A method for detecting rotor damping bar faults in large AC synchronous motors

Abstract

The present invention relates to the field of motor detection technology, and discloses a method for detecting faults in the rotor damping strips of a large AC synchronous motor, which is used to detect all damping strips distributed around the circumference of the rotor core. Short-circuit rings welded to the damping strips are provided on both sides of the rotor core. The detection method utilizes a detection device, which includes a fixing mechanism and a knocking mechanism. The fixing mechanism includes a fixing portion, which is used to position and fix the detection device on the motor rotor; the knocking mechanism includes a knocking portion, which is used to release from the knocking mechanism and knock on the damping strip to be detected; and the method determines whether the damping strip to be detected is faulty based on the sound echo emitted when the knocking portion knocks on the damping strip to be detected. If the sound echo is normal, the state of the damping strip to be detected is normal; if the sound echo is abnormal, the state of the damping strip to be detected is abnormal. The present invention can perform fault detection on all damping strips on the motor under the same conditions, and the detection is highly standardized and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of motor detection, in particular to a method for detecting faults of a large AC synchronous motor rotor damping bar. Background Art

[0002] Large AC synchronous motors are widely used in heavy industry and manufacturing. Their rotor damping systems have long attracted widespread attention due to their high failure rates. The primary load-bearing components in the rotor damping system are the damping bars, which are distributed around the rotor in a cage-like pattern. During operation, these bars are subject to significant electromagnetic and centrifugal forces, which can lead to loosening and breakage. In mild cases, these problems can cause motor overcurrent and shutdown, while in severe cases, they can break and fly out, causing major equipment failures such as motor bore scavenging, posing a significant threat to smooth production.

[0003] Due to the small gap between the rotor and stator, it is impossible to observe the overall condition of the damping strips in depth during routine inspections. When inspecting the damping strips of a motor, if conventional ultrasonic, endoscopic and other inspection methods are used, the inspection results are often not as good as expected due to the compactness of the rotor structure. The inspection cost is also generally high, and the use of the inspection equipment requires the operator to master professional skills. In addition, for some motors with more compact rotor structures, the distance between the rotor core and the short-circuit ring is very small, and the inspection equipment cannot be installed normally, which makes inspection very difficult. Therefore, in response to the above problems, it is urgent to find a suitable method to conduct systematic and standardized inspections of the motor rotor damping strips to avoid the influence of factors such as personnel skills, tools, and equipment conditions on the inspection results. Summary of the Invention

[0004] The present invention aims to provide a method for detecting faults in the damping bars of a large AC synchronous motor rotor. The method can detect faults in all damping bars on the motor rotor, with a high degree of standardization and low detection cost.

[0005] The technical solution of the present invention is: a method for detecting rotor damping bar faults of a large AC synchronous motor, which is used to detect all damping bars distributed around the central axis of the rotor core, wherein short-circuit rings are provided on both axial sides of the rotor core, and the ends of the damping bars extend outside the rotor core and are connected to the short-circuit rings. The detection method is based on a detection device, which includes a fixing mechanism and a tapping mechanism. The fixing mechanism includes a fixing portion, which is used to position and fix the detection device on the motor rotor; the tapping mechanism includes a tapping portion, which is used to release from the tapping mechanism and tap the damping bar to be detected;

[0006] During the test, the fixing portion is first pre-connected to the motor rotor, and the position of the detection device is adjusted so that a movement channel is reserved between the striking portion and the damping strip to be tested; the fixing portion is then adjusted so that the relative position between the detection device and the motor rotor is fixed; and finally, the striking portion is released so that the striking portion strikes the damping strip to be tested along the movement channel.

[0007] For a motor to be tested, the sound echo emitted by the knocking part when the damping strip is normally installed is defined as a normal echo, and the other echoes are abnormal echoes. Whether the damping strip to be tested is faulty is judged based on the sound echo emitted when the knocking part knocks on the damping strip to be tested. If the sound echo is a normal echo, it is determined that the state of the damping strip to be tested is normal; if the sound echo is an abnormal echo, it is re-tested. If the re-test still produces an abnormal echo, it is determined that the state of the damping strip to be tested is abnormal.

