Electric motor stator, drive motor and electric drive system

Abstract

This application provides a motor stator, a drive motor, and an electric drive system. The motor stator includes a stator core disposed within a motor housing and stator windings disposed within axially penetrating stator slots in the stator core. The stator core is formed by stacking core laminations, which include first-type core laminations disposed at at least one end and second-type core laminations disposed in the remaining portion. The first-type core laminations have closed slots for forming stator slots, and the second-type core laminations have open slots for forming stator slots. An axially penetrating first cooling channel is formed inside the stator windings. An oil baffle ring is also provided at at least one end of the stator core, which connects to the motor housing and the first-type core laminations and forms an oil reservoir that communicates with the first cooling channel. The oil reservoir, in conjunction with the first cooling channel, achieves direct and sufficient cooling of the stator windings, thereby supporting the motor to operate at higher power and torque densities.

Description

Technical Field

[0001] This application relates to the field of motor technology, and more specifically, to motor stators, drive motors, and electric drive systems. Background Technology

[0002] The operating performance of an electric motor, such as torque density and power density, is affected by the cooling effect of the stator and rotor, especially the cooling effect of the stator windings.

[0003] Currently, few motors are designed to directly cool the stator windings. Instead, they indirectly cool the stator windings by cooling the yoke, which has a very limited cooling effect and has become a bottleneck in improving the motor's torque density and power density.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] This application provides a motor stator, a drive motor, and an electric drive system that can achieve direct and sufficient cooling of the stator windings, improve the heat exchange capacity of the stator windings, and thus help the motor improve torque density and power density.

[0006] According to one aspect of this application, a motor stator is provided, comprising a stator core disposed within a motor housing and a stator winding disposed within an axially penetrating stator slot of the stator core, wherein: the stator core is formed by stacking core laminations, the core laminations comprising a first type of core lamination disposed at at least one end of the stator core and a second type of core lamination disposed in the remaining portion of the stator core, the first type of core lamination having a closed slot for forming the stator slot, and the second type of core lamination having an open slot for forming the stator slot, the opening of the open slot being located on the radial inner wall of the second type of core lamination; an axially penetrating first cooling channel is formed inside the stator winding; an oil baffle ring is also provided at at least one end of the stator core, the oil baffle ring being connected to the motor housing and the first type of core lamination and forming an oil storage cavity, the oil storage cavity communicating with the first cooling channel, and the motor housing having an opening communicating with the oil storage cavity and the outside.

[0007] In some embodiments, the oil baffle ring is fixed to the end of the stator winding by a potting compound, and the end of the stator winding includes at least the welded end of the stator winding.

[0008] In some embodiments, the oil baffle ring is provided with an axial cavity in which the potting compound is contained.

[0009] In some embodiments, the oil baffle ring includes a first annular portion, a second annular portion, and a third annular portion. The annular surfaces of the first and third annular portions extend axially, and the annular surface of the second annular portion extends radially. The second annular portion is connected between the first and third annular portions, and the first, second, and third annular portions form the axial cavity. The annular surface of the first annular portion is connected to the inner wall of the motor housing, and the end face of the third annular portion is connected to the end edge of the radial inner wall of the first type of iron core lamination.

[0010] In some embodiments, the annular surface of the first annular portion is sealed against the inner wall of the motor housing by a sealing ring, and / or the end face of the third annular portion is sealed against the end edge of the radial inner wall of the first type of iron core lamination by a lip seal.

[0011] In some embodiments, the stator winding disposed in the slot of each core lamination forms a winding gap, and the winding gaps of each core lamination are axially connected to form the first cooling channel, and the winding gaps of each core lamination are the same or different.

[0012] In some embodiments, the winding gap of each core lamination is formed in any of the following forms: one or more gaps formed by stator windings located in the same radial plane; one or more gaps formed by stator windings located in different radial planes; one or more gaps formed by grooves between adjacent conductors of the stator winding.

