An intelligent motor shaft quality detection system for permanent magnet motor production

Abstract

The present invention relates to the technical field of motor shaft quality detection, and in particular to an intelligent motor shaft quality detection system for permanent magnet motor production. The system loads a counterweight onto a corresponding portion of a motor shaft to be detected through a loading unit, fixes the motor shaft, after the counterweight is assembled, to a corresponding position through a fixing unit, determines through a driving unit that the motor shaft rotates at a corresponding speed, performs real-time detection through a detection unit to obtain corresponding vibration amplitudes at both ends of the motor shaft, determines through an analysis unit whether an instruction test process for the motor shaft is qualified based on each vibration amplitude, generates a corresponding instruction through the analysis unit if it is determined to be unqualified, and determines through a control unit to adjust corresponding parameters or issue a corresponding notification based on the instruction, thereby adjusting various links of the test system, thereby improving the quality test process for the motor shaft and thus improving the production efficiency of the permanent magnet motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motor shaft quality detection, and in particular to a motor shaft quality intelligent detection system for permanent magnet motor production. Background Art

[0002] In the production of permanent magnet motors, the motor shaft, a core transmission component, has a quality that directly impacts the motor's performance, reliability, and service life. Traditional motor shaft quality inspection relies primarily on manual measurement or semi-automated equipment, resulting in low efficiency, insufficient accuracy, and poor consistency. Dynamic balancing of the motor shaft is an essential step in permanent magnet motor production, but traditional inspection methods are no longer sufficient to meet the dynamic balancing requirements of modern manufacturing.

[0003] Chinese patent application publication number: CN111969779A, provides a motor shaft dynamic balancing device and its control method, and a motor. This technical solution is provided on the main shaft by a balancing unit including at least two balancing blocks arranged along the circumferential direction, a detection unit is used to detect the vibration signal of the main shaft, and a control unit controls the current applied to each balancing block based on the detected vibration signal, thereby accurately balancing the imbalance of the motor shaft during rotation and realizing the automatic balancing function of the shaft. Although this technical solution achieves the balance of the imbalance of the motor shaft during rotation, this technical solution can only accurately balance the imbalance of the motor shaft during rotation, and does not realize the function of adjusting the system for dynamic balancing performance detection of the motor shaft, thereby failing to ensure the quality of the motor shaft. Summary of the Invention

[0004] To this end, the present invention provides an intelligent motor shaft quality detection system for permanent magnet motor production, which is used to overcome the problem that the existing technology only realizes automatic balancing of the motor shaft but does not make corresponding adjustments to the system for dynamic balancing performance detection of the motor shaft, thereby resulting in low efficiency of motor shaft quality detection.

[0005] To achieve the above objectives, the present invention provides a motor shaft quality intelligent detection system for permanent magnet motor production, comprising:

[0006] A feeding unit, used for conveying a plurality of motor shafts to be tested;

[0007] A fixing unit connected to the feeding unit, comprising two bearings and a base for fixing and clamping the bearings, and used to embed the two ends of the motor shaft into the positions where the two bearings are located;

[0008] a loading unit connected to the fixing unit and used to assemble a plurality of counterweights to corresponding portions of the motor shaft, wherein the corresponding portions include two ends of the motor shaft;

[0009] a drive unit connected to the fixed motor shaft and configured to drive the motor shaft to rotate at a corresponding speed;

[0010] a detection unit connected to the motor shaft and comprising a plurality of sensors for detecting the two ends of the rotating motor shaft in real time to obtain corresponding vibration amplitudes;

[0011] an analyzing unit connected to the detecting unit, configured to determine whether the quality test process for the motor shaft is qualified based on the obtained vibration amplitudes, and to generate an instruction if it is determined to be unqualified;

[0012] A control unit is respectively connected to the analyzing unit, the fixing unit, the loading unit and the detecting unit, and is used to determine, based on the instructions, whether to adjust the installation angle of the counterweight block, or the clamping force of the fixing unit, or the sampling frequency of the detecting unit, or to reconnect the driving unit and the motor shaft, or to issue a notification that the motor shaft is unqualified.

[0013] Furthermore, the analysis unit is further configured to determine whether the quality test process for the motor shaft is qualified based on a comparison result of the vibration amplitude average value and a preset vibration amplitude average value, or to determine whether the quality test process for the motor shaft is qualified in combination with the vibration amplitude ratio;

[0014] Wherein, the analyzing unit is further configured to determine a cause of failure based on a difference between the average vibration amplitude value and the preset average vibration amplitude value when determining that the quality test process for the motor shaft fails;

[0015] Among them, the two vibration amplitudes obtained by detecting the two ends of the motor shaft are divided into a first vibration amplitude and a second vibration amplitude greater than or equal to the first vibration amplitude according to the numerical value, and the vibration amplitude average value is obtained by calculating the average value of the first vibration amplitude and the second vibration amplitude; the vibration amplitude ratio is the ratio of the first vibration amplitude to the second vibration amplitude.

