CN117914028A - Stator assembly and motor - Google Patents

Abstract

The application relates to a stator assembly and a motor, wherein the stator assembly comprises a stator, two guide rings and a shell, the stator comprises an iron core and a winding, the winding is provided with extension parts positioned at two opposite sides of the iron core along a first direction, and the outer side wall of the iron core is provided with a sinking groove; the two guide rings are arranged at the two opposite ends of the stator along the first direction and sleeved outside the extension part, and guide holes penetrating through the inner side wall and the outer side wall of the guide rings are arranged on the guide rings; the shell is sleeved outside the stator and the guide ring, a groove extending along the first direction is arranged on the inner side wall of the shell, and a cooling medium inlet which penetrates through the shell and is communicated with the groove is arranged on the shell; wherein the first direction is parallel to the axial direction of the iron core; the extending direction of the sinking groove is intersected with the first direction; the shell is in interference fit with the stator, the groove is simultaneously communicated with the sink groove and the diversion hole, and the cooling medium inlet, the groove, the sink groove and the diversion hole are combined to form a cooling medium runner. The application can solve the problems of reduced motor performance, efficiency, reliability and service life caused by motor heating.

Description

Stator assembly and motor

Technical Field

The application relates to the technical field of motors, in particular to a stator assembly and a motor.

Background

Along with the increasing demands of people on high-performance pure electric vehicles, high performance, high efficiency and low cost become development trends of motor technologies, and the improvement of motor power and the reduction of motor size become key measures for realizing product competitiveness of each host factory. However, with the increase of the power density, the heating problem of the motor is more and more prominent, if a good cooling structure is not provided, the heat generated by the motor is difficult to be taken away rapidly, so that the working temperature of motor parts is higher, and the performance, efficiency, reliability and service life of the motor are seriously reduced.

Disclosure of Invention

Based on the above, it is necessary to provide a stator assembly and a motor aiming at the problems that the motor heating causes higher working temperature of motor parts and seriously reduces the performance, efficiency, reliability and service life of the motor.

According to one aspect of the present application, there is provided a stator assembly comprising: the stator comprises an iron core and a winding, wherein the winding is provided with protruding parts respectively positioned at two opposite sides of the iron core along a first direction, and a sinking groove is formed in the outer side wall of the iron core; the two guide rings are respectively arranged at two opposite ends of the stator along the first direction and sleeved outside the extending part, and guide holes penetrating through the inner side wall and the outer side wall of the guide rings are formed in the guide rings; the shell is sleeved outside the stator and the guide ring, a groove extending along the first direction is formed in the inner side wall of the shell, and a cooling medium inlet which penetrates through the shell and is communicated with the groove is formed in the shell; wherein the first direction is parallel to the axial direction of the iron core; the extending direction of the sinking groove is intersected with the first direction; the shell is in interference fit with the stator, and the groove is simultaneously communicated with the sink groove and the diversion hole, so that the cooling medium inlet, the groove, the sink groove and the diversion hole are combined to form a cooling medium runner.

According to the stator assembly provided by the application, the guide rings are respectively arranged at the two opposite ends of the stator, the outer part of the stator is sleeved with the shell in interference fit with the guide rings, the outer side wall of the iron core of the stator is provided with the sink groove, the inner side wall of the shell is provided with the groove, the shell is provided with the cooling medium inlet communicated with the groove, the guide rings are provided with the guide holes, and the cooling medium inlet, the groove, the sink groove and the guide holes are combined to form the cooling medium flow passage, so that the cooling medium can flow out through the cooling medium flow passage and drop on the winding of the stator through the guide holes, and the cooling effect is achieved.

In some embodiments, the stator includes a plurality of the iron cores stacked along a first direction, each of the iron cores having the sink groove thereon; each sinking groove is communicated with the groove. Therefore, the cooling medium can flow into each sinking groove to exchange heat with each iron core correspondingly, so that the cooling effect is improved.