[0013] In some embodiments, the stator winding is a flat wire winding.

[0014] In some embodiments, a foamed insulating paper or an injection-molded insulating layer is provided between the stator winding and the stator slot.

[0015] In some embodiments, the teeth and / or yoke of the stator core form an axially penetrating second cooling channel, and the oil storage cavity is also connected to the second cooling channel.

[0016] In some embodiments, the first type of core lamination and the oil baffle ring are disposed at the oil inlet end of the stator core, and the second type of core lamination is disposed at the body portion and the oil outlet end of the stator core.

[0017] In some embodiments, the first type of core lamination and the oil baffle ring are disposed at the oil inlet and oil outlet ends of the stator core, and the second type of core lamination is disposed in the body portion of the stator core.

[0018] According to another aspect of this application, a drive motor is provided, the drive motor being configured with a motor stator as described in any of the above embodiments.

[0019] According to another aspect of this application, an electric drive system is provided, the electric drive system being configured with the aforementioned drive motor.

[0020] The beneficial effects of this application compared to the prior art include at least the following:

[0021] The motor stator of this application features open slots in the second type of iron core laminations to facilitate the arrangement of the stator windings; and closed slots in the first type of iron core laminations to facilitate the connection of the oil retaining rings, further facilitating the formation of an oil reservoir for sufficient cooling of the winding ends. This oil reservoir, in conjunction with a first cooling channel formed inside the stator windings, achieves direct and sufficient cooling of the stator windings with low cost and simple manufacturing process, improving the heat dissipation efficiency of the stator windings and supporting the motor to operate at higher power and torque densities. The motor stator of this application can be applied to scenarios requiring high power and torque densities, such as drive motors for new energy vehicles.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0024] Figure 1 This illustration shows a structural schematic diagram of a motor stator in one embodiment of this application;

[0025] Figure 2 Show Figure 1 Enlarged structural diagram of region A in the middle;

[0026] Figure 3 This illustration shows a structural schematic diagram of a first type of iron core lamination in an embodiment of this application;

[0027] Figure 4 This illustration shows a structural schematic diagram of a second type of iron core lamination in an embodiment of this application;

[0028] Figure 5 This invention illustrates another structural schematic diagram of the motor stator in an embodiment of this application;

[0029] Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 The following are schematic diagrams illustrating several structures of winding gaps in embodiments of this application;

[0030] Figure 11 This illustration shows another structural diagram of the first type of iron core lamination in the embodiments of this application;

[0031] Figure 12 This illustration shows another structural diagram of the second type of iron core lamination in the embodiments of this application. Detailed Implementation

[0032] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to those described herein. Rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0033] The accompanying drawings are merely illustrative of this application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted.

[0034] The use of terms such as "first," "second," and similar words in the specific description does not indicate any order, quantity, or importance, but is merely used to distinguish different components. The term "multiple" means two or more, unless otherwise explicitly specified. Furthermore, in the description of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection within two elements.

[0035] It should be noted that, unless otherwise specified, the embodiments of this application and the features in different embodiments can be combined with each other.

[0036] Figure 1 This diagram illustrates one structure of a motor stator. Figure 2 Indicate Figure 1 The magnified structure of region A in the middle, Figure 3 The structure of the first type of iron core lamination is shown. Figure 4 The structure of the second type of iron core lamination is shown. Figure 5 This illustrates another structure of a motor stator. (Combined with...) Figures 1 to 5 As shown:

