Stator structure and circumferential oil-cooled flat wire motor

Abstract

The invention relates to a stator structure and a circumferential oil cooling flat wire motor, at least one notch cooling punching sheet group is arranged in the middle of a stator core, and the notch cooling punching sheet group comprises first punching sheets on two sides and second punching sheets clamped between the first punching sheets on the two sides; the stator cooling oil way comprises an opening oil groove and an oil guide oil groove. The first stator teeth arranged on the first punching sheet at intervals are provided with the oil guide grooves along the radial direction; the oil guide oil grooves comprise first oil guide oil grooves, the radial outer sides of the first oil guide oil grooves are communicated with the opening oil grooves, the opening oil grooves are built inwards from the yoke portion edge of the first punching sheet, and the radial inner sides of the first oil guide oil grooves extend to be close to the tooth tops of the first stator teeth. And at the position of the outer diameter opening oil groove, the oil is guided to be close to the tooth crest of the motor through the oil guide oil groove along the radial direction, namely a conductor close to the notch, so that the heat dissipation path of the notch conductor is shortened, and the temperature rise of the conductor close to the notch in the groove is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a stator structure and a flat wire motor with circumferential oil cooling. 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 ring spraying, and axial oil channels opened in the yoke part 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. Due to 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 most urgent key problems 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 by using the cavity area of the iron core; 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 problem of deterioration of the performance of the stator iron 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 windings; Advantages: The cooling effect on the windings 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 may cause potential scratches on the paint film, increasing the insulation risk).

[0008] Such as Figure 18As shown in the figure, the temperature field distribution diagram of the whole machine under the traditional oil-cooled motor oil circuit scheme: Under the condition of continuous power at the highest speed, the AC effect of the conductor is very obvious, and the AC loss is concentrated in the conductor at the slot opening, resulting in the slot inner and slot opening areas becoming the highest points of temperature rise risk; The SPD oil circuit is the most powerful cooling oil circuit scheme for current mass production projects: oil passes through the stator yoke + oil is sprayed on the outer surface of the winding from the stator end face + oil cooling through the hollow shaft of the rotor + two-layer oil channels in the rotor weight reduction holes + oil is splashed on the inner surface of the end part by the rotor baffle; The entire stator scheme has been optimized and iterated 4 times, but the high-temperature area in the slot has not been effectively improved. Summary of the Invention

[0009] In order to solve the above problems, the first object of the present invention is to provide a stator structure. By setting a set of slot opening cooling punching sheets in the circumferential direction at the middle position of the winding in the axial direction or at the 1 / 4, 1 / 2, 3 / 4 positions in the axial direction, it is possible to specifically cool the middle position of the slot inner and slot opening in the axial direction of the winding, which is a region that is difficult to cover by the current oil-cooling scheme, with refinement and pertinence; The heat transfer path between the slot opening, near the air gap and other regions of the winding and the cooling oil is shortened to the greatest extent, and the heat dissipation efficiency is improved.

[0010] In order 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 punching sheets. Multiple stator teeth are circumferentially arranged on the inner wall of the stator core. Stator slots for installing hairpin conductors are formed between adjacent stator teeth. A stator cooling oil circuit is provided on the stator core. Ears are formed on both sides of the top of the stator teeth. The slot opening of the stator slot is formed between the opposite ears. Its characteristics are as follows: The multiple stator punching sheets include at least one set of slot opening cooling punching sheet groups stacked together, and at least two sets of axial cooling punching sheet groups; At least one set of slot opening cooling punching sheet groups is arranged in the middle of the stator core. The slot opening cooling punching sheet group includes first punching sheets on both sides and a second punching sheet sandwiched between the first punching sheets on both sides; The stator cooling oil circuit includes an open oil groove and a guiding oil groove; The guiding oil groove is radially provided on the upper edge of the first stator teeth arranged at intervals on the first punching sheet; The guiding oil groove includes a first guiding oil groove, the radial outer side of which communicates with the open oil groove. The open oil groove is constructed inward from the yoke edge of the first punching sheet, and the radial inner side of the first guiding oil groove extends close to the top of the first stator tooth.

