A drum-shaped dual-tapered dynamic and static pressure radial sliding bearing

Abstract

A drum-shaped double-cone dynamic and static pressure radial sliding bearing comprises a bearing outer ring and a bearing inner ring, the bearing outer ring and the bearing inner ring being gap-fitted; the bearing inner ring is composed of a hollow cylinder and two hollow truncated cones, the lower bases of the two hollow truncated cones being connected to the two ends of the hollow cylinder respectively; the tapered surfaces of the two hollow truncated cones and the inner surface of the bearing outer ring form a divergent area gap, and the outer surface of the hollow cylinder and the inner surface of the bearing outer ring form a static pressure area gap; at the position corresponding to the static pressure bearing area on the outer surface of the bearing outer ring, an air inlet groove is provided, and a plurality of air inlet throttling devices are uniformly distributed in the air inlet groove in the circumferential direction. The bearing can form a stable lubricating film and can bear a certain bidirectional axial load by constructing a wedge-shaped gap to form a dynamic and static pressure effect, has strong static and dynamic pressure effects, and has good stability and dynamic performance.

Description

Technical Field

[0001] This invention belongs to the field of sliding bearing technology and relates to a drum-shaped double-cone surface hydrostatic radial sliding bearing. Background Technology

[0002] Sliding bearings, due to the fluid film gap formed during their operation, are suitable for high-speed conditions and possess characteristics such as extremely low friction coefficient and minimal interfacial wear, leading to their increasing use in various rotating machinery systems. The lubricating medium for fluid radial sliding bearings can be liquid or gas. Liquid lubrication, especially oil-lubricated sliding bearings, offers higher load-bearing capacity and better stability. Gas-lubricated radial sliding bearings offer advantages such as high rotor precision, low friction loss, low environmental requirements, and cleanliness, and are also used in various high-precision machine tools, high-speed aerodynamic devices, precision equipment, and instrument systems. However, traditional radial sliding bearings generally struggle to withstand axial loads and exhibit poor high-speed stability. Furthermore, as the operating conditions of bearings become increasingly complex, the need for new structures to address these issues is becoming increasingly urgent.

[0003] Regarding the proposal of new structures for sliding bearings, various documents and patents have discussed strategies for updating bearing structures. For example, a new bearing structure combining rolling and sliding has been proposed. Zhang Guoyuan et al. disclosed an adjustable positioning rolling-sliding radial composite bearing (application number: CN 112128237 A). Its structure mainly consists of elastic cylindrical rollers, fixed bearing shells, and tilting bearing shells installed on a cylindrical bearing housing. The fixed bearing shells are fixed to the bearing housing, and a bearing shell fulcrum adjuster is fixed at the pin hole on the outer surface of the bearing housing to finely adjust the clearance between the rotor and the tilting bearing shell, ensuring a good oil film thickness. The strict separation of the three components avoids excessive wear and jamming of the bearing caused by roller slippage and compression under impact loads, effectively extending the bearing's life. For example, Zhang Guoyuan et al. disclosed a combined radial-sliding thrust bearing (application number: CN 112128236 A). This invention combines a radial bearing with a thrust bearing. The radial bearing structure is the same as the aforementioned patent. The main structure of the thrust bearing is that the mirror plate is fixed on the rotor end face, the double-truncated cone thrust bearing seat is installed at the lower end of the radial bearing seat, and the tilting pad is installed on the second truncated cone. Its structure is a columnar structure with an inclination angle, which can form a wedge-shaped oil film with the mirror plate to improve the bearing performance. Compared with the prior art, this invention effectively improves the bearing life.

[0004] On the other hand, for the development of new structures for sliding bearings, a solution is to change the surface characteristics of the bearing or the mating rotor, i.e., surface modification. One approach is to create grooves or microtextures in the inner diameter of the bearing, and the other is to modify the surface of the mating rotor (grooving or microtexturing). However, for sliding bearings used with smaller diameter rotors, such as air radial sliding bearings, the first approach is difficult to implement in terms of grooving or texturing in the inner diameter, and the bearing clearance needs to be designed more precisely during high-speed operation; otherwise, bearing instability is very likely to occur under high-speed conditions. The second approach is not easy to implement in practical engineering because, in reality, the design of rotors and bearings belongs to different departments, and the bearing, as a basic component, cannot impose requirements on the design of the rotor. In addition, the modification of the rotor surface may affect the overall strength of the rotor, which may even affect the safety and stability of rotor operation.