[0016] Furthermore, the analysis unit is further configured to determine whether to adjust the counterweight based on a comparison result of the vibration amplitude ratio and a critical vibration amplitude ratio.

[0017] Furthermore, the analysis unit is further configured to adjust the installation angle of the counterweight when the vibration amplitude ratio is less than or equal to the critical vibration amplitude ratio, and to generate a corresponding instruction based on a comparison result of the amplitude ratio difference with a preset amplitude ratio difference to determine the adjustment of the installation angle of each counterweight, wherein the adjustment amplitude of the installation angle is positively correlated with the amplitude ratio difference;

[0018] The control unit is further configured to control the loading unit to adjust the installation angle of each counterweight based on the instruction;

[0019] The amplitude ratio difference is the absolute value of the difference between the critical vibration amplitude ratio and the vibration amplitude ratio.

[0020] Furthermore, the analysis unit is further configured to reacquire the vibration amplitude ratio after completing the adjustment of the installation angle of each counterweight block and compare it with the critical vibration amplitude ratio to determine whether to reconnect the drive unit and the motor shaft;

[0021] The analyzing unit is further configured to generate a corresponding instruction to determine reconnecting the driving unit and the motor shaft when the vibration amplitude ratio is less than or greater than the critical vibration amplitude ratio;

[0022] The control unit is further configured to control the driving unit to disconnect and reconnect with the motor shaft based on the instruction.

[0023] Furthermore, the analysis unit is further configured to determine the reason why the quality test process of the motor shaft fails based on a comparison result of the amplitude average difference and a preset amplitude average difference;

[0024] The analyzing unit determines based on the cause that the motor shaft is unqualified, or issues an instruction to adjust the sampling frequency of the detecting unit during data acquisition, or obtains a plurality of historical vibration amplitude average values and corresponding times based on the determination result and plots a time-vibration amplitude curve, and re-determines the processing based on the time-vibration amplitude curve;

[0025] The amplitude average difference is the difference between the vibration amplitude average value and the preset vibration amplitude average value.

[0026] Furthermore, the analysis unit is further configured to determine whether to increase the clamping force of the fixing unit based on a comparison result of the amplitude curve integral and the critical amplitude curve integral;

[0027] The amplitude curve integral is obtained by integrating the time-vibration amplitude curve.

[0028] Furthermore, the analysis unit is further configured to increase the clamping force of the fixing unit when the integral of the amplitude curve is greater than the integral of the critical amplitude curve, and to generate a corresponding instruction based on a comparison result of the curve integral difference with a preset curve integral difference to determine an increase amplitude of the clamping force of the fixing unit, wherein the increase amplitude of the clamping force is positively correlated with the curve integral difference;

[0029] The control unit is further configured to control the fixing unit to increase the clamping force based on the instruction;

[0030] The curve integral difference is the difference between the amplitude curve integral and the critical amplitude curve integral.

[0031] Furthermore, the analysis unit is further configured to reacquire the amplitude curve integral after completing the clamping force increase adjustment of the fixing unit and compare it with the critical amplitude curve integral to determine whether to replace the bearing in the fixing unit;

[0032] The analysis unit is further configured to generate a corresponding instruction to determine replacement of the bearing when the amplitude curve integral is greater than the critical amplitude curve integral;

[0033] The control unit is further configured to issue a notification to replace the two bearings in the fixing unit based on the instruction.

[0034] Furthermore, the analysis unit is further configured to determine to increase the sampling frequency when the amplitude average difference is greater than the preset amplitude average difference, and further configured to generate a corresponding instruction based on a comparison result of the average difference ratio with the preset average difference ratio to determine an increase amplitude of the sampling frequency, wherein the increase amplitude is positively correlated with the average difference ratio;

[0035] The control unit is further configured to control the detection unit to increase the sampling frequency based on the instruction;

[0036] The average difference ratio is the ratio of the amplitude average difference to the preset amplitude average difference.

[0037] Compared with the prior art, the beneficial effect of the intelligent motor shaft quality detection system for permanent magnet motor production of the present invention is that the system loads the counterweight block to the corresponding part of the motor shaft to be detected through the loading unit, fixes the motor shaft with the counterweight block assembled to the corresponding position through the fixing unit, determines that the motor shaft rotates at the corresponding speed through the driving unit, performs real-time detection through the detection unit to obtain the corresponding vibration amplitudes at both ends of the motor shaft, determines whether the instruction test process for the motor shaft is qualified based on each vibration amplitude through the analysis unit, generates corresponding instructions through the analysis unit if it is determined to be unqualified, and determines the adjustment of corresponding parameters or issues corresponding notifications based on the instructions by the control unit, thereby adjusting each link of the test system, thereby improving the quality test process of the motor shaft, and thus improving the production efficiency of the permanent magnet motor.

[0038] Furthermore, when the present invention makes a comparison judgment based on the average vibration amplitude value and the preset average vibration amplitude value, it further re-judges the quality test process of the motor shaft based on the vibration amplitude ratio and the critical vibration amplitude ratio to ensure the accuracy of the judgment result.

