Bearing for yaw gearbox

Abstract

The utility model relates to the technical field of wind driven generators, and discloses a bearing for a yaw gearbox, which comprises a bearing inner ring and a bearing outer ring, an inner raceway is arranged on the bearing inner ring, an outer raceway is arranged on the bearing outer ring, the inner raceway and the outer raceway are combined to form a first raceway and a second raceway, the second raceway is positioned below the first raceway, and the first raceway is positioned below the second raceway. The reference diameters of the first raceway and the second raceway are the same, an upper rolling ball and a lower rolling ball are respectively mounted in the first raceway and the second raceway, the contact angle of the bearing is not greater than 35 degrees, and the diameter of the lower rolling ball is greater than that of the upper rolling ball; the upper end of the bearing outer ring protrudes in the radial direction to form a mounting table. In practical application, the output assembly of the yaw gearbox is simpler and more compact in structure, the number of the bearings is reduced, the lubrication complexity of the output assembly is reduced, full lubrication of the bearings is guaranteed, and the service life of parts is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbines, and particularly relates to a bearing for a yaw gearbox. Background Art

[0002] As a speed reducer, the yaw gearbox is an important component of a wind turbine generator set. The yaw gearbox is vertically installed, and from top to bottom, it successively includes an input component, a planetary component (usually four-stage), and an output component. The output component of the yaw gearbox includes an output gear shaft and an output housing. To ensure the stable output of the output gear shaft, a plurality of independent bearings are vertically arranged between the existing output gear shaft and the output housing. For example, the output device of the wind turbine gearbox disclosed in the Chinese patent with the publication number CN201129435Y. However, this structure makes the overall structure of the output component not compact enough, occupies a large space in the fan nacelle, and the multi-bearing structure means that a more complex lubrication system is required to ensure that each bearing can be fully lubricated, and at the same time, it may increase the difficulty of heat dissipation and affect the service life of the yaw gearbox. Content of the Utility Model

[0003] The utility model aims to provide a bearing for a yaw gearbox to solve the problems of poor structural compactness of the output component of the yaw gearbox and high bearing lubrication difficulty.

[0004] To achieve the above object, the utility model adopts the following technical scheme: A bearing for a yaw gearbox includes an inner bearing ring and an outer bearing ring. An inner raceway is formed on the inner bearing ring, and an outer raceway is formed on the outer bearing ring. The inner raceway and the outer raceway are combined to form a first raceway and a second raceway. The second raceway is located below the first raceway, and the pitch circle diameters of the first raceway and the second raceway are the same. Upper balls and lower balls are respectively installed in the first raceway and the second raceway. The contact angle of the bearing is not greater than 35°. The diameter of the lower ball is larger than that of the upper ball; a mounting table protrudes radially from the upper end of the outer bearing ring.

[0005] The principle and advantages of this scheme are as follows:

[0006] 1. In this scheme, the contact angle between the balls and the raceways is within 35°. Therefore, under the condition of bearing the same load, compared with the traditional structure using multiple bearings to cooperate in force, the bearing structure of this scheme is more compact and smaller; secondly, the smaller contact angle enables the upper and lower balls to share the load applied to the bearing more evenly, thus reducing the probability that a single ball bears an excessive load. Therefore, the upper ball generally does not reach its maximum load-bearing potential. Furthermore, in this scheme, the upper and lower balls are designed with different diameters, one small and one large. Such a design not only effectively ensures that the upper ball can exert its maximum load-bearing potential and improves economy, but also effectively reduces the height of the bearing by reducing the diameter of the upper ball and improves the compactness of the structure.

[0007] 2. This solution uses upper and lower rolling balls with different diameters to form a double-row ball bearing with the inner ring and outer ring of the bearing, replacing multiple independently sealed tapered roller bearings in the existing yaw output assembly. The double-row ball bearing can provide a radial and axial load-bearing capacity equal to or even greater than that of tapered roller bearings in a smaller space, effectively ensuring the bearing structure strength and anti-deformation ability. At the same time, concentrating the upper and lower rolling balls in the same bearing reduces the overall spatial span of the bearing structure, greatly reducing the overall volume of the output assembly, improving the structural compactness, facilitating the lightweight and miniaturization design of wind turbines, increasing the space utilization rate, and reducing the manufacturing cost.

