Motor shaft quality intelligent detection system for permanent magnet motor production

Abstract

The invention relates to the technical field of motor shaft quality detection, in particular to a motor shaft quality intelligent detection system for permanent magnet motor production. According to the system, a balancing weight is loaded to a corresponding part of a motor shaft to be detected through a loading unit, the motor shaft assembled with the balancing weight is fixed to a corresponding position through a fixing unit, the motor shaft is determined to rotate according to a corresponding rotating speed through a driving unit, and corresponding vibration amplitudes at the two ends of the motor shaft are obtained through real-time detection of a detection unit. Whether the instruction testing process of the motor shaft is qualified or not is judged through the analysis unit based on the vibration amplitudes, a corresponding instruction is generated through the analysis unit under the condition that the instruction testing process is determined to be unqualified, and the control unit determines adjustment of corresponding parameters or sends out a corresponding notification based on the instruction, so that all links of the testing system are adjusted. Therefore, the quality testing process of the motor shaft is improved, and the production efficiency of the permanent magnet motor is improved.

Description

Technical Field

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

[0002] In the production process of permanent magnet motors, as the core transmission component, the quality of the motor shaft is directly related to the performance, reliability, and service life of the motor. Traditional motor shaft quality detection mainly relies on manual measurement or semi-automatic equipment, which has problems such as low detection efficiency, insufficient accuracy, and poor consistency. And the dynamic balance detection of the motor shaft is an indispensable link in the production of permanent magnet motors, and traditional detection methods have been difficult to meet the requirements of modern manufacturing for dynamic balance detection.

[0003] Chinese Patent Application Publication No.: CN111969779A, provides a dynamic balance device for a motor shaft, its control method, and a motor. This technical solution sets a balance unit including at least two balance blocks arranged circumferentially on the main shaft. The detection unit is used to detect the vibration signal of the main shaft, and the control unit controls the current applied to each balance block based on the detected vibration signal, so as to accurately balance the unbalance amount when the motor shaft rotates, and realize the automatic balancing function of the rotating shaft. Although this technical solution realizes the balance of the unbalance amount during the rotation of the motor shaft, this technical solution only can accurately balance the unbalance amount when the motor shaft rotates, and does not have the function of adjusting the system for detecting the dynamic balance performance of the motor shaft, thus unable to ensure the quality of the motor shaft. Summary of the Invention

[0004] Therefore, the present invention provides an intelligent detection system for the quality of motor shafts used in the production of permanent magnet motors to overcome the problem in the prior art that only the balance of the motor shaft is automatically balanced, and the system for detecting the dynamic balance performance of the motor shaft is not correspondingly adjusted, which will cause low efficiency in the quality detection of the motor shaft.

[0005] To achieve the above object, the present invention provides an intelligent detection system for the quality of motor shafts used in the production of permanent magnet motors, including: A feeding unit for conveying a plurality of motor shafts to be detected; A fixing unit connected to the feeding unit, including two bearings and a base for fixing and clamping the bearings, for embedding the two ends of the motor shaft into the positions where the two bearings are located; A loading unit connected to the fixing unit for assembling a plurality of counterweight blocks to corresponding parts of the motor shaft, where the corresponding parts include the two shaft ends of the motor shaft; A driving unit connected to the fixed motor shaft for driving the motor shaft to rotate at a corresponding speed; The detection unit, which is connected to the motor shaft, includes a plurality of sensors for detecting the two shaft ends of the motor shaft in a rotating state in real time to obtain corresponding vibration amplitudes; The analysis unit, which is connected to the detection unit, is used to determine whether the quality test process for the motor shaft is qualified based on the obtained vibration amplitudes, and is used to generate an instruction when it is determined to be unqualified; The control unit, which is respectively connected to the analysis unit, the fixing unit, the loading unit and the detection unit, is used to determine to adjust the installation angle of the counterweight, or the clamping force of the fixing unit, or the sampling frequency of the detection unit, or reconnect the driving unit to the motor shaft, or issue a notice determining that the motor shaft is unqualified based on the instruction.

