Motor stator cooling oil channel structure
Patent Information
- Application Number
- CN202522111138.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-10-13
- Estimated Expiration
- 2035-09-30
AI Technical Summary
[0005]为解决背景技术中存在的技术问题，本实用新型提出一种电机定子冷却油道结构，有效解决了现有技术中散热效率低、传扭功能不足和绕组端部冷却不佳的问题
[0017]本实用新型的有益效果：本实用新型提供的电机定子冷却油道结构，通过在定子铁芯内部设置导油通道，使冷却油直接流经绕组内部，实现了对绕组本体的高效直接冷却，同时利用环形储油槽对第一绕组端部进行浸泡冷却，并通过导油通道将冷却油引导至第二绕组端部进行定向喷淋，从而形成了浸油、直接流动和喷淋相结合的多层次冷却方式，显著提升了绕组的整体散热效果，并且取消了定子铁芯表面开槽，保证了定子铁芯与电机机壳之间的完整接触面积，提供了足够的扭转力矩，避免了传扭功能失效的风险，该结构还简化了冷却系统，通过进油铁芯、喷油铁芯和导油铁芯的协同作用，实现了冷却油的顺畅流动和精准分配，减少了对淋油环等外部组件的依赖，降低了物料成本和生产成本，不仅大幅提高了电机的冷却效率和运行可靠性，还增强了结构的紧凑性和工艺性，适用于高功率密度电机的散热需求，具有突出的实用性和经济性。
Smart Images
Figure CN224852134U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of motor cooling technology, and relates to an oil-cooled motor, specifically a motor stator cooling oil channel structure. Background Technology
[0002] With the development of vehicle electrification, the demand for motor power density is increasing, and flat-wire motors with high power density and high torque density are gradually becoming a research hotspot. However, high torque density and high power density also mean high heat generation. If the heat generated by the motor cannot be dissipated in time, the motor temperature will become too high. When the motor temperature is too high, it will affect the motor's performance, and in severe cases, it will damage the motor's insulation and cause permanent demagnetization of the permanent magnets. Therefore, effective cooling of all heat-generating parts of the motor is necessary to ensure stable and safe operation.
[0003] Existing motor cooling technologies are mainly divided into natural cooling, air cooling, water cooling, and oil cooling. Oil-cooled motors generally have oil circuits installed on components such as the motor housing and core, and are connected to external components such as oil pumps, heat exchangers, and filters. During operation, cooling oil enters the oil circuit from the motor inlet, and carries away the internal heat of the motor by flowing through the oil circuits of the motor housing and core and spraying onto the windings. After cooling the motor, the cooling oil flows out from the outlet, passes through components such as heat exchangers and filters, and returns to the oil tank, completing the cooling cycle.
[0004] Currently, most common cooling oil channel solutions involve slotting the surface of the stator core, which is far from the stator heat source winding, resulting in limited heat dissipation efficiency and poor cooling effect. Furthermore, the surface slotting reduces the contact area between the stator core surface and the inner circle of the housing, which cannot provide sufficient torsional torque and poses a risk of failure in the torsion transmission function. In addition, the oil spraying solution at the winding end only uses an oil spraying ring, which has a limited spraying area and poor heat dissipation effect. Utility Model Content
[0005] To address the technical problems existing in the background art, this utility model proposes a motor stator cooling oil channel structure, which effectively solves the problems of low heat dissipation efficiency, insufficient torque transmission function and poor cooling of winding ends in the prior art.
[0006] The objective of this utility model can be achieved through the following technical solutions:
[0007] A stator cooling oil channel structure for an electric motor includes: a stator core, an annular oil reservoir, and windings. The annular oil reservoir is coaxially disposed at one end of the stator core. Multiple oil guide channels arranged in an annular array are provided on the stator core along the axial direction. The oil guide channels axially penetrate the stator core and communicate with the annular oil reservoir. The windings are disposed within the oil guide channels. The two ends of the windings extend outward from the oil guide channels to form a first winding end and a second winding end, respectively. The first winding end extends into the annular oil reservoir and is cooled by immersion in cooling oil within the annular oil reservoir. The cooling oil flows along the oil guide channels from the first winding end to the second winding end, spraying cooling onto the second winding end.