[0005] For the first approach, many researchers have proposed new bearing structures. For example, patent application CN113431844A, entitled "A High-Speed ​​Spiral Groove Small Orifice Throttling Hydrostatic Gas Bearing Device," discloses a hydrostatic gas bearing with an external air supply hole and small orifice throttle, and an internal spiral groove and axial micro-groove. This invention's hydrostatic gas bearing can achieve the goal of avoiding dry friction and improving stability during rotor start-up and shutdown. When the rotor is running at high speed, the continuous high-pressure external air supply can be stopped, and the rotation of the journal can force the gas into the spiral groove, thereby improving the overall performance of the bearing. However, the spiral groove is located on the inner side of the bearing, and the axial micro-groove is located in the middle of the inner side, making processing relatively difficult. Another example is patent CN 110242671A, entitled "A Conical Foil Hydrostatic Air Bearing," which discloses a conical bearing with radial foils. Its structure transforms a hollow cylinder into a hollow cone and installs radial foils on the outer side. This invention can withstand both radial and axial forces simultaneously and has a large load-bearing capacity. However, it does not specify the fit between the bearing and the rotor. When the rotor starts and stops, it cannot form an effective oil film thickness, resulting in excessive frictional resistance and affecting the stability of the rotor.

[0006] In recent years, researchers have proposed surface modification methods to improve the performance of sliding bearings and have made some theoretical progress. For example, regarding the influence of surface microtextures on bearing performance, Ding Hao et al. established bearing models considering different microtexture shapes and used fluid dynamics methods to calculate their load-bearing capacity, thus understanding the influence of microtexture shape and depth on the load-bearing capacity of gas dynamic bearings. The results show that surface microtextures have a certain influence on the load-bearing performance of gas dynamic bearings [Ding Hao, Gao Qiang, Feng Wei, Liu Baoguo, Li Xingyu. Influence of Surface Microtextures on Load-Bearing Performance of Gas Dynamic Bearings [J]. Bearings, 2022, 10: 105-110.]. This type of method to improve bearing performance through surface modification is increasingly attracting the attention of researchers and is also an important direction for the development of bearing technology.

[0007] In summary, based on the new structural requirements of sliding bearings and the progress of theoretical research, it is necessary to develop solutions that are easier to manufacture and improve their overall performance. Summary of the Invention

[0008] In order to overcome the shortcomings of the prior art, the present invention aims to provide a drum-shaped double-cone surface hydrostatic radial sliding bearing. By constructing a wedge-shaped gap to form a hydrostatic effect, the bearing can form a stable lubricating film and can withstand a certain bidirectional axial load. It has strong hydrostatic and hydrostatic effects and good stability and dynamic performance.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A drum-shaped double-cone dynamic-static radial sliding bearing includes an outer ring and an inner ring, wherein the outer ring and the inner ring are clearance-fitted.

[0011] The inner ring of the bearing is composed of a hollow cylinder and two hollow truncated cones. The lower bottom surfaces of the two hollow truncated cones are respectively connected to the two ends of the hollow cylinder. A diverging region gap is formed between the conical inclined surfaces of the two hollow truncated cones and the inner surface of the outer ring of the bearing, and a hydrostatic region gap is formed between the outer surface of the hollow cylinder and the inner surface of the outer ring of the bearing.

[0012] An air inlet groove is provided on the outer surface of the bearing outer ring at a position corresponding to the hydrostatic bearing area, and multiple air inlet throttling devices are evenly distributed circumferentially in the air inlet groove.

[0013] In one embodiment, the minimum clearance between the outer ring and the inner ring of the bearing is 0.1-50 μm.

[0014] In one embodiment, the outer ring of the bearing is a hollow cylinder, and the air inlet groove is formed circumferentially on the outer surface of the hollow cylinder; the center lines of the hollow cylinder and the two hollow truncated cones coincide, and the lower bottom surfaces of the two hollow truncated cones are equal to and fit against the two bottom surfaces of the hollow cylinder.

[0015] In one embodiment, the intake throttling device is a circular through hole with its axis orthogonal to the axis of the bearing outer ring. Its diameter ranges from 0.5 to 5 mm, and its length is 0.4 to 0.9 times the thickness of the bearing outer ring. The length-to-diameter ratio is between 1 and 20, which satisfies the short-nails throttling condition.

[0016] In one embodiment, a rectangular pressure chamber is provided at the end of the intake throttling device. The depth of the rectangular pressure chamber is 0.5 to 5 mm; the axial length is 1 / 9 to 2 / 9 of the bearing width; and the ratio of the circumferential length to the axial length is 0.8 to 1.2.

