CN115912700A

CN115912700A - Motor stator assembly and motor

Info

Publication number: CN115912700A
Application number: CN202211346798.6A
Authority: CN
Inventors: 喻泽文; 王东雄; 郭俊; 张经纬; 周坤
Original assignee: Dongfeng Motor Group Co Ltd
Current assignee: Dongfeng Motor Group Co Ltd
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2023-04-04
Also published as: WO2024093547A1

Abstract

The invention provides a motor stator component and a motor, which relate to the field of motors and comprise a plurality of stator iron chips, wherein each stator iron chip is provided with a central hole and an annular outer wall, and the stator iron chip is provided with a plurality of wire grooves which are arranged at intervals along the circumferential direction; along the radial direction, the wall surface of each wire groove close to the annular outer wall is sunken towards the annular outer wall to form a cooling groove; each stator iron core piece is laminated along the axial direction, the wire grooves of each stator iron core piece are communicated in the axial direction to form a wire winding channel, the cooling grooves of each stator iron core piece are communicated in the axial direction to form a cooling channel, wherein the wall surfaces of the wire grooves are flush in the wire grooves forming the wire winding channel, and the wall surfaces of the cooling grooves are not flush in the cooling grooves forming the cooling channel. The cooling channel is formed by connecting the cooling groove through the cooling groove, so that heat can be effectively dissipated, and the harmonic waves of the motor can be effectively inhibited through the non-flush arrangement of the wall surface of the cooling groove, so that the noise of the motor is reduced.

Description

Motor stator assembly and motor

Technical Field

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

Background

Along with the rapid development of new energy automobile technology, people have higher and higher requirements on the noise of a new energy automobile driving motor, and simultaneously along with the increase of the power density of the motor, the requirement on the heat dissipation capacity of the motor is also greatly improved. Adopt stator chute can effectively reduce motor stator harmonic, reduce the motor noise, but the manufacturing of stator chute is very complicated, needs special frock, is difficult to guarantee the angular tolerance of chute. Meanwhile, for the heat dissipation requirement of the motor, a complex cooling oil duct design is adopted, only the end part of the winding can be cooled, the winding in the wire slot cannot be cooled and lubricated, and the heat dissipation and cooling efficiency is reduced.

Disclosure of Invention

The invention provides a motor stator assembly and a motor, which aim to solve the technical problems of suppressing motor harmonic waves and reducing motor noise while improving the heat dissipation and cooling efficiency of a motor stator.

An embodiment of the present invention provides a stator assembly of an electric machine, including: each stator core piece is provided with a central hole and an annular outer wall, and the stator core pieces are provided with a plurality of wire grooves which are arranged at intervals along the circumferential direction; in the radial direction, the wall surface of each wire groove close to the annular outer wall is sunken towards the annular outer wall to form a cooling groove; the stator iron core pieces are stacked in the axial direction, the wire grooves of the stator iron core pieces are communicated in the axial direction to form wire winding channels, the cooling grooves of the stator iron core pieces are communicated in the axial direction to form cooling channels, the wall surfaces of the wire grooves in the wire grooves forming the wire winding channels are flush, and the wall surfaces of the cooling grooves in the cooling grooves forming the cooling channels are not flush.

Furthermore, the maximum length of one end of the cooling slot in the stator core sheet, which is perpendicular to the central line of the slot, is the maximum offset distance, and the extending direction of the central line of the slot is the same as the radial direction; at least two different sets of the cooling slots of the maximum offset distance exist in the stator core sheet.

Furthermore, the shapes of the cooling grooves in the stator core sheet are the same, the center lines of the cooling grooves are parallel to the center line of the wire casing, and the distance between the center line of the cooling groove and the center line of the wire casing is the center distance; at least two groups of cooling grooves with different center distances exist in the stator iron core sheet.

Further, the cooling slots of each stator core piece are communicated in the axial direction to form a cooling channel, and at least two groups of cooling slots with different center distances exist in the cooling channel.

Further, in the axial direction, a plurality of stator iron core pieces are laminated to form stator iron core groups, and the center distances of the cooling grooves of two adjacent stator iron core groups are different.

Further, the central line of each cooling slot in the stator iron core sheet is overlapped with the central line of the wire slot, and at least two groups of cooling slots with different circumferential sizes exist in the stator iron core sheet.

Further, the cooling slots of the stator core pieces are communicated in the axial direction to form a cooling channel, and at least two groups of cooling slots with different circumferential sizes exist in the cooling channel.

Further, one end, closest to the annular outer wall, of the cooling groove in the stator core piece is a maximum concave end, and the shortest distance from the maximum concave end to the wire groove is the radial depth; there are at least two different sets of the cooling slots of the radial depth in the stator core pieces.

Further, the cooling slots of each stator core piece are communicated in the axial direction to form a cooling channel, and at least two groups of cooling slots with different radial depths exist in the cooling channel.

Furthermore, an included angle exists between the extending direction of the wall surface of the cooling groove in the stator core sheet and the central line direction of the wire groove; at least two groups of cooling grooves with different angles and included angles exist in the stator iron core sheet.

Further, the cooling grooves of the stator core pieces are communicated in the axial direction to form a cooling channel, and at least two groups of cooling grooves with different angles and included angles exist in the cooling channel.

Further, stator module still includes the stator and leads the oiled-plate, the stator lead the oiled-plate with the stator iron core piece is connected, the stator leads the oiled-plate to have leads the oil groove, lead the oil groove with cooling channel intercommunication.

Further, the stator oil guide plate is located between the two stator iron core pieces, and oil guide grooves are formed in two sides of the stator oil guide plate.

Further, the oil guide grooves on the same side of the stator oil guide plate are arranged at intervals, and the oil guide grooves on the two sides of the stator oil guide plate are arranged in a staggered mode.

Furthermore, the wall surfaces of the cooling grooves of the stator iron core sheets on two sides of the stator oil guide plate are flush.

Further, in the axial direction, the number of the stator core pieces on both sides of the stator oil guide plate is the same, and the cooling slots of the stator core pieces on both sides of the stator oil guide plate are symmetrical with respect to the stator oil guide plate.

An embodiment of the present invention further provides a motor, including: the stator assembly described above; a casing enclosing a containing cavity, wherein the stator assembly is positioned in the containing cavity; a rotor assembly positioned within the central bore of the stator assembly.

Further, the stator assembly further comprises a stator oil guide plate, and the stator oil guide plate is provided with an oil guide groove; the housing includes: the oil inlet nozzle is communicated with the annular oil duct, and the oil guide groove is communicated with the cooling channel and the annular oil duct.

Further, the chassis has a plurality of heat radiating fins.