[0006] Further, the analysis unit is also used to determine whether the quality test process for the motor shaft is qualified based on the comparison result between the average vibration amplitude and the preset average vibration amplitude, or to determine whether the quality test process for the motor shaft is qualified by combining the vibration amplitude ratio; Among them, the analysis unit is also used to determine the cause of unqualified based on the difference between the average vibration amplitude and the preset average vibration amplitude when it is determined that the quality test process for the motor shaft is unqualified; Among them, the two vibration amplitudes obtained by detecting the two ends of the motor shaft are classified into a first vibration amplitude and a second vibration amplitude greater than or equal to the first vibration amplitude according to the numerical size, and the average vibration amplitude is calculated 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.

[0007] Further, the analysis unit is also used to determine whether to adjust the counterweight by combining the comparison result between the vibration amplitude ratio and the critical vibration amplitude ratio.

[0008] Further, the analysis unit is also used 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 is also used to generate a corresponding instruction based on the comparison result between the amplitude ratio difference and the preset amplitude ratio difference to determine the installation angle of each counterweight, and the adjustment range 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 based on the instruction; Among them, the amplitude ratio difference is the absolute value of the difference between the critical vibration amplitude ratio and the vibration amplitude ratio.

[0009] Further, the analysis unit is further configured to re-obtain the vibration amplitude ratio after completing the adjustment of the installation angles of the counterweights, and compare it with the critical vibration amplitude ratio to determine whether to reconnect the drive unit to the motor shaft; The analysis unit is further configured to generate a corresponding instruction to determine to reconnect the drive unit to 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 drive unit to disconnect from the motor shaft and reconnect based on the instruction.

[0010] Further, the analysis unit is further configured to determine the reason for the failure of the quality test process of the motor shaft based on the comparison result between the amplitude average difference and the preset amplitude average difference; The analysis unit determines to issue a notice determining that the motor shaft is unqualified based on the reason, or an instruction to adjust the sampling frequency during data acquisition by the detection unit, or obtains several historical vibration amplitude averages and corresponding times based on the determination result and draws a time-vibration amplitude curve, and re-determines the process 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.

[0011] Further, the analysis unit is further configured to determine whether to increase the clamping force of the fixing unit based on the comparison result between the amplitude curve integral and the critical amplitude curve integral; Wherein, the amplitude curve integral is obtained by integrating the time-vibration amplitude curve.

[0012] Further, the analysis unit is further configured to increase the clamping force of the fixing unit when the amplitude curve integral is greater than the critical amplitude curve integral, and is further configured to generate a corresponding instruction based on the comparison result between the curve integral difference and the preset curve integral difference to determine the increase amplitude of the clamping force of the fixing unit, and 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; Wherein, the curve integral difference is the difference between the amplitude curve integral and the critical amplitude curve integral.

[0013] Further, the analysis unit is further configured to re-obtain the amplitude curve integral after completing the adjustment of increasing the clamping force 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 to replace the bearing when the integral of the amplitude curve is greater than the critical amplitude curve integral; The control unit is further configured to send a notice to replace the two bearings in the fixing unit based on the instruction.

[0014] Further, the analysis unit is further configured to determine to increase the sampling frequency when the average amplitude difference is greater than the preset average amplitude difference, and is further configured to generate a corresponding instruction based on the comparison result between 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 further configured to control the detection unit to increase the sampling frequency based on the instruction; Wherein, the average difference ratio is the ratio of the average amplitude difference to the preset average amplitude difference.

