Stator structure and oil cooling flat wire motor thereof

Abstract

The invention relates to a stator structure and an oil cooling flat wire motor thereof, the stator structure comprises a stator iron core formed by laminating a plurality of stator punching sheets, the stator iron core is provided with a stator cooling oil path, the inner wall of the stator iron core is circumferentially provided with a plurality of rows of hairpin conductor groups, one row of hairpin conductor group comprises a plurality of hairpin conductors longitudinally arranged in a stator groove, and the hairpin conductors are arranged in the stator groove. A plurality of stator teeth are arranged on the inner wall of the stator punching sheet in the circumferential direction, a stator groove is formed between every two adjacent stator teeth, lug parts are formed on the two sides of the tooth top of each stator tooth, a groove opening of each stator groove and a first conductor installation area are formed between the lug parts on the outer side of each stator groove from outside to inside, and the first conductor installation area is in a trapezoid shape with the caliber gradually increasing from outside to inside. And a trapezoidal first hairpin conductor is adaptively arranged in the first conductor mounting area. According to the scheme, the trapezoidal conductor shape is equal to the mode that the center of gravity of the conductor changes phase and is far away from the notch leakage magnetic field, the copper amount of the first hairpin conductor is reduced, alternating current copper consumption is reduced, and the total heating value of the conductor at the notch is reduced from the loss source.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a stator structure and an oil-cooled flat wire motor thereof. Background Art

[0002] New energy vehicle drive motors pursue high power, low cost, and high reliability, and there are more and more solutions for oil-cooled flat wire motors.

[0003] Currently, common stator oil circuits include oil pipe spraying, end oil guide ring spraying, and axial oil channels opened in the yoke of the stator core, etc.

[0004] Currently, common stator oil cooling solutions (including combinations of the above solutions, etc.) can better achieve the cooling of the iron core and end windings, reduce the temperature at the corresponding positions, and improve the overall reliability of the motor.

[0005] However, the current mainstream stator oil cooling solutions still cannot solve the problem of high temperature risk of conductors in the stator slots, especially near the slot openings. Constrained by the thermal anisotropy of pure copper and insulating materials in the slots, and the fact that the electromagnetic dimensions of the stator slots are very sensitive to the performance of the motor, in the existing oil cooling solutions, the conductors in the slots cannot be directly cooled by the cooling oil. Coupled with the development trend of high speed and high power of drive motors, the design speed of the motor is getting higher and higher, the power density is getting larger and larger, the AC loss density of the flat wire conductors at the slot openings is relatively large, and the heat generation is serious. The problem of temperature rise of the conductors at the slot openings has become one of the key problems that most urgently need to be solved in the high speed and high power of current flat wire motors. The industry's attention to the cooling of windings in the slots and at the slot openings has reached an unprecedented high level, and the demand for a new cooling solution that is more direct and efficient for the conductors in the slots or at the slot openings is very urgent.

[0006] Such as Figure 1 The Schaeffler patent shown: The conductors in each layer in the slot are distributed dispersedly, and an axial oil channel is formed with the iron core cavity area; Advantages: Each layer of conductors can be directly cooled, the heat dissipation efficiency is high, and the insulation risk is reduced; Disadvantages: The stator slot shape is too complex, the processing is complex, and the deterioration problem of the performance of the stator core is prominent, and it has a great impact on the electromagnetic performance.

[0007] Such as Figure 2 The General Motors patent shown: Closed slot design, without dipping paint and insulating paper, directly filling oil in the slot to directly cool the winding; Advantages: The cooling effect on the winding is theoretically the best; Disadvantages: The winding fixing effect is poor, the NVH problem deteriorates, and the requirement for the cleanliness of the oil is extremely high (otherwise, impurities in the oil will potentially scratch the paint film, increasing the insulation risk). Summary of the Invention