[0039] Furthermore, when the present invention determines that the counterweight needs to be adjusted through the comparison result of the vibration amplitude ratio and the critical vibration amplitude, the amplitude of the adjusted counterweight angle can be determined based on the comparison result of the amplitude ratio difference and the preset amplitude ratio difference, thereby eliminating the influence of the counterweight on the quality test process of the motor shaft, and ensuring that the reason for the failure of the quality test process of the motor shaft is accurately determined.

[0040] Furthermore, when the present invention determines the reason why the quality test process of the motor shaft fails by comparing the amplitude average difference with the preset amplitude average difference, the corresponding processing method can be determined according to the reason, including increasing the sampling frequency of the detection unit or issuing a reason for determining that the motor shaft fails.

[0041] Furthermore, the present invention also determines whether to increase the clamping force of the fixing unit based on the comparison result of the amplitude curve integral and the critical amplitude curve integral, and determines the increase amplitude of the clamping force of the fixing unit based on the comparison result of the curve integral difference and the preset curve integral difference, thereby eliminating the influence of insufficient pre-tightening force of the fixing unit to improve the accuracy of the quality test of the motor shaft.

[0042] Furthermore, the present invention can determine to issue a notice to replace the bearings in the fixing unit when it is determined based on the integral of the amplitude curve that there is no need to increase the clamping force of the fixing unit when the clamping force of the fixing unit is increased, so as to eliminate the influence of the fixing unit on the quality testing process, thereby improving the accuracy of the quality test of the motor shaft.

[0043] Furthermore, when the present invention determines that the sampling frequency of the detection unit is insufficient, it can also determine the increase in the sampling frequency based on the comparison result of the average difference ratio and the preset average difference ratio to improve the sampling accuracy and thereby improve the quality test efficiency of the motor shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a module schematic diagram of the motor shaft quality intelligent detection system for permanent magnet motor production according to the present invention;

[0045] Figure 2 Schematic diagram of the process of applying the intelligent detection system for motor shaft quality in permanent magnet motor production according to the present invention;

[0046] Figure 3 This is a logic decision diagram for determining whether a quality test process of a motor shaft is qualified based on the average value of the vibration amplitude and corresponding processing according to the present invention;

[0047] Figure 4 This is a logic decision diagram for determining the reasons for failure in the quality test process of the motor shaft based on the average amplitude difference and the corresponding processing according to the present invention. DETAILED DESCRIPTION

[0048] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0049] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the term "connection" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0051] Please refer to Figure 1As shown, it is a module diagram of the intelligent detection system for motor shaft quality used in the production of permanent magnet motors in this embodiment. The system includes a feeding unit, a loading unit, a fixing unit, a driving unit, a detection unit, an analysis unit, and a control unit. The feeding unit can use a conveying device with a continuous conveying function to convey the motor shafts one by one from the production line to the next link; the fixing unit is connected to the feeding unit, and the fixing unit includes two bearings and a base for fixing and clamping the bearings. The fixing unit is used to assemble the two ends of the motor shaft into the two bearings, and also limits the axial movement of the motor shaft through the base. In this embodiment, dynamic balancing detection is only performed when the motor shaft is rotating; the loading unit is connected to the fixing unit to assemble a number of counterweights to the corresponding parts of the motor shaft. The loading unit can assemble counterweights to multiple motor shafts at the same time, The corresponding parts include the two ends of the motor shaft, more specifically the surface of the shaft end, and the centrifugal force imbalance generated when the motor shaft rotates is offset by the counterweight. When performing dynamic balancing performance testing, the counterweight (or balance block) is used to simulate the load condition of a motor shaft in actual operation after being assembled into a permanent magnet motor, so as to more realistically detect the dynamic balancing performance of the motor shaft. The counterweight is determined according to different models of permanent magnet motors; the driving unit includes a driving motor, which is connected to the fixed motor shaft. The connection method can be selected to be connected to the shaft through a pulley, and the driving motor shaft is rotated at a speed required by the dynamic balancing test standard. The detection speed should be close to or slightly higher than the actual working speed. At the same time, if a permanent magnet motor (such as 3000RPM) is tested, a staged test can be carried out. Each stage has a corresponding rated speed. The staged test rated speeds are: 800 / 1200 / 1500 / 2000 / 2500 / 3000RPM, etc.; the detection unit is connected to the motor shaft, and includes a number of sensors. The sensor types include eddy current displacement sensors, strain type vibration sensors, etc. The vibration amplitude generated when the motor shaft rotates at the corresponding speed is obtained by the sensor; the analysis unit is connected to the detection unit to analyze the vibration amplitude based on the acquired Each vibration amplitude determines whether the quality test process of the motor shaft is qualified, and the analysis unit can determine the corresponding reason when it is determined to be unqualified; the analysis unit is connected to the analysis unit to generate an instruction when it is determined that the quality test process of the motor shaft is unqualified; the control unit is respectively connected to the analysis unit, the fixing unit, the loading unit and the detection unit to determine whether to adjust the installation angle of the counterweight block, or the clamping force of the fixing unit, or the sampling frequency of the detection unit based on the instruction, or reconnect the drive unit and the motor shaft, or issue a notification that the motor shaft is determined to be unqualified.

