Method for improving bearing capacity of bearing bush and bearing bush

Abstract

The application discloses a method for improving bearing capacity of a bearing bush and the bearing bush, and adopts a laser cladding process to form a layer of babbitt alloy on a bearing bush base body, the babbitt alloy layer is unevenly distributed on the bearing bush base body, and the proportion of hard phase particles in a bearing area of the bearing bush base body is greater than that in a non-bearing area, so that the bearing capacity and the creep resistance of the bearing bush are improved.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, specifically to a method for improving the load-bearing capacity of bearings and a bearing itself. Background Technology

[0002] The bearing bush is the part of a sliding bearing that contacts the journal, and its shape is a semi-cylindrical surface resembling a tile. Babbitt alloy has good compliance, fatigue resistance, and embedding properties, and can be widely used as a wear-resistant layer in bearing bushes. Babbitt alloy is usually attached to the bearing bush substrate by centrifugal casting. During the centrifugal casting process, the composition of the alloy solution remains constant, resulting in a uniform distribution of hard phase particles in the soft phase matrix of the Babbitt alloy layer. The soft phase matrix gives the Babbitt alloy layer excellent embedding properties, compliance, and anti-galling properties. After break-in, the soft phase matrix becomes concave and the hard phase particles become convex, creating a small gap between the bearing bush and the bearing, which serves as an oil reservoir and lubrication channel, reducing friction between the sliding bearing and the bearing bush. At the same time, the convex hard phase particles support the sliding bearing, which is beneficial for bearing loads.

[0003] However, Babbitt alloy has a relatively low melting point, hardness, and yield strength compared to other metals. Under high-speed and heavy-load operating conditions, after the sliding bearing reaches thermal equilibrium, the operating temperature of the bearing bearing's load-bearing area increases. When the temperature of the load-bearing area reaches above 0.3Tm (Tm is the melting point of Babbitt alloy), the Babbitt alloy layer in this area exhibits a significant creep effect. When the temperature of the load-bearing area is greater than 0.5Tm, the Babbitt alloy layer in this area is extremely prone to creep. That is, the increase in the operating temperature of the load-bearing area causes a decrease in the mechanical properties of Babbitt alloy, thereby reducing the load-bearing capacity and fatigue strength of the bearing bearing. Summary of the Invention

[0004] To improve the load-bearing capacity of bearing bushes, this invention provides a method and a bearing bush for improving the load-bearing capacity of bearing bushes, thereby improving the load-bearing capacity and creep resistance of bearing bushes.

[0005] To achieve the above objectives, the specific solution adopted by the present invention is as follows: a method for improving the load-bearing capacity of bearing bushes, wherein a Babbitt alloy layer is formed on the bearing bush substrate using a laser cladding process, wherein the Babbitt alloy layer is non-uniformly distributed on the bearing bush substrate, and the proportion of hard phase particles in the load-bearing area of ​​the bearing bush substrate is greater than the proportion of hard phase particles in the non-load-bearing area.

[0006] An optimized solution to the above-mentioned method for improving the load-bearing capacity of bearings includes the following steps:

[0007] S1, determine the load-bearing and non-load-bearing areas of the bearing substrate;

[0008] S2, using laser cladding technology to clad contact layer I on the load-bearing area and contact layer II on the non-load-bearing area;

[0009] S3 uses laser cladding to clad Babbitt alloy layer I on contact layer I and Babbitt alloy layer II on contact layer II; the proportion of hard phase particles in Babbitt alloy layer I is greater than that in Babbitt alloy layer II.

[0010] As another optimization of the above-mentioned method for improving the bearing capacity of the bearing bush: the laser cladding process in S2 and S3 adopts a dual-nozzle powder feeding method. The dual nozzles include a first nozzle for conveying mixed powders of Sn, Fe, As, Bi, Zn, Al and Cd and a second nozzle for conveying Sb and Cu metal powders. The diameter of the first nozzle is larger than the diameter of the second nozzle.

[0011] As an alternative optimization of the above-mentioned method for improving the bearing capacity, step S2 includes:

[0012] S201, The laser cladding head is located at the junction of the load-bearing area and the non-load-bearing area. The laser cladding head includes a fiber laser that is perpendicular to the inner wall of the bearing and can form a laser spot on the bearing substrate, and multiple sets of dual nozzles that are spaced around the laser spot.