[0017] In one embodiment, the hollow truncated cone has multiple sets of modified groove structures or microtextures evenly distributed along the circumference of its conical inclined surface, and the two hollow truncated cones have the same number of modified groove structures or microtextures and are symmetrically distributed.

[0018] In one embodiment, the groove type of the modified groove structure is a spiral groove, a rectangular groove, or a triangular groove, with a groove depth of 0.1–10 μm, to facilitate the formation of a dynamic pressure effect; the microtexture is a combination of multiple rows of circular micropits, triangular micropits, square micropits, or rectangular micropits, with the total area of ​​the microtexture accounting for 1 / 3 to 2 / 3 of the area of ​​the conical inclined surface, and a pit depth of 0.1–3 mm, to facilitate the formation of a local static pressure effect in the microtexture portion.

[0019] In one embodiment, when the groove type of the modified groove structure is a helical groove, there are multiple sets of helical grooves; the helical grooves on the two hollow truncated cones rotate in opposite directions; when the inner ring of the bearing rotates counterclockwise, the rotation direction of the helical grooves on the two hollow truncated cones is consistent with the fluid flow trend, promoting fluid circulation and maintaining lubrication effect; when the inner ring of the bearing rotates clockwise, the rotation direction of the helical grooves on the two hollow truncated cones is opposite to the fluid flow trend, reducing bearing flow rate and improving bearing hydrostatic effect.

[0020] In one embodiment, the axial lengths of the divergence region gap and the static pressure region gap are equal, and the taper of the hollow truncated cone ranges from 0.5 to 10°. It is designed according to the external axial force it bears or to increase the bearing flow rate to achieve bearing cooling. When the taper increases, the axial limit load that the bearing can bear increases, and at the same time, the increase in the bearing divergence region gap leads to an increase in the bearing flow rate, thereby improving the bearing heat dissipation capacity. When the taper decreases, the radial limit load that the bearing can bear increases, and at the same time, the decrease in the bearing divergence region gap leads to a decrease in the bearing flow rate, thereby reducing the bearing heat dissipation capacity.

[0021] In one embodiment, the inner bore of the bearing inner ring is either interference-fitted or transition-fitted with the shaft.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. The innovative split-type fluid-lubricated sliding bearing structure adopted in this invention can be designed with reasonable throttling devices and groove parameters according to working conditions to increase load-bearing capacity and film stiffness. Specifically, at higher speeds, the helical grooves or micro-textures symmetrically distributed on the two conical inclined surfaces of the bearing inner ring enhance the hydrodynamic effect to improve load-bearing capacity and film stiffness; at lower speeds, the hydrostatic effect of the fluid is enhanced through short capillary micro-flow and higher external air supply pressure to improve load-bearing performance, etc.

[0024] 2. The present invention has a micron-level gap between the inner and outer rings and a millimeter-level pressure chamber, which can obtain a more stable air film and improve the bearing's load-bearing capacity.

[0025] 3. The truncated conical structure used in the inner ring of this invention has a large gap at both ends during operation, which can effectively press the medium into the bearing and can also withstand the impact of axial and radial forces at the same time, thus improving the service life of the bearing. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 This is the front view of the bearing outer ring.

[0028] Figure 3 This is a radial cross-sectional view of the outer ring of the bearing.

[0029] Figure 4 This is a schematic diagram of the inner ring of the bearing's spiral groove.

[0030] Figure 5 This is a schematic diagram of the inner ring of the bearing's triangular microtextured structure. Detailed Implementation

[0031] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0032] This invention creates a hydrostatic radial sliding bearing with a wedge-shaped gap to achieve a hydrostatic effect. Specifically, it is a separable hydrostatic radial sliding bearing with an inner ring having a drum-shaped double conical surface and an outer ring having a throttling device, thereby improving the bearing's static load-bearing characteristics and enhancing its dynamic operating characteristics.

[0033] Specifically, such as Figures 1 to 5As shown, the present invention provides a drum-shaped double-cone surface hydrostatic radial sliding bearing, comprising an outer ring 1 and an inner ring 2. The outer ring 1 and the inner ring 2 are in a clearance fit relationship. The inner ring 2 is coaxially arranged in the outer ring 1. The inner hole of the inner ring 2 is either interference fit or transition fit with the shaft.