[0008] To solve the above problems, the first object of the present invention is to provide a stator structure. By optimizing the stator slot shape, stator tooth shape, changing and optimizing the size of the flat copper wire, adding an axial oil guiding passage near the winding, and adopting the current common oil cooling cycle of "oil inlet in the middle of the stator and oil spraying at the front and rear ends", the heat transfer path from heat sources such as the winding and iron core to the cooling oil can be shortened to the greatest extent, and the heat dissipation efficiency can be improved. Especially for the conductor at the slot opening, the oil cooling efficiency is significantly improved, and the temperature rise is significantly improved. The second object of the present invention is to provide an oil-cooled flat wire motor. To achieve the above object, the present invention adopts the following technical solutions: A stator structure includes a stator core formed by laminating multiple stator punchings. A stator cooling oil passage is provided on the stator core. A plurality of rows of hairpin conductor groups are circumferentially provided on the inner wall of the stator core. One row of hairpin conductor groups includes a plurality of hairpin conductors longitudinally arranged in the stator slots. It is characterized in that: a plurality of stator teeth are circumferentially provided on the inner wall of the stator punching. The stator slots are formed between adjacent stator teeth. Ears are formed on both sides of the tooth top of the stator teeth. The slot opening of the stator slot and the first conductor installation area are respectively formed from outside to inside between the ears outside the stator slot. The first conductor installation area is trapezoidal with a gradually increasing inner diameter from outside to inside. A trapezoidal first hairpin conductor is adaptively provided in the first conductor installation area.

[0009] Preferably, a third conductor installation area is provided inside the stator slot. Both sides of the third conductor installation area are inclined outward to form a trapezoid with a gradually increasing inner diameter from outside to inside. A trapezoidal third hairpin conductor is adaptively provided in the third conductor installation area. A plurality of second hairpin conductors are provided in the stator slot between the first hairpin conductor and the third hairpin conductor.

[0010] Preferably, the multiple stator punchings include a second punching group in the middle and first punching groups on both sides of the second punching group. The first punching group includes multiple stacked first punchings. The second punching group includes multiple stacked second punchings. The outer diameter of the second punching is smaller than that of the first punching. An oil storage channel is formed between the second punching group and the first punching groups on both sides.

[0011] Preferably, the stator cooling oil passage includes an oil distribution passage, a first axial cooling oil passage, a second axial cooling oil passage, and the oil storage channel. The first axial cooling oil passage and the second axial cooling oil passage are provided on the first punching group. The oil distribution passage is provided on the second punching group and guides the oil in the oil storage channel to the first axial cooling oil passage and the second axial cooling oil passage.

[0012] Preferably, the stator teeth include first stator teeth on the first punching sheet and second stator teeth on the second punching sheet, and the outer contours of the first stator teeth and the second stator teeth are the same; a plurality of oil distribution grooves are radially provided on the second punching sheet, one end of the oil distribution grooves communicates with the oil storage channel, and the other end extends to the second stator teeth to communicate with the first axial cooling oil channel and the second axial cooling oil channel.

[0013] Preferably, first cooling oil grooves are constructed on the first ear portions on both sides of the top of the first stator teeth, and a plurality of stacked first cooling oil grooves form a first axial cooling oil channel.

[0014] Preferably, a first axial oil distribution cooling groove is formed by enclosing the second ear portions on both sides of the top of the second stator teeth. The first axial oil distribution cooling groove communicates the first cooling oil groove and the oil distribution groove, and the area of the first axial oil distribution cooling groove is larger than the areas of the two first cooling oil grooves.

[0015] Preferably, second cooling oil grooves are formed on the first stator teeth on both sides of the third conductor installation area, and a plurality of stacked second cooling oil grooves form a second axial cooling oil channel.

[0016] Preferably, second axial oil distribution cooling grooves are provided on both sides of the bottom of the second stator teeth. The second axial oil distribution cooling grooves communicate the second cooling oil grooves and the oil distribution grooves. The second axial oil distribution cooling grooves include long strip grooves corresponding to the second cooling oil grooves, and cut grooves formed by cutting from the side wall of the oil distribution groove to the long strip grooves. The cut grooves communicate with the long strip grooves, and the inner diameter of the oil distribution groove gradually decreases from outside to inside.

