A yaw gear box structure

Abstract

The utility model relates to the field of wind driven generator discloses a yaw gear box structure, including output gear axle, epicyclic gear frame and output box, the output gear axle sleeve is established in the inside of epicyclic gear frame, the output box sleeve is established in the outside of epicyclic gear frame, is provided with cross roller bearing and roller bearing between epicyclic gear frame and output box, and roller bearing is located below cross roller bearing, and the connecting portion between output gear axle and epicyclic gear frame includes spline connecting section and interference connecting section, and spline connecting section is located at the bottom of epicyclic gear frame. The utility model can reduce the overall height of yaw gear box output end, reduce total weight, solve the problem that the yaw gear box structure height is big, and the weight is heavy.

Description

Technical Field

[0001] This utility model relates to the field of wind turbine generators, specifically to a yaw gearbox structure. Background Technology

[0002] The yaw gearbox is one of the core transmission components of a wind turbine generator. Its core function is to drive the wind turbine system to precisely "align with the wind"—by transmitting power to adjust the nacelle's orientation, ensuring that the wind turbine is always facing the incoming wind direction, directly affecting the unit's wind energy capture efficiency and operational stability. Since wind power equipment is mostly deployed in the field (such as plateaus, coastlines, and mountains), the operating conditions are harsh. It must not only withstand long-term exposure to strong gusts, alternating loads, and the corrosive effects of complex environments such as low temperatures and high humidity, but also places extremely high demands on the equipment's compactness, lightweight design, and ease of maintenance. For example, with limited nacelle space, excessively heavy / large components will increase hoisting and maintenance costs.

[0003] Existing yaw gearboxes typically employ a vertical mounting structure, consisting of an input assembly, a planetary assembly (usually four stages), and an output assembly from top to bottom. The output assembly is assembled as follows: the output gear shaft is axially locked to the output housing by nuts, with the two bearings isolated by an oil seal. This structure reveals significant drawbacks in practical applications: 1. Redundant overall layout and insufficient adaptability: The total height of the planetary components and output components is too large, resulting in a bulky overall gearbox. Since the internal space of the wind turbine nacelle is already limited, the excessive height will compress the layout space of other components, while increasing the center of gravity of the nacelle and weakening the stability of the unit under strong wind conditions.

[0004] 2. Loose structure of output components, high cost and load risk: The output components are not compact enough, and the span between the two tapered roller bearings is too large. This directly leads to a simultaneous increase in the height and wall thickness of the output housing, and the shaft length of the output gear shaft also increases accordingly. This not only significantly increases the weight of the output components (increasing the load on the engine compartment and hoisting costs), but also causes the gearbox to experience increased vibration and accelerated bearing wear under alternating loads due to the large bearing span and reduced shaft rigidity. This reduces the service life of the components and increases the frequency and cost of field maintenance. Utility Model Content

[0005] The present invention aims to provide a yaw gearbox structure to reduce the overall height of the output end of the yaw gearbox, reduce the total weight, and solve the problems of large height and heavy weight of existing yaw gearbox structures.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A yaw gearbox structure includes an output gear shaft, a planetary carrier, and an output housing. The output gear shaft is sleeved inside the planetary carrier, and the output housing is sleeved outside the planetary carrier. A crossed roller bearing and a roller bearing are provided between the planetary carrier and the output housing. The roller bearing is located below the crossed roller bearing. The connection between the output gear shaft and the planetary carrier includes a spline connection section and an interference fit section. The spline connection section is located at the bottom of the planetary carrier.

[0007] Preferably, as an improvement, the output gear shaft consists of a large diameter section, a medium diameter section, and a small diameter section from bottom to top. The medium diameter section is splinedly connected to the planetary carrier to form the spline connection section. The root of the small diameter section is interference-fitted to the planetary carrier to form the interference connection section. The free end of the small diameter section is threadedly connected to a limit nut.

[0008] Preferably, as an improvement, a first inner raceway is provided on the outer side of the planetary carrier, a first outer raceway that mates with the first inner raceway is provided on the inner side of the output housing, a crossed roller bearing is provided between the first inner raceway and the first outer raceway, a second inner raceway is provided on the outer side of the planetary carrier, a second outer raceway that mates with the second inner raceway is provided on the inner side of the output housing, and a roller bearing is provided between the second inner raceway and the second outer raceway.

[0009] Preferably, as an improvement, an oil seal is provided below the roller bearing, and the oil seal is located between the planetary carrier and the output housing.

[0010] Preferably, as an improvement, the planetary carrier has a radially formed plugging hole that communicates with the first inner raceway. A plug is provided in the plugging hole with clearance fit. The planetary carrier has an axially formed tapered pin hole that communicates perpendicularly with the plugging hole. A tapered pin is provided in the tapered pin hole with interference fit fit.

[0011] Preferably, as an improvement, the limiting nut is disposed between the output gear shaft and the planet carrier, with the top of the limiting nut lower than the top of the planet carrier and the output gear shaft.

