Multi-layer damping backing bearing structure for suppressing vibration

Abstract

The invention discloses a multi-layer damping backing bearing structure for suppressing vibration. The multi-layer damping backing bearing structure comprises a bearing outer ring; the bearing inner ring is rotatably matched with the bearing outer ring, an inner cavity is formed between the bearing inner ring and the bearing outer ring, and the inner cavity is used for containing lubricating liquid; the roller and the retainer are arranged in the inner cavity, and the shape of a pocket in the retainer is matched with that of the roller; wherein the inner side of the bearing outer ring and the outer side of the bearing inner ring are respectively provided with a roller path, and the rollers are uniformly distributed along the axial direction of the roller paths. The multiple layers of damping rings are arranged on the two sides of the bearing inner ring, the stress dispersion part is arranged on the circumferential surface, and the stress dispersion part and the multiple layers of damping rings coincide at certain positions in the axial direction, so that a three-stage energy attenuation path of damping energy dissipation, stress dispersion and structure cooperation is formed, and efficient suppression of axial vibration is achieved; the defect that in the prior art, the vibration suppression capacity is insufficient under complex working conditions is overcome.

Description

Technical Field

[0001] The invention relates to the technical field of bearings, and in particular to a multi-layer damping backing bearing structure for suppressing vibration. Background Art

[0002] During the operation of multi-roll cold rolling mills and hot straightening mills, due to the extreme working conditions where the rolling force can reach thousands of kN, the high-frequency vibrations caused by the friction and rotation of the high-speed rotating rollers may cause resonance in key parts of the bearing (such as rollers and cages). This resonance will cause the lubricating film in the contact area between the rollers and the inner and outer rings to rupture, which will lead to increased local friction and discontinuous lubrication.

[0003] It is worth noting that the rupture of the lubricating film will destroy the dynamic balance of the bearing components, causing the resonance frequency and the natural frequency of the equipment to have a superposition effect, forming a vicious cycle. This process will not only lead to a significant amplification of the amplitude of medium and high frequency vibrations, but will also be accompanied by abnormally sharp noises, further deteriorating the equipment operating environment and threatening production safety.

[0004] Therefore, in view of the defect that traditional bearings have insufficient vibration suppression ability under complex working conditions, it is necessary to provide a multi-layer damping backing bearing structure for suppressing vibration to solve the above technical problems. Summary of the invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a multi-layer damping backing bearing structure for suppressing vibration.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a multi-layer damping backing bearing structure for suppressing vibration, comprising:

[0007] Bearing outer ring;

[0008] A bearing inner ring, the bearing inner ring and the bearing outer ring are rotatably matched, an inner cavity is formed between the bearing inner ring and the bearing outer ring, and the inner cavity is used to contain lubricating liquid;

[0009] The roller and the cage are both arranged in the inner cavity, and the shape of the pocket on the cage is adapted to the roller;

[0010] Wherein, the inner side of the outer ring of the bearing and the outer side of the inner ring of the bearing are both provided with raceways, and the rollers are evenly distributed along the axial direction of the raceways;

[0011] The bearing inner ring comprises:

[0012] A bearing part, wherein first grooves are formed on both sides of the bearing part, and multiple layers of damping rings are arranged in the first grooves;

[0013] The stress dispersion part is arranged on the surface of the bearing part, and a plurality of arc convexities are arranged at the position of the stress dispersion part corresponding to the raceway.

[0014] In a preferred embodiment of the present invention, the multi-layer damping ring includes:

[0015] An outer damping ring,

[0016] An inner damping ring nested inside the outer damping ring;

[0017] Wherein, the surface roughness of the outer damping ring is greater than that of the inner damping ring.

[0018] In a preferred embodiment of the present invention, the number of the inner damping rings is several, and with the axis of the bearing inner ring as the center, a plurality of the inner damping rings are nested in sequence from inside to outside along the radial direction;

[0019] The surface roughness of the outer inner damping ring is greater than that of the inner inner damping ring.

[0020] In a preferred embodiment of the present invention, a second groove is formed on the circumferential surface of the bearing part, and the stress dispersion part is arranged on the surface of the second groove; the raceway is arranged at the bottom of the second groove;

[0021] The stress dispersion part is a porous sintered layer made of iron-based powder metallurgy material by sintering, with a thickness of 0.8 - 2.0 mm and a porosity of 10% - 30%.

[0022] In a preferred embodiment of the present invention, the surface roughness Ra of the outer damping ring is 3.2 - 6.3 μm, and the surface roughness Ra of the inner damping ring is 0.8 - 1.6 μm.

