A ceramic retainer with a crown-shaped multi-stage shunt network and a composite manufacturing method thereof

Abstract

The application discloses a ceramic retainer with a crown-shaped multi-stage shunt network and a composite manufacturing method thereof, and belongs to the technical field of ceramic bearing manufacturing. The application sets an asymmetric dynamic pressure oil collecting groove on the outer cylindrical surface isolation beam of the retainer base body. The oil collecting groove forcibly intercepts and guides lubricating oil at high speed by using the specific configuration of the flow guide slope and the blocking barrier wall. The base body is internally provided with a crown-shaped multi-stage shunt network in communication with the oil collecting groove. The network is composed of a primary trunk, a secondary axial branch and a tertiary tangential spraying flow channel which are gradually reduced in diameter according to the Murray law. The end of the network forms a micro nozzle array with a circumferential tangential attack angle on the vertical inner wall of the pocket hole. The application realizes active capture, efficient shunt and high-pressure injection of lubricating medium under super high speed, effectively penetrates the air barrier and lubricates the friction pair, and ensures the structural rigidity of the ceramic base body, thereby solving the problems of oil interruption, burning and fragmentation under extreme working conditions.

Description

Technical Field

[0001] This invention relates to the field of ceramic bearing manufacturing technology, and more particularly to a ceramic cage with a canopy-like multi-stage distribution network and its composite manufacturing method. Background Technology

[0002] As a core support component in precision manufacturing and high-end equipment, the performance of ceramic bearings under extreme service environments directly determines the reliability and lifespan of high-end equipment such as aero-engines and precision machine tools. Currently, most high-speed ceramic bearings used in industrial applications employ hybrid ceramic structures, with their cages primarily made of organic polymer materials such as phenolic laminated tubing (bakelite), polyetheretherketone (PEEK), or polytetrafluoroethylene (PTFE). However, the actual operation of high-end equipment often involves extreme conditions such as ultra-high speed, high vacuum, strong corrosion, and high frictional shear heat. These polymer materials suffer from problems such as low temperature limits, poor thermal conductivity, and insufficient stiffness. Under the continuous action of high-speed centrifugal force and high-frequency alternating impact, they are prone to thermal degradation and impact wear deformation, ultimately leading to cage chatter and guide instability. Therefore, adopting all-ceramic cages with high stiffness, high thermal conductivity, low density, and stable temperature resistance has become an inevitable trend to improve the extreme service performance of ceramic bearings.

[0003] However, ceramic materials are typically hard, brittle, and difficult to machine, and their cages are highly susceptible to lubrication shortages and breakage during ultra-high-speed operation. When the bearing is in the ultra-high-speed range, severe air turbulence forms around the outer cylindrical surface of the cage and the circular pocket, creating an air barrier effect that prevents the entry of external fluid lubricating media. Simultaneously, under strong centrifugal force, thin oil mist is prone to radially outward disordered ejection, leading to oil cut-off in the friction contact area between the rolling elements and the vertical inner wall of the circular pocket. Localized instantaneous dry friction can induce thermal stress concentration and microscopic grain boundary cracking on the brittle ceramic surface, ultimately causing the entire cage to break and fail.

[0004] Chinese invention patent CN111022487A discloses a sealed bearing. This design increases the internal oil storage space of the bearing by machining annular oil grooves on the inner diameter of the bearing outer ring and the outer diameter of the cage. However, the oil grooves in this design are completely open structures, and the stored lubricating oil is easily thrown out of the grooves under strong centrifugal force, failing to form a continuous and effective oil film in the contact area requiring lubrication. More importantly, this design completely fails to address how to overcome the air barrier effect at ultra-high speeds; its annular oil grooves lack active guidance and pressure-driven mechanisms, and the lubricating oil cannot be forcibly delivered to the friction interface, thus its effectiveness is minimal under ultra-high speed conditions. Furthermore, its cage is made of polymer materials such as PEEK, which is not suitable for all-ceramic bearing applications requiring extremely high rigidity.

[0005] For example, Chinese invention patent CN102844579A proposes a rolling bearing with a crown-shaped cage. This design features a grease-receiving recess on the annular body between adjacent pockets of the crown-shaped cage, connected to the pockets via a connecting port. Its working principle utilizes the relative movement of the balls within the pockets to scrape the grease adhering to the balls and transfer it to the receiving recess for storage, reducing the grease's stirring resistance and thus lowering the bearing torque. While this design is ingenious, the driving force for scraping and transferring grease relies entirely on the relative movement between the balls and the cage. This force is extremely weak and completely insufficient to overcome the powerful air barrier pressure at ultra-high speeds. Furthermore, its connecting port and recess structure are simple and lack the function of pressurizing and accelerating the fluid, thus failing to form a jet with sufficient kinetic energy to penetrate the air barrier. More importantly, the cage material of this solution is still synthetic resin (such as PEEK, PA, etc.), and its structural design is based on the ease of processing of plastics, without taking into account the brittleness and difficulty of processing ceramic materials. Its complex thin-walled structure and concave features are almost impossible to manufacture on ceramic materials by conventional means, and no manufacturing solution suitable for ceramic materials is provided.

