Lead-bismuth dynamic pressure lubrication bearing structure with low wall surface slippage rate and design method of lead-bismuth dynamic pressure lubrication bearing structure

Abstract

The invention discloses a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate and a design method thereof, the lead-bismuth dynamic pressure lubrication bearing structure comprises a rotating shaft and a radial sliding bearing, and the rotating shaft is arranged in the radial sliding bearing; a plurality of first grooves are formed in the side face, making contact with the liquid lead-bismuth alloy, of the rotating shaft. The first grooves are evenly distributed in the shaft neck of the rotating shaft in the circumferential direction. The radial sliding bearing comprises a shell and a tile block. According to the lead-bismuth dynamic pressure lubrication bearing structure with the low wall surface slippage rate and the design method thereof, the wall surface slippage rate of a gap of the lead-bismuth dynamic pressure lubrication bearing can be increased, a lead-bismuth dynamic pressure bearing with liquid lead-bismuth alloy as lubricating liquid is helped to effectively generate a dynamic pressure oil film, and rub-impact between the lead-bismuth bearing and a shaft is reduced; therefore, excessive heating and violent vibration of the oil film are avoided, bearing efficiency is improved, and the service life of the bearing is prolonged.

Description

Technical Field

[0001] The present invention belongs to the field of bearings, and in particular relates to a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate and a design method thereof. Background Art

[0002] Lead-bismuth bearings are special bearings that use lead-bismuth alloy as a lubricating medium or key structural material. Their core feature is that they utilize the liquid lubrication properties of lead-bismuth alloy in high-temperature environments, making them suitable for extreme working conditions such as the main pumps of nuclear power plants. The design of lead-bismuth bearings is based on the liquid properties of lead-bismuth alloy at specific temperatures (such as above 300°C). By filling the bearing gap with lead-bismuth alloy as a lubricating medium, or directly using it as a lubricating layer for the bearing, and utilizing its low melting point, high thermal conductivity and good fluidity, a stable liquid lubricating film is formed during high-speed rotation, thereby reducing the friction coefficient, reducing wear, and effectively taking away heat. This design is particularly suitable for extreme environments that need to withstand high temperatures, high pressures, and strong radiation.

[0003] Lead-bismuth bearings are a crucial component of the secondary primary circulation system of new-generation nuclear power plants, supporting the entire secondary primary circulation system's shafting. Compared to traditional nuclear main pump bearings, such as those lubricated with sodium or water, lead-bismuth bearings utilize a new liquid alloy, lead-bismuth, as a lubricant. This offers advantages such as high thermal conductivity and efficient heat dissipation, but also has certain drawbacks.

[0004] Since the density of liquid lead-bismuth alloy is greater than that of conventional lubricating oil, the slip rate of lead-bismuth alloy near the wall is low, and slip is likely to occur in the gap of the lead-bismuth hydrodynamic bearing, making it difficult to form a stable hydrodynamic oil film, thereby reducing the bearing's load-bearing capacity, affecting the stability of the shaft system, and even causing friction failures between the shaft and the sliding bearing, leading to serious problems such as heat and severe vibration. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a lead-bismuth hydrodynamic lubrication bearing structure with low wall slip rate and a design method thereof, which can help form a hydrodynamic oil film so that the pump shaft can rotate stably.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A lead-bismuth hydrodynamic lubrication bearing structure with low wall slip rate comprises a rotating shaft and a radial sliding bearing, wherein the rotating shaft is arranged inside the radial sliding bearing; a side groove structure is provided on the side of the rotating shaft that contacts the liquid lead-bismuth alloy, wherein the side groove structure comprises a plurality of first grooves, which are uniformly distributed circumferentially on the journal of the rotating shaft.

[0008] A further improvement of the present invention is that the radial sliding bearing includes a housing and a shoe.

[0009] A further improvement of the present invention is that the type of the radial sliding bearing in the rotating shaft and the radial sliding bearing is a cylindrical bearing, or an elliptical bearing, a partial bearing, a staggered bearing, or a radial sliding bearing with multiple oil leaves.