An embodiment of the present invention provides a stator assembly of a motor, including: the stator core pieces are provided with a central hole and an annular outer wall and are provided with a plurality of wire grooves which are arranged at intervals along the circumferential direction; along the radial direction, the wall surface of each wire groove close to the annular outer wall is sunken towards the annular outer wall to form a cooling groove; each stator iron core piece is laminated along the axial direction, the wire grooves of each stator iron core piece are communicated in the axial direction to form a wire winding channel, the cooling grooves of each stator iron core piece are communicated in the axial direction to form a cooling channel, wherein the wall surfaces of the wire grooves are flush in the wire grooves forming the wire winding channel, and the wall surfaces of the cooling grooves are not flush in the cooling grooves forming the cooling channel. The cooling channels are axially connected to form the cooling channel and communicated with the winding channel, so that cooling liquid directly flows into the winding channel; meanwhile, the stator core sheets rotate at different angles in the axial direction to meet the requirement of non-flush arrangement of the wall surfaces of the cooling grooves in the cooling channel, motor harmonic waves can be effectively restrained, the noise of the motor is reduced, the contact area between the cooling liquid and the stator assembly is increased due to the non-flush arrangement of the wall surfaces in the cooling channel, the flowing speed of the cooling liquid can be slowed down when the cooling liquid flows through the channel with the changed cross section, the heat exchange time of the cooling liquid is prolonged, and the cooling efficiency is further improved.

Drawings

Fig. 1 is a schematic structural diagram of a stator assembly according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an axial view of a stator assembly according to an embodiment of the present invention;

FIG. 3 is an enlarged view of portion A of FIG. 2;

fig. 4 is a schematic structural diagram of a stator core segment in a stator assembly according to an embodiment of the present invention;

FIG. 5 is an enlarged view of portion B of FIG. 4;

fig. 6 is a schematic structural view of another stator core piece in a stator assembly according to an embodiment of the present invention;

fig. 7 is a schematic structural view of another stator core piece in a stator assembly according to an embodiment of the present invention;

FIG. 8 is a schematic structural view of another stator core segment of a stator assembly according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a stator oil guide plate in a stator assembly according to an embodiment of the present invention;

FIG. 10 is a schematic structural view of another stator assembly provided in accordance with an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a motor according to an embodiment of the present invention;

fig. 12 is a cross-sectional view of an electric machine provided in accordance with an embodiment of the present invention;

fig. 13 is a schematic view of a housing structure of a motor according to an embodiment of the present invention.

Description of the reference numerals

1. A motor; 10. a stator assembly; 11. a stator core piece; 111. a central bore; 112. an annular outer wall; 113. a wire slot; 1131. a trunking centerline; 114. a cooling tank; 1141. a cooling bath centerline; 12. a trunking channel; 13. a cooling channel; 14. a coil winding; 15. a stator oil guide plate; 151. an oil guide groove; 152. an oil guide wire groove; 153. an oil guide cooling tank; 20. a housing; 21. an accommodating chamber; 22. an oil inlet nozzle; 23. an annular oil passage; 24. a step; 25. a heat sink; 30. a rotor assembly.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The individual features described in the embodiments can be combined in any suitable manner without departing from the scope, for example different embodiments and aspects can be formed by combining different features. In order to avoid unnecessary repetition, various possible combinations of the specific features of the invention will not be described further.

In the following description, the term "first/second/so" is used merely to distinguish different objects and does not mean that there is a common or relationship between the objects. It should be understood that the description of the "upper", "lower", "outer" and "inner" directions as related to the orientation in the normal use state, and the "left" and "right" directions indicate the left and right directions indicated in the corresponding schematic drawings, and may or may not be the left and right directions in the normal use state.

It should be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a component of' 8230; \8230;" does not exclude the presence of another like element in a process, method, article, or apparatus that comprises the element. The term "coupled", where not otherwise specified, includes both direct and indirect connections.

In particular embodiments, a motor-stator assembly is suitable for use with any type of motor, and for example, the stator assembly may be suitable for use with a dc motor; the stator assembly may be adapted for use with an ac electric machine. Meanwhile, the motor having the stator assembly may be applicable to any electrical device, and for example, the motor may be applicable to a water pump; the motor may also be adapted to be used, for example, in a motor vehicle drive motor. For convenience of description, the stator assembly is exemplified below by taking the stator assembly as an example where the stator assembly can be applied to an ac motor, and the motor is applied to an automobile driving motor. The type of the motor and the type of the motor equipment used by the motor do not affect the structure of the stator assembly of the motor.

In some embodiments, as shown in fig. 1-3, the stator assembly 10 includes a plurality of stator laminations 11, each stator lamination 11 having a central bore 111 and an annular outer wall 112, and the stator laminations 11 having a plurality of wire slots 113 circumferentially spaced apart. Specifically, the motor 1 includes a stator assembly 10, a casing 20 and a rotor assembly 30, the stator assembly 10 includes a plurality of stator laminations 11 axially stacked to form a stator core, in order to facilitate axial staggered stacking, a positioning hole may be formed in an annular outer wall 112, the stator laminations 11 are in an annular structure, a central hole 111 is formed in the middle of the stator laminations 11, a plurality of slots 113 are formed in the stator laminations 11 at intervals along the circumferential direction, each slot 113 is communicated with the central hole 111, a position where the slot 113 is connected with the central hole 111 is a notch, a specific radial dimension and an axial dimension of the stator laminations 11 are not limited here, the radial direction is a linear direction of a circular surface of the stator laminations 11 along the diameter or the radius, the axial direction and the radial direction are perpendicular to the thickness direction of the stator laminations 11, the number of the slots 113 in the stator laminations 11, the shape and the size of the notch are not limited, and the requirements are met, for example, the stator laminations 11 are provided with 18 slots 113 at intervals along the circumferential direction, and the slots are square slots with chamfers.

In the radial direction, the wall of each wire chase 113 adjacent to the annular outer wall 112 is recessed toward the annular outer wall 112 to form a cooling trough 114. Specifically, it can be understood that each wire chase 113 in the stator lamination 11 is recessed toward the annular outer wall 112 near the wall of the annular outer wall 112, the recessed space region is a cooling trough 114, the cooling trough 114 provides a space for flowing of cooling liquid, and the cooling liquid can assist in heat dissipation and can also play a role in lubrication. The wire chase 113 is in communication with the cooling chase 114, and the shape and size of the cooling chase 114 are not limited herein, which may be determined according to practical situations, and it should be emphasized that the cooling chases 114 in the stator core sheet 11 are not identical, and the non-identical includes that the cooling chases 114 have different sizes, or the cooling chase 114 has different shapes, or the cooling chase 114 has different recessed positions with respect to the wire chase 113. The specific structure will be described in detail below, which is merely illustrative, for example, the circumferential dimensions of adjacent cooling slots 114 in the stator core pieces 11 are different; for example, the radial dimensions of adjacent cooling slots 114 in the stator core pieces 11 are different; for example, the adjacent cooling slots 114 in the stator lamination 11 have the same shape and size, the distance between the cooling slot center line 1141 and the slot center line 1131 of the slot 113 is the center distance, and the center distances of the two adjacent cooling slots 114 are different.