[0008] Compared with the prior art, the beneficial effects of the present invention are embodied in that: the present invention judges the state of the damping strip by the type of sound produced when the knocking part hits the damping strip. In order to perform a simple and accurate detection of the damping strip, the present invention designs a detection device. During detection, the detection device is detachably fixed to the motor rotor. After the fixation is completed, an unobstructed movement channel can be formed between the knocking part of the detection device and the damping strip to be detected. Finally, the knocking part is released to allow the knocking part to act on the damping strip to be detected. As for the type of sound produced when the knocking part knocks the damping strip, if the damping strip is installed normally, the sound produced should be crisp and short, and when the damping strip is loose or broken, the sound produced is dull and dragging. For experienced operators, It is very easy to distinguish between the two sound echoes. For inexperienced operators, as long as they hear the difference between the two sound echoes on site, they can easily and accurately complete the detection work. The operator does not need to master professional skills. Strictly following the above operations can perform fault detection on all damping strips on the motor rotor. In other words, a single detection device can be used to complete the detection of all damping strips on the motor. The detection is highly standardized and the cost of detection is low. During the detection process, only the knocking part needs to hit the damping strip between the rotor core and the short-circuit ring. The distance requirement between the rotor core and the short-circuit ring is relatively small. In summary, the detection method of the present invention has low requirements on factors such as personnel skills, tools, and equipment conditions, and has low cost.

[0009] In the aforementioned large AC synchronous motor rotor damping strip fault detection method, when different damping strips on the same motor are tested, it is ensured that the position of the knocking part on the damping strip to be tested and the knocking force on the damping strip to be tested remain consistent during each test.

[0010] In the aforementioned large AC synchronous motor rotor damping strip fault detection method, when different damping strips on the same motor are detected, the same detection device is used to sequentially detect all damping strips along the circumference of the motor rotor.

[0011] In the aforementioned large AC synchronous motor rotor damping bar fault detection method, part of the fixing portion is inserted and connected between the rotor core and the short-circuit ring, and the gap between the rotor core and the short-circuit ring constitutes the end of the movement channel.

[0012] In the aforementioned large AC synchronous motor rotor damping bar fault detection method, the extension direction of the motion channel is in the radial direction of the motor rotor.

[0013] In the aforementioned large AC synchronous motor rotor damping strip fault detection method, if the sound echo is an abnormal echo, it is re-inspected. If the re-inspection still shows an abnormal echo, it is determined that the state of the damping strip to be detected is abnormal, including: when the sound echo is an abnormal echo, the damping strip under inspection is re-inspected three times. If the sound echo in each re-inspection is an abnormal echo, it is determined that the state of the damping strip is abnormal.

[0014] In the aforementioned large AC synchronous motor rotor damping strip fault detection method, the fixing portion includes a first opening portion and a second opening portion, the first opening portion and the second opening portion cooperate to form a hollow mounting cavity, the knocking mechanism is installed in the mounting cavity, the knocking mechanism includes a pulling portion, a knocking portion and a tension spring, the knocking portion is connected to the bottom of the pulling portion, the tension spring is sleeved outside the knocking portion, and one end is connected to the pulling portion and the other end is connected to the bottom of the mounting cavity;

[0015] The relative distance between the first support portion and the second support portion is adjustable. When the first support portion and the second support portion are closed to each other, the bottom of the installation cavity is closed and the knocking portion is against the inner bottom of the installation cavity; when the first support portion and the second support portion are separated from each other, the bottom of the installation cavity is opened to form the movement channel.

