An underwater rotating tower bearing of a floating offshore wind turbine and a method of assembling the same

Abstract

The application discloses a kind of offshore floating type fan underwater rotating tower bearing and its assembling method, including upper inner ring, middle inner ring, middle outer ring, lower inner ring and lower outer ring;The upper inner ring and lower inner ring are respectively arranged at the top and bottom of the middle inner ring, and are fixedly connected with each other;The middle outer ring is rotatably sleeved on the outside of the middle inner ring by a first rolling component, and is rotatably connected with the upper inner ring by a second rolling component, and the second rolling component is located above and outside the first rolling component;The lower outer ring is sleeved on the outside of the lower inner ring, and is located at the bottom of the middle outer ring.The application can effectively reduce the space occupied by the rotating tower bearing, improve the sealing reliability, and ensure the long-term stable operation of the deep-sea floating type fan.

Description

Technical Field

[0001] This invention relates to the technical field of turret bearings for offshore floating wind turbines, and in particular to an underwater turret bearing for an offshore floating wind turbine and its assembly method. Background Technology

[0002] Floating offshore wind turbines are a core technology for overcoming bottlenecks in deep-sea wind power development. Semi-submersible platforms are the most widely used commercially, adaptable to water depths of 60–1000 meters, and capable of efficiently developing high-quality wind resources in deep seas. Compared to stationary turbines, they offer significant advantages in resource utilization, environmental protection, and overall life-cycle economics. Single-point mooring turret bearings, as key components for passive yaw and submarine cable connections in floating wind turbines, are submerged in seawater environments below 20 meters for extended periods. They must withstand complex wind and wave loads and rotate from 0 to 360° at speeds below 0.01 rpm, requiring extremely high structural compactness and sealing reliability. Currently, most turret bearings in the industry use three-row cylindrical roller bearings, which have significant drawbacks: firstly, they occupy a large overall space, hindering compact platform layout; secondly, under complex marine loads, the sealing structure deforms significantly, leading to a high risk of seal failure and susceptibility to seawater erosion and impurity intrusion, making it difficult to guarantee stable operation throughout the turbine's life cycle and restricting the long-term reliable application of deep-sea floating wind power equipment. Summary of the Invention

[0003] The primary objective of this invention is to overcome the shortcomings of the prior art and provide an underwater turret bearing for offshore floating wind turbines, which can effectively reduce the space occupied by the turret bearing, improve sealing reliability, and ensure the long-term stable operation of deep-sea floating wind turbines.

[0004] The second objective of this invention is to provide a method for assembling underwater turret bearings for offshore floating wind turbines.

[0005] The third objective of this invention is to provide a method for determining the rated life of underwater turret bearings for offshore floating wind turbines.

[0006] The first objective of this invention is achieved through the following technical solution:

[0007] A floating turret bearing for an offshore wind turbine includes an upper inner ring, a middle inner ring, a middle outer ring, a lower inner ring, and a lower outer ring. The upper and lower inner rings are respectively disposed at the top and bottom of the middle inner ring and are fixedly connected to each other. The middle outer ring is rotatably fitted onto the outside of the middle inner ring via a first rolling assembly and is rotatably connected to the upper inner ring via a second rolling assembly, wherein the second rolling assembly is located above and outside the first rolling assembly. The first rolling assembly includes a tapered roller cage, a row of tapered rollers mounted on the tapered roller cage, and a first spacer block disposed between adjacent tapered rollers. The second rolling assembly includes a cylindrical roller cage, a row of cylindrical rollers mounted on the cylindrical roller cage, and a second spacer block disposed between adjacent cylindrical rollers. The lower outer ring is fitted onto the lower inner ring. The upper inner ring is located outside the middle outer ring and at the bottom of the middle outer ring. A first seal is provided between the upper inner ring and the middle outer ring, and on the outside of the cylindrical roller. The first seal is used to prevent contaminants inside the turret nacelle from entering the bearing. A second seal is provided between the middle inner ring, the middle outer ring, and the lower inner ring. The second seal is used to prevent the leakage of lubricating grease from the bearing. Multiple third seals are provided between the lower inner ring and the lower outer ring from top to bottom at intervals. A sealing ring is provided between each pair of adjacent third seals to support each seal. The multiple third seals work together to prevent seawater from entering the bearing. A fourth seal is provided between the inner circumferential surface of the lower outer ring and the bottom surface of the lower inner ring. The fourth seal is located below the multiple third seals and is used to prevent aquatic organisms from entering the bearing.

[0008] Furthermore, a first raceway for mounting tapered rollers is provided on the outer circumferential surface of the middle inner ring and the inner circumferential surface of the middle outer ring; a second raceway for mounting cylindrical rollers is provided on the bottom surface of the upper inner ring and the top surface of the middle outer ring.

