Gearboxes, drive trains and wind turbine generator sets

Abstract

This invention discloses a gearbox, transmission chain, and wind turbine generator set. The gearbox includes a differential planetary gear set, a quasi-planetary gear set, and a basic planetary gear set arranged sequentially. It also includes an input shaft, an output shaft, and a main bearing. The input shaft is fixedly connected to the outer ring of the bearing and the hub. The quasi-planetary gear set is arranged inside the main bearing, and its planetary carrier is fixedly connected to the inner ring of the bearing and the main frame. The output shaft is fixedly connected to the generator rotor, and the generator stator is fixedly connected to the rear housing of the gearbox. This gearbox uses differential planetary and quasi-planetary gear transmission to achieve power splitting, resulting in high power density and high reliability. The rotation of the bearing outer ring reduces the bearing diameter and lowers bearing costs. By arranging the quasi-planetary gear set inside the main bearing, and placing the differential planetary gear set in the rear cavity of the hub, while the basic planetary gear set and the generator are arranged in the front cavity of the main frame, the length of the transmission chain is shortened, reducing the bending moment of the wind turbine on the tower, thereby reducing the overall cost of the wind turbine generator set.

Description

Technical Field

[0001] This invention relates to a gearbox, a transmission chain, and a wind turbine generator set. Background Technology

[0002] In recent years, wind power technology has developed rapidly, but the high prices of materials such as rare earth permanent magnets, copper, and silicon steel have led to excessively high generator costs, especially for direct-drive turbines. To reduce the cost of wind turbine generators, semi-direct-drive turbines have emerged and are developing rapidly, especially as the units become larger, demonstrating their advantages. Currently, there are two structural forms in semi-direct-drive drivetrains: one is a single-bearing (double-row tapered bearing) integrated with the gearbox, and the other is a dual-bearing (two single-row tapered bearings) integrated with the gearbox.

[0003] The system uses a single double-row tapered roller bearing directly connected to the hub and gearbox. The gearbox and generator are located between the hub and the tower, eliminating the need for a main shaft and resulting in a compact structure. However, the outer rings of the bearings are mostly fixed, leading to a larger bearing diameter and higher cost. If the wind turbine is hoisted as a whole, bolts need to be tightened inside the hub, making installation inconvenient and the assembly process complex, thus increasing the overall structure complexity and cost. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of large bearings and high cost in the existing wind turbine generator set, and to provide a gearbox, transmission chain and wind turbine generator set.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A gearbox includes components arranged sequentially, and the gearbox further includes a bearing, an input shaft, and an output shaft;

[0007] The differential planetary gear set includes a differential planetary ring gear, differential planetary planetary gears, a differential planetary sun gear, and a differential planetary planetary carrier. The input shaft is connected to the differential planetary planetary carrier, and the differential planetary planetary gears are fixed to the differential planetary planetary carrier by flexible pins. The quasi-planetary gear set includes a quasi-planetary ring gear, quasi-planetary planetary gears, a quasi-planetary sun gear, and a quasi-planetary planetary carrier. The quasi-planetary planetary carrier is fixed, the input shaft is connected to the quasi-planetary ring gear, and the quasi-planetary sun gear is connected to the differential planetary ring gear.

[0008] The basic planetary gear set includes a basic planetary ring gear, basic planetary planetary gears, a basic planetary sun gear, and a basic planetary planetary carrier. The basic planetary ring gear is connected to the quasi-planetary planetary carrier, the differential planetary sun gear is connected to the basic planetary planetary carrier, and the basic planetary sun gear is connected to the output shaft.

[0009] In this design, the power from the hub is transmitted to the input shaft, with a portion going to the quasi-planetary ring gear and a portion to the differential planetary carrier. The power transmitted to the quasi-planetary ring gear is then increased in speed and reduced in torque by the quasi-planetary gear transmission before being transmitted to the differential planetary ring gear via the sun gear. The differential planetary sun gear then combines the power of the differential planetary carrier and the differential planetary ring gear for output. This gearbox uses differential planetary and quasi-planetary gear transmissions to achieve power splitting and combining, reducing the load on the quasi-planetary ring gear and decreasing its diameter. This results in increased power density, reduced size, and improved reliability of the gearbox, thereby lowering the overall cost of the gearbox.

