Axial flux motor oil cooled rotor

Abstract

The application discloses an axial flux motor oil-cooling rotor, which comprises a rotating shaft and a rotating disc, the rotating disc is fixed on the rotating shaft, a plurality of oil guide channels extending from the center to the outer side are arranged in the rotating disc, the plurality of oil guide channels are distributed along the circumferential direction, an oil throwing hole is arranged at the end of the oil guide channel on the rotating disc, the oil throwing hole extends from the side of the rotating disc to the oil guide channel, an oil guide hole is arranged in the rotating shaft along the axial direction, the oil guide hole extends to the rotating disc and forms an oil collecting groove, an oil outlet hole is arranged on the outer surface of the rotating shaft to the oil collecting groove, and the oil outlet hole is communicated with the oil guide channel, and the oil guide hole, the oil guide channel and the oil throwing hole are arranged, centrifugal force is used to throw the cooling oil to the inside of the motor, and the stator end winding is directly cooled.

Description

Technical Field

[0001] This invention belongs to the field of motor rotor technology, and more specifically relates to an oil-cooled rotor for an axial flux motor. Background Technology

[0002] Axial flux permanent magnet synchronous motors have a more compact axial structure, higher torque density and power density compared to traditional radial flux permanent magnet synchronous motors, and are attracting increasing attention.

[0003] Due to their unique structure, axial flux motors have longer outer end windings, resulting in higher resistance losses and greater heat generation; while the inner end windings have tighter contact, leading to heat accumulation. Furthermore, the heat dissipation conditions of the end windings are worse than those of the windings within the stator core slots. Therefore, the highest temperature point of an axial flux motor winding is generally at the end, and improving the motor's torque and power density requires creating favorable heat dissipation conditions for the end windings.

[0004] For a dual-stator single-rotor axial flux motor, its structure consists of a central rotor and stators on both sides, with the motor windings located close to the largest heat source inside the motor. Excessive temperature can cause demagnetization of the permanent magnets, directly affecting the motor's performance.

[0005] Traditional axial flux motors typically dissipate heat through cooling fins on the frame and end covers, or by water cooling of the end covers. However, with this method of heat dissipation alone, the large amount of heat generated by the motor windings cannot be dissipated in time when the contact between the stator core and the end covers is generally poor and the load is heavy. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for directly cooling the stator end windings by using centrifugal force to throw cooling oil into the motor through oil guide holes, oil guide channels, and oil throwing holes.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an axial flux motor oil-cooled rotor, comprising a rotating shaft and a turntable, the turntable being fixed on the rotating shaft, and having a plurality of oil guiding channels extending outward from the center within the turntable, the plurality of oil guiding channels being distributed along the circumferential direction, and having oil throwing holes at the ends of the corresponding oil guiding channels on the turntable, the oil throwing holes extending from the side of the turntable to the oil guiding channels, having oil guiding holes axially within the rotating shaft, the oil guiding holes extending to the turntable and forming an oil collecting groove, and having oil outlet holes on the outer surface of the rotating shaft extending to the oil collecting groove, the oil outlet holes being connected to the oil guiding channels.

[0008] Furthermore, a circular boss is provided on the outer side of the turntable corresponding to the oil slinger hole, and the oil slinger hole passes through the circular boss.

[0009] Furthermore, the surface of the circular boss is provided with several rectangular grooves, which pass through the oil-slinging hole.

[0010] Furthermore, the oil guiding channel includes long oil channels and short oil channels, which are alternately distributed along the circumference.

[0011] Furthermore, a limiting platform is provided on one side of the rotating shaft corresponding to the turntable. The turntable is sleeved on the rotating shaft, and a nut is threadedly connected to the rotating shaft. The nut and the limiting platform are located on both sides of the turntable.

[0012] Furthermore, the turntable includes a left half and a right half, which are separated by the middle of the turntable. An oil guide groove is provided on the opposite side of the left half and the right half. When the left half and the right half are closed, the oil guide groove forms an oil guide channel.

[0013] Furthermore, an anti-rotation structure is provided between the left and right halves.

[0014] Furthermore, the anti-rotation structure includes a positioning protrusion and a positioning groove, which are distributed on the left and right halves.

[0015] Furthermore, the turntable is provided with several weight-reducing holes.

[0016] Furthermore, both the left and right halves are provided with magnetic grooves. The openings on the opposite sides of the magnetic grooves in the left and right halves are larger than the openings on the sides that are far apart from each other. During installation, the magnets are clamped and fixed in the magnetic mounting grooves by the left and right halves.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the left and right halves of the turntable have the same structure, which helps to maintain product consistency and reduce manufacturing costs. The oil guide channel is formed by the oil guide grooves of the left and right halves. The oil guide grooves are distributed on the surfaces of the left and right halves, which is easy to process and easy to adjust the length. By setting a circular boss at the end of the oil throwing hole, the air velocity at the position of the circular boss will increase when the turntable rotates. According to Bernoulli's formula, the faster the fluid velocity, the lower its pressure. The fluid velocity is fast and the pressure is low at the circular boss, which increases the fluid pressure difference between the stator and rotor air gap and indirectly increases heat exchange. Attached Figure Description

[0018] Figure 1 The three-dimensional structure of the present invention Figure 1 ;

[0019] Figure 2 The three-dimensional structure of the present invention Figure 2 ;

[0020] Figure 3 for Figure 2 Cross-sectional view at point AA;

[0021] Figure 4 This is the front view of the present invention;

[0022] Figure 5 for Figure 4 Sectional view at point BB;

[0023] Figure 6 for Figure 4 Sectional view at point CC;

[0024] Figure 7 This is an exploded view of the present invention.