In some embodiments, a plurality of the sinking grooves are arranged on the same iron core at intervals along the circumferential direction of the iron core. Therefore, the flow of the cooling medium in unit time can be improved, and the cooling effect is improved.

In some embodiments, the sinking grooves on two adjacent iron cores are arranged in a staggered manner in the circumferential direction of the iron cores. Thus, the grooves on the iron cores are combined to form a spiral channel, so that the heat exchange area is increased, and the cooling effect is improved.

In some embodiments, the countersink on two adjacent cores has an overlap region that overlaps in the circumferential direction of the cores; the overlapping area is communicated with the groove, so that medium circulation between the groove and the sink groove is better ensured.

In some embodiments, a plurality of welding seams are arranged on the outer side wall of each iron core, and the welding seams of a plurality of iron cores are aligned. The plurality of welding seams can be one or more welding seams. Based on the above, after the multi-section iron cores of the stator are rotationally laminated, the welding seams of the multi-section iron cores are connected into a straight line, and a plurality of iron cores are continuously welded into a whole through the welding seams.

In some embodiments, the deflector ring is provided with a plurality of deflector holes which are arranged at intervals along the circumferential direction of the deflector ring. Therefore, the guide ring can guide the cooling medium to different circumferential positions of the iron core, and the cooling effect is improved.

In some embodiments, the plurality of deflector holes are unevenly distributed along the circumference of the deflector ring; for example, the distribution position of the diversion holes can be designed according to the placement angle of the stator. Illustratively, when the axial direction of the stator is parallel to the horizontal direction, the stator has an upper portion and a lower portion opposite to each other in the up-down direction, and thus, a plurality of guide holes may be provided in the upper portion of the guide ring without providing the guide holes in the lower portion, considering that the cooling medium may be more easily concentrated in the lower portion by gravity. In this way, the cooling medium can be filled in the flow channel of the lower part first and then flows out from the diversion holes of the upper part, so that heat exchange between the upper part and the lower part and the cooling medium can be ensured.

Optionally, the apertures of at least two of the deflector holes are not equal. For example, the aperture of the deflector hole in the upper portion of the deflector ring is larger than the aperture of the deflector hole in the lower portion of the deflector ring. Based on the above, the plurality of diversion holes distributed on the diversion ring at intervals along the circumferential direction can compensate stator cooling difference caused by the difference of the flow velocity of the cooling medium at different positions.

In some embodiments, a plurality of grooves are formed in the inner side wall of the shell at intervals along the circumferential direction of the shell, so that the heat exchange area is increased, and the cooling effect is improved.

Optionally, the housing comprises an aluminum alloy, and the groove is cast on the housing. Based on the above, the shell is cast by adopting aluminum alloy, and the plurality of axial grooves on the inner side wall of the shell can be cast directly without additional machining.

According to another aspect of the application there is provided an electrical machine comprising a stator assembly as hereinbefore described. According to the motor provided by the application, the guide rings are respectively arranged at the two opposite ends of the stator, the outer part of the stator is sleeved with the shell in interference fit with the guide rings, the outer side wall of the iron core of the stator is provided with the sink groove, the inner side wall of the shell is provided with the groove, the shell is provided with the cooling medium inlet communicated with the groove, the guide rings are provided with the guide holes, and the cooling medium inlet, the groove, the sink groove and the guide holes are combined to form the cooling medium flow passage, so that the cooling medium can flow out through the cooling medium flow passage and drop on the winding of the stator through the guide holes, and the cooling effect is achieved.

Drawings

Fig. 1 is a schematic perspective view of a stator assembly according to an embodiment of the present application.

Fig. 2 shows an exploded view of a stator assembly in an embodiment of the application.

Fig. 3 shows a schematic structural view of a core according to an embodiment of the present application.

Fig. 4 shows a schematic structural diagram of a baffle ring according to an embodiment of the present application.

