A method, system and apparatus for modifying a differential ring gear

Abstract

The application discloses a method, a system and an apparatus for modifying a differential gear ring. The method comprises establishing a simulation model of the differential gear; performing misalignment analysis on the simulation model of the differential gear under multiple phases to determine the misalignment amount of the differential gear ring; performing contact surface pressure analysis on the differential gear ring under multiple phases based on the misalignment amount of the differential gear ring to determine a first modification area of the differential gear ring; performing transmission error analysis on the differential gear ring under multiple phases based on the misalignment amount of the differential gear ring to determine a second modification area of the differential gear ring; and determining modification parameters of the differential gear ring according to the first modification area and the second modification area. The misalignment analysis and the contact surface pressure analysis on the differential gear ring make the first modification area meet the misalignment amount and the contact surface pressure requirement of the differential gear ring. The transmission error analysis on the differential gear ring under multiple phases makes the modification parameters take into account the transmission error and the strength under multiple phases.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical parts, in particular to a differential gear ring reshaping method, a differential gear ring reshaping system and a differential gear ring reshaping device. BACKGROUND

[0002] With the popularity of vehicles, users have higher and higher requirements for the riding experience. NVH (Noise, Vibration, Harshness) is increasingly concerned. The most commonly used way to improve NVH is micro-reshaping of gears. The existing micro-reshaping of gears (such as involute helical gears) is usually only for the reshaping of a certain specific working condition, and the optimization target can only be a single target value of contact spot or peak-to-peak transmission error. The result of the reshaping can only solve one of them, and the other factor can only be slightly improved or remain unchanged, or the NVH performance of one specific working condition is solved, while the other working conditions still have no improvement effect or even deterioration.

[0003] For differential gear ring reshaping, since the differential gear is provided with a window, the axial stiffness and gear misalignment of the differential gear are different in different rotational positions. The existing micro-reshaping of gears is difficult to meet the strength and NVH performance of the differential gear ring. Especially under the change of the axial stiffness and strength of the differential gear in different rotational phases, the existing micro-reshaping of gears is difficult to consider the strength and NVH performance. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a differential gear ring reshaping method, a differential gear ring reshaping system and a differential gear ring reshaping device to solve the problem that the existing micro-reshaping of gears is difficult to consider the strength and NVH performance in differential gear ring reshaping.

[0005] In order to solve the above problems, the following technical solutions are adopted in the present application:

[0006] The present application provides a differential gear ring reshaping method, comprising:

[0007] establishing a simulation model of a differential gear;

[0008] performing misalignment analysis on the simulation model of the differential gear under multiple phases to determine the misalignment of the differential gear ring;

[0009] performing contact surface pressure analysis on the differential gear ring under multiple phases based on the misalignment of the differential gear ring to determine a first reshaping area of the differential gear ring, wherein the contact surface pressure of the first reshaping area is less than a preset pressure value;

[0010] Based on the misalignment of the differential gear ring, a multi-phase transmission error analysis is performed on the differential gear ring to determine the second modification area of ​​the differential gear ring, wherein the transmission error of the second modification area is less than a preset error value.

[0011] The modification parameters of the differential gear ring are determined based on the first modification region and the second modification region.

[0012] Furthermore, the multiple phases include the differential rotation at 0°, 45°, and 90°. The specific steps for performing multi-phase misalignment analysis on the simulation model of the differential include:

[0013] When the differential is rotated at 0°, 45° and 90° respectively, the simulation model of the differential is subjected to misalignment analysis, and the largest misalignment is determined as the misalignment of the differential ring gear.

[0014] Furthermore, before performing multi-phase misalignment analysis on the simulation model of the differential, the reshaping method further includes:

[0015] Determine the direction of rotation of the differential gear ring;

[0016] If the differential ring gear is right-handed, it abuts against the differential housing boss, with the differential ring gear located on the side of the housing boss away from the first axis of the differential. Further, after determining the vehicle's driving condition, the reshaping method also includes:

[0017] If the differential gear ring is left-handed, then the differential gear ring is abutted against the housing boss, and the differential gear ring is located on the side of the housing boss near the first axis of the differential.

[0018] Furthermore, the step of performing multi-phase contact surface pressure analysis on the differential gear ring based on the misalignment specifically includes:

[0019] Based on the misalignment of the differential gear ring, the tooth direction modification range and tooth profile modification range of the differential gear ring are determined.

[0020] Multi-phase contact surface pressure analysis was performed on the differential gear ring.

[0021] The first modification area of ​​the differential gear ring is determined based on the tooth profile modification range, the tooth shape modification range, and the preset modification window.

[0022] Furthermore, the profile modification parameters of the differential gear ring include tooth profile tilt deviation, tooth profile bulging amount, tooth direction tilt deviation, and tooth direction bulging amount.

[0023] The application further provides a modification system of a differential gear ring, which is used to perform the modification method of the differential gear ring, and comprises a simulation model establishing module, a contact surface pressure analyzing module, a transmission error analyzing module and a modification parameter calculating module, wherein

[0024] The simulation model establishing module is used to establish a simulation model of the differential gear ring.

