A three-stage speed increasing transmission system of a fan

Abstract

The utility model discloses a kind of fan three-stage speed increasing transmission systems, belong to wind power generation technical field, the system includes the main shaft connected by first-stage planetary speed increaser and fan hub, first-stage planetary speed increaser, two-stage bevel gear speed increaser and third-stage speed increasing mechanism are connected in sequence, main shaft is independent of main force beam, only transmission torque, third-stage speed increasing mechanism can adopt two kinds of schemes of three-stage bevel gear speed increaser or synchronous belt transmission assembly, high efficient speed increasing can be realized, by the 90 degree commutation of two-stage bevel gear speed increaser, generator can be arranged in low position platform close to tower, significantly reduce the gravity center of cabin, the utility model solves the main shaft load coupling, speed increasing efficiency and the difficult problem of high gravity center of traditional transmission system, compact structure, strong adaptability, assembly and maintenance are simple.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation equipment technology, specifically to a transmission system for wind turbine generator sets, and in particular to a wind turbine transmission system with a three-stage speed increase and a low center of gravity layout. Background Technology

[0002] In megawatt-class wind turbine generators, the drivetrain is the core component that converts the low-speed mechanical energy captured by the wind turbine into the high-speed rotational energy required by the generator. Traditional drivetrain schemes typically employ single- or two-stage gearboxes for speed increase. The main shaft must simultaneously bear the enormous bending load caused by the wind turbine and transmit torque. This load coupling leads to stress concentration on the main shaft, short fatigue life, and excessive design for safety, increasing weight and cost. Furthermore, the limited number of speed-increasing stages makes it difficult to efficiently match the extremely low speed of the wind turbine with the high speed of the generator, resulting in transmission efficiency losses. The generator is usually located at the rear or outer side of the nacelle, causing the nacelle's center of gravity to be relatively high, affecting the overall stability against overturning in harsh wind conditions. The drivetrain system has a complex structure, requires stringent alignment precision, and is difficult and costly to assemble on-site and maintain. Therefore, there is an urgent need for a new drivetrain system that can decouple the main shaft load, achieve efficient speed increase, lower the nacelle's center of gravity, and possess good adaptability. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a three-stage speed-increasing transmission system for wind turbines. This system effectively solves the problems of traditional transmission systems, such as main shaft load coupling, low speed-increasing efficiency, high nacelle center of gravity, limited design options, and complex assembly, through a dual-scheme design that dedicates the main shaft to torque transmission and provides three-stage speed increase.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A three-stage speed-increasing transmission system for wind turbines includes a power input unit, a three-stage speed-increasing unit, and a power output unit. Its core feature is that the main shaft is independent of the main load-bearing beam of the nacelle, serving only as a torque transmission member; the three-stage speed-increasing unit adopts a modular design, consisting of a common structure for the first two stages and an optional structure for the third stage.

[0005] In terms of structural connections: The power input unit includes a hub connected to the main shaft via a primary planetary speed increaser. The hub is connected to the planetary carrier at the input end of the primary planetary speed increaser, and the main shaft is connected to the sun gear (also called the intermediate gear) at the output end of the primary planetary speed increaser. The internal gear ring (or external gear ring) of the primary planetary speed increaser is fixed. The other end of the main shaft is connected to a secondary bevel gear speed increaser. The power input unit has no structural connection to the main load-bearing beam.

[0006] The first two stages of the three-stage speed-up unit are fixed structures: the output of the first-stage planetary speed-up unit is connected to the input of the second-stage bevel gear speed-up unit via a main shaft. The second-stage bevel gear speed-up unit uses an orthogonal bevel gear pair to achieve a 90-degree power reversal.

[0007] The third-level speedup provides two optional connection options: Option 1 (Bevel Gear Scheme): The output end of the two-stage bevel gear speed increaser is connected to the input end of the three-stage bevel gear speed increaser via a drive shaft. The three-stage bevel gear speed increaser also uses an orthogonal bevel gear pair to achieve a 90-degree rotation of the power direction, and its output end is rigidly connected to the input shaft of the generator via a high-torque coupling.

[0008] Option 2 (Synchronous Belt Solution): The output of the two-stage bevel gear speed increaser directly drives the three-stage synchronous belt drive pulley. The drive pulley drives the driven pulley mounted on the generator input shaft via the arc-tooth synchronous belt. An automatic tensioning device is installed on the outer side of the synchronous belt to maintain transmission stability.