[0015] Compared with the prior art, the beneficial effect of an 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 the motor shaft to rotate at the corresponding speed through the driving unit, obtains the vibration amplitudes corresponding to both ends of the motor shaft through real-time detection by the detection unit, determines whether the instruction test process for the motor shaft is qualified based on each vibration amplitude by the analysis unit, generates a corresponding instruction by the analysis unit in the case of determining unqualified, and the control unit determines the adjustment of the corresponding parameters or sends a corresponding notice based on the instruction, so as to adjust each link 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.

[0016] Further, when the present invention makes a comparison and determination based on the average value of the vibration amplitude and the preset average value of the vibration amplitude, it further re-determines the quality test process of the motor shaft according to the vibration amplitude ratio and the critical vibration amplitude ratio to ensure the accuracy of the determination result.

[0017] Further, when the present invention determines that the counterweight block needs to be adjusted based on the comparison result between the vibration amplitude ratio and the critical vibration amplitude, it can determine the adjustment amplitude of the included angle of the counterweight block based on the comparison result between the amplitude ratio difference and the preset amplitude ratio difference, so as to eliminate the influence of the counterweight block on the quality test process of the motor shaft and ensure accurately determining the reason for the unqualified quality test process of the motor shaft.

[0018] Further, when the present invention determines the reason for the unqualified quality test process of the motor shaft based on the comparison result between the amplitude average difference and the preset amplitude average difference, corresponding processing methods can be determined according to the reason, including increasing the sampling frequency of the detection unit or giving out the reason for determining that the motor shaft is unqualified.

[0019] Further, the present invention also determines to increase the clamping force of the fixing unit according to the comparison result between 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 between 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 for the motor shaft.

[0020] Further, when the present invention determines that there is no need to increase the clamping force of the fixing unit based on the amplitude curve integral again under the condition that the clamping force of the fixing unit is increased, it can be determined to give out a notice to replace the bearing in the fixing unit to eliminate the influence of the fixing unit on the quality test process, thereby improving the accuracy of the quality test for the motor shaft.

[0021] Further, when it is determined that the sampling frequency of the detection unit is insufficient, the present invention can also determine the increase amplitude of the sampling frequency based on the comparison result between the average difference ratio and the preset average difference ratio to improve the sampling accuracy, thereby improving the quality test efficiency of the motor shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a module schematic diagram of the intelligent detection system for the quality of the motor shaft used in the production of permanent magnet motors according to the present invention; Figure 2 It is a flowchart of the application method of the intelligent detection system for the quality of the motor shaft used in the production of permanent magnet motors according to the present invention; Figure 3 It is a logic decision diagram for determining whether the quality test process of the motor shaft is qualified and corresponding processing based on the vibration amplitude average value according to the present invention; Figure 4 It is a logic decision diagram for determining the reason for the unqualified quality test process of the motor shaft based on the amplitude average difference and corresponding processing according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and do not limit the protection scope of the present invention.

