Sealing structure of oil-cooled motor stator and oil-cooled motor

Abstract

The utility model provides a sealing structure of an oil cooling motor stator and an oil cooling motor, the sealing structure comprises a casing and a sealing ring, the sealing ring is respectively connected with the front end and the rear end of the casing through a sealing flange and a rear end cover, and the casing, the sealing flange and the rear end cover support the sealing ring. The motor shell, the sealing flange, the sealing ring and the rear end cover form a sealing cavity, the stator is located in the sealing cavity, the rotor is located outside the sealing cavity, the stator is isolated from the rotor, oil immersion cooling of the stator in the sealing cavity is facilitated, and therefore the motor is rapidly cooled. The sealing ring comprises a front flange ring, a sleeve and a rear flange ring. The front flange ring and the rear flange ring are located at the front end and the rear end of the sleeve respectively. A first sealing piece is arranged on the end face, connected with the sealing flange, of the front flange ring, a second sealing piece is arranged on the end face, connected with the rear end cover, of the rear flange ring, the sleeve is supported and connected through the front flange ring and the rear flange ring, and the reliability of the sealing structure is improved through the arrangement of the first sealing piece and the second sealing piece.

Description

Technical Field

[0001] This utility model belongs to the field of motor cooling technology, and particularly relates to a sealing structure for an oil-cooled motor stator and an oil-cooled motor. Background Technology

[0002] With the development of the wind power market, the capacity of single wind turbines is getting larger and larger, the power density and torque density of generators are constantly increasing, and the temperature of generators under operating conditions is also constantly rising, thus requiring efficient cooling methods.

[0003] Currently, the mainstream cooling method for wind turbines larger than 10MW is a combination of air and water cooling. The air-water cooler is located on top of the generator and cools the motor in two ways: first, by cooling the windings, rotor, and other heat-generating components through airflow; second, by removing heat from the iron core through water channels on the outer wall of the casing. However, for larger turbines, the heat removed by air cooling is limited. Furthermore, the water cooling channels are located on the outermost side of the stator core, some distance from the generator's heat source, the stator windings, and are separated by the stator yoke and the inner wall of the casing. Therefore, the water cooling path is relatively long, affecting cooling efficiency. Although a combination of air and water cooling is used, the cooling effect is not ideal.

[0004] Currently, the most efficient method for generator cooling is direct oil cooling. Direct oil cooling mainly includes end-spray oil cooling, hollow conductor circulating oil cooling, and stator immersion oil cooling. Spray oil cooling refers to cooling the stator core and stator winding ends of the stator assembly by spraying oil through an oil spraying device. However, this generates some oil churning losses, and uneven spraying can also affect cooling efficiency. Hollow conductor circulating oil cooling involves inserting hollow conductors into the core, allowing cooling oil to carry away heat through the hollow conductors. However, this structure is complex and too costly for large wind turbines. Stator immersion oil cooling directly carries away a large amount of heat through the heat source windings, resulting in extremely high efficiency. To significantly increase the torque density of the generator, stator immersion oil cooling is an excellent choice for high-power wind turbines. However, the difficulty in implementing stator immersion oil cooling lies in installing seals within the stator rotor air gap to seal the flowing cooling oil within the stator. Existing stator sealing structures have poor reliability. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the sealing structure of the stator in the prior art has poor reliability. This utility model provides a sealing structure for the stator of an oil-cooled motor and an oil-cooled motor.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] This utility model provides a sealing structure for an oil-cooled motor stator. The sealing structure includes a housing and a sealing ring. The sealing ring is connected to the front and rear ends of the housing via sealing flanges and a rear end cover, respectively. The housing, sealing flanges, sealing ring, and rear end cover form a sealing cavity. The stator is located inside the sealing cavity so that the cooling oil filling the sealing cavity cools the stator. The rotor is located outside the sealing cavity. The sealing ring includes a front flange ring, a sleeve, and a rear flange ring. The front flange ring and the rear flange ring are located at the front and rear ends of the sleeve, respectively. A first sealing element is provided on the end face of the front flange ring connected to the sealing flange, and a second sealing element is provided on the end face of the rear flange ring connected to the rear end cover.

