Gearbox gear shaft fault synchronization detection, processing method and system

Abstract

The present invention discloses a synchronous detection and processing method and system for gear shaft fault of a gearbox, wherein the method comprises: S1: a first detection device is set on the inner shaft of the gear, and a second detection device is set on the gear of the gearbox; S2: the first detection device is used to perform high-frequency sampling and acquisition on the inner shaft of the gear without cracks and the inner shaft of the gear with cracks, respectively, and multiple vibration levels are set; S3: the second detection device collects the second signal of the gearbox gear when it runs at different speeds in a wear-free state through high-frequency sampling, and sets the standard range of the second signal at different speeds; S4: during the operation of the gearbox gear, the first signal and the second signal are synchronously collected; S5: whether to alarm or stop the operation. The present invention synchronously detects gear shaft faults of the gearbox, and the two detections are mutually restricted and independent, which can discover and deal with potential safety hazards and avoid secondary injuries.

Description

Technical Field

[0001] The present invention relates to the field of gearbox fault detection, and in particular to a gearbox gear shaft fault synchronization detection and processing method and system. Background Art

[0002] The gearbox is the main kinetic energy transmission device of the car. The gearbox gears and gear inner shafts need to transmit torque to the next unit during operation. Long-term alternating loads will cause wear of the gearbox gears and the gear inner shafts arranged on the inner periphery of the gearbox gears, and then cracks will appear.

[0003] Among them, the common gearbox component fault detection method usually requires sensing obvious fault signals. Usually when the data changes, serious wear has occurred in the box and may cause wear debris. The wear debris will affect the normal operation of other parts and cause secondary damage to other parts in the gearbox.

[0004] In the prior art, some methods also realize early fault detection by combining torque, vibration and other signals, wherein the vibration signal is usually judged by noise and other signals. For example, the invention patent with publication number CN115901238A provides a gear detection method, system, gearbox and electric vehicle. The method comprises: installing the gear to be detected into the gearbox, and measuring the vibration and noise value of the gearbox by using the production line end-of-line test EOL system; performing Fourier transform on the vibration and noise value of the gearbox to obtain the amplitude spectrum diagram of the gear to be detected; another example is the invention patent with publication number CN115901243A, which relates to a gear fault detection method, device, medium, equipment and system. The method includes: obtaining a first angular acceleration signal of the second gear rotating shaft when the first gear rotates counterclockwise at a first preset speed and when the torque of the second gear is the first preset torque; obtaining a second angular acceleration signal of the second gear rotating shaft when the first gear rotates clockwise at a second preset speed and when the torque of the second gear is the second preset torque; performing axis separation signal processing on the first angular acceleration signal and the second angular acceleration signal respectively to obtain a first time domain signal and a second time domain signal of the rotating shaft where the gear to be tested is located. In combination with the first time domain signal and / or the second time domain signal, bumps and bruises on the gear meshing surface, especially slight bumps and bruises on the gear meshing surface, can be detected, thereby improving the accuracy of the gear fault detection method. However, there are major problems with both torque detection and noise detection. First, when using common shaft torque sensors to test shaft torque, bearing friction cannot be avoided, which may affect the accuracy of the test. In addition, the installation space of the torque sensor is large, resulting in limited space application. In addition, the torque test is affected by factors such as transmission eccentricity error, errors caused by uneven scales of the indexing plate, and installation errors, which may lead to inaccurate measurement results. Second, when the gearbox is operating, there is a lot of noise interference, which may be caused by a variety of factors, not just shaft vibration, but also factors such as bearing manufacturing accuracy, installation fit, and lubrication conditions. These factors may lead to misjudgment of the true cause of shaft vibration. In addition, the relationship between noise and vibration is complex. For example, bearing vibration and noise may be caused by a variety of reasons, including but not limited to changes in the number of rolling elements, local damage, improper fit between inner and outer rings and adjacent components, and entry of contaminants. Therefore, noise detection may not accurately reflect the specific parameters of vibration, such as vibration frequency and amplitude. Summary of the invention

[0005] Therefore, in order to solve the above problems, the present invention provides a method and system for synchronous detection and processing of gear shaft faults in a gearbox.