[0037] The motor stator provided in this application embodiment includes a stator core 200 disposed within a motor housing 100 and a stator winding 300 disposed within axially penetrating stator slots (211, 221) of the stator core 200. The stator core 200 is formed by stacking core laminations (210, 220). The core laminations (210, 220) include a first type of core lamination 210 disposed at at least one end of the stator core 200 and a second type of core lamination 220 disposed in the remaining portion of the stator core 200. The first type of core lamination 210 is provided with a closed slot 211 for forming the stator slots (211, 221), and the second type of core lamination 220 is provided with an open slot 221 for forming the stator slots (211, 221). The opening of the open slot 221 is located on the radial inner wall 222 of the second type of core lamination 220. Here, axial direction refers to the Z-axis direction of the motor stator, and radial direction X is the direction perpendicular to the axial direction. A first cooling channel 310 is formed inside the stator winding 300, extending axially. At least one end of the stator core 200 is also provided with an oil retainer ring 400, which is connected to the motor housing 100 and the first type of core lamination 210, forming an oil storage cavity 440. The oil storage cavity 440 is connected to the first cooling channel 310, and the motor housing 100 is provided with an opening 110 connecting the oil storage cavity 440 to the outside.

[0038] The radial inner walls of the first type of core lamination 210 and the second type of core lamination 220 face the motor rotor. The second type of core lamination 220 has an open slot 221, which facilitates the placement of the stator winding 300 into the stator slots (211, 221) and reduces electromagnetic losses, optimizing electromagnetic performance. The first type of core lamination 210 has a closed slot 211, forming a continuous, sealed structure at the slot opening on its radial inner wall, increasing structural strength and facilitating connection with the oil baffle ring 400, preventing the oil baffle ring 400 from encroaching on the air gap between the motor stator and rotor. Both the open slot 221 and the closed slot 211 are axially continuous, allowing them to be stacked to form axially continuous stator slots (211, 221).

[0039] At at least one end of the stator core 200, an oil reservoir 440 is formed by the cooperation of an oil retainer ring 400, the motor housing 100, and the first type of core lamination 210. This reservoir accumulates suitable cooling media, such as cooling oil, entering through the opening, ensuring that at least one end of the stator winding 300 is immersed in oil for adequate cooling. Furthermore, a first cooling channel 310 is formed inside the stator winding 300, communicating with the oil reservoir 440. This allows the cooling medium to flow into the first cooling channel 310 for direct and adequate cooling of the stator winding 300.

[0040] The first type of core lamination 210 can be disposed at one or both ends of the stator core 200. Correspondingly, one or both ends of the stator core 200 are also provided with oil retaining rings 400 that cooperate with the first type of core lamination 210. Specifically, in some implementations, combined with Figures 1 to 4 As shown, the first type of core lamination 210 and the oil baffle ring 400 are disposed at the oil inlet end 200a of the stator core 200, and the second type of core lamination 220 are disposed at the body and oil outlet end of the stator core 200, so that the stator winding 300 is in a one-end oil-immersed mode. In the one-end oil-immersed mode, the cooling medium enters the oil storage chamber 440 from the opening 110 at the oil inlet end 200a and accumulates in the oil storage chamber 440, which fully cools the first end 300a of the stator winding 300 (the first end 300a is preferably the welded end of the stator winding 300). Further, under pressure, the cooling medium flows into the first cooling channel 310, which directly and fully cools the stator winding 300, and then flows to the second end 300b of the stator winding 300 by spraying or other suitable means to cool the second end 300b, and then flows out from the opening 120 at the oil outlet end 200b. The flow direction of the cooling medium can be referenced. Figure 1 The arrow is a dashed line.

[0041] In other implementations, combining Figures 3 to 5 As shown, the first type of core lamination 210 and the oil retaining ring 400 are disposed at the oil inlet end 200a and the oil outlet end 200b of the stator core 200, and the second type of core lamination 220 is disposed in the body of the stator core 200, so that the stator winding 300 is in a two-end oil-immersion mode. In the two-end oil-immersion mode, oil storage cavities 440 are formed at both the first and second ends of the stator winding 300 to achieve sufficient cooling of both ends of the stator winding 300; at the same time, in conjunction with the first cooling channel 310 formed inside the stator winding 300, direct and sufficient cooling of the entire stator winding 300 is achieved. The flow direction of the cooling medium can be referred to Figure 5 The arrow is a dashed line. Figure 5 In the middle, the specific structures of the stator winding 300, the first cooling channel 310, and the oil baffle ring 400 are similar to those of the stator winding 300. Figure 1 The details are not shown because they are consistent with the Chinese standard.