[0008] In this design, the sealing ring is connected to the front and rear ends of the housing via sealing flanges and a rear end cover, respectively. The housing, sealing flanges, and rear end cover support the sealing ring, and together they form a sealing cavity. The stator is placed inside the sealing cavity, while the rotor is outside, thus isolating the stator from the rotor and facilitating immersion-type cooling of the stator within the sealing cavity, thereby quickly and effectively reducing the motor temperature. The sealing ring includes a front flange ring, a sleeve, and a rear flange ring. The front flange ring is positioned at the front end of the sleeve, and the rear flange ring is positioned at the rear end of the sleeve. The sleeve is supported by the front and rear flange rings, and the front flange ring is connected to the sealing flange, while the rear flange ring is connected to the rear end cover. The sleeve is connected via the front and rear flange rings. A first sealing element is provided on the end face where the front flange ring connects to the sealing flange, and a second sealing element is provided on the end face where the rear flange ring connects to the rear end cover, further ensuring the sealing performance of the sealing ring installation and improving the reliability of the sealing structure.

[0009] Preferably, the sleeve, the front flange ring, and the rear flange ring are bonded together to form an integral structure, with the outer diameter of the front flange ring bonded to the inner diameter of the sleeve, and the inner diameter of the rear flange ring bonded to the outer diameter of the sleeve.

[0010] In this design, the sleeve, the front flange ring, and the rear flange ring are bonded together with adhesive to form an integrated structure, which facilitates transportation and installation. Moreover, the adhesive bonding method avoids the need for additional sealing treatment at the connection point. The outer diameter of the front flange ring is bonded to the inner diameter of the sleeve, so that the front flange ring is located outside the sealing cavity and does not occupy the space of the sealing cavity. This relatively shortens the size of the sleeve and reserves space for the installation of the rotor, thus ensuring a safe distance between the sleeve and the rotor.

[0011] Preferably, both the front flange ring and the rear flange ring are made of metal, and the sleeve is made of fiber composite material.

[0012] In this design, both the front and rear flange rings are made of metal, while the sleeve is made of fiber composite material. This makes the front and rear flange rings rigid materials. The connection between the sleeve and the front and rear flange rings enhances the rigidity of the sleeve, thereby ensuring that the sealing ring as a whole has good rigidity. The sleeve is made of fiber composite material, such as carbon fiber composite material or glass fiber reinforced plastic, which means that the sleeve is made of non-metallic material. This can avoid or reduce the loss caused by eddy currents in the sleeve.

[0013] Preferably, the sealing flange is provided with a first stepped portion, the front flange ring abuts against the first stepped portion and is connected to the first stepped portion by fasteners, the first stepped portion includes a radial section and an axial section, and both the radial section and the axial section are provided with the first sealing element to form a radial seal and a circumferential seal between the sealing flange and the front flange ring.

[0014] In this design, a first step is provided on the sealing flange. The front flange ring abuts against the step and is connected by fasteners to achieve the connection between the front flange ring and the sealing ring. The radial and axial sections of the first step have contact surfaces with the front flange ring, and a first sealing element is provided on both the radial and axial sections to perform radial and axial sealing between the sealing flange and the front flange ring, ensuring the sealing ring's isolation and sealing effect between the stator and the rotor.

[0015] Preferably, the outer wall of the front flange ring has a positioning stop, one end of which abuts against the front end of the sleeve, and the other end of which is spaced from the axial section.

[0016] In this design, the outer wall of the front flange ring has a positioning stop. One end of the positioning stop abuts against the front end of the sleeve, and the other end of the positioning stop is spaced apart from the axial section. The positioning stop facilitates the positioning and installation of the sleeve on one side, and the other side of the positioning stop maintains a certain assembly distance from the axial section of the sealing flange.

[0017] Preferably, the rear end cover abuts against the outer wall of the rear flange ring, the rear end of the rear flange ring is provided with a second step portion, the rear end cover is provided with a countersunk portion corresponding to the position of the second step portion, the second step portion is located inside the countersunk portion, in the radial direction, the second step portion abuts against the countersunk portion, and in the axial direction, the second step portion and the countersunk portion are spaced apart.

[0018] In this design, the rear flange ring has a second step at its rear end, and the rear end cover has a recessed portion corresponding to the position of the second step. The second step is located inside the recessed portion, and in the radial direction, the second step abuts against the recessed portion. The cooperation between the second step and the recessed portion can prevent the rear flange ring from falling off.