[0016] In the aforementioned large AC synchronous motor rotor damping strip fault detection method, the fixing mechanism includes a screw rod, the first support part and the second support part are connected via the screw rod, the screw rod passes through the installation cavity, and an adjusting nut is connected to the screw rods on both sides outside the installation cavity. A plane bearing is fixed on the outer wall of the first support part and the second support part, the screw rod passes through the plane bearing, and the adjusting nut is movably connected to the plane bearing.

[0017] In the aforementioned large AC synchronous motor rotor damping bar fault detection method, an embedding groove is provided at the bottom of the installation cavity, and the embedding groove is formed by the bottom of the first support part and the second support part, and the bottom of the tension spring is limited in the embedding groove.

[0018] In the aforementioned large AC synchronous motor rotor damping bar fault detection method, an elastic latch assembly is fixed on the outer side wall of the first support portion and / or the second support portion, and the elastic latch assembly includes a movable latch, and the pulling portion is provided with a latch groove for inserting the movable latch. When the movable latch is inserted into the latch groove, the tension spring is in a stretched state, and the bottom end of the knocking portion is flush with the bottom plane of the mounting cavity.

[0019] In the aforementioned large AC synchronous motor rotor damping bar fault detection method, grooves are provided along the circumference of the outer side walls of the first opening portion and the second opening portion, and elastic hoop is nested in the grooves. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the detection device of the present invention before being installed on the motor rotor;

[0021] Figure 2 yes Figure 1 A local enlarged view at point A;

[0022] Figure 3 This is a schematic diagram of the detection device of the present invention after being installed on the motor rotor and before the knocking part is released;

[0023] Figure 4 yes Figure 3 A partial enlarged view at point B;

[0024] Figure 5 This is a schematic diagram of the state of the detection device of the present invention after being installed on the motor rotor and the knocking part is released;

[0025] Figure 6 yes Figure 5 A partial enlarged view at point C.

[0026] Figure markings: 1-damping strip, 2-short-circuit ring, 3-fixing mechanism, 4-tapping mechanism, 5-rotor core, 6-movement channel, 7-screw, 8-adjusting nut, 9-plane bearing, 10-elastic latch assembly, 31-fixing part, 32-installation cavity, 41-tapping part, 42-pulling part, 43-tension spring, 101-movable latch, 102-latch trigger button, 300-flat feeler, 311-first support part, 312-second support part, 321-embedded groove, 400-silicone pad, 421-latch groove, 500-elastic sleeve. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0028] The embodiment of the present invention provides a large AC synchronous motor rotor damping bar fault detection method for detecting all damping bars 1 distributed around the rotor core 5. All damping bars 1 completely penetrate the rotor core 5 along the axial direction of the rotor core 5. A short-circuit ring 2 is provided on each side of the rotor core 5. The ends of the damping bars 1 extend to the outside of the rotor core 5 and are welded to the short-circuit ring 2. Figure 1 、 3 , 5 only schematically depicts the short-circuit ring 2 on one side of the rotor core 5. The detection method is based on a detection device. The specific detection device can be referenced. Figures 1 to 6 The detection device includes a fixing mechanism 3 and a knocking mechanism 4. The fixing mechanism 3 includes a fixing portion 31, and the fixing portion 31 is used to position and fix the detection device on the motor rotor; the knocking mechanism 4 includes a knocking portion 41, and the knocking portion 41 is used to release from the knocking mechanism 4 and knock on the damping strip 1 to be detected;

[0029] During testing, first, the fixing portion 31 is pre-connected to the motor rotor, and the position of the testing device is adjusted so that a movement channel 6 is reserved between the striking portion 41 and the damping strip 1 to be tested; then, the fixing portion 31 is adjusted so that the relative position between the testing device and the motor rotor is fixed; finally, the striking portion 41 is released so that the striking portion 41 strikes the damping strip 1 to be tested along the movement channel 6;

[0030] For a motor to be tested, the sound echo emitted by the knocking part 41 when the damping strip 1 is normally installed is defined as a normal echo, and the other echoes are abnormal echoes. Whether the damping strip 1 to be tested is faulty is judged based on the sound echo emitted when the knocking part 41 knocks on the damping strip 1 to be tested. If the sound echo is a normal echo, it is determined that the state of the damping strip 1 to be tested is normal; if the sound echo is an abnormal echo, it is re-tested. If the re-test still produces an abnormal echo, it is determined that the state of the damping strip 1 to be tested is abnormal.

