A differential case performance analysis method and device and a vehicle

Abstract

The application discloses a differential shell performance analysis method and device and a vehicle, and relates to the technical field of simulation analysis, and comprises the following steps: a differential shell assembly finite element model of a differential shell is established; gear meshing force loading points are arranged in the differential shell assembly finite element model, and a differential shell torsion angle of each gear meshing force loading point is determined; the differential shell stress of the gear meshing force loading points is calculated according to the differential shell torsion angle; the impact fatigue damage of the gear meshing force loading points is calculated according to the differential shell stress; and the differential shell is analyzed to meet the impact fatigue performance requirement in response to all the impact fatigue damages being less than a preset threshold. The application restores the real meshing stress position of the gear under impact load, ensures the consistency of simulation and test loading points, effectively improves the fatigue simulation precision, and thus effectively improves the precision of the bench test verification.

Description

Technical Field

[0001] This invention relates to the field of simulation analysis technology, and in particular to a method for analyzing the performance of a differential housing, a device for analyzing the performance of a differential housing, and a vehicle. Background Technology

[0002] Electric vehicle drive motors possess characteristics such as fast torque response, high torque at low speeds, and the ability to generate reverse impact torque through regenerative braking. The transmission system is subjected to frequent alternating positive and negative torsional impact loads. As a critical component of the transmission system, the differential housing is highly susceptible to impact fatigue failure at locations such as the window, planetary gear shaft bore, and transition fillets under alternating positive and negative drive torque impacts. Therefore, simulations of the impact fatigue performance under alternating positive and negative drive torques and bench fatigue tests are necessary to optimize the impact fatigue performance of the housing.

[0003] In impact fatigue performance simulation, loading points are generally arranged along the circumference of the driven gear of the differential, and then alternating torque loads of forward and reverse drive are applied at the loading points to calculate the stress of the differential housing. For example, patent CN115270583A, "Method and System for Torsional Impact Fatigue Analysis of Automobile Differential", randomly divides the circumference of the main reduction gear into equal parts and uses the divided positions as loading points to apply gear meshing force; patent CN116451521A, "Method for Calculating Impact Fatigue Life of Electric Vehicle Differential Housing", determines the loading points according to the number of axes of symmetry, but only the loading points at the axis of symmetry are fixed, while other loading positions are randomly selected; the paper "Simulation Analysis Method for Fatigue Life of Differential Housing" randomly divides the circumference of the differential gear into equal parts, and does not consider the symmetry of the differential when dividing.

[0004] Therefore, the uniformly distributed loading points in the simulation are random. During bench testing, it is difficult to obtain the positions of these loading points, thus affecting the consistency between the simulation and the bench test, resulting in poor simulation accuracy. Furthermore, the loading points in the simulation do not match the actual gear force positions in the bench test, neglecting the crucial physical phenomenon of gear meshing point offset caused by the elastic torsion of the differential housing under alternating torque loads of forward and reverse drives. This further contributes to the poor accuracy of the differential housing fatigue simulation. Summary of the Invention

[0005] The purpose of this invention is to provide a method, device, electronic equipment, storage medium, and vehicle for analyzing the performance of a differential housing. This invention addresses the problem of mismatch between the loading point in simulation and the actual gear force position in bench tests, and solves a key physical problem of poor accuracy in differential housing fatigue simulation caused by neglecting the gear meshing point offset due to the elastic torsion of the differential housing under alternating torque loads of forward and reverse drives.

[0006] This invention provides the following solution:

[0007] According to one aspect of the present invention, a method for analyzing the performance of a differential housing is provided, comprising:

[0008] A finite element model of the differential housing assembly is established. In the finite element model of the differential housing assembly, gear meshing force loading points are arranged, and the differential housing torsional angle of each gear meshing force loading point is determined.

[0009] Calculate the differential housing stress at the gear meshing force loading point based on the differential housing torsion angle.

[0010] Calculate the impact fatigue damage at the gear meshing force loading point based on the differential housing stress.

[0011] Since all the aforementioned impact fatigue damage is less than a preset threshold, the differential housing is analyzed to meet the impact fatigue performance requirements.

[0012] Preferably, determining the differential housing torsional angle at each gear meshing force loading point includes:

[0013] Determine the finite element model boundary conditions, bolt preload, and gear meshing force at each gear meshing force loading point applied to the finite element model of the differential housing assembly;

[0014] Based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force, the torsional angle calculation conditions of each gear meshing force loading point are calculated.

[0015] By rotating the gear meshing force application point around the differential housing axis by an angle, the differential housing torsion angle for each torsion angle calculation condition is obtained.

[0016] Preferably, the gear meshing force includes the forward drive impact gear meshing force corresponding to the forward drive impact torque and the reverse drive impact gear meshing force corresponding to the reverse drive impact torque;

[0017] The calculation of the torsional angle at each gear meshing force loading point based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force includes:

[0018] The forward impact torsional angle calculation condition at the gear meshing force loading point is determined based on the meshing force of the forward impact gear and the preload of the bolt.

[0019] Based on the meshing force of the anti-drive impact gear and the preload of the bolt, the calculation condition of the anti-drive impact torsion angle at the gear meshing force loading point is determined.

