Weight-reduction small-size yaw gearbox output shaft structure

Abstract

The utility model relates to the technical field of wind driven generators, and discloses a weight reduction type small-size yaw gearbox output shaft structure which comprises an output gear shaft, a planet carrier and a bearing assembly, a radial fastening unit and an axial fastening unit are arranged between the output gear shaft and the planet carrier, the bearing assembly is arranged on the periphery of the planet carrier in a sleeved mode, and the bearing assembly is arranged on the planet carrier. The bearing assembly comprises a bearing inner ring and a bearing outer ring, a first roller path and a second roller path are arranged in the bearing assembly, the second roller path is located below the first roller path, the reference diameters of the second roller path and the first roller path are the same, an upper rolling ball and a lower rolling ball are installed in the first roller path and the second roller path respectively, the contact angle of the bearing assembly is not larger than 35 degrees, and the diameter of the lower rolling ball is larger 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. According to the scheme, the problems that an output assembly of the yaw gearbox is low in compactness and large in height and weight are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbines, and particularly relates to a weight-reducing and small-volume output shaft structure of a yaw gearbox. Background Art

[0002] As a speed reducer, the yaw gearbox is an important component of a wind power generation unit. 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 total height of the final-stage planetary component and the output component of the existing yaw gearbox is relatively large, the output positioning structure is not compact, and the weight is relatively large, which increases the moment of inertia of the yaw system, increases the energy consumption during startup and shutdown, and affects the overall efficiency of the wind power generation system. At the same time, under frequent yaw operations, the high energy consumption will directly affect the power generation cost and economic benefits of the wind turbine unit.

[0003] The applicant optimized and improved the structure for the above-mentioned defects and applied for a Chinese patent, a yaw gearbox with the publication number CN217713572U. In the technical solution disclosed in this patent, the outer rings of the multi-stage planetary gear assemblies are directly formed on the output housing, so that the gear ring and the original output housing are combined into a whole, reducing the machining and assembly of the gearbox parts; and a convex ring and an inner step are formed on the output housing, and a first spherical plain bearing and a second spherical plain bearing are respectively installed through the inner step. The spherical plain bearings are used to replace the tapered roller bearings, so that the first spherical plain bearing and the second spherical plain bearing are close to each other, reducing the installation distance between the two and lowering the height of the output housing. Although the above output shaft structure has greatly improved the total height and weight of the yaw gearbox, the applicant found in the subsequent further analysis and research process that there is still room for further improvement in the above structure. Therefore, the applicant further provides a weight-reducing and small-volume output shaft structure of a yaw gearbox with a simple structure and high structural compactness. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a weight-reducing and small-volume output shaft structure of a yaw gearbox, which reduces the overall volume and weight of the output component of the yaw gearbox and reduces the equipment cost.

[0005] To achieve the above object, the present utility model adopts the following technical solution: A weight-reducing and small-volume output shaft structure of a yaw gearbox, comprising an output gear shaft, a planet carrier and a bearing assembly. A radial fastening unit and an axial fastening unit are provided between the output gear shaft and the planet carrier. The bearing assembly is sleeved on the outer periphery of the planet carrier. The bearing assembly includes an inner bearing ring and an outer bearing ring. A first raceway and a second raceway are provided inside the bearing assembly. 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. An upper rolling ball and a lower rolling ball are respectively installed in the first raceway and the second raceway. The contact angle of the bearing assembly is not greater than 35°. The diameter of the lower rolling ball is larger than that of the upper rolling ball; an installation platform protrudes radially from the upper end of the outer bearing ring.

[0006] The principle and advantages of this solution are as follows:

[0007] 1. In this solution, the end of the output gear shaft extends into the inner hole of the planet carrier for fixation, and the bearing assembly is sleeved on the outer periphery of the planet carrier, so that the output gear shaft, the planet carrier and the bearing assembly are highly integrated horizontally, reducing the longitudinal occupied space of the structure, making the overall structure more compact, and thus reducing the total height of the output assembly; Secondly, the outer bearing ring of this solution acts as the output housing, effectively reducing the number of components compared with the prior art, making the overall structure simpler, reducing the height while reducing the overall volume and weight of the output assembly, effectively reducing the production and manufacturing cost.

