Gear fault simulation method and system based on complex transmission rigid-flexible coupling model

Abstract

The invention discloses a gear fault simulation method and system based on a complex transmission rigid-flexible coupling model, and the method comprises the steps: considering the time-varying meshing stiffness, transmission error, meshing impact and other nonlinear factors of a gear, and meanwhile, considering the flexible deformation analysis of a weak-stiffness member, and building a rigid-flexible coupling model of a complex gear transmission system; time-varying meshing stiffness of gear meshing in different fault states is calculated according to an energy method, and gear fault meshing force in different fault types is calculated according to the lumped parameter model of the fault gear; different types of gear faults are described by implanting different fault meshing forces into a gear meshing pair of the rigid-flexible coupling model of the complex gear transmission system; and solving the rigid-flexible coupling model after the fault is implanted to obtain a vibration signal calculation result of the rigid-flexible coupling complex gear transmission system containing the gear fault, so that simulation of the gear fault in the complex gear transmission system is realized, and support is provided for fault diagnosis of the complex gear transmission system.

Description

Technical Field

[0001] The present invention belongs to the field of complex transmission gear transmission system fault simulation, and in particular relates to a gear fault simulation method and system based on a complex transmission rigid-flexible coupling model. Background Art

[0002] In the past 20 years, as gear transmission systems have developed towards high power density, high precision, low vibration, and high reliability, the transmission load and design size of complex gear transmission systems have been further increased. Complex gear transmission systems have the advantages of large transmission ratio and strong load-bearing capacity, so they are widely used in the transmission systems of wind turbines, helicopters, heavy vehicles and other equipment. As a key functional component, it is very important to ensure the reliability of complex gear transmission systems under complex working conditions. In actual engineering, the operating conditions of equipment are often complex and diverse, and effective actual operating data is difficult to obtain. Therefore, in order to ensure the safe and stable operation of mechanical equipment, timely detect faults and realize fault diagnosis so as to formulate corresponding maintenance strategies, it is very critical to accurately conduct dynamic performance research, fault simulation and fault diagnosis research of complex gear transmission systems.

[0003] At present, some achievements have been made in the research on gear fault simulation in transmission system, but generally speaking, there are still the following deficiencies:

[0004] The traditional gear transmission system lumped parameter dynamic model has certain limitations in establishing the model of complex systems, and it is difficult to fully describe the dynamic characteristics of complex gear transmission systems. The finite element model considers a large number of degrees of freedom and can accurately calculate the dynamic characteristics of the gear transmission system, but the processing process is complex, the amount of calculation is large, and the requirements for computer hardware and software are high. Most of the existing gear transmission system fault simulation research is based on lumped parameter models or finite element models, but the models established by the lumped parameter method and the finite element method are mostly simple models, and there are still deficiencies in the fault simulation of complex gear transmission systems; the pure rigid multi-body dynamic model of the complex gear transmission system ignores the flexible deformation of the weak rigidity components in the system. The flexible deformation of the components directly affects the dynamic characteristics of the system as the internal excitation of the planetary gear transmission system, and then affects the accuracy of the gear fault simulation results, which is not conducive to the accurate diagnosis of the fault. Most of the existing gear transmission system multi-body dynamic models are not accurate or have low computational efficiency. To study the fault simulation of multi-stage complex gear transmission systems and improve the calculation accuracy of the dynamic response under the fault state, it is necessary to consider the flexible deformation of the components in the working state of the gear transmission system; on the other hand, the flexible deformation provides more modal information for the components, and the calculation and analysis time will also be greatly increased.