[0034] Among them, the outer surface of the outer ring 1 of the bearing is provided with a circumferential air inlet groove 1-1, and multiple air inlet throttling devices 1-2 are evenly distributed in the circumferential direction in the air inlet groove 1-1.

[0035] The bearing inner ring 2 is composed of a hollow cylinder 2-1 and two symmetrical hollow truncated cones 2-2. The hollow truncated cone 2-2 is a frustum-shaped structure obtained by truncating a hollow cone. Here, "hollow" means it has a through hole along its central axis; the central axis of the through hole is consistent with the central axis of the cone or frustum. Similarly, the hollow cylinder 2-1 is a cylinder with an axial through hole; the central axis of the through hole is consistent with the central axis of the cylinder. The lower bases of the two hollow truncated cones 2-2 are connected to the two ends of the hollow cylinder 2-1. Clearly, the hollow portion of the hollow cylinder 2-1 (i.e., the "through hole") and the hollow portions of the two hollow truncated cones 2-2 (i.e., the "through holes") are of equal diameter and coaxial; that is, the centerlines of the hollow cylinder 2-1 and the two hollow truncated cones 2-2 coincide. For example, the lower base surfaces of the two hollow truncated cones 2-2 are equal to and fit against the two base surfaces of the hollow cylinder 2-1. In this invention, the "lower base surface" refers to the larger base surface in the frustum-shaped cross-section structure. Correspondingly, the "upper base surface" refers to the smaller base surface in the frustum-shaped cross-section structure. The two ends of the inner ring 2 of the bearing are the "upper base surfaces" of the two hollow truncated cones 2-2.

[0036] When the inner ring 2 of the bearing is placed inside the outer ring 1, a diverging region gap is formed between the conical surfaces of the two hollow truncated cones 2-2 and the inner surface of the outer ring 1, while a static pressure region gap is formed between the outer surface of the hollow cylinder 2-1 and the inner surface of the outer ring 1. The inlet groove 1-1 corresponds to the position of the static pressure bearing region. The diverging region gap promotes the formation of dynamic pressure during the rotation of the inner ring, while the static pressure region gap creates a static pressure effect under the influence of the inlet throttling device. Therefore, during operation, the larger gaps at both ends and the smaller gap in the middle effectively force the medium into the bearing, and it can simultaneously withstand the impact of axial and radial forces, thus improving the bearing's service life.

[0037] The axial lengths of the three gaps are all the same. The taper of the truncated cone is designed according to the actual working conditions to obtain different divergence zone gaps, thereby improving the mechanical and heat dissipation performance of the bearing.

[0038] In some embodiments of the present invention, the minimum gap between the outer ring 1 and the inner ring 2 of the bearing is 0.1-50 μm, which is a micrometer-level gap.

[0039] In some embodiments of the present invention, the outer ring 1 of the bearing is a hollow cylinder, which is defined similarly to the aforementioned hollow cylinder 2-1, i.e., a cylinder with an axially penetrating hole. The inner ring 2 of the bearing is coaxially located in this axially penetrating hole. There is one intake groove 1-1, or multiple symmetrically arranged, circumferentially formed on the outer surface of the hollow cylinder. The intake throttling devices 1-2 are arranged in a single row, i.e., all intake throttling devices 1-2 are located on the same circumference and are preferably evenly distributed. The number of intake throttling devices 1-2 is generally 4-16, and the number is designed according to the bearing operating conditions and structural parameters.

[0040] In some embodiments of the present invention, the intake throttling device 1-2 is a circular through hole with its axis orthogonal to the axis of the bearing outer ring 1. Its diameter ranges from 0.5 to 3 mm, its length is 0.4 to 0.9 times the thickness of the bearing outer ring 1, and the length-to-diameter ratio ranges from 1 to 20, satisfying the short-nails throttling condition.

[0041] In some embodiments of the present invention, a rectangular pressure chamber 1-3 is further provided at the end of the intake throttling device 1-2. Both ends of the intake throttling device 1-2 are connected to the intake groove 1-1 and the rectangular pressure chamber 1-3, respectively, and the axis of the intake throttling device 1-2 coincides with the geometric center line of the rectangular pressure chamber 1-3. The rectangular pressure chamber 1-3 refers to a chamber whose cross-section along the vertical axis is rectangular or approximately rectangular, with a cavity depth (i.e., radial length) in the mm range, ranging from 0.5 to 5 mm; an axial length of 1 / 9 to 2 / 9 of the bearing width; and a ratio of circumferential length to axial length of 0.8 to 1.2. The micron-level gap between the inner and outer rings and the millimeter-level cavity depth of the pressure chamber can obtain a more stable air film and improve the bearing's load-bearing capacity. Specifically, the depth parameters can be rationally designed based on the bearing's hydrostatic load-bearing characteristics.

