a rotary motor 31 is installed on one side of the top of the main frame 1, the output end of the rotary motor 31 is connected to a rotary gear 32 through a coupling, and sliding support seats 34 are correspondingly installed on both sides of the main frame 1. A rotary gear disk 33 is rotatably installed between the two sliding support seats 34, and the rotary gear disk 33 and the rotary gear 32 mesh with each other, and a clamping device 4 is installed on the inner wall of the rotary gear disc 33. When the clamping position of the motor shaft needs to be adjusted to update the clamping point, the displacement motor 21 is started to drive the screw slide 23 to move, thereby driving the shaft support 22 to move, applying an axial force to the motor shaft so that it can adjust its position. When the motor shaft needs to be rotated, the rotary motor 31 is started to drive the rotary gear 32 to rotate, thereby driving the rotary gear disc 33 to rotate, so as to adjust the circumferential position of the motor shaft and facilitate circumferential detection.

[0038] The clamping device 4 includes a connecting shell 41, and a wall-adhering wheel 43 is rotatably installed between the inner walls of both sides of the connecting shell 41. A number of electromagnets 47 are evenly installed on the outer walls of the wall-adhering wheel 43. Permanent magnets 46 are fixedly installed on the inner walls of both sides of the connecting shell 41. The permanent magnets 46 and the electromagnets 47 are magnetically attracted to each other. When the axial position of the motor shaft is adjusted, the surface of the motor shaft is moved in contact with the wall-adhering wheel 43, and the wall-adhering wheel 43 is used to prevent it from falling. When the belt is adjusted to a suitable position, it is necessary to rotate the wall-adhering wheel 43 to a certain angle to align with the surface of the motor shaft. At this time, the electromagnet 47 closest to the permanent magnet 46 is energized, so that the electromagnet 47 is aligned with the permanent magnet 46, which facilitates subsequent clamping work.

[0039] An inner hole 431 is provided inside the wall-adhering wheel 43, and a main air pipe 432 is fixedly installed between the two end faces of the inner hole 431, and one end of the main air pipe 432 extends out of the side wall of the wall-adhering wheel 43, and an air pump 44 is fixedly installed on the outer wall of one side of the connecting shell 41, and the output end of the air pump 44 is connected to the main air pipe 432, and bronchial tubes 434 are evenly installed on the main air pipe 432, and an electromagnetic valve 433 is installed on the bronchial tube 434. The side wall of the inner hole 431 is evenly extended outward to provide a mounting groove 45, and a fixing pipe 451 is fixedly installed inside the mounting groove 45, and the outer side of the fixing pipe 451 is slidably sleeved with a clamping block 42, and the outer side of the fixing pipe 451 is sleeved with a spring 452, and one end of the spring 452 is connected to the clamping block 42. When clamping, first align a certain mounting groove 45 with the surface of the motor shaft, start the air pump 44 to pump air into the main air pipe of the inner hole 431 In 432, the two solenoid valves 433 at the corresponding positions are opened, so that air is injected into the corresponding two fixed tubes 451. The pressure of the air pushes the clamping block 42 outward and firmly presses against the surface of the motor shaft, thereby clamping the motor shaft. When clamping is not needed, it is only necessary to remove the air pressure of the air pump 44 so that there is no pressure in the mounting groove 45. At this time, due to the elastic recovery effect of the spring 452, the clamping block 42 is retracted inward, and the motor shaft and the wall-adhering wheel 43 can rotate and move relative to each other. This clamping and releasing method can form a multi-position clamping, which is convenient for updating the clamping position. Compared with conventional electric clamps, this structure can not affect the movement of the motor shaft during normal lateral feed and can smoothly maintain its lateral position so that it will not fall. Conventional clamping methods cannot adjust the lateral position of the motor shaft and can restore the clamping state at any position.

[0040] A method for detecting damage to a motor shaft of a new energy vehicle comprises the following steps:

[0041] S1. Perform a preliminary scan of the motor shaft using the eddy current detection method. The eddy current sensor generates an alternating current and detects the eddy current signal to estimate the approximate distribution of torsional cracks and fatigue cracks in the shaft, and set the step-feed scanning parameters of the circumferential step-scan method.

