Marine motor cooling system

Abstract

The invention discloses a marine motor cooling system, and belongs to the field of thermal management of high-power-density permanent magnet synchronous motors. The marine motor cooling system includes: a stator having windings; the rotor is rotatably sleeved in the stator and is provided with a body and a hollow rotating shaft fixedly connected with the body; and the oil dispersing ring is connected to the stator. The rotating shaft and the body jointly form a communicated first oil way, and the first oil way passes through the body and is provided with a first oil spraying opening facing the inner surface of the stator. The stator and the oil dispersing ring jointly form a communicated second oil way, and the second oil way is provided with a second oil spraying opening facing the surface of the winding from the oil dispersing ring. The cooling system can achieve a good cooling effect.

Description

Technical Field

[0001] The present invention belongs to the field of thermal management of high power density permanent magnet synchronous motors, and in particular, the present invention relates to a marine motor cooling system, which is particularly suitable for marine permanent magnet synchronous motors. Background Art

[0002] At present, in the field of ships, electric drive technology is developing rapidly. New technologies are constantly emerging to meet the needs of the market. Since marine motors work in harsh natural environments, small spaces and high load conditions, the reliability of motor operation is challenged. In particular, the very prominent thermal problem seriously affects the safety of marine motors. For this reason, designers and users are very concerned about the heating problem of motors.

[0003] At present, domestic and foreign practitioners have proposed corresponding thermal management technologies for the heating problem of permanent magnet motors under the above working conditions. At present, a lot of fruitful work has been done in the research of cooling systems. There are many ways such as water cooling, oil-water mixing, and full oil cooling, and some results have been achieved. However, due to the poor cooling effect in actual work and the overly complex cooling structure, marine motors have brought certain difficulties in maintenance and maintenance.

[0004] In addition, due to the effect of the stator lateral leakage flux, the eddy current loss of the top turn strand of the stator winding is high, and the heat dissipation condition of the top turn winding is poor, which causes the temperature of the stator top turn strand to be significantly higher than that of other strands. In this way, when overloaded, the top turn temperature may exceed the insulation tolerance temperature. The top turn temperature of the stator is high, and the heat generated through the air gap will cause the temperature of the rotor permanent magnet to be too high. In severe cases, the rotor permanent magnet will suffer from thermal demagnetization, and the armature winding temperature will further increase, causing the stator winding to burn out or the efficiency to decrease.

[0005] Therefore, it is necessary to design a new and efficient cooling system to reduce the top turn winding temperature. At the same time, it is also very important to ensure the safe operation of marine motors. Summary of the invention

[0006] An example of the present invention provides a marine motor cooling system to improve cooling effect and reduce winding temperature.

[0007] The scheme of the present invention is as follows.

[0008] A marine motor cooling system comprises:

[0009] a stator having windings;

[0010] The rotor is rotatably sleeved in the stator and comprises a body and a hollow rotating shaft fixedly connected to the body;

[0011] and, an oil spreading ring connected to the stator;

[0012] The rotating shaft and the body together form a first oil circuit connected to each other, the first oil circuit passes through the body and has a first oil injection port on the inner surface facing the stator, and the stator and the oil diffuser ring together form a second oil circuit connected to each other, the second oil circuit has a second oil injection port on the surface of the oil diffuser ring facing the winding.

[0013] Optionally, the oil dispersion ring is provided with oil dispersion fins adjacent to the second oil injection port.

[0014] Optionally, the oil dispersion fins are parallel to the axial direction of the rotating shaft.

[0015] Optionally, the oil dispersion fins are perpendicular to the axial direction of the rotating shaft.

[0016] Optionally, the rotating shaft has a positioning boss.

[0017] Optionally, the rotating shaft has a positioning keyway.

[0018] Optionally, the body is formed by stacking a plurality of punching sheets, and the rotating shaft has a punching sheet mounting boss.

[0019] Optionally, the rotating shaft is provided with an oil-swinging hole opposite to the winding, and the oil-swinging hole is communicated with the hollow cavity of the rotating shaft.

[0020] Optionally, punching baffles are respectively provided at both ends of the rotating shaft.

[0021] Optionally, the main body is formed by stacking a plurality of punch sheets, the plurality of punch sheets are divided into a plurality of punch sheet groups, a barrier ring is provided between two adjacent punch sheet groups, the barrier ring has radially distributed transverse grooves, and the side wall is provided with longitudinal grooves connected to the transverse grooves.