[0009] The entire speed-increasing unit (except for the main shaft and the first-stage planetary speed-increasing machine) is fixed to the lower platform via a base. The generator is also installed on this platform and is located in the area near the center of the tower.

[0010] In terms of working principle: 1. Decoupling of power transmission and load: The torque driven by the wind turbine is directly transmitted to the first-stage planetary speed increaser through the hub. After being increased in speed, the torque is transmitted backward through the main shaft in a pure torsional manner. Since the main shaft does not bear bending loads, its stress state is greatly simplified, improving reliability and service life.

[0011] 2. The three-stage growth process: First-stage speed increase: Completed within the first-stage planetary speed increaser, utilizing the planetary gear system to achieve the first large speed ratio increase and bear the highest input torque.

[0012] Secondary speed increase and first reversal: Power enters the secondary bevel gear speed increaser, which, while achieving secondary speed increase, changes the axis of rotation by 90 degrees (for example, from horizontal to vertical).

[0013] Third-level growth rate: In the bevel gear scheme, the power is increased for the third time through a three-stage bevel gear speed increaser, and the axis of rotation is changed by 90 degrees again (returning to the horizontal direction), finally outputting at a high speed that meets the requirements of the generator.

[0014] In the synchronous belt scheme, power is output from the two-stage bevel gear speed increaser and then achieves a third speed increase through synchronous belt transmission, keeping the axial direction unchanged or making minor adjustments, and finally driving the generator.

[0015] 3. Low center of gravity layout: By using the first 90-degree reversal of the two-stage bevel gear speed increaser, the transmission path is directed towards the center of the tower, allowing the generator to be moved from the outside of the traditional nacelle to the lower platform area closer to the tower, which significantly lowers the center of gravity of the entire nacelle.

[0016] 4. Dual-solution compatibility: The bevel gear solution has high torque density and transmission efficiency, making it suitable for mainstream scenarios with high reliability and high power; the synchronous belt solution has the advantages of light weight, low noise, no lubrication and low maintenance requirements, making it particularly suitable for application scenarios with special requirements for weight, noise or ease of maintenance.

[0017] Specifically, this utility model discloses a three-stage speed-increasing transmission system for a wind turbine, comprising a power input unit, a three-stage speed-increasing unit, and a power output unit, adapted to the hub, main shaft, and generator of a wind turbine; the main shaft is set independently of the main load-bearing beam, and one end of it is rigidly connected to the hub through a first-stage planetary speed-increasing machine, forming a pure torque transmission path dedicated to transmitting torque.

[0018] Furthermore, the three-level speed-up unit includes, in sequence: A single-stage planetary speed increaser, with its input end connected to the hub and its output end connected to the main shaft; A two-stage bevel gear speed increaser, whose input end is rigidly connected to the output end of the main shaft, is used to achieve the first 90° power reversal and the second speed increase; The third-stage speed-increasing mechanism has its input end connected to the output end of the second-stage bevel gear speed-increasing machine, and is used to achieve three-stage speed-increasing and output power to the generator.

[0019] Furthermore, the three-stage speed-increasing mechanism is a three-stage bevel gear speed-increasing machine, whose input end is connected to the output end of the two-stage bevel gear speed-increasing machine, and whose output end is rigidly connected to the input shaft of the generator, in order to realize the second 90° power reversal, so that the final power output direction is parallel to the main shaft axis.

[0020] Furthermore, the three-stage speed-increasing mechanism includes a synchronous belt drive assembly, which comprises: The third-stage synchronous belt drive pulley is rigidly connected to the output end of the second-stage bevel gear speed increaser; The three-stage synchronous belt driven pulley is mounted and fixed on the input shaft of the generator; The three-stage synchronous belt is meshed on the driving pulley and the driven pulley to achieve three-stage speed-increasing transmission.

[0021] Furthermore, the synchronous belt drive assembly also includes an automatic tensioning device, wherein the tension wheel of the automatic tensioning device is elastically or hydraulically pressed against the outer side of the three-stage synchronous belt to compensate for the slack of the synchronous belt.

[0022] Furthermore, the three-stage synchronous belt is a circular arc tooth steel wire rope reinforced synchronous belt.

