Cooling structure of segmented stator core and flat wire motor

Abstract

The utility model relates to a cooling structure of a segmented stator core and a flat wire motor, the cooling structure comprises a stator core, the stator core comprises at least two segments including a first iron core segment and a second iron core segment, a gap is left between the first iron core segment and the second iron core segment, and the first iron core segment and the second iron core segment are arranged in parallel. The stator slots on the first iron core section and the second iron core section are open slots and are formed by enclosing two adjacent stator teeth, two sides of one end, close to the rotor, of each stator tooth are respectively provided with a convex block, and each convex block is provided with a notch and shoulder oil duct hole. According to the utility model, the absolute value of AC copper loss is reduced; meanwhile, a groove shoulder area is secondarily utilized, an oil duct hole is designed, the temperature of a groove opening conductor is further reduced from the heat dissipation angle due to the fact that a cooling medium is close to a heating source, the oil duct is close to an air gap and is also close to a permanent magnet on the rotor side, the heat transfer path is short, a good cooling effect on the permanent magnet is achieved, and the high-temperature demagnetization risk of the permanent magnet is greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and more specifically to a cooling structure of a segmented stator core and a flat wire motor. Background Art

[0002] Permanent magnet synchronous motors for new energy vehicles are currently developing towards higher torque power density and higher speed. With the promotion and application of high-voltage silicon carbide power devices, automotive motors are also gradually developing towards high voltage. The above trends have put forward higher requirements on the performance, safety, cost and other aspects of the design of automotive drive motors.

[0003] At present, more and more flat wire motors are used in the domestic new energy vehicle industry. Compared with conventional circular windings, the most notable feature of flat wire windings is that the pure copper slot full rate is higher, the DC resistance and copper loss are reduced, and the winding wire layout is more balanced and symmetrical, which has higher requirements for design and process. Existing automotive drive oil-cooled motors pay more attention to the cooling of the winding ends. Combined with the design of the stator core oil channel, it can certainly improve the balance of motor winding cooling as a whole, and achieve a relatively balanced temperature distribution of the end winding and the winding in the slot. However, from the perspective of improving the output power density, the high-speed of flat wire motors has received more and more attention. One adverse effect of high speed is that the high-frequency AC skin effect of the winding is very prominent, resulting in a high proportion of AC copper loss in the slot conductor at high speed, and the copper loss distribution in the slot is extremely uneven. The corresponding slot conductor has a higher temperature under high speed conditions, and the existing oil cooling method cannot effectively cool this area, resulting in the existence of high temperature risk points. Utility Model Content

[0004] In order to solve the above technical problems, the purpose of the utility model is to provide a cooling structure for a segmented stator core, which can have a good cooling effect on the winding conductors on both sides of the motor air gap and the rotor permanent magnets, and the risks of local overheating of the slot conductors and high-temperature demagnetization of the permanent magnets are greatly reduced.

[0005] In order to achieve the above first utility model purpose, the utility model adopts the following technical solutions:

[0006] A cooling structure for a segmented stator core comprises a stator core, wherein the stator core is at least two sections, including a first core section and a second core section, a gap is left between the first core section and the second core section, stator slots on the first core section and the second core section are open slots, formed by enclosing two adjacent stator teeth, protrusions are respectively provided on both sides of one end of the stator tooth close to a rotor, and the protrusions are provided with slot shoulder oil passage holes.

[0007] As a preferred solution, one end of the stator slot away from the stator core yoke is formed into a funnel-shaped closing structure.

[0008] As a preferred solution, the cross-sectional shape of the notch shoulder oil channel hole is circular, diamond-shaped or rectangular.

[0009] As a preferred solution, the width of the gap between the first core segment and the second core segment is 8-10 mm.

[0010] As a preferred solution, the inner sides of the first core segment and the second core segment are connected via a middle sealing ring.

[0011] As a preferred solution, the middle sealing ring comprises a ring body, at least one side of which is provided with a fixing protrusion for plugging into an opening of a stator slot of the first core segment or the second core segment.

