Double-row planetary gear fault impact time interval estimation method and fault diagnosis method

Abstract

The application belongs to the technical field of fault diagnosis. A double-row planetary gear fault impact time interval estimation method and a fault diagnosis method are provided. By clearly taking a specific fault tooth as the initial meshing tooth and determining the fault impact time interval according to the meshing working parameters of each component, the focus is focused on the meshing process of the specific fault gear, the fault impact situation of a certain row of gears can be analyzed relatively independently, the interference of the vibration signals of other components and the possible fault signals of the other row of gears is reduced, more accurate time interval estimation is realized, and the accuracy of subsequent double-row planetary gear fault diagnosis is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault diagnosis, and in particular to a double-row planetary gear fault impact time interval estimation method and a fault diagnosis method. BACKGROUND

[0002] The statements in this section merely provide background technology related to the present application and do not necessarily constitute prior art.

[0003] Double-row planetary gear mechanisms are widely used in automatic transmissions and complex transmission systems due to their compact structure and large transmission ratio. A typical double-row planetary gear structure includes a sun gear, a first row of planetary gears (meshing with the sun gear, sun gear side planetary gears), a second row of planetary gears (meshing with the ring gear, ring gear side planetary gears), and a ring gear. Among them, each planetary gear in the first row of planetary gear set is usually meshed with the corresponding planetary gear in the second row of planetary gear set. In the typical design of shared planet carrier, the two rows of planetary gears usually have the same rotation frequency. In this structure, accurately calculating the fault impact time interval generated between the fault teeth of a certain planetary gear and the different gear pairs it meshes with (for example, when the sun gear side planetary gear fails, the impact generated by its meshing with the sun gear and the subsequent impact generated by its meshing with the corresponding second row of planetary gears; when the ring gear side planetary gear fails, the impact generated by its meshing with the first row of planetary gears and the subsequent impact generated by its meshing with the ring gear) is crucial for accurately locating the position of the faulty planetary gear.

[0004] However, there are significant technical difficulties in the operation of this double-row planetary gear system: the vibration signals generated by the first row of planetary gear set, the second row of planetary gear set and other core components (such as the sun gear, the planet carrier, etc.) will be generated simultaneously and severely overlapped by multiple sources. Specifically, when a certain row of planetary gear set (for example, the first row of planetary gear set) fails, the characteristic fault impact signal generated by it is easily mixed with the vibration signal generated by the normal operation of the system and the possible fault signal of the other row of planetary gear set (the second row of planetary gear set). This complex signal coupling phenomenon directly leads to the following technical defects: it is difficult to reliably identify and separate the tooth breakage fault impact characteristics pointing to a specific row (such as the sun gear side or the ring gear side) of planetary gear from the complex signal, and thus it is impossible to accurately determine the specific planetary gear and its position where the fault occurs, limiting the accuracy and reliability of fault diagnosis. SUMMARY

[0005] In order to solve the problems in the prior art, the application provides a double-row planetary gear fault impact time interval estimation method and a fault diagnosis method, which can relatively independently analyze the fault impact of a certain row of gears, reduces the interference of vibration signals of other components and possible fault signals of another row of gears, realizes more accurate time interval estimation, and guarantees the accuracy of double-row planetary gear fault diagnosis.

[0006] In order to achieve the above object, the application adopts the following technical scheme:

[0007] In the first aspect, the application provides a double-row planetary gear fault impact time interval estimation method.

[0008] The double-row planetary gear fault impact time interval estimation method comprises the following processes:

[0009] For a fault tooth in the first row of planetary gear sets meshing with the sun gear, the time when the fault tooth meshes with the sun gear is taken as an initial time point, and based on actual operation parameters (including gear teeth, modulus, rotating speed and phase relationship) of the double-row planetary gear system, a first time difference required for the fault tooth to move from the meshing point of the sun gear to the meshing point of the second row of planetary gears is calculated, and the first time difference is taken as the fault impact time interval of the sun gear meshing row of planetary gears.

[0010] For a fault tooth in the second row of planetary gear sets meshing with the ring gear, the time when the fault tooth meshes with the first row of planetary gears (assuming that the first row of planetary gears is not faulty, when the second row of planetary gears is faulty, the time defined by the fault tooth of the first row of planetary gears is taken as the reference, and the time point corresponding to the second row of planetary gears is calculated according to the delay amount according to the meshing relationship) is taken as an initial time point, and based on actual operation parameters (including gear teeth, modulus, rotating speed and phase relationship) of the double-row planetary gear system, a second time difference required for the fault tooth to move from the meshing point between the planetary gear sets to the meshing point of the ring gear is calculated, and the second time difference is taken as the fault impact time interval of the ring gear meshing row of planetary gears.

[0011] In the second aspect, the application provides a double-row planetary gear fault impact time interval estimation system.

[0012] The double-row planetary gear fault impact time interval estimation system comprises:

[0013] The first fault impact interval estimation unit is configured to, for a fault tooth in the first row of planetary gear set engaged with the sun gear, take the time when the tooth is engaged with the sun gear as an initial time point, calculate a first time difference required for the fault tooth to move from the engagement point between the sun gear and the first row of planetary gear set to the engagement point with the second row of planetary gear set based on actual operation parameters of the double-row planetary gear system (including gear teeth, modulus, rotational speed and phase relationship), and take the first time difference as the fault impact time interval of the sun gear engaged with the first row of planetary gear set.

