A high load backing bearing with a multi-layer composite wall thickness outer race

Abstract

This invention discloses a high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring. The bearing's dynamic blocking transition layer is composed of polyhedral rigid microparticles and a viscoplastic matrix, with the microparticle volume fraction limited within a critical blocking threshold range. Under quasi-static radial heavy loads, the microparticles are in a blocked state, forming a rigid force chain that transmits hydrostatic stress. Under high-frequency transverse shear stress wave excitation, the matrix undergoes transient superplastic rheology, and the force chain enters a locally unblocked state, resulting in micro-rheology and a sudden drop in transverse shear stiffness. Based on the orthogonal decoupling of stress states and the dual-state phase transition characteristics, this invention actively disrupts the subsurface standing wave resonance condition, resolving the contradiction between macroscopic compressive strength and microscopic dissipation. This effectively suppresses deep peeling failure under high-speed, heavy-load conditions, and its material selection and process design fully embody the energy-saving and high-efficiency concept of green manufacturing.

Description

Technical Field

[0001] This invention relates to a bearing, and more particularly to a high load-bearing backing bearing having a multi-layered composite wall thickness outer ring. Background Technology

[0002] High-load-bearing backed bearings are widely used in the support roll assemblies of high-end green manufacturing equipment such as multi-roll cold rolling mills and large leveling machines. Under these extreme heavy-load conditions, the outer ring of the bearing not only needs to withstand radial hydrostatic pressure stress of up to hundreds of megapascals, but also needs to operate continuously at extremely high rolling line speeds, making its physical service environment extremely harsh.

[0003] To address the problem of stress concentration and overall fatigue fracture in traditional single-layer thick-walled outer rings under high loads, existing technologies have gradually developed multi-layer composite thick-walled outer ring structures. These structures are typically composed of an outer high-hardness, wear-resistant working layer and an inner high-toughness support layer. However, in actual high-speed, heavy-load operation, such multi-layer composite bearings are prone to sudden, catastrophic peeling failures at the interface between different materials, severely restricting the continuous operation cycle of the equipment.

[0004] Regarding the aforementioned peeling failure phenomenon of composite interfaces, those skilled in the art generally analyze the cause of failure based on the quasi-static Hertzian contact theory. The industry's conventional understanding tends to be that the root cause of peeling is insufficient metallurgical bonding strength between different material layers, or that the point of maximum shear stress happens to fall on the composite interface. Therefore, existing improvement solutions largely focus on using advanced processes such as electron beam welding or hot isostatic pressing to try to improve the rigid bonding strength of the interface, or by adjusting the outer layer wall thickness ratio to force the peak shear stress to shift to the outside or inside.

[0005] However, existing technologies completely ignore the unique elastic dynamic energy trapping effect under high-speed, heavy-load conditions. When the outer ring of the bearing rolls against the support roller at extremely high speeds, the transient excitation in the contact area transmits high-frequency transverse shear stress waves inward. Due to the significant differences in the elastic modulus and density of the materials in the multilayer composite structure, the stress waves undergo strong total reflection due to the acoustic impedance step when propagating downward to the composite interface. The reflected stress waves and the incident stress waves from the subsequent rolling action of the rolling elements are superimposed at the subsurface, forming localized standing waves. It is this standing wave that causes the microcrystalline lattice at the interface to undergo high-frequency microplastic strain cycles several times greater than the macroscopic load in a very short time, ultimately leading to grain boundary tearing. The more the industry strengthens the rigid bonding of the interface, the more drastic the stiffness change at the interface becomes, the larger the amplitude of the reflected wave, and the more severe the standing wave resonance damage.

[0006] In summary, existing technologies are caught in an insurmountable physical contradiction when addressing the failure problem of multilayer composite bearings. On the one hand, to withstand enormous macroscopic radial static loads, the composite interface must possess extremely high rigidity and density, free from any softening or structural defects. On the other hand, to eliminate interface reflections of high-frequency stress waves, this region must possess extremely high wave transmission or dynamic energy dissipation capabilities. Existing composite bearing structures based on static mechanical design are fundamentally unable to effectively decouple the contradiction between macroscopic compressive strength and microscopic energy dissipation, resulting in a persistent inability to achieve breakthroughs in the fatigue life of high-load-bearing backed bearings. Summary of the Invention

[0007] This invention overcomes the shortcomings of the prior art and provides a high load-bearing backing bearing with a multi-layer composite wall thickness outer ring.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring, comprising:

[0009] The inner ring, the rolling element and the multi-layer composite outer ring, wherein the multi-layer composite outer ring includes, from the outside to the inside, a hardened working layer, a dynamic blocking transition layer and a tough support layer;

[0010] The dynamic blocking transition layer is a strain rate-triggered phase change material layer, which consists of polyhedral rigid microparticles and a viscoplastic matrix encapsulating the polyhedral rigid microparticles.

[0011] The volume fraction of the polyhedral rigid microparticles in the dynamic blocking transition layer is limited within the critical blocking threshold range, so that the dynamic blocking transition layer possesses a two-state phase transition characteristic based on orthogonal decoupling of stress state:

[0012] When subjected to a quasi-static radial heavy load below the critical shear strain rate, the polyhedral rigid microparticles are in a blocked state. Adjacent polyhedral rigid microparticles mechanically interlock with each other to form a rigid force chain network that runs through the radial direction of the dynamic blocking transition layer, so as to transmit radial hydrostatic stress.

[0013] When subjected to high-frequency transverse shear stress wave excitation above the critical shear strain rate, the viscoplastic matrix undergoes transient superplastic rheological softening, causing the rigid force chain network to enter a locally unblocked state and undergo micro-rheology. This triggers a nonlinear drop in the local transverse shear stiffness of the dynamic blocking transition layer, thereby disrupting the standing wave resonance condition formed by the reflected wave and incident wave generated by the high-frequency transverse shear stress wave on the subsurface of the multilayer composite outer ring.

[0014] In a preferred embodiment of the present invention, the critical blocking threshold range is 62% to 66%.

