A high-efficiency and high-precision modeling method for contact analysis of face gear split-torque transmission structure

Abstract

This invention discloses a high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures, belonging to the field of aerospace technology. The method includes: dividing the gear structure and solving to obtain the coordinates of all nodes on the numerical tooth surface of the face gear pair; based on the coordinates of all nodes on the numerical tooth surface, introducing the axial installation error, shaft intersection error, and axis offset error of the face gear, establishing a structural mesh model of the face gear torque transmission system; defining contact pair relationships and boundary conditions on the structural mesh model; and performing convergence calculations on the structural mesh model based on the defined contact pairs and boundary conditions to complete the face gear contact analysis. By constructing a local tooth segment model structure of the meshing region between the face gear and the cylindrical gear in the face gear pair to replace the full tooth model structure for finite element contact analysis, the computational efficiency is improved, effectively avoiding the problem of high workload and low efficiency in contact analysis due to the large number of finite element meshes in the face gear torque transmission system.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, and specifically relates to a high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures. Background Technology

[0002] The face gear torque splitting transmission configuration combines the advantages of face gears and torque splitting transmission configurations, featuring high transmission ratio, compact structure, and light weight. It can greatly reduce the size and weight of the transmission system while meeting the requirements of high power-to-weight ratio, high torque, and high reduction ratio of helicopter main gearboxes.

[0003] However, in practical applications, the face gear torque split transmission configuration deviates from the ideal meshing position due to manufacturing errors, installation errors, structural deformation, bearing stiffness, and configuration arrangement. This weakens the strength and reliability of the gear teeth and also causes uneven load distribution and vibration noise in the various branches of the torque split transmission system. Tooth surface contact marks can effectively reflect the meshing state of the gear pair and the relative positional relationship of each branch gear pair. During the application verification of the face gear torque split transmission system's main reducer, inconsistencies in the position and size of the tooth surface marks on the upper and lower face gears were observed, reflecting different relative installation errors between the face gear and the cylindrical gear at each meshing point. Therefore, it is necessary to conduct contact mark analysis of the face gear torque split transmission system, study the optimization design of face gear pair contact marks and meshing performance, and develop differentiated profile modification design methods for each face gear pair to obtain good meshing marks for each face gear pair in the face gear torque split transmission system, ensuring that the transmission system has good load-sharing performance, strength level, and reliability.

[0004] The conventional method for gear modeling involves calculating a series of discrete points on the tooth surface of the face gear based on the tooth surface equation. These discrete points are then imported into 3D design software to obtain a 3D model of the gear. This 3D model is then imported into ABAQUS (a general-purpose finite element analysis software) for mesh generation, resulting in a meshed finite element model of the face gear. This is a relatively simple modeling method. However, due to the significant human intervention involved in data exchange between different software programs, it can lead to a loss of tooth surface accuracy. When designing multiple sets of parameters, it requires substantial manual labor. Therefore, parametric automatic mesh generation technology is essential.

[0005] Furthermore, the most researched modeling method in current technology is the parametric finite element automatic modeling of involute cylindrical gears. However, due to the simplicity of the involute equation, it is generally written out using the built-in language of finite element analysis software to generate a series of discrete nodes, and then other nodes are obtained through interpolation to generate a mesh model. But the tooth surface equation of face gears is complex and not easy to solve, so the existing methods for generating cylindrical gear mesh models cannot be completely applied. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures, the method comprising: The numerical coordinates of all nodes on the tooth surface of the face gear pair are obtained by dividing the gear structure and solving the problem. Based on the coordinates of all nodes on the numerical tooth surface, the axial installation error, shaft intersection error, and axis offset error of the face gear are introduced to establish a structural mesh model of the face gear torque transmission system. Contact pair relationships and boundary conditions are defined on the structural mesh model. Based on the defined contact pairs and boundary conditions, convergence calculations are performed on the structural mesh model to complete the face gear contact analysis.

[0007] Furthermore, by dividing the gear structure and solving, the numerical coordinates of all nodes on the tooth surface of the face gear pair are obtained, including: The gear end face is divided into the working tooth surface region, the transition curved surface region, and the gear body region; Obtain the coordinates of several structural points on the gear end face after division; Points are set on each side of the face gear to determine the node distribution on each side; Based on the coordinates of the structural points and the distribution of points on each side, the numerical coordinates of all nodes on the tooth surface of the generated face gear pair are solved using a linear interpolation algorithm.

[0008] Furthermore, the structural mesh model of the face gear torque transmission system is established, including: Based on the coordinates of all nodes on the numerical tooth surface, a local tooth segment model structure is constructed for the meshing region between the face gear and the cylindrical gear in the face gear pair. Determine the included angle between the meshing tooth grooves of the face gear and the cylindrical gear in the local tooth segment model structure respectively; The phase condition of the cylindrical gear in the face gear torque transmission system is determined based on the included angle. Based on the aforementioned phase conditions, the axial installation error, shaft intersection error, and axis offset error of the face gear are introduced to establish a structural mesh model of the face gear torque transmission system.