[0014] The second fault impact interval estimation unit is configured to, for a fault tooth in the second row of planetary gear set engaged with the ring gear, take the time when the tooth is engaged with the first row of planetary gear set (assuming that the first row of planetary gear set is not faulty, when the second row of planetary gear set is faulty, the time defined by the fault tooth of the first row of planetary gear set is taken as the reference, and the time point corresponding to the second row of planetary gear set is calculated according to the delay amount according to the engagement relationship) as an initial time point, calculate a second time difference required for the fault tooth to move from the engagement point between the planetary gear sets to the engagement point with the ring gear based on actual operation parameters of the double-row planetary gear system (including gear teeth, modulus, rotational speed and phase relationship), and take the second time difference as the fault impact time interval of the ring gear engaged with the first row of planetary gear set.

[0015] In a third aspect, the present application provides a double-row planetary gear fault diagnosis method.

[0016] A double-row planetary gear fault diagnosis method comprises the following processes:

[0017] According to the double-row planetary gear fault impact time interval estimation method of the first aspect of the present application, the fault impact time interval of the sun gear engaged with the first row of planetary gear set and the fault impact time interval of the ring gear engaged with the first row of planetary gear set are first determined respectively;

[0018] The fault diagnosis is performed in combination with the fault impact time interval of the sun gear engaged with the first row of planetary gear set and the corresponding broken tooth phenomenological model (a model describing phenomena based on observation and experimental data), to obtain the fault diagnosis result of the sun gear engaged with the first row of planetary gear set;

[0019] The fault diagnosis is performed in combination with the fault impact time interval of the ring gear engaged with the first row of planetary gear set and the corresponding broken tooth phenomenological model, to obtain the fault diagnosis result of the ring gear engaged with the first row of planetary gear set.

[0020] In a fourth aspect, the present application provides a double-row planetary gear fault diagnosis system.

[0021] A double-row planetary gear fault diagnosis system comprises the following processes:

[0022] The impact time interval determination unit is configured to determine the fault impact time interval of the sun gear and the planetary gear (i.e., the first row of planetary gears) and the fault impact time interval of the ring gear and the planetary gear (i.e., the second row of planetary gears) respectively according to the double-row planetary gear fault impact time interval estimation method of the first aspect of the present application.

[0023] The sun gear and planetary gear fault diagnosis unit is configured to perform fault diagnosis in combination with the fault impact time interval of the sun gear and the planetary gear and the corresponding broken tooth phenomenological model to obtain the fault diagnosis result of the sun gear and the planetary gear.

[0024] The ring gear and planetary gear fault diagnosis unit is configured to perform fault diagnosis in combination with the fault impact time interval of the ring gear and the planetary gear and the corresponding broken tooth phenomenological model to obtain the fault diagnosis result of the ring gear and the planetary gear.

[0025] In a fifth aspect, the present application provides a computer device, comprising: a processor and a computer readable storage medium.

[0026] The processor is adapted to execute a computer program.

[0027] The computer readable storage medium has a computer program stored therein, and the computer program is executed by the processor to implement the double-row planetary gear fault impact time interval estimation method of the first aspect of the present application; or implement the double-row planetary gear fault diagnosis method of the third aspect of the present application.

[0028] In a sixth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is adapted to be loaded and executed by a processor to implement the double-row planetary gear fault impact time interval estimation method of the first aspect of the present application; or implement the double-row planetary gear fault diagnosis method of the third aspect of the present application.

[0029] In a seventh aspect, the present application provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the double-row planetary gear fault impact time interval estimation method of the first aspect of the present application; or implement the double-row planetary gear fault diagnosis method of the third aspect of the present application.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] This invention innovatively proposes a method for estimating the fault impact time interval of a double-row planetary gear. This method uses a specific faulty tooth as the initial meshing tooth and derives the fault impact time interval strictly based on the system's meshing operating parameters. This precisely focuses the analysis on the meshing timing process of the specific faulty gear. This design allows for the relatively independent analysis of the fault impact characteristics of a certain row of planetary gears (sun gear side or ring gear side), effectively reducing the interference of vibration signals from other components and potential fault signals from another row of planetary gears. This achieves a higher accuracy in estimating the fault impact time interval, laying a solid foundation for the subsequent accurate fault diagnosis of double-row planetary gears.

[0032] This invention innovatively proposes a fault diagnosis method for double-row planetary gears. This method makes full use of the aforementioned precisely determined fault impact time interval, which can effectively cope with the challenge of severe aliasing of multi-source vibration signals during system operation, accurately locate the impact information of the target faulty planetary gear, and significantly reduce the interference of signals from other components and non-target gear rows. At the same time, by combining the fault impact time interval with the phenomenological model of tooth breakage for diagnostic analysis, it can fully integrate the physical characteristics and laws of tooth breakage faults, thereby significantly improving the diagnostic accuracy and reliability of tooth breakage faults of planetary gears on the sun gear side and planetary gears on the gear ring side, providing strong support for timely fault detection and handling.

[0033] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0035] Figure 1 A flowchart illustrating a method for estimating the fault impact time interval of a double-row planetary gear, provided as an exemplary embodiment of the present invention;

[0036] Figure 2 A schematic diagram of a double-row planetary gear provided for an exemplary embodiment of the present invention;

[0037] Figure 3 Provided as an exemplary embodiment of the present invention meshing pairs and Schematic diagram of meshing pairs;

[0038] Figure 4 Provided as an exemplary embodiment of the present invention meshing pairs and A schematic diagram of the meshing of a meshing pair;

[0039] Figure 5 A flowchart of a double-row planetary gear fault diagnosis method provided for an exemplary embodiment of the present application is shown in FIG. 1.