[0020] Preferably, the step of rotating the gear meshing force application point around the differential housing rotation axis to obtain the differential housing torsion angle for each torsion angle calculation condition includes:

[0021] By rotating the gear meshing force application point around the differential housing axis, we obtain the differential housing forward drive impact torsion angle generated under the forward drive impact torsion angle calculation condition and the differential housing reverse drive impact torsion angle generated under the reverse drive impact torsion angle calculation condition.

[0022] Preferably, the step of calculating the differential housing stress at the gear meshing force loading point based on the differential housing torsional angle includes:

[0023] The gear meshing force loading point used to calculate the differential housing torsion angle is rotated according to the differential housing torsion angle to obtain the stress loading point;

[0024] At the stress loading point, the bolt preload force of the differential housing and the gear meshing force at the corresponding gear meshing force loading point are applied;

[0025] Based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force, the differential housing stress at the stress loading point is determined.

[0026] Preferably, the gear meshing force includes the forward drive impact gear meshing force corresponding to the forward drive impact torque and the reverse drive impact gear meshing force corresponding to the reverse drive impact torque;

[0027] The determination of the differential housing stress at the stress loading point based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force includes:

[0028] Based on the boundary conditions of the finite element model, the bolt preload, and the meshing force of the forward drive impact gear, the stress of the forward drive impact differential housing is determined.

[0029] Based on the boundary conditions of the finite element model, the bolt preload, and the meshing force of the reverse impact gear, the stress of the reverse impact differential housing is determined.

[0030] Preferably, the step of calculating the impact fatigue damage at the gear meshing force loading point based on the differential housing stress includes:

[0031] For each stress loading point, among the forward drive impact differential housing stress and the reverse drive impact differential housing stress at the stress loading point, one is determined as the peak stress and the other is determined as the trough stress.

[0032] Calculate the damage stress spectrum at the stress loading point based on the peak stress and the trough stress.

[0033] The impact fatigue damage of the damage stress spectrum is calculated based on the power function formula and the linear fatigue cumulative damage rule formula.

[0034] Preferably, arranging gear meshing force loading points in the finite element model of the differential housing assembly includes:

[0035] The gear meshing force loading point is arranged at the intersection of the plane formed by the bolt axis, the tapered bearing axis and the driven gear pitch circle;

[0036] The gear meshing force loading point is arranged at the intersection of the equidistant line between the axes of two adjacent bolts and the plane containing the axis of the tapered bearing with the pitch circle of the driven gear.

[0037] According to a second aspect of the present invention, a differential housing performance analysis apparatus is provided, comprising:

[0038] An angle determination module is used to establish a finite element model of the differential housing assembly, in which gear meshing force loading points are arranged and the differential housing torsional angle of each gear meshing force loading point is determined.

[0039] The stress calculation module is used to calculate the differential housing stress at the gear meshing force loading point based on the differential housing torsional angle.

[0040] The impact fatigue damage calculation module is used to calculate the impact fatigue damage at the gear meshing force loading point based on the stress of the differential housing.

[0041] An analysis module is used to analyze whether the differential housing meets the impact fatigue performance requirements in response to all of the impact fatigue damages being less than a preset threshold.

[0042] According to three aspects of the present invention, an electronic device is provided, comprising: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0043] The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the differential housing performance analysis method.

[0044] According to four aspects of the present invention, a computer-readable storage medium is provided, comprising: storing a computer program executable by an electronic device, wherein when the computer program is run on the electronic device, the electronic device performs the steps of a differential housing performance analysis method.

[0045] According to five aspects of the present invention, a vehicle is provided, comprising:

[0046] Electronic equipment used to implement the steps of a method for analyzing the performance of a differential housing;

[0047] The processor runs a program, and when the program runs, it executes the steps of the differential housing performance analysis method based on data output from electronic devices.

[0048] Storage medium for storing programs that, when run, execute steps of a differential housing performance analysis method based on data output from electronic devices.

[0049] The above solution achieves the following beneficial technical effects:

[0050] This invention arranges gear meshing force loading points in the finite element model of the differential housing assembly, which not only helps to keep the loading points of the simulation consistent with those of the bench test, but also captures the weakest state of the differential housing fatigue performance, thus maximizing the reliability of the differential housing.

[0051] This invention determines the differential housing torsion angle at each gear meshing force loading point, and then calculates the differential housing stress at the gear meshing force loading point based on the differential housing torsion angle. This can restore the actual meshing force position of the gears under impact load, ensure the consistency between the simulation and the test loading points, and effectively improve the accuracy of fatigue simulation.

[0052] This invention determines that the differential housing meets the impact fatigue performance requirements when all impact fatigue damage is less than a preset threshold. This ensures the consistency between simulation and test loading conditions to the greatest extent, thereby effectively improving the accuracy of bench test verification. Attached Figure Description

[0053] Figure 1 This is a flowchart of a differential housing performance analysis method provided by one or more embodiments of the present invention.

[0054] Figure 2 This is a schematic diagram of the differential housing torsional angle loading point arrangement provided in a specific embodiment of the present invention; wherein, Figure 2 Points 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, 4-2, 5-1, 5-2, 6-1, 6-2, 7-1, 7-2, 8-1, 8-2, 9-1, 9-2, 10-1, and 10-2 are all gear meshing force loading points.

[0055] Figure 3 This is a schematic diagram of the stress loading point of the differential housing provided in a specific embodiment of the present invention.

[0056] Figure 4 This is a schematic diagram of the differential housing stress corresponding to the forward drive impact stress condition 1 provided in a specific embodiment of the present invention.

