Gearbox vibration limit value calculation method and system, electronic device, medium

Abstract

The application discloses a kind of gear box vibration limiting value calculation method and system, electronic equipment, medium, the method is first constructed the dynamics model of gear box and is solved, obtains the torsional vibration angular displacement of each gear under working condition, then calculates and obtains the dynamic meshing force of each gear pair under working condition, and obtains the maximum value of gear pair meshing force under working condition, after calculating the maximum value of gear pair meshing force under life limiting condition, the dynamic meshing force of each gear pair under working condition is corrected, obtains the dynamic meshing force of each gear pair under life limiting condition, finally, the vibration limiting value at gear box vibration measuring point is determined based on the dynamic meshing force of each gear pair under life limiting condition;Firstly, the theoretical solution line of gear box vibration limiting value is proposed, the vibration limiting value at gear box vibration measuring point can be determined by theoretical calculation, and the setting accuracy and interpretability of gear box vibration limiting value are improved.

Description

Methods and systems for calculating vibration limits of gearboxes, electronic equipment, and media. Technical Field

[0001] This invention relates to the field of gearbox vibration monitoring technology, and in particular to a method and system for calculating the vibration limit value of a gearbox, an electronic device, and a computer-readable storage medium. Background Technology

[0002] Gearboxes are widely used in aviation, shipbuilding, and engineering machinery. Their main function is to transmit input power or torque from the prime mover and change the input speed, while also enabling parallel or split-drive transmission. During operation, gearboxes are subjected to both internal excitations (including time-varying meshing stiffness, time-varying meshing damping, unbalanced inertial forces, and errors) and external excitations (including input torque fluctuations and output torque fluctuations), often resulting in significant vibration and noise. Therefore, to ensure the safe and reliable operation of gearboxes, vibration monitoring and the setting of corresponding vibration limits are generally necessary. However, current technologies rely on manual experience to set these vibration limits, rather than theoretical calculations, leading to inaccurate limits and hindering accurate vibration monitoring. Although existing technologies have proposed some theoretical calculation methods for vibration limit values, such as Chinese invention patent application CN117744453A which discloses a method for calculating the vibration limit value of an engine and Chinese invention patent application CN111473859A which discloses a method for determining the vibration limit value of an engine, the existing theoretical calculation methods for the vibration limit value of an engine cannot be applied to the gearbox because the internal and external excitations of the gearbox vibration are completely different from those of the engine. Summary of the Invention

[0003] This invention provides a method and system for calculating the vibration limit value of a gearbox, an electronic device, and a computer-readable storage medium. It can determine the vibration limit value at the vibration measurement point of the gearbox through theoretical calculation, without relying on test results or historical data of similar gearboxes, and without relying on human experience. This improves the accuracy and interpretability of setting the vibration limit value of the gearbox, and is beneficial for accurate vibration monitoring of the gearbox.

[0004] According to one aspect of the present invention, a method for calculating the vibration limit value of a gearbox is provided. The gearbox includes a first gear, a second gear, a third gear, a fourth gear, a fifth gear, and a sixth gear. Power is input from the first gear, which meshes with the second and third gears on two branches to split and transmit power. The second gear transmits power to the fourth gear through a first elastic shaft, and the third gear transmits power to the fifth gear through a second elastic shaft. Both the fourth and fifth gears mesh with the sixth gear, which then outputs the combined power. Each gear includes two helical gears with opposite helix angles, connected by a shaft segment. The method includes the following:

[0005] Determine the design parameters of the gearbox;

[0006] Based on the design parameters, a dynamic model of the gearbox is constructed using the lumped parameter method, and the dynamic model is solved to obtain the torsional vibration angular displacement of each gear under working conditions.

[0007] The dynamic meshing force of each gear pair under working conditions is calculated based on the torsional vibration angular displacement of each gear, and the maximum meshing force of the gear pair under working conditions is obtained.

[0008] Calculate the maximum meshing force of the gear pair under life-limited conditions;

[0009] Based on the maximum meshing force of the gear pair under the life-limited state and the maximum meshing force of the gear pair under the working state, the dynamic meshing force of each gear pair under the working state is corrected to obtain the dynamic meshing force of each gear pair under the life-limited state.

[0010] The vibration limit value at the gearbox vibration measurement point is determined based on the dynamic meshing force of each gear pair under the life-limited state.

[0011] Furthermore, the dynamic model of the gearbox is as follows:

[0012] ;

[0013] ;

[0014] ;

[0015] ;

[0016] ;

[0017] ;