[0006] To alleviate the problems of insufficient lubrication and thermal damage at high speeds, existing patents mostly focus on the layout adjustment of the external macrostructure and auxiliary heat dissipation design. Chinese utility model patent CN223076724U proposes a zirconia ceramic structural component with heat dissipation holes and reinforcing ribs, which increases the heat dissipation area by opening funnel-shaped heat dissipation holes on the outer ring and guides hot air convection; Chinese invention patent CN108374832A proposes a bearing cage structure with a double sliding groove design, which distributes the impact load of the rolling elements by setting two sets of independent mechanical sliding grooves on the surface of the cage.

[0007] However, under ultra-high-speed operating conditions of ceramic bearings, existing technologies lack effective reverse turbulence drainage channels. External lubricating oil mist cannot penetrate the air barrier to enter the friction contact area of ​​the pocket's inner wall, resulting in insufficient lubrication medium supply. Furthermore, the existing cage's internal flow channels lack gradient design for flow rate and pressure drop, resulting in significant internal flow resistance and hindering lubricant flow. Moreover, blindly increasing the cross-sectional area or depth of the flow channels directly weakens the structural strength of the ceramic matrix itself, reducing its tensile load-bearing capacity. Therefore, there is an urgent need for a high-speed ceramic bearing cage that balances matrix structural strength and fluid penetration drainage capability to solve the problems of sudden breakage and lubrication deficiency under ultra-high-speed operating conditions. Summary of the Invention

[0008] To address the aforementioned technical problems, a ceramic cage with a canopy-like multi-level flow distribution network and its preparation method are provided. This method can enhance the fluid penetration and drainage capacity under ultra-high-speed conditions while ensuring the structural strength of the cage matrix, thereby reducing the risk of bearing breakage and lubrication deficiency.

[0009] The technical means employed in this invention are as follows: A ceramic cage with a canopy-like multi-stage flow distribution network includes a cage ceramic substrate with a circular thin-walled structure. The substrate has an outer circumferential cylindrical surface, an inner cylindrical surface, and a plurality of pockets evenly distributed along the circumferential direction for receiving rolling elements. A separation beam is formed between adjacent pockets. An asymmetric dynamic pressure oil collection groove is provided on the outer cylindrical surface. The asymmetric dynamic pressure oil collection groove is used to block and guide external air and lubricating oil mist by utilizing its own asymmetric geometric structure when the cage rotates at high speed with the bearing, thereby generating local dynamic pressure to overcome air blockage and collect external lubricating oil. The interior of the substrate is also provided with a canopy-shaped multi-level distribution network that is connected to the asymmetric hydrodynamic oil collection groove. The canopy-shaped multi-level distribution network is an integrated three-dimensional flow channel system embedded in the interior of the substrate. It includes a main flow channel, branch flow channels and spray flow channels that are distributed in a hierarchical manner. The end of the canopy-shaped multi-level distribution network extends to the vertical inner wall of the pocket to form a micro-nozzle for spraying lubricating medium onto the rolling element.

[0010] Furthermore, the asymmetric hydrodynamic oil collection trough is arranged on the isolation beam as follows: The oil collection groove is recessed inward from the outer circumferential surface of the isolation beam. It includes a guide ramp that extends smoothly in the circumferential direction and cuts into the interior of the base, and a blocking wall that spans the axial width of the isolation beam and is radially upright or has a preset angle. Specifically, the inclination angle of the guide ramp is 15°~25°, and the verticality of the blocking wall is 85°~90°. The bottom of the guide slope and the bottom of the blocking wall meet and connect at the lowest point of the asymmetric dynamic pressure oil collection tank, and this meeting point constitutes the entrance of the canopy-shaped multi-stage diversion network.

[0011] Furthermore, the radial wall thickness of the substrate is divided into three functional regions from the outside to the inside: a surface dynamic pressure trapping region for trapping lubricating oil, a middle spraying region for conveying and spraying lubricating oil, and a deep solid stiffness region for withstanding the centrifugal tensile stress generated by high-speed rotation. The asymmetric dynamic pressure oil collection groove is completely set within the surface dynamic pressure collection area. The middle spray area wraps the friction contact area between the rolling element and the vertical inner wall of the pocket in radial depth. The canopy-shaped multi-stage diversion network is completely set within the middle spray area. The deep solid stiffness area is constructed as a complete annular ceramic solid without any built-in diversion channels or flow channels.

[0012] Furthermore, the canopy-shaped multi-level diversion network includes a primary main channel, two secondary axial branch channels, and four tertiary tangential spray channels; The primary main flow channel starts from the bottom of the asymmetric dynamic pressure oil collection tank and extends along the radial direction of the substrate into the middle layer spray zone; The secondary axial branch flow channel includes a first branch and a second branch. The first branch and the second branch are formed symmetrically at the end of the primary main flow channel and extend towards the axial sides of the isolation beam, thereby splitting the flow path of the lubricating medium in the axial direction for the first time. The three-stage tangential spray channel includes four channels formed by secondary branching from the tail ends of the first branch and the second branch. These four channels penetrate the interior of the isolation beam at an inclined manner and extend to the vertical inner wall of two pockets adjacent to the isolation beam, thereby splitting the flow path of the lubricating medium in the circumferential direction for the second time. The end nozzles of the four three-stage tangential spray channels are distributed in a depth range of 35% to 55% of the total radial wall thickness of the substrate.