[0005] Therefore, there is an urgent need for a method that can simulate faults in complex gear transmission systems and at the same time guarantee the accuracy and computational efficiency of simulation results to a certain extent. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a gear fault simulation method based on a rigid-flexible coupling model of a complex transmission system in response to the above-mentioned deficiencies in the prior art, so as to solve the technical problems that fault data of a complex gear transmission system in actual equipment operation is difficult to obtain, and at the same time, the fault simulation accuracy is not high and the simulation calculation efficiency is low; a rigid-flexible coupling model of a complex gear transmission system is established, the flexibility of weak-rigidity components is taken into account, and the fault meshing forces when gear faults such as broken teeth, tooth root cracks and tooth surface peeling occur are calculated, and the fault meshing forces are respectively implanted into the rigid-flexible coupling model of the complex gear transmission system.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a gear fault simulation method based on a complex transmission rigid-flexible coupling model, comprising the following steps:

[0008] According to the two-dimensional topological structure diagram of the complex transmission gear transmission system and the principle of multi-body dynamics, the pure rigid body model of the complex gear transmission system is established by applying bearing force elements and gear force elements to describe the kinematic pairs between components, considering nonlinear factors including gear time-varying meshing stiffness, transmission error and meshing impact;

[0009] According to the load distribution in the actual working of the gear transmission system and the finite element substructure reduction theory, the gear shaft, gear ring and housing that are prone to deformation are treated flexibly;

[0010] According to the structure and force relationship between the various components of the gear transmission system, the flexible gear shaft, gear ring and housing are coupled with the pure rigid body model of the complex gear transmission system through hinge points and force elements, so as to establish a rigid-flexible coupling dynamic model of a trouble-free complex gear transmission system.

[0011] The time-varying mesh stiffness of the gear mesh in the healthy state and the faulty state is calculated according to the energy method;

[0012] A translation-torsion coupling dynamic model of gear meshing is established according to a lumped parameter method, and the gear fault meshing force under different fault types is calculated by using the translation-torsion coupling dynamic model and the time-varying meshing stiffness;

[0013] The gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling dynamic model of the complex gear transmission system to describe different types of gear faults.

[0014] The input torque is set at the input end of the rigid-flexible coupling dynamic model after the fault is implanted to simulate the power input of the motor, and the torsional damping is set at the output end to describe the load condition of the transmission gear transmission system. The dynamic simulation model is solved to obtain the vibration signal calculation results of the rigid-flexible coupling complex gear transmission system containing gear faults, thereby realizing the simulation analysis of gear faults in complex gear transmission systems.

[0015] Furthermore, according to the structure of the complex transmission system, the kinematic pair relationship between the components is analyzed and a two-dimensional topological structure diagram of the complex transmission gear transmission system is drawn.

[0016] Furthermore, the rigid-flexible coupling dynamic model of the complex gear transmission system established includes: a set of compound planetary gear trains, a set of bevel gears, multiple sets of parallel axis gear transmissions, and bearing and gear transmission system models.

[0017] Furthermore, the rigid-flexible coupling dynamic model of the complex gear transmission system is established in the multi-body dynamics simulation software SIMPACK according to the principle of relative coordinate system;

[0018] Among them, the geometric models of gears at all levels in the rigid-flexible coupling dynamic model of the complex gear transmission system are all modeled parametrically. The meshing between gears is simulated by FE225 force element. FE225 force element takes into account many nonlinear factors, including tooth side clearance, time-varying meshing stiffness, and time-varying transmission error. The gears are fixedly hinged to the transmission shaft and rotate with the shaft. The transmission shaft and the housing are connected by bearings. The transmission shaft and the housing are simulated by FE186 force element. FE186 force element applies springs, damping and torque in multiple directions of the shaft, including axial translation, radial translation, axial torsion and tilt torsion between two marked points.

[0019] Furthermore, in the established rigid-flexible coupling dynamic model, the flexible bodies include: a large ring gear of a compound planetary gear train, a small ring gear of a compound planetary gear train, a transmission main shaft of a compound planetary gear train, a transmission shaft at the input end, and a box;

[0020] In the rigid-flexible coupling dynamics model, the flexible body is created according to the finite element substructure modal reduction method, and the Craig-Bampton component modal synthesis method is used to convert the overall mass matrix M generated by the finite element method into g and the stiffness matrix K g Transformed into reduced mass and stiffness matrices, respectively M r and K r , retain the first k-order modes, and the undamped free vibration equation corresponding to the flexible body is:

[0021]

[0022] in:

[0023]