[0042] In some embodiments of the present invention, multiple sets of modified groove structures 2-2-1 or other microtextures are evenly distributed along the circumferential direction on the conical inclined surface of the hollow truncated cone 2-2, and the number of modified groove structures 2-2-1 or microtextures on the two hollow truncated cones 2-2 is the same and they are symmetrically distributed.

[0043] In some embodiments of the present invention, the groove type of the modified groove structure 2-2-1 is a spiral groove, a rectangular groove, or a triangular groove, with 4 to 16 grooves, at the micrometer level, ranging from 0.1 to 10 μm, to facilitate the formation of a dynamic pressure effect; the microtexture is a combination of multiple rows of circular micropits, triangular micropits, square micropits, or rectangular micropits, etc., with the total area of ​​the microtexture accounting for 1 / 3 to 2 / 3 of the area of ​​the conical inclined surface, and the pit depth being 0.1 to 3 mm, to facilitate the formation of a local static pressure effect in the microtexture portion.

[0044] In some embodiments of the present invention, when the groove type of the modified groove structure 2-2-1 is a spiral groove, there are multiple sets of spiral grooves, which can be in the form of various types of line logarithmic, involute, unfolded, etc.; the spiral grooves on the two hollow truncated cones 2-2 rotate in opposite directions, that is, the spiral grooves on the two hollow truncated cones 2-2 are symmetrical about the bearing width center plane. In the embodiment, the spiral groove on the left side of the cone is left-handed, and the spiral groove on the right side is right-handed. When the bearing inner ring 2 rotates counterclockwise, the rotation direction of the spiral grooves on the two hollow truncated cones 2-2 is consistent with the fluid flow trend, promoting fluid circulation and maintaining the lubrication effect; when the bearing inner ring 2 rotates clockwise, the rotation direction of the spiral grooves on the two hollow truncated cones 2-2 is opposite to the fluid flow trend, reducing the bearing flow rate and improving the bearing static pressure effect.

[0045] In some embodiments of the present invention, the axial lengths of the divergence region gap and the hydrostatic region gap are equal, and the taper of the hollow truncated cone 2-2 ranges from approximately 0.5 to 10°, designed according to the external axial force it bears or to increase bearing flow rate to achieve bearing cooling. Specifically: when the taper increases, the axial ultimate load that the bearing can withstand increases, and at the same time, the increased bearing divergence region gap leads to an increased bearing flow rate, thereby improving the bearing's heat dissipation capacity; when the taper decreases, the radial ultimate load that the bearing can withstand increases, and at the same time, the decreased bearing divergence region gap leads to a decreased bearing flow rate, thereby reducing the bearing's heat dissipation capacity.

[0046] The following are two specific embodiments of the present invention.

[0047] Example 1:

[0048] A drum-shaped double-tapered hydrostatic radial bearing is proposed for high-speed, heavy-load applications. A further detailed description is provided below with reference to the accompanying drawings:

[0049] Reference Figure 1 The present invention includes an outer ring 1 and an inner ring 2 of a bearing, wherein:

[0050] The outer ring 1 of the bearing has the following structure: Figure 2 and Figure 3 It is equipped with an air intake slot 1-1, an air intake throttling device 1-2 and a rectangular pressure chamber 1-3.

[0051] The bearing outer ring 1 is a hollow cylinder. An air inlet groove 1-1 is formed circumferentially on the outer surface of the hollow cylinder. Multiple single-row air inlet throttling devices 1-2 are evenly distributed in the groove, and some of the air inlet throttling devices 1-2 have rectangular pressure chambers 1-3 at their ends. In this embodiment, the outer diameter of the outer ring is 60 mm, the inner diameter is 50 mm, the thickness is 5 mm, the width is 9 mm, and the depth of the air inlet groove is 1 mm.

[0052] The single-row intake throttling device 1-2 is located in the intake slot 1-1, such as Figure 2 As shown, they are evenly distributed circumferentially, with all the centers located on the center line of the air intake slot; there are 8 in number, with a length of 3mm and a diameter of 0.5mm, and the length-to-diameter ratio is 6, which meets the parameter range of the short-hair fine flow structure device.

