Motor stator cooling oil circuit structure

Abstract

The utility model provides a motor stator cooling oil circuit structure, including the stator core who is stacked by multiple groups of stator punching sheet group pressure, the inside of stator core is provided with the cooling oil circuit of axial extension, the cooling oil circuit includes the axial oil hole formed on the stator punching sheet group, and the annular oil groove formed on at least partial stator punching sheet group, the axial oil hole and annular oil groove intercommunication to constitute integrated oil circuit passage for cooling medium flow. This structure not only effectively conquers the industry pain point of uneven cooling, high cost and poor reliability in the prior art, but also realizes the precise regulation and control of cooling performance through the detail design of step structure, brings the significant improvement of cooling uniformity, temperature rise control and overall energy efficiency, provides a simple, efficient and reliable solution for the thermal management of high power density motor, and has very high industrial application value.

Description

Technical Field

[0001] This utility model relates to the field of motor cooling technology, specifically to a motor stator cooling oil circuit structure. Background Technology

[0002] In today's industrial and transportation sectors, electric motors, as core power components, are crucial for their performance and reliability. During high-speed rotation, the heat source of an electric motor is primarily concentrated in the stator and rotor windings and core. These components generate a significant amount of heat during operation, and prolonged exposure to high temperatures can severely impact and reduce the motor's efficiency and lifespan. In fact, the efficiency limit of an electric motor is typically constrained by its thermal limit. Through superior heat dissipation technology, the power density and torque density of a motor within the same size can be significantly improved, thereby enhancing its performance and lifespan.

[0003] With the promotion and application of new energy vehicles, their motor cooling technology is developing rapidly. Currently, there are two main types of motor stator cooling methods, but both have certain technical drawbacks. On the one hand, some cooling methods achieve this by adding oil pipes for localized spraying. For example... Figure 1 As shown, this cooling method has the following problems: First, the limited cooling area leads to uneven cooling. Only the areas sprayed with oil nozzles have good cooling effects, while other areas have relatively poor cooling effects, especially the bottom of the motor where the temperature rise is high, which seriously affects the overall performance and service life of the motor; Second, this cooling method requires the addition of oil pipes, which undoubtedly increases costs and reduces the economic efficiency of the product.

[0004] On the other hand, for oil passage structures with axial oil passages, such as Figure 2 As shown, the current domestic method for improving the cooling of the coil at the iron core end is to add oil spray rings at both ends of the iron core. However, this cooling method also has obvious drawbacks. The fit between the oil spray ring and the iron core end is very precise; improper fit can easily lead to oil leakage. To solve the oil leakage problem, a rubber sealing structure needs to be added to the mating area between the oil spray ring and the iron core. This not only complicates the assembly process but also further increases costs and reduces the product's market competitiveness.

[0005] In summary, existing stator assembly cooling technologies suffer from poor cooling performance, high costs, and complex assembly, and urgently need improvement. Utility Model Content

[0006] Based on the above description, this utility model provides a motor stator cooling oil circuit structure to solve the technical problems of poor cooling effect, high cost and complicated assembly in the existing motor stator cooling methods.

[0007] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: This utility model provides a stator cooling oil circuit structure for an electric motor, including a stator core formed by stacking multiple sets of stator laminations; The stator core is provided with axially extending cooling oil passages inside; The cooling oil passage includes axial oil holes formed on the stator laminations and annular oil grooves formed on at least a portion of the stator laminations. The axial oil hole and the annular oil groove are interconnected to form an integrated oil passage for the flow of cooling medium.

[0008] As a further improvement of this utility model, the multiple sets of stator laminations include at least one set of first stator laminations and at least one set of second stator laminations. The first stator lamination group is formed by stacking first type stator laminations, and the first type stator laminations are provided with the axial oil holes; The second stator lamination group is formed by stacking second type stator laminations, and the second type stator laminations are also provided with the axial oil holes.

[0009] As a further improvement of this utility model, the multiple sets of stator laminations also include a third set of stator laminations; The third stator lamination group is formed by stacking third type stator laminations, and the third type stator laminations are provided with the annular oil groove; The axial oil hole of the second stator lamination group is connected to the annular oil groove of the third stator lamination group.