[0008] Furthermore, the inner ring of the stator core has multiple first stator slots arranged in a ring array along the axial direction. An oil guide pipe is adapted to be inserted into the first stator slot to form an oil guide channel. The middle part of the oil guide pipe is clearance-fitted with the winding so that the cooling oil flows along the gap between the winding and the inner wall of the oil guide pipe. The end of the oil guide pipe is interference-fitted with the winding to clamp and fix the two ends of the winding.
[0009] Furthermore, an oil inlet core is coaxially arranged between the annular oil reservoir and the stator core. The oil inlet core is sealed to the slot of the annular oil reservoir. The inner ring of the oil inlet core is provided with multiple second stator slots corresponding to multiple first stator slots along the axial direction. An oil guide pipe is adapted to be inserted into the second stator slot so that the end of the first winding passes through the second stator slot and extends into the annular oil reservoir.
[0010] Furthermore, the outer ring of the oil inlet core is provided with multiple oil inlet channels arranged in a ring array along the axial direction. The oil guide channel is provided with a first oil guide hole at one end near the oil inlet core. The multiple oil inlet channels on the oil inlet core are respectively connected to the first oil guide holes of the multiple oil guide channels.
[0011] Furthermore, an oil-injecting core is coaxially arranged at the end of the stator core away from the annular oil reservoir. The inner ring of the oil-injecting core has multiple third stator slots corresponding to multiple first stator slots along the axial direction. The oil guide pipe is adapted to be inserted into the third stator slot so that the end of the second winding passes through the third stator slot and extends out of the oil-injecting core.
[0012] Furthermore, the outer ring of the oil injection core is provided with multiple oil injection channels arranged in a ring array along the axial direction. The end of the oil guide channel near the oil injection core is provided with a second oil guide hole. The multiple oil injection channels on the oil injection core are respectively connected to the second oil guide holes of the multiple oil guide channels.
[0013] Furthermore, the oil injection channel is inclined axially from the outer ring to the inner ring of the oil injection core to spray cooling oil onto the end of the second winding located in the inner ring.
[0014] Furthermore, an oil guide core is coaxially arranged between the stator core and the oil inlet core to connect the multiple oil inlet channels on the oil inlet core with the first oil guide holes of the multiple oil guide channels respectively. Another oil guide core is coaxially arranged between the stator core and the oil injection core to connect the second oil guide holes of the multiple oil guide channels with the multiple oil injection channels on the oil injection core respectively.
[0015] Furthermore, the inner ring of the oil guide core is provided with multiple fourth stator slots along the axial direction, corresponding to multiple first stator slots. The oil guide tube is adapted to be inserted into the fourth stator slot. The outer ring of the oil guide core is provided with multiple oil collection grooves arranged in a ring array along the axial direction. The multiple oil collection grooves are respectively connected to multiple oil inlet channels / injection channels. Each oil collection groove is connected to a fourth stator slot through an oil passage. The multiple oil passages are respectively connected to the first oil guide hole / second oil guide hole of multiple oil guide channels.
[0016] Furthermore, one end of the oil guide tube is connected to an end plate that is adapted to the end wall of the stator core. The end of the oil guide tube connected to the end plate has a through hole. Multiple oil guide tubes arranged in a ring on the end plate are integrally injection molded with the end plate to form an injection molded body. The oil guide tubes of the two injection molded bodies are respectively inserted into the first stator slot from both ends of the stator core and are joined together in the first stator slot to form an oil guide channel. The through holes on the oil guide tubes of the two injection molded bodies respectively form the first oil guide hole and the second oil guide hole.