[0009] Furthermore, both the first and second raceways are precision turned or ground, with a surface roughness of not less than Ra1.0 and a flatness of not less than 0.05. Each raceway is non-concave. The contact angle of the first raceway on the inner circumference of the outer ring is 18°~21°. An oil groove is machined at the lowest point of the first raceway on the inner ring.

[0010] Furthermore, a reserved stop is provided at the mating surface of the upper inner ring and the middle inner ring to facilitate assembly; a reserved groove is provided on the middle inner ring for the installation of the second seal; and a reserved groove is provided on the upper inner ring for the installation of the first seal.

[0011] Furthermore, the bottom flange of the inner ring in the middle makes point contact with the spherical base surface of the tapered roller, and the contact height is 1 / 2 to 2 / 3 of the flange height; the spherical radius of the spherical base surface of the tapered roller is 300 to 1000 mm.

[0012] Furthermore, both the second and third seals are rubber contact seals; and the lip of the second seal is positioned upwards, while the lip of the third seal is positioned downwards.

[0013] Furthermore, the sealing ring is made of forged steel and has grease injection holes on it to facilitate grease lubrication of each sealing component.

[0014] Furthermore, the inner part of the middle outer ring is provided with a first grease injection hole for injecting grease into the first raceway and the second raceway, and a grease discharge hole for discharging grease; the inlet of the first grease injection hole and the outlet of the grease discharge hole are both located on the top surface of the middle outer ring, and the inlet of the grease discharge hole is connected to the bottom of the first raceway; the inner part of the lower outer ring is provided with a second grease injection hole for injecting grease into the grease injection holes of each sealing ring, and the second grease injection hole is connected to the first grease injection hole.

[0015] The second objective of this invention is achieved through the following technical solution:

[0016] A method for assembling an underwater turret bearing for a floating offshore wind turbine includes the following steps:

[0017] S1. Based on the machining dimensions of the cylindrical roller and the middle inner ring and the design preload of the bearing, the mating surfaces of the middle inner ring and the upper inner ring are ground together. After grinding, the middle inner ring is placed on the preset mounting platform using a three-point support method, and leveled and calibrated using a level to ensure that the levelness is controlled within 0.1mm / m.

[0018] S2. Assemble the first rolling assembly on the first raceway of the inner ring in the middle, so that a clearance of 1.5~3.0mm is reserved between the tapered roller and the tapered roller cage to prevent the bearing from jamming after deformation under load.

[0019] S3. Use a three-point lifting method to lift the middle outer ring above the first rolling component. Before lowering it into place, level and calibrate the middle outer ring to ensure that the levelness is controlled within 0.1mm / m. Then complete the positioning and assembly.

[0020] S4. Assemble the second rolling assembly onto the second raceway of the outer ring in the middle; leave a gap of 1.5~3.0mm between each cylindrical roller;

[0021] S5. Use a power tool to press the first seal into the reserved groove of the upper inner ring to ensure that the first seal is installed in place circumferentially; apply grease to the mating contact surface between the first seal and the reserved groove of the upper inner ring.

[0022] S6. After flipping the upper inner ring, align and assemble it with the reserved stop at the mating surface of the middle inner ring; connect the upper inner ring and the middle inner ring with connecting bolts and tighten them to the specified torque; after assembly, rotate the middle outer ring to make the cylindrical rollers contact the corresponding raceways evenly and release the internal stress generated during the assembly process.

[0023] S7. Assemble the fourth seal and multiple third seals in the lower outer ring according to the preset positions. When installing multiple third seals, install each third seal in a bottom-to-top order. After installation, check the assembly of each seal to ensure that the gap between the seals meets the preset requirements.

[0024] S8. Use a power tool to press the second seal into the reserved groove of the inner ring, with its lip facing upwards, to ensure that the second seal is installed in place circumferentially; apply grease to the mating contact surface between the second seal and the reserved groove of the inner ring.

[0025] S9. Assemble the lower inner ring inside the lower outer ring using three pre-set support seats. Apply grease to the contact area between the lower inner ring and each third seal to complete the assembly with the lower outer ring. Hoist the assembled middle inner ring, middle outer ring and upper inner ring as a whole onto the top of the lower inner ring and lower outer ring, connect them with bolts and tighten them to the specified torque.

[0026] S10. Perform a preset number of rotations on the lower outer ring and the middle outer ring to ensure that each roller is evenly fitted with the corresponding raceway and that each seal is in full contact with the grease, thus completing the overall assembly.