Fig. 5 shows a schematic structural view of the housing in an embodiment of the present application.

Fig. 6 shows a schematic diagram of a cooling medium flow passage according to an embodiment of the present application.

Fig. 7 shows a schematic view of a cooling medium flow passage according to another embodiment of the present application.

Reference numerals illustrate:

1. a stator assembly;

10. a stator; 11. an iron core; 111. sinking grooves; 112. welding seams; 12. a winding;

20. A guide ring; 21. a deflector aperture; 211. a cooling medium outlet;

30. a housing; 31. a groove; 32. a cooling medium inlet;

40. a cooling medium flow passage;

x, first direction.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

Fig. 1 is a schematic perspective view of a stator assembly according to an embodiment of the present application. Fig. 2 shows an exploded view of a stator assembly in an embodiment of the application. Fig. 3 shows a schematic structural view of a core according to an embodiment of the present application. Fig. 4 shows a schematic structural diagram of a baffle ring according to an embodiment of the present application. Fig. 5 shows a schematic structural view of the housing in an embodiment of the present application. Fig. 6 shows a schematic diagram of a cooling medium flow passage according to an embodiment of the present application. Fig. 7 shows a schematic view of a cooling medium flow passage according to another embodiment of the present application.

Referring to fig. 1 and2, a stator assembly 1 according to an embodiment of the present application includes a stator 10, two guide rings 20, and a housing 30.

Referring to fig. 2 and 3, the stator 10 includes a core 11 and windings 12, the windings 12 having extensions respectively located at opposite sides of the core 11 in a first direction X, and a countersink 111 provided on an outer sidewall of the core 11.

Referring to fig. 2 and 4, two guide rings 20 are respectively disposed at opposite ends of the stator 10 along the first direction X and sleeved outside the extension portion, and guide holes 21 penetrating through the inner side wall and the outer side wall of the guide rings 20 are formed on the guide rings.

Referring to fig. 1, 2 and 5, the casing 30 is sleeved outside the stator 10 and the guide ring 20, a groove 31 extending along the first direction X is formed on the inner side wall of the casing 30, and a cooling medium inlet 32 penetrating the casing 30 and communicating with the groove 31 is formed on the casing 30.

Referring to fig. 2 and 6 or 7, in which the first direction X is parallel to the axial direction of the core 11, the extending direction of the sink 111 intersects the first direction X, for example, the sink 111 extends in the circumferential direction of the core 11. The housing 30 is interference fit with the stator 10, and the grooves 31 are simultaneously communicated with the sink 111 and the guide holes 21, so that the cooling medium inlets 32, the grooves 31, the sink 111 and the guide holes 21 are combined to form the cooling medium flow passages 40. Based on this, the cooling medium flow passage 40 is formed by combining the cooling medium inlet 32, the groove 31, the sink 111, and the deflector hole 21, so that the cooling medium can flow out through the cooling medium flow passage 40 through the deflector hole 21 and drop on the windings 12 of the stator 10 to achieve the cooling effect.

It is understood that the deflector hole 21 forms the cooling medium outlet 211 of the cooling medium flow passage 40.

Optionally, the guide ring 20 is sleeved outside the extension of the winding 12, and the outer side wall of the guide ring 20 is flush with the outer side wall of the iron core 11. In this way, the housing 30 is in interference fit with the stator 10 and also can be in interference fit with the guide ring 20, so that the housing 30 and the guide ring 20 can be in sealing connection, and the leakage phenomenon between the guide hole 21 and the groove 31 is not easy to occur.

Optionally, the length of the groove 31 on the inner side wall of the housing 30 along the first direction X is greater than the length of the stator 10, so that the groove 31 can guide the cooling medium to each part of the stator 10, and ensure that different parts of the stator 10 along the length direction can effectively dissipate heat.

