Method, device, electronic device and storage medium for determining fit tolerance

Abstract

The present invention discloses a method, device, electronic device and storage medium for determining fit tolerance. The method comprises: constructing a finite element model based on a transmission input shaft, a motor output shaft, a first bearing, a second bearing and a third bearing, and meshing the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing to obtain at least one refined mesh to be used; applying different forces to the finite element model to determine the radial deformation amount of each refined mesh to be used corresponding to the transmission input shaft and the motor output shaft under different forces; determining the target deformation amount based on each radial deformation amount; determining the fit tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount. The method solves the problem of low accuracy in determining the fit tolerance based on artificial experience in the prior art, and achieves the effect of improving the accuracy of fit tolerance calculation.

Description

Technical Field

[0001] The present invention relates to the field of computer processing technology, and in particular to a method, device, electronic equipment and storage medium for determining a fit tolerance. Background Art

[0002] A three-bearing motor transmission refers to a transmission with a three-bearing structural assembly. During the product design process of the three-bearing motor transmission, in order to optimize the performance of the three-bearing motor transmission, the most suitable inter-axis fit tolerance is usually defined for the three-bearing motor transmission so that the motor output shaft and the transmission input shaft can be matched based on the fit tolerance.

[0003] The method for determining the inter-shaft fitting tolerance in the prior art is usually based on the personal experience of engineers to determine the fitting tolerance, and then the performance of the three-bearing motor transmission based on the fitting tolerance is tested through simulation test technology. The fitting tolerance determined based on personal experience has poor accuracy, which leads to poor simulation test accuracy and low efficiency, resulting in a long simulation test cycle and a large waste of production and development costs. Summary of the invention

[0004] The present invention provides a method, device, electronic device and storage medium for determining a fit tolerance, so as to achieve the technical effect of improving the accuracy of determining the fit tolerance between shafts and improving the test accuracy and efficiency.

[0005] According to one aspect of the present invention, a method for determining a fit tolerance is provided, the method comprising:

[0006] Based on the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing, a finite element model is constructed, and contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing are meshed to obtain at least one refined mesh to be used;

[0007] Apply different forces to the finite element model to determine the radial deformation amount of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces; wherein the direction of the radial deformation amount is perpendicular to the bottom surface of the corresponding shaft;

[0008] Based on each radial deformation amount, determining the target deformation amount;

[0009] Based on the target deformation amount, a fitting tolerance between the transmission input shaft and the motor output shaft is determined.

[0010] According to another aspect of the present invention, there is provided a device for determining a matching tolerance, the device comprising:

[0011] A module for determining a refined mesh to be used, configured to construct a finite element model based on a transmission input shaft, a motor output shaft, a first bearing, a second bearing, and a third bearing, and to mesh contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing, and the third bearing to obtain at least one refined mesh to be used;

[0012] A radial deformation determination module is used to apply different forces to the finite element model to determine the radial deformation of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces; wherein the direction of the radial deformation is perpendicular to the bottom surface of the corresponding shaft;

[0013] A target shape variable determination module is used to determine the target shape variable based on each radial shape variable;

[0014] A matching tolerance determination module is used to determine a matching tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount.

[0015] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0016] at least one processor; and

[0017] a memory communicatively connected to the at least one processor; wherein,

[0018] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for determining the fitting tolerance described in any embodiment of the present invention.

[0019] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the method for determining the fitting tolerance described in any embodiment of the present invention when executed.

[0020] The technical solution of the embodiment of the present invention is to obtain at least one refined grid to be used by meshing the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing in the finite element model, and apply different types of forces to the finite element model to determine the radial deformation of each refined grid to be used corresponding to the transmission input shaft and the motor output shaft under different forces, determine the target deformation based on each radial deformation, and then determine the fitting tolerance between the transmission input shaft and the motor output shaft based on the target deformation, thereby solving the problem of low accuracy in determining the fitting tolerance between the shafts of the three-bearing structure based on manual experience in the prior art, and achieving the determination of the radial deformation corresponding to the transmission input shaft and the motor output shaft under different types of forces when different types of forces are applied to the finite element model, combining different test conditions, determining the target deformation based on the radial deformation under each test condition, and determining the fitting tolerance between the shafts of the three-bearing structure based on the target deformation, while improving the accuracy of determining the fitting tolerance between the shafts, achieving the technical effect of improving the test accuracy and efficiency.

[0021] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is a flow chart of a method for determining a fitting tolerance provided according to Embodiment 1 of the present invention;

[0024] Figure 2 is a schematic diagram of a three-bearing structure provided according to Embodiment 1 of the present invention;

[0025] Figure 3 is a schematic diagram of a spline position grid provided according to Embodiment 1 of the present invention;

[0026] Figure 4 is a schematic diagram of the symmetrical axis of the spline of the motor output shaft provided in accordance with the first embodiment of the present invention;

[0027] Figure 5 Schematic diagram of mesh partitioning and refinement of a single spline tooth surface provided according to the first embodiment of the present invention;

[0028] Figure 6 is a schematic diagram of the geometric structure of a bearing provided according to the first embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of the geometric structure of the outer ring of a bearing provided according to the first embodiment of the present invention;