[0006] The present invention is achieved through the following technical solutions:

[0007] The synchronous detection and processing method of the gear shaft fault of the gearbox includes the following steps:

[0008] S1: a first detection device for detecting the eccentric vibration intensity of the gear inner shaft is arranged on the gear inner shaft, and a second detection device for detecting the stress and strain magnitude of the gear meshing portion of the gearbox is arranged on the gearbox gear, wherein the measuring points of the first detection device are located at the two end faces of the gear inner shaft, and the measuring points of the second detection device are located at the root of each tooth of the gearbox gear;

[0009] S2: using a first detection device to perform high-frequency sampling and acquisition on a gear inner shaft without cracks and a gear inner shaft with cracks, respectively, to obtain first signals of the gear inner shaft with / without cracks, respectively, and to set multiple vibration levels for reflecting the vibration state of the gear inner shaft according to the two first signals;

[0010] S21: using a first detection device to perform high-frequency sampling and acquisition on a crack-free gear inner shaft to obtain a plurality of first signals of the gear inner shaft in a crack-free state;

[0011] S22: using a first detection device to perform high-frequency sampling and acquisition on the cracked gear inner shaft to obtain a plurality of first signals of the gear inner shaft in a cracked state;

[0012] S23: At the same time as step S22, the crack opening and closing changes caused by the changes in the eccentric vibration intensity of the gear inner shaft during the operation of the gear inner shaft are recorded;

[0013] S24: Combining the change amplitude of the first signal in step S22 and step S23 and the change of crack opening and closing, deriving a change relationship between the two;

[0014] S25: In combination with steps S21 to S24, multiple vibration levels are set based on the amplitude changes of multiple first signals of the gear inner shaft in the state of having / not having cracks;

[0015] S3: The second detection device collects the second signal when the gearbox gear rotates at any operating speed in a wear-free state through high-frequency sampling, and sets the second signal collected at each speed as the second signal standard range at the speed;

[0016] S4: during the operation of the gearbox gear, the first detection device and the second detection device synchronously collect the first signal and the second signal;

[0017] S5: Determine whether to alarm based on the first signal and the second signal collected in real time. When at least one of the first signal and the second signal triggers an alarm, switch the gearbox to a neutral position and stop running.

[0018] Preferably, the first detection device is a capacitive vibration sensor, comprising two capacitive sensor plates arranged at both ends of the inner shaft of the gear, the first signal is the capacitance value C of the capacitive vibration sensor, and the relationship between the distance d between the two capacitive sensor plates and the capacitance value C is: C=εA / d, wherein ‌ε represents the dielectric constant on both sides of the shaft end, and ‌A represents the electrode area.

[0019] Preferably, in step S2, the distance between the two capacitive sensor plates is d=L0+Dsin(θ / 2), wherein L0 is the distance between the two ends of the inner shaft of the gear in a crack-free state; D is the shaft diameter where the crack is located; θ is the opening angle of the crack, and the change in the size of θ when the inner shaft of the gear rotates conforms to the switching function model f(ψ), ψ is the difference between the direction angle of the crack and the rotor vortex angle, when ψ is zero, the crack is fully open, when ψ is π / 2 or 3π / 2, the crack is half open and half closed, and when ψ is π, the crack is fully closed.

[0020] Preferably, the distance between the two capacitive sensor plates is d = L0 + kDsin(θ / 2), wherein k represents a crack extension factor.

[0021] Preferably, in step S25, when the inner shaft of the gear is in a crack-free state, the amplitude variation of the sampling values ​​of the multiple first signals is within 2%, and this floating range is set to the first vibration level; when the inner shaft of the gear is in a cracked state, when the amplitude variation of the multiple first signals is within 2%-10%, eccentric vibration occurs in the inner shaft of the gear, but the crack does not expand, and this floating range is set to the second vibration level; when the amplitude variation of the multiple first signals exceeds 10%, cracks occur in the inner shaft of the gear and the floating of the first signals becomes larger and larger, and the crack expands, and this floating range is set to the third vibration level.

[0022] Preferably, in step S5, when the change amplitude of multiple first signals collected in real time within a period of time is at the third vibration level, it is in an alarm state, and the gear is switched to the neutral gear position and the operation is stopped.

[0023] Preferably, the second detection device comprises a strain gauge arranged at the root of each tooth of the gearbox gear.

[0024] Preferably, in step S3, a second signal of the gearbox gear when it runs at any speed in a wear-free state is obtained by a second detection device as the standard signal value corresponding to each speed, and three speed levels of low speed, medium speed and high speed are set respectively, and corresponding allowable error ranges are set according to different speed levels. If the error between the second signal value currently collected in real time and the standard signal value exceeds the allowable error range within the speed level to which the current speed belongs, it is regarded as abnormal data, wherein, at the low speed level, the speed is ≤2000rpm, and the allowable error range between the second signal collected when the speed is within the low speed level and the standard signal value is ±5%; at the medium speed level, the speed is 2000rpm-4000rpm, and the allowable error range between the second signal collected when the speed is within the medium speed level and the standard signal value is ±10%; at the high speed level, the speed is ≥4000rpm, and the allowable error range between the second signal collected when the speed is within the high speed level and the standard signal value is ±8%.

