A method for explicit dynamics simulation of cylindrical roller bearings and extraction of roller runout angle

Abstract

The invention belongs to the technical field of bearing transmission, and specifically relates to a method for explicit dynamics simulation of a cylindrical roller bearing and extraction of a roller runout angle: the geometric parameters of the cylindrical roller bearing are calculated based on basic parameters; a cylindrical roller bearing grid model and a rigid shell unit are created; overlapping nodes of the inner and outer rings and the inner and outer ring rigid shell units are respectively merged, a Section module is created, and material properties of rollers, cages, and inner and outer rings are set; each component is assigned a Section and material property, contact settings are performed on the cylindrical roller, cage, inner ring, and outer ring, and static friction coefficients and dynamic friction coefficients are given; boundary conditions, rotation speeds, and loads are applied to the bearing model according to working conditions, and related parameters are defined for solution; an absolute reference axis and a relative reference axis are respectively set in a result file, and the runout angle parameters are extracted by measuring the angle between the two axes; the invention is helpful in forming a design model of a cylindrical roller bearing, thereby improving the design level and quality of the cylindrical roller bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing transmission, and in particular to a method for explicit dynamics simulation of a cylindrical roller bearing and extraction of a roller runout angle. Background Art

[0002] Rolling bearings are essential core components in transmission systems. They play a crucial role in the aviation and automotive industries, thanks to their high precision, low friction torque, and long service life. Their performance is crucial for the stable operation of aircraft engines and helicopter main reducers. The complex mechanical relationships between rolling bearing components during service life make dynamic finite element simulation an essential step in bearing design. Currently, dynamic finite element simulations of rolling bearings focus primarily on dynamic characteristics such as stress, strain, velocity, and acceleration, while research on the roller runout of cylindrical roller bearings during operation is rare. During operation, the roller axis of a cylindrical roller bearing is not always aligned with the bearing axis; instead, there is a constant, shifting angle between the two. This roller runout can cause uneven load loading on the roller contact line, leading to localized wear and even burns in the presence of insufficient lubricant. When the runout angle is too large, the bearing can collide significantly with the cage during operation. In some extreme conditions, the rollers can even become stuck in the cage, causing the rollers to slip in the raceways. Therefore, studying roller runout is of great significance to bearing design, optimization, and application. However, currently, most methods for extracting roller runout angle parameters use discontinuous or specific position methods. Methods for extracting the continuous variation of the roller runout angle over time still have shortcomings and some technical issues.

[0003] In order to solve the above problems, the present invention designs a method for explicit dynamics simulation of cylindrical roller bearings and extraction of roller runout angle. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for explicit dynamics simulation of cylindrical roller bearings and extraction of roller runout angles.

[0005] In order to achieve the purpose of the present invention, the present invention will be implemented by adopting the following technical solutions.

[0006] A method for explicit dynamics simulation of a cylindrical roller bearing and extraction of roller runout angles comprises the following steps:

[0007] S101. Calculating geometric parameters of the cylindrical rollers, cage, inner ring, and outer ring in the cylindrical roller bearing based on basic parameters of the cylindrical rollers, cage, inner ring, and outer ring in the cylindrical roller bearing;

[0008] S102. Creating mesh models of the rollers, cage, inner ring, and outer ring in the cylindrical roller bearing, as well as outer ring rigid shell elements and inner ring rigid shell elements, based on geometric parameters of the cylindrical rollers, cage, inner ring, and outer ring in the cylindrical roller bearing;

[0009] S103, merging the outer ring rigid shell elements with the overlapping nodes of the outer ring, applying fixed constraints, merging the inner ring rigid shell elements with the overlapping nodes of the inner ring, and applying rotational speed and radial load;

[0010] S104. Define the elastic modulus, density, and Poisson's ratio of the cylindrical roller, cage, inner ring, outer ring, and outer ring rigid shell element and inner ring rigid shell element in the bearing;

[0011] S105. Change the ID in sequence and assign the Section and material properties to each part;

[0012] S106, performing contact settings on the cylindrical roller, the cage, the inner ring, and the outer ring, and setting the static friction coefficient, the dynamic friction coefficient, and the exponential attenuation coefficient;

[0013] S107. According to the actual working conditions of the bearing, the bearing speed, radial load, loading time, and the direction of the load and speed are set; the solution accuracy, hourglass control, and energy output of the display dynamics model are defined to ensure the overall solution quality; the time step and solution time are set to define the overall simulation duration;

[0014] S108. Set the solution memory and the number of CPU cores, submit the calculation in LS-DYNA, import the solution results into LS-PrePost for processing, set the absolute reference axis of the rigid shell element and the relative reference axis on the cylindrical roller in the solution result file, and extract the runout angle parameter of the cylindrical roller during operation by measuring the angle between the two axes.