[0052] Please refer to Figure 2As shown in FIG, it is a flow chart of the detection method of the motor shaft quality intelligent detection system for permanent magnet motor production in this embodiment. The process includes at least the following steps:

[0053] S1: Several motor shafts to be tested are transported through the feeding unit;

[0054] S2: Insert both ends of the motor shaft into the positions of the two bearings in the fixing unit through the fixing unit;

[0055] S3: Assembling a plurality of counterweights to corresponding portions of the motor shaft by a loading unit, wherein the corresponding portions include two shaft ends of the motor shaft;

[0056] S4: driving the motor shaft to rotate at a corresponding speed through the driving unit;

[0057] S5: Using a plurality of sensors in the detection unit to detect the two ends of the rotating motor shaft in real time to obtain the corresponding vibration amplitude;

[0058] S6: obtaining each vibration amplitude through the analysis unit and determining whether the quality test process for the motor shaft is qualified, and generating an instruction if it is determined to be unqualified;

[0059] S7: The control unit determines based on the instruction whether to adjust the installation angle of the counterweight, the clamping force of the fixing unit, the sampling frequency of the detection unit, reconnect the drive unit and the motor shaft, or issue a notification that the motor shaft is unqualified.

[0060] See also Figure 3 As shown, it is a logic decision diagram for determining whether the quality test process of the motor shaft is qualified based on the average value of the vibration amplitude and the corresponding processing in this embodiment. The analysis unit is also used to determine whether the quality test process of the motor shaft is qualified based on the comparison result of the average value of the vibration amplitude and the preset average value of the vibration amplitude, or to determine whether the quality test process of the motor shaft is qualified in combination with the vibration amplitude ratio; wherein, the analysis unit is also used to determine the reason for the failure based on the difference between the average value of the vibration amplitude and the preset average value of the vibration amplitude when determining that the quality test process of the motor shaft is unqualified; wherein, the two vibration amplitudes obtained by detecting the two ends of the motor shaft are divided into a first vibration amplitude and a second vibration amplitude greater than or equal to the first vibration amplitude according to the numerical value, and the vibration amplitude average is obtained by averaging the first vibration amplitude and the second vibration amplitude; the vibration amplitude ratio is the ratio of the first vibration amplitude to the second vibration amplitude.

[0061] Specifically, in this embodiment, the vibration amplitude detection is performed on specific points at the two ends of the motor shaft. The specific points do not overlap with the parts on the motor shaft where the counterweight is installed and connected to the drive unit. The two vibration amplitudes obtained can be distinguished as a first vibration amplitude and a second vibration amplitude; the preset vibration amplitude average value Q0 can be divided into a first preset vibration amplitude average value Q1 and a second vibration amplitude average value Q2. In this embodiment, taking a permanent magnet motor with a rated speed of 3000r / min as an example, Q1=0.05mm can be set. At this time, Q1 is the qualified limit, corresponding to the safety threshold of the vibration amplitude. Q2=0.08mm. At this time, Q2 is the unqualified limit, corresponding to the dangerous threshold of the vibration amplitude. The comparison process based on the vibration amplitude average value Q with Q1 and Q2 is as follows:

[0062] It should be noted that in this embodiment, the dynamic balance performance of the motor shaft is tested. If Q is less than or equal to Q1, it means that the current vibration amplitude average value Q is relatively small and meets the qualified limit requirements. It also means that the residual unbalance generated by the current motor shaft during rotation is within a safe range, that is, there are no problems with the motor shaft itself or the testing process. Therefore, it can be directly determined that the quality test process for the motor shaft is qualified and the dynamic balance performance of the motor shaft is also qualified. If Q is greater than Q1 and less than or equal to Q2, it is impossible to specifically determine whether there are problems with the test process and the motor shaft itself based on the current Q alone. It is necessary to introduce a new parameter, the vibration amplitude ratio W, for comprehensive judgment to avoid relying on a single indicator to improve the accuracy of the judgment process. Specifically, it is further judged based on the comparison result of the vibration amplitude ratio W and the critical vibration amplitude ratio W0. If Q is greater than Q1, it means that the current vibration amplitude average Q value is relatively large, and the value of Q exceeds the maximum standard of the motor shaft vibration amplitude set by the dynamic balance performance test, that is, it exceeds the unqualified limit. Therefore, it can be determined that the current quality test process for the motor shaft is unqualified, or that the dynamic balance performance of the motor shaft is not up to standard. At this time, the difference obtained by subtracting Q from Q0 can be used. In this embodiment, the difference between Q2 and Q is more specifically used to determine the cause, and determine whether it is a problem with the motor shaft itself or a problem with the detection system. It is understandable that in the embodiment of the present invention, Q1 and Q2 are not specifically limited, and the above values are not limited thereto. Those skilled in the art can adjust Q1 and Q2 according to actual needs. For example, new Q1=0.05mm and Q2=0.085mm can also be set.

