An electric machine and power system

Abstract

The utility model relates to a kind of motor and power system, motor includes stator core, winding and liquid inlet piece, the inner wall of stator core is opened with multiple stator slots along axial direction;Winding is set in stator slot, winding includes multiple flat copper wire, flat copper wire is hollow inside and forms cooling cavity;Flat copper wire has first structure and second structure located outside stator core and respectively extends the axial both ends of stator core, first structure is opened with first liquid guide hole, second structure is opened with second liquid guide hole;Liquid inlet piece is set to the side of one end of stator core and encloses first cavity, first cavity is opened with liquid inlet;Liquid inlet, first cavity, first liquid guide hole, cooling cavity and second liquid guide hole are sequentially communicated.Using the scheme, through the cooperation setting of hollow flat copper wire and first cavity, flowing coolant can cover the length direction of entire winding, that is, the uniform cooling of winding is realized, and the stability of cooling process is ensured.

Description

Technical Field

[0001] This utility model relates to the field of motor cooling technology, and in particular to a motor and power system. Background Technology

[0002] In the field of thermal management of electric motors in new energy vehicles, motor cooling and heat dissipation is one of the important issues in motor design. As the main heat-generating component of the motor stator, if the stator winding cannot be cooled in a timely and effective manner, it will lead to excessively high winding temperature, which in turn will cause short circuit faults caused by insulation damage; increased copper wire resistance leading to decreased motor efficiency; and accelerated aging of components, thus shortening the motor life.

[0003] Commonly used cooling methods for windings include oil spraying and slot cooling (grooving along the length of the copper wire surface). Oil spraying has the problem of uneven cooling of the motor stator windings, while slot cooling can improve the problem of uneven cooling, but this method will bring problems such as oil leakage risk. Utility Model Content

[0004] Based on this, an electric motor and power system are provided to solve the problems of uneven cooling of flat wires or easy oil leakage during cooling in the prior art.

[0005] On the one hand, this utility model provides an electric motor, which includes: The stator core has multiple stator slots axially formed on its inner wall. The winding, located in the stator slot, includes multiple flat copper wires, the flat copper wires being hollow inside and forming a cooling cavity; the flat copper wires have a first structure and a second structure located outside the stator core and extending out of both ends of the stator core axially, the first structure having a first liquid guiding hole and the second structure having a second liquid guiding hole. A liquid inlet is provided at one end of the stator core along the axial direction and forms a first cavity, wherein the first cavity has a liquid inlet. The portion of the first structure with the first liquid guiding hole is housed within the first cavity, thereby connecting the liquid inlet, the first cavity, the first liquid guiding hole, the cooling cavity, and the second liquid guiding hole in sequence.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] In one implementation, the first structure is divided into a connecting part and a liquid guiding part along its length. The liquid inlet covers the outer periphery of the connecting part, and the first liquid guiding hole is opened in the liquid guiding part. The liquid guiding part is housed in the first cavity.

[0008] In one implementation, the first cavity is annular.

[0009] In one implementation, the axial length of the connecting part is not less than the axial length of the liquid guiding part.

[0010] In one implementation, the motor also includes: The housing surrounds the stator core, and its inner wall, together with the liquid inlet, forms the first cavity.

[0011] In one implementation, the liquid inlet is an injection-molded part, and is connected to the connecting part and the housing as a whole through injection molding; The liquid inlet is annular and includes a first wall and a second wall connected together. The first wall extends radially and covers the outer periphery of the connecting part. The second wall extends in a direction parallel to the axial axis. The outer peripheral surface of the first wall is connected to the housing, and the end of the second wall away from the first wall is connected to the housing.

[0012] In one implementation, the outer wall of the housing is provided with a protruding connecting pipe, and the liquid inlet passes through the connecting pipe and communicates with the first cavity.

[0013] In one implementation, the first liquid guiding hole is opened in the width direction of the liquid guiding portion, and / or at the end of the liquid guiding portion.

[0014] In one implementation, the flat copper wire is a U-shaped hairpin coil, each flat copper wire including a second structure disposed at the bottom of the U-shape and two first structures disposed on both sides of the top of the U-shape.

[0015] On the other hand, this utility model also provides a power system, including an electric motor.

