Motor end portion oil immersion and cooling structure

Abstract

The utility model relates to a kind of motor end part oil immersion and cooling structure, including shell, stator core and flat wire conductor, the both ends of shell are equipped with oil storage cavity, and oil inlet hole and oil outlet hole are equipped on shell;Flat wire conductor and stator core are also equipped with insulation framework between, and the end of insulation framework at oil inlet is also equipped with convex edge, and convex edge, stator core and shell inner wall form circumferential oil path, and part of oil inlet hole is communicated with circumferential oil path;Slot bottom oil path and slot oil path are also opened on insulation framework, and the end of insulation framework and stator core end surface form radial oil path communicated with slot bottom oil path and slot oil path;Stator core is also opened with a yoke part oil channel, and the end of insulation framework at oil inlet is also opened with end part oil hole communicated with yoke part oil channel.The utility model structure not only carries out cooling to end part winding, but also can guide cooling oil to different positions of slot conductor and stator core, realizes the efficient cooling of motor main heat source.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a motor end oil immersion and cooling structure. Background Technology

[0002] With the increasing demands for motor power density and efficiency in fields such as new energy vehicles and high-end industrial drives, flat wire winding motors have been widely used due to their advantages such as high slot fill factor, high power density, and high efficiency. However, the increase in power density inevitably leads to a sharp increase in the amount of heat generated inside the motor. How to efficiently dissipate heat, especially the heat in the hot spot area at the winding ends, has become a key challenge in motor design.

[0003] Oil cooling technology is considered a more efficient solution due to the higher specific heat capacity of its cooling medium (oil) and its potential for direct contact with heat sources. Existing motor oil cooling solutions mainly include: stator slot oil cooling: some solutions attempt to introduce cooling oil into the stator slots to directly cool the flat wire conductors. However, the flat wire conductors are closely packed in the slots, requiring extremely high insulation, making the design of oil channels very difficult. Improper design can easily lead to oil blockage, insulation failure, or localized overheating. More importantly, existing solutions often neglect the continuous cooling of the connection area between the end windings and the slot windings. Cooling oil cannot flow smoothly from the slots to the ends, or vice versa, resulting in insufficient cooling of the end area, which generates the most heat.

[0004] Furthermore, for motors using flat conductors, the end windings typically require complex twisting and welding to form a hairpin structure, resulting in a complex and compact design that further complicates the design of the cooling oil flow channels. Traditional spraying or simple immersion structures make it difficult for cooling oil to penetrate the gaps between the layers of the flat conductors, and also fail to achieve differentiated and targeted cooling of the flat conductors at different locations from the slot opening to the slot bottom.

[0005] Therefore, existing oil-cooling solutions generally suffer from the following technical defects: Uneven and insufficient end cooling: Cooling oil cannot evenly and comprehensively cover all end windings, posing a risk of localized overheating. Disconnection between slot and end cooling: The cooling path is discontinuous; slot cooling and end cooling are independent of each other, failing to form a coordinated and efficient cooling circuit. Insulation safety risks: Introducing oil channels into the narrow stator slots places extremely high demands on the design and manufacturing of the insulation frame, posing a potential risk of insulation breakdown. Utility Model Content

[0006] In order to solve the above-mentioned technical problems, the purpose of this utility model is to provide an oil immersion and cooling structure for the motor end, which can realize efficient and uniform immersion cooling of the end winding of the flat wire motor, while establishing a continuous cooling path from the slot to the end, and ensuring the absolute reliability of insulation.