[0023] In a preferred embodiment of the present invention, the inner diameter of the second groove is smaller than the outer diameter of the multi-layer damping ring.

[0024] In a preferred embodiment of the present invention, a plurality of the arc convexities are distributed according to a logarithmic curve, with a height of 3 - 8 μm.

[0025] In a preferred embodiment of the present invention, the preparation method of the stress dispersion part includes the following steps:

[0026] S1. Mix iron-based powder, pore-forming agent, functional additive and nickel powder evenly. Among them, the pore-forming agent includes urea and calcium carbonate. During the mixing process, the two pore-forming agents are respectively mixed with part of the mixture;

[0027] S2, designing a modular mold according to the size of the bearing part, including a pre-molding cavity of the second groove, pre-laying a urea pore-forming agent powder layer in the mold, applying a high pressure of 700-800 MPa, and then filling the mixed powder containing calcium carbonate, and pressing the mixture as a whole to obtain a green body;

[0028] S3, sintering the green body in stages and regulating the atmosphere, regulating the pore gradient distribution in the sintered layer, and preparing a sintered layer with a thickness of 0.8 to 2.0 mm on the surface of the bearing portion;

[0029] S4, using methane to perform surface carburization treatment on the sintered layer;

[0030] S5. Use a grinder to finely grind the surface of the sintered layer. After removing the surface oxide layer, use a laser engraving machine to etch the arc convexity at the position corresponding to the raceway according to the logarithmic curve path.

[0031] In a preferred embodiment of the present invention, the staged sintering and atmosphere control include:

[0032] Preheating decomposition stage: the temperature is controlled at 200-300℃, during which high-purity nitrogen is passed;

[0033] Buffer layer activation stage: temperature controlled at 600-800°C, with H2 / CH4 mixed atmosphere;

[0034] High temperature densification stage: the temperature is controlled at 1250℃, and H2 is passed during this period;

[0035] Gradient compaction stage: the temperature is controlled at 1150°C, a N2 / Ar mixed atmosphere is passed through, and axial pressure is applied.

[0036] In a preferred embodiment of the present invention, the pore size and porosity of the portion of the stress dispersion portion corresponding to the raceway are smaller than those of the remaining portions.

[0037] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0038] (1) The present invention provides a multi-layer damping backing bearing structure for suppressing vibration. By arranging multi-layer damping rings on both sides of the inner ring of the bearing, a stress dispersion portion is arranged on the circumferential surface, and the stress dispersion portion and the multi-layer damping ring have a certain position overlap in the axial direction, a three-level energy attenuation path of "damping energy dissipation-stress dispersion-structural synergy" is formed, thereby achieving efficient suppression of axial vibration and solving the defect of insufficient vibration suppression capability of the prior art under complex working conditions.

[0039] (2) The present invention provides multiple damping rings on both sides of the inner ring of the bearing, including an outer damping ring and an inner damping ring, and multiple damping rings are nested in sequence from the inside to the outside along the radial direction. The surface roughness of the outer damping ring is greater than that of the inner damping ring. The nested multiple damping rings gradually attenuate vibrations at different radial positions, which is suitable for the situation with large radial vibrations and can effectively suppress the propagation of radial vibrations.

[0040] (3) The present invention provides a stress dispersion part on the circumferential surface of the inner ring of the bearing, which is a porous sintered layer made of iron-based powder metallurgy material to disperse the impact vibration from the roller shaft and reduce stress concentration. A number of arc convexities are provided at the position corresponding to the raceway on the surface of the stress dispersion part, and the arc convexities are in local contact with the surface of the roller, optimizing the contact conditions between the roller and the stress dispersion part and improving the vibration damping performance and stability of the bearing structure.

[0041] (4) Through the multi-field coupling gradient sintering and laser precision forming technology, the present invention constructs a stress dispersion layer with a functional gradient pore distribution in the bearing inner ring load-bearing part, synchronously realizing high-strength load-bearing in the convexity area and high energy absorption characteristics as a whole, and optimizing the roller contact stress distribution through a micro-scale arc convexity array, significantly improving the vibration damping performance, fatigue life and operation stability of the bearing system, and effectively reducing the local stress concentration coefficient. Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0043] Figure 1 It is an overall three-dimensional structure diagram of the preferred embodiment of the present invention;

[0044] Figure 2 It is a three-dimensional schematic diagram of the internal structure of the preferred embodiment of the present invention;

[0045] Figure 3 It is a sectional view of the preferred embodiment of the present invention;

[0046] In the figure: 1. Bearing outer ring; 2. Bearing inner ring; 21. Load-bearing part; 22. Stress dispersion part; 23. Multiple damping rings; 24. Outer damping ring; 25. Inner damping ring; 3. Roller; 4. Raceway. Detailed Embodiments

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0049] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the protection scope of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Therefore, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0050] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood through specific situations.