[0009] Furthermore, establishing a structural mesh model of a face gear torque transmission system also includes the step of selecting analysis elements, including: First-order elements are selected as the basic element type for finite element analysis. The first-order element is an eight-node linear hexahedral element.

[0010] Furthermore, the contact pair relationships defined on the structural mesh model include: The contact type, interaction properties, and master-slave relationship between the face gear and the cylindrical gear.

[0011] Furthermore, the boundary conditions defined on the structural mesh model include: Rigid reference points are established on the rotation axes of the face gear and the cylindrical gear, respectively, and each rigid reference point contains multiple degrees of freedom of motion. The rigid reference points of the face gear and the cylindrical gear are coupled to generate coupling reference points for the face gear and the cylindrical gear respectively. The torque and angular displacement of the face gear torque transmission system are applied based on the coupling reference point.

[0012] Furthermore, generating the coupling reference point for the face gear pair also includes a step of convergent solution for the contact process between the face gear and the cylindrical gear, including: Fix multiple degrees of freedom of motion of the rigid reference point of the cylindrical gear, release the axial rotational degree of freedom of the rigid reference point of the face gear and fix the remaining degrees of freedom, and apply an initial torque; The torque applied to the face gear is gradually increased to the full load condition, while keeping other boundary conditions unchanged; Release the axial rotational degree of freedom of the cylindrical gear and apply a preset angular displacement load until a convergent solution is obtained.

[0013] Furthermore, the face gear includes a first face gear and a second face gear, and the cylindrical gear includes an input cylindrical gear, an idler gear, and a tail-drive cylindrical gear. The convergence calculation of the structural mesh model based on the defined contact pairs and boundary conditions includes: Apply angular displacement to the first and second face gears, input the cylindrical gear, idler gear, and tail drive cylindrical gear as constraint states, and establish the face gear contact pair; Constraints are applied to the first and second face gears. The input cylindrical gear, idler gear, and tail drive cylindrical gear are in a constrained state. A contact pair is established between the input cylindrical gear and the first and second face gears. Small and medium loads were applied to the first gear face, and the rotational constraint of the second gear face was released. The input cylindrical gear was rotated and loaded, while the idler gear and the tail gear were in a released rotational state. The establishment of the contact pair of the finite element analysis model of the gear face was tested. Elastic support and load are applied to the first gear, the rotational constraint is released from the second gear, the rated torque is applied to the input cylindrical gear, and the idler gear and the tail gear are released from their constraints.

[0014] In this embodiment of the invention, a high-efficiency and high-precision modeling system for contact analysis of face gear torque transmission structures is also provided. The system includes: a solution unit, a construction unit, and a convergence unit. The solver element is configured to divide the gear structure and solve for the numerical coordinates of all nodes on the tooth surface of the face gear pair; The building unit is configured to be based on the coordinate points of all nodes of the numerical tooth surface, and the axial installation error, shaft intersection error and axis offset error of the face gear are introduced to establish the structural mesh model of the face gear torque transmission system; The convergence unit is configured to define contact pair relationships and boundary conditions on the structural mesh model, and perform convergence calculations on the structural mesh model based on the defined contact pairs and boundary conditions to complete the face gear contact analysis.

[0015] In this embodiment of the invention, a computer storage medium is also provided, the computer storage medium storing one or more instructions, which, when executed by one or more computers, cause the one or more computers to perform the method described in this invention.

[0016] Compared with the prior art, the present invention has the following advantages: This invention presents a high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures. It constructs a local tooth segment model structure in the meshing region between the face gear and the cylindrical gear in a face gear pair to replace the full tooth model structure for finite element contact analysis, improving computational efficiency and effectively avoiding the problem of high workload and low efficiency due to the large number of finite element meshes in face gear torque transmission systems. It enables contact analysis of face gear torque transmission systems, allowing for the study of contact imprints and meshing performance optimization design of face gear pairs, as well as differentiated profile design methods for each face gear pair, to obtain good meshing imprints for each face gear pair in the face gear torque transmission system. Based on the characteristics of face gear torque transmission systems with multiple transmission branches that influence and couple with each other, a parametric finite element modeling method for contact analysis of face gear torque transmission systems is formed, considering the influence of system structural deformation, installation errors, and machining errors. Furthermore, when the face gear tooth surface parameters change, the contact analysis model can be quickly modified, improving analysis efficiency.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This invention illustrates a flowchart of a high-efficiency and high-precision modeling method for contact analysis of a face gear torque transmission structure according to an embodiment of the present invention. Figure 2 This diagram illustrates the Inp file modeling process of the five-tooth finite element model in an embodiment of the present invention. Figure 3 A schematic diagram of the structured mesh division of the gear end face in an embodiment of the present invention is shown; Figure 4 A schematic diagram of a five-tooth mesh model of a face gear transmission in an embodiment of the present invention is shown; Figure 5 A schematic diagram of the coupling method of the face gear pair in an embodiment of the present invention is shown; Figure 6(a) shows a schematic diagram of the installation between the face gear structure and the five-tooth model in an embodiment of the present invention; Figure 6(b) shows a schematic diagram of the installation between the cylindrical gear structure and the five-tooth model in an embodiment of the present invention; Figure 7 A schematic diagram of the finite element mesh model of the face gear torque splitting transmission system in an embodiment of the present invention is shown; Figure 8(a) shows a schematic diagram of the elastic support of the first gear finite element model in an embodiment of the present invention; Figure 8(b) shows a schematic diagram of the elastic support of the second-face gear finite element model in an embodiment of the present invention; Figure 8(c) shows a schematic diagram of the elastic support of the input cylindrical gear finite element model in an embodiment of the present invention; Figure 8(d) shows a schematic diagram of the elastic support of the idler wheel finite element model in an embodiment of the present invention; Figure 8(e) shows a schematic diagram of the elastic support of the tail-drive cylindrical gear finite element model in an embodiment of the present invention; Figure 9 A schematic diagram of the input torque and input rotation angle of the finite element model of the face gear torque splitting transmission system in an embodiment of the present invention is shown; Figure 10 A schematic diagram of the high-efficiency and high-precision modeling system for contact analysis of face gear torque transmission structure in an embodiment of the present invention is shown.