[0013] Furthermore, the micro-nozzle is formed by the opening of the end of the three-stage tangential spray channel on the vertical inner wall of the pocket, and the multiple micro-nozzles are distributed in an array on the vertical inner wall; The orifice axis of the micro-nozzle is not perpendicular to the vertical inner wall of the pocket, but forms an acute circumferential tangential angle of attack with the vertical inner wall at its orifice position, specifically 15°~20°. This angle of attack is set such that the direction of the lubricating medium jet ejected from the micro-nozzle is consistent with the predetermined rotational motion direction of the rolling element, thereby reducing the resistance when the jet enters the contact area.

[0014] Furthermore, the pipe diameters of the primary main flow channel, the secondary axial branch flow channel, and the tertiary tangential spray flow channel numerically satisfy the cubic conservation relationship of Murray's law, that is, for each branching node, the cubic value of its parent pipe diameter is equal to the sum of the cubic values ​​of its two daughter pipe diameters, thereby minimizing flow loss and maximizing the conversion efficiency of fluid kinetic energy during the gradual contraction of the flow channel.

[0015] On the other hand, the present invention also provides a composite manufacturing method for manufacturing the ceramic retainer, comprising the following steps: Step 1: Using ceramic additive manufacturing process, a ceramic retainer blank with the asymmetric dynamic pressure oil collection groove, the canopy-shaped multi-level diversion network and the pocket is integrally formed, and subtractive machining allowances are reserved on the outer cylindrical surface, inner cylindrical surface and vertical inner wall of the pocket for subsequent precision machining. Step 2: The ceramic cage blank is subjected to degreasing treatment and high-temperature solid-state sintering treatment in sequence to remove the organic binder inside the blank and realize the densification between ceramic particles, thereby obtaining a ceramic cage blank with an integrated structure. Step 3: Using diamond as a grinding tool, the ceramic cage blank is subjected to multi-step combined precision grinding and polishing. This step includes first grinding the outer cylindrical surface and the inner cylindrical surface to establish a precise positioning reference, and then precision grinding and polishing the vertical inner wall of the pocket to make its dimensional accuracy and surface roughness meet the standards of high-speed bearing operation. Step 4: A fluid abrasive flow machining process is adopted, in which an abrasive suspension with micro-cutting capability is forced into the outer ring asymmetric dynamic pressure oil collection tank under pressure and forced to flow through the internal channels of the entire canopy-shaped multi-stage distribution network, and finally discharged from the micro nozzle. In this way, the abrasive flow is used to flush, clean and polish the inner walls and bifurcation turning points of the various channels deeply embedded in the matrix.

[0016] Furthermore, the ceramic additive manufacturing process in step 1 adopts photopolymerization 3D printing technology. The ceramic slurry used is prepared by mixing photosensitive resin, dispersant, surface modifier and one or more ceramic powders selected from silicon nitride, zirconium oxide or silicon carbide, and a ceramic blank containing complex three-dimensional internal channels is constructed by photopolymerization layer by layer.

[0017] Furthermore, in step 3, when grinding and polishing the vertical inner wall of the pocket, a multi-axis linkage CNC system is used to control the processing trajectory of the micro-diameter diamond grinding head. This processing trajectory is optimized to ensure that the edge of the micro nozzle does not produce burrs or chipping defects after processing, and to ensure that the roundness and perpendicularity of the vertical inner wall of the pocket meet the design specifications.

[0018] Furthermore, in step 4, by programmatically adjusting and controlling the three process parameters of the abrasive suspension—the extrusion pressure, the abrasive particle size, and the number of cyclic rinsing cycles—the surface quality of the inner wall of the canopy-shaped multi-level distribution network with different pore sizes can be graded and improved. The extrusion pressure is set to be able to drive the abrasive to pass smoothly through the smallest three-level tangential spray channel, and the number of cyclic rinsing cycles is set to be sufficient to eliminate the internal microscopic step effect generated during additive manufacturing.

[0019] Compared with the prior art, the present invention has the following advantages: 1. This invention utilizes the geometric configuration of an asymmetric dynamic pressure oil collection groove to intercept turbulent airflow in the outer ring under high-speed rotation and generate local dynamic pressure, forcibly capturing external lubricating oil mist. The collected lubricating medium is transformed into a high-kinetic-energy fluid through a multi-stage network with progressively decreasing flow channel diameter, utilizing the cross-sectional velocity amplification effect. Finally, it is ejected in the forward direction by micro-nozzles with a specific tangential angle of attack, penetrating the ultra-high-speed air barrier and achieving spray lubrication of the friction contact area between the rolling element and the vertical inner wall of the pocket. Specifically, this invention utilizes the asymmetric dynamic pressure oil collection groove designed on the isolation beam of the outer cylindrical surface, taking advantage of high-speed airflow, which is traditionally considered unfavorable. The asymmetric configuration of the guide ramp and the blocking baffle of this oil collection groove can convert the kinetic energy of the turbulent airflow generated by high-speed rotation into static pressure energy. This actively forces the external lubricating oil mist, which is blocked by the air barrier, into the flow channel inlet. This mechanism completely overturns the passive lubrication methods in existing technologies that rely on gravity, capillary force, or mechanical scraping by rolling elements. For the first time, it achieves active capture and forced supply of lubricating medium under ultra-high speed conditions, completely solving the problem of oil cut-off caused by air blockage and ensuring that the friction interface can still obtain sufficient lubricating medium at the extreme speed.