[0025] The contact surface pressure analyzing module is used to analyze the contact surface pressure of the differential gear ring under multiple phases to determine a first modification area of the differential gear ring.

[0026] The transmission error analyzing module is used to analyze the transmission error of the differential gear ring under multiple phases to determine a second modification area of the differential gear ring.

[0027] The modification parameter calculating module is used to determine the modification parameter of the differential gear ring according to the first modification area and the second modification area.

[0028] Further, the modification system further comprises a position determining module, which is used to determine the installation position of the differential gear ring according to the driving condition of the vehicle.

[0029] The application further provides a modification device of a differential gear ring, which comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the modification method of the differential gear ring when the computer program is executed.

[0030] The modification method of the differential gear ring provided by the application is based on the misalignment amount of the differential gear ring, and the contact surface pressure of the differential gear ring under multiple phases is analyzed to determine a first modification area of the differential gear ring, wherein the contact surface pressure of the first modification area is less than a preset pressure value, so that the first modification area meets the misalignment amount and the contact surface pressure requirement of the differential gear ring. The transmission error of the differential gear ring under multiple phases is analyzed based on the misalignment amount of the differential gear ring to determine a second modification area of the differential gear ring, wherein the transmission error of the second modification area is less than a preset error value; and the modification parameter of the differential gear ring is determined according to the first modification area and the second modification area, so that the modification parameter of the differential gear ring takes into account the transmission error and the strength under multiple phases.

[0031] The modification system of the differential gear ring of the embodiment of the present application is used to perform the modification method of the differential gear ring, and comprises an emulation model establishing module, a contact surface pressure intensity analyzing module, a transmission error analyzing module and a modification parameter calculating module. The contact surface pressure intensity analyzing module analyzes the contact surface pressure intensity of the differential gear ring under multiple phases to determine a first modification region of the differential gear ring. The transmission error analyzing module analyzes the transmission error of the differential gear ring under multiple phases to determine a second modification region of the differential gear ring. The modification parameter calculating module determines the modification parameter of the differential gear ring according to the first modification region and the second modification region, so that the modification parameter of the differential gear ring takes into account the transmission error and the strength under multiple phases.

[0032] The modification device of the differential gear ring of the embodiment of the present application comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the modification method of the differential gear ring is implemented, so that the modification parameter of the differential gear ring is determined according to the first modification region and the second modification region, and the modification parameter of the differential gear ring takes into account the transmission error and the strength under multiple phases. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flowchart of a modification method of a differential gear ring is provided for the embodiment of the present application;

[0034] Figure 2 A flowchart of another modification method of a differential gear ring is provided for the embodiment of the present application;

[0035] Figure 3 A flowchart of still another modification method of a differential gear ring is provided for the embodiment of the present application;

[0036] Figure 4 A system block diagram of a modification system of a differential gear ring is provided for the embodiment of the present application;

[0037] Figure 5 A structural diagram of a differential is provided for the embodiment of the present application;

[0038] Figure 6 Another structural diagram of a differential is provided for the embodiment of the present application;

[0039] Figure 7 A schematic diagram of a misplacement analysis of a differential gear ring is provided for the embodiment of the present application;

[0040] Figure 8 A schematic diagram of a contact surface pressure intensity analysis of a differential gear ring is provided for the embodiment of the present application;

[0041] Figure 9 A schematic diagram of transmission error analysis of a differential gear ring according to an embodiment of the present application is provided.

[0042] Figure 10 A schematic diagram of misalignment of a differential gear ring according to the prior art is provided.

[0043] Figure 11 A schematic diagram of a structure of a differential according to the prior art is provided.

[0044] Explanation of Reference Signs:

[0045] 1 - housing boss, 2 - planetary gear shaft, 3 - planetary gear, 4 - half shaft gear, 5 - spacer, 6 - fixing pin, 7 - differential gear ring, 8 - fixing bolt, P - first axis, Q - windowing. DETAILED DESCRIPTION

[0046] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0047] It should be noted that the embodiments and technical features in the embodiments of the present application can be combined with each other without conflict, and the detailed description in the specific embodiments should be understood as an explanation and description of the purpose of the present application, and should not be regarded as an improper limitation on the present application.

[0048] It should be understood that the orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. These orientation terms are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as a limitation on the present application.

[0049] As shown in Figure 5 , Figure 10 and Figure 11 , in a passenger car transmission, the function of the differential is to make the left and right drive wheels rotate at different angular speeds when the car is turning or driving on uneven road surfaces, so as to ensure that the two sides of the drive wheels and the ground are in rolling motion. In order to better reflect the different misalignment of the differential gear ring 7, the positive and negative misalignment in Figure 10 is now described.