[0019] Preferably, the sealing structure further includes an outer end cap, which is connected to the outside of the rear end cap by fasteners, and the outer end cap extends inwardly to a support platform for supporting the rear flange ring.

[0020] In this design, the outer end cover is equipped with a support platform to support the rear flange ring from below. The outer end cover is connected to the outside of the rear end cover by fasteners, thereby fixing the rear flange ring to the rear end cover.

[0021] Preferably, both the front flange ring and the rear flange ring have tooling interfaces in the axial direction.

[0022] In this design, both the front flange ring and the rear flange ring are provided with tooling interfaces along the axial direction, such as threaded holes, to facilitate the connection of tooling and to achieve the overall installation and transportation of the sealing ring, thereby avoiding the difficulties of transporting and installing individual sleeves.

[0023] Preferably, both the first seal and the second seal are O-rings, and the O-rings are made of rubber.

[0024] In this design, both the first and second seals are O-rings, and the choice of rubber as the material ensures that both seals are elastic elements, enabling reliable sealing and providing a certain degree of cushioning.

[0025] This utility model also provides an oil-cooled motor, which includes a stator and a rotor, and also includes the sealing structure as described above, wherein the rotor is located outside the sealing structure and has a gap with the sleeve.

[0026] The positive and progressive effects of this utility model are as follows: The sealing structure connects the sealing ring to the front and rear ends of the housing via sealing flanges and a rear end cover, respectively. The housing, sealing flanges, and rear end cover support the sealing ring, and together they form a sealing cavity. The stator is placed inside the sealing cavity, while the rotor is outside, thus isolating the stator from the rotor and facilitating immersion-type cooling of the stator within the sealing cavity, thereby quickly and effectively reducing the motor temperature. The sealing ring includes a front flange ring, a sleeve, and a rear flange ring. The front flange ring is positioned at the front end of the sleeve, and the rear flange ring is positioned at the rear end of the sleeve. The sleeve is supported by the front and rear flange rings, and the front flange ring connects to the sealing flange, while the rear flange ring connects to the rear end cover. The sleeve is connected via the front and rear flange rings. A first sealing element is provided on the end face where the front flange ring connects to the sealing flange, and a second sealing element is provided on the end face where the rear flange ring connects to the rear end cover, further ensuring the sealing performance of the sealing ring installation and improving the reliability of the sealing structure. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the stator sealing structure of an oil-cooled motor.

[0028] Figure 2 This is an assembly drawing of the stator sealing structure, rotor, and outer end cover.

[0029] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0030] Figure 4 This is a cross-sectional view of the sealing ring structure.

[0031] Figure 5 This is the assembly drawing for the front flange ring.

[0032] Figure 6 This is the assembly drawing for the rear flange ring.

[0033] Explanation of reference numerals in the attached figures

[0034] Sealing structure 1

[0035] Case 2

[0036] Sealing ring 3

[0037] Sealing flange 4

[0038] Rear cover 5

[0039] Sealed cavity 6

[0040] Stator 7

[0041] Rotor 8

[0042] Front flange ring 9

[0043] Sleeve 10

[0044] Rear flange ring 11

[0045] First sealing element 12

[0046] Second sealing element 13

[0047] First step section 14

[0048] Fastener 15

[0049] Radial segment 16

[0050] Axial segment 17

[0051] Positioning stop 18

[0052] Second step section 19

[0053] 20 sinkhole sections

[0054] Outer end cap 21

[0055] Tooling Interface 22

[0056] Bolt washer 23

[0057] Iron core 23

[0058] Winding 24

[0059] Phase ring 25

[0060] Front flange 26

[0061] Rear flange 27 Detailed Implementation

[0062] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the embodiments.