[0030] Figure 8 It is a schematic diagram of establishing an RBE3 unit on the outer surface of a bearing according to the first embodiment of the present invention;

[0031] Fig. 9 is a schematic diagram of the geometric structure of the motor output shaft provided in Embodiment 1 of the present invention;

[0032] Fig.10 It is a schematic diagram of establishing an RBE3 unit on the outer surface of a motor shaft according to the first embodiment of the present invention;

[0033] Fig.11 is a schematic diagram of a planed surface of a transmission input shaft provided according to a first embodiment of the present invention;

[0034] Fig.12 It is a schematic diagram of establishing an RBE3 unit according to the gear meshing point of the transmission input shaft provided by the first embodiment of the present invention;

[0035] Fig.13 is a schematic diagram of a planed surface of a motor output shaft provided according to the first embodiment of the present invention;

[0036] Fig.14 is a structural schematic diagram of a device for determining a matching tolerance provided according to a third embodiment of the present invention;

[0037] Fig.15 It is a structural schematic diagram of an electronic device for implementing the method for determining the fitting tolerance according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first", "second", "target" and "original" in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprises", "includes" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0040] Embodiment 1

[0041] Figure 1 1 is a flowchart of a method for determining a fit tolerance according to a first embodiment of the present invention. This embodiment is applicable to the case of determining the fit tolerance between shafts. The method can be executed by a fit tolerance determination device. The fit tolerance determination device can be implemented in the form of hardware and / or software. The fit tolerance determination device can be configured in a computing device. Figure 1 As shown, the method includes:

[0042] S110. Construct a finite element model based on the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing, and mesh the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing to obtain at least one refined mesh to be used.

[0043] In practical applications, a finite element model of a three-bearing structure assembly can be established. For example, the three-bearing structure includes a transmission input shaft, a motor output shaft, a first bearing, a second bearing, and a third bearing. Figure 2 , Figure 2 It can be represented as a schematic diagram of a three-bearing structure, and the three-bearing structure can be composed of a transmission input shaft 210, a motor output shaft 250, a first bearing 220, a second bearing 230 and a third bearing 240. All components in the three-bearing structure can be meshed, and the meshes after division can be assembled together to construct a finite element model. When meshing, the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing can be meshed in a refined manner to obtain at least one refined mesh to be used, and the remaining partial structure can be meshed in a coarse manner to obtain at least one coarse mesh. It can be understood that the refined mesh to be used is smaller in volume than the coarse mesh. Exemplarily, the transmission input shaft and the motor output shaft are in contact with each other by splines, which can be referred to. Figure 3 , Figure 3 It can be represented as a spline position grid diagram. The tooth surface grids of the motor output shaft spline 2501 and the transmission input shaft spline 2101 can be divided into partitions and grids, and the spline tooth surface is coarsened in the middle and refined at both ends to form a spline tooth surface refined grid and a spline tooth surface coarsened grid. In the actual modeling process, Figure 4 As shown, it can be represented as a schematic diagram of the motor shaft spline axis symmetry. Then the motor output shaft spline 2501 and the transmission input shaft spline 2101 can both be modeled using axisymmetry based on the symmetry characteristics of the spline. For example, only a single spline tooth surface mesh is established. Figure 5 , a spline tooth surface in the motor output shaft spline 2501 can be divided into a spline tooth surface fine mesh 25011 (i.e., a fine mesh to be used) and a spline tooth surface coarse mesh 25012, and then a complete spline mesh model can be established through axisymmetry. Accordingly, a complete finite element model of the three-bearing structure assembly can be obtained.

[0044] It should be noted that in order to improve the accuracy of constructing the finite element model of the three-bearing structure, mechanical property parameters, such as material properties or strain, deformation gradient, etc., can be added to the finite element model so that the actual mechanical properties of the corresponding components can be characterized based on the mechanical property parameters corresponding to each grid.

[0045] Optionally, the method further includes: determining mechanical property data corresponding to the finite element model; and updating the finite element model based on the mechanical property data.

[0046] Among them, the mechanical property data includes material property data and structural property data.

[0047] In practical applications, corresponding mechanical property data can be defined for the finite element model. For example, the elastic modulus of the finite element model is defined as E=210000MPa, Poisson's ratio μ=0.3, and all finite element models are linear elastic materials and other mechanical property data. The finite element model can be updated based on the defined mechanical property data to obtain a finite element model with mechanical properties.

[0048] It should be noted that in order to prevent the rigid body displacement of the model and better meet the conditions for finite element solution, constraints can be defined for the finite element model when establishing the finite element model. For example, when applying loads to the finite element model, the rotation of certain components in the three-bearing structure can be restricted.

[0049] Optionally, the method further includes: determining a first model boundary condition and a second model boundary condition corresponding to the finite element model; and updating the finite element model based on the first model boundary condition and the second model boundary condition.

[0050] The first model boundary condition is determined based on fixing the first bearing, the second bearing and the third bearing, for example, fixing all degrees of freedom of the bearing except the axial rotational degree of freedom. The second model boundary condition is determined based on fixing the motor output shaft, for example, fixing the axial rotational degree of freedom of the motor output shaft.