[0025] It should be noted that in the description of the present invention, unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0026] Please refer to as Figure 1As shown in the figure, it is a schematic diagram of the modules of the intelligent quality inspection system for the motor shaft 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 detecting unit, an analyzing unit, and a control unit. The feeding unit can adopt a conveying device with continuous conveying function to convey motor shafts one by one from the production line to the next link; the fixing unit is connected to the feeding unit. The fixing unit includes two bearings and a base for fixing and clamping the bearings. The fixing unit is used to axially fit the two ends of the motor shaft into the two bearings, and also limit the axial movement of the motor shaft through the base. In this embodiment, the dynamic balance detection is only carried out when the motor shaft is rotating; the loading unit is connected to the fixing unit and is used to assemble several counterweight blocks to the corresponding parts of the motor shaft. The loading unit can assemble counterweight blocks to multiple motor shafts at the same time. Among them, the corresponding parts include the two shaft ends of the motor shaft, and more specifically, it can be the shaft end surface. The centrifugal force unbalance generated during the rotation of the motor shaft is offset by the counterweight. When performing the dynamic balance performance detection, the load condition of the motor shaft after being assembled into the permanent magnet motor in the actual operating state is simulated through the counterweight block (or balance block), so as to more accurately detect the dynamic balance performance of the motor shaft. Among them, the counterweight block is determined according to different models of permanent magnet motors; the driving unit includes a driving motor, and the driving motor is connected to the fixed motor shaft. The connection method can be selected to be connected to the shaft through a pulley. The driving motor shaft rotates at the speed required by the dynamic balance detection 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 3000 RPM) is detected, it can be tested in stages, and each stage has a corresponding rated speed. The rated speeds for staged testing are: 800 / 1200 / 1500 / 2000 / 2500 / 3000 RPM, etc.; the detecting unit is connected to the motor shaft and includes several sensors. The types of sensors include eddy current displacement sensors, strain type vibration sensors, etc. The vibration amplitude generated by the motor shaft when rotating at the corresponding speed is obtained through the sensors; the analyzing unit is connected to the detecting unit and is used to determine whether the quality test process of the motor shaft is qualified based on the obtained vibration amplitudes. When the analyzing unit determines that it is unqualified, it can determine the corresponding reason; the analyzing unit is connected to the analyzing unit and is used 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 analyzing unit, the fixing unit, the loading unit, and the detecting unit, and is used to determine and 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 reconnect the driving unit and the motor shaft, or issue a notice of determining that the motor shaft is unqualified based on the instruction.

[0027] Please refer to Figure 2As shown, it is a schematic flowchart of the detection method of the intelligent detection system for the quality of motor shafts used in the production of permanent magnet motors in this embodiment. This process includes at least the following steps: S1: Convey a number of motor shafts to be detected through a feeding unit; S2: Embed both ends of the motor shaft into the positions where two bearings in the fixing unit are located through the fixing unit; S3: Assemble a number of counterweight blocks to the corresponding parts of the motor shaft through a loading unit, where the corresponding parts include the two shaft ends of the motor shaft; S4: Drive the motor shaft to rotate at a corresponding speed through a driving unit; S5: Real-time detect the two shaft ends of the motor shaft in the rotating state through a number of sensors in the detection unit to obtain the corresponding vibration amplitudes; S6: Obtain each vibration amplitude through an analysis unit and determine whether the quality test process of the motor shaft is qualified, and generate an instruction in the case of determining unqualified; S7: Based on the instruction, the control unit determines 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, or reconnect the driving unit to the motor shaft, or issue a notice of determining the motor shaft as unqualified.

[0028] Please refer to Figure 3 As shown, it is a logical decision diagram for determining whether the quality test process of the motor shaft is qualified and the corresponding processing based on the average value of vibration amplitudes 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 between the average value of vibration amplitudes and the preset average value of vibration amplitudes, or determine whether the quality test process of the motor shaft is qualified by combining the vibration amplitude ratio; wherein, the analysis unit is also used to determine the reason for unqualified based on the difference between the average value of vibration amplitudes and the preset average value of vibration amplitudes in the case of determining that the quality test process of the motor shaft is unqualified; wherein, the two vibration amplitudes obtained by detecting both ends of the motor shaft are classified into a first vibration amplitude and a second vibration amplitude greater than or equal to the first vibration amplitude according to the numerical size, and the average value of vibration amplitudes is calculated through 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.

