Ultra-high-speed motor bearing anti-deformation crown retainer and manufacturing method

Abstract

The application discloses an anti-deformation crown-shaped cage of a super-speed motor bearing and a manufacturing method, and belongs to the technical field of motor bearings. The anti-deformation crown-shaped cage of the super-speed motor bearing is printed by a functionally graded material, the functionally graded material comprises hard-phase material and soft-phase material, the hard-phase material is glass fiber, and the soft-phase material is nylon 66; the equivalent elastic modulus of the functionally graded material continuously and gradually changes along the axial direction from the bottom of the pocket hole to the end of the locking claw, so that the elastic modulus of the bottom area of the pocket hole is higher than that of the end area of the locking claw, and the ovalization deformation of the pocket hole and the centrifugal deformation of the locking claw are cooperatively inhibited; the functionally graded material is introduced to actively reconstruct the stiffness field of the crown-shaped cage; the toughness phase is constructed in the locking claw area to absorb collision energy, the reinforced phase is formed in the pocket hole area to weaken stress concentration, and the stiffness gradient is established at the connecting position to inhibit the umbrella effect; and the application provides the crown-shaped cage with the characteristics of high toughness, gradient and high strength and a design method thereof.

Description

Technical Field

[0001] This invention relates to the field of motor bearing technology, specifically to a deformation-resistant crown cage for ultra-high-speed motor bearings and its manufacturing method. Background Technology

[0002] The development trend of electric drive systems for new energy vehicles is to continuously increase their power density, which requires drive motor bearings to operate stably under ultra-high-speed conditions. Therefore, breaking through the speed limit of deep groove ball bearings has become a core challenge in this technological field. Under ultra-high-speed operating conditions, the crown cage inside the bearing is its weakest link, prone to structural deformation and failure. Specifically, this manifests as: radial "umbrella-shaped" deformation, causing friction between the cage and the bearing rings, resulting in wear; and circumferential "elliptical" deformation of the pocket, leading to increased collisions between the rolling elements and the pocket, causing vibration, noise, and even cage breakage.

[0003] To address the aforementioned problems, existing technologies have proposed improvement solutions, but all have fundamental limitations. For example, SKF's hollow locking claw structure, while improving the limiting speed to some extent through weight reduction (e.g., enabling the 6208 bearing to reach 20,000 r / min), leads to a geometric increase in centrifugal deformation with further speed increases. FAG's hole bottom thickening method, although improving the strength threshold through local reinforcement, introduces significant mass imbalance, which in turn exacerbates collision impacts at high speeds. Therefore, this invention proposes a deformation-resistant crown cage for ultra-high-speed motor bearings and its manufacturing method. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems in the prior art and provide a deformation-resistant crown cage for ultra-high speed motor bearings and its manufacturing method. It aims to break through the mainstream shape optimization suppression mode, introduce functionally graded materials, and realize the active reconstruction of the stiffness field of the crown cage. In this invention, the locking claw area is constructed with a low-modulus tough phase to absorb collision energy, the pocket area forms a high-modulus reinforcing phase to weaken stress concentration, and the connection part establishes a stiffness gradient to suppress the umbrella effect. This invention proposes a crown cage with the characteristics of "high toughness-gradient-high strength" and its design method.

[0005] The present invention provides a deformation-resistant crown cage for ultra-high speed motor bearings, which is printed from functionally graded materials. The equivalent elastic modulus of the functionally graded materials gradually changes along the axial direction from the bottom of the pocket to the end of the locking claw, so that the elastic modulus of the bottom region of the pocket is higher than that of the end region of the locking claw, so as to synergistically suppress the elliptic deformation of the pocket and the centrifugal deformation of the locking claw.

[0006] Preferably, the functionally graded material includes a hard phase material and a soft phase material, wherein the hard phase material is glass fiber, carbon fiber or high modulus polymer, and the soft phase material is PA66, PA12, PA11 or PEEK.

[0007] Preferably, the volume fraction of the hard phase material along the normalized axial coordinate x satisfies a power-law distribution, a cubic Hermite smooth distribution, or a Sigmoid distribution.