[0025] Preferably, in step S5, the current speed of the transmission gear is first determined, and the current second signal value is obtained. If the error between the current second signal value and the standard signal value exceeds the allowable error range within the speed level to which the current speed belongs, it is regarded as abnormal data and the test is repeated; if abnormal data still appears after repeated testing, it is in an alarm state, and the gear is switched to the neutral position and the operation is stopped.

[0026] The synchronous detection and processing system of gear shaft fault of gearbox includes:

[0027] A first detection unit includes a first detection device for detecting the eccentric vibration intensity of the gear inner shaft, wherein the measurement points of the first detection device are located at two end surfaces of the gear inner shaft;

[0028] The second detection unit includes a second detection device for detecting the stress and strain magnitude at the meshing position of the gearbox, wherein the measurement point of the second detection device is located at the root of each tooth of the gearbox;

[0029] a threshold setting unit, comprising a first threshold unit for setting a plurality of vibration levels of the gear inner shaft vibration state according to first signals of the gear inner shaft without cracks and the gear inner shaft with cracks, and a second threshold unit for setting a standard range according to a second signal measured at any operable speed of the gear of the gearbox in a wear-free state;

[0030] A main control module is used to synchronously receive a first signal sent by a first detection unit and a second signal sent by a second detection unit during the operation of the gearbox gear, and compare the first signal with the vibration level divided by the first threshold unit, and compare the second signal with the standard range divided by the second threshold unit, to determine whether to alarm, and if so, to issue an alarm instruction, and if no alarm is needed, to output sampling data of the first signal and / or the second signal;

[0031] An alarm module, used for sending an alarm signal;

[0032] The PC side is used to receive and record the alarm command issued by the main control module and the sampling data of the first signal and / or the second signal, and issue a locking command when receiving the alarm command;

[0033] The locking system is used to receive a locking command and, after receiving the locking command, switch the transmission to a neutral position and stop running.

[0034] The beneficial effects of the technical solution of the present invention are mainly reflected in:

[0035] 1. This solution detects gear inner shaft faults through eccentric vibration, can monitor the vibration of the gear inner shaft in real time, pre-detect the gear inner shaft with / without cracks, and obtain the eccentric vibration range under normal conditions and different fault conditions. The vibration level is formulated in combination with the influence of the breathing opening and closing law of the crack on the eccentric vibration intensity, so as to accurately judge the fault risk. Once abnormal vibration is found, the fault can be discovered in time and the faulty component can be quickly located to avoid the equipment from running in a faulty state, thereby reducing the risk of equipment damage. In addition, by detecting the gear inner shaft through eccentric vibration, potential safety hazards can be discovered and dealt with in time to ensure the stable operation of the equipment and avoid secondary injuries caused by gear inner shaft faults.

[0036] 2. Sampling stress and strain to detect the wear state of the gearbox gear. The stress and strain detection technology has high sensitivity and accuracy, is suitable for dynamic measurement, and can capture the real-time stress and strain changes of the gear during operation. At the same time, the stress and strain detection technology allows simultaneous measurement of multiple points, so that a measuring point is set at the root of each tooth of the gearbox gear, which is convenient for high-frequency detection, making the measurement data stable and reliable, and convenient for recording and analysis. The stress concentration area of ​​the gear can be intuitively observed, which is convenient for predicting and preventing further wear of the gear. At the same time, the strain gauge is small in size and light in weight, which is suitable for long-distance data transmission. In addition, different stress ranges are provided according to the different speeds of the gearbox gear, which can accurately and sensitively judge the wear condition of the gear, and repeat the judgment when abnormal data occurs to avoid mismeasurement.

[0037] 3. The eccentric vibration detection of the gear inner shaft and the stress and strain detection of the gearbox gear are carried out simultaneously and work together for the gearbox fault detection. When at least one of the two has abnormal data, an alarm will be triggered and the gearbox will be reminded to stop running, thereby ensuring that the two detection units are mutually restricted while ensuring their independence, thereby ensuring the accuracy of the two detection methods at the same time and avoiding secondary damage to other components in the gearbox due to the failure of one of the gearbox gears or the gear inner shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the synchronous detection and processing method of the gear shaft fault of the gearbox;

[0039] Figure 2 It is a schematic diagram of a synchronous detection and processing system for a gear shaft fault of a gearbox;

[0040] Figure 3 This is a schematic diagram of assembling the first detection device and the second detection device in a gearbox in one embodiment. DETAILED DESCRIPTION

[0041] In order to make the purpose, advantages and features of the present invention more clearly and in detail, the following preferred embodiments are used for illustration and explanation. The embodiments are only typical examples of the application of the technical solution of the present invention. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection claimed by the present invention.

