Compact yaw gearbox output structure

Abstract

The utility model relates to the technical field of wind driven generators, and discloses a compact yaw gearbox output structure, which comprises a planet carrier, an output box body and an output gear shaft, the planet carrier and the output box body are respectively integrated with an inner raceway and an outer raceway, and a plurality of rows of rolling balls are arranged between the inner raceway and the outer raceway; the output gear shaft is sleeved with the planet carrier, and a limiting unit and a fixing unit are arranged between the output gear shaft and the planet carrier from top to bottom and used for fixing the output gear shaft in the axial direction and the radial direction correspondingly. The limiting unit comprises an axial limiting groove formed in the top of the planet carrier, a limiting nut is arranged in the axial limiting groove, the limiting nut is in threaded connection with an end journal of the output gear shaft, the fixing unit protrudes out of the axial limiting groove in the radial direction and forms a limiting step, and the bottom face of the limiting nut is in lap joint with the limiting step. In practical application, the overall size and weight of the output shaft structure are effectively reduced, and miniaturization is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbines, in particular to a compact yaw gearbox output structure. Background Art

[0002] As a reducer, the yaw gearbox is an important component of the wind turbine generator set. The yaw gearbox is installed vertically, and from top to bottom, it consists of an input component, a planetary component (usually four stages), and an output component. The total height of the final planetary component and the output component of the existing yaw gearbox is relatively large, and the output positioning structure is not compact and heavy, which increases the rotational inertia of the yaw system, increases energy consumption during starting and stopping, and affects the overall efficiency of the wind power generation system. Under frequent yaw operations, the higher energy consumption will directly affect the power generation cost and economic benefits of the wind turbine. Moreover, as offshore wind power and onshore wind power have entered the stage of large-scale development, considering the installation space limitations and production costs of wind power gearboxes, more and more yaw gearboxes tend to be small drive models, and the miniaturization of reducers is becoming increasingly important. Utility Model Content

[0003] The utility model aims to provide a compact yaw gearbox output structure, improve the structural compactness, and reduce the overall weight and volume of the yaw gearbox.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a compact yaw gearbox output structure, including a planetary carrier, an output housing and an output gear shaft, the planetary carrier and the output housing are respectively integrated with inner and outer raceways, and multiple rows of balls are installed between the inner and outer raceways; the output gear shaft sleeve is arranged inside the planetary carrier, and a limiting unit and a fixing unit are provided between the two from top to bottom, which respectively fix the output gear shaft axially and radially; the limiting unit includes an axial limiting groove opened at the top of the planetary carrier, a limiting nut is provided in the axial limiting groove, the limiting nut is threadedly connected to the end journal of the output gear shaft, the fixing unit radially protrudes from the axial limiting groove and forms a limiting step, and the bottom surface of the limiting nut overlaps the limiting step.

[0005] In response to the problems of the total height of the final-stage planetary assembly and output assembly of the yaw gearbox being large, the output positioning structure being not compact, and the weight being large, the applicant has carried out preliminary structural optimization. Specifically, the end of the output gear shaft is inserted into the inner hole of the planetary carrier for fixation, and the bearing assembly is sleeved on the outer periphery of the planetary carrier, so that the output gear shaft, the planetary carrier and the bearing assembly are highly integrated in the horizontal direction, reducing the longitudinal space occupied by the structure, making the overall structure more compact, and thus reducing the total height of the output assembly; and, using the outer ring of the bearing as the output box body effectively reduces the number of components compared to traditional yaw gearboxes, making the overall structure simpler, reducing the height, and reducing the overall volume and weight of the output assembly.

[0006] Although the above optimization and improvement have greatly improved the overall 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, and therefore proposed this solution.

[0007] Beneficial effects of this program:

[0008] 1. In this solution, the inner ring structure of the bearing is eliminated, and the inner and outer raceways are integrated into the planetary carrier and the output housing, which reduces the number of parts and the weight of the overall structure, and effectively reduces the radial dimension. Secondly, in this solution, an axial limit groove is opened on the top of the planetary carrier, and the limit nut threadedly connected to the end journal of the output gear shaft is located in the axial limit groove. The axial length of the output gear shaft and the planetary carrier is increased, and the overall axial dimension of the output shaft structure is reduced. The axial and radial dimensions of the output shaft structure are both reduced, which makes the overall volume of the yaw gearbox further smaller and the overall weight reduced, making the yaw gearbox more compact and lightweight as a whole.

