Oil cooling electric drive system and vehicle

Abstract

The invention provides an oil cooling electric drive system and a vehicle, the oil cooling electric drive system comprises a shell assembly, the shell assembly is provided with a shell accommodating cavity, and the shell assembly is provided with a cooling flow channel used for oil liquid circulation; the stator assembly is arranged in the shell accommodating cavity, the stator assembly is connected with the shell assembly, the stator assembly is provided with a stator inner side accommodating cavity, and the stator inner side accommodating cavity is communicated with the shell accommodating cavity; the stator inner side oil spraying pipe assembly is located in the stator inner side containing cavity, the stator inner side oil spraying pipe assembly communicates with the cooling flow channel, and the stator inner side oil spraying pipe assembly comprises a first stator inner side oil spraying pipe and a second stator inner side oil spraying pipe; the first stator inner side oil spraying pipe and the second stator inner side oil spraying pipe are arranged at intervals in the axial direction of the stator assembly. The technical problem that the upper portion of a stator inner side winding of an existing oil cooling electric drive system in the prior art is insufficient in cooling under the working condition that the rotating speed of an oil pump is small is solved.

Description

Technical Field

[0001] This invention relates to the field of oil-cooled electric drive technology, and more specifically, to an oil-cooled electric drive system and vehicle. Background Technology

[0002] As electric drive systems for new energy vehicles develop towards higher power density and miniaturization, efficient cooling of motor windings is a key technology for improving the power density, reliability, and energy efficiency of electric drive systems. Currently, cooling of the motor stator windings and lubrication of the bearings need to be achieved through cooling structure design. In order to make the cooling more uniform, bidirectional cooling of the inner and outer windings of the motor is required. However, under the condition of low oil pump speed, the flow rate of lubricating oil into the inner stator oil spray pipe is small. Due to the influence of gravity, the spray height of the top nozzle of the inner stator oil spray pipe is insufficient, which cannot effectively cool the upper part of the inner winding of the motor, resulting in uneven heating and local overheating of the motor. Summary of the Invention

[0003] The main objective of this invention is to provide an oil-cooled electric drive system and vehicle to solve the technical problem of insufficient cooling above the stator inner winding in existing oil-cooled electric drive systems when the oil pump speed is relatively low.

[0004] To achieve the above objectives, according to one aspect of the present invention, an oil-cooled electric drive system is provided, comprising: a housing assembly having a housing cavity and a cooling channel for circulating oil; a stator assembly disposed within the housing cavity and connected to the housing assembly, the stator assembly having an inner stator cavity communicating with the housing cavity; and an inner stator oil-draining pipe assembly located within the inner stator cavity and communicating with the cooling channel, the inner stator oil-draining pipe assembly including a first inner stator oil-draining pipe and a second inner stator oil-draining pipe, the first inner stator oil-draining pipe and the second inner stator oil-draining pipe being spaced apart along the axial direction of the stator assembly, at least one of the first inner stator oil-draining pipe and the second inner stator oil-draining pipe including: an upper chamber and a lower chamber, the upper chamber and the lower chamber being connected through a throttling orifice, the upper chamber having a plurality of injection ports for guiding oil to be injected onto the inner side of the stator winding.

[0005] Furthermore, the oil-cooled electric drive system also includes: a rotor assembly, which is disposed within the housing cavity, and a portion of the rotor assembly is disposed within the stator inner cavity. The rotor assembly is movably connected to the housing assembly. The rotor assembly is spaced apart from the stator inner oil-draining pipe assembly. The rotor assembly includes a rotor and a shaft. The first stator inner oil-draining pipe is located at the first end of the rotor, and the second stator inner oil-draining pipe is located at the second end of the rotor.

[0006] Further, the upper chamber includes: an upper chamber body; a main flow channel extending circumferentially along the upper chamber and connected to the upper chamber body; a first branch channel extending circumferentially along the upper chamber and connected to one end of the main flow channel, the first branch channel having a first injection port; and a second branch channel extending circumferentially along the upper chamber, spaced apart from the first branch channel and connected to one end of the main flow channel, the second branch channel having a second injection port; wherein the first injection port and the second injection port are respectively used to guide the cold medium to be injected to the inside of the stator winding.

[0007] Furthermore, the upper chamber has a third injection port, and the upper chamber also has a fourth, fifth, and sixth injection ports, which are circumferentially spaced apart.

