A bearing sealing structure of a semi-direct-drive wind turbine generator

Abstract

The application relates to a bearing sealing structure of a semi-direct-drive wind power generator, which comprises a hollow shaft, a cylindrical roller bearing sleeved on the hollow shaft and a bearing sleeve installed on an outer ring of the cylindrical roller bearing, the bearing sealing structure comprises a fixed part fixed on the bearing sleeve and a rotating part fixed on the hollow shaft, three sealing cavities, namely an inner sealing cavity, an outer sealing cavity and a flat pressure cavity, are formed between the fixed part, the rotating part and the bearing sleeve, an oil discharge gap and an inner oil collecting groove communicated with the oil discharge gap are arranged in the inner sealing cavity, an outer oil discharge pipe and an outer oil collecting groove communicated with the outer oil discharge pipe are arranged in the outer sealing cavity, a gas supplement hole is arranged on a transmission flange, and the gas supplement hole communicates the flat pressure cavity with a cabin. The application improves the bearing sealing reliability, and avoids bearing oil leakage and oil mist overflow.

Description

Technical Field

[0001] This invention patent relates to the field of semi-direct drive wind turbines, specifically to a bearing sealing structure for semi-direct drive wind turbines. Background Technology

[0002] Semi-direct-drive wind turbine bearings typically use rolling bearings with oil lubrication. These operate in environments with large temperature differences and are difficult to maintain. Contact seals are prone to aging and have short lifespans. Therefore, semi-direct-drive wind turbine bearings usually employ non-contact labyrinth seals. While non-contact labyrinth seals are maintenance-free and have a long lifespan, oil leakage and oil mist overflow still occur frequently during the operation of semi-direct-drive wind turbines. The reliability of the bearing seals still needs improvement, a problem that is difficult to completely avoid in semi-direct-drive wind turbines. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a semi-direct drive wind turbine bearing sealing structure. From the aspects of oil blocking, oil drainage, and oil mist prevention, this invention improves the traditional bearing sealing structure and proposes a sealing structure consisting of three labyrinth seals, two sets of oil drainage holes, and one set of air inlet holes, so as to improve the bearing sealing reliability and avoid bearing oil leakage and oil mist overflow.

[0004] According to the technical solution provided by the present invention, a semi-direct drive wind turbine bearing sealing structure includes a hollow shaft, a cylindrical roller bearing sleeved on the hollow shaft, and a bearing sleeve installed on the outer ring of the cylindrical roller bearing. The bearing sealing structure includes a fixing member fixed on the bearing sleeve and a rotating member fixed on the hollow shaft. The fixing member, the rotating member, and the bearing sleeve form three sealing cavities: an inner sealing cavity, an outer sealing cavity, and a flat pressure cavity. The inner sealing cavity communicates with the cylindrical roller bearing, and the outer sealing cavity communicates with the sealing cavity. The fixing member and the rotating member are both disposed at one end of the cylindrical roller bearing.

[0005] The inner sealing cavity is provided with an oil drain notch, an inner oil collection groove connected to the oil drain notch, and an inner oil drain pipe connected to the inner oil collection groove. The outer sealing cavity is provided with an outer oil collection groove and an outer oil drain pipe connected to the outer oil collection groove. The transmission flange is provided with an air inlet hole, which connects the pressure equalization chamber and the engine room.

[0006] As a further improvement of the present invention, the fixing member includes an inner labyrinth ring, an outer labyrinth ring, and a sealing cap;

[0007] The rotating component includes an inner spacer ring, an outer spacer ring, and a transmission flange;

[0008] The inner spacer ring, outer spacer ring, and transmission flange are fixed side by side on the hollow shaft. The inner side of the inner labyrinth ring mates with the inner spacer ring, and the outer side of the inner labyrinth ring is fixed to the bearing sleeve. The inner side of the outer labyrinth ring mates with the outer spacer ring, and the outer side of the outer labyrinth ring is fixed to the bearing sleeve. The sealing cover is fixed to the bearing sleeve.

[0009] The bearing sleeve, inner labyrinth ring, and inner spacer ring form an inner sealing cavity; the inner labyrinth ring, outer spacer ring, bearing sleeve, and outer labyrinth ring form an outer sealing cavity; and the outer labyrinth ring, sealing cover, and transmission flange form a pressure-balancing cavity.

