A three-row cylindrical roller variable pitch bearing

Abstract

The utility model relates to the technical field of bearing for wind generating set, concretely is a kind of three-row cylindrical roller type variable pitch bearing.The outer diameter side of inner ring is provided with annular convex part, the end face of annular convex part near paddle side is the first inner ring raceway surface perpendicular to the axial direction of bearing, the end face of annular convex part near hub side is the second inner ring raceway surface with the acute angle / obtuse angle of the axial direction of bearing, the outer ring surface of annular convex part is provided with ring groove, and the groove bottom of ring groove includes third inner ring raceway surface;The annular recess of outer ring includes the first outer ring raceway surface parallel and facing the first inner ring raceway surface, the second outer ring raceway surface parallel and facing the second inner ring raceway surface and the third outer ring raceway surface facing the third inner ring raceway surface;Second axial cylindrical roller is arranged between the second inner ring raceway surface and the second outer ring raceway surface.It will second axial cylindrical roller be inclined to certain angle, optimize roller partial load, avoid stress concentration, and then improve bearing carrying capacity and bearing life.

Description

Technical Field

[0001] This utility model relates to the technical field of bearings for wind turbine generator sets, specifically a three-row cylindrical roller pitch bearing. Background Technology

[0002] Pitch bearings are a crucial component of wind turbine generators, primarily bearing the weight of the turbine blades and wind loads. As a vital part driving the blade oscillation, they support the turbine blades and transmit the pitch driving force to them. The load on the pitch bearing is significantly influenced by wind direction, wind force, and blade attitude, exhibiting considerable randomness. Furthermore, pitch bearings have a high lifespan, typically 20 years or longer, and their performance and reliability directly affect the normal operation of the wind turbine.

[0003] Pitch bearings bear axial force, radial force, and overturning moment. Under the combined action of wind force and the weight of the blades themselves, the overturning moment is the most significant load borne by the pitch bearing. The structural forms of pitch bearings in wind turbine generators are generally double-row four-point contact ball bearings and three-row cylindrical roller bearings. In recent years, the three-row cylindrical roller pitch bearing structure has become the mainstream in high-power wind turbines. Its three rows of cylindrical rollers consist of two rows of axial cylindrical rollers and one row of radial cylindrical rollers. The two rows of axial cylindrical rollers and their corresponding raceways bear the greater load, with the row of axial rollers closer to the hub bearing a relatively larger load.

[0004] Currently, most three-row cylindrical roller bearings employ two rows of parallel axial cylindrical rollers, i.e., two rows of thrust cylindrical rollers with a bearing contact angle of 90°. Under the action of overturning moment, the bearing's shaft ring (inner ring) and housing ring (outer ring) will undergo certain deformation, relative displacement, and deflection, as well as some deformation of the raceways, ultimately leading to an off-center load on the rollers. Severe off-center loading can cause stress concentration at the roller edges, affecting the bearing's ultimate load-carrying capacity, while also exacerbating raceway and roller damage, thus reducing bearing life. Utility Model Content

[0005] In view of the shortcomings of the prior art, this utility model provides a three-row cylindrical roller pitch bearing, which tilts the second axial cylindrical rollers at a certain angle to optimize the roller off-center loading, avoid stress concentration, and thus improve the bearing load capacity and bearing life.

[0006] To achieve the above objectives, the present invention provides a three-row cylindrical roller pitch bearing, comprising an inner ring, an outer ring, a first axial cylindrical roller, a second axial cylindrical roller, and a third radial cylindrical roller. An annular protrusion is provided on the outer diameter side of the inner ring. The end face of the annular protrusion near the blade side is a first inner ring raceway surface perpendicular to the bearing's axial direction. The end face of the annular protrusion near the hub side is a second inner ring raceway surface forming an acute / obtuse angle with the bearing's axial direction. An annular groove is formed on the outer ring surface of the annular protrusion, and the bottom of the groove includes the third inner ring raceway surface. The outer ring has an annular recess on its inner diameter side. The annular recess includes a first outer ring raceway surface parallel to and facing the first inner ring raceway surface, a second outer ring raceway surface parallel to and facing the second inner ring raceway surface, and a third outer ring raceway surface facing the third inner ring raceway surface. A first axial cylindrical roller is disposed between the first inner ring raceway surface and the first outer ring raceway surface. A second axial cylindrical roller is disposed between the second inner ring raceway surface and the second outer ring raceway surface. A third radial cylindrical roller is disposed between the third inner ring raceway surface and the third outer ring raceway surface.