[0040] Figure 6 A schematic diagram of a double-row planetary gear fault impact time interval estimation system provided for an exemplary embodiment of the present application is shown in FIG. 2.

[0041] Figure 7 A schematic diagram of a double-row planetary gear fault diagnosis system provided for an exemplary embodiment of the present application is shown in FIG. 3.

[0042] Figure 8 A schematic diagram of a computer device provided for an exemplary embodiment of the present application is shown in FIG. 4. DETAILED DESCRIPTION

[0043] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0044] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0045] The present implementation proposes a double-row planetary gear fault impact time interval estimation method, as shown in FIG. 1, including the following processes: Figure 1

[0046] S101: For a fault tooth in the first row of planetary gear set meshing with the sun gear, the time when the tooth enters meshing with the sun gear is taken as the initial time point; based on the actual operating parameters of the double-row planetary gear system (including gear tooth number, modulus, speed, and phase relationship), the first time difference required for the fault tooth to move from the sun gear meshing point to meshing with the second row of planetary gear is calculated, and the first time difference is taken as the fault impact time interval of the sun gear meshing planetary gear;

[0047] S102: For a fault tooth in the second row of planetary gear set meshing with the ring gear, the time when the tooth enters meshing with the first row of planetary gear (assuming that the first row of planetary gear is not faulty, when the second row of planetary gear is faulty, the time defined by the first row of planetary gear fault tooth is taken as the reference, and the time point corresponding to the second row of planetary gear is calculated according to the delay amount according to the meshing relationship); based on the system operating parameters, the second time difference required for the fault tooth to move from the planetary gear set meshing point to the ring gear meshing point is calculated, and the second time difference is taken as the fault impact time interval of the ring gear meshing planetary gear.

[0048] ​Double-row planetary gear structures are often used as key subsystems in multi-stage planetary gear transmission systems to achieve power transmission and torque amplification. A typical structure includes a sun gear, a first row of planetary gears and a second row of planetary gears, a ring gear, and a planet carrier. These components form multiple meshing gear pairs, with phase differences existing between different gear pairs. This invention uses a two-stage transmission structure comprising a first-stage single-row planetary gear system and a second-stage double-row planetary gear system as an example for illustration. Figure 2 As shown, the two-stage transmission structure includes: a first stage (single-row planetary gear system): its sun gear is fixed and meshes with a set of planetary gears; a second stage (double-row planetary gear system): including a second-stage sun gear for input power, a first-row planetary gear (sun gear side) meshing with the second-stage sun gear, and a second-row planetary gear (ring gear side) meshing with the ring gear; the two-stage gear system shares a planet carrier and a ring gear: the planetary gears of the first stage and the second-row planetary gears (ring gear side) of the second stage both mesh with different parts of the same ring gear, which adopts a floating support method. Figure 2 The working state of the structure is shown: power is input from the second-stage sun gear, transmitted through the first row of planetary gears (sun gear side) to the second row of planetary gears (gear ring side), driving the common gear ring of the floating support to rotate; the rotation of the common gear ring in turn drives the first-stage planetary gears to rotate; since the first-stage sun gear is fixed, the final power is output by the planet carrier in terms of torque and speed.

[0049] In this implementation, based on the planetary gear transmission mechanism, the velocity characteristic equation of the double-row planetary gear system is:

[0050] (1);

[0051] The velocity characteristic equation of a single-row planetary gear system is:

[0052] (2);

[0053] In the formula: The rotational speed of the first-stage sun gear (in this structure) ); It is the rotational speed of the second-stage sun gear. It is the rotational speed of the gear ring. It is the rotational speed of the planetary carrier (two-stage common planetary carrier and ring gear). , and These represent the number of teeth on the planetary gears and the sun gear, respectively.

[0054] Meshing frequency of planetary gears The formula is:

[0055] (3);

[0056] in: the number of teeth of the reference gear, the rotational speed of the reference gear relative to the planet carrier.

[0057] The second stage sun gear input torque is set to 700rmp, and the load torque is 200N. According to the formulas (1)-(3), the rotational speed of each component of the double-row planetary gear and the meshing frequency can be calculated, as shown in Table 1.

[0058] Table 1: Rotational speed of each component of the double-row planetary gear and meshing frequency

[0059]

[0060] In analyzing the phase relationship between the sun gear-planet gear pair, the gear pair is selected as the reference gear pair, and it is assumed that at time, the gear pair is engaged at the initial engagement point, and the phase difference between the gear pair and the gear pair is defined as . Similarly, the phase difference between the gear pair and the gear pair is defined as , the phase difference between the gear pair and the gear pair is defined as , the phase difference between the gear pair and the gear pair is defined as , the phase difference between the gear pair and the gear pair is defined as , and the phase difference between the gear pair is defined as . In this way, the phase relationship between any two gear pairs in the planetary gear train can be obtained. , , , , , The value range satisfies (-1, 1). First, the function is defined, and the calculation value is kept between (-1, 1), wherein the function is used to round to the nearest integer in the zero direction, and the function is used to remove the integer part of the value and keep the decimal part. When the gear pair is selected as the reference gear pair, the phase difference between the same gear pair is independent of the selected reference point. If the sun gear rotates counterclockwise relative to the planet carrier, the ring gear rotates counterclockwise relative to the planet carrier, and the phase difference between the sun gear and the ring gear is 、 、 The following formula can be calculated:

[0061] (4);

[0062] (5);

[0063] (6);

[0064] Wherein, is the angle parameter, represent the conversion function.