[0042] At the same time, it is stated that in the description of the scheme, it should be noted that the directions or positional relationships indicated by the terms "center", "up", "down", "left", "right", "front", "back", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0043] In addition, the terms "first" and "second" in this solution are only used for descriptive purposes and cannot be understood as indicating or implying the order of importance, or implicitly indicating the number of technical features shown. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0044] The present invention discloses a method for synchronously detecting and processing a gear shaft fault of a gearbox. Figure 1 As shown, the following steps are included:

[0045] S1: A first detection device for detecting the eccentric vibration intensity of the gear inner shaft is arranged on the gear inner shaft, and a second detection device for detecting the stress and strain magnitude at the gear meshing point of the gearbox is arranged on the gearbox gear. The measuring points of the first detection device are located at the two end faces of the gear inner shaft, and the measuring points of the second detection device are located at the root of each tooth of the gearbox gear, so as to ensure that stress and strain monitoring data can be obtained for each tooth each time it meshes.

[0046] S2: using a first detection device to perform high-frequency sampling and acquisition on a gear inner shaft without cracks and a gear inner shaft with cracks, respectively, to obtain first signals of the gear inner shaft with / without cracks, respectively, and to set multiple vibration levels for reflecting the vibration state of the gear inner shaft according to the two first signals;

[0047] The step S2 specifically includes the following steps:

[0048] S21: using a first detection device to perform high-frequency sampling and acquisition on a crack-free gear inner shaft to obtain a plurality of first signals of the gear inner shaft in a crack-free state; the plurality of first signals in this step are used as a criterion for determining whether the gear inner shaft is in a fault-free state;

[0049] S22: using a first detection device to perform high-frequency sampling and acquisition on the cracked gear inner shaft to obtain a plurality of first signals of the gear inner shaft in a cracked state;

[0050] Among them, the crack on the gear inner shaft will open and close regularly as the gear inner shaft rotates, and the overall opening and closing changes are breathing-like. As the number of crack opening and closing increases, the crack will further expand, resulting in an increase in the eccentricity of the gear inner shaft. The greater the eccentric vibration intensity, the greater the opening and closing degree. Therefore, by recording this series of changes and recording the first signal sampling value fluctuations accompanying the crack and eccentric vibration intensity changes, the sampling value and amplitude changes of the first signal can be combined with the crack state of the gear inner shaft.

[0051] S23: At the same time as step S22, the crack opening and closing changes caused by the changes in the eccentric vibration intensity of the gear inner shaft during the operation of the gear inner shaft are recorded;

[0052] S24: Combining the change amplitude of the first signal in step S22 and step S23 and the change of crack opening and closing, deriving a change relationship between the two;

[0053] S25: In combination with step S21-step S24, multiple vibration levels are set according to the amplitude changes of multiple first signals of the gear inner shaft in the state with / without cracks; through the above steps S21-step S24, the sampling value characteristics of the first signal of the gear inner shaft in the state without cracks, and the sampling value characteristics of the first signal when the gear inner shaft has cracks and the cracks are in different states can be obtained respectively; and multiple vibration levels are divided according to the above characteristics, each level corresponds to a state of the gear inner shaft, and at the same time corresponds to a first signal sampling value of a certain amplitude.

[0054] S3: The second detection device collects the second signal of the gearbox gear when it rotates at any operating speed in a wear-free state through high-frequency sampling, and sets the second signal collected at each speed as the standard range of the second signal at that speed; since the change in speed will cause the stress at the root of the gear to change, thereby causing the second signal to change; specifically, when the speed is smaller, the meshing contact area of ​​the gearbox gear is larger, resulting in increased contact stress, and conversely, the faster the speed, the shorter the contact time between the gears, the smaller the contact area, and the stress is reduced accordingly; therefore, it is necessary to set the standard range of the second signal according to different speeds to determine whether the second signal has an abnormal value at the current speed.

[0055] S4: Based on the abnormality judgment criteria of the first signal and the second signal provided in the above steps S2 and S3, during the operation of the gearbox gear, the first detection device and the second detection device synchronously collect the first signal and the second signal.

[0056] S5: Determine whether to alarm based on the first signal and the second signal collected in real time. When at least one of the first signal and the second signal triggers an alarm, switch the gearbox to a neutral position and stop running.