[0020] In the diagram: 1. Face gear; 2. Cylindrical gear; 3. Cylindrical gear coupling surface; 4. Face gear coupling surface; 5. Tooth groove; 6. Dense grid; 7. Sparse grid; 8. First face gear; 9. Second face gear; 10. First input cylindrical gear; 11. Second input cylindrical gear; 12. First idler gear; 13. Second idler gear; 14. Tail drive cylindrical gear. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Based on the characteristics of multi-branch transmission and mutual influence and coupling in face gear torque transmission systems, this invention proposes a high-efficiency and high-precision finite element modeling method for contact analysis of face gear torque transmission structures, taking into account the effects of system structural deformation, installation errors, and machining errors. This lays the foundation for contact imprint analysis of face gear torque transmission systems.

[0023] This invention provides a parametric finite element modeling method for contact analysis of face gear torque transmission. Based on the M-language of Matlab software, a program is written to solve for the numerical tooth surface coordinates of the face gear pair. The gear teeth are structurally divided to obtain the coordinates of several structural points on the end face. Linear interpolation is performed based on the edge point distribution to obtain the coordinates of all nodes on the gear tooth structure. Parametric finite element automatic modeling is then performed using the numerical tooth surface coordinates and the INP file in ABAQUS. Different finite element models can be obtained by modifying the face gear pair design parameters in the program, and the mesh density of the finite element model can be controlled by controlling the number of interpolation points. Furthermore, based on the assembly coordinate system, the axial error, shaft intersection angle error, and axis offset error of the face gear are introduced. Through coordinate transformation, the coordinates of all nodes of the face gear pair are transferred to the global coordinate system of the finite element analysis. Based on the gear pair meshing angle obtained from Tooth Contact Analysis (TCA), the face gear pair is precisely assembled.

[0024] Due to the large number of finite element meshes in the face gear torque transmission system, the contact analysis workload is enormous. In order to achieve rapid modeling of finite element models of face gear pairs with different profile parameters, this embodiment of the invention uses a five-tooth model structure instead of a full-tooth model structure for finite element contact analysis. A parameterized tooth mesh generation program is established based on the face gear pair tooth surface equation, which can quickly generate five-tooth pair finite element meshes under arbitrary profile conditions.

[0025] In this embodiment of the invention, a face gear pair refers to a gear pair consisting of a face gear and a cylindrical gear meshing with it. The face gear includes a first face gear and a second face gear, and the cylindrical gear includes an input cylindrical gear, an idler gear, and a tail gear.

[0026] Optionally, the overlap ratio of the face gear pair is approximately 1.5 to 3.0, generally not exceeding 3.0. The five-pair tooth finite element model established in this embodiment of the invention can realize the calculation of contact marks. Figure 2 This diagram illustrates the Inp file modeling process of the five-tooth finite element model in an embodiment of the present invention. Figure 2 In this study, a numerical tooth surface solution method for face gears is adopted to obtain a series of discrete points on the tooth surface. Parametric finite element automatic modeling is then performed using the numerical tooth surface point coordinates and the INP file in ABAQUS. The main process is as follows: Establish gear geometry: Using the M-language of Matlab software, a program was written to solve for the numerical coordinates of the tooth surface points of the gear pair. The gear teeth were structurally divided to obtain the coordinates of several structural points on the end face. Based on the distribution of points on the edge, linear interpolation was performed to obtain the coordinates of all nodes on the gear tooth structure.

[0027] Geometric Assembly: Based on the obtained coordinates of all nodes on the gear tooth structure, the axial error, shaft intersection angle error, and axis offset error of the face gear are introduced. Through coordinate transformation, the coordinates of all nodes of the face gear pair are transferred into the global coordinate system of the finite element analysis. Based on the gear pair meshing angle obtained from TCA analysis, the face gear pair is precisely assembled.

[0028] Define material properties, contact pairs, and analysis steps; determine loads and boundary conditions; and perform convergence calculations on the structural mesh model based on the defined material properties, contact pairs, and analysis steps to complete the face gear contact analysis.