[0015] The polyhedral rigid microparticles are made of tungsten carbide ceramic or silicon nitride ceramic, and their average particle size is 5μm~15μm.

[0016] The viscoplastic matrix is ​​made of an amorphous alloy, the glass transition temperature of which is higher than the rated operating temperature of the high load-bearing backing bearing, and the viscosity of which decreases exponentially with increasing shear strain rate, thus providing the physical basis for the transient superplastic rheological softening.

[0017] In a preferred embodiment of the present invention, the first bonding surface between the hardened working layer and the dynamic blocking transition layer is microscopically an asymmetric subcycloidal topological interface.

[0018] The asymmetric subcycloid topological interface exhibits a periodic undulating structure with alternating peaks and troughs along the circumference of the multilayer composite outer ring, and the radial depth difference between the peaks and troughs... Satisfying the destructive interference condition:

[0019] ;

[0020] in, This refers to the propagation speed of the high-frequency transverse shear stress wave in the hardened working layer. The high-load-bearing backing bearing generates the high-frequency transverse shear stress wave through the load-bearing area of ​​the multi-layer composite outer ring at the rated limiting speed.

[0021] The stress wave reflected from the trough and the stress wave reflected from the crest produce a 180-degree phase difference when crossing the first interface, so as to convert the high-frequency transverse shear stress wave into micro-thermal energy dissipation through destructive interference.

[0022] In a preferred embodiment of the present invention, the hardened working layer facing the inner side of the dynamic blocking transition layer and the tough support layer facing the outer side of the dynamic blocking transition layer are provided with dovetail-shaped macro-limiting teeth that extend inward and nest in each other along the circumferential direction on the macro-contour.

[0023] The dynamic blocking transition layer completely fills the tortuous gap formed between the opposing dovetail-shaped macroscopic limiting teeth;

[0024] The radial overlap depth of the dovetail-shaped macroscopic limiting teeth is greater than the maximum permissible microrheological displacement of the dynamic blocking transition layer in the local unblocking state, so as to macroscopically constrain the hardened working layer and prevent it from undergoing macroscopic radial collapse or circumferential slippage during the transient superplastic rheological softening.

[0025] In a preferred embodiment of the present invention, a micron-sized low-resistivity phase is uniformly dispersed in the viscoplastic matrix within the dynamic blocking transition layer, wherein the low-resistivity phase is microporous or spherical free graphite.

[0026] The volume fraction of the low-impedance phase in the dynamic blocking transition layer is distributed in an exponentially increasing gradient from the outside to the inside in the radial direction, so that the macroscopic acoustic impedance between the hardened working layer and the tough support layer is continuously and smoothly transitioned, eliminating the total reflection of stress waves caused by macroscopic acoustic impedance step.

[0027] In a preferred embodiment of the present invention, the outer diameter surface of the multilayer composite outer ring is a non-standard cylindrical surface, and its radial wall thickness exhibits a non-uniform amplitude micro-fluctuation along the circumferential direction as a Fourier series expansion.

[0028] The amplitude range of the non-uniform micro-fluctuation is 5μm~20μm, so that the local mass and local bending stiffness of the multi-layer composite outer ring along any cross section in the circumferential direction exhibit non-periodic continuous variation.

[0029] The non-periodic continuous variation is used to eliminate the single global circumferential natural frequency of the multi-layer composite outer ring, so that the resonance induced by the excitation force is confined to the local region, forming a modal localization effect.

[0030] In a preferred embodiment of the present invention, the radial thickness of the dynamic blocking transition layer is related to the half wavelength of the high-frequency transverse shear stress wave. Matching;

[0031] When the antinode of the standing wave resonance condition is located within the dynamic blocking transition layer, the extremely high local shear strain rate at the antinode preferentially triggers the local unblocking state of the dynamic blocking transition layer at the antinode, resulting in a sudden drop in the local transverse shear stiffness at the antinode and causing a transient drift of the natural frequency at the antinode.

[0032] The transient drift of the natural frequency actively disrupts the phase maintenance basis of the standing wave resonance condition, forming an adaptive mode detuning negative feedback mechanism to suppress the growth of standing waves.

[0033] In a preferred embodiment of the present invention, a micron-level spiral heat dissipation channel is provided on the outer side of the tough support layer and near the edge of the dynamic blocking transition layer, which is connected to the end face of the multilayer composite outer ring.

[0034] The spiral helix angle of the micron-level spiral heat dissipation channel is matched with the rated rotation direction of the high load-bearing backing bearing. This is used to utilize the centrifugal pumping effect generated when the bearing rotates at high speed to discharge the micro-heat generated by the micro-friction dissipation of the dynamic blockage transition layer under the local unblocking state, thereby preventing the viscoplastic matrix from undergoing irreversible thermodynamic softening.

[0035] In a preferred embodiment of the present invention, the hardened working layer, the dynamic blocking transition layer and the toughening support layer are integrally formed metallurgically bonded components by hot isostatic pressing or laser directional energy deposition.

[0036] At the junction of the dynamic blocking transition layer, the hardened working layer, and the tough support layer, there are element interdiffusion zones with radial widths of 10μm to 50μm. The polyhedral rigid microparticles are partially embedded in the element interdiffusion zones to enhance the interface anchoring force of the rigid force chain network under the quasi-static radial heavy load.

[0037] In a preferred embodiment of the present invention, the high load-bearing backing bearing is applied in the support roll assembly of a multi-roll cold rolling mill;

[0038] The outer diameter surface of the multi-layer composite outer ring is in direct contact with the support roller during operation, and the peak value of the radial hydrostatic pressure stress it bears is greater than 500 MPa. Furthermore, the excitation frequency of the high-frequency transverse shear stress wave generated by the high-load-bearing backing bearing at the ultimate rolling speed is greater than the critical frequency threshold that triggers the transient superplastic rheological softening of the viscoplastic matrix.