[0020] 2. The canopy-like multi-stage flow distribution network constructed in this invention, through a primary trunk, secondary branches, and tertiary spraying, progressively diverts a single fluid inlet to two adjacent pockets, ensuring that each rolling element receives an equal and stable lubrication supply. Simultaneously, the diameter of each flow channel is optimized according to Murray's law, ensuring minimal pressure loss when the fluid flows through the complex three-dimensional network. More importantly, the progressively narrowing flow channel design itself constitutes a natural fluid accelerator, efficiently converting the pressure energy of the lubricating medium into the kinetic energy of high-speed jetting. Finally, this high-speed fluid is ejected from a micro-nozzle with a specific circumferential tangential angle of attack, capable of penetrating any residual air barriers with immense momentum and precisely entering the contact area between the rolling element and the pocket wall in the direction of the rolling element's rotation. This high-pressure, high-speed, directional jet lubrication method, compared to existing seepage or scraping lubrication technologies, improves penetration and film-forming capabilities by several orders of magnitude, effectively establishing a high-strength dynamic pressure oil film and significantly reducing the coefficient of friction and temperature rise.

[0021] 3. The greatest structural breakthrough of this invention lies in the functional division of the radial wall thickness, confining the flow channels to the surface and middle layers. This eliminates the built-in flow channels within the deep solid rigidity zone, allowing it to bear centrifugal tensile stress and alternating loads. This significantly reduces the risk of sudden breakage without weakening the matrix strength. Under ultra-high-speed rotation, the maximum centrifugal tensile stress borne by the cage occurs near its inner ring. Placing the flow channels in the relatively low-stress outer region, while allowing the inner, intact ceramic ring (accounting for 30%–40% of the wall thickness) to bear the maximum stress, is an optimal mechanical distribution scheme. This allows the invention to achieve efficient lubrication through complex internal flow channels while maximizing the preservation of the overall tensile strength and stiffness of the matrix, effectively avoiding structural discontinuities and stress concentrations caused by the flow channels, thus minimizing the risk of high-speed centrifugal breakage. It is suitable for all-ceramic bearings and can be directly applied to aero-engine spindle bearings, high-parameter precision machine tool spindles, and high-speed rotating support systems operating in extreme environments such as high vacuum, strong corrosion, and intense frictional shear heat. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a zirconia ceramic cage in an example of the present invention.

[0024] Figure 2 This is a schematic diagram of the dynamic pressure oil collection tank structure in an example of the present invention.

[0025] Figure 3 This is a schematic diagram showing the distribution of different functional areas of the cage isolation beam in an example of the present invention.

[0026] Figure 4 This is a schematic diagram of a three-level tree canopy-shaped distribution network in an example of the present invention.

[0027] Among them, 1. cage base; 11. outer cylindrical surface; 12. inner cylindrical surface; 2. pocket; 3. isolation beam; 4. oil collection groove; 41. guide slope; 42. barrier wall; 5. primary main flow channel; 6. secondary axial branch flow channel; 61. first secondary axial branch flow channel; 62. second secondary axial branch flow channel; 7. tangential spray flow channel; 71. first tangential spray flow channel; 72. second tangential spray flow channel; 73. third tangential spray flow channel; 74. fourth tangential spray flow channel; 8. micro nozzle. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] 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 embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0032] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0035] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. This embodiment is illustrated using a zirconia ceramic cage for a P4-grade 7008C angular contact ball bearing as an example.

[0036] like Figure 1 As shown, this embodiment of the invention provides a ceramic cage with a canopy-like multi-stage flow distribution network, which mainly includes a cage ceramic substrate 1 with a circular annular thin-walled structure. The substrate 1 has an outer cylindrical surface 11, an inner cylindrical surface 12, and a plurality of pockets 2 evenly distributed along the circumference to accommodate rolling elements. In this embodiment, the number of pockets 2 is preferably 12. The solid portion between two adjacent pockets 2 constitutes a separation beam 3.

[0037] In this embodiment, the total radial wall thickness of the substrate 1 is 2.7 mm. For example... Figure 3 As shown, to balance lubrication performance and structural strength under ultra-high-speed rotation, the matrix 1 is clearly divided into three functional regions from the outside to the inside along the radial wall thickness direction: a surface dynamic pressure trapping zone A for collecting lubricating oil, a middle spray zone B for conveying and spraying lubricating oil, and a deep solid stiffness zone C for withstanding the centrifugal tensile stress generated by high-speed rotation. The radial thickness of the surface dynamic pressure trapping zone A is 0.54 mm (accounting for 20% of the total wall thickness); the radial thickness of the middle spray zone B is 1.215 mm (accounting for 45% of the total wall thickness), and this zone precisely wraps the friction contact area between the rolling element and the vertical inner wall of the pocket 2 in radial depth; the radial thickness of the deep solid stiffness zone C is 0.945 mm (accounting for 35% of the total wall thickness). Furthermore, the deep solid stiffness zone C is constructed as a complete annular ceramic solid without any built-in diversion channels or hole structures, in order to concentrate the centrifugal stress under ultra-high speed rotation and effectively avoid the risk of stress concentration and breakage caused by internal flow channels.