[0063] Furthermore, the analysis unit is further configured to determine whether to adjust the counterweight based on a comparison result of the vibration amplitude ratio and a critical vibration amplitude ratio.

[0064] Specifically, in this embodiment, when the first vibration amplitude is equal to the second vibration amplitude, the vibration amplitude ratio W is equal to 1, so the critical vibration amplitude ratio W0 is set to 1. The comparison process based on the vibration amplitude ratio W and W0 is as follows:

[0065] If W is less than or greater than W0, it is determined that there is a difference between the current vibration amplitude ratio W and W0, and it is determined that the first vibration amplitude and the second vibration amplitude are not equal. Therefore, it can be determined that when Q is greater than Q1 and less than or equal to Q2, it is due to a problem with the counterweights at both ends of the motor shaft. At this time, the first vibration amplitude and the second vibration amplitude can be adjusted by adjusting the installation angle of the two counterweights so that the two are equal in value to eliminate the influence of the counterweights on the dynamic balance performance test of the motor shaft. After adjusting the installation angle of the counterweights, it is necessary to re-test. If W is equal to W0, it is determined that the current first vibration amplitude and the second vibration amplitude are equal, and the two counterweights do not affect the motor shaft test process. At this time, if Q is greater than Q1 and less than or equal to Q2, it means that there are other problems in the current quality test process of the motor shaft, which causes Q to be unable to be less than Q1. At this time, the cause can be determined by the difference between Q2 and Q.

[0066] Furthermore, the analysis unit is also used to adjust the installation angle of the counterweight block when the vibration amplitude ratio is less than or equal to the critical vibration amplitude ratio, and is also used to generate corresponding instructions based on the comparison result of the amplitude ratio difference and the preset amplitude ratio difference to determine the adjustment of the installation angle of each counterweight block, and the adjustment amplitude of the installation angle is positively correlated with the amplitude ratio difference; the control unit is also used to control the loading unit to adjust the installation angle of each counterweight block based on the instruction; wherein the amplitude ratio difference is the absolute value of the difference between the critical vibration amplitude ratio and the vibration amplitude ratio.

[0067] Specifically, in this embodiment, the preset amplitude ratio difference F0 can be divided into a first preset amplitude ratio difference F1 and a second preset amplitude ratio difference F2, with F1 set to 0.1 and F2 set to 0.2. By comparing F1 and F2 with F, the adjustment range of the installation angle can be accurately determined. The larger F is, the larger the corresponding adjustment range is. When the angle between the counterweights on both sides increases, the exciting force decreases and the vibration amplitude decreases accordingly. Therefore, the angle between the two counterweights can be increased and adjusted at the same time. The comparison process based on the amplitude ratio difference F with F1 and F2 is as follows:

[0068] If F is less than or equal to F1, an instruction for the first position adjustment coefficient is generated by the analysis unit, and the control unit issues a notification to adjust the counterweight block based on the instruction. After receiving the notification, the loading unit increases the angle of the counterweight block by 3° on the basis of the original angle; if F is greater than F1 and less than or equal to F2, an instruction for the second position adjustment coefficient is generated by the analysis unit, and the control unit issues a notification to adjust the counterweight block based on the instruction. After receiving the notification, the loading unit increases the angle of the counterweight block by 4° on the basis of the original angle; if F is greater than F2, an instruction for the third position adjustment coefficient is generated by the analysis unit, and the control unit issues a notification to adjust the counterweight block based on the instruction. After receiving the notification, the loading unit increases the angle of the counterweight block by 5° on the basis of the original angle. The increased value of the angle can also be set to other values that meet the requirements. It should be noted that the angle of the counterweight block shall not exceed the maximum angle set in the dynamic balance performance test after the increase. It can be understood that F1 and F2 are not specifically limited in the embodiments of the invention, and the above values are not limited to this. Those skilled in the art can adjust F1 and F2 according to actual needs. For example, new F1=0.12 and F2=0.22 can also be set.

[0069] Furthermore, the analysis unit is also used to re-acquire the vibration amplitude ratio after completing the installation angle adjustment of each counterweight block and compare it with the critical vibration amplitude ratio to determine whether to reconnect the drive unit and the motor shaft; the analysis unit is also used to generate a corresponding instruction to determine to reconnect the drive unit and the motor shaft when the vibration amplitude ratio is less than or greater than the critical vibration amplitude ratio; the control unit is also used to control the drive unit to disconnect from the motor shaft and reconnect based on the instruction.