[0008] The second objective of this invention is to disclose the manufacturing method of the aforementioned anti-deformation crown cage for ultra-high speed motor bearings, establish a flexible dynamic model of the crown cage, perform dynamic simulation on the bearing system under the target ultra-high speed operating conditions, and obtain and output the elliptic deformation of the cage pocket in the working state, the centrifugal deformation of the locking claw, and the spatial stress distribution at the bottom of the pocket and the locking claw.

[0009] Based on Eshelby inclusion theory and combined with the modified Mori-Tanaka model, a mapping relationship between the component distribution and equivalent elastic modulus of functionally graded materials is established. Taking the elliptic deformation of the pocket and the centrifugal deformation of the locking claw as optimization objectives, and the constraint that the maximum working stress at the bottom of the pocket and the locking claw does not exceed the allowable stress of the material, the component distribution function and the structural geometric parameters of the cage are optimized in a coordinated manner. The optimal material gradient distribution function and the optimal structural geometric parameters are determined and output.

[0010] Additive manufacturing of the solid cage is carried out based on the determined optimal material gradient distribution function and optimal structural geometry parameters.

[0011] Preferably, the method for establishing a flexible dynamic model of the coronary retainer is as follows:

[0012] A multibody dynamics model of the bearing system is constructed: Multibody dynamic equations are established for the bearing inner ring, outer ring, rolling elements, and cage. Simultaneously, an elastohydrodynamic lubrication model of the contact interface between the rolling elements and the raceway is established, and a lubrication drag coefficient mapping relationship based on a convolutional neural network is integrated to efficiently solve for interface friction loads. This constructs a highly convergent system dynamics model for obtaining the transient motion behavior of the bearing assembly. A flexible mechanical model of the cage pocket is constructed: The crown-shaped cage structure is discretized into side beams, cross beams, and locking claw components. Curved constant-section beam elements, straight variable-section beam elements, and curved variable-section beam elements are used to model each component, deriving their elastic deformation equations under centrifugal loads. These equations are then combined to form the flexible mechanical model of the cage. By constructing a ball-pocket lubrication collision algorithm, the bearing system dynamics model and the cage flexible mechanical model are bidirectionally coupled to form a crown-shaped cage flexible dynamics model, used to solve for the transient motion and deformation response of the cage under the combined action of centrifugal loads and rolling element collision loads.

[0013] Preferably, the lubrication drag coefficient mapping relationship based on convolutional neural network is obtained in the following way: a ball-disc drag test is conducted based on bearing operating parameters to obtain a lubrication friction performance database; the database is input into the convolutional neural network for training to obtain a mapping relationship with the equivalent radius of the contact interface, entrainment speed, sliding speed, contact load and grease temperature as inputs and the lubrication drag coefficient as output.

[0014] Preferably, the specific method for additive manufacturing of the solid cage based on the determined optimal material gradient distribution function and optimal structural geometric parameters is as follows:

[0015] A fused deposition modeling (FDM) system equipped with a dual-nozzle co-extrusion system is used to feed glass fiber and nylon materials respectively, with the feeding amounts of glass fiber and nylon materials adjustable in real time. Using the optimal material gradient distribution function as the basis for real-time feeding control, a servo system precisely controls the feeding ratio of the two nozzles, achieving real-time and accurate adjustment of the fiber volume fraction during the printing process. A three-dimensional geometric model of the cage is constructed based on the optimal structural geometric parameters, and based on the optimal material gradient distribution function, an adaptive slicing algorithm generates layer-by-layer printing instructions that control the material switching ratio of the nozzles within a radial unit step. Using the fused deposition modeling system, according to the layer-by-layer printing instructions, the dual-nozzle co-extrusion system controls the feeding ratio of hard phase material and soft phase material, printing layer by layer to prepare the functionally graded material crown cage.