[0007] To achieve the above-mentioned objectives, this utility model adopts the following technical solution: An end-oil immersion and cooling structure for an electric motor includes a housing, a stator core, and flat wire conductors. The stator core is fixed to the inner wall of the housing, and the flat wire conductors are inserted into the stator core. End sealing sleeves are provided at both ends of the housing. The end sealing sleeves, the inner wall of the housing, and the end face of the stator core form an oil storage cavity. An oil inlet is provided at one oil storage cavity, and an oil outlet is provided at the other oil storage cavity. An insulating frame is also provided between the flat wire conductors and the stator core. A raised edge is provided at one end of the insulating frame at the oil inlet. The raised edge, the stator core, and the inner wall of the housing form a circumferential oil passage, and a portion of the oil inlet communicates with the circumferential oil passage. The insulating frame is also provided with a slot bottom oil passage and a slot opening oil passage, and a radial oil passage is formed between one end of the insulating frame and the end face of the stator core, which is connected to the slot bottom oil passage and the slot opening oil passage; a ring of yoke oil passage is also provided on the stator core, and an end oil hole connected to the yoke oil passage is also provided at the end of the insulating frame located at the oil inlet hole.

[0008] As a preferred embodiment: the insulating frame includes an end extension ring A, an end extension ring B, and a conductor insulating tube connecting the two. The inner ring of the end extension ring A is provided with a convex ring A on the side facing the stator core. The convex ring A of the conductor insulating tube is fixed. A dividing strip is provided around the convex ring A, and a radial oil passage is formed between adjacent dividing strips.

[0009] As a preferred embodiment, the end extension ring A is further provided with a conductor hole A aligned with the conductor insulating tube, and the end oil hole is located around the conductor hole A and is staggered with the conductor hole A.

[0010] As a preferred embodiment: the end extension ring B is provided with a conductor hole B that communicates with the conductor insulating tube, and the groove oil passage is located near the center of the conductor insulating tube and the conductor hole B, and the groove bottom oil passage is located at the outer edge of the conductor insulating tube and the conductor hole B.

[0011] As a preferred embodiment: the end sealing sleeve includes an end sealing ring and a sleeve extending to one side from the middle of the end sealing ring, and the end of the sleeve away from the end sealing ring is also provided with a stepped surface, which is in close contact with the insulating skeleton.

[0012] As a preferred embodiment: the inner ring of the end extension ring B is further provided with a convex ring B, and a sealing ring is further provided between the stepped surface and the convex ring B or the insulating skeleton.

[0013] As a preferred embodiment, the outer ring of the end sealing ring is provided with a flange facing the stator core.

[0014] As a preferred embodiment, the outer diameter of the end extension ring A is larger than the outer diameter of the end extension ring B.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention constructs a multi-path, three-dimensional, forced-circulation oil-immersion cooling system. This structure not only enables efficient immersion cooling of the end windings, but also, through a unique insulating skeleton design, precisely guides the cooling oil to different positions of the slot conductors and the stator core, achieving comprehensive, uniform, and efficient cooling of the motor's main heat sources (end windings, slot windings, and stator core). Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional structural diagram of the present invention; Figure 3 This is an exploded structural diagram of the present invention; Figure 4 and Figure 5 This is a schematic diagram of the assembly structure of the insulating frame and stator core of this utility model; Figure 6 This is a schematic diagram of the insulating frame of this utility model; Figure 7 and Figure 8 These are two enlarged schematic diagrams of the insulating frame of this utility model.

[0018] The markings in the diagram are as follows: 1. Shell; 11. Oil inlet; 12. Oil outlet; 13. Circumferential oil passage; 2. Stator core; 21. Yoke oil passage; 22. Stator slot; 3. Insulating frame; 31. End extension ring A; 310. Conductor hole A; 311. End oil hole; 312. Separator strip; 32. End extension ring B; 321. Conductor hole B; 322. Convex ring B; 33. Conductor insulating tube; 324. Slot bottom oil passage; 323. Slot opening oil passage; 4. End sealing sleeve; 42. Sleeve; 41. End sealing ring; 43. Stepped surface; 44. Flanged edge; 5. Flat conductor; 6. Sealing ring. Detailed Implementation