[0016] The beneficial effects of this utility model are as follows: This solution sets the interior of the flat copper wire as a hollow cooling cavity, and opens a first liquid guiding hole and a second liquid guiding hole at both ends of the flat copper wire extending from the stator core, respectively, forming a complete channel for the coolant to enter and exit the flat copper wire. The flowing coolant can fully cool the winding, achieving uniform cooling of the winding. At the same time, a liquid inlet is set at one end of the stator core and forms a first cavity. After the coolant is introduced into the first cavity through the liquid inlet, it flows through the first liquid guiding hole, the cooling cavity and the second liquid guiding hole in sequence with the help of hydraulic pressure, forming a complete cooling circuit. In summary, this solution, through the combined setting of the hollow flat copper wire and the first cavity, allows the flowing coolant to cover the entire length of the winding, thus achieving uniform cooling of the winding and ensuring the stability of the cooling process.

[0017] In addition, the hollow flat copper wire used in this solution has excellent sealing performance, and the first cavity is located outside the stator core, which avoids the risk of oil leakage inside the stator core caused by opening oil guide grooves in the length direction of the flat copper wire in the prior art, and further improves the reliability of the overall structure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the axial cross-sectional structure of the motor in one embodiment; Figure 2 for Figure 1 A magnified schematic diagram of the partial structure at point A in the middle; Figure 3 This is a partial structural diagram of the motor in one embodiment; Figure 4 This is a partial structural diagram of the motor in another embodiment; Figure 5 This is a schematic diagram of the connection structure between the flat copper wire and the stator core in one embodiment; Figure 6 This is a schematic diagram of the structure of the flat copper wire in one embodiment; Figure 7 This is a partial structural diagram of the second structure in one embodiment; Figure 8 This is a partial structural diagram of the first structure in one embodiment.

[0019] In the attached diagram, the components represented by each number are as follows: 1. Stator core; 11. Stator slot; 2. Flat copper wire; 21. First structure; 211. First liquid guiding hole; 212. Connecting part; 213. Liquid guiding part; 22. Second structure; 221. Second liquid guiding hole; 3. Liquid inlet; 31. First wall; 32. Second wall; 41. First cavity; 42. Liquid inlet; 5. Shell; 51. Connecting pipe section. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit its scope. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show components relevant to this utility model and are not drawn according to the actual number, shape, and size of the components. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. The structures, proportions, sizes, etc., depicted in the accompanying drawings are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed in this utility model.

[0021] A type of motor, see Figure 1 and Figure 3 The motor includes a stator core 1, windings, and a liquid inlet 3. The inner wall of the stator core 1 has multiple stator slots 11 along the axial direction. The windings are disposed in the stator slots 11 and include multiple flat copper wires 2. The flat copper wires 2 are hollow inside and form a cooling cavity. The flat copper wires 2 have a first structure 21 and a second structure 22 located outside the stator core 1 and extending to both ends of the stator core 1 along the axial direction. The first structure 21 has a first liquid guide hole 211 and the second structure 22 has a second liquid guide hole 221. The liquid inlet 3 is disposed at one end of the stator core 1 along the axial direction and forms a first cavity 41. The first cavity 41 has a liquid inlet 42. The portion of the first structure 21 with the first liquid guide hole 211 is housed in the first cavity 41, so that the liquid inlet 42, the first cavity 41, the first liquid guide hole 211, the cooling cavity, and the second liquid guide hole 221 are sequentially connected.

[0022] This solution incorporates a hollow cooling cavity within the flat copper wire 2. A first liquid guide hole 211 and a second liquid guide hole 221 are respectively opened at both ends of the flat copper wire 2 extending from the stator core 1, forming a complete channel for coolant entry and exit from the flat copper wire 2. This allows for sufficient and uniform cooling of the windings through the flowing coolant. Simultaneously, a liquid inlet 3 is installed at one end of the stator core 1, forming a first cavity 41. After the coolant is introduced into the first cavity 41 through the inlet 42, it flows sequentially through the first liquid guide hole 211, the cooling cavity, and the second liquid guide hole 221 using hydraulic pressure, forming a complete cooling circuit. In summary, this solution, through the combined arrangement of the hollow flat copper wire 2 and the first cavity 41, allows the flowing coolant to cover the entire length of the winding, achieving both uniform cooling and ensuring the stability of the cooling process. In addition, the hollow flat copper wire 2 used in this solution has excellent sealing performance, and the first cavity 41 is located outside the stator core 1, which avoids the risk of oil leakage inside the stator core 1 caused by opening an oil guide groove in the length direction of the flat copper wire 2 in the prior art, and further improves the reliability of the overall structure.