[0063] This utility model provides a sealing structure 1 for an oil-cooled motor stator 7, such as... Figure 1-Figure 2 As shown, the sealing structure 1 includes a housing 2 and a sealing ring 3. The sealing ring 3 is connected to the front and rear ends of the housing 2 via sealing flanges 4 and rear end caps 5, respectively. The housing 2, sealing flanges 4, sealing ring 3, and rear end caps 5 form a sealing cavity 6, which is filled with a cooling medium, such as cooling oil. The stator 7 is located inside the sealing cavity 6, so that the stator 7 is directly immersed in the cooling oil. The cooling oil filled in the sealing cavity 6 cools the stator. The rotor 8 is located outside the sealing cavity 6, so that the rotor 8 is isolated from the stator 6. The sealing ring 3 includes a front flange ring 9, a sleeve 10, and a rear flange ring 11. The front flange ring 9 and the rear flange ring 11 are located at the front and rear ends of the sleeve 10, respectively. A first sealing element 12 is provided on the end face of the front flange ring 9 connected to the sealing flange 4, and a second sealing element 13 is provided on the end face of the rear flange ring 11 connected to the rear end cap 5.

[0064] The sealing ring 3 is connected to the front and rear ends of the housing 2 via sealing flanges 4 and rear end caps 5, respectively. The housing 2, sealing flanges 4, and rear end caps 5 support the sealing ring 3, and together they form a sealing cavity 6. The stator 7 is placed inside the sealing cavity 6 and is directly immersed in cooling oil. The cooling oil filling the sealing cavity 6 cools the stator. The rotor 8 is located outside the sealing cavity 6, thus isolating the stator 7 from the rotor 8 and facilitating immersion cooling of the stator 7 within the sealing cavity 6, thereby quickly and effectively reducing the motor temperature. The sealing ring 3 includes a front flange ring 9, a sleeve 10, and a rear flange ring. 11. A front flange ring 9 is positioned at the front end of the sleeve 10, and a rear flange ring 11 is positioned at the rear end of the sleeve 10. The sleeve 10 is supported by the front flange ring 9 and the rear flange ring 11. The front flange ring 9 connects to the sealing flange 4, and the rear flange ring 11 connects to the rear end cover 5. The sleeve 10 is connected via the front flange ring 9 and the rear flange ring 11. A first sealing element 12 is provided on the end face where the front flange ring 9 connects to the sealing flange 4, and a second sealing element 13 is provided on the end face where the rear flange ring 11 connects to the rear end cover 5. This further ensures the sealing performance of the sealing ring 3 and improves the reliability of the sealing structure 1. The two ends of the housing 2 are also connected to a front flange 26 and a rear flange 27. The front flange 26 and the sealing flange 4 are two separate components, connected as a whole by fasteners 15. Fasteners 15 can be bolts; alternatively, the front flange 26 and the sealing flange 4 can be a single piece. Figure 3 The outer side of the sleeve 10 shown is attached to or connected to the stator 7. The inner wall of the sleeve 10 has a gap C with the rotor 8 to ensure a safe distance, thereby ensuring the safe operation of the motor. An axial elastic seal is installed between the rear end cover 5 and the housing 2. The axial elastic seal is an O-ring.

[0065] like Figure 1 As shown, the stator 7's core 23, winding 24, and phase ring 25 are all located in the sealed cavity 6, meaning that the electronic heating element is placed in the sealed cavity 6 for oil cooling. The front flange ring 9 and the rear flange ring 11 are spaced apart from the winding 24, and the rear flange ring 11 is also spaced apart from the phase ring 25, thus ensuring a certain installation distance. Figure 1-Figure 2 The central axis D is the central axis.

[0066] like Figure 4As shown, the sleeve 10, front flange ring 9, and rear flange ring 11 are bonded together to form an integral structure. The outer diameter of the front flange ring 9 is bonded to the inner diameter of the sleeve 10, and the inner diameter of the rear flange ring 11 is bonded to the outer diameter of the sleeve 10. Bonding the sleeve 10, front flange ring 9, and rear flange ring 11 together with adhesive facilitates transportation and installation. Furthermore, adhesive bonding avoids the need for additional sealing at the connection points. Bonding the outer diameter of the front flange ring 9 to the inner diameter of the sleeve 10 places the front flange ring 9 outside the sealing cavity 6, preventing it from occupying space within the sealing cavity 6. This relatively shortens the size of the sleeve 10, reserving space for the installation of the rotor 8, thus ensuring a safe distance between the sleeve 10 and the rotor 8. Figure 4 As shown, one of the front flange ring 9 and the rear flange ring 11 is located inside the sealing cavity 6, and the other is located outside the sealing cavity 6. This design not only shortens the size of the sleeve 10, leaving space for the installation of the rotor 8, but also enhances the rigidity of the sleeve 10.