[0007] Furthermore, the second inner raceway surface is inclined from the inside out and from the blade side to the hub side.

[0008] Preferably, the inclination angle of the second inner ring raceway surface is 5 to 10 degrees.

[0009] Furthermore, the outer ring includes a first outer ring near the blade side and a second outer ring near the hub side.

[0010] Furthermore, the first outer ring raceway surface and the third outer ring raceway surface are disposed on the first outer ring, and the second outer ring raceway surface is disposed on the second outer ring.

[0011] Furthermore, the first outer ring has a first outer ring mounting hole, and the second outer ring has a second outer ring mounting hole, with the first outer ring mounting hole and the second outer ring mounting hole being coaxially arranged.

[0012] Furthermore, a first cage is provided between the first outer ring and the inner ring, and the first axial cylindrical roller is installed in the first cage; a third cage is provided between the first outer ring and the inner ring, and the third radial cylindrical roller is installed in the third cage; a second cage is provided between the second outer ring and the inner ring, the outer ring of the second cage being closer to the hub side than the inner ring, and the second axial cylindrical roller is installed in the second cage.

[0013] Furthermore, the inner ring has an inner ring mounting hole.

[0014] Furthermore, a first seal and a second seal are provided between the inner ring and the outer ring, one near one end face of the bearing and the other near one end face of the bearing.

[0015] Furthermore, the first axial cylindrical roller and the second axial cylindrical roller have the same dimensions.

[0016] The beneficial effects of this utility model are as follows: tilting the second axial cylindrical roller near the hub side at a certain angle can reduce or avoid the roller's unbalanced load phenomenon, avoid stress concentration at the roller edge, improve the bearing's ultimate load capacity, reduce damage caused by the collision between the raceway and the roller, and thus improve the bearing's life. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a three-row cylindrical roller pitch bearing in one embodiment of the present invention; Figure 2 This is a partially enlarged view of the position of the second axial cylindrical rollers in a three-row cylindrical roller pitch bearing according to an embodiment of the present invention; Figure 3 A schematic diagram showing the eccentric loading of a single roller in the front bearing; Figure 4 A schematic diagram illustrating the situation where the single roller of the front bearing is severely overloaded. Figure 5 This is a schematic diagram showing the contact stress on a single roller of a three-row cylindrical roller pitch bearing in one embodiment of the present invention. In the picture: 100. Inner ring; 110. Annular protrusion; 111. First inner ring raceway surface; 112. Second inner ring raceway surface; 113. Annular groove; 1131. Third inner ring raceway surface; 120. Inner ring mounting hole; 130. First seal; 140. Second seal. 200, Outer ring; 210, Annular recess; 211, First outer ring raceway surface; 212, Second outer ring raceway surface; 213, Third outer ring raceway surface; 220, First outer ring; 221, First outer ring mounting hole; 230, Second outer ring; 231, Second outer ring mounting hole. 300. First axial cylindrical roller. 400. Second axial cylindrical roller. 500, Third radial cylindrical roller, 600. First cage, 700, Third Cage 800. Second cage; 810. Outer ring; 820. Inner ring. 10. Blade side; 20. Hub side. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0019] See Figure 1 and Figure 2 This diagram illustrates a three-row cylindrical roller pitch bearing according to an embodiment of the present invention. It includes an inner ring 100, an outer ring 200, a first axial cylindrical roller 300, a second axial cylindrical roller 400, and a third radial cylindrical roller 500. An annular protrusion 110 is provided on the outer diameter side of the inner ring 100. The end face of the annular protrusion 110 near the blade side 10 is a first inner ring raceway surface 111 perpendicular to the bearing's axial direction. The end face of the annular protrusion 110 near the hub side 20 is a second inner ring raceway surface 112 forming an acute / obtuse angle with the bearing's axial direction. An annular groove 113 is formed on the outer ring surface of the annular protrusion 110. The bottom of the groove 113 includes the third inner ring raceway surface 112. 131; An annular recess 210 is provided on the inner diameter side of the outer ring 200. The annular recess 210 includes a first outer ring raceway surface 211 parallel to and facing the first inner ring raceway surface 111, a second outer ring raceway surface 212 parallel to and facing the second inner ring raceway surface 112, and a third outer ring raceway surface 213 facing the third inner ring raceway surface 1131; a first axial cylindrical roller 300 is disposed between the first inner ring raceway surface 111 and the first outer ring raceway surface 211; a second axial cylindrical roller 400 is disposed between the second inner ring raceway surface 112 and the second outer ring raceway surface 212; and a third radial cylindrical roller 500 is disposed between the third inner ring raceway surface 1131 and the third outer ring raceway surface 213. Preferably, in one embodiment, the second inner ring raceway surface 112 is inclined from the inside to the outside, from the blade side 10 to the hub side 20.