[0013] S202, Set the cladding parameters for cladding contact layer I in the load-bearing area;

[0014] S203, adjust the cladding parameters to clad the contact layer II in the non-load-bearing area.

[0015] As another optimization scheme of the above-mentioned method for improving the bearing capacity: In S202, the cladding parameters include: cladding power of 0.5-2KW, cladding rate of 80-200cm / min, cladding width of 0.8-2.5mm, powder feeding speed of the first nozzle of 12-25g / min, powder feeding speed of the second nozzle of 2.5-5.7g / min, bearing movement distance equal to bearing width, and bearing rotation angle of ξ=3a / 5r~4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing.

[0016] As another optimization of the above-mentioned method for improving the bearing capacity of the bearing bush, in S203, the adjusted cladding parameters include: the powder feeding speed of the first nozzle is 12-25 g / min, and the powder feeding speed of the second nozzle is 2.2-4.2 g / min.

[0017] As another optimized scheme of the above-mentioned method for improving the bearing capacity: In S3, the cladding parameters of Babbitt alloy layer I are as follows: cladding power is 0.5-2KW, cladding rate is 80-200cm / min, cladding width is 0.8-2.5mm, powder feeding speed of the first nozzle is 12-25g / min, powder feeding speed of the second nozzle is 2.5-5.7g / min, bearing movement distance is the bearing width, and bearing rotation angle is ξ=3a / 5r~4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing.

[0018] As another optimized scheme of the above-mentioned method for improving the bearing capacity: In S3, the cladding parameters of Babbitt alloy layer II include: cladding power of 0.5-2KW, cladding rate of 80-200cm / min, cladding width of 0.8-2.5mm, powder feeding speed of the first nozzle of 12-25g / min, powder feeding speed of the second nozzle of 2.2-4.2g / min, bearing movement distance equal to bearing width, and bearing rotation angle of ξ=3a / 5r~4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing.

[0019] A bearing bush includes a bearing bush base and a Babbitt alloy layer covering the inner wall of the bearing bush base. The Babbitt alloy layer is divided into a Babbitt alloy layer I located in the load-bearing area and a Babbitt alloy layer II located in the non-load-bearing area. A contact layer I is formed between the Babbitt alloy layer I and the bearing bush base, and a contact layer II is formed between the Babbitt alloy layer II and the bearing bush base.

[0020] As an optimized solution to the above-mentioned bearing method: the hard phase particles of the Babbitt alloy layer I account for 20% to 30%, and the hard phase particles of the Babbitt alloy layer II account for 15% to 20%.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention provides a method and a bearing for improving the load-bearing capacity of bearing bushes. The method uses laser cladding technology to form a non-uniform Babbitt alloy layer on the bearing bush substrate. Specifically, by adjusting the powder spraying speed of the first nozzle and the second nozzle, the proportion of hard phase particles in the load-bearing area is increased, thereby increasing the hardness of the Babbitt alloy layer, improving the load-bearing capacity of the bearing bush, and reducing the damage caused by creep behavior to the bearing bush. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the distribution of hard phase particles within the Babbitt alloy layer of the bearing bush.

[0024] Figure 2 This is a schematic diagram of the dual-nozzle distribution;

[0025] Reference numerals: 1. Bearing substrate, 2. Babbitt metal layer, 3. Hard phase particles, 4. Laser spot, 5. Second nozzle, 6. First nozzle. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art, such as the method of adjusting cladding parameters, the operation of fiber laser, and the method of determining the carrier area and non-carrier area.