[0067] Both the front flange ring 9 and the rear flange ring 11 are made of metal materials, while the sleeve 10 is made of fiber composite material. This makes the front flange ring 9 and the rear flange ring 11 rigid materials. When the sleeve 10 is connected to the front flange ring 9 and the rear flange ring 11, it can enhance the rigidity of the sleeve 10, thereby ensuring that the sealing ring 3 as a whole has good rigidity. The sleeve 10 is made of fiber composite material, such as carbon fiber composite material, glass fiber reinforced plastic, etc. That is, the sleeve 10 uses non-metallic materials, which can avoid or reduce the loss caused by eddy currents in the sleeve 10.

[0068] like Figure 1 , Figure 2 as well as Figure 5 As shown, the sealing flange 4 is provided with a first stepped portion 14. The front flange ring 9 abuts against the first stepped portion 14 and is connected to the first stepped portion 14 by fasteners 15. The first stepped portion 14 includes a radial section 16 and an axial section 17. Both the radial section 16 and the axial section 17 are provided with first sealing elements 12 to form radial and circumferential seals between the sealing flange 4 and the front flange ring 9. The sealing flange 4 is provided with a first stepped portion 14. The front flange ring 9 abuts against the stepped portion and is connected by fasteners 15 to realize the connection between the front flange ring 9 and the sealing ring 3. The radial section 16 and the axial section 17 of the first stepped portion 14 have contact surfaces with the front flange ring 9, and both the radial section 16 and the axial section 17 are provided with first sealing elements 12 to provide radial and axial seals between the sealing flange 4 and the front flange ring 9, ensuring the sealing effect of the sealing ring 3 on the isolation and sealing between the stator 7 and the rotor 8.

[0069] Both the first seal 12 and the second seal 13 are O-rings, and the O-rings are made of rubber. The fact that both the first seal 12 and the second seal 13 are O-rings, and that the material is rubber, ensures that both are elastic elements, achieving not only reliable sealing but also a certain degree of cushioning. Figure 5 As shown, the radial section 16 has a mounting groove for installing O-rings, and the front flange ring 9 also has a mounting groove for installing O-rings at the position corresponding to the axial section 17. The O-rings are placed in the mounting grooves to provide axial and radial sealing at the connection between the front flange ring 9 and the sealing flange 4. Of course, in other embodiments, the mounting grooves can all be provided on the sealing flange 4 or all on the front flange ring 9.

[0070] like Figure 5 As shown, the outer wall of the front flange ring 9 has a positioning stop 18. One end of the positioning stop 18 abuts against the front end of the sleeve 10, and the other end of the positioning stop 18 is spaced apart from the axial section 17. The positioning stop 18 facilitates the positioning and installation of the sleeve 10 on one side, and maintains a certain assembly clearance with the axial section 17 of the sealing flange 4 on the other side to meet a certain creepage distance.

[0071] like Figure 6 As shown, the rear end cover 5 abuts against the outer wall of the rear flange ring 11. Two second sealing elements 13 are provided on the end faces of the rear end cover 5 and the rear flange ring 11 where they abut. The rear end of the rear flange ring 11 is provided with a second step portion 19. The rear end cover 5 is provided with a recessed portion 20 corresponding to the position of the second step portion 19. The second step portion 19 is located inside the recessed portion 20. In the radial direction, the second step portion 19 abuts against the recessed portion 20. In the axial direction, the second step portion 19 and the recessed portion 20 are spaced apart. The second step portion 19 is provided at the rear end of the rear flange ring 11, and the rear end cover 5 is provided with a recessed portion 20 corresponding to the position of the second step portion 19. The second step portion 19 is located inside the recessed portion 20. In the radial direction, the second step portion 19 abuts against the recessed portion 20. The cooperation between the second step portion 19 and the recessed portion 20 can prevent the rear flange ring 11 from falling off. In the axial direction, the second step portion 19 and the recessed portion 20 are spaced apart to ensure a certain safety distance. An installation groove for installing the second seal 13 is provided on the rear flange ring 11 at the position where it abuts against the rear end cover 5. In this embodiment, there are two second seals 13. Of course, in other embodiments, one or more can be provided as needed. The number of installation grooves for installing the second seal 13 is matched accordingly. The position of the installation groove for installing the second seal 13 can also be provided on the rear end cover 5.