[0019] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0023] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can 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.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments: like Figures 1 to 5 As shown, a motor end oil immersion and cooling structure includes a housing 1, a stator core 2, and a flat wire conductor 5. The stator core 2 is fixed to the inner wall of the housing 1, and the flat wire conductor 5 is inserted into the stator slot 22 of the stator core 2. End sealing sleeves 4 are provided at both ends of the housing 1. The end sealing sleeves 4, the inner wall of the housing 1, and the end face of the stator core 2 form an oil storage cavity. An oil inlet 11 is provided on the housing 1 at one oil storage cavity, and an oil outlet 12 is provided at the other oil storage cavity. An insulating frame 3 is also provided between the flat wire conductor 5 and the stator core 2, and the insulating frame 3 is located at the oil inlet... One end of the hole 11 is also provided with a raised edge, the raised edge, the stator core and the inner wall of the housing 1 form a circumferential oil passage 13, and part of the oil inlet hole 11 is connected to the circumferential oil passage 13; the insulating frame 3 is also provided with a slot bottom oil passage 324 and a slot opening oil passage 323, and one end of the insulating frame 3 and the end face of the stator core 2 form a radial oil passage connected to the slot bottom oil passage 324 and the slot opening oil passage 323; a ring of yoke oil passage 21 is also provided on the stator core 2, and the end of the insulating frame 3 located at the oil inlet hole 11 is also provided with an end oil hole 311 connected to the yoke oil passage 21.

[0026] In this invention, the oil reservoirs at both ends of the motor completely immerse the entire motor end winding in cooling oil, maximizing the contact area with the heat source and achieving extremely high heat exchange efficiency. Furthermore, by setting up an inlet and an outlet oil port, a pressure difference is established across the entire motor, driving the cooling oil to flow from one reservoir to the other, rather than passively remaining stationary. This ensures continuous flow and renewal of the cooling oil, preventing a decrease in cooling efficiency due to oil saturation from heat absorption. This is fundamentally different from traditional point-spraying, upgrading from "local spraying" to "overall immersion + forced circulation," fundamentally solving the problems of uneven and insufficient end cooling.

[0027] This invention also includes a circumferential oil passage, which acts as an annular "oil collecting ring" or "distributor" to evenly distribute the cooling oil flowing in from a single oil inlet in a circumferential direction. This ensures that the cooling oil does not only rush to a localized area, but can enter the subsequent cooling channels evenly in a 360-degree manner, providing balanced cooling for the entire stator circumference and effectively preventing localized overheating. It provides the first structured, low-resistance channel for cooling oil to enter the motor interior.

[0028] This invention also achieves layered cooling: flat wire conductors within the stator slot are typically divided into layers near the slot opening and layers near the slot bottom. Due to different heat dissipation paths, their temperature distributions also differ. By separately setting oil passages at the slot opening and bottom, flat wire conductors at different locations within the slot can be directly cooled simultaneously, solving the problem of difficult cooling of conductors within the slot in traditional solutions. Simultaneously, the radial oil passages act as a "bridge" connecting the end oil storage chamber and the oil passages within the slot, allowing cooling oil to flow smoothly from the ends into the depths of the stator slot, or conversely, carrying heat from within the slot to the end oil storage chamber. This completely solves the problem of disconnect between cooling within the slot and end cooling, forming a continuous three-dimensional cooling network from the bottom to the ends.

[0029] This invention also effectively cools the stator core. During motor operation, the stator core generates hysteresis loss and eddy current loss (iron loss). The yoke oil passage directly carries away the heat generated by the core, preventing overheating and performance degradation. The structure in this invention provides an independent, parallel cooling path for the cooling oil. The cooling oil can directly enter the yoke oil passage through the end oil holes, specifically cooling the stator core. This allows the entire cooling system to simultaneously and efficiently handle both the copper loss generated by the windings and the iron loss generated by the core, improving the overall cooling capacity of the system.

[0030] like Figures 6 to 8 As shown, the insulating frame 3 includes an end extension ring A31, an end extension ring B32, and a conductor insulating tube 33 connecting the two. The inner ring of the end extension ring A31 is provided with a convex ring A on the side facing the stator core 2. The convex ring A of the conductor insulating tube 33 is fixed. A ring of separators 312 is provided around the convex ring A, and a radial oil passage is formed between adjacent separators.

