Permanent magnet direct drive generator and system

Abstract

The present invention relates to the technical field of power generation, and in particular to a permanent magnet direct-drive generator and system, wherein the permanent magnet direct-drive generator comprises a main shaft, a rotor, a rotor sleeve, a shell, a stator, a stator sleeve, an end cover, a first support member and a second support member. The rotor is mounted on the main shaft, and a rotor sleeve is sleeved on the outer side of the rotor to seal the rotor in the rotor sleeve. The stator is then mounted in the shell, and a stator sleeve is sleeved on the outer side of the stator to seal the stator in the stator sleeve. The rotor and the stator can be sealed. When the permanent magnet direct-drive generator works underwater, the rotor and the stator can be prevented from being exposed to water. The sealed cavity between the end cover, the second support member, the main shaft, the rotor sleeve, the first support member, and the stator sleeve allows water to circulate inside and outside the generator. The sealing requirement for the generator is low, and there is no need to use a multi-layer lip seal seal. The structure of the permanent magnet direct-drive generator is simplified and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, and in particular to a permanent magnet direct-drive generator and system. Background Art

[0002] Tidal power generation is a new energy power generation technology. It is a technology that uses the potential energy of water level difference to generate electricity. Like tidal energy, it is generated by the tidal force of the moon and the sun. The principle of tidal power generation is to use the impact of the tide to make the blades of the turbine rotate, thereby driving the generator to generate electricity.

[0003] Tidal energy generator sets mostly use doubly-fed generator systems, permanent magnet semi-direct drive generator systems, permanent magnet direct drive generator systems and hydraulic generator systems. In the permanent magnet direct drive generator system, the generator is directly connected to the turbine, eliminating the intermediate gearbox, greatly improving the overall reliability and operating efficiency of the system.

[0004] Permanent magnet direct-drive generators in the prior art usually require three or more layers of lip seals, oil seals or air seals to isolate the air inside the generator from the external seawater to ensure that the generator can operate reliably underwater. However, generators with this structure have high requirements for sealing reliability. If the seals are damaged or deteriorated when working underwater, leakage will occur, causing water to enter the generator and damage the generator. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art that the generator has high requirements on sealing reliability and damage to the sealing component may cause water intrusion and damage to the generator.

[0006] In order to solve the above problems, the present invention provides a permanent magnet direct drive generator, comprising:

[0007] Spindle;

[0008] A rotor, fixedly mounted on the main shaft;

[0009] A rotor sleeve, the interior of which is a cavity, is sleeved on the main shaft, and the rotor is located in the cavity;

[0010] A shell, the interior of which is a hollow cavity, and the main shaft is rotatably mounted in the shell;

[0011] A stator, fixedly mounted on the inner wall of the housing;

[0012] A stator sleeve is sleeved inside the housing, and the stator is located between the housing and the stator sleeve;

[0013] An end cover, fixedly connected to the shell;

[0014] A first support member, mounted on the main shaft and fixedly connected to the stator sleeve;

[0015] A second support member is mounted on the main shaft and fixedly connected to the end cover. A sealed cavity suitable for containing water is formed between the end cover, the second support member, the main shaft, the rotor sleeve, the first support member and the stator sleeve.

[0016] Furthermore, in this permanent magnet direct-drive generator, the shell includes a first cylinder and a first annular flange and a second annular flange located at both ends of the first cylinder, an annular limiting rib is provided on the inner wall of the first cylinder, the stator abuts against the annular limiting rib, the first annular flange is connected to the end cover, and the second annular flange is connected to the stator sleeve.

[0017] Furthermore, in this permanent magnet direct drive generator, the end cover includes a cover body and a third annular flange arranged at the edge of the cover body, and the third annular flange is connected to the first annular flange.

[0018] Furthermore, in this permanent magnet direct drive generator, the stator sleeve includes a second cylinder, a fourth annular flange and a fifth annular flange, the second cylinder extends into the first cylinder, the fifth annular flange is connected to the third annular flange, and the fourth annular flange is connected to the second annular flange.