The stator core pieces 11 are stacked in the axial direction, the slots 113 of the stator core pieces 11 are axially communicated to form the slot channels 12, and the cooling slots 114 of the stator core pieces 11 are axially communicated to form the cooling channels 13. Specifically, the stator core pieces 11 are of an annular structure, the stator core pieces 11 are axially stacked to form stator core sets, it is to be noted that in the same stator core set, the slots 113 of the axially adjacent stator core pieces 11 can be completely the same, and the cooling slots 114 of the axially adjacent stator core pieces 11 can also be completely overlapped, the stator core pieces are axially stacked to form a stator core, the number of axially stacked stator core pieces 11 is not limited, for example, the stator core has 6 stator core sets, each stator core set has 30 stator core pieces 11, 30 stator core pieces 11 are axially stacked to form a stator core set, 6 stator core sets are axially stacked to form a stator core, the slots 113 of the stator core pieces 11 of the 6 stator core sets are axially communicated to form a slot channel 12, the slot channel 12 provides a space for the coil winding 14, the cooling slots 114 of the 6 stator core sets are axially communicated to form a cooling channel 13, the cooling channel 13 provides a space for the flow of cooling liquid, so that the cooling liquid can flow through the stator core pieces 11 to form a cooling channel 12 for the coil winding 14, and the cooling liquid cooling channel 13 of the stator core pieces can be uniformly communicated with the cooling slot channel 12, thereby achieving the uniform cooling of the cooling coil 13 in the stator core set, and the cooling coil winding channel 13, and the cooling channel 12 can be communicated with the cooling channel 13, and the cooling liquid of the cooling coil, and the cooling channel 13 in the stator core pieces at the stator core set, and the cooling channel 12 can be communicated uniformly communicated, and the cooling channel 13 can be communicated. The coolant liquid flows out through the two ends of the wire chase channels 12 after flowing through the coil winding 14, the coolant liquid flowing out from the two ends of each wire chase channel 12 forms a shower effect, so that the copper wires at the end part of the coil winding 14 can be uniformly cooled, the cooling uniformity of the end part of the coil winding 14 in the circumferential direction is ensured, the local overheating of the coil winding 14 is avoided, and the cooling effect is further improved. It should be noted that, the structure form of the cooling liquid specifically introduced into the cooling channel 13 is not limited herein, and any structure capable of introducing the cooling liquid into the cooling channel 13 is satisfactory, for example, the end of the cooling channel 13 is directly communicated with the oil inlet nozzle 22 of the motor 1, and the oil inlet nozzle 22 is an inlet of the motor 1 for introducing the cooling liquid. For example, the stator assembly 10 further includes a stator oil guide plate 15, the stator oil guide plate 15 has an oil guide groove 151, and the oil guide groove 151 guides the cooling fluid of the oil inlet 22 of the motor 1 into the cooling passage 13, as described in detail below.

Among the wire grooves 113 forming the coil winding 14, the wall surfaces of the wire grooves 113 are flush, and among the cooling grooves 114 forming the cooling passage 13, the wall surfaces of the cooling grooves 114 are not flush. As shown in fig. 2 and 3, specifically, each stator lamination 11 is laminated in the axial direction, and the slots 113 in each stator lamination 11 are flush with the wall surface of the coil winding 14 formed in the axial direction, that is, the wall surfaces of two adjacent slots 113 in the axial direction are in the same plane. The cooling grooves 114 in each stator core segment 11 are not flush with the wall surfaces of the cooling passages 13 formed in the axial direction, i.e., the wall surfaces of the cooling grooves 114 in which at least a part of the number of stator core segments 11 are present in the axial direction are not in the same plane as the wall surfaces of the remaining cooling grooves 114 in the cooling passages 13. The wall surfaces of the cooling grooves 114 in the cooling channels 13 are not arranged in a flush manner, so that the motor harmonic can be effectively inhibited, the motor noise can be reduced, meanwhile, the contact area of the cooling liquid with the stator assembly 10 in the cooling channels 13 can be increased, and the cooling efficiency can be further improved. Any arrangement mode which can meet the condition that the wall surfaces of the cooling grooves 114 in the cooling channels 13 are not arranged in a flush manner meets the requirement, exemplarily, the shapes of the cooling grooves 114 in the stator core sheet 11 are the same, the cooling groove center line 1141 is parallel to the wire chase center line 1131, and the distance between the cooling groove center line 1141 and the wire chase center line 1131 is the center distance; at least two sets of cooling slots 114 with different center distances are present in the stator lamination 11, and the specific structure will be described in detail below. Illustratively, each cooling slot centerline 1141 of the stator lamination segment 11 coincides with the slot centerline 1131, and at least two sets of cooling slots 114 of different circumferential dimensions exist in the stator lamination segment 11, and the specific structure will be described in detail below.

An embodiment of the present invention provides a stator assembly of a motor, including: each stator core piece is provided with a central hole and an annular outer wall, and the stator core pieces are provided with a plurality of wire grooves which are arranged at intervals along the circumferential direction; along the radial direction, the wall surface of each wire groove close to the annular outer wall is sunken towards the annular outer wall to form a cooling groove; each stator iron core piece is laminated along the axial direction, the wire grooves of each stator iron core piece are communicated in the axial direction to form a wire winding channel, the cooling grooves of each stator iron core piece are communicated in the axial direction to form a cooling channel, wherein the wall surfaces of the wire grooves are flush in the wire grooves forming the wire winding channel, and the wall surfaces of the cooling grooves are not flush in the cooling grooves forming the cooling channel. The cooling channels are axially connected to form the cooling channels and are communicated with the winding channels, so that cooling liquid directly flows into the winding channels; meanwhile, the stator core sheets rotate at different angles in the axial direction to meet the requirement of non-flush arrangement of the wall surfaces of the cooling grooves in the cooling channel, motor harmonic waves can be effectively restrained, the noise of the motor is reduced, the contact area between the cooling liquid and the stator assembly is increased due to the non-flush arrangement of the wall surfaces in the cooling channel, the flowing speed of the cooling liquid can be slowed down when the cooling liquid flows through the channel with the changed cross section, the heat exchange time of the cooling liquid is prolonged, and the cooling efficiency is further improved.