[0010] As a further improvement of this utility model, the axial oil holes on each stator lamination of the stator core are located at different positions in the radial direction, and the distances of any two adjacent axial oil holes from the center are different to form a step, thereby forming a stepped structure at the end of the cooling oil passage for adjusting the oil injection angle.

[0011] Preferably, the cross-sectional shape of the axial oil hole is square, circular, or elliptical.

[0012] As a further improvement of this utility model, the multiple sets of stator laminations are stacked in a rotational stacking manner.

[0013] Specifically, taking the first stator lamination group at one end as a reference, subsequent stator lamination groups are stacked in sequence with the adjacent stator lamination groups after rotating by a predetermined angle in the same direction, so that the axial oil holes are distributed in a non-linear manner in the circumferential direction.

[0014] When the stator lamination has three lugs, the predetermined angle is a multiple of 120 degrees; When the stator lamination has four lugs, the predetermined angle is a multiple of 90 degrees; When the stator lamination has no ears, the predetermined angle is a multiple of 360° / n, where n is the number of oil holes.

[0015] Specifically, when there are three lugs on the stator lamination, the predetermined angle is 0°, 120°, or -120°; When the stator lamination has four lugs, the predetermined angle is 0°, 90°, 180°, or -90°.

[0016] As a further improvement of this utility model, the axial oil holes are evenly distributed in the circumferential direction of the stator core.

[0017] Compared with the prior art, the motor stator cooling oil circuit structure provided by this utility model has the following beneficial technical effects: 1. High integration, reduced costs: The cooling oil circuit is directly integrated inside the stator core, eliminating the need for separate oil pipes and oil injection rings, which significantly reduces material and assembly costs.

[0018] 2. Uniform cooling and excellent performance: Axial oil channels are evenly distributed throughout the circumference of the entire iron core, with a large cooling area, ensuring that all parts of the stator winding can be effectively cooled, solving the problem of local overheating, and thus improving the performance of the motor.

[0019] 3. End cooling optimization: By changing the stepped structure formed by the cross-sectional area of ​​the oil hole, the angle and range of the end oil spray can be precisely adjusted, which effectively improves the cooling effect of the iron core end coil, a traditional cooling dead zone.

[0020] 4. High reliability: Compared to the oil injection ring structure which is prone to oil leakage, the integrated oil circuit structure of this invention is simple, has low sealing requirements, and is more reliable in operation. Furthermore, the end-effectors primarily rely on pressure injection, minimizing the impact of gravity and ensuring good cooling for the motor's bottom coils.

[0021] In summary, this invention innovatively integrates the cooling oil circuit into the stator core, rather than simply adding components. It optimizes the structure from its core, achieving a harmonious unity of "functional integration" and "performance enhancement." It effectively overcomes the industry pain points of uneven cooling, high cost, and poor reliability in existing technologies. Furthermore, through detailed designs such as the stepped structure, it achieves precise control of cooling performance. This structure ultimately leads to significant improvements in cooling uniformity, temperature rise control, and overall energy efficiency, providing a simple, efficient, and reliable solution for the thermal management of high-power-density motors, and possesses extremely high industrial application value. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a localized spray cooling structure in existing technology 1; Figure 2 This is a schematic diagram of the oil injection ring cooling structure of the prior art 2; Figure 3 This is a schematic diagram of the overall structure of the stator oil circuit provided in an embodiment of the present utility model; Figure 4 This is a schematic diagram of the oil circuit structure extracted from the stator core in an embodiment of this utility model; Figure 5 This is a simulation diagram of the spraying effect of the coil at the output end in an embodiment of this utility model; Figure 6 This is a simulation diagram of the spraying effect of the non-outgoing coil in an embodiment of this utility model; Figure 7 This is a structural diagram of the first type of stator lamination in the embodiments of this utility model; Figure 8 This is a structural diagram of the second type of stator lamination in the embodiments of this utility model; Figure 9 This is a structural diagram of the third type of stator lamination in the embodiments of this utility model; Figure 10 This is an overall structural diagram of the stator core in an embodiment of this utility model; Figure 11 This is a schematic diagram of the wireframe of the stator core in an embodiment of this utility model; Figure 12 This is an exploded view of the stator core in an embodiment of this utility model; Figure 13 This is a cross-sectional view of the stator core oil circuit structure in an embodiment of this utility model.