[0042] S2. Different scanning trajectories are set according to the respective characteristics of torsion cracks and fatigue cracks. A circumferential step-by-step scanning method with a large feed step is used for the axial region of the torsion crack, a spiral scanning method is used for the axial region of the fatigue crack, and a circumferential step-by-step scanning method with a small feed step is used for the region where the two cracks overlap.

[0043] S3. After clamping one end of the motor shaft using the clamping device 4, the rotary gear disc 33 rotates and drives the motor shaft to rotate. An ultrasonic transmitter is used to generate high-frequency sound waves to scan the motor shaft for cracks. After the motor shaft rotates one circle in the axial area of the circumferential step scanning method, the ultrasonic transmitter and ultrasonic receiver are driven to move and feed laterally to perform ultrasonic testing. In the axial area of the spiral scanning method, ultrasonic testing is performed by rotating the motor shaft while moving the ultrasonic transmitter and ultrasonic receiver laterally, and the clamping point is continuously updated.

[0044] S4, the ultrasonic receiver receives the reflected signal and analyzes its characteristics to identify the crack, transmits the signal received by the ultrasonic wave to the scanning image generation module, converts the detection result into an image signal and generates it on the display screen;

[0045] In S1, the specific process of detecting eddy current signals is as follows: fix the eddy current sensor to the surface of the motor shaft, ensure that it is in good contact with the shaft surface, start the power supply of the eddy current sensor, and generate an alternating current through the internal circuit. This alternating current will generate an alternating magnetic field in the sensor coil. When the alternating magnetic field acts on the motor shaft, eddy currents will be generated on its surface. At this time:

[0046] S1-1. When the eddy current sensor detects a twisted crack, it will cause uneven eddy current flow, resulting in phase change, displacement and distortion on the waveform;

[0047] S1-2. When the eddy current sensor detects a fatigue crack, the signal strength is significantly reduced, the frequency in the signal changes, and additional noise appears;

[0048] S1-3. When setting the step-feed scanning parameters of the circumferential step-scanning method, the more severe the waveform displacement is, the smaller the step-feed distance k is. The axial area is divided into several sections, which are recorded as {l1, l2...l n}, n is the paragraph number, and the coordinates are {o1~o2, o2~o3, ..., o n―1 ~o n}, the displacement deviation of the normal eddy current signal at time zero is recorded as F α0 , the displacement deviation of the current paragraph at time zero is recorded as F αi , where i∈1 ～ n, then the relative size of the waveform displacement is The distance of the step feed of the current paragraph Where k0 is the default step feed distance, and γ is the waveform displacement conversion coefficient. The step feed distance is adaptively adjusted according to the severity of the distortion crack. The more severe the crack, the smaller the set feed distance and the more detailed the inspection, which is convenient for improving the inspection effect while saving the inspection time as much as possible.

[0049] In S3, the specific method for updating the clamping point is:

[0050] When using the spiral scanning method to detect a certain axial area, first divide this axial area into multiple clamping sections, each clamping section has a length of l0, retract the clamping block 42, start the screw slide 23 to drive the motor shaft to move laterally, and use the wall wheel 43 to maintain the position during movement. After reaching the edge of this axial area, the clamping block 42 is expanded and the motor shaft and the rotating gear disc 33 are fixed. At this time, driving the rotating gear disc 33 to rotate can drive the motor shaft to rotate to complete the ultrasonic spiral scanning. The axial length of each scan is l0. After reaching the length of l0, the clamping block 42 is retracted again. This reciprocating process completes the update of the clamping point. After the clamping point is updated, the lateral positions of the ultrasonic transmitter and the ultrasonic receiver need to be updated synchronously so that scanning can continue at the same position of the motor shaft when continuing the spiral scanning method.