[0019] Furthermore, in this permanent magnet direct drive generator, water is provided in the sealed cavity.

[0020] Furthermore, the permanent magnet direct drive generator further comprises:

[0021] The bearing is installed on the main shaft and abuts against the inner wall of the cover body.

[0022] Furthermore, in this permanent magnet direct drive generator, the interior of the main shaft is a cavity, a mounting seat is provided on the exterior of the main shaft, and the rotor sleeve is fixedly connected to the mounting seat.

[0023] Furthermore, the permanent magnet direct drive generator further comprises:

[0024] The filter element is arranged outside the first support element.

[0025] Furthermore, in this permanent magnet direct drive generator, a liquid injection hole is provided on the end cover, and the liquid injection hole is communicated with the sealing cavity.

[0026] The present invention also provides a permanent magnet direct drive power generation system, comprising:

[0027] The above permanent magnet direct drive generator;

[0028] A liquid storage box, connected to the liquid injection hole;

[0029] A hub connected to an end of the main shaft away from the end cover;

[0030] The impeller is fixedly connected to the hub.

[0031] The present invention has the following advantages:

[0032] 1. The permanent magnet direct-drive generator provided by the present invention comprises a main shaft, a rotor, a rotor sleeve, a shell, a stator, a stator sleeve, an end cover, a first support member and a second support member. The rotor is fixedly mounted on the main shaft, the rotor sleeve has a cavity inside and is sleeved on the main shaft, the rotor is located in the cavity, the shell has a cavity inside, the main shaft is rotatably mounted in the shell, the stator is fixedly mounted on the inner wall of the shell, the stator sleeve is sleeved inside the shell, the stator is located between the shell and the stator sleeve, the end cover is fixedly connected to the shell, the first support member is mounted on the main shaft and is fixedly connected to the stator sleeve, the second support member is mounted on the main shaft and is fixedly connected to the end cover, and a sealed cavity suitable for accommodating water is formed between the end cover, the second support member, the main shaft, the rotor sleeve, the first support member and the stator sleeve.

[0033] By installing the rotor on the main shaft, and sleeved the rotor sleeve on the outside of the rotor, sealing the rotor in the rotor sleeve, and then installing the stator in the housing, and sleeved the stator sleeve on the outside of the stator, and sealing the stator in the stator sleeve, the rotor and the stator can be sealed, and when the permanent magnet direct-drive generator works underwater, the rotor and the stator can be prevented from being exposed to water. The first support member arranged between the main shaft and the stator sleeve and the second support member arranged on the main shaft and connected to the end cover can bear the radial bearing capacity of the main shaft and support the main shaft. The sealed cavity between the end cover, the second support member, the main shaft, the rotor sleeve, the first support member, and the stator sleeve allows water to circulate inside and outside the generator. The sealing requirements for the generator are low, and there is no need to use multi-layer lip seals. The structure of the permanent magnet direct-drive generator is simplified and the manufacturing cost is reduced.

[0034] 2. The permanent magnet direct-drive generator provided by the present invention has a shell comprising a first cylinder and a first annular convex edge and a second annular convex edge located at both ends of the first cylinder. By arranging annular limiting convex ribs on the inner wall of the first cylinder, the stator can abut against the annular limiting convex ribs after installation, thereby improving the stability of the stator. The first annular convex edge is connected to the end cover, and the second annular convex edge is connected to the stator sleeve, so that the stator is sealed in the cavity formed by the shell and the stator sleeve, which has better sealing performance.

[0035] 3. The permanent magnet direct-drive generator provided by the present invention has a stator sleeve comprising a second cylinder, a fourth annular flange and a fifth annular flange. The second cylinder extends into the first cylinder, the fifth annular flange is connected to the third annular flange, and the fourth annular flange is connected to the second annular flange, so that a sealed cavity is formed between the shell, the stator sleeve and the end cover, which can provide more reliable sealing for the stator when operating underwater.