[0008] 2. In this solution, a connected first raceway and a second raceway are integrated between the inner bearing ring and the outer bearing ring, and the upper rolling ball and the lower rolling ball are concentrated in the same bearing to form a double-row ball bearing. Under the same load, the double-row ball bearing can provide greater radial and axial load-bearing capacities in a smaller space. While ensuring the bearing structure strength and anti-deformation ability, the structural dimensions of the bearing assembly in this solution can be more miniaturized, the overall space span is reduced, effectively reducing the height and weight of the output assembly, which is beneficial to the lightweight and miniaturized design of the wind turbine generator set, improving the space utilization rate; Secondly, compared with the design of multiple independent bearings of the existing yaw output assembly, not only the number of bearings is significantly reduced, but also the bearing structure is 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 the gearbox; Moreover, the reduction in the number of bearings effectively simplifies the internal structure of the yaw gearbox, reduces the design complexity and assembly difficulty, improves the production efficiency, and is also convenient for subsequent maintenance and repair work.

[0009] 3. In this solution, the contact angle of the bearing assembly is within 35°. Therefore, under the condition of bearing the same load, compared with the traditional structure that uses multiple bearings to cooperate in bearing force, the structure of this bearing assembly is more compact and smaller. Secondly, the smaller contact angle enables the upper and lower rolling balls to share the load applied to the bearing more evenly, thus reducing the probability that a single rolling ball bears an excessive load. Therefore, the upper rolling ball generally does not reach its maximum load-bearing potential. Furthermore, in this solution, the upper and lower rolling balls are designed with different diameters, one larger and one smaller. Such a design not only effectively ensures that the upper rolling ball can exert its maximum load-bearing potential and improves economy, but also effectively reduces the height of the bearing assembly and the overall output assembly by reducing the diameter of the upper rolling ball, thereby improving the compactness of the structure.

[0010] 4. In this solution, the pitch circle diameters of the first raceway and the second raceway are the same, which helps to distribute the load between the upper and lower rolling balls more evenly, and can maintain a better force balance even under dynamic working conditions, avoiding excessive force on a single rolling element, thereby prolonging the service life of the bearing. At the same time, the same pitch circle diameter ensures that the upper and lower rolling balls can maintain the same radial movement 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 operation stability of the entire wind power generation system.

[0011] 5. In this solution, the upper end of the bearing outer ring protrudes radially to form a mounting platform, which simplifies the installation process of the bearing in the yaw gearbox, provides a stable mounting interface, ensures the correct and reliable positioning of the bearing, avoids initial faults caused by improper installation, and improves the assembly efficiency.

[0012] Furthermore, the radial fastening unit is a spline structure.

[0013] The spline structure makes the transmission between the planet carrier and the output gear shaft more stable, can effectively prevent slippage between the two, ensure synchronous rotation between the two, and improve the operation stability of the overall fan.

[0014] Furthermore, the axial fastening unit includes a fixing bolt for connecting the planet carrier and the output gear shaft and a gasket located between the fixing bolt and the planet carrier. The end of the fixing bolt extends into the output gear shaft, and a gasket groove is opened in the upper part of the planet carrier, and the gasket is fixed in the gasket groove.

[0015] The above-mentioned connection and fixation of the planet carrier and the output gear shaft by the fixing bolt effectively reduce the overall structure height. In addition, the setting of the gasket is for one thing to reduce the frictional damage between the fixing bolt and the planet carrier, and for another thing to enable the pressing force of the fixing bolt to be applied to the planet carrier more evenly.

[0016] Further, the lower end faces of the bearing assembly and the planet carrier are flush. The upper end face of the output gear shaft fits with the upper end face of the inner hole of the planet carrier. The output gear shaft is a stepped shaft, and there is a gap between the middle step face thereof and the lower end face of the planet carrier. The bearing assembly is provided with fastening bolts for connecting with the planet carrier.

[0017] For the above output gear shaft structure, the fastening bolts lift the inner ring of the bearing upward and connect and fix it with the planet carrier to prevent the inner ring of the bearing from falling off downward. Moreover, the fastening bolts can share part of the axial load and enhance the axial load capacity of the bearing assembly.