[0010] As a further improvement of the present invention, the fixing member and the rotating member do not contact each other.

[0011] As a further improvement of the present invention, both the inner labyrinth ring and the outer labyrinth ring are provided with oil-blocking grooves and oil-slinging inclined surfaces.

[0012] As a further improvement of the present invention, the inclination angle of the inner oil drain pipe and the outer oil drain pipe is in the range of 12° to 16°.

[0013] As a further improvement of the present invention, the other end of the cylindrical roller bearing is a non-sealed area.

[0014] The beneficial effects of this invention are as follows:

[0015] Unlike the original sealing structure, the inner and outer spacer rings have increased the number of sealing grooves and lengthened the labyrinth path, thereby reducing the amount of lubricating oil entering the next sealing cavity through the labyrinth. The inner and outer labyrinth rings also feature oil-retaining grooves and oil-throwing ramps. Lubricating oil entering the oil-retaining grooves under centrifugal force can still return to the sealing cavity through the oil-throwing ramps, further reducing the amount of lubricating oil entering the next sealing cavity through the labyrinth. A new sealing cap is added to balance the air pressure inside and outside the bearing seal, preventing oil mist from being drawn into the negative pressure zone. Through these structural optimizations, the reliability of the bearing seal is improved, preventing bearing oil leakage and oil mist overflow. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the semi-direct drive generator bearing sealing structure described in this invention.

[0017] Figure 2 This is a schematic diagram of the three-chamber structure of the present invention.

[0018] Figure 3 and Figure 4 for Figure 2 A longitudinal sectional view.

[0019] Figure 5 This is a schematic diagram showing the assembly location of the present invention in a generator.

[0020] Figure 6 This is an enlarged view of the inner and outer sealing cavities.

[0021] Explanation of reference numerals in the attached drawings: 1. Bearing sleeve; 2. Inner labyrinth ring; 3. Outer labyrinth ring; 4. Sealing cap; 5. Hollow shaft; 6. Inner spacer ring; 7. Outer spacer ring; 8. Transmission flange; 9. Inner sealing cavity; 10. Outer sealing cavity; 11. Pressure equalization cavity; 12. Oil inlet; 13. Cylindrical roller bearing; 14. Inner oil collection groove; 15. Inner oil drain pipe; 16. Outer oil collection groove; 17. Outer oil drain pipe; 18. Air inlet; 19. Engine compartment; 20. Negative pressure zone; 21. Oil drain notch; 22. Oil baffle groove; 23. Oil slinger slope; 24. Non-sealed area. Detailed Implementation

[0022] The present invention will now be further described with reference to the embodiments shown in the accompanying drawings:

[0023] As shown in the figure, a semi-direct drive wind turbine bearing sealing structure includes a hollow shaft 5, a cylindrical roller bearing 13 sleeved on the hollow shaft 5, and a bearing sleeve 1 installed on the outer ring of the cylindrical roller bearing 13. The bearing sealing structure includes a fixing member fixed on the bearing sleeve 1 and a rotating member fixed on the hollow shaft 5. The fixing member, the rotating member, and the bearing sleeve 1 form three sealing cavities: an inner sealing cavity 9, an outer sealing cavity 10, and a flat pressure cavity 11. The inner sealing cavity 9 communicates with the cylindrical roller bearing 13, and the outer sealing cavity 10 communicates with the inner sealing cavity 9. The fixing member and the rotating member are both located at one end of the cylindrical roller bearing 13.

[0024] The inner sealing cavity 9 is provided with an oil drain notch 21, an inner oil collection groove 14 communicating with the oil drain notch 21, and an inner oil drain pipe 15 communicating with the inner oil collection groove 14. The outer sealing cavity 10 is provided with an outer oil collection groove 16 and an outer oil drain pipe 17 communicating with the outer oil collection groove 16. The transmission flange 8 is provided with an air inlet 18, which communicates with the pressure equalization cavity 11 and the engine room 19.