[0018] in, , , and Let these represent the mass matrix, damping matrix, stiffness matrix, and torsional vibration angular displacement vector, respectively. Represents the excitation force vector. and They represent The first and second derivatives, Represents a diagonal matrix. This represents the polar moment of inertia at the equivalent node located at the geometric center of the helical gear. The subscripts 1L, 2L, 3L, 4L, 5L, and 6L represent the left helical gears of the first, second, third, fourth, fifth, and sixth gears, respectively. The subscripts 1R, 2R, 3R, 4R, 5R, and 6R represent the right helical gears of the first, second, third, fourth, fifth, and sixth gears, respectively. This represents the polar moment of inertia at the equivalent node at the geometric center of the left helical gear of the first gear. The stiffness matrix is ​​represented by [symbol]. The meshing stiffness submatrix in the i-th row and j-th column. Represents the stiffness matrix The torsional stiffness submatrix in the i-th row and j-th column, i / j=1,2,3,4,5,6. This represents the angular displacement of the helical gear's torsional vibration about its axis. This represents the torsional vibration angular displacement of the left helical gear of the first gear about its axis; the superscript T indicates transpose. and Indicates input torque and output torque. and These represent the base circle radius and helix angle of the helical gear, respectively. and These represent the base circle radius and helix angle of the left helical gear of the first gear, respectively. This indicates the meshing stiffness of each gear pair. This represents the overall transmission error of each gear pair. This indicates the meshing damping of each gear pair. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R represent the numbers of each gear pair. This indicates the meshing stiffness of the gear pair formed by the left helical gear of the first gear and the left helical gear of the second gear. This represents the combined transmission error of the gear pair formed by the left helical gear of the first gear and the left helical gear of the second gear. This indicates the meshing damping of the gear pair formed by the left helical gear of the first gear and the left helical gear of the second gear. express The first derivative.

[0019] Furthermore, the dynamic meshing force of each gear pair under working conditions is calculated based on the following formula:

[0020] ;

[0021] in, This represents the dynamic meshing force of each gear pair under working conditions. This indicates the relative meshing displacement of each gear pair along its line of meshing. This indicates the meshing stiffness of each gear pair. This indicates the meshing damping of each gear pair. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R represent the numbers of each gear pair. This represents the dynamic meshing force of the gear pair consisting of the left helical gear of the first gear and the left helical gear of the second gear during operation. This indicates the relative meshing displacement of the gear pair formed by the left helical gear of the first gear and the left helical gear of the second gear along their line of meshing. This indicates the meshing stiffness of the gear pair formed by the left helical gear of the first gear and the left helical gear of the second gear. This indicates the meshing damping of the gear pair formed by the left helical gear of the first gear and the left helical gear of the second gear. express The first derivative, Indicates the normal pressure angle of a helical gear. The subscripts 1L, 4L, and 5L represent the left helical gears of the first, fourth, and fifth gears, respectively, while the subscripts 1R, 4R, and 5R represent the right helical gears of the first, fourth, and fifth gears, respectively.

[0022] Furthermore, the process of calculating the maximum meshing force of the gear pair under the life-limited state includes the following:

[0023] The maximum number of contact stress cycles is calculated based on the given gear contact fatigue life.

[0024] Find the corresponding maximum stress amplitude in the stress-life curve of the material based on the maximum number of contact stress cycles.

[0025] The maximum contact stress on the tooth surface is calculated based on the maximum stress amplitude.

[0026] The maximum meshing force of the gear pair under life-limited conditions is calculated based on the maximum contact stress on the tooth surface.

[0027] Furthermore, the maximum contact stress on the tooth surface is calculated based on the following formula:

[0028] ;

[0029] in, This indicates the maximum contact stress on the tooth surface. Indicates the maximum stress amplitude. This indicates the contact fatigue safety factor.

[0030] Furthermore, the dynamic meshing force of each gear pair under working conditions is corrected based on the following formula:

[0031] ;

[0032] in, This represents the dynamic meshing force of each gear pair under life-limited conditions. This represents the dynamic meshing force of each gear pair under working conditions. This indicates the maximum meshing force of the gear pair under working conditions. This indicates the maximum meshing force of the gear pair under life-limited conditions.

[0033] Furthermore, the design parameters include material parameters, gear parameters, and shaft parameters.

[0034] In addition, the present invention also provides a vibration limit calculation system for a gearbox, the gearbox including a first gear, a second gear, a third gear, a fourth gear, a fifth gear, and a sixth gear. Power is input from the first gear, which meshes with the second and third gears on two branches to split and transmit power. The second gear transmits power to the fourth gear through a first elastic shaft, and the third gear transmits power to the fifth gear through a second elastic shaft. Both the fourth and fifth gears mesh with the sixth gear, which then outputs the combined power. Each gear includes two helical gears with opposite helix angles, and the two helical gears are connected by a shaft segment. The system includes:

[0035] The design parameter setting module is used to determine the design parameters of the gearbox.

[0036] The dynamics solution module is used to construct the dynamic model of the gearbox based on the design parameters using the lumped parameter method, and to solve the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions.

[0037] The first calculation module is used to calculate the dynamic meshing force of each gear pair under working conditions based on the torsional vibration angular displacement of each gear, and to obtain the maximum value of the gear pair meshing force under working conditions.

[0038] The second calculation module is used to calculate the maximum meshing force of the gear pair under the life-limited state.

[0039] The third calculation module is used to correct the dynamic meshing force of each gear pair in the working state based on the maximum meshing force of the gear pair under the life-limited state and the maximum meshing force of the gear pair in the working state, so as to obtain the dynamic meshing force of each gear pair under the life-limited state.

[0040] The vibration limit value determination module is used to determine the vibration limit value at the gearbox vibration measurement point based on the dynamic meshing force of each gear pair under the life limit state.

[0041] In addition, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the method described above by calling the computer program stored in the memory.

[0042] In addition, the present invention provides a computer-readable storage medium for storing a computer program for calculating the vibration limit value of a gearbox, wherein the computer program, when run on a computer, performs the steps of the method described above.