[0011] Preferably, the stator cooling oil circuit further includes a closed rectangular oil groove. The guiding oil groove further includes a second guiding oil groove, the radial outer side of which communicates with the closed rectangular oil groove, and the closed rectangular oil groove communicates with the open oil groove.

[0012] Preferably, in the two first punching sheets of the notch cooling punching sheet group, the open oil groove of one punching sheet is arranged corresponding to the closed rectangular oil groove of the other punching sheet, so that the first oil guiding grooves and the second oil guiding grooves of the two first punching sheets are correspondingly arranged up and down; an oil guiding hole for axially communicating the upper and lower oil guiding grooves is constructed at the inner end of the second stator tooth corresponding to the oil guiding groove on the second punching sheet.

[0013] Preferably, the inner end of the oil guiding groove extends to both side ears of the first stator tooth, and the oil guiding hole is trapezoidal and has the same shape as the inner end of the oil guiding groove.

[0014] Preferably, the stator cooling oil path further includes an axial cooling oil passage. The axial cooling punching sheet group includes a plurality of third punching sheets stacked. A plurality of groups of cooling hole groups are circumferentially and regularly arranged on the yoke part of the third punching sheet. The plurality of groups of cooling hole groups on the plurality of third punching sheets are stacked to form an axial cooling oil passage, and the plurality of groups of cooling hole groups are respectively correspondingly communicated with the oil guiding grooves and the closed rectangular oil grooves on the first punching sheet.

[0015] Preferably, each group of cooling hole groups includes three cooling holes, and the three cooling holes are arranged corresponding to two stator slots.

[0016] Preferably, the plurality of stator punching sheets include a group of notch cooling punching sheet groups and two groups of axial cooling punching sheet groups symmetrically clamped on both sides of the notch cooling punching sheet group.

[0017] Preferably, the plurality of stator punching sheets include a plurality of groups of notch cooling punching sheet groups and a plurality of groups of axial cooling punching sheet groups stacked alternately.

[0018] Preferably, the axial thickness of the first punching sheet and the second punching sheet is less than or equal to 3 mm, and the first punching sheet and the second punching sheet are made of silicon steel sheet or amorphous material or SMC material.

[0019] A flat wire motor with circumferential oil cooling includes a motor housing, and is characterized in that: it further includes a stator structure described in any one of the above, and a plurality of oil inlet holes corresponding to and communicating with the open oil grooves are circumferentially opened on the motor housing.

[0020] The present invention adopts the above technical solutions and has the following beneficial effects: ①, a radial oil guiding path is set at key positions such as the axial 1 / 2, and the cooling oil flows near the notch: the cooling oil entering the motor cavity from the outside of the motor housing, at the position of the outer diameter open oil groove, is guided to near the tooth top of the motor through the radially directed oil guiding groove - correspondingly approaching the conductor near the notch, shortening the heat dissipation path of the conductor near the notch in the slot, and improving the temperature rise of the conductor near the notch in the slot.

[0021] ② After the cooling oil reaches the notch of the oil tank, it flows axially through the oil guiding holes at the corresponding top positions of the second punching sheet to the staggered slot positions of the first punching sheet, and then flows out from the closed rectangular oil grooves of the corresponding adjacent slots. For the same punching sheet, it serves as both the oil inlet and the oil outlet, improving the material utilization rate and having a high integration level.

[0022] ③ The cooling oil flows upward radially in the adjacent slots. After gathering from the closed rectangular oil groove area, it then flows axially toward the stator end through the corresponding yoke cooling hole groups of the third punching sheet and finally sprays out from the stator end face to cool the end windings. Although the third punching sheet is similar to the traditional yoke oil circuit, in terms of details, it corresponds to the slotting of the first punching sheet, with each group of two slots corresponding to 3 oil channels. They are distributed periodically in the circumferential direction, and enough space is reserved between adjacent yoke oil channel groups for uses such as weld seams and positioning slots, making the magnetic circuit more symmetrical.

[0023] ④ The design of the spaced oil guiding grooves only affects half of the teeth but can cool the conductors at the notches of all the slots, with high heat dissipation efficiency.