[0009] 2. In this solution, the bearing inner ring structure is eliminated, the number of parts is reduced, the overall assembly relationship of the output shaft structure is reduced, the possibility of failure risk between the output shaft structure and the yaw gearbox during operation is reduced, and the overall structure operates more reliably and stably.

[0010] 3. Reducing the number of parts can reduce the difficulty and cycle of assembly, reduce production costs, and at the same time reduce the risk of failure between the output shaft structure and the yaw gearbox during operation, effectively reducing maintenance costs.

[0011] Furthermore, the fixing unit is a spline structure, including internal splines provided on the planetary carrier and external splines on the outer periphery of the output gear shaft.

[0012] Furthermore, an isolation sealing unit is provided between the lower end face of the spline structure and the upper end face of the gear of the output gear shaft. The isolation sealing unit includes a filling pad and O-rings arranged on the upper and lower sides of the filling pad. The upper and lower end faces of the filling pad are in contact with the output gear shaft and the planetary carrier.

[0013] Furthermore, there are two rows of balls, and the planetary frame is provided with a first filling hole and a second filling hole for loading upper and lower balls. The first and second filling holes are staggered in opposite directions on the circumference, and the first and second filling holes are both provided with matching blocking blocks.

[0014] Furthermore, the planetary carrier is provided with a positioning unit for positioning the two blocking blocks, and the positioning unit includes a tapered hole opened on the planetary carrier and the blocking block and communicating with each other, and a tapered pin installed in the tapered hole.

[0015] Furthermore, the diameter of the lower rolling ball is larger than that of the upper rolling ball.

[0016] Furthermore, the diameter ratio of the upper and lower rolling balls is 0.7-0.9.

[0017] Furthermore, an upper oil seal and a lower oil seal are provided between the planetary carrier and the output housing.

[0018] Furthermore, the upper end of the output box body protrudes radially outward to form a mounting platform.

[0019] Furthermore, the inner and outer raceways are integrated with an upper raceway and a lower raceway that are interconnected. Both the upper raceway and the lower raceway are peach-shaped cross-section raceways and have the same pitch circle diameter.

[0020] This program also has the following beneficial effects:

[0021] 1. In this solution, the output gear shaft and the planetary carrier are interference fit, and a fixing unit is provided in the middle journal section of the output gear shaft. The spline structure makes the transmission between the planetary carrier and the output gear shaft more stable, which can effectively prevent the two from slipping, ensure the same frequency rotation between the two, and improve the overall operation stability of the fan.

[0022] 2. This solution provides an isolation sealing unit between the lower end face of the spline structure and the upper end face of the gear of the output gear shaft, that is, at the retreat groove of the spline structure. The retreat groove space between the planetary carrier and the output gear shaft is effectively filled and sealed by the filling pad and the O-rings on both sides. On the one hand, the inside of the gear box is sealed with oil. On the other hand, since there is a clearance fit between the filling pad and the inner hole of the planetary carrier, that is, there is a clearance fit between the filling pad and the first blocking block, the filling pad and the O-ring can prevent grease from entering the oil, thereby achieving oil and grease sealing. Secondly, the limiting nut threaded on the end journal of the output gear shaft also stabilizes and fixes the isolation sealing unit when achieving axial limitation, thereby enhancing the overall oil and grease sealing effect and preventing the output gear shaft from displacement and causing seal failure.

[0023] 3. Compared with the multiple independent tapered roller bearings in the output shaft structure of the traditional yaw gearbox, the bearing structure in this solution is a double-row ball bearing. The double-row ball bearing can provide radial and axial load-bearing capacity equal to or even greater than that of the tapered roller bearing in a smaller space, effectively ensuring the strength and deformation resistance of the bearing structure; at the same time, the upper and lower balls are concentrated in the same bearing to reduce the overall spatial span of the bearing structure, greatly reducing the overall volume of the output assembly and improving the compactness of the structure; and the double-row balls in this solution are upper and lower balls with larger and smaller diameters, and the diameter of the lower ball is larger than that of the upper ball. Such a design not only effectively ensures that the upper ball can exert its maximum load-bearing potential and improve economy, but also effectively reduces the height of the bearing assembly and the overall output assembly by reducing the diameter of the upper ball, thereby improving the compactness of the structure.