[0036] 4. In the permanent magnet direct-drive generator provided by the present invention, a sealed cavity is formed between the end cover, the second support member, the main shaft, the rotor sleeve, the first support member and the stator sleeve and is filled with water. By filling the sealed cavity with water, the pressure inside the permanent magnet direct-drive generator is made the same as the pressure of water in the external environment, thereby reducing the damage to the structure of the permanent magnet direct-drive generator by the external water pressure, thereby increasing the service life of the permanent magnet direct-drive generator structure.

[0037] 5. In the permanent magnet direct drive generator provided by the present invention, a bearing is installed on the inner wall where the main shaft abuts against the cover body to provide support for the rotation of the main shaft and reduce friction.

[0038] 6. The permanent magnet direct-drive generator provided by the present invention has a main shaft with a cavity inside and a mounting seat provided outside the main shaft. The rotor sleeve is fixedly connected to the mounting seat. By sealing the rotor in the rotor sleeve, the sealing of the rotor can be improved when running underwater to prevent water in the external environment from damaging the rotor. The main shaft has a cavity structure inside, which reduces the overall weight of the generator, so that the main shaft, hub and blades are at a neutral density underwater, reducing the radial force that the seal needs to bear.

[0039] 7. The permanent magnet direct drive generator provided by the present invention has a filter element disposed outside the first support element, which can filter out some large particles of floating matter and prevent the floating matter from entering the generator.

[0040] 8. The permanent magnet direct drive power generation system provided by the present invention includes a permanent magnet direct drive generator, a liquid storage tank, a hub and an impeller. The liquid storage tank is connected to the liquid injection hole, the hub is connected to the end of the main shaft away from the end cover, and the impeller is fixedly connected to the hub.

[0041] Water can be injected into the sealed cavity inside the permanent magnet direct drive generator through the liquid storage tank, so that the pressure inside the permanent magnet direct drive generator is the same as the water pressure in the external environment, reducing the damage to the structure of the permanent magnet direct drive generator caused by the external water pressure, thereby increasing the service life of the permanent magnet direct drive generator structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 A cross-sectional view of a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0044] Figure 2 A schematic diagram of the structure of a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0045] Figure 3 A schematic structural diagram of a permanent magnet direct-drive generator from another perspective provided by an embodiment of the present invention;

[0046] Figure 4 A schematic diagram of the structure of a housing in a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0047] Figure 5 A cross-sectional view of a housing in a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0048] Figure 6 A schematic structural diagram of an end cover of a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0049] Figure 7 A cross-sectional view of an end cover of a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0050] Figure 8 A schematic structural diagram of a stator sleeve in a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0051] Fig. 9 A schematic structural diagram of a main shaft in a permanent magnet direct-drive generator provided in an embodiment of the present invention;

[0052] Fig.10 A cross-sectional view of a main shaft in a permanent magnet direct-drive generator provided in an embodiment of the present invention.

[0053] Description of reference numerals:

[0054] 1. Spindle; 11. Mounting seat; 12. First step; 13. Second step; 14. Third step; 15. Fourth step; 16. Fifth step; 17. Sixth annular flange; 2. Rotor; 3. Rotor sleeve; 4. Shell; 41. First cylinder; 42. First annular flange; 43. Second annular flange; 44. Annular limiting rib; 5. Stator; 6. Stator sleeve; 61. Second cylinder; 62. Fourth annular flange; 63. Fifth annular flange; 7. End cover; 71. Cover; 72. Third annular flange; 8. First support member; 9. Second support member; 10. Bearing. DETAILED DESCRIPTION

[0055] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0059] Example 1

[0060] like Figures 1 to 10As shown, the permanent magnet direct-drive generator provided in this embodiment includes a main shaft 1, a rotor 2, a rotor sleeve 3, a shell 4, a stator 5, a stator sleeve 6, an end cover 7, a first support member 8 and a second support member 9. The rotor 2 is fixedly mounted on the main shaft 1, the rotor sleeve 3 has a cavity inside and is sleeved on the main shaft 1, the rotor 2 is located in the cavity, the shell 4 has a cavity inside, the main shaft 1 is rotatably mounted in the shell 4, the stator 5 is fixedly mounted on the inner wall of the shell 4, the stator sleeve 6 is sleeved inside the shell 4, the stator 5 is located between the shell 4 and the stator sleeve 6, the end cover 7 is fixedly connected to the shell 4, the first support member 8 is mounted on the main shaft 1 and is fixedly connected to the stator sleeve 6, the second support member 9 is mounted on the main shaft 1 and is fixedly connected to the end cover 7, and a sealed cavity suitable for accommodating water is formed between the end cover 7, the second support member 9, the main shaft 1, the rotor sleeve 3, the first support member 8 and the stator 5 sleeve.