[0027] Example 1

[0028] A method for improving the load-bearing capacity of bearing bushes involves forming a Babbitt alloy layer on the bearing bush substrate using a laser cladding process. The elemental mass percentages in the Babbitt alloy layer are as follows: Pb: not more than 0.35%, Sb: 10.0–12.0%, Cu: 5.5–6.5%, Fe: not more than 0.08%, As: not more than 0.05%, Bi: not more than 0.05%, Zn: not more than 0.005%, Al: not more than 0.005%, Cd: not more than 0.05%, with the balance including Sn and trace amounts of unavoidable impurities. Sb and Cu improve the alloy's strength and hardness, while a small amount of As prevents segregation and grain refinement. The Babbitt alloy layer (SnSb) 11 The microstructure of Cu6 is a tin-based α-solid solution, Cu6Sn5, and SnSb. Among them, Cu6Sn5 is not only a hard particle but also has ductility, making SnSb... 11 Cu6 exhibits good plasticity. Cu6Sn5 and SnSb distort the matrix structure, increasing the deformation resistance of the Babbitt alloy layer and thus improving its strength. Simultaneously, the Cu6Sn5 phase possesses high thermal stability, enabling it to resist creep deformation under bearing operating conditions. The Babbitt alloy layer is non-uniformly distributed on the bearing matrix. The proportion of hard phase particles in the load-bearing region is greater than that in the non-load-bearing region. Furthermore, the Sb and Cu mass percentages in the load-bearing region are higher than those in the intermediate and non-load-bearing regions. This increases the proportion of hard phase particles in the load-bearing region, enhancing the hardness of the Babbitt alloy layer and consequently improving the bearing's load-bearing capacity while reducing the damage caused by metal creep.

[0029] The specific steps for preparing a Babbitt alloy layer using laser cladding include:

[0030] S1, determine the load-bearing area, intermediate area and non-load-bearing area of ​​the bearing substrate, specifically:

[0031] S101, based on the Reynolds equation and the finite element method, the oil film pressure distribution of the bearing is obtained, and the strain of the Babbitt alloy layer is divided into elastic strain and creep strain, i.e., ε = ε e +ε c , where ε e For elastic strain, ε c For creep strain.

[0032] ε c =f1(σ)f2(t)f3(T)

[0033] Where σ is the stress on the Babbitt alloy layer, t is time, and T is temperature.

[0034] The creep equation for the Babbitt alloy layer is:

[0035]

[0036] Where σ is the stress on the Babbitt alloy layer, t is time, and T is temperature.

[0037] The Reynolds equation is:

[0038]

[0039] Where, r j Let θ be the rotor radius, θ be the circumferential angle, p be the bearing oil film pressure, z be the axial direction, h be the oil film thickness, t be the time, ω be the rotor angular velocity, and μ be the lubricating oil viscosity.

[0040] The specific steps are as follows: a) Determine the bearing geometry and operating conditions, and numerically solve the Reynolds equation to obtain the initial oil film pressure p0 and initial oil film thickness h0 at each node; b) Incorporate elastic deformation, and calculate the elastic deformation of each node based on the initial oil film pressure and initial oil film thickness to obtain the oil film thickness h1. Correct h1, and substitute the corrected h1 into the Reynolds equation from step a to obtain the oil film pressure p1; c) Repeat steps a and b until the error between adjacent oil film pressures is less than the error accuracy requirement; d) Incorporate creep deformation based on step c, and calculate the creep deformation of each node; e) Repeat steps a and b until the oil film pressure meets the error accuracy requirement. Finally, the oil film pressure distribution at each node is obtained.

[0041] S102, the oil film temperature distribution is obtained based on the bearing internal thermal balance model. The oil film temperature distribution equation obtained from the sliding bearing internal thermal balance model is:

[0042]

[0043] Where ρ1, c1, and k1 are the density, specific heat capacity, and thermal conductivity of the lubricating oil, respectively; T is the oil film temperature; μ is the viscosity of the lubricating oil; u and w are the velocity field distributions of the oil film along the rotor circumferential and axial directions, respectively; and x, y, and z are the axial, radial, and axial directions of the oil film, respectively.

[0044] S103, the area with the highest oil film pressure and oil film temperature and its extended region are the load-bearing area. Creep strain is mainly concentrated in the central area with a large load, and the area with the highest oil film pressure and oil film temperature is the first to show creep phenomenon and continues to extend outward. That is, the area with the highest oil film pressure and oil film temperature and its extended region are the load-bearing area.