Referring to fig. 5, optionally, a connector is provided at the cooling medium inlet 32, and the connector is used for connecting with the cooling medium input mechanism to convey the cooling medium into the cooling medium flow channel 40.

Optionally, the cooling medium inlet 32 is provided at a middle section in the length direction of the casing 30. For example, the cooling medium inlets 32 are used for the housing 30 at equal distances between the end surfaces of the opposite ends to each other in the first direction X. Based on this, the cooling medium can be more uniformly dispersed to both ends of the cooling medium flow passage 40 in the first direction X, thereby making the heat dissipation of the stator 10 more uniform.

Referring to fig. 2 and 3, in some embodiments, the stator 10 includes a plurality of cores 11 stacked in the first direction X, each core 11 having a slot 111, each slot 111 being in communication with the slot 31. When the number of grooves 31 is plural, each of the sinking grooves 111 may be selectively provided to communicate with at least one groove 31. In this way, the cooling medium can flow into each of the sinking grooves 111, and exchange heat with each of the cores 11 accordingly, thereby improving the cooling effect.

Optionally, a plurality of sink grooves 111 are provided on the same core 11 at intervals along the circumferential direction thereof, so that the flow rate of the cooling medium in unit time can be increased, thereby increasing the cooling effect.

Alternatively, the plurality of the sink grooves 111 on the outer side wall of the core 11 are all equal in size, and the interval between any adjacent two of the sink grooves 111 on the same core 11 is equal. In this way, the cooling medium can be evenly distributed around the stator 10.

Alternatively, the countersunk grooves 111 on two adjacent cores 11 are arranged in a staggered manner in the circumferential direction of the cores 11. Thus, the sinking grooves 111 on the iron cores 11 are combined to form a spiral channel, so that the heat exchange area is increased, and the cooling effect is improved.

Illustratively, the segments of the multi-segment core 11 of the stator 10 are stacked by rotating at a uniform angle, thereby ensuring that the respective slots 111 of the stator 10 are spirally connected in the axial direction.

Alternatively, the sink grooves 111 on the adjacent two cores 11 have overlapping areas overlapping in the circumferential direction of the cores 11, the overlapping areas being in communication with the grooves 31, thereby better securing the medium communication between the grooves 31 and the sink grooves 111.

Illustratively, the circumferential width of the groove 31 is greater than the width of the non-overlapping region. In this way, it is possible to effectively ensure that the overlapping region of the sink 111 on the adjacent two cores 11 communicates with the slot 31.

Referring to fig. 3, in some embodiments, a plurality of welds 112 are provided on the outer sidewall of each core 11, and the welds 112 of the plurality of cores 11 are aligned. Wherein the number of welds 112 may specifically be one or more welds 112. In this way, after the multi-stage cores 11 of the stator 10 are rotationally stacked, the weld beads 112 of the multi-stage cores 11 are connected in a straight line, and the plurality of cores 11 are continuously welded together by the weld beads 112.

Referring to fig. 4, in some embodiments, the deflector ring 20 is provided with a plurality of deflector holes 21 spaced along its circumference. In this way, the guide ring 20 can guide the cooling medium to different circumferential positions of the iron core 11, thereby improving the cooling effect.

Optionally, the plurality of deflector holes 21 are unevenly distributed along the circumference of the deflector ring 20. For example, the distribution positions of the deflector holes 21 may be designed according to the placement angle of the stator 10.

Illustratively, when the axial direction of the stator 10 is parallel to the horizontal direction, the stator 10 has upper and lower portions opposite to each other in the up-down direction, and thus, a plurality of guide holes 21 may be provided in the upper portion of the guide ring 20 without providing the guide holes 21 in the lower portion, considering that the cooling medium may be more easily concentrated in the lower portion by gravity. In this way, the cooling medium can be made to fill the flow passage of the lower portion first and then flow out from the deflector hole 21 of the upper portion, thereby ensuring that both the upper portion and the lower portion can exchange heat with the cooling medium.