[0025] The fastener includes an inner labyrinth ring 2, an outer labyrinth ring 3, and a sealing cap 4;

[0026] The rotating component includes an inner spacer ring 6, an outer spacer ring 7, and a transmission flange 8;

[0027] The inner spacer ring 6, the outer spacer ring 7, and the transmission flange 8 are fixed side by side on the hollow shaft 5. The bottom end of the inner labyrinth ring 2 is engaged with the inner spacer ring 6, and the upper end of the inner labyrinth ring 2 is fixed with the bearing sleeve 1. The bottom end of the outer labyrinth ring 3 is engaged with the outer spacer ring 7, and the top end of the outer labyrinth ring 3 is fixed with the bearing sleeve 1. The sealing cover 4 is fixed on the bearing sleeve 1.

[0028] The bearing sleeve 1, the inner labyrinth ring 2, and the inner spacer ring 6 form an inner sealing cavity 9; the inner labyrinth ring 2, the outer spacer ring 7, the bearing sleeve 1, and the outer labyrinth ring 3 form an outer sealing cavity 10; and the outer labyrinth ring 3, the sealing cover 4, and the transmission flange 8 form a pressure-flattening cavity 11. The fixed component and the rotating component do not contact each other.

[0029] like Figure 6 As shown, to enhance the sealing effect, both the inner labyrinth ring 2 and the outer labyrinth ring 3 are provided with oil-blocking grooves 22 and oil-throwing inclined surfaces 23. The lubricating oil that enters the oil-blocking grooves 22 can still return to the sealing cavity through the oil-throwing inclined surfaces 23.

[0030] The inner oil drain pipe 15 and the outer oil drain pipe 17 are required to have a sufficient tilt angle, that is, a tilt angle greater than the motor tilt angle by more than 5°. The tilt angle is usually in the range of 12° to 16°. The inner oil drain pipe 15 and the outer oil drain pipe 17 are not connected to prevent the lubricating oil in the inner sealing cavity 9 from flowing into the outer sealing cavity 10 through the oil drain pipe.

[0031] The other end of the cylindrical roller bearing 13 is provided with a non-sealed area 24 to allow oil to drain from the bearing.

[0032] The installation and working principle of this invention are as follows:

[0033] like Figure 2 As shown, the inner spacer ring 6 is heated and then fitted onto the hollow shaft 5. Machining ensures the coaxiality of the sealing grooves on the inner spacer ring 6. The inner labyrinth ring 2 is bolted to the bearing sleeve 1. A stop is used for positioning between the inner labyrinth ring 2 and the bearing sleeve 1 to ensure the coaxiality of the sealing grooves on the inner labyrinth ring 2. The coaxiality requirements during machining ensure a uniform labyrinth radial clearance between the inner spacer ring 6 and the inner labyrinth ring 2. The inner spacer ring 6, bearing sleeve 1, and inner labyrinth ring 2 form the first labyrinth seal. Next, the outer spacer ring 7 is heated and then fitted onto the hollow shaft 5. Machining ensures the coaxiality of the sealing grooves on the outer spacer ring 7. The outer labyrinth ring 3 is bolted onto the bearing sleeve 1. A stop is used for positioning between the outer labyrinth ring 3 and the bearing sleeve 1 to ensure the coaxiality of the sealing grooves on the outer labyrinth ring 3. The coaxiality requirements during machining ensure a uniform labyrinth radial clearance between the outer spacer ring 7 and the outer labyrinth ring 3. The inner labyrinth ring 2, outer spacer ring 7, bearing sleeve 1, and outer labyrinth ring 3 form the second labyrinth seal. The transmission flange 8 is then bolted onto the hollow shaft 5, with a stop-lock positioning between the transmission flange 8 and the hollow shaft 5 to ensure the coaxiality of the sealing grooves on the transmission flange 8. The sealing cover 4 is bolted onto the bearing sleeve 1, with a stop-lock positioning between the sealing cover 4 and the bearing sleeve 1 to ensure the coaxiality of the sealing grooves on the sealing cover 4. By adhering to the coaxiality requirements during machining, the uniform radial gap of the labyrinth between the transmission flange 8 and the sealing cover 4 is ensured. The transmission flange 8, outer labyrinth ring 3, and sealing cover 4 form the third labyrinth seal.