[0051] In practical applications, boundary constraints can be imposed on finite element models. The model boundary constraints can be divided into two categories: the first model boundary conditions and the second model boundary conditions. For example, when the first model boundary conditions are imposed, that is, all degrees of freedom of the bearing except the axial rotational degree of freedom are fixed, the outer rings of the first bearing, the second bearing, and the third bearing can be fixed to simulate the support of the transmission and the motor housing to the bearing. Take the first bearing as an example to illustrate the fixing process of the outer ring of the bearing, such as Figure 6 As shown, it can be expressed as a schematic diagram of the bearing geometry. When fixing the bearing outer ring 2201, it is necessary to apply the RBE3 unit, such as Figure 7 As shown, it can be represented as a schematic diagram of the geometric structure of the outer ring of the bearing. The main point 2202 of the RBE3 unit selects the outer ring surface of the outer ring of the bearing 2201, and the geometric center of the bearing is selected from the point 2203, as shown in FIG. Figure 8 As shown, it can be represented as a schematic diagram of establishing an RBE3 unit on the outer surface of the bearing. The freedom degree of the RBE3 unit from point 2203 around the 6 o'clock direction of the cylindrical coordinate system 2204 is not constrained, and all other degrees of freedom are constrained. The Z axis of the cylindrical coordinate system 2204 is along the axis of the gear shaft, the R axis is along the radial direction of the gear shaft, and the t axis is determined by Z and R according to the right-hand rule. When applying the second model boundary condition, that is, fixing the axial rotation freedom of the motor output shaft, for example, see Fig. 9 , Fig. 9 It can be represented as a schematic diagram of the geometric structure of the motor output shaft. When the motor output shaft is fixed at 250, it needs to be applied with the help of the RBE3 unit. Fig.10 , which can be represented as a schematic diagram of establishing an RBE3 unit on the outer surface of the motor shaft, the main point 2502 of the RBE3 unit 2504 selects the outer surface of the motor output shaft 250, and the secondary point 2505 selects the geometric center of the motor output shaft 250, and only constrains the 6 o'clock direction degree of freedom of the secondary point 2505 of the RBE3 unit 2504 around the cylindrical coordinate system 2503. In the process of force analysis of the finite element model, all degrees of freedom of the bearing except the axial rotation degree of freedom, and the axial rotation degree of freedom of the motor output shaft are fixed, so as to improve the accuracy of model analysis.

[0052] S120, applying different forces to the finite element model to determine radial deformation amounts of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces.

[0053] Among them, the acting force can be understood as a load. Optionally, the acting force includes bearing interference force, transmission gear meshing force and motor eccentric load. The transmission gear meshing force is determined based on the gear pitch diameter of the transmission input shaft, the gear transmission torque, the gear normal pressure angle and the helix angle at the gear pitch circle. The bearing interference force can be understood as the interference force between the contact areas of the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing. The motor eccentric load can be understood as a radial electromagnetic force. The direction of the radial deformation is perpendicular to the bottom surface of the corresponding shaft.

[0054] In practical applications, at least one force, including bearing interference force, transmission gear meshing force and motor eccentric load, can be applied to the finite element model. In this way, each mesh in the finite element model may produce corresponding deformation, and the radial deformation amount of each refined mesh to be used at the transmission input shaft and the motor output shaft under different forces can be obtained, so as to determine the fitting tolerance between the transmission input shaft and the motor output shaft based on the radial deformation amount.

[0055] It should be noted that in order to improve the accuracy of the fit tolerance calculation, different test conditions can be designed, and different forces can be applied under different test conditions. Correspondingly, the radial deformation of each refined grid to be used under different test conditions can be obtained. For example, there can be three test conditions, which can be: preload condition, gear force condition, and eccentric force condition. The boundary conditions used for the three test conditions are the first model boundary conditions and the second model boundary conditions. Among them, when performing the preload condition test, only the interference of the inner ring of the bearing, that is, the bearing interference force, can be loaded, and the transmission gear meshing force and the motor eccentric load are not applied. When performing the gear force condition test, the transmission gear meshing force can be applied on the basis of the preload condition. When performing the eccentric force condition test, the motor eccentric load can be applied on the basis of the preload condition. The following is a detailed description of the implementation methods of the three test conditions:

[0056] When performing a preload condition test, optionally, different forces are applied to the finite element model to determine the radial deformation amounts of each refined mesh to be used corresponding to the transmission input shaft and the motor output shaft under different forces, including: applying a bearing interference force to the second bearing in the finite element model to obtain the radial deformation amounts of each refined mesh to be used corresponding to the inner wall of the transmission input shaft at the second bearing position.

[0057] It should be noted that, taking into account the calculation accuracy and convergence of the interference contact between shafts, when the contact areas of the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing are cut, regular geometric areas are formed, and corresponding interference contact relationships can be established at the contact part grids, that is, the corresponding bearing interference forces are set.

[0058] In practical applications, in order to improve the calculation efficiency, the bearing interference force can be applied to the second bearing in the finite element model, and then the finite element model of the three-bearing structure can be calculated and analyzed. The time period of each test condition can be set to 1, the time increment can be set to 0.1, and the Newton-Raphson method can be used to iteratively calculate and output the analysis results of the three-bearing finite element model during the preload condition test. Further, the analysis results can be processed to extract the radial deformation of each refined grid to be used on the inner wall (i.e., the inner surface) of the transmission input shaft at the position corresponding to the second bearing position, for example, see Fig.11 , Fig.11 It can be represented as a schematic cross-sectional view of the transmission input shaft, and the radial deformation amount of each refined grid to be used on the shaft inner wall 2101 of the transmission input shaft 210 at the position corresponding to the second bearing position can be obtained.