[0053] Rectangular pressure chambers 1-3, such as Figure 3 As shown, its upper end is connected to the intake throttling device 1-2, which can further enhance the static pressure effect at the tail of the throttling device. The axis of the intake throttling device coincides with the geometric center line of the pressure chamber, and the axis of the intake throttling device is orthogonal to the axis of the hollow cylinder. The end connects the gap between the outer ring and the inner ring, providing sufficient liquid for the bearing and meeting the bearing lubrication requirements. In combination with the static pressure bearing characteristics, the depth of the pressure chamber is designed to be 1mm. The deep cavity cross section is a rectangular cross section structure, with a circumferential length of 2.4mm and an axial length of 2mm, and the ratio of the two is 1.2.

[0054] The inner ring 2 of the bearing has the following structure: Figure 4 It includes a hollow cylinder 2-1 and a hollow truncated cone 2-2, with a modified groove structure 2-2-1 provided on the hollow truncated cone 2-2.

[0055] Specifically, the bearing inner ring 2 consists of a hollow cylinder 2-1 and a pair of symmetrical hollow truncated cones 2-2. The center lines of these three components coincide. The lower surfaces of the two hollow truncated cones 2-2 overlap with the two lower surfaces of the hollow cylinder 2-1. The two ends of the inner ring are the upper surfaces of the two hollow truncated cones 2-2. The two conical inclined surfaces form a diverging gap region. The hollow cylinder 2-1 is located between the small ends of the two cones, forming a hydrostatic bearing region. The inner diameter of the inner ring is interference-fitted with the shaft, allowing the inner ring to rotate with the rotor. The outer diameter of the inner ring is 50 mm, and the inner diameter is 40 mm.

[0056] The inner ring 2 and outer ring 1 of the bearing are clearance fits. Three clearances are formed between the outer and inner rings: a diverging region clearance formed by the left and right tapered outer sides of the inner ring and the inner diameter of the outer ring; and a static pressure region clearance formed by the middle section between the outer diameter of the inner ring and the inner diameter of the outer ring. The diverging region clearance promotes the formation of dynamic pressure during the rotation of the inner ring, while the static pressure region clearance creates a static pressure effect when passing through the intake throttling device. All three clearances have the same axial length of 3 mm, and the static pressure region clearance is 5 μm.

[0057] The taper of the cone is 3°. The taper directly affects the size of the divergent clearance area formed by the outer left and right conical outer sides of the inner ring and the divergent area formed by the inner diameter of the outer ring. In this embodiment, the bearing is in a high-speed, heavy-load environment. To prevent bearing structural deformation and potential temperature rise exceeding the limit due to excessive bearing temperature, the design of the truncated cone taper must ensure that the bearing has good heat dissipation performance. Therefore, the presence of the taper can increase the bearing flow rate and thus reduce the bearing temperature rise. At the same time, changing the taper of the cone will result in different bearing load-bearing performance. That is, increasing the taper increases the axial load that the drum-shaped double-cone hydrostatic radial bearing can bear; decreasing the taper decreases the axial load of the drum-shaped double-cone hydrostatic radial bearing. Therefore, considering all factors, the taper of the truncated cone is set to 3°.

[0058] The truncated cone has multiple sets of modified groove structures 2-2-1 evenly distributed circumferentially on its outer surface. The modified grooves are multiple sets of spiral grooves, with the grooves on the left and right sides of the cone rotating in opposite directions (i.e., the spiral grooves on the two hollow truncated cones 2-2 are symmetrical about the center plane of the bearing width). The spiral groove on the left side of the cone is left-handed, and the spiral groove on the right side is right-handed. When the inner ring 2 of the bearing rotates counterclockwise, the rotation direction of the spiral grooves on the left and right sides of the cone is consistent with the fluid flow trend, promoting fluid circulation and maintaining the lubrication effect. When the inner ring 2 of the bearing rotates clockwise, the rotation direction of the spiral grooves on the left and right sides of the cone is opposite to the fluid flow trend, reducing the bearing flow rate and improving the bearing static pressure effect. In this embodiment, there are 16 modified grooves on the side of the cone, with a groove depth of 1μm and a spiral angle of 45°. The width of the spiral groove is 2mm.

[0059] Example 2:

[0060] The invention will now be described in further detail with reference to the accompanying drawings, taking a sliding bearing for the main shaft of a wind turbine generator as an example:

[0061] Reference Figure 1 The present invention includes an outer ring 1 and an inner ring 2 of a bearing, wherein:

[0062] The outer ring 1 of the bearing has the following structure: Figure 2 and Figure 3 It is equipped with an air intake slot 1-1, an air intake throttling device 1-2 and a rectangular pressure chamber 1-3.