[0039] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0040] This invention introduces a dynamic blocking transition layer composed of polyhedral rigid microparticles and a viscoplastic matrix between the hardened working layer and the tough support layer, and limits the volume fraction of microparticles within the critical blocking threshold range. Under quasi-static heavy load, this transition layer relies on the mechanical interlocking of particles to form a rigid force chain to transmit radial hydrostatic stress. Under high-frequency shear stress wave excitation, the matrix undergoes transient superplastic rheology, which promotes microscopic local deblocking rheology of the force chain. This dual-state phase transition characteristic based on orthogonal decoupling of stress states directly destroys the standing wave resonance condition. Compared with the defects of existing technologies that simply pursue high interface rigidity and result in total reflection of stress waves and tearing of standing waves, this invention fundamentally eliminates the deep catastrophic peeling caused by high-frequency microplastic strain accumulation, and achieves a nonlinear leap in macroscopic extremely high load-bearing capacity and microscopic extremely strong fatigue life.

[0041] This invention designs the microscopic interface between the hardened working layer and the dynamic blocking transition layer as an asymmetric subcycloidal topological interface, and precisely controls the radial depth difference between the crest and trough to meet the quarter-wavelength condition. This causes the stress waves reflected from the trough and crest to generate a 180-degree phase difference when crossing the interface, resulting in destructive interference. This mechanism directly converts the mechanical energy of the high-frequency transverse shear stress wave into micro-thermal energy dissipation. Compared with the existing technology where smooth interfaces or wavy surfaces arbitrarily set only to increase friction are prone to blind spots that easily cause constructive interference of reflected waves, this invention completely cuts off the physical path of superposition of reflected and incident waves, providing an extremely concealed and efficient acoustic stealth defense for the dynamic stability of bearings at extreme speeds.

[0042] This invention creates a strong mechanical interlock and displacement constraint on the hardened working layer in macroscopic geometric space by alternately setting nested dovetail-shaped macroscopic limiting teeth along the circumferential contour of the mating surface and setting their radial overlap depth to be greater than the maximum allowable microscopic rheological displacement. This ensures that when the dynamic blocking transition layer undergoes transient superplastic rheological softening, its microscopic rheology is strictly limited to a local micrometer-level space. This overcomes the technical prejudice that the introduction of a softening mechanism inside the load-bearing layer will inevitably lead to the overall collapse of the bearing, which is commonly believed by those skilled in the art. It perfectly resolves the physical contradiction between microscopic high-frequency dissipation and macroscopic structural stiffness, ensuring that the outer ring of the bearing will never experience macroscopic radial collapse or circumferential slippage under extreme heavy load conditions.

[0043] This invention achieves a continuous and smooth transition of macroscopic acoustic impedance between the hardened working layer and the tough support layer by uniformly dispersing a micron-sized low-impedance phase in the viscoplastic matrix of the dynamic blocking transition layer and dissipating the phase with an exponentially increasing volume fraction from the outside to the inside along the radial direction. This material distribution feature directly eliminates the macroscopic acoustic impedance step phenomenon, allowing residual stress waves to smoothly penetrate the interface and dissipate into the core. Compared with the problems of abrupt acoustic impedance changes and severe energy accumulation of stress waves at the interface caused by direct composite of multiple heterogeneous materials in the prior art, this invention greatly reduces the peak value of the maximum subsurface shear stress and significantly improves the overall dynamic wave transmission continuity of the composite outer ring.

[0044] This invention designs the outer diameter surface of the multi-layer composite outer ring as a non-uniform amplitude micro-fluctuation structure with radial wall thickness expanding in a Fourier series along the circumference. This endows the outer ring with non-periodic continuous variation of local mass and local bending stiffness at any cross section along the circumference. It breaks the inherent single global circumferential natural frequency of the standard cylindrical outer ring, which restricts the resonance caused by excitation force to a very small local area. Compared with the inherent defects of existing bearings with uniform wall thickness, which are prone to global circumferential resonance and overall breakage during high-speed operation, this invention forms an excellent modal localization effect, enabling the bearing to maintain extremely high structural integrity under wide frequency excitation conditions.

[0045] This invention matches the radial thickness of the dynamic blocking transition layer with the half-wavelength of the high-frequency transverse shear stress wave. When the antinode of the standing wave is located within this layer, the extremely high local shear strain rate preferentially triggers the local unblocking state, causing a sharp drop in local transverse shear stiffness and inducing transient drift of the natural frequency. This actively disrupts the phase maintenance basis of the standing wave resonance condition, forming an adaptive mode detuning negative feedback mechanism that suppresses the growth of the standing wave. Compared with the static defense mode of existing technologies that passively withstand stress wave impacts and cannot self-regulate the resonance state, this invention achieves a deep synergy between the microscopic phase transformation of materials and macroscopic elastic dynamics, endowing the bearing with intelligent dissipation capabilities that adapt to strong forces and protect itself.

[0046] This invention creates a micron-level spiral heat dissipation channel connecting to the end face on the outer edge of the strong and tough support layer, and matches the spiral helix angle direction with the bearing rotation direction. By utilizing the centrifugal pumping effect generated when the bearing rotates at high speed to form forced convection, the micro-heat generated by micro-friction dissipation in the dynamically blocked transition layer under local unblocked state is continuously discharged to the outside. Compared with the existing closed composite bearings where internal heat cannot be dissipated, leading to the risk of material performance degradation, this invention effectively prevents the viscoplastic matrix from undergoing irreversible thermodynamic softening due to excessive temperature rise, and ensures the long-term stable cycle of the phase change dissipation mechanism.