[0024] 4. In this solution, the pitch circle diameters of the upper and lower raceways are the same, which helps to distribute the load between the upper and lower balls more evenly, maintaining a good force balance even under dynamically changing working conditions, avoiding excessive stress on a single rolling element, and thus extending the service life of the bearings. At the same time, the same pitch circle diameter ensures that the upper and lower balls can maintain a consistent radial motion trajectory during rotation, ensuring high-precision operation of the yaw gearbox. The improved coaxiality reduces vibration and noise during operation, and improves the operating stability of the entire wind power generation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an embodiment of the present utility model. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific implementation methods:

[0027] The reference numerals in the drawings of the specification include: planetary carrier 1, output gear shaft 2, output housing 3, mounting inner hole 4, axial limit groove 5, fixing unit 6, limit nut 7, upper ball 8, lower ball 9, upper oil seal 10, lower oil seal 11, filling gasket 12, O-ring 13, first blocking block 14, second blocking block 15, tapered hole 16, and tapered pin 17.

[0028] The embodiment is basically as shown in the attached Figure 1 As shown:

[0029] A compact yaw gearbox output structure includes a planetary carrier 1, an output box body 3 and an output gear shaft 2. The planetary carrier 1 is provided with an installation inner hole 4 for accommodating the output gear shaft 2. The output gear shaft 2 extends into the installation inner hole and is interference-fitted with the planetary carrier 1. There is a gap between the bottom surface of the planetary carrier 1 and the upper end surface of the gear of the output gear shaft 2. A limiting unit and a fixing unit 6 are provided from top to bottom between the planetary carrier 1 and the output gear shaft 2. The fixing unit 6 is a spline structure, including an internal spline provided on the planetary carrier 1 and an external spline on the outer periphery of the output gear shaft 2. The fixing unit 6 makes the planetary carrier 1 The planetary carrier 1 and the output gear shaft 2 are fitted with an interference fit and a spline in both directions, which can effectively prevent the two from slipping, ensure that the two rotate at the same frequency, and improve the overall stability of the fan operation; the limiting unit includes an axial limiting groove 5 opened at the top of the planetary carrier 1, and a limiting nut 7 installed in the axial limiting groove 5, the fixing unit 6 radially protrudes from the axial limiting groove 5 and forms a limiting step, the bottom surface of the limiting nut 7 overlaps the limiting step, and the limiting nut 7 is threadedly connected to the end journal of the output gear shaft 2 to prevent the output gear shaft 2 from axial displacement. The upper end of the output housing 3 protrudes radially outward to form a mounting platform, which simplifies the installation process of the yaw gearbox, provides a stable installation interface, ensures correct and reliable positioning, avoids initial failures caused by improper installation, and improves assembly efficiency.

[0030] The planet carrier 1 and the output housing 3 are respectively integrated with inner and outer raceways, and multiple rows of balls are installed between the inner and outer raceways. The number of ball rows is not less than two rows. In this embodiment, double rows of balls are used to form a double-row ball bearing. An upper oil seal 10 and a lower oil seal 11 are provided between the planet carrier 1 and the output housing 3, thereby forming a grease-lubricated cavity for the double rows of balls. Compared with the multiple independent tapered roller bearings in the output shaft structure of the traditional yaw gearbox, the double-row ball bearing can provide radial and axial load-bearing capacity equal to or even greater than that of the tapered roller bearing in a smaller space, effectively ensuring the strength and deformation resistance of the bearing structure, thereby reducing the overall height of the output shaft structure by reducing the size of the bearing structure.