[0015] As a preferred solution of the present invention, the grid models of the cylindrical roller, inner ring and outer ring are generated by Butterfly Blocks in the grid generator; the cage grid model is generated based on a two-dimensional monomer grid and rotation.

[0016] As a preferred solution of the present invention, the outer ring rigid shell element and the inner ring rigid shell element are generated by Cylinder Shell in the shell generator.

[0017] As a preferred solution of the present invention, the material properties of the cylindrical roller, cage, inner ring and outer ring are set to linear elastic materials; the material properties of the outer ring rigid shell unit and the inner ring rigid shell unit are set to rigid materials, wherein the material properties of the outer ring rigid shell unit are subject to full degree of freedom constraints, and the material properties of the inner ring rigid shell unit are subject to partial degree of freedom constraints.

[0018] As a preferred solution of the present invention, the contact is set to automatic surface-to-surface contact, wherein the roller is selected as the slave surface and the cage and the inner and outer rings are selected as the master surface.

[0019] As a preferred solution of the present invention, the bearing model includes an inner ring rigid shell unit and a cage mesh model, wherein the inner ring rigid shell unit is the application object of load and speed, and the cage mesh model is the constraint object of boundary conditions.

[0020] As a preferred solution of the present invention, the direction of the load is radial; the rotation direction of the speed is circumferential of the bearing; and the boundary condition is to constrain the axial displacement of the retainer end face node.

[0021] As a preferred embodiment of the present invention, the absolute reference axis is composed of the two end face nodes of the inner ring and / or outer ring rigid shell unit in the axial direction; the relative reference circumference is composed of the two end face center point nodes of the cylindrical roller.

[0022] As a further technical solution of the present invention, by repeatedly executing steps S101 to S108 in the extraction method, it is possible to analyze the influence of load, rotation speed and cage structure on the roller runout angle within a certain range, and optimize the bearing structure to reduce bearing vibration and noise. Beneficial effects

[0023] The present invention extracts the roller's runout angle to study the uneven load on the roller contact line during bearing operation, analyzes the influence of speed, load, and cage structural parameters on it, and optimizes the bearing structural parameters to reduce the vibration of the rolling bearing, reduce the noise of mechanical equipment, and increase the service life.

[0024] Given the basic parameters of the bearing, the present invention establishes a cylindrical roller bearing mesh model and rigid shell elements, sets the material properties and constraint characteristics of each bearing component, defines the bearing load and speed curve and applies boundary conditions, sets solution and output parameters, etc., solves the problem in LS-DYNA and imports the result file into LS-PrePost. By picking nodes and setting absolute and relative reference frames, the roller runout angle is extracted, and the bearing is optimized by analyzing the influence of the roller runout angle on the bearing load.

[0025] The method proposed in the present invention helps to form a finite element simulation model of cylindrical roller bearing dynamics and a roller runout angle extraction method, thereby improving the design level and quality of roller bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a design flow chart of a cylindrical roller bearing explicit dynamics simulation and roller runout angle extraction method provided by an embodiment of the present invention;

[0027] Figure 2 This is a specific implementation process of a cylindrical roller bearing explicit dynamics simulation and roller runout angle extraction method provided by an embodiment of the present invention;

[0028] Figure 3 is a grid model of a cylindrical roller bearing according to an embodiment of the present invention;

[0029] Figure 4 The invention provides an embodiment of the roller runout angle extraction reference axis setting;

[0030] Figure 5 This is a graph showing the continuous change of the roller deflection angle over time in an embodiment provided by the present invention. DETAILED DESCRIPTION