[0043] The present invention has the following beneficial effects:

[0044] The method for calculating the vibration limit value of a gearbox in this invention first constructs a dynamic model of the gearbox using the lumped parameter method based on the gearbox's design parameters, and solves the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions. Then, based on the torsional vibration angular displacement of each gear, the dynamic meshing force of each gear pair under working conditions is calculated, and the maximum value of the gear pair meshing force under working conditions is obtained. After calculating the maximum value of the gear pair meshing force under the life-limited state, the dynamic meshing force of each gear pair under working conditions is corrected, thereby obtaining the dynamic meshing force of each gear pair under the life-limited state. Finally, based on the dynamic meshing force of each gear pair under the life-limited state, the vibration limit value at the gearbox vibration measurement point is determined. This method proposes for the first time a theoretical solution path for the gearbox vibration limit value, which can determine the vibration limit value at the gearbox vibration measurement point through theoretical calculation, without relying on experimental results or historical data of similar gearboxes, and without relying on human experience. This improves the accuracy and interpretability of setting the gearbox vibration limit value, and is beneficial for accurate vibration monitoring of the gearbox.

[0045] In addition, the gearbox vibration limit calculation system of the present invention also has the above-mentioned advantages.

[0046] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0047] The accompanying drawings, which form part of this application, 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 undue limitation of the invention. In the drawings:

[0048] Figure 1 is a structural schematic diagram of the gearbox according to a preferred embodiment of this application;

[0049] Figure 2 is a flowchart illustrating the method for calculating the vibration limit value of a gearbox according to a preferred embodiment of this application;

[0050] Figure 3 is a schematic diagram of the dynamic model of a preferred embodiment of this application;

[0051] Figure 4 is a schematic diagram of the dynamic meshing force curve of a gear pair in the working state in a preferred embodiment of this application;

[0052] Figure 5 is a schematic diagram of the sub-process of step S4 in Figure 2;

[0053] Figure 6 is a schematic diagram of the variation law of tooth surface contact stress in a preferred embodiment of this application;

[0054] Figure 7 is a schematic diagram of the dynamic meshing force curve of a gear pair under the life-limited state in a preferred embodiment of this application;

[0055] Figure 8 is a schematic diagram of the module structure of a gearbox vibration limit value calculation system according to another embodiment of this application.

[0056] Explanation of reference numerals in the attached figures

[0057] 1. First gear; 2. Second gear; 3. Third gear; 4. Fourth gear; 5. Fifth gear; 6. Sixth gear; 7. First elastic shaft; 8. Second elastic shaft. Detailed Implementation

[0058] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] Referring to Figure 1, the gearbox of the aero-engine in this application includes a first gear 1, a second gear 2, a third gear 3, a fourth gear 4, a fifth gear 5, and a sixth gear 6. Power is input from the first gear 1, which meshes with the second gear 2 and the third gear 3 on two separate branches to distribute the power. The two branches transmit power to the fourth gear 4 and the fifth gear 5 via the first elastic shaft 7 and the second elastic shaft 8, respectively. Both the fourth gear 4 and the fifth gear 5 mesh with the sixth gear 6, which then combines the power and outputs it. Each gear can be considered as a herringbone gear composed of two helical gears with opposite helix angles. The relief groove between the two helical gears is considered as a shaft segment. The two helical gears are connected by the shaft segment. The helical gear on the left side of the shaft segment is defined as the left helical gear, and the helical gear on the right side of the shaft segment is defined as the right helical gear. In this configuration, the left helical gear of the first gear 1 forms a gear pair with the left helical gear of the second gear 2 and the left helical gear of the third gear 3, respectively; the right helical gear of the first gear 1 forms a gear pair with the right helical gear of the second gear 2 and the right helical gear of the third gear 3, respectively; the left helical gear of the sixth gear 6 forms a gear pair with the left helical gear of the fourth gear 4 and the left helical gear of the fifth gear 5, respectively; and the right helical gear of the sixth gear 6 forms a gear pair with the right helical gear of the fourth gear 4 and the right helical gear of the fifth gear 5, respectively.

[0060] For ease of description, this application uses subscripts 1L, 2L, 3L, 4L, 5L, and 6L to represent the left helical gears of the first gear 1, second gear 2, third gear 3, fourth gear 4, fifth gear 5, and sixth gear 6, respectively; and subscripts 1R, 2R, 3R, 4R, 5R, and 6R to represent the right helical gears of the same gears. That is, the numbers in the subscripts indicate gear numbers, with L representing the left helical gear and R representing the right helical gear. Subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R are also used to represent the numbers of each gear pair, for example... 12L represents the gear pair consisting of the left helical gears of the first gear 1 and the second gear 2; 12R represents the gear pair consisting of the right helical gears of the first gear 1 and the second gear 2; 13L represents the gear pair consisting of the left helical gears of the first gear 1 and the third gear 3; 13R represents the gear pair consisting of the right helical gears of the first gear 1 and the third gear 3; 46L represents the gear pair consisting of the left helical gears of the fourth gear 4 and the sixth gear 6; 46R represents the gear pair consisting of the right helical gears of the fourth gear 4 and the sixth gear 6; 56L represents the gear pair consisting of the left helical gears of the fifth gear 5 and the sixth gear 6; 56R represents the gear pair consisting of the right helical gears of the fifth gear 5 and the sixth gear 6.