[0008] 3. In this solution, the diameter of the lower rolling ball is larger than that of the upper rolling ball. The lower rolling ball provides a larger support surface during rotation, enhancing the radial load-bearing capacity of the bearing. When the larger lower rolling ball bears the same load, the contact stress is reduced, improving the anti-fatigue strength and operating stability of the bearing.

[0009] 4. In this solution, the pitch circle diameters of the first raceway and the second raceway are the same, which helps to more evenly distribute the load between the upper and lower rolling balls. Even under dynamically changing working conditions, it can maintain a good force balance, avoiding excessive stress on a single rolling element, thereby extending the bearing service life. At the same time, the same pitch circle diameter ensures that the upper and lower rolling balls can maintain a consistent radial motion trajectory during rotation, ensuring the high-precision operation of the yaw gearbox, and the improvement of coaxiality reduces vibration and noise during operation, improving the operating stability of the entire wind power generation system.

[0010] 5. Compared with the multi-bearing design of the existing yaw output assembly, the double-row ball bearing design of this solution not only significantly reduces the number of bearings, but also makes the bearing structure more concentrated, making the bearing lubrication system more concentrated and efficient. While reducing the lubrication points, it also reduces the complexity of the cooling system, helps to maintain a good operating temperature, and extends the service life of the bearing and gearbox.

[0011] 6. Reducing the number of bearings in this solution effectively simplifies the internal structure of the yaw gearbox, reduces the design complexity and assembly difficulty, improves production efficiency, and also facilitates subsequent maintenance and repair work.

[0012] 7. In this solution, the upper end of the outer ring of the bearing protrudes radially to form a mounting platform, simplifying the installation process of the bearing in the yaw gearbox, providing a stable mounting interface, ensuring the correct and reliable positioning of the bearing, avoiding initial failures caused by improper installation, and improving the assembly efficiency.

[0013] Furthermore, the diameter ratio of the upper rolling ball to the lower rolling ball is 0.7 - 0.9.

[0014] Within the above diameter ratio range, the upper and lower rolling balls are uniformly stressed. When the diameter ratio of the two rolling balls is less than the above range, that is, the diameter of the upper rolling ball located above is too small to meet its own stress requirements; when the diameter ratio of the two rolling balls is greater than the above range, originally the lower rolling ball bears more load. After the diameter of the upper rolling ball increases, it will try to participate in the load sharing more equally. However, due to physical limitations, the increase in the load-bearing capacity of the upper rolling ball is not completely linear. Therefore, it cannot significantly reduce the burden on the lower layer. Even in the case of improper adjustment, on the contrary, due to uneven load distribution, the stress on the large-diameter rolling ball in the lower layer increases, the fatigue damage of the lower rolling ball increases, and the service life is reduced.

[0015] Further, the contact angle is 30°.

[0016] When the contact angle is 30°, firstly, it can more effectively control the centrifugal force of the rolling ball under high-speed application conditions, ensuring the long-term stability and safe operation of the bearing at high speed; secondly, when bearing dynamic loads, the 30° contact angle can provide better rolling guidance and control, reduce non-linear vibration, improve the dynamic response performance of the entire system, and at the same time reduce wear and energy consumption.

[0017] Further, both the first raceway and the second raceway are raceways with a peach-shaped cross-section. The peach-shaped design of the raceway cross-section makes the bearing stress more uniform.

[0018] Further, a shoulder is provided between the first raceway and the second raceway, and the height of the shoulder is 3 - 6 mm.

[0019] The shoulder is provided to provide guidance and limit for the upper and lower rolling balls. In a dynamic load and vibration environment, the shoulder can effectively restrict the movement trajectory of the rolling ball, reduce unnecessary degrees of freedom of movement, and improve the overall working reliability of the bearing.

[0020] The height of the shoulder is designed to be 3 - 6 mm. Firstly, if the height of the shoulder is too high, the center distance between the upper and lower rolling balls will increase. Since the first and second raceways are no longer adjacent, the radial reaction force transmitted from the upper rolling ball to the bearing housing will cause slight elastic deformation of the bearing housing. This deformation will cause the contact pressure at the lower rolling ball to increase because more force is required to balance the external load and the internal preload, so that the force borne by the lower rolling ball increases compared to when the center distance is smaller; secondly, if the height of the shoulder is too high, the overall height of the bearing will increase, which is contradictory to the purpose of a compact structure.