[0047] This invention employs hot isostatic pressing or laser-directed energy deposition processes to integrally form each layer, creating inter-diffusion zones at the interfaces and embedding polyhedral rigid microparticles within them. This achieves deep fusion of heterogeneous materials at the atomic level and provides robust boundary anchoring points for the rigid force chain network. This significantly enhances the interfacial anchoring force and shear strength between layers under quasi-static radial heavy loads. Compared to traditional mechanical inlay or ordinary welding processes, which are prone to macroscopic interlayer slippage under heavy loads, this invention ensures the overall structural density and macroscopic load-bearing limit of the multilayer composite outer ring when subjected to ultra-high hydrostatic pressure stress. Attached Figure Description

[0048] 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 only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the overall structure of a high load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to the present invention;

[0050] Figure 2 This is a partially enlarged cross-sectional schematic diagram of the multilayer composite outer ring of the present invention;

[0051] Figure 3 This is a schematic diagram of the structure of the dovetail-shaped macroscopic limiting tooth of a preferred embodiment of the present invention;

[0052] In the diagram: 1. Inner ring; 2. Rolling element; 3. Multi-layer composite outer ring; 4. Hardened working layer; 5. Dynamic blocking transition layer; 6. Strong and tough support layer; 7. Dovetail-shaped macroscopic limiting tooth. Detailed Implementation

[0053] 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. 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.

[0054] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0055] Example 1: As Figures 1 to 3 As shown, a high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring includes:

[0056] The inner ring, the rolling element and the multi-layer composite outer ring, wherein the multi-layer composite outer ring includes, from the outside to the inside, a hardened working layer, a dynamic blocking transition layer and a tough support layer;

[0057] The dynamic blocking transition layer is a strain rate-triggered phase change material layer, which consists of polyhedral rigid microparticles and a viscoplastic matrix encapsulating the polyhedral rigid microparticles.

[0058] The volume fraction of the polyhedral rigid microparticles in the dynamic blocking transition layer is limited within the critical blocking threshold range, so that the dynamic blocking transition layer possesses a two-state phase transition characteristic based on orthogonal decoupling of stress state:

[0059] When subjected to a quasi-static radial heavy load below the critical shear strain rate, the polyhedral rigid microparticles are in a blocked state. Adjacent polyhedral rigid microparticles mechanically interlock with each other to form a rigid force chain network that runs through the radial direction of the dynamic blocking transition layer, so as to transmit radial hydrostatic stress.

[0060] When subjected to high-frequency transverse shear stress wave excitation above the critical shear strain rate, the viscoplastic matrix undergoes transient superplastic rheological softening, causing the rigid force chain network to enter a locally unblocked state and undergo micro-rheology. This triggers a nonlinear drop in the local transverse shear stiffness of the dynamic blocking transition layer, thereby disrupting the standing wave resonance condition formed by the reflected wave and incident wave generated by the high-frequency transverse shear stress wave on the subsurface of the multilayer composite outer ring.

[0061] Specifically, the rolling element is a cylindrical roller or a needle roller.

[0062] To address the challenges of operating conditions involving both extreme heavy loads and high-frequency vibrations, the multi-layered composite outer ring, from the outside in, is metallurgically bonded and includes a hardened working layer, a dynamic blocking transition layer, and a strong and tough support layer.

[0063] The hardened working layer uses high-purity high-carbon chromium bearing steel to provide extremely high macroscopic contact fatigue life, such as GCr15SiMn material.

[0064] The strong and tough support layer uses low-modulus and high-toughness alloy structural steel to absorb macroscopic impact deformation, such as 42CrMo4 material; the high load-bearing backing bearing withstands a radial hydrostatic pressure stress peak greater than 500MPa during operation.

[0065] Preferably, on the inner surface of the hardened working layer facing the dynamic blocking transition layer and on the outer surface of the tough support layer facing the dynamic blocking transition layer, dovetail-shaped macroscopic limiting teeth are alternately machined in the circumferential direction, extending inward and nesting into each other. The dynamic blocking transition layer completely fills the tortuous gap formed between the opposing dovetail-shaped macroscopic limiting teeth; thereby avoiding the situation where the bearing collapses as a whole due to the introduction of a transition layer with rheological properties into the bearing layer.

[0066] The maximum allowable microrheological displacement of the dynamic blocking transition layer when it enters a locally unblocked state under extreme high-frequency excitation is set as follows: This displacement is typically on the order of 5 μm to 15 μm.

[0067] In this embodiment, the radial overlap depth of the opposing dovetail-shaped macroscopic limiting teeth is... Strictly designed to be greater than or equal to This design constitutes a rigid physical safety net. Even if the dynamic blocking transition layer undergoes transient superplastic rheological softening within microseconds, the outer hardened working layer will be mechanically locked by the inner dovetail teeth. In macroscopic geometry, the hardened working layer is completely deprived of the degree of freedom to undergo macroscopic radial collapse or circumferential large-scale slippage, thereby resolving the physical contradiction between microscopic high-frequency dissipation and macroscopic structural stiffness.

[0068] Conventional outer rings with uniform wall thickness have a fixed global circumferential natural frequency during high-speed operation, which easily leads to resonance and breakage. In this embodiment, the outer diameter surface of the multi-layer composite outer ring is processed into a non-standard cylindrical surface, and its radial wall thickness exhibits non-uniform amplitude micro-fluctuations along the circumference, which are expanded using a Fourier series. The amplitude range of these non-uniform amplitude micro-fluctuations is controlled between 5μm and 20μm. Due to the extremely small amplitude, it is completely within the elastic deformation coordination tolerance range of the support roller and the bearing outer ring, and does not affect the macroscopic roundness fit and stable operation.

[0069] This micrometer-level wall thickness variation causes the local mass and local bending stiffness of the multilayer composite outer ring to change non-periodically and continuously across any cross-section along the circumference, completely eliminating the single global circumferential natural frequency of the outer ring. When a local area is subjected to an excitation force of a specific frequency in an attempt to induce resonance, the resonant wave cannot be propagated and amplified circumferentially because the natural frequencies of adjacent areas have already drifted, thus forming an excellent modal localization effect.

[0070] Example 2: Preferably, the first bonding surface is not a smooth transition at the microscopic level, but is formed into an asymmetric subcycloid topological interface by a high-precision laser directional energy deposition process. The asymmetric subcycloid topological interface has a periodic undulating structure with alternating peaks and troughs along the circumference of the multilayer composite outer ring.

[0071] To enable the topological interface to possess acoustic cloaking capabilities, the radial depth difference between its crests and troughs... It must be strictly matched with the wavelength of high-frequency stress waves under specific working conditions.