[0057] Figure 5 This is a schematic diagram of the differential housing stress corresponding to the reverse drive impact stress condition 1 provided in a specific embodiment of the present invention.

[0058] Figure 6 This is a schematic diagram of differential housing damage corresponding to 30,000 cycles of the first damage stress spectrum provided in a specific embodiment of the present invention.

[0059] Figure 7 This is a schematic diagram of differential housing damage calculated based on the gear meshing force corresponding to the applied forward and reverse drive impact torques at point 1, according to a specific embodiment of the present invention.

[0060] Figure 8 This is a structural diagram of a differential housing performance analysis device provided in one or more embodiments of the present invention.

[0061] Figure 9 This is an electronic device structural block diagram of a differential housing performance analysis method provided in one or more embodiments of the present invention. Detailed Implementation

[0062] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] Figure 1 This is a flowchart of a differential housing performance analysis method provided by one or more embodiments of the present invention.

[0064] like Figure 1 The differential housing performance analysis method shown includes:

[0065] Step S1: Establish a finite element model of the differential housing assembly. In the finite element model of the differential housing assembly, arrange the gear meshing force loading points and determine the differential housing torsion angle of each gear meshing force loading point.

[0066] Using a finite element model, solid meshes were generated for the differential housing, planetary gears, half-shaft gears, slotted shaft, pins, driven gears, shims, bolts, and tapered bearings in the differential assembly. The meshes for contacting parts were finely divided, while the meshes for non-contact parts were coarsely divided. This approach aimed to reduce the computational scale and improve the model's computational speed without compromising force transmission accuracy.

[0067] Then, by defining the contact relationships between the contacting components, a finite element model of the differential housing assembly is established.

[0068] In the finite element model of the differential housing assembly, the elastic modulus E and Poisson's ratio μ of the materials of each component in the finite element model are defined. The elastic modulus of the differential housing finite element model material is defined. Poisson's ratio Elastic modulus of materials in finite element models of planetary gears, half-shaft gears, slotted shafts, pins, driven gears, shims, bolts, and tapered bearings. Poisson's ratio All materials are linearly elastic.

[0069] In the finite element model of the differential housing assembly, gear meshing force loading points are arranged according to the structural characteristics of the differential housing to facilitate the calculation of the differential housing torsion angle at each gear meshing force loading point.

[0070] Step S2: Calculate the differential housing stress at the gear meshing force loading point based on the differential housing torsion angle.

[0071] In this embodiment, the loading point can be redefined according to the torsion angle, the load calculated by the finite element model can be applied, and the stress calculation conditions can be defined to calculate the differential housing stress at the gear meshing force loading point under each stress calculation condition.

[0072] The loads calculated by the finite element model include bolt preload and gear meshing force at each gear meshing point.

[0073] Step S3: Calculate the impact fatigue damage at the gear meshing force loading point based on the differential housing stress.

[0074] The peak stress and trough stress required for impact fatigue damage are defined in the differential housing stress. Then, the impact fatigue damage at the gear meshing force loading point is calculated using the power function formula and the linear fatigue cumulative damage rule formula.

[0075] Step S4: In response to all impact fatigue damage being less than a preset threshold, the differential housing is analyzed to meet the impact fatigue performance requirements.

[0076] The preset threshold can be 1, meaning that if all calculated impact fatigue damage values ​​are less than 1, the differential housing meets the impact fatigue performance requirements. If there are impact fatigue damage values ​​greater than 1, the differential housing structure needs to be optimized.

[0077] The following embodiments will provide a detailed description of the present invention in conjunction with the accompanying drawings.

[0078] In this embodiment, the boundary conditions of the finite element model applied to the differential housing assembly finite element model include two parts: first, fixing the outer rings of the bearings at both ends of the differential to simulate the supporting effect of the reducer housing on the differential bearings; second, constraining the rotational degrees of freedom of the half-shaft gear to simulate the supporting reaction force of the half-shaft on the half-shaft gear. The outer rings of the bearings at both ends of the differential need to be fixed using multi-point constraint (MPC) elements (Rigid Body Element Type 3, RBE3). The principal point of the RBE3 element is selected from the nodes on the outer surface of the outer rings of the bearings at both ends of the differential, and the secondary point is selected from the point on the axis of the bearing outer ring corresponding to the middle position of the outer ring width. The rotation of the half-shaft gear needs to be fixed using RBE3 elements. The principal point of the RBE3 element is selected from the nodes on the surface of the spline teeth of the half-shaft gear, and the secondary point is selected from a point on the center line of the differential housing.

[0079] Furthermore, since the differential housing is a rotating part, it is usually designed symmetrically in its circumferential direction. Therefore, the gear meshing force loading points can be arranged at the intersection of the plane formed by the bolt axis, the tapered bearing axis, and the driven gear pitch circle. The gear meshing force loading points can also be arranged at the intersection of the equidistant line between two adjacent bolt axes, the plane containing the tapered bearing axis, and the driven gear pitch circle. Alternatively, the gear meshing force loading points can be named point 1, point 2, ..., point n according to their sequential order on the gear pitch circle.

[0080] This embodiment utilizes the symmetry of the differential housing to arrange gear meshing force loading points at typical structural locations. These gear meshing force loading points cover the location with the maximum stiffness (the location where the plane formed by the bolt axis and the cone bearing axis intersects with the driven gear pitch circle) and the location with the minimum stiffness (the location where the equidistant line between two adjacent bolt axes and the plane containing the cone bearing axis intersects with the driven gear pitch circle). This not only helps to keep the loading points consistent between simulation and bench testing, but also captures the weakest state of fatigue performance of the differential housing, thus maximizing the reliability of the differential housing.