[0029] In this embodiment of the invention, based on the format of the INP file, the preprocessing process for finite element analysis can be completed using the obtained node information and material parameters. The entire process is programmed in M ​​language to generate an INP file that can be used in ABAQUS for preprocessing of face gear transmission contact analysis. Different finite element models can be obtained by modifying the face gear pair design parameters in the program, and the mesh density of the finite element model can be controlled by controlling the number of interpolation points.

[0030] Figure 1 A schematic diagram of the high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structure according to an embodiment of the present invention is shown. Figure 1 The method includes: dividing the gear structure to obtain the coordinates of all nodes on the numerical tooth surface of the face gear pair; based on the coordinates of all nodes on the numerical tooth surface, introducing the axial installation error, shaft intersection error, and axis offset error of the face gear, and establishing a structural mesh model of the face gear torque transmission system; defining contact pair relationships and boundary conditions on the structural mesh model, and performing convergence calculation on the structural mesh model based on the defined contact pairs and boundary conditions to complete the face gear contact analysis.

[0031] In this embodiment of the invention, a specific description is given of the contact analysis and modeling method for a face gear torque transmission structure: Step S1: Divide the gear structure and solve to obtain the coordinates of all nodes on the tooth surface of the face gear pair.

[0032] In this embodiment of the invention, the process of dividing the gear structure to obtain the coordinates of all nodes on the tooth surface of the face gear pair includes: dividing the gear end face into a working tooth surface region, a transition surface region, and a wheel body region; obtaining the coordinates of several structural points on the divided gear end face; setting up points on each side of the face gear to determine the node distribution on each side; and generating the coordinates of all nodes on the tooth surface of the face gear pair using a linear interpolation algorithm based on the coordinates of the structural points and the point distribution on each side.

[0033] Specifically, Figure 3 The diagram illustrates a structured mesh division of the gear end face in an embodiment of the present invention. Since the shape of the gear teeth is not suitable for direct structured mesh division, it is necessary to decompose the structure of the gear teeth to determine their coordinates. Figure 3 In the process, the gear teeth are divided into two symmetrical parts along the center of the tooth thickness, and each part is further divided as follows: Figure 3 The diagram shows three parts: part ① is the working tooth surface area, part ② is the transition curved surface area, and part ③ is the wheel body.

[0034] Optionally, in this embodiment of the invention, in order to speed up the calculation, the working tooth surface area and the transition curved surface area are divided into a denser grid by controlling the grid density of the number of seed points on the edge, while the wheel body part is divided into a smaller grid.

[0035] For example, in this embodiment of the invention, a coaxial torsion transmission configuration gear pair is contacted by dividing a relatively dense mesh near the tooth surface. For multi-tooth modeling, it is only necessary to array the nodes of the single-tooth model and then connect the tooth root portion. Figure 4 A schematic diagram of a five-tooth mesh model of a face gear transmission in an embodiment of the present invention is shown. Figure 4 In the middle, the meshing part of the face gear 1 and the cylindrical gear 2 is divided into a denser grid, while the wheel body part near the rotation axis of the face gear 1 and the cylindrical gear 2 is divided into a smaller grid.

[0036] Step S2: Based on the coordinates of all nodes on the numerical tooth surface, introduce the axial installation error, shaft intersection error and axis offset error of the face gear, and establish the structural mesh model of the face gear torque transmission system.

[0037] In this embodiment of the invention, establishing a structural mesh model of the face gear torque transmission system includes: constructing a local tooth segment model structure of the meshing region between the face gear and the cylindrical gear in the face gear pair based on the coordinate points of all nodes on the numerical tooth surface; determining the included angle between the meshing tooth grooves of the face gear and the cylindrical gear in the local tooth segment model structure; determining the phase condition of the cylindrical gear in the face gear torque transmission system according to the included angle; and, based on the phase condition, introducing the axial installation error, shaft intersection angle error, and axis offset error of the face gear to establish a structural mesh model of the face gear torque transmission system.

[0038] It should be noted that, due to the large number of finite element meshes in the face gear torque transmission system, the contact analysis workload is enormous. In order to improve computational efficiency, a five-tooth model structure is used instead of a full-tooth model structure for finite element contact analysis in this embodiment of the invention. Considering the convenience of modeling gears with different parameters, the accuracy of gear pair contact analysis calculation, and the calculation time, the teeth of the face gear and cylindrical gear are separated from the hub.

[0039] Figure 6(a) shows a schematic diagram of the installation between the face gear structure and the five-tooth model in an embodiment of the present invention. For the installation of the face gear five-tooth model, Figure 6(a) shows the included angle of the tooth grooves of the five five-tooth models meshing with the first input cylindrical gear 10, the second input cylindrical gear 11, the first idler gear 12, the second idler gear 13, and the tail drive cylindrical gear 14. This represents the angle between the first input cylindrical gear 10 and the first idler gear 12. This represents the included angle between the first input cylindrical gear 10 and the tail drive cylindrical gear 14. This indicates the angle between the tail drive cylindrical gear 14 and the second idler gear 13. This indicates the angle between the second idler gear 13 and the second input cylindrical gear 11. This represents the angle between the second input cylindrical gear 11 and the first idler gear 12, where XC represents the coordinate in the X direction, YC represents the coordinate in the Y direction, and ZC represents the coordinate in the Z direction. Based on the tooth distribution, the angle between the five tooth slots should be an integer multiple of the angle of a single tooth of the face gear, i.e. In the formula, z is the number of teeth on the face gear. N i It is a positive integer.