[0065] When the rotation direction is opposite, the engagement phase is changed from the lead to the lag, and the lag phase is negative:

[0066] (7);

[0067] (8);

[0068] (9).

[0069] In the calculation of the engagement phase relationship between different kinds of engagement pairs 、 、 The initial engagement point is selected as the reference point, so the initial engagement point is selected as the reference point in the calculation of the engagement phase relationship between different kinds of engagement pairs, and the subsequent calculation and derivation process is carried out.

[0070] As Figure 3 shown, is the sun gear, is the first row of planetary gears, is the second row of planetary gears, is the gear ring; represent the sun gear center, represent the first row of planetary gear centers, is the second row of planetary gear centers, and the gear ring center and the sun gear center are theoretically at the same point ; is the pressure angle; are the gear ring base circle radius and the addendum circle radius respectively; are the sun gear base circle radius and the addendum circle radius respectively; are the first row of planetary gear base circle radius and the addendum circle radius respectively; are the second row of planetary gear base circle radius and the addendum circle radius respectively; and respectively engaging pair and theoretical meshing line of the engaging pair; and respectively engaging pair and actual meshing line of the engaging pair; and is engaging pair and engaging node of the engaging pair; and is actual meshing starting point and is the center of the circle the point on the first row of planetary gear base circle enveloped by the circle with the center of point is the base circle tooth thickness of the planetary gear; is the engaging pair at the meshing starting point when engaging the meshing point of the engaging pair, is the point the center of the circle the point on the first row of planetary gear base circle enveloped by the circle with the center of .

[0071] In the analysis of the first phase difference relative to , the reference engaging pair is selected, unlike most existing methods, assuming at this moment, the engaging pair engages at the initial meshing point , that is, the initial meshing point is selected as the reference point, engages at the point , the phase difference of the engaging pair and the engaging pair can be expressed as:

[0072] (10).

[0073] Since the contact of the engaging pair and engaging pair is on opposite planetary gear tooth surfaces, the distance between point is the base circle tooth thickness of the planetary gear, according to the meshing characteristics of the gear, the point to point The arc distance between the two adjacent teeth is an integer multiple of the base circle pitch According to the nature of the integer function, It can be further expressed as:

[0074] (11);

[0075] Wherein,

[0076] (12);

[0077] (13);

[0078] (14);

[0079] (15);

[0080] (16);

[0081] (17);

[0082] (18);

[0083] In the formula, The pressure angle; The base circle radius, the addendum circle radius and the pitch circle radius of the planetary gear respectively; The sun gear pitch circle radius, The ring gear pitch circle radius, The modulus is represented.

[0084] The formulas (10)-(18) are solved simultaneously, and the parameters in Table 1 are substituted into the formulas, and the standard gear relationship can be obtained .

[0085] As shown in Figure 4 , the sun gear is , the first row of planetary gears is , the second row of planetary gears is , and the ring gear is ; The center of the sun gear is represented by , the center of the first row of planetary gears is represented by , the center of the second row of planetary gears is represented by , and the center of the ring gear and the center of the sun gear are theoretically in the same point ; The pressure angle; The base circle radius and the addendum circle radius of the ring gear respectively; The base circle radius and the addendum circle radius of the sun gear respectively; The base circle radius and the addendum circle radius of the first row of planetary gears respectively; respectively the base circle radius and the addendum circle radius of the second row of planetary gears; and is the theoretical line of action, and is the actual line of action. and respectively the line of action of the engagement pair and the actual line of action of the engagement pair; and is the line of action of the engagement pair and the engagement node of the engagement pair; and is the actual engagement starting point and is the center of the circle the radius of the circle the point on the base circle of the second row of planetary gears that is enveloped by the circle with the center is the base circle tooth thickness of the planetary gear; is the engagement pair at the engagement starting point when engaging the engagement point of the engagement pair, is the point the center of the circle the radius of the circle the point on the base circle of the second row of planetary gears that is enveloped by the circle with the center In the analysis of the phase difference between the reference engagement pair is selected, and it is assumed that at the moment, the engagement pair engages at the initial engagement point , engages at the point , the phase difference between the engagement pair and the engagement pair can be expressed as:

[0086] (19);

[0087] According to the engagement characteristics of the gear, the arc distance between the point and the point is an integer multiple of the base circle tooth pitch , which can be further expressed as:

[0088] (20);

[0089] ​wherein,

[0090] (21);

[0091] (22);

[0092] (23);

[0093] (24);

[0094] wherein, is the pressure angle; are the base circle radius, the addendum circle radius and the pitch circle radius of the planetary gear respectively represents the modulus, and the phase difference can be obtained by substituting the parameters into the above formula .

[0095] the phase difference of the meshing pair and the phase difference of the meshing pair is:

[0096] (25).

[0097] When the tooth breakage fault occurs in the planetary gear meshing with the sun gear, only one planetary gear has the tooth breakage fault, and the other planetary gears are normal. It is assumed that the fault tooth is the initial meshing tooth, i.e., the first tooth, which directly contacts the sun gear and the planetary gear meshing with the ring gear. At the initial moment , the fault tooth just enters the meshing with the sun gear, and the corresponding model needs to be calculated. The time interval from the meshing with the sun gear to the meshing with another planetary gear is .