[0057] In some embodiments, the first detection device is a capacitive vibration sensor, including two capacitive sensor plates arranged at both ends of the inner shaft of the gear, such as Figure 3 As shown, it includes a first electrode plate 201 and a second electrode plate 202, the first signal is the capacitance value C of the capacitive vibration sensor, and the relationship between the distance d between the two capacitive sensor plates (that is, the distance between the first electrode plate 201 and the second electrode plate 202) and the capacitance value C is: C=εA / d, wherein ‌ε represents the dielectric constant on both sides of the shaft end, ‌A represents the electrode area. It can be seen from the above relationship that when d is smaller, the first signal is larger, and vice versa, the first signal is smaller.

[0058] In the step S2, when there is a crack on the inner shaft of the gear, the crack will open and close with the rotation of the inner shaft of the gear, that is, the width of the crack will open and close with the rotation time; when the crack opens, the effective distance between the two capacitive sensor plates may increase, and when the crack closes, the effective distance between the plates may decrease; through steps S22-S24, the influence of the breathing opening and closing changes of the crack on the inner shaft of the gear with a crack on the distance d of the two capacitive sensor plates is monitored, and the formula is obtained: d=L0+Dsin(θ / 2);

[0059] Wherein, d is the distance between the two capacitive sensor plates; L0 is the distance between the two ends of the gear inner shaft in the crack-free state; D is the shaft diameter where the crack is located; θ is the opening angle of the crack; the change in the size of θ when the gear inner shaft rotates conforms to the switching function model f(ψ), and the switching function f(ψ) simulates the activity state of the crack on the gear inner shaft during the operation of the gear inner shaft through the angle ψ. Its fitting formula is approximately expressed by the cosine function cos(ψ). The expression method of the switching function is the existing technology and will not be repeated here. Wherein, ψ is the difference between the direction angle of the crack and the rotor vortex angle. When ψ is zero, the crack is fully open, and the crack is at the maximum angle it can open at present. When ψ is π / 2 or 3π / 2, the crack is Half open and half closed, when ψ is π, the crack is fully closed; on the one hand, by monitoring the amplitude of the change in the capacitance value C, the change in the distance d between the two capacitance sensor plates can be determined, and then whether the crack further expands; on the other hand, it can be seen from the above that when the crack opening angle changes in a breathing-like opening and closing manner, the distance d between the two capacitance sensor plates will change, so the capacitance value C collected by the capacitance sensor will also change with the opening and closing rules. As the number of opening and closing times increases, the crack will continue to expand, further strengthening the eccentric vibration intensity of the inner shaft of the gear, thereby increasing the opening and closing frequency of the crack. By monitoring the changing frequency of the capacitance value C, it can also be monitored whether the eccentric vibration intensity of the inner shaft of the gear is strengthened, and then it can be determined whether the crack expands.

[0060] In a preferred embodiment, since the crack expands with the increase of the number of opening and closing times, as the crack expands, the eccentric vibration intensity of the gear inner shaft and the degree of opening and closing of the crack are further increased, so the distance d between the first electrode plate 201 and the second electrode plate 202 located at both ends of the gear inner shaft will also change. From the crack source to the fracture failure, the expansion of the crack is dynamically changing. At the same time, the change in the distance d caused by the crack expansion is also dynamic. Therefore, the crack expansion factor k can also be quoted to represent the influence of the dynamic expansion of the crack on the distance d. At this time, the distance d between the two capacitive sensor plates is d = L0 + kDsin (θ / 2), where k represents the crack expansion factor; in the prior art, the crack expansion factor k is usually expressed by the stress intensity factor ‌, which is used to describe the trend and rate of crack expansion in the material. The value of the stress intensity factor depends on the properties of the material, the geometry of the crack and the stress state it is subjected to. Those skilled in the art can determine the specific stress intensity factor value through existing experiments or theoretical calculations, which will not be repeated here.

[0061] At this time, in step S25, according to step S21, when the inner shaft of the gear is in a crack-free state, the amplitude change of the sampling values ​​of the multiple first signals is within 2%, and the amplitude change is the variance of the multiple first signals in step S21. This floating range is set to the first vibration level. In other embodiments, the amplitude change can also be obtained by other means, which will not be elaborated here. In subsequent real-time detection, if the amplitude change between the multiple first signals within a sampling time domain is within 2%, it can be judged that the inner shaft of the gear is currently in a fault-free state.