[0072] Assuming this high-load-bearing backing bearing is used in extreme rolling speeds In the cold rolling mill, under extremely high contact stress, the high-frequency collisions between the rolling elements and the microscopic protrusions of the outer ring, as well as the acoustic emission energy released by the slippage of lattice dislocations, are mainly concentrated in the ultrasonic frequency band; spectral analysis reveals that the critical excitation frequency that easily induces fatal standing wave tearing at the subsurface is... Approximately 2MHz, or 2×10 6 Hz.

[0073] The density of the hardened working layer is known. shear modulus According to elastic wave theory, the propagation velocity of transverse shear stress waves in this layer Therefore, the wavelength of this fatal high-frequency transverse shear stress wave can be determined. That is, 1595μm.

[0074] According to the physical conditions of destructive interference In this embodiment, the radial depth difference between the crests and troughs of the asymmetric subcycloid topological interface is precisely processed into... In actual manufacturing, the engineering tolerance for this depth difference is controlled at 399±5μm.

[0075] When the downward-propagating high-frequency transverse shear stress wave reaches the first interface, part of the wave is reflected from the crest, and the other part continues to propagate downwards for 399 μm before being reflected from the trough. Because the wave reflected from the trough travels a longer distance than the wave reflected from the crest... The optical path difference between the two results in an absolute phase difference of 180° when they return upwards across the first mating surface.

[0076] At this moment, the crest of the reflected wave and the trough of the reflected wave perfectly overlap in space, resulting in destructive interference; the mechanical energy of the high-frequency transverse shear stress wave is instantly canceled out and converted into weak heat dissipation. This mechanism completely cuts off the physical path for the reflected wave to superimpose with the subsequent incident wave to form a standing wave, providing the bearing with an extremely concealed and efficient dynamic defense.

[0077] Example 3: This example focuses on disclosing in detail the specific composition, microstructure, and spatial distribution gradient of the core phase change material layer inside the multilayer composite outer ring, namely the dynamic blocking transition layer, in order to provide the material basis for realizing the two-state orthogonal decoupling mechanism.

[0078] The dynamic blocking transition layer is composed of polyhedral rigid microparticles and a viscoplastic matrix that encapsulates these microparticles.

[0079] To ensure that a strong mechanical interlocking effect can be generated between the microparticles when subjected to macroscopic static loads, the polyhedral rigid microparticles selected in this embodiment are tungsten carbide ceramics or silicon nitride ceramics with extremely high elastic modulus, and their average particle size is strictly controlled between 5μm and 15μm.

[0080] The surface morphology of microparticles must exhibit the irregular angular shape of a polyhedron, avoiding the use of smooth spherical particles, because the angular edges of a polyhedron are the geometric anchor points for forming a microscopic rigid force chain network.

[0081] The volume fraction of polyhedral rigid microparticles in the dynamic blocking transition layer is a critical core parameter for triggering the phase transition mechanism. In this embodiment, this volume fraction is precisely limited to the critical blocking threshold range of 62% to 66%, preferably 64%.

[0082] If the volume fraction is less than 62%, the distance between the particles is too large, and they cannot form a continuous load-bearing chain under pressure, which will cause the bearing to plastically collapse under heavy load.

[0083] If the volume fraction is higher than 66%, the particulate system will enter an overcrowded consolidation state and lose its ability to dissipate micro-rheological energy under high-frequency excitation.

[0084] The viscoplastic matrix encapsulating the aforementioned microparticles is made of an amorphous alloy material, namely metallic glass. The glass transition temperature of this amorphous alloy is designed to be higher than the rated limit operating temperature of the high-load-bearing backing bearing, typically set above 400°C, to ensure that it does not undergo macroscopic thermal melting during normal operation.

[0085] More importantly, this amorphous alloy possesses unique adiabatic shear phase transformation characteristics under extremely high strain rates. Under normal operating conditions below the glass transition temperature, the matrix exhibits a high-strength solid state; when a high-frequency transverse shear stress wave passes by, the extremely high local shear strain rate leads to intense micro-friction between microparticles; due to the extremely high excitation frequency, the heat generated by friction cannot be dissipated within microseconds, resulting in an extremely localized adiabatic temperature rise.

[0086] The localized adiabatic temperature rise instantaneously breaks through the glass transition temperature of the amorphous alloy, causing it to instantly transition to a supercooled liquid phase region within a nanoscale local area, thus exhibiting transient superplastic rheology. After the peak passes and the excitation stress disappears, the surrounding massive cold matrix acts as a rapid heat sink, causing this microscopic rheological region to undergo rapid quenching within microseconds, refreezing into a high-strength amorphous solid. This thermodynamic cycle of adiabatic softening combined with rapid quenching constitutes the physical foundation of the reversible unblocking mechanism of this invention.

[0087] To further eliminate the macroscopic acoustic impedance step phenomenon caused by the difference in material density and elastic modulus between the hardened working layer and the tough support layer, this embodiment also uniformly disperses a micron-sized low impedance phase, specifically microporous or spherical free graphite, in the viscoplastic matrix of the dynamic blocking transition layer.

[0088] In terms of spatial distribution, the volume fraction of the low-impedance phase exhibits an exponentially increasing gradient distribution from the outside to the inside along the radial direction of the multilayer composite outer ring. This enables the macroscopic acoustic impedance of the dynamic blocking transition layer to achieve a continuous and smooth transition from high impedance on the outside to low impedance on the inside, completely eliminating the abrupt acoustic impedance interface. This allows residual stress waves to smoothly penetrate the interface without reflection and dissipate into the inner core.

[0089] Example 4: This example combines the physical structure and material composition provided in the above examples to deduce in detail the dynamic working process of the high load-bearing backing bearing under specific working conditions, so as to prove the effectiveness of its two-state orthogonal decoupling mechanism and the mechanical principle of preventing macroscopic collapse.