[0081] For example, Figure 2 This is a schematic diagram of the differential housing torsional angle loading point arrangement provided in a specific embodiment of the present invention. (See diagram below.) Figure 2As shown, gear meshing force loading points 1-1 and 1-2 are arranged at the intersection of plane 1 formed by the bolt axis and the tapered bearing axis and the driven gear pitch circle; gear meshing force loading points 2-1 and 2-2 are arranged at the intersection of plane 2 formed by the bolt axis and the tapered bearing axis and the driven gear pitch circle; gear meshing force loading points 3-1 and 3-2 are arranged at the intersection of plane 3 formed by the bolt axis and the tapered bearing axis and the driven gear pitch circle; gear meshing force loading points 4-1 and 4-2 are arranged at the intersection of plane 4 formed by the bolt axis and the tapered bearing axis and the driven gear pitch circle; and gear meshing force loading points 5-1 and 5-2 are arranged at the intersection of plane 5 formed by the bolt axis and the tapered bearing axis and the driven gear pitch circle.

[0082] Arrange gear meshing force loading points 6-1 and 6-2 at the intersection of the equidistant line between two adjacent bolt axes, the plane containing the cone bearing axis 6, and the driven gear pitch circle; arrange gear meshing force loading points 7-1 and 7-2 at the intersection of the equidistant line between two adjacent bolt axes, the plane containing the cone bearing axis 7, and the driven gear pitch circle; arrange gear meshing force loading points 8-1 and 8-2 at the intersection of the equidistant line between two adjacent bolt axes, the plane containing the cone bearing axis 8, and the driven gear pitch circle; arrange gear meshing force loading points 8-1 and 8-2 at the intersection of the equidistant line between two adjacent bolt axes, the plane containing the cone bearing axis 9, and the driven gear pitch circle. Place the gear meshing force loading points 9-1 and 9-2; arrange the gear meshing force loading points 10-1 and 10-2 at the intersection of the equidistant line between the axes of two adjacent bolts, the plane containing the cone bearing axis 10, and the driven gear pitch circle; name the points 1-1, 7-2, 2-1, 8-2, 3-1, 9-2, 4-1, 10-2, 5-1, 6-1, 1-2, 7-1, 2-2, 8-1, 3-2, 9-1, 4-2, 10-1, 5-2, and 6-2 as points 1, 2, 3, ..., 20 according to the order of the gear meshing force loading points on the gear pitch circle;

[0083] Based on the location of the loading point, an RBE3 element is created at the corresponding driven gear pitch circle to apply the gear meshing force to the differential housing finite element model.

[0084] In this embodiment, it is also necessary to apply finite element model calculation loads to the differential housing assembly finite element model, including bolt preload and gear meshing force at each loading point.

[0085] The bolt preload is obtained from the relationship between the bolt diameter and the bolt tightening torque, and then applied to the bolt. The gear meshing force is the impact torque M borne by the differential, including the forward drive impact torque M_f and the reverse drive impact torque M_r. The impact torque is converted into gear meshing force according to the gear meshing parameters and gear load calculation formula, and then applied to the determined gear meshing force loading points, such as points 1, 2, ..., n in the above embodiment. Among them, the forward drive impact M_f is equal to 4900 Nm, and the reverse drive impact torque M_r is equal to 2400 Nm.

[0086] The bolt preload can be calculated using the following formula, with the direction of action along the bolt's axial direction.

[0087]

[0088] In the formula, F is the bolt preload, T is the bolt tightening torque, k is the bolt tightening torque coefficient, which can be taken as 0.18, and D is the bolt diameter.

[0089] The gear meshing force at each gear meshing force application point is calculated using the formula from the maximum impact torque. It is decomposed into circumferential force, radial force and axial force, and applied by means of a local cylindrical coordinate system defined on the rotation axis of the differential. The Z-axis of the coordinate system is along the axis of the differential, R is along the radial direction of the differential, and t is determined by Z and R according to the right-hand rule.

[0090] in, The circumferential force of the differential gear. The radial force on the differential gear. Let D be the axial force on the differential gear, and D be the gear pitch circle diameter. The normal pressure angle of the gear. The helix angle at the pitch circle of the gear.

[0091] Furthermore, based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force, the torsional angle calculation conditions at each gear meshing force loading point are calculated. The gear meshing force includes the forward impact gear meshing force corresponding to the forward impact torque and the reverse impact gear meshing force corresponding to the reverse impact torque. Therefore, based on the forward impact gear meshing force and the bolt preload, the forward impact torsional angle calculation conditions at the gear meshing force loading points are determined; similarly, based on the reverse impact gear meshing force and the bolt preload, the reverse impact torsional angle calculation conditions at the gear meshing force loading points are determined.

[0092] Based on the gear meshing force loading points (point 1, point 2, ..., point n) arranged above, the forward drive impact torsion angle working condition 1 includes the finite element model boundary conditions, bolt preload and gear meshing force corresponding to M_f at point 1;

[0093] The positive drive impact torsion angle working condition 2 includes the finite element model boundary conditions, bolt preload and gear meshing force corresponding to M_f at point 2; ......;

[0095] The forward drive impact torsion angle working condition 20 includes the finite element model boundary conditions, bolt preload, and gear meshing force corresponding to M_f at point 20.