[0017] An oil-cooled flat wire motor includes a housing, and is characterized in that: it further includes a stator structure according to any one of the above, and a plurality of oil inlet holes are provided on the housing and communicate with the stator cooling oil circuit.

[0018] The present invention adopts the above technical solutions and has the following beneficial effects: ① First, the first hairpin conductor at the slot opening is made trapezoidal, and in cooperation with the elevation of the stator tooth top, a first cooling oil channel at the slot opening of the stator tooth top is reserved; the AC effect of the first hairpin conductor is the most prominent. The trapezoidal conductor shape is equivalent to the center of gravity of the conductor moving away from the slot opening leakage magnetic field, and the copper amount of the first hairpin conductor is reduced, reducing the AC copper loss and reducing the total heat generation of the conductor at the slot opening from the source of loss.

[0019] ② After the tooth top is lifted, ears are constructed, and axial cooling oil channels are excavated. In cooperation with the overall oil circuit structure of the machine, an axial oil circuit is directly applied to the slot opening position, reducing the temperature rise at the slot opening position from the perspective of heat dissipation. And because this oil circuit is closest to the air gap, in addition to improving the cooling effect on the stator slot opening conductor, the cooling effect on the rotor side magnet component is also significantly improved (the cooling path of the magnet is also significantly shortened).

[0020] ③, Since the effective cross-sectional area of the slot conductor becomes smaller, in order to balance the efficiency requirements of the whole machine under medium and low speed CLTC conditions, etc., the third hairpin conductor at the bottom of the slot is configured into a corresponding trapezoid to "compensate" for the reduced copper area of the slot conductor, ensuring that the overall pure copper slot fill factor and resistance remain unchanged. Due to the characteristics of the flat wire parallel slot, a second axial cooling oil duct is added at the bottom of the tooth close to the winding for heat dissipation, which has little impact on the electromagnetic performance and balances the electromagnetic performance and winding temperature.

[0021] ④, The outer diameter of the second stator punching < the first stator punching, so as to form a circumferential annular oil storage duct outside the second stator punching to distribute oil to all the stator tooth oil ducts, realizing the oil cooling cycle of "oil enters from the middle of the stator and is sprayed at the front and rear ends" of the whole machine; The second stator punching mainly realizes the radial oil distribution and oil guiding of the oil duct. It can use traditional silicon steel sheets or be formed in one piece by SMC materials, and is integrally laminated with the normal silicon steel sheet iron core. The axial lamination thickness is recommended to be 6 - 8 mm, so as to have a low and controllable impact on the electromagnetic performance.

[0022] ⑤, The oil duct at the notch position of the radial oil distribution groove is made into a narrowed state to balance the oil volume distribution between the upper and lower layers and avoid the situation of less oil cooling at the bottom of the groove.

[0023] ⑥, The inlet and outlet positions of the oil duct can be flexibly adjusted according to the changes of the whole machine boundary: The total oil inlet hole (on the machine shell) is located in the middle of the stator axially and directly above the circumference; When there are changes in the whole machine boundary, it can also be adjusted to various forms such as "oil enters from the front end and is sprayed at the rear end" or "oil enters from the rear end and is sprayed at the front end", etc., and only need to adjust the relative position of the components composed of the second punching group in the axial space; However, it is still recommended to set the second punching group in the middle in this case (because the temperature is the highest at the middle position of the winding axially).

[0024] ⑦, There are only two types of stator punching shapes, with flexible solutions, low cost, simple process implementation, and little impact on the electromagnetic performance. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the Schaeffler patent in the prior art.

[0026] Figure 2 It is a schematic diagram of the General Motors patent in the prior art.

[0027] Figure 3 It is a schematic diagram of the oil inlet hole arrangement on an oil-cooled flat wire motor.

[0028] Figure 4 It is a three-dimensional structure schematic diagram of the stator core.

[0029] Figure 5 It is an assembly schematic diagram of the first punching group and the second punching group.

[0030] Figure 6 It is a schematic assembly diagram of multiple hairpin conductors and stator slots.