In some embodiments, as shown in fig. 4 to 6, the maximum length of one end of the cooling slot 114 in the stator core sheet 11 perpendicular to the slot centerline 1131 is the maximum offset distance, and the extension direction of the slot centerline 1131 is the same as the radial direction; at least two different sets of cooling slots 114 of maximum offset distance are present in the stator lamination 11. Specifically, the plurality of slots 113 are arranged at intervals along the circumferential direction of the stator core sheet 11, each slot 113 is completely the same, each slot 113 is communicated with the cooling slot 114, each cooling slot 114 is not completely the same, the maximum length of one end of each cooling slot 114, which is perpendicular to the slot center line 1131, is the maximum offset distance, the slot center line 1131 can be understood as the middle line of the slot 113, the extending direction of the slot center line 1131 is the same as the radial direction, and the slots 113 can be symmetrical with respect to the slot center line 1131; the shape of the cooling slot 114 is not limited, and the cooling slot 114 may be symmetrical with respect to the trunking centerline 1131, or may not be symmetrical with respect to the trunking centerline 1131, and the maximum offset distance may be understood as a perpendicular to the trunking centerline 1131 at any position of the cooling slot 114 in a group in which the cooling slot 114 communicates with the trunking 113, and the maximum offset distance is the maximum length among the perpendicular lines. At least two groups of cooling grooves 114 with different maximum offset distances exist in the stator core sheet 11, any structure which can meet the requirement that two or more groups of cooling grooves 114 with different maximum offset distances exist in the stator core sheet 11 meets the requirement, and the distribution form of the specific structures of different cooling grooves 114 on the stator core sheet 11 is not limited, and the structures can be distributed at intervals and can be distributed randomly. Illustratively, three cooling slots 114 with different shapes exist in the stator core sheet 11, and the maximum offset distances of the cooling slots 114 with different shapes are different; illustratively, there are three different sizes of cooling slots 114 in the stator lamination 11, and the maximum offset distances of the three different sizes of cooling slots 114 are different.

In some embodiments, as shown in fig. 4 and 5, the cooling slots 114 in the stator core sheet 11 have the same shape, the cooling slot center line 1141 is parallel to the slot center line 1131, and the distance between the cooling slot center line 1141 and the slot center line 1131 is the center distance; at least two sets of cooling slots 114 of different center distances are present in the stator lamination 11. Under the condition that the shapes of the cooling slots 114 are the same, in order to ensure that the maximum offset distances are different, a communication structure at different positions can be adopted, specifically, the slot center line 1131 is located in the middle of the slot 113, the cooling slot center line 1141 can be located on one side of the slot center line 1131, that is, the cooling slot center line 1141 is not overlapped with the slot center line 1131, the cooling slot center line 1141 is parallel to the slot center line 1131, the distance between the two is the center distance, and the difference of the maximum offset distances is ensured by controlling the difference of the center distances, exemplarily, three different cooling slots 114 exist in the stator core sheet 11, the first cooling slot center line 1141 is offset to one side of the slot center line 1131, the center distance is L1, the second cooling slot center line 1141 is overlapped with the slot center line 1131, the center distance is L2, that is L2 equal to 0, the third cooling slot center line 1141 is offset to one side of the slot 1131 opposite to the first, the center distance is L3, the values of the L1 and the L3 can be the same, or different, the three cooling slots can be sequentially circulated along the circumferential direction, that the stator core sheet 114 is L2, that is sequentially performed along the circumferential direction.

In some embodiments, as shown in fig. 5, the cooling slots 114 of each stator lamination 11 are communicated in the axial direction to form the cooling channel 13, and at least two sets of cooling slots 114 with different center distances exist in the cooling channel 13. Specifically, the cooling channel 13 is formed by laminating the cooling slots 114 of the stator core pieces 11 in the axial direction, in order to satisfy the requirement that the wall surfaces of the cooling slots 114 in the cooling channel 13 are not flush, thereby effectively suppressing motor harmonics and reducing motor noise, at least two groups of cooling slots 114 with different center distances exist in the cooling channel 13, it can be understood that when a plurality of stator core pieces are laminated in the axial direction, at least a part of the stator core pieces deflect at angles in the axial direction, and the number of specific deflection degrees is not required, so as to satisfy the requirement that the wall surfaces of the coil windings 14 formed in the axial direction by the slots 113 in the stator core pieces 11 are flush, and the wall surfaces of the cooling channels 13 formed in the axial direction by the cooling slots 114 in the stator core pieces 11 are not flush. Illustratively, the stator core has 6 stator iron core groups, which are sequentially the 1 st group to the 6 th group along the axial direction, each stator iron core group has 30 stator iron core pieces 11, 48 wire slots 113 are arranged in the stator iron core pieces 11 along the circumferential direction, each wire slot 113 is communicated with a cooling slot 114, that is, 48 cooling slots 114 are arranged in the stator iron core pieces 11 along the circumferential direction, three cooling slots 114 with different center distances exist in the stator iron core pieces 11, the three cooling slots 114 are sequentially circulated for 16 times along the circumferential direction according to the center distances of L1, L2 and L3, one cooling slot 114 is set to be the cooling slot number 1, the center distance is L1, the cooling slot 114 on the adjacent side is the cooling slot number 2, the center distance is L2, one side of the cooling slot number 2 is the cooling slot number 3, the center distance is L3, and in the axial direction, the cooling groove 1 114 of the stator core plate 11 of the 1 st group corresponds to the cooling groove 1 114 of the stator core plate 11 of the 2 nd group, the cooling groove 1 114 of the stator core plate 11 of the 2 nd group corresponds to the cooling groove 2 of the stator core plate 11 of the 3 rd group, the cooling groove 2 114 of the stator core plate 11 of the 3 rd group corresponds to the cooling groove 2 of the stator core plate 11 of the 4 th group, the cooling groove 2 114 of the stator core plate 11 of the 4 th group corresponds to the cooling groove 3 of the stator core plate 11 of the 5 th group, and the cooling groove 3 114 of the stator core plate 11 of the 5 th group corresponds to the cooling groove 3 of the stator core plate 11 of the 6 th group, that is, the cooling passage 13 formed in the axial direction from the cooling groove 1 of the stator core plate 11 of the 1 st group is sequentially composed of the cooling grooves 114 of the center distances L1, L2, L3, and L3.