[0023] Furthermore, the arrangement of the secondary bevel gear speed increaser and the tertiary speed increaser allows the generator to be positioned on the lower platform near the center of the tower.

[0024] Furthermore, the first-stage planetary speed increaser and the second-stage bevel gear speed increaser are integrated into a pre-assembled modular transmission unit.

[0025] Compared with the prior art, the present invention has the following advantages.

[0026] 1. This utility model completely separates the main shaft from the main load-bearing beam, and connects the main shaft to the hub only through a single-stage planetary speed increaser. The main shaft only undertakes the function of pure torque transmission in the transmission chain. This structure fundamentally eliminates the coupling of bending moment and torque in traditional structures, greatly simplifies the stress state of the main shaft, helps to improve its fatigue life and reliability, and allows for lighter design.

[0027] 2. This utility model adopts a three-stage series layout of planetary speed increaser - bevel gear speed increaser - final stage speed increaser, which can achieve a larger overall transmission ratio and more effectively increase the low speed of the wind turbine to the high speed required by the generator. Through the orthogonal transmission of the second-stage bevel gear speed increaser, the first 90° reversal of the transmission path is realized, creating conditions for optimizing the overall layout of the machine.

[0028] 3. The power reversing structure described above allows the transmission path to bend towards the center of the tower, thus allowing the generator to be placed in the lower platform area near the tower, rather than the traditional rear of the nacelle. This layout significantly reduces the overall center of gravity of the nacelle, helping to improve the overturning stability of the wind turbine under wind loads.

[0029] 4. This utility model's third-stage speed-increasing mechanism offers two optional solutions: gear transmission and synchronous belt transmission. The bevel gear solution has a compact structure and high transmission rigidity, making it suitable for high-load scenarios; the synchronous belt solution has the advantages of buffering and vibration reduction, light weight, no need for lubrication, lower operating noise, and its automatic tensioning device can maintain transmission reliability. Both solutions share the first two stages of modules, increasing the system's adaptability to different application requirements.

[0030] 5. This utility model integrates the primary planetary speed increaser and the secondary bevel gear speed increaser into a pre-assembled modular unit, reducing the stringent requirements for coaxiality and other precision during on-site installation and simplifying the assembly process. The synchronous belt solution itself has lubrication-free characteristics, reducing the workload of regular maintenance; while the gear solution typically adopts an integral housing structure, which also facilitates diagnosis and replacement. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings.

[0032] Figure 1 This is a schematic diagram of the structure of the present invention for synchronous belt speed increase.

[0033] Figure 2 for Figure 1 A top-view structural diagram.

[0034] Figure 3 This is a schematic diagram of the structure of the all-gear transmission of this utility model.

[0035] Figure 4 for Figure 3 A top-view structural diagram.

[0036] In the diagram: 1. Hub; 2. Main shaft; 3. Generator; 4. Main load-bearing beam; 5. First-stage planetary speed increaser; 6. Second-stage bevel gear speed increaser; 7. Third-stage bevel gear speed increaser; 8. Lower platform; 9. Third-stage synchronous belt drive pulley; 10. Third-stage synchronous belt; 11. Third-stage synchronous belt driven pulley; 12. Automatic tensioning device. Detailed Implementation

[0037] The present invention will be further described below with reference to specific embodiments.

[0038] Example 1

[0039] like Figure 3 , Figure 4 As shown, this embodiment provides a three-stage speed-increasing system using all-gear transmission. The wind turbine drives the hub 1 to rotate, and the torque is initially increased and carried by the first-stage planetary speed-increasing machine 5 built into the hub 1. The increased power is transmitted to the second-stage bevel gear speed-increasing machine 6 through the main shaft 2 (which is only subjected to torque at this time), achieving a second speed-increasing and changing the power direction from horizontal to vertical. Subsequently, the power is transmitted to the third-stage bevel gear speed-increasing machine 7, completing the third speed-increasing and turning the power direction back to horizontal, and finally driving the generator 3 to rotate at high speed through the coupling. The generator 3 is fixed on the lower platform 8, which is located at the top of the tower. The main load-bearing beam 4 is connected to the hub 1 through the beam-hub connecting bearing. The main shaft 2 does not bear the supporting bending moment, realizing pure torsional transmission.