[0020] It should be noted that in traditional three-row cylindrical roller pitch bearings, the different deflection distances of the raceway on the outer diameter side and the inner diameter side result in a larger load on one side of the rollers, leading to a certain degree of unbalanced load distribution. In contrast, the aforementioned three-row cylindrical roller pitch bearing, under the action of overturning moment, undergoes deformation, relative displacement, and deflection of the inner ring 100 and outer ring 200. By tilting the second axial cylindrical roller 400 on the hub side 20, the raceway distance changes more evenly when the bearing's shaft ring (inner ring 100) and seat ring (outer ring 200) deflect relative to each other, resulting in a more centered load on the rollers.

[0021] First, a three-row cylindrical roller pitch bearing is designed normally. Then, based on the bearing load and simulation analysis results, the roller tilt angle is adjusted. After determining the roller tilt angle, the raceway, oil groove, cage, etc., are designed accordingly. Preferably, in one embodiment, the tilt angle range of the second inner ring raceway surface 112 from the inside to the outside, and from the blade side 10 to the hub side 20, is 5 degrees to 10 degrees. It should be noted that smaller or larger angle ranges may also be used. The purpose of setting the cylindrical tilt angle is to achieve an acceptable contact stress state. The specific operation includes first setting an initial angle based on the stress distribution of the untilted rollers and design experience, and then repeatedly adjusting it based on experience and the stress state after adjusting the angle.

[0022] See 3 and Figure 4 Both figures represent the stress distribution curves of a single roller before the improvement. The horizontal axis in the graph represents the distance along the length of the roller, and the vertical axis represents the contact stress between the roller and the raceway at the corresponding position. As can be seen from the curves, the rollers on the higher side have higher stress, while those on the lower side have lower stress, indicating uneven stress distribution and a phenomenon of roller eccentricity. Figure 4 As shown, if the stress difference is significant, especially if the stress curve at one edge of the roller still shows an upward trend, it indicates a severe case of eccentric loading. See also [reference needed]. Figure 5 The purpose of this invention is to reduce the eccentric load on the rollers. Through the improvements made in this invention, a more ideal stress curve is approximately as follows: Figure 5 As shown, the roller is subjected to relatively balanced forces along its length, and the load on the roller is relatively centered, which improves the eccentric loading of the roller. Even if the ideal stress curve is not reached, that is, the position of the bulge in the middle of the curve is not exactly in the middle, the position of the bulge is slightly off-center, which still improves the eccentric loading of the roller to a certain extent.

[0023] The aforementioned three-row cylindrical roller pitch bearing tilts the second axial cylindrical roller 400 at a certain angle to optimize roller eccentricity, avoid stress concentration, and improve bearing load capacity and life. The angle between the second inner ring raceway surface 112 and the second outer ring raceway surface 212 is equal to or approximately equal to the tilt angle of the second axial cylindrical roller 400 to improve fit. Additionally, as... Figure 1 As shown, in this embodiment, the radius of the inner oil groove of the raceway is adjusted to facilitate processing and avoid sharp corners and interference.

[0024] In one embodiment, the outer ring 200 includes a first outer ring 220 near the blade side 10 and a second outer ring 230 near the hub side 20.

[0025] In one embodiment, the first outer ring raceway surface 211 and the third outer ring raceway surface 213 are disposed on the first outer ring 220, and the second outer ring raceway surface 212 is disposed on the second outer ring 230.

[0026] In one embodiment, the first outer ring 220 has a first outer ring mounting hole 221, and the second outer ring 230 has a second outer ring mounting hole 231. The first outer ring mounting hole 221 and the second outer ring mounting hole 231 are coaxially arranged to facilitate the connection of the outer ring 200 to the hub.