[0061] In this embodiment, the sealing requirements for the first support member 8 are low, allowing water circulation inside and outside the generator. The first support member 8 can be mechanically sealed, and only needs to provide a radial bearing capacity of a main shaft 1 and prevent large particles including marine organisms from entering the generator. Large-sized bearings are not required, which reduces costs and maintenance requirements.

[0062] In this embodiment, the rotor 2 is made of permanent magnets, and the stator 5 is made of winding coils.

[0063] By installing the rotor 2 on the main shaft 1, and sleeved the rotor sleeve 3 on the outside of the rotor 2, the rotor 2 is sealed in the rotor sleeve 3, and then the stator 5 is installed in the housing 4, and the stator sleeve 6 is sleeved on the outside of the stator 5, and the stator 5 is sealed in the stator sleeve 6, the rotor 2 and the stator 5 can be sealed, and when the permanent magnet direct-drive generator works underwater, the rotor 2 and the stator 5 can be prevented from being exposed to water. The first support member 8 arranged between the main shaft 1 and the stator sleeve 6 and the second support member 9 arranged on the main shaft 1 and connected to the end cover 7 can bear active radial bearing force and support the main shaft. The sealed cavity between the end cover 7, the second support member 9, the main shaft 1, the rotor sleeve 3, the first support member 8, and the stator sleeve 6 allows water circulation inside and outside the generator, and the sealing requirements for the generator are low, and there is no need to use a multi-layer lip seal seal, which simplifies the structure of the permanent magnet direct-drive generator and reduces the cost of manufacturing and use.

[0064] Since water is allowed to enter the sealed cavity, the resistance to the rotation of the main shaft 1 in water is much greater than the resistance in the air, so that the rotation speed of the main shaft 1 is relatively low, which meets the low speed design requirements of the direct-drive generator.

[0065] like Figure 4 and Figure 5As shown, the shell 4 includes a first cylinder 41 and a first annular flange 42 and a second annular flange 43 located at both ends of the first cylinder 41. By arranging an annular limiting rib 44 on the inner wall of the first cylinder 41, the stator 5 can abut against the annular limiting rib 44 after installation, thereby improving the stability of the stator 5. The first annular flange 42 is connected to the end cover 7, and the second annular flange 43 is connected to the stator sleeve 6, so that the stator 5 is sealed in the cavity formed by the shell 4 and the stator sleeve 6, which has better sealing performance.

[0066] like Figure 6 and Figure 7 As shown, the end cover 7 includes a cover body 71 and a third annular flange 72 arranged at the edge of the cover body 71 , and the third annular flange 72 is connected to the first annular flange 42 .

[0067] like Figure 8 As shown, the stator sleeve 6 includes a second cylinder 61, a fourth annular flange 62 and a fifth annular flange 63. The second cylinder 61 extends into the first cylinder 41, the fifth annular flange 63 is connected to the third annular flange 72, and the fourth annular flange 62 is connected to the second annular flange 43, so that a sealed cavity is formed between the housing 4, the stator sleeve 6 and the end cover 7, which can provide more reliable sealing for the stator 5 when operating underwater.

[0068] In this embodiment, a plurality of bolt holes are provided on the first annular flange 42, the second annular flange 43, the third annular flange 72, the fourth annular flange 62 and the fifth annular flange 63. The third annular flange 72 is fixedly connected to the first annular flange 42 by bolts, the fifth annular flange 63 is fixedly connected to the third annular flange 72 by bolts, and the fourth annular flange 62 is fixedly connected to the second annular flange 43 by bolts.