[0040] Figure 6(b) shows a schematic diagram of the installation between the cylindrical gear structure and the five-tooth model in an embodiment of the present invention. Regarding the installation of the input cylindrical gear five-tooth model, as shown in Figure 6(b), to ensure the installation of the input cylindrical gear on the face gear, the included angle of the input cylindrical gear is designed to be the same as that on the face gear. and Equal. Since the input cylindrical gear needs to mesh with both the first and second face gears simultaneously, the angle between the meshing ends of the input cylindrical gear and the face gears should be maximized. For example, the angle can be selected based on the number of teeth on the input cylindrical gear. The angle of 5 gear teeth, i.e. Select the included angle The angle of 6 gear teeth, i.e. In the formula, z is the number of teeth of the face gear.

[0041] In this embodiment of the invention, the included angles of the first idler gear 12, the second idler gear 13, the tail gear 14 and the input gear are the same, and will not be described again here.

[0042] Based on the aforementioned five-tooth mesh modeling method for face gears, in this embodiment of the invention, the axial installation error, shaft intersection angle error, and axis offset error of the face gear are introduced based on the phase condition to establish a structural mesh model of the face gear torque transmission system.

[0043] Optionally, in this embodiment of the invention, Matlab software is used to generate a five-tooth mesh model of each gear in the face gear torque transmission system, and the mesh of special structural parts such as cylindrical gears and face gear hubs is divided into structured meshes.

[0044] To save computation time and improve computational efficiency, in this embodiment of the invention, the contact area of ​​the five-tooth model is divided into a denser mesh, while the hub portions of other cylindrical gears and face gears are divided into a sparser mesh. Figure 7 A schematic diagram of the finite element mesh model of the face gear torque splitting transmission system in an embodiment of the present invention is shown. Figure 7 In the model, the contact position of the five-tooth model is divided into a dense mesh (6), while the hub parts of other cylindrical gears and face gears are divided into a sparse mesh (7).

[0045] Optionally, in this embodiment of the invention, establishing the structural mesh model of the face gear torque transmission system further includes the step of selecting analysis elements, including: selecting a first-order element as the basic element type for finite element analysis, wherein the first-order element is an eight-node linear hexahedral element.

[0046] Specifically, ABAQUS uses a simple master-slave contact algorithm: this means that nodes on the slave surface cannot invade any part of the master surface, while the master surface can invade the slave surface between nodes on the slave surface. Because the cylindrical gear material is relatively hard, the cylindrical gear tooth surface is chosen as the master surface, and the face gear tooth surface as the slave surface. Since second-order elements can cause problems in calculating the equivalent load on nodes under uniformly distributed pressure in contact analysis, in this embodiment of the invention, an eight-node linear hexahedral element is selected as the first-order element.

[0047] Step S3: Define contact pair relationships and boundary conditions on the structural mesh model, and perform convergence calculation on the structural mesh model based on the defined contact pairs and boundary conditions to complete the face gear contact analysis.

[0048] Step S31: Define the contact pair.

[0049] In this embodiment of the invention, the contact pair relationships defined on the structural mesh model include: the contact type, interaction attributes, and master-slave relationship between the face gear and the cylindrical gear.

[0050] Specifically, in finite element analysis, contact conditions are a special type of discontinuous constraint. During contact analysis, potential contact pairs must be created on the model. The contact type and interaction properties between contact pairs need to be defined. The interaction between each contact pair consists of two parts: one is the normal interaction between the contact surfaces, which describes the gap between the two contact surfaces; the other is the tangential interaction between the contact surfaces, which describes the relative sliding and possible frictional shear stress between the two contact surfaces. In this embodiment of the invention, the contact between the two tooth surfaces is defined as surface-to-surface contact, the normal behavior is defined as hard contact, allowing contact separation, and the tangential behavior is frictionless.

[0051] For example, when defining a contact pair, the driving and driven relationship between the two gears in the gear pair needs to be determined. Based on the power flow transmission of the face gear torque transmission system, the driving and driven surfaces also need to be preset when defining a contact pair in ABAQUS. The driving and driven surface relationship of the gear pair in the face gear torque transmission system is shown in Table 1. Since system deformation may result in tooth-to-tooth contact, the definition of the tooth groove needs to be clearly defined when defining the driving and driven surfaces.

[0052] Table 1. Definitions of the driving and driven surfaces in the torque distribution system model.

[0053] Step S32: Define boundary conditions.

[0054] In this embodiment of the invention, defining boundary conditions on the structural mesh model includes: establishing rigid reference points on the rotation axes of the face gear and the cylindrical gear, respectively, wherein the rigid reference points contain multiple degrees of freedom; coupling the rigid reference points of the face gear and the cylindrical gear to generate coupling reference points for the face gear and the cylindrical gear, respectively; and applying the torque and angular displacement of the face gear torque transmission system based on the coupling reference points.