[0012] In order to achieve the above second utility model purpose, the utility model adopts the following technical solutions:

[0013] A flat wire motor comprises a casing, a rotor assembly and a stator assembly, wherein the stator assembly is fixed on the inner side of the casing, the rotor assembly is arranged on the inner side of the stator assembly and is rotatably connected to the casing at both ends, and the stator assembly adopts the cooling structure described in any one of the first four items above.

[0014] A flat wire motor comprises a casing, a rotor assembly and a stator assembly, wherein the stator assembly is fixed on the inner side of the casing, the rotor assembly is arranged on the inner side of the stator assembly and is rotatably connected to the casing at both ends, the stator assembly adopts the cooling structure described in any one of the last two items above, and the middle sealing ring, the inner wall of the casing, the opposite ends of the first core segment and the second core segment form a middle cooling area, and the casing is also provided with a through hole for the entry and exit of cooling liquid.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The utility model improves the geometric dimensions of the stator slot height, so that the slot conductor is far away from the air gap, reducing the absolute value of AC copper loss from the perspective of heat generation. Secondly, the slot becomes higher and the slot shoulder space is larger. From the perspective of reducing magnetic leakage and reducing performance loss, the slot shoulder area is "re-utilized" and the oil channel hole is designed. Since the cooling medium is close to the heat source, the temperature of the slot conductor is further reduced from the perspective of heat dissipation. At the same time, since the oil channel is close to the air gap and the permanent magnet on the rotor side, the heat transfer path is short, and the permanent magnet has a good cooling effect, which greatly reduces the risk of high-temperature demagnetization of the permanent magnet. The structure of the utility model is relatively simple to implement and has little impact on design and production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0019] Figure 2 , Figure 3 and Figure 4 They are schematic diagrams of the structures of three different shapes of slot shoulder oil passage oil holes on the stator core of the utility model;

[0020] Figure 5 It is a schematic diagram of the motor structure and the oil channel cooling path of the utility model. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more, unless otherwise clearly defined.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0028] like Figure 1 and Figure 5 As shown, a flat wire motor includes a housing 12, a rotor assembly and a stator assembly, wherein the stator assembly is fixed on the inner side of the housing 12, the rotor assembly is arranged on the inner side of the stator assembly, and both ends are rotatably connected to the housing 12, the rotor assembly includes a rotating shaft 15 and a rotor core 14, the stator assembly includes a stator core and a flat wire winding inserted in a stator slot 10 of the stator core, the stator core is at least two sections, including a first core section 3 and a second core section 5, a gap 13 is left between the first core section 3 and the second core section 5, and the width of the gap 13 is 8 to 10 mm.

[0029] The inner sides of the first core segment 3 and the second core segment 5 are connected by a middle sealing ring 4, and the middle sealing ring 4 includes a ring body, and at least one side of the ring body is provided with a fixing protrusion for plugging into the stator slot opening of the stator core. The middle sealing ring can prevent cooling oil from entering the rotor, thereby affecting the performance of the motor; the middle sealing ring 4, the inner wall of the housing 12, and the opposite ends of the first core segment 3 and the second core segment 5 form a middle cooling area, and the housing 12 is also provided with a through hole for the coolant to enter and exit;

[0030] like Figures 2 to 4As shown, the stator slots 10 on the first core segment 3 and the second core segment 5 are open slots, formed by two adjacent stator teeth, and the end of the stator slot 10 away from the stator core yoke 8 is a funnel-shaped closing structure. The two sides of the stator tooth close to the rotor end are respectively provided with protrusions, and the protrusions are provided with slot shoulder oil passage holes 11; the cross-sectional shape of the slot shoulder oil passage hole 11 is circular, rhombus or rectangular.

[0031] In the utility model, one stator tooth corresponds to two oil passage holes, which vary according to the number of stator slots. The design of the slot shoulder oil passage has a good cooling effect on the winding conductors on both sides of the motor air gap and the rotor permanent magnets, and the risks of local overheating of the slot conductor and high-temperature demagnetization of the permanent magnet are greatly reduced.