[0024] ⑤ It is process-friendly, has a low cost, and a low deterioration of electromagnetic performance: The axial thicknesses of the first punching sheet and the second punching sheet are both ≤ 3 mm, ensuring that the axial thickness of the combined overall notch cooling component is ≤ 9 mm, accounting for a proportion of the entire stack thickness dimension < 10%. The materials of the first punching sheet and the second punching sheet can be traditional silicon steel sheets or non-crystalline or SMC materials with lower iron losses. The axially symmetric oil circuit design in the front and back ensures that the front and back axially iron cores are evenly cooled by the cooling oil, making the overall temperature of the entire machine stator side more balanced and avoiding the occurrence of local overheating points.

[0025] ⑥ The combination of punching sheets 1 - 2 - 1 for notch cooling can be modularized into a "notch cooling punching sheet group". According to boundary differences such as different stack thicknesses and temperature reduction requirements, multiple "notch cooling punching sheet groups" can be set in the axial length, with a wide range of applications. Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the Schaeffler patent in the prior art.

[0027] Figure 2 It is a schematic diagram of the General Motors patent in the prior art.

[0028] Figure 3 It is a schematic diagram of the arrangement of the oil inlet holes on a flat wire motor with circumferential oil cooling.

[0029] Figure 4 It is a schematic diagram of setting a notch cooling punching sheet group at the axial middle position of the stator core for the first scheme.

[0030] Figure 5 It is a schematic diagram of the cooperation between the notch cooling punching sheet group and the axial cooling punching sheet group.

[0031] Figure 6 It is a three-dimensional structural schematic diagram of a notch-cooled punching sheet group.

[0032] Figure 7 It is a planar structural schematic diagram of the first punching sheet.

[0033] Figure 8 It is Figure 7 An enlarged schematic diagram of location A in

[0034] Figure 9 It is a planar structural schematic diagram of the second punching sheet.

[0035] Figure 10 It is Figure 9 An enlarged schematic diagram of location B in

[0036] Figure 11 It is a planar structural schematic diagram of the third punching sheet.

[0037] Figure 12 It is Figure 11 An enlarged schematic diagram of location C in

[0038] Figure 13 It is a disassembled structural schematic diagram of the stator core of the first scheme.

[0039] Figure 14 It is a flow direction schematic diagram of the stator cooling oil circuit on the stator core of the first scheme.

[0040] Figure 15 It is a schematic diagram of arranging notch-cooled punching sheet groups at the 1 / 4, 1 / 2, and 3 / 4 positions in the axial direction of the stator core of the second scheme.

[0041] Figure 16 It is a disassembled structural schematic diagram of the stator core of the second scheme.

[0042] Figure 17 It is a partial basin map of the internal cooling oil circuit of the stator core.

[0043] Figure 18 It is a motor temperature field distribution map of the traditional oil circuit scheme.

[0044] Figure 19 It is a motor temperature field distribution map of the oil circuit scheme of this case. Specific implementation manners

[0045] The embodiments of the present invention will be described in detail below. 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.

[0046] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 a limitation to the present invention.

[0047] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the 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" is two or more, unless otherwise clearly defined.

[0048] In the present invention, unless otherwise clearly specified and defined, the terms such as "mounted", "connected", "connected to", "fixed" should 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.

[0049] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" 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 other features therebetween. Moreover, the first feature being "above", "over" and "on" 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 "under" 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:

[0050] As Figures 4 to 17 shown, a stator structure includes a stator core 100 formed by laminating a plurality of stator laminations. A plurality of stator teeth are circumferentially arranged on the inner wall of the stator core 100. A stator slot 1 for installing hairpin conductors is formed between adjacent stator teeth. A stator cooling oil passage is provided on the stator core 100. Ears 2 are formed on both sides of the top of the stator teeth. A notch of the stator slot 1 is formed between the opposite ears 2. The multiple stator punching sheets include at least one set of notch cooling punching sheet group 3 stacked together, and at least two sets of axial cooling punching sheet groups 4; at least one set of notch cooling punching sheet group 3 is arranged in the middle of the stator core 100, and the notch cooling punching sheet group 3 includes first punching sheets 5 on both sides and a second punching sheet 6 clamped between the first punching sheets 5 on both sides; The stator cooling oil path includes an open oil groove 7 and a guiding oil groove; the guiding oil groove is arranged radially along the first stator teeth 9 arranged at intervals on the first punching sheet 5; the guiding oil groove includes a first guiding oil groove 8, the radially outer side of which communicates with the open oil groove 7, the open oil groove 7 is constructed inward from the yoke edge of the first punching sheet 5, and the radially inner side of the first guiding oil groove 8 extends close to the tooth top of the first stator tooth 9.