[0055] Specifically, in order to apply torque to the model, this embodiment of the invention proposes a method for applying torque to a rigid region, which effectively reduces the degrees of freedom of the finite element model. Figure 5 A schematic diagram of the coupling method of the face gear pair in an embodiment of the present invention is shown. Figure 5 In this design, rigid reference points O1 and O2 are established on the rotation axes of face gear 1 and cylindrical gear 2, respectively. These reference points have six degrees of freedom: X, Y, Z, U1, U2, and U3. The motion of these six degrees of freedom is rigidly coupled to some nodes on the gears. It should be noted that the coupling surface 3 of the cylindrical gear is selected from the inner ring and two side surfaces, with the inner ring being the side closer to the rotation axis. The coupling surface 4 of the face gear is selected from the bottom surface and two side surfaces, with the bottom surface being the side of the face gear away from the cylindrical gear.

[0056] Optionally, in this embodiment of the invention, generating the coupling reference point of the face gear pair further includes a step of convergent solution of the contact process between the face gear and the cylindrical gear, including: fixing multiple kinematic degrees of freedom of the rigid reference point of the cylindrical gear, releasing the axial rotational degree of freedom of the rigid reference point of the face gear and fixing the remaining degrees of freedom, and applying an initial torque; gradually increasing the torque applied to the face gear to the full load condition while keeping other boundary conditions unchanged; releasing the axial rotational degree of freedom of the cylindrical gear and applying a preset angular displacement load until a convergent solution is obtained.

[0057] Specifically, in the contact analysis of the face gear transmission, an angular displacement from engagement to disengagement, obtained through TCA analysis, is applied to the cylindrical gear, while a reverse load torque is applied to the face gear to impede the rotation of the cylindrical gear. During the contact process of the tooth surfaces under load, the solution is not easily converged, requiring multiple analysis steps to progressively apply the angular displacement and load, making convergence easier. This embodiment of the invention includes three analysis steps: Fix six degrees of freedom of the cylindrical gear reference point, release the axial rotational degree of freedom of the face gear reference point, and fix the other degrees of freedom, and apply a small torque to the face gear. Increase the torque applied to the face gear to full load, while keeping other conditions unchanged; Release the axial rotational degree of freedom of the cylindrical gear and apply a designed angular displacement to the cylindrical gear.

[0058] Step S33: Perform convergence calculation on the structural mesh model based on the defined contact pairs and boundary conditions.

[0059] In this embodiment of the invention, when performing finite element simulation analysis, it is necessary to set boundary conditions such as stiffness, constraints, and displacement of the finite element model, and to apply torque and angular displacement based on the created coupling reference points. Figures 8(a)-8(e) show the finite element models of the elastic supports of the first face gear, the second face gear, the input cylindrical gear, the idler gear, and the tail drive cylindrical gear.

[0060] Figure 8(a) shows a schematic diagram of the elastic support of the first face gear finite element model in an embodiment of the present invention. In Figure 8(a), the coupling reference point P is a point on the axis of the first face gear 8. The coupling reference point P is coupled to the hub bearing support surface and acts as a moving node of the spring element. It can also apply torque and rotational angular displacement. kx , ky , kz , kθx , kθy , kθz These are the radial stiffness and angular stiffness of the bearing of the first gear 8 in the local coordinate system, respectively.

[0061] Figure 8(b) shows a schematic diagram of the elastic support of the second gear finite element model in an embodiment of the present invention. In Figure 8(b), the coupling reference point P is a point on the axis of the second gear 9. The coupling reference point P is coupled to the hub bearing support surface and acts as a moving node of the spring element. It can also apply torque and rotational angular displacement. kx , ky , kz , kθx , kθy , kθz These are the radial stiffness and angular stiffness of the bearing of the second gear 9 in the local coordinate system, respectively.

[0062] Figure 8(c) shows a schematic diagram of the elastic support of the input cylindrical gear finite element model in an embodiment of the present invention. In Figure 8(c), the coupling reference point P is a point on the axis of the input cylindrical gear. The coupling reference point P is coupled to the hub bearing support surface and acts as a moving node of the spring element. It can also apply torque and rotational angular displacement. kx , ky , kz , kθx , kθy , kθz These represent the radial stiffness and angular stiffness of the bearing of the input cylindrical gear in the local coordinate system, respectively.

[0063] Figure 8(d) shows a schematic diagram of the elastic support of the idler wheel finite element model in an embodiment of the present invention. In Figure 8(d), the coupling reference point P is a point on the axis of the idler wheel, and the bearing support surface of the idler wheel includes P. 内 and P 外 Two bearing support surfaces, through P 内 and P 外 Apply torque and rotational angular displacement, kx , ky , kz , kθx , kθy , kθz These represent the radial stiffness and angular stiffness of the idler wheel's bearing in the local coordinate system, respectively.

[0064] Figure 8(e) shows a schematic diagram of the elastic support of the finite element model of the tail-drive cylindrical gear in an embodiment of the present invention. In Figure 8(e), the coupling reference point P is a point on the axis of the tail-drive cylindrical gear. The bearing support surface of the tail-drive cylindrical gear includes P. 内 and P 外 Two bearing support surfaces, through P 内 and P 外 Apply torque and rotational angular displacement, kx , ky , kz , kθx , kθy , kθz These represent the radial stiffness and angular stiffness of the bearings of the tail drive cylindrical gear in the local coordinate system.