[0031] In this embodiment, the abnormality of the damping strip 1 mainly refers to looseness and breakage. The normal reverberation is the sound reverberation produced by the knocking portion 41 when the damping strip 1 is properly installed. The abnormal reverberation is generally the sound reverberation produced by the knocking portion 41 when the damping strip 1 is loose or broken. It can be considered that all reverberations other than the normal reverberation are abnormal reverberations. The sound reverberation strictly refers to the frequency of the sound produced by the knocking portion 41 knocking the damping strip 1. However, since the sound frequency of the normal damping strip 1 of different motors may vary, the specific value of the frequency is not elaborated in this embodiment. Normal reverberation and abnormal reverberation are relative sound reverberation states. For those skilled in the art, it should be easy to distinguish between the two sounds. Normal reverberation is relatively crisp and short, while abnormal reverberation is relatively dull and dragging. Here, even for those outside the field, to distinguish between the two sound reverberations, one only needs to manually ensure that a certain damping strip 1 is normal or abnormal before performing the knocking action, and the normal reverberation and abnormal reverberation can be defined.

[0032] Optionally, when testing different damping strips 1 on the same motor, ensure that the position of the knocking part 41 on the damping strip 1 to be tested and the knocking force on the damping strip 1 to be tested remain consistent during each testing process.

[0033] In this embodiment, although the difference between normal reverberation and abnormal reverberation is very obvious, when testing all the damping strips 1 on the same motor, keeping the position of the knocking part 41 on the damping strip 1 to be tested and the knocking force consistent helps to test all the damping strips 1 of the motor under the same conditions. The damping strips 1 tested under this condition have higher accuracy and a higher fault detection rate.

[0034] Optionally, when testing different damping strips 1 on the same motor, the same testing device is used to sequentially test all the damping strips 1 along the circumferential direction of the motor rotor.

[0035] In this embodiment, the same detection device can complete the detection of all damping strips 1 on the motor. At the same time, the detection device can also be applied to different motor detections. All damping strips 1 can be detected in sequence along the circumference of the motor rotor to ensure that no detection is missed. For the damping strips 1 detected to be faulty, stickers can be marked on them so that they can be uniformly inspected or replaced after all damping strips 1 have been inspected.

[0036] Optionally, part of the fixing portion 31 is inserted and connected between the rotor core 5 and the short-circuit ring 2 , and the gap between the rotor core 5 and the short-circuit ring 2 constitutes an end of the movement channel 6 .

[0037] In this embodiment, connecting the fixing part 31 between the rotor core 5 and the short-circuit ring 2 reflects that the detection device perfectly fits the structure of the motor rotor. At the same time, the detection device can be adapted to motors of various specifications and sizes. The gap between the rotor core 5 and the short-circuit ring 2 also constitutes a part of the motion channel 6, with high space utilization. Reusing this distance also allows the released knocking part 41 to have a shorter motion stroke, thereby reducing the probability of scratches and collisions throughout the entire motion stroke, and ultimately helps to accurately detect all damping strips 1 of the motor under the same conditions.

[0038] Optionally, the extension direction of the motion channel 6 is in the radial direction of the motor rotor.

[0039] In this embodiment, since the knocking part 41 is released along the motion channel 6, it can be broadly considered that the damping strip 1 and the knocking part 41 are both arranged along the radial direction of the motor rotor. When all the damping strips 1 are tested, the knocking part 41 is released along the radial direction of the motor rotor, and then knocks onto the damping strip 1, which helps to accurately detect all the damping strips 1 of the motor under the same conditions.