[0024] In the formula, x b and x i are the generalized displacements of the master node and slave node that retain the first k modes, X g is the generalized displacement of the nodes of the overall finite element model, χ is the modal matrix, recorded as:

[0025]

[0026] Among them Ψ i k is the interface modal matrix, is the constraint mode matrix, I is the identity matrix,

[0027] The reduced flexible body is coupled with the rigid body model of other components, and finally a rigid-flexible coupling model of the complex gear transmission system is established. According to the Lagrangian principle, the rigid-flexible coupling dynamic equation of the system is obtained as follows:

[0028]

[0029] Where: L is the system generalized coordinate kinetic energy, ξ is the system generalized coordinate, Γ is the energy loss function, Φ is the system constraint function, λ is the Lagrangian multiplier corresponding to the system constraint equation, Q is the projection of the generalized force on Φ,

[0030] According to the above principles, the rigid-flexible coupling dynamics model of the complex gear transmission system is established in the multi-body dynamics software SIMPACK.

[0031] Furthermore, gear failure types include gear tooth breakage, tooth root cracks, and tooth surface spalling.

[0032] Furthermore, when calculating the time-varying mesh stiffness of gear meshing in healthy state and fault state respectively according to the energy method, the time-varying mesh stiffness of gear under three fault forms of gear broken tooth, tooth root crack and tooth surface spalling is first calculated by analytical energy method, and then verified by finite element method;

[0033] According to the verified time-varying meshing stiffness of the gear, the dynamic meshing force F of the gear pair with fault is obtained as:

[0034]

[0035] Among them, k i is the time-varying meshing stiffness of the i-th pair of teeth in the gear pair, c i is the meshing damping coefficient of the i-th pair of teeth in the gear pair, and δ is the dynamic transmission error of the gear pair.

[0036] Furthermore, the gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling model of the complex gear transmission system. When describing different types of gear faults, the calculated fault meshing force is applied to the meshing line of the faulty gear in the rigid-flexible coupling model of the overall complex gear transmission system. The meshing force containing different fault forms is applied to the gear meshing line to complete the modeling of different types of gear faults.

[0037] Furthermore, after the fault implantation is completed, the rigid-flexible coupling model of the complex gear transmission system with different fault types is simulated in the multi-body dynamics software SIMPACK, and the dynamic simulation model is solved according to the SODASRT 2 integration method. The dynamic simulation model realizes simulation analysis under different working conditions by adjusting the transmission relationship of the compound planetary gear system, and finally obtains the vibration signal of the model, thereby realizing the gear fault simulation calculation based on the rigid-flexible coupling model of the complex gear transmission system.

[0038] In addition, a gear fault simulation system based on a complex transmission rigid-flexible coupling model is provided, including a pure rigid body model construction module, a rigid-flexible coupling dynamic model construction module, a time-varying meshing stiffness acquisition module, a gear fault loading module, and an analysis module;

[0039] The pure rigid body model building module is used to establish a pure rigid body model of a complex gear transmission system based on the two-dimensional topological structure diagram of the complex transmission gear transmission system and the principle of multi-body dynamics, by applying bearing force elements and gear force elements to describe the kinematic pairs between components, and considering nonlinear factors including gear time-varying meshing stiffness, transmission error and meshing impact;

[0040] The rigid-flexible coupling dynamic model building module is used to make the gear shaft, gear ring and housing that are prone to deformation flexible according to the load distribution in the actual work of the gear transmission system and the finite element substructure reduction theory; according to the structure and force relationship between the various components of the gear transmission system, the flexible gear shaft, gear ring and housing are coupled with the pure rigid body model of the complex gear transmission system through hinge points and force elements, so as to establish a rigid-flexible coupling dynamic model of a trouble-free complex gear transmission system;

[0041] The time-varying mesh stiffness acquisition module is used to calculate the time-varying mesh stiffness of the gear meshing in a healthy state and a faulty state according to the energy method;