[0031] The above structure clarifies the specific composition of the insulation skeleton and modularizes its functions. By setting "separator bars" to form "radial oil passages," it's equivalent to setting multiple evenly distributed "toll booths" or "distribution ports" before the oil enters the internal oil passages from the circumferential oil passages. This further ensures that the cooling oil is evenly distributed to each stator slot, avoiding situations where the oil flow is too concentrated in some areas while insufficient in others, achieving a more microscopic level of balanced flow distribution.

[0032] The end extension ring A31 is also provided with a conductor hole A310 aligned with the conductor insulation tube 33. The end oil hole 311 is located around the conductor hole A310 and is staggered with the conductor hole A310. The "conductor hole" used for cooling the winding and the "end oil hole" used for cooling the iron core are staggered. This has two advantages: first, the structure is compact and makes full use of the space of the end extension ring; second, it avoids interference, ensuring that the oil passage leading to the yoke is independent and unobstructed, and will not be blocked by the winding or other structures, thus ensuring the reliability of the iron core cooling path.

[0033] The end extension ring B32 has a conductor hole B321 communicating with the conductor insulation tube 33, and the slot opening oil passage 323 is located near the center of the conductor insulation tube 33 and the conductor hole B321. The slot bottom oil passage 324 is located at the outer edge of the conductor insulation tube 33 and the conductor hole B321. The above structure clearly defines the specific positions of the slot opening oil passage and the slot bottom oil passage at the outlet end (end extension ring B). This positioning conforms to the motor's heating characteristics: the slot opening conductor is closer to the air gap, resulting in relatively better heat dissipation conditions, but still requiring enhanced cooling; while the slot bottom conductor is deeply embedded, with the longest heat dissipation path, making it the hottest spot within the slot. By setting the slot bottom oil passage at the outer edge, it can be cooled more effectively. This differentiated oil passage layout maximizes cooling efficiency.

[0034] The outer diameter of the end extension ring A31 is larger than that of the end extension ring B32. The larger outer diameter of end extension ring A is because it needs to perform more functions: forming circumferential oil passages and opening end oil holes, requiring more structural space. End extension ring B primarily functions as the oil outlet and the outlet for the oil passage within the tank. This differentiated design makes the insulation skeleton structure more rational, with clear functional zoning, achieving material savings and structural lightweighting while meeting cooling requirements.

[0035] The end sealing sleeve 4 includes an end sealing ring 41 and a sleeve 42 extending to one side from the middle of the end sealing ring 41. The end of the sleeve 42 away from the end sealing ring 41 also has a stepped surface 43, which abuts against the insulating frame 3. The stepped surface of the end sealing sleeve abuts against the insulating frame, forming an axial positioning and sealing surface. This not only helps with accurate positioning during assembly, but more importantly, it cooperates with the subsequent sealing ring to effectively prevent pressurized oil in the oil reservoir from leaking from the gap between the insulating frame and the end sealing sleeve, ensuring the integrity of the entire closed oil circuit system.

[0036] The inner ring of the end extension ring B32 is further provided with a convex ring B322, and a sealing ring 6 is provided between the stepped surface 43 and the convex ring B322 or the insulating frame 3. By setting the sealing ring, a reliable seal is formed between the stepped surface and the convex ring B or the insulating frame. It completely solves the risk of high-pressure oil leakage from the rotating rotor shaft area, and is an important safety guarantee to ensure that the "oil-immersed" structure can be realized without leakage accidents. The outer ring of the end sealing ring 41 is provided with a flange 44 facing the stator core 2. The "flange" of the outer ring of the end sealing ring increases the contact and sealing area with the inner wall of the housing. It can form a tighter fit with the housing and prevent oil leakage from the radial gap between the housing and the end sealing ring. At the same time, the flange structure may also play a certain guiding and reinforcing role, making assembly easier and the structure more stable.