In some embodiments, in the axial direction, a plurality of stator core pieces 11 are stacked to form a stator iron set, and the center distances of the cooling slots 114 of two adjacent stator iron sets are different. In order to further suppress motor harmonics and reduce motor noise, each stator iron chip set can be deflected in the axial direction so as to satisfy the requirement that the center distances of the cooling slots 114 of two adjacent stator iron chip sets are different, and the specific deflection degree is not limited, for example, the number of the stator iron chip sets 11 and the arrangement form of the cooling slots 114 are the same as those of the previous embodiment, there are also three cooling slots 114 with different center distances, the three cooling slots 114 are circulated for 16 times in the circumferential direction according to the center distances of L1, L2 and L3, in the axial direction, the cooling slot No. 1 114 of the stator iron chip set 1 corresponds to the cooling slot No. 2 114 of the stator iron chip set 2, the No. 2 cooling groove 114 of the 2 nd group stator core plate 11 corresponds to the No. 3 cooling groove 114 of the 3 rd group stator core plate 11, the No. 3 cooling groove 114 of the 3 rd group stator core plate 11 corresponds to the No. 2 cooling groove 114 of the 4 th group stator core plate 11, the No. 2 cooling groove 114 of the 4 th group stator core plate 11 corresponds to the No. 1 cooling groove 114 of the 5 th group stator core plate 11, and the No. 1 cooling groove 114 of the 5 th group stator core plate 11 corresponds to the No. 2 cooling groove 114 of the 6 th group stator core plate 11, that is, the cooling channel 13 formed in the axial direction from the No. 1 cooling groove 114 of the 1 st group stator core plate 11 is composed of the cooling grooves 114 of the center distances L1, L2, L3, L2, L1, and L2 in this order.

In some embodiments, as shown in fig. 6, each cooling slot centerline 1141 in the stator core piece 11 coincides with the wireway centerline 1131, there being at least two sets of cooling slots 114 of different circumferential dimensions in the stator core piece 11. In the case that each cooling slot center line 1141 coincides with the slot center line 1131, in order to ensure that the maximum offset distance is different, cooling slots 114 with different circumferential sizes are adopted on the stator core sheet 11, the circumferential size can be understood as the width of the cooling slot 114 in the circumferential direction, and the line segment thereof is an arc shape, specifically, the slot center line 1131 is located at the middle position of the slot 113, the cooling slot center line 1141 coincides with the slot center line 1131, the specific shape of the cooling slot 114 is not limited, and the maximum offset distance is ensured by adopting the cooling slots 114 with different circumferential sizes, illustratively, three different cooling slots 114 exist in the stator core sheet 11, the circumferential size of the first cooling slot 114 is A1, the circumferential size of the second cooling slot 114 is A2, and the circumferential size of the third cooling slot 114 is A3, where the values of A1, A2 and A3 are different, and the three different cooling slots 114 in the stator core sheet 11 can alternately circulate in the circumferential direction, that is, the circumferential sizes A1, A2, and A3 circulate in sequence.

In some embodiments, the cooling slots 114 of each stator lamination 11 are communicated in the axial direction to form the cooling channel 13, and at least two sets of cooling slots 114 with different circumferential sizes exist in the cooling channel 13. Specifically, the cooling channel 13 is formed by laminating the cooling slots 114 of the stator core pieces 11 in the axial direction, in order to satisfy the requirement that the wall surfaces of the cooling slots 114 in the cooling channel 13 are not flush, thereby effectively suppressing motor harmonics and reducing motor noise, at least two groups of cooling slots 114 with different circumferential dimensions exist in the cooling channel 13, it can be understood that when a plurality of stator core pieces are laminated in the axial direction, at least a part of the stator core pieces deflect at angles in the axial direction, the number of specifically deflected degrees does not make a requirement, the requirement that the wall surfaces of the coil windings 14 formed in the axial direction by the slots 113 in each stator core piece 11 are flush is satisfied, and the wall surfaces of the cooling channels 13 formed in the axial direction by the cooling slots 114 in each stator core piece 11 are not flush. Illustratively, the stator core has 6 groups of stator iron core groups, which are sequentially from the 1 st group to the 6 th group along the axial direction, 48 wire grooves 113 are arranged in the stator iron core piece 11 along the circumferential direction, each wire groove 113 is communicated with a cooling groove 114, that is, 48 cooling grooves 114 are arranged in the stator iron core piece 11 along the circumferential direction, three cooling grooves 114 with different center distances exist in the stator iron core piece 11, the three cooling grooves 114 are sequentially circulated for 16 times along the circumferential direction according to circumferential dimensions A1, A2 and A3, one of the cooling grooves 114 is set to be the cooling groove 114 No. 1, the circumferential dimension A1, the cooling groove 114 on the adjacent side is set to be the cooling groove 114 No. 2, one side of the cooling groove 114 No. 2 is the cooling groove 114 No. 3, the circumferential dimension A3 is set in the axial direction, the No. 1 cooling groove 114 of the 1 st group stator core piece 11 corresponds to the No. 2 cooling groove 114 of the 2 nd group stator core piece 11, the No. 2 cooling groove 114 of the 2 nd group stator core piece 11 corresponds to the No. 3 cooling groove 114 of the 3 rd group stator core piece 11, the No. 3 cooling groove 114 of the 3 rd group stator core piece 11 corresponds to the No. 3 cooling groove 114 of the 4 th group stator core piece 11, the No. 3 cooling groove 114 of the 4 th group stator core piece 11 corresponds to the No. 2 cooling groove 114 of the 5 th group stator core piece 11, and the No. 2 cooling groove 114 of the 5 th group stator core piece 11 corresponds to the No. 1 cooling groove 114 of the 6 th group stator core piece 11, that is, the cooling passage 13 formed in the axial direction from the No. 1 cooling groove 114 of the 1 st group stator core piece 11 is composed of the cooling grooves 114 of the circumferential dimensions A1, A2, A3, A2, A1 in order.

In some embodiments, as shown in fig. 7, the end of the cooling slot 114 closest to the annular outer wall 112 in the stator lamination sheet 11 is the maximum recessed end, and the shortest distance from the maximum recessed end to the wire slot 113 is the radial depth; at least two sets of cooling slots 114 of different radial depth are present in the stator lamination 11. Specifically, the stator core sheet 11 has a plurality of slots 113 arranged at intervals along the circumferential direction, each slot 113 is completely the same, each slot 113 is communicated with a cooling slot 114, each cooling slot 114 is not completely the same, one end of the cooling slot 114 closest to the annular outer wall 112 is a maximum recessed end, and the shortest distance from the maximum recessed end to the slot 113 is a radial depth; the maximum recessed end can be understood as a point on the cooling groove 114 that is the shortest distance from the annular outer wall 112, the shortest distance from the cooling groove 114 to the wire groove 113 communicating with the cooling groove 114 being the radial depth, and at least two sets of cooling grooves 114 of different radial depths are present in the stator core sheet 11. Any structure which can meet the requirement that two or more groups of cooling grooves 114 with different radial depths exist in the stator core sheet 11 meets the requirement, and the distribution form of the specific structures of the different cooling grooves 114 on the stator core sheet 11 is not limited, and the structures can be distributed at intervals and can be randomly distributed. Illustratively, three different cooling slots 114 are present in the stator core sheet 11, the radial depth of the first cooling slot 114 is B1, the radial depth of the second cooling slot 114 is B2, and the radial depth of the third cooling slot 114 is B3, where the values of B1, B2, and B3 are different, and the three different cooling slots 114 in the stator core sheet 11 may alternately circulate in the circumferential direction, that is, the radial depths B1, B2, and B3 circulate sequentially.