[0018] Further, the output gear shaft is a stepped shaft, and there is a gap between its upper end face and the lower end face of the gasket. The lower end face of the bearing assembly is lower than the lower end face of the planet carrier and fits with the middle step face of the output gear shaft. A transition hole is formed between the inner hole of the planet carrier and the gasket groove. The gasket groove, the transition hole and the inner hole are stepped and connected. A snap ring is arranged in the transition hole, and the snap ring is fixed at the end of the output gear shaft.

[0019] When the output gear shaft is not in contact and connection with the planet carrier in the longitudinal direction, the snap ring axially limits the output gear shaft to prevent the output gear shaft from generating axial displacement and disengaging downward from the planet carrier during operation, causing an operation accident.

[0020] Further, the diameter ratio of the upper rolling ball to the lower rolling ball is 0.7 - 0.9.

[0021] Within the above diameter ratio range, the upper and lower rolling balls 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 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 lower large-diameter rolling ball increases, and the fatigue damage of the lower rolling ball increases, reducing the service life.

[0022] Further, oil seals are respectively arranged between the upper and lower ends of the bearing outer ring and the inner ring of the bearing and the planet carrier. An installation groove is formed inside the installation table, and the bottom of the installation groove is flush with the upper end face of the inner ring of the bearing. The oil seal located above is arranged in the installation groove. The lower part of the planet carrier is stepped, and its shoulder is located in the installation groove and is installed on the inner ring of the bearing.

[0023] The oil seals on the upper and lower sides form a sealed lubricating space between the inner ring and the outer ring 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. The shoulder of the planet carrier is located within the mounting groove and mounted on the inner ring of the bearing, which is conducive to installation and positioning, simplifying the installation process. At the same time, the shoulder of the planet carrier presses and fixes the oil seal within the mounting groove, eliminating the need for additional structures to fix the oil seal, making the positioning between the bearing and the planet carrier more accurate and enhancing the structural precision of the output assembly.

[0024] Furthermore, 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 force distribution on the bearing more uniform.

[0025] Furthermore, a shoulder is provided between the first raceway and the second raceway, and the height of the shoulder is 3 - 6 mm.

[0026] The shoulder is provided to guide and limit the upper and lower rolling balls. In a dynamic load and vibration environment, the shoulder can effectively restrict the movement trajectory of the rolling balls, reducing unnecessary degrees of freedom of movement and improving the overall working reliability of the bearing.

[0027] The height of the shoulder is designed to be 3 - 6 mm. First, 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 inner and outer rings of the bearing will cause slight elastic deformation of the inner and outer rings of the bearing. 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, resulting in an increase in the force borne by the lower rolling ball compared to when the center distance is smaller. Second, 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.

[0028] Furthermore, a final stage sun gear is coaxially installed above the planet carrier, and a receiving hole for accommodating the head of the fixing bolt is provided at the bottom of the final stage sun gear.

[0029] The above setting reduces the occupied space of the fixing bolt in the longitudinal direction and effectively reduces the overall height of the output assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the first embodiment of the present invention.

[0031] Figure 2 It is a schematic diagram of the structure of the bearing assembly of the first embodiment of the present invention.

[0032] Figure 3 It is a schematic diagram of the overall structure of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following is a further detailed description through specific embodiments:

[0034] The reference numerals in the accompanying drawings of the specification include: output gear shaft 1, planet carrier 2, inner hole 21, axial fastening unit 3, fixing bolt 31, gasket 32, radial fastening unit 4, bearing assembly 5, bearing inner ring 51, bearing outer ring 52, first raceway 53, second raceway 54, upper rolling ball 55, lower rolling ball 56, shoulder 57, mounting table 58, mounting groove 59, oil seal 6, fastening bolt 7, final stage sun gear 8, receiving hole 9, transition hole 10, snap ring 11.