[0029] Specifically, in this embodiment, the vibration amplitude detection is performed on specific points at both ends of the motor shaft. The specific points do not overlap with the parts where the counterweight is installed on the motor shaft and the parts connected to the drive unit. The two vibration amplitudes obtained can be classified as the first vibration amplitude and the second vibration amplitude. The preset average vibration amplitude Q0 can be divided into the first preset average vibration amplitude Q1 and the second average vibration amplitude Q2. In this embodiment, taking a permanent magnet motor with a rated speed of 3000 r / min as an example, Q1 = 0.05 mm can be set. At this time, Q1 is the qualified limit, corresponding to the safety threshold of the vibration amplitude, and Q2 = 0.08 mm. At this time, Q2 is the unqualified limit, corresponding to the dangerous threshold of the vibration amplitude. The specific process of comparing the average vibration amplitude Q with Q1 and Q2 is as follows: It should be clear that in this embodiment, the dynamic balance performance of the motor shaft is detected. If Q is less than or equal to Q1, it means that the current value of the average vibration amplitude Q is relatively small, meeting the qualified limit requirements, and it also means that the residual unbalance generated during the rotation of the current motor shaft is within the safe range, that is, there are no problems with the motor shaft itself and the detection process. Therefore, it can be directly determined that the quality test process of 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, based on the current Q alone, it is impossible to specifically determine whether there are problems with the test process and the motor shaft itself. It is necessary to introduce a new parameter, the vibration amplitude ratio W, for comprehensive judgment to avoid relying on a single index and improve the accuracy of the judgment process. Specifically, it is further determined based on the comparison result between the vibration amplitude ratio W and the critical vibration amplitude ratio W0. If Q is greater than Q1, it means that the current value of the average vibration amplitude Q is relatively large, and the value of Q exceeds the maximum standard of the vibration amplitude of the motor shaft set for the dynamic balance performance test, that is, it exceeds the unqualified limit. Therefore, it can be determined that the current quality test process of the motor shaft is unqualified, or the dynamic balance performance of the motor shaft does not meet the standard. At this time, the difference obtained by subtracting Q from Q0 can be used to determine the reason in this embodiment, more specifically, the difference between Q2 and Q, to determine whether the problem lies with the motor shaft itself or the detection system. It can be understood that in the embodiments of the present invention, Q1 and Q2 are not specifically limited, and the above values are not limited to this. Those skilled in the art can adjust Q1 and Q2 according to actual needs. For example, new Q1 = 0.05 mm and Q2 = 0.085 mm can also be set.

[0030] Furthermore, the analysis unit is also used to determine whether to adjust the counterweight in combination with the comparison result between the vibration amplitude ratio and the critical vibration amplitude ratio.

[0031] 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. Therefore, the critical vibration amplitude ratio W0 is set to 1. The specific process of comparing the vibration amplitude ratio W with W0 is as follows: 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 problems with the counterweights at both ends of the motor shaft. At this time, the installation angles of the two counterweights can be adjusted to adjust the first vibration amplitude and the second vibration amplitude so that they are equal in value, so as to eliminate the influence of the counterweights on the dynamic balance performance test of the motor shaft. After adjusting the installation angles of the counterweights, it is necessary to perform re-detection. 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, resulting in Q not being able to be less than Q1. At this time, the reason can be determined through the difference between Q2 and Q.

[0032] Furthermore, the analysis unit is also used to adjust the installation angles of the counterweights 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 between the amplitude ratio difference and the preset amplitude ratio difference to determine the installation angles of the counterweights to be adjusted. The adjustment range 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 angles of the counterweights based on the instructions; wherein, the amplitude ratio difference is the absolute value of the difference between the critical vibration amplitude ratio and the vibration amplitude ratio.

[0033] Specifically, in this embodiment, the preset amplitude ratio difference F0 can be divided into the first preset amplitude ratio difference F1 and the second preset amplitude ratio difference F2. Set F1 = 0.1 and F2 = 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 included angle between the counterweights on both sides increases, the exciting force decreases and the vibration amplitude decreases accordingly. Therefore, the included angle between the two counterweights can be increased at the same time. The specific process of comparing the amplitude ratio difference F with F1 and F2 is as follows: If F is less than or equal to F1, the analysis unit generates an instruction for the first position adjustment coefficient, and the control unit issues a notice to adjust the counterweight based on the instruction. After receiving the notice, the loading unit increases the original angle of the counterweight by 3°. If F is greater than F1 and less than or equal to F2, the analysis unit generates an instruction for the second position adjustment coefficient, and the control unit issues a notice to adjust the counterweight based on the instruction. After receiving the notice, the loading unit increases the original angle of the counterweight by 4°. If F is greater than F2, the analysis unit generates an instruction for the third position adjustment coefficient, and the control unit issues a notice to adjust the counterweight based on the instruction. After receiving the notice, the loading unit increases the original angle of the counterweight by 5°. 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 after increase shall not exceed the maximum angle set in the dynamic balance performance test. It can be understood that in the embodiments of the invention, F1 and F2 are not specifically limited, and the above values are not limited thereto. Those skilled in the art can adjust F1 and F2 according to actual needs. For example, new values of F1 = 0.12 and F2 = 0.22 can also be set.