[0050] During normal vehicle operation, the torque transmitted by the differential causes the differential ring gear 7 to experience an axial force along the axial direction of the half-shaft gear 4. Existing gear micro-modification optimization targets only a single objective value: the contact patch or the peak-to-peak value of the transmission error. The modification often only addresses one of these factors, while the other factor is only slightly improved or remains unchanged. It may improve NVH performance under one specific operating condition, but not under others. Because the differential has a window Q, its axial stiffness varies in different rotational positions, resulting in different actual misalignment of the differential ring gear 7. Existing gear micro-modification methods struggle to simultaneously address both the tooth surface contact strength and NVH performance of the differential ring gear 7.

[0051] In view of this, such as Figure 1 , Figure 5 and Figure 6 As shown in the figure, this application provides a method for modifying the profile of a differential gear ring, including:

[0052] S1. Establish a simulation model of the differential;

[0053] S2. Perform multi-phase misalignment analysis on the simulation model of the differential to determine the misalignment amount of the differential ring gear;

[0054] S3. Based on the misalignment of the differential gear ring, perform multi-phase contact surface pressure analysis on the differential gear ring to determine the first modification area of ​​the differential gear ring, wherein the contact surface pressure of the first modification area is less than the preset pressure value.

[0055] S4. Based on the misalignment of the differential gear ring, perform multi-phase transmission error analysis on the differential gear ring to determine the second modification area of ​​the differential gear ring, wherein the transmission error of the second modification area is less than the preset error value.

[0056] S5. Determine the modification parameters of the differential gear ring based on the first modification area and the second modification area.

[0057] Specifically, a finite element model of the differential is established, and the model is meshed. For example, a symmetrical bevel gear differential is widely used in automobiles, including a housing boss 1, a planetary gear shaft 2, planetary gears 3, half-shaft gears 4, a washer 5, a retaining pin 6, a differential gear ring 7, and a retaining bolt 8. To ensure the installation of planetary gears 3 and half-shaft gears 4, the differential has a window Q. The retaining pin 6 is used to fix the planetary gear shaft 2. A finite element model of the symmetrical bevel gear differential is established, and the model is meshed.

[0058] The simulation model of the differential is analyzed for misalignment in multiple phases to determine the misalignment amount of the differential ring gear. Since the differential is provided with a window Q, the axial stiffness of the differential is different in different rotational positions, and the misalignment amount of the differential ring gear 7 is also different. After the simulation model of the differential is established, the simulation model of the differential is analyzed for misalignment in multiple phases to determine the misalignment amount of the differential ring gear 7 in different rotational phases. The maximum misalignment amount of the differential ring gear 7 in different rotational phases is selected as the misalignment amount of the differential ring gear, and the misalignment amount of the differential ring gear is used as a reference basis for subsequent analysis. For example, the simulation model of the differential is analyzed for misalignment in different phases, and the maximum misalignment amount is denoted as f_(shmax). The tooth direction modification amount optimization range of the differential ring gear 7 can be taken as 2 times, i.e. ±2f_(sh max). In the rotational phase of 45°, the misalignment amount of the ring gear is the maximum, and the value is 20um. Therefore, the tooth direction modification amount optimization range is taken as ±40um.

[0059] Based on the misalignment amount of the differential ring gear, the contact surface pressure of the differential ring gear 7 is analyzed in multiple phases to determine the first modification region of the differential ring gear 7, wherein the contact surface pressure of the first modification region is less than a preset pressure value. For example, the preset contact surface pressure value is 1800MPa. According to the modification process parameters of the differential ring gear 7 and the misalignment amount in the previous process, a suitable modification window is selected, and the contact surface pressure of the differential ring gear 7 in different phases is analyzed, i.e. multi-objective optimization analysis of gear contact surface pressure in different phases. From the contact surface pressure analysis graph of the differential ring gear 7, the first modification region of the differential ring gear 7 is determined through the selected modification window, wherein, as shown in Figure 8 the horizontal axis is the tooth direction modification region, and the vertical axis is the tooth shape direction modification region. The position region of the selected modification window is the gear modification region that satisfies the contact surface pressure.

[0060] Based on the misalignment amount of the differential ring gear 7, the transmission error of the differential ring gear 7 is analyzed in multiple phases to determine the second modification region of the differential ring gear 7, wherein the transmission error of the second modification region is less than a preset error value. For example, the preset error value is 0.5um, i.e. the transmission error target value of the gear pair in which the differential ring gear 7 is located is 0.5um. According to the modification process parameters of the differential ring gear 7 and the misalignment amount, a suitable modification window is selected. Based on the modification window, the second modification region of the differential ring gear 7 is determined from the transmission error analysis results of the differential ring gear 7 in different phases, wherein the horizontal axis is the tooth direction modification region, and the vertical axis is the tooth shape direction modification region. The position region of the selected modification window is the modification region that satisfies the transmission error analysis.

[0061] The modification parameters of the differential gear ring 7 are determined according to the first modification region and the second modification region. It should be noted that the values of the modification parameters of the differential gear ring 7 determined in the first modification region and the second modification region are not the same, and the first modification region and the second modification region partially overlap, and the overlapping part of the first modification region and the second modification region is the modification parameter of the differential gear ring 7.