[0090] When a high-load-bearing backed bearing operates in a multi-roll cold rolling mill and bears the radial load transmitted by the support rolls, the multi-layer composite outer ring is in a quasi-static radial heavy-load state. At this time, the externally applied radial hydrostatic pressure forces the polyhedral rigid microparticles inside the dynamic blocking transition layer to squeeze each other. Since the particle volume fraction is in the critical blocking threshold range of 62% to 66%, the squeezing force causes the edges of the polyhedral particles to tightly mesh, entering the blocking state. Adjacent microparticles spontaneously arrange themselves to form a rigid force chain network that runs through the radial direction of the transition layer. In this state, the viscoplastic matrix is ​​constrained in the gaps between particles and cannot flow. The entire dynamic blocking transition layer exhibits high macroscopic compressive yield strength, which transmits the radial load to the inner ring and prevents the bearing from macroscopically collapsing.

[0091] When a bearing operates at its limiting speed, the rolling elements frequently press against the outer ring's load-bearing area, generating high-frequency transverse shear stress waves from the contact area towards the subsurface. These stress waves propagate downwards and are reflected and superimposed at the composite interface, thus forming standing wave resonance. At this point, the two-state orthogonal decoupling mechanism is triggered.

[0092] The antinodes of standing wave resonance represent the regions with the largest amplitude and concentrated energy. When the antinodes are located inside the dynamic blocking transition layer, a high transverse shear strain rate is generated in this local region. When this shear strain rate exceeds the critical shear strain rate of the amorphous alloy matrix, it triggers transient superplastic rheological softening of the matrix. The softening of the matrix causes the originally tightly interlocked rigid force chains to lose lateral restraint. Under the drive of transverse shear force, microparticles undergo micron-level dislocation and friction. This local region enters a local unblocking state and undergoes micro-rheology.

[0093] Local unblocking directly leads to a nonlinear decrease in the transverse shear stiffness of the region, and the decrease in stiffness inevitably causes a transient drift of the natural frequency of the local region. The standing wave that originally resonated here is disrupted by the change in the natural frequency of the medium, which destroys the foundation for maintaining the phase of the resonance. This forms an adaptive mode detuning mechanism, in which the energy of the standing wave triggers material softening, the softening changes the frequency, and the frequency change ultimately inhibits the growth of the standing wave. In this process, the mechanical energy of the high-frequency transverse shear stress wave is converted into heat energy dissipation by the friction between microparticles.

[0094] The aforementioned unblocking rheological process occurs on a microsecond-scale time scale and within a micrometer-scale spatial locality. After the high-frequency wave peak passes, under the continuous action of macroscopic radial hydrostatic stress, the microparticles are recompacted and locked within a microsecond time, restoring to a rigid blocking state. At the same time, the external dovetail-shaped macroscopic limiting teeth provide displacement constraints in geometric space. Therefore, this transient microscopic softening will not develop into macroscopic plastic deformation.

[0095] To handle the heat generated by micro-friction dissipation, this embodiment features a micron-level spiral heat dissipation channel on the outer surface of the strong support layer, near the edge of the dynamic blocking transition layer, connecting to the end face of the multi-layer composite outer ring. The spiral helix angle of this channel is aligned with the rated rotation direction of the bearing. When the bearing rotates at high speed, due to the extremely high relative linear velocity between the spiral channel and the surface of the external support roller, the air or lubricating medium within the channel is forcibly compressed and transported along the spiral helix angle under the action of fluid viscous shear drag. This hydrodynamic spiral pumping effect generates a strong axial pressure gradient, forming forced convection, and continuously pumping the micro-heat generated by the dynamic blocking transition layer axially to the end face of the outer ring for discharge. This prevents the viscoplastic matrix from undergoing irreversible thermodynamic softening due to heat accumulation, ensuring the stable cycle of the phase change dissipation mechanism.

[0096] Example 5: This example discloses in detail the molding process and interface bonding characteristics of the multilayer composite outer ring to illustrate the physical basis for the absence of macroscopic interlayer slippage under quasi-static radial heavy load.

[0097] The hardened working layer, dynamic blocking transition layer, and toughening support layer are metallurgically bonded components integrally formed through hot isostatic pressing or laser-directed energy deposition processes.

[0098] In this embodiment, hot isostatic pressing is preferably used to fill the space between the prefabricated strong and tough support layer and the hardened working layer with a mixture of prepared polyhedral rigid microparticles and amorphous alloy powder, thereby achieving densification and interface sintering under high temperature and high pressure.

[0099] Before hot isostatic pressing (HIP), the powder filling of the dynamic blocking transition layer is carried out using a multi-path centrifugal powder distribution process or a variable powder feed rate process using laser additive manufacturing. Taking free graphite as a low-resistivity phase as an example, the mixing ratio of amorphous alloy powder and graphite powder in the powder feeder is digitally controlled, and the powder is laid layer by layer from the outside to the inside in the radial direction, so that the mass fraction of graphite powder increases according to a preset exponential function curve. Then, the whole system is subjected to hot isostatic pressing sintering to solidify the exponential gradient distribution.

[0100] During the molding process, by controlling the holding time and temperature parameters, element interdiffusion zones with radial widths of 10μm to 50μm are induced at the junctions of the dynamic blocking transition layer, the hardened working layer, and the toughening support layer. Within these element interdiffusion zones, iron and carbon elements in the hardened working layer migrate across the interface with alloying elements in the viscoplastic matrix, forming a concentration gradient solid solution.

[0101] Meanwhile, since the melting point of polyhedral rigid microparticles is much higher than the processing temperature of hot isostatic pressing, some of the polyhedral rigid microparticles located at the edge are mechanically pressed into and embedded in the mutual diffusion zone of the elements under the action of extremely high hydrostatic pressure. This provides a solid boundary anchor point for the rigid force chain network in the dynamic blocking transition layer, which greatly enhances the interface shear strength under quasi-static radial heavy load. From the manufacturing process perspective, this ensures the overall structural compactness of the multilayer composite outer ring when subjected to ultra-high hydrostatic pressure stress.

[0102] Example 6: In order to objectively verify the technical effect of the multi-layer composite wall thickness outer ring with dynamic blocking transition layer provided by the present invention under extreme working conditions, this example provides comparative experimental and finite element dynamic simulation data.