[0051] In the above technical solution, a radial oil guiding path is arranged at key positions such as the axial 1 / 2, and the cooling oil flows near the notch: the cooling oil entering the motor cavity from the outside of the motor housing, at the position of the outer diameter open oil groove, is guided to the vicinity of the tooth top of the motor through the guiding oil groove in the radial direction - correspondingly approaching the conductor near the notch, shortening the heat dissipation path of the conductor near the notch in the slot, and improving the temperature rise of the conductor near the notch in the slot.

[0052] Further, the stator cooling oil path further includes a closed rectangular oil groove 10, and the guiding oil groove further includes a second guiding oil groove 11, the radially outer side of which communicates with the closed rectangular oil groove 10, and the closed rectangular oil groove 10 communicates with the open oil groove 7. In this technical solution, the same punching sheet acts as both an oil inlet and an oil outlet, improving the material utilization rate and having a high integration degree.

[0053] Further, among the two first punching sheets 5 of the notch cooling punching sheet group 3, the open oil groove 7 of one of them is arranged corresponding to the closed rectangular oil groove 10 of the other, so that the first guiding oil groove 8 and the second guiding oil groove 11 of the two first punching sheets 5 are correspondingly arranged up and down; a guiding oil hole 13 axially communicating the upper and lower guiding oil grooves is constructed at the inner end of the second stator tooth 12 corresponding to the guiding oil groove on the second punching sheet 6. In this technical solution, after the cooling oil reaches the notch, it passes through the guiding oil hole axially at the corresponding slot top position of the second punching sheet, and flows axially to the position of the staggered slot of the first punching sheet and flows out from the closed rectangular oil groove of the corresponding adjacent slot.

[0054] Further, the inner end of the guiding oil groove extends to both ear parts 2 of the first stator tooth 9, and the guiding oil hole 13 is trapezoidal and has the same shape as the inner end of the guiding oil groove. In this technical solution, the guiding oil hole 13 is trapezoidal and has the same shape as the inner end of the guiding oil groove, which can avoid the accumulation of oil volume at the tooth top, accelerate the oil flow, and at the same time, make the cooling oil closer to the conductor and the notch, improving the heat dissipation effect.

[0055] Further, the stator cooling oil circuit further includes an axial cooling oil passage. The axial cooling punching sheet group 4 includes a plurality of third punching sheets 14 stacked together. A plurality of groups of cooling hole groups are circumferentially and regularly arranged on the yoke portion of the third punching sheet 14. The plurality of groups of cooling hole groups on the plurality of third punching sheets 14 are stacked to form an axial cooling oil passage. The plurality of groups of cooling hole groups are respectively in corresponding communication with the oil guiding grooves and the closed rectangular oil grooves 10 on the first punching sheet 5. In this technical solution, the cooling oil flows upward in the radial direction along the adjacent slots. After gathering in the area of the closed rectangular oil grooves, it then flows axially along the cooling hole groups corresponding to the yoke portion of the third punching sheet towards the end of the stator, and finally sprays out from the end face of the stator to cool the end windings.

[0056] Further, each group of cooling hole groups includes three cooling holes 15, and the three cooling holes 15 are arranged corresponding to two stator slots 1. In this technical solution, there are 3 oil passages corresponding to each group of two slots; they are periodically distributed in the circumferential direction, and enough space is reserved between adjacent yoke oil passage groups for uses such as weld seams and positioning slots, making the magnetic circuit more symmetrical.