[0017] The beneficial effects of this utility model are as follows: The motor stator cooling oil channel structure provided by this utility model, by setting an oil guide channel inside the stator core, allows the cooling oil to flow directly through the winding, achieving efficient and direct cooling of the winding body. At the same time, the end of the first winding is immersed and cooled using an annular oil reservoir, and the cooling oil is guided to the end of the second winding for directional spraying through the oil guide channel. This forms a multi-layer cooling method combining oil immersion, direct flow, and spraying, which significantly improves the overall heat dissipation effect of the winding. Furthermore, it eliminates the need for slotting on the surface of the stator core, ensuring a complete contact area between the stator core and the motor housing, providing sufficient torsional torque, and avoiding the risk of torque transmission failure. This structure also simplifies the cooling system. Through the synergistic effect of the oil inlet core, oil spraying core, and oil guide core, smooth flow and precise distribution of cooling oil are achieved, reducing dependence on external components such as oil spraying rings, and lowering material and production costs. It not only significantly improves the cooling efficiency and operational reliability of the motor, but also enhances the compactness and manufacturability of the structure. It is suitable for the heat dissipation needs of high power density motors and has outstanding practicality and economy. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the oil passage structure of this utility model.
[0019] Figure 2 This is a schematic diagram of the oil guiding channel of this utility model.
[0020] Figure 3 This is a schematic diagram of the stator core of this utility model.
[0021] Figure 4 This is a schematic diagram of the injection molded body of this utility model.
[0022] Figure 5 This is a schematic diagram of the annular oil storage tank of this utility model.
[0023] Figure 6 This is a schematic diagram of the oil inlet iron core of this utility model.
[0024] Figure 7 This is a schematic diagram of the oil-spraying iron core of this utility model.
[0025] Figure 8 This is a schematic diagram of the oil-conducting iron core of this utility model.
[0026] Figure 9 This is a schematic diagram of the oil injection channel of this utility model. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0028] like Figure 1-2 As shown, this utility model provides a motor stator cooling oil channel structure, including: a stator core 1, an annular oil reservoir 2, windings 3, and a motor housing 8. The stator core 1 is disposed inside the motor housing 8. The annular oil reservoir 2 is coaxially disposed at one end of the stator core 1. Multiple oil guiding channels 4 arranged in an annular array are axially arranged on the stator core 1. The oil guiding channels 4 axially penetrate the stator core 1 and communicate with the annular oil reservoir 2. The windings 3 are disposed within the oil guiding channels 4. The two ends of the windings 3 extend outward from the oil guiding channels 4 to form a first winding end 31 and a second winding end 32, respectively. The end 31 of the winding extends into the annular oil reservoir 2, where it is cooled by immersion in the cooling oil. The cooling oil then flows along the oil guide channel 4 from the end 31 of the first winding to the end 32 of the second winding, where it is sprayed to cool the end 32. This simultaneously achieves oil immersion cooling of the end 31 of the first winding, direct cooling of the winding 3 within the oil guide channel 4, and spray cooling of the end 32 of the second winding. This greatly improves the cooling effect of the winding 3 and eliminates the need for slotting on the surface of the stator core 1, ensuring the effective contact area and torsional torque requirements between the surface of the stator core 1 and the motor housing 8.
[0029] like Figure 3 As shown, the inner ring of the stator core 1 has multiple first stator slots 11 arranged in a ring array along the axial direction. Oil guide pipes 41 are adapted to be inserted into the first stator slots 11 to form oil guide channels 4. Specifically, as... Figure 4 As shown, one end of the oil guide pipe 41 is connected to an end plate 44 that is adapted to the end wall of the stator core 1. Multiple oil guide pipes 41 arranged in a ring on the end plate 44 are integrally injection molded with the end plate 44 to form an injection molded body. The injection molded body is made of PA66-GF30 material. Two injection molded bodies are provided. The oil guide pipes 41 of the two injection molded bodies are respectively adapted to be inserted into the first stator slot 11 from both ends of the stator core 1, and are joined together in the first stator slot 11 to form an oil guide channel 4, which facilitates installation and replacement.
[0030] The middle part of the oil guide pipe 41 is clearance-fitted with the winding 3 to allow cooling oil to flow along the gap between the winding 3 and the inner wall of the oil guide pipe 41, realizing the flow of cooling oil from the end 31 of the first winding to the end 32 of the second winding, thereby cooling the winding. The end of the oil guide pipe 41 gradually narrows and is interference-fitted with the winding 3 to clamp and fix both ends of the winding 3, preventing the winding 3 from loosening. However, due to the narrowing of the end of the oil guide pipe 41, the cooling oil in the annular oil reservoir 2 cannot smoothly enter the oil guide channel 4, and the cooling oil in the oil guide channel 4 cannot smoothly spray from the other end to the end 32 of the second winding. Therefore, a through hole 45 is provided at the end of the oil guide pipe 41 connected to the end plate 44. The through holes 45 on the oil guide pipes 41 of the two injection molded bodies form the first oil guide hole 42 and the second oil guide hole 43, respectively. The cooling oil enters the oil guide channel 4 through the first oil guide hole 42 and exits the cooling oil in the oil guide channel 4 through the second oil guide hole 43.