[0027] The third objective of this invention is achieved through the following technical solution:

[0028] A method for determining the rated life of an underwater turret bearing for a floating offshore wind turbine includes the following steps:

[0029] S1. Calculate the rated load of the tapered roller train:

[0030] Calculate the rolling element load on the inner ring based on the diameter and pitch circle diameter of the tapered roller. As shown in the following formula:

[0031] ;

[0032] ;

[0033] in, To reduce the coefficient, For dimensionless parameters, The diameter of the tapered roller. The pitch circle diameter of the tapered roller. The length of the tapered roller. The number of tapered rollers;

[0034] Based on the rolling element load on the inner ring Calculate the basic rated dynamic load on any slice of the inner ring in the middle. As shown in the following formula:

[0035] ;

[0036] in, Number of slices;

[0037] Calculate the rolling element load on the outer ring in the middle section based on the diameter and pitch circle diameter of the tapered roller. As shown in the following formula:

[0038] ;

[0039] Based on the rolling element load of the outer ring in the middle Calculate the basic rated dynamic load on any slice of the outer ring in the middle section. As shown in the following formula:

[0040] ;

[0041] S2. Calculate the rated load of the cylindrical roller train:

[0042] Calculate the rolling element load on the upper inner ring based on the diameter and pitch circle diameter of the cylindrical rollers. As shown in the following formula:

[0043] ;

[0044] ;

[0045] in, To reduce the coefficient, For dimensionless parameters, The diameter of the cylindrical roller is... The pitch circle diameter of the cylindrical roller. The length of the cylindrical roller. This represents the number of cylindrical rollers.

[0046] Based on the rolling element load on the upper inner ring Calculate the basic rated dynamic load on any slice of the upper inner ring. As shown in the following formula:

[0047] ;

[0048] Calculate the rolling element load on the outer ring at the center based on the diameter and pitch circle diameter of the cylindrical rollers. As shown in the following formula:

[0049] ;

[0050] Based on the rolling element load on the middle outer ring Calculate the basic rated dynamic load on any slice of the outer ring in the middle section. As shown in the following formula:

[0051] ;

[0052] S3. Calculate the equivalent load of the tapered roller train:

[0053] When the inner ring rotates under relative load in the middle section, calculate the inner ring number of the corresponding raceway in the middle section of the tapered roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0054] ;

[0055] in, The load on each tapered roller of the inner ring in the middle section is calculated based on the static balance equation of bearings in ISO 16281 standard.

[0056] With the inner ring rotating under relative load, calculate the outer ring of the corresponding raceway in the middle of the tapered roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0057] ;

[0058] in, The load on each tapered roller of the middle outer ring is calculated based on the ISO 16281 standard bearing static balance equation;

[0059] S4. Calculate the equivalent load on the cylindrical roller train:

[0060] Under the condition of relative load rotation of the upper inner ring, calculate the number of the upper inner ring of the corresponding raceway of the cylindrical roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0061] ;

[0062] in, The load on each cylindrical roller of the upper inner ring is calculated based on the ISO 16281 standard bearing static balance equation.

[0063] With the upper inner ring rotating under relative load, calculate the number of the outer ring in the middle of the raceway corresponding to the cylindrical roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0064] ;

[0065] in, The load on each cylindrical roller of the middle outer ring is calculated based on the ISO16281 standard bearing static balance equation;

[0066] S5. Finally, calculate the reference rated life of the entire bearing set. As shown in the following formula:

[0067] .

[0068] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0069] 1. Compared with conventional three-row cylindrical roller turret bearings, this invention uses a single row of cylindrical rollers and a single row of tapered rollers, requiring less space and greatly reducing the space occupied. It is estimated that the space occupied will be reduced by more than 15%.

[0070] 2. Compared with existing turret bearings, this invention can better guarantee the sealing performance of the bearing. According to FEA simulation results, the sealing deformation under this structure can be reduced by 50%, which can effectively ensure the operational reliability of the unit throughout its entire life cycle.

[0071] 3. Compared with existing turret bearings, the present invention has a shorter lever arm for load transfer to the seal, and by using tapered rollers, the bearing rigidity is better, significantly improving the resistance to deformation under rated load. Attached Figure Description

[0072] Figure 1 This is a schematic diagram of the turret bearing of the present invention.