[0022] The scheme of the present invention has the following effects:

[0023] 1) The stator inner surface oil cooling technology can effectively suppress the temperature rise of the winding, thereby solving the overheating problem caused by large eddy current loss of the winding and poor heat dissipation conditions, and improving the reliability of the motor.

[0024] 2) The winding drip irrigation structure can increase the contact area and uniformity between the winding and the cooling oil, and improve the cooling effect of the end winding.

[0025] 3) The oil cooling structure inside the rotor solves the problem of excessive temperature in the middle axial part, effectively reduces the temperature of the permanent magnets, and reduces the risk of thermal demagnetization of the permanent magnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] For a clearer explanation, the following briefly introduces the drawings required for the description.

[0027] Figure 1 It is a structural schematic diagram of a two-port full oil-cooled motor solution in an embodiment of the present invention;

[0028] Figure 2 Schematic diagram of the structure of a single boss shaft in an embodiment of the present invention;

[0029] Figure 3 It is a structural schematic diagram of the oil brush ring solution 1 in the embodiment of the present invention;

[0030] Figure 4 Schematic diagram of a single-sided stepped shaft structure in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the double-sided stepped shaft structure in an embodiment of the present invention;

[0032] Figure 6 Schematic diagram of the structure of the barrier ring solution 2 in the embodiment of the present invention;

[0033] Figure 7 It is a structural schematic diagram of the end spray oil dispersion ring-1 in an embodiment of the present invention;

[0034] Figure 8 It is a schematic structural diagram of the end spray oil dispersion ring-2 in an embodiment of the present invention;

[0035] Fig. 9 It is a schematic diagram of the structure of the rotor staggered stacking oil circuit solution in an embodiment of the present invention;

[0036] Fig.10 It is a schematic structural diagram of the radial and axial oil cooling solutions for the rotor in an embodiment of the present invention;

[0037] Fig.11 It is a schematic structural diagram of the rotor shaft structure of the radial and axial oil cooling scheme in the embodiment of the present invention;

[0038] Fig.12 Schematic diagram of the structure of a barrier ring with an axial oil guide hole in an embodiment of the present invention;

[0039] Fig.13 It is a structural schematic diagram of a single-side stepped shaft rotor oil cooling solution 1 in an embodiment of the present invention;

[0040] Fig.14 It is a structural schematic diagram of a double-sided stepped shaft rotor oil cooling solution 2 in an embodiment of the present invention;

[0041] Fig.15 Schematic diagram of the structure of the end baffle in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] At present, the mainstream cooling solutions for drive motors include water cooling, oil cooling and oil-water mixed cooling solutions. Among them, water-cooled motors achieve motor cooling by setting a water cooling jacket on the outer surface of the stator. However, the water cooling solution is only suitable for motors with lower power and has limited cooling performance.

[0043] The oil-cooled motor solution refers to the use of gearbox oil to directly cool the end windings by means of oil throwing on the rotating shaft and spraying the end windings. At present, most drive motor oil cooling solutions also set axial oil holes on the outer circle of the stator, and the cooling oil passes through the axial oil holes to cool the motor stator.

[0044] Oil-water mixed cooling scheme, water cooling the stator outer surface, oil cooling the end winding.

[0045] Among the above cooling solutions, the oil-water mixed cooling solution is the best, but the system is complex and requires additional water cooling system accessories, but the water cooling cannot directly contact the cooled parts. The oil cooling solution has a better cooling effect because it can directly contact the gear oil inside the gear box, so the system structure is more compact and simple.

[0046] However, currently most cooling oil circuits only exist on the outer surface of the stator and the center of the rotating shaft, and cannot reach the inside of the motor, especially the area near the top turn winding of the straight segment. Calculation and test results show that the temperature in this area is the highest. Therefore, the implementation of the present invention can greatly improve the cooling effect of the motor and increase the continuous power density.

[0047] In view of the thermal problems of permanent magnet motors under the above working conditions, a lot of fruitful work has been done in the research of cooling systems, including water cooling, oil-water mixing, full oil cooling and other methods, and some results have been achieved. However, in actual work, due to the poor cooling effect and overly complex cooling structure, the motor has brought certain difficulties in maintenance and care.