[0051] As Figure 1 and Figure 2 shown, a multi-layer damping back-up bearing structure for suppressing vibration includes: a bearing outer ring 1, a bearing inner ring 2, rollers 3 and a cage.

[0052] It should be noted that the outer ring 1 and the inner ring 2 of the bearing are the main supporting structures of the bearing. Among them, the inner ring 2 of the bearing is located at the central part of the bearing and is matched with the roller shaft to play a role in supporting and rotating. The outer ring 1 of the bearing is located on the radial outer side of the inner ring 2 of the bearing and is matched with the bearing seat, the fixing frame or the box body to play a role in fixing and supporting. In this application, the radial direction of the bearing is the direction of the diameter of the cross-section of the bearing, and the axial direction is the direction of the connection line of the centers of the two circular bottom surfaces of the cylindrical bearing.

[0053] The outer ring 1 of the bearing is arranged on the circumferential outer side of the inner ring 2 of the bearing, and the inner ring 2 of the bearing is rotatably matched with the outer ring 1 of the bearing. In addition, an inner cavity for accommodating lubricating fluid is formed between the inner ring 2 of the bearing and the outer ring 1 of the bearing, and the rollers 3 are arranged to roll in the inner cavity.

[0054] Furthermore, raceways 4 are provided on the circumferential inner side surface of the outer ring 1 of the bearing and on the circumferential outer side surface of the inner ring 2 of the bearing. The rollers 3 are arranged to roll in the raceways 4, and a plurality of rollers 3 are evenly distributed along the axial direction of the raceways 4. In addition, a cage is also arranged in the inner cavity to maintain the position and spacing of the rollers 3. The cage includes a cage seat and cage beams. The cage seat is the basic part of the cage and provides support for the cage beams. The cage beams are evenly arranged in the middle of the cage seat and together with the cage seat form pocket holes. The rollers 3 are spherical rolling elements, and the shape of the pocket holes is adapted to that of the rollers 3, which is the accommodating space for the rollers 3 to ensure the correct position and stable movement of the rollers 3 in the bearing.

[0055] The outer ring 1 of the bearing is also provided with a dust cover for closing the open end of the outer ring 1 of the bearing to prevent external impurities from entering the inner cavity.

[0056] As Figure 3 shown, the inner ring 2 of the bearing further includes: a bearing part 21, and a stress dispersion part 22 provided on the surface of the bearing part 21. Among them, the bearing part 21 is made of high-carbon chromium bearing steel or carburizing steel. First grooves are provided on both radial side surfaces of the bearing part 21, and the first grooves are configured as ring structures coaxial with the inner ring 2 of the bearing. A plurality of damping rings 23 are arranged in the first grooves, and the plurality of damping rings 23 reduce vibration and noise during the operation of the roller shaft.

[0057] The multi-layer damping ring 23 further includes: an outer damping ring 24, and a plurality of inner damping rings 25 nested inside the outer damping ring 24; the number of the inner damping rings 25 is at least one, and the surface roughness of the outer damping ring 24 is greater than that of the inner damping rings 25, so that the multi-layer damping ring 23 can reduce vibration and noise of the roller shaft at different rotational speeds. It should be noted that when the roller shaft operates and generates impact vibration, when the vibration wave is transmitted to the multi-layer damping ring 23, the damping ring will generate a reaction force to resist the vibration. The multi-layer damping ring 23 and the side wall of the first groove generate relative motion and friction to generate heat, and the vibration noise is attenuated and dissipated in the form of heat. When the roller shaft rotates at a low speed, the inner damping rings 25 generate relative motion due to their small surface roughness and generate dynamic friction, while the outer damping ring 24 does not generate relative motion and generates static friction; when the roller shaft rotates at a high speed, both the outer damping ring 24 and the inner damping rings 25 generate relative motion and generate dynamic friction, so that the multi-layer damping ring 23 can produce a good vibration reduction and noise reduction effect on the roller shaft with variable speed motion.