[0096] The reverse-drive impact torsion angle working condition 1 includes the finite element model boundary conditions, bolt preload and gear meshing force corresponding to M_r at point 1;

[0097] The reverse-drive impact torsion angle working condition 2 includes the finite element model boundary conditions, the bolt preload in step S42 and the gear meshing force corresponding to M_r at point 2; ......;

[0099] The reverse impact torsion angle working condition 20 includes the boundary conditions of the finite element model, the bolt preload, and the gear meshing force corresponding to M_r at point 20.

[0100] Furthermore, based on the defined order of gear meshing force loading points, the order of the torsional angle calculation conditions for each gear meshing force loading point is determined. Thus, based on the order of the torsional angle calculation conditions for each gear meshing force loading point, the gear meshing force loading point is rotated around the differential housing axis to obtain the differential housing forward impact torsional angle generated under the forward drive impact torsional angle calculation condition and the differential housing reverse drive impact torsional angle generated under the reverse drive impact torsional angle calculation condition.

[0101] For example, calculate the rotation angles of points 1, 2, ..., 20 around the differential housing axis, including the angles generated by forward drive impact torsion angle condition 1. The angle generated by the forward drive impact torsion angle working condition 2 ... the angle generated by the forward drive impact torsion angle condition 20 And the rotation angle generated by the reverse thrust impact torsion angle working condition 1 The angle generated by the reverse thrust torsion angle working condition 2 ...the angle generated by the reverse thrust impact torsion angle working condition 20 ;

[0102] Taking forward drive impact torsion angle condition 1 and reverse drive impact torsion angle condition 1 as examples, the calculated torsion angle is explained. For forward drive impact torsion angle condition 1, the corresponding torsion angle is... Counter-drive impact torsion angle working condition 1 corresponds to .

[0103] Next, the gear meshing force loading point used to calculate the differential housing torsional angle is rotated according to the differential housing torsional angle to obtain the stress loading point. It should be noted that the differential housing torsional angle includes both forward drive impact torsional angle and reverse drive impact torsional angle; therefore, the stress loading points correspond to both forward drive impact stress loading points and reverse drive impact stress loading points.

[0104] For example, according to The direction and magnitude of rotation will cause point 1 to rotate around the axis of rotation of the differential housing. , and obtain the positive drive impact stress loading point f (1);

[0105] according to The direction and magnitude of the rotation will cause point 2 to rotate around the axis of rotation of the differential housing. , and obtain the positive drive impact stress loading point f (2); ......;

[0107] according to The direction and magnitude of rotation will cause point 20 to rotate around the axis of rotation of the differential housing. , and obtain the positive drive impact stress loading point f (20).

[0108] according to The direction and magnitude of rotation will cause point 1 to rotate around the axis of rotation of the differential housing. , and obtain the anti-drive impact stress loading point r (1);

[0109] according to The direction and magnitude of the rotation will cause point 2 to rotate around the axis of rotation of the differential housing. , and obtain the anti-drag impact stress loading point r (2); ......;

[0111] according to The direction and magnitude of rotation will cause point 20 to rotate around the axis of rotation of the differential housing. , and obtain the anti-dive impact stress loading point r (20);

[0112] Based on the positions of points f(1), f(2), ..., f(20), and r(1), r(2), ..., r(20), RBE3 elements are established at the corresponding driven gear pitch circles to reapply the gear meshing force to the differential housing finite element model.

[0113] Taking point 1 as an example, the calculated torsion angle is shown. Figure 3 This is a schematic diagram of the stress loading point of the differential housing provided in a specific embodiment of the present invention. Figure 3 As shown, point 1 rotates. Then obtain point f(1), rotate point 1. Then point r(1) is obtained.

[0114] At the stress loading point, the bolt preload of the differential housing and the corresponding gear meshing force are applied. The stress of the positive drive impact differential housing is determined based on the boundary conditions of the finite element model, the bolt preload, and the meshing force of the positive drive impact gear. The stress of the negative drive impact differential housing is determined based on the boundary conditions of the finite element model, the bolt preload, and the meshing force of the negative drive impact gear. For example, the gear meshing force corresponding to the positive drive impact torque M_f needs to be applied to points f(1), f(2), ..., f(20), respectively, and the gear meshing force corresponding to the negative drive impact torque M_r needs to be applied to points r(1), r(2), ..., r(20), respectively.

[0115] Furthermore, based on the boundary conditions of the finite element model, the bolt preload and the gear meshing force, the stress calculation conditions are defined, namely, the positive drive impact stress condition 1 includes the boundary conditions of the finite element model, the bolt preload and the gear meshing force corresponding to M_f at point f (1);

[0116] The positive drive impact stress condition 2 includes the boundary conditions of the finite element model, the bolt preload and the gear meshing force corresponding to M_f at point f (2); ......;

[0118] The forward drive impact stress condition 20 includes the finite element model boundary conditions, bolt preload and gear meshing force corresponding to M_f at point f (20).

[0119] The reverse drive impact stress condition 1 includes the boundary conditions of the finite element model, the bolt preload and the gear meshing force corresponding to M_r at point r (1);

[0120] The reverse drive impact stress condition 2 includes the boundary conditions of the finite element model, the bolt preload and the gear meshing force corresponding to M_r at point r (2); ......;

[0122] The reverse impact stress condition 20 includes the boundary conditions of the finite element model, the bolt preload and the gear meshing force corresponding to M_r at point r (20).