[0073] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0074] Figure 3 This is a schematic diagram of the installation of the turret bearing of the present invention. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0076] Example 1:

[0077] like Figures 1 to 3 As shown, this embodiment provides an underwater turret bearing for a floating offshore wind turbine, including an upper inner ring 1, a middle inner ring 2, a middle outer ring 3, a lower inner ring 4, and a lower outer ring 5. The upper inner ring 1 and the lower inner ring 4 are respectively disposed at the top and bottom of the middle inner ring 2 and are fixedly connected to each other by connecting bolts. Each inner ring is connected to the flange 15 of the submarine cable, and each outer ring is connected to the entire floating offshore wind turbine 16, transmitting the power generated by the wind turbine to the outside through the submarine cable. The middle outer ring 3 is rotatably sleeved on the outside of the middle inner ring 2 through a first rolling assembly and is rotatably connected to the upper inner ring 1 through a second rolling assembly. The second rolling assembly is located above and outside the first rolling assembly. The first rolling assembly includes a tapered roller cage (not shown in the figure), a row of tapered rollers 6 mounted on the tapered roller cage, and a first spacer block (not shown in the figure) disposed between adjacent tapered rollers 6. The turret bearing mainly bears radial loads, with a small amount of bending moment and axial force. The tapered rollers 6 mainly bear the radial load and bending moment of the fan. The second rolling assembly includes a cylindrical roller cage (not shown in the figure), a row of cylindrical rollers 7 mounted on the cylindrical roller cage, and a second spacer block (not shown in the figure) disposed between adjacent cylindrical rollers 7. The second isolation block 8 is made of plastic and is suitable for low-speed, heavy-load conditions. It bears the derived axial force from the tapered rollers 6 and a portion of the axial load of the fan through the cylindrical rollers 7. The lower outer ring 5 is fitted outside the lower inner ring 4 and is located at the bottom of the middle outer ring 3. A first seal 9 is provided between the upper inner ring 1 and the middle outer ring 3, and outside the cylindrical rollers 7. This first seal 9 is used to prevent contaminants inside the turret nacelle from entering the bearing. A second seal 10 is provided between the middle inner ring 2, the middle outer ring 3, and the lower inner ring 4. This second seal 10 is used to prevent grease from entering the bearing. External leakage; a plurality of third seals 11 are arranged sequentially from top to bottom between the lower inner ring 4 and the lower outer ring 5. A sealing ring 12 is provided between each pair of adjacent third seals 11 to support each seal. The sealing ring 12 is made of forged steel and has a grease injection hole 1201 on it to facilitate grease lubrication of each seal. The multiple third seals 11 work together to prevent seawater from entering the bearing. A fourth seal 14 is provided between the inner circumferential surface of the lower outer ring 5 and the bottom surface of the lower inner ring 4. The fourth seal 14 is located below the multiple third seals 11 and is used to prevent aquatic organisms, shells, seaweed, etc. from entering the bearing.

[0078] The outer circumferential surface of the middle inner ring 2 and the inner circumferential surface of the middle outer ring 3 are provided with first raceways for mounting tapered rollers 6; the bottom surface of the upper inner ring 1 and the top surface of the middle outer ring 3 are provided with second raceways for mounting cylindrical rollers 7. Both the first and second raceways are precision turned or ground, and the surface roughness of each raceway is not less than Ra1.0, and the flatness of each raceway is not less than 0.05. Each raceway adopts a non-concave design; the contact angle of the first raceway on the inner circumferential surface of the middle outer ring 3 is 18°~21°; an oil groove 201 is machined at the lowest point of the first raceway of the middle inner ring 2. During the raceway machining process, the oil groove 201 facilitates tool retraction and ensures that the machining is in place.

[0079] The upper inner ring 1 and the middle inner ring 2 have a reserved stop 13 for easy assembly at their mating surfaces; the middle inner ring 2 has a reserved groove 202 for the installation of the second seal 10; the upper inner ring 1 has a reserved groove 101 for the installation of the first seal 9.

[0080] The bottom flange 203 of the inner ring 2 in the middle section makes point contact with the spherical base surface of the tapered roller 6, and the contact height is 1 / 2 to 2 / 3 of the height of the flange 203; the spherical radius of the spherical base surface of the tapered roller 6 is 300 to 1000 mm.

[0081] Both the second seal 10 and the third seal 11 are rubber contact seals; and the lip of the second seal 10 is set facing upwards, while the lip of the third seal 11 is set facing downwards.

[0082] The bearing in this embodiment uses negative clearance, which is mainly achieved by grinding the mating surfaces of the upper inner ring 1 and the middle inner ring 2.