[0032] The cooling structure of the motor in the utility model is that the oil enters the middle of the stator core and flows out to the front and rear core ends, and the cooling path of the oil outlet hole is respectively arranged at the lower part of the front and rear end space. The above structure has obvious advantages. First, the geometric dimensions of the stator slot height are improved, so that the slot conductor is far away from the air gap, and the absolute value of the AC copper loss is reduced from the perspective of heat generation. Secondly, the slot becomes higher and the slot shoulder space is larger. From the perspective of reducing magnetic leakage and reducing performance loss, the slot shoulder area is "reused" and designed into a circular, diamond or rectangular oil channel hole. Since the cooling medium is close to the heat source, the temperature of the slot conductor is further reduced from the perspective of heat dissipation. At the same time, since the oil channel is close to the air gap and is also close to the permanent magnet on the rotor side, the heat transfer path is short, and the permanent magnet has a good cooling effect, and the risk of high-temperature demagnetization of the permanent magnet is greatly reduced. Finally, combined with other existing mainstream stator core oil channels, end winding oil injection designs, etc., different oil channel series and parallel forms can be realized, and the temperature distribution of the stator winding without dead angles can be fully realized. Balanced and controllable.

[0033] The utility model has a significant cooling effect on areas that are difficult to cool with traditional oil cooling methods, such as winding conductors and permanent magnets on both sides of the air gap, making the temperature field distribution of the motor more balanced, reasonable and controllable within the full operating range, and the overall structure is relatively simple to implement, with little impact on design and production. In general, it is a new oil-cooled flat wire motor design that takes into account both performance and cost.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0035] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A cooling structure for a segmented stator core, comprising a stator core (200), characterized in that: The stator core (200) is at least composed of two sections, including a first core section (3) and a second core section (5); a gap (13) is left between the first core section (3) and the second core section (5); the stator slots (10) on the first core section (3) and the second core section (5) are open slots formed by enclosing two adjacent stator teeth; protrusions are respectively provided on both sides of one end of the stator teeth close to the rotor; and the protrusions are provided with slot shoulder oil passage holes (11).

2. The cooling structure of a segmented stator core according to claim 1, characterized in that: One end of the stator slot (10) away from the stator core yoke (8) is in a funnel-shaped closing structure.

3. The cooling structure of a segmented stator core according to claim 1, characterized in that: The cross-sectional shape of the notch shoulder oil passage hole (11) is circular, rhombus or rectangular.

4. The cooling structure of a segmented stator core according to claim 1, characterized in that: The width of the gap (13) between the first core segment (3) and the second core segment (5) is 8 to 10 mm.

5. The cooling structure of a segmented stator core according to claim 1, characterized in that: The inner sides of the first core segment (3) and the second core segment (5) are connected via a middle sealing ring (4).

6. A cooling structure for a segmented stator core according to claim 5, characterized in that: The middle sealing ring (4) comprises a ring body, at least one side of which is provided with a fixing protrusion for plugging into the opening of the stator slot (10) of the first core segment (3) or the second core segment (5).

7. A flat wire motor, comprising a housing (12), a rotor assembly and a stator assembly, wherein the stator assembly is fixed to the inner side of the housing (12), the rotor assembly is arranged on the inner side of the stator assembly, and both ends are rotatably connected to the housing (12), and the stator assembly adopts the cooling structure as described in any one of claims 1 to 4.

8. A flat wire motor, comprising a housing (12), a rotor assembly and a stator assembly, wherein the stator assembly is fixed on the inner side of the housing (12), the rotor assembly is arranged on the inner side of the stator assembly, and both ends are rotatably connected to the housing (12), the stator assembly adopts the cooling structure as described in claim 5 or 6, and the middle sealing ring (4), the inner wall of the housing (12), the first core segment (3) and the opposite ends of the second core segment (5) form a middle cooling area, and the housing (12) is also provided with a through hole for the entry and exit of cooling liquid.

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