Centrifugal deformation analysis method for new energy electric drive ball bearing retainer

Abstract

The invention provides a centrifugal deformation analysis method for a new energy electric drive ball bearing retainer, which comprises the following steps of: acquiring initial conditions of the retainer, establishing a three-dimensional solid model of the retainer, performing grid division on the three-dimensional solid model, endowing the model with material attributes, performing grid division on the retainer, dividing the retainer into N units, the centrifugal force of the cage grid unit is calculated, a tiny volume element method is adopted, corresponding loads are applied to the cage grid unit to simulate the actual working condition of the cage under high-speed operation, and the equivalent stress and radial deformation conditions of the cage under different rotating speeds of the cage are calculated and extracted. According to the method, the problem that the equivalent stress and deformation calculation result of the bearing retainer under the high-speed operation working condition is greatly deviated from the actual condition at present can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cage analysis, and in particular to a centrifugal deformation analysis method for a cage of a new energy electric drive ball bearing. Background Art

[0002] The bearing cage refers to a bearing part that partially wraps all or part of the rolling elements and moves with them. It can isolate the rolling elements and usually guide the rolling elements and keep them in the bearing. It is an important component of the rolling bearing, and its quality has a direct impact on the bearing accuracy. At present, there is a lack of reasonable analysis methods for the centrifugal deformation analysis of the cage of new energy electric drive ball bearings. Most of the calculated results have a large deviation from the actual results. In fact, the centrifugal analysis of high-speed cages requires the use of the mechanical basis of finite element analysis. The three major mechanical equations and boundary conditions of spatial problems in the mechanical basis of finite element analysis are used to simulate the actual stress conditions of the bearing cage under high-speed operation conditions. When the bearing is running at high speed, the deformation and stress conditions of the cage play an important role in the design of the cage. Summary of the invention

[0003] The purpose of the present invention is to provide a centrifugal deformation analysis method for a new energy electric drive ball bearing cage, which can solve the problem that the equivalent stress and deformation calculation results of the current bearing cage under high-speed operation conditions have a large deviation from the actual ones.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a centrifugal deformation analysis method of a new energy electric drive ball bearing cage, comprising the following steps: Step 1, obtaining the initial conditions of the cage; Step 2: Establish a three-dimensional solid model of the cage, divide the three-dimensional solid model into grids, and assign material properties to the model; Step 3: Divide the cage into N units by meshing the cage, and calculate the centrifugal force of the cage mesh unit by formulas (1) to (4). F j =Δm j ω 2 r j (1) ω=2πn (2) In the formula, F j is the centrifugal force of the jth block of the cage; Δm j is the mass of the jth block of the cage; ω is the angular velocity of the cage; r j D is the radius of the jth block of the cage; w D is the diameter of the bearing rolling element; pw is the bearing pitch diameter; α is the working contact angle; nc is the cage speed; n i is the inner ring rotation speed; Step 4: By using formulas (5) to (9), the method of small volume elements is used to apply corresponding loads to the cage grid unit to simulate the actual working conditions of the cage under high-speed operation. σ ij =D ijkl ε kl (7) In the formula, σ ij,j The subscript in the equation represents the physical quantity σ ij Find the partial derivative in the j direction, σ ij Where i is the direction of the force, j is the normal direction of the force surface; is the unit volume force acting on the grid element along the i direction; ε ij is the strain component; u i,j The subscript in represents u i Find the partial derivative in the j direction, u i is the displacement component along the i direction; u j,i The subscript in represents u j Find the partial derivative in the i direction, u j is the displacement component along the j direction; D ijkl ε kl is the elasticity matrix; It is in S u The displacement along the i direction is specified above; n j is the direction cosine of the external normal at a boundary point; is the surface force acting along the i direction; S u is the given displacement boundary, S p is the given force boundary; Step 5: Calculate and extract the cage equivalent stress and radial deformation at different cage speeds.

[0005] Preferably, the initial conditions of the cage in step 1 include structural parameters, material properties of density, elastic modulus, Poisson's ratio, and cage rotation speed.

[0006] Preferably, in step 2, Soildworks or UG three-dimensional design software is used to establish a three-dimensional solid model of the cage.

[0007] Preferably, in step 2, Hypermesh is used to mesh the three-dimensional solid model of the cage.