[0016] The third objective of this invention is to provide an ultra-high speed motor bearing, comprising an inner ring, an outer ring, rolling elements, and a cage, wherein the cage is the aforementioned ultra-high speed motor bearing anti-deformation crown cage.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention introduces functionally graded materials and uses a directional stiffness control method to construct a crown retainer structure, forming a novel crown retainer with directional quantitative deformation control capability. The high-modulus reinforcing phase of this novel crown retainer reduces the local stress level by increasing the structural stiffness of the pocket area, while the low-modulus tough phase efficiently absorbs the collision energy of the locking claw area by virtue of the material deformation characteristics. The axially continuously distributed gradient stiffness effectively alleviates the umbrella-shaped deformation problem under ultra-high speed operation, solving the problem that the centrifugal deformation of SKF's hollow locking claw structure increases geometrically after speed increase and the problem that the thickening of the hole bottom of FAG exacerbates the collision impact at high speed.

[0018] The cage provided by this invention exhibits excellent dynamic stability and deformation resistance under ultra-high-speed conditions, and can withstand higher centrifugal loads and impact excitations, thereby pushing the stable operating speed of deep groove ball bearings to a new level. It breaks through the bearing speed bottleneck in increasing power density of electric drive systems, providing key bearing technology support for achieving smaller, lighter, and more powerful drive systems in fields such as new energy vehicles. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a novel coronal retainer according to an embodiment of the present invention.

[0020] Figure 2 This is a structural diagram of the bearing crown cage.

[0021] Figure 3 This is a front view of the bearing crown cage unit structure.

[0022] Figure 4 This shows the deformation of a conventional coronal cage during movement.

[0023] Figure 5 The deformation of the crown bearing cage with stiffness gradient constructed for an embodiment of the present invention during movement. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” indicate that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0026] Research has revealed that the failure of crown cages under high-speed operating conditions is essentially a deformation mismatch problem caused by the coupling effect of centrifugal load and collision excitation. Specifically: In the radial dimension, the centrifugal deformation of the cantilever structure exhibits an umbrella-shaped effect (the deformation is distributed in a gradient along the extension direction of the cantilever beam), causing cage-ring rubbing and stress concentration at the bottom of the hole, leading to wear and fracture failure modes; in the circumferential dimension, the mismatch in the pocket clearance and ellipticization of the shape intensify the transient collision between the ball and the pocket, evolving into noise and fracture failure modes. This reflects the contradiction of increasing motor power density: while increasing speed enhances power, it may lead to nonlinear growth of dynamic load, thereby causing rapid failure of the bearing crown cage.

[0027] From a materials mechanics perspective, existing crown cages are mostly made of homogeneous materials, exhibiting a single modulus characteristic. This makes them unsuitable for the differentiated strength, stiffness, and toughness requirements of different regions of the cage under ultra-high-speed conditions. Furthermore, they fail to meet the heterogeneous mechanical properties of the cage in the spatial dimension, resulting in insufficient structural stability under complex dynamic loads. This ultimately limits further increases in bearing speed and consequently restricts the leap in power density of electric drive systems. Traditional homogeneous cage materials such as nylon, polyimide, and polyetheretherketone are limited by their global isoelastic modulus characteristics. Forcibly modifying them to improve local properties may lead to a reverse decline in overall performance. For example, while glass fiber reinforcement increases the modulus of the pocket area, it also significantly weakens the impact toughness of the locking claw area.

[0028] Therefore, this invention proposes a new anti-deformation crown cage for ultra-high speed motor bearings and its manufacturing method.

[0029] This invention provides a deformation-resistant crown-shaped retainer for ultra-high-speed motor bearings, which is printed from functionally graded materials. The functionally graded materials include hard phase materials and soft phase materials. The hard phase materials can be glass fiber, carbon fiber, high-modulus polymers (such as aramid fiber), etc.; the soft phase materials can be PA66, PA12, PA11, PEEK, etc. As an example, in this embodiment, the hard phase material is glass fiber, and the soft phase material is nylon 66. In this embodiment, the equivalent elastic modulus of the functionally graded materials gradually changes along the axial direction from the bottom of the pocket to the end of the locking claw, so that the elastic modulus of the bottom region of the pocket is higher than that of the end region of the locking claw, so as to synergistically suppress the elliptic deformation of the pocket and the centrifugal deformation of the locking claw.