[0058] The width of the outer damping ring 24 is equal to the width of the inner damping rings 25, and with the axis of the inner ring 2 of the bearing as the center, a plurality of inner damping rings 25 are nested in sequence from the inside to the outside in the radial direction, and the surface roughness of the outer inner damping ring 25 is greater than that of the inner inner damping ring 25; the multi-layer damping rings 23 nested in sequence attenuate the vibration step by step at different radial positions, which is applicable to the case of large radial vibration and can effectively inhibit the propagation of radial vibration.

[0059] The surface roughness Ra of the outer damping ring 24 is 3.2 - 6.3 μm, and the surface roughness Ra of the inner damping rings 25 is 0.8 - 1.6 μm; the width of the first groove is greater than the width of the multi-layer damping ring 23 to ensure that there is a pre-tightening force after the multi-layer damping ring 23 is embedded; in addition, a chamfer with R≥0.5 mm is provided at the bottom of the first groove to reduce stress concentration, and the surface roughness Ra of the groove wall of the first groove is 0.2 - 0.5 μm, which is closely attached to the multi-layer damping ring 23.

[0060] In another embodiment, the width of the outer damping ring 24 is greater than the width of the inner damping rings 25, and with the axis of the inner ring 2 of the bearing as the center, a plurality of inner damping rings 25 are nested in sequence from the inside to the outside in the meridional direction, and the surface roughness of the outer inner damping ring 25 is greater than that of the inner inner damping ring 25.

[0061] It should be noted that the outer damping ring 24 and the inner damping rings 25 are made of the same material (metal or metallurgical composite material), and grooves with different densities and shapes are etched on their surfaces to achieve the design of different surface roughnesses. For example: staggered diamond grid grooves are etched on the surface of the outer damping ring 24, with a density of 30 - 40 lines / cm 2 , while parallel linear grooves are etched on the surface of the inner damping rings 25, and the groove spacing is 0.2 - 0.3 mm.

[0062] Furthermore, a second groove is formed on the circumferential surface of the bearing portion 21, and the stress dispersion portion 22 is arranged on the surface of the second groove, and the surface of the stress dispersion portion 22 is flush with the circumferential surface of the bearing portion 21; in addition, the raceway 4 is arranged at the bottom of the second groove.

[0063] In this embodiment, the stress dispersion portion 22 is a porous sintered layer made of iron-based powder metallurgy material, which disperses the impact vibration from the roller shaft and reduces stress concentration; a number of arc convexities are arranged on the surface of the stress dispersion layer corresponding to the raceway 4, and the arc convexities are in partial contact with the surface of the roller 3, thereby optimizing the contact condition between the roller 3 and the stress dispersion layer and improving the vibration reduction performance and stability of the bearing structure.

[0064] Specifically, the method for preparing the stress dispersion portion 22 includes the following steps:

[0065] Step S1, iron-based powder, pore-forming agent, functional additive and nickel powder are mixed in a three-dimensional mixer at a speed of 20 to 30 r / min for 1 to 2 hours to ensure the uniformity of the powder, and after mixing, the mixture is sieved through a 100-mesh sieve to remove lumps.

[0066] Among them, the iron-based powder is reduced iron powder with a particle size of 50 to 100 μm and a purity of ≥ 98.5%;

[0067] Pore-forming agent: urea (particle size 50-100μm), decomposition temperature 180-220℃, addition amount 10wt%, its low temperature decomposition characteristics can form 0.05-0.1mm fine closed pores; calcium carbonate (particle size 100-150μm), decomposition temperature 600-800℃, addition amount 20wt%, combined with CH ,4 The activated carbon (C*) produced by pyrolysis regulates pore connectivity;

[0068] Functional additives: zinc stearate, added at 1wt%, to improve forming properties; graphite powder, added at 1wt%, to assist carbon diffusion;

[0069] The amount of nickel powder added is 0.5-2% to improve toughness.

[0070] It should be noted that, during the mixing process, the two pore-forming agents are mixed with part of the mixed material respectively.

[0071] Step S2, designing a modular mold according to the size of the bearing portion 21 of the inner ring 2 of the bearing, including a pre-molding cavity of the second groove, pre-laying a urea pore-forming agent powder layer in the mold with a thickness of 0.4 mm, and applying a local high pressure of 700-800 MPa; then filling the mixed powder containing calcium carbonate, and pressing the mixture as a whole to obtain a green body, with a green body thickness of 0.1-0.3 mm reserved for subsequent sintering shrinkage compensation;

[0072] The pressure during the overall pressing process is controlled at 600 - 800 MPa; after pressing is completed, the pressure is maintained for 2 - 5 minutes to ensure that the density of the green body reaches 80 - 85% of the theoretical density.

