A method for optimizing the raceway profile of a spherically seated roller bearing inner ring

Abstract

The application discloses a kind of optimization methods of the inner ring raceway profile of self-aligning roller bearing, according to the actual stress of bearing, it is modeled simulation analysis, obtains the simulation data such as bearing stress and strain condition;Through the optimization of bearing inner ring raceway profile, improve the uneven stress of bearing roller and raceway;Through the feedback of actual application to the optimization of bearing profile, obtain the optimal inner ring raceway profile.The application optimizes the inner ring raceway profile of self-aligning roller bearing on the basis of keeping the original good self-aligning function of self-aligning roller bearing, more adapt to actual working condition.Optimized inner ring raceway profile reduces the friction and friction heat of roller and inner ring raceway, effectively reduces the contact stress at roller and inner ring raceway by finite element simulation analysis and actual preparation verification method, solves the uneven stress problem of roller, reduces the failure rate, improves the load capacity, wear resistance, service life and other performances of inner ring raceway.

Description

Technical Field

[0001] This invention belongs to the field of self-aligning roller bearing design, and particularly relates to a method for optimizing the raceway profile of the inner ring of a self-aligning roller bearing. Background Technology

[0002] Self-aligning roller bearings are mainly used in engineering machinery such as gearboxes. The most common type is the spherical roller bearing, which features double-row rollers. The outer ring has one common spherical raceway, and the inner ring has two raceways inclined at an angle relative to the bearing axis. This bearing primarily bears radial loads and can also withstand bidirectional axial loads, but it cannot withstand pure axial loads. It has a relatively high load-bearing capacity. Generally, the outer ring uses a spherical raceway, and the center of curvature of the outer ring raceway surface coincides with the bearing center, thus providing good self-aligning performance and compensating for coaxiality errors. However, the inner ring profile is more complex than the outer ring, with both raceways being individual arcs. The setting of parameters such as the center position and distance of these arcs affects bearing performance. Bearings experience different stresses under different operating conditions, and incorrect parameter settings can cause or exacerbate uneven stress on the bearing. Therefore, the setting of the inner ring raceway parameters cannot be generalized; the inner ring raceway profile must be optimized for different operating conditions and stresses to avoid uneven stress leading to bearing deformation, cracks, and other defects.

[0003] Chinese patent CN 102619875 A discloses a self-aligning roller bearing for the main shaft of a wind turbine and its design method. Through stress analysis, a bearing that meets the requirements is designed. However, this design method is only applicable to bearings for the main shaft of wind turbines, and it reduces the contact stress between the rollers and the raceway by adjusting the size of the front and rear rows of rollers.

[0004] Chinese patent CN 111222207 A discloses a design method for the optimal cone angle of the large flange of the inner ring of a tapered roller bearing. The method calculates the optimal cone angle of the large flange through iterative calculation, thereby reducing the stress and deformation of the flange and minimizing frictional heat generated during processing. However, this invention only considers the stress condition of the flange and does not optimize the overall profile of the inner ring raceway.

[0005] While the aforementioned patents have improved bearing performance to some extent in certain aspects, none of them have optimized the bearing inner ring raceway profile based on the actual stress conditions under which the bearing rollers and inner ring raceway are subjected to stress, in order to reduce the uneven stress distribution between the bearing rollers and the inner ring raceway.

[0006] Therefore, it is necessary to optimize the profile of the inner ring raceway of the bearing according to the actual working conditions, and to provide a universal method for optimizing the inner ring raceway profile of self-aligning roller bearings. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, this invention proposes an optimization method for the inner ring raceway profile of a self-aligning roller bearing. This method can improve the uneven stress distribution that occurs during actual use of the roller bearing, reduce wear on the rollers and inner ring raceway, and increase the load-bearing capacity of the inner ring raceway.

[0008] The design concept of this invention is based on the existing inner ring raceway of self-aligning roller bearings. It models and simulates the bearing according to the actual stress conditions to obtain simulation data such as bearing stress and strain. By optimizing the inner ring raceway profile, the uneven stress between the bearing rollers and the raceway is improved. Through feedback on the optimization of the bearing profile in practical applications, the optimal inner ring raceway profile is obtained.