[0042] In summary, combining Figures 1 to 5As shown, the motor stator of this application has an open slot 221 provided in the second type of iron core lamination 220 to facilitate the arrangement of the stator winding 300; and a closed slot 211 provided in the first type of iron core lamination 210 to facilitate the connection of the oil retaining ring 400, further facilitating the formation of an oil storage cavity 440 for sufficient cooling of the winding ends. The oil storage cavity 440, in conjunction with the first cooling channel 310 formed inside the stator winding 300, achieves direct and sufficient cooling of the stator winding 300 with low cost and simple process, improving the heat dissipation efficiency of the stator winding 300 and supporting the motor to operate at higher power density and torque density. The motor stator of this application can be applied to scenarios requiring high power density and high torque density, such as drive motors for new energy vehicles.

[0043] In some embodiments, refer to Figure 1 and Figure 2 As shown, the oil baffle ring 400 is fixed to the end of the stator winding 300 by potting compound 480. The end of the stator winding 300 includes at least the welded end of the stator winding 300 (i.e., the first end 300a of the stator winding 300). By potting with the potting compound 480, the oil baffle ring 400 is fixed on the one hand, and the welded end of the stator winding is insulated and protected on the other hand.

[0044] In some embodiments, the oil baffle ring 400 is provided with an axial cavity 400', in which potting compound 480 is contained. The process of fixing the oil baffle ring 400 to the end of the stator winding 300 by the potting compound 480 includes, for example, injecting liquid potting compound 480 into the axial cavity 400' of the oil baffle ring 400, whereby the presence of the axial cavity 400' can contain and confine the potting compound 480; then immersing the welded portion of the welded end of the stator winding 300 in the potting compound 480, so that the potting compound 480 fully covers the welded portion; and then curing the potting compound 480, so that the potting compound 480, the oil baffle ring 400, and the end of the stator winding 300 are firmly bonded together, thereby fixing the oil baffle ring 400 to the end of the stator winding 300.

[0045] Continue to combine Figure 1 and Figure 2As shown, in some embodiments, the oil baffle ring 400 includes a first annular portion 410, a second annular portion 420, and a third annular portion 430. The annular surfaces of the first annular portion 410 and the third annular portion 430 extend axially in a "Z" direction, and the annular surface of the second annular portion 420 extends radially in a "X" direction. The second annular portion 420 connects between the first annular portion 410 and the third annular portion 430, forming an axial cavity 400'. The annular surface of the first annular portion 410 is connected to the inner wall of the motor housing 100, and the end face 430a of the third annular portion 430 is connected to the end edge 210a of the radial inner wall of the first type of iron core lamination 210. Thus, through the structural design of the first annular portion 410, the second annular portion 420, and the third annular portion 430, an axial cavity 400' is formed, and a stable connection with the motor housing 100 and the first type of iron core lamination 210 is achieved.

[0046] In other embodiments, the oil retaining ring 400 can be designed with other suitable structures, such as forming an arc-shaped cross-section, as long as it has an axial cavity to accommodate the potting compound 480 and is easy to connect with the motor housing 100 and the first type of iron core lamination 210 to form a stable oil storage cavity 440.

[0047] Furthermore, in some embodiments, the annular surface of the first annular portion 410 is sealed against the inner wall of the motor housing 100 by a sealing ring 411, and / or, the end face of the third annular portion 430 is sealed against the end edge 210b of the radial inner wall of the first type of iron core lamination 210 by a lip seal 433. This ensures a sealed connection between the oil baffle ring 400 and the motor housing 100 and the first type of iron core lamination 210, preventing the cooling medium in the oil reservoir 440 from leaking into the rotor side, allowing the cooling medium to enter the first cooling channel 310, and achieving direct and sufficient cooling of the stator winding 300.