[0040] Optionally, if the sound echo is an abnormal echo, it is re-inspected. If the re-inspection still shows an abnormal echo, the state of the damping strip 1 to be inspected is determined to be abnormal, including: when the sound echo is an abnormal echo, the damping strip 1 is re-inspected three times. If the sound echo in each re-inspection is an abnormal echo, the state of the damping strip 1 is determined to be abnormal.

[0041] In this embodiment, when an abnormal echo occurs, it is rechecked three times to ensure the accuracy of the detection.

[0042] Optionally, refer to Figure 1 and Figure 2 The fixing portion 31 includes a first support portion 311 and a second support portion 312. The first support portion 311 and the second support portion 312 cooperate to form a hollow mounting cavity 32. The knocking mechanism 4 is installed in the mounting cavity 32. The knocking mechanism 4 includes a pulling portion 42, a knocking portion 41 and a tension spring 43. The knocking portion 41 is connected to the bottom of the pulling portion 42. The tension spring 43 is sleeved outside the knocking portion 41, and one end is connected to the pulling portion 42, and the other end is connected to the bottom of the mounting cavity 32.

[0043] The relative distance between the first opening portion 311 and the second opening portion 312 is adjustable. When the first opening portion 311 and the second opening portion 312 are closed together, Figure 1 , the bottom of the installation cavity 32 is closed, and the knocking portion 41 is against the inner bottom of the installation cavity 32; when the first support portion 311 and the second support portion 312 are separated from each other, Figure 3 and Figure 5 The bottom of the installation cavity 32 is opened to form a movement channel 6.

[0044] In this embodiment, the ends of the first support portion 311 and the second support portion 312 are provided with flat feelers 300 for clamping at the gap between the rotor core 5 and the short-circuit ring 2. The flat feelers 300 are relatively thin and do not affect the width of the movement channel 6 after being clamped between the rotor core 5 and the short-circuit ring 2.

[0045] In this embodiment, when the first support portion 311 and the second support portion 312 are closed together, the detection device is in a non-working state, and the detection device should be in this state after use; when the first support portion 311 and the second support portion 312 are separated from each other until they are clamped between the rotor core 5 and the short-circuit ring 2, the detection device is in a working state. At this time, the elastic potential energy stored in the tension spring 43 can be used to release the knocking portion 41, so that it can hit the damping strip 1 to be detected along the motion channel 6. As long as the length of the tension spring 43 is kept consistent, the force of the knocking portion 41 hitting the damping strip 1 can be kept constant in theory.

[0046] Optionally, the fixing mechanism 3 includes a screw rod 7, and the first support portion 311 and the second support portion 312 are connected via the screw rod 7. The screw rod 7 passes through the installation cavity 32. An adjusting nut 8 is connected to the screw rod 7 on both sides outside the installation cavity 32. A plane bearing 9 is fixed on the outer wall of the first support portion 311 and the second support portion 312. The screw rod 7 passes through the plane bearing 9, and the adjusting nut 8 is movably connected to the plane bearing 9.

[0047] In this embodiment, the closing and separation of the first support portion 311 and the second support portion 312 are achieved by operating the adjusting nuts 8 on both sides. The adjusting nut 8 and the plane bearing 9 installed on the first support portion 311 are taken as an adjustment example. During the adjustment process, the first support portion 311, the adjusting nut 8 and the plane bearing 9 move synchronously along the screw rod 7. The adjusting nut 8 and the plane bearing 9 are movably connected, and the plane bearing 9 and the outer wall of the first support portion 311 are fixedly connected. There is no threaded connection between the plane bearing 9, the first support portion 311 and the screw rod 7. It can be regarded as the screw rod 7 that passes through the plane bearing 9 and the side wall of the first support portion 311 and does not contact the two. When the adjusting nut 8 is rotated to feed outward, the first support portion 311 is fed outward synchronously under the drive of the adjusting nut 8. What needs to be ensured here is that when the first support portion 311 and the second support portion 312 are closed, the inner walls of the first support portion 311 and the second support portion 312 just rest against the pull-out portion 42. When the first support portion 311 and the second support portion 312 need to be separated, the feed amount of the adjusting nuts 8 on both sides needs to be kept consistent.