[0072] The sealing structure 1 also includes an outer end cap 21, which is connected to the outside of the rear end cap 5 by fasteners 15. The outer end cap 21 extends inward to form a support platform for supporting the rear flange ring 11. The outer end cap 21 is provided with a support platform to support the rear flange ring 11 from below. The outer end cap 21 is connected to the outside of the rear end cap 5 by fasteners 15, thereby fixing the rear flange ring 11 to the rear end cap 5. The fasteners 15 include bolts and bolt washers 23 located on the outside for fixing the bolts.

[0073] like Figure 2 , Figures 5-6 Both the front flange ring 9 and the rear flange ring 11 have tooling interfaces 22 in the axial direction. If threaded holes are provided on the front flange ring 9 and the rear flange ring 11, it is convenient to connect the tooling to realize the overall installation and transportation of the sealing ring 3, thereby avoiding the difficulties of transporting and installing a single sleeve 10.

[0074] This utility model also provides an oil-cooled motor, which includes a stator 7 and a rotor 8, and also includes a sealing structure 1 as described above. The rotor 8 is located outside the sealing structure 1 and has a gap C with the sleeve 10.

[0075] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model 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 this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A sealing structure for an oil-cooled motor stator, characterized in that, The sealing structure includes a housing and a sealing ring. The sealing ring is connected to the front and rear ends of the housing via sealing flanges and a rear end cover, respectively. The housing, sealing flanges, sealing ring, and rear end cover form a sealing cavity. The stator is located inside the sealing cavity so that the cooling oil filling the sealing cavity cools the stator. The rotor is located outside the sealing cavity. The sealing ring includes a front flange ring, a sleeve, and a rear flange ring. The front flange ring and the rear flange ring are located at the front and rear ends of the sleeve, respectively. A first sealing element is provided on the end face of the front flange ring connected to the sealing flange, and a second sealing element is provided on the end face of the rear flange ring connected to the rear end cover.

2. The sealing structure as described in claim 1, characterized in that, The sleeve, the front flange ring, and the rear flange ring are bonded together to form an integral structure. The outer diameter of the front flange ring is bonded to the inner diameter of the sleeve, and the inner diameter of the rear flange ring is bonded to the outer diameter of the sleeve.

3. The sealing structure as described in claim 2, characterized in that, Both the front flange ring and the rear flange ring are made of metal, and the sleeve is made of fiber composite material.

4. The sealing structure as described in claim 1, characterized in that, The sealing flange is provided with a first stepped portion, and the front flange ring abuts against the first stepped portion and is connected to the first stepped portion by fasteners. The first stepped portion includes a radial section and an axial section, and the first sealing element is provided on both the radial section and the axial section to form a radial seal and a circumferential seal between the sealing flange and the front flange ring.

5. The sealing structure as described in claim 4, characterized in that, The outer wall of the front flange ring has a positioning stop, one end of which abuts against the front end of the sleeve, and the other end of which is spaced from the axial section.

6. The sealing structure as described in claim 4, characterized in that, The rear end cover abuts against the outer wall of the rear flange ring. The rear end of the rear flange ring is provided with a second step portion. The rear end cover is provided with a recessed portion corresponding to the position of the second step portion. The second step portion is located inside the recessed portion. In the radial direction, the second step portion abuts against the recessed portion.

7. The sealing structure as described in claim 6, characterized in that, The sealing structure also includes an outer end cap, which is connected to the outside of the rear end cap by fasteners, and the outer end cap extends inward to a support platform for supporting the rear flange ring.

8. The sealing structure as described in claim 2, characterized in that, Both the front flange ring and the rear flange ring have tooling interfaces along the axial direction.

9. The sealing structure as described in claim 1, characterized in that, Both the first and second seals are O-rings, and the O-rings are made of rubber.

10. An oil-cooled motor, the oil-cooled motor comprising a stator and a rotor, characterized in that, The oil-cooled motor further includes a sealing structure as described in any one of claims 1-9, wherein the rotor is located outside the sealing structure and has a gap with the sleeve.

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