[0073] Step S3: Carry out staged sintering and atmosphere regulation on the green body, regulate the pore gradient distribution within the sintered layer, and prepare a sintered layer with a thickness of 0.8 - 2.0 mm on the surface of the bearing part 21 to achieve the coordination of high strength in the convexity area and high energy absorption performance as a whole. It is specifically divided into four stages, which will be described in detail below.

[0074] Preheating and decomposition stage: The temperature is controlled at 200 - 300 °C, and the heating rate is 5 °C / min. During this period, high-purity nitrogen is passed through to decompose urea and form initial pores in the dense layer.

[0075] Buffer layer activation stage: The temperature is controlled at 600 - 800 °C, and the heating rate is 3 °C / min. During this period, a H2 / CH4 mixed atmosphere is passed through. The decomposition of calcium carbonate and carbon diffusion act synergistically. The activated carbon generated by the cracking of CH4 diffuses along the grain boundaries to form nano-carbon chains, maintaining pore connectivity.

[0076] High-temperature densification stage: The temperature is controlled at 1250 °C. During this period, H2 is passed through to achieve matrix densification through grain boundary diffusion, and at the same time, the pores are spheroidized and stabilized.

[0077] Gradient compaction stage: The temperature is controlled at 1150 °C. During this period, a N2 / Ar mixed atmosphere is passed through, and an axial pressure (80 MPa) is applied to selectively close the pores in the convexity area, and finally achieve precise control of the porosity of the dense layer.

[0078] In this step, urea decomposes into NH3 and CO2 at 200 - 300 °C. After the gas escapes, small closed pores with a size of 0.05 - 0.1 mm are left; at the high-temperature stage, H2 reduces the surface oxides, promotes grain boundary diffusion, and the porosity drops to 10 - 15%, obtaining a dense layer corresponding to the circular arc convexity area.

[0079] The formation of the buffer layer is because calcium carbonate decomposes into CaO and CO2 at 600 - 800 °C. CO2 reacts with CH4 to generate activated carbon (C*), and the carbon diffuses to the grain boundaries of the matrix, inhibiting pore closure; the activated carbon forms nano-carbon chains, enhancing pore connectivity, and the porosity is stabilized at 20 - 30%, obtaining a buffer layer other than the dense layer.

[0080] Step S4: Carry out surface carburizing treatment on the sintered layer using methane for 2 h at 900 °C, with a carbon potential of 0.7 - 0.8% to increase the surface hardness of the sintered layer.

[0081] Step S5: Use a grinding machine to finely grind the surface of the sintered layer. After removing the surface oxide layer, use a laser engraving machine to etch an arc convexity at the position corresponding to the raceway 4 according to a logarithmic curve path. The height of the arc convexity is 3 - 8 μm, the radius of curvature R = 0.5 - 1.5 mm, and the distribution density is 5 - 10 pieces / mm 2 .

[0082] Through the multi-field coupling gradient sintering and laser precision forming technology, the present invention constructs a stress dispersion layer with a functionally graded pore distribution in the bearing part 21 of the inner ring 2, synchronously realizing the high-strength load-bearing in the convexity area and the high energy absorption characteristics of the whole, and optimizing the contact stress distribution of the roller 3 through the micro-scale arc convexity array, significantly improving the vibration damping performance, fatigue life and operation stability of the bearing system, and effectively reducing the local stress concentration coefficient.

[0083] It should be noted that the stress dispersion layer adopts an iron-based powder metallurgy porous material, which contains a micro-scale pore structure inside and can store lubricating oil as a "lubricating oil reservoir". During the operation of the bearing, especially when the lubricating film fails briefly or the local pressure increases, these pores can release lubricating oil through capillary action or in response to pressure changes to ensure that the contact surface is continuously well lubricated. In addition, this special pore distribution helps to reduce the local contact pressure in the contact area between the roller 3 and the inner ring. As the roller 3 rolls, the elastic deformation caused by the existence of pores in the stress dispersion layer can disperse the load more evenly, making the lubricating film thickness more consistent and reducing the risk of lubricating film rupture caused by pressure concentration.

[0084] After introducing the arc convexity design, the traditional surface contact between the roller 3 and the inner ring is converted into a point contact form. This transformation reduces the actual contact area, reduces the pressure per unit area, and thus reduces the local shear stress borne by the lubricating film and delays the rupture process of the lubricating film. At the same time, the point contact also promotes the uniform flow of the lubricating fluid in the contact area and avoids the occurrence of turbulence or lubricating fluid stagnation.