[0025] Reference numerals: 1. Rotating shaft; 11. Oil guide hole; 111. Oil collection groove; 12. Oil outlet hole; 13. Limiting platform; 2. Turntable; 21. Left half; 211. Oil guide groove; 22. Right half; 221. Magnet groove; 23. Oil guide channel; 24. Oil slinger hole; 3. Nut; 4. Circular boss; 41. Rectangular groove; 5. Magnet; 61. Inner weight reduction hole; 62. Outer weight reduction hole; 63. Weight reduction hole between magnet grooves. Detailed Implementation

[0026] Reference Figures 1 to 7 The embodiments of the axial flux motor oil-cooled rotor of the present invention are further described.

[0027] In the description of this invention, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this invention, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0029] An axial flux motor oil-cooled rotor includes a rotating shaft 1 and a turntable 2. The turntable 2 is fixed on the rotating shaft 1. Several oil guiding channels 23 extending from the center to the outside are opened in the turntable 2. The oil guiding channels 23 are distributed along the circumference. An oil throwing hole 24 is opened at the end of the oil guiding channel 23 on the turntable 2. The oil throwing hole 24 extends from the side of the turntable 2 to the oil guiding channel 23. An oil guiding hole 11 is opened in the rotating shaft 1 along the axial direction. The oil guiding hole 11 extends to the turntable 2 and forms an oil collecting groove 111. An oil outlet hole 12 is opened on the outer surface of the rotating shaft 1 to the oil collecting groove 111. The oil outlet hole 12 is connected to the oil guiding channel 23.

[0030] Typically, one end of the oil guide hole 11 passes through the rotating shaft 1, and this end also serves as the oil inlet. Cooling oil enters the oil guide hole 11 and reaches the oil collection groove 111. As the rotating shaft 1 and the turntable 2 rotate at high speed, the cooling oil passes through the oil outlet hole 12 to the oil guide channel 23, and then is thrown out through the oil guide hole 11 to the windings inside the motor for cooling.

[0031] In this embodiment, the oil guide hole 11 and the oil guide channel 23 are in one-to-one correspondence, such as... Figure 5 As shown, the oil slinger hole 24 is preferably arranged at an angle to the rotor end face. The spray angle of the cooling oil can be controlled by adjusting this angle.

[0032] In this embodiment, the oil slinger hole 24 is connected to the end of the oil guide channel 23, and each end of the oil guide channel 23 has two oil guide holes 11, which face the two sides of the turntable 2 respectively.

[0033] In this embodiment, the beginning refers to the direction from which the cooling oil comes in, and the end refers to the direction from which the cooling oil goes.

[0034] In this preferred embodiment, a circular boss 4 is provided on the outer side of the turntable 2 corresponding to the oil throwing hole 24, and the oil throwing hole 24 passes through the circular boss 4.

[0035] like Figure 3 As shown, the small-diameter end face of the circular boss 4 faces outward, and the large-diameter end face faces the turntable 2. When rotating, the air velocity at the circular boss 4 will increase. The fluid velocity at the circular boss 4 is fast and the pressure is low, which increases the fluid pressure difference between the stator and rotor air gap and indirectly increases heat exchange.

[0036] In this preferred embodiment, the surface of the circular boss 4 is provided with a plurality of rectangular grooves 41, and the rectangular grooves 41 pass through the oil-slinging hole 24.

[0037] like Figure 3 As shown, the rectangular slot 41 allows air to pass through and allows some cooling oil to pass through.

[0038] In this preferred embodiment, the oil guiding channel 23 includes a long oil channel and a short oil channel, which are alternately distributed along the circumference.

[0039] Generally speaking, the turntable 2 has several magnets 5. Preferably, the oil slinger 24 at the short oil passage is arranged on the inner side of the magnet 5, that is, close to the rotating shaft 1, and the oil slinger 24 at the long oil passage is arranged on the outer side of the magnet 5, that is, away from the rotating shaft 1.

[0040] In this preferred embodiment, a limiting platform 13 is provided on one side of the rotating shaft 1 corresponding to the turntable 2. The turntable 2 is sleeved on the rotating shaft 1, and a nut 3 is threadedly connected to the rotating shaft 1. The nut 3 and the limiting platform 13 are located on both sides of the turntable 2.