[0010] Preferably, the gearbox further includes a main bearing, which is a double-row tapered roller bearing; the input shaft of the gearbox is fixedly connected to the outer ring of the main bearing, and the inner ring of the main bearing is fixedly connected to the quasi-planetary carrier.

[0011] In this design, the gearbox is placed inside a double-row tapered bearing, reducing the number of bearing housings, effectively shortening the transmission chain length, and reducing overall costs.

[0012] Preferably, each planetary gear of the differential planetary gear group and the quasi-planetary gear group is equipped with a flexible pin structure for load sharing. The flexible pin shaft of the flexible pin structure is interference-fitted with its corresponding planet carrier, and the pin sleeve of the flexible pin structure is interference-fitted with the flexible pin shaft. The pin sleeve is used to support the planet bearings and planet gears of the corresponding planetary gear train.

[0013] In this scheme, when the two tangential forces of the ring gear and the sun gear of each planetary gear train are applied to the planet gears, the angular deflection caused by the bending of the flexible pin on the planet carrier can be offset by the angular deflection caused by the bending of the cantilever pin sleeve at the other end of the flexible pin in the opposite direction, so that each planet gear floats in parallel, thereby distributing the load evenly among each planet gear, achieving load equalization, and thus improving the life of the gears.

[0014] Preferably, the quasi-planetary sun gear is connected to the differential planetary gear ring via a conical disk; the quasi-planetary sun gear and the differential planetary gear ring are integral, and both the quasi-planetary sun gear and the differential planetary gear ring are floating components.

[0015] In this design, a conical disc connects the quasi-planetary sun gear and the differential gear ring, resulting in a simple connection structure. By setting the quasi-planetary sun gear and the differential gear ring as floating components, more uniform tooth surface contact and better force distribution are ensured, thereby improving the reliability of the gear set.

[0016] Preferably, the gearbox employs a three-stage transmission, and the total transmission ratio of the gearbox can reach 50 to 100.

[0017] In this solution, multi-stage transmission is adopted, which improves the overall transmission ratio of the gearbox, making the gearbox adaptable to various working environments, increasing the output speed of the gearbox, reducing the output torque, and making the generator smaller, effectively reducing the cost of the generator.

[0018] A drive train includes a gearbox as described above, and the drive train also includes a generator having a rotor connected to the output shaft.

[0019] In this design, the engine rotor in the transmission chain is directly connected to the output shaft, which effectively shortens the length of the transmission chain and reduces its volume.

[0020] A wind turbine generator set includes a drive train as described above, and the wind turbine generator set also includes a hub connected to the input shaft.

[0021] Preferably, the wind turbine generator set further includes a main frame, which is connected to the quasi-planetary planetary carrier, the differential planetary gear set is disposed in the rear cavity of the hub, and the basic planetary gear set is disposed in the front cavity of the main frame.

[0022] In this design, the differential planetary gear set is placed in the hub cavity, and the basic planetary gear set is placed in the main frame cavity. This reduces the volume occupied by the transmission part of the entire wind turbine generator set and lowers the cost of the transmission part. At the same time, the main frame, quasi-planetary carrier flange, and main bearing inner ring of the wind turbine generator set are fixed together, shortening the distance between the hub center and the tower center and reducing the bending moment generated by the weight of the wind turbine on the tower.

[0023] Preferably, the wind turbine generator set further includes a rotor locking disc, which is located between the main bearing and the main frame, and the input shaft, the outer ring of the main bearing, the rotor locking disc, and the hub are connected and fixed.

[0024] In this design, the wind turbine locking disc is positioned between the main bearing and the main frame. The input shaft, the outer ring of the bearing, the wind turbine locking disc, and the hub are connected and fixed together. The outer ring of the bearing rotates, reducing the bearing diameter and lowering the cost of the main bearing.

[0025] Preferably, the gearbox also includes a rear housing, one end of which is fixedly connected to the basic planetary gear ring and the quasi-planetary planetary carrier, and the other end of which is connected to the stator of the generator. The diameter of the rear housing and the generator is smaller than the diameter of the front flange of the main frame. The output shaft is connected to the basic planetary sun gear via a spline.