[0083] The inner part of the middle outer ring 3 has a first grease injection hole 301 for injecting grease into the first raceway and the second raceway, and a grease discharge hole 302 for discharging grease. In this embodiment, there are 16 to 20 first grease injection holes 301, which are evenly distributed around the circumference inside the middle outer ring 3. The inlet of the first grease injection hole 301 and the outlet of the grease discharge hole 302 are both located on the top surface of the middle outer ring 3. The inlet of the grease discharge hole 302 is connected to the bottom of the first raceway, and the diameter of the grease discharge hole 302 needs to be about 2 to 5 mm larger than the diameter of the first grease injection hole 301. The main purpose is to ensure that the pressure of the grease discharge hole 302 is lower than that of the grease injection hole, with a pressure difference of about 1 to 2 bar. This better ensures that the grease is discharged from the grease discharge hole 302 and that the seal is not prone to leakage. The inner part of the lower outer ring 5 has a second grease injection hole 501 for injecting grease into the grease injection holes 1201 of each sealing ring 12. The second grease injection hole 501 is connected to the first grease injection hole 301. The above-mentioned bearings are lubricated with grease, and the grease is usually Fuchs 585K or Fuchs 585KPLUS grease. By adopting centralized lubrication and regular grease application, the annual maintenance grease amount is generally 1 / 3 of the total volume of the cavity, and the grease application frequency is generally once a week.

[0084] Example 2:

[0085] This embodiment provides an assembly method for the underwater turret bearing of the offshore floating wind turbine described in Embodiment 1, including the following steps:

[0086] S1. Based on the machining dimensions of the cylindrical roller 7 and the middle inner ring 2, as well as the design preload of the bearing, the mating surfaces of the middle inner ring 2 and the upper inner ring 1 are ground together. Generally, the initial clearance is around -0.1mm. After grinding, the middle inner ring 2 is placed on the preset mounting platform using a three-point support method, and leveled and calibrated using a level to ensure that the levelness is controlled within 0.1mm / m.

[0087] S2. Assemble the first rolling assembly on the first raceway of the inner ring 2 in the middle, so that a gap of 1.5~3.0mm is reserved between the tapered roller 6 and the tapered roller cage to prevent the bearing from jamming after deformation under load. When assembling the tapered roller 6, rust-preventive oil should be applied while installing to prevent rusting during storage in the workshop.

[0088] S3. The middle outer ring 3 is hoisted to the top of the first rolling assembly using a three-point lifting method. Before lowering it into place, the middle outer ring 3 is leveled and calibrated to ensure that the levelness is controlled within 0.1mm / m, so that the tapered roller 6 can make more uniform contact with the corresponding raceway and prevent problems such as uneven loading. Then the positioning and assembly are completed.

[0089] S4. Assemble the second rolling assembly on the second raceway of the middle outer ring 3; leave a gap of 1.5~3.0mm between each cylindrical roller 7; when assembling the cylindrical roller 7, apply anti-rust oil while installing to prevent rusting during workshop storage; place the cylindrical roller 7 as far out as possible to prevent scratches and other problems when installing the upper inner ring 1.

[0090] S5. Use a power tool to press the first seal 9 into the reserved groove 101 of the upper inner ring 1, ensuring that the first seal 9 is installed in place circumferentially and that no part protrudes; apply grease to the mating contact surface between the first seal 9 and the reserved groove 101 of the upper inner ring 1 to ensure sufficient lubrication.

[0091] S6. After flipping the upper inner ring 1, align and assemble it with the reserved stop 13 at the mating surface of the middle inner ring 2; connect the upper inner ring 1 and the middle inner ring 2 with connecting bolts and tighten them with the specified torque; after assembly, rotate the middle outer ring 3 to make the cylindrical roller 7 evenly contact the corresponding raceway and release the internal stress generated during the assembly process.

[0092] S7. Assemble the fourth seal 14 and multiple third seals 11 in the lower outer ring 5 according to the preset positions; ensure that the fourth seal 14 is installed in place circumferentially, without any protrusion or failure to be installed; when installing multiple third seals 11, each third seal 11 shall be installed in a bottom-up order; after installation, check the assembly of each seal to ensure that the gap between the seals meets the preset requirements.

[0093] S8. Use a power tool to press the second seal 10 into the reserved groove 202 of the inner ring 2, with its lip facing upward, to ensure that the second seal 10 is installed in place circumferentially; apply grease to the mating contact surface between the second seal 10 and the reserved groove 202 of the inner ring 2.

[0094] S9. Assemble the lower inner ring 4 inside the lower outer ring 5 through three preset support seats. Apply grease to the contact area between the lower inner ring 4 and each third seal 11 to complete the assembly with the lower outer ring 5. Hoist the assembled middle inner ring 2, middle outer ring 3 and upper inner ring 1 as a whole onto the top of the lower inner ring 4 and lower outer ring 5, connect them with bolts and tighten them to the specified torque.

[0095] S10. Perform a preset number of rotations on the lower outer ring 5 and the middle outer ring 3 to ensure that each roller is evenly fitted with the corresponding raceway and that each seal is in full contact with the grease, thus completing the overall assembly.