[0031] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. The following embodiments are implemented based on the technical solutions of the present invention, and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0033] As an embodiment of the present invention, Figure 1-5 As shown, a method for explicit dynamics simulation of cylindrical roller bearings and extraction of roller runout angle includes the following steps:

[0034] Calculate the geometric parameters of cylindrical roller bearing rollers, cages, inner and outer rings through the basic parameters of cylindrical roller bearing rollers, cages, inner and outer rings;

[0035] In LS-PrePost, ButterflyBlocks in the Block Mesher is used to generate meshes for the cylindrical roller and inner and outer rings based on the geometric parameters. The cage mesh is generated based on the 2D monomer mesh and rotation. The Cylinder Shell in the Shell Generator is used to generate shell elements for the outer ring constraint and inner ring shell elements for applying load and speed.

[0036] In the Section module, create a SOLID section for each element of the bearing cage, rollers, inner and outer rings and use the full integration format. Create a SHELL section for the inner ring shell element and the outer ring shell element respectively. Give a shear factor of 0.833 and set the shell element thickness to 0.5 mm. Use the full integration format.

[0037] The material properties of the cylindrical roller, cage, inner ring, and outer ring are set to linear elastic materials. The density of the inner and outer rings and roller materials is 7870 kg / m3, the elastic modulus is 2.09×1011Pa, and the Poisson's ratio is 0.3. The density of the cage material is 7870 kg / m3, the elastic modulus is 2.09×1011Pa, and the Poisson's ratio is 0.295.

[0038] The material properties of the outer ring rigid shell element and the inner ring rigid shell element are set as rigid materials, and the material density of the inner and outer ring materials is given as 7870 kg / m3, the elastic modulus is 2.09×1011Pa, and the Poisson's ratio is 0.3;

[0039] In the Duplicate Nodes of the mesh tool, first set the duplicate node tolerance to 0.011mm, then display the duplicate nodes and merge them to complete the common node settings of the outer ring and outer ring rigid shell elements, and the inner ring and inner ring rigid shell elements.

[0040] In the Part module, each part is given PartID, material properties and Section defined in S102;

[0041] In the Contact module, the automatic surface-to-surface contact method is used. The roller-inner ring contact is set to a dynamic friction coefficient of 0.15, a static friction coefficient of 0.2, and an exponential decay coefficient of 1×10-5; the roller-outer ring contact is set to a dynamic friction coefficient of 0.15, a static friction coefficient of 0.2, and an exponential decay coefficient of 1×10-5; and the roller-cage contact is set to a dynamic friction coefficient of 0.001, a static friction coefficient of 0.002, and an exponential decay coefficient of 1×10-5. The roller is in slave surface contact, while the inner and outer rings and the cage are in primary surface contact.

[0042] The load is defined as 5118N and the speed is defined as 20900rpm. The ramp loading method is given in the startup phase.

[0043] In the LOAD module, select the inner ring rigid shell element as the load application object, and the load direction is radial;

[0044] In the Boundary module, select the inner ring rigid shell element as the speed application object and the bearing circumference as the rotation direction;

[0045] Select the cage end face node to constrain its axial displacement;

[0046] In the CONTROL module, set the solution accuracy OSU to 1 and INN to 4; set the hourglass control IHQ and OH to 4 and 0.1 respectively; set the energy output HGEN, RWEN, SLNTEN, RYLEN, and IRGEN to 2, set the solution time to 0.05s, and the time step to 5×10-4s;

[0047] Set global damping in GLOBAL in the DAMPING module, and set the system damping constant to 0.02;

[0048] In the DATABASE module, set the output format to LS-DYNA database format using FORMAT. The calculation results are output in D3PLOT format with an output time interval of 2.778×10-5s.

[0049] In the Keyword module, set the calculation storage to 9999999 and the number of CPU cores to 12. In the ANSYS Mechanical APDL Product Launcher solver, select the LS-DYNA Solver simulation environment and correctly select the working directory and K file import directory. After the solution is complete, import the result file into LS-PrePost. In the Measure module, select node angle measurement. Set the absolute reference axis by picking the two end face nodes in the direction of the rigid shell element axis. Select the midpoint nodes of the two end faces of the cylindrical roller to set the relative reference axis. Then output the continuous value of the angle between the two reference axes as it changes over time.