[0069] like Figure 1 As shown, in this embodiment, a sealed cavity is formed between the end cover 7, the second support member 9, the main shaft 1, the rotor sleeve 3, the first support member 8 and the stator 5 sleeve and is filled with water. By filling the sealed cavity with water, the pressure inside the permanent magnet direct-drive generator is made the same as the water pressure in the external environment, thereby reducing the damage of the permanent magnet direct-drive generator structure to the external water pressure, so as to improve the service life of the permanent magnet direct-drive generator structure.

[0070] In this embodiment, the water filled in the sealed cavity can be clean fresh water, which can reduce the corrosion of the water to the inside of the generator. In this embodiment, the water pressure of the water filled in the sealed cavity is slightly greater than the water pressure in the external environment. When the seal is damaged, since the internal pressure of the generator is greater than the external pressure, external seawater can be prevented from entering the generator, thereby reducing the corrosion of the generator by seawater.

[0071] like Figure 1As shown, the bearing 10 is installed on the inner wall where the main shaft 1 abuts against the cover body 71 to provide support for the rotation of the main shaft 1 and reduce friction. In this embodiment, two bearings 10 are provided.

[0072] In this embodiment, the bearing 10 preferably adopts a single-layer lip seal bearing 10. This type of bearing 10 has a simple structure and is easy to install. It can bear a large radial force without using a large-sized bearing 10, thereby reducing the cost of use and the maintenance requirements.

[0073] In this embodiment, the second support member 9 preferably adopts a rotating active seal, which can seal the bearing 10 on one side of the end cover 7 when running underwater, preventing seawater from entering the side of the end cover 7 where the bearing 10 is provided and causing damage to the bearing 10 or internal sensors.

[0074] like Fig. 9 and Fig.10 As shown, the interior of the main shaft 1 is a cavity, and a mounting seat 11 is provided on the outside of the main shaft 1. The rotor sleeve 3 is fixedly connected to the mounting seat 11. By sealing the rotor 2 in the rotor sleeve 3, the sealing performance of the rotor 2 can be improved when running underwater, and water in the external environment can be prevented from damaging the rotor 2. The interior of the main shaft 1 is a cavity structure, which reduces the overall weight of the generator, so that the main shaft 1, the hub and the blades are at a neutral density underwater, reducing the radial force that the seal needs to bear.

[0075] In this embodiment, the main shaft 1 is in a five-step shape, the first support member 8 is installed on the first step 12, the rotor 2 is installed on the second step, the second support member 9 is installed on the third step 14, and the bearings 10 are respectively arranged on the fourth step 15 and the fifth step 16.

[0076] Preferably, in this embodiment, the end of the internal cavity of the main shaft 1 close to the fifth step 16 is a blind hole structure, and the end close to the first step 12 is provided with a sixth annular flange 17 suitable for connecting with the hub.

[0077] In this embodiment, the diameter of the main shaft 1 gradually decreases from the first step 12 to the fifth step 16, so that the size of the bearing 10 installed on the fifth step 16 can be reduced, avoiding the problem of high cost caused by using large-sized bearings.

[0078] In this embodiment, a filter is provided outside the first support member 8 to filter out some large particles of floating objects, thereby preventing floating objects and marine organisms from entering the generator.

[0079] In this embodiment, a liquid injection hole is provided on the end cover 7, and the liquid injection hole is communicated with the sealing cavity, and clean fresh water can be injected into the sealing cavity through the liquid injection hole.

[0080] Example 2

[0081] The permanent magnet direct drive power generation system provided by the present invention comprises the permanent magnet direct drive generator, a liquid storage tank, a hub and an impeller in Example 1, the liquid storage tank is connected to the liquid injection hole, the hub is connected to the end of the main shaft 1 away from the end cover 7, and the impeller is fixedly connected to the hub.