[0023] For details, see Figure 1 and Figure 2 This solution features a first cavity 41 through which coolant is introduced into the flat copper wire 2. This provides the following technical advantages: First liquid guide holes 211 are located within the first cavity 41, creating a concentrated liquid guide area. This allows for the introduction of coolant into one or more flat copper wires 2 without requiring precise alignment of the first liquid guide holes 211 on each wire, simplifying the setup and assembly complexity. The first cavity 41 also effectively buffers pressure fluctuations during coolant introduction. Its large volume ensures a balanced coolant flow, guaranteeing that coolant enters the cooling chamber of each flat copper wire 2 at a stable pressure and flow rate, preventing uneven cooling due to insufficient coolant supply to a single wire. Furthermore, the closed structure of the first cavity 41 prevents coolant leakage or splashing during introduction into the flat copper wire 2, providing a reliable pre-conditioning for the complete cooling circuit flowing through the first liquid guide hole 211, the cooling chamber, and the second liquid guide hole 221.

[0024] In some embodiments, see Figure 1 and Figure 2The first structure 21 is divided into a connecting portion 212 and a liquid guiding portion 213 along its length. The liquid inlet 3 covers the outer periphery of the connecting portion 212, and the first liquid guiding hole 211 is opened in the liquid guiding portion 213. The liquid guiding portion 213 is housed within the first cavity 41. Thus, the first structure 21 is divided into two parts. The liquid guiding portion 213 is disposed within the first cavity 41 to facilitate communication between the first liquid guiding hole 211 and the first cavity 41. The outer periphery of the connecting portion 212 is covered by the liquid inlet 3 to achieve a complete seal between the first cavity 41 and the connection structure of the flat copper wire 2, thus preventing coolant leakage.

[0025] In some embodiments, see Figure 1 and Figure 4 The first cavity 41 is annular. In this way, the annular first cavity 41 matches the distribution structure of the windings on the stator core 1, which can effectively reduce the number of first cavities 41. For example, only one first cavity 41 can be set to connect to all the flat copper wires 2 of the windings. When the coolant is supplied to all the flat copper wires 2 through one first cavity 41, all the liquid guiding parts 213 of the entire motor are housed in the first cavity 41, resulting in a high degree of integration of the overall structure.

[0026] Specifically, the overall structural integration is highest when a first cavity 41 is set up. The first cavity 41 serves as a centralized liquid guiding area, supplying coolant to the first liquid guiding holes 211 on all the flat copper wires 2, effectively simplifying the design and assembly complexity of the liquid guiding structure. Due to the large volume of the first cavity 41, the coolant flow rate is low, the pressure distribution is uniform, and the size and number of the first liquid guiding holes 211 and second liquid guiding holes 221 on each flat copper wire 2 are identical, ensuring that the coolant flow rate through each flat copper wire 2 is the same. This means that the coolant uniformly cools each flat copper wire 2, thereby achieving uniform cooling of the entire winding.

[0027] In some embodiments, see Figure 1 and Figure 2 The axial length of the connecting portion 212 is not less than the axial length of the liquid guiding portion 213. In this way, as a structure enclosed by the liquid inlet 3, the length of the connecting portion 212 is limited to be not less than that of the liquid guiding portion 213, ensuring that the first structure 21 has a sufficiently long dimension to be enclosed, ensuring the sealing of the connection position between the connecting portion 212 and the liquid inlet 3, and avoiding leakage at the connection position.

[0028] In some embodiments, see Figure 1 and Figure 2The motor also includes a housing 5, which surrounds the stator core 1. The inner wall of the housing 5 and the liquid inlet 3 together form a first cavity 41. In this way, the housing 5 and the liquid inlet 3 together form the first cavity 41, so that the housing 5 also serves as the outer wall of the first cavity 41, thereby connecting the housing 5 with the liquid inlet 3 and providing support to improve the stability of the first cavity 41.

[0029] In some embodiments, see Figure 1 and Figure 2 The liquid inlet 3 is an injection-molded part, and it is connected to the connecting part 212 and the housing 5 as a whole through injection molding. In this way, the liquid inlet 3 is wrapped around the outer periphery of the connecting part 212 by injection molding, filling the tiny gaps between the connecting parts 212 and avoiding the problem of coolant leakage at the connection position between the connecting part 212 and the liquid inlet 3, thereby improving the sealing performance. The liquid inlet 3 is connected to the housing 5 by injection molding to form the first cavity 41. No additional connection structure is required between the liquid inlet 3 and the housing 5. The two form a stable connection structure through injection molding to ensure the sealing performance of the first cavity 41.