[0062] According to step S22-step S24, when the amplitude variation of multiple first signals is within 2%-10% (obtained by the variance of multiple first signals when eccentric vibration occurs on the gear shaft but the crack does not expand (collection is stopped when the crack begins to expand)), the gear shaft has eccentric vibration but the crack does not expand. This floating range is set to the second vibration level. In the subsequent real-time detection, if the amplitude variation between multiple first signals is within 2%-10% within a sampling time domain, it can be judged that the gear shaft is currently in a cracked state. In a potential fault state; when the amplitude change of multiple first signals exceeds 10% (obtained by the variance of multiple first signals in a certain time domain when the crack of the inner shaft of the gear is expanding), a crack appears in the inner shaft of the gear and the fluctuation of the first signal becomes larger and larger, and the crack expands. This floating range is set to the third vibration level. In subsequent real-time detection, if the amplitude change between multiple first signals exceeds 10% within a sampling time domain, it is in an alarm state. It can be judged that the inner shaft of the gear is currently in a fault state and the crack has expanded. At this time, the gear is switched to the neutral gear position and the operation is stopped.

[0063] In a preferred embodiment, in step S5, if the amplitude change between multiple first signals within a sampling time domain is at the second vibration level, the collection and judgment are repeated once; if the amplitude change between the multiple first signals is at the third vibration level, it is in an alarm state, and it can be determined that the inner shaft of the gear is currently in a fault state and the crack has expanded. At this time, the gear is switched to the neutral position and the operation is stopped.

[0064] In some embodiments, the second detection device includes a strain gauge arranged at the root of each tooth of the transmission gear. In a preferred embodiment, the strain gauge is not only arranged at the root of each tooth of the transmission gear, but also needs to contact the bottom of the tooth groove of the transmission gear, so as to ensure that the rotation state of the transmission gear and the inner shaft of the gear can also affect the stress-strain monitoring data, further increase the induction variable of the second signal, and improve the sensitivity of the second detection device.

[0065] In one embodiment, in step S3, a second signal of the gearbox gear running at any speed in a wear-free state is acquired by a second detection device as a standard signal value corresponding to each speed, and three speed levels of low speed, medium speed and high speed are set respectively, and corresponding allowable error ranges are set according to different speed levels. If the error between the second signal value currently acquired in real time and the standard signal value exceeds the allowable error range within the speed level to which the current speed belongs, it is regarded as abnormal data, wherein, at the low speed level, the speed is ≤2000rpm, and when the speed is within the low speed level, the allowable error range between the second signal acquired and the standard signal value is ±5%; at the medium speed level, the speed is 2000rpm-4000rpm, when The allowable error range between the second signal collected when the speed is within the medium speed level and the standard signal value is ±10%; at the high speed level, the speed is ≥4000rpm, and the allowable error range between the second signal collected when the speed is within the high speed level and the standard signal value is ±8%; for example: assuming that through step S3, the standard signal value (stress value) corresponding to the speed of 1500rpm is collected as 260Mpa; when the current speed is monitored to be 1500rpm in step S5, and the second signal value (stress value) measured in real time is 270Mpa, the error between the second signal value collected in real time and the standard signal value at the current speed is 3.8%, which is within the allowable error range (±5%), so it can be judged that no abnormal data has occurred.

[0066] In step S5, the current speed of the transmission gear is first determined, and the current second signal value is obtained. If the error between the current second signal value and the standard signal value exceeds the allowable error range within the speed level to which the current speed belongs, it is regarded as abnormal data and the test is repeated; if abnormal data still appears after repeated testing, it is in an alarm state, and the gear is switched to the neutral position and the operation is stopped.

[0067] In one embodiment, in the high-frequency sampling of the above-mentioned steps S2 and S3, the high-frequency sampling frequencies of the first detection device and the second detection device are both 1KHz, with an interval of 1ms, that is, 1000 samples per second; in step S5, the real-time sampling frequency of the first detection device is 1KHz, with an interval of 1ms, that is, 1000 samples per second, and the data collected by the first detection device is subjected to (spectral) analysis to obtain a distribution, and a judgment is made once per second, and the amplitude changes between all the first signals currently collected are obtained each time the judgment is made, and the vibration level to which the amplitude change of the current first signal belongs is judged by the system; the second detection device collects and makes a judgment once per second, and the data collected by the second detection device is compared with the standard signal value of the current speed respectively. If the error between the two is within the allowable error range within the speed level to which the current speed belongs, it is judged that no abnormal data has occurred.