[0057] As Figure 4 , 13 and Figure 14 show, the plurality of stator punching sheets include a group of notch cooling punching sheet group 3 and two groups of axial cooling punching sheet groups 4 symmetrically clamped on both sides of the notch cooling punching sheet group 3. This case is the first solution, which is a schematic diagram of setting the notch cooling punching sheet group at the axial middle position of the stator core. As Figure 15 and 16 show, the plurality of stator punching sheets include a plurality of groups of notch cooling punching sheet groups 3 and a plurality of groups of axial cooling punching sheet groups 4 stacked alternately. In this technical solution, this case is the second solution, which is a schematic diagram of setting the notch cooling punching sheet group at the 1 / 4, 1 / 2, and 3 / 4 positions of the axial direction of the stator core. The axially symmetrical oil circuit design in the front and back ensures that the front and back axial iron cores are evenly cooled by the cooling oil, making the overall temperature of the whole machine stator side more balanced and avoiding local overheating points. The combination of the punching sheets 1 - 2 - 1 for notch cooling can be modularized into a "notch cooling punching sheet group". According to boundary differences such as different stack thicknesses and temperature reduction requirements, multiple "notch cooling punching sheet groups" can be set in the axial length, with a wide range of applications.

[0058] Further, the axial thickness of the first punching sheet 5 and the second punching sheet 6 is less than or equal to 3 mm, and the first punching sheet 5 and the second punching sheet 6 are made of silicon steel sheets or amorphous materials or SMC materials. In this technical solution, it is process - friendly, with low cost and low deterioration of electromagnetic performance: the axial thicknesses of both the first punching sheet and the second punching sheet are ≤3 mm, ensuring that the axial thickness of the combined overall notch cooling component is ≤9 mm, accounting for a proportion of the entire stack thickness dimension <10%; the materials of the first punching sheet and the second punching sheet can be traditional silicon steel sheets, or amorphous or SMC materials with lower iron loss.

[0059] As Figure 18As shown, the motor temperature field distribution of the traditional oil circuit scheme based on the simulation of the 16150 rpm 80 kW continuous operating point of a certain project is as follows Figure 19 As shown, compared with the traditional oil circuit scheme, the highest temperature at the slot and slot opening in this scheme drops by about 15°C, which is a significant decrease. The temperature on the stator side of the whole machine is more balanced and reasonable as a whole, proving that this scheme can play a good role in improving the temperature inside the slot. Embodiment 2:

[0060] As Figure 3 A flat wire motor with circumferential oil cooling as shown, includes a motor housing 16 and a stator structure in Embodiment 1. A plurality of oil inlet holes 17 corresponding to and communicating with the open oil grooves 7 are circumferentially provided on the motor housing 16. The external interface of the oil circuit is flexible, and the oil inlet holes can be set at any position.

[0061] Aiming at the problem that the existing stator oil cooling scheme still cannot solve the high-temperature risk of the conductors in the stator slot, especially near the slot opening, on the basis of not sacrificing the overall performance of the motor, by setting a slot opening cooling punching sheet group in the circumferential direction at the middle position of the winding axis or at the 1 / 4, 1 / 2, 3 / 4 positions of the axis, it can specifically cool the middle position of the slot and slot opening in the axial direction of the winding - an area that is difficult to cover by the current oil cooling scheme, to achieve refined and targeted cooling, and to maximize the shortening of the heat transfer path of the winding slot opening, near the air gap and other areas to the cooling oil, and improve the heat dissipation efficiency. Especially for the axial slot conductors (the hottest area of the whole machine under high-speed operating conditions) - the oil cooling efficiency is significantly improved, and the temperature rise is significantly improved.

[0062] At the same time, compared with the existing cooling schemes, this scheme does not occupy the effective area in the slot, has the least impact on the stator tooth-slot shape, sacrifices the least electromagnetic performance, and maximally meets the overall performance requirements of the vehicle for power, endurance, etc.

[0063] 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.

[0064] There are only 3 types of stator punching sheet shapes, with few sheet shapes. 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 process-friendly and there is no need to worry about blocking the oil duct during dipping paint, etc. The oil inlet component in the middle of the iron core can also be processed with soft magnetic materials such as SMC. In addition, the oil duct has a small flow resistance, a small burden on the oil pump, and a high oil circuit balance.