[0065] Figure 9 This diagram illustrates the input torque and input rotation angle of the finite element model of the face gear torque transmission system in an embodiment of the present invention. Figure 9 In the figure, the first gear 8 and the second gear 9 are arranged coaxially opposite each other. The first input cylindrical gear 10, the second input cylindrical gear 11, the first idler gear 12, the second idler gear 13 and the tail gear 14 are assembled between the first gear 8 and the second gear 9 according to the structural layout requirements. The input torque (input torque T) of the first input cylindrical gear 10 and the second input cylindrical gear 11 is applied to the coupling reference point P in Figure 8(c). The angular displacement of the first gear 8 is applied to the coupling reference point P in Figure 8(a) and finally acts on the bearing support surface.

[0066] In this embodiment of the invention, the face gear torque transmission system model has many contact pairs. To improve the model's computational convergence, in addition to the initial analysis step, five analysis steps are required. Initially, no constraints are applied to all gears. The first step involves applying angular displacement to the first face gear 8 and the second face gear 9, and setting the input cylindrical gear, idler gear, and tail-drive cylindrical gear 14 as constraints to establish face gear contact pairs. The second step involves applying constraints to the first face gear 8 and the second face gear 9, and setting the input cylindrical gear, idler gear, and tail-drive cylindrical gear 14 as constraints to establish contact pairs between the input cylindrical gear and the first face gear 8 and the second face gear 9. The third step involves applying constraints to the first face gear... Step 8: Apply a small load, release the rotational constraint of the second face gear 9, allow the input cylindrical gear to rotate and be loaded, and keep the idler gear and tail-drive cylindrical gear 14 in a released rotational state; Step 4: Apply a medium load to the first face gear 8, release the rotational constraint of the second face gear 9, allow the input cylindrical gear to rotate and be loaded, and keep the idler gear and tail-drive cylindrical gear 14 in a released rotational state. The establishment of the contact pair in the finite element analysis model of the face gears is tested through steps 3 and 4; Step 5: Apply elastic support and load to the first face gear 8, release the rotational constraint of the second face gear 9, apply the rated torque to the input cylindrical gear, and release the constraints of the idler gear and tail-drive cylindrical gear 14 to complete the face gear contact analysis at the input gear. The first four analysis steps are used to establish contact for all gear pairs. The fifth analysis step is the analysis calculation under rated load. The boundary conditions for each analysis step are shown in Table 2.

[0067] Table 2 Boundary conditions for the analysis step

[0068] In this embodiment of the invention, the terms "small load" and "medium load" are defined based on the rated load. The small load is set to 20% of the rated load, and the medium load is set to 50% of the rated load. It should be noted that the definitions of small and medium loads in this example are merely illustrative; in actual applications, the parameters can be adjusted according to actual needs.

[0069] This invention also provides a high-efficiency and high-precision modeling system for contact analysis of face gear torque transmission structures. Figure 10 A schematic diagram of the high-efficiency and high-precision modeling system for contact analysis of a face gear torque transmission structure in an embodiment of the present invention is shown. Figure 10 The system comprises: a solution unit, a construction unit, and a convergence unit. The solution unit is configured to divide the gear structure and solve for the coordinates of all nodes on the numerical tooth surface of the face gear pair. The construction unit is configured to establish a structural mesh model of the face gear torque transmission system based on the coordinates of all nodes on the numerical tooth surface, introducing the axial installation error, shaft intersection error, and axis offset error of the face gear. The convergence unit is configured to define the contact pair relationship and boundary conditions on the structural mesh model, and perform convergence calculation on the structural mesh model based on the defined contact pair and boundary conditions to complete the face gear contact analysis.

[0070] In this embodiment of the invention, a computer storage medium is also provided, which stores one or more instructions, which, when executed by one or more computers, cause the one or more computers to implement the contact analysis modeling method for face gear torque transmission structure described in this embodiment of the invention.

[0071] This invention presents a high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures. It constructs a local tooth segment model structure in the meshing region between the face gear and the cylindrical gear in a face gear pair to replace the full tooth model structure for finite element contact analysis, improving computational efficiency and effectively avoiding the problem of high workload and low efficiency due to the large number of finite element meshes in face gear torque transmission systems. It enables contact analysis of face gear torque transmission systems, allowing for the study of contact imprints and meshing performance optimization design of face gear pairs, as well as differentiated profile design methods for each face gear pair, to obtain good meshing imprints for each face gear pair in the face gear torque transmission system. Based on the characteristics of face gear torque transmission systems with multiple transmission branches that influence and couple with each other, a parametric finite element modeling method for contact analysis of face gear torque transmission systems is formed, considering the influence of system structural deformation, installation errors, and machining errors. Furthermore, when the face gear tooth surface parameters change, the contact analysis model can be quickly modified, improving analysis efficiency.