[0042] The gear fault loading module is used to establish a translation-torsion coupling dynamic model of gear meshing according to the lumped parameter method, and calculate the gear fault meshing force under different fault types through the translation-torsion coupling dynamic model and the time-varying meshing stiffness; the gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling dynamic model of the complex gear transmission system to describe different types of gear faults;

[0043] The analysis module is used to set the input torque at the input end of the rigid-flexible coupling dynamic model after the fault is implanted to simulate the power input of the motor, set the torsional damping at the output end to describe the load condition of the transmission gear transmission system, solve the dynamic simulation model, and obtain the vibration signal calculation results of the rigid-flexible coupling complex gear transmission system containing gear faults, so as to realize the simulation analysis of gear faults in complex gear transmission systems.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] The present invention establishes a rigid-flexible coupling model of a complex gear transmission system, taking into account the flexibility of weak-rigidity components, and on the basis of multi-body dynamics, taking into account the influence of various internal excitations and nonlinear factors under the actual operating conditions of the complex gear transmission system, and using the energy method to calculate the time-varying meshing stiffness of the gears under the fault state, and finally calculating the fault meshing force, and implanting the fault meshing force into the rigid-flexible coupling model of the complex system, and finally performing simulation calculations based on the multi-body dynamics software SIMPACK, which can realize the implantation and simulation calculations of different fault forms, and obtain a large amount of dynamic response data containing fault signals, so it is more in line with the needs of fault simulation of complex gear transmission systems;

[0046] Considering that the present invention is based on the flexible body modeling theory and the rigid-flexible coupling dynamics theory, the flexibility of the large ring gear of the compound planetary gear train, the small ring gear of the compound planetary gear train, the transmission main shaft of the compound planetary gear train, the input end transmission shaft and the box body is taken into consideration, and the weak rigidity components that are prone to deformation during the actual operation of the complex gear transmission system are established as flexible bodies, and the remaining components still maintain rigidity, thereby achieving the goal of ensuring the calculation accuracy while improving the calculation efficiency; BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a flow chart of an implementable method of the present invention;

[0048] Figure 2 It is a dynamic model of complex gear transmission system;

[0049] Figure 3 This is a schematic diagram of a gear failure. DETAILED DESCRIPTION

[0050] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0053] The present invention provides a gear fault simulation method based on a complex transmission rigid-flexible coupling model. According to the structure of the complex transmission gear transmission system, the kinematic pair relationship between the components is analyzed and a two-dimensional topological structure diagram of the complex transmission gear transmission system is drawn; based on the two-dimensional topological structure diagram and the principle of multi-body dynamics, the kinematic pairs between the components are described by applying bearing force elements and gear force elements, and a pure rigid body model of the complex gear transmission system is established; based on the load distribution in the actual work of the gear transmission system, the finite element substructure reduction theory is adopted to flexibly process the components that are prone to deformation, such as longer gear shafts, gear rings and housings; according to the structure and force relationship between the components of the gear transmission system, the flexibly processed gear shafts, gear rings and housings are coupled with the pure rigid body model of the complex gear transmission system through hinge points and force elements, so as to establish a fault-free rigid-flexible coupling dynamic model of the complex gear transmission system. According to the energy method, the time-varying meshing stiffness of gear meshing under different fault states is calculated respectively; according to the concentrated parameter method, the translation-torsion coupling dynamic model of gear meshing is established, and the gear fault meshing force under different fault types is calculated through the translation-torsion coupling dynamic model and the time-varying meshing stiffness; the gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling model of the complex gear transmission system to describe different types of gear faults; the input torque is set at the input end of the rigid-flexible coupling model after the fault is implanted to simulate the power input of the motor, and the torsional damping is set at the output end to describe the load condition of the transmission gear transmission system, and the dynamic simulation model is solved to obtain the calculation result of the vibration signal of the rigid-flexible coupling complex gear transmission system containing gear faults, so as to realize the simulation of gear faults in the complex gear transmission system and provide support for the fault diagnosis of the complex gear transmission system.