[0031] Figure 7 It is a schematic plan view of the first punching sheet.

[0032] Figure 8 It is Figure 7 an enlarged schematic view of part A in

[0033] Figure 9 It is a schematic plan view of the second punching sheet.

[0034] Figure 10 It is Figure 9 an enlarged schematic view of part B in

[0035] Figure 11 It is a schematic diagram of the oil flow domain on the stator core.

[0036] Figure 12 It is a schematic diagram of the oil flow domain on the stator core from an enlarged perspective.

[0037] Figure 13 It is a schematic diagram of the oil flow domain on the stator core from another perspective.

[0038] Figure 14 It is the temperature field distribution of the motor with the traditional oil circuit scheme.

[0039] Figure 15 It is the temperature field distribution of the motor with the oil circuit scheme of this patent. Specific embodiments

[0040] The following describes in detail the embodiments of the present invention. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship 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 should not be construed as limiting the present invention.

[0042] In addition, 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more, unless otherwise clearly defined.

[0043] In the present invention, unless otherwise clearly specified and defined, the terms such as "mounted", "connected", "connected to", "fixed" and the like shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature. Embodiment 1:

[0045] As Figures 3 to 13 shown, a stator structure includes a stator core 100 formed by laminating a plurality of stator punching sheets. A stator cooling oil passage is provided on the stator core 100. A plurality of rows of hairpin conductor groups are circumferentially provided on the inner wall of the stator core 100. A row of hairpin conductor groups includes a plurality of hairpin conductors longitudinally arranged in the stator slot 1. A plurality of stator teeth 2 are circumferentially provided on the inner wall of the stator punching sheet. The stator slots 1 are formed between adjacent stator teeth 2. Ears 3 are formed on both sides of the tooth top of the stator teeth 2. The notch of the stator slot 1 and a first conductor mounting area 4 are respectively formed from outside to inside between the ears 3 outside the stator slot 1. The first conductor mounting area 4 is trapezoidal with a gradually increasing inner diameter from outside to inside. A trapezoidal first hairpin conductor 5 is adaptively provided in the first conductor mounting area 4.

[0046] In the above technical solution, first, the first hairpin conductor of the slot opening is made trapezoidal. In cooperation with the elevation of the stator tooth tip, a first cooling oil passage of the stator tooth tip slot opening is reserved. The AC effect of the first hairpin conductor is the most prominent. The trapezoidal conductor shape is equivalent to the center of gravity of the conductor moving away from the slot opening leakage magnetic field, and reduces the copper amount of the first hairpin conductor, reducing the AC copper loss and reducing the total heat generation of the conductor at the slot opening position from the source of loss.

[0047] Preferably, a third conductor installation area 6 is provided inside the stator slot 1. Both sides of the third conductor installation area 6 slope outward to form a trapezoid with a gradually increasing inner diameter from outside to inside. A trapezoidal third hairpin conductor 7 is adaptively provided in the third conductor installation area 6. A plurality of second hairpin conductors 8 are provided in the stator slot 1 between the first hairpin conductor 5 and the third hairpin conductor 7. In this technical solution, since the effective cross-sectional area of the slot opening conductor becomes smaller, in order to take into account the efficiency requirements of the whole machine under medium and low speed CLTC working conditions, etc., the third hairpin conductor at the slot bottom is configured into a corresponding trapezoid to "compensate" the reduced copper area of the slot opening conductor, ensuring that the overall pure copper slot fill factor and resistance remain unchanged.

[0048] Preferably, the multi-piece stator punching includes a second punching group 9 in the middle and first punching groups 10 on both sides of the second punching group 9. The first punching group 10 includes a plurality of stacked first punchings 11. The second punching group 9 includes a plurality of stacked second punchings 12. The outer diameter of the second punching 12 is smaller than the outer diameter of the first punching 11. An oil storage oil passage 13 is formed between the second punching group 9 and the first punching groups 10 on both sides. In this technical solution, the outer diameter of the second stator punching < the outer diameter of the first stator punching, so as to form a circumferential annular oil storage oil passage outside the second stator punching to distribute oil to all the stator tooth oil circuits.