[0034] Further, the analysis unit is further configured to re-obtain the vibration amplitude ratio after completing the adjustment of the installation angles of the counterweights and compare it with the critical vibration amplitude ratio to determine whether to reconnect the drive unit to the motor shaft; the analysis unit is further configured to generate a corresponding instruction to determine to reconnect the drive unit to 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 drive unit to disconnect from the motor shaft and reconnect based on the instruction.

[0035] 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. A corresponding instruction can be generated by the analysis unit, 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 unstable initial connection. If W is equal to W0, it indicates that there is indeed a problem with the current mass test process of the motor shaft, and the reason is determined by the difference between Q2 and Q.

[0036] Please refer to Figure 4As shown, it is a logic decision diagram for determining the reasons for the unqualified quality test process of the motor shaft based on the amplitude average difference and the corresponding processing in this embodiment. The analysis unit is further configured to determine the reasons for the unqualified quality test process of the motor shaft based on the comparison result between the amplitude average difference and the preset amplitude average difference; the analysis unit determines to issue a notice of determining the motor shaft as unqualified based on the reasons, or an instruction to adjust the sampling frequency of the detection unit during data acquisition, or obtains several historical vibration amplitude averages and the corresponding times based on the determination result and draws 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 and the preset vibration amplitude average.

[0037] 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. Set H1 = 0.002mm and H2 = 0.004mm. The amplitude average difference H is the difference between the vibration amplitude average Q and the second preset vibration amplitude average Q2. Therefore, the specific reasons for unqualified can be accurately determined by comparing H1 and H2 with H. The specific process of comparing the amplitude average difference H with H1 and H2 is as follows: When H is less than or equal to H1, the difference between the vibration amplitude average and the preset vibration amplitude average is relatively small, and the influence generated by the current quality test system can be ignored. At this time, it is determined that the reason for unqualified is that there is a problem with the motor shaft itself, which causes the test process to be unqualified, and a notice of unqualified 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 vibration amplitude averages and the current vibration amplitude average, and then combines the times corresponding to each vibration amplitude average to draw a time-vibration amplitude curve. Integral calculation is performed through this curve to obtain the amplitude curve integral and re-determine the corresponding processing method based on this. If H is greater than H2, it indicates that there is still a problem with the current quality test process. Therefore, it is determined that the reason for unqualified is that the sampling frequency of the current detection unit during data sampling is insufficient, resulting in incomplete acquisition of some high-frequency components. Therefore, the problem existing in the high-speed dynamic balance detection process can be solved by increasing the sampling frequency. It can be understood that in the embodiment of the invention, no specific limitations are imposed on H1 and H2, and the above values are not limited to this. 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 also be set.

[0038] Furthermore, the analysis unit is further configured to determine whether to increase the clamping force of the fixing unit based on the comparison result between the amplitude curve integral and the critical amplitude curve integral; wherein, the amplitude curve integral is obtained by integrating the time-vibration amplitude curve.