[0059] When performing the gear force working condition test, optionally, different forces are applied to the finite element model to determine the radial deformation amounts of each refined mesh to be used corresponding to the transmission input shaft and the motor output shaft under different forces, including: determining the gear meshing node based on the gear pitch circle diameter of the transmission input shaft in the finite element model; when the bearing interference force is applied to the second bearing in the finite element model, applying the transmission gear meshing force to the gear meshing node to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position, and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

[0060] In practical applications, the gear meshing nodes can be determined based on the gear pitch diameter of the transmission input shaft in the finite element model, for example, see Fig.12 , Fig.12 It can be represented as a schematic diagram of establishing an RBE3 unit for the gear meshing point of the transmission input shaft. The slave point 2102 of the RBE3 unit 2105 can be used as the primary active gear meshing node, and the unit nodes on the nearby tooth surface 2103 and tooth surface 2104 are the main points of the RBE3 unit 2105. The primary active gear meshing node 2102 can be used as the node where the transmission gear meshing force needs to be applied, that is, the gear meshing node, which is on the gear pitch circle diameter. When determining the gear meshing force, the gear meshing force can be calculated according to formula (1) based on the gear transmission torque M of the transmission input shaft, the gear meshing parameters and the gear load. Formula (1) is as follows:

[0061]

[0062] The gear meshing force includes the circumferential force F of the gear. t , radial force F r and axial force F a, which can be applied with the help of a local cylindrical coordinate system defined on the axis of the transmission input shaft. M is the torque transmitted by the gear, i.e. the gear transmission torque, d is the gear pitch diameter, α n is the normal pressure angle of the gear, and β is the helix angle at the gear pitch circle. When the bearing interference force is applied to the second bearing in the finite element model, the transmission gear meshing force can be applied to the gear meshing node, and then the finite element model calculation and analysis of the three-bearing structure can be performed. The Newton-Raphson method can be used to iteratively calculate and output the analysis results of the three-bearing finite element model during the gear force condition test. Furthermore, the analysis results can be processed to extract the radial deformation variables corresponding to the inner wall (i.e., inner surface) of the transmission input shaft at the second bearing position, and the radial deformation variables corresponding to the outer wall (i.e., outer surface) of the motor output shaft at the second bearing position. For example, see Fig.13 , Fig.13 It can be represented as a schematic diagram of the motor output shaft section, where Fig.13 The middle mark 2506 can represent the shaft outer wall 2506 of the motor output shaft 250 at a position corresponding to the second bearing position.

[0063] When performing the eccentric force working condition test, optionally, different forces are applied to the finite element model to determine the radial deformation amounts of each refined mesh to be used corresponding to the transmission input shaft and the motor output shaft under different forces, including: determining the motor load starting point of the motor output shaft in the finite element model; when applying the bearing interference force to the second bearing in the finite element model, applying the motor eccentric load to the motor load starting point to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position, and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

[0064] In practical applications, the RBE3 unit can be used to determine the RBE3 unit's slave point as the motor load slave point of the motor output shaft in the finite element model. When the bearing interference force is applied to the second bearing in the finite element model, an eccentric load can be applied to the motor load slave point, for example, Fig.10 , the eccentric load F (maximum unilateral magnetic pull) to which the motor output shaft is subjected during operation can be applied to the slave point 2505 of the RBE3 unit 2504 in a static load manner, and the direction of the eccentric load is the R axis direction of the cylindrical coordinate system 2503. Further, the finite element model of the three-bearing structure can be calculated and analyzed, and the Newton-Raphson method can be used to iteratively calculate and output the analysis results of the three-bearing finite element model during the eccentric force working condition test. The analysis results can be processed to extract the radial deformation variables corresponding to the inner wall (i.e., inner surface) of the transmission input shaft at the second bearing position, and the radial deformation variables corresponding to the outer wall (i.e., outer surface) of the motor output shaft at the second bearing position.

[0065] S130: Determine a target deformation amount based on each radial deformation amount.

[0066] In practical applications, each radial deformation variable can be processed to obtain a target deformation variable for determining the fitting tolerance. For example, the corresponding radial deformation variable to be used can be determined among the radial deformation variables under each test condition, and then the target deformation variable can be determined based on the determined radial deformation variables to be used.

[0067] Optionally, the minimum radial deformation of the inner wall of the transmission input shaft at the second bearing position under different forces is determined; and the maximum radial deformation of the outer wall of the motor output shaft at the second bearing position under different forces is determined; based on each minimum radial deformation and each maximum radial deformation, the target deformation is determined.