[0026] The positive and progressive effects of this invention are as follows: the gearbox uses differential planetary and quasi-planetary gear transmission to achieve power splitting, resulting in high power density and high reliability; the outer ring of the bearing rotates, reducing the bearing diameter and lowering bearing costs. By arranging the quasi-planetary gearbox segments inside the main bearing, and placing the differential planetary gear segments in the rear cavity of the hub, while the basic planetary gear segments and generator are arranged in the front cavity of the main frame, the length of the transmission chain is shortened, the bending moment of the wind turbine on the tower is reduced, and thus the overall cost of the wind turbine generator set is lowered. Attached Figure Description

[0027] Figure 1 This is a schematic cross-sectional view of a gearbox according to an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the overall transmission structure of a wind turbine generator set according to an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures

[0030] Gearbox 1

[0031] Input axis 11

[0032] Output shaft 12

[0033] Differential planetary gear set 100

[0034] Differential planetary gear ring 101

[0035] Differential Planetary Gear 102

[0036] Differential planetary sun gear 103

[0037] Differential Planetary Carrier 104

[0038] Quasi-planetary gear set 200

[0039] Quasi-planetary gear ring 201

[0040] Quasi-planetary planetary wheel 202

[0041] Quasi-planetary sun wheel 203

[0042] Quasi-planetary planetary support 204

[0043] Basic planetary gear set 300

[0044] Basic planetary gear ring 301

[0045] Basic Planetary Wheel 302

[0046] Basic planetary sun gear 303

[0047] Basic planetary frame 304

[0048] Double row tapered bearing 13

[0049] Conical disk 14

[0050] Generator 2

[0051] Rotor 20

[0052] Stator 21

[0053] Wheel Hub 3

[0054] Mainframe 4

[0055] Windmill Locking Disc 5

[0056] Gearbox rear housing 7 Detailed Implementation

[0057] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments.

[0058] A gearbox 1, such as Figure 1 As shown, the gearbox 1 includes a differential planetary gear set 100, a quasi-planetary gear set 200 and a basic planetary gear set 300 arranged in sequence. The gearbox 1 also includes an input shaft 11 and an output shaft 12.

[0059] The differential planetary gear set 100 includes a differential planetary gear ring 101, differential planetary planetary gears 102, differential planetary sun gear 103, and differential planetary carrier 104. The input shaft 11 is connected to the differential planetary carrier 104, and the differential planetary planetary gears 102 are fixed to the differential planetary carrier 104 by flexible pins. The quasi-planetary gear set 200 includes a quasi-planetary gear ring 201, quasi-planetary planetary gears 202, quasi-planetary sun gear 203, and quasi-planetary carrier 204. The quasi-planetary carrier 204 is connected and fixed to the inner ring of the main bearing 13 and the main frame 4 of the wind turbine generator set. The quasi-planetary gear ring 201 is connected to the input shaft 11, and the quasi-planetary sun gear 203 is connected to the differential planetary gear ring 101.

[0060] The basic planetary gear set 300 includes a basic planetary ring gear 301, basic planetary planetary gears 302, a basic planetary sun gear 303, and a basic planetary carrier 304. The basic planetary ring gear 301 is connected to the quasi-planetary carrier 204, the differential planetary sun gear 103 is connected to the basic planetary carrier 304, the basic planetary planetary gears 302 are mounted on the basic planetary carrier 304, and the basic planetary sun gear 303 is connected to the output shaft 12.

[0061] In this embodiment, the gearbox 1 is composed of a closed planetary gear transmission and a first-stage planetary gear transmission. The closed planetary gear transmission is a combination of a first-stage differential planetary gear transmission and a first-stage quasi-planetary gear transmission, which is a power-split type transmission.

[0062] In this embodiment, the power from the hub 3 is transmitted to the input shaft 11, with a portion going to the quasi-planetary ring gear 201 and a portion to the differential planetary carrier 104. The power transmitted to the quasi-planetary ring gear 201 is then increased in speed and reduced in torque by the quasi-planetary gear transmission before being transmitted to the differential planetary ring gear 101 via the quasi-planetary sun gear 203. The differential planetary sun gear 103 combines the power of the differential planetary carrier 104 with the power of the differential planetary ring gear 101 for output. This gearbox uses differential planetary and quasi-planetary gear transmissions to achieve power splitting and combining, reducing the load on the quasi-planetary ring gear and decreasing its diameter. This results in increased power density, reduced size, and improved reliability of the gearbox, thereby reducing the overall cost of the gearbox.