[0048] In some embodiments, combined with Figure 1 , Figures 3 to 5 As shown, the stator windings 300 disposed in the slots of each core lamination (210, 220) form winding gaps 310'. The winding gaps 310' of each core lamination (210, 220) are axially connected to form a first cooling channel 310. The winding gaps 310' of each core lamination (210, 220) can be the same or different. Specifically, Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 The diagram illustrates several structures for winding gaps, combined with... Figure 3 , Figure 4 , Figures 6 to 8As shown: The winding gap 310' formed in the first type of core lamination 210 can be one or more gaps formed by stator windings 300 located in the same radial plane, for example... Figure 3 and Figure 6 The winding gap 310' shown in the diagram; the winding gap 310' formed in the first type of core lamination 210 can also be one or more gaps formed by stator windings 300 located in different radial planes, for example Figure 7 and Figure 8 The winding gap 310' shown in the diagram; similarly, the winding gap 310' formed in the second type of core lamination 220 can be one or more gaps formed by stator windings 300 located in the same radial plane, for example... Figure 4 and Figure 6 The winding gap 310' shown in the diagram; the winding gap 310' formed in the second type of core lamination 220 can also be one or more gaps formed by stator windings 300 located in different radial planes, for example Figure 7 and Figure 8 The winding gap of 310' is shown in the diagram. (Combined with...) Figure 9 and Figure 10 As shown: The winding gaps 310' formed in the first type of core lamination 210 / second type of core lamination 220 can also be one or more gaps formed by the grooves between adjacent conductors 300' of the stator winding 300. One or more winding gaps 310' of each core lamination (210, 220) with the same or different structures are axially connected to form one or more first cooling channels 310, thus adapting to different winding structures and the design requirements of different motors, enhancing versatility. Preferably, the stator winding 300 is a flat wire winding to improve motor performance and facilitate the formation of winding gaps 310', but this is not a limitation.

[0049] In some embodiments, combined with Figure 1 and Figure 2 As shown, a foamed insulating paper or injection-molded insulating layer (uniformly labeled 500 in the figure) is provided between the stator winding 300 and the stator slot. Using foamed insulating paper or injection-molded insulating layer, which does not require dripping / impregnation of varnish, can prevent the cooling channels in the stator slot from being blocked by insulating materials (such as dripping / impregnation of varnish), ensuring the unobstructed flow of cooling channels in the slot.

[0050] Figure 11 This illustrates another structure of the first type of iron core lamination. Figure 12 This diagram illustrates another structure of the second type of iron core lamination, combined with... Figure 1 , Figure 2 , Figure 11 and Figure 12As shown, in some embodiments, the teeth and / or yoke of the stator core 200 form an axially penetrating second cooling channel 260, and the oil storage cavity 440 is also connected to the second cooling channel 260 so that the cooling medium flows into the second cooling channel 260 to directly and fully cool the stator core 200, balance the cooling effect of the stator winding 300 and the stator core 200, and improve the overall heat dissipation capacity of the motor.

[0051] This application also provides a drive motor configured with a motor stator as described in any of the above embodiments. For example, the drive motor can be configured as follows: Figure 1 The motor stator shown has one end of its windings immersed in oil, achieving a cooling mode of oil immersion at one end and oil spraying at the other, thus balancing cooling and electromagnetic performance. For example, the drive motor can be configured as follows... Figure 5 The motor stator shown has oil-immersed winding ends, which enables oil-immersed cooling at both ends, resulting in more uniform heat dissipation. It is suitable for high-power motors and can provide a more balanced cooling effect.

[0052] This application also provides an electric drive system configured with a drive motor as described in the above embodiments. The electric drive system can be applied to high-performance electric drive scenarios such as new energy vehicles, improving the overall system efficiency.