[0010] A further improvement of the present invention is that the bearing liquid inlet holes in the rotating shaft and the radial sliding bearing are arranged on the side surfaces of the bearing seat.

[0011] A further improvement of the present invention is that another form of the side groove structure is a stationary shaft and a rotating bearing, and a plurality of second grooves are formed on the inner surface of the rotating bearing.

[0012] A further improvement of the present invention is that the type of the rotating bearing among the stationary shaft and the rotating bearing is a cylindrical bush bearing.

[0013] A design method for a lead-bismuth dynamic pressure lubricated bearing structure with low wall slip rate comprises the following steps:

[0014] Step S1, inputting operating parameters, physical parameters of the lead-bismuth alloy, and shaft dimensions;

[0015] Step S2: selecting the groove position according to the active component. The groove should be located on the active component. If the shaft is the active component, the groove is located on the side of the shaft; if the bearing is the active component, the groove is located on the bearing shell surface of the bearing;

[0016] Step S3, calculating the specific pressure p and linear velocity v according to the basic working conditions of the shaft diameter, rotational speed, and load condition, the calculation formulas of the specific pressure p and linear velocity v are: p = F / DB, v = ωD / 2, where F is the load, D is the shaft diameter, B is the bearing width, and ω is the shaft rotational speed;

[0017] Step S4, preliminarily selecting parameters within the numerical range of the groove parameters according to the specific pressure p and the linear velocity v;

[0018] Step S5: Design the bearing according to the input working conditions and the preliminarily selected groove parameters;

[0019] Step S6, adjusting the parameters of the groove, and then performing the bearing design described in step S5;

[0020] Step S7: Output appropriate groove parameters, including groove wrap angle φ, length ratio L / B, depth ratio A / C, and groove number N, as well as bearing parameters, including clearance ratio, preload, convergence ratio, installation angle, and filling factor.

[0021] A further improvement of the present invention is that step S4 is specifically as follows:

[0022] Step S4, based on the specific pressure p and linear velocity v calculated in step S3, preliminarily select the groove parameters; the shape of the first groove and the second groove is V-shaped, and the groove parameters include: groove wrap angle φ, that is, the central angle of the groove relative to the center of the journal; depth ratio A / C, that is, the ratio of depth A to gap C; length ratio L / B, the ratio of groove length L to bearing width B; groove number N, that is, the number of all circumferential grooves; the value range of length ratio L / B should be: 0.5~0.8, the value range of groove depth ratio A / C should be: 0.2~0.5, and the value range of groove wrap angle φ should be 0.4~2°; the greater the specific pressure p, the greater the corresponding length ratio L / B, groove depth ratio A / C, and groove wrap angle φ should also be; the higher the linear velocity v, the smaller the corresponding length ratio L / B and groove depth ratio A / C should be, and the greater the groove wrap angle φ should also be; the groove number N should satisfy: N<2π / φ.

[0023] A further improvement of the present invention is that step S5 is specifically as follows:

[0024] Step S51: Select the bearing type and clearance ratio based on the linear velocity v. When the linear velocity is less than 20 m / s, cylindrical pad bearings are generally selected. When the linear velocity is between 20 m / s and 60 m / s, multi-pad fixed bearings with preload are generally selected. When the linear velocity exceeds 60 m / s, tilting pad bearings are selected. The bearing clearance ratio should be between 0.001 and 0.003. The higher the linear velocity v, the larger the clearance ratio should be.

[0025] Step S52: adjusting the bearing width B according to the specific pressure p so that the specific pressure p is controlled within a set range;

[0026] Step S53: Check the bearing temperature, flow, power consumption, stiffness and damping bearing characteristics. If the design requirements of the shafting are not met, repeatedly adjust the key structural parameters of the clearance ratio, aspect ratio, preload and convergence ratio. If the key structural parameters of the bearing are adjusted to meet the design requirements, proceed to step S7; otherwise, proceed to step S6.