[0030] Functionally graded materials (FJTs) are materials whose Young's modulus is controlled by adjusting the volume fraction ratio of hard and soft phases. This invention employs a directional stiffness control method, introducing both soft and hard phase materials to construct a crown-shaped retainer structure, forming a novel crown retainer with directional and quantitative deformation control capabilities. Leveraging existing low-cost, high-efficiency 3D printing technology, FJTs can achieve object property control within a 0.1 mm range, with Young's modulus spanning 1.4 MPa to 1.2 GPa. Within a 12 mm axial width of the crown retainer, deformation suppression can be achieved by fabricating FJTs with Young's modulus spanning 1 GPa to 15 GPa. A continuous stiffness transition mechanism is constructed in the axial direction, from the high-modulus reinforcing phase in the pocket region to the low-modulus toughening phase in the locking claw region. Specifically, the high-modulus reinforcing phase reduces local stress levels by increasing the structural stiffness of the pocket region, while the low-modulus toughening phase efficiently absorbs the collision energy of the locking claw region due to the material deformation characteristics. The axially continuously distributed gradient stiffness effectively alleviates the umbrella-shaped deformation problem under ultra-high speed operation. By establishing the material composition gradient function and geometric feature matching criteria, a crown retainer that balances stiffness enhancement and toughness improvement is finally designed and printed.

[0031] The volume fraction of the hard phase material described in this invention is distributed along the normalized axial coordinate x, satisfying a power-law distribution, a cubic Hermite smooth distribution, or a Sigmoid distribution. More specifically, the method for determining the volume fraction of the hard phase material in this invention is as follows:

[0032] (1) Definition of coordinates and design variables

[0033] Let the axial direction of the cage from the pocket side to the locking claw side be the gradient direction, and define the normalized coordinates:

[0034] ;in, To maintain the axial distance between a point on the frame and the pocket side; The axial length of the cage from the pocket side to the locking claw side .

[0035] Two-phase volume fractions satisfy ,in This represents the volume fraction of the hard phase (glass fiber phase). The volume fraction of the soft phase (PA66). The design variable is taken as... .

[0036] (2) Free end deflection (under centrifugal uniformly distributed load) (under the influence)

[0037] ; For centrifugal uniformly distributed load; The fourth power of the axial length of the cage from the pocket side to the locking claw side .

[0038] The design should meet the following requirements: This is also a constraint condition for solving the component distribution. This represents the maximum deflection without interference. This represents the change in elastic modulus of functionally graded composite materials. This represents the area moment of inertia. This usually refers to bending stiffness, and the bending stiffness distribution is as follows: )

[0039] Elastic modulus of functionally graded composite materials It can be represented as:

[0040] ;

[0041] in: ; These represent the average stresses of the hard phase and the soft phase, respectively. These represent the average strain of the hard phase and the soft phase, respectively.

[0042] (3) Three distribution functions

[0043] To achieve "rigid fixed end, soft free end, and smooth transition" while also considering manufacturing constraints, this embodiment provides... There are three parameterized functions; you can choose any one or use them in combination.

[0044] ①Power-law distribution

[0045]

[0046] This distribution matches the deflection weight, and the deflection function at the lower end of the uniformly distributed load contains the following: ,index Allow The "hardness weight" is concentrated at the constraint end to suppress the "umbrella shape".

[0047] ② Cubic Hermite smooth distribution

[0048] Zero-slope version:

[0049] ;

[0050] Smooth at both ends: A slope of 0 at both ends can significantly reduce interfacial shear stress and peeling risk, making it manufacturing-friendly.

[0051] Generalized Hermite version (adjustable end slope):

[0052] ;

[0053] ;

[0054]

[0055] Controllable curvature: Generalized Hermite via The steeper the gradient band is closer to one end, the easier it is to balance strength and energy absorption.

[0056] ③Sigmoid distribution

[0057] ;

[0058] Controllable transition position and width: The "hard-soft" transition center; Determining the gradient band width makes it easier to align the soft area with the "claw side".

[0059] (4) Manufacturing and Constraints

[0060] ;

[0061] in and Minimum controllable gradient and layer thickness limit for dual-nozzle / online mixing.