[0012] Preferably, as an improvement, the length of the spline connection between the output gear shaft and the planet carrier is greater than the length of the interference fit connection between the output gear shaft and the planet carrier.

[0013] The principles and advantages of this scheme are: 1. This solution uses crossed roller bearings and roller bearings. By having the planetary carrier and the output housing directly form the inner and outer raceways of the two bearings, the two bearings, which were originally arranged in layers along the axial direction, are integrated into a radially compact structure. On the one hand, the bearings, bearing housings, and other components that originally needed to be stacked sequentially along the axial direction are compressed into the same radial space, directly eliminating the axial height redundancy corresponding to the bearing span in the original structure, and significantly reducing the total height of the planetary assembly and the output assembly. On the other hand, the integrated design eliminates the redundant structures such as the output housing wall thickness and the output gear shaft length that were added to accommodate the span of the two bearings in the original structure. At the same time, after the bearings are integrated, there is no need for independent bearing housings and other auxiliary components, which simplifies the number of parts and reduces the material usage of the output housing and gear shaft, thereby reducing the overall weight of the gearbox while reducing the height.

[0014] 2. This design employs a structure combining crossed roller bearings and regular roller bearings, with the roller bearings positioned below the crossed roller bearings. The roller bearings primarily bear radial loads (the closer to the bottom, the greater the radial load), while the crossed roller bearings above assist in bearing radial loads and can also support axial loads. Compared to existing technologies using ball bearings, this design better supports radial loads and has a greater load-bearing capacity.

[0015] 3. The output gear shaft and planetary carrier are connected using a combination of spline and interference fit, resulting in good connection stability and high structural strength. A limiting nut is also threaded at the end to restrict axial movement, further enhancing structural strength and stability. The output gear shaft is structured from bottom to top as a large-diameter section, a medium-diameter section, and a small-diameter section. This creates a step at the shoulder of the medium-diameter section, and the root of the medium-diameter section is interference-fitted to the planetary carrier, specifically on the step plane. The planetary carrier blocks the output gear shaft axially from above, further limiting its axial movement.

[0016] 4. The spline connection section is positioned below the interference fit section, with the corresponding spline on the planetary carrier located at its bottom. This arrangement significantly reduces assembly difficulty (the output gear shaft is installed into the planetary carrier from below during assembly). Compared to structures where the spline connection section is positioned above the interference fit section (hidden in the middle, invisible from the bottom), requiring blind assembly, this design allows for direct alignment of the splines before installation, reducing assembly difficulty, improving assembly accuracy, and lowering assembly risks. Furthermore, since the load increases towards the bottom, placing the spline connection section at the bottom allows for better load bearing, improving assembly stability. Moreover, the length of the spline connection section is greater than that of the interference fit section, enabling it to bear the primary connection force, ensuring connection strength and stability.

[0017] 5. By using crossed roller bearings, there is no need to add an oil seal at the top of the planetary carrier. Compared to structures with oil seals at both the top and bottom of the planetary carrier, the overall height can be further reduced. Furthermore, the top of the planetary carrier needs to be connected to the entire machine, meaning the top oil seal is located in the middle of the transmission structure. Installing an oil seal at this location is difficult, and even if forced in, it may be misaligned, leading to the risk of oil leakage. This solution, using a combination of crossed roller bearings and roller bearings, only requires an oil seal at the bottom, fundamentally solving both of the above problems.

[0018] 6. The structure using a combination of crossed roller bearings and ball bearings eliminates the need for a filling channel in the ball bearings, while the crossed roller bearings only require one filling channel. Therefore, only one plugging hole needs to be set in the radial direction of the planetary carrier to form a filling channel. Compared with the existing structure that requires two plugging holes to form two filling channels when using two ball bearings, this solution can significantly improve the structural strength of the gearbox by requiring only one plugging hole.

[0019] 7. A small diameter section is provided at the top of the output gear shaft, and the limiting nut is set at this small diameter section so that it is located between the output gear shaft and the planet carrier, rather than protruding above the top of the output gear shaft and the planet carrier, which can further avoid increasing the height. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0021] The reference numerals in the accompanying drawings include: 1. Limit nut, 2. Output gear shaft, 3. Planetary carrier, 4. Output housing, 5. Oil seal, 6. Roller bearing, 7. Tapered pin, 8. Plug, 9. Crossed roller bearing, 10. Large diameter section, 11. Medium diameter section, 12. Small diameter section. Detailed Implementation