[0008] Furthermore, the housing assembly includes: an outer shell, which is connected to the stator assembly and the stator inner oil drain pipe assembly, and the outer shell is provided with a first cooling channel for circulating oil; and an end cap, which is located at one end of the outer shell and is detachably connected to the outer shell, and the end cap is provided with a second cooling channel for circulating oil; wherein the first cooling channel and the second cooling channel form a cooling channel, and the end cap and the outer shell enclose a housing cavity.

[0009] Furthermore, the oil-cooled electric drive system also includes: a first motor stator outer oil-drenching ring, which is located within the housing cavity and connected to the stator assembly; and a second motor stator outer oil-drenching ring, which is located within the housing cavity and spaced apart from the first motor stator outer oil-drenching ring, and connected to the stator assembly.

[0010] Furthermore, the first cooling channel includes: a first oil channel, which is connected to an external oil tank and has a third outlet, which is connected to the outer oil-drenching ring of the first motor stator and the outer oil-drenching ring of the second motor stator; a second oil channel, which is connected to the first oil channel and has a first outlet and a second outlet, the first outlet being connected to the inner oil-drenching pipe of the second stator; and a third oil channel, one end of which is connected to one end of the first oil channel.

[0011] Furthermore, the second cooling channel includes a fourth oil channel, which is connected to the third oil channel. The fourth oil channel has a fourth outlet and a fifth outlet, and the fourth outlet is connected to the inlet of the oil spray pipe inside the first stator.

[0012] Furthermore, the inner diameter of the first injection port is set to gradually decrease, and / or the inner diameter of the second injection port is set to gradually decrease.

[0013] According to another aspect of the present invention, a vehicle is provided, including an oil-cooled electric drive system, wherein the oil-cooled electric drive system is the oil-cooled electric drive system described above.

[0014] By incorporating a stator inner oil-drenching pipe assembly containing first and second stator inner oil-drenching pipes into the oil-cooled electric drive system, and employing methods such as guiding lubricating oil with guide grooves, designing the injection nozzles with trapezoidal cross-sections, and implementing truncation designs between some nozzles, the speed and height of the oil ejected from the upper injection nozzles are increased while maintaining the total flow rate into the stator inner oil-drenching pipes. This achieves effective cooling of the area above the motor inner windings. Simultaneously, the throttling orifice reduces the flow rate of lubricating oil into the downward chamber, allowing more lubricating oil to accumulate in the upper chamber to reduce filling time. The truncation design reduces the volume of the inner cavity of the oil-drenching pipes for earlier cooling, ultimately reducing the peak temperature and copper loss of the motor windings, improving heat dissipation efficiency, and thus enhancing the reliability, energy efficiency, and overall vehicle range of the electric drive system. This solves the technical problem of insufficient cooling of the area above the stator inner windings in existing oil-cooled electric drive systems under conditions of low oil pump speed. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0016] Figure 1 A structural diagram of a first embodiment of an oil-cooled electric drive system according to the present invention is shown;

[0017] Figure 2 A structural diagram of a second embodiment of the oil-cooled electric drive system according to the present invention is shown;

[0018] Figure 3 A structural diagram of a third embodiment of the oil-cooled electric drive system according to the present invention is shown;

[0019] Figure 4 A partial structural diagram of a fourth embodiment of the oil-cooled electric drive system according to the present invention is shown;

[0020] Figure 5 A partial structural diagram of a fifth embodiment of the oil-cooled electric drive system according to the present invention is shown;

[0021] Figure 6 A partial structural diagram of a sixth embodiment of the oil-cooled electric drive system according to the present invention is shown;

[0022] Figure 7 A partial structural diagram of a seventh embodiment of an oil-cooled electric drive system according to the present invention is shown.

[0023] The above figures include the following reference numerals:

[0024] 1. End cap; 101. Fourth oil passage; 102. Fourth outlet; 103. Fifth outlet;

[0025] 2. Outer shell; 201. First oil passage; 202. Second oil passage; 203. Third oil passage; 204. First outlet; 205. Second outlet; 206. Third outlet;

[0026] 3. Oil spray pipe inside the first stator; 301. Inlet; 302. First injection port; 303. Second injection port; 304. Third injection port; 305. Fourth injection port; 306. Fifth injection port; 307. Sixth injection port; 308. Main flow channel; 309. First branch channel; 310. Second branch channel; 311. Throttling orifice; 312. Upper chamber; 313. Lower chamber;