[0008] Preferably, the centrifugal force of the retaining frame in step 3 is a centrifugal load in the radial direction generated by its own rotation.

[0009] Preferably, in step 4, according to the mechanical equations of spatial problems and boundary condition related theories in the mechanics foundation of finite element analysis, through formulas (5) to (9), a method of micro-volume elements is used to apply corresponding loads to the cage grid units to simulate the actual working conditions of the cage under high-speed operation.

[0010] Preferably, in step 5, finite element analysis software is used to calculate and extract the equivalent stress and radial deformation of the retaining frame.

[0011] The beneficial effects of the present invention are:

[0012] This scheme is based on finite element theory and finite element analysis software. According to the relevant theories of space problems in the mechanical foundation of finite element analysis, the method of micro-element is used to apply loads to the cage grid unit to simulate the actual working conditions of the cage under high-speed operation. Then the equivalent stress and deformation of the cage are calculated. The present invention solves the problem of how to analyze the stress and deformation of the cage under high-speed operation of the bearing, and provides a technical reference for subsequent scholars to study the design of the cage, making the cage design more reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 Schematic diagram of a 6206 cage model in an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram of a 6208 cage model in an embodiment of the present invention;

[0016] Figure 3 A schematic diagram of the force on the cage grid unit in an embodiment of the present invention;

[0017] Figure 4 This is a theoretical schematic diagram of a finite element space problem in an embodiment of the present invention;

[0018] Figure 5 Schematic diagram of finite element analysis boundary conditions in an embodiment of the present invention;

[0019] Figure 6 Schematic diagram of equivalent stress of 6206 cage under different working conditions in an embodiment of the present invention;

[0020] Figure 7Schematic diagram of the deformation of the 6206 cage under different working conditions in the embodiment of the present invention;

[0021] Figure 8 Schematic diagram of equivalent stress of 6208 cage under different working conditions in an embodiment of the present invention;

[0022] Fig. 9 Schematic diagram of the deformation of the retaining frame 6208 under different working conditions in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings.

[0024] The present invention discloses a centrifugal deformation analysis method for a new energy electric drive ball bearing cage. The equivalent stress and deformation of the cage are obtained by calculation. The present invention takes the 6206 and 6208 new energy motor bearing cages as examples. Figure 1 , 2 The following is a schematic diagram of the 6206 and 6208 cage models. It mainly includes the following steps:

[0025] Step 1: Obtain the initial conditions of the cage: structural parameters, material properties such as density, elastic modulus, Poisson's ratio, and cage rotation speed.

[0026] Step 2: Model establishment and meshing: Use 3D design software such as Soildworks and UG to establish a 3D solid model of the cage, use Hypermesh to mesh the 3D solid model of the cage, and assign material properties to the model.

[0027] Step 3: Calculation of the centrifugal force of the cage: The centrifugal force of the cage is the centrifugal load in the radial direction generated by its own rotation. The cage is divided into N units by meshing, and the centrifugal force of the cage mesh unit is calculated by formulas (1) to (4). The centrifugal force on the cage mesh unit is as follows: Figure 3 As shown; F j =Δm j ω 2 r j (1) ω=2πn (2) In the formula, F j is the centrifugal force of the jth block of the cage; Δm j is the mass of the jth block of the cage; ω is the angular velocity of the cage; r j D is the radius of the jth block of the cage; w D is the diameter of the bearing rolling element; pw is the bearing pitch diameter; α is the working contact angle; n cis the cage speed; n i is the inner ring rotation speed.

[0028] Step 4: Boundary condition setting: Based on the mechanical equations of spatial problems and the boundary condition related theories in the finite element analysis mechanics foundation, through formulas (5) to (9), the method of small volume elements is adopted, such as Figure 4 , 5 As shown, corresponding loads are applied to the cage grid units to simulate the actual working conditions of the cage under high-speed operation. σ ij =D ijkl ε kl (7) In the formula, σ ij,j The subscript in the equation represents the physical quantity σ ij Find the partial derivative in the j direction, σ ij Where i is the direction of the force, j is the normal direction of the force surface; is the unit volume force acting on the grid element along the i direction; ε ij is the strain component; u i,j The subscript in represents u i Find the partial derivative in the j direction, u i is the displacement component along the i direction; u j,i The subscript in represents u j Find the partial derivative in the i direction, u j is the displacement component along the j direction; D ijkl ε kl is the elasticity matrix; It is in S u The displacement along the i direction is specified above; n j is the direction cosine of the external normal at a boundary point; is the surface force acting along the i direction; S u is the given displacement boundary, S p is the given force boundary.