[0070] Specifically, in this embodiment, after adjusting each counterweight, the analysis unit re-obtains the vibration amplitude ratio W, and then compares it with the critical vibration amplitude ratio W0. If W is still less than or greater than W0, it is determined that there is a problem with the connection between the drive unit and the motor shaft. The analysis unit can generate a corresponding instruction, and the control unit can control the drive unit to stop rotating and disconnect from the motor shaft based on the instruction, and then reconnect to the motor shaft to eliminate the influence of the initial connection instability; if W is equal to W0, it means that there is indeed a problem with the current quality test process for the motor shaft, and the cause is determined by the difference between Q2 and Q.

[0071] See also Figure 4As shown, it is a logical decision diagram for determining the reason for the failure of the quality test process of the motor shaft based on the average amplitude difference and the corresponding processing according to this embodiment. The analysis unit is also used to determine the reason for the failure of the quality test process of the motor shaft based on the comparison result of the average amplitude difference and the preset average amplitude difference; the analysis unit determines to issue a notice of failure of the motor shaft based on the reason, or adjust the sampling frequency of the detection unit during the data acquisition process, or obtain several historical vibration amplitude average values and corresponding times based on the determination result and draw a time-vibration amplitude curve, and re-determine the processing based on the time-vibration amplitude curve; wherein, the average amplitude difference is the difference between the average vibration amplitude and the preset average vibration amplitude.

[0072] Specifically, in this embodiment, the preset amplitude average difference H0 can be divided into a first preset amplitude average difference H1 and a second preset amplitude average difference H2, and H1=0.002mm and H2=0.004mm are set. The amplitude average difference H is the difference between the vibration amplitude average value Q and the second preset vibration amplitude average value Q2. Therefore, the specific cause of the failure can be accurately determined by comparing H1 and H2 with H. The comparison process based on the amplitude average difference H with H1 and H2 is as follows:

[0073] If H is less than or equal to H1, the difference between the average vibration amplitude value and the preset average vibration amplitude value is relatively small, and the impact of the current quality test system can be ignored. At this time, the reason for the failure is that there is a problem with the motor shaft itself, which in turn causes the test process to fail, and a notification of the failure of the motor shaft test is directly issued. If H is greater than H1 and less than or equal to H2, the analysis unit obtains several historical average vibration amplitude values and the current average vibration amplitude value, and then draws a time-vibration amplitude curve based on the time corresponding to each vibration amplitude average value. The curve is integrated and calculated to obtain the amplitude curve integral and the corresponding processing method is re-determined based on this. If H is greater than H2, it means that there are still problems with the current quality test process. Therefore, the reason for the failure is that the sampling frequency of the current detection unit during the data sampling process is insufficient, resulting in some high-frequency components not being fully acquired. Therefore, the problems in the high-speed dynamic balancing detection process can be solved by increasing the sampling frequency. It is understandable that H1 and H2 are not specifically limited in the embodiments of the invention, and the above values are not limited thereto. Those skilled in the art can adjust H1 and H2 according to actual needs. For example, new H1=0.003mm and H2=0.005mm can be set.

[0074] Furthermore, the analysis unit is also used to determine whether to increase the clamping force of the fixing unit based on a comparison result of the amplitude curve integral and the critical amplitude curve integral; wherein the amplitude curve integral is obtained by integrating the time-vibration amplitude curve.

[0075] Specifically, in this embodiment, the critical amplitude curve integral L0 is set to 0.6 μm·s, and the comparison process based on the amplitude curve integral L and the critical curve integral L0 is as follows:

[0076] If L is less than or equal to L0, it means that the average value Q of the vibration amplitude at each current time node is mostly less than the critical value. At this time, the reason for the failure of the quality test process of the motor shaft is determined to be that there is a problem with the motor shaft itself, and a notification of the failure of the motor shaft is directly issued. If L is greater than L0, the reason for the failure is that the clamping force of the base on the bearing in the current fixed unit is insufficient. The difference between L and L0 can be used to determine whether to increase the clamping force of the fixed unit. In this embodiment, the clamping force of the bearing is adjusted by the base to eliminate the influence of the instability of the bearing when the motor shaft rotates. It can be understood that L0 is not specifically limited in the embodiments of the invention, and the above values are not limited to this. Those skilled in the art can adjust L0 according to actual needs. For example, a new L0=0.65μm·s can also be set.

[0077] Furthermore, the analysis unit is also used to increase the clamping force of the fixed unit when the amplitude curve integral is greater than the critical amplitude curve integral, and is also used to generate a corresponding instruction based on the comparison result of the curve integral difference and the preset curve integral difference to determine the increase amplitude of the clamping force of the fixed unit, and the increase amplitude of the clamping force is positively correlated with the curve integral difference; the control unit is also used to control the fixed unit to increase the clamping force based on the instruction; wherein, the curve integral difference is the difference between the amplitude curve integral and the critical amplitude curve integral.