[0045] S2, a laser cladding process is used to clad contact layer I on the load-bearing area and contact layer II on the non-load-bearing area. The laser cladding process employs a dual-nozzle powder feeding method. The dual nozzles include a first nozzle 6 for feeding mixed powders of Sn, Fe, As, Bi, Zn, Al, and Cd, and a second nozzle 5 for feeding Sb and Cu metal powders. The diameter of the first nozzle 6 is larger than the diameter of the second nozzle 5, and the diameter is determined by the mass ratio of each powder-feeding metal. When the powder feeding rates of the first nozzle 6 and the second nozzle 5 are the same, the ratio of the diameter of the first nozzle 6 to the diameter of the second nozzle 5 is proportional to the square root of the mass ratio of the powder-feeding metal from the first nozzle to the powder-feeding metal from the second nozzle.

[0046] S201, the laser cladding head is positioned at the oil inlet of the bearing. The laser cladding head includes a fiber laser perpendicular to the inner wall of the bearing bush and capable of forming a laser spot 4 on the bearing bush substrate, and multiple sets of dual nozzles spaced apart around the laser spot 4. Figure 2 As shown, the fiber laser forms a circular laser spot 4 on the inner wall of the bearing bush, and the first nozzle 6 and the second nozzle 5 are tilted towards the inner wall of the bearing bush; multiple sets of dual nozzles are distributed circumferentially along the laser spot 4, and the first nozzle 6 and the second nozzle 5 are alternately arranged. The circumferential interval angle between two adjacent sets of dual nozzles is the same, so that the metal powder can be fully mixed and the performance of the Babbitt alloy layer can be improved.

[0047] S202, cladding parameters are set for cladding contact layer I in the bearing area. In this embodiment, the powder feeding rate and powder feeding quality of the first and second nozzles are controlled by the flow rate of inert gas. The cladding parameters of contact layer I include: cladding power of 0.5-2KW, cladding rate of 80-200cm / min, cladding width of 0.8-2.5mm, powder feeding speed of the first nozzle of 12-25g / min, powder feeding speed of the second nozzle of 2.5-5.7g / min, bearing movement distance equal to the bearing width, and bearing rotation angle of ξ = 3a / 5r ~ 4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing. In this embodiment, the cladding power is 0.5KW, the cladding rate is 80cm / min, the cladding width is 0.8mm, the powder feeding speed of the first nozzle is 12g / min, the powder feeding speed of the second nozzle is 5.7g / min, the bearing movement distance is the bearing width, the bearing rotation angle is ξ=3a / 5r, the laser cladding head is arranged at the junction of the load-bearing area and the non-load-bearing area, first cladding the load-bearing area, starting from one axial edge of the bearing, the bearing moves along the axial direction until it is cladding to the other axial edge of the bearing, forming a contact layer I; the bearing is rotated, starting from one axial edge of the bearing, the bearing moves along the axial direction until it is cladding to the other axial edge of the bearing, forming another contact layer I, that is, the two contact layers I are distributed in a "Z" shape, until a contact layer I that is bonded to the bearing substrate is formed in the load-bearing area, the hard phase particles of the first contact layer account for 20%-30%.

[0048] S203, Adjust the cladding parameters to clad contact layer II in the non-load-bearing area. The cladding parameters for contact layer II include: cladding rate of 80-200 cm / min, cladding width of 0.8-2.5 mm, powder feeding speed of the first nozzle of 12-25 g / min, powder feeding speed of the second nozzle of 2.2-4.2 g / min, bearing movement distance equal to the bearing width, and bearing rotation angle ξ = 3a / 5r ~ 4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing. Adjust the cladding parameters to clad the non-load-bearing area, i.e., reduce the powder feeding speed of the second nozzle to 2.2-4.2 g / min. In this embodiment, the cladding rate is 100 cm / min, the cladding width is 0.8 mm, the powder feeding speed of the first nozzle is 12 g / min, the powder feeding speed of the second nozzle is 4.2 g / min, the bearing travels a distance equal to the bearing width, and the bearing rotates at an angle ξ = 3a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing. The cladding parameters are adjusted to clad the non-load-bearing area, i.e., the powder feeding speed of the second nozzle is reduced to 4.2 g / min. Cladding begins from one axial edge of the bearing, and the bearing moves along the axial direction until it clads to the other axial edge, forming a contact layer II. The bearing is rotated, and cladding begins from one axial edge, moving along the axial direction until it clads to the other axial edge, forming another contact layer II. The two contact layers II are distributed in a "Z" shape until a contact layer II bonded to the bearing substrate is formed in the load-bearing area. The hard phase content of the second contact layer is 15%-20%. The hard phase content of contact layer one is greater than that of contact layer two.