[0096] Example 3:

[0097] This embodiment provides a method for determining the rated life of the underwater turret bearing of a floating offshore wind turbine as described in Embodiment 1, including the following steps:

[0098] S1. Calculate the rated load of the tapered roller train:

[0099] Calculate the rolling element load on the inner ring 2 based on the diameter and pitch circle diameter of the tapered roller 6. As shown in the following formula:

[0100] ;

[0101] ;

[0102] in, To reduce the coefficient, For dimensionless parameters, The diameter of the tapered roller 6 is... The pitch circle diameter of the tapered roller 6 is... The length of the tapered roller 6, The number of tapered rollers (6).

[0103] Based on the rolling element load on the inner ring 2 in the middle Calculate the basic rated dynamic load on any slice of the inner circle 2 in the middle. As shown in the following formula:

[0104] ;

[0105] in, Number of slices;

[0106] Calculate the rolling element load on the outer ring 3 in the middle based on the diameter and pitch circle diameter of the tapered roller 6. As shown in the following formula:

[0107] ;

[0108] Based on the rolling element load of the outer ring 3 in the middle Calculate the basic rated dynamic load on any slice of the outer ring 3 in the middle section. As shown in the following formula:

[0109] ;

[0110] S2. Calculate the rated load of the cylindrical roller train:

[0111] Calculate the rolling element load on the upper inner ring 1 based on the diameter and pitch circle diameter of the cylindrical roller 7. As shown in the following formula:

[0112] ;

[0113] ;

[0114] in, To reduce the coefficient, For dimensionless parameters, The diameter of the cylindrical roller 7 is... The pitch circle diameter of cylindrical roller 7. The length of cylindrical roller 7, There are 7 cylindrical rollers;

[0115] Based on the rolling element load on the upper inner ring 1 Calculate the basic rated dynamic load on any slice of the upper inner ring 1. As shown in the following formula:

[0116] ;

[0117] Calculate the rolling element load on the outer ring 3 in the middle based on the diameter and pitch circle diameter of the cylindrical roller 7. As shown in the following formula:

[0118] ;

[0119] Based on the rolling element load on the outer ring 3 in the middle Calculate the basic rated dynamic load on any slice of the outer ring 3 in the middle section. As shown in the following formula:

[0120] ;

[0121] S3. Calculate the equivalent load of the tapered roller train:

[0122] Under the condition of relative load rotation of the inner ring 2 in the middle, calculate the inner ring 2 in the middle of the raceway corresponding to the tapered roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0123] ;

[0124] in, The load borne by each tapered roller 6 of the inner ring 2 in the middle is calculated based on the static balance equation of bearings in ISO 16281 standard.

[0125] With the inner ring 2 rotating under relative load, calculate the outer ring 3 in the middle of the raceway corresponding to the tapered roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0126] ;

[0127] in, The load borne by each tapered roller 6 of the outer ring 3 in the middle is calculated based on the bearing static balance equation of ISO16281 standard;

[0128] S4. Calculate the equivalent load on the cylindrical roller train:

[0129] Under the condition of relative load rotation of the upper inner ring 1, calculate the upper inner ring 1 of the raceway corresponding to the cylindrical roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0130] ;

[0131] in, The load borne by each cylindrical roller 7 of the upper inner ring 1 is calculated based on the bearing static balance equation of ISO16281 standard;

[0132] With the upper inner ring 1 rotating under relative load, calculate the outer ring 3 in the middle of the raceway corresponding to the cylindrical roller row. Equivalent dynamic load on a slice As shown in the following formula:

[0133] ;

[0134] in, The load borne by each cylindrical roller 7 of the middle outer ring 3 is calculated based on the bearing static balance equation of ISO16281 standard;

[0135] S5. Finally, calculate the reference rated life of the entire bearing set. As shown in the following formula:

[0136] .

[0137] This embodiment combines an innovative bearing structure to establish a life calculation model adapted to the bearing structure, making the life assessment results more consistent with actual use conditions and with higher assessment accuracy. It can provide a reliable quantitative basis for bearing design optimization, performance verification and engineering application, which is conducive to improving the scientificity and reliability of the overall design of underwater equipment, and has strong theoretical value and engineering practicality.