[0021] Further, threaded through-holes are uniformly provided along the circumference of the mounting table.

[0022] The threaded through-holes facilitate the threaded connection of the mounting table with other parts, and the bearing outer ring with the mounting table acts as an output box, reducing the overall number of components of the output structure and making the structure more compact.

[0023] Further, oil seals are provided on the upper and lower sides of the inner bearing ring and the outer bearing ring.

[0024] The oil seals on the upper and lower sides form a sealed lubricating space between the inner bearing ring and the outer bearing ring, effectively preventing dust and impurities from entering the bearing interior, reducing the friction and wear between the rolling balls and the raceways, and extending the service life of the bearing.

[0025] Further, an installation groove is formed on the inner side of the installation table, and the bottom of the installation groove is flush with the upper end surface of the inner bearing ring. The oil seal on the upper side is fixed in the installation groove.

[0026] The installation table is provided with an installation groove on the inner side and the upper-side oil seal is fixed by its own structure, eliminating the need for an additional structure to fix the oil seal. This not only simplifies the overall structure and installation process but also makes the positioning between the bearing assembly and the planet carrier more accurate, improving the structural accuracy of the output assembly.

[0027] Further, first filling holes and second filling holes are respectively formed at the height positions of the first raceway and the second raceway on the inner bearing ring. The first filling holes and the second filling holes are staggered horizontally. First filling blocks and second filling blocks are respectively installed in the first filling holes and the second filling holes. The ends of the first filling blocks and the second filling blocks facing the outer bearing ring have the same shape as the first raceway and the second raceway.

[0028] The above settings are for the convenience of filling the rolling balls into the first and second raceways and preventing the rolling balls from deviating from the raceways. Second, the horizontal staggering of the first filling holes and the second filling holes avoids the stress concentration and weakened bearing capacity of the inner bearing ring caused by the vertical overlap of the first filling holes and the second filling holes in the same vertical area, ensuring the overall structural strength of the bearing.

[0029] Further, axially penetrating pin holes are formed at the first filling holes and the second filling holes on the inner bearing ring. Through holes corresponding to the pin holes on the inner bearing ring are formed on the first filling blocks and the second filling blocks. Positioning pins are installed in the pin holes and the through holes.

[0030] The positioning pins assembled in the pin holes and the through holes make the connection between the filling blocks and the inner bearing ring more stable, and also help to prevent the filling blocks from shaking under dynamic conditions and affecting the movement track of the rolling balls, thus improving the overall working reliability of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present utility model.

[0032] Figure 2 It is an assembly schematic diagram of the bearing and the planet carrier of Embodiment 1 of the present utility model.

[0033] Figure 3 It is an exploded structural diagram of Embodiment 2.

[0034] Figure 4 It is a schematic structural diagram of the bearing inner ring in the second embodiment. Detailed implementation manners

[0035] The following is a further detailed description through specific implementation manners:

[0036] The reference numerals in the accompanying drawings of the specification include: planet carrier 100, output gear shaft 200, bearing inner ring 1, bearing outer ring 2, first raceway 3, second raceway 4, upper rolling ball 5, lower rolling ball 6, mounting table 7, oil seal 8, shoulder 9, mounting groove 10, first filling hole 11, second filling hole 12, first filling block 13, second filling block 14, positioning pin 15.