[0061] As shown in Figure 2, a preferred embodiment of this application provides a method for calculating the vibration limit value of a gearbox, including the following:

[0062] Step S1: Determine the design parameters of the gearbox;

[0063] Step S2: Based on the design parameters, construct the dynamic model of the gearbox using the lumped parameter method, and solve the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions;

[0064] Step S3: Calculate the dynamic meshing force of each gear pair under working conditions based on the torsional vibration angular displacement of each gear, and obtain the maximum value of the gear pair meshing force under working conditions;

[0065] Step S4: Calculate the maximum meshing force of the gear pair under the life-limited condition;

[0066] Step S5: Based on the maximum meshing force of the gear pair under the life-limited state and the maximum meshing force of the gear pair under the working state, the dynamic meshing force of each gear pair under the working state is corrected to obtain the dynamic meshing force of each gear pair under the life-limited state.

[0067] Step S6: Determine the vibration limit value at the gearbox vibration measurement point based on the dynamic meshing force of each gear pair under the life limit state.

[0068] It is understood that the gearbox vibration limit calculation method in this embodiment first constructs a dynamic model of the gearbox based on the gearbox design parameters using the lumped parameter method, and solves the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions. Then, based on the torsional vibration angular displacement of each gear, the dynamic meshing force of each gear pair under working conditions is calculated, and the maximum value of the gear pair meshing force under working conditions is obtained. After calculating the maximum value of the gear pair meshing force under the life-limited state, the dynamic meshing force of each gear pair under working conditions is corrected, thereby obtaining the dynamic meshing force of each gear pair under the life-limited state. Finally, based on the dynamic meshing force of each gear pair under the life-limited state, the vibration limit value at the gearbox vibration measurement point is determined. This method proposes a theoretical solution path for the gearbox vibration limit value for the first time. The vibration limit value at the gearbox vibration measurement point can be determined by theoretical calculation, without relying on experimental results or historical data of similar gearboxes, and without relying on human experience. This improves the accuracy and interpretability of setting the gearbox vibration limit value, which is beneficial for accurate vibration monitoring of the gearbox.

[0069] In step S1, the design parameters of the gearbox are first set, including material parameters, gear parameters, and shaft parameters. For example, material parameters include the material properties of major components such as the casing, gears, shafts, and bearings; gear parameters include the number of teeth, module, helix angle, pressure angle, tooth width, mass, moment of inertia, meshing stiffness, and meshing damping; and shaft parameters include the shaft stiffness.

[0070] In step S2, this application constructs a dynamic model of the gearbox, i.e., the nonlinear vibration equation of the gear train, based on the transmission form of the gear train and design parameters using the lumped parameter method. Specifically, each gear in the gear train is considered as a rigid disk, and its mechanical properties are described by lumped mass and moment of inertia. The gears are connected by meshing stiffness and meshing damping. Piecewise nonlinear functions are used to describe gear backlash, and the time-varying meshing stiffness of the gear pair is fitted by the second harmonic function of the Fourier series. The dynamic equation of each lumped mass in the gear train is established according to Newton's second law, and the nonlinear vibration equations of the gear train are formed by combining them according to the connection relationship. The dynamic model of the gear train is shown in Figure 3. In addition, the definition of each character in Figure 3 is: k m c m e, δ represent the meshing stiffness, meshing damping, overall transmission error, and relative meshing displacement along the meshing line direction of the gear pair, respectively. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R indicate the gear pair number. k 24t k 35t J represents the torsional stiffness of the first elastic shaft 7 and the second elastic shaft 8. 1L J represents the polar moment of inertia at the equivalent node located at the geometric center of the left helical gear of the first gear 1. 1R J 2L J 2R J 3L J 3R J 4L J 4R J 5L J 5R J 6L J 6R The definitions are similar, both representing the polar moment of inertia of the corresponding helical gear, θ. 1L This represents the torsional vibration angular displacement of the left helical gear of the first gear 1 about its axis, and the rest are represented by θ. 1R θ 2L θ 2R θ 3L θ 3R θ 4L θ 4R θ 5L θ 5R θ 6L θ 6R The definitions are similar, both representing the torsional vibration angular displacement of the corresponding helical gear about its axis, T. in T out These represent the input torque and the output torque, respectively.

[0071] The nonlinear vibration equation of the gear train can be expressed as:

[0072] ;

[0073] ;

[0074] ;

[0075] ;

[0076] ;

[0077] ;