[0082] Directly connecting the generator to the hub of the turbine eliminates the intermediate gearbox, greatly improving the overall reliability and working efficiency of the system. Water can be injected into the sealed cavity inside the permanent magnet direct-drive generator through the liquid storage tank, so that the pressure inside the permanent magnet direct-drive generator is the same as the water pressure in the external environment, reducing the damage to the structure of the permanent magnet direct-drive generator caused by external water pressure, thereby increasing the service life of the permanent magnet direct-drive generator structure and further increasing the service life of the power generation system.

[0083] By allowing water to circulate inside and outside the generator through the sealed cavity between the end cover 7, the second support member 9, the main shaft 1, the rotor sleeve 3, the first support member 8, and the stator sleeve 6, the sealing requirements for the generator are reduced, and there is no need to use multi-layer seals, which simplifies the structure of the permanent magnet direct-drive generator and reduces the manufacturing cost.

[0084] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A permanent magnet direct drive generator, characterized in that: include: A main shaft (1), the main shaft (1) being connected to a hub of the turbine; A rotor (2) fixedly mounted on the main shaft (1); A rotor sleeve (3) having a hollow interior and being sleeved on the main shaft (1); the rotor (2) being located in the hollow cavity; and the rotor (2) being sealed in the rotor sleeve (3); A shell (4) having a hollow interior, wherein the main shaft (1) is rotatably mounted in the shell (4); A stator (5) is fixedly mounted on the inner wall of the housing (4); A stator sleeve (6) is sleeved inside the housing (4), the stator (5) is located between the housing (4) and the stator sleeve (6), and the stator (5) is sealed inside the stator sleeve (6); An end cover (7) fixedly connected to the housing (4); A first support member (8) is mounted on the main shaft (1) and fixedly connected to the stator sleeve (6); A second support member (9) is mounted on the main shaft (1) and fixedly connected to the end cover (7); a sealed cavity suitable for containing water is formed between the end cover (7), the second support member (9), the main shaft (1), the rotor sleeve (3), the first support member (8) and the stator (5) sleeve.

2. The permanent magnet direct drive generator according to claim 1, characterized in that: The housing (4) comprises a first cylinder (41) and a first annular flange (42) and a second annular flange (43) located at two ends of the first cylinder (41); an annular limiting rib (44) is provided on the inner wall of the first cylinder (41); the stator (5) abuts against the annular limiting rib (44); the first annular flange (42) is connected to the end cover (7); and the second annular flange (43) is connected to the stator sleeve (6).

3. The permanent magnet direct drive generator according to claim 2, characterized in that: The end cover (7) comprises a cover body (71) and a third annular flange (72) arranged at the edge of the cover body (71), and the third annular flange (72) is connected to the first annular flange (42).

4. The permanent magnet direct drive generator according to claim 3, characterized in that: The stator sleeve (6) comprises a second cylinder (61), a fourth annular flange (62) and a fifth annular flange (63); the second cylinder (61) extends into the first cylinder (41); the fifth annular flange (63) is connected to the third annular flange (72); and the fourth annular flange (62) is connected to the second annular flange (43).

5. The permanent magnet direct drive generator according to claim 3 or 4, characterized in that: Water is arranged in the sealed cavity.

6. The permanent magnet direct drive generator according to claim 5, characterized in that: Also includes: The bearing (10) is mounted on the main shaft (1) and abuts against the inner wall of the cover body (71).

7. The permanent magnet direct drive generator according to claim 6, characterized in that: The interior of the main shaft (1) is a hollow cavity, the exterior of the main shaft (1) is provided with a mounting seat (11), and the rotor sleeve (3) is fixedly connected to the mounting seat (11).

8. The permanent magnet direct drive generator according to claim 7, characterized in that: Also includes: A filter element is arranged outside the first support element (8).

9. The permanent magnet direct drive generator according to claim 8, characterized in that: The end cover (7) is provided with a liquid injection hole, and the liquid injection hole is communicated with the sealing cavity.

10. A permanent magnet direct drive power generation system, characterized in that: include: The permanent magnet direct drive generator according to claim 9; A liquid storage box, connected to the liquid injection hole; A hub connected to an end of the main shaft (1) away from the end cover (7); The impeller is fixedly connected to the hub.

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