[0027] A further improvement of the present invention is that step S6 is specifically as follows:

[0028] Step S61, calculate the minimum liquid film thickness h lim : Among them Rz B +R z1 It is the sum of the ten-point heights of the microscopic unevenness of the journal and the bearing at the ideal position, i.e., line X--X. The axis coaxiality within the bearing width is the Y---Y line. is the average deflection, i.e., ZZ line;

[0029] Step S62: Check the minimum liquid film thickness h lim Whether it meets: hmin ≥[h min ]=S(R1+R2+y1+y2), where S m For margin, heavy-load bearings usually take S m =2~3; R1 and R2 are the average heights of the unevenness of the journal and bearing surface; y1 is the deflection of the journal in the bearing, and y2 is the journal offset; if it is not satisfied, appropriately increase the groove angle φ, depth ratio A / C, length ratio L / B, or appropriately reduce the groove spacing.

[0030] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0031] The present invention provides a lead-bismuth hydrodynamic lubricated bearing structure with low wall slip velocity and its design method. Because liquid lead-bismuth alloy is difficult to be driven by smooth rotating components, the fluid has a low wall slip velocity, preventing the formation of a hydrodynamic wedge angle. With this improvement, when a rotating shaft or rotating bearing rotates relative to another component, the groove drives the liquid lead-bismuth alloy to flow in the bearing gap. Gravity creates an eccentricity between the bearing and the shaft, allowing the liquid lead-bismuth alloy to enter the wedge angle formed between the bearing and the shaft, thereby generating a hydrodynamic effect. The pressure generated by this hydrodynamic effect stabilizes the gap between the shaft and the bearing, allowing the rotating shaft or rotating bearing to rotate stably. Therefore, the present invention can increase the wall slip velocity of the lead-bismuth hydrodynamic lubricated bearing gap, helping the lead-bismuth hydrodynamic bearing, which uses liquid lead-bismuth alloy as a lubricant, to effectively generate a hydrodynamic oil film, reducing friction between the lead-bismuth bearing and the shaft, thereby avoiding excessive heating and severe vibration of the oil film, improving bearing efficiency, and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 It is an overall schematic diagram of the rotating shaft-tilt pad bearing in the present invention.

[0034] Figure 2 is a cross-sectional view of the rotating shaft-tilt pad bearing at the journal of the present invention;

[0035] Figure 3 yes Figure 2 A partial enlarged view of point A in the middle;

[0036] Figure 4 It is an overall schematic diagram of the stationary shaft-rotating bearing of the present invention.

[0037] Figure 5 yes Figure 4 A partial enlarged view of point B in the middle.

[0038] Figure 6 (a) and (b) are schematic diagrams of the key structural parameters of the present invention.

[0039] Figure 7 It is a design flow chart of the lead-bismuth bearing structure of the present invention.

[0040] Description of reference numerals:

[0041] 1. Rotating shaft; 2. Radial sliding bearing; 3. First groove; 4. Stationary shaft; 5. Rotating bearing; 6. Second groove; 7. Bearing liquid inlet hole. DETAILED DESCRIPTION

[0042] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 understood as limiting the present invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0045] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0046] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0047] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0048] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0049] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0050] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0051] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0052] Example 1

[0053] like Figures 1 to 5 As shown, the present invention provides a lead-bismuth hydrodynamic lubrication bearing structure with low wall slip rate, comprising a rotating shaft 1 and a radial sliding bearing 2, wherein the rotating shaft 1 is arranged inside the radial sliding bearing 2; a plurality of first grooves 3 are provided on the side of the rotating shaft 1 in contact with the liquid lead-bismuth alloy, and the first grooves 3 are evenly distributed circumferentially on the journal of the rotating shaft 1; the radial sliding bearing 2 comprises a housing and a shoe.

[0054] As a preferred technical solution of the present invention, another form of the side groove structure is a stationary shaft 4 and a rotating bearing 5, wherein the inner surface of the rotating bearing is provided with multiple second grooves 6. With this technical solution, the structure can be applied to various shafting structures, expanding the scope of application.