[0078] in, , , and Let these represent the mass matrix, damping matrix, stiffness matrix, and torsional vibration angular displacement vector, respectively. Represents the excitation force vector. and They represent The first and second derivatives, Represents a diagonal matrix. The term represents the polar moment of inertia at the equivalent node located at the geometric center of the helical gear. Subscripts 1L, 2L, 3L, 4L, 5L, and 6L represent the left helical gears of gears 1, 2, 3, 4, 5, and 6, respectively. Subscripts 1R, 2R, 3R, 4R, 5R, and 6R represent the right helical gears of gears 1, 2, 3, 3, 4, 5, and 6, respectively. Let represent the polar moment of inertia at the equivalent node at the geometric center of the left helical gear of the first gear 1, and the rest... The definitions are similar, both representing the polar moment of inertia at the equivalent node at the geometric center of the corresponding helical gear. The stiffness matrix is ​​represented by [symbol]. The meshing stiffness submatrix in the i-th row and j-th column. Represents the stiffness matrix The torsional stiffness submatrix in the i-th row and j-th column, i / j=1,2,3,4,5,6. This represents the angular displacement of the helical gear's torsional vibration about its axis. This represents the torsional vibration angular displacement of the left helical gear of the first gear 1 about its axis, and the rest... The definitions are similar, representing the torsional vibration angular displacement of the corresponding helical gear about its axis, with the superscript T indicating transpose. and Indicates input torque and output torque. and These represent the base circle radius and helix angle of the helical gear, respectively. and These represent the base circle radius and helix angle of the left helical gear of the first gear 1, respectively. This indicates the meshing stiffness of each gear pair. This represents the overall transmission error of each gear pair. This indicates the meshing damping of each gear pair. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R represent the numbers of each gear pair. This indicates the meshing stiffness of the gear pair formed by the left helical gear of the first gear 1 and the left helical gear of the second gear 2. This represents the combined transmission error of the gear pair consisting of the left helical gear of the first gear 1 and the left helical gear of the second gear 2. This indicates the meshing damping of the gear pair formed by the left helical gear of the first gear 1 and the left helical gear of the second gear 2. express The first derivative.

[0079] In addition, stiffness matrix Each submatrix in can be represented as:

[0080] ;

[0081] ;

[0082] ;

[0083] ;

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] ;

[0089] ;

[0090] ;

[0091] ;

[0092] ;

[0093] ;

[0094] ;

[0095] in, This represents the torsional stiffness of the shaft segment of the first gear 1, and the rest... The definitions are similar, both representing the torsional stiffness of the shaft segment of the corresponding gear. , These represent the torsional stiffness of the first elastic shaft 7 and the second elastic shaft 8, respectively.

[0096] After constructing the nonlinear vibration equations of the gear train, the fourth-order variable-step-size Runge-Kutta method is used to solve the nonlinear vibration equations of the gear train, thereby obtaining the torsional vibration angular displacement vector under operating conditions. The value of θ is obtained, which gives the torsional vibration angular displacement θ of each gear under working conditions. 1L (t), θ 1R (t), θ 2L (t), θ 2R (t), θ 3L (t), θ 3R (t), θ 4L (t), θ 4R (t), θ 5L (t), θ 5R (t), θ 6L (t), θ 6R (t). Among them, the fourth-order variable step size Runge-Kutta method is an existing technology, and the specific solution process and principle will not be elaborated here.

[0097] Furthermore, in step S3, after calculating the torsional vibration angular displacement of each gear under working conditions, the relative meshing displacement of each gear pair along the meshing line direction under working conditions is... for:

[0098] ;

[0099] ;

[0100] The relative meshing displacement of each gear pair along the line of meshing and the dynamic meshing force have the following relationship:

[0101] ;

[0102] Therefore, the dynamic meshing force of each gear pair under working conditions can be calculated based on the following formula:

[0103] ;

[0104] in, This represents the dynamic meshing force of each gear pair under working conditions. This indicates the relative meshing displacement of each gear pair along its line of meshing. This indicates the meshing stiffness of each gear pair. This indicates the meshing damping of each gear pair. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R represent the numbers of each gear pair. This represents the dynamic meshing force of the gear pair consisting of the left helical gear of the first gear 1 and the left helical gear of the second gear 2 during operation. This indicates the relative meshing displacement of the gear pair formed by the left helical gear of the first gear 1 and the left helical gear of the second gear 2 along their line of meshing. This indicates the meshing stiffness of the gear pair formed by the left helical gear of the first gear 1 and the left helical gear of the second gear 2. This indicates the meshing damping of the gear pair formed by the left helical gear of the first gear 1 and the left helical gear of the second gear 2. express The first derivative, This represents the normal pressure angle of a helical gear; all helical gears have the same normal pressure angle. The subscripts 1L, 4L, and 5L represent the left helical gears of the first gear 1, the fourth gear 4, and the fifth gear 5, respectively, while the subscripts 1R, 4R, and 5R represent the right helical gears of the first gear 1, the fourth gear 4, and the fifth gear 5, respectively.

[0105] After calculating the dynamic meshing force of each gear pair at multiple times and under various working conditions, the dynamic meshing force curve of each gear pair under working conditions can be generated. For example, the dynamic meshing force curve of a certain gear pair under working conditions is shown in Figure 4. It can be seen that the dynamic meshing force under working conditions... The meshing force varies periodically with the gear meshing cycle. Therefore, the maximum meshing force of each gear pair under working conditions can be obtained based on the dynamic meshing force curve of each gear pair under working conditions. Additionally, in Figure 4... This represents the nominal value of the gear pair meshing force under working conditions. , This indicates the torque borne by the pinion in the gear pair. This indicates the pitch circle diameter of the pinion.

[0106] Additionally, as shown in Figure 5, in step S4, the process of calculating the maximum meshing force of the gear pair under the life-limited state includes the following:

[0107] Step S41: Calculate the maximum number of contact stress cycles based on the given gear contact fatigue life;

[0108] Step S42: Find the corresponding maximum stress amplitude in the stress-life curve of the material based on the maximum number of contact stress cycles;

[0109] Step S43: Calculate the maximum contact stress on the tooth surface based on the maximum stress amplitude;

[0110] Step S44: Calculate the maximum meshing force of the gear pair under the life-limited state based on the maximum contact stress on the tooth surface.