[0051] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0052] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A new energy vehicle motor shaft damage detection system, characterized by: The system includes an eddy current detection module, an ultrasonic detection module, and a trajectory setting module. The eddy current detection module uses the eddy current detection method to scan the motor shaft and estimate the approximate distribution of torsion cracks and fatigue cracks. The ultrasonic detection module is used to scan the axial areas of torsion cracks and fatigue cracks using a spiral scanning method and a circumferential step scanning method. The trajectory setting module is used to set the scanning trajectory according to the axial distribution of fatigue cracks and torsion cracks.

2. A new energy vehicle motor shaft damage detection system according to claim 1, characterized in that: The eddy current detection module includes an eddy current sensor, a signal processing unit, and a data acquisition module. The signal processing unit is electrically connected to the eddy current sensor, and the data acquisition module is electrically connected to the signal processing unit. The eddy current sensor is used to generate an alternating current and detect eddy current signals to estimate the crack distribution in the motor shaft. The signal processing unit is used to analyze changes in the eddy current signal to determine the presence and location of the crack. The data acquisition module is used to collect real-time data of eddy current detection and transmit it to the control system. The ultrasonic detection module includes an ultrasonic transmitter, an ultrasonic receiver, a scanning control module, and a scanning image generation module. The ultrasonic receiver is electrically connected to the scanning image generation module, and the scanning control module is electrically connected to the ultrasonic transmitter. The ultrasonic transmitter is used to generate high-frequency sound waves and send them to the motor shaft for crack scanning. The ultrasonic receiver is used to receive the reflected sound wave signal and analyze its characteristics to identify the crack. The scanning control module is responsible for controlling the execution of the spiral scanning method and the circumferential stepping scanning method to ensure coverage of the entire detection area. The scanning image generation module is used to convert the ultrasonic signal into an image signal and generate it on the screen. The trajectory setting module includes an area planning module and a parameter setting module. The area planning module is electrically connected to the data acquisition module, and the parameter setting module is electrically connected to the area planning module. The area planning module is used to set the axial areas of the shaft in which the spiral scanning method and the circumferential step scanning method are specifically applied. The parameter setting module is used to set the step feed scanning parameters of the circumferential step scanning method.

3. The new energy vehicle motor shaft damage detection system according to claim 2 is characterized in that: The invention also includes a main frame (1), wherein the bottom of the main frame (1) is fixedly connected to a displacement motor (21) by welding, the top of the displacement motor (21) is provided with a screw slide (23), the slide portion of the screw slide (23) is connected to a shaft support (22), a rotary motor (31) is installed on one side of the top of the main frame (1), the output end of the rotary motor (31) is connected to a rotary gear (32) through a coupling, and sliding support seats (34) are correspondingly installed on both sides of the main frame (1), a rotary gear disk (33) is rotatably installed between the two sliding support seats (34), the rotary gear disk (33) and the rotary gear (32) are meshed with each other, and a clamping device (4) is installed on the inner wall of the rotary gear disk (33).

4. The new energy vehicle motor shaft damage detection system according to claim 3 is characterized in that: The clamping device (4) comprises a connecting shell (41), a wall-adhering wheel (43) is rotatably mounted between the inner walls of both sides of the connecting shell (41), a plurality of electromagnets (47) are evenly mounted on the outer walls of the wall-adhering wheel (43), and permanent magnets (46) are fixedly mounted on the inner walls of both sides of the connecting shell (41), and the permanent magnets (46) and the electromagnets (47) are magnetically attracted to each other.

5. The new energy vehicle motor shaft damage detection system according to claim 4 is characterized in that: An inner hole (431) is provided inside the wall-adhering wheel (43), and a main air pipe (432) is fixedly installed between the two end surfaces of the inner hole (431). One end of the main air pipe (432) extends out of the side wall of the wall-adhering wheel (43). An air pump (44) is fixedly installed on the outer wall of one side of the connecting shell (41). The output end of the air pump (44) is connected to the main air pipe (432). The main air pipe (432) is evenly installed with bronchial ( 434), a solenoid valve (433) is installed on the bronchus (434), the side wall of the inner hole (431) is uniformly extended outward to form a mounting groove (45), a fixed tube (451) is fixedly installed inside the mounting groove (45), the outside of the fixed tube (451) is slidably sleeved with a clamping block (42), the outside of the fixed tube (451) is sleeved with a spring (452), and one end of the spring (452) is connected to the clamping block (42).