[0023] The numbers in the diagram are: 1. First type of stator lamination; 2. Second type of stator lamination; 3. Third type of stator lamination; 4. Stator core; 5. First stator lamination group-1; 6. Second stator lamination group-1; 7. Second stator lamination group-2; 8. Third stator lamination group; 9. Second stator lamination group-3; 10. Second stator lamination group-4; 11. First stator lamination group-2. Detailed Implementation

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "provided with" and "connected," etc., should be interpreted broadly. For example, "connected" 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 an indirect connection through an intermediate medium; it can also refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] Combination Figures 3 to 13 This embodiment provides a motor stator cooling oil circuit structure. The core of this structure is to highly integrate the cooling oil circuit inside the stator core, and achieve efficient and uniform cooling effect through specific lamination combination and stacking method.

[0027] The motor stator cooling oil circuit structure provided in this embodiment of the utility model is as follows: Figure 3 As shown, it includes a stator core formed by stacking multiple sets of stator laminations; the stator core has an axially extending cooling oil passage inside; the cooling oil passage includes axial oil holes formed on the stator laminations and annular oil grooves formed on at least a portion of the stator laminations; the axial oil holes and the annular oil grooves are interconnected to form an integrated oil passage channel for the flow of cooling medium.

[0028] Specifically, the multiple stator lamination groups include at least one first stator lamination group and at least one second stator lamination group.

[0029] The first stator lamination group (including the first stator lamination group-1 5 and the first stator lamination group-2 11) is formed by stacking the first type of stator lamination 1, and the first type of stator lamination 1 is provided with axial oil holes; the second stator lamination group (including the second stator lamination group-1 6; the second stator lamination group-2 7; the second stator lamination group-3 9; the second stator lamination group-4 10) is formed by stacking the second type of stator lamination 2, and the second type of stator lamination 2 is also provided with axial oil holes.

[0030] The cross-sectional shape of the axial oil hole is square, circular, or elliptical.

[0031] More specifically, such as Figure 7 As shown, the first type of stator lamination forms the axial end of the stator core. Its key structural feature is that multiple square axial oil holes are uniformly formed circumferentially on the lamination body. The main function of these oil holes is to form axial outlet channels for cooling oil.

[0032] The size of the square oil holes on the first type of stator lamination stacks (i.e., the first stator lamination stack-15 and the first stator lamination stack-211) located at both ends differs from the size of the oil holes in the inner lamination stacks, thus forming a stepped structure at the end of the oil circuit. This stepped structure is used to adjust the direction and scattering range of the cooling oil when it is sprayed out, which is the key to optimizing the cooling effect of the end coil.

[0033] like Figure 8 As shown, the second type of stator laminations constitutes the axial central body of the stator core. It also has square axial oil holes evenly distributed circumferentially, but the size of these oil holes differs from that of the first type of stator lamination 1. Multiple second-type stator laminations 2 are stacked to form multiple second-stator lamination groups (including second-stator lamination group-1 6, second-stator lamination group-2 7, second-stator lamination group-3 9, and second-stator lamination group-4 10). The axial oil holes on these lamination groups collectively constitute the main channel for the axial flow of cooling oil within the stator core.

[0034] Based on the above embodiments, the multiple stator lamination groups also include a third stator lamination group 8; the third stator lamination group 8 is formed by stacking third type stator laminations 3, and the third type stator laminations 3 are provided with an annular oil groove; the axial oil holes of the second stator lamination group are connected to the annular oil groove of the third stator lamination group.

[0035] like Figure 9 As shown, the third type of stator lamination 3 is a key component for oil distribution, and its core feature is the presence of an annular oil groove. Multiple third type stator laminations 3 are stacked to form a third stator lamination group 8. The function of this annular oil groove is to act as an integrated distribution cavity, which can redistribute the cooling oil flowing in from one end in the circumferential direction and guide it evenly to each axial oil hole connected to it, thus ensuring the uniformity of cooling.

[0036] The above-mentioned lamination groups are stacked in a specific order to form a complete stator core 4, such as... Figures 10 to 12 As shown, the stacking sequence from one end to the other is as follows: First stator lamination group -1 5 - Second stator lamination group -1 6 - Second stator lamination group -2 7 - Third stator lamination group 8 - Second stator lamination group -3 9 - Second stator lamination group -4 10 - First stator lamination group -2 11.