[0111] Specifically, gear life includes contact fatigue life L H and bending fatigue life L F This application uses contact fatigue life to set the life limit state. Since teeth in meshing have dynamic contact stress on their tooth surfaces, while teeth not in mesh do not, this application considers the variation law of the dynamic contact stress on the tooth surface as a pulsating cycle, as shown in Figure 6. Indicates stress amplitude, , , This represents the maximum and minimum values ​​of the tooth surface contact stress. , Considering the contact fatigue safety factor, the stress amplitude acting on the gear teeth is: , This indicates the stress amplitude acting on the gear teeth. This indicates the contact fatigue safety factor.

[0112] Therefore, given the gear contact fatigue life L H Then, it can be based on the formula: The maximum number of contact stress cycles was calculated. , Indicates the number of teeth on the gear. This indicates the gear speed.

[0113] Then, since the contact fatigue limit and stress-life curve (i.e., SN curve) of the material are measured under pulsating cyclic conditions, the maximum stress amplitude can be directly found in the SN curve of the material based on the maximum number of contact stress cycles. The maximum contact stress on the tooth surface is then calculated based on the following formula:

[0114] ;

[0115] in, This indicates the maximum contact stress on the tooth surface. This represents the maximum stress amplitude acting on the gear teeth. This indicates the contact fatigue safety factor.

[0116] Finally, according to the conversion relationship between gear contact stress and dynamic meshing force in the national standard: The maximum contact stress on the tooth surface can then be calculated based on the following formula: , This represents the maximum meshing force of the gear pair under life-limited conditions. This represents the single-pair meshing coefficient of the pinion in a gear pair. Represents the coefficient of the node region. Represents the elastic coefficient. This represents the overlap factor used in contact strength calculations. This represents the helix angle factor used in contact strength calculations. Indicates the use of coefficients, Indicates the dynamic load factor. This represents the tooth load distribution factor used in contact strength calculations. This represents the inter-tooth load distribution coefficient used in contact strength calculations. Indicates tooth width. This indicates the ratio of the number of teeth between the large gear and the small gear in a gear pair. This indicates the pitch circle diameter of the pinion.

[0117] In addition, in step S5, the dynamic meshing force of each gear pair under working conditions is corrected based on the following formula:

[0118] ;

[0119] in, This represents the dynamic meshing force of each gear pair under life-limited conditions. This represents the dynamic meshing force of each gear pair under working conditions. This indicates the maximum meshing force of the gear pair under working conditions. This represents the maximum meshing force of the gear pair under life-limited conditions. Additionally, the dynamic meshing force curve of a certain gear pair under life-limited conditions is shown in Figure 7.

[0120] It is understood that this application corrects the dynamic meshing force of the gear pair under working conditions based on the ratio between the maximum meshing force of the gear pair under the life-limited state and the maximum meshing force of the gear pair under the working state. This allows for the accurate determination of the dynamic meshing force of the gear pair under the life-limited state, providing an accurate data basis for the subsequent vibration limit value determination process.

[0121] In addition, in step S6, a force analysis is performed based on the gear support structure, which can be based on the dynamic meshing force of each gear pair under the life-limited state. Obtain the dynamic support reaction force of the corresponding support bearing under the life-limited state. Then, a transient dynamic analysis model of the gearbox casing was established using finite element software such as ANSYS, and dynamic support reactions of the bearings were applied at the corresponding bearing housing positions. By solving the transient dynamic analysis model, a vibration velocity distribution cloud map or a vibration acceleration distribution cloud map of the gearbox casing can be obtained. The vibration velocity or acceleration corresponding to the vibration measurement point of the gearbox can then be found in the cloud map and used as the vibration velocity limit value or vibration acceleration limit value at that measurement point. The specific force analysis and transient dynamic analysis are existing technologies, and their detailed processes and principles will not be elaborated here.

[0122] In addition, the present invention also provides a vibration limit value calculation system for a gearbox, preferably employing the above-described gearbox vibration limit value calculation method. The gearbox includes a first gear 1, a second gear 2, a third gear 3, a fourth gear 4, a fifth gear 5, and a sixth gear 6. Power is input from the first gear 1, which meshes with the second gear 2 and the third gear 3 on two branches to distribute the power. The second gear 2 transmits power to the fourth gear 4 via a first elastic shaft 7, and the third gear 3 transmits power to the fifth gear 5 via a second elastic shaft 8. Both the fourth gear 4 and the fifth gear 5 mesh with the sixth gear 6, which then outputs the combined power. Each gear includes two helical gears with opposite helix angles, connected by a shaft segment. As shown in Figure 8, the gearbox vibration limit value calculation system includes:

[0123] The design parameter setting module is used to determine the design parameters of the gearbox.

[0124] The dynamics solution module is used to construct the dynamic model of the gearbox based on the design parameters using the lumped parameter method, and to solve the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions.

[0125] The first calculation module is used to calculate the dynamic meshing force of each gear pair under working conditions based on the torsional vibration angular displacement of each gear, and to obtain the maximum value of the gear pair meshing force under working conditions.

[0126] The second calculation module is used to calculate the maximum meshing force of the gear pair under the life-limited state.