[0027] 4. Oil-drenching ring on the outer side of the first motor stator;

[0028] 5. Stator assembly;

[0029] 6. Oil-drenching ring on the outer side of the second motor stator;

[0030] 7. Rotor;

[0031] 8. Oil spray pipe inside the second stator;

[0032] 9. Second motor bearing;

[0033] 10. Shaft;

[0034] 11. First motor bearing. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] 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.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0039] As new energy vehicles increasingly demand higher driving range, improved power performance, and greater installation space, electric drive systems are exhibiting a clear trend towards higher power density and miniaturization. This is achieved by optimizing motor structure (such as using multi-layer flat wire windings and SiC power semiconductors) to increase power output per unit weight. This trend leads to a dramatic increase in the internal heat load of the motor. As a core heat-generating component, the heat dissipation efficiency of the motor windings directly determines the performance ceiling of the electric drive system. Efficient cooling can prevent insulation aging caused by high temperatures, extending component lifespan (e.g., Huichuan commercial vehicle oil-cooled motors achieve a million-kilometer design life through optimized cooling). Simultaneously, it suppresses energy efficiency degradation caused by increased resistance at high temperatures, enabling the motor to operate stably under higher loads and further improving power density.

[0040] The currently mainstream oil cooling technology achieves dual core functions through an integrated design: as the oil circulates through the cooling channels, it both removes heat from the stator windings via spraying and provides lubrication for rotating components such as bearings, thus solving the problem of synergistic cooling and lubrication. To achieve uniform heat dissipation across the entire surface, the industry generally adopts a bidirectional cooling solution—because the stator windings are arranged in a ring shape, cooling only one side will lead to axial or radial temperature differences, similar to the insulation thermal stress problem caused by unidirectional cooling in steam turbine generators. Bidirectional cooling can effectively balance the temperature field and ensure the structural stability of the core and windings.

[0041] However, this solution has significant bottlenecks under certain operating conditions: when the vehicle is in low-load scenarios such as low-speed driving or idling charging, the oil pump reduces its speed to match energy consumption demands, resulting in a sharp decrease in the flow rate of lubricating oil into the stator's inner oil spray pipe. Due to gravity and fluid dynamics, the lower nozzle of the oil spray pipe can maintain a basic spraying effect due to natural oil settling, while the top nozzle needs to overcome gravity to spray upwards. When the flow rate is insufficient, its spray kinetic energy is greatly reduced, and the spray height cannot cover the upper area of ​​the inner winding. This phenomenon is similar to the principle of insufficient oil supply in a variable frequency compressor at low speeds, both due to the inability of fluid dynamics to overcome the limitations of gravity at low flow rates. Ultimately, this leads to an uneven temperature distribution in the inner winding of the motor, with the lower part cold and the upper part hot. Localized overheating occurs in the top area, accelerating the aging of the insulation layer in this area and exacerbating copper losses due to increased local resistance, creating a vicious cycle of "overheating-energy efficiency reduction." In severe cases, this may lead to thermal breakdown, restricting the reliability and adaptability of the electric drive system.

[0042] This application provides an oil-cooled electric drive system, such as... Figures 1-4 As shown, it includes: a housing assembly having a housing cavity and a cooling channel for circulating oil; a stator assembly 5 disposed within the housing cavity and connected to the housing assembly, the stator assembly 5 having an inner stator cavity communicating with the housing cavity; and an inner stator oil-draining pipe assembly located within the inner stator cavity and communicating with the cooling channel. The inner stator oil-draining pipe assembly includes a first inner stator oil-draining pipe 3 and a second inner stator oil-draining pipe 8, which are spaced apart along the axial direction of the stator assembly 5. At least one of the first inner stator oil-draining pipe 3 and the second inner stator oil-draining pipe 8 includes: an upper chamber 312 and a lower chamber 313 communicating through a throttling orifice 311. The upper chamber 312 has multiple injection ports for guiding oil to be sprayed onto the inner side of the stator winding.