[0035] Embodiment 1

[0036] Basically as shown in the attached Figure 1 - Figure 2 drawing: A weight-reduced and small-volume yaw gearbox output shaft structure includes an output gear shaft 1, a planet carrier 2, and a bearing assembly 5. An inner hole 21 is opened at the bottom of the planet carrier 2. The output gear shaft 1 is a two-stage stepped shaft. The upper end of the output gear shaft 1 extends upward into the inner hole 21 for interference fit. The bearing assembly 5 is sleeved on the outer periphery of the planet carrier 2 and is in interference fit or spline fit with the planet carrier 2 to prevent slippage between the two. A radial fastening unit 4 and an axial fastening unit 3 are provided between the output gear shaft 1 and the planet carrier 2. The radial fastening unit 4 is a spline structure. The spline structure includes an internal spline provided in the inner hole of the planet carrier 2 and an external spline at the end of the output gear shaft 1. Through the spline structure, the connection between the planet carrier 2 and the output gear shaft 1 is made more stable, effectively preventing slippage, ensuring synchronous rotation between the two, and ensuring the smooth operation of the fan. The axial fastening unit 3 includes a fixing bolt 31 and a gasket 32. The fixing bolt 31 passes through the planet carrier 2 from top to bottom and extends its end into the output gear shaft 1. The length of the rod body of the fixing bolt 31 located inside the output gear shaft 1 is not less than 1 / 2 of the depth of the inner hole 21, so as to ensure the stable connection between the planet carrier 2 and the output gear shaft 1. A gasket groove is opened at the upper part of the planet carrier 2. The gasket 32 is fixed in the gasket groove to separate the planet carrier 2 from the fixing bolt 31, so as to reduce the direct friction loss between the two and ensure that the pressing force of the fixing bolt 31 can be evenly applied to the planet carrier 2. A final stage sun gear 8 is coaxially installed above the planet carrier 2. A receiving hole 9 for receiving the head of the fixing bolt 31 is opened at the bottom of the final stage sun gear 8. In this way, the occupied space of the fixing bolt 31 in the longitudinal direction is effectively reduced, and the overall height of the output assembly is lowered.

[0037] The lower end face of the bearing assembly 5 is flush with the lower end face of the planet carrier 2. The upper end face of the output gear shaft 1 is in contact with the upper end face of the inner hole 21. There is a gap between the middle step face of the output gear shaft 1 and the lower end face of the planet carrier 2. The bearing assembly 5 includes an inner bearing ring 51 and an outer bearing ring 52. A fastening bolt 7 is provided on the inner bearing ring 51. The fastening bolt 7 lifts the inner bearing ring 51 upward and is connected and fixed to the planet carrier 2 to prevent the inner bearing ring 51 from falling off downward due to being suspended at the bottom. Moreover, the fastening bolt 7 can share part of the axial load and enhance the axial load capacity of the bearing assembly 5. The upper end of the outer bearing ring 52 protrudes radially to form a mounting table 58. The upper end face of the mounting table 58 is higher than the upper end face of the inner bearing ring 51. An installation groove 59 is opened on the inner side of the mounting table 58. The bottom of the installation groove 59 is flush with the upper end face of the inner bearing ring 51. The lower part of the planet carrier 2 is stepped. The shoulder of the planet carrier 2 is located in the installation groove 59 and is mounted on the inner bearing ring 51. This facilitates the rapid positioning and assembly of the planet carrier 2, simplifies the installation process and cycle. There is also a threaded hole (not shown in the figure) on the mounting table 58. The threaded hole design facilitates the threaded connection of the outer bearing ring 52 with other structures. The above settings enable the output gear shaft 1, the planet carrier 2, and the bearing assembly 5 to be highly integrated horizontally, reduce the longitudinal occupied space, make the overall structure more compact, and thus reduce the total height of the output assembly. Secondly, the outer bearing ring 52 with the mounting table 58 serves as the connection between the output housing and other structures. Compared with the prior art, the number of parts is effectively reduced, the overall structure is simpler, the overall weight of the output assembly is reduced while the height is reduced, and the production and manufacturing cost is effectively reduced.