[0065] 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 can be combined in a suitable manner in any one or more embodiments or examples.

[0066] 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 plurality of stator teeth being circumferentially arranged on the inner wall of the stator core (100), a stator slot (1) for installing a hairpin conductor being formed between adjacent stator teeth, a stator cooling oil passage being arranged on the stator core (100), ears (2) being formed on both sides of the top of the stator teeth, a notch of the stator slot (1) being formed between the opposite ears (2), characterized in that: The plurality of stator punching sheets comprises at least one stacked group of slot cooling punching sheets (3) and at least two groups of axial cooling punching sheets (4); at least one group of slot cooling punching sheets (3) is arranged in the middle of the stator core (100), and the slot cooling punching sheet group (3) comprises first punching sheets (5) on both sides and second punching sheets (6) sandwiched between the first punching sheets (5) on both sides; The stator cooling oil circuit comprises an open oil groove (7) and an oil guide groove; the oil guide groove is radially arranged on the first stator teeth (9) arranged at intervals on the first punching plate (5); the oil guide groove comprises a first oil guide groove (8), the radial outer side of which is connected to the open oil groove (7), the open oil groove (7) is constructed inwardly from the edge of the yoke of the first punching plate (5), and the radial inner side of the first oil guide groove (8) extends close to the tooth top of the first stator tooth (9).

2. A stator structure according to claim 1, characterized in that: The stator cooling oil circuit further comprises a closed rectangular oil groove (10), and the oil guide groove further comprises a second oil guide groove (11), the radial outer side of which is connected to the closed rectangular oil groove (10), and the closed rectangular oil groove (10) is connected to the open oil groove (7).

3. A stator structure according to claim 2, characterized in that: In the two first punching sheets (5) of the slot cooling punching sheet group (3), the open oil groove (7) of one of the punching sheets is arranged correspondingly to the closed rectangular oil groove (10) of the other punching sheet, so that the first oil guide groove (8) and the second oil guide groove (11) of the two first punching sheets (5) correspond to each other up and down; and an oil guide hole (13) axially communicating with the upper and lower oil guide grooves is constructed at the inner end of the second stator tooth (12) on the second punching sheet (6) corresponding to the oil guide groove.

4. A stator structure according to claim 3, characterized in that: The inner end of the oil guide groove extends to the ears (2) on both sides of the first stator tooth (9), and the oil guide hole (13) is trapezoidal in shape and has the same shape as the inner end of the oil guide groove.

5. A stator structure according to claim 3, characterized in that: The stator cooling oil circuit also includes an axial cooling oil passage, the axial cooling punching plate group (4) includes a plurality of stacked third punching plates (14), a plurality of cooling hole groups are regularly arranged circumferentially on the yoke of the third punching plate (14), the plurality of cooling hole groups on the plurality of third punching plates (14) are stacked to form the axial cooling oil passage, and the plurality of cooling hole groups are respectively connected to the oil guide groove and the closed rectangular oil groove (10) on the first punching plate (5).

6. A stator structure according to claim 5, characterized in that: Each cooling hole group comprises three cooling holes (15), and the three cooling holes (15) are arranged corresponding to the two stator slots (1).

7. A stator structure according to claim 1, characterized in that: The multiple stator punching sheets comprise a group of slot cooling punching sheets (3) and two groups of axial cooling punching sheets (4) symmetrically clamped on both sides of the slot cooling punching sheet group (3).

8. A stator structure according to claim 1, characterized in that: The multiple stator punching sheets include multiple groups of slot cooling punching sheet groups (3) and multiple groups of axial cooling punching sheet groups (4) that are alternately stacked.

9. A stator structure according to claim 7 or 8, characterized in that: The axial thickness of the first punching sheet (5) and the second punching sheet (6) is less than or equal to 3 mm, and the first punching sheet (5) and the second punching sheet (6) are made of silicon steel sheets or amorphous materials or SMC materials.

10. A circumferential oil-cooled flat wire motor, comprising a housing (16), 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 (17) corresponding to and communicating with the open oil grooves (7) are circumferentially opened on the casing (16).

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