[0037] Among them, the axial oil holes on each stator lamination of the stator core 4 are located in different radial positions, and the distances of any two adjacent axial oil holes from the center are different to form a step, so as to form a stepped structure at the end of the cooling oil passage for adjusting the oil injection angle.

[0038] The connection relationship of the cooling oil circuit is as follows: Figure 13 The cross-sectional view shows: cooling oil from Figure 13Entering from the left inlet, the oil first flows through the axial oil holes of the second stator lamination group -4 10 and the second stator lamination group -3 9.

[0039] Subsequently, the oil enters the annular oil groove of the third stator lamination group 8. Here, the oil is buffered and evenly distributed circumferentially.

[0040] After being evenly distributed, a portion of the oil continues to flow to the left, passing through the axial oil holes of the second stator lamination group-2 7 and the second stator lamination group-1 6, and finally being ejected from the stepped oil hole of the first stator lamination group-1 5 to cool the end coil on the left side.

[0041] Another portion of the oil flows directly to the right from the annular oil groove of the third stator lamination group 8, passes through the axial oil holes of the second stator lamination group-3 9 and the second stator lamination group-4 10, and is finally sprayed out from the stepped oil hole of the first stator lamination group-2 11 to cool the end coil on the right side.

[0042] It should be noted that a key manufacturing process in this embodiment is rotational stacking. Taking the first stator lamination group at one end as a reference, subsequent stator lamination groups are stacked in sequence with the adjacent stator lamination groups after rotating by a predetermined angle in the same direction, so that the axial oil holes are distributed in a non-linear manner in the circumferential direction.

[0043] When there are 3 lugs on the stator lamination, the predetermined angle is a multiple of 120 degrees; When there are 4 lugs on the stator lamination, the predetermined angle is a multiple of 90 degrees; When the stator laminations do not have ears, the predetermined angle is a multiple of 360° / n, where n is the number of oil holes.

[0044] Specifically, when there are 3 ears on the stator lamination, the predetermined angle is 0°, 120° or -120°; When the stator lamination has 4 lugs, the predetermined angles are 0°, 90°, 180°, or -90°.

[0045] Specifically, not all lamination groups are simply stacked and aligned axially. Using the first stator lamination group -15 as a reference, subsequent lamination groups are rotated at a specific angle, as shown in the following example: Second stator lamination group -1 6 rotated 0°; Second stator lamination group -2 7 rotates -120°; Third stator lamination group 8 rotates 0°; Second stator lamination group -3 9 rotates 120°; Second stator lamination group -4 10 rotated 0°; First stator lamination group -2 11 rotated 0°.

[0046] This rotating stacking method results in a non-linear distribution of the cooling oil path formed by the series of axial oil holes in the circumferential direction. The beneficial effect is that when the cooling oil flows through the oil path, its flow path changes circumferentially, which helps the oil to be more fully agitated and diffused, thus more evenly wetting and cooling the stator windings and avoiding the cooling dead zones that may exist in traditional straight oil paths. Figure 5 and Figure 6 The simulation results intuitively demonstrate that both the coils at the output end and the coils at the non-output end achieve excellent spray coverage, verifying the effectiveness of this design.

[0047] This embodiment successfully constructs a highly efficient and uniform integrated cooling system inside the stator core through an innovative combination of three types of stator laminations with clearly defined functions and a rotary lamination process. It eliminates the need for external oil pipes and oil injection rings, and achieves precise and efficient cooling of the stator windings, especially the end coils, through the special structure of the internal oil circuit (especially the stepped structure and the rotary non-linear path).

[0048] Compared with the prior art, the motor stator cooling oil circuit structure provided in this embodiment of the utility model has the following beneficial technical effects: 1. High integration, reduced costs: The cooling oil circuit is directly integrated inside the stator core, eliminating the need for separate oil pipes and oil injection rings, which significantly reduces material and assembly costs.

[0049] 2. Uniform cooling and excellent performance: Axial oil channels are evenly distributed throughout the circumference of the entire iron core, with a large cooling area, ensuring that all parts of the stator winding can be effectively cooled, solving the problem of local overheating, and thus improving the performance of the motor.