[0068] In practical applications, for the preload condition test, the minimum radial deformation of the transmission input shaft at the second bearing position corresponding to the inner wall of the shaft can be extracted, which is recorded as u1; for the gear force condition test, the minimum radial deformation of the transmission input shaft at the second bearing position corresponding to the inner wall of the shaft can be extracted, which is recorded as u2, and the maximum radial deformation of the motor output shaft at the second bearing position corresponding to the outer wall of the shaft can be extracted, which is recorded as u3; for the eccentric force condition test, the minimum radial deformation of the transmission input shaft at the second bearing position corresponding to the inner wall of the shaft can be extracted, which is recorded as u4, and the maximum radial deformation of the motor output shaft at the second bearing position corresponding to the outer wall of the shaft can be extracted, which is recorded as u5. The radial deformation obtained under the three working conditions can be calculated according to formula (2) to obtain the target deformation under the combined action of bearing interference, gear force and eccentric force, which is recorded as, formula (2) is as follows:

[0069] U=∑|u i |,(i=1,2,…,5)(2)

[0070] Among them, U can be expressed as the target shape variable, u i , (i=1,2,…,5) is the corresponding radial deformation obtained under the three test conditions.

[0071] S140. Determine the fitting tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount.

[0072] In practical applications, the inter-shaft fit tolerance of the motor output shaft and the transmission input shaft at the corresponding position of the intermediate bearing under the three-bearing structure can be determined based on the target deformation variable. Optionally, the inter-shaft fit tolerance should be greater than the obtained target deformation variable U.

[0073] The technical solution of this embodiment is to obtain at least one refined grid to be used by meshing the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing in the finite element model, and apply different types of forces to the finite element model to determine the radial deformation amounts of each refined grid to be used corresponding to the transmission input shaft and the motor output shaft under different forces, determine the target deformation amount based on each radial deformation amount, and then determine the fitting tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount, thereby solving the problem of low accuracy in determining the fitting tolerance between the shafts of the three-bearing structure based on manual experience in the prior art, and achieving the determination of the radial deformation amounts corresponding to the transmission input shaft and the motor output shaft under different types of forces when different types of forces are applied to the finite element model, combining different test conditions, determining the target deformation amount based on the radial deformation amount under each test condition, and determining the fitting tolerance between the shafts of the three-bearing structure based on the target deformation amount, thereby improving the accuracy of determining the fitting tolerance between the shafts and achieving the technical effect of improving the test accuracy and efficiency.

[0074] Embodiment 2

[0075] As an optional embodiment of the above embodiment, in order to make those skilled in the art further understand the technical solution of the embodiment of the present invention, a specific application scenario example is given. For details, please refer to the following specific content.

[0076] For example, see Figure 2 , a finite element model of the three-bearing structure assembly can be established, and all the components in the three-bearing structure are meshed separately. The three-bearing structure includes the transmission input shaft 210, the motor output shaft 250, the first bearing 220, the second bearing 230 and the third bearing 240, and the divided meshes are assembled together to construct a finite element model. When meshing, the contact parts between the transmission input shaft 210, the motor output shaft 250, the first bearing 220, the second bearing 230 and the third bearing 240 can be refined meshed to obtain at least one refined mesh to be used, and the remaining partial structure can be coarsely meshed to obtain at least one coarse mesh. Exemplarily, the transmission input shaft and the motor output shaft are in contact with each other by splines, and you can continue to refer to Figure 3 Considering the calculation accuracy and speed, the tooth surface mesh of the motor output shaft spline 2501 and the transmission input shaft spline 2101 can be divided into partitions, and the spline tooth surface is coarsened in the middle and refined at both ends to form a spline tooth surface fine mesh and a spline tooth surface coarse mesh. Figure 4The motor output shaft spline 2501 and the transmission input shaft spline 2101 can both be modeled using axisymmetry based on the symmetry characteristics of the spline. For example, only a single spline tooth surface mesh is established. Figure 5 , a spline tooth surface in the motor output shaft spline 2501 can be divided into a spline tooth surface refined grid 25011 (i.e., a refined grid to be used) and a spline tooth surface coarse grid 25012, and then a complete spline mesh model can be established through axisymmetry. At the same time, considering the calculation accuracy and calculation convergence of interference contact, the contact areas of the transmission input shaft 210, the motor output shaft 250, the first bearing 220, the second bearing 230 and the third bearing 240 can be cut to form a regular geometric area, so that the unit nodes of the contact part grid correspond one to one, and the corresponding interference contact relationship is established.

[0077] On the basis of the above scheme, the elastic modulus of the finite element model can be defined as E=210000MPa, Poisson's ratio μ=0.3, and all finite element models are linear elastic materials and other mechanical property data. Finite element model boundary conditions can also be applied, namely the first model boundary condition and the second model boundary condition, where the first model boundary condition is to fix all degrees of freedom of the bearing except the axial rotation degree of freedom. The second model boundary condition is to fix the axial rotation degree of freedom of the motor output shaft. It should be noted that the first model boundary condition and the second model boundary condition can separately constrain the finite element model. For example, continue to refer to Figure 6 , in fixed Figure 6 When the outer ring of the middle bearing is 2201, it is necessary to apply it with the help of RBE3 unit. Figure 7 , the main point 2202 of the RBE3 unit selects the outer ring surface of the bearing outer ring 2201, and the bearing geometric center is selected from point 2203. Figure 8 , when the boundary is constrained, the freedom of the RBE3 unit from point 2203 around the 6 o'clock direction of the cylindrical coordinate system 2204 can be unconstrained, and all other degrees of freedom are constrained. The Z axis of the cylindrical coordinate system 2204 is along the axis of the gear shaft, the R axis is along the radial direction of the gear shaft, and the t axis is determined by Z and R according to the right-hand rule. When the axial rotation freedom of the motor output shaft 250 is fixed, continue to refer to Fig. 9 , needs to be applied with the help of RBE3 unit, see Fig.10 , the main point 2502 of the RBE3 unit 2504 selects the outer surface of the motor output shaft 250, and the secondary point 2505 selects the geometric center of the motor output shaft 250. When the boundary is constrained, only the 6 o'clock direction degree of freedom of the secondary point 2505 of the RBE3 unit 2504 around the cylindrical coordinate system 2503 can be constrained. In the process of force analysis of the finite element model, all degrees of freedom of the bearing except the axial rotation degree of freedom and the axial rotation degree of freedom of the motor output shaft are fixed, thereby improving the accuracy of model analysis.