[0037] This invention uses an integral injection molding process for the stator core to replace the inserted insulating paper. It employs an integral insulating skeleton formed by injection molding using PPS+GF or epoxy encapsulation material EMC, constructing an insulation and oil circuit scheme for the stator slots and end faces. This ensures that both ends of the stator core are sealed oil cavities. Cooling oil enters the oil cavity at one end of the stator core, and through the structure at one end of the injection-molded skeleton, the oil flow is rationally distributed to the three radially distributed axial oil channels (yoke, slot bottom, and slot opening) of the stator core, and flows out from the oil storage cavity at the other end, forming a complete oil circuit circulation.

[0038] 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.

[0039] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled 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 spirit 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 shall still fall within the scope of the technical solution of the present invention.

Claims

1. An oil-immersed and cooling structure for the end of a motor, comprising a housing (1), a stator core (2), and a flat wire conductor (5), wherein the stator core (2) is fixed to the inner wall of the housing (1), and the flat wire conductor (5) is inserted into the stator core (2), characterized in that: The housing (1) is provided with end sealing sleeves (4) at both ends. The end sealing sleeves (4), the inner wall of the housing (1) and the end face of the stator core (2) form an oil storage cavity. The housing (1) is provided with an oil inlet hole (11) at one oil storage cavity and an oil outlet hole (12) at the other oil storage cavity. An insulating skeleton (3) is also provided between the flat wire conductor (5) and the stator core (2). The insulating skeleton (3) is also provided with a protruding edge at one end of the oil inlet hole (11). The protruding edge, the stator core and the inner wall of the housing (1) form a circumferential oil passage (13). Part of the oil inlet hole (11) is connected to the circumferential oil passage (13). The insulating frame (3) is also provided with a bottom oil passage (324) and a top oil passage (323), and a radial oil passage is formed between one end of the insulating frame (3) and the end face of the stator core (2) that is connected to the bottom oil passage (324) and the top oil passage (323); a ring of yoke oil passage (21) is also provided on the stator core (2), and an end oil hole (311) connected to the yoke oil passage (21) is also provided at one end of the insulating frame (3) located at the oil inlet hole (11).

2. The motor end oil immersion and cooling structure according to claim 1, characterized in that: The insulating frame (3) includes an end extension ring A (31), an end extension ring B (32), and a conductor insulating tube (33) connecting the two. The inner ring of the end extension ring A (31) is provided with a convex ring A on the side facing the stator core (2). The convex ring A of the conductor insulating tube (33) is fixed. A ring of separators (312) is provided around the convex ring A, and a radial oil passage is formed between adjacent separators.

3. The motor end oil immersion and cooling structure according to claim 2, characterized in that: The end extension ring A (31) is also provided with a conductor hole A (310) aligned with the conductor insulating tube (33). The end oil hole (311) is located around the conductor hole A (310) and is staggered with the conductor hole A (310).

4. The motor end oil immersion and cooling structure according to claim 2, characterized in that: The end extension ring B (32) is provided with a conductor hole B (321) that communicates with the conductor insulating tube (33), and the groove oil passage (323) is located on the conductor insulating tube (33) and the conductor hole B (321) near the center. The groove bottom oil passage (324) is located on the outer edge of the conductor insulating tube (33) and the conductor hole B (321).

5. The motor end oil immersion and cooling structure according to claim 1, characterized in that: The end sealing sleeve (4) includes an end sealing ring (41) and a sleeve (42) extending to one side from the middle of the end sealing ring (41). The sleeve (42) is also provided with a stepped surface (43) at the end away from the end sealing ring (41). The stepped surface (43) is close to the insulating frame (3).

6. The motor end oil immersion and cooling structure according to claim 5, characterized in that: The inner ring of the end extension ring B (32) is also provided with a convex ring B (322), and a sealing ring (6) is also provided between the stepped surface (43) and the convex ring B (322) or the insulating frame (3).

7. The motor end oil immersion and cooling structure according to claim 5, characterized in that: The outer ring of the end sealing ring (41) is provided with a flange (44) facing the stator core (2).

8. The motor end oil immersion and cooling structure according to claim 1, characterized in that: The outer diameter of the end extension ring A (31) is greater than the outer diameter of the end extension ring B (32).

Images