[0078] Specifically, in this embodiment, the clamping force is adjusted in real time, that is, the preload force of the base in the fixing unit on the two bearings is adjusted to better fix the motor shaft and eliminate the influence of unstable factors during the rotation of the motor shaft. The preset curve integral difference V0 is divided into a first preset curve integral difference V1 and a second preset curve integral difference V2. V1=0.1μm·s and V2=0.15μm·s are set. The set V1 and V2 are compared with V to refine the increase in the clamping force. The comparison process based on the curve integral difference V with V1 and V2 is as follows:

[0079] If V is less than or equal to V1, the analysis unit generates an instruction for a first clamping force adjustment coefficient, and the control unit determines, based on the instruction, that the clamping force in the fixed unit is increased by 10% from the initial value. If V is greater than V1 and less than or equal to V2, the analysis unit generates an instruction for a second clamping force adjustment coefficient, and the control unit determines, based on the instruction, that the clamping force is increased by 15% from the initial value. If V is greater than V2, the analysis unit generates an instruction for a third clamping force adjustment coefficient, and the control unit determines, based on the instruction, that the clamping force is increased by 20% from the initial value. It should be noted that the increase in the clamping force can also be set to other values that meet the requirements. It is understood that V1 and V2 are not specifically limited in the embodiments of the invention, and the above values are not limited thereto. Those skilled in the art can adjust V1 and V2 according to actual needs. For example, new values of V1 = 0.16 μm·s and V2 = 0.21 μm·s can be set.

[0080] Furthermore, the analysis unit is also used to re-acquire the amplitude curve integral after completing the clamping force increase adjustment of the fixing unit and compare it with the critical amplitude curve integral to determine whether to replace the bearing in the fixing unit; the analysis unit is also used to generate a corresponding instruction to determine to replace the bearing when the amplitude curve integral is greater than the critical amplitude curve integral; the control unit is also used to issue a notification to replace the two bearings in the fixing unit based on the instruction.

[0081] Specifically, in this embodiment, after increasing the clamping force of the fixing unit, the analysis unit re-acquires the amplitude curve integral L and compares L with L0. If L is still greater than L0, it is determined that the bearing in the fixing unit is unsuitable. In this case, the control unit issues a bearing replacement notification and replaces the bearing with a new, suitable one. If L is still less than or equal to L0, it is determined that the motor shaft failed the quality test due to a problem with the motor shaft itself.

[0082] Furthermore, the analysis unit is also used to determine whether to increase the sampling frequency when the amplitude average difference is greater than the preset amplitude average difference, and is also used to generate a corresponding instruction based on the comparison result of the average difference ratio and the preset average difference ratio to determine the increase amplitude of the sampling frequency, and the increase amplitude is positively correlated with the average difference ratio; the control unit is also used to control the detection unit to increase the sampling frequency based on the instruction; wherein the average difference ratio is the ratio of the amplitude average difference to the preset amplitude average difference.

[0083] Specifically, in this embodiment, when the amplitude average difference H is greater than the second preset amplitude average difference H2, the preset average difference ratio M0 can be divided into a first preset average difference ratio M1 and a second preset average difference ratio M2. When the amplitude average difference H1 is greater than the second preset amplitude average difference H2, M1=1.2 and M2=1.4 are set. The set M1 and M2 are compared with M to refine the increase in the sampling frequency. The comparison process based on the average difference ratio M with M1 and M2 is as follows:

[0084] If M is less than or equal to M1, the analysis unit generates an instruction for a first frequency adjustment coefficient, and the control unit determines, based on the instruction, to increase the original sampling frequency by 30%; if M is greater than M1 and less than or equal to M2, the analysis unit generates an instruction for a second frequency adjustment coefficient, and the control unit determines, based on the instruction, to increase the original sampling frequency by 35%; if M is greater than M2, the analysis unit generates an instruction for a third frequency adjustment coefficient, and the control unit determines, based on the instruction, to increase the original sampling frequency by 50%. It should be noted that the increase in the sampling frequency can also be set to other values that meet the requirements, and the increased sampling frequency also meets the standards. It is understandable that M1 and M2 are not specifically limited in the embodiments of the present invention, and the above values are not limited thereto. Those skilled in the art can adjust M1 and M2 according to actual needs. For example, new M1=1.3 and M2=1.5 can also be set.