[0062] In addition, this invention also proposes a manufacturing method for an anti-deformation crown cage for ultra-high speed motor bearings. The method includes the design and manufacturing of the anti-deformation crown cage for ultra-high speed motor bearings, specifically including flexible dynamic modeling of the crown cage and deformation analysis of the pocket, co-design and additive manufacturing of the crown cage material gradient and structural parameters, and experimental evaluation of the dynamic performance of the novel crown cage under ultra-high speed conditions.

[0063] More specifically, in the flexible dynamic modeling of the crown cage and the deformation analysis of the pocket, firstly, a multi-scale, highly convergent dynamic model of the bearing for ultra-high-speed operation is constructed: considering surface roughness, non-Newtonian fluid dynamics, and thermal effects, a point-contact elastohydrodynamic (EHL) numerical analysis model is established to obtain the spatiotemporal distribution of compressive and shear stresses within the contact interface. Referring to ball-disc drag tests, based on bearing structural parameters and service conditions, the value ranges of key parameters such as the equivalent radius of the contact interface, entrainment speed, sliding speed, contact load, and grease temperature are determined. An interface lubrication friction performance database is established, and this database is input into a convolutional neural network to obtain the mapping relationship between key parameters and lubrication drag coefficients. Considering the waviness and roundness distribution characteristics of the contact surface, the deformation coordination-geometric compatibility equation between internal bearing components is derived; combining multibody dynamics theory with the above drag mapping relationship, the load-friction load vector equation of the component contact interface is formed. Based on the spatial motion and contact characteristics of the bearing rings and rolling elements, nonlinear equations are introduced to constrain the normal motion vector of the bearing surface, reducing the overall dimension of the differential equation system. This allows for the construction of a multi-scale, highly convergent deep groove ball bearing dynamic model to obtain the transient motion behavior of the bearing assembly. By synergistically addressing both lubrication friction solutions and equation dimension reduction, the convergence efficiency of the dynamic model is improved, providing a theoretical basis for flexible dynamic modeling of the cage.

[0064] Secondly, a method for discretizing and flexibly modeling the crown retainer structure based on beam element theory is established. Considering the shape and load characteristics of a typical crown retainer under ultra-high-speed conditions, the overall structure is divided into three components: side beams, crossbeams, and locking claws. For high centrifugal load fields, semi-flexible elements are used, and beam element theory with different cross-sectional characteristics is introduced to model each part: curved constant-section beam elements are used for discretization of the side beams, straight variable-section beam elements for the crossbeams, and curved variable-section beam elements for the locking claws. The elastic deformation equations of each part of the pocket under self-weight and centrifugal loads are derived and combined to form a flexible mechanical model of the crown retainer pocket. The model is then verified using finite element software, and parameters and boundary conditions are corrected. Based on this, the deformation and stress distribution characteristics of the pocket under ultra-high-speed conditions are determined, with a focus on the centrifugal deformation of the locking claws and the maximum stress at the bottom of the pocket. Furthermore, the centrifugal deformation variation laws of the pockets of retainers with different structural features and dimensional parameters under variable speed conditions are compared, forming a preliminary design basis for the structure and dimensions of the crown retainer.