[0048] In addition, due to the effect of the stator lateral leakage flux, the eddy current loss of the top turn strands of the stator winding is high, and the heat dissipation condition of the top turn winding is poor, causing the temperature of the stator top turn strands to be significantly higher than the temperature of other strands. Therefore, when overloaded, the top turn temperature may exceed the insulation tolerance temperature.

[0049] The top turn temperature of the stator is high, and the heat generated by the air gap will cause the temperature of the rotor permanent magnet to be too high. In severe cases, the rotor permanent magnet will suffer from thermal demagnetization, and the temperature of the armature winding will further increase, causing the stator winding to burn out or reduce efficiency.

[0050] Therefore, it is necessary to design a new and efficient cooling system to reduce the temperature of the top turn winding. At the same time, it is also very important to ensure the safe operation of the motor.

[0051] Marine motor cooling system includes:

[0052] a stator having windings;

[0053] The rotor is rotatably sleeved in the stator and comprises a body and a hollow rotating shaft fixedly connected to the body;

[0054] and, an oil spreading ring connected to the stator;

[0055] The rotating shaft and the body together form a first oil circuit connected to each other, the first oil circuit passes through the body and has a first oil injection port on the inner surface facing the stator, and the stator and the oil diffuser ring together form a second oil circuit connected to each other, the second oil circuit has a second oil injection port on the surface of the oil diffuser ring facing the winding.

[0056] The oil spreading ring is provided with an oil spreading fin adjacent to the second oil injection port. In different examples, the oil spreading fin can be parallel to the axial direction of the rotating shaft, or can be perpendicular to the axial direction of the rotating shaft. The oil spreading fin can increase the distribution area of ​​the oil, so that more winding areas can contact the cooling oil, thereby obtaining a higher cooling effect.

[0057] In order to increase the convenience of installation, the rotating shaft has a positioning boss. Further, the rotating shaft can also be provided with a positioning keyway as required.

[0058] Furthermore, the body of the rotor is formed by stacking a plurality of punching sheets, and the rotating shaft has a punching sheet mounting boss accordingly.

[0059] The winding is cooled mainly by the heat dissipation ring. To improve the cooling effect, the shaft can be provided with an oil-slinging hole opposite to the winding, and the oil-slinging hole is connected to the hollow cavity of the shaft. In this way, the winding can be cooled by cooling oil on both sides from the radial direction of the motor (the direction perpendicular to the axis of the shaft).

[0060] In order to prevent the punching sheet from shaking or shifting, punching sheet baffles can be provided at both ends of the rotating shaft to limit the punching sheet.

[0061] As a further requirement for heat dissipation, the body of the rotor is composed of a plurality of stacked sheets, and all the rotor sheets are divided into a plurality of sheet groups. Each sheet group may include a plurality of sheets. On this basis, there is a barrier ring between two adjacent sheet groups, the barrier ring has radially distributed transverse grooves, and the side wall is provided with longitudinal grooves connected to the transverse grooves. In this way, the cooling oil introduced through the hollow structure of the rotating shaft can pass through the barrier ring, and then through the body of the rotor, and further contact the inner surface of the stator to achieve cooling.

[0062] Through the above scheme, this patent proposes a full oil-cooled two-port cooling system. The system has an improved cooling effect and also reduces the complexity of the cooling system.

[0063] The following is a description with reference to the accompanying drawings.

[0064] like Figure 1 As shown, the rotating shaft 501 (601, 701) is hollow, and the oil injection hole is opposite to the central hole of the shaft, that is, the oil inlet 502 (602, 702, 802). The shaft rotates, and then the oil is pumped into the rotating shaft by the oil pump.

[0065] At one end of the shaft, set Figure 2 The positioning boss 503 is used to place the first set of rotor laminations. This set of laminations is set according to design requirements. For example, if the rotor 102 is divided into 6 sections (102-1, 102-2, 102-3, 102-4, 102-5, 102-6), then each section has 10 laminations, which is 1 / 6 of the total length of the rotor laminations.

[0066] Then, a barrier ring 301 is put on the back of the first set of punches. Figure 3 Several radial holes 302 called oil-spinning holes are opened along the circumference in the middle of the barrier ring 301, and the rotating shaft 501 also has several radial oil-spinning holes 504 (603, 703) below the barrier ring.

[0067] The rotating shaft can also be a stepped rotating shaft 601 (such as Figure 4 ) or shaft 701 (such as Figure 5 )form.