[0103] Experimental group setup:

[0104] Comparative Example 1: Traditional single-layer thick-walled backing bearing, made of a single material GCr15SiMn, with a cylindrical surface of equal wall thickness.

[0105] Comparative Example 2: A traditional multilayer composite backing bearing with an outer layer of GCr15SiMn and an inner layer of 42CrMo4. The interface is a conventional metallurgical bond with a smooth transition, without a dynamic blocking transition layer or microstructure.

[0106] Example group: High load-bearing backing bearings using the structure and material parameters described in Examples 1 to 3 of the present invention, comprising polyhedral rigid microparticles with a volume fraction of 64%, an amorphous alloy matrix, an asymmetric subcycloid topological interface, and dovetail-shaped macroscopic limiting teeth.

[0107] Test conditions:

[0108] Simulates the extreme operating conditions of a multi-roll cold rolling mill. The peak radial hydrostatic stress applied is 550 MPa; the excitation source is set to a frequency... High-frequency transverse shear stress waves are used to simulate the acoustic emission of rolling body high-frequency rolling and lattice dislocation slip under extreme rolling line speed.

[0109] Life tests were conducted using a high-frequency contact fatigue testing machine, and physical parameters were extracted using an acoustic emission sensor and a subsurface stress ultrasonic testing device. The test results are shown in Table 1.

[0110] Table 1 Test Indicators and Data Results

[0111]

[0112] Among them, the failure mode characteristics of Comparative Example 1 are: subsurface conventional fatigue microcrack propagation, which eventually leads to shallow spalling;

[0113] The failure mode characteristics of Comparative Example 2 are as follows: strong stress wave reflection and standing wave resonance occur at the composite interface, resulting in a large-scale, deep, catastrophic peeling without any warning.

[0114] The failure mode characteristics of the example group are as follows: the fatigue life test limit is reached, no macroscopic peeling occurs, and only normal wear is present on the surface.

[0115] As shown in Table 1, by comparing the test data of Comparative Example 1 and Comparative Example 2, after introducing a conventional multilayer composite structure, the interfacial standing wave resonance amplitude increased from 1.8 μm to 5.6 μm, the peak value of the maximum subsurface shear stress increased from 412 MPa to 485 MPa, and the fatigue life increased from 1.2 × 10⁻⁶ MPa. 7 The next decrease was to 0.7×10. 7 This data set objectively reflects that under high-frequency excitation conditions, the acoustic impedance step at the interface of conventional heteromaterials leads to stress wave reflection superposition, thereby accelerating grain boundary tearing.

[0116] Comparing the Example Group with Comparative Example 2, it can be seen that the peak value of the maximum subsurface shear stress in the Example Group of the present invention is significantly reduced to 235 MPa, and the amplitude of the interface standing wave resonance is suppressed to an extremely low level of 0.2 μm. This indicates that the high-frequency transverse shear stress wave undergoes effective destructive interference when crossing the asymmetric subcycloid topological interface. At the same time, the residual stress wave triggers the transient superplastic rheology of the viscoplastic matrix, the dynamic blocking transition layer enters a locally unblocked state, dissipates mechanical energy through micro-rheology and induces modal detuning, completely destroying the physical conditions for standing wave resonance.

[0117] In addition, under the same radial heavy load and high-frequency excitation conditions, the fatigue spalling life of the example group reached 4.8 × 10⁻⁶. 7 The cycle repeats. Combined with the synchronous decrease in stress and amplitude data, this verifies the physical process by which the dynamically blocked transition layer maintains rigid force chain transmission under macroscopic hydrostatic stress, while undergoing localized deblocking rheology under high-frequency transverse shear stress waves. This mechanism dissipates the high-frequency strain energy that would trigger grain boundary tearing while maintaining macroscopic load-bearing stiffness, thereby extending the overall fatigue life of the multilayer composite outer ring.

[0118] In summary, this invention proposes a high-load-bearing backing bearing with a multi-layered composite thick outer ring. By configuring a dynamic blocking transition layer at a critical blocking threshold between the hardened working layer and the toughened support layer, and combining an asymmetric subcycloidal topological interface with dovetail-shaped macroscopic limiting teeth, a dual-state phase transition defense system based on orthogonal decoupling of stress states is constructed. This structure enables the multi-layered composite outer ring to transmit hydrostatic pressure stress through a rigid force chain network to ensure macroscopic load-bearing stiffness under quasi-static radial heavy loads. Under high-frequency transverse shear stress wave excitation, the transient superplastic rheology of the viscoplastic matrix and the local deblocking rheology of microparticles induce a nonlinear drop in transverse shear stiffness and a transient drift in the natural frequency. This physical mechanism, combined with the destructive interference effect of the interface, actively disrupts the maintenance conditions of subsurface standing wave resonance, converting the high-frequency strain energy that causes grain boundary tearing into micro-thermal energy dissipation. This resolves the contradiction between macroscopic compressive stiffness and microscopic high-frequency dissipation at the physical level, effectively suppressing deep peeling failure of the multi-layered composite bearing under high-speed heavy load conditions.

[0119] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring, characterized in that, include: The inner ring, the rolling element and the multi-layer composite outer ring, wherein the multi-layer composite outer ring includes, from the outside to the inside, a hardened working layer, a dynamic blocking transition layer and a tough support layer; The dynamic blocking transition layer is a strain rate-triggered phase change material layer, which consists of polyhedral rigid microparticles and a viscoplastic matrix encapsulating the polyhedral rigid microparticles. The volume fraction of the polyhedral rigid microparticles in the dynamic blocking transition layer is limited within the critical blocking threshold range, so that the dynamic blocking transition layer possesses a two-state phase transition characteristic based on orthogonal decoupling of stress state: When subjected to a quasi-static radial heavy load below the critical shear strain rate, the polyhedral rigid microparticles are in a blocked state. Adjacent polyhedral rigid microparticles mechanically interlock with each other to form a rigid force chain network that runs through the radial direction of the dynamic blocking transition layer, so as to transmit radial hydrostatic stress. When subjected to high-frequency transverse shear stress wave excitation above the critical shear strain rate, the viscoplastic matrix undergoes transient superplastic rheological softening, causing the rigid force chain network to enter a locally unblocked state and undergo micro-rheology. This triggers a nonlinear drop in the local transverse shear stiffness of the dynamic blocking transition layer, thereby disrupting the standing wave resonance condition formed by the reflected wave and incident wave generated by the high-frequency transverse shear stress wave on the subsurface of the multilayer composite outer ring.