[0053] The motor stator of this application can also be used in any other suitable motor to improve the power density and torque density of the motor by directly and fully cooling the stator winding 300. Motors equipped with the motor stator of this application can also be used in any other suitable electric system to achieve efficient and stable operation through excellent cooling performance.

[0054] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A motor stator, comprising a stator core disposed within a motor housing and a stator winding disposed within an axially penetrating stator slot of the stator core, characterized in that: The stator core is formed by stacking core laminations. The core laminations include a first type of core lamination disposed at at least one end of the stator core and a second type of core lamination disposed in the remaining part of the stator core. The first type of core lamination is provided with a closed slot for forming the stator slot, and the second type of core lamination is provided with an open slot for forming the stator slot. The opening of the open slot is located on the radial inner wall of the second type of core lamination. The stator winding has an axially penetrating first cooling channel inside; At least one end of the stator core is provided with an oil baffle ring, which is connected to the motor housing and the first type of core lamination and forms an oil storage cavity. The oil storage cavity is connected to the first cooling channel, and the motor housing is provided with an opening that connects the oil storage cavity to the outside.

2. The motor stator of claim 1, wherein, The oil baffle ring is fixed to the end of the stator winding by a potting compound, and the end of the stator winding includes at least the welded end of the stator winding.

3. The motor stator of claim 2, wherein, The oil baffle ring is provided with an axial cavity, and the potting compound is contained in the axial cavity.

4. The motor stator of claim 3, wherein, The oil baffle ring includes a first annular portion, a second annular portion, and a third annular portion. The annular surfaces of the first annular portion and the third annular portion extend axially, and the annular surface of the second annular portion extends radially. The second annular portion is connected between the first annular portion and the third annular portion, and the first annular portion, the second annular portion, and the third annular portion form the axial cavity. The annular surface of the first annular portion is connected to the inner wall of the motor housing, and the end face of the third annular portion is connected to the end edge of the radial inner wall of the first type of iron core lamination.

5. The motor stator of claim 4, wherein, The annular surface of the first annular portion is sealed to the inner wall of the motor housing by a sealing ring, and / or the end face of the third annular portion is sealed to the end edge of the radial inner wall of the first type of iron core lamination by a lip seal.

6. The motor stator of claim 1, wherein, The stator windings disposed in the slots of each of the core laminations form a winding gap, and the winding gaps of each core lamination are axially connected to form the first cooling channel. The winding gaps of each core lamination may be the same or different.

7. The motor stator of claim 6, wherein, The winding gap of each of the aforementioned core laminations can be formed in any of the following forms: One or more gaps formed by stator windings located in the same radial plane; One or more gaps formed by stator windings located in different radial planes; One or more gaps formed by the grooves between adjacent conductors of a stator winding.

8. The motor stator of claim 1, wherein, The stator winding is a flat wire winding.

9. The motor stator of claim 1, wherein, A foamed insulating paper or an injection-molded insulating layer is provided between the stator winding and the stator slot.

10. The motor stator of claim 1, wherein, The teeth and / or yoke of the stator core form an axially penetrating second cooling channel, and the oil storage cavity is also connected to the second cooling channel.

11. An electrical machine stator according to any one of claims 1 to 10, characterised in that, The first type of core lamination and the oil baffle ring are disposed at the oil inlet end of the stator core, and the second type of core lamination are disposed at the body part and the oil outlet end of the stator core.

12. An electrical machine stator according to any one of claims 1 to 10, characterised in that, The first type of core lamination and the oil baffle ring are disposed at the oil inlet and oil outlet ends of the stator core, and the second type of core lamination is disposed in the body of the stator core.

13. A drive motor characterized by The drive motor is equipped with a motor stator as described in any one of claims 1 to 12.

14. An electric drive system, characterized by The electric drive system is equipped with the drive motor as described in claim 13.

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