[0055] As a preferred technical solution of the present invention, the radial sliding bearing 2 in the rotating shaft-tilting pad bearing configuration is not limited to cylindrical pad bearings; various radial sliding bearings, such as elliptical pads, partial pads, offset pads, and multi-oil vane bearings, can also be used. The rotating bearing 5 in the stationary shaft-rotating bearing configuration is limited to cylindrical pad bearings. This technical solution enables the present structure to be applied to a variety of hydrodynamic bearings using liquid lead-bismuth alloy as the lubricant.

[0056] As a preferred technical solution of the present invention, the bearing fluid inlet 7 in the rotating shaft-tilting pad bearing type can be arranged on the side of the bearing seat. This technical solution can ensure that the fluid supply to the stationary shaft-rotating bearing is not interrupted.

[0057] Example 2

[0058] The present invention provides a design method for a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate, comprising the following steps:

[0059] Step S1: Input basic conditions such as working parameters, physical parameters of lead-bismuth alloy, and shaft dimensions.

[0060] Step S2: Select the groove position according to the active component. The groove should be located on the active component. If the shaft is the active component, the groove is located on the side of the shaft; if the bearing is the active component, the groove is located on the bearing shell surface of the bearing.

[0061] Step S3, calculate the specific pressure p and linear velocity v according to the basic working conditions such as the shaft diameter, rotational speed, and load conditions. The calculation formulas for the specific pressure p and linear velocity v are: p = F / DB, v = ωD / 2, where F is the load, D is the shaft diameter, B is the bearing width, and ω is the shaft rotational speed.

[0062] Step S4: Preliminary selection of parameters within the numerical range of the groove parameters according to the specific pressure p and the linear velocity v.

[0063] Step S5: Design the bearing according to the input working conditions and the preliminarily selected groove parameters.

[0064] Step S6: Adjust the parameters of the groove, and then proceed with the bearing design described in step S5.

[0065] Step S7: Output appropriate groove parameters, including groove wrap angle φ, length ratio L / B, depth ratio A / C, and groove number N, as well as bearing parameters, including clearance ratio, preload, convergence ratio, installation angle, filling factor, etc.

[0066] As a preferred technical solution of the present invention, step S4 is specifically as follows:

[0067] Step S4: Preliminary groove parameters are selected based on the specific pressure p and linear velocity v calculated in step S3. The first groove 3 and the second groove 6 are V-shaped. The groove parameters include: groove wrap angle φ, which is the central angle of the groove relative to the journal center; depth ratio A / C, which is the ratio of depth A to clearance C; length ratio L / B, which is the ratio of groove length L to bearing width B; and groove number N, which is the total number of grooves along the circumference. The length ratio L / B should be in the range of 0.5-0.8, the groove depth ratio A / C should be in the range of 0.2-0.5, and the groove wrap angle φ should be in the range of 0.4-2°. The greater the specific pressure p, the greater the length ratio L / B, groove depth ratio A / C, and groove wrap angle φ. The higher the linear velocity v, the smaller the length ratio L / B and groove depth ratio A / C, and the greater the groove wrap angle φ. The number N of grooves should satisfy the following: N < 2π / φ.

[0068] As a preferred technical solution of the present invention, step S5 is specifically as follows:

[0069] Step S51: Select the bearing type and clearance ratio based on the linear velocity v. When the linear velocity is less than 20 m / s, cylindrical pad bearings are generally used. When the linear velocity is between 20 m / s and 60 m / s, multi-pad fixed bearings with preload are generally selected. When the linear velocity exceeds 60 m / s, tilting pad bearings are selected. Generally speaking, the bearing clearance ratio should be between 0.001 and 0.003. The higher the linear velocity v, the larger the clearance ratio should be.

[0070] Step S52: adjusting the bearing width B according to the specific pressure p so that the specific pressure p is controlled within a reasonable range.

[0071] Step S53: Check bearing characteristics such as temperature, flow rate, power consumption, stiffness, and damping. If these characteristics do not meet the shafting design requirements, repeated adjustments are required to key structural parameters such as clearance ratio, aspect ratio, preload, and convergence ratio. If these key structural parameters meet the design requirements, proceed to step S7; otherwise, proceed to step S6.