[0027] In one embodiment, a first retainer 600 is disposed between the first outer ring 220 and the inner ring 100, and a first axial cylindrical roller 300 is fitted into the first retainer 600; a third retainer 700 is disposed between the first outer ring 220 and the inner ring 100, and a third radial cylindrical roller 500 is fitted into the third retainer 700. See also Figure 2 A second cage 800 is provided between the second outer ring 230 and the inner ring 100. The second cage 800 includes an outer ring 810, an inner ring 820, and beams (not shown in the figure) disposed between the outer ring 810 and the inner ring 820. Pockets for mounting rollers are formed between adjacent beams. The outer ring 810 of the second cage 800 is closer to the hub side than the inner ring 820. The second axial cylindrical roller 400 is installed in the second cage 800. In the above embodiment, the second axial cylindrical roller 400 and raceway are arranged at an angle, and the second cage 800 is designed to accommodate the angled rollers, facilitating ring machining and bearing assembly, and improving the stability of bearing operation.

[0028] In one embodiment, the inner ring 100 has an inner ring mounting hole 120 to facilitate the connection between the inner ring 100 and the blade.

[0029] In one embodiment, a first seal 130 near one end face of the bearing and a second seal 140 near the other end face of the bearing are provided between the inner ring 100 and the outer ring 200. This arrangement can reduce the entry of dust and other impurities into the bearing and reduce the outflow of lubricating oil injected into the bearing, thereby optimizing the lubrication effect of the bearing.

[0030] In one embodiment, the first axial cylindrical roller 300 and the second axial cylindrical roller 400 are of the same size.

[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "above," "below," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

Claims

1. A three-row cylindrical roller pitch bearing, characterized in that: include The inner ring has an annular protrusion on the outer diameter side. The end face of the annular protrusion near the blade side is a first inner ring raceway surface perpendicular to the bearing axis. The end face of the annular protrusion near the hub side is a second inner ring raceway surface at an acute / obtuse angle to the bearing axis. The outer ring surface of the annular protrusion has an annular groove, and the bottom of the annular groove includes a third inner ring raceway surface. The outer ring has an annular recess on the inner diameter side. The annular recess includes a first outer ring raceway surface that is parallel to and faces the first inner ring raceway surface, a second outer ring raceway surface that is parallel to and faces the second inner ring raceway surface, and a third outer ring raceway surface that faces the third inner ring raceway surface. A first axial cylindrical roller is disposed between the first inner ring raceway surface and the first outer ring raceway surface; The second axial cylindrical roller is disposed between the raceway surface of the second inner ring and the raceway surface of the second outer ring. A third radial cylindrical roller is disposed between the third inner raceway surface and the third outer raceway surface.

2. The three-row cylindrical roller pitch bearing according to claim 1, characterized in that: The second inner raceway surface is inclined from the inside out and from the blade side to the hub side.

3. A three-row cylindrical roller pitch bearing according to claim 2, characterized in that: The inclination angle of the second inner ring raceway surface is 5 to 10 degrees.

4. A three-row cylindrical roller pitch bearing according to any one of claims 1-3, characterized in that: The outer ring includes a first outer ring near the blade side and a second outer ring near the hub side.

5. A three-row cylindrical roller pitch bearing according to claim 4, characterized in that: The first outer ring raceway surface and the third outer ring raceway surface are disposed on the first outer ring, and the second outer ring raceway surface is disposed on the second outer ring.

6. A three-row cylindrical roller pitch bearing according to claim 4, characterized in that: The first outer ring has a first outer ring mounting hole, and the second outer ring has a second outer ring mounting hole. The first outer ring mounting hole and the second outer ring mounting hole are coaxially arranged.

7. A three-row cylindrical roller pitch bearing according to claim 4, characterized in that: A second retainer is provided between the second outer ring and the inner ring. The outer ring of the second retainer is closer to the hub side than the inner ring. The second axial cylindrical roller is installed in the second retainer.

8. A three-row cylindrical roller pitch bearing according to any one of claims 1-3, characterized in that: The inner ring has an inner ring mounting hole.

9. A three-row cylindrical roller pitch bearing according to any one of claims 1-3, characterized in that: A first seal is provided between the inner ring and the outer ring, near one end face of the bearing and a second seal is provided near the other end face of the bearing.

10. A three-row cylindrical roller pitch bearing according to any one of claims 1-3, characterized in that: The first axial cylindrical roller and the second axial cylindrical roller have the same dimensions.

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