[0038] like Figure 2 As shown, on the outer cylindrical surface 11, in the area directly above each isolation beam 3, i.e., within the surface dynamic pressure trapping area A, an asymmetric dynamic pressure oil collecting groove 4 is provided. The asymmetric dynamic pressure oil collecting groove 4 is used to impede and guide external air and lubricating oil mist by utilizing its own asymmetric geometry when the cage rotates at high speed with the bearing, thereby generating local dynamic pressure to overcome the air barrier and collect external lubricating oil.

[0039] Specifically, the asymmetric hydrodynamic oil collection trough 4 is formed by an inward indentation from the outer circumferential surface of the isolation beam 3. It includes a guide ramp 41 that extends smoothly in the circumferential direction and cuts into the interior of the base, and a blocking wall 42 that spans the axial width of the isolation beam 3 and is radially upright or has a predetermined angle. The bottom of the guide ramp 41 and the bottom of the blocking wall 42 meet and connect at the lowest point of the asymmetric hydrodynamic oil collection trough 4, and this meeting point constitutes the inlet of the canopy-shaped multi-stage diversion network.

[0040] In this embodiment, the inclination angle of the guide ramp 41 is 15°, and the verticality of the blocking wall 42 is 88°. The axial width of the asymmetric dynamic pressure oil collection groove 4 is designed to be 8.22 mm (approximately 60% of the total axial width of the base), its total circumferential arc length is designed to be 50% of the total circumferential arc length of the isolation beam 3, and its maximum radial depth, i.e., the deepest bottom of the groove, is designed to be 0.405 mm (15% of the total radial wall thickness of the base, 2.7 mm).

[0041] In this embodiment, the inclination angle of the guide ramp 41 specifically refers to the acute angle between the surface tangent of the guide ramp 41 and the tangent direction of the circular motion at that point on the axial section passing through the center of the cage shaft. The perpendicularity of the blocking wall 42 specifically refers to the angle between the surface of the blocking wall 42 and the radial direction on the axial section passing through the center of the cage shaft. The inclination direction of the guide ramp 41 is consistent with the predetermined rotation direction of the cage in the bearing, so that air and oil mist moving along the rotation direction can be guided along the guide ramp 41 to the deepest part of the oil collection groove 4. If the bearing rotation direction changes, the inclination direction of the oil collection groove should be adjusted accordingly.

[0042] Combination Figure 3 and Figure 4 The interior of the substrate 1 is also provided with a canopy-shaped multi-level distribution network that communicates with the asymmetric hydrodynamic oil collection groove 4. The canopy-shaped multi-level distribution network is an integrated three-dimensional flow channel system embedded in the interior of the substrate. It includes a main flow channel, branch flow channels and spray flow channels that are distributed in a hierarchical manner, and its end extends through the vertical inner wall of the pocket 2 to form a micro-nozzle 8 for spraying lubricating medium onto the rolling element.

[0043] The integrated structure described in this invention refers to a ceramic retainer in which all walls of the substrate 1, the asymmetric dynamic pressure oil collection groove 4, and the canopy-shaped multi-level distribution network are composed of the same continuous ceramic material with grains firmly bonded together through grain boundaries. There are no welding, bonding, or mechanical assembly interfaces between them; it is a completely continuous and uniform whole at the material level. This integration ensures the continuity of force flow under stress and eliminates weak points caused by poor interface bonding.

[0044] Specifically, in this embodiment, the canopy-shaped multi-level distribution network is entirely located within the middle spray zone B, comprising one primary main channel 5, two secondary axial branch channels 6, and four tertiary tangential spray channels 7. Each level of the channel completes a hierarchical cascade within the middle spray zone B; its specific connection and distribution are as follows: The primary main flow channel 5 starts from the bottom of the asymmetric dynamic pressure oil collection tank 4 and extends vertically along the radial direction of the substrate 1 into the middle spray zone B. Its aperture is designed to be 0.30 mm (approximately 24.7% of the radial thickness of the middle spray zone, which is 1.215 mm).

[0045] The secondary axial branch flow channel 6 includes a first branch 61 and a second branch 62. The first branch 61 and the second branch 62 are formed symmetrically at the end of the primary main flow channel 5 and extend towards both axial sides of the isolation beam 3, thereby splitting the flow path of the lubricating medium axially for the first time. The total included angle between the two branches in the axial-radial section is 45°, and they extend obliquely into the depth of the middle spray zone B to increase the axial spacing. In this embodiment, the single orifice diameter of both the first branch 61 and the second branch 62 is designed to be 0.238 mm (approximately 75% of the orifice diameter of the primary main flow channel).

[0046] The three-stage tangential spray channel 7 comprises four channels formed by secondary branching from the tail ends of the first branch 61 and the second branch 62, namely, the first tangential spray channel 71, the second tangential spray channel 72, the third tangential spray channel 73, and the fourth tangential spray channel 74. The four channels penetrate the interior of the isolation beam 3 at an angle and extend to the vertical inner walls of the two adjacent pockets 2, thereby diverting the flow path of the lubricating medium a second time in the circumferential direction. The single orifice diameter of each of the four three-stage tangential spray channels 7 is designed to be 0.189 mm (approximately 75.5% of the orifice diameter of the secondary axial branch channel).

