A low-friction three-row cylindrical roller main shaft bearing for a high-power wind turbine generator

Abstract

The application provides a low-friction three-row cylindrical roller main shaft bearing of a high-power wind turbine, which comprises an inner ring and an outer ring, two axial raceways and a radial raceway are formed between the inner ring and the outer ring, a plurality of axial cylindrical rollers and an axial retainer for keeping the plurality of axial cylindrical rollers spaced apart in the circumferential direction are arranged in the two axial raceways, respectively, spherical grooves are arranged on the axial end faces and the inner circumferential faces of the axial retainer and the radial retainer, steel balls limited by cover plates are arranged in the spherical grooves, the steel balls can partially pass through the cover plates and rollingly contact the surfaces of the adjacent inner ring or outer ring, the axial support and the radial support of the retainer are realized by using the steel balls, the gap between the retainer and the adjacent bearing ring is kept, the large-area sliding friction between the end face or the inner circumferential face of the retainer and the bearing ring is avoided, and the original sliding contact is converted into the rolling contact of the steel balls.

Description

Technical Field

[0001] This invention belongs to the field of wind power bearing technology, specifically relating to a low-friction three-row cylindrical roller main shaft bearing for high-power wind turbine generators. Background Technology

[0002] Three-row cylindrical roller main shaft bearings typically consist of an inner ring, an outer ring, and three rows of cylindrical rollers positioned between the inner and outer rings. Two rows of cylindrical rollers primarily bear axial loads, while the third row primarily bears radial loads. Each row of cylindrical rollers is spaced apart circumferentially by corresponding cages. These bearings are characterized by high load-bearing capacity, high rigidity, and strong anti-overturning capability, and can be used in the main shaft support of high-power wind turbines to bear axial loads, radial loads, and overturning moments transmitted by the wind turbine and main shaft. Because the main shaft bearings of high-power wind turbines are typically large in size, bear high loads, operate in complex environments, and undergo long continuous operation times, high requirements are placed on the operational stability, wear resistance, and service life of the internal cages of the main shaft bearings.

[0003] In traditional three-row cylindrical roller bearings, the cage is typically supported by one end face on the surface of an adjacent inner or outer ring. During operation, the cage rotates with the cylindrical rollers around the bearing axis, creating sliding friction between the cage end face and the adjacent ring surface. This frictional resistance and heat generation can lead to wear on both the cage end face and the ring surface. Furthermore, when the cage experiences radial misalignment during operation, its inner circumferential surface may contact the outer circumferential surface of the inner ring, further increasing the internal operating resistance of the bearing. For large-sized, heavy-load, and continuously operating high-power wind turbine bearings, this friction and wear can easily cause excessive cage temperature rise, deformation, and shortened service life, ultimately affecting the operational stability and lifespan of the main bearing. Summary of the Invention

[0004] This invention provides a low-friction three-row cylindrical roller spindle bearing for high-power wind turbines, which solves the problem mentioned in the background art that existing three-row cylindrical roller bearings used in the wind power field are prone to sliding friction between the cage and the raceway surface or the cylindrical rollers, resulting in severe cage heating and wear and short service life.

[0005] The technical solution adopted in this invention is as follows: a low-friction three-row cylindrical roller main shaft bearing for high-power wind turbine generator sets, comprising an inner ring and an outer ring. Two axial raceways and one radial raceway are formed between the inner and outer rings. Multiple axial cylindrical rollers and axial cages for circumferentially spaced holding the multiple axial cylindrical rollers are respectively arranged in the two axial raceways. Multiple radial cylindrical rollers and radial cages for circumferentially spaced holding the multiple radial cylindrical rollers are arranged in the radial raceway. Multiple spherical grooves are provided on the two axial end faces and the inner circumferential surface of the axial and radial cages. A steel ball is rotatably installed in each spherical groove. A cover plate is provided at the opening of the spherical groove to prevent the steel ball from detaching from the groove. The cover plate has a through hole for the steel ball to partially pass through. The steel ball located on the axial end face rolls in contact with the surface of the adjacent inner or outer ring, and the steel ball located on the inner circumferential surface rolls in contact with the outer circumferential surface of the inner ring, so that a gap is maintained between the axial and radial cages and the adjacent inner and outer rings.

[0006] One of the inner and outer rings is an integral ring structure, and the other is a separate ring structure.