[0098] As Figure 3 shown, at the initial moment, the meshing with the sun gear is , and the meshing with another planetary gear is . The interval between the two time periods is:

[0099] (26);

[0100] wherein,

[0101] (27);

[0102] wherein,

[0103] (28);

[0104] wherein, is the tooth thickness of the planetary gear base circle, which is calculated by formula (14), For Gear pair and The angle of the center line is calculated by formula (15), The pressure angle is; The base circle radius and the addendum circle radius of the planetary gear are respectively calculated by formula (16), .

[0105] As Figure 4 shown, the initial time is in engagement, when in contact with another planetary gear, in engagement, the interval between the two time periods is:

[0106] (29);

[0107] Wherein,

[0108] (30);

[0109] (31);

[0110] In the formula, The base circle thickness of the planetary gear is calculated by formula (14), The pressure angle is; Gear pair and The angle of the center line is calculated by formula (24), The pressure angle is; The base circle radius and the addendum circle radius of the planetary gear are respectively calculated by formula (16), The base circle radius and the addendum circle radius of the ring gear are respectively calculated by formula (17), .

[0111] Based on the time interval calculated above, Figure 5 A double-row planetary gear fault diagnosis method is shown, comprising the following processes:

[0112] S501: Combined with the fault impact time interval of the sun gear and the corresponding broken tooth phenomenological model, the fault diagnosis result of the sun gear and the planetary gear is obtained;

[0113] S502: Combined with the fault impact time interval of the ring gear and the corresponding broken tooth phenomenological model, the fault diagnosis result of the ring gear and the planetary gear is obtained.

[0114] The present application uses a periodic function with meshing frequency as the base frequency to simulate the gear system vibration signal model under the condition of no fault, and uses a rectangular window function Amplitude modulation was applied to the fault-free vibration signal to obtain a phenomenological model of the vibration signal under the fault condition of broken teeth in the first row of planetary gears:

[0115] (32);

[0116] (33);

[0117] (34);

[0118] In the formula, For the first Expression for the vibration signal of a sun gear-planet gear pair. Indicates the first Expression for the vibration signal of a planetary gear-planetary gear meshing pair Indicates all teeth with faults The expression for the vibration signal generated by a meshing gear pair; This represents the rotational frequency of the first set of planetary gears relative to the planet carrier. Assuming... The fault amplitude of the gear pair is 10. The gear pair fault amplitude is 5. In the time domain image, the sensor receives two periodic pulse sequences with a time interval of 0.0213s. Simultaneously, in the frequency domain image, frequencies appear around the meshing frequency. The modulation sidebands. The time-domain periodic pulse series interval characteristics and frequency-domain sideband distribution characteristics can be used to detect broken tooth faults in planetary gears meshing with the sun gear.

[0119] When a broken tooth occurs in a planetary gear meshing with the ring gear, only one planetary gear experiences the fault, while the other planetary gears continue to operate normally. Assuming the faulty tooth is the initial meshing tooth, i.e., the first tooth, it affects the ring gear and the first row of planetary gears in direct contact with it. Initially... The faulty tooth of the second row of planetary gears meshes with the first row of planetary gears, generating an impact. After a period of time, the faulty tooth of the second row of planetary gears begins to mesh with the gear ring, generating an impact. The time interval between the two is... Similarly, based on the variation law of meshing stiffness of the gear pair and the fault modulation mechanism, a periodic function with the meshing frequency as the fundamental frequency is used to simulate the vibration signal model of the gear system under fault-free conditions, and a rectangular window function is used. Amplitude modulation was applied to the fault-free vibration signal to obtain a phenomenological model of the vibration signal under the fault condition of broken teeth in the second row of planetary gears:

[0120] (35);

[0121] (36);

[0122] (37);

[0123] wherein, is the nth planet gear-planet gear meshing pair vibration signal expression, is the nth double-row planet gear-ring gear meshing pair vibration signal expression, is the vibration signal expression generated by all gear pairs meshing with the fault tooth, is the rotational frequency of the planet gear relative to the planet carrier connected to the ring gear.

[0124] According to formula (37), a simulation experiment is performed, assuming that the gear pair fault amplitude is 10, the gear pair fault amplitude is 5, in the time domain image, the sensor periodically receives two pulse sequences with a time interval of 0.0340s, and the modulation sideband around the meshing frequency is described in the frequency domain image ; thus, the time domain pulse interval feature and the frequency domain sideband distribution feature can detect the broken tooth fault of the planet gear meshing with the sun gear of the double-row planet gear system.

[0125] Specifically, the vibration law of the planet gear meshing with the sun gear when it fails is that the vibration frequency domain image exists modulation harmonics with an interval of the relative rotational frequency of the planet gear relative to the planet carrier around the meshing frequency , that is, the fault characteristic frequency ; since the fault tooth meshes with the sun gear and another planet gear, respectively, there are two periodic pulse sequences with a time interval of in the time domain image, and the time interval of the two pulse sequences is .

[0126] The vibration law of the planet gear meshing with the ring gear when it fails is that the vibration frequency domain image exists modulation harmonics with an interval of the relative rotational frequency of the planet gear relative to the planet carrier around the meshing frequency , that is, the fault characteristic frequency ; there are two periodic pulse sequences with a time interval of in the time domain image, and the time interval of the two pulse sequences is .