[0054] The present invention provides a gear fault modeling and simulation method based on a rigid-flexible coupling model of a complex gear transmission system. It considers nonlinear factors such as time-varying meshing stiffness, transmission error, meshing impact, and the flexible deformation of weak-rigidity components. It analyzes and establishes a rigid-flexible coupling model of a complex gear transmission system. The gear fault forms simulated based on the model include broken teeth, tooth root cracks, and tooth surface peeling, providing support for fault diagnosis of complex gear transmission systems and ensuring stable operation of equipment. Figure 1 As shown, the present invention proposes a gear fault modeling and simulation method based on a rigid-flexible coupling model of a complex gear transmission system, comprising the following steps:

[0055] S1, according to the structure of the complex transmission gear transmission system, analyze the kinematic relationship between the components and draw a two-dimensional topological structure diagram of the complex transmission gear transmission system.

[0056] S2, based on the two-dimensional topological structure diagram obtained in S1 and the principle of multi-body dynamics, the kinematic pairs between the components are described by applying bearing force elements and gear force elements, and the dynamics software SIMPACK is used to establish a pure rigid body model of the complex gear transmission system. The model specifically includes the fan drive gear assembly, the input front transmission assembly, the compound planetary gear train and the gear box, etc. The specific model is as follows Figure 2 shown.

[0057] S3, according to the load distribution in the actual operation of the gear transmission system, the finite element substructure reduction theory is used to make the parts that are prone to deformation flexible, such as longer gear shafts, gear rings, and housings. In the rigid-flexible coupling model, the flexible body is created according to the finite element substructure modal reduction method, and the Craig-Bampton component modal synthesis method is used to convert the overall mass matrix M generated by the finite element method into g and the stiffness matrix K g Transformed into reduced mass and stiffness matrices, respectively M r and K r , retain the first k-order modes, and the undamped free vibration equation corresponding to the flexible body is:

[0058]

[0059] S4, the flexible gear shaft, gear ring and housing are coupled with the pure rigid body model through hinge points and force elements to establish a rigid-flexible coupling dynamic model of a trouble-free complex gear transmission system. According to the Lagrangian principle, the rigid-flexible coupling dynamic equation of the complex gear transmission system can be obtained as follows:

[0060]

[0061] The final dynamic equation based on the Lagrange equation is in differential form:

[0062]

[0063] Among them, M, are the mass matrix of the flexible body and its derivative with respect to time, is the time derivative of the generalized coordinates of the flexible body, K is the stiffness matrix in generalized coordinates, f g is the gravity of the multi-body, and D is the damping matrix in generalized coordinates.

[0064] S5, according to the energy method, the time-varying meshing stiffness of the gear meshing in the healthy state and the fault state is calculated respectively, and then the finite element method is used to verify it. There are three types of faults, namely gear tooth breakage, tooth root cracks and tooth surface spalling. The specific fault forms are as follows Figure 3 As shown. The time-varying meshing stiffness k1 of a single pair of gears in a gear pair can be expressed as:

[0065]

[0066] The time-varying meshing stiffness k2 of double-tooth meshing can be expressed as:

[0067]

[0068] Where i represents the i-th gear pair, k h is the Hertzian contact stiffness of the gear, k a1 , k a2 are the axial compression stiffness of gears 1 and 2, respectively, k b1 , k b2 are the bending stiffness of gears 1 and 2, respectively, k f1 , k f2 are the elastic matrix stiffness of gears 1 and 2 respectively.

[0069] S6, according to the lumped parameter method, the translation-torsion coupling dynamic model of gear meshing is established, and the gear fault meshing force under different fault types is calculated by the translation-torsion coupling dynamic model and the gear time-varying meshing stiffness obtained in S2; the dynamic meshing force F of the gear pair with fault is obtained as:

[0070]

[0071] S7, the gear fault meshing force calculated by the analytical method is applied to the meshing line of the faulty gear in the rigid-flexible coupling dynamic model of the overall complex gear transmission system, and the meshing force containing different fault forms is applied to the gear meshing line. Different types of gear faults are described by implanting different fault meshing forces into the gear meshing pair of the rigid-flexible coupling dynamic model of the complex gear transmission system.