[0043] In this embodiment, the cooling channels of the housing assembly provide a stable oil supply to the stator inner oil-drenching pipe assembly. The first stator inner oil-drenching pipe 3 and the second stator inner oil-drenching pipe 8 are spaced apart along the axial direction of the stator assembly 5, providing comprehensive cooling coverage for windings in different axial regions within the stator assembly 5, significantly improving axial cooling uniformity. Simultaneously, at least one of the first stator inner oil-drenching pipe 3 and the second stator inner oil-drenching pipe 8 has an upper chamber 312 connected to a lower chamber 313 via a throttling orifice 311. The structure effectively reduces the loss of oil to the lower chamber 313 by means of the throttling orifice 311, accelerates the accumulation of oil in the upper chamber 312 and establishes the injection pressure. The multiple injection ports of the upper chamber 312 can accurately guide the oil to be sprayed to the inside of the stator winding. Even under the condition of low oil pump speed and insufficient oil flow, it can ensure effective spraying to the inside of the stator winding, avoid local overheating problems. Moreover, the overall structure is well compatible with the housing assembly and stator assembly 5, further improving the reliability and adaptability of the electric drive system cooling.

[0044] Furthermore, the oil-cooled electric drive system also includes: a rotor assembly, which is disposed in the housing cavity, and a portion of the rotor assembly is disposed in the stator inner cavity. The rotor assembly is movably connected to the housing assembly. The rotor assembly is spaced apart from the stator inner oil-draining pipe assembly. The rotor assembly includes a rotor 7 and a shaft 10. The first stator inner oil-draining pipe 3 is located at the first end of the rotor 7, and the second stator inner oil-draining pipe 8 is located at the second end of the rotor 7.

[0045] In this embodiment, the rotor assembly is located within the housing cavity of the housing assembly and partially within the stator inner cavity of the stator assembly 5. While movably connected to the housing assembly, it is also spaced apart from the stator inner oil spray pipe assembly, effectively avoiding structural interference during operation and ensuring smooth and stable system operation. Furthermore, the first stator inner oil spray pipe 3 is located at the first end of the rotor 7, and the second stator inner oil spray pipe 8 is located at the second end of the rotor 7. This distribution along both ends of the rotor 7 axial direction, combined with the spaced arrangement of both along the stator assembly 5 axial direction, provides precise and comprehensive spray cooling to the windings in the areas corresponding to both ends of the rotor 7 on the inner side of the stator assembly 5, significantly improving the axial cooling uniformity of the stator windings and preventing localized overheating. Simultaneously, the rational layout of the rotor assembly provides suitable space for oil flow between the housing cavity and the stator inner cavity, ensuring the reliability of oil supply and circulation in the cooling channels, further enhancing the cooling efficiency and operational adaptability of the electric drive system.

[0046] In one exemplary embodiment, such as Figures 5-7As shown, the upper chamber 312 includes: an upper chamber body; a main flow channel 308, which extends circumferentially along the upper chamber 312 and is connected to the upper chamber body; a first branch channel 309, which extends circumferentially along the upper chamber 312 and is connected to one end of the main flow channel 308, and has a first injection port 302; and a second branch channel 310, which extends circumferentially along the upper chamber 312 and is spaced apart from the first branch channel 309, and is connected to one end of the main flow channel 308, and has a second injection port 303; wherein the first injection port 302 and the second injection port 303 are respectively used to guide the cold medium to be injected to the inside of the stator winding.

[0047] The main flow channel 308, extending circumferentially along the upper chamber 312, is connected to the main body of the upper chamber and can guide the cooling medium to achieve rapid and uniform circumferential distribution within the upper chamber 312, providing a stable medium supply for precise spraying. The first branch channel 309 and the second branch channel 310, extending circumferentially along the upper chamber 312 and arranged at intervals, are respectively connected to one end of the main flow channel 308, which can efficiently guide the cooling medium distributed by the main flow channel 308 into the channel body, and then precisely spray it onto the inside of the stator winding through the first spray port 302 of the first branch channel 309 and the second spray port 303 of the second branch channel 310, greatly improving the cooling uniformity, avoiding local cooling blind spots, and thus improving the cooling efficiency and reliability of the electric drive system.

[0048] Furthermore, the upper chamber 312 has a third injection port 304, a fourth injection port 305, a fifth injection port 306, and a sixth injection port 307, which are circumferentially spaced. Building upon the existing main flow channel 308 achieving circumferential uniform distribution of refrigerant, and the first branch channel 309 spraying refrigerant through the first injection port 302 and the second branch channel 310 spraying refrigerant through the second injection port 303, the newly added third injection port 304, along with the fourth, fifth, and sixth injection ports 305, 306, and 307, forms a circumferentially spaced multi-injection port pattern. This allows the refrigerant to precisely cover the entire inner area of ​​the stator winding through multiple circumferential points, completely eliminating localized cooling blind spots and significantly improving cooling uniformity. Combined with the uniform distribution effect of the main flow channel 308, this further enhances cooling efficiency and the operational reliability of the electric drive system.