[0127] Figure 6 A double-row planet gear fault impact time interval estimation system is shown, comprising:

[0128] ​​​The first fault impact interval estimation unit 601 is configured to, for the fault tooth in the first row of planetary gear set engaged with the sun gear, take the time when the tooth is engaged with the sun gear as the initial time point; based on the actual operation parameters of the double-row planetary gear system (including gear tooth number, modulus, rotation speed and phase relationship), calculate the first time difference required for the fault tooth to move from the sun gear engagement point to the engagement with the second row of planetary gears, and take the first time difference as the fault impact time interval of the sun gear engaged planetary gear;

[0129] The second fault impact interval estimation unit 602 is configured to, for the fault tooth in the second row of planetary gear set engaged with the ring gear, take the time when the tooth is engaged with the first row of planetary gears (assuming that the first row of planetary gears is not faulty, when the second row of planetary gears is faulty, the time defined by the fault tooth of the first row of planetary gears is taken as the reference, and the time point corresponding to the second row of planetary gears is calculated according to the delay amount according to the engagement relationship) as the initial time point; based on the system operation parameters, calculate the second time difference required for the fault tooth to move from the inter-row planetary gear engagement point to the ring gear engagement point, and take the second time difference as the fault impact time interval of the ring gear engaged planetary gear

[0130] Figure 7 A double-row planetary gear fault diagnosis system is shown, comprising:

[0131] The impact time interval determination unit 701 is configured to determine the fault impact time interval of the sun gear engaged planetary gear (i.e. the first row of planetary gears) and the fault impact time interval of the ring gear engaged planetary gear (i.e. the second row of planetary gears) respectively;

[0132] The sun gear engaged planetary gear fault diagnosis unit 702 is configured to combine the fault impact time interval of the sun gear engaged planetary gear and the corresponding broken tooth phenomenological model to perform fault diagnosis, and obtain the fault diagnosis result of the sun gear engaged planetary gear;

[0133] The ring gear engaged planetary gear fault diagnosis unit 703 is configured to combine the fault impact time interval of the ring gear engaged planetary gear and the corresponding broken tooth phenomenological model to perform fault diagnosis, and obtain the fault diagnosis result of the ring gear engaged planetary gear.

[0134] It can be understood that each of the above units can be combined into one or several other units to constitute, or some of the units can be further split into a plurality of units with smaller functions to constitute, which can achieve the same operation without affecting the implementation of the technical effects of the embodiments of the present application. The above units are divided based on logical functions. In actual application, the function of one unit can also be implemented by multiple units, or the functions of multiple units are implemented by one unit. In other embodiments of the present application, the system can also include other units. In actual application, these functions can also be assisted by other units, and can be implemented by multiple units.

[0135] According to another embodiment of the present application, the system described in the embodiment can be constructed by running a computer program (including program codes) capable of performing each step involved in the corresponding method of the present application on a general computing device such as a computer including processing elements and storage elements such as a Central Processing Unit (CPU), a Random Access Memory (RAM), a Read Only Memory (ROM), etc., the computer program can be recorded on a computer readable recording medium, and loaded into the above computing device through the computer readable recording medium, and run therein.

[0136] Figure 8 A computer device is shown, which includes a processor 801, a communication interface 802, and a computer readable storage medium 803. Wherein the processor 801, the communication interface 802 and the computer readable storage medium 803 can be connected through a bus or other means.

[0137] Wherein, the communication interface 802 is used for receiving and sending data, the computer readable storage medium 803 can be stored in the memory of the electronic device, the computer readable storage medium 803 is used for storing computer programs, the computer programs include program instructions, and the processor 801 is used for executing the program instructions stored in the computer readable storage medium 803.

[0138] The processor 801 is the computing core and control core of the electronic device, which is suitable for implementing one or more instructions, and is particularly suitable for loading and executing one or more instructions to realize the corresponding method flow or corresponding function.

[0139] The processor 801 is configured to perform the following process:

[0140] For the fault tooth in the first row of planet gear set meshing with the sun gear, the time when the tooth enters meshing with the sun gear is taken as the initial time point; based on the actual operation parameters of the double-row planet gear system (including gear tooth number, modulus, speed and phase relationship), the first time difference required for the fault tooth to move from the meshing point of the sun gear to the meshing point of the second row of planet gears is calculated, and the first time difference is taken as the fault impact time interval of the sun gear meshing planet gear; for the fault tooth in the second row of planet gear set meshing with the gear ring, the time when the tooth enters meshing with the first row of planet gears (assuming that the first row of planet gears does not fail, when the second row of planet gears fails, the time defined by the fault tooth of the first row of planet gears is taken as the reference, and the time point corresponding to the second row of planet gears is calculated according to the delay amount) is taken as the initial time point; based on the system operation parameters, the second time difference required for the fault tooth to move from the meshing point between the planet gear sets to the meshing point of the gear ring is calculated, and the second time difference is taken as the fault impact time interval of the gear ring meshing planet gear.

[0141] Alternatively, the fault impact time interval of the sun gear meshing planet gear and the corresponding broken tooth phenomenological model are combined to perform fault diagnosis, and the fault diagnosis result of the sun gear meshing planet gear is obtained; the fault impact time interval of the gear ring meshing planet gear and the corresponding broken tooth phenomenological model are combined to perform fault diagnosis, and the fault diagnosis result of the gear ring meshing planet gear is obtained.

[0142] The application also provides a computer readable storage medium, which is a memory device in an electronic device and is used for storing programs and data. It can be understood that the computer readable storage medium herein can include a built-in storage medium in the electronic device, and of course can also include an expansion storage medium supported by the electronic device. The computer readable storage medium provides a storage space which stores a processing system of the electronic device.