[0049] S3, using laser cladding, Babbitt alloy layer I is clad onto contact layer I, and Babbitt alloy layer II is clad onto contact layer II. The proportion of hard phase particles in Babbitt alloy layer I is greater than that in Babbitt alloy layer II. After the cladding of contact layers I and II is completed, the laser cladding head is repositioned at the junction of the load-bearing and non-load-bearing areas. Therefore, Babbitt alloy layer I is clad first on top of contact layer I, and then Babbitt alloy layer II is clad on top of contact layer II.

[0050] Specifically, the cladding parameters for the first Babbitt alloy layer are set as follows: cladding power of 0.5-1kW, cladding rate of 80-130cm / min, cladding width of 0.8-1.8mm, powder feeding speed of the first nozzle of 12-19g / min, powder feeding speed of the second nozzle of 2.5-4.3g / min, bearing movement distance equal to the bearing width, and bearing rotation angle of ξ = 3a / 5r ~ 4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing. In this embodiment, the cladding power is 0.5kW, the cladding rate is 80cm / min, the cladding width is 0.8mm, the powder feeding speed of the first nozzle is 12g / min, the powder feeding speed of the second nozzle is 4.3g / min, the bearing movement distance is the bearing width, and the bearing rotation angle is ξ=3a / 5r. Cladding begins from one axial edge of the bearing, and the bearing moves along the axial direction until it is clad to the other axial edge of the bearing, forming a Babbitt alloy layer 1. The bearing is rotated, and cladding begins from one axial edge of the bearing, and the bearing moves along the axial direction until it is clad to the other axial edge of the bearing, forming another Babbitt alloy layer 1. That is, the two Babbitt alloy layers 1 are distributed in a "Z" shape until the contact layer 1 forms a Babbitt alloy layer 1. The hard phase ratio of the Babbitt alloy layer 1 is 20%~30%.

[0051] Specifically, the cladding parameters for the second Babbitt alloy layer are set as follows: cladding power of 0.5-1kW, cladding rate of 80-130cm / min, cladding width of 0.8-1.8mm, powder feeding speed of the first nozzle of 12-19g / min, powder feeding speed of the second nozzle of 2.2-3.9g / min, bearing movement distance equal to bearing width, and bearing rotation angle of ξ = 3a / 5r ~ 4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing. The cladding process begins at one axial edge of the bearing bush and continues along the axial direction until it reaches the other axial edge, forming a second Babbitt alloy layer. The bearing bush is then rotated, and the cladding process continues at one axial edge until it reaches the other axial edge, forming another second Babbitt alloy layer. The two second Babbitt alloy layers are arranged in a "Z" shape until they contact each other to form a second Babbitt alloy layer. The hard phase particles in the second Babbitt alloy layer account for 15% to 20%.

[0052] The above-mentioned Babbitt alloy layer one and Babbitt alloy layer two are cyclically clad until three layers of Babbitt alloy layer one are formed on contact layer one and three layers of Babbitt alloy layer two are formed on contact layer two.

[0053] The cladding power, powder feeding rate, and bearing movement rate of cladding contact layer one and contact layer two are all lower than those of cladding Babbitt alloy layer one and Babbitt alloy layer two, which ensures the contact strength between the contact layer and the bearing substrate.

[0054] Example 2

[0055] A bearing bush includes a bearing bush substrate 1 and a Babbitt alloy layer 2 covering the inner wall of the bearing bush substrate 1. The Babbitt alloy layer 2 is divided into a Babbitt alloy layer I located in the load-bearing area and a Babbitt alloy layer II located in the non-load-bearing area. A contact layer I is formed between the Babbitt alloy layer I and the bearing bush substrate, and a contact layer II is formed between the Babbitt alloy layer II and the bearing bush substrate. The hard phase particles account for 20-30% of the composition of the contact layer I, 15-25% of the composition of the contact layer II, 25-30% of the composition of the Babbitt alloy layer I, and 20-25% of the composition of the Babbitt alloy layer II.