[0049] In this embodiment, the housing assembly includes: an outer shell 2, which is connected to the stator assembly 5 and the stator inner oil drain pipe assembly, and the outer shell 2 is provided with a first cooling channel for circulating oil; and an end cap 1, which is located at one end of the outer shell 2 and is detachably connected to the outer shell 2, and the end cap 1 is provided with a second cooling channel for circulating oil; wherein the first cooling channel and the second cooling channel form a cooling channel, and the end cap 1 and the outer shell 2 enclose a housing cavity. The outer casing 2 is connected to the stator assembly 5 and the stator inner oil-draining pipe assembly, providing stable support for the internal core components and ensuring the stability of the overall structure. The end cover 1 is located at one end of the outer casing 2 and is detachably connected, facilitating system assembly, inspection, and maintenance and replacement of internal components. The first cooling channel of the outer casing 2 and the second cooling channel of the end cover 1 combine to form a complete cooling channel, enabling smooth flow of oil within the casing assembly and continuously supplying the medium to components requiring cooling and lubrication, such as the stator inner oil-draining pipe assembly and bearings. At the same time, the housing cavity enclosed by the end cover 1 and the outer casing 2 provides a closed installation space for the rotor assembly, stator assembly 5, etc., protecting internal components from external environmental influences and creating suitable space for oil circulation, further improving the reliability and maintenance convenience of the oil-cooled electric drive system.

[0050] Specifically, the oil-cooled electric drive system also includes: a first motor stator outer oil-drenching ring 4, located within the housing cavity and connected to the stator assembly 5; and a second motor stator outer oil-drenching ring 6, also located within the housing cavity, spaced apart from the first motor stator outer oil-drenching ring 4, and connected to the stator assembly 5. The rotating shaft 10 is connected to the rotor and located inside the stator assembly 5.

[0051] The first motor stator outer oil-drenching ring 4 and the second motor stator outer oil-drenching ring 6 have significant advantages: both are located within the housing cavity and connected to the stator assembly 5, allowing them to precisely correspond to the outer area of ​​the stator assembly 5 and ensure the accuracy of the oil spraying position; at the same time, the second motor stator outer oil-drenching ring 6 and the first motor stator outer oil-drenching ring 4 are spaced apart, enabling comprehensive spraying of different axial areas on the outer side of the stator assembly 5. Combined with the cooling of the inner side by the stator inner oil-drenching pipe assembly, a full-area cooling system that coordinates the inner and outer sides of the stator is formed, significantly eliminating the cooling blind zone on the outer side of the stator winding, greatly improving cooling uniformity, avoiding the impact of local overheating on the outer side on the electric drive system performance, and further enhancing the system's heat dissipation efficiency and operational reliability.

[0052] Further, the first cooling channel includes: a first oil channel 201, which is connected to an external oil tank and has a third outlet 206, which is connected to the outer oil-drenching ring 4 of the first motor stator and the outer oil-drenching ring 6 of the second motor stator; a second oil channel 202, which is connected to the first oil channel 201 and has a first outlet 204 and a second outlet 205, which is connected to the inner oil-drenching pipe 8 of the second stator; and a third oil channel 203, one end of which is connected to one end of the first oil channel 201. The first oil passage 201, serving as the core oil supply starting point, is connected to an external oil tank, providing a continuous and stable supply of oil to the entire cooling and lubrication system, ensuring reliable supply from the source. Its third outlet 206 is directly connected to the outer oil-drenching ring 4 of the first motor stator and the outer oil-drenching ring 6 of the second motor stator, accurately delivering oil to the two outer oil-drenching rings to help achieve comprehensive cooling of the outer side of the stator assembly 5. The second oil passage 202, connected to the first oil passage 201, provides oil to the inner oil-drenching pipe 8 of the second stator through the first outlet 204, meeting the cooling needs of the inner side of the stator assembly 5. At the same time, its second outlet 205 can also provide lubricating medium to the second motor bearing 9, achieving coordinated supply of cooling and lubrication.