[0034] like Figure 1 As shown, lubricating oil is sprayed into the cylindrical roller bearing 13 through the oil inlet 12 above the bearing sleeve 1 and then enters the inner sealing cavity 9. Most of the lubricating oil in the inner sealing cavity 9 is as follows: Figure 3 As shown, the oil collects in the inner oil collection groove 14 below the bearing sleeve 1 and is discharged through the inner oil drain pipe 15. A small amount of lubricating oil passes through the first seal and enters the outer sealing cavity 10. This portion of lubricating oil is as follows: Figure 4 As shown, the oil collects at the outer oil collection groove 16 below the bearing sleeve 1 and is discharged through the outer oil drain pipe 17. Finally, a small amount of lubricating oil in the form of oil mist enters the equalization chamber 11. Figure 5 As shown, the pressure equalization chamber 11 is connected to the engine compartment 19 through the air inlet 18 on the transmission flange 8, in order to balance the air pressure inside and outside the bearing seal and prevent the oil mist generated during the bearing rotation from being sucked into the negative pressure zone 20 inside the generator through the pressure equalization chamber 11.

Claims

1. A semi-direct drive wind turbine bearing sealing structure, comprising a hollow shaft (5), a cylindrical roller bearing (13) sleeved on the hollow shaft (5), and a bearing sleeve (1) mounted on the outer ring of the cylindrical roller bearing (13), characterized in that, The bearing sealing structure includes a fixing member fixed on the bearing sleeve (1) and a rotating member fixed on the hollow shaft (5). The fixing member, the rotating member, and the bearing sleeve (1) form three sealing cavities: an inner sealing cavity (9), an outer sealing cavity (10), and a flat pressure cavity (11). The inner sealing cavity (9) communicates with the cylindrical roller bearing (13), and the outer sealing cavity (10) communicates with the inner sealing cavity (9). Both the fixing member and the rotating member are located at one end of the cylindrical roller bearing (13). The inner sealing cavity (9) is provided with an oil drain notch (21), an inner oil collection groove (14) connected to the oil drain notch (21), and an inner oil drain pipe (15) connected to the inner oil collection groove (14). The outer sealing cavity (10) is provided with an outer oil collection groove (16) and an outer oil drain pipe (17) connected to the outer oil collection groove (16). The inner oil drain pipe (15) and the outer oil drain pipe (17) are not connected. The transmission flange (8) is provided with an air inlet (18), which is connected to the pressure equalization cavity (11) and the engine room (19). The fixing component includes an inner labyrinth ring (2), an outer labyrinth ring (3), and a sealing cap (4); the rotating component includes an inner spacer ring (6), an outer spacer ring (7), and a transmission flange (8); the inner spacer ring (6), the outer spacer ring (7), and the transmission flange (8) are fixed side by side on the hollow shaft (5), the inner side of the inner labyrinth ring (2) is engaged with the inner spacer ring (6), the outer side of the inner labyrinth ring (2) is fixed with the bearing sleeve (1), and the inner side of the outer labyrinth ring (3) is engaged with the outer spacer ring (6). 7) The outer side of the outer labyrinth ring (3) is fixed to the bearing sleeve (1), and the sealing cover (4) is fixed on the bearing sleeve (1); wherein the bearing sleeve (1), the inner labyrinth ring (2) and the inner spacer ring (6) form an inner sealing cavity (9), the inner labyrinth ring (2), the outer spacer ring (7), the bearing sleeve (1) and the outer labyrinth ring (3) form an outer sealing cavity (10), and the outer labyrinth ring (3), the sealing cover (4) and the transmission flange (8) form a flat pressure cavity (11).

2. The semi-direct drive wind turbine bearing sealing structure as described in claim 1, characterized in that, The fixed component and the rotating component do not come into contact.

3. The semi-direct drive wind turbine bearing sealing structure as described in claim 1, characterized in that, Both the inner labyrinth ring (2) and the outer labyrinth ring (3) are provided with oil-blocking grooves (22) and oil-slinging inclined surfaces (23).

4. The semi-direct drive wind turbine bearing sealing structure as described in claim 1, characterized in that, The inclination angles of the inner drain pipe (15) and the outer drain pipe (17) are in the range of 12° to 16°.

5. The semi-direct drive wind turbine bearing sealing structure as described in claim 1, characterized in that, The other end of the cylindrical roller bearing (13) is a non-sealed area (24).

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