[0085] Next, specimens of the stress dispersion part 22 are prepared using different sintering methods respectively.

[0086] Experimental group:

[0087] Step 1: Mix iron-based powder, 10wt% urea, 1wt% zinc stearate, 1wt% graphite powder and 1.5wt% nickel powder evenly, and sieve to obtain urea pore-forming agent powder; mix iron-based powder, 20wt% calcium carbonate, 1wt% zinc stearate, 1wt% graphite powder and 1.5wt% nickel powder evenly, and sieve to obtain calcium carbonate pore-forming agent powder.

[0088] Step 2: Pre-lay urea pore-forming agent powder with a thickness of 0.4 mm in a rectangular mold and apply a pressure of 700 MPa; then fill in calcium carbonate pore-forming agent powder, with an overall pressing pressure of 600 MPa, keep the pressure for 2 - 5 minutes, and the density of the green body is 80 - 85% of the theoretical density.

[0089] Step 3: Carry out staged sintering and atmosphere regulation on the green body, specifically:

[0090] Preheating and decomposition stage: Control the temperature at 200 - 300 °C, the heating rate at 5 °C / min, and the nitrogen atmosphere;

[0091] Buffer layer activation stage: Control the temperature at 600 - 800 °C, the heating rate at 3 °C / min, and the H2 / CH4 mixed atmosphere;

[0092] High-temperature densification stage: Control the temperature at 1250 °C and the H2 atmosphere;

[0093] Gradient compaction stage: Control the temperature at 1150 °C and the N2 / Ar mixed atmosphere, and apply an axial pressure of 80 MPa during this period.

[0094] Step 4: Carry out surface carburization treatment on the sintered layer with methane for 2 h at 900 °C.

[0095] Control group:

[0096] Based on the experimental group, the difference is that: only calcium carbonate is used as the pore-forming agent, the mixed powder is filled into the mold at one time and pressed; then, sintering is carried out at 1250 °C and the nitrogen atmosphere to obtain a sintered layer, and then carburization treatment is carried out to obtain the stress dispersion part 22 specimen.

[0097] Respectively conduct hardness tests and vibration energy absorption tests on the specimens prepared in the above experimental group and control group; for the hardness test, use a Vickers hardness tester, take 3 specimens for each group, measure 5 points on the surface, middle, and bottom of each specimen, record the data, and take the average value after excluding the maximum and minimum values. The results are shown in Table 1.

[0098] Table 1. Hardness test

[0099] Test area Hardness of experimental group (HV) Hardness of control group (HV) Significance of difference (p value) Surface 625±18 435±32 p<0.01 Middle 485±22 405±28 p<0.05 Bottom surface 555±20 385±30 p<0.01

[0100] The experimental group achieved a performance breakthrough through a multi-scale collaborative strengthening mechanism: urea and calcium carbonate decomposed in stages to form a gradient distribution of "closed pore layer - connected porous layer". The surface dense layer formed high-carbon martensite after carburizing treatment, with a microhardness of 625 HV, a 43.7% increase compared to the control group (435 HV). The micro-contact pair composed of the high-hard surface and the arc convexity generated a stable hydrodynamic lubrication effect during the roller movement, improving the oil film thickness in the contact area and significantly reducing friction fluctuations. In addition, the nano-carbon chains (5 - 8 nm) generated during the H2 / CH4 atmosphere sintering were distributed along the grain boundaries, forming a three-dimensional reinforcement network, increasing the hardness of the matrix bonding area to 555 HV (385 HV for the control group), and inhibiting the deep expansion of plastic deformation.

[0101] In the control group, due to the single pore structure (uniform pore size), the surface and matrix hardness were similar (435 HV → 385 HV), lacking gradient load-bearing capacity. During roller contact, micron-scale plastic flow easily occurred in the arc convexity area due to insufficient hardness.

[0102] For the vibration energy absorption test, an electromagnetic vibration table was used. The specimen was rigidly connected to the vibration table through a fixture. A preloading force of 200 N was used to simulate the bearing working condition. A Polytec PSV-500 scanning laser vibrometer was used for axial sinusoidal frequency sweep vibration, with a frequency sweep range of 10 - 1500 Hz. The test results are shown in Table 2 below.