[0062] By analyzing the differential gear ring misalignment and the contact surface pressure, the first modification region meets the misalignment amount and the contact surface pressure requirement of the differential gear ring, and the transmission error analysis of the differential gear ring under multiple phases is performed, so that the modification parameters consider the transmission error and strength under multiple phases.

[0063] It should be understood that due to the windowing Q of the differential, the axial stiffness of the differential is different in different rotational positions, resulting in different misalignment amounts of the differential gear ring 7. In order to ensure the contact strength and NVH performance of the differential gear ring 7, the differential gear ring 7 under different rotational phases needs to be modified to ensure the reliability and NVH performance of the differential gear ring 7. Among them, the contact strength of the differential gear ring 7 mainly concerns the tooth surface contact surface pressure, and the target value is usually determined according to the contact strength SN curve of the differential gear ring 7; the NVH performance mainly concerns the transmission error of the gear pair where the differential gear ring 7 is located, and the target value is usually determined according to the database of different manufacturers. It should be noted that the misalignment analysis under multiple phases, the transmission error analysis under multiple phases, and the contact surface pressure analysis under multiple phases at least include three different phases of the differential. In order to consider the analysis efficiency and phase number of the above three kinds of analysis, it is appropriate to analyze the differential under three different phases, and more number of positions can be used to further improve the analysis modification precision under the condition of allowing. For example, the differential gear ring misalignment analysis, transmission error analysis, and contact surface pressure analysis under four different phases.

[0064] In order to better understand the modification method of the differential gear ring of the embodiment of the present application, the steps of the modification method of the differential gear ring are described in detail below.

[0065] S1, establish a simulation model of the differential.

[0066] Specifically, a finite element model of the symmetrical bevel gear differential is established, and the model includes the shell boss 1, the planetary gear shaft 2, the planetary gear 3, the half shaft gear 4, the gasket 5, the fixed pin 6, the differential gear ring 7 and the fixed bolt 8. After the finite element model of the symmetrical bevel gear differential is established, meshing is performed.

[0067] As shown in Figure 2 In an embodiment, before the misalignment analysis of the simulation model of the differential under multiple phases, the modification method further includes:

[0068] S11, judging the rotation direction of the differential gear ring;

[0069] S11, if the rotation direction of the differential gear ring is right-handed, the differential gear ring is abutted against the housing boss of the differential, and the differential gear ring is located on the side of the housing boss away from the first axis of the differential.

[0070] Specifically, in the gearbox, the differential gear ring 7 is usually a driven gear, and the rotation direction of the differential gear ring 7 is judged under the premise that the gearbox structure has been determined. The greater the axial force of the differential gear ring 7, the higher the axial stiffness of the differential gear ring 7 needs to have, which is used to reduce deformation and thus avoid the reliability and NVH problems caused by gear contact load imbalance. For example, in a three-shaft reduction gearbox, according to the rotation direction of the input shaft, it is determined that the vehicle is front-drive or reverse-drive.

[0071] In normal use of the vehicle, the front-drive is used for starting acceleration or overtaking acceleration, and the reverse-drive is used for coasting or reversing, and the torque usually does not reach the peak value (about 50% Tmax), therefore, the differential gear ring 7 should preferably have sufficient axial stiffness in the front-drive condition. If the vehicle is front-drive, the rotation direction of the differential gear ring 7 is right-handed, the axial force direction of the differential gear ring 7 is matched with the position of the housing boss 1, the differential gear ring 7 is abutted against the housing boss 1 of the differential, and the differential gear ring 7 is located on the side of the housing boss 1 away from the first axis P of the differential. For example, as shown in the position of the differential gear ring 7 in the installation position of the differential gear ring 7, Figure 5 the differential gear ring 7 is fixed on the left side of the housing boss 1, and the axial stiffness of the differential gear ring 7 is greater, which can provide sufficient stiffness support to the right axial force.

[0072] It should be noted that the above description is only for the vehicle as front-drive and the rotation direction of the differential gear ring 7 as right-handed, and should not be understood as improper limitation of the present application. In other cases where the differential gear ring is subjected to the same force, the arrangement form and position of the differential gear ring 7 and the housing boss 1 are also consistent with the above case. Since the vehicle is in the front-drive condition, the load condition of the differential gear ring 7 is relatively severe, and most of the existing differential gear rings 7 are right-handed, the above description is only for the vehicle as front-drive and the rotation direction of the differential gear ring 7 as right-handed.

[0073] In an embodiment, after the step of S11, judging the driving condition of the vehicle, the modification method further comprises:

[0074] S12, if the rotation direction of the differential gear ring is left-handed, the differential gear ring is abutted against the housing boss, and the differential gear ring is located on the side of the housing boss close to the first axis of the differential.