[0040] Example 2

[0041] like Figure 1 , Figure 2As shown, this embodiment provides a three-stage speed-increasing system employing a gear-synchronous belt hybrid transmission. The structure, connection method, and function of the first two stages of transmission (i.e., the first-stage planetary speed increaser 5 and the second-stage bevel gear speed increaser 6) are completely identical to those in Embodiment 1. The difference lies in the third stage: the output shaft of the second-stage bevel gear speed increaser 6 directly drives the third-stage synchronous belt drive pulley 9. The drive pulley 9 transmits power to the third-stage synchronous belt driven pulley 11, mounted on the input shaft of the generator 3, via a circular arc toothed steel wire rope reinforced synchronous belt 10, achieving a third speed increase. To ensure transmission reliability, an automatic tensioning device 12 is provided to continuously and elastically tension the synchronous belt 10. This solution simplifies the end structure and reduces weight and noise.

[0042] In both embodiments, due to the commutation effect of the second-stage bevel gear speed increaser 6, the generator 3 is positioned closer to the center of the tower on the lower platform 8 area, rather than at the rear of the nacelle, thus effectively lowering the overall center of gravity. The first-stage planetary speed increaser 5 and the second-stage bevel gear speed increaser 6 can be pre-assembled and debugged into a compact module in the factory, significantly reducing the precision requirements and time required for on-site installation.

[0043] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A three-stage speed-increasing transmission system for a wind turbine, characterized in that, It includes a power input unit, a three-stage speed-up unit and a power output unit, which are adapted to the hub (1), main shaft (2) and generator (3) of the wind turbine; the main shaft (2) is set independently of the main load-bearing beam (4), and one end of it is rigidly connected to the hub (1) through a first-stage planetary speed-up unit (5) to form a pure torque transmission path dedicated to transmitting torque.

2. The three-stage speed-increasing transmission system for a wind turbine according to claim 1, characterized in that, The three-level speed-up units include, in sequence: The first-stage planetary speed increaser (5) has its input end connected to the hub (1) and its output end connected to the main shaft (2); The input end of the two-stage bevel gear speed increaser (6) is rigidly connected to the output end of the main shaft (2) to achieve the first 90° power reversal and the second speed increase; The three-stage speed-increasing mechanism has its input end connected to the output end of the two-stage bevel gear speed-increasing machine (6) to achieve three-stage speed-increasing and output power to the generator (3).

3. The three-stage speed-increasing transmission system for a wind turbine according to claim 2, characterized in that, The three-stage speed-increasing mechanism is a three-stage bevel gear speed-increasing machine (7), whose input end is connected to the output end of the two-stage bevel gear speed-increasing machine (6), and whose output end is rigidly connected to the input shaft of the generator (3), in order to realize the second 90° power reversal, so that the final power output direction is parallel to the axis of the main shaft (2).

4. The three-stage speed-increasing transmission system for a wind turbine according to claim 2, characterized in that, The three-stage speed-increasing mechanism includes a synchronous belt drive assembly, which includes: The third-stage synchronous belt drive pulley (9) is rigidly connected to the output end of the second-stage bevel gear speed increaser (6); The three-stage synchronous belt driven pulley (11) is mounted and fixed on the input shaft of the generator (3); The three-stage synchronous belt (10) is meshed on the driving pulley (9) and the driven pulley (11) to achieve three-stage speed-up transmission.

5. The three-stage speed-increasing transmission system for a wind turbine according to claim 4, characterized in that, The synchronous belt drive assembly also includes an automatic tensioning device (12), the tension wheel of which is elastically or hydraulically pressed against the outside of the three-stage synchronous belt (10) to compensate for the slack of the synchronous belt.

6. The three-stage speed-increasing transmission system for a wind turbine according to claim 5, characterized in that, The three-stage synchronous belt (10) is a circular arc tooth steel wire rope reinforced synchronous belt.

7. The three-stage speed-increasing transmission system for a wind turbine according to any one of claims 2 to 6, characterized in that, The arrangement of the secondary bevel gear speed increaser (6) and the tertiary speed increaser mechanism allows the generator (3) to be placed on the lower platform (8) near the center of the tower.

8. The three-stage speed-increasing transmission system for a wind turbine according to any one of claims 1 to 6, characterized in that, The first-stage planetary speed increaser (5) and the second-stage bevel gear speed increaser (6) are integrated into a pre-assembled modular transmission unit.

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