[0127] The third calculation module is used to correct the dynamic meshing force of each gear pair in the working state based on the maximum meshing force of the gear pair under the life-limited state and the maximum meshing force of the gear pair in the working state, so as to obtain the dynamic meshing force of each gear pair under the life-limited state.

[0128] The vibration limit value determination module is used to determine the vibration limit value at the gearbox vibration measurement point based on the dynamic meshing force of each gear pair under the life limit state.

[0129] It is understood that the gearbox vibration limit calculation system of this embodiment first constructs a dynamic model of the gearbox based on the gearbox design parameters using the lumped parameter method, and solves the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions. Then, based on the torsional vibration angular displacement of each gear, it calculates the dynamic meshing force of each gear pair under working conditions and obtains the maximum value of the gear pair meshing force under working conditions. After calculating the maximum value of the gear pair meshing force under the life-limited state, it corrects the dynamic meshing force of each gear pair under working conditions, thereby obtaining the dynamic meshing force of each gear pair under the life-limited state. Finally, based on the dynamic meshing force of each gear pair under the life-limited state, it determines the vibration limit value at the gearbox vibration measurement point. This system proposes for the first time a theoretical solution path for gearbox vibration limit values. It can determine the vibration limit value at the gearbox vibration measurement point through theoretical calculation, without relying on experimental results or historical data of similar gearboxes, and without relying on human experience. This improves the accuracy and interpretability of setting gearbox vibration limit values, which is beneficial for accurate vibration monitoring of gearboxes.

[0130] In addition, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the method described above by calling the computer program stored in the memory.

[0131] In addition, the present invention provides a computer-readable storage medium for storing a computer program for calculating the vibration limit value of a gearbox, wherein the computer program, when run on a computer, performs the steps of the method described above.

[0132] Common computer-readable storage media include: floppy disks, flexible disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, any other optical media, punch cards, paper tape, any other physical media with perforated patterns, random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), flash erasable programmable read-only memory (FLASH-EPROM), any other memory chips or cartridges, or any other media readable by a computer. Instructions may further be transmitted or received by a transmission medium. The term transmission medium can include any tangible or intangible medium used to store, encode, or carry instructions for execution by a machine, and includes digital or analog carrier communication signals or intangible media that facilitate communication of such instructions. Transmission media include coaxial cables, copper wires, and optical fibers, which contain conductors for transmitting a bus of computer data signals.

[0133] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0134] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0135] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0136] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0137] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0138] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0139] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for calculating the vibration limit value of a gearbox, wherein the gearbox includes a first gear (1), a second gear (2), a third gear (3), a fourth gear (4), a fifth gear (5), and a sixth gear (6). Power is input from the first gear (1), which meshes with the second gear (2) and the third gear (3) on two branches to split and transmit power. The second gear (2) transmits power to the fourth gear (4) through a first elastic shaft (7), and the third gear (3) transmits power to the fifth gear (5) through a second elastic shaft (8). The fourth gear (4) and the fifth gear (5) both mesh with the sixth gear (6), and the sixth gear (6) outputs the combined power. Each gear includes two helical gears with opposite helix angles, and the two helical gears are connected by a shaft segment. The method includes the following: Determine the design parameters of the gearbox; Based on the design parameters, a dynamic model of the gearbox is constructed using the lumped parameter method, and the dynamic model is solved to obtain the torsional vibration angular displacement of each gear under working conditions. The dynamic meshing force of each gear pair under working conditions is calculated based on the torsional vibration angular displacement of each gear, and the maximum meshing force of the gear pair under working conditions is obtained. Calculate the maximum meshing force of the gear pair under the life-limited condition; based on the maximum meshing force of the gear pair under the life-limited condition and the maximum meshing force of the gear pair under the working condition, correct the dynamic meshing force of each gear pair under the working condition to obtain the dynamic meshing force of each gear pair under the life-limited condition; correct the dynamic meshing force of each gear pair under the working condition based on the following formula: ;in, This represents the dynamic meshing force of each gear pair under life-limited conditions. This represents the dynamic meshing force of each gear pair under working conditions. This indicates the maximum meshing force of the gear pair under working conditions. This represents the maximum meshing force of the gear pair under the life-limited condition; the vibration limit value at the gearbox vibration measurement point is determined based on the dynamic meshing force of each gear pair under the life-limited condition.

2. The method for calculating the vibration limit value of a gearbox as described in claim 1, characterized in that, The dynamic model of the gearbox is as follows: ； ； ； ； ； ;in, 、 、 and Let these represent the mass matrix, damping matrix, stiffness matrix, and torsional vibration angular displacement vector, respectively. Represents the excitation force vector. and They represent The first and second derivatives, Represents a diagonal matrix. The polar moment of inertia is represented by the equivalent node located at the geometric center of the helical gear. The subscripts 1L, 2L, 3L, 4L, 5L and 6L represent the left helical gears of the first gear (1), second gear (2), third gear (3), fourth gear (4), fifth gear (5) and sixth gear (6), respectively. The subscripts 1R, 2R, 3R, 4R, 5R and 6R represent the right helical gears of the first gear (1), second gear (2), third gear (3), fourth gear (4), fifth gear (5) and sixth gear (6), respectively. Let represent the polar moment of inertia at the equivalent node at the geometric center of the left helical gear of the first gear (1). Represents the stiffness matrix The meshing stiffness submatrix in the i-th row and j-th column. Represents the stiffness matrix The torsional stiffness submatrix in the i-th row and j-th column, i / j=1,2,3,4,5,6. This represents the angular displacement of the helical gear's torsional vibration about its axis. This indicates the torsional vibration angular displacement of the left helical gear of the first gear (1) about its axis, with the superscript T indicating transpose. and Indicates input torque and output torque. and These represent the base circle radius and helix angle of the helical gear, respectively. and These represent the base circle radius and helix angle of the left helical gear of the first gear (1), respectively. This indicates the meshing stiffness of each gear pair. This represents the overall transmission error of each gear pair. This indicates the meshing damping of each gear pair. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R represent the numbers of each gear pair. The meshing stiffness of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2) is indicated. The combined transmission error of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2) is represented by the following: This indicates the meshing damping of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2). express The first derivative.