[0063] The bearing outer ring 1 has the same structure as in embodiment 1, except for the structural parameters. In this embodiment, the outer diameter is 800mm, the inner diameter is 700mm, the thickness is 50mm, the width is 90mm, and the inlet groove depth is 10mm. The externally supplied medium must be high-pressure lubricating oil to ensure a good lubrication film on the bearing.

[0064] The single-row intake throttling device 1-2 is located in the intake slot 1-1, such as Figure 2As shown, they are evenly distributed circumferentially, with all centers located on the centerline of the air intake slot; there are 12 in total, with a 30° interval between adjacent throttling devices. The length is 30mm and the diameter is 3mm, with a length-to-diameter ratio of 10, which meets the parameter range of the short-hair fine-flow structure device.

[0065] Rectangular pressure chambers 1-3, such as Figure 3 As shown, its upper end is connected to the intake throttling device 1-2, which can further enhance the static pressure effect at the tail of the throttling device. The axis of the intake throttling device coincides with the geometric center line of the pressure chamber. The axis of the intake throttling device is orthogonal to the axis of the hollow cylinder. The end connects the gap between the outer ring and the inner ring, providing sufficient liquid for the bearing and meeting the bearing lubrication requirements. In combination with the bearing's static pressure bearing characteristics, the depth of the pressure chamber is designed to be 10mm. The deep cavity cross section is a rectangular cross section structure, with a circumferential length of 12mm and an axial length of 10mm, and the ratio of the two is 1.2.

[0066] The inner ring 2 of the bearing has the following structure: Figure 4 It includes a hollow cylinder 2-1 and a hollow truncated cone 2-2. On the hollow truncated cone 2-2, the modified groove structure 2-2-1 is replaced by a microtexture.

[0067] Specifically, the bearing inner ring 2 consists of a hollow cylinder 2-1 and a pair of symmetrical hollow truncated cones 2-2. The center lines of these three components coincide. The lower surfaces of the two hollow truncated cones 2-2 overlap with the two lower surfaces of the hollow cylinder 2-1. The two ends of the inner ring are the upper surfaces of the two hollow truncated cones 2-2. The two conical inclined surfaces form a diverging gap region. The hollow cylinder 2-1 is located between the small ends of the two cones, forming a hydrostatic bearing region. The inner diameter of the inner ring transitions with the spindle, allowing the inner ring to rotate with the spindle. The outer diameter of the inner ring is 700 mm, and the inner diameter is 650 mm.

[0068] The inner ring 2 and outer ring 1 of the bearing have a clearance fit, forming three gaps between the outer and inner rings. All three gaps have the same axial length of 30 mm, with a 20 μm gap in the hydrostatic region. In this embodiment, the bearing bears a very large load, therefore a sufficient oil film thickness is required to ensure the normal operation of the bearing.

[0069] The cone's taper is 0.5°. Since the wind turbine main shaft bearing bears the weight of the blades and hub, as well as the force exerted on the main shaft by the wind through the rotor, it primarily bears radial force. Changing the cone's taper will result in different bearing load-bearing capacities. Increasing the taper increases the axial load that the drum-shaped double-cone dynamic-static radial bearing can bear; decreasing the taper increases the maximum radial load but decreases the axial load. To improve the bearing's load-bearing capacity, the truncated cone's taper is designed to be 0.5° based on the ratio of the radial limit load to the axial limit load.

[0070] The truncated cone has multiple sets of microtextures 2-2-1 evenly distributed along the circumference on its outer surface. The microtexture consists of double rows of triangular micro-pits, with 16 sets distributed on each side. The left and right sides of the cone are symmetrical. The triangles are equilateral triangles with a side length of 10 mm, occupying 2 / 3 of the total side area, and the groove depth is 2 mm. The use of triangular microtextures improves the bearing capacity and can also create a local static pressure effect on the side of the truncated cone.