[0103] Table 2. Vibration Energy Absorption Test

[0104] Frequency band (Hz) η value of experimental group (%) η value of control group (%) Resonance peak attenuation rate (%) 50-200 72±3 48±5 68 200-500 85±2 53±4 82 500-1000 79±4 41±6 91 1000-1500 66±5 35±7 54

[0105] In the 200 - 500 Hz frequency band (η = 85%) for the experimental group, the vibration wavelength (6 - 15 mm) in this frequency band formed a sub-resonance coupling with the connected pores in the buffer layer, and the proportion of energy absorbed by the elastic deformation of the pores was high. The nano-carbon chain network increased the elastic modulus of the buffer layer, achieving complete elastic recovery under 20% strain. In the frequency band above 1000 Hz (η = 66%): high-frequency short-wave vibrations (wavelength < 3 mm) were absorbed by the closed pores in the dense layer through the micro-plastic dissipation mechanism, and the energy conversion efficiency generated by the dislocation slip on the pore walls was relatively high. The high-hard surface (620 HV) of the carburized layer simultaneously inhibited the initiation of surface microcracks caused by high-frequency vibrations.

[0106] In the control group, due to the uniform pores, an effective frequency band - pore response correlation could not be established. When the 200 - 500 Hz vibration wave penetrated the pores, it generated relatively small elastic deformation, and the energy dissipation path was single.

[0107] Such as Figure 3As shown, the inner diameter of the second groove is smaller than the outer diameter of the multi-layer damping ring 23. That is to say, there is a certain axial position overlap between the stress dispersion part 22 and the multi-layer damping ring 23, forming a three-level energy attenuation path of "damping energy dissipation - stress dispersion - structural coordination" to achieve efficient suppression of axial vibration.

[0108] It should be noted that for the first-level vibration absorption: the multi-layer damping ring 23 is embedded in the first groove, and the surface roughness difference (outer layer Ra = 3.2 - 6.3 μm, inner layer Ra = 0.8 - 1.6 μm) forms a friction pair with the groove wall of the bearing inner ring 2; when axial vibration is transmitted to the damping ring: under low-speed conditions, the outer damping ring 24 has high surface roughness and generates static friction with the groove wall, dissipating vibration energy through plastic deformation of surface micro-protrusions and interface slip; under high-speed conditions, both the inner and outer damping rings 24 generate relative motion due to dynamic friction, and the surface grooves (diamond / parallel line type) further dissipate energy through shear deformation, converting vibration kinetic energy into heat. For the second-level energy dispersion: the stress dispersion part 22 is a porous layer of iron-based powder metallurgy with a porosity gradient (convexity area 10 - 15% → buffer layer 20 - 30%); the dense layer (convexity area) has fine closed pores and carburized and strengthened surfaces to absorb high-frequency vibration and suppress stress concentration; the rest serves as a buffer layer, and the interconnected pores enhanced by nano-carbon chains absorb low-frequency vibration through elastic deformation, evenly dispersing the energy to the matrix; moreover, the arc convexity array forms point contact with the roller 3, optimizing the stress distribution, further reducing the local peak stress, and avoiding fatigue failure caused by vibration. The axial part of the multi-layer damping ring 23 overlaps with the stress dispersion part 22 to ensure that the axial vibration energy transfer path is: axial vibration → multi-layer damping ring 23 (friction energy dissipation) → stress dispersion part 22 (porosity dispersion), forming a directional energy attenuation path, enabling the axial vibration energy to be gradually dissipated along the shortest straight path during the transfer process, thereby significantly reducing the lateral diffusion of vibration to the bearing outer ring 1, cage or roller 3, and avoiding resonance or additional stress caused by vibration transfer to other components.

[0109] The present invention constructs a directional and efficient vibration attenuation path through the axially partially overlapping stress dispersion part 22 and multi-layer damping ring 23, ensuring that energy is gradually dissipated along the shortest path during the transfer process, and significantly reducing the interference of vibration on other components of the bearing.

[0110] In summary, the present invention provides a multi-layer damping back-up bearing structure for suppressing vibration. By arranging multi-layer damping rings 23 on both sides of the bearing inner ring 2 and a stress dispersion part 22 on the circumferential surface, and there is a certain axial position overlap between the stress dispersion part 22 and the multi-layer damping ring 23, forming a three-level energy attenuation path of "damping energy dissipation - stress dispersion - structural coordination" to achieve efficient suppression of axial vibration, solving the defect of insufficient vibration suppression ability of the prior art under complex working conditions.