[0031] An oil inlet core 5 is coaxially arranged between the annular oil reservoir 2 and the stator core 1. The oil inlet core 5 is sealed to the slot at one end of the annular oil reservoir 2 to form a closed inner cavity within the annular oil reservoir 2. Figure 5 As shown, an oil inlet 21 is provided on one side of the annular oil reservoir 2 to fill the inner cavity of the annular oil reservoir 2 with cooling oil. A protruding key structure 22 is provided on the other side of the annular oil reservoir 2 to achieve circumferential positioning of the annular oil reservoir 2 in the motor housing 8, ensuring that the oil inlet 21 is aligned with the opening on the motor housing 8.
[0032] like Figure 6As shown, the inner ring of the oil inlet core 5 has multiple second stator slots 51 corresponding to multiple first stator slots 11 along the axial direction. The oil guide pipe 41 near one end of the annular oil reservoir 2 is adapted to be inserted into the second stator slot 51 so that the end 31 of the first winding passes through the second stator slot 51 and extends into the annular oil reservoir 2. The outer ring of the oil inlet core 5 has multiple oil inlet channels 52 arranged in annular array along the axial direction. The first oil guide hole 42 is located at one end of the oil guide channel 4 near the oil inlet core 5. The multiple oil inlet channels 52 on the oil inlet core 5 are respectively connected to the first oil guide holes 42 of the multiple oil guide channels 4 so that the cooling oil in the annular oil reservoir 2 enters the oil guide channel 4 from the first oil guide hole 42 through the oil inlet channel 52 on the oil inlet core 5.
[0033] An oil-spraying core 6 is coaxially mounted on the end of the stator core 1 furthest from the annular oil reservoir 2, such as... Figure 7 As shown, the inner ring of the oil-injecting core 6 has multiple third stator slots 61 corresponding to multiple first stator slots 11 along the axial direction. The oil guide pipe 41 at the end away from the annular oil reservoir 2 is adapted to be inserted into the third stator slot 61 so that the end of the second winding 32 extends out of the oil-injecting core 6 through the third stator slot 61. The outer ring of the oil-injecting core 6 has multiple oil injection channels 62 arranged in an annular array along the axial direction. The second oil guide hole 43 is located at the end of the oil guide channel 4 near the oil-injecting core 6. The multiple oil injection channels 62 on the oil-injecting core 6 are respectively connected to the second oil guide holes 43 of the multiple oil guide channels 4 so that the cooling oil in the oil guide channel 4 is sprayed from the oil injection channels 62 on the oil-injecting core 6 through the second oil guide holes 43 to the end of the second winding 32. Specifically, the oil injection channel 62 is inclined from the outer ring to the inner ring along the axial direction of the oil injection core 6 so as to spray the cooling oil onto the end 32 of the second winding extending from the inner ring, thereby reducing the use of the oil spraying ring, saving materials, and reducing production costs.
[0034] An oil guide core 7 is coaxially arranged between the stator core 1 and the oil inlet core 5 to connect the multiple oil inlet channels 52 on the oil inlet core 5 to the first oil guide holes 42 of the multiple oil guide channels 4 respectively. Another oil guide core 7 is coaxially arranged between the stator core 1 and the oil injection core 6 to connect the second oil guide holes 43 of the multiple oil guide channels 4 to the multiple oil injection channels 62 on the oil injection core 6 respectively. Specifically, as shown... Figure 8 As shown, the inner ring of the oil guide core 7 has multiple fourth stator slots 71 along the axial direction, corresponding to multiple first stator slots 11. The oil guide tubes 41 of the two injection molded bodies are respectively adapted to be inserted into the fourth stator slots 71 of the two oil guide cores 7.