[0037] Embodiment 1

[0038] Basically as shown in the attached Figure 1 - Figure 2 As shown: A bearing for a yaw gearbox includes a bearing inner ring 1 and a bearing outer ring 2. During specific assembly, the outer edge of the planet carrier 100 is placed on the upper end surface of the bearing inner ring 1, and an interference fit or a spline interference fit is performed between the bearing inner ring 1 and the outer circumference of the bottom of the planet carrier 100. The lower end surface of the bearing inner ring 1 is in contact with the middle step surface of the output gear shaft 200; an inner raceway is provided on the bearing inner ring 1, and an outer raceway is provided on the bearing outer ring 2. The inner raceway and the outer raceway are combined to form a first raceway 3 and a second raceway 4. The second raceway 4 is located below the first raceway 3. The pitch circle diameters of the first raceway 3 and the second raceway 4 are the same. Both the first raceway 3 and the second raceway 4 are raceways with a peach-shaped cross-section, so that the bearing force is more uniform; upper rolling balls 5 and lower rolling balls 6 are respectively installed in the first raceway 3 and the second raceway 4. The contact angle of the bearing is 20° - 35°. In this way, under the condition of bearing the same load, compared with the structure of using multiple bearings to cooperate in bearing force in the traditional way, the structure of this bearing is more compact and smaller. Preferably, the contact angle in this embodiment is 30°. At this contact angle, the centrifugal force of the rolling balls can be more effectively controlled, ensuring the lasting stability and safe operation of the bearing under high-speed conditions. At the same time, when bearing dynamic loads, the 30° contact angle can provide better rolling guidance and control, reduce non-linear vibration, improve the dynamic response performance of the entire system, and at the same time reduce wear and energy consumption.

[0039] The upper end of the outer ring 2 of the bearing protrudes radially to form a mounting table 7. Threaded holes (not shown in the figure) are evenly arranged along the circumferential direction of the mounting table 7 and are threadedly connected to other components. The outer ring 2 of the bearing with the mounting table 7 serves as the output box body, reducing the overall components of the output structure and making the structure more compact. Oil seals 8 are provided on the upper and lower sides of the inner ring 1 and the outer ring 2 of the bearing. The oil seals 8 form a sealed lubricating space between the inner ring 1 and the outer ring 2 of the bearing, effectively preventing dust and impurities from entering the bearing interior, reducing the friction and wear between the rolling balls and the raceways, and extending the service life of the bearing. Preferably, a mounting groove 10 is formed inside the mounting table 7. The bottom of the mounting groove 10 is flush with the upper end surface of the inner ring 1 of the bearing. The upper oil seal 8 is placed in the mounting groove 10. Through the mounting groove 10, the upper oil seal 8 is fixed by using the self-structures of the outer ring 2 of the bearing and the planet carrier 100, eliminating the need for an additional structure to fix the oil seal, effectively simplifying the overall structure and the installation process, making the positioning between the bearing and the planet carrier 100 more accurate, and improving the structural accuracy of the output assembly.

[0040] Preferably, the diameter of the lower rolling ball 6 is larger than that of the upper rolling ball 5, and the diameter ratio of the upper rolling ball 5 to the lower rolling ball 6 is 0.7 - 0.9. Within the above diameter ratio range, both the upper rolling ball 5 and the lower rolling ball 6 are evenly stressed. When the diameter ratio of the two rolling balls is less than the above range, that is, the diameter of the upper rolling ball 5 located above is too small to meet its own stress requirements. When the diameter ratio of the two rolling balls is greater than the above range, originally the lower rolling ball 6 bears more loads. After the diameter of the upper rolling ball 5 increases, it will try to participate in the load sharing more equally. However, due to physical limitations, the increase in the load-bearing capacity of the upper rolling ball 5 is not completely linear. Therefore, it cannot significantly reduce the burden on the lower layer. Even in the case of improper adjustment, due to uneven load distribution, the stress on the lower large-diameter rolling ball increases, resulting in an increase in the fatigue damage of the lower rolling ball 6 and a reduction in its service life.

[0041] A shoulder 9 is provided between the first raceway 3 and the second raceway 4. The movement trajectories of the upper rolling ball 5 and the lower rolling ball 6 are restricted by the shoulder 9, reducing unnecessary degrees of freedom of movement and improving the overall working reliability of the bearing. The height of the shoulder 9 is 3 - 6 mm. In this embodiment, the height of the shoulder 9 is set to 5 mm. First, if the height of the shoulder 9 is too high, the center distance between the upper rolling ball 5 and the lower rolling ball 6 will increase. Since the first raceway 3 and the second raceway 4 are no longer adjacent, the radial reaction force transmitted by the upper rolling ball 5 to the bearing housing will cause a slight elastic deformation of the bearing housing. This deformation will cause the contact pressure at the lower rolling ball 6 to increase, resulting in the need for more force to balance the external load and the internal preload force. Thus, the force borne by the lower rolling ball 6 increases compared to when the center distance is smaller. Second, if the height of the shoulder 9 is too high, the overall height of the bearing will increase, which is contradictory to the purpose of a compact structure.