[0143] In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and the instructions can be one or more computer programs (including program codes). It should be noted that the computer readable storage medium herein can be a high-speed RAM memory, or a non-volatile memory such as at least one disk memory; optionally, it can also be at least one computer readable storage medium located away from the aforementioned processor.

[0144] In one embodiment, one or more instructions are stored in the computer readable storage medium; the processor loads and executes the one or more instructions stored in the computer readable storage medium to realize the following process:

[0145] For the fault tooth in the first row of planet gear set meshing with the sun gear, the time when the tooth meshes with the sun gear is taken as the initial time point; based on the actual operation parameters of the double-row planet gear system (including gear teeth, modulus, speed and phase relationship), the first time difference required for the fault tooth to move from the sun gear meshing point to meshing with the second row of planet gear is calculated, and the first time difference is taken as the fault impact time interval of the sun gear meshing with the planet gear; for the fault tooth in the second row of planet gear set meshing with the gear ring, the time when the tooth meshes with the first row of planet gear (assuming that the first row of planet gear does not fail, when the second row of planet gear fails, the time defined by the first row of planet gear fault tooth is accurate, and the time point corresponding to the second row of planet gear is calculated according to the delay amount of the meshing relationship) is taken as the initial time point; based on the system operation parameters, the second time difference required for the fault tooth to move from the inter-planet gear set meshing point to the gear ring meshing point is calculated, and the second time difference is taken as the fault impact time interval of the gear ring meshing with the planet gear.

[0146] Alternatively, the fault impact time interval of the sun gear meshing with the planet gear and the corresponding broken tooth phenomenological model are combined for fault diagnosis to obtain the fault diagnosis result of the sun gear meshing with the planet gear; the fault impact time interval of the gear ring meshing with the planet gear and the corresponding broken tooth phenomenological model are combined for fault diagnosis to obtain the fault diagnosis result of the gear ring meshing with the planet gear.

[0147] The application also provides a computer program product or a computer program, which comprises computer instructions stored in a computer readable storage medium. The processor of the electronic device reads the computer instructions from the computer readable storage medium, and the processor executes the computer instructions to enable the electronic device to perform the following processes:

[0148] For the fault tooth in the first row of planet gear set meshing with the sun gear, the time when the tooth meshes with the sun gear is taken as the initial time point; based on the actual operation parameters of the double-row planet gear system (including gear teeth, modulus, speed and phase relationship), the first time difference required for the fault tooth to move from the sun gear meshing point to meshing with the second row of planet gear is calculated, and the first time difference is taken as the fault impact time interval of the sun gear meshing with the planet gear; for the fault tooth in the second row of planet gear set meshing with the gear ring, the time when the tooth meshes with the first row of planet gear (assuming that the first row of planet gear does not fail, when the second row of planet gear fails, the time defined by the first row of planet gear fault tooth is accurate, and the time point corresponding to the second row of planet gear is calculated according to the delay amount of the meshing relationship) is taken as the initial time point; based on the system operation parameters, the second time difference required for the fault tooth to move from the inter-planet gear set meshing point to the gear ring meshing point is calculated, and the second time difference is taken as the fault impact time interval of the gear ring meshing with the planet gear.

[0149] Alternatively, the fault diagnosis is performed in combination with the fault impact time interval of the sun gear and the corresponding broken tooth phenomenological model to obtain the fault diagnosis result of the sun gear and the planet gear; the fault diagnosis is performed in combination with the fault impact time interval of the ring gear and the planet gear and the corresponding broken tooth phenomenological model to obtain the fault diagnosis result of the ring gear and the planet gear.

[0150] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present application can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0151] In the above embodiments, all or part can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. Computer instructions can be stored in a computer-readable storage medium or transmitted by a computer-readable storage medium. Computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (for example, coaxial cable, optical fiber, digital line) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium that the computer can access or a data processing device such as a server, data center, etc. containing one or more available media sets. The available media can be magnetic media (for example, floppy disk, hard disk, magnetic tape), optical media (for example, DVD), or semiconductor media (for example, solid state disk) and the like.