[0047] In this embodiment, the pipe diameters of the primary main flow channel 5, the secondary axial branch flow channel 6, and the tertiary tangential spray flow channel 7 basically satisfy the cubic conservation relationship of Murray's law. That is, for each branch node, the cubic value of the diameter of its parent pipe is equal to the sum of the cubic values ​​of the diameters of its two daughter pipes, thereby minimizing flow loss and maximizing the conversion efficiency of fluid kinetic energy during the gradual contraction of the flow channel.

[0048] In this embodiment, the orifice diameters of each flow channel satisfy the cubic sum conservation law of Murray's Law, that is, the cubic of the orifice diameter of the primary main flow channel is equal to the sum of the cubic diameters of the two secondary branch flow channels, and the cubic of the orifice diameter of a single secondary branch flow channel is equal to the sum of the cubic diameters of the two tertiary flow channels branching from it.

[0049] The micro-nozzle 8 is formed by opening the end of the three-stage tangential spray channel 7 on the vertical inner wall of the pocket 2. The end nozzles of the four three-stage tangential spray channels 7 are distributed within a depth range of 35% to 55% of the total radial wall thickness of the substrate. In this embodiment, they are specifically distributed at a radial depth of 1.485 mm from the outer cylindrical surface (corresponding to the 55% depth position of the total radial wall thickness of the substrate).

[0050] In this embodiment, a plurality of micro-nozzles 8 are arranged in an array on the vertical inner wall. Optionally, the micro-nozzles 8 are evenly arranged in two axial columns and two circumferential rows on the vertical inner wall 21 of a single pocket 2. The orifice axis of the micro-nozzle 8 is not perpendicular to the vertical inner wall of the pocket 2, but forms an acute circumferential tangential angle of attack with the tangential direction of the vertical inner wall at its orifice position. In this embodiment, the angle of attack is specifically 18°, which is set such that the direction of the lubricating medium jet ejected from the micro-nozzle 8 is consistent with the predetermined rotational motion direction of the rolling element, so as to reduce the resistance when the jet enters the contact area.

[0051] During this process, as the flow channel diameter decreases from 0.30 mm to 0.238 mm and then to 0.189 mm, a velocity amplification effect is triggered by the gradual contraction of the flow channel, significantly increasing the kinetic energy of the oil mist medium. Ultimately, the high-kinetic-energy lubricating fluid is ejected at high speed from the micro-nozzle 8 along a circumferential tangential angle of attack of 18°, precisely entering the collision contact area between the ball and the vertical inner wall 21 of the pocket 2, in accordance with the rotational motion of the ball, achieving all-round spray lubrication.

[0052] When the cage rotates at high frequency with the bearing, a strong reverse turbulent air barrier is generated between the outer ring and the outer cylindrical surface 11. When the external lubricating oil mist moves with the airflow to the asymmetric dynamic pressure oil collection groove 4, the turbulent airflow is forcibly blocked due to the 88° vertical verticality of the obstruction baffle 42. Under the dynamic pressure effect of the outer ring, the oil mist overcomes the air barrier and is forced into the inlet of the primary main flow channel 5. After the oil mist enters, it flows through the first branch 61 and the second branch 62 for the first axial split, and then branches again into four three-stage tangential spray channels 7. During this process, due to the gradual decrease in pipe diameter, the velocity amplification effect of the gradual contraction of the flow channel is triggered, and the kinetic energy of the oil mist medium is significantly increased. Finally, the high-kinetic-energy lubricating fluid is ejected at high speed from the micro nozzle 8 at a circumferential tangential angle of attack of 18°, and is precisely injected into the collision contact area between the ball and the vertical inner wall of the pocket 2 in accordance with the rotational motion of the ball, achieving all-round spray lubrication. Meanwhile, the non-porous deep solid stiffness zone C, which accounts for 35% (0.945mm) of the thickness, effectively locks the overall tensile stiffness of the cage, bears most of the centrifugal tensile stress, and ensures that the cage does not suddenly break during ultra-high-speed operation.

[0053] This embodiment also provides a composite manufacturing method for manufacturing the above-mentioned ceramic cage, specifically including the following steps: Step 1: Using a ceramic additive manufacturing process, a ceramic retainer blank with the asymmetric dynamic pressure oil collection groove 4, the canopy-shaped multi-level diversion network, and the pocket 2 is integrally formed. In this embodiment, the ceramic additive manufacturing process preferably employs photopolymerization 3D printing technology, and the ceramic slurry used is prepared by mixing photosensitive resin, dispersant, surface modifier, and one or more ceramic powders selected from silicon nitride, zirconium oxide, or silicon carbide.

[0054] In this embodiment, the slurry is prepared by mixing photosensitive resin liquid, ester surface modifier, polyacrylic acid dispersant and zirconia ceramic micro powder with a median particle size of 0.5 μm, wherein the volume solid content of zirconia micro powder is 52 vol.

[0055] A ceramic preform containing complex three-dimensional internal flow channels is constructed by layer-by-layer photopolymerization (layer thickness 25μm). Subtractive machining allowances are reserved on the outer cylindrical surface 11, the inner cylindrical surface 12, and the vertical inner wall of the pocket 2 of the preform for subsequent precision machining. In this embodiment, a subtractive grinding allowance of 0.35 mm is uniformly reserved.