[0123] Therefore, according to the order of stress calculation conditions, the differential housing stress corresponding to each stress calculation condition is calculated separately. The differential housing stress is illustrated using forward drive impact stress condition 1 and reverse drive impact stress condition 1 as examples. Figure 4 This is a schematic diagram of the differential housing stress corresponding to forward drive impact stress condition 1 provided in a specific embodiment of the present invention. For example... Figure 4 As shown, this represents the differential housing stress corresponding to forward drive impact stress condition 1. Figure 5This is a schematic diagram of the differential housing stress corresponding to the reverse drive impact stress condition 1 provided in a specific embodiment of the present invention. For example... Figure 5 The figure shows the differential housing stress corresponding to the reverse drive impact stress condition 1.

[0124] For each stress loading point, one of the stresses on the front drive impact differential housing and the stress on the back drive impact differential housing at the stress loading point is determined as the peak stress and the other as the trough stress; the damage stress spectrum of the stress loading point is calculated based on the peak stress and the trough stress.

[0125] For example, the first damage stress spectrum: take the stress corresponding to either the forward drive impact stress condition 1 or the reverse drive impact stress condition 1 as the peak stress, and the stress corresponding to the other condition as the trough stress.

[0126] Second damage stress spectrum: Take the stress corresponding to either the forward drive impact stress condition 2 or the reverse drive impact stress condition 2 as the peak stress, and the stress corresponding to the other condition as the trough stress. ......;

[0128] Damage stress spectrum 20: Take the stress corresponding to either the forward drive impact stress condition 20 or the reverse drive impact stress condition 20 as the peak stress, and the stress corresponding to the other condition as the trough stress.

[0129] The stress spectra of the first damage, the stress spectra of the second damage, ..., the stress spectra of the 20th damage are all cycled 30,000 times;

[0130] The impact fatigue damage of the damage stress spectrum is calculated based on the power function formula and the linear fatigue cumulative damage (Palmgren-Miner) rule formula.

[0131] The formula for the power function is as follows:

[0132]

[0133] In the formula, denoted as stress amplitude; m and C are constants related to the material and stress ratio, and N is the number of cycles on the stress-life curve.

[0134] The formula for the linear fatigue cumulative damage law is as follows:

[0135]

[0136] In the formula, D represents high-cycle fatigue damage; n represents the stress amplitude. The number of loops.

[0137] Taking the damage of the first damage stress spectrum as an example, the damage to the differential housing is illustrated. Figure 6This is a schematic diagram of differential housing damage corresponding to 30,000 cycles of the first damage stress spectrum provided in a specific embodiment of the present invention. (See diagram below.) Figure 6 As shown, this is the differential housing damage corresponding to 30,000 cycles of the first damage stress spectrum. The maximum value is 0.95, which is less than 1 and meets the requirements.

[0138] Figure 7 This is a schematic diagram of differential housing damage calculated based on the gear meshing forces corresponding to the applied forward and reverse drive impact torques at point 1, according to a specific embodiment of the present invention. Figure 7 As shown, the differential housing damage is calculated by applying the gear meshing force corresponding to M_f and the gear meshing force corresponding to M_r at point 1, respectively. Figure 6 and Figure 7 The comparison shows that the differential housing damage calculated using this embodiment is 17.3% higher, indicating a significant change in damage.

[0139] This embodiment first applies forward and reverse drive impact torques to determine the differential housing torsional angle at each initial loading point. Then, based on the torsional angle offset, it regenerates the gear meshing force loading points and applies the load a second time to calculate the true stress field. This addresses the inherent error of existing technologies that use fixed loading points and ignore impact deformation offsets. Furthermore, by uniformly selecting gear meshing force loading points based on features such as bolts and bearing axes on the differential housing, it solves the problem of inconsistent loading points between simulation and bench tests caused by randomly arranging gear meshing force loading points in existing technologies.

[0140] In this embodiment, when conducting fatigue bench tests on the differential housing using simulated loading points (i.e., the arranged gear meshing force loading points), it is only necessary to apply the forward and reverse drive impact torques for the first time to ensure that the bench test and simulated loading points are consistent. Other gear meshing force loading points can be obtained by rotating the differential by the corresponding angle according to the principle of uniform distribution of loading points. This maximizes the consistency between the simulation and test loading conditions and effectively improves the accuracy of bench test verification.

[0141] Figure 8 This is a structural diagram of a differential housing performance analysis device provided in one or more embodiments of the present invention.

[0142] like Figure 8 The differential housing performance analysis device shown includes: an angle determination module, a stress calculation module, an impact fatigue damage calculation module, and an analysis module.

[0143] An angle determination module is used to establish a finite element model of the differential housing assembly, in which gear meshing force loading points are arranged and the differential housing torsional angle of each gear meshing force loading point is determined.

[0144] The stress calculation module is used to calculate the differential housing stress at the gear meshing force loading point based on the differential housing torsional angle.

[0145] The impact fatigue damage calculation module is used to calculate the impact fatigue damage at the gear meshing force loading point based on the stress of the differential housing.

[0146] An analysis module is used to analyze whether the differential housing meets the impact fatigue performance requirements in response to all of the impact fatigue damages being less than a preset threshold.