[0007] Both the axial and radial cages are provided with multiple pockets for accommodating cylindrical rollers, and a crossbeam is formed on the cage between two adjacent pockets.

[0008] The spherical grooves are formed on the crossbeam, and multiple spherical grooves located on each axial end face and inner circumferential surface are evenly distributed along the circumference of the corresponding cage.

[0009] Multiple spherical grooves located on the same axial end face are spaced apart on part of the crossbeam, and the spherical grooves located on two axial end faces are staggered along the circumference of the corresponding cage.

[0010] The axial retainer and the radial retainer are respectively provided with mounting grooves for mounting the cover plate, and the cover plate is fixedly installed in the mounting groove.

[0011] The minimum diameter of the through hole is smaller than the diameter of the steel ball, and a portion of the steel ball passes through the through hole and protrudes from the side of the cover plate away from the spherical groove.

[0012] The wall of the through hole near the center of the steel ball is an arc shape that matches the outer surface of the steel ball; or, the diameter of the through hole gradually increases along the direction near the center of the steel ball to form a tapered flare.

[0013] The diameter of the spherical groove is larger than the diameter of the steel ball, so that a rotational gap is formed between the steel ball and the spherical groove to allow the steel ball to rotate.

[0014] Both the axial cage and the radial cage are integrally machined solid cages made of brass.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention provides spherical grooves on the axial end faces and inner circumferential surfaces of the axial and radial cages, and places steel balls, limited by cover plates, within these grooves. The steel balls partially extend beyond the cover plates and roll into contact with the surfaces of adjacent inner or outer rings. This utilizes the steel balls to provide axial and radial support to each cage, maintaining a gap between the cage and adjacent bearing rings. This prevents large-area sliding friction between the cage end faces or inner circumferential surfaces and the bearing rings, transforming the original sliding contact into rolling contact with the steel balls. Simultaneously, the steel balls are reliably confined within the spherical grooves by the cover plates, ensuring stable support for the bearing in forward, reverse, or vertical installation states. This reduces frictional resistance and heat generation during bearing operation, decreases wear on the cages and bearing rings, and improves bearing stability and service life. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the three rows of cylindrical rollers of the present invention;

[0018] Figure 2 For the partial magnification view of the present invention Figure 1 ;

[0019] Figure 3 For the partial magnification view of the present invention Figure 2 ;

[0020] Figure 4 This is a partial perspective view of the axial retainer of the present invention;

[0021] Figure 5 This is a partial perspective view of the radial retainer of the present invention;

[0022] Figure 6 This is a cross-sectional view of the cover plate of the present invention.

[0023] in:

[0024] 1. Inner ring; 2. Axial cage; 3. Axial raceway; 4. First outer ring; 5. Radial cage; 6. Second outer ring; 7. Radial raceway; 8. Steel ball; 9. Cover plate; 901. Through hole; 10. Axial cylindrical roller; 11. Radial cylindrical roller; 12. Mounting groove; 13. Spherical groove; 14. Pocket; 15. Crossbeam. Detailed Implementation

[0025] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figure 1-6 As shown, this embodiment provides a low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators, including an inner ring 1 and an outer ring. One of the inner ring 1 and the outer ring is an integral ring structure, and the other is a split ring structure. Specifically, in this embodiment, the inner ring 1 is an integral ring structure, and the outer ring includes a first outer ring 4 and a second outer ring 6 arranged axially opposite each other. The first outer ring 4 and the second outer ring 6 are fixedly connected by bolts to facilitate bearing assembly.

[0027] Three raceways are formed between the inner ring 1 and the outer ring. These three raceways include two axial raceways 3 spaced apart along the axial direction and a radial raceway 7 located between the two axial raceways 3. Each of the two axial raceways 3 contains a plurality of axial cylindrical rollers 10 and an axial cage 2 for holding the plurality of axial cylindrical rollers 10 at circumferential intervals. The radial raceway 7 contains a plurality of radial cylindrical rollers 11 and a radial cage 5 for holding the plurality of radial cylindrical rollers 11 at circumferential intervals. The axial cylindrical rollers 10 primarily bear the axial load of the bearing, while the radial cylindrical rollers 11 primarily bear the radial load of the bearing.