[0072] S8, set the input torque at the input end of the rigid-flexible coupling dynamic model after the fault is implanted to simulate the power input of the motor, set the torsional damping at the output end to describe the load condition of the transmission gear transmission system, and simulate the rigid-flexible coupling model of the complex gear transmission system with different fault forms in the multi-body dynamics software SIMPACK. The dynamic simulation model is solved according to the SODASRT 2 integration method. The simulation model realizes simulation analysis under different working conditions by adjusting the transmission relationship of the compound planetary gear system and adjusting the input and output, and finally obtains the vibration signal of the model, thereby realizing the gear fault simulation calculation based on the rigid-flexible coupling model of the complex gear transmission system.

[0073] In summary, the present invention provides a gear fault simulation method based on a complex transmission rigid-flexible coupling model. According to the structure of the complex transmission gear transmission system, based on the topological structure diagram and the principle of multi-body dynamics, the motion pairs between the components are described by applying bearing force elements and gear force elements, and a pure rigid body model of the complex gear transmission system is established; the finite element substructure reduction theory is adopted to make the weak rigidity component flexible and couple it with the remaining rigid body component models through hinge points and force elements, so as to establish a rigid-flexible coupling dynamic model of a fault-free complex gear transmission system. According to the energy method, the time-varying meshing stiffness of the gear meshing under different fault states is calculated respectively; according to the concentrated parameter method, the translation-torsion coupling dynamic model of the gear meshing is established, and the gear fault meshing force under different fault types is calculated through the dynamic model and the gear time-varying meshing stiffness; different types of gear faults are described by implanting different fault meshing forces into the gear meshing pair of the rigid-flexible coupling model of the complex gear transmission system; the rigid-flexible coupling model after the implantation of the fault is solved, and the vibration signal calculation result of the rigid-flexible coupling complex gear transmission system containing the gear fault is obtained, so as to realize the simulation of the gear fault in the complex gear transmission system and provide support for the fault diagnosis of the complex gear transmission system.

[0074] Based on the concept of the method, the present invention can also provide a gear fault simulation system based on a complex transmission rigid-flexible coupling model, including a pure rigid body model construction module, a rigid-flexible coupling dynamics model construction module, a time-varying meshing stiffness acquisition module, a gear fault loading module, and an analysis module;

[0075] The pure rigid body model building module is used to establish a pure rigid body model of a complex gear transmission system based on the two-dimensional topological structure diagram of the complex transmission gear transmission system and the principle of multi-body dynamics, by applying bearing force elements and gear force elements to describe the kinematic pairs between components, and considering nonlinear factors including gear time-varying meshing stiffness, transmission error and meshing impact;

[0076] The rigid-flexible coupling dynamic model building module is used to make the gear shaft, gear ring and housing that are prone to deformation flexible according to the load distribution in the actual work of the gear transmission system and the finite element substructure reduction theory; according to the structure and force relationship between the various components of the gear transmission system, the flexible gear shaft, gear ring and housing are coupled with the pure rigid body model of the complex gear transmission system through hinge points and force elements, so as to establish a rigid-flexible coupling dynamic model of a trouble-free complex gear transmission system;

[0077] The time-varying mesh stiffness acquisition module is used to calculate the time-varying mesh stiffness of the gear meshing in a healthy state and a faulty state according to the energy method;

[0078] The gear fault loading module is used to establish a translation-torsion coupling dynamic model of gear meshing according to the lumped parameter method, and calculate the gear fault meshing force under different fault types through the translation-torsion coupling dynamic model and the time-varying meshing stiffness; the gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling dynamic model of the complex gear transmission system to describe different types of gear faults;

[0079] The analysis module is used to set the input torque at the input end of the rigid-flexible coupling dynamic model after the fault is implanted to simulate the power input of the motor, set the torsional damping at the output end to describe the load condition of the transmission gear transmission system, solve the dynamic simulation model, and obtain the vibration signal calculation results of the rigid-flexible coupling complex gear transmission system containing gear faults, so as to realize the simulation analysis of gear faults in complex gear transmission systems.