[0111] Based on the inspiration of the ideal embodiments of the present invention, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A multi-layer damping backing bearing structure for suppressing vibration, characterized in that: include: Bearing outer ring; A bearing inner ring, the bearing inner ring and the bearing outer ring are rotatably matched, an inner cavity is formed between the bearing inner ring and the bearing outer ring, and the inner cavity is used to contain lubricating liquid; The roller and the cage are both arranged in the inner cavity, and the shape of the pocket on the cage is adapted to the roller; Wherein, the inner side of the outer ring of the bearing and the outer side of the inner ring of the bearing are both provided with raceways, and the rollers are evenly distributed along the axial direction of the raceways; The bearing inner ring comprises: A bearing part, wherein first grooves are formed on both sides of the bearing part, and multiple layers of damping rings are arranged in the first grooves; The stress dispersion part is arranged on the surface of the bearing part, and the position of the stress dispersion part corresponding to the raceway is provided with a plurality of arc convexities.

2. A multi-layer damping backing bearing structure for suppressing vibration according to claim 1, characterized in that: The multi-layer damping ring comprises: Outer damping ring, An inner damping ring is nested in the outer damping ring; Wherein, the surface roughness of the outer damping ring is greater than the surface roughness of the inner damping ring.

3. A multi-layer damping backing bearing structure for suppressing vibration according to claim 2, characterized in that: The number of the inner damping rings is several, and the plurality of inner damping rings are nested in sequence from inside to outside along the radial direction with the axis of the inner ring of the bearing as the center; The surface roughness of the outer inner damping ring is greater than the surface roughness of the inner damping ring.

4. A multi-layer damping backing bearing structure for suppressing vibration according to claim 1, characterized in that: A second groove is formed on the circumferential surface of the bearing portion, and the stress dispersion portion is arranged on the surface of the second groove; the raceway is arranged at the bottom of the second groove; The stress dispersion part is a porous sintered layer made by sintering iron-based powder metallurgy materials, with a thickness of 0.8-2.0 mm and a porosity of 10%-30%.

5. A multi-layer damping backing bearing structure for suppressing vibration according to claim 2, characterized in that: The surface roughness of the outer damping ring is Ra=3.2-6.3 μm, and the surface roughness of the inner damping ring is Ra=0.8-1.6 μm.

6. A multi-layer damping backing bearing structure for suppressing vibration according to claim 4, characterized in that: The inner diameter of the second groove is smaller than the outer diameter of the multi-layer damping ring.

7. A multi-layer damping backing bearing structure for suppressing vibration according to claim 1, characterized in that: The convexities of the arcs are distributed in a logarithmic curve, with a height of 3 to 8 μm.

8. A multi-layer damping backing bearing structure for suppressing vibration according to claim 4, characterized in that: The method for preparing the stress dispersion portion comprises the following steps: S1. Evenly mix the iron-based powder, the pore-forming agent, the functional additive and the nickel powder, wherein the pore-forming agent includes urea and calcium carbonate. During the mixing process, the two pore-forming agents are mixed with part of the mixed material respectively; S2, designing a modular mold according to the size of the bearing part, including a pre-molding cavity of the second groove, pre-laying a urea pore-forming agent powder layer in the mold, applying a high pressure of 700-800 MPa, and then filling the mixed powder containing calcium carbonate, and pressing the mixture as a whole to obtain a green body; S3, sintering the green body in stages and regulating the atmosphere, regulating the pore gradient distribution in the sintered layer, and preparing a sintered layer with a thickness of 0.8 to 2.0 mm on the surface of the bearing portion; S4, using methane to perform surface carburization treatment on the sintered layer; S5. Use a grinder to finely grind the surface of the sintered layer to remove the surface oxide layer, and then use a laser engraving machine to etch the arc convexity at the position corresponding to the raceway according to the logarithmic curve path.

9. A multi-layer damping backing bearing structure for suppressing vibration according to claim 8, characterized in that: The staged sintering and atmosphere control include: Preheating decomposition stage: the temperature is controlled at 200-300℃, during which high-purity nitrogen is passed; Buffer layer activation stage: temperature controlled at 600-800°C, with H2 / CH4 mixed atmosphere; High temperature densification stage: the temperature is controlled at 1250℃, and H2 is passed during this period; Gradient compaction stage: the temperature is controlled at 1150°C, a N2 / Ar mixed atmosphere is passed through, and axial pressure is applied.

10. A multi-layer damping backing bearing structure for suppressing vibration according to claim 4, characterized in that: The pore size and porosity of the portion of the stress dispersion portion corresponding to the raceway are smaller than those of the other portions.

Images