[0072] As a preferred technical solution of the present invention, step S6 is specifically as follows:

[0073] Step S61, calculate the minimum liquid film thickness h lim : Among them Rz B +R z1 It is the sum of the ten-point heights of the microscopic roughness of the journal and the bearing at the ideal position (X--X line). It is the axis coaxiality within the bearing width (Y---Y line), is the average deflection (ZZ line).

[0074] Step S62: Check the minimum liquid film thickness h lim Whether it meets: h min ≥[h min ]=S(R1+R2+y1+y2)(mm), where S m For margin, heavy-load bearings usually take S m = 2-3; R1 and R2 are the average heights of the journal and bearing surface roughness; y1 is the journal deflection in the bearing, and y2 is the journal offset. If these conditions are not met, appropriately increase the groove wrap angle φ, depth ratio A / C, length ratio L / B, or reduce the groove spacing.

[0075] Working Principle: Liquid lead-bismuth alloy is difficult to be driven by rotating parts with smooth surfaces, and the fluid has a low wall slip rate, thus preventing the formation of a dynamic pressure wedge angle. After improvements, when the rotating shaft 1 or the rotating bearing 5 rotates relative to another component, the groove drives the liquid lead-bismuth alloy to flow in the bearing gap. The bearing and the shaft produce an eccentricity under the action of gravity, allowing the liquid lead-bismuth alloy to enter the wedge angle formed between the bearing and the shaft, thereby generating a dynamic pressure effect. The pressure generated by the dynamic pressure effect stabilizes the gap between the shaft and the bearing, allowing the rotating shaft 1 or the rotating bearing 4 to rotate stably.

[0076] In summary, the lead-bismuth hydrodynamic lubrication bearing structure with low wall slip rate and the design method thereof of the present invention can improve the wall slip rate of the lead-bismuth hydrodynamic lubrication bearing gap, help the lead-bismuth hydrodynamic bearing with liquid lead-bismuth alloy as lubricant to effectively generate a hydrodynamic oil film, reduce the friction between the lead-bismuth bearing and the shaft, thereby avoiding excessive heating and violent vibration of the oil film, improving the bearing efficiency and extending its service life.

[0077] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0078] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A lead-bismuth dynamic pressure lubricated bearing structure with low wall slip rate, characterized in that: The invention comprises a rotating shaft (1) and a radial sliding bearing (2), wherein the rotating shaft (1) is arranged inside the radial sliding bearing (2); a side groove structure is provided on the side of the rotating shaft (1) in contact with the liquid lead-bismuth alloy, wherein the side groove structure comprises a plurality of first grooves (3), wherein the first grooves (3) are evenly distributed circumferentially on the journal of the rotating shaft (1).

2. A lead-bismuth dynamic pressure lubrication bearing structure with low wall slip velocity according to claim 1, characterized in that: The radial sliding bearing (2) comprises a housing and a shoe.

3. The lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate according to claim 1, characterized in that: The type of the radial sliding bearing (2) in the rotating shaft (1) and the radial sliding bearing (2) is a cylindrical bearing, or an elliptical bearing, a partial bearing, a dislocated bearing, or a radial sliding bearing with multiple oil leaves.

4. The lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate according to claim 1, characterized in that: The bearing liquid inlet holes (7) in the rotating shaft (1) and the radial sliding bearing (2) are arranged on the side surfaces of the bearing seat.

5. The lead-bismuth dynamic pressure lubrication bearing structure with low wall slip velocity according to claim 1, characterized in that: Another form of the side groove structure is a stationary shaft (4) and a rotating bearing (5), wherein the inner surface of the rotating bearing is provided with a plurality of second grooves (6).

6. A lead-bismuth dynamic pressure lubrication bearing structure with low wall slip velocity according to claim 5, characterized in that: Among the stationary shaft (4) and the rotating bearing (5), the rotating bearing (5) is a cylindrical bush bearing.