[0065] Furthermore, a scheme for modeling the flexible dynamics and elucidating the deformation mechanism of the crown cage is proposed: The contact area between the ball and the pocket under service conditions is defined. Combining the element node distribution characteristics of the discrete pocket inner surface, a ball-pocket lubrication collision algorithm based on surface feature recognition is constructed. This achieves bidirectional coupling between the bearing dynamics model and the pocket flexible mechanical model, forming a crown cage flexible dynamics model. This model obtains the deformation characteristics and stress distribution of the pocket under the combined action of self-generated centrifugal load and rolling element collision friction load. Simulations are performed under different speed-load conditions to obtain the cage's motion-deformation behavior. Using the ultimate stress of the cage material as a reference, the mechanism of fracture failure due to excessive stress at the bottom of the pocket is elucidated. Using the shortest distance between the inner surfaces of the two locking claws in the same pocket as a characterizing quantity, the failure process of the bearing experiencing complete cage disengagement is reproduced. The influence relationship between different structural parameters and pocket clearance values ​​on cage deformation is further determined, providing a basis for subsequent material and structural optimization. In the collaborative design of material gradient and structural parameters, it is necessary to establish a mapping mechanism between the functionally graded material composition distribution function and bending stiffness. Glass fiber can significantly improve the heat distortion temperature and creep / relaxation resistance under long-term load. Nylon 66 can perform plastic deformation and viscoelastic energy dissipation under transient impact of ball-pocket under high-speed conditions, reducing stress peaks. Moreover, the use of Nylon 66 can make the interlayer welding performance of FDM relatively excellent, and the layers are not easy to peel off. This invention uses glass fiber (hard phase material) and Nylon 66 (PA66) material (soft phase material) as material control objects. Based on Eshelby inclusion theory and combined with the modified Mori-Tanaka model, it derives the mapping expression between the internal composition relationship of functionally graded materials and the equivalent elastic modulus. It parametrically describes the linear, exponential and piecewise gradient distribution forms in one-dimensional space and quantifies the influence weight of each gradient coefficient on the equivalent elastic modulus. By combining the geometric parameters such as the shape and size of the target structure, and based on the governing equations of functionally graded materials (FJTs) and Timoshenko beam theory, an integral expression relating local modulus gradient and bending stiffness is established, clarifying the mechanism by which local modulus control optimizes overall stiffness. Considering multi-source external excitation loads, the influence of different component gradient distribution coefficients on the bending stiffness, stress, and deformation distribution of the structure is analyzed, revealing the deformation suppression capability of FJTs under service conditions and providing theoretical support for the optimization of material-structure systems.

[0066] Based on this, a material gradient-geometric structure co-design for cage deformation suppression is implemented: combining the geometric characteristics and dimensional parameters of the crown cage pocket, a flexible mechanical model of the pocket is constructed using the aforementioned component function-bending stiffness mathematical expression to determine the deformation and stress state inside the pocket under different speed conditions. Considering the circumferential non-uniform collision excitation characteristics of the pocket, a flexible dynamic model of the crown cage is established to achieve coordinated control of local stiffness and global deformation; the focus is on the centrifugal expansion of weak parts such as the locking claw and the overall shape change of the pocket, as well as their impact on key parameters such as pocket gap and bottom stress, and the quantitative relationships, degree of influence, and trend of change of each parameter are given. Furthermore, the mapping relationship between functionally graded material component parameters and cage structural parameters (including pocket radius, thickness, locking claw length, etc.) and pocket elliptic deformation and overall centrifugal expansion deformation is clarified, and the influence mechanism of material composition and structure on the maximum stress at the bottom of the pocket is explained; under different speed conditions, the graded material cage and the non-graded material cage are compared to determine the component spatial distribution function and optimal structural characteristics suitable for ultra-high speed conditions.

[0067] Subsequently, a solid crown-shaped retainer with optimal material composition and structural characteristics was fabricated. This invention employs a fused deposition modeling (FDM) system equipped with a dual-nozzle co-extrusion system and a dynamic mixing module. The dual-nozzle co-extrusion system separately delivers glass fiber and nylon materials, while the dynamic mixing module controls the delivery volume of glass fiber and nylon materials in real time. By controlling the supply of nylon composite materials with different glass fiber contents, the fiber volume fraction is precisely adjusted in real time. An adaptive slicing algorithm is established based on the pocket geometry, fusing the material composition gradient function with spatial structure data to generate layered G-code instructions. This controls the material switching ratio of the nozzle within a radial unit step, ensuring the gradient distribution at the pocket surface matches the mechanical properties. After verification using virtual printing instructions, actual printing is performed on a 3D printing device. Orthogonal experiments are used to optimize the printing parameters, using nozzle temperature, scanning speed, and layer thickness as design variables. The microstructure is observed using a scanning electron microscope to characterize the continuity and spatial distribution of the material composition gradient. Digital image correlation methods are used to detect the stability of the elastic modulus distribution of the solid structure under bending loads. To address the thin-walled characteristics of the pocket, hot air can be used to assist in controlling the cooling rate when necessary to suppress warping and ensure service performance.