[0053] In an exemplary embodiment, the second cooling channel includes a fourth oil channel 101, which is connected to the third oil channel 203. The fourth oil channel 101 has a fourth outlet 102 and a fifth outlet 103. The fourth outlet 102 is connected to the inlet 301 of the first stator inner side oil spray pipe 3. The fourth oil passage 101 is directly connected to the third oil passage 203 of the first cooling channel, seamlessly receiving the oil transported by the first cooling channel to form a complete and continuous oil flow path, ensuring the stability and continuity of oil supply. The fourth outlet 102 of the fourth oil passage 101 is precisely connected to the inlet 301 of the first stator inner oil spray pipe 3, which can directionally transport the oil to the first stator inner oil spray pipe 3, providing a precise medium supply for the winding cooling of the corresponding area inside the stator assembly 5. Combined with the cooling of the second stator inner oil spray pipe 8, it achieves full coverage of the stator inner area. At the same time, the fifth outlet 103 of the fourth oil passage 101 can be used to lubricate the first motor bearing 11, further expanding the functional uses of the oil. This allows the second cooling channel to meet the cooling needs of the stator inner area while also taking into account the lubrication needs of the motor bearing. The overall design efficiently connects the upstream and downstream channels, fully covering the core components that need cooling and lubrication, and significantly improving the medium distribution efficiency and operational reliability of the oil-cooled electric drive system.

[0054] Furthermore, the inner diameter of the first injection port 302 is gradually decreasing, and / or the inner diameter of the second injection port 303 is gradually decreasing. The advantage of the gradually decreasing inner diameter of the first injection port 302 and the second injection port 303 is significant. This structure can utilize the throttling effect to increase the flow velocity and kinetic energy of the oil ejected from the first injection port 302 and the second injection port 303 after the oil is distributed to the first branch channel 309 and the second branch channel 310 through the gradually decreasing inner diameter. Even under conditions of low oil pump speed and insufficient oil flow, it can effectively increase the jet height, ensuring precise and effective spray cooling of the upper inner area of ​​the stator winding, and solving the problem of the top cooling blind zone caused by insufficient flow velocity in traditional nozzles.

[0055] According to another specific embodiment of this application, a vehicle is also provided, including an oil-cooled electric drive system, which is the oil-cooled electric drive system described above.

[0056] In this embodiment, the vehicle is equipped with the aforementioned oil-cooled electric drive system. The first stator inner oil-drenching pipe 3 and the second stator inner oil-drenching pipe 8 are arranged axially along the stator assembly 5. Combined with the first motor stator outer oil-drenching ring 4 and the second motor stator outer oil-drenching ring 6, a comprehensive cooling system covering the outside of the stator assembly 5 is formed. This effectively suppresses overheating of the motor windings during high-load operation, ensuring the continuous stability of the vehicle's power output and preventing insufficient power due to motor thermal attenuation during rapid acceleration and hill climbing. Simultaneously, the tapered inner diameter design of the first injection port 302 and / or the second injection port 303, and the throttling within the upper chamber 312... The flow-limiting effect of the orifice 311 on the oil can increase the kinetic energy of the oil injection and the oil accumulation speed in the upper chamber 312 under low-speed conditions such as low-speed driving of the vehicle, thereby reducing copper losses in the motor windings, significantly optimizing the energy efficiency of the electric drive system, and thus extending the vehicle's driving range. In addition, the detachable connection between the end cover 1 and the outer shell 2 in the housing assembly, and the precise connection between the first cooling channel and the second cooling channel, not only improve the ease of assembly and maintenance of the electric drive system, but also reduce the subsequent maintenance costs of the vehicle. At the same time, the closed housing cavity can protect the core components of the electric drive from dust and moisture corrosion, further enhancing the reliability of the vehicle under complex road conditions and comprehensively improving the user's driving experience.

[0057] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 9 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0058] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0059] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An oil-cooled electric drive system, characterized in that, include: A housing assembly having a housing receiving cavity and a cooling channel for the flow of oil; Stator assembly (5), the stator assembly (5) is disposed in the housing cavity, the stator assembly (5) is connected to the housing assembly, the stator assembly (5) has an inner stator cavity, the inner stator cavity is connected to the housing cavity; The stator inner side oil spray pipe assembly is located in the stator inner side receiving cavity and is connected to the cooling flow channel. The stator inner side oil spray pipe assembly includes a first stator inner side oil spray pipe (3) and a second stator inner side oil spray pipe (8). The first stator inner side oil spray pipe (3) and the second stator inner side oil spray pipe (8) are spaced apart along the axial direction of the stator assembly (5). At least one of the first stator inner side oil spray pipe (3) and the second stator inner side oil spray pipe (8) includes an upper chamber (312) and a lower chamber (313). The upper chamber (312) and the lower chamber (313) are connected through a throttling hole (311). The upper chamber (312) has multiple injection ports, which are used to guide the oil to be sprayed to the inside of the stator winding.