[0031] Through the above-mentioned arrangement, the bearing structure is directly integrated into the planetary carrier 1 and the output housing 3, and the traditional bearing inner and outer ring structure is eliminated, which not only effectively reduces the number of parts and the total weight, but also effectively reduces the radial dimension. Moreover, an axial limit groove 5 is opened on the top of the planetary carrier 1, and the limit nut 7 threadedly connected to the end journal of the output gear shaft 2 is located in the axial limit groove 5. The axial length of the output gear shaft 2 and the planetary carrier 1 is increased, and the overall axial dimension of the output shaft structure is reduced; the axial and radial dimensions of the output shaft structure are both reduced, so that the overall volume of the yaw gearbox is further reduced, and the overall weight is reduced, making the yaw gearbox as a whole more compact and lightweight.

[0032] An isolation sealing unit is provided between the lower end face of the spline structure and the upper end face of the gear of the output gear shaft 2, that is, at the back cut of the spline structure. The isolation sealing unit includes a filling pad 12 and O-rings 13 provided on the upper and lower sides of the filling pad 12. The upper O-ring 13 is installed in the groove on the filling pad 12. The upper and lower end faces of the filling pad 12 fit with the output gear shaft 2 and the planetary carrier 1. The lower O-ring 13 is installed in the groove on the end face of the journal of the output gear shaft 2. The planetary carrier 1 and the output gear shaft 2 are sealed by the filling pad 12 and the O-rings 13 on both sides. The space between the backhoes is effectively filled and sealed. On the one hand, the gear box is sealed with oil. On the other hand, since there is a clearance fit between the filling gasket 4 and the inner hole of the planetary carrier 1, that is, there is a clearance fit between the filling gasket 4 and the first blocking block 14, the filling gasket 4 and the O-ring 13 can prevent grease from entering the oil, thereby achieving oil and grease sealing. Secondly, the limiting nut 7 threadedly connected to the end journal of the output gear shaft 2 also stabilizes and fixes the isolation sealing unit when achieving axial limitation, thereby enhancing the overall oil and grease sealing effect and preventing the output gear shaft 2 from displacement and causing seal failure.

[0033] Preferably, the double-row balls include an upper ball 8 and a lower ball 9, each with a larger diameter and a smaller diameter. The diameter of the lower ball 9 is larger than that of the upper ball 8, and the ratio of their diameters is 0.7-0.9. Within this diameter ratio range, the upper ball 8 and the lower ball 9 are subjected to uniform force. When the diameter ratio of the two balls is smaller than the above range, the diameter of the upper ball 8 located above is too small to meet its own force requirements. When the diameter ratio of the two balls is larger than the above range, the lower ball 9 originally carries more load. After the diameter of the upper ball 8 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 ball 8 is not completely linear, so it cannot significantly reduce the burden on the lower layer. In fact, in the case of improper adjustment, the force on the large-diameter ball in the lower layer increases due to uneven load distribution, and the fatigue damage of the lower ball 9 increases, thereby reducing its service life.

[0034] The inner and outer raceways integrate the upper raceway and the lower raceway which are interconnected. Both the upper raceway and the lower raceway are peach-shaped cross-section raceways with the same pitch circle diameter. The peach-shaped design of the raceway cross-section makes the bearing force distribution more uniform, and the equal pitch circle diameter of the upper raceway and the lower raceway helps to more evenly distribute the load between the upper ball 8 and the lower ball 9. Even under dynamically changing working conditions, it can maintain a good force balance, avoid excessive force on a single rolling body, thereby extending the service life of the bearing. At the same time, the improvement of coaxiality reduces vibration and noise during operation, and improves the operating stability of the entire wind power generation system. A shoulder is provided between the upper raceway and the lower raceway, and the height of the shoulder is not higher than 5 mm. Firstly, if the height of the shoulder is too high, the center distance between the upper ball 8 and the lower ball 9 will increase. Since the upper and lower raceways are no longer adjacent, the radial reaction force transmitted by the upper ball 8 to the planetary carrier 1 and the output box 3 will cause them to produce slight elastic deformation. This deformation will increase the contact pressure at the lower ball 9, because more force is needed to balance the external load and the internal preload, thereby increasing the force borne by the lower ball 9 compared to when the center distance is smaller; secondly, if the height of the shoulder is too high, the overall height of the bearing structure will increase, which is inconsistent with the purpose of compact structure.