[0068] This invention also conducts synergistic optimization of functionally graded material composition parameters and pocket structure parameters through dynamic performance experiments under ultra-high-speed conditions, as detailed below:

[0069] A machine vision-based method for capturing the motion-deformation state of a cage is constructed. Targeting the structural features of the crown-shaped cage, a U-Net network is used to crop and segment single-frame images, identifying and extracting the bearing contour and position information. Zernike moment subpixel edge detection is used to preprocess the contour edges. A circle detection algorithm based on random Hough transform is employed to clean the contour, eliminating interference from non-cage factors such as the inner and outer rings and rolling elements, thus obtaining the centroid position of the cage within the target image. Using the pocket connection and locking claw marks as reference points, a template matching method is applied to process the image sequence, determining template images with clear pocket deformation. The motion state of the pocket at the same location in different frames is extracted, and the deformation information under service conditions is deduced by combining the initial pocket state. Based on this method, on an ultra-high-speed precision bearing testing platform, a high-speed imaging system is used to acquire bearing motion images, completing the cage motion-deformation test under different operating conditions. Based on this, the aforementioned flexible dynamic model is verified and corrected.

[0070] Furthermore, a modeling and evaluation process for the ultra-high-speed performance of crown cages with deformation suppression function was established: flexible dynamic models of conventional crown cages and functionally graded modulus (FGM) crown cages were constructed respectively, and the differences between the two in terms of pocket deformation and bearing dynamic performance were compared. Using the fabricated FGM cage sample as the object, real-time spatial position data of the cage was simultaneously acquired using a high-speed bearing test bench and a high-speed imaging system; based on cage state capture and flexible dynamic modeling, a spatial registration model of experimental motion state and simulated deformation information was established, and the cage centroid trajectory and pocket radial deformation were obtained using experimental data. The spatial deformation and stress distribution of the cage were analyzed using the model to improve the accuracy of operational state parameter evaluation. With dynamic stability evaluation index as the optimization objective, under the constraint of composite material 3D printing accuracy, the NSGA-II multi-objective genetic algorithm was used to collaboratively optimize the FGM material composition parameters and pocket structure parameters, forming the basis for dynamic performance optimization design of ultra-high-speed bearing cages.

[0071] This invention addresses the failure challenges faced by drive motor bearing cages under ultra-high-speed conditions, such as accelerated wear, structural fracture, and vibration noise, through multi-regional performance synergistic regulation. This results in a novel crown-shaped cage structure that simultaneously manages circumferential and radial deformation. This fundamentally solves the mismatch between the cage stiffness field and the dynamic load field in the spatiotemporal distribution caused by increased rotational speed, providing core technological support for overcoming the bearing speed bottleneck in increasing power density of electric drive systems.

[0072] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a deformation-resistant crown cage for an ultra-high-speed motor bearing, characterized in that, The anti-deformation crown cage of the ultra-high speed motor bearing is printed from a functionally graded material. The equivalent elastic modulus of the functionally graded material gradually changes along the axial direction from the bottom of the pocket to the end of the locking claw, so that the elastic modulus of the bottom region of the pocket is higher than that of the end region of the locking claw, so as to synergistically suppress the elliptic deformation of the pocket and the centrifugal deformation of the locking claw. The manufacturing method of the aforementioned anti-deformation crown cage for ultra-high speed motor bearings includes: A flexible dynamic model of the crown cage is established, and the bearing system under the target ultra-high speed condition is dynamically simulated. The elliptic deformation of the cage pocket, the centrifugal deformation of the locking claw, and the spatial stress distribution at the bottom of the pocket and the locking claw are obtained and output in the working state. Based on Eshelby inclusion theory and combined with the modified Mori-Tanaka model, a mapping relationship between the component distribution and equivalent elastic modulus of functionally graded materials is established. Taking the elliptic deformation of the pocket and the centrifugal deformation of the locking claw as optimization objectives, and the constraint that the maximum working stress at the bottom of the pocket and the locking claw does not exceed the allowable stress of the material, the component distribution function and the structural geometric parameters of the cage are optimized in a coordinated manner. The optimal material gradient distribution function and the optimal structural geometric parameters are determined and output. Additive manufacturing of the solid cage is carried out based on the determined optimal material gradient distribution function and optimal structural geometry parameters.