[0029] Step 5. Analysis and calculation: In the finite element analysis software, input different cage rotation speeds and extract the cage equivalent stress and radial deformation.

[0030] Taking the 6206 and 6208 new energy motor bearing cages as an example, the equivalent stress and deformation of the cage are calculated when the inner ring speed of the bearing is 10000r / min, 13000r / min, and 16000r / min. The calculation results are as follows: Figure 6-9 shown.

[0031] It should be noted that the parts not described in detail in the above embodiments are all prior art.

[0032] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention should be covered within the protection scope of the present invention.

Claims

1. A centrifugal deformation analysis method for a new energy electric drive ball bearing cage, characterized by: The following steps are involved: Step 1, obtaining the initial conditions of the cage; Step 2: Establish a three-dimensional solid model of the cage, divide the three-dimensional solid model into grids, and assign material properties to the model; Step 3: Divide the cage into N units by meshing the cage, and calculate the centrifugal force of the cage mesh unit by formulas (1) to (4). F j =Δm j oh 2 r j (1) ω=2πn (2) In the formula, F j is the centrifugal force of the jth block of the cage; Δm j is the mass of the jth block of the cage; ω is the angular velocity of the cage; r j D is the radius of the jth block of the cage; w D is the diameter of the bearing rolling element; pw is the bearing pitch diameter; α is the working contact angle; n c is the cage speed; n i is the inner ring rotation speed; Step 4: By using formulas (5) to (9), the method of small volume elements is used to apply corresponding loads to the cage grid unit to simulate the actual working conditions of the cage under high-speed operation. s ij =D ijkl e kl (7) In the formula, σ ij,j The subscript in the equation represents the physical quantity σ ij Find the partial derivative in the j direction, σ ij Where i is the direction of the force, j is the normal direction of the force surface; is the unit volume force acting on the grid element along the i direction; ε ij is the strain component; u i,j The subscript in represents u i Find the partial derivative in the j direction, u i is the displacement component along the i direction; u j,i The subscript in represents u j Find the partial derivative in the i direction, u j is the displacement component along the j direction; D ijkl ε kl is the elasticity matrix; It is in S u The displacement along the i direction is specified above; n j is the direction cosine of the external normal at a boundary point; is the surface force acting along the i direction; S u is the given displacement boundary, S p is the given force boundary; Step 5: Calculate and extract the cage equivalent stress and radial deformation at different cage speeds.

2. The centrifugal deformation analysis method for a new energy electric drive ball bearing cage according to claim 1 is characterized by: The initial conditions of the cage in step 1 include structural parameters, material properties of density, elastic modulus, Poisson's ratio, and cage rotation speed.

3. The centrifugal deformation analysis method for a new energy electric drive ball bearing cage according to claim 1 is characterized by: In step 2, Soildworks and UG three-dimensional design software are used to establish a three-dimensional solid model of the cage.

4. A centrifugal deformation analysis method for a new energy electric drive ball bearing cage according to claim 3, characterized in that: In the step 2, Hypermesh is used to mesh the three-dimensional solid model of the cage.

5. The centrifugal deformation analysis method for a new energy electric drive ball bearing cage according to claim 1 is characterized by: The centrifugal force of the retaining frame in step 3 is a centrifugal load in the radial direction generated by the retaining frame's own rotation.

6. The centrifugal deformation analysis method for a new energy electric drive ball bearing cage according to claim 1 is characterized by: In step 4, according to the mechanical equations of spatial problems and the boundary condition related theories in the finite element analysis mechanics foundation, through formulas (5) to (9), the method of micro-volume elements is used to apply corresponding loads to the cage grid units to simulate the actual working conditions of the cage under high-speed operation.

7. The centrifugal deformation analysis method for a new energy electric drive ball bearing cage according to claim 1 is characterized by: In step 5, finite element analysis software is used to calculate and extract the equivalent stress and radial deformation of the cage.

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