[0068] The barrier ring oil-slinging hole 302 corresponds to the shaft oil-slinging hole 504 one by one, ensuring that the shaft center oil can be smoothly spun out to the inner surface of the stator through the shaft oil-slinging hole and the barrier ring oil-slinging hole.

[0069] Preferably, the barrier ring 301 is in clearance with the rotating shaft, and finally the axial positioning is completed by the end baffle 401. It can also be sleeved on the rear of the first core segment by heating, and fixed on the surface of the rotor shaft after thermal expansion and contraction; or a shallow groove (positioning keyway) can be milled on the shaft, and the barrier ring is pushed in and embedded in it to limit the axial movement of the first core segment.

[0070] In order to reduce the axial space occupied by the barrier ring, the barrier ring can also be Figure 6 A groove 302 is formed on one side of the barrier ring, and then the barrier ring 301 is fitted with the punching sheet of the rotor 102 to form a cooling oil passage between the two.

[0071] A second section of punching sheets is arranged behind the barrier ring, followed by a second barrier ring, and so on to complete the installation of the entire rotor core.

[0072] Finally, the end baffle 401 is used to restrict the axial movement of the entire rotor core. Figure 1 shown.

[0073] When the oil enters the oil supply passage (hollow cavity) of the rotating shaft, the oil is thrown to the inner surface of the stator through the radial passages of the plurality of barrier rings 301, thereby completing direct cooling of the stator teeth and the straight segment windings.

[0074] Preferably, oil-throwing holes 704 (803, 604) are provided on the rotating shafts on both sides of the core to cool the inner surface of the end windings and improve the cooling effect.

[0075] Preferably, the stator yoke is provided with an oil guide hole, and the cooling oil is supplied from the stator 105

[0076] The axial middle inlet 104 enters the outer surface of the stator, and flows to the end windings through the stator oil cooling channel 103 on both sides of the axial direction to achieve stator oil cooling.

[0077] Preferably, an oil spreading ring 201 (such as Figure 7 ), the stator cooling oil flows out from the stator end and enters the oil dispersion ring through the oil inlet 202. The oil dispersion ring 201 can also be as Figure 8 The structure shown.

[0078] The inner surface of the oil spreading ring is provided with a plurality of small oil spray holes 204, and oil spreading fins 203 are provided around the oil spray holes. After the oil flows out through the oil spray holes, it is evenly sprayed to the end windings through the oil spreading fins to improve the cooling effect. Figure 7 As shown, it is parallel to the axial axis. The oil injection hole 204 can also be in other shapes.

[0079] The rotor radial oil injection can also be as follows Fig. 9 As shown, by stacking rotor punchings in an offset manner, a radial oil flow channel 901 is formed. The rotor is thrown out through the shaft oil throwing hole 504, enters the rotor radial oil flow channel 901, and then thrown out to flow to the inner surface of the stator.

[0080] Preferably, the rotor oil-spinning cooling of the stator inner surface may also be carried out by Fig.10 The solution shown. A barrier ring 301 is set in the middle of the rotating shaft. On the one hand, the barrier ring throws the cooling oil to the inner surface of the stator to cool the middle position of the axial inner surface. On the other hand, the oil circuit enters the rotor through the axial through hole of the barrier ring to achieve direct cooling of the rotor and permanent magnets.

[0081] The hollow rotating shaft 801 is provided with a positioning boss 805 in the middle of the axial direction. Fig.11 A plurality of radial oil injection holes 806 are arranged along the axial direction on the boss.

[0082] Preferably, the boss is placed as follows Fig.12 The barrier ring 301 is provided with an axial through hole 303 , and the axial through hole 303 of the barrier ring completely corresponds to the rotor oil cooling channel 105 .

[0083] An annular groove 304 is provided on one side of the barrier ring 301 with the axial through hole. The annular groove connects the radial oil-slinging hole 302 and the axial through hole 303. The radial oil cooling channel enters the axial through hole through the annular groove and flows into the inside of the rotor.

[0084] The two-port oil cooling system can implement a combination of all or part of the above solutions to achieve efficient cooling of the motor and improve the reliability of the motor.

[0085] For different embodiments, the cooling scheme is as follows.

[0086] Embodiment 1

[0087] like Figure 1 As shown, the cooling oil enters from the axial middle position 104 of the stator, flows out from the end of the punching sheet of the stator 103, and enters the internal oil collecting cavity of the end winding spray oil ring 201.

