High-efficiency oil-cooled motor

Abstract

The present invention relates to a high-efficiency oil-cooled motor, comprising a stator, a rotor, and a case. The stator comprises a stator core ring and stator teeth. The stator core ring comprises a yoke core ring and an inner core ring. A plurality of stator teeth are circumferentially spaced and removably disposed between the yoke core ring and the inner core ring. A plurality of axial oil grooves are spaced apart in the inner core ring. An end oil guide plate is provided at at least one of the upper and lower ends of the stator. The end oil guide plate has a rectangular groove. An outer diameter oil groove and an inner diameter oil groove are formed on the inside and outside of the rectangular groove, respectively. A radial oil passage is formed between adjacent winding holes. The outer diameter oil groove communicates with an oil supply port. An axial oil hole is further provided inside the rectangular groove, communicating with the axial oil groove. The present invention makes full use of stamped stator slot material, ensures excellent processability, effectively cools local overheating points in the motor stator, reduces motor material costs, and provides good performance output.

Description

[Technical Field]

[0001] This application claims priority from a Chinese patent application filed with the China Patent Office on February 27, 2023, bearing application number 202310170230.1 and entitled "High-efficiency oil-cooled motor," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a permanent magnet synchronous drive motor for a new energy vehicle, and more particularly to a high-efficiency oil-cooled motor. [Background technology]

[0003] With the development of new energy vehicles both domestically and globally, the demand for their drive motors is increasing day by day. Whether it is automobile manufacturers or motor suppliers, they have begun to develop the new energy drive motor industry, and the competition is fierce. However, as the prices of motor raw materials are currently rising across the board, motor manufacturers are continually optimizing costs to produce motors that combine excellent performance and cost-effectiveness as much as possible. Silicon steel sheets are the main components of motors. In the process of punching the stator core of a typical motor, the punched stator slot material is generally disposed of as waste. Since the weight of the stator slot material is about 1 / 5 of the weight of the raw steel sheets of the stator and rotor silicon, this results in a large amount of waste.

[0004] In addition, the axial cross-sectional area of ​​the flat wire motor winding is large, and the flat wire winding near the notch of the motor is subjected to the action of the air gap harmonic magnetic field, which causes the proximity effect and skin effect in the winding, resulting in large eddy current loss and higher temperature. In addition, the heat dissipation path in the axial middle segment of the motor is long, resulting in poor heat dissipation effect. As a result, the temperature distribution of the motor stator is such that the temperature at the inner diameter and its axially intermediate segment is generally higher than at other locations. The cooling methods for the stator of a conventional motor are mainly case water cooling or winding spray cooling. However, no matter what cooling method is used, it is difficult to cool the notch position and the middle segment of the winding, and there is also a risk of local insulation failure.

[0005] As described above, in the new energy drive motor market where competition is becoming increasingly fierce, it is very important to manufacture products with good performance and lower prices. Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION In order to solve the above technical problems, the present invention aims to provide a high-efficiency oil-cooled motor, which can improve the efficiency of raw material usage and motor performance. [Means for solving the problem]

[0007] In order to achieve the above object of the invention, the present invention employs the following configuration: A high-efficiency oil-cooled motor including a stator, a rotor, and a case, wherein the stator includes a stator core ring and stator teeth, the stator core ring including a yoke core ring and an inner diameter core ring that are concentrically arranged, a plurality of stator teeth are detachably provided between the yoke core ring and the inner diameter core ring at intervals along the circumference, a winding groove is formed between two adjacent stator teeth, a flat wire winding is inserted into the winding groove, and a gap is maintained between both sides of the flat wire winding near the outer edge and the winding groove, and the inner diameter core The ring is provided with a plurality of axial oil grooves at intervals, the axial oil grooves being located inside the winding grooves, an end oil guide plate is provided at at least one of the upper and lower ends of the stator, and the end oil guide plate has a rectangular groove formed therein, and an outer diameter oil groove and an inner diameter oil groove are formed on the inside and outside of the rectangular groove, respectively, a radial oil passage is formed between adjacent winding holes, both ends of the radial oil passage communicate with the outer diameter oil groove and the inner diameter oil groove, respectively, the outer diameter oil groove communicates with an oil supply port, and an axial oil hole communicating with the axial oil groove is further provided inside the rectangular groove.

[0008] As a preferred solution, arc-shaped notches are provided on both sides of the outer edge of the rectangular groove, and the gaps between the arc-shaped notches and the two sides of the winding groove form oil drainage grooves.

[0009] In a preferred solution, the cross section of the stator tooth is trapezoidal, with the width of one end of the stator tooth close to the yoke core ring being greater than the width of the other end of the stator tooth close to the inner diameter core ring.

[0010] As a preferred solution, an oil supply port and an end oil discharge hole are provided on the side wall of the case, an annular intermediate segment oil groove and an end oil groove are arranged at intervals on the inner wall of the case, and a plurality of parallel-connected axial oil passages are arranged at intervals between the intermediate segment oil groove and the end oil groove. The two ends of the parallel-connected axial oil passage are connected to the intermediate segment oil groove and the end oil groove, respectively, the oil supply port is connected to the intermediate segment oil groove, and the end oil discharge hole is located on the side wall between the end oil guide plate and the case end cap.

[0011] As a preferred solution, both ends of the stator teeth are inserted or engaged with the yoke core ring and the inner diameter core ring, respectively.

[0012] As a preferred solution, one end of the stator tooth is provided with a tooth bottom protruding engagement portion or a tooth bottom recessing engagement portion, and the inner wall of the yoke core ring is provided with an engagement groove A or an engagement groove B that engages with the tooth bottom protruding engagement portion or the tooth bottom recessing engagement portion.

[0013] In a preferred solution, the stator teeth include a stator tooth