[0009] The technical solution of the present invention is as follows: A method for optimizing the raceway profile of the inner ring of a self-aligning roller bearing, comprising the following steps:

[0010] Step 1: Modeling and Simulation

[0011] Based on the actual working conditions of the bearing, a finite element model of the contact interaction between the rollers and the inner ring raceway is established to simulate the contact force and strain between the bearing rollers and raceway.

[0012] Based on Hertz contact theory, the contact stress at a certain point is distributed according to a semi-ellipsoidal law, as shown in the following formula:

[0013]

[0014] Where a and b are the major and minor semi-axes of the contact ellipse, respectively, and x and y are the x and y coordinates of the point. The maximum contact stress is:

[0015]

[0016] Where Q is the total contact pressure.

[0017] The Hertz formula for contact deformation δ is:

[0018]

[0019] Where E′ is the equivalent elastic modulus, m a Let be the semi-major axis coefficient of the contact ellipse, and ∑ρ be the sum of the principal curvatures at the contact point between the roller and the inner raceway. K(e) is the first-kind complete elliptic integral relating to the elliptic eccentricity e. For the integration variable, the formula is as follows:

[0020]

[0021] Step 2: Simulation Result Analysis

[0022] The simulation results were analyzed, including the stress and strain at the contact point between the bearing roller and the inner ring raceway after loading, and the theoretical wear of the inner ring material. Material wear is inversely proportional to the p×v factor, where p is the normal pressure at the inner ring contact point and v is the relative sliding velocity between the roller and the inner ring. The distribution of the p×v factor along the roller axis under load was determined using finite element software, thereby assessing the wear of the inner ring raceway.

[0023] Step 3: Optimize the inner ring profile

[0024] While considering the self-aligning performance of the bearing, the inner ring raceway profile was optimized based on simulation results. For areas with high contact stress and severe wear between the rollers and the inner ring raceway, the inner ring raceway profile parameters were adjusted to obtain a new inner ring raceway profile. These profile parameters include the raceway radius of curvature R, the flange width a, and the flange bottom diameter d. a , width h of the middle stop, diameter d of the middle stop h And the distance W between the centers of curvature of the two raceways.

[0025] Step 4: Determine if the profile is optimal

[0026] Substitute the optimized raceway profile into steps one and two for simulation verification. If the stress-strain is in the optimal state, proceed to step five; if the stress-strain is not in the optimal state, proceed to step three to continue adjusting the raceway profile of the bearing inner ring until the stress reaches the optimal state.

[0027] Step 5: Bearing fabrication and bearing performance evaluation

[0028] Based on the simulation-optimized profile, corresponding self-aligning roller bearings were manufactured and installed for application under actual working conditions. The bearing performance after optimizing the inner ring profile was evaluated, including self-aligning function, stress conditions, load-carrying capacity, friction and wear performance, and contact fatigue strength.

[0029] The beneficial results achieved by this invention are as follows:

[0030] This invention, while maintaining the original excellent self-aligning function of self-aligning roller bearings, optimizes the inner ring raceway profile to better adapt to actual working conditions. The optimized inner ring raceway profile reduces the friction and frictional heat generated between the rollers and the inner ring raceway. Through finite element simulation analysis and actual fabrication verification, it effectively reduces the contact stress between the rollers and the inner ring raceway, solves the problem of uneven roller stress, lowers the failure rate, and improves the load-bearing capacity, wear resistance, and service life of the inner ring raceway. Attached Figure Description

[0031] Figure 1 This is a flowchart of the optimization method of the present invention.

[0032] Figure 2 Schematic diagram of bearing inner ring profile parameters. Detailed Implementation

[0033] To further understand the optimization method of the raceway profile of the outer ring of a self-aligning roller bearing, the invention will be described in detail below with reference to examples.

[0034] The method for optimizing the raceway profile of the outer ring of a self-aligning roller bearing according to the present invention comprises the following specific implementation steps:

[0035] Step 1: Select the commonly used self-aligning roller bearing 22336MBA-W33 for vibrating machinery. Its inner ring is as follows: Figure 2 As shown, based on the actual working conditions, Abaqus finite element analysis software was selected to establish a finite element model of the contact interaction between the roller and the outer raceway, and to simulate parameters such as contact force and strain.