[0038] An inner raceway is opened on the inner bearing ring 51, and an outer raceway is opened on the outer bearing ring 52. The inner raceway and the outer raceway are combined to form a first raceway 53 and a second raceway 54. The second raceway 54 is located below the first raceway 53, and the pitch circle diameters of the first raceway 53 and the second raceway 54 are the same. Upper rolling balls 55 and lower rolling balls 56 are respectively installed in the first raceway 53 and the second raceway 54. Both the first raceway 53 and the second raceway 54 are raceways with a peach-shaped cross-section. The peach-shaped cross-section enables four-point contact between the upper rolling balls 55 and the first raceway 53, and between the lower rolling balls 56 and the second raceway 54, making the bearing force distribution more uniform. The contact angle of the bearing assembly 5 is 20 - 35°. In this way, under the condition of bearing the same load, compared with the traditional structure using multiple bearings to cooperate in bearing force, the bearing assembly 5 of the present invention is more compact, more miniaturized, and the total height of the output assembly is smaller. Preferably, in this embodiment, the contact angle is 30°. At this contact angle, the centrifugal force of the rolling balls can be more effectively controlled, ensuring the long-term stable and safe operation of the bearing assembly 5 at high speed. 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 reduce wear and energy consumption preferably.

[0039] Preferably, the diameter of the lower rolling ball 56 is larger than that of the upper rolling ball 55. The diameter ratio of the upper rolling ball 55 to the lower rolling ball 56 is 0.7 - 0.9. Within this diameter ratio range, both the upper rolling ball 55 and the lower rolling ball 56 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 55 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 56 bears more load. After the diameter of the upper rolling ball 55 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 55 is not completely linear, so 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, and the fatigue damage of the lower rolling ball 56 increases, reducing its service life.

[0040] A shoulder 57 is provided between the first raceway 53 and the second raceway 54. The shoulder 57 provides guidance and limit for the upper rolling ball 55 and the lower rolling ball 56, and effectively restricts the movement trajectory of the rolling balls, improving the overall working reliability of the bearing; preferably, the height of the shoulder 57 is designed to be 3 - 6 mm. In this embodiment, the height of the shoulder 57 is 5 mm. First, if the shoulder 57 is too high, the center distance between the upper rolling ball 55 and the lower rolling ball 56 will increase. Since the first raceway 53 and the second raceway 54 are no longer adjacent, the radial reaction force transmitted from the upper rolling ball 55 to the bearing inner ring 51 and the bearing outer ring 52 will cause slight elastic deformation of the bearing inner ring 51 and the bearing outer ring 52. This deformation will cause the contact pressure at the lower rolling ball 56 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 56 increases compared to when the center distance is smaller; second, if the height of the shoulder 57 is too high, the overall height of the bearing will increase, which is contradictory to the purpose of a compact structure.

[0041] Seals 6 are provided between the upper and lower ends of the bearing outer ring 52 and the bearing inner ring 51 and the planet carrier 2 respectively. The seals 6 on the upper and lower sides form a closed lubrication space between the bearing inner ring 51 and the bearing outer ring 52, 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; the seal 6 on the upper side is installed in the installation groove 59 and is located between the bearing outer ring 52 and the planet carrier 2. In this way, the fixation of the upper seal 6 is realized by using the existing structure without additionally setting a structure to fix the seal 6, which not only simplifies the overall structure and the installation process, but also makes the positioning between the bearing and the planet carrier 2 more accurate, improving the structural accuracy of the output assembly.

[0042] Embodiment 2

[0043] Compared with Embodiment 1, as Figure 3As shown in the figure, in this embodiment, there are gaps between the upper end face of the output gear shaft 1 and the lower end face of the gasket 32, and between the middle step face of the output gear shaft 1 and the lower end face of the planet carrier 2. The lower end face of the bearing assembly 5 is lower than the lower end face of the planet carrier 2 and is in contact with the middle step face of the output gear shaft 1. During the assembly process, the fixing bolt 31 can pre-tighten the bearing assembly 5 to improve the stiffness of the bearing assembly 5. In order to prevent the output gear shaft 1 from generating axial displacement during operation and disengaging downward from the planet carrier 2, causing an operation accident, in this embodiment, a transition hole 10 is provided between the inner hole 21 and the gasket groove 32. The gasket groove, the transition hole 10, and the inner hole 21 are in a stepped shape and are connected to each other. A circlip 11 is provided in the transition hole 10. A circlip groove is provided at the end of the output gear shaft 1. The circlip 11 is fixed in the circlip groove to axially limit the output gear shaft 1. A circlip gasket is provided between the circlip 11 and the upper end face of the spline. Preferably, the bottom of the bearing inner ring 51 is supported by the output gear shaft 1, and the bearing inner ring 51 is no longer suspended. There is no need to provide a fastening bolt 7 between the bearing inner ring 51 and the planet carrier 2, which not only reduces the processing time and cost of parts but also simplifies the overall assembly process.