[0049] Preferably, the stator cooling oil passage includes an oil distribution oil passage, a first axial cooling oil passage, a second axial cooling oil passage, and the oil storage oil passage 13. The first axial cooling oil passage and the second axial cooling oil passage are arranged on the first punching group 10. The oil distribution oil passage is arranged on the second punching group 9 and guides the oil in the oil storage oil passage 13 to the first axial cooling oil passage and the second axial cooling oil passage. The stator tooth 2 includes a first stator tooth 22 on the first punching 11 and a second stator tooth 23 on the second punching 12. The outer contours of the first stator tooth 22 and the second stator tooth 23 are the same. A plurality of oil distribution oil grooves 14 are radially provided on the second punching 12. One end of the oil distribution oil groove 14 communicates with the oil storage oil passage 13, and the other end extends to the second stator tooth 23 to communicate with the first axial cooling oil passage and the second axial cooling oil passage.

[0050] The above solution realizes the oil cooling cycle of "injecting oil into the middle of the stator and spraying oil at the front and rear ends" for the whole machine; the second stator punching mainly realizes the radial oil distribution and oil guiding of the oil circuit. It can use traditional silicon steel sheets or be formed in one piece with SMC materials, and is integrally laminated with the normal silicon steel sheet core. The axial lamination thickness is preferably 6-8 mm to have a lower and controllable impact on the electromagnetic performance.

[0051] Preferably, first cooling oil grooves 15 are constructed on both sides of the top of the 22 teeth of the first stator tooth 22. The stacked multiple first cooling oil grooves 15 form a first axial cooling oil passage. In this technical solution, after the first tooth top is lifted, the first ear part is constructed, and the first axial cooling oil passage is dug out. In cooperation with the oil circuit structure of the whole machine, an axial oil circuit is directly applied to the slot opening position, reducing the temperature rise at the slot opening position from the perspective of heat dissipation. And because this oil circuit is the closest to the air gap, in addition to improving the cooling effect on the stator slot opening conductor, the cooling effect on the rotor side magnet component is also significantly improved (the cooling path of the magnet is also significantly shortened).

[0052] Preferably, second ear parts 32 on both sides of the top of the 23 teeth of the second stator tooth 23 enclose to form a first axial oil distribution and cooling groove 16. The first axial oil distribution and cooling groove 16 communicates with the first cooling oil groove 15 and the oil distribution oil groove 14, and the area of the first axial oil distribution and cooling groove 16 is larger than the area of the two first cooling oil grooves 15. In this technical solution, after the second tooth top is lifted, the second ear part is constructed, and the second ear part encloses to form a first axial oil distribution and cooling groove. The first axial oil distribution and cooling groove not only distributes oil to the two first axial cooling oil passages on both sides, but also, due to its large area and being arranged in the middle of the stator core, has a better cooling effect on the area where heat is concentrated in the middle of the stator core.

[0053] Preferably, second cooling oil grooves 17 are formed on the first stator tooth 22 on both sides of the third conductor installation area 6. The stacked multiple second cooling oil grooves 17 form a second axial cooling oil passage. In this technical solution, due to the characteristics of the flat wire parallel slots, a second axial cooling oil passage is added at the bottom of the tooth close to the winding for heat dissipation, which has a small impact on the electromagnetic performance and takes into account the balance between the electromagnetic performance and the winding temperature.

[0054] Preferably, second axial oil distribution and cooling grooves 18 are opened on both sides of the bottom of the second stator tooth 23. The second axial oil distribution and cooling grooves 18 communicate with the second cooling oil grooves 17 and the oil distribution oil groove 14. The second axial oil distribution and cooling grooves 18 include long grooves 19 corresponding to the second cooling oil grooves 17, and cutout grooves 20 cut from the side wall of the oil distribution oil groove 14 to the long grooves 19. The cutout grooves 20 communicate with the long grooves 19, and the inner diameter of the oil distribution oil groove 14 gradually becomes smaller from outside to inside. In this technical solution, because the openings on both sides of the cutout groove are small, the oil circuit at the slot opening position of the oil guiding groove for radial oil distribution is made in a narrowed state to balance the oil quantity distribution of the upper and lower layers and avoid the situation of less oil cooling at the bottom of the slot. Embodiment 2:

[0055] As Figure 3 shown, an oil-cooled flat wire motor includes a housing. A stator structure in Embodiment 1 is arranged inside the housing. A plurality of oil inlet holes 21 are formed in the housing and are communicated with the stator cooling oil circuit. In this technical solution, the inlet and outlet positions of the oil circuit can be flexibly adjusted according to the change of the whole machine boundary: the oil inlet holes (on the housing) are located in the middle of the stator axially and directly above the circumference; when there is a change in the whole machine boundary, it can also be adjusted to various forms such as "front-end inlet and rear-end oil injection" or "rear-end inlet and front-end oil injection", etc., and only the relative position of the components formed by the second punching sheet group in the axial space needs to be adjusted; however, the form of arranging the second punching sheet group in the middle in this case is still recommended (because the temperature is the highest at the middle position of the winding axially).

[0056] For the existing stator oil-cooling scheme, the problem of the high-temperature risk of the conductors in the stator slots, especially near the slot openings, still cannot be solved. The above scheme can optimize the stator slot shape, stator tooth shape, change and optimize the size of the flat copper wire, increase the axial oil conduction oil circuit near the winding, and adopt the current common oil circuit scheme of "oil inlet in the middle of the stator and oil injection at the front and rear ends", which can maximize the shortening of the heat transfer path between the heat sources such as the winding and the iron core and the cooling oil, and improve the heat dissipation efficiency. Especially for the slot opening conductors, the oil-cooling efficiency is significantly improved, and the temperature rise is significantly improved.

[0057] At the same time, the scheme proposed in this scheme compared with the current in-slot cooling schemes on the market: occupies the least effective area in the slot, has the least influence on the shape of the stator teeth and slots, sacrifices the least electromagnetic performance, and maximally meets the overall performance requirements of the vehicle for power, endurance, etc.; as Figure 14 shown, the motor temperature field distribution of the traditional oil circuit scheme based on the simulation of a certain project at the continuous working condition point of 16150 rpm 80 kW, as Figure 15 shown, compared with the traditional oil circuit scheme, the highest temperature in the slot and slot opening of this scheme drops by about 17 °C, and the drop is obvious. The temperature on the stator side of the whole machine is more balanced and reasonable as a whole; it is proved that this scheme can play a better role in improving the temperature in the slot.

[0058] This scheme is very friendly to the process. The axial oil duct near the winding is formed by punching the silicon steel sheet to form an oil outlet duct, with a relatively low comprehensive cost, convenient processing, and high cost performance. The external interface of the oil circuit is flexible, the oil inlet hole can be set at any position, and the number of stator punching sheet types is small; the new oil circuit scheme has a wide applicability and is applicable to different designs such as the number of slots and the number of conductors in the slot; it is friendly to the process, and there is no need to worry about blocking the oil duct during dipping paint, etc., and the increase in sheet types is small. The oil inlet space in the middle of the iron core or the oil inlet space at the end can be processed with soft magnetic materials such as SMC; the flow resistance of the oil duct is small, the burden on the oil pump is small, and the oil circuit balance degree is high.

[0059] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0060] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A stator structure, comprising a stator core (100) formed by laminating a plurality of stator punching sheets, a stator cooling oil circuit being provided on the stator core (100), a plurality of rows of hairpin conductor groups being circumferentially provided on an inner wall of the stator core (100), a row of hairpin conductor groups comprising a plurality of hairpin conductors longitudinally arranged in stator slots (1), characterized in that: A plurality of stator teeth (2) are provided in the circumferential direction of the inner wall of the stator punching sheet, the stator slot (1) is formed between adjacent stator teeth (2), ears (3) are formed on both sides of the tooth top of the stator tooth (2), and the ears (3) on the outer side of the stator slot (1) respectively form a notch of the stator slot (1) and a first conductor installation area (4) from the outside to the inside, the first conductor installation area (4) is in a trapezoidal shape with a diameter gradually increasing from the outside to the inside, and a first hairpin conductor (5) in a trapezoidal shape is adapted to be provided in the first conductor installation area (4).