[0056] Step 2: The ceramic cage blank is subjected to degreasing and high-temperature solid-state sintering treatment in sequence. Specifically, the temperature is slowly increased to 600°C at a heating rate of 0.2°C / min and held for 4 hours to remove the organic binder photosensitive resin inside the blank. Then, high-temperature solid-state sintering is carried out at 1480°C for 3 hours to achieve dense bonding between ceramic particles, thereby obtaining a zirconia ceramic cage blank with an integrated structure.

[0057] Step 3: Using diamond as the grinding tool, the ceramic cage blank undergoes multi-step precision grinding and polishing. This step includes first grinding the outer cylindrical surface 11 and the inner cylindrical surface 12 to establish a precise positioning reference. Then, a multi-axis CNC system controls the machining trajectory of a φ1.5mm diamond grinding head to perform precision grinding and polishing on the vertical inner wall of the pocket 2. This machining trajectory is optimized to ensure that the edge of the micro-nozzle 8 does not produce burrs or chipping defects after processing, and to ensure that the roundness and perpendicularity of the vertical inner wall of the pocket are better than 3μm, and the surface roughness Ra reaches 0.1μm, meeting the standards for high-speed bearing operation.

[0058] Step 4: A fluid abrasive flow machining process is employed. Under pressure, an abrasive suspension with micro-cutting capabilities (e.g., diamond powder with a particle size of 5 μm) is forced into the outer asymmetric dynamic pressure oil collection tank 4 and compelled to flow through the internal channels of the entire canopy-shaped multi-stage distribution network, ultimately exiting from the micro-nozzle 8. In this embodiment, the extrusion pressure is set to 4.5 MPa, and 200 cycles of alternating forward and reverse high-pressure cyclic scouring are performed. This step utilizes the abrasive flow to scour, clean, and polish the inner walls and bifurcation points of the various channels deeply embedded within the matrix, thereby eliminating the internal microscopic step effect and local burrs left by additive manufacturing, reducing the internal roughness of the channels to below Ra 0.2 μm, significantly reducing internal flow resistance, and avoiding stress concentration at internal sharp corners.

[0059] This embodiment utilizes an asymmetric dynamic pressure oil collection groove to intercept turbulent airflow in the outer ring and generate local dynamic pressure under high-speed rotation, forcibly capturing external lubricating oil mist. Furthermore, by incorporating a canopy-shaped multi-stage flow channel within the zirconia cage, the flow velocity amplification effect generated by the progressively decreasing aperture structure and the tangential angle-of-attack nozzles enhance the guiding kinetic energy of the lubricating medium, enabling it to penetrate the air barrier formed at ultra-high speeds and solving the problem of insufficient lubrication in the friction contact area of ​​the vertical inner wall of the pocket. Simultaneously, this multi-stage flow channel is spatially arranged only in the surface and middle layers, ensuring that the deep solid rigidity zone near the inner ring remains a complete, non-porous annular ceramic entity, which bears the centrifugal tensile stress under ultra-high-speed operation, reducing the risk of high-speed centrifugal breakage of the cage.

[0060] In summary, this embodiment successfully achieves the use of asymmetric dynamic pressure oil collection grooves to break through air barriers and capture oil mist under ultra-high speed conditions, and efficiently and directionally distributes lubricating oil to the pocket friction pair through a canopy-shaped multi-stage distribution network. At the same time, the partitioned design ensures the structural rigidity of the ceramic matrix, effectively solving the problems of oil cut-off burning and cracking under extreme conditions.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ceramic retainer with a canopy-like multi-level distribution network, characterized in that, The cage includes a ceramic substrate with a thin-walled, annular structure. The substrate has an outer cylindrical surface, an inner cylindrical surface, and multiple pockets evenly distributed along the circumferential direction for accommodating rolling elements. A separation beam is formed between adjacent pockets. An asymmetric dynamic pressure oil collection groove is provided on the outer cylindrical surface. The asymmetric dynamic pressure oil collection groove is used to block and guide external air and lubricating oil mist by utilizing its own asymmetric geometric structure when the cage rotates at high speed with the bearing, thereby generating local dynamic pressure to overcome air blockage and collect external lubricating oil. The interior of the substrate is also provided with a canopy-shaped multi-level distribution network that is connected to the asymmetric hydrodynamic oil collection groove. The canopy-shaped multi-level distribution network is an integrated three-dimensional flow channel system embedded in the interior of the substrate. It includes a main flow channel, branch flow channels and spray flow channels that are distributed in a hierarchical manner. The end of the canopy-shaped multi-level distribution network extends to the vertical inner wall of the pocket to form a micro-nozzle for spraying lubricating medium onto the rolling element.

2. The ceramic retainer according to claim 1, characterized in that: The asymmetric hydrodynamic oil collection trough is configured on the isolation beam as follows: The oil collection groove is recessed inward from the outer circumferential surface of the isolation beam. It includes a guide ramp that extends smoothly in the circumferential direction and cuts into the interior of the base, and a blocking wall that spans the axial width of the isolation beam and is radially upright or has a preset angle. The bottom of the guide slope and the bottom of the blocking wall meet and connect at the lowest point of the asymmetric dynamic pressure oil collection tank, and this meeting point constitutes the entrance of the canopy-shaped multi-stage diversion network.