In some embodiments, the cooling slots 114 of each stator lamination 11 are axially connected to form the cooling channel 13, and at least two sets of cooling slots 114 with different radial depths exist in the cooling channel 13. Specifically, the cooling channel 13 is formed by laminating the cooling slots 114 of the stator core pieces 11 in the axial direction, in order to satisfy the requirement that the wall surfaces of the cooling slots 114 in the cooling channel 13 are not flush, thereby effectively suppressing motor harmonics and reducing motor noise, at least two groups of cooling slots 114 with different radial depths exist in the cooling channel 13, it can be understood that when a plurality of stator core pieces are laminated in the axial direction, at least a part of the stator core pieces deflect at angles in the axial direction, and the number of specific deflection degrees does not make a requirement, so as to satisfy the requirement that the wall surfaces of the coil windings 14 formed in the axial direction by the slots 113 in the stator core pieces 11 are flush, and the wall surfaces of the cooling channels 13 formed in the axial direction by the cooling slots 114 in the stator core pieces 11 are not flush. Illustratively, the stator core has 6 groups of stator core groups, which are sequentially from group 1 to group 6 along the axial direction, 48 wire grooves 113 are arranged in the stator core sheet 11 along the circumferential direction, each wire groove 113 is communicated with a cooling groove 114, that is, 48 cooling grooves 114 are arranged in the stator core sheet 11 along the circumferential direction, cooling grooves 114 with three different radial depths exist in the stator core sheet 11, the three cooling grooves 114 are sequentially circulated for 16 times along the circumferential direction according to the radial depths B1, B2 and B3, one cooling groove 114 is set to be the cooling groove 114 No. 1, the radial depth B1, the cooling groove 114 on the adjacent side is the cooling groove 114 No. 2, the radial depth B2, one side of the cooling groove 114 No. 2 is the cooling groove 114 No. 3, the radial depth B3, and in the axial direction, the No. 1 cooling groove 114 of the 1 st group of stator core pieces 11 corresponds to the No. 2 cooling groove 114 of the 2 nd group of stator core pieces 11, the No. 2 cooling groove 114 of the 2 nd group of stator core pieces 11 corresponds to the No. 3 cooling groove 114 of the 3 rd group of stator core pieces 11, the No. 3 cooling groove 114 of the 3 rd group of stator core pieces 11 corresponds to the No. 3 cooling groove 114 of the 4 th group of stator core pieces 11, the No. 3 cooling groove 114 of the 4 th group of stator core pieces 11 corresponds to the No. 2 cooling groove 114 of the 5 th group of stator core pieces 11, and the No. 2 cooling groove 114 of the 5 th group of stator core pieces 11 corresponds to the No. 1 cooling groove 114 of the 6 th group of stator core pieces 11, that is, the cooling passage 13 formed in the axial direction from the No. 1 cooling groove 114 of the 1 st group of stator core pieces 11 is composed of the cooling grooves 114 of radial depths B1, B2, B3, B2, B1 in order.

In some embodiments, as shown in fig. 8, the wall surface of the cooling slot 114 in the stator core sheet 11 extends at an angle to the centerline of the slot; at least two groups of cooling grooves 114 with different included angles exist in the stator iron core sheet 11. Specifically, a plurality of wire casings 113 that stator iron core piece 11 set up along circumference interval, each wire casing 113 is identical, each wire casing 113 all communicates cooling bath 114, each cooling bath 114 is not identical, there is the contained angle in the extending direction of the wall of cooling bath 114 and wire casing central line 1131 among the stator iron core piece 11, the extending direction of the wall of cooling bath 114 can be understood as the direction that is close to annular outer wall 112, there is the contained angle in wire casing central line 1131 and cooling bath central line 1141, there are the cooling bath 114 of the different contained angles of two sets of angles at least in the stator iron core piece 11. Any structure of the cooling slots 114 that can satisfy the requirement that two or more groups of different included angles exist in the stator core sheet 11 meets the requirement, and the distribution form of the specific structure of the different cooling slots 114 on the stator core sheet 11 is not limited, and the cooling slots can be distributed at intervals and can be distributed randomly. Illustratively, three different cooling slots 114 exist in the stator core sheet 11, an included angle between the extending direction of the wall surface of the first cooling slot 114 and the central line 1131 of the wire chase is C1, an included angle between the extending direction of the wall surface of the second cooling slot 114 and the central line 1131 of the wire chase is C2, an included angle between the extending direction of the wall surface of the third cooling slot 114 and the central line 1131 of the wire chase is C3, wherein the numerical values of C1, C2 and C3 are different, and three different cooling slots 114 in the stator core sheet 11 can alternately circulate along the circumferential direction, that is, the included angles C1, C2 and C3 circulate sequentially.

In some embodiments, the cooling slots 114 of the stator core pieces 11 are communicated in the axial direction to form the cooling channels 13, and at least two groups of cooling slots 114 with different included angles exist in the cooling channels 13. Specifically, the cooling channels 13 are formed by axially laminating the cooling slots 114 of the stator core pieces 11, in order to satisfy the requirement that the wall surfaces of the cooling slots 114 in the cooling channels 13 are not flush, so as to effectively suppress motor harmonics and reduce motor noise, at least two groups of cooling slots 114 with included angles of different angles exist in the cooling channels 13, it can be understood that when a plurality of stator core pieces are axially laminated, at least a part of stator core pieces deflect in the axial direction by a certain amount of stator core pieces, and the specific deflection degree is not required, so as to satisfy the requirement that the wall surfaces of the coil windings 14 formed in the axial direction by the slots 113 in the stator core pieces 11 are flush, and the wall surfaces of the cooling channels 13 formed in the axial direction by the cooling slots 114 in the stator core pieces 11 are not flush. Illustratively, the stator core has 6 sets of stator iron core sets, which are sequentially from the 1 st set to the 6 th set along the axial direction, 48 wire slots 113 are arranged in the stator iron core piece 11 along the circumferential direction, each wire slot 113 is communicated with a cooling slot 114, that is, 48 cooling slots 114 are arranged in the stator iron core piece 11 along the circumferential direction, cooling slots 114 with three different included angles exist in the stator iron core piece 11, the three cooling slots 114 circulate for 16 times along the circumferential direction according to included angles C1, C2 and C3, one of the cooling slots 114 is set to be the No. 1 cooling slot 114, an included angle existing between the extending direction of the wall surface of the cooling slot 114 and the axial direction is C1, the cooling slot 114 on the adjacent side is the No. 2 cooling slot 114, one side of the included angle C2 and the No. 2 cooling slot 114 is the No. 3 cooling slot 114, the included angle C3 is in the axial direction, the No. 1 cooling groove 114 of the 1 st group of stator core pieces 11 corresponds to the No. 2 cooling groove 114 of the 2 nd group of stator core pieces 11, the No. 2 cooling groove 114 of the 2 nd group of stator core pieces 11 corresponds to the No. 3 cooling groove 114 of the 3 rd group of stator core pieces 11, the No. 3 cooling groove 114 of the 3 rd group of stator core pieces 11 corresponds to the No. 3 cooling groove 114 of the 4 th group of stator core pieces 11, the No. 3 cooling groove 114 of the 4 th group of stator core pieces 11 corresponds to the No. 2 cooling groove 114 of the 5 th group of stator core pieces 11, and the No. 2 cooling groove 114 of the 5 th group of stator core pieces 11 corresponds to the No. 1 cooling groove 114 of the 6 th group of stator core pieces 11, that is, the cooling passage 13 formed in the axial direction from the No. 1 cooling groove 114 of the 1 st group of stator core pieces 11 is composed of the cooling grooves 114 of included angles C1, C2, C3, C2, C1 in order.