Claims

1. A drum-shaped dual-tapered hydrostatic radial slide bearing, characterized in that It includes an outer ring (1) and an inner ring (2) of the bearing, wherein the outer ring (1) and the inner ring (2) of the bearing are clearance-fitted, and the clearance at the minimum clearance is 0.1~50μm; The bearing inner ring (2) is composed of a hollow cylinder (2-1) and two hollow truncated cones (2-2). The bottom surfaces of the two hollow truncated cones (2-2) are respectively connected to the two ends of the hollow cylinder (2-1). A diverging region gap is formed between the conical inclined surfaces of the two hollow truncated cones (2-2) and the inner surface of the bearing outer ring (1). A hydrostatic region gap is formed between the outer surface of the hollow cylinder (2-1) and the inner surface of the bearing outer ring (1). An air inlet groove (1-1) is provided on the outer surface of the outer ring (1) of the bearing, corresponding to the position of the hydrostatic bearing area. Multiple air inlet throttling devices (1-2) are evenly distributed in the circumferential direction in the air inlet groove (1-1). The outer ring (1) of the bearing is a hollow cylinder, and the air inlet groove (1-1) is opened circumferentially on the outer surface of the hollow cylinder; the center lines of the hollow cylinder (2-1) and the two hollow truncated cones (2-2) coincide, and the bottom surfaces of the two hollow truncated cones (2-2) are equal to and fit against the two bottom surfaces of the hollow cylinder (2-1).

2. The toroidal double-cone hydrostatic radial bearing according to claim 1, characterized in that The intake throttling device (1-2) is a circular through hole with its axis orthogonal to the axis of the bearing outer ring (1). Its diameter ranges from 0.5 to 5 mm, and its length is 0.4 to 0.9 times the thickness of the bearing outer ring (1). The length-to-diameter ratio is between 1 and 20, which satisfies the short-hair flow condition.

3. The toroidal double-cone hydrostatic radial bearing of claim 1, wherein, The intake throttling device (1-2) is provided with a rectangular pressure chamber (1-3) at its end. The depth of the rectangular pressure chamber (1-3) is 0.5~5mm; the axial length is 1 / 9~2 / 9 of the bearing width; and the ratio of the circumferential length to the axial length is 0.8~1.

2.

4. The toroidal double-cone hydrostatic radial bearing of claim 1, wherein, The hollow truncated cone (2-2) has multiple sets of modified groove structures (2-2-1) or microtextures evenly distributed along the circumference of the conical inclined surface. The number of modified groove structures (2-2-1) or microtextures on the two hollow truncated cones (2-2) is the same and they are symmetrically distributed.

5. The toroidal double-cone hydrostatic radial bearing of claim 4, wherein, The modified groove structure (2-2-1) has a spiral groove, a rectangular groove, or a triangular groove with a groove depth of 0.1~10μm to facilitate the formation of dynamic pressure effect; the microtexture consists of multiple rows of circular micropits, triangular micropits, square micropits, or rectangular micropits, with the total area of ​​the microtexture accounting for 1 / 3~2 / 3 of the area of ​​the conical inclined surface and a pit depth of 0.1~3mm to facilitate the formation of local static pressure effect in the microtexture part.

6. The toroidal double-cone hydrostatic radial bearing of claim 5, wherein, When the groove type of the modified groove structure (2-2-1) is a spiral groove, there are multiple sets of spiral grooves; the spiral grooves on the two hollow truncated cones (2-2) rotate in opposite directions; when the inner ring (2) of the bearing rotates counterclockwise, the spiral grooves on the two hollow truncated cones (2-2) rotate in the same direction as the fluid flow trend, promoting fluid circulation and maintaining lubrication effect; when the inner ring (2) of the bearing rotates clockwise, the spiral grooves on the two hollow truncated cones (2-2) rotate in the opposite direction to the fluid flow trend, reducing bearing flow rate and improving bearing static pressure effect.

7. The toroidal double-cone hydrostatic radial bearing of claim 1, wherein, The axial lengths of the divergence region gap and the static pressure region gap are equal. The taper of the hollow truncated cone (2-2) ranges from 0.5 to 10°. It is designed according to the external axial force it bears or to increase the bearing flow rate to achieve bearing cooling. When the taper increases, the axial limit load that the bearing can bear increases. At the same time, the increase in the bearing divergence region gap leads to an increase in the bearing flow rate, thereby improving the bearing heat dissipation capacity. When the taper decreases, the radial limit load that the bearing can bear increases. At the same time, the decrease in the bearing divergence region gap leads to a decrease in the bearing flow rate, thereby reducing the bearing heat dissipation capacity.

8. The drum-shaped double-cone surface hydrostatic radial sliding bearing according to claim 1, characterized in that, The inner hole of the bearing inner ring (2) is either interference-fitted or transition-fitted with the shaft.

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