3. The method for calculating the vibration limit value of a gearbox as described in claim 1, characterized in that, The dynamic meshing force of each gear pair under working conditions is calculated based on the following formula: ;in, This represents the dynamic meshing force of each gear pair under working conditions. This indicates the relative meshing displacement of each gear pair along its line of meshing. This indicates the meshing stiffness of each gear pair. This indicates the meshing damping of each gear pair. The subscripts 12L, 12R, 13L, 13R, 46L, 46R, 56L, and 56R represent the numbers of each gear pair. The dynamic meshing force of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2) in the working state is represented by the following: The relative meshing displacement along the meshing line direction of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2) is indicated. The meshing stiffness of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2) is indicated. This indicates the meshing damping of the gear pair consisting of the left helical gear of the first gear (1) and the left helical gear of the second gear (2). express The first derivative, Indicates the normal pressure angle of a helical gear. The helix angle of the helical gear is indicated by the subscripts 1L, 4L and 5L, which represent the left helical gears of the first gear (1), the fourth gear (4) and the fifth gear (5) respectively. The subscripts 1R, 4R and 5R represent the right helical gears of the first gear (1), the fourth gear (4) and the fifth gear (5) respectively.

4. The method for calculating the vibration limit value of a gearbox as described in claim 1, characterized in that, The process of calculating the maximum meshing force of the gear pair under the life-limited state includes the following: The maximum number of contact stress cycles is calculated based on the given gear contact fatigue life. Find the corresponding maximum stress amplitude in the stress-life curve of the material based on the maximum number of contact stress cycles. The maximum contact stress on the tooth surface is calculated based on the maximum stress amplitude. The maximum meshing force of the gear pair under life-limited conditions is calculated based on the maximum contact stress on the tooth surface.

5. The method for calculating the vibration limit value of a gearbox as described in claim 4, characterized in that, The maximum contact stress on the tooth surface is calculated based on the following formula: ;in, This indicates the maximum contact stress on the tooth surface. Indicates the maximum stress amplitude. This indicates the contact fatigue safety factor.

6. The method for calculating the vibration limit value of a gearbox as described in claim 1, characterized in that, The design parameters include material parameters, gear parameters, and shaft parameters.

7. A vibration limit calculation system for a gearbox, the gearbox comprising a first gear (1), a second gear (2), a third gear (3), a fourth gear (4), a fifth gear (5), and a sixth gear (6), wherein power is input by the first gear (1), the first gear (1) meshes with the second gear (2) and the third gear (3) on two branches to split and transmit power, the second gear (2) transmits power to the fourth gear (4) through a first elastic shaft (7), the third gear (3) transmits power to the fifth gear (5) through a second elastic shaft (8), the fourth gear (4) and the fifth gear (5) both mesh with the sixth gear (6), and the sixth gear (6) outputs the combined power, each gear comprising two helical gears with opposite helix angles, the two helical gears being connected by a shaft segment, characterized in that, The system includes: a design parameter setting module for determining the design parameters of the gearbox; a dynamics solution module for constructing a dynamic model of the gearbox based on the design parameters using the lumped parameter method, and solving the dynamic model to obtain the torsional vibration angular displacement of each gear under working conditions; a first calculation module for calculating the dynamic meshing force of each gear pair under working conditions based on the torsional vibration angular displacement of each gear, and obtaining the maximum value of the gear pair meshing force under working conditions; a second calculation module for calculating the maximum value of the gear pair meshing force under life-limited conditions; and a third calculation module for correcting the dynamic meshing force of each gear pair under working conditions based on the maximum value of the gear pair meshing force under life-limited conditions and the maximum value of the gear pair meshing force under working conditions, obtaining the dynamic meshing force of each gear pair under life-limited conditions; the dynamic meshing force of each gear pair under working conditions is corrected based on the following formula: ;in, This represents the dynamic meshing force of each gear pair under life-limited conditions. This represents the dynamic meshing force of each gear pair under working conditions. This indicates the maximum meshing force of the gear pair under working conditions. This indicates the maximum meshing force of the gear pair under life-limited conditions; the vibration limit value determination module is used to determine the vibration limit value at the gearbox vibration measurement point based on the dynamic meshing force of each gear pair under life-limited conditions.

8. An electronic device, characterized in that, The method includes a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the method as described in any one of claims 1 to 6 by calling the computer program stored in the memory.

9. A computer-readable storage medium for storing a computer program that calculates vibration limit values ​​for a gearbox, characterized in that, The computer program, when run on a computer, performs the steps of the method as described in any one of claims 1 to 6.

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