[0056] In this embodiment, the hard phase particles of contact layer two account for 15%, the hard phase particles of Babbitt alloy layer I account for 25%, and the hard phase particles of Babbitt alloy layer II account for 20%.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for improving the load-bearing capacity of a bearing bush, comprising forming a Babbitt alloy layer on a bearing bush substrate (1) using a laser cladding process, characterized in that: The Babbitt alloy layer is non-uniformly distributed on the bearing substrate (1), and the proportion of hard phase particles in the bearing substrate (1) is greater than that in the non-bearing area. Includes the following steps: S1, determine the load-bearing area and non-load-bearing area of ​​the bearing substrate (1); S101, based on the Reynolds equation and the finite element method, the oil film pressure distribution of the bearing is obtained, and the strain of the Babbitt alloy layer is divided into elastic strain and creep strain; S102, the oil film temperature distribution is obtained based on the bearing internal thermal balance model; S103, the area with the highest oil film pressure and oil film temperature and its extended area are the load-bearing area; S2, using laser cladding technology to clad contact layer I on the load-bearing area and contact layer II on the non-load-bearing area; S3, using laser cladding process to clad Babbitt alloy layer I on contact layer I and Babbitt alloy layer II on contact layer II; The proportion of hard phase particles in Babbitt alloy layer I is greater than that in Babbitt alloy layer II. The proportion of hard phase particles (3) in Babbitt alloy layer I is 20%~30%, and the proportion of hard phase particles (3) in Babbitt alloy layer II is 15%~20%. The laser cladding process in S2 and S3 adopts a dual-nozzle powder feeding method. The dual nozzles include a first nozzle (6) for conveying mixed powders of Sn, Fe, As, Bi, Zn, Al and Cd and a second nozzle (5) for conveying metal powders of Sb and Cu. The diameter of the first nozzle (6) is larger than the diameter of the second nozzle (5).

2. The method for improving the load-bearing capacity of a bearing bush as described in claim 1, characterized in that: S2 includes: S201, the laser cladding head is located at the junction of the load-bearing area and the non-load-bearing area. The laser cladding head includes a fiber laser that is perpendicular to the inner wall of the bearing and can form a laser spot on the bearing substrate (1) and multiple sets of dual nozzles that are spaced around the laser spot. S202, Set the cladding parameters for cladding contact layer I in the load-bearing area; S203, adjust the cladding parameters to clad the contact layer II in the non-load-bearing area.

3. The method for improving the load-bearing capacity of a bearing bush as described in claim 2, characterized in that: In S202, the cladding parameters include: cladding power of 0.5-2KW, cladding rate of 80-200cm / min, cladding width of 0.8-2.5mm, powder feeding speed of the first nozzle (6) of 12-25g / min, powder feeding speed of the second nozzle (5) of 2.5-5.7g / min, bearing movement distance of the bearing width, and bearing rotation angle of ξ=3a / 5r~4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing.

4. The method for improving the bearing capacity of a bearing bush as described in claim 2, characterized in that: In S203, the adjusted cladding parameters include: the powder feeding speed of the first nozzle (6) is 12-25 g / min, and the powder feeding speed of the second nozzle (5) is 2.2-4.2 g / min.

5. The method for improving the load-bearing capacity of a bearing bush as described in claim 1, characterized in that: In S3, the cladding parameters of the Babbitt alloy layer I are as follows: cladding power is 0.5-2KW, cladding rate is 80-200cm / min, cladding width is 0.8-2.5mm, powder feeding speed of the first nozzle (6) is 12-25g / min, powder feeding speed of the second nozzle (5) is 2.5-5.7g / min, the bearing moving distance is the bearing width, and the bearing rotation angle is ξ=3a / 5r~4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing.

6. The method for improving the load-bearing capacity of a bearing bush as described in claim 1, characterized in that: In S3, the cladding parameters of the Babbitt alloy layer II include: cladding power of 0.5-2KW, cladding rate of 80-200cm / min, cladding width of 0.8-2.5mm, powder feeding speed of the first nozzle (6) of 12-25g / min, powder feeding speed of the second nozzle (5) of 2.2-4.2g / min, bearing movement distance of the bearing width, and bearing rotation angle of ξ=3a / 5r~4a / 5r, where a is the cladding width of the bearing and r is the radius of curvature of the bearing.

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