[0028] Both the axial cage 2 and the radial cage 5 are provided with multiple pockets 14 for accommodating cylindrical rollers, and a crossbeam 15 is formed on the cage between two adjacent pockets 14. Both the axial cage 2 and the radial cage 5 are integrally machined solid cages made of brass. Using solid brass cages ensures high structural strength, while the good wear resistance and self-lubricating properties of brass reduce frictional loss during operation, making them suitable for long-term operation of high-power wind turbine main shaft bearings.

[0029] Multiple spherical grooves 13 are provided on both axial end faces and inner circumferential surfaces of the axial cage 2 and the radial cage 5. A steel ball 8 is rotatably installed in each spherical groove 13. A cover plate 9 is provided at the opening of the spherical groove 13 to prevent the steel ball 8 from detaching from the spherical groove 13. The cover plate 9 has a through hole 901 for the steel ball 8 to partially pass through. The steel balls 8 located on the axial end faces of the axial cage 2 and the radial cage 5 roll in contact with the surfaces of the adjacent inner ring 1 or outer ring, respectively. The steel balls 8 located on the inner circumferential surfaces of the axial cage 2 and the radial cage 5 roll in contact with the outer circumferential surface of the inner ring 1. Thus, the axial cage 2 and the radial cage 5 are supported by multiple steel balls 8, maintaining a gap between the axial cage 2 and the radial cage 5 and the adjacent inner ring 1 and outer ring.

[0030] Specifically, the spherical groove 13 is provided at the position of the crossbeam 15 of the cage. Since the crossbeam 15 is located between two adjacent pockets 14, it has good structural strength. By setting the spherical groove 13 on the crossbeam 15, the retention function of the pockets 14 on the cylindrical roller can be avoided, and the crossbeam 15 can be used to reliably support the steel ball 8.

[0031] Furthermore, the multiple spherical grooves 13 located on each axial end face and inner circumferential surface are evenly distributed along the circumference of the corresponding cage, so that the multiple steel balls 8 can provide uniform support force along the circumference of the cage, avoiding excessive local stress on the cage and causing tilting or displacement.

[0032] In this embodiment, multiple spherical grooves 13 located on the same axial end face are spaced apart on a portion of the crossbeams 15. That is, not every crossbeam 15 is provided with a spherical groove 13; only enough is sufficient to support the cage for the steel balls 8. Simultaneously, the spherical grooves 13 located on two axial end faces are staggered along the circumference of the corresponding cage. This arrangement avoids simultaneously creating spherical grooves 13 on both axial end faces of the same crossbeam 15, which would weaken the crossbeam 15's cross-section, thus ensuring the overall structural strength of the cage. Furthermore, while meeting the cage support requirements, it reduces the number of steel balls 8, lowering the processing difficulty.

[0033] Furthermore, to facilitate the secure installation of the cover plate 9, the axial retainer 2 and the radial retainer 5 are respectively provided with mounting grooves 12 for installing the cover plate 9, and the cover plate 9 is fixedly installed in the mounting grooves 12. The cover plate 9 covers the opening of the spherical groove 13 to prevent the steel ball 8 from detaching from the spherical groove 13. The minimum diameter of the through hole 901 is smaller than the diameter of the steel ball 8, and a portion of the steel ball 8 passes through the through hole 901 and protrudes from the side of the cover plate 9 away from the spherical groove 13, so that the steel ball 8 can contact the adjacent inner ring 1 or outer ring surface and roll.

[0034] Furthermore, the wall of the through hole 901 near the center of the steel ball 8 is an arc shape that matches the outer surface of the steel ball 8 (not shown in the figure); or, the diameter of the through hole 901 gradually increases along the direction near the center of the steel ball 8 to form a tapered flare (e.g., Figure 6 (As shown). With the above structure, the cover plate 9 can more reliably restrict the steel ball 8, while avoiding large interference between the cover plate 9 and the steel ball 8, so that the steel ball 8 can maintain normal rotation.

[0035] The spherical groove 13 has a larger spherical diameter than the steel ball 8, so that a rotational gap is formed between the steel ball 8 and the spherical groove 13 to allow the steel ball 8 to rotate. Thus, the steel ball 8 can rotate within a certain range in the spherical groove 13 and form rolling contact with the surface of the adjacent raceway during bearing operation.