[0068] like Figure 2 , Figure 3 As shown, the gearbox gear shaft fault synchronous detection and processing system includes:

[0069] The first detection unit includes a first detection device for detecting the eccentric vibration intensity of the gear inner shaft, wherein the measurement points of the first detection device are located at two end faces of the gear inner shaft; in one embodiment, the first detection device is a capacitive vibration sensor, including a first pole plate 201 and a second pole plate 202 arranged at both ends of the gear inner shaft, and also includes a first optical fiber 4 respectively connected to the two pole plates, the two first optical fibers are connected by a first optical fiber rotary connector 6, and the first optical fiber rotary connector 6 is connected to the main control module by signal;

[0070] The second detection unit includes a second detection device for detecting the stress and strain magnitude at the meshing position of the gearbox, wherein the measuring point of the second detection device is located at the root of each tooth of the gearbox; the second detection device includes a strain gauge 1 arranged at the root of each tooth of the gearbox, each strain gauge 1 is connected to a second optical fiber 3, and the second optical fiber 3 is connected to a second optical fiber rotary connector 5, and the second optical fiber rotary connector 5 is also connected to a pressure sensor, and the pressure sensor is connected to a pressure / resistance converter, and the stress and strain data can be converted into a resistance value through the pressure / resistance converter and transmitted to the main control system;

[0071] The threshold setting unit includes a first threshold unit for setting a plurality of vibration levels of the gear inner shaft vibration state according to a first signal of a gear inner shaft without cracks and a gear inner shaft with cracks, and a second threshold unit for setting a standard range according to a second signal measured at any operable speed of the gearbox gear in a wear-free state; the setting method of the first threshold unit for the plurality of vibration levels of the first signal can refer to the above step S2, and the setting method of the second threshold unit for the standard range of the second signal can refer to the above step S3, which will not be described in detail here;

[0072] A main control module is used to synchronously receive a first signal sent by a first detection unit and a second signal sent by a second detection unit during the operation of the gearbox gear, and compare the first signal with the vibration level divided by the first threshold unit, and compare the second signal with the standard range divided by the second threshold unit, to determine whether to alarm, and if so, to issue an alarm instruction, and if no alarm is needed, to output sampling data of the first signal and / or the second signal;

[0073] An alarm module, used for sending an alarm signal;

[0074] The PC side is used to receive and record the alarm command issued by the main control module and the sampling data of the first signal and / or the second signal, and issue a locking command when receiving the alarm command;

[0075] The locking system is used to receive a locking command and, after receiving the locking command, switch the transmission to a neutral position and stop running.

[0076] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. Synchronous detection and treatment methods of gearbox gear shaft failure, Features: The following steps are involved: S1: a first detection device for detecting the eccentric vibration intensity of the gear inner shaft is arranged on the gear inner shaft, and a second detection device for detecting the stress and strain magnitude of the gear meshing portion of the gearbox is arranged on the gearbox gear, wherein the measuring points of the first detection device are located at the two end faces of the gear inner shaft, and the measuring points of the second detection device are located at the root of each tooth of the gearbox gear; S2: using a first detection device to perform high-frequency sampling and acquisition on a gear inner shaft without cracks and a gear inner shaft with cracks, respectively, to obtain first signals of the gear inner shaft with / without cracks, respectively, and to set multiple vibration levels for reflecting the vibration state of the gear inner shaft according to the two first signals; S21: using a first detection device to perform high-frequency sampling and acquisition on a crack-free gear inner shaft to obtain a plurality of first signals of the gear inner shaft in a crack-free state; S22: using a first detection device to perform high-frequency sampling and acquisition on the cracked gear inner shaft to obtain a plurality of first signals of the gear inner shaft in a cracked state; S23: At the same time as step S22, the crack opening and closing changes caused by the changes in the eccentric vibration intensity of the gear inner shaft during the operation of the gear inner shaft are recorded; S24: Combining the change amplitude of the first signal in step S22 and step S23 and the change of crack opening and closing, deriving a change relationship between the two; S25: In combination with steps S21 to S24, multiple vibration levels are set based on the amplitude changes of multiple first signals of the gear inner shaft in the state of having / not having cracks; S3: The second detection device collects the second signal when the gearbox gear rotates at any operating speed in a wear-free state through high-frequency sampling, and sets the second signal collected at each speed as the second signal standard range at the speed; S4: during the operation of the gearbox gear, the first detection device and the second detection device synchronously collect the first signal and the second signal; S5: Determine whether to alarm based on the first signal and the second signal collected in real time. When at least one of the first signal and the second signal triggers an alarm, switch the gearbox to a neutral position and stop running.

2. The synchronous detection and processing method for gearbox gear shaft fault according to claim 1, Features: The first detection device is a capacitive vibration sensor, including two capacitive sensor plates arranged at both ends of the inner shaft of the gear. The first signal is the capacitance value C of the capacitive vibration sensor. The relationship between the distance d between the two capacitive sensor plates and the capacitance value C is: C=εA / d, wherein ‌ε represents the dielectric constant on both sides of the shaft end, and ‌A represents the electrode area.