[0063] In this embodiment, the gearbox 1 further includes a main bearing 13, which is a double-row tapered roller bearing. The input shaft 11 of the gearbox 1 is fixedly connected to the outer ring of the main bearing 13, and the inner ring of the main bearing 13 is fixedly connected to the quasi-planetary carrier 204. By arranging the gearbox 1 inside the main bearing 13, there is only one main bearing 13, which is integrated with the gearbox 1, reducing the number of bearing housings, effectively shortening the length of the transmission chain, and reducing the overall cost.

[0064] In this embodiment, each planetary gear of the differential planetary planetary gear 102 and the quasi-planetary planetary gear 202 employs a flexible pin structure for load sharing. The flexible pin shaft of the flexible pin structure is interference-fitted with its corresponding planet carrier, and the pin sleeve of the flexible pin structure is interference-fitted with the flexible pin shaft. The pin sleeve is used to support the planetary bearings and planetary gears of the corresponding planetary gear train. When the two tangential forces of the ring gear and the sun gear of each planetary gear train are applied to the planetary gears, the angular deflection caused by the bending of the cantilever flexible pin shaft on the planet carrier can be offset by the angular deflection caused by the bending of the cantilever pin sleeve at the other end of the flexible pin shaft in the opposite direction, causing each planetary gear to float in parallel, thereby distributing the load evenly among each planetary gear, achieving load sharing, and thus improving the gear life.

[0065] In this embodiment, the quasi-planetary sun gear 203 is connected to the differential planetary gear ring 101 via a conical disk 14. This integral unit is not fixed to related components by bearings and is free in both the axial and radial directions (the free movement distance is limited in the specific design), so they are floating. When meshing with the flexible pin planetary gears, they will adapt to each other during transmission, resulting in better load sharing on the tooth surface and improving gear life.

[0066] In this embodiment, gearbox 1 adopts a three-stage transmission, and the total transmission ratio of gearbox 1 can reach 50 to 100. By adopting a multi-stage transmission, the overall transmission ratio of gearbox 1 is improved, making gearbox 1 adaptable to various working environments, increasing the output speed of gearbox 1, reducing the output torque, and allowing generator 2 to be smaller in size, effectively reducing the cost of generator 2.

[0067] A transmission chain includes a gearbox 1 as described above, and the transmission chain also includes a generator 2, which includes a rotor 20 connected to an output shaft 12.

[0068] In this embodiment, the generator rotor 20 in the transmission chain is directly connected to the output shaft 12, which effectively shortens the length of the transmission chain and reduces its volume.

[0069] A type of wind turbine generator, such as Figure 2 As shown, the wind turbine generator set includes the drive chain as described above, and the wind turbine generator set also includes a hub 3, which is connected to the gearbox input shaft 11 and the outer ring of the main bearing 13.

[0070] In this embodiment, the hub 3 is fixed to the outer ring of the bearing, and the thread is on the hub 3. When the hub 3 is lifted as a whole, the connecting bolts are tightened on the main frame 4 for easy installation.

[0071] In this embodiment, the wind turbine generator set also includes a main frame 4, which is connected to a quasi-planetary planetary carrier 204. The differential planetary gear set 100 is located in the rear cavity of the hub 3, and the basic planetary gear set 300 is located in the front cavity of the main frame 4.

[0072] The wind turbine generator set also includes a rotor locking disc 5, which is located between the main bearing and the main frame 4. The input shaft 11, the outer ring of the double-row tapered bearing 13, and the rotor locking disc 5 and the hub 3 are connected and fixed.

[0073] The gearbox 1 is also provided with a rear housing 7. One end of the rear housing 7 is fixedly connected to the quasi-planetary planetary carrier 204, and the other end of the rear housing 7 is connected to the stator 21 of the generator 2. The diameter of the rear housing 7 and the generator 2 is smaller than the diameter of the front flange of the main frame 4. The output shaft 12 is connected to the basic planetary sun gear 303 by a spline.

[0074] like Figure 1 , Figure 2 As shown, the input shaft 11 of the gearbox 1 is bolted together with the outer ring of the main bearing 13, the impeller locking disc 5, and the hub 3. The inner ring of the main bearing 13 is bolted together with the quasi-planetary carrier 204 and the main frame 4. The hub 3 and the main frame 4 are divided into rotating and fixed parts by the main bearing 13.