[0048] When operating the adjusting nut 8 , an operating tool such as a wrench can be used as a lever arm connected to the adjusting nut 8 to operate the adjusting nut 8 more effortlessly.

[0049] Optionally, an embedding groove 321 is provided at the bottom of the mounting cavity 32. The embedding groove 321 is formed by the cooperation of the bottom of the first opening portion 311 and the second opening portion 312. The bottom of the tension spring 43 is limited in the embedding groove 321. That is to say, the first opening portion 311 and the second opening portion 312 respectively participate in forming a part of the embedding groove 321. When the first opening portion 311 and the second opening portion 312 are closed or separated, the length of the embedding groove 321 itself will also change to a certain extent. For details, please compare Figure 2 and Figure 4 For reference, in this embodiment, even when the length of the embedding groove 321 is changed to the longest, the tension spring 43 does not fall out of the embedding groove 321 .

[0050] In this embodiment, the bottom end of the tension spring 43 is connected to the bottom of the mounting cavity 32, and the knocking part 41 passes through the inside of the tension spring 43. When the first support part 311 and the second support part 312 are separated, since the tension spring 43 needs to maintain relative movement with the above two, an embedded groove 321 is provided to limit the tension spring 43 in the vertical direction, and at the same time, relative movement with the tension spring 43 can be achieved in the horizontal direction.

[0051] It should be noted that during the operation of the adjusting nut 8, after the fixing portion 31 is connected to the gap between the rotor core 5 and the short-circuit ring 2, the diameter setting of the tension spring 43 needs to ensure that the tension spring 43 does not fall out of the embedding groove 321, that is, it does not slide upward from the movement channel 6.

[0052] It should be noted that the screw rod 7 passes through the first opening portion 311 and the second opening portion 312 . Inside the installation cavity 32 , the screw rod 7 is completely arranged to avoid the tension spring 43 and the knocking portion 41 .

[0053] Optionally, an elastic latch assembly 10 is fixed on the outer wall of the first support portion 311 and / or the second support portion 312, and the elastic latch assembly 10 includes a movable latch 101. The pulling portion 42 is provided with a latch groove 421 for inserting the movable latch 101. When the movable latch 101 is inserted into the latch groove 421, the tension spring 43 is in a stretched state, and the bottom end of the knocking portion 41 is flush with the bottom plane of the mounting cavity 32.

[0054] In this embodiment, the elastic latch assembly 10 is fixed only on the outer side wall of the first support portion 311. The elastic latch assembly 10 can be a conventional commercially available elastic latch assembly 10 including a movable latch 101 and a latch trigger button 102. It is only required that the movable latch 101 can retract when the latch trigger button 102 is pressed; the setting of the elastic latch assembly 10 can enable the movable latch 101 to be inserted into the latch groove 421 on the pulling portion 42 when the detection device is not working or before the knocking portion 41 is released, so that when all the damping strips 1 are detected, the elongation of the tension spring 43 after the detection device is installed can be kept consistent, so that the force of the knocking portion 41 hitting the damping strip 1 is constant, which is helpful to detect all the damping strips 1 of the motor under the same conditions.

[0055] Optionally, grooves are provided along the circumference of the outer side walls of the first opening portion 311 and the second opening portion 312 , and the elastic hoop 500 is nested in the grooves.

[0056] In this embodiment, although the cooperation between the screw rod 7 and the adjusting nut 8 can maintain the relative position stability between the first support portion 311 and the second support portion 312, the setting of the elastic hoop 500 provides a pre-tightening force for the connection between the first support portion 311 and the second support portion 312. When the adjusting nut 8 is adjusted, the pre-tightening force generated by the elastic hoop 500 can ensure that the first support portion 311 and the second support portion 312 will not produce a slight looseness on the screw rod 7, further improving the stability of the installation of the detection device.