[0078] On the basis of the above scheme, different test conditions can be designed, and different forces can be applied under different test conditions. Correspondingly, the radial deformation of each refined grid to be used under different test conditions can be obtained. For example, the test conditions can be: preload condition, gear force condition, and eccentric force condition. The boundary conditions used for these three test conditions are the first model boundary conditions and the second model boundary conditions. Among them, when performing the preload condition test, only the interference of the inner ring of the bearing, that is, the bearing interference force, can be loaded, and the transmission gear meshing force and the motor eccentric load are not applied. When performing the gear force condition test, the transmission gear meshing force can be applied on the basis of the preload condition. For example, continue to refer to Fig.12 , the primary driving gear meshing node 2102 can be used as the slave point of the RBE3 unit 2105, and the unit nodes on the nearby tooth surface 2103 and tooth surface 2104 can be used as the master point of the RBE3 unit 2105. The primary driving gear meshing node 2102 can be used as the node where the transmission gear meshing force needs to be applied, that is, the gear meshing node, which is on the gear pitch diameter. When determining the transmission gear meshing force, the gear meshing force can be calculated according to formula (1) based on the gear transmission torque of the transmission input shaft, the gear meshing parameters and the gear load. Formula (1) is as follows:

[0079]

[0080] The gear meshing force includes the circumferential force F of the gear. t , radial force F r and axial force F a , which can be applied with the help of a local cylindrical coordinate system defined on the axis of the transmission input shaft. M is the torque transmitted by the gear, i.e. the gear transmission torque, d is the gear pitch diameter, α n is the normal pressure angle of the gear, and β is the helix angle at the pitch circle of the gear. When performing the eccentric force condition test, the motor eccentric load can be applied on the basis of the preload condition, for example, continue to refer to Fig.10, the eccentric load F (maximum unilateral magnetic pull) to which the motor output shaft is subjected during operation can be applied to the slave point 2505 of the RBE3 unit 2504 in a static load manner, and the direction of the eccentric load is the R-axis direction of the cylindrical coordinate system 2503. The time period of each test condition can be set to 1, and the time increment can be set to 0.1. The Newton-Raphson method is used to iteratively calculate and output the analysis results of the three-bearing finite element model in the three working condition tests. The smallest radial deformation of the radial deformations corresponding to the inner wall of the transmission input shaft at the second bearing position can be extracted, denoted as u1; for the gear force working condition test, the smallest radial deformation of the radial deformations corresponding to the inner wall of the transmission input shaft at the second bearing position can be extracted, denoted as u2, and the largest radial deformation of the radial deformations corresponding to the outer wall of the motor output shaft at the second bearing position can be extracted, denoted as u3; for the eccentric force working condition test, the smallest radial deformation of the radial deformations corresponding to the inner wall of the transmission input shaft at the second bearing position can be extracted, denoted as u4, and the largest radial deformation of the radial deformations corresponding to the outer wall of the motor output shaft at the second bearing position can be extracted, denoted as u5. The radial deformations obtained under the three working conditions can be calculated according to formula (2) to obtain the target deformation under the combined action of bearing interference, gear force and eccentric force, denoted as, formula (2) is as follows:

[0081] U=∑|u i |,(i=1,2,…,5)(2)

[0082] Among them, U can be expressed as the target shape variable, u i , (i=1,2,…,5) are the corresponding radial deformations obtained under the three test conditions. Furthermore, the inter-shaft fit tolerance of the motor output shaft and the transmission input shaft at the corresponding position of the intermediate bearing under the three-bearing structure can be determined based on the target deformation variable. Optionally, the inter-shaft fit tolerance should be greater than the target deformation variable U obtained.

[0083] The technical solution of this embodiment is to obtain at least one refined grid to be used by meshing the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing in the finite element model, and apply different types of forces to the finite element model to determine the radial deformation amounts of each refined grid to be used corresponding to the transmission input shaft and the motor output shaft under different forces, determine the target deformation amount based on each radial deformation amount, and then determine the fitting tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount, thereby solving the problem of low accuracy in determining the fitting tolerance between the shafts of the three-bearing structure based on manual experience in the prior art, and achieving the determination of the radial deformation amounts corresponding to the transmission input shaft and the motor output shaft under different types of forces when different types of forces are applied to the finite element model, combining different test conditions, determining the target deformation amount based on the radial deformation amount under each test condition, and determining the fitting tolerance between the shafts of the three-bearing structure based on the target deformation amount, thereby improving the accuracy of determining the fitting tolerance between the shafts and achieving the technical effect of improving the test accuracy and efficiency.