[0030] The liquid inlet 3 is annular and includes a first wall 31 and a second wall 32 connected together. The first wall 31 extends radially and covers the outer periphery of the connecting part 212. The second wall 32 extends in a direction parallel to the axial axis. The outer peripheral surface of the first wall 31 is connected to the housing 5. The end of the second wall 32 away from the first wall 31 is connected to the housing 5.

[0031] For details, see Figure 1 and Figure 4 The liquid inlet 3 has an annular structure and an L-shaped radial cross-section. The liquid inlet 3 forms two sides of the annular first cavity 41, and the shell 5 forms the other two sides of the annular first cavity 41.

[0032] Specifically, the liquid inlet component 3 is formed by injection molding. The injection molding material is usually polyamide (PA), polycarbonate (PC), or polyphenylene sulfide (PPS), which have properties such as high temperature resistance up to 240℃ and electrical insulation. The liquid inlet component 3 acts as an injection-molded filler layer, wrapping the protruding ends of the flat copper wires 2, i.e., wrapping the connecting part 212. This fills the tiny gaps between the flat copper wires 2, effectively preventing short circuits between stator windings, improving the electrical safety of the motor; reducing loosening and displacement, improving structural stability; increasing the overall mechanical strength of the stator, making it more resistant to vibration and impact, and extending the motor's service life. In addition, it provides dust and water resistance, offering excellent sealing performance.

[0033] The liquid inlet component 3 is formed by injection molding using a specialized mold. The corresponding injection molding process is as follows: ① Pretreatment: The motor stator is preheated to remove moisture and impurities, ensuring insulation performance during injection molding. ② Injection mold preparation: The stator is placed into the injection mold, ensuring accurate positioning. ③ Injection: Molten plastic material is injected into the mold using an injection molding machine. ④ Cooling and solidification: The injection-molded stator is cooled and solidified in the mold, ensuring complete shaping of the plastic material. ⑤ Demolding and post-processing: The injection-molded stator is removed from the mold and undergoes post-processing steps such as trimming flash, inspection, and testing.

[0034] In some embodiments, see Figure 1 The outer wall of the housing 5 is provided with a protruding connecting pipe portion 51, and the liquid inlet 42 passes through the connecting pipe portion 51 and communicates with the first cavity 41. In this way, the connecting pipe portion 51 is provided to facilitate the connection of the coolant inlet pipe. For example, it can be connected to the connecting pipe portion 51 by means of a sleeve, thereby realizing the docking and fixation with the coolant inlet pipe.

[0035] Specifically, the connecting pipe portion 51 is disposed on the outer wall of the housing 5, and at least one connecting pipe portion 51 is provided; for example, the connecting pipe portion 51 can be one, two, or more.

[0036] In some embodiments, see Figure 8 The first liquid guiding hole 211 is opened in the width direction of the liquid guiding portion 213 and / or at the end of the liquid guiding portion 213. In this way, opening multiple first liquid guiding holes 211 can facilitate the efficiency of coolant entering the flat copper wire 2. For example, the first liquid guiding hole 211 can be opened in the width direction of the liquid guiding portion 213, or it can be opened at the end of the liquid guiding portion 213, or it can be opened in both the width direction and the end of the liquid guiding portion 213 at the same time. In addition, multiple first liquid guiding holes 211 opened in the width direction of the liquid guiding portion 213 can be provided, such as the first liquid guiding holes 211 at this position being evenly arranged along the length direction of the flat copper wire 2.

[0037] Specifically, each flat copper wire 2 is welded at its end. The first liquid guide hole 211 located at the end may be blocked by the solder joint due to different welding processes. In this case, the coolant can flow into the flat copper wire 2 from the first liquid guide hole 211 opened in the width direction of the liquid guide section 213.

[0038] Specifically, the coolant can be cooling oil.

[0039] For details, see Figure 6 and Figure 7 The second structure 22 has multiple second liquid guiding holes 221, such as two, three or more, to improve the efficiency of coolant outflow.

[0040] In some embodiments, see Figure 5 and Figure 6 The flat copper wire 2 is a U-shaped hairpin coil. Each flat copper wire 2 includes a second structure 22 disposed at the bottom of the U-shape and two first structures 21 disposed on both sides of the top of the U-shape. Thus, the U-shaped hairpin coil has first liquid guiding holes 211 respectively opened on the two first structures 21 on both sides of the top of the U-shape to introduce coolant, and a second liquid guiding hole 221 opened on the second structure 22 at the bottom of the U-shape to discharge coolant.