[0057] In an optional embodiment of the present invention, since the detection method of all damping strips 1 on the motor rotor is the same, only a single damping strip 1 on the motor rotor is tested as an example. The whole process is as follows:

[0058] First, refer to Figure 1 and Figure 2 , showing a state of the detection device before installation. At this time, the bottom of the first support part 311 and the second support part 312 remain completely closed, the pull-out part 42 is clamped, and the bottom end of the knocking part 41 is against the bottom of the installation cavity 32. Take the detection device, and extend the flat feeler 300 at the end of the first support part 311 and the second support part 312 between the rotor core 5 and the short-circuit ring 2. During actual operation, a layer of silicone pad 400 can be placed on the outer bottom of the first support part 311 and the second support part 312 outside the flat feeler 300. The thickness of the silicone pad 400 can be adaptively selected. It is only necessary to ensure that after the silicone pad 400 is against the outer wall of the rotor core 5 and the short-circuit ring 2, the bottom end of the flat feeler 300 does not touch the damping strip 1 to be detected.

[0059] Then, refer to Figure 3 and Figure 4, adjust the adjusting nuts 8 on both sides of the screw rod 7 to ensure that the feed amount of the adjusting nuts 8 on both sides is the same, until the flat feelers 300 at the ends of the first support portion 311 and the second support portion 312 just contact the rotor core 5 or the short-circuit ring 2. At this time, the position of the entire detection device can still be moved with a little force, and the position of the detection device can be fine-tuned so that the knocking part 41 inside the detection device and the damping strip 1 to be detected are located in the radial direction of the motor rotor, that is, the formed motion channel 6 is arranged along the radial direction of the motor rotor. At this time, adjust the adjusting nuts 8 on both sides of the screw rod 7 to make the relative position between the detection device and the motor rotor completely fixed, that is, the position of the detection device can no longer be moved.

[0060] Finally, reference Figure 5 and Figure 6 , press the latch trigger button 102 on the elastic latch assembly 10, the knocking part 41 is released, and under the action of the potential energy of the tension spring 43, it strikes the damping strip 1 to be tested along the movement channel 6. The operator judges whether the damping strip 1 to be tested is faulty based on the sound echo emitted when the knocking part 41 strikes the damping strip 1 to be tested. If the sound echo is normal, it is determined that the state of the damping strip 1 to be tested is normal; if the sound echo is abnormal, the damping strip 1 to be tested is re-inspected three times. If the sound echo is abnormal in each re-inspection, it is determined that the state of the damping strip 1 is abnormal.

[0061] After the inspection of a single damping strip 1 is completed, the operator first acts on the pulling part 42 to pull the knocking part 41 back from the motion channel 6, and inserts the movable pin 101 on the elastic pin assembly 10 into the pin slot 421 of the pulling part 42 to complete the fixation. At this time, it is only necessary to slightly adjust the feed amount of the adjusting nuts 8 on both sides of the screw rod 7 to ensure that the entire inspection device can be removed. Then, when inspecting other damping strips 1 on the same motor in the future, the adjusting nuts 8 on both sides of the screw rod 7 only need to be slightly adjusted when installing the inspection device, which helps to improve the inspection efficiency.