[0044] The above are only embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics well known in the art 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, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to explain the content of the claims.

Claims

1. A weight-reducing small-volume yaw gearbox output shaft structure, characterized in that: It includes an output gear shaft, a planet carrier and a bearing assembly. A radial fastening unit and an axial fastening unit are provided between the output gear shaft and the planet carrier. The bearing assembly is sleeved on the outer periphery of the planet carrier. The bearing assembly includes an inner bearing ring and an outer bearing ring. A first raceway and a second raceway are provided in the bearing assembly. 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 rolling balls and lower rolling balls are respectively installed in the first raceway and the second raceway. The contact angle of the bearing assembly is not greater than 35°. The diameter of the lower rolling balls is larger than that of the upper rolling balls. The upper end of the outer bearing ring protrudes radially to form a mounting table.

2. The output shaft structure of a weight-reduced and small-sized yaw gearbox according to claim 1, characterized in that: The radial fastening unit is a spline structure.

3. The output shaft structure of a weight-reduced and small-volume yaw gearbox according to claim 2, characterized in that: The axial fastening unit includes a fixing bolt for connecting the planet carrier and the output gear shaft and a gasket located between the fixing bolt and the planet carrier. The end of the fixing bolt extends into the output gear shaft. A gasket groove is formed in the upper part of the planet carrier, and the gasket is fixed in the gasket groove.

4. A weight-reduced and small-volume output shaft structure of a yaw gearbox according to claim 3, characterized in that: The lower end surfaces of the bearing assembly and the planet carrier are flush. The upper end surface of the output gear shaft is in contact with the upper end surface of the inner hole of the planet carrier. The output gear shaft is a stepped shaft, and there is a gap between its middle step surface and the lower end surface of the planet carrier. The bearing assembly is provided with fastening bolts for connecting with the planet carrier.

5. The output shaft structure of a weight-reducing and small-volume yaw gearbox according to claim 3, characterized in that: The output gear shaft is a stepped shaft, and there is a gap between its upper end surface and the lower end surface of the gasket. The lower end surface of the bearing assembly is lower than the lower end surface of the planet carrier and is in contact with the middle step surface of the output gear shaft. A transition hole is formed between the inner hole of the planet carrier and the gasket groove. The gasket groove, the transition hole and the inner hole are stepped and connected. A snap ring is provided in the transition hole, and the snap ring is fixed at the end of the output gear shaft.

6. A lightweight and small-sized yaw gearbox output shaft structure according to any one of claims 1-5, characterized in that: The diameter ratio of the upper rolling balls to the lower rolling balls is 0.7 - 0.

9.

7. The output shaft structure of a weight-reducing and small-volume yaw gearbox according to claim 6, characterized in that: Oil seals are respectively provided between the upper and lower ends of the outer bearing ring and the inner bearing ring and the planet carrier. An installation groove is formed inside the mounting table, and the bottom of the installation groove is flush with the upper end surface of the inner bearing ring. The oil seal located above is arranged in the installation groove. The lower part of the planet carrier is stepped, and its shoulder is located in the installation groove and is mounted on the inner bearing ring.

8. The output shaft structure of a weight-reducing and small-volume yaw gearbox according to claim 7, characterized in that: Both the first raceway and the second raceway are raceways with a peach-shaped cross-section.

9. The output shaft structure of a weight-reducing and small-volume yaw gearbox according to claim 8, 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.

10. A weight-reduced and small-volume output shaft structure of a yaw gearbox according to claim 9, characterized in that: A final stage sun gear is coaxially installed above the planet carrier, and a receiving hole for receiving the head of the fixing bolt is formed at the bottom of the final stage sun gear.

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