[0035] The outer ring of the oil guide core 7 is provided with multiple oil collecting grooves 72 arranged in a ring array along the axial direction. The multiple oil collecting grooves 72 on the oil guide core 7 between the stator core 1 and the oil inlet core 5 are respectively connected to multiple oil inlet channels 52 on the oil inlet core 5. The multiple oil collecting grooves 72 on the oil guide core 7 between the stator core 1 and the oil injection core 6 are respectively connected to multiple oil injection channels 62 on the oil injection core 6. Each oil collecting groove 72 on the oil guide core 7 is connected to a fourth stator groove 71 through an oil passage 73. The multiple oil passages 73 on the oil guide core 7 between the stator core 1 and the oil inlet core 5 are respectively connected to the first oil guide holes 42 of multiple oil guide channels 4. The multiple oil passages 73 on the oil guide core 7 between the stator core 1 and the oil injection core 6 are respectively connected to the second oil guide holes 43 of multiple oil guide channels 4.
[0036] The stator core 1 is formed by stacking multiple conventional laminations using a bonding process, and it forms the middle section of the motor stator. The oil inlet core 5 is formed by stacking 2-3 oil inlet laminations using a bonding process. The oil guide core 7 is formed by stacking 2-3 oil guide laminations using a bonding process. Figure 9 As shown, the oil-injecting core 6 uses 3-4 oil-injecting laminations, with staggered oil injection holes on adjacent laminations. By stacking 3-4 laminations and aligning the staggered oil injection holes, an oil injection channel 62 with a certain angle is formed. Furthermore, the stator core 1, oil inlet core 5, oil-injecting core 6, and oil guide core 7 each have a first positioning groove 12, a second positioning groove 53, a third positioning groove 63, and a fourth positioning groove 74 on one side of their circumference to achieve circumferential positioning of each core within the motor housing 8, ensuring that the channels on each core can be properly matched and connected.
[0037] In summary, the cooling oil channel provided in this application is as follows: Cooling oil is added to the inner cavity of the annular oil reservoir 2 through the oil inlet 21 of the annular oil reservoir 2, immersing and cooling the end 31 of the first winding that extends into the annular oil reservoir 2; at the same time, the cooling oil enters the oil collection groove 72 of the first oil guide core 7 through the oil inlet channel 52 on the oil inlet core 5, and then enters the oil guide channel 4 from the first oil guide hole 42 through the oil passage 73, and flows along the gap between the winding 3 and the inner wall of the oil guide pipe 41 in the oil guide channel 4, directly cooling the winding 3; the cooling oil flows from the end 31 of the first winding to the end 32 of the second winding in the oil guide channel 4, and enters the oil collection groove 72 through the oil passage 73 of the second oil guide core 7 through the second oil guide hole 43, and finally sprays the second winding end 32 from the oil spray channel 62 on the oil spray core 6 to achieve cooling and heat dissipation of the winding 3.
[0038] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.
Claims
1. A stator cooling oil passage structure for an electric motor, characterized in that, include: The stator core (1), the annular oil reservoir (2), and the winding (3) are arranged coaxially at one end of the stator core (1). The stator core (1) is provided with multiple oil guide channels (4) arranged in annular array along the axial direction. The oil guide channels (4) axially penetrate the stator core (1) and communicate with the annular oil reservoir (2). The winding (3) is arranged in the oil guide channel (4). The two ends of the winding (3) extend to the outside of the oil guide channel (4) to form the first winding end (31) and the second winding end (32). The first winding end (31) extends into the annular oil reservoir (2) and is cooled by immersion in the cooling oil in the annular oil reservoir (2). The cooling oil flows from the first winding end (31) to the second winding end (32) along the oil guide channel (4) to spray and cool the second winding end (32).
2. The cooling oil passage structure according to claim 1, characterized in that, The inner ring of the stator core (1) has multiple first stator slots (11) arranged in a ring array along the axial direction. An oil guide pipe (41) is adapted to be inserted into the first stator slot (11) to form an oil guide channel (4). The middle part of the oil guide pipe (41) is clearance-fitted with the winding (3) so that the cooling oil flows along the gap between the winding (3) and the inner wall of the oil guide pipe (41). The end of the oil guide pipe (41) is interference-fitted with the winding (3) to clamp and fix the two ends of the winding (3).