[0022] The following detailed description illustrates the specific implementation method: Example like Figure 1As shown, a yaw gearbox structure includes an output gear shaft 2, a planetary carrier 3, and an output housing 4. The output gear shaft 2 is fitted inside the planetary carrier 3, and the output housing 4 is fitted outside the planetary carrier 3. Specifically, the planetary carrier 3 has a mounting hole in the middle for mounting the output gear shaft 2, and the output gear shaft 2 is installed in the mounting hole. The output gear shaft 2 consists of a large diameter section 10, a medium diameter section 11, and a small diameter section 12 from bottom to top. The large diameter section 10, medium diameter section 11, and small diameter section 12 are integrally formed. The medium diameter section 11 is splinedly connected to the planetary carrier 3 to form a splined connection section, that is, splines are machined on the outer wall of the medium diameter section 11 and on the inner wall of the medium diameter section 11 corresponding to the mounting hole. The root of the small diameter section 12 is interference-fitted to the planetary carrier 3 to form an interference-fit connection section, and the length of the splined connection section is greater than the length of the interference-fit connection section. The free end of the small diameter section 12 is threadedly connected to a limiting nut 1. The limiting nut 1 is located between the output gear shaft 2 and the planet carrier 3, and the top of the limiting nut 1 is lower than the top of the planet carrier 3 and the output gear shaft 2.

[0023] A crossed roller bearing 9 and a roller bearing 6 are disposed between the planetary carrier 3 and the output housing 4, with the roller bearing 6 located below the crossed roller bearing 9. Specifically, the planetary carrier 3 has a first inner raceway on its outer side, and the output housing 4 has a first outer raceway on its inner side that mates with the first inner raceway. The crossed roller bearing 9 is installed between the first inner raceway and the first outer raceway. The planetary carrier 3 has a radially opening plug hole that communicates with the first inner raceway to form a filling channel for the crossed roller bearing 9. A plug 8 is fitted into the plug hole with a clearance fit. The planetary carrier 3 has an axially opening tapered pin hole that communicates perpendicularly with the plug hole. A tapered pin 7 is fitted into the tapered pin hole with an interference fit, and the tapered pin 7 is inserted into the tapered pin hole to position the plug 8 on the planetary carrier 3. The planetary carrier 3 has a second inner raceway on its outer side, and the output housing 4 has a second outer raceway that mates with the second inner raceway. The roller bearing 6 is installed between the second inner raceway and the second outer raceway. The first inner raceway, the first outer raceway, the second inner raceway, and the second outer raceway are all square. An oil seal 5 is installed below the roller bearing 6. The oil seal 5 is inserted into the mating surface of the planetary carrier 3 and the output housing 4 to isolate the outside air.

[0024] In this embodiment, the inner and outer raceways of the crossed roller bearing 9 and the roller bearing 6 are integrated on the planetary carrier 3 and the output housing 4. The crossed roller bearing 9 and the roller bearing 6 are integrated in the radial direction of the gearbox, which greatly reduces the height of the gearbox. At the same time, the bearing housing and other structures are eliminated, reducing the overall weight of the gearbox and achieving a lightweight design.

[0025] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A yaw gearbox structure, characterized in that: It includes an output gear shaft, a planetary carrier, and an output housing. The output gear shaft is fitted inside the planetary carrier, and the output housing is fitted outside the planetary carrier. Crossed roller bearings and roller bearings are provided between the planetary carrier and the output housing. The roller bearings are located below the crossed roller bearings. The connection between the output gear shaft and the planetary carrier includes a spline connection section and an interference fit section. The spline connection section is located at the bottom of the planetary carrier.

2. The yaw gearbox structure according to claim 1, characterized in that: The output gear shaft consists of a large diameter section, a medium diameter section, and a small diameter section from bottom to top. The medium diameter section is splined to the planetary carrier to form the spline connection section. The root of the small diameter section is interference-fitted to the planetary carrier to form the interference connection section. The free end of the small diameter section is threaded with a limit nut.

3. The yaw gearbox structure according to claim 2, characterized in that: The planetary carrier has a first inner raceway on its outer side, and the output housing has a first outer raceway that mates with the first inner raceway on its inner side. A crossed roller bearing is positioned between the first inner raceway and the first outer raceway. The planetary carrier has a second inner raceway on its outer side, and the output housing has a second outer raceway that mates with the second inner raceway on its inner side. A roller bearing is positioned between the second inner raceway and the second outer raceway.

4. The yaw gearbox structure according to claim 3, characterized in that: An oil seal is located below the roller bearing, between the planetary carrier and the output housing.

5. A yaw gearbox structure according to claim 4, characterized in that: The planetary carrier has a radially opened plugging hole that communicates with the first inner raceway. A plug is connected to the plugging hole with a clearance fit. The planetary carrier has an axially opened tapered pin hole that communicates perpendicularly with the plugging hole. A tapered pin is connected to the tapered pin hole with an interference fit.

6. A yaw gearbox structure according to claim 5, characterized in that: The limiting nut is positioned between the output gear shaft and the planetary carrier, with the top of the limiting nut lower than the top of the planetary carrier and the output gear shaft.

7. A yaw gearbox structure according to claim 6, characterized in that: The length of the spline connection between the output gear shaft and the planetary carrier is greater than the length of the interference fit connection between the output gear shaft and the planetary carrier.

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