[0075] Specifically, the vehicle is in a reverse driving condition, the rotation direction of the differential gear ring is left-handed, the differential gear ring 7 abuts against the housing boss 1, and the differential gear ring 7 is located on the side of the housing boss 1 close to the first axis P of the differential, wherein the first axis P is the central axis of the planetary gear shaft 2, so that after the differential gear ring 7 is fixed on the right side of the housing boss 1, the stiffness support of the differential gear ring 7 is adapted to the reverse driving condition of the vehicle, and the stiffness support requirement of the vehicle in the reverse driving condition is met.

[0076] S2, dislocation analysis is performed on the simulation model of the differential under multiple phases to determine the dislocation amount of the differential gear ring.

[0077] Specifically, since the differential is provided with the window Q, the axial stiffness of the differential is different in different rotation positions, and the dislocation amount of the differential gear ring 7 is also different. After the simulation model of the differential is established, dislocation analysis is performed on the simulation model of the differential under multiple phases to determine the dislocation amount of the differential gear ring 7 under different rotation phases.

[0078] As shown in FIG. 1, Figure 7 the multiple phases include 0°, 45° and 90° rotation of the differential, and the step of performing dislocation analysis on the simulation model of the differential under multiple phases specifically includes:

[0079] When the differential rotates by 0°, 45° and 90° respectively, dislocation analysis is performed on the simulation model of the differential, and the maximum dislocation amount among them is determined as the dislocation amount of the differential gear ring.

[0080] Specifically, when the differential rotates, the position of the window Q changes. Since the position of the window Q is different in different rotation positions of the differential, the dislocation amount of the differential has multiple phases including 0°, 45° and 90° rotation of the differential. When the differential rotates by 0°, 45° and 90° respectively, dislocation analysis is performed on the simulation model of the differential respectively, and the maximum one among the dislocation amounts of the differential gear ring 7 under 0°, 45° and 90° rotation phases is selected as the dislocation amount of the differential gear ring. For example, under 0°, 45° and 90° rotation phases, dislocation analysis is performed on the simulation model of the differential, and the maximum dislocation amount is recorded as f_(shmax). The tooth direction modification amount optimization range of the differential gear ring 7 can be taken as 2 times of f_(shmax), i.e. ±2f_(shmax). When rotated to the 45° phase, the dislocation amount of the gear ring is the maximum, and the value is 20um. Therefore, the tooth direction modification amount optimization range is taken as ±40um.

[0081] S3, based on the dislocation amount of the differential gear ring, contact surface pressure analysis is performed on the differential gear ring under multiple phases to determine a first modification region of the differential gear ring, wherein the contact surface pressure of the first modification region is less than a preset pressure value.

[0082] Specifically, according to the current differential gear ring 7 modification process parameters and the gear ring misalignment amount, a modification window is determined, a first modification area is selected from the contact surface pressure analysis results of the differential gear ring 7 through the modification window, the first modification area meets the contact surface pressure requirement of the differential gear ring 7, and can also be adapted to the differential gear ring 7 modification process. For example, as shown in Figure 8 the horizontal axis is the transverse direction modification area, and the vertical axis is the tooth shape direction modification area. According to the current differential gear ring 7 modification process parameters and the gear ring misalignment amount, a modification window is determined, and a first modification area is determined from the contact surface pressure analysis results of the differential gear ring 7 at different phases. For example, the preset contact surface pressure value is 1800MPa, and the contact surface pressure of the first modification area is less than 1800MPa.

[0083] In an embodiment, as shown in Figure 3 and Figure 8 S3, based on the misalignment amount of the differential gear ring, the step of performing contact surface pressure analysis of the differential gear ring at multiple phases, specifically includes:

[0084] S31, based on the misalignment amount of the differential gear ring, determining the transverse modification range and the tooth shape modification range of the differential gear ring;

[0085] S32, performing contact surface pressure analysis of the differential gear ring at multiple phases;

[0086] S33, determining the first modification area of the differential gear ring according to the transverse modification range, the tooth shape modification range, and the preset modification window.

[0087] Specifically, based on the misalignment amount of the differential gear ring, the transverse modification range and the tooth shape modification range of the differential gear ring 7 are determined, and the contact surface pressure analysis of the differential gear ring at multiple phases is performed. For example, after establishing the simulation model of the differential gear, the differential gear is rotated at 0°, 45° and 90°, respectively, and the contact surface pressure analysis of the simulation model of the differential gear is performed. In the contact surface pressure analysis results of the differential gear ring 7 at 0°, 45° and 90° rotation phases, the contact surface pressure requirement of the differential gear ring 7 is met.

[0088] According to the transverse modification range, the tooth shape modification range, and the preset modification window, the first modification area of the differential gear ring 7 is determined, wherein the parameters in the first modification area of the differential gear ring can meet the modification process and the gear ring misalignment amount. For example, as shown in Figure 8As shown in the figure, the horizontal axis is the transverse direction modification area, and the vertical axis is the tooth profile modification area. According to the current modification process parameters and the tooth ring misalignment amount of the differential gear ring 7, the transverse modification range and the tooth profile modification range of the differential gear ring are determined, and then according to the transverse modification range, the tooth profile modification range and the preset modification window, the first modification area is determined in the contact surface pressure analysis result of the differential gear ring 7 at different phases. For example, the preset contact surface pressure value is 1800MPa, and the contact surface pressure of the first modification area is less than 1800MPa.