[0138] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A type of underwater turret bearing for a floating offshore wind turbine, characterized in that: The device includes an upper inner ring, a middle inner ring, a middle outer ring, a lower inner ring, and a lower outer ring. The upper and lower inner rings are respectively located at the top and bottom of the middle inner ring and are fixedly connected to each other. The middle outer ring is rotatably fitted onto the outside of the middle inner ring via a first rolling assembly and is rotatably connected to the upper inner ring via a second rolling assembly, with the second rolling assembly located above and outside the first rolling assembly. The first rolling assembly includes a tapered roller cage, a row of tapered rollers mounted on the tapered roller cage, and a first spacer block disposed between adjacent tapered rollers. The second rolling assembly includes a cylindrical roller cage, a row of cylindrical rollers mounted on the cylindrical roller cage, and a second spacer block disposed between adjacent cylindrical rollers. The lower outer ring is fitted onto the outside of the lower inner ring, and... Located at the bottom of the middle outer ring; a first seal is provided between the upper inner ring and the middle outer ring, and on the outside of the cylindrical roller, the first seal being used to prevent contaminants inside the turret nacelle from entering the bearing; a second seal is provided between the middle inner ring, the middle outer ring, and the lower inner ring, the second seal being used to prevent the leakage of lubricating grease from the bearing; multiple third seals are provided sequentially from top to bottom between the lower inner ring and the lower outer ring, with sealing rings between each pair of adjacent third seals to support each seal, the multiple third seals working together to prevent seawater from entering the bearing; a fourth seal is provided between the inner circumferential surface of the lower outer ring and the bottom surface of the lower inner ring, and this fourth seal is located below the multiple third seals, used to prevent aquatic organisms from entering the bearing.

2. The underwater turret bearing for a floating offshore wind turbine according to claim 1, characterized in that: The outer circumferential surface of the middle inner ring and the inner circumferential surface of the middle outer ring are provided with a first raceway for mounting tapered rollers; the bottom surface of the upper inner ring and the top surface of the middle outer ring are provided with a second raceway for mounting cylindrical rollers.

3. The underwater turret bearing for a floating offshore wind turbine according to claim 2, characterized in that: Both the first and second raceways are precision turned or ground, with a surface roughness of not less than Ra1.0 and a flatness of not less than 0.

05. Each raceway is non-concave. The contact angle of the first raceway on the inner circumference of the outer ring is 18°~21°. An oil groove is machined at the lowest point of the first raceway on the inner ring.

4. The underwater turret bearing for a floating offshore wind turbine according to claim 1, characterized in that: The upper inner ring and the middle inner ring have a reserved stop at their mating surfaces to facilitate assembly; the middle inner ring has a reserved groove for installing the second seal; and the upper inner ring has a reserved groove for installing the first seal.

5. The underwater turret bearing for a floating offshore wind turbine according to claim 1, characterized in that: The bottom flange of the inner ring in the middle section makes point contact with the spherical base surface of the tapered roller, and the contact height is 1 / 2 to 2 / 3 of the flange height; the spherical radius of the spherical base surface of the tapered roller is 300 to 1000 mm.

6. The underwater turret bearing for a floating offshore wind turbine according to claim 1, characterized in that: Both the second and third seals are rubber contact seals; the lip of the second seal faces upward, and the lip of the third seal faces downward.

7. The underwater turret bearing for a floating offshore wind turbine according to claim 6, characterized in that: The sealing ring is made of forged steel and has grease injection holes for easy lubrication of the various seals.

8. The underwater turret bearing for a floating offshore wind turbine according to claim 1, characterized in that: The middle outer ring has a first grease injection hole for injecting grease into the first raceway and the second raceway, and a grease discharge hole for discharging grease. The inlet of the first grease injection hole and the outlet of the grease discharge hole are both located on the top surface of the middle outer ring, and the inlet of the grease discharge hole is connected to the bottom of the first raceway. The lower outer ring has a second grease injection hole for injecting grease into the grease injection holes of each sealing ring, and the second grease injection hole is connected to the first grease injection hole.