[0147] An angle determination module is used to determine the finite element model boundary conditions, bolt preload, and gear meshing force at each gear meshing force loading point applied to the finite element model of the differential housing assembly; based on the finite element model boundary conditions, bolt preload, and gear meshing force, it calculates the torsional angle calculation conditions at each gear meshing force loading point; and rotates the gear meshing force loading point around the differential housing rotation axis to obtain the differential housing torsional angle for each torsional angle calculation condition.

[0148] The gear meshing force includes the forward drive impact gear meshing force corresponding to the forward drive impact torque and the reverse drive impact gear meshing force corresponding to the reverse drive impact torque; the angle determination module is used to determine the forward drive impact torsion angle calculation condition at the gear meshing force loading point based on the forward drive impact gear meshing force and the bolt preload force; and to determine the reverse drive impact torsion angle calculation condition at the gear meshing force loading point based on the reverse drive impact gear meshing force and the bolt preload force.

[0149] The angle determination module is used to determine the rotation angle of the gear meshing force loading point around the rotation axis of the differential housing, thereby obtaining the differential housing forward impact torsion angle generated under the forward drive impact torsion angle calculation condition and the differential housing reverse drive impact torsion angle generated under the reverse drive impact torsion angle calculation condition.

[0150] The stress calculation module is used to rotate the gear meshing force loading point used to calculate the differential housing torsion angle according to the differential housing torsion angle to obtain the stress loading point; at the stress loading point, the bolt preload force of the differential housing and the corresponding gear meshing force of the gear meshing force loading point are applied; based on the boundary conditions of the finite element model, the bolt preload force and the gear meshing force, the differential housing stress at the stress loading point is determined.

[0151] The gear meshing force includes the forward drive impact gear meshing force corresponding to the forward drive impact torque and the reverse drive impact gear meshing force corresponding to the reverse drive impact torque; the stress calculation module is used to determine the stress of the forward drive impact differential housing based on the boundary conditions of the finite element model, the bolt preload, and the forward drive impact gear meshing force; and to determine the stress of the reverse drive impact differential housing based on the boundary conditions of the finite element model, the bolt preload, and the reverse drive impact gear meshing force.

[0152] The impact fatigue damage calculation module is used to determine, for each stress loading point, one of the stresses on the forward drive impact differential housing and the stress on the reverse drive impact differential housing at the stress loading point as a peak stress and the other as a trough stress; calculate the damage stress spectrum of the stress loading point based on the peak stress and the trough stress; and calculate the impact fatigue damage of the damage stress spectrum according to the power function formula and the linear fatigue cumulative damage rule formula.

[0153] The angle determination module is also used to arrange gear meshing force loading points at the intersection of the plane formed by the bolt axis and the tapered bearing axis with the driven gear pitch circle; and to arrange gear meshing force loading points at the intersection of the equidistant line between two adjacent bolt axes, the plane containing the tapered bearing axis, and the driven gear pitch circle.

[0154] Figure 9 This is an electronic device structural block diagram of a differential housing performance analysis method provided in one or more embodiments of the present invention.

[0155] like Figure 9 As shown, the present invention provides an electronic device, including: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0156] The memory stores a computer program that, when executed by a processor, causes the processor to perform steps of a differential housing performance analysis method.

[0157] The present invention also provides a computer-readable storage medium storing a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of a differential housing performance analysis method.

[0158] The present invention also provides a vehicle, comprising:

[0159] Electronic equipment for implementing steps based on a differential housing performance analysis method;

[0160] The processor runs a program, and when the program runs, it executes the steps of the differential housing performance analysis method based on data output from electronic devices.

[0161] Storage medium for storing programs that, when run, execute steps of a differential housing performance analysis method based on data output from electronic devices.

[0162] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0163] The electronic device comprises a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on the operating system. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory. The operating system can be any one or more computer operating systems that control the electronic device through processes, such as Linux, Unix, Android, iOS, or Windows. Furthermore, in this embodiment of the invention, the electronic device can be a smartphone, tablet computer, or other handheld device, or a desktop computer, portable computer, or other electronic device; there is no particular limitation in this embodiment.

[0164] In this embodiment of the invention, the executing entity for electronic device control can be an electronic device itself, or a functional module within an electronic device capable of calling and executing a program. The electronic device can obtain the firmware corresponding to the storage medium. This firmware is provided by the supplier, and different storage media may have the same or different firmware; no limitation is made here. After obtaining the firmware corresponding to the storage medium, the electronic device can write this firmware into the storage medium; specifically, it burns the firmware corresponding to the storage medium into the storage medium. The process of burning the firmware into the storage medium can be implemented using existing technology, and will not be elaborated upon in this embodiment of the invention.

[0165] Electronic devices can also obtain reset commands corresponding to the storage media. The reset commands corresponding to the storage media are provided by the supplier. The reset commands corresponding to different storage media can be the same or different, and no restrictions are imposed here.

[0166] At this time, the storage medium of the electronic device is a storage medium on which the corresponding firmware has been written. The electronic device can respond to the reset command corresponding to the storage medium on which the corresponding firmware has been written, thereby resetting the storage medium on which the corresponding firmware has been written according to the reset command. The process of resetting the storage medium according to the reset command can be implemented by existing technology and will not be described in detail in this embodiment of the invention.

[0167] For ease of description, the above apparatus is described by dividing it into various units and modules according to their functions. Of course, in implementing this invention, the functions of each unit and module can be implemented in one or more software and / or hardware.