[0035] The planetary carrier 1 is provided with a first loading hole and a second loading hole for loading the upper ball 8 and the lower ball 9. The first loading hole and the second loading hole are staggered in opposite directions on the circumference to avoid overlapping holes above and below, which may weaken the bearing capacity of the area. The first and second loading holes are respectively provided with a first blocking block 14 and a second blocking block 15 that transitionally cooperate with them. The planetary carrier 1 is provided with a positioning unit for positioning the two blocking blocks. The positioning unit includes a tapered hole 16 connected to the planetary carrier 1 and the blocking block and a tapered pin 17 installed in the tapered hole 16. The tapered hole 16 can be a through hole that axially passes through the planetary carrier 1 or a blind hole that does not pass through. If the tapered hole 16 is a blind hole, a ventilation groove needs to be provided on the side of the tapered pin 17. The tapered hole 16 and the tapered pin 17 are designed to ensure the machining accuracy of the raceway, but this structure is still retained during assembly. First, it ensures the overall structural rigidity of the planetary carrier 1 after assembly, and second, it prevents lubricating oil from leaking along the tapered hole 16 to ensure a clean environment inside the gearbox.

[0036] The above description is merely an embodiment of the present invention, and the commonly known specific technical solutions and / or features of the solution 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 variations and improvements can be made, which should also be considered as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A compact yaw gearbox output structure, characterized by: It includes a planetary carrier, an output box and an output gear shaft. The planetary carrier and the output box are respectively integrated with inner and outer raceways, and multiple rows of balls are installed between the inner and outer raceways; the output gear shaft sleeve is arranged inside the planetary carrier, and a limiting unit and a fixing unit are provided between the two from top to bottom to fix the output gear shaft axially and radially respectively; the limiting unit includes an axial limiting groove opened on the top of the planetary carrier, a limiting nut is provided in the axial limiting groove, and the limiting nut is threadedly connected to the end journal of the output gear shaft, the fixing unit radially protrudes from the axial limiting groove and forms a limiting step, and the bottom surface of the limiting nut overlaps the limiting step.

2. The compact yaw gearbox output structure according to claim 1, characterized in that: The fixing unit is a spline structure, comprising an internal spline provided on the planet carrier and an external spline on the outer periphery of the output gear shaft.

3. The compact yaw gearbox output structure according to claim 2, characterized in that: An isolation sealing unit is provided between the lower end face of the spline structure and the upper end face of the gear of the output gear shaft. The isolation sealing unit includes a filling pad and O-rings arranged on the upper and lower sides of the filling pad. The upper and lower end faces of the filling pad are in contact with the output gear shaft and the planetary carrier.

4. The compact yaw gearbox output structure according to claim 3, characterized in that: There are two rows of balls, which are divided into upper balls and lower balls. The planetary frame is provided with a first filling hole and a second filling hole for filling the upper and lower balls. The first and second filling holes are staggered in opposite directions on the circumference, and the first and second filling holes are both provided with matching blocking blocks.

5. The compact yaw gearbox output structure according to claim 4, characterized in that: The planetary frame is provided with a positioning unit for positioning the two blocking blocks. The positioning unit comprises a tapered hole connected to the planetary frame and the blocking block and a tapered pin installed in the tapered hole.

6. The compact yaw gearbox output structure according to claim 4, characterized in that: The diameter of the lower rolling ball is larger than that of the upper rolling ball.

7. The compact yaw gearbox output structure according to claim 6, characterized in that: The diameter ratio of the upper and lower rolling balls is 0.7-0.

9.

8. The compact yaw gearbox output structure according to claim 7, characterized in that: An upper oil seal and a lower oil seal are provided between the planet carrier and the output box.

9. The compact yaw gearbox output structure according to claim 8, characterized in that: The upper end of the output box body protrudes radially outward to form a mounting platform.

10. The compact yaw gearbox output structure according to claim 9, characterized in that: The inner and outer raceways are integrated with an upper raceway and a lower raceway which are interconnected. Both the upper raceway and the lower raceway are peach-shaped cross-section raceways and have the same pitch circle diameter.

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