[0036] During bearing operation, the axial cage 2 and radial cage 5 rotate with their corresponding rollers. Since the steel balls 8 are installed within the spherical grooves 13 of the cage and are limited by the cover plate 9, the steel balls 8 are always held in their predetermined positions. The steel balls 8 provide support to the cage, maintaining a clearance between the cage body and the inner and outer rings, preventing direct contact between the cage and the raceways. Furthermore, the steel balls 8 form rolling contact with the raceway surface, transforming the traditional sliding friction between the cage and raceways into rolling friction of the steel balls 8. This reduces frictional resistance and heat generation during bearing operation, minimizes cage wear, and improves the operational stability and service life of the extra-large three-row cylindrical roller bearing. Because the axial cage 2 and radial cage 5 are equipped with steel ball 8 support structures at multiple locations, the cage can remain suspended by the steel balls 8 regardless of whether the bearing is installed in a forward, reverse, or vertical orientation, further enhancing the bearing's adaptability to different installation conditions.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-friction three-row cylindrical roller main shaft bearing for high-power wind turbine generator sets, comprising an inner ring (1) and an outer ring, wherein two axial raceways (3) and one radial raceway (7) are formed between the inner ring (1) and the outer ring, wherein multiple axial cylindrical rollers (10) and axial cages (2) for holding the multiple axial cylindrical rollers (10) at circumferential intervals are respectively arranged in the two axial raceways (3), and multiple radial cylindrical rollers (11) and radial cages (5) for holding the multiple radial cylindrical rollers (11) at circumferential intervals are arranged in the radial raceway (7), characterized in that: Multiple spherical grooves (13) are provided on both axial end faces and inner circumferential surfaces of the axial retainer (2) and the radial retainer (5). A steel ball (8) is rotatably installed in each spherical groove (13). A cover plate (9) is provided at the opening of the spherical groove (13) to prevent the steel ball (8) from falling out of the spherical groove (13). A through hole (901) is provided on the cover plate (9) for the steel ball (8) to partially pass through. The steel ball (8) located on the axial end face rolls in contact with the adjacent inner ring (1) or outer ring surface, and the steel ball (8) located on the inner circumferential surface rolls in contact with the outer circumferential surface of the inner ring (1) so that the axial cage (2) and the radial cage (5) maintain a gap with the adjacent inner ring (1) and outer ring.

2. The low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 1, characterized in that: One of the inner ring (1) and the outer ring is an integral ring structure, and the other is a split ring structure.

3. The low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 1, characterized in that: Both the axial cage (2) and the radial cage (5) are provided with multiple pockets (14) for accommodating cylindrical rollers, and a crossbeam (15) is formed on the cage between two adjacent pockets (14).

4. The low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 3, characterized in that: The spherical grooves (13) are opened on the crossbeam (15), and the multiple spherical grooves (13) located on each axial end face and inner circumferential surface are evenly distributed along the circumference of the corresponding cage.

5. The low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 4, characterized in that: Multiple spherical grooves (13) located on the same axial end face are spaced apart on part of the crossbeam (15), and the spherical grooves (13) located on two axial end faces are staggered along the circumference of the corresponding cage.

6. The low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 1, characterized in that: The axial retainer (2) and the radial retainer (5) are respectively provided with mounting grooves (12) for mounting the cover plate (9), and the cover plate (9) is fixedly installed in the mounting groove (12).

7. The low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 1, characterized in that: The minimum diameter of the through hole (901) is smaller than the diameter of the steel ball (8), and a portion of the steel ball (8) passes through the through hole (901) and protrudes from the cover plate (9) on the side away from the spherical groove (13).

8. A low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 7, characterized in that: The wall of the through hole (901) on the side near the center of the steel ball (8) is an arc shape that matches the outer surface of the steel ball (8); or, the diameter of the through hole (901) gradually increases along the direction near the center of the steel ball (8) to form a tapered flare.

9. A low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 1, characterized in that: The spherical groove (13) has a larger diameter than the steel ball (8) so that a rotational gap is formed between the steel ball (8) and the spherical groove (13) to allow the steel ball (8) to rotate.

10. A low-friction three-row cylindrical roller spindle bearing for high-power wind turbine generators according to claim 1, characterized in that: Both the axial cage (2) and the radial cage (5) are solid cages that are machined in one piece and are made of brass.

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