2. The manufacturing method of the anti-deformation crown cage for ultra-high speed motor bearings as described in claim 1, characterized in that, The method for establishing a flexible dynamic model of the coronal retainer is as follows: A multibody dynamics model of the bearing system is constructed: Multibody dynamic equations are established, including the inner ring, outer ring, rolling elements, and cage. Simultaneously, an elastohydrodynamic lubrication model of the contact interface between the rolling elements and the raceway is established, and a lubrication drag coefficient mapping relationship based on a convolutional neural network is integrated to efficiently solve for interface friction loads. This constructs a highly convergent multibody dynamics model of the bearing system for obtaining the transient motion behavior of the bearing assembly. A flexible mechanical model of the cage pocket is constructed: The crown-shaped cage structure is discretized into side beams, cross beams, and locking claw components. Curved constant-section beam elements, straight variable-section beam elements, and curved variable-section beam elements are used to model each component, deriving their elastic deformation equations under centrifugal loads. These equations are then combined to form the flexible mechanical model of the cage. By constructing a ball-pocket lubrication collision algorithm, the bearing system dynamics model and the cage flexible mechanical model are bidirectionally coupled to form a crown-shaped cage flexible dynamics model, used to solve for the transient motion and deformation response of the cage under the combined action of centrifugal loads and rolling element collision loads.

3. The manufacturing method of the anti-deformation crown cage of an ultra-high speed motor bearing as described in claim 2, wherein the lubrication drag coefficient mapping relationship based on a convolutional neural network is obtained by: conducting a ball-disc drag test based on bearing operating parameters to obtain a lubrication friction performance database; inputting the database into a convolutional neural network for training to obtain a mapping relationship with the equivalent radius of the contact interface, entrainment speed, sliding speed, contact load and grease temperature as inputs and the lubrication drag coefficient as output.

4. The manufacturing method of the anti-deformation crown cage for ultra-high speed motor bearings as described in claim 1, characterized in that, The specific method for additive manufacturing of solid cages based on the determined optimal material gradient distribution function and optimal structural geometry parameters is as follows: The fused deposition modeling equipment is equipped with a dual-nozzle co-extrusion system, which is used to transport the hard phase material and the soft phase material of the functionally graded material respectively, and the transport volume of the hard phase material and the soft phase material is controlled in real time. Using the optimal material gradient distribution function as the basis for real-time material feeding control, a servo system precisely controls the feeding ratio of the dual nozzles to achieve real-time and precise adjustment of hard and soft phase materials during the printing process. A three-dimensional geometric model of the cage is constructed based on the optimal structural geometric parameters, and an adaptive slicing algorithm generates layered printing instructions that control the material switching ratio of the nozzles within a radial unit step, based on the optimal material gradient distribution function. Using a fused deposition modeling (FDM) system, the feeding ratio of hard and soft phase materials is controlled by a dual-nozzle co-extrusion system according to the layered printing instructions, and layers are printed sequentially to prepare the functionally graded material crown cage.

5. The manufacturing method of the anti-deformation crown cage for ultra-high speed motor bearings as described in claim 1, characterized in that, The functionally graded material includes a hard phase material and a soft phase material. The hard phase material is glass fiber, carbon fiber, or a high-modulus polymer, and the soft phase material is PA66, PA12, PA11, or PEEK.

6. The method for manufacturing a deformation-resistant crown cage for an ultra-high-speed motor bearing as described in claim 5, characterized in that, The volume fraction of the hard phase material is distributed along the normalized axial coordinate x, satisfying a power-law distribution, a cubic Hermite smooth distribution, or a Sigmoid distribution.

7. A high-speed motor bearing, comprising an inner ring, an outer ring, rolling elements, and a cage, characterized in that, The cage is an anti-deformation crown cage for ultra-high speed motor bearings manufactured by the manufacturing method described in any one of claims 1-6.

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