[0084] Embodiment 3

[0085] Fig.14 Schematic diagram of a device for determining a matching tolerance according to Embodiment 3 of the present invention. Fig.14 As shown, the apparatus includes: a module 410 for determining a refined grid to be used, a module 420 for determining a radial deformation amount, a module 430 for determining a target deformation amount, and a module 440 for determining a fitting tolerance.

[0086] Among them, the module 410 for determining the refined mesh to be used is used to construct a finite element model based on the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing, and to mesh the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing to obtain at least one refined mesh to be used; the module 420 for determining the radial deformation amount is used to apply different forces to the finite element model to determine the radial deformation amount of each refined mesh to be used corresponding to the transmission input shaft and the motor output shaft under different forces; wherein the direction of the radial deformation amount is perpendicular to the bottom surface of the corresponding shaft; the module 430 for determining the target deformation amount based on each radial deformation amount; the module 440 for determining the fitting tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount.

[0087] The technical solution of this embodiment is to obtain at least one refined grid to be used by meshing the contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing in the finite element model, and apply different types of forces to the finite element model to determine the radial deformation amounts of each refined grid to be used corresponding to the transmission input shaft and the motor output shaft under different forces, determine the target deformation amount based on each radial deformation amount, and then determine the fitting tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount, thereby solving the problem of low accuracy in determining the fitting tolerance between the shafts of the three-bearing structure based on manual experience in the prior art, and achieving the determination of the radial deformation amounts corresponding to the transmission input shaft and the motor output shaft under different types of forces when different types of forces are applied to the finite element model, combining different test conditions, determining the target deformation amount based on the radial deformation amount under each test condition, and determining the fitting tolerance between the shafts of the three-bearing structure based on the target deformation amount, thereby improving the accuracy of determining the fitting tolerance between the shafts and achieving the technical effect of improving the test accuracy and efficiency.

[0088] On the basis of the above device, optionally, the device further includes a finite element model first updating module, and the finite element model first updating module includes a mechanical characteristic data determining unit and a finite element model first updating unit.

[0089] A mechanical property data determination unit, used to determine mechanical property data corresponding to the finite element model; wherein the mechanical property data includes material property data and structural property data;

[0090] The first finite element model updating unit is used to update the finite element model based on the mechanical characteristic data.

[0091] On the basis of the above device, optionally, the device further includes a finite element model second updating module, and the finite element model second updating module includes a boundary condition determination unit and a finite element model second updating unit.

[0092] a boundary condition determination unit, configured to determine a first model boundary condition and a second model boundary condition corresponding to the finite element model; wherein the first model boundary condition is determined based on fixing the first bearing, the second bearing and the third bearing, and the second model boundary condition is determined based on fixing the motor output shaft;

[0093] The second finite element model updating unit is used to update the finite element model based on the first model boundary condition and the second model boundary condition.

[0094] Based on the above device, optionally, the device also includes a force determination module.

[0095] A force determination module is used to determine various forces applied to the finite element model; wherein the forces include bearing interference force, transmission gear meshing force and motor eccentric load, and the transmission gear meshing force is determined based on the gear pitch circle diameter of the transmission input shaft, the gear transmission torque, the gear normal pressure angle and the helix angle at the gear pitch circle.

[0096] On the basis of the above device, optionally, the radial deformation amount determining module 420 includes a radial deformation amount determining first unit.

[0097] The first unit for determining the radial deformation amount is used to apply the bearing interference force to the second bearing in the finite element model to obtain the radial deformation amount of each refined grid to be used corresponding to the shaft inner wall of the transmission input shaft at the second bearing position.

[0098] On the basis of the above device, optionally, the radial deformation amount determining module 420 includes a radial deformation amount determining second unit, and the radial deformation amount determining second unit includes a gear meshing node determining subunit and a radial deformation amount determining second subunit.

[0099] a gear meshing node determination subunit, configured to determine a gear meshing node based on a gear pitch circle diameter of the transmission input shaft in the finite element model;

[0100] The second radial deformation determination subunit is used to apply the transmission gear meshing force to the gear meshing node when the bearing interference force is applied to the second bearing in the finite element model, so as to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position, and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

[0101] On the basis of the above device, optionally, the radial deformation amount determining module 420 includes a radial deformation amount determining third unit, and the radial deformation amount determining third unit includes a motor load sub-point determining sub-unit and a radial deformation amount determining third sub-unit.

[0102] A motor load point determination unit, used to determine the motor load point of the motor output shaft in the finite element model;

[0103] The radial deformation amount determines the third subunit, which is used to apply the motor eccentric load to the motor load from the point when the bearing interference force is applied to the second bearing in the finite element model, so as to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position, and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

[0104] On the basis of the above device, optionally, the target deformation amount determination module 430 includes a minimum radial deformation amount determination unit, a maximum radial deformation amount determination unit and a target deformation amount determination unit.