[0050] Based on the above-mentioned runout angle extraction method, by repeating steps S101 to S108, the influence of load, speed and cage structure on the roller runout angle within a certain range can be analyzed, and the bearing structure can be optimized to reduce its vibration and noise, which plays an important role.

[0051] A finite element simulation model for the dynamics of cylindrical roller bearings was established, taking into account both computational efficiency and the overall design of the bearing structure, and a method for extracting the cylindrical roller runout angle parameters was developed.

[0052] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A method for explicit dynamics simulation of a cylindrical roller bearing and extraction of roller runout angle, comprising the following steps: S101. Calculating geometric parameters of the cylindrical rollers, the cage, the inner ring and the outer ring in the cylindrical roller bearing according to basic parameters of the cylindrical rollers, the cage, the inner ring and the outer ring in the cylindrical roller bearing; S102, creating mesh models of the rollers, cage, inner ring and outer ring in the cylindrical roller bearing, as well as outer ring rigid shell elements and inner ring rigid shell elements according to geometric parameters of the cylindrical rollers, cage, inner ring and outer ring in the cylindrical roller bearing; It is characterized by further comprising the following steps: S103, merging the outer ring rigid shell unit with the overlapping nodes of the outer ring, and applying fixed constraints; merging the inner ring rigid shell unit with the overlapping nodes of the inner ring, and applying rotation speed and radial load; S104. Define the elastic modulus, density, and Poisson's ratio of the cylindrical roller, cage, inner ring, outer ring, and outer ring rigid shell unit and inner ring rigid shell unit in the bearing; S105, change the ID in sequence and assign Section and material properties to each part; S106, performing contact setting for the cylindrical roller, the cage, the inner ring and the outer ring, and setting the static friction coefficient, the dynamic friction coefficient and the exponential attenuation coefficient; S107. According to the actual working condition of the bearing, the bearing speed, radial load and loading time, as well as the direction of action of the load and speed are set; the solution accuracy, hourglass control and energy output of the display dynamics model are defined to ensure the overall solution quality; the time step and solution time are set to define the overall simulation duration; S108. Set the solution memory and the number of CPU cores, submit the calculation in LS-DYNA, import the solution results into LS-PrePost for processing, set the absolute reference axis of the rigid shell unit and the relative reference axis on the cylindrical roller in the solution result file, and extract the runout angle parameter of the cylindrical roller during operation by measuring the angle between the two axes.

2. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: The mesh models of the cylindrical roller, inner ring and outer ring are generated by ButterflyBlocks in the mesh generator; the cage mesh model is generated based on two-dimensional monomer mesh and rotation.

3. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: The outer circle rigid shell element and the inner circle rigid shell element are generated by CylinderShell in the shell generator.

4. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: The material properties of the cylindrical roller, cage, inner ring and outer ring are set as linear elastic materials; the material properties of the outer ring rigid shell unit and the inner ring rigid shell unit are set as rigid materials, wherein the material properties of the outer ring rigid shell unit are subject to full freedom constraints, and the material properties of the inner ring rigid shell unit are subject to partial freedom constraints.

5. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: The contact is set to automatic surface-to-surface contact, wherein the roller is selected as the secondary surface and the cage and the inner and outer rings are selected as the primary surfaces.

6. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: The inner ring rigid shell unit is an object to which load and rotation speed are applied; the cage mesh model is an object to which boundary conditions are constrained.

7. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 6, characterized in that: The direction of the load is radial; the rotation direction of the speed is circumferentially of the bearing; and the boundary condition is to constrain the axial displacement of the node of the cage end face.

8. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: The absolute reference axis is composed of the two end surface nodes of the inner ring and / or outer ring rigid shell unit in the axial direction; the relative reference circumference is composed of the two end surface center point nodes of the cylindrical roller.

9. The method for explicit dynamics simulation and roller runout angle extraction of cylindrical roller bearings according to claim 1, characterized in that: By repeatedly executing steps S101 to S108 in the extraction method, it is possible to analyze the influence of load, rotation speed and cage structure on the roller runout angle within a certain range, and optimize the bearing structure to reduce the vibration and noise of the bearing.

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