3. The ceramic retainer according to claim 1, characterized in that: The radial wall thickness of the substrate is divided into three functional regions from the outside to the inside: a surface dynamic pressure trapping zone for capturing lubricating oil, a middle spraying zone for conveying and spraying lubricating oil, and a deep solid stiffness zone for withstanding the centrifugal tensile stress generated by high-speed rotation. The asymmetric dynamic pressure oil collection tank is completely located within the surface dynamic pressure collection zone, the canopy-shaped multi-stage diversion network is completely located within the middle spray zone, and the deep solid rigidity zone is constructed as a complete annular ceramic solid without any built-in diversion channels or flow paths.

4. The ceramic retainer according to claim 3, characterized in that: The canopy-shaped multi-level diversion network includes a primary main channel, two secondary axial branch channels, and four tertiary tangential spray channels; The primary main flow channel starts from the bottom of the asymmetric dynamic pressure oil collection tank and extends along the radial direction of the substrate into the middle layer spray zone; The secondary axial branch flow channel includes a first branch and a second branch. The first branch and the second branch are formed symmetrically at the end of the primary main flow channel and extend towards the axial sides of the isolation beam, thereby splitting the flow path of the lubricating medium in the axial direction for the first time. The three-stage tangential spray channel includes four channels formed by secondary branching from the tail ends of the first branch and the second branch. These four channels penetrate the interior of the isolation beam at an inclined manner and extend to the vertical inner wall of two pockets adjacent to the isolation beam, thereby splitting the flow path of the lubricating medium a second time in the circumferential direction.

5. The ceramic retainer according to claim 4, characterized in that: The micro-nozzle is formed by the opening of the end of the three-stage tangential spray channel on the vertical inner wall of the pocket, and the multiple micro-nozzles are distributed in an array on the vertical inner wall. The orifice axis of the micro-nozzle is not perpendicular to the vertical inner wall of the pocket, but forms an acute circumferential tangential angle of attack with the vertical inner wall at its orifice position. The angle of attack is set such that the direction of the lubricating medium jet ejected from the micro-nozzle is consistent with the predetermined rotational motion direction of the rolling element.

6. The ceramic retainer according to claim 4, characterized in that: The pipe diameters of the primary main flow channel, the secondary axial branch flow channel, and the tertiary tangential spray flow channel numerically satisfy the cubic conservation relationship of Murray's Law. That is, for each branching node, the cubic value of its parent pipe diameter is equal to the sum of the cubic values ​​of its two daughter pipe diameters, thereby minimizing flow loss and maximizing the conversion efficiency of fluid kinetic energy during the gradual contraction of the flow channel.

7. A composite manufacturing method for manufacturing a ceramic retainer as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1: Using ceramic additive manufacturing process, a ceramic retainer blank with the asymmetric dynamic pressure oil collection groove, the canopy-shaped multi-level diversion network and the pocket is integrally formed, and subtractive machining allowances are reserved on the outer cylindrical surface, inner cylindrical surface and vertical inner wall of the pocket for subsequent precision machining. Step 2: The ceramic cage blank is subjected to degreasing treatment and high-temperature solid-state sintering treatment in sequence to obtain a ceramic cage blank with an integrated structure. Step 3: Using diamond as a grinding tool, the ceramic cage blank is subjected to multi-step combined precision grinding and polishing. This step includes first grinding the outer cylindrical surface and the inner cylindrical surface to establish a precise positioning reference, and then precision grinding and polishing the vertical inner wall of the pocket to make its dimensional accuracy and surface roughness meet the standards of high-speed bearing operation. Step 4: A fluid abrasive flow machining process is adopted, in which an abrasive suspension with micro-cutting capability is forced into the outer ring asymmetric dynamic pressure oil collection tank under pressure and forced to flow through the internal channels of the entire canopy-shaped multi-stage distribution network, and finally discharged from the micro nozzle. In this way, the abrasive flow is used to flush, clean and polish the inner walls and bifurcation turning points of the various channels deeply embedded in the matrix.

8. The composite manufacturing method according to claim 7, characterized in that: The ceramic additive manufacturing process in step 1 uses photopolymerization 3D printing technology. The ceramic slurry used is prepared by mixing photosensitive resin, dispersant, surface modifier and one or more ceramic powders selected from silicon nitride, zirconium oxide or silicon carbide. A ceramic blank containing complex three-dimensional internal flow channels is constructed by photopolymerization layer by layer.

9. The composite manufacturing method according to claim 7, characterized in that: In step 3, when grinding and polishing the vertical inner wall of the pocket, a multi-axis linkage CNC system is used to control the processing trajectory of the micro-diameter diamond grinding head. The processing trajectory is optimized to ensure that the edge of the micro nozzle does not produce burrs or chipping defects after processing, and to ensure that the roundness and perpendicularity of the vertical inner wall of the pocket meet the design specifications.

10. The composite manufacturing method according to claim 7, characterized in that: In step 4, the surface quality of the inner wall of the canopy-shaped multi-level diversion network with different pore sizes is improved by programmatically adjusting and controlling the three process parameters of the abrasive suspension, abrasive particle size, and number of cycles.

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