[0105] a minimum radial deformation amount determining unit, used to determine the minimum radial deformation amount of the shaft inner wall of the transmission input shaft at the second bearing position under different forces; and

[0106] a maximum radial deformation determination unit, used to determine the maximum radial deformation of the outer wall of the motor output shaft at the second bearing position under different forces;

[0107] The target deformation amount determination unit is used to determine the target deformation amount based on each minimum radial deformation amount and each maximum radial deformation amount.

[0108] The fit tolerance determination device provided in the embodiment of the present invention can execute the fit tolerance determination method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0109] Embodiment 4

[0110] Fig.15 1 is a schematic diagram of the structure of an electronic device for implementing the method for determining the matching tolerance of an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0111] like Fig.15 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0112] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0113] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the fit tolerance determination method.

[0114] In some embodiments, the fit tolerance determination method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the fit tolerance determination method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the fit tolerance determination method in any other appropriate manner (e.g., by means of firmware).

[0115] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0116] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0117] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0118] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0119] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0120] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0121] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0122] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a fit tolerance, characterized in that: include: Based on the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing, a finite element model is constructed, and contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing and the third bearing are meshed to obtain at least one refined mesh to be used; Apply different forces to the finite element model to determine the radial deformation amount of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces; wherein the direction of the radial deformation amount is perpendicular to the bottom surface of the corresponding shaft; Based on each radial deformation amount, determining the target deformation amount; Based on the target deformation amount, determining the matching tolerance between the transmission input shaft and the motor output shaft; The method further comprises: determining various forces applied to the finite element model; wherein the forces include bearing interference force and transmission gear meshing force; The step of applying different forces to the finite element model to determine radial deformation amounts of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces includes: determining a gear meshing node based on a gear pitch diameter of the transmission input shaft in the finite element model; When the bearing interference force is applied to the second bearing in the finite element model, the transmission gear meshing force is applied to the gear meshing node to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

2. The method according to claim 1, characterized in that Also includes: Determining mechanical property data corresponding to the finite element model; wherein the mechanical property data includes material property data and structural property data; The finite element model is updated based on the mechanical property data.

3. The method according to claim 1, characterized in that Also includes: Determine a first model boundary condition and a second model boundary condition corresponding to the finite element model; wherein the first model boundary condition is determined based on fixing the first bearing, the second bearing and the third bearing, and the second model boundary condition is determined based on fixing the motor output shaft; The finite element model is updated based on the first model boundary condition and the second model boundary condition.

4. The method according to claim 1, characterized in that: The acting force also includes an eccentric load of the motor, and the transmission gear meshing force is determined based on the gear pitch diameter of the transmission input shaft, the gear transmission torque, the gear normal pressure angle, and the helix angle at the gear pitch circle.

5. The method according to claim 1, characterized in that The step of applying different forces to the finite element model to determine radial deformation amounts of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces includes: The bearing interference force is applied to the second bearing in the finite element model to obtain radial deformation amounts of each refined grid to be used corresponding to the inner wall of the transmission input shaft at the second bearing position.

6. The method according to claim 4, characterized in that The step of applying different forces to the finite element model to determine radial deformation amounts of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces includes: Determining a motor load from a point on the motor output shaft in the finite element model; When the bearing interference force is applied to the second bearing in the finite element model, the motor eccentric load is applied to the motor load from the point to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

7. The method according to claim 1, characterized in that The step of determining a target deformation amount based on each radial deformation amount includes: determining the minimum radial deformation of the inner wall of the transmission input shaft at the second bearing position under different forces; and Determine the maximum radial deformation of the outer wall of the motor output shaft at the second bearing position under different forces; The target deformation amount is determined based on the minimum radial deformation amounts and the maximum radial deformation amounts.

8. A device for determining a fit tolerance, for implementing the method for determining a fit tolerance as claimed in any one of claims 1 to 7, comprising: A module for determining a refined mesh to be used, configured to construct a finite element model based on a transmission input shaft, a motor output shaft, a first bearing, a second bearing, and a third bearing, and to mesh contact parts between the transmission input shaft, the motor output shaft, the first bearing, the second bearing, and the third bearing to obtain at least one refined mesh to be used; A radial deformation determination module is used to apply different forces to the finite element model to determine the radial deformation of each to-be-used refined grid corresponding to the transmission input shaft and the motor output shaft under different forces; wherein the direction of the radial deformation is perpendicular to the bottom surface of the corresponding shaft; A target shape variable determination module is used to determine the target shape variable based on each radial shape variable; A matching tolerance determination module, configured to determine a matching tolerance between the transmission input shaft and the motor output shaft based on the target deformation amount; The device further comprises a force determination module; the force determination module is used to determine various forces applied to the finite element model; wherein the forces include bearing interference force and transmission gear meshing force; The radial deformation amount determination module includes: a gear meshing node determination subunit, which is used to determine the gear meshing node based on the gear pitch circle diameter of the transmission input shaft in the finite element model; a radial deformation amount determination second determination subunit, which is used to apply the transmission gear meshing force to the gear meshing node when the bearing interference force is applied to the second bearing in the finite element model, so as to obtain the radial deformation amounts corresponding to the inner wall of the transmission input shaft at the second bearing position, and the radial deformation amounts corresponding to the outer wall of the motor output shaft at the second bearing position.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the method for determining a fit tolerance according to any one of claims 1 to 7.

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