[0089] It should be noted that the transverse modification range and the tooth profile modification range of the differential gear ring 7 are different under different misalignment amounts of the differential gear ring, and then the selection of the first modification area in the subsequent contact surface pressure analysis.

[0090] S4, based on the misalignment amount of the differential gear ring, the transmission error analysis of the differential gear ring at different phases is carried out to determine the second modification area of the differential gear ring, wherein the transmission error of the second modification area is less than the preset error value.

[0091] Specifically, as shown in the figure, Figure 9 According to the current modification process parameters and the tooth ring misalignment amount of the differential gear ring 7, a suitable modification window is selected, and based on the modification window, the second modification area of the differential gear ring 7 is determined from the transmission error analysis result of the differential gear ring 7 at different phases, wherein the transmission error of the second modification area is less than the preset error value. For example, the preset error value is 0.5um, that is, the transmission error target value of the gear pair where the differential gear ring 7 is located is 0.5um, and the determined second modification area is the modification area that meets the transmission error analysis.

[0092] S5, determining the modification parameters of the differential gear ring according to the first modification area and the second modification area.

[0093] Specifically, the modification parameters of the differential gear ring 7 determined in the first modification area and the second modification area are different in value, and the first modification area and the second modification area have a partially overlapping area, and the overlapping part of the first modification area and the second modification area is determined as the modification parameter of the differential gear ring 7.

[0094] In an embodiment, the modification parameters of the differential gear ring 7 include tooth profile tilt deviation, tooth profile crown amount, tooth direction tilt deviation and tooth direction crown amount. Specifically, the modification parameters of the differential gear ring 7 are determined according to the first modification region and the second modification region, and the modification parameters of the differential gear ring 7 include gear ring tooth profile modification amount and tooth direction modification amount, wherein the gear ring tooth profile modification amount includes tooth profile tilt deviation fHa and tooth profile crown amount Ca; the tooth direction modification amount includes tooth direction tilt deviation fHb and tooth direction crown amount Cb. For example, the tooth profile tilt deviation fHa, the tooth profile crown amount Ca, the tooth direction tilt deviation fHb and the tooth direction crown amount Cb of the differential gear ring 7 are determined according to the first modification region and the second modification region.

[0095] In order to better understand the modification method of the differential gear ring of the embodiment of the present application, the process of modifying the differential gear ring will be described in detail below.

[0096] (1) Gear ring installation position design: the axial force direction of the gear ring is determined according to the transmission direction of the driving gear and the rotation direction of the gear, and the axial force of the driven gear is equal in size and opposite in direction to that of the driving gear. In the gearbox, the differential gear ring 7 is usually a driven gear, and the rotation direction of the differential gear ring 7 can be easily determined under the premise of the structure of the gearbox. The greater the axial force of the differential gear ring 7, the higher the axial stiffness of the gear ring required to reduce deformation and thus avoid the reliability and NVH problems caused by gear contact load imbalance. For example, in a three-shaft reduction gearbox, the clockwise rotation direction of the input shaft is observed to determine whether it is a positive drive or a reverse drive.

[0097] In normal use of the vehicle, the peak torque is used in the positive drive for starting acceleration or overtaking acceleration, and the reverse drive is used in the sliding or reversing working condition, and the torque usually does not use the peak torque (about 50% Tmax), so the differential gear ring 7 should preferably have sufficient axial stiffness in the positive drive working condition. The installation position of the differential gear ring 7 of the reduction gearbox is shown in the position of the differential gear ring 7 fixed to the left side of the housing boss 1, and the differential gear ring 7 has a large axial stiffness, which has sufficient stiffness support under the right-down axial force. Figure 5

[0098] (2) Gear ring micro-modification design: in the gear micro-modification design of the differential gear ring 7, the influence of the stiffness difference of the differential gear ring 7 at different rotation phases needs to be considered comprehensively. Generally, the fixed pin 6 is taken as the reference, and the multi-objective optimization of the gear face contact surface pressure and transmission error is performed at 0 degrees, 45 degrees and 90 degrees, and the modification parameters are determined according to the optimization results. The modification parameters of the differential gear ring 7 involve: (I) differential rotation phase; (II) gear ring tooth profile modification amount: tooth profile tilt deviation fHa and tooth profile crown amount Ca; (III) tooth direction modification amount: tooth direction tilt deviation fHb and tooth direction crown amount Cb.