[0036] Step 2: Analyze the simulation results, mainly including the stress and strain at the contact point between the bearing roller and the inner raceway after loading, and the theoretical wear of the inner raceway material.

[0037] Step 3: While considering the self-aligning performance of the bearing, optimize the inner ring raceway profile based on the simulation results. This mainly targets areas with high contact stress and severe wear between the rollers and the inner ring raceway. By adjusting the inner ring raceway profile, a new inner ring raceway profile is obtained. The specific adjustment method is as follows:

[0038] W′=W+0.5mm

[0039] d h ′=d h -0.2mm

[0040] in:

[0041] W′ is the distance between the centers of curvature of the two raceways after optimization;

[0042] d h ′ represents the optimized diameter of the middle retaining edge.

[0043] Step 4: Substitute the optimized inner ring raceway profile into steps 1 and 2 for simulation verification. The verification shows that the bearing stress and strain under this profile reach the optimal state. The optimized profile is determined to be the optimal profile for the bearing inner ring raceway.

[0044] Step 5: Based on the simulation-optimized profile, fabricate the corresponding self-aligning roller bearing and apply it under actual working conditions. Evaluate the bearing performance after optimizing the inner ring profile.

[0045] The foregoing description illustrates the basic steps, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for optimizing the raceway profile of the inner ring of a self-aligning roller bearing, characterized in that: Includes the following steps: Step 1: Modeling and Simulation Based on the actual working conditions of the bearing, a finite element model of the contact interaction between the rollers and the inner ring raceway is established to simulate the contact force and strain between the bearing rollers and the raceway. Based on Hertz contact theory, the contact stress at a certain point is distributed according to a semi-ellipsoidal law, as shown in the following formula: Where a and b are the major and minor semi-axises of the contact ellipse, respectively, and x and y are the x and y coordinates of the point; the maximum contact stress is: Where Q is the total contact pressure; The Hertz formula for contact deformation δ is: Where E′ is the equivalent elastic modulus, m a Let be the semi-major axis coefficient of the contact ellipse, ∑ρ be the sum of the principal curvatures at the contact point between the roller and the inner raceway, and K(e) be the first-kind complete elliptic integral related to the eccentricity e of the ellipse. For the integration variable, the formula is as follows: Step 2: Simulation Result Analysis The simulation results are analyzed, including the stress and strain at the contact point between the bearing roller and the inner ring raceway after loading, and the theoretical wear of the inner ring material. The wear of the material is inversely proportional to the p×v factor, where p is the normal pressure at the contact point of the inner ring and v is the relative sliding velocity between the roller and the inner ring. The distribution of the p×v factor along the roller axis under load is determined by finite element software, thereby determining the wear of the inner ring raceway. Step 3: Optimize the inner ring profile While considering the self-aligning performance of the bearing, the inner ring raceway profile of the bearing is optimized based on simulation results. For areas with high contact stress and severe wear between the rollers and the inner ring raceway, the inner ring raceway profile parameters are adjusted to obtain a new inner ring raceway profile. These profile parameters include the raceway radius of curvature R, the flange width a, and the flange bottom diameter d. a , width h of the middle stop, diameter d of the middle stop h and the distance W between the centers of curvature of the two raceways; Step 4: Determine if the profile is optimal Substitute the optimized raceway profile into steps one and two for simulation verification; if the stress and strain are in the optimal state, proceed to step five; if the stress and strain are not in the optimal state, proceed to step three to continue adjusting the raceway profile of the bearing inner ring until the stress reaches the optimal state. Step 5: Bearing fabrication and bearing performance evaluation Based on the simulation optimization profile, the corresponding self-aligning roller bearings were manufactured and installed for application under actual working conditions; the bearing performance after optimizing the inner ring profile was evaluated, and the bearing performance included self-aligning function, stress condition, load-bearing capacity, friction and wear performance, and contact fatigue strength.

Images