In some embodiments, as shown in fig. 9 and 10, in order to rapidly introduce the cooling fluid into the cooling channel 13, the stator assembly 10 further includes a stator oil guide plate 15, the stator oil guide plate 15 is connected to the stator core sheet 11, the stator oil guide plate 15 has an oil guide groove 151, and the oil guide groove 151 communicates with the cooling channel 13. Specifically, the stator oil guide plate 15 has an oil guide groove 152 identical to the wire groove 113 of the stator core sheet 11, and an oil guide cooling groove 153 identical to the cooling groove 114 of the stator core sheet 11. When the stator oil guide plate 15 and the stator core plate 11 are axially laminated, the oil guide slot 152 of the stator oil guide plate 15 coincides with the slot 113 of the stator core plate 11 to form the slot channel 12 together, the oil guide cooling slot 153 of the stator oil guide plate 15 may coincide with or may not coincide with the cooling slot 114 of the stator core plate 11, and the oil guide cooling slot 153 of the stator oil guide plate 15 and the cooling slot 114 of the stator core plate 11 form the cooling channel 13 together. The stator oil guide plate 15 may be disposed at an end of the plurality of stator core pieces 11 forming the stator core, or may be disposed between the plurality of stator core pieces 11, a connection manner between the stator oil guide plate 15 and the stator core pieces 11 is not limited, and the stator oil guide plate 15 and the stator core pieces 11 may be bonded or may be connected by welding. The stator oil guide plate 15 has an oil guide groove 151, and the size of the oil guide groove 151 is not limited, for example, the oil guide groove 151 is radially arranged. The oil guide groove 151 can communicate the cooling channel 13 with a space outside the annular outer wall 112 of the stator core plate 11, so that the cooling liquid outside the annular outer wall 112 flows into the cooling channel 13 through the oil guide groove 151, and further flows into the wire chase channel 12 through the cooling channel 13 to cool the coil winding 14.

In some embodiments, as shown in fig. 10, in order to improve the efficiency of cooling and heat dissipation, the stator oil guide plate 15 is located between the two stator core pieces 11, and oil guide grooves 151 are formed on both sides of the stator oil guide plate 15. Specifically, lead oiled plate 15 with the stator and set up between two stator iron core pieces 11, coolant liquid through leading oil groove 151 flows into behind the cooling channel 13, can follow the both ends of axial flow direction cooling channel 13, the flow path of coolant liquid has been shortened, accelerate coolant liquid circulation, improve the radiating efficiency, stator is led oiled plate 15 both sides and all has and is led oil groove 151 simultaneously, it does not do the injectly specifically to arrange the form, for example, the stator is led oiled plate 15 and is set up with the oil groove 151 interval of leading of the same side, the stator is led the crisscross setting of oil groove 151 of leading of oiled plate 15 both sides, thereby improve refrigerated homogeneity.

In some embodiments, as shown in fig. 10, the wall surfaces of the cooling slots 114 of the stator core pieces 11 on both sides of the stator oil guide plate 15 are flush. Specifically, in order to rapidly introduce the cooling liquid in the oil guide groove 151 into the cooling channel 13, the stator oil guide plate 15 has the same oil guide cooling groove 153 as the cooling groove 114 of the stator core sheet 11, and the wall surfaces of the cooling groove 114 of the stator core sheet 11 on both sides of the stator oil guide plate 15 are flush, that is, the oil guide cooling groove 153 of the stator oil guide plate 15 is flush with the wall surfaces of the cooling groove 114 of the stator core sheet 11 on both sides of the stator oil guide plate 15, so as to facilitate rapid introduction of the cooling liquid in the oil guide groove 151 into the cooling channel 13.

In some embodiments, as shown in fig. 10, in order to further improve the uniformity of cooling and heat dissipation, the number of the stator core pieces 11 on both sides of the stator oil guide plate 15 is the same in the axial direction, and the cooling grooves 114 of the stator core pieces 11 on both sides of the stator oil guide plate 15 are symmetrical with respect to the stator oil guide plate 15. Specifically, the stator oil guide plate 15 is located between the plurality of stator core pieces 11, the number of the stator core pieces 11 on both sides of the stator oil guide plate 15 is the same, the distance from the cooling liquid entering through the oil guide groove 151 to both ends of the cooling channel 13 is the same, the cooling grooves 114 of the stator core pieces 11 on both sides of the stator oil guide plate 15 are symmetrical with respect to the stator oil guide plate 15, it is ensured that paths flowing through both ends of the cooling channel 13 are completely the same after the cooling liquid enters the cooling channel 13, and the time of cooling circulation of the coil windings 14 on both sides of the stator oil guide plate 15 is the same, thereby ensuring the uniformity of cooling on both sides of the stator oil guide plate 15.

The present embodiment provides an electrical machine suitable for use in a stator assembly as shown in any of figures 1 to 10. Referring to fig. 11, the motor 1 includes a stator assembly 10, a casing 20 and a rotor assembly 30, the casing 20 surrounds and forms an accommodating cavity 21, and the stator assembly 10 is located in the accommodating cavity 21; the rotor assembly 30 is located in the central bore 111 of the stator assembly 10. Specifically, the specific shape and size of the casing 20 are not limited, the casing 20 surrounds to form an accommodating cavity 21, the accommodating cavity 21 is used for accommodating the stator assembly 10 and the rotor assembly 30, the stator assembly 10 is connected with the casing 20, in order to facilitate the limitation of axial movement of the stator core piece 11, a step 24 is arranged on the inner wall of the casing 20, the stator core piece 11 is axially limited in the process of installing the stator core piece 11, and the size of the specific step 24 is not limited and meets the actual requirements. The plurality of stator laminations 11 are axially stacked to form a stator core, the central holes 111 of the plurality of stator laminations 11 form a central channel, and the rotor assembly 30 is positioned in the central holes 111 of the plurality of stator laminations 11 to form a central channel.