[0062] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0063] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for detecting rotor damping bar faults in a large AC synchronous motor, comprising detecting all damping bars distributed around the central axis of a rotor core, wherein short-circuit rings are provided on both axial sides of the rotor core, and the ends of the damping bars extend outside the rotor core and connect to the short-circuit rings. The method is characterized by: The detection method is based on a detection device, which includes a fixing mechanism and a knocking mechanism. The fixing mechanism includes a fixing portion, which is used to position and fix the detection device on the motor rotor; the knocking mechanism includes a knocking portion, which is used to release from the knocking mechanism and knock the damping strip to be detected. During testing, the fixing portion is first pre-connected to the motor rotor, and the position of the testing device is adjusted so that a movement channel is reserved between the striking portion and the damping strip to be tested; the fixing portion is then adjusted so that the relative position between the testing device and the motor rotor is fixed; and finally, the striking portion is released so that the striking portion strikes the damping strip to be tested along the movement channel. For a motor to be tested, the sound echo emitted by the knocking part when the damping strip is normally installed is defined as a normal echo, and the other echoes are defined as abnormal echoes. Whether the damping strip to be tested is faulty is determined based on the sound echo emitted when the knocking part knocks on the damping strip to be tested. If the sound echo is a normal echo, the state of the damping strip to be tested is determined to be normal; if the sound echo is an abnormal echo, the damping strip to be tested is re-tested. If the re-test still produces an abnormal echo, the state of the damping strip to be tested is determined to be abnormal. The fixing portion includes a first support portion and a second support portion, the first support portion and the second support portion cooperate to form a hollow mounting cavity, the knocking mechanism is installed in the mounting cavity, the knocking mechanism includes a pull-out portion, a knocking portion and a tension spring, the knocking portion is connected to the bottom of the pull-out portion, the tension spring is sleeved outside the knocking portion, and one end is connected to the pull-out portion, and the other end is connected to the bottom of the mounting cavity; The relative distance between the first support portion and the second support portion is adjustable. When the first support portion and the second support portion are closed to each other, the bottom of the installation cavity is closed and the knocking portion is against the inner bottom of the installation cavity; when the first support portion and the second support portion are separated from each other, the bottom of the installation cavity is opened to form the movement channel.

2. The large AC synchronous motor rotor damping bar fault detection method according to claim 1, characterized in that: When testing different damping strips on the same motor, ensure that the position of the knocking part on the damping strip to be tested and the knocking force on the damping strip to be tested remain consistent during each testing process.

3. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, wherein: When testing different damping strips on the same motor, the same testing device is used to test all the damping strips in sequence along the circumference of the motor rotor.

4. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, wherein: Part of the fixing portion is inserted and connected between the rotor core and the short-circuit ring, and the gap between the rotor core and the short-circuit ring constitutes an end of the movement channel.

5. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, characterized in that: The extending direction of the movement channel is in the radial direction of the motor rotor.

6. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, characterized in that: If the sound echo is an abnormal echo, it is re-inspected. If the re-inspection still shows an abnormal echo, the state of the damping strip to be inspected is determined to be abnormal, including: when the sound echo is an abnormal echo, the damping strip under inspection is re-inspected three times. If the sound echo in each re-inspection is an abnormal echo, the state of the damping strip is determined to be abnormal.

7. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, characterized in that: The fixing mechanism includes a screw rod, the first support part and the second support part are connected via the screw rod, the screw rod passes through the installation cavity, an adjusting nut is connected to the screw rods on both sides outside the installation cavity, a plane bearing is fixed on the outer side wall of the first support part and the second support part, the screw rod passes through the plane bearing, and the adjusting nut is movably connected to the plane bearing.

8. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, characterized in that: An embedding groove is provided at the bottom of the installation cavity. The embedding groove is formed by the cooperation of the bottom of the first opening portion and the bottom of the second opening portion. The bottom of the tension spring is limited in the embedding groove.

9. The method for detecting rotor damping bar faults of a large AC synchronous motor according to claim 1, characterized in that: An elastic latch assembly is fixed on the outer side wall of the first support portion and / or the second support portion, and the elastic latch assembly includes a movable latch. The pulling portion is provided with a latch groove for inserting the movable latch. When the movable latch is inserted into the latch groove, the tension spring is in a stretched state, and the bottom end of the knocking portion is flush with the bottom plane of the mounting cavity.

Images