Alternatively, the shape of the deflector hole 21 is a circle, an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, or a combination of at least two of them.

Alternatively, the apertures of at least two of the pilot holes 21 are not equal. For example, the aperture of the deflector hole 21 at the upper portion of the deflector ring 20 is larger than the aperture of the deflector hole 21 at the lower portion of the deflector ring 20.

Based on this, the plurality of deflector holes 21 circumferentially spaced on the deflector ring 20 can compensate for the cooling difference of the stator 10 caused by the difference in the flow velocity of the cooling medium at different positions.

In some embodiments, a plurality of grooves 31 are formed on the inner side wall of the housing 30 at intervals along the circumferential direction thereof, so as to increase the heat exchange area and improve the cooling effect.

Optionally, the housing 30 comprises an aluminum alloy and the groove 31 is cast into the housing 30. Based on this, the housing 30 is cast from an aluminum alloy, and the plurality of axial grooves 31 in the inner sidewall of the housing 30 can be cast directly without additional machining.

In an exemplary embodiment, the stator assembly 1 includes a stator 10, two guide rings 20, and a housing 30.

The stator 10 includes a plurality of cores 11 stacked in an axial direction thereof, and windings 12 having protruding portions respectively located at opposite sides of the cores 11 in the first direction X. The outer side wall of each iron core 11 is provided with a plurality of sinking grooves 111 which are uniformly arranged at intervals along the circumferential direction, and the sinking grooves 111 on two adjacent iron cores 11 are arranged in a staggered manner along the circumferential direction. In this way, a plurality of spiral grooves uniformly spaced in the circumferential direction can be formed in the outer side wall of the stator 10.

The two guide rings 20 are respectively arranged at two opposite ends of the stator 10 along the first direction X and sleeved outside the extending parts of the windings 12, and a plurality of guide holes 21 penetrating through the inner side wall and the outer side wall of the guide rings 20 are arranged on the guide rings. The axial direction of the deflector ring 20 is parallel to the horizontal direction, the deflector ring 20 has an upper portion and a lower portion opposite to each other in the up-down direction, and the deflector holes 21 are distributed on the upper portion of the deflector ring 20.

The casing 30 is sleeved outside the stator 10 and the guide ring 20, a groove 31 extending along the axial direction of the casing 30 is arranged on the inner side wall of the casing 30, and a cooling medium inlet 32 penetrating the casing 30 and communicating with the groove 31 is arranged on the casing 30.

The housing 30 is interference fit with the stator 10, and the grooves 31 are simultaneously communicated with the sink 111 and the guide holes 21, so that the cooling medium inlets 32, the grooves 31, the sink 111 and the guide holes 21 are combined to form the cooling medium flow passages 40.

The stator assembly 1 provided in this embodiment does not need to add additional parts and higher cost, does not need to be assembled with complex high precision, and can efficiently dissipate heat of the motor stator 10, thereby improving the performance, efficiency and service life of the motor.

The cooling medium flows into the circumferential sinking groove 111 of the stator 10 from the cooling medium inlet 32 on the shell 30 through the axial groove 31 on the inner side wall of the shell 30, and fills the plurality of spiral cooling medium flow channels 40 in the axial direction of the stator 10 through the interaction and penetration of the axial groove 31 and the circumferential sinking groove 111, so that the flow resistance of the cooling medium is effectively reduced, the heat exchange area is increased, and the cooling effect is improved. Meanwhile, after the cooling medium flows out through the plurality of spiral cooling medium flow channels 40, the cooling medium is guided by the guide rings 20 at the two ends of the stator 10, flows out from the guide holes 21 of the guide rings 20 and drops on the windings 12 of the stator 10, so that the cooling effect can be further improved, and the temperature of the motor can be quickly reduced.