6. A new energy vehicle motor shaft damage detection method, characterized by: The following steps are involved: S1. Perform a preliminary scan of the motor shaft using the eddy current detection method. The eddy current sensor generates an alternating current and detects the eddy current signal to estimate the approximate distribution of torsional cracks and fatigue cracks in the shaft, and set the step-feed scanning parameters of the circumferential step-scan method. S2. Different scanning trajectories are set according to the respective characteristics of torsion cracks and fatigue cracks. A circumferential step-by-step scanning method with a large feed step is used for the axial region of the torsion crack, a spiral scanning method is used for the axial region of the fatigue crack, and a circumferential step-by-step scanning method with a small feed step is used for the region where the two cracks overlap. S3. After clamping one end of the motor shaft using the clamping device (4), the rotary gear disc (33) is rotated to drive the motor shaft to rotate, and an ultrasonic transmitter is used to generate high-frequency sound waves to scan the motor shaft for cracks. After the motor shaft is rotated once in the axial region of the circumferential step scanning method, the ultrasonic transmitter and the ultrasonic receiver are driven to move and feed laterally to perform ultrasonic testing. In the axial region of the spiral scanning method, ultrasonic testing is performed by rotating the motor shaft while feeding the ultrasonic transmitter and the ultrasonic receiver laterally, and the clamping point is continuously updated. S4. The ultrasonic receiver receives the reflected signal and analyzes its characteristics to identify the crack, transmits the signal received by the ultrasonic wave to the scanning image generation module, converts the detection result into an image signal and generates it on the display screen.

7. A new energy vehicle motor shaft damage detection method according to claim 6, characterized in that: In S1, the specific process of detecting eddy current signals is as follows: fix the eddy current sensor on the surface of the motor shaft to ensure good contact with the shaft surface, start the power supply of the eddy current sensor, and generate an alternating current through the internal circuit. This alternating current will generate an alternating magnetic field in the sensor coil. When the alternating magnetic field acts on the motor shaft, eddy currents will be generated on its surface. At this time: S1-1. When the eddy current sensor detects a twisted crack, it will cause uneven eddy current flow, resulting in phase change, displacement and distortion on the waveform; S1-2. When the eddy current sensor detects a fatigue crack, the signal strength is significantly reduced, the frequency in the signal changes, and additional noise appears; S1-3. When setting the step-feed scanning parameters of the circumferential step-scanning method, the more severe the waveform displacement is, the smaller the step-feed distance k is. The axial area is divided into several sections, which are recorded as {l1, l2...l n }, n is the paragraph number, and the coordinates are {o1~o2, o2~o3, ..., o n―1 ~o n }, the displacement deviation of the normal eddy current signal at time zero is recorded as F α0 , the displacement deviation of the current paragraph at time zero is recorded as F αi , where i∈1~n, then the relative size of the waveform displacement is The distance of the step feed of the current paragraph Where k0 is the default stepping distance, and γ is the waveform displacement conversion coefficient.

8. The method for detecting motor shaft damage in a new energy vehicle according to claim 7, wherein: In S3, the specific method for updating the clamping point is: When a certain axial area is detected by the spiral scanning method, the axial area is first divided into a plurality of clamping sections, each of which has a length of l0. The clamping block (42) is retracted, and the screw slide (23) is started to drive the motor shaft to move laterally. The position is maintained by the wall wheel (43) during the movement. After reaching the edge of the axial area, the clamping block (42) is unfolded and the motor shaft and the rotating gear disc (33) are fixed. At this time, the rotating gear disc (33) is driven to rotate to drive the motor shaft to rotate to complete the ultrasonic spiral scanning. The axial length of each scanning is l0. After reaching the length of l0, the clamping block (42) is retracted again. This reciprocating process completes the update of the clamping point.

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