[0039] Specifically, in this embodiment, the critical amplitude curve integral L0 is set to 0.6 μm·s. The comparison process between the amplitude curve integral L and the critical curve integral L0 is as follows: If L is less than or equal to L0, it indicates that the average vibration amplitude Q at each current time node is mostly less than the critical value. At this time, it is determined that the reason for the unqualified quality test of the motor shaft is that there is a problem with the motor shaft itself, and a notice of unqualified motor shaft is directly issued. If L is greater than L0, it is determined that the reason for the unqualified is that the clamping force of the base on the bearing in the current fixing unit is insufficient. The increased clamping force of the fixing unit can be determined by the difference between L and L0. In this embodiment, the clamping force of the bearing is adjusted through the base to eliminate the influence caused by the instability of the bearing when the motor shaft rotates. It can be understood that in the invention embodiment, L0 is not specifically limited, and the above value is not limited to this. Those skilled in the art can adjust L0 according to actual needs. For example, a new L0 = 0.65 μm·s can also be set.

[0040] Furthermore, the analysis unit is further configured to increase the clamping force of the fixing unit when the amplitude curve integral is greater than the critical amplitude curve integral, and is further configured to generate a corresponding instruction based on the comparison result between the curve integral difference and the preset curve integral difference to determine the increase amplitude of the clamping force of the fixing unit. 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; wherein, the curve integral difference is the difference between the amplitude curve integral and the critical amplitude curve integral.

[0041] Specifically, in this embodiment, the clamping force is adjusted in real time, that is, the pre-tightening force of the base on the two bearings in the fixing unit is adjusted to better fix the motor shaft and eliminate the influence caused by 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 is set to 0.1 μm·s and V2 is set to 0.15 μm·s. The increase amplitude of the clamping force is refined by comparing the set V1 and V2 with V. The comparison process between the curve integral difference V and V1 and V2 is as follows: If V is less than or equal to V1, the analysis unit generates an instruction for the first clamping force adjustment coefficient, and the control unit determines based on the instruction that the clamping force in the fixing unit increases by 10% on the basis of the initial value; if V is greater than V1 and less than or equal to V2, the analysis unit generates an instruction for the second clamping force adjustment coefficient, and the control unit determines based on the instruction that the clamping force increases by 15% on the basis of the initial value; if V is greater than V2, the analysis unit generates an instruction for the third clamping force adjustment coefficient, and the control unit determines based on the instruction that the clamping force increases by 20% on the basis of the initial value. It should be noted that the increase amplitude of the clamping force can also be set to other values that meet the requirements. It can be understood that in the invention embodiment, V1 and V2 are not specifically limited, and the above values are not limited to this. Those skilled in the art can adjust V1 and V2 according to actual needs. For example, new values of V1 = 0.16μm·s and V2 = 0.21μm·s can also be set.

[0042] Further, the analysis unit is further configured to re-obtain the integral of the amplitude curve and compare it with the critical amplitude curve integral after completing the adjustment of increasing the clamping force of the fixing unit to determine whether to replace the bearing in the fixing unit; the analysis unit is further configured to generate a corresponding instruction to determine to replace the bearing when the integral of the amplitude curve is greater than the critical amplitude curve integral; the control unit is further configured to send a notice to replace the two bearings in the fixing unit based on the instruction.

[0043] Specifically, in this embodiment, after increasing the clamping force of the fixing unit, the analysis unit re-obtains the integral L of the amplitude curve and compares L with L0. If L is still greater than L0, it is determined that the bearing in the fixing unit is not properly matched. At this time, a notice to replace the bearing can be sent through the control unit to replace it with a new and suitable bearing. If L is still less than or equal to L0, it is determined that the reason for the unqualified quality test of the motor shaft is a problem with the motor shaft itself.

[0044] Further, the analysis unit is further configured to determine to increase the sampling frequency when the average amplitude difference is greater than the preset average amplitude difference, and is further configured 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 further configured to control the detection unit to increase the sampling frequency based on the instruction; wherein, the average difference ratio is the ratio of the average amplitude difference to the preset average amplitude difference.