The plurality of grooves 31 axially on the inner side wall of the housing 30 may be directly formed by casting without additional machining. Meanwhile, the sunk grooves 111 of the stator 10 along the circumferential direction have the same structural size, the stator 10 is formed by rotationally laminating and welding the axial multi-section iron cores 11, and each iron core 11 has the same structure, small number of parts, simple process and low manufacturing cost.

No additional parts are arranged between the stator 10 and the shell 30, the shell 30 is connected with the stator 10 in an interference fit manner, the overall rigidity is better, and the NVH and the reliability of the motor are better. The motor NVH refers to noise, vibration and harshness (Noise, vibration, harshness) of the motor, which are shown to the outside during operation.

Based on the same object, the application also provides an electric machine comprising the stator assembly 1 of the above-described embodiment. Based on this, when the motor is required to be cooled during operation, the cooling medium can be introduced into the cooling medium flow passage 40 formed by combining the cooling medium inlet 32, the groove 31, the sink 111 and the diversion hole 21, and heat exchange is performed with each part of the motor by using the cooling medium during the circulation of the cooling medium flow passage 40, so as to achieve the cooling effect. At the cooling medium outlet 211 of the cooling medium flow passage 40, the cooling medium can flow out through the diversion holes 21 and drop down on the windings 12 of the stator 10, thereby further improving the cooling effect.

The motor provided by the application has the following advantages due to the stator assembly 1 comprising the above embodiment: the stator 10 has good heat dissipation performance, low temperature rise of parts, good motor performance and high efficiency; meanwhile, the cost is low, and NVH and reliability are better.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. A stator assembly, comprising:

The stator comprises an iron core and a winding, wherein the winding is provided with protruding parts respectively positioned at two opposite sides of the iron core along a first direction, and a sinking groove is formed in the outer side wall of the iron core;

the two guide rings are respectively arranged at two opposite ends of the stator along the first direction and sleeved outside the extending part, and guide holes penetrating through the inner side wall and the outer side wall of the guide rings are formed in the guide rings; and

The shell is sleeved outside the stator and the guide ring, a groove extending along the first direction is formed in the inner side wall of the shell, and a cooling medium inlet which penetrates through the shell and is communicated with the groove is formed in the shell;

wherein the first direction is parallel to the axial direction of the iron core;

the extending direction of the sinking groove is intersected with the first direction;

The shell is in interference fit with the stator, and the groove is simultaneously communicated with the sink groove and the diversion hole, so that the cooling medium inlet, the groove, the sink groove and the diversion hole are combined to form a cooling medium runner.

2. The stator assembly of claim 1, wherein the stator includes a plurality of the cores stacked in a first direction, each of the cores having the countersink disposed thereon;

each sinking groove is communicated with the groove.

3. The stator assembly of claim 2 wherein a plurality of said countersinks are provided on the same core at circumferentially spaced intervals.

4. The stator assembly of claim 2, wherein the countersunk slots on adjacent two of the cores are offset in a circumferential direction of the cores.

5. The stator assembly of claim 4, wherein the countersink on adjacent two of the cores has an overlap region that overlaps in a circumferential direction of the cores;

the overlap region communicates with the groove.

6. The stator assembly of claim 2 wherein a plurality of welds are provided on an outer sidewall of each of said cores, said welds of a plurality of said cores being aligned.

7. The stator assembly according to any one of claims 1 to 6, wherein the deflector ring is provided with a plurality of the deflector holes spaced apart along a circumferential direction thereof.

8. The stator assembly of claim 7, wherein a plurality of the deflector holes are unevenly distributed along a circumference of the deflector ring; and/or

The apertures of at least two of the deflector holes are not equal.

9. The stator assembly according to any one of claims 1-6 wherein the housing has a plurality of circumferentially spaced grooves on an inner side wall thereof; and/or

The housing comprises an aluminum alloy and the groove is cast on the housing.

10. An electric machine comprising a stator assembly as claimed in any one of claims 1 to 9.