[0075] The load from the wind turbine, including thrust and bending moment, is transmitted to the main frame 4 via the tapered rollers of the double-row tapered bearing 13. The input shaft 11 of the gearbox 1 is also connected to the quasi-planetary gear ring 201 and the differential planetary carrier 104. Torque is transmitted to the quasi-planetary gear ring 201 and the differential planetary carrier 104 via the input shaft 11 of the gearbox 1, thus achieving power splitting. Since only the outer ring of the double-row tapered bearing 13 and the flanges of related components are arranged between the hub 3 and the main frame 4, the distance from the center of the hub 3 to the center of the tower is effectively shortened, effectively reducing the bending moment generated on the tower by the weight of the wind turbine.

[0076] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A gearbox, characterized in that, The gearbox includes a differential planetary gear set, a quasi-planetary gear set, and a basic planetary gear set arranged in sequence. The gearbox also includes an input shaft and an output shaft. The differential planetary gear set includes a differential planetary ring gear, differential planetary planetary gears, a differential planetary sun gear, and a differential planetary planetary carrier. The input shaft is connected to the differential planetary planetary carrier, and the differential planetary planetary gears are fixed to the differential planetary planetary carrier by flexible pins. The quasi-planetary gear set includes a quasi-planetary ring gear, quasi-planetary planetary gears, a quasi-planetary sun gear, and a quasi-planetary planetary carrier. The quasi-planetary planetary carrier is fixed, the input shaft is connected to the quasi-planetary ring gear, and the quasi-planetary sun gear is connected to the differential planetary ring gear. The basic planetary gear set includes a basic planetary ring gear, basic planetary planetary gears, a basic planetary sun gear, and a basic planetary planetary carrier. The basic planetary ring gear is connected to the quasi-planetary planetary carrier, the differential planetary sun gear is connected to the basic planetary planetary carrier, and the basic planetary sun gear is connected to the output shaft. The gearbox also includes a main bearing, which is a double-row tapered roller bearing; the input shaft of the gearbox is fixedly connected to the outer ring of the main bearing, and the inner ring of the main bearing is fixedly connected to the quasi-planetary carrier.

2. The gearbox as described in claim 1, characterized in that, Each planetary gear in the differential planetary group and the quasi-planetary group is equipped with a flexible pin structure for load sharing. The flexible pin shaft of the flexible pin structure is interference-fitted with its corresponding planet carrier, and the pin sleeve of the flexible pin structure is interference-fitted with the flexible pin shaft. The pin sleeve is used to support the planetary bearings and planetary gears of the corresponding planetary gear train.

3. The gearbox as described in claim 1, characterized in that, The quasi-planetary sun gear is connected to the differential planetary gear ring via a conical disk; the quasi-planetary sun gear and the differential planetary gear ring are integral, and both are floating components.

4. The gearbox as described in claim 1, characterized in that, The gearbox adopts a three-stage transmission, and the total transmission ratio of the gearbox can reach 50~100.

5. A transmission chain, characterized in that, The drive train includes a gearbox as described in any one of claims 1-4, and the drive train further includes a generator, the generator including a rotor connected to the output shaft.

6. A wind turbine generator set, characterized in that, The wind turbine generator set includes the drive train as described in claim 5, and the wind turbine generator set also includes a hub connected to the input shaft.

7. The wind turbine generator set as described in claim 6, characterized in that, The wind turbine generator set also includes a main frame, which is connected to the quasi-planetary planetary carrier. The differential planetary gear set is located in the cavity of the hub, and the basic planetary gear set is located in the cavity of the main frame.

8. The wind turbine generator set as described in claim 7, characterized in that, The wind turbine generator set also includes a rotor locking disc, which is located between the main bearing and the main frame. The input shaft, the outer ring of the main bearing, the rotor locking disc, and the hub are connected and fixed.

9. The wind turbine generator set as described in claim 7, characterized in that, The gearbox also has a rear housing, one end of which is fixedly connected to the basic planetary gear ring and the quasi-planetary planetary carrier, and the other end of which is connected to the end cover of the generator. The diameter of the rear housing and the generator is smaller than the diameter of the front flange of the main frame. The output shaft is connected to the basic planetary sun gear via a spline.

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