[0085] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0086] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An intelligent detection system for motor shaft quality used in permanent magnet motor production, characterized in that: include: A feeding unit, used for conveying a plurality of motor shafts to be tested; A fixing unit connected to the feeding unit, comprising two bearings and a base for fixing and clamping the bearings, and used to embed the two ends of the motor shaft into the positions where the two bearings are located; a loading unit connected to the fixing unit and used to assemble a plurality of counterweights to corresponding portions of the motor shaft, wherein the corresponding portions include two ends of the motor shaft; a drive unit connected to the fixed motor shaft and configured to drive the motor shaft to rotate at a corresponding speed; a detection unit connected to the motor shaft and comprising a plurality of sensors for detecting the two ends of the rotating motor shaft in real time to obtain corresponding vibration amplitudes; an analyzing unit connected to the detecting unit, configured to determine whether the quality test process for the motor shaft is qualified based on the obtained vibration amplitudes, and to generate an instruction if it is determined to be unqualified; a control unit, connected to the analyzing unit, the fixing unit, the loading unit, and the detecting unit, respectively, for determining, based on the instruction, whether to adjust the installation angle of the counterweight, the clamping force of the fixing unit, or the sampling frequency of the detecting unit, or to reconnect the driving unit and the motor shaft, or to issue a notification that the motor shaft is unqualified; The analysis unit is further configured to determine whether the quality test process for the motor shaft is qualified based on a comparison result of the vibration amplitude average value and a preset vibration amplitude average value, or to determine whether the quality test process for the motor shaft is qualified in combination with the vibration amplitude ratio; Wherein, the analyzing unit is further configured to determine a cause of failure based on a difference between the average vibration amplitude value and the preset average vibration amplitude value when determining that the quality test process for the motor shaft fails; The two vibration amplitudes detected at both ends of the motor shaft are divided into a first vibration amplitude and a second vibration amplitude greater than or equal to the first vibration amplitude according to their numerical values, and the vibration amplitude average value is obtained by averaging the first vibration amplitude and the second vibration amplitude; the vibration amplitude ratio is the ratio of the first vibration amplitude to the second vibration amplitude; The analysis unit is further configured to determine a reason why the quality test process of the motor shaft fails based on a comparison result of the amplitude average difference and a preset amplitude average difference; The analyzing unit determines based on the cause that the motor shaft is unqualified, or issues an instruction to adjust the sampling frequency of the detecting unit during data acquisition, or obtains a plurality of historical vibration amplitude average values and corresponding times based on the determination result and plots a time-vibration amplitude curve, and re-determines the processing based on the time-vibration amplitude curve; Wherein, the amplitude average difference is the difference between the vibration amplitude average value and the preset vibration amplitude average value; The analyzing unit is further configured to determine to increase the sampling frequency if the amplitude average difference is greater than the preset amplitude average difference, and further configured to generate a corresponding instruction based on a comparison result of the average difference ratio with the preset average difference ratio to determine an increase amplitude of the sampling frequency, wherein the increase amplitude is positively correlated with the average difference ratio; The control unit is further configured to control the detection unit to increase the sampling frequency based on the instruction; The average difference ratio is the ratio of the amplitude average difference to the preset amplitude average difference.

2. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 1 is characterized in that: The analysis unit is further configured to determine whether to adjust the counterweight based on a comparison result of the vibration amplitude ratio and a critical vibration amplitude ratio.

3. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 2, characterized in that: The analyzing unit is further configured to adjust the installation angle of the counterweight when the vibration amplitude ratio is less than or equal to the critical vibration amplitude ratio, and to generate a corresponding instruction based on a comparison result of the amplitude ratio difference with a preset amplitude ratio difference to determine the adjustment of the installation angle of each counterweight, wherein the adjustment amplitude of the installation angle is positively correlated with the amplitude ratio difference; The control unit is further configured to control the loading unit to adjust the installation angle of each counterweight based on the instruction; The amplitude ratio difference is the absolute value of the difference between the critical vibration amplitude ratio and the vibration amplitude ratio.

4. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 3 is characterized in that: The analyzing unit is further configured to reacquire the vibration amplitude ratio after completing the adjustment of the installation angle of each counterweight and compare it with the critical vibration amplitude ratio to determine whether to reconnect the drive unit and the motor shaft; The analyzing unit is further configured to generate a corresponding instruction to determine reconnecting the driving unit and the motor shaft when the vibration amplitude ratio is less than or greater than the critical vibration amplitude ratio; The control unit is further configured to control the driving unit to disconnect and reconnect with the motor shaft based on the instruction.

5. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 1 is characterized in that: The analysis unit is further configured to determine whether to increase the clamping force of the fixing unit based on a comparison result of the amplitude curve integral and the critical amplitude curve integral; The amplitude curve integral is obtained by integrating the time-vibration amplitude curve.

6. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 5, characterized in that: The analyzing unit is further configured to increase the clamping force of the fixing unit when the integral of the amplitude curve is greater than the integral of the critical amplitude curve, and to generate a corresponding instruction based on a comparison result of the curve integral difference with a preset curve integral difference to determine an increase amplitude of the clamping force of the fixing unit, wherein the increase amplitude of the clamping force is positively correlated with the curve integral difference; The control unit is further configured to control the fixing unit to increase the clamping force based on the instruction; The curve integral difference is the difference between the amplitude curve integral and the critical amplitude curve integral.

7. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 6, characterized in that: The analysis unit is further configured to reacquire the amplitude curve integral after completing the clamping force increase adjustment of the fixing unit and compare it with the critical amplitude curve integral to determine whether to replace the bearing in the fixing unit; The analysis unit is further configured to generate a corresponding instruction to determine replacement of the bearing when the amplitude curve integral is greater than the critical amplitude curve integral; The control unit is further configured to issue a notification to replace the two bearings in the fixing unit based on the instruction.

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