[0088] A plurality of oil spray holes 204 are provided in the oil collecting cavity toward the end winding side, and oil dispersion fins 203 are provided on both sides of the spray holes. Figure 7 or Figure 8 As shown, from the perspective of processing technology, the preferred oil dispersion fins are perpendicular to the axial direction or parallel to the axial direction;

[0089] When the cooling oil flows out from the oil spray hole 204, the oil is evenly dripped onto the outer surface of the end winding through the oil spreading fins 203, thereby improving the uniformity of the distribution of the cooling oil on the surface of the end winding and improving the cooling effect;

[0090] Preferably, the end winding spray cooling oil dispersion ring 201 is arranged on the upper half of the circumference;

[0091] The stator inner surface cooling is achieved by dividing the rotor 102 into several groups, and using a plurality of Figure 3 or Figure 5 The barrier ring 301 shown is isolated;

[0092] The barrier ring 301 has an axial positioning function and provides a path for the oil to be thrown to the inner surface of the stator;

[0093] The barrier ring 301 may have oil-spinning holes 302 opened radially, and the oil-spinning holes may be multiple groups along the circumferential direction;

[0094] The multiple sets of rotor punching sheets and barrier rings are fixed on the hollow shaft. Figure 2 , Figure 4 and Figure 5 As shown, a positioning boss 503 is provided to position the first section of the core (multiple punching sheets are stacked), and then a blocking ring 301 is placed immediately thereafter, and so on, and finally a baffle 401 ( Fig.15 ) completes axial positioning.

[0095] The rotating shaft may also be Figure 5 , Fig.14 The stepped shaft 701 shown in FIG. 1 is used to fix the first set of rotor punchings on the Figure 5 The first section boss 705 is shown, and the second group is installed on the second section boss 706. This section of the shaft is provided with a positioning keyway 605 (804), and then the blocking ring is installed on the adjacent blocking ring mounting boss 703 (606) to prevent the core from axial movement, and the remaining rotor punching groups and blocking rings are installed in sequence;

[0096] The hollow shaft may also be Figure 4 ,and Fig.13 For the double-sided stepped shaft structure shown in the figure, when installing, install the punching sheet set and oil brush ring from the middle to the second side in the above order. Figure 4 and Fig.13 As shown, at the rotating shaft position where the barrier ring is located, oil-slinging holes are also arranged in the radial direction, and multiple groups can be arranged along the axial direction, but it must be ensured that the positions of the rotating shaft oil-brushing holes and the barrier ring oil-slinging holes correspond to each other one by one;

[0097] Preferably, the radial oil-slinging hole 302 of the barrier ring is processed into a racetrack-shaped long hole to reduce the required assembly accuracy;

[0098] In order to reduce the thickness of the barrier ring 301, radial grooves are preferably provided on one or both sides of the barrier ring, such as Figure 6 As shown, the oil throwing passage is formed by axially pressing the rotor punching sheet;

[0099] The barrier ring 301 can be installed by interference fit or threading;

[0100] Finally, baffles are installed on both sides of the rotor to limit the axial movement of the rotor punching. Fig.15 As shown, radial oil-spinning holes 402 are also provided at appropriate positions of the baffle 401, and oil-spinning holes are also provided at corresponding positions of the rotating shaft to achieve oil-spinning cooling of the inner surface of the end winding.

[0101] Preferably, if space permits, an oil-spinning hole is directly provided on the rotating shaft to realize oil-spinning cooling of the inner surface of the end winding, and the end baffle avoids the position of the oil-spinning hole;

[0102] like Fig.13 or Fig.14 As shown, the cooling oil is pumped into the hollow shaft through the end. On the one hand, the cooling oil is thrown to the inner surface of the end winding through the oil-throwing holes on both sides of the shaft to achieve cooling of the end winding. On the other hand, the cooling oil enters the straight segment oil-throwing hole and passes through the barrier ring oil-throwing hole 302 to the inner surface of the stator to achieve cooling of the stator teeth and the straight segment winding.

[0103] The final implementation is as follows Figure 1 , Fig.13 or Fig.14 Two-port oil cooling system shown.