[0168] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined.

[0169] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0170] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for analyzing the performance of a differential housing, characterized in that, include: A finite element model of the differential housing assembly is established. In the finite element model of the differential housing assembly, gear meshing force loading points are arranged, and the differential housing torsional angle of each gear meshing force loading point is determined. Calculate the differential housing stress at the gear meshing force loading point based on the differential housing torsion angle. Calculate the impact fatigue damage at the gear meshing force loading point based on the differential housing stress. Since all the aforementioned impact fatigue damage is less than a preset threshold, the differential housing is analyzed to meet the impact fatigue performance requirements.

2. The differential housing performance analysis method according to claim 1, characterized in that, Determining the differential housing torsional angle at each gear meshing force loading point includes: Determine the finite element model boundary conditions, bolt preload, and gear meshing force at each gear meshing force loading point applied to the finite element model of the differential housing assembly; Based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force, the torsional angle calculation conditions of each gear meshing force loading point are calculated. By rotating the gear meshing force application point around the differential housing axis by an angle, the differential housing torsion angle for each torsion angle calculation condition is obtained.

3. The differential housing performance analysis method according to claim 2, characterized in that, The gear meshing force includes the positive drive impact gear meshing force corresponding to the positive drive impact torque and the reverse drive impact gear meshing force corresponding to the reverse drive impact torque; The calculation of the torsional angle at each gear meshing force loading point based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force includes: The forward impact torsional angle calculation condition at the gear meshing force loading point is determined based on the meshing force of the forward impact gear and the preload of the bolt. Based on the meshing force of the anti-drive impact gear and the preload of the bolt, the calculation condition of the anti-drive impact torsion angle at the gear meshing force loading point is determined.

4. The differential housing performance analysis method according to claim 3, characterized in that, The step of rotating the gear meshing force application point around the differential housing axis to obtain the differential housing torsion angle for each torsion angle calculation condition includes: By rotating the gear meshing force application point around the differential housing axis, we obtain the differential housing forward drive impact torsion angle generated under the forward drive impact torsion angle calculation condition and the differential housing reverse drive impact torsion angle generated under the reverse drive impact torsion angle calculation condition.

5. The differential housing performance analysis method according to claim 2, characterized in that, The step of calculating the differential housing stress at the gear meshing force loading point based on the differential housing torsional angle includes: The gear meshing force loading point used to calculate the differential housing torsion angle is rotated according to the differential housing torsion angle to obtain the stress loading point; At the stress loading point, the bolt preload force of the differential housing and the gear meshing force at the corresponding gear meshing force loading point are applied; Based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force, the differential housing stress at the stress loading point is determined.

6. The differential housing performance analysis method according to claim 5, characterized in that, The gear meshing force includes the positive drive impact gear meshing force corresponding to the positive drive impact torque and the reverse drive impact gear meshing force corresponding to the reverse drive impact torque; The determination of the differential housing stress at the stress loading point based on the boundary conditions of the finite element model, the bolt preload, and the gear meshing force includes: Based on the boundary conditions of the finite element model, the bolt preload, and the meshing force of the forward drive impact gear, the stress of the forward drive impact differential housing is determined. Based on the boundary conditions of the finite element model, the bolt preload, and the meshing force of the reverse impact gear, the stress of the reverse impact differential housing is determined.

7. The differential housing performance analysis method according to claim 6, characterized in that, The calculation of impact fatigue damage at the gear meshing force loading point based on the differential housing stress includes: For each stress loading point, among the forward drive impact differential housing stress and the reverse drive impact differential housing stress at the stress loading point, one is determined as the peak stress and the other is determined as the trough stress. Calculate the damage stress spectrum at the stress loading point based on the peak stress and the trough stress. The impact fatigue damage of the damage stress spectrum is calculated based on the power function formula and the linear fatigue cumulative damage rule formula.

8. The differential housing performance analysis method according to claim 1, characterized in that, The arrangement of gear meshing force loading points in the finite element model of the differential housing assembly includes: The gear meshing force loading point is arranged at the intersection of the plane formed by the bolt axis, the tapered bearing axis and the driven gear pitch circle; The gear meshing force loading point is arranged at the intersection of the equidistant line between the axes of two adjacent bolts and the plane containing the axis of the tapered bearing with the pitch circle of the driven gear.

9. A differential housing performance analysis device, characterized in that, The method described using any one of claims 1-8 includes: An angle determination module is used to establish a finite element model of the differential housing assembly, in which gear meshing force loading points are arranged and the differential housing torsional angle of each gear meshing force loading point is determined. The stress calculation module is used to calculate the differential housing stress at the gear meshing force loading point based on the differential housing torsional angle. The impact fatigue damage calculation module is used to calculate the impact fatigue damage at the gear meshing force loading point based on the stress of the differential housing. An analysis module is used to analyze whether the differential housing meets the impact fatigue performance requirements in response to all of the impact fatigue damages being less than a preset threshold.

10. A vehicle, characterized in that, include: An electronic device for implementing the steps of the differential housing performance analysis method as described in any one of claims 1 to 8; A processor that runs a program, and when the program runs, it performs the steps of the differential housing performance analysis method as described in any one of claims 1 to 8 by taking data output from an electronic device. A storage medium for storing a program that, when run, performs the steps of the differential housing performance analysis method as described in any one of claims 1 to 8 on data output from an electronic device.

Images