9. A method for assembling an underwater turret bearing for a floating offshore wind turbine according to any one of claims 1 to 8, characterized in that, Including the following steps: S1. Based on the machining dimensions of the cylindrical roller and the middle inner ring and the design preload of the bearing, the mating surfaces of the middle inner ring and the upper inner ring are ground together. After grinding, the middle inner ring is placed on the preset mounting platform using a three-point support method, and leveled and calibrated using a level to ensure that the levelness is controlled within 0.1mm / m. S2. Assemble the first rolling assembly on the first raceway of the inner ring in the middle, so that a clearance of 1.5~3.0mm is reserved between the tapered roller and the tapered roller cage to prevent the bearing from jamming after deformation under load. S3. Use a three-point lifting method to lift the middle outer ring above the first rolling component. Before lowering it into place, level and calibrate the middle outer ring to ensure that the levelness is controlled within 0.1mm / m. Then complete the positioning and assembly. S4. Assemble the second rolling assembly onto the second raceway of the outer ring in the middle; leave a gap of 1.5~3.0mm between each cylindrical roller; S5. Use a power tool to press the first seal into the reserved groove of the upper inner ring to ensure that the first seal is installed in place circumferentially; apply grease to the mating contact surface between the first seal and the reserved groove of the upper inner ring. S6. After flipping the upper inner ring, align and assemble it with the reserved stop at the mating surface of the middle inner ring; connect the upper inner ring and the middle inner ring with connecting bolts and tighten them to the specified torque; after assembly, rotate the middle outer ring to make the cylindrical rollers contact the corresponding raceways evenly and release the internal stress generated during the assembly process. S7. Assemble the fourth seal and multiple third seals in the lower outer ring according to the preset positions. When installing multiple third seals, install each third seal in a bottom-to-top order. After installation, check the assembly of each seal to ensure that the gap between the seals meets the preset requirements. S8. Use a power tool to press the second seal into the reserved groove of the inner ring, with its lip facing upwards, to ensure that the second seal is installed in place circumferentially; apply grease to the mating contact surface between the second seal and the reserved groove of the inner ring. S9. Assemble the lower inner ring inside the lower outer ring using three pre-set support seats. Apply grease to the contact area between the lower inner ring and each third seal to complete the assembly with the lower outer ring. Hoist the assembled middle inner ring, middle outer ring and upper inner ring as a whole onto the top of the lower inner ring and lower outer ring, connect them with bolts and tighten them to the specified torque. S10. Perform a preset number of rotations on the lower outer ring and the middle outer ring to ensure that each roller is evenly fitted with the corresponding raceway and that each seal is in full contact with the grease, thus completing the overall assembly.

10. A method for determining the rated life of an underwater turret bearing for a floating offshore wind turbine according to any one of claims 1 to 8, characterized in that, Including the following steps: S1. Calculate the rated load of the tapered roller train: Calculate the rolling element load on the inner ring based on the diameter and pitch circle diameter of the tapered roller. As shown in the following formula: ； ； in, To reduce the coefficient, For dimensionless parameters, The diameter of the tapered roller. The pitch circle diameter of the tapered roller. The length of the tapered roller. The number of tapered rollers; Based on the rolling element load on the inner ring Calculate the basic rated dynamic load on any slice of the inner ring in the middle. As shown in the following formula: ； in, Number of slices; Calculate the rolling element load on the outer ring in the middle section based on the diameter and pitch circle diameter of the tapered roller. As shown in the following formula: ； Based on the rolling element load of the outer ring in the middle Calculate the basic rated dynamic load on any slice of the outer ring in the middle section. As shown in the following formula: ； S2. Calculate the rated load of the cylindrical roller train: Calculate the rolling element load on the upper inner ring based on the diameter and pitch circle diameter of the cylindrical rollers. As shown in the following formula: ； ； in, To reduce the coefficient, For dimensionless parameters, The diameter of the cylindrical roller is... The pitch circle diameter of the cylindrical roller. The length of the cylindrical roller. This represents the number of cylindrical rollers. Based on the rolling element load on the upper inner ring Calculate the basic rated dynamic load on any slice of the upper inner ring. As shown in the following formula: ； Calculate the rolling element load on the outer ring at the center based on the diameter and pitch circle diameter of the cylindrical rollers. As shown in the following formula: ； Based on the rolling element load on the middle outer ring Calculate the basic rated dynamic load on any slice of the outer ring in the middle section. As shown in the following formula: ； S3. Calculate the equivalent load of the tapered roller train: When the inner ring rotates under relative load in the middle section, calculate the inner ring number of the corresponding raceway in the middle section of the tapered roller row. Equivalent dynamic load on a slice As shown in the following formula: ； in, The load on each tapered roller of the inner ring in the middle section is calculated based on the static balance equation of bearings in ISO 16281 standard. With the inner ring rotating under relative load, calculate the outer ring of the corresponding raceway in the middle of the tapered roller row. Equivalent dynamic load on a slice As shown in the following formula: ； in, The load on each tapered roller of the middle outer ring is calculated based on the ISO 16281 standard bearing static balance equation; S4. Calculate the equivalent load on the cylindrical roller train: Under the condition of relative load rotation of the upper inner ring, calculate the number of the upper inner ring of the corresponding raceway of the cylindrical roller row. Equivalent dynamic load on a slice As shown in the following formula: ； in, The load on each cylindrical roller of the upper inner ring is calculated based on the ISO 16281 standard bearing static balance equation. With the upper inner ring rotating under relative load, calculate the number of the outer ring in the middle of the raceway corresponding to the cylindrical roller row. Equivalent dynamic load on a slice As shown in the following formula: ； in, The load on each cylindrical roller of the middle outer ring is calculated based on the ISO16281 standard bearing static balance equation; S5. Finally, calculate the reference rated life of the entire bearing set. As shown in the following formula: 。

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