3. The cooling oil passage structure according to claim 2, characterized in that, An oil inlet core (5) is coaxially arranged between the annular oil reservoir (2) and the stator core (1). The oil inlet core (5) is sealed to the slot of the annular oil reservoir (2). The inner ring of the oil inlet core (5) is provided with multiple second stator slots (51) corresponding to multiple first stator slots (11) along the axial direction. The oil guide pipe (41) is adapted to be inserted into the second stator slot (51) so that the end of the first winding (31) passes through the second stator slot (51) and extends into the annular oil reservoir (2).
4. The cooling oil passage structure according to claim 3, characterized in that, The outer ring of the oil inlet core (5) is provided with multiple oil inlet channels (52) arranged in a ring array along the axial direction. The oil guide channel (4) is provided with a first oil guide hole (42) at one end near the oil inlet core (5). The multiple oil inlet channels (52) on the oil inlet core (5) are respectively connected to the first oil guide holes (42) of the multiple oil guide channels (4).
5. The cooling oil passage structure according to claim 4, characterized in that, An oil-spraying core (6) is coaxially arranged at one end of the stator core (1) away from the annular oil reservoir (2). The inner ring of the oil-spraying core (6) is provided with multiple third stator slots (61) corresponding to multiple first stator slots (11) along the axial direction. The oil guide pipe (41) is adapted to be inserted into the third stator slot (61) so that the end of the second winding (32) passes through the third stator slot (61) and extends out of the oil-spraying core (6).
6. The cooling oil passage structure according to claim 5, characterized in that, The outer ring of the oil injection core (6) is provided with multiple oil injection channels (62) arranged in a ring array along the axial direction. The oil guide channel (4) is provided with a second oil guide hole (43) at one end near the oil injection core (6). The multiple oil injection channels (62) on the oil injection core (6) are respectively connected to the second oil guide holes (43) of the multiple oil guide channels (4).
7. The cooling oil passage structure according to claim 6, characterized in that, The oil injection channel (62) is inclined along the axial direction from the outer ring to the inner ring of the oil injection core (6) so as to spray the cooling oil to the end (32) of the second winding located in the inner ring.
8. The cooling oil passage structure according to claim 7, characterized in that, An oil guide core (7) is coaxially arranged between the stator core (1) and the oil inlet core (5) to connect the multiple oil inlet channels (52) on the oil inlet core (5) to the first oil guide holes (42) of the multiple oil guide channels (4) respectively. Another oil guide core (7) is coaxially arranged between the stator core (1) and the oil injection core (6) to connect the second oil guide holes (43) of the multiple oil guide channels (4) to the multiple oil injection channels (62) on the oil injection core (6) respectively.
9. The cooling oil passage structure according to claim 8, characterized in that, The inner ring of the oil guide core (7) is provided with multiple fourth stator slots (71) corresponding to multiple first stator slots (11) along the axial direction. The oil guide pipe (41) is adapted to be inserted into the fourth stator slot (71). The outer ring of the oil guide core (7) is provided with multiple oil collection grooves (72) arranged in a ring array along the axial direction. The multiple oil collection grooves (72) are respectively connected to multiple oil inlet channels (52) / oil injection channels (62). Each oil collection groove (72) is connected to a fourth stator slot (71) through an oil passage (73). The multiple oil passages (73) are respectively connected to the first oil guide hole (42) / second oil guide hole (43) of multiple oil guide channels (4).
10. The cooling oil passage structure according to claim 9, characterized in that, One end of the oil guide tube (41) is connected to an end plate (44) that is adapted to the end wall of the stator core (1). The end of the oil guide tube (41) connected to the end plate (44) has a through hole (45). Multiple oil guide tubes (41) arranged in a ring on the end plate (44) are integrally injection molded with the end plate (44) to form an injection molded body. The oil guide tubes (41) of the two injection molded bodies are respectively inserted into the first stator slot (11) from both ends of the stator core (1) and are connected in the first stator slot (11) to form an oil guide channel (4). The through holes (45) on the oil guide tubes (41) of the two injection molded bodies respectively form the first oil guide hole (42) and the second oil guide hole (43).