7. The design method of a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate according to claim 5, characterized in that: The following steps are involved: Step S1, inputting operating parameters, physical parameters of the lead-bismuth alloy, and shaft dimensions; Step S2: selecting the groove position according to the active component. The groove should be located on the active component. If the shaft is the active component, the groove is located on the side of the shaft; if the bearing is the active component, the groove is located on the bearing shell surface of the bearing; Step S3, calculating the specific pressure p and linear velocity v according to the basic working conditions of the shaft diameter, rotational speed, and load condition, the calculation formulas of the specific pressure p and linear velocity v are: p = F / DB, v = ωD / 2, where F is the load, D is the shaft diameter, B is the bearing width, and ω is the shaft rotational speed; Step S4, preliminarily selecting parameters within the numerical range of the groove parameters according to the specific pressure p and the linear velocity v; Step S5: Design the bearing according to the input working conditions and the preliminarily selected groove parameters; Step S6, adjusting the parameters of the groove, and then performing the bearing design described in step S5; Step S7: Output appropriate groove parameters, including groove wrap angle φ, length ratio L / B, depth ratio A / C, and groove number N, as well as bearing parameters, including clearance ratio, preload, convergence ratio, installation angle, and filling factor.

8. The design method of a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate according to claim 7, characterized in that: The step S4 is specifically as follows: Step S4, preliminarily selecting groove parameters according to the specific pressure p and linear velocity v calculated in step S3; the shape of the first groove (3) and the second groove (6) is V-shaped, and the parameters of the groove include: groove wrap angle φ, that is, the central angle of the groove relative to the center of the journal; depth ratio A / C, that is, the ratio of depth A to gap C; length ratio L / B, that is, the ratio of groove length L to bearing width B; groove number N, that is, the number of all grooves in the circumferential direction; the value range of length ratio L / B should be: 0.5-0.8, the value range of groove depth ratio A / C should be: 0.2-0.5, and the value range of groove wrap angle φ should be: 0.4-2°; the greater the specific pressure p, the greater the corresponding length ratio L / B, groove depth ratio A / C, and groove wrap angle φ should also be; the higher the linear velocity v, the smaller the corresponding length ratio L / B, groove depth ratio A / C should be, and the greater the groove wrap angle φ should also be; the groove number N should satisfy: N<2π / φ.

9. The design method of a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate according to claim 7, characterized in that: The step S5 is specifically as follows: Step S51: Select the bearing type and clearance ratio based on the linear velocity v. When the linear velocity is less than 20 m / s, cylindrical pad bearings are generally selected. When the linear velocity is between 20 m / s and 60 m / s, multi-pad fixed bearings with preload are generally selected. When the linear velocity exceeds 60 m / s, tilting pad bearings are selected. The bearing clearance ratio should be between 0.001 and 0.

003. The higher the linear velocity v, the larger the clearance ratio should be. Step S52: adjusting the bearing width B according to the specific pressure p so that the specific pressure p is controlled within a set range; Step S53: Check the bearing's temperature, flow rate, power consumption, stiffness, and damping characteristics. If the bearing's design requirements are not met, repeatedly adjust the key structural parameters of the clearance ratio, aspect ratio, preload, and convergence ratio. If the key structural parameters of the bearing meet the design requirements, proceed to step S7. Otherwise, proceed to step S6.

10. The design method of a lead-bismuth dynamic pressure lubrication bearing structure with low wall slip rate according to claim 7, characterized in that: The step S6 is specifically as follows: Step S61, calculate the minimum liquid film thickness h lim : Among them Rz B +R z1 It is the sum of the ten-point heights of the microscopic unevenness of the journal and the bearing at the ideal position, i.e., line X--X. The axis coaxiality within the bearing width is the Y---Y line. is the average deflection, i.e., ZZ line; Step S62: Check the minimum liquid film thickness h lim Whether it meets: h min ≥[h min ]=S(R1+R2+y1+y2), where S m For margin, heavy-load bearings usually take S m =2~3; R1 and R2 are the average heights of the unevenness of the journal and bearing surface; y1 is the deflection of the journal in the bearing, and y2 is the journal offset; if it is not satisfied, appropriately increase the groove angle φ, depth ratio A / C, length ratio L / B, or appropriately reduce the groove spacing.

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