[0072] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-efficiency and high-precision modeling method for contact analysis of a face gear torque transmission structure, characterized in that, The method includes: The numerical coordinates of all nodes on the tooth surface of the face gear pair are obtained by dividing the gear structure and solving the problem. Based on the coordinates of all nodes on the numerical tooth surface, the axial installation error, shaft intersection error, and axis offset error of the face gear are introduced to establish a structural mesh model of the face gear torque transmission system. Contact pair relationships and boundary conditions are defined on the structural mesh model. Based on the defined contact pairs and boundary conditions, convergence calculations are performed on the structural mesh model to complete the face gear contact analysis.

2. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 1, characterized in that, The numerical coordinates of all nodes on the tooth surface of the face gear pair are obtained by solving the gear structure by dividing it into parts. The gear end face is divided into the working tooth surface region, the transition curved surface region, and the gear body region; Obtain the coordinates of several structural points on the gear end face after division; Points are set on each side of the face gear to determine the node distribution on each side; Based on the coordinates of the structural points and the distribution of points on each side, the coordinates of all nodes on the tooth surface of the generated face gear pair are solved by a linear interpolation algorithm.

3. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 1 or 2, characterized in that, The structural mesh model of the face gear torque splitting transmission system includes: Based on the coordinates of all nodes on the numerical tooth surface, a local tooth segment model structure is constructed for the meshing region between the face gear and the cylindrical gear in the face gear pair. Determine the included angle between the meshing tooth grooves of the face gear and the cylindrical gear in the local tooth segment model structure respectively; The phase condition of the cylindrical gear in the face gear torque transmission system is determined based on the included angle. Based on the aforementioned phase conditions, the axial installation error, shaft intersection error, and axis offset error of the face gear are introduced to establish a structural mesh model of the face gear torque transmission system.

4. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 3, characterized in that, Establishing a structural mesh model of a face gear torque-split transmission system also includes the step of selecting analysis elements, including: First-order elements are selected as the basic element type for finite element analysis. The first-order element is an eight-node linear hexahedral element.

5. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 3, characterized in that, The contact pair relationships defined on the structured mesh model include: The contact type, interaction properties, and master-slave relationship between the face gear and the cylindrical gear.

6. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 3, is characterized in that, Boundary conditions are defined on the structured mesh model, including: Rigid reference points are established on the rotation axes of the face gear and the cylindrical gear, respectively, and each rigid reference point contains multiple degrees of freedom of motion. The rigid reference points of the face gear and the cylindrical gear are coupled to generate coupling reference points for the face gear and the cylindrical gear respectively. The torque and angular displacement of the face gear torque transmission system are applied based on the coupling reference point.

7. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 6, characterized in that, The generation of coupling reference points for the face gear pair also includes a convergent solution step for the contact process between the face gear and the cylindrical gear, including: Fix multiple degrees of freedom of motion of the rigid reference point of the cylindrical gear, release the axial rotational degree of freedom of the rigid reference point of the face gear and fix the remaining degrees of freedom, and apply an initial torque; The torque applied to the face gear is gradually increased to the full load condition, while keeping other boundary conditions unchanged; Release the axial rotational degree of freedom of the cylindrical gear and apply a preset angular displacement load until a convergent solution is obtained.

8. The high-efficiency and high-precision modeling method for contact analysis of face gear torque transmission structures according to claim 6, characterized in that, The face gear includes a first face gear and a second face gear, and the cylindrical gear includes an input cylindrical gear, an idler gear, and a tail-drive cylindrical gear. The convergence calculation of the structural mesh model based on the defined contact pairs and boundary conditions includes: Apply angular displacement to the first and second face gears, input the cylindrical gear, idler gear, and tail drive cylindrical gear as constraint states, and establish the face gear contact pair; Constraints are applied to the first and second face gears. The input cylindrical gear, idler gear, and tail drive cylindrical gear are in a constrained state. A contact pair is established between the input cylindrical gear and the first and second face gears. Small and medium loads were applied to the first gear face, and the rotational constraint of the second gear face was released. The input cylindrical gear was rotated and loaded, while the idler gear and the tail gear were in a released rotational state. The establishment of the contact pair of the finite element analysis model of the gear face was tested. Elastic support and load are applied to the first gear, the rotational constraint is released from the second gear, the rated torque is applied to the input cylindrical gear, and the idler gear and the tail gear are released from their constraints.

9. A high-efficiency and high-precision modeling system for contact analysis of face gear torque transmission structures, characterized in that, The system includes: a solution unit, a construction unit, and a convergence unit. The solver element is configured to divide the gear structure and solve for the numerical coordinates of all nodes on the tooth surface of the face gear pair; The building unit is configured to be based on the coordinate points of all nodes of the numerical tooth surface, and the axial installation error, shaft intersection error and axis offset error of the face gear are introduced to establish the structural mesh model of the face gear torque transmission system; The convergence unit is configured to define contact pair relationships and boundary conditions on the structural mesh model, and perform convergence calculations on the structural mesh model based on the defined contact pairs and boundary conditions to complete the face gear contact analysis.

10. A computer storage medium, characterized in that, The computer storage medium stores one or more instructions that, when executed by one or more computers, cause the one or more computers to perform the method of any one of claims 1-8.

Images