In some embodiments, as shown in fig. 12 and 13, the stator assembly 10 further includes a stator oil guide plate 15, the stator oil guide plate 15 has an oil guide groove 151, the casing 20 includes an oil inlet 22 and a circumferential oil passage 23, the oil inlet 22 is communicated with the circumferential oil passage 23, and the oil guide groove 151 is communicated with the cooling passage 13 and the circumferential oil passage 23. Specifically, in order to make the coolant liquid evenly get into cooling channel 13 through oil guide groove 151, the inside of casing 20 is provided with hoop oil duct 23, and hoop oil duct 23 is the recess of the inside sunken formation of casing 20, and encircles the round along the inside of casing 20 for fill the coolant liquid, the sunken degree of depth and the axial width of hoop oil duct 23 do not do the injecing, accord with the demand can. The annular oil duct 23 is communicated with the oil inlet nozzle 22, the cooling liquid enters the annular oil duct 23 of the motor 1 through the oil inlet nozzle 22, the annular oil duct 23 is full of the cooling liquid, one end of the oil guide groove 151 of the stator oil guide plate 15 is communicated with the annular oil duct 23, the other end of the oil guide groove 151 is communicated with the cooling channel 13, so that the cooling liquid of the annular oil duct 23 is uniformly guided into the cooling channel 13 through the oil guide grooves 151, the cooling channel 13 is full of the cooling liquid, and the cooling uniformity of the coil winding 14 in the integral trunking channel 12 is ensured.

In some embodiments, as shown in fig. 13, in order to assist the motor 1 in dissipating heat, the casing 20 has a plurality of heat dissipation fins 25, and the number and arrangement of the heat dissipation fins 25 are not limited, as long as the requirement of the auxiliary motor 1 for dissipating heat is met, for example, axial heat dissipation fins are arranged on the outer surface of the casing 20 to assist in dissipating heat.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. An electric machine stator assembly, comprising:

each stator core piece is provided with a central hole and an annular outer wall, and the stator core pieces are provided with a plurality of wire grooves which are arranged at intervals along the circumferential direction;

in the radial direction, the wall surface of each wire groove close to the annular outer wall is sunken towards the annular outer wall to form a cooling groove;

each stator core sheet is laminated along the axial direction, the wire grooves of each stator core sheet are communicated in the axial direction to form a wire winding channel, the cooling grooves of each stator core sheet are communicated in the axial direction to form a cooling channel,

wherein, in the wire casing forming the winding channel, the wall surface of each wire casing is flush, and in the cooling groove forming the cooling channel, the wall surface of each cooling groove is not flush.

2. The stator assembly of claim 1, wherein a maximum length of one end of the cooling slot in the stator core piece perpendicular to a slot centerline is a maximum offset distance, and the slot centerline extends in the same direction as the radial direction;

at least two different sets of the cooling slots of the maximum offset distance exist in the stator core sheet.

3. The stator assembly of claim 2, wherein each of the cooling slots in the stator laminations are identical in shape, a cooling slot centerline is parallel to the slot centerline, and the distance between the cooling slot centerline and the slot centerline is a center distance;

at least two groups of cooling grooves with different center distances exist in the stator iron core sheet.

4. The stator assembly of claim 3 wherein said cooling slots of each of said stator laminations communicate in an axial direction to form a cooling channel, and wherein there are at least two different sets of said cooling slots at said center-to-center distance.

5. The stator assembly of claim 4 wherein a plurality of said stator laminations are stacked in an axial direction to form sets of stator laminations, said cooling slots of adjacent two of said sets of stator laminations being spaced at different centers.

6. The stator assembly of claim 2 wherein each of said cooling slot centerlines in said stator laminations coincide with said wire slot centerlines, and wherein there are at least two different sets of said cooling slots of different circumferential dimensions in said stator laminations.

7. The stator assembly of claim 6 wherein said cooling slots of each of said stator laminations communicate in an axial direction to form a cooling channel, and wherein there are at least two sets of said cooling slots of different circumferential dimensions.

8. The stator assembly of claim 1, wherein an end of the cooling slots in the stator core pieces nearest the outer annular wall is a maximum depressed end, and a shortest distance from the maximum depressed end to the wire slots is a radial depth;

there are at least two different sets of the cooling slots of the radial depth in the stator core pieces.

9. The stator assembly of claim 8 wherein said cooling slots of each of said stator laminations communicate in an axial direction to form cooling channels, at least two different sets of said cooling slots of said radial depth being present in said cooling channels.

10. The stator assembly of claim 1, characterized in that the extension direction of the wall surface of the cooling slot in the stator core sheet forms an included angle with the centerline direction of the slot;

and at least two groups of cooling grooves with different angles are arranged in the stator iron core sheet.

11. The stator assembly of claim 10 wherein said cooling slots of each of said stator laminations are axially interconnected to form a cooling channel, and wherein at least two sets of said angled cooling slots having different angles are present in said cooling channel.

12. The stator assembly of claim 1, further comprising a stator oil guide plate coupled to the stator core pieces, the stator oil guide plate having an oil guide slot in communication with the cooling channel.

13. The stator assembly of claim 12 wherein said stator oil guide plate is located between two of said stator core pieces, said stator oil guide plate having oil guide slots on both sides.

14. The stator assembly of claim 13, wherein the oil guiding grooves on the same side of the stator oil guiding plate are spaced apart, and the oil guiding grooves on both sides of the stator oil guiding plate are staggered.

15. The stator assembly of claim 13 wherein wall surfaces of said cooling slots of said stator core pieces on both sides of said stator oil guide plate are flush.

16. The stator assembly of claim 15 wherein said stator laminations on both sides of said stator oil guide plate are equal in number in an axial direction, said cooling slots of said stator laminations on both sides of said stator oil guide plate being symmetrical about said stator oil guide plate.

17. An electric machine, comprising:

the stator assembly of any of claims 1-16;

a casing enclosing a containing cavity, wherein the stator assembly is positioned in the containing cavity;

a rotor assembly positioned within the central bore of the stator assembly.

18. The electric machine of claim 17, wherein the stator assembly further comprises a stator oil guide plate having an oil guide groove;

the housing includes: the oil inlet nozzle is communicated with the annular oil duct, and the oil guide groove is communicated with the cooling channel and the annular oil duct.

19. The electric machine of claim 17 wherein the housing has a plurality of fins.