2. The oil-cooled electric drive system according to claim 1, characterized in that, The oil-cooled electric drive system also includes: The rotor assembly is disposed in the housing cavity, and a portion of the rotor assembly is disposed in the stator inner cavity. The rotor assembly is movably connected to the housing assembly. The rotor assembly is spaced apart from the stator inner oil spray pipe assembly. The rotor assembly includes a rotor (7) and a shaft (10). The first stator inner oil spray pipe (3) is located at the first end of the rotor (7), and the second stator inner oil spray pipe (8) is located at the second end of the rotor (7).

3. The oil-cooled electric drive system according to claim 1 or 2, characterized in that, The upper chamber (312) includes: Upper chamber main body; A main flow channel (308) extends circumferentially along the upper chamber (312) and is connected to the main body of the upper chamber. The first branch groove (309) extends circumferentially along the upper chamber (312), and the first branch groove (309) is connected to one end of the main flow groove (308). The first branch groove (309) has a first injection port (302). The second branch groove (310) extends circumferentially along the upper chamber (312), and is spaced apart from the first branch groove (309). The second branch groove (310) is connected to one end of the main flow groove (308), and has a second injection port (303). The first injection port (302) and the second injection port (303) are respectively used to guide the cold medium to be injected into the inner side of the stator winding.

4. The oil-cooled electric drive system according to claim 3, characterized in that, The upper chamber (312) has a third injection port (304), and the upper chamber (312) has a fourth injection port (305), a fifth injection port (306) and a sixth injection port (307), which are circumferentially spaced apart.

5. The oil-cooled electric drive system according to claim 3, characterized in that, The housing assembly includes: The outer casing (2) is connected to the stator assembly (5) and the stator inner oil spray pipe assembly. The outer casing (2) is provided with a first cooling channel for the flow of oil. End cap (1), the end cap (1) is located at one end of the outer shell (2), the end cap (1) is detachably connected to the outer shell (2), and the end cap (1) is provided with a second cooling channel for the flow of oil; The first cooling channel and the second cooling channel form the cooling channel, and the end cap (1) and the outer shell (2) surround the housing cavity.

6. The oil-cooled electric drive system according to claim 5, characterized in that, The oil-cooled electric drive system also includes: The first motor stator outer oil-draining ring (4) is located inside the housing cavity and is connected to the stator assembly (5). The second motor stator outer oil-drenching ring (6) is located inside the housing cavity. The second motor stator outer oil-drenching ring (6) is spaced apart from the first motor stator outer oil-drenching ring (4). The second motor stator outer oil-drenching ring (6) is connected to the stator assembly (5).

7. The oil-cooled electric drive system according to claim 6, characterized in that, The first cooling channel includes: The first oil passage (201) is connected to the external oil tank. The first oil passage (201) has a third outlet (206), which is connected to the first motor stator outer oil-drenching ring (4) and the second motor stator outer oil-drenching ring (6). The second oil passage (202) is connected to the first oil passage (201). The second oil passage (202) has a first outlet (204) and a second outlet (205). The first outlet (204) is connected to the second stator inner side oil spray pipe (8). The third oil passage (203) has one port connected to one port of the first oil passage (201).

8. The oil-cooled electric drive system according to claim 7, characterized in that, The second cooling channel includes: The fourth oil passage (101) is connected to the third oil passage (203). The fourth oil passage (101) has a fourth outlet (102) and a fifth outlet (103). The fourth outlet (102) is connected to the inlet (301) of the first stator inner side oil spray pipe (3).

9. The oil-cooled electric drive system according to claim 3, characterized in that, The inner diameter of the first injection port (302) is set to gradually decrease, and / or the inner diameter of the second injection port (303) is set to gradually decrease.

10. A vehicle comprising an oil-cooled electric drive system, characterized in that, The oil-cooled electric drive system is the oil-cooled electric drive system according to any one of claims 1-9.

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