[0041] A power system includes an electric motor. The motor is cooled by a cooling structure, achieving uniform cooling of the motor stator.

[0042] This solution utilizes the injection-molded first cavity 41 to ensure its sealing performance. Combined with the hollow flat copper wires 2, it forms a cooling oil path, transforming each flat copper wire 2 into an independent oil flow channel. 1. The core cooling of the hollow flat copper wire 2 is more conducive to rotor heat dissipation than surface cooling such as end oil spraying, and the cooling effect is the best. 2. Each and every section of flat wire has cooling oil channels, which fundamentally solves the problem of uneven cooling of the stator winding; 3. The winding end on the oil outlet side is the area with the highest temperature. By placing the temperature sensor in this area, no additional safety margin is required when formulating the thermal management strategy, and the ultimate capacity of the motor can be explored. 4. The injection-molded filler layer combined with the hollow flat copper wire 2 forms an oil circuit, and a sealed structure is formed between the injection-molded filler layer and the shell 5, which is not affected by the flatness of the iron core end and has no risk of leakage; the hollow flat wire itself is a sealed oil circuit, which is not affected by stator cracking and has no risk of leakage; the entire oil circuit does not require a complex sealing design, the structure is simple and the reliability is high. 5. End winding injection molding improves the electrical safety, structural stability, and overall mechanical strength of the motor windings. It can replace the stator winding end coating process, making the motor more resistant to vibration and impact, and extending the motor's service life.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. In this utility model, unless otherwise explicitly specified and limited, the terms "installed," "connected," "joined," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two components or an interaction between two components, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0045] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electric motor, characterized in that, The motor includes: The stator core (1) has multiple stator slots (11) axially formed on its inner wall. The winding is disposed in the stator slot (11) and includes multiple flat copper wires (2). The flat copper wires (2) are hollow inside and form a cooling cavity. The flat copper wires (2) have a first structure (21) and a second structure (22) located outside the stator core (1) and extending out of the two ends of the stator core (1) respectively. The first structure (21) has a first liquid guiding hole (211) and the second structure (22) has a second liquid guiding hole (221). The liquid inlet (3) is disposed at one end of the stator core (1) along the axial direction and forms a first cavity (41), wherein the first cavity (41) is provided with a liquid inlet (42). The portion of the first structure (21) with the first liquid guiding hole (211) is housed within the first cavity (41), such that the liquid inlet (42), the first cavity (41), the first liquid guiding hole (211), the cooling cavity, and the second liquid guiding hole (221) are sequentially connected.

2. The motor according to claim 1, characterized in that, The first structure (21) is divided into a connecting part (212) and a liquid guiding part (213) along the length direction. The liquid inlet (3) covers the outer periphery of the connecting part (212). The first liquid guiding hole (211) is opened in the liquid guiding part (213). The liquid guiding part (213) is housed in the first cavity (41).

3. The motor according to claim 2, characterized in that, The first cavity (41) is annular.

4. The motor according to claim 2, characterized in that, The length of the connecting part (212) in the axial direction is not less than the length of the liquid guiding part (213) in the axial direction.

5. The motor according to claim 2, characterized in that, The motor also includes: The housing (5) surrounds the stator core (1), and its inner wall together with the liquid inlet (3) forms the first cavity (41).

6. The motor according to claim 5, characterized in that, The liquid inlet (3) is an injection molded part, and is connected to the connecting part (212) and the housing (5) as a whole through injection molding; The liquid inlet (3) is annular and includes a first wall (31) and a second wall (32) connected together. The first wall (31) extends radially and covers the outer periphery of the connecting part (212). The second wall (32) extends in a direction parallel to the axial axis. The outer peripheral surface of the first wall (31) is connected to the housing (5). The end of the second wall (32) away from the first wall (31) is connected to the housing (5).

7. The motor according to claim 5, characterized in that, The outer wall of the housing (5) is provided with a protruding connecting pipe (51), and the liquid inlet (42) passes through the connecting pipe (51) and communicates with the first cavity (41).

8. The motor according to claim 2, characterized in that, The first liquid guiding hole (211) is opened in the width direction of the liquid guiding part (213) and / or at the end of the liquid guiding part (213).

9. The motor according to claim 1, characterized in that, The flat copper wire (2) is a U-shaped hairpin coil, and each flat copper wire (2) includes a second structure (22) disposed at the bottom of the U-shape and two first structures (21) disposed on both sides of the top of the U-shape.

10. A power system, characterized in that, Includes the motor as described in any one of claims 1 to 9.

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