3. The synchronous detection and processing method for gearbox gear shaft fault according to claim 2, Features: In step S2, the distance between the two capacitive sensor plates is d=L 0 +Dsin(θ / 2), where L 0 is the distance between the two ends of the gear inner shaft in the crack-free state; D is the shaft diameter where the crack is located; θ is the opening angle of the crack. The change in the size of θ when the gear inner shaft rotates conforms to the switching function model f(ψ), where ψ is the difference between the direction angle of the crack and the rotor vortex angle. When ψ is zero, the crack is fully open, when ψ is π / 2 or 3π / 2, the crack is half open and half closed, and when ψ is π, the crack is fully closed.

4. The synchronous detection and processing method for gearbox gear shaft fault according to claim 3, Features: The distance between the two capacitive sensor plates is d = L 0 +kDsin(θ / 2), where k represents the crack growth factor.

5. The synchronous detection and processing method of gearbox gear shaft fault according to claim 1, Features: In step S25, when the inner shaft of the gear is in a crack-free state, the amplitude change of the sampling values ​​of the multiple first signals is within 2%, and this floating range is set to the first vibration level; when the inner shaft of the gear is in a cracked state, when the amplitude change of the multiple first signals is within 2%-10%, eccentric vibration occurs in the inner shaft of the gear, but the crack does not expand, and this floating range is set to the second vibration level; when the amplitude change of the multiple first signals exceeds 10%, cracks appear in the inner shaft of the gear and the floating of the first signals becomes larger and larger, and the crack expands, and this floating range is set to the third vibration level.

6. The synchronous detection and processing method for gearbox gear shaft fault according to claim 5, Features: In step S5, when the change amplitude of multiple first signals collected in real time within a period of time is at the third vibration level, it is in an alarm state, and the gear is switched to the neutral gear position and the operation is stopped.

7. The synchronous detection and processing method for gearbox gear shaft fault according to claim 1, Features: The second detection device includes a strain gauge arranged at the root of each tooth of the gearbox gear.

8. The synchronous detection and processing method for gearbox gear shaft fault according to claim 1, Features: In the step S3, a second signal is acquired by a second detection device when the gearbox gear runs at any speed in a wear-free state, and is used as the standard signal value corresponding to each speed. Three speed levels, namely low speed, medium speed and high speed, are set respectively, and corresponding allowable error ranges are set according to different speed levels. If the error between the second signal value currently acquired in real time and the standard signal value exceeds the allowable error range within the speed level to which the current speed belongs, it is regarded as abnormal data, wherein, at the low speed level, the speed is ≤2000rpm, and the allowable error range between the second signal acquired when the speed is within the low speed level and the standard signal value is ±5%; at the medium speed level, the speed is 2000rpm-4000rpm, and the allowable error range between the second signal acquired when the speed is within the medium speed level and the standard signal value is ±10%; at the high speed level, the speed is ≥4000rpm, and the allowable error range between the second signal acquired when the speed is within the high speed level and the standard signal value is ±8%.

9. The synchronous detection and processing method for gearbox gear shaft fault according to claim 8, Features: In step S5, the current speed of the transmission gear is first determined, and the current second signal value is obtained. If the error between the current second signal value and the standard signal value exceeds the allowable error range within the speed level to which the current speed belongs, it is regarded as abnormal data and the test is repeated; if abnormal data still appears after repeated testing, it is in an alarm state, and the gear is switched to the neutral position and the operation is stopped.

10. Gearbox gear shaft fault synchronous detection and processing system, Features: include: A first detection unit includes a first detection device for detecting the eccentric vibration intensity of the gear inner shaft, wherein the measurement points of the first detection device are located at two end surfaces of the gear inner shaft; The second detection unit includes a second detection device for detecting the stress and strain magnitude at the meshing position of the gearbox, wherein the measurement point of the second detection device is located at the root of each tooth of the gearbox; a threshold setting unit, comprising a first threshold unit for setting a plurality of vibration levels of the gear inner shaft vibration state according to first signals of the gear inner shaft without cracks and the gear inner shaft with cracks, and a second threshold unit for setting a standard range according to a second signal measured at any operable speed of the gear of the gearbox in a wear-free state; A main control module is used to synchronously receive a first signal sent by a first detection unit and a second signal sent by a second detection unit during the operation of the gearbox gear, and compare the first signal with the vibration level divided by the first threshold unit, and compare the second signal with the standard range divided by the second threshold unit, to determine whether to alarm, and if so, to issue an alarm instruction, and if no alarm is needed, to output sampling data of the first signal and / or the second signal; An alarm module, used for sending an alarm signal; The PC side is used to receive and record the alarm command issued by the main control module and the sampling data of the first signal and / or the second signal, and issue a locking command when receiving the alarm command; The locking system is used to receive a locking command and, after receiving the locking command, switch the transmission to a neutral position and stop running.

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