2. The high load-bearing backing bearing with a multi-layer composite wall thickness outer ring according to claim 1, characterized in that, The critical blocking threshold range is 62% to 66%; The polyhedral rigid microparticles are made of tungsten carbide ceramic or silicon nitride ceramic, and their average particle size is 5μm~15μm. The viscoplastic matrix is ​​made of an amorphous alloy, the glass transition temperature of which is higher than the rated operating temperature of the high load-bearing backing bearing, and the viscosity of which decreases exponentially with increasing shear strain rate, thus providing the physical basis for the transient superplastic rheological softening.

3. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, The first interface between the hardened working layer and the dynamic blocking transition layer is microscopically an asymmetric subcycloidal topological interface. The asymmetric subcycloid topological interface exhibits a periodic undulating structure with alternating peaks and troughs along the circumference of the multilayer composite outer ring, and the radial depth difference between the peaks and troughs... Satisfying the destructive interference condition: ； in, This refers to the propagation speed of the high-frequency transverse shear stress wave in the hardened working layer. The high-load-bearing backing bearing generates the high-frequency transverse shear stress wave through the load-bearing area of ​​the multi-layer composite outer ring at the rated limiting speed. The stress wave reflected from the trough and the stress wave reflected from the crest produce a 180-degree phase difference when crossing the first interface, so as to convert the high-frequency transverse shear stress wave into micro-thermal energy dissipation through destructive interference.

4. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, The hardened working layer facing the inner side of the dynamic blocking transition layer and the tough support layer facing the outer side of the dynamic blocking transition layer are provided with dovetail-shaped macro-limiting teeth that extend inward and nest in each other along the circumferential direction on the macro-contour. The dynamic blocking transition layer completely fills the tortuous gap formed between the opposing dovetail-shaped macroscopic limiting teeth; The radial overlap depth of the dovetail-shaped macroscopic limiting teeth is greater than the maximum permissible microrheological displacement of the dynamic blocking transition layer in the local unblocking state, so as to macroscopically constrain the hardened working layer and prevent it from undergoing macroscopic radial collapse or circumferential slippage during the transient superplastic rheological softening.

5. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1 or 4, characterized in that, The viscoplastic matrix within the dynamic blocking transition layer also contains a micron-sized low-resistivity phase, which is microporous or spherical free graphite. The volume fraction of the low-impedance phase in the dynamic blocking transition layer is distributed in an exponentially increasing gradient from the outside to the inside in the radial direction, so that the macroscopic acoustic impedance between the hardened working layer and the tough support layer is continuously and smoothly transitioned, eliminating the total reflection of stress waves caused by macroscopic acoustic impedance step.

6. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, The outer diameter surface of the multi-layer composite outer ring is a non-standard cylindrical surface, and its radial wall thickness exhibits a non-uniform amplitude slight fluctuation along the circumferential direction with a Fourier series expansion. The amplitude range of the non-uniform amplitude micro-fluctuation is 5μm~20μm, so that the local mass and local bending stiffness of the multi-layer composite outer ring along any cross section in the circumferential direction exhibit non-periodic continuous variation. The non-periodic continuous variation is used to eliminate the single global circumferential natural frequency of the multi-layer composite outer ring, so that the resonance induced by the excitation force is confined to the local region, forming a modal localization effect.

7. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, The radial thickness of the dynamic blocking transition layer is related to the half wavelength of the high-frequency transverse shear stress wave. Matching; When the antinode of the standing wave resonance condition is located within the dynamic blocking transition layer, the extremely high local shear strain rate at the antinode preferentially triggers the local unblocking state of the dynamic blocking transition layer at the antinode, resulting in a sudden drop in the local transverse shear stiffness at the antinode and causing a transient drift of the natural frequency at the antinode. The transient drift of the natural frequency actively disrupts the phase maintenance basis of the standing wave resonance condition, forming an adaptive mode detuning negative feedback mechanism to suppress the growth of standing waves.

8. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, On the outer side of the tough support layer and near the edge of the dynamic blocking transition layer, a micron-level spiral heat dissipation channel is formed, which connects to the end face of the multi-layer composite outer ring. The spiral helix angle of the micron-level spiral heat dissipation channel is matched with the rated rotation direction of the high load-bearing backing bearing. This is used to utilize the centrifugal pumping effect generated when the bearing rotates at high speed to discharge the micro-heat generated by the micro-friction dissipation of the dynamic blockage transition layer under the local unblocking state, thereby preventing the viscoplastic matrix from undergoing irreversible thermodynamic softening.

9. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, The hardened working layer, the dynamic blocking transition layer, and the toughening support layer are integrally formed metallurgically bonded components through hot isostatic pressing or laser directional energy deposition. At the junction of the dynamic blocking transition layer, the hardened working layer, and the tough support layer, there are element interdiffusion zones with radial widths of 10μm to 50μm. The polyhedral rigid microparticles are partially embedded in the element interdiffusion zones to enhance the interface anchoring force of the rigid force chain network under the quasi-static radial heavy load.

10. A high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring according to claim 1, characterized in that, The high-load-bearing backing bearing is used in the support roll assembly of a multi-roll cold rolling mill; The outer diameter surface of the multi-layer composite outer ring is in direct contact with the support roller during operation, and the peak value of the radial hydrostatic pressure stress it bears is greater than 500 MPa. Furthermore, the excitation frequency of the high-frequency transverse shear stress wave generated by the high-load-bearing backing bearing at the ultimate rolling speed is greater than the critical frequency threshold that triggers the transient superplastic rheological softening of the viscoplastic matrix.

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