[0045] Specifically, in this embodiment, specifically 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, set M1 = 1.2 and M2 = 1.4. Compare the set M1 and M2 with M to refine the increase amplitude of the sampling frequency. The specific process of comparing the average difference ratio M with M1 and M2 is as follows: If M is less than or equal to M1, the analysis unit generates an instruction for the 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 the 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 the 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 amplitude of the sampling frequency can also be set to other values that meet the requirements, and the increased sampling frequency also meets the standards. It can be understood that in the embodiments of the invention, M1 and M1 are not specifically limited, and the above values are not limited to this. Those skilled in the art can adjust M1 and M1 according to actual needs. For example, new M1 = 1.3 and M2 = 1.5 can also be set.

[0046] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

[0047] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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 inspected; 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 for assembling a plurality of counterweights to corresponding parts of the motor shaft, wherein the corresponding parts include two shaft ends of the motor shaft; A driving unit, connected to the fixed motor shaft, for driving the motor shaft to rotate at a corresponding speed; A detection unit, which is connected to the motor shaft and includes a plurality of sensors for detecting two ends of the motor shaft in a rotating state in real time to obtain a corresponding vibration amplitude; an analysis unit connected to the detection unit, for determining whether the quality test process for the motor shaft is qualified based on the acquired vibration amplitudes, and for generating an instruction if it is determined to be unqualified; 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.

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 also used to determine whether the quality test process for the motor shaft is qualified based on the comparison result of the vibration amplitude average value and the 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 analysis unit is further used to determine the cause of the failure based on the difference between the vibration amplitude average value and the preset vibration amplitude average value when it is determined that the quality test process for the motor shaft fails; 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.

3. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 2 is characterized in that: The analysis unit is also used to determine whether to adjust the counterweight based on the comparison result of the vibration amplitude ratio and the critical 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 analysis unit is further 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 a corresponding instruction based on a comparison result of the amplitude ratio difference and a 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; The amplitude ratio difference is the absolute value of the difference between the critical vibration amplitude ratio and the vibration amplitude ratio.

5. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 4 is characterized in that: The analysis unit is also used to re-acquire 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; The analysis unit is further configured 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 further configured to control the drive unit to disconnect and reconnect with the motor shaft based on the instruction.

6. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 2 is characterized in that: The analysis unit is also used to determine the reason why the quality test process of the motor shaft fails based on the comparison result of the amplitude average difference and the preset amplitude average difference; The analysis unit determines to issue a notification that the motor shaft is unqualified based on the cause, or to adjust the sampling frequency of the detection unit during data acquisition, or obtains a number of historical vibration amplitude average values ​​and corresponding times based on the determination result and draws a time-vibration amplitude curve, and re-determines the processing based on the time-vibration amplitude curve; The amplitude average difference is the difference between the vibration amplitude average value and the preset vibration amplitude average value.

7. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 6 is characterized in that: 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; The amplitude curve integral is obtained by integrating the time-vibration amplitude curve.

8. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 7 is characterized in that: The analysis unit is further used 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 and 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 used 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.

9. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 8, characterized in that: The analysis unit is also used to reacquire the integral of the amplitude curve after completing the clamping force increase adjustment of the fixing unit and compare it with the integral of the critical amplitude curve to determine whether to replace the bearing in the fixing unit; The analysis unit is further used to generate a corresponding instruction to determine to replace the bearing when the integral of the amplitude curve is greater than the integral of the critical amplitude curve; The control unit is further configured to issue a notification to replace the two bearings in the fixing unit based on the instruction.

10. The motor shaft quality intelligent detection system for permanent magnet motor production according to claim 6, characterized in that: The analysis unit is further used to determine to increase the sampling frequency when the amplitude average difference is greater than the preset amplitude average difference, and to generate a corresponding instruction based on a comparison result of the average difference ratio with the preset average difference ratio to determine the increase amplitude of the sampling frequency, wherein the increase amplitude is positively correlated with the average difference ratio; The control unit is further used 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.

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