[0042] Embodiment Two

[0043] Compared with Embodiment One, asFigure 3 - Figure 4 As shown, in this embodiment, the bearing inner ring 1 is respectively provided with a first filling hole 11 and a second filling hole 12 at the height positions of the first raceway 3 and the second raceway 4. The first filling hole 11 and the second filling hole 12 are staggeredly arranged in the horizontal position. A first filling block 13 and a second filling block 14 are respectively installed in the first filling hole 11 and the second filling hole 12. The ends of the first filling block 13 and the second filling block 14 facing the bearing outer ring 2 have the same shape as the first raceway 3 and the second raceway 4. The staggered arrangement of the first filling hole 11 and the second filling hole 12 in the horizontal position avoids the stress concentration and the reduction of the bearing capacity of the bearing inner ring 1 caused by the vertical overlap of the first filling hole 11 and the second filling hole 12 in the same vertical area, and ensures the overall structural strength of the bearing.

[0044] The bearing inner ring 1 is provided with axially penetrating pin holes at the first filling hole 11 and the second filling hole 12. Through holes corresponding to the pin holes of the bearing inner ring 1 are provided on the first filling block 13 and the second filling block 14. A positioning pin 15 is installed in the pin holes and the through holes. The assembly of the positioning pin 15 in the pin holes and the through holes makes the connection between the filling block and the bearing inner ring 1 more stable, and also helps to avoid the shaking of the filling block under dynamic conditions, which affects the movement trajectory of the rolling balls, so as to improve the overall working reliability of the bearing.

[0045] The above are only the embodiments of the present invention. The well-known specific technical solutions and / or common knowledge such as characteristics are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention. These will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application shall be subject to the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. A bearing for a yaw gearbox, characterized in that: It includes an inner bearing ring and an outer bearing ring. An inner raceway is formed on the inner bearing ring, and an outer raceway is formed on the outer bearing ring. The inner raceway and the outer raceway are combined to form a first raceway and a second raceway. The second raceway is located below the first raceway, and the pitch circle diameters of the first raceway and the second raceway are the same. Upper balls and lower balls are respectively installed in the first raceway and the second raceway. The contact angle of the bearing is not greater than 35°, and the diameter of the lower balls is larger than that of the upper balls. The upper end of the outer bearing ring protrudes radially to form a mounting table.

2. The bearing for a yaw gearbox according to claim 1, characterized in that: The diameter ratio of the upper balls to the lower balls is 0.7 - 0.

9.

3. The bearing for a yaw gearbox according to claim 2, wherein: The contact angle is 30°.

4. The bearing for a yaw gearbox according to claim 3, characterized in that: Both the first raceway and the second raceway are raceways with a peach-shaped cross-section.

5. The bearing for a yaw gearbox according to claim 4, characterized in that: A shoulder is provided between the first raceway and the second raceway, and the height of the shoulder is 3 - 6 mm.

6. The bearing for a yaw gearbox according to claim 5, wherein: Threaded through holes are evenly arranged along the circumference of the mounting table.

7. A bearing for a yaw gearbox according to claim 6, characterized in that: Oil seals are provided on the upper and lower sides of the inner bearing ring and the outer bearing ring.

8. A bearing for a yaw gearbox according to claim 7, characterized in that: An installation groove is formed on the inner side of the mounting table. The bottom of the installation groove is flush with the upper end face of the inner bearing ring, and the oil seal on the upper side is fixed in the installation groove.

9. A bearing for a yaw gearbox according to claim 8, characterized in that: The inner bearing ring is respectively provided with a first filling hole and a second filling hole at the height positions of the first raceway and the second raceway. The first filling hole and the second filling hole are staggered in the horizontal position. A first filling block and a second filling block are respectively installed in the first filling hole and the second filling hole. The ends of the first filling block and the second filling block facing the outer bearing ring have the same shape as the first raceway and the second raceway.

10. A bearing for a yaw gearbox according to claim 9, characterized in that: The inner bearing ring is provided with axially penetrating pin holes at the positions of the first filling hole and the second filling hole. Through holes corresponding to the pin holes of the inner bearing ring are formed on the first filling block and the second filling block, and positioning pins are installed in the pin holes and the through holes.

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