2. A stator structure according to claim 1, characterized in that: A third conductor installation area (6) is provided on the inner side of the stator slot (1), and the two sides of the third conductor installation area (6) are inclined outwards to form a trapezoidal shape with a diameter gradually increasing from the outside to the inside. A third hairpin conductor (7) in a trapezoidal shape is adapted to be provided in the third conductor installation area (6), and a plurality of second hairpin conductors (8) are provided in the stator slot (1) between the first hairpin conductor (5) and the third hairpin conductor (7).

3. A stator structure according to claim 2, characterized in that: The multiple stator sheets include a second sheet group (9) in the middle and first sheet groups (10) on both sides of the second sheet group (9), the first sheet group (10) includes multiple stacked first sheets (11), the second sheet group (9) includes multiple stacked second sheets (12), the outer diameter of the second sheets (12) is smaller than the outer diameter of the first sheets (11), and an oil storage passage (13) is formed between the second sheet group (9) and the first sheet groups (10) on both sides.

4. A stator structure according to claim 3, characterized in that: The stator cooling oil circuit comprises an oil separation channel, a first axial cooling oil channel, a second axial cooling oil channel and the oil storage channel (13); the first axial cooling oil channel and the second axial cooling oil channel are arranged on the first punching plate group (10); the oil separation channel is arranged on the second punching plate group (9) and guides the oil in the oil storage channel (13) to the first axial cooling oil channel and the second axial cooling oil channel.

5. A stator structure according to claim 4, characterized in that: The stator teeth (2) comprise a first stator tooth (22) on a first punching sheet (11) and a second stator tooth (23) on a second punching sheet (12), wherein the first stator tooth (22) and the second stator tooth (23) have the same outer profile; a plurality of oil separation grooves (14) are radially provided on the second punching sheet (12), wherein one end of the oil separation groove (14) is in communication with the oil storage channel (13), and the other end extends to the second stator tooth (23) and is in communication with the first axial cooling channel and the second axial cooling channel.

6. A stator structure according to claim 5, characterized in that: First cooling oil grooves (15) are constructed on the first ears (31) on both sides of the tooth top of the first stator tooth (22), and a plurality of stacked first cooling oil grooves (15) form a first axial cooling oil channel.

7. A stator structure according to claim 6, characterized in that: The second ears (32) on both sides of the tooth top of the second stator tooth (23) enclose a first axial oil separation cooling groove (16), the first axial oil separation cooling groove (16) is connected to the first cooling oil groove (15) and the oil separation groove (14), and the area of ​​the first axial oil separation cooling groove (16) is greater than the areas of the two first cooling oil grooves (15).

8. A stator structure according to claim 5, characterized in that: Second cooling oil grooves (17) are formed on the first stator teeth (22) on both sides of the third conductor installation area (6), and a plurality of stacked second cooling oil grooves (17) form a second axial cooling oil channel.

9. A stator structure according to claim 5, characterized in that: Second axial oil separation cooling grooves (18) are provided on both sides of the bottom of the second stator tooth (23). The second axial oil separation cooling grooves (18) are connected to the second cooling oil groove (17) and the oil separation groove (14). The second axial oil separation cooling grooves (18) include a long groove (19) corresponding to the second cooling oil groove (17), and a notch groove (20) formed by cutting from the side wall of the oil separation groove (14) toward the long groove (19). The notch groove (20) is connected to the long groove (19). The diameter of the oil separation groove (14) gradually decreases from the outside to the inside.

10. An oil-cooled flat wire motor, comprising a housing, characterized in that: It also comprises a stator structure as claimed in any one of claims 1 to 9, wherein a plurality of oil inlet holes (21) are provided on the casing and communicate with the stator cooling oil circuit.

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