[0080] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A gear fault simulation method based on a complex transmission rigid-flexible coupling model, characterized in that: The following steps are involved: According to the two-dimensional topological structure diagram of the complex transmission gear transmission system and the principle of multi-body dynamics, the pure rigid body model of the complex gear transmission system is established by applying bearing force elements and gear force elements to describe the kinematic pairs between components, considering nonlinear factors including gear time-varying meshing stiffness, transmission error and meshing impact; According to the load distribution in the actual working of the gear transmission system and the finite element substructure reduction theory, the gear shaft, gear ring and housing that are prone to deformation are treated flexibly; According to the structure and force relationship between the various components of the gear transmission system, the flexible gear shaft, gear ring and housing are coupled with the pure rigid body model of the complex gear transmission system through hinge points and force elements, so as to establish a rigid-flexible coupling dynamic model of a trouble-free complex gear transmission system. The time-varying mesh stiffness of the gear mesh in the healthy state and the faulty state is calculated according to the energy method; A translation-torsion coupling dynamic model of gear meshing is established according to a lumped parameter method, and the gear fault meshing force under different fault types is calculated by using the translation-torsion coupling dynamic model and the time-varying meshing stiffness; The gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling dynamic model of the complex gear transmission system to describe different types of gear faults. The input torque is set at the input end of the rigid-flexible coupling dynamic model after the fault is implanted to simulate the power input of the motor, and the torsional damping is set at the output end to describe the load condition of the transmission gear transmission system. The dynamic simulation model is solved to obtain the vibration signal calculation results of the rigid-flexible coupling complex gear transmission system containing gear faults, thereby realizing the simulation analysis of gear faults in complex gear transmission systems.

2. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: According to the structure of the complex transmission system, the kinematic pair relationship between the components is analyzed and the two-dimensional topological structure diagram of the complex transmission gear transmission system is drawn.

3. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: The rigid-flexible coupling dynamic model of the complex gear transmission system established includes: a set of compound planetary gear trains, a set of bevel gears, multiple sets of parallel axis gear transmissions, and bearing and gear transmission system models.

4. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: The rigid-flexible coupling dynamic model of the complex gear transmission system is established in the multi-body dynamics simulation software SIMPACK according to the principle of relative coordinate system; Among them, the geometric models of gears at all levels in the rigid-flexible coupling dynamic model of the complex gear transmission system are all modeled parametrically. The meshing between gears is simulated by FE225 force element. FE225 force element takes into account many nonlinear factors, including tooth side clearance, time-varying meshing stiffness, and time-varying transmission error. The gears are fixedly hinged to the transmission shaft and rotate with the shaft. The transmission shaft and the housing are connected by bearings. The transmission shaft and the housing are simulated by FE186 force element. FE186 force element applies springs, damping and torque in multiple directions of the shaft, including axial translation, radial translation, axial torsion and tilt torsion between two marked points.

5. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: In the rigid-flexible coupling dynamic model established, the flexible bodies include: the large ring gear of the compound planetary gear train, the small ring gear of the compound planetary gear train, the main transmission shaft of the compound planetary gear train, the input end transmission shaft and the box; In the rigid-flexible coupling dynamics model, the flexible body is created according to the finite element substructure modal reduction method, and the Craig-Bampton component modal synthesis method is used to convert the overall mass matrix M generated by the finite element method into g and the stiffness matrix K g Transformed into reduced mass and stiffness matrices, M r and K r , retain the first k-order modes, and the undamped free vibration equation corresponding to the flexible body is: in: In the formula, x b and x i are the generalized displacements of the master node and slave node that retain the first k modes, X g is the generalized displacement of the nodes of the overall finite element model, χ is the modal matrix, recorded as: Among them Ψ i k is the interface modal matrix, Ψ c k is the constraint mode matrix, I is the identity matrix, The reduced flexible body is coupled with the rigid body model of other components, and finally a rigid-flexible coupling model of the complex gear transmission system is established. According to the Lagrangian principle, the rigid-flexible coupling dynamic equation of the system is obtained as follows: Where: L is the system generalized coordinate kinetic energy, ξ is the system generalized coordinate, Γ is the energy loss function, Φ is the system constraint function, λ is the Lagrangian multiplier corresponding to the system constraint equation, Q is the projection of the generalized force on Φ, According to the above principles, the rigid-flexible coupling dynamics model of the complex gear transmission system is established in the multi-body dynamics software SIMPACK.

6. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: Gear failure types include gear tooth breakage, tooth root cracks and tooth surface spalling.

7. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: When calculating the time-varying mesh stiffness of gear meshing under healthy state and fault state respectively according to the energy method, the time-varying mesh stiffness of gear under three fault forms of gear broken tooth, tooth root crack and tooth surface spalling is first calculated by analytical energy method, and then verified by finite element method; According to the verified time-varying meshing stiffness of the gear, the dynamic meshing force F of the gear pair with fault is obtained as: Among them, k i is the time-varying meshing stiffness of the i-th pair of teeth in the gear pair, c i is the meshing damping coefficient of the i-th pair of teeth in the gear pair, and δ is the dynamic transmission error of the gear pair.

8. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: The gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling model of the complex gear transmission system. When describing different types of gear faults, the calculated fault meshing force is applied to the meshing line of the faulty gear in the rigid-flexible coupling model of the overall complex gear transmission system. The meshing force containing different fault forms is applied to the gear meshing line to complete the modeling of different types of gear faults.

9. The gear fault simulation method based on the complex transmission rigid-flexible coupling model according to claim 1 is characterized in that: After the fault implantation is completed, the rigid-flexible coupling model of the complex gear transmission system with different fault types is simulated in the multi-body dynamics software SIMPACK. The dynamic simulation model is solved according to the SODASRT 2 integration method. The dynamic simulation model realizes simulation analysis under different working conditions by adjusting the transmission relationship of the compound planetary gear system. Finally, the vibration signal of the model is obtained, thereby realizing the gear fault simulation calculation based on the rigid-flexible coupling model of the complex gear transmission system.

10. A gear fault simulation system based on a rigid-flexible coupling model of a complex transmission system, characterized in that: It includes a pure rigid body model building module, a rigid-flexible coupling dynamic model building module, a time-varying meshing stiffness acquisition module, a gear fault loading module, and an analysis module; The pure rigid body model building module is used to establish a pure rigid body model of a complex gear transmission system based on the two-dimensional topological structure diagram of the complex transmission gear transmission system and the principle of multi-body dynamics, by applying bearing force elements and gear force elements to describe the kinematic pairs between components, and considering nonlinear factors including gear time-varying meshing stiffness, transmission error and meshing impact; The rigid-flexible coupling dynamic model building module is used to make the gear shaft, gear ring and housing that are prone to deformation flexible according to the load distribution in the actual work of the gear transmission system and the finite element substructure reduction theory; according to the structure and force relationship between the various components of the gear transmission system, the flexible gear shaft, gear ring and housing are coupled with the pure rigid body model of the complex gear transmission system through hinge points and force elements, so as to establish a rigid-flexible coupling dynamic model of a trouble-free complex gear transmission system; The time-varying mesh stiffness acquisition module is used to calculate the time-varying mesh stiffness of the gear meshing in a healthy state and a faulty state according to the energy method; The gear fault loading module is used to establish a translation-torsion coupling dynamic model of gear meshing according to a lumped parameter method, and calculate the gear fault meshing force under different fault types through the translation-torsion coupling dynamic model and the time-varying meshing stiffness; The gear fault meshing force under different fault types is implanted into the gear meshing pair of the rigid-flexible coupling dynamic model of the complex gear transmission system to describe different types of gear faults. The analysis module is used to set the input torque at the input end of the rigid-flexible coupling dynamic model after the fault is implanted to simulate the power input of the motor, set the torsional damping at the output end to describe the load condition of the transmission gear transmission system, solve the dynamic simulation model, and obtain the vibration signal calculation results of the rigid-flexible coupling complex gear transmission system containing gear faults, so as to realize the simulation analysis of gear faults in complex gear transmission systems.

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