[0050] 3. End cooling optimization: By changing the stepped structure formed by the cross-sectional area of ​​the oil hole, the angle and range of the end oil spray can be precisely adjusted, which effectively improves the cooling effect of the iron core end coil, a traditional cooling dead zone.

[0051] 4. High reliability: Compared to the oil injection ring structure which is prone to oil leakage, the integrated oil circuit structure of this invention is simple, has low sealing requirements, and is more reliable in operation. Furthermore, the end-effectors primarily rely on pressure injection, minimizing the impact of gravity and ensuring good cooling for the motor's bottom coils.

[0052] In summary, this utility model embodiment innovatively integrates the cooling oil circuit into the stator core, rather than simply adding components. It optimizes the structure from its core, achieving a harmonious unity of "functional integration" and "performance enhancement." It effectively overcomes the industry pain points of uneven cooling, high cost, and poor reliability in existing technologies. Furthermore, through detailed designs such as the stepped structure, it achieves precise control of cooling performance. This structure ultimately leads to significant improvements in cooling uniformity, temperature rise control, and overall energy efficiency, providing a simple, efficient, and reliable solution for the thermal management of high-power-density motors, and possesses extremely high industrial application value.

[0053] In the description of this specification, references to terms such as "specific example" or "some examples" refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are 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.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A stator cooling oil circuit structure for an electric motor, characterized in that, Including a stator core formed by stacking multiple sets of stator laminations; The stator core is provided with axially extending cooling oil passages inside; The cooling oil passage includes axial oil holes formed on the stator laminations and annular oil grooves formed on at least a portion of the stator laminations. The axial oil hole and the annular oil groove are interconnected to form an integrated oil passage for the flow of cooling medium.

2. The motor stator cooling oil circuit structure according to claim 1, characterized in that, The multiple sets of stator laminations include at least one first set of stator laminations and at least one second set of stator laminations; The first stator lamination group is formed by stacking first type stator laminations, and the first type stator laminations are provided with the axial oil holes; The second stator lamination group is formed by stacking second type stator laminations, and the second type stator laminations are also provided with the axial oil holes.

3. The motor stator cooling oil circuit structure according to claim 2, characterized in that, The multiple sets of stator laminations also include a third set of stator laminations; The third stator lamination group is formed by stacking third type stator laminations, and the third type stator laminations are provided with the annular oil groove; The axial oil hole of the second stator lamination group is connected to the annular oil groove of the third stator lamination group.

4. The motor stator cooling oil circuit structure according to claim 1, characterized in that, The axial oil holes on each stator lamination of the stator core are located at different positions in the radial direction, and the distances of any two adjacent axial oil holes from the center are different to form a step, thereby forming a stepped structure at the end of the cooling oil passage for adjusting the oil injection angle.

5. The motor stator cooling oil circuit structure according to claim 4, characterized in that, The cross-sectional shape of the axial oil hole is square, circular, or elliptical.

6. The motor stator cooling oil circuit structure according to claim 3, characterized in that, The multiple sets of stator laminations are stacked in a rotational stacking manner.

7. The motor stator cooling oil circuit structure according to claim 6, characterized in that, Taking the first stator lamination group at one end as a reference, the second stator lamination group, the third stator lamination group, another second stator lamination group, and another first stator lamination group are stacked in sequence with the adjacent stator lamination group after being rotated by a predetermined angle in the same direction, so that the axial oil holes are distributed in a non-linear manner in the circumferential direction.

8. The motor stator cooling oil circuit structure according to claim 7, characterized in that, When the stator lamination has three lugs, the predetermined angle is a multiple of 120 degrees; When the stator lamination has four lugs, the predetermined angle is a multiple of 90 degrees; When the stator lamination has no ears, the predetermined angle is a multiple of 360° / n, where n is the number of oil holes.

9. The motor stator cooling oil circuit structure according to claim 7, characterized in that, When there are 3 lugs on the stator lamination, the predetermined angle is 0°, 120° or -120°; When the stator lamination has four lugs, the predetermined angle is 0°, 90°, 180°, or -90°.

10. The motor stator cooling oil circuit structure according to any one of claims 1 to 9, characterized in that, The axial oil holes are evenly distributed in the circumferential direction of the stator core.

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