[0152] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for estimating fault impact time interval of a double-row planetary gear, characterized in that, a two-stage transmission structure is used, the two-stage transmission structure comprising a single-row planetary gear train of a first stage and a double-row planetary gear train of a second stage; a first-stage sun gear in the single-row planetary gear train of the first stage is fixed, and the first-stage sun gear is engaged with a set of planetary gears; the double-row planetary gear train of the second stage comprises a second-stage sun gear inputting power, a first-row planetary gear engaged with the second-stage sun gear, and a second-row planetary gear engaged with a ring gear; the two-stage transmission structure shares a carrier and the ring gear, the planetary gears of the single-row planetary gear train of the first stage and the second-row planetary gears of the double-row planetary gear train of the second stage are engaged with different parts of the same ring gear in a floating support manner; the method comprises the following processes: for a fault tooth in the first-row planetary gear set engaged with the sun gear, taking the time when the fault tooth is engaged with the sun gear as an initial time point, and based on actual operating parameters of the double-row planetary gear system, a first time difference required for the fault tooth to move from the sun gear engagement point to the second-row planetary gear engagement point is calculated in combination with the initial time point, and the first time difference is taken as the fault impact time interval of the sun gear engagement planetary gear; for a fault tooth in the second-row planetary gear set engaged with the ring gear, taking the time when the fault tooth is engaged with the first-row planetary gear as an initial time point, and based on actual operating parameters of the double-row planetary gear system, a second time difference required for the fault tooth to move from the inter- planetary gear set engagement point to the ring gear engagement point is calculated in combination with the initial time point, and the second time difference is taken as the fault impact time interval of the ring gear engagement planetary gear; The fault impact time interval of the sun gear engaging with the planetary gear is: ; in, , , The base circle tooth thickness of the planetary gear is [missing information]. for Gear pair and The included angle between the lines connecting the centers of the gear pair. For pressure angle, These are the base circle radius and addendum circle radius of the first row of planetary gears, respectively. A gear pair represents the sun gear and the first planetary gear in the first row. A gear pair consisting of planetary gears Gear pair represents the first planetary gear in the first row. The first planetary gear and the first planetary gear in the second row of planetary gears A gear pair consisting of planetary gears , and These respectively represent the center of the sun gear and the first planetary gear in the first row. The center of the first planetary gear and the first planetary gear in the second row. The center of each planetary gear; The fault impact time interval of the ring gear meshing with the planetary gear is: ; , , The base circle tooth thickness of the planetary gear is [missing information]. for Gear pair and The angle between the lines connecting the centers of the circles. For pressure angle, These are the base circle radius and the addendum circle radius of the planetary gear, respectively. These are the base circle radius and the addendum circle radius of the gear ring, respectively. A gear pair represents the gear ring and the first gear in the second row of planetary gears. A gear pair consisting of planetary gears Gear pair represents the first planetary gear in the first row. The first planetary gear and the first planetary gear in the second row of planetary gears A gear pair consisting of planetary gears , and Representing the center of the gear ring and the first planetary gear in the first row, respectively. The center of the first planetary gear and the first planetary gear in the second row. The center of each planetary gear, the center of the ring gear, and the center of the sun gear are all... ; engagement pair and phase difference of the engagement pair are: wherein, represent engagement pair and phase difference of the engagement pair, represent engagement pair and phase difference of the engagement pair.

2. A double-row planetary gear fault impact time interval estimation system characterized by, the method for estimating fault impact time interval of a double-row planetary gear according to claim 1 comprises: a first fault impact interval estimation unit configured to, for a fault tooth in the first-row planetary gear set engaged with the sun gear, take the time when the fault tooth is engaged with the sun gear as an initial time point, and based on actual operating parameters of the double-row planetary gear system, calculate a first time difference required for the fault tooth to move from the sun gear engagement point to the second-row planetary gear engagement point in combination with the initial time point, and take the first time difference as the fault impact time interval of the sun gear engagement planetary gear; a second fault impact interval estimation unit configured to, for a fault tooth in the second-row planetary gear set engaged with the ring gear, take the time when the fault tooth is engaged with the first-row planetary gear as an initial time point, and based on actual operating parameters of the double-row planetary gear system, calculate a second time difference required for the fault tooth to move from the inter- planetary gear set engagement point to the ring gear engagement point in combination with the initial time point, and take the second time difference as the fault impact time interval of the ring gear engagement planetary gear.

3. A double-row planetary gear fault diagnosis method characterized by comprising: The method for estimating fault impact time interval of a double-row planetary gear according to claim 1 comprises: determining the fault impact time interval of the planetary gear engaged with the sun gear and the fault impact time interval of the planetary gear engaged with the ring gear, respectively; performing fault diagnosis on the fault impact time interval of the sun gear engagement planetary gear and the corresponding broken tooth epiphenomenal model to obtain a fault diagnosis result of the sun gear engagement planetary gear. The fault impact time interval of the sun gear side planetary gear is substituted into the corresponding planetary gear broken tooth phenomenological model to determine the corresponding time domain image and frequency domain image for the fault diagnosis of the planetary gear meshing with the sun gear. The fault impact time interval of the sun gear side planetary gear is substituted into the corresponding planetary gear broken tooth phenomenological model to determine the corresponding time domain image and frequency domain image for the fault diagnosis of the planetary gear meshing with the sun gear.

4. A double-row planetary gear fault diagnosis system characterized by comprising: The method comprises the following processes: The impact time interval determination unit is configured to determine the fault impact time interval of the planetary gear meshing with the sun gear and the fault impact time interval of the planetary gear meshing with the ring gear respectively according to the double-row planetary gear fault impact time interval estimation method in claim 1; The sun gear side planetary gear fault diagnosis unit is configured to combine the fault impact time interval of the sun gear side planetary gear and the corresponding broken tooth phenomenological model to perform fault diagnosis, and obtain the fault diagnosis result of the sun gear side planetary gear; The ring gear side planetary gear fault diagnosis unit is configured to combine the fault impact time interval of the ring gear side planetary gear and the corresponding broken tooth phenomenological model to perform fault diagnosis, and obtain the fault diagnosis result of the ring gear side planetary gear; The fault impact time interval of the sun gear side planetary gear is substituted into the corresponding planetary gear broken tooth phenomenological model to determine the corresponding time domain image and frequency domain image for the fault diagnosis of the planetary gear meshing with the sun gear.

5. A computer device, comprising: The computer readable storage medium stores a computer program, and the computer program is adapted to be loaded and executed by the processor to implement the double-row planetary gear fault impact time interval estimation method in claim 1; or implement the double-row planetary gear fault diagnosis method in claim 3. The computer program product comprises a computer program, and the computer program is executed by the processor to implement the double-row planetary gear fault impact time interval estimation method in claim 1; or implement the double-row planetary gear fault diagnosis method in claim 3. ​ ​ 6. A computer-readable storage medium, characterized in that, ​ 7. A computer program product, characterised in that, ​

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