[0099] ​A simulation model of the differential is established, and the finite element mesh of the differential housing is described as follows: Figure 6 As shown. Under different phases, the misalignment analysis of the main reduction gear pair is performed, and the maximum misalignment is denoted as f_(sh max). Typically, the optimization range for tooth profile modification can be twice this value, i.e., ±2f_(sh max). The misalignment analysis results of the differential ring gear 7 under different phases are shown below. Figure 7 As shown, the misalignment of the differential gear ring 7 is the largest at 45° phase, which is 20µm. Therefore, the optimal range for tooth profile modification is ±40µm.

[0100] Multi-objective optimization analysis of the contact surface pressure of differential ring gear 7 was performed under different phases. The optimization results of the contact surface pressure of differential ring gear 7 are as follows: Figure 8 As shown, the horizontal axis represents the tooth-direction modification area, the vertical axis represents the tooth profile modification area, and the first modification area is the selected area, which is the gear modification area that meets the design target of the contact surface pressure. For example, the target contact pressure value of the gear ring of a three-axis reducer is 1800 MPa.

[0101] (3) Under different phases, a multi-objective optimization analysis of the transmission error of the differential gear ring 7 was performed. The optimization results of the transmission error of the differential gear ring 7 are as follows: Figure 9 As shown, the horizontal axis represents the tooth-direction modification area, the vertical axis represents the tooth-profile modification area, and the second modification area is... Figure 9 The area highlighted in the box represents the gear profile modification area that meets the design target for transmission error. For example, the target transmission error for the gear pair containing the ring gear of a three-axis reducer is 0.5µm.

[0102] (4) Determination of the profile modification parameters for the differential ring gear 7. Based on the multi-objective optimization results of the contact surface pressure and the multi-objective optimization results of the transmission error of the differential ring gear 7, the profile modification parameters for the differential ring gear 7 are determined. Figure 8 and Figure 9 The range of modification parameters selected in the middle box can meet the gear contact surface pressure and gear transmission error of the differential gear ring 7 under different rotation phases. That is, the range determined by the first modification area and the second modification area is the final modification parameter.

[0103] It should be noted that the above process also includes the design of the installation position of the differential ring gear 7. Based on the direction of the gear's forward drive torque and the ring gear's rotation direction, the installation position of the differential ring gear 7 is determined to ensure it has sufficient axial stiffness, thereby reducing gear misalignment. The differential is then meshed using finite element analysis and imported into micro-design software. Under set operating conditions, gear misalignment is evaluated. The gear misalignment evaluation determines the multi-objective optimization range for the gear direction. Multi-objective optimization of gear contact surface pressure and gear transmission error is performed under different phases. The combined optimization results determine the optimal modification scheme that satisfies both gear contact surface pressure and gear transmission error.

[0104] As Figure 4 shown in the drawings, the embodiment of the present application also provides a modification system 100 of a differential gear ring, the modification system 100 is used for performing the modification method of the differential gear ring, and the modification system 100 comprises a simulation model establishing module 110, a contact surface pressure analysis module 120, a transmission error analysis module 130 and a modification parameter calculation module 140, wherein the simulation model establishing module 110 is used for establishing a simulation model of the differential gear, the contact surface pressure analysis module 120 is used for performing contact surface pressure analysis on the differential gear ring under multiple phases to determine a first modification area of the differential gear ring, the transmission error analysis module 130 is used for performing transmission error analysis on the differential gear ring under multiple phases to determine a second modification area of the differential gear ring, and the modification parameter calculation module 140 is used for determining modification parameters of the differential gear ring according to the first modification area and the second modification area.

[0105] Specifically, after the simulation model establishing module 110 establishes the simulation model of the differential gear, the contact surface pressure analysis module 120 performs contact surface pressure analysis on the differential gear ring under multiple phases according to the misalignment amount of the differential gear ring 7 to determine the first modification area of the differential gear ring. The transmission error analysis module 130 performs transmission error analysis on the differential gear ring under multiple phases according to the misalignment amount of the differential gear ring 7 to determine the second modification area of the differential gear ring, and the modification parameter calculation module 140 determines the modification parameters of the differential gear ring according to the first modification area and the second modification area. For example, when the differential gear rotates at 0°, 45° and 90° respectively, the contact surface pressure analysis module 120 performs contact surface pressure analysis on the simulation model of the differential gear respectively, and in the contact surface pressure analysis results of the differential gear ring 7 under the rotation phases of 0°, 45° and 90°, the first modification area of the differential gear ring meets the contact surface pressure requirement of the differential gear ring 7. The transmission error analysis module 130 performs transmission error analysis on the simulation model of the differential gear respectively, and in the transmission error analysis results of the differential gear ring 7 under the rotation phases of 0°, 45° and 90°, the second modification area meets the transmission error requirement of the differential gear ring 7. The modification parameter calculation module 140 determines the tooth profile tilt deviation fHa, the tooth profile crown amount Ca, the tooth direction tilt deviation fHb and the tooth direction crown amount Cb of the differential gear ring 7 according to the first modification area and the second modification area.