[0104] Embodiment 2

[0105] like Fig. 9 As shown, the cooling structure of the stator outer surface, the end winding outer surface and the end winding inner surface oil-spinning cooling are the same as those in Embodiment 1, except that the stator inner surface cooling system eliminates the barrier ring and forms a radial oil-spinning passage by staggered stacking of rotor punchings;

[0106] Embodiment 3

[0107] like Fig.10 As shown, only the oil-slinging hole 806 is provided in the middle of the rotating shaft 801, and the rotor punchings are divided into two groups. A barrier ring 301 with an axial oil guide hole is placed in the middle. The cooling oil enters from the center of the rotating shaft, and a part of it cools the inner surface of the end winding through the oil-slinging holes 302 at both ends; the other part enters the barrier ring 301 in the middle, and then is divided in the barrier ring, and one part is directly thrown to the inner surface of the stator along the radial channel of the barrier ring, and the other part enters the rotor punchings on both sides through the axial oil guide hole, and finally flows out from both sides of the rotor and is thrown to the inner surface of the end winding;

[0108] Preferred as Fig. 9 As shown, an axial oil guide hole is provided between the outer edge of the rotor and the middle position of the lower V-shaped permanent magnet to cut off the heat flow from the stator side to the rotor through the air gap, thereby destroying the rotor magnetic circuit as much as possible and maximizing the cooling effect;

[0109] The barrier ring 301 with the axial oil guide passage is as follows: Fig.12 As shown, the axial oil guide hole on the barrier ring corresponds to the axial oil guide hole on the rotor punching plate one by one;

[0110] End baffles 401 are set on both sides of the rotor punching to limit the axial movement of the rotor. The end baffles 401 are provided with oil-spinning holes 402 below the end windings for oil-spinning cooling of the end windings.

[0111] The barrier ring has an annular groove 304 on its side, together with the radial oil-slinging hole 302 and the axial oil-guiding hole 303. The annular groove is opened at the position of the axial oil-guiding hole, and the depth of the annular groove must reach the position of the radial oil-slinging hole, so that the radial oil-slinging hole is connected with the oil-guiding groove, thereby realizing the cooling oil diversion in the barrier ring;

[0112] Preferably, the axial oil guide hole on the barrier ring 301 is slightly larger than the oil guide hole on the rotor punching to reduce the required assembly accuracy.

[0113] The oil-spinning shaft is only arranged at the middle axial position. Fig.11 As shown, a plurality of radial oil-slinging holes 806 are arranged in the circumferential direction on the middle boss 805, and positioning key slots 804 are arranged on both sides of the boss for installing and positioning the rotor punching sheets.

[0114] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings. The above are only preferred embodiments of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made according to the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present invention.

Claims

1. A marine motor cooling system, characterized in that: include: a stator having windings; The rotor is rotatably sleeved in the stator and comprises a body and a hollow rotating shaft fixedly connected to the body; and, an oil spreading ring connected to the stator; The rotating shaft and the body together form a first oil circuit connected to each other, the first oil circuit passes through the body and has a first oil injection port on the inner surface facing the stator, and the stator and the oil diffuser ring together form a second oil circuit connected to each other, the second oil circuit has a second oil injection port on the surface of the oil diffuser ring facing the winding.

2. The marine motor cooling system according to claim 1, characterized in that: The oil dispersion ring is provided with oil dispersion fins adjacent to the second oil injection port.

3. The marine motor cooling system according to claim 2, characterized in that: The oil dispersion fins are parallel to the axial direction of the rotating shaft.

4. The marine motor cooling system according to claim 2, characterized in that: The oil dispersion fins are perpendicular to the axial direction of the rotating shaft.

5. The marine motor cooling system according to claim 1, characterized in that: The rotating shaft has a positioning boss.

6. The marine motor cooling system according to claim 1 or 5, characterized in that: The rotating shaft has a positioning keyway.

7. The marine motor cooling system according to claim 1, characterized in that: The body is formed by stacking a plurality of punching sheets, and the rotating shaft is provided with a punching sheet mounting boss.

8. The marine motor cooling system according to claim 6 or 7, characterized in that: The rotating shaft is provided with an oil-swinging hole opposite to the winding, and the oil-swinging hole is communicated with the hollow cavity of the rotating shaft.

9. The marine motor cooling system according to claim 1, characterized in that: Punching baffles are respectively arranged at both ends of the rotating shaft.

10. The marine motor cooling system according to claim 1, characterized in that: The main body is formed by stacking a plurality of punching sheets, wherein the plurality of punching sheets are divided into a plurality of punching sheet groups, and a barrier ring is arranged between two adjacent punching sheet groups. The barrier ring has radially distributed transverse grooves, and the side wall is provided with longitudinal grooves connected with the transverse grooves.

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