[0041] During the conversion process, the turntable 2 is placed on the rotating shaft 1 and locked with the nut 3. In order to ensure that the rotating shaft 1 and the turntable 2 are properly fixed, a key and keyway are usually provided between the rotating shaft 1 and the turntable 2 to achieve the purpose of relatively fixing the circumference of the rotating shaft 1 and the turntable 2, and to achieve the alignment of the oil guide channel 23 and the oil guide hole 11.

[0042] In this preferred embodiment, the turntable 2 includes a left half 21 and a right half 22, which are separated by the middle of the turntable 2. An oil guide groove 211 is provided on the opposite side of the left half 21 and the right half 22. When the left half 21 and the right half 22 are closed, the oil guide groove 211 forms an oil guide channel 23.

[0043] The left half 21 and the right half 22 have the same structure and can be symmetrical. After assembly, the left half 21 and the right half 22 fit together completely. Preferably, chamfers are machined on the end faces of the left half 21 and the right half 22 away from the rotating shaft 1.

[0044] like Figure 6 As shown, the lower magnet slot 221 is not fitted with magnet 5. In this embodiment, magnet slots 221 are provided on both the left half 21 and the right half 22. The inner and outer arc radii of the magnet slots 221 near the two end faces of the rotor are smaller than the inner and outer arc radii of the center position. That is, the opening of the magnet slots 221 on the opposite side of the left half 21 and the right half 22 is larger, while the opening on the side away from the center is smaller. Its function is to fix the magnet 5 in the axial direction. That is, during installation, the magnet 5 is clamped and fixed in the magnet 5 mounting slot by the left half 21 and the right half 22.

[0045] In this preferred embodiment, an anti-rotation structure is provided between the left half 21 and the right half 22.

[0046] Specifically, the anti-rotation structure includes a positioning protrusion and a positioning groove, which are distributed on the left half 21 and the right half 22. The positioning protrusion and the positioning groove can be distributed on the left half 21 and the right half 22 respectively, as long as they can cooperate with each other.

[0047] In this preferred embodiment, the turntable 2 is provided with several weight-reducing holes.

[0048] like Figure 4 As shown, the weight reduction holes include an inner weight reduction hole 61, an outer weight reduction hole 62, and a weight reduction hole 63 between the magnet slots. The inner weight reduction holes 61 and the outer weight reduction holes 62 are strip-shaped holes with a constant width, evenly distributed on the turntable 2. The weight reduction holes 63 between the magnet slots are strip-shaped holes with a width that gradually increases from the inner side to the outer side, evenly distributed on the outer side of the short oil passage.

[0049] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An oil-cooled rotor for an axial flux motor, comprising a shaft and a turntable, characterized in that: The turntable is fixed on the rotating shaft. Several oil guiding channels extending from the center to the outside are opened inside the turntable. The oil guiding channels are distributed along the circumference. An oil throwing hole is opened at the end of the oil guiding channel on the turntable. The oil throwing hole extends from the side of the turntable to the oil guiding channel. An oil guiding hole is opened axially inside the rotating shaft. The oil guiding hole extends to the turntable and forms an oil collecting groove. An oil outlet hole is opened on the outer surface of the rotating shaft to the oil collecting groove. The oil outlet hole is connected to the oil guiding channel. A circular boss is provided on the outer side of the turntable corresponding to the oil throwing hole. The oil throwing hole passes through the circular boss. The small diameter end face of the circular boss faces outward, and the large diameter end face faces the turntable.

2. The axial flux motor oil-cooled rotor according to claim 1, characterized in that: The surface of the circular boss is provided with several rectangular grooves, which pass through the oil-slinging hole.

3. The axial flux motor oil-cooled rotor according to claim 2, characterized in that: The oil guiding channel includes long oil channels and short oil channels, which are alternately distributed along the circumference.

4. The axial flux motor oil-cooled rotor according to claim 3, characterized in that: A limiting platform is provided on one side of the rotating shaft corresponding to the turntable. The turntable is sleeved on the rotating shaft, and a nut is threadedly connected to the rotating shaft. The nut and the limiting platform are located on both sides of the turntable.

5. The axial flux motor oil-cooled rotor according to claim 4, characterized in that: The turntable includes a left half and a right half, which are separated by the middle of the turntable. An oil guide groove is provided on the opposite side of the left half and the right half. When the left half and the right half are closed, the oil guide groove forms an oil guide channel.

6. The axial flux motor oil-cooled rotor according to claim 5, characterized in that: An anti-rotation structure is provided between the left and right halves.

7. The axial flux motor oil-cooled rotor according to claim 6, characterized in that: The anti-rotation structure includes a positioning protrusion and a positioning groove, which are distributed on the left and right halves.

8. The oil-cooled rotor of the axial flux motor according to claim 7, characterized in that: The turntable has several weight-reducing holes.

9. The axial flux motor oil-cooled rotor according to claim 8, characterized in that: Both the left and right halves are provided with magnetic steel grooves. The openings on the opposite sides of the magnetic steel grooves in the left and right halves are larger than the openings on the sides that are far apart from each other. During installation, the magnets are clamped and fixed in the magnetic steel mounting grooves through the left and right halves.

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