[0106] In an embodiment, the reshaping system 100 further comprises a position determining module configured to determine the installation position of the differential ring gear according to the driving condition of the vehicle. Specifically, in normal use of the vehicle, there are forward driving or reverse driving conditions, and the differential ring gear 7 is usually a driven gear. Under the premise that the structure of the transmission has been determined, the position determining module determines the installation position of the differential ring gear according to the driving condition of the vehicle. For example, when the vehicle is forward driving, the differential ring gear 7 abuts against the housing boss 1 of the differential, and the differential ring gear 7 is located on the side of the housing boss 1 away from the first axis P of the differential. When the vehicle is reverse driving, the differential ring gear 7 abuts against the housing boss 1, and the differential ring gear 7 is located on the side of the housing boss 1 close to the first axis P of the differential. Since the position determining module determines the installation position of the differential ring gear according to the driving condition of the vehicle, the stiffness support of the differential ring gear 7 is adapted to the forward driving or reverse driving condition of the vehicle, and the stiffness support requirement of the vehicle under the forward driving or reverse driving condition is met.

[0107] The embodiment of the present application further provides a differential ring gear reshaping device, which comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the differential ring gear reshaping method when executing the computer program.

[0108] For example, the computer program can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the differential ring gear reshaping method of the embodiment of the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the gear reshaping device. The differential ring gear reshaping device can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The gear reshaping device can include, but is not limited to, a processor, a memory. Those skilled in the art can understand that the schematic diagram is only an example of the gear reshaping device, and does not limit the gear reshaping device, and can include more or fewer components than the diagram, or combine certain components, or different components, for example, the gear reshaping device can further include an input / output device, a network access device, a bus, and the like.

[0109] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the technical solutions recorded in the foregoing embodiments have been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed by the present application.

Claims

1. A method for modifying the profile of a differential gear ring, characterized in that, include: Establish a simulation model of the differential; Multiple phase misalignment analyses were performed on the simulation model of the differential to determine the misalignment amount of the differential ring gear. Based on the misalignment of the differential gear ring, a multi-phase contact surface pressure analysis is performed on the differential gear ring to determine the first modified area of ​​the differential gear ring, wherein the contact surface pressure of the first modified area is less than a preset pressure value. Based on the misalignment of the differential gear ring, a multi-phase transmission error analysis is performed on the differential gear ring to determine the second modification area of ​​the differential gear ring, wherein the transmission error of the second modification area is less than a preset error value. The modification parameters of the differential gear ring are determined based on the first modification region and the second modification region. Before performing multi-phase misalignment analysis on the simulation model of the differential, the reshaping method further includes: Determine the direction of rotation of the differential gear ring; if the direction of rotation of the differential gear ring is right-handed, then place the differential gear ring against the housing boss of the differential, with the differential gear ring located on the side of the housing boss away from the first axis of the differential; if the direction of rotation of the differential gear ring is left-handed, then place the differential gear ring against the housing boss, with the differential gear ring located on the side of the housing boss closer to the first axis of the differential.

2. The reshaping method according to claim 1, characterized in that, The multiple phases include rotations of the differential of 0°, 45°, and 90°. The specific steps for performing multi-phase misalignment analysis on the simulation model of the differential include: When the differential is rotated at 0°, 45° and 90° respectively, the simulation model of the differential is subjected to misalignment analysis, and the largest misalignment is determined as the misalignment of the differential ring gear.

3. The reshaping method according to claim 1, characterized in that, The steps for performing multi-phase contact surface pressure analysis on the differential gear ring based on the misalignment amount specifically include: Based on the misalignment of the differential gear ring, the tooth direction modification range and tooth profile modification range of the differential gear ring are determined. Multi-phase contact surface pressure analysis was performed on the differential gear ring. The first modification area of ​​the differential gear ring is determined based on the tooth profile modification range, the tooth shape modification range, and the preset modification window.

4. The reshaping method according to claim 1, characterized in that, The profile modification parameters of the differential gear ring include tooth profile tilt deviation, tooth profile bulging amount, tooth direction tilt deviation, and tooth direction bulging amount.

5. A differential gear ring profile modification system, characterized in that, The shaping system is used to execute the differential gear ring shaping method according to any one of claims 1 to 4. The shaping system includes a simulation model establishment module, a contact surface pressure analysis module, a transmission error analysis module, and a shaping parameter calculation module. The simulation model building module is used to build a simulation model of the differential; The contact surface pressure analysis module is used to perform multi-phase contact surface pressure analysis on the differential gear ring to determine the first modification area of ​​the differential gear ring. The transmission error analysis module is used to perform multi-phase transmission error analysis on the differential gear ring to determine the second modification area of ​​the differential gear ring. The profile modification parameter calculation module is used to determine the profile modification parameters of the differential gear ring based on the first profile modification area and the second profile modification area.

6. The shaping system according to claim 5, characterized in that, The shaping system also includes a position determination module, which is used to determine the installation position of the differential ring gear according to the driving conditions of the vehicle.

7. A device for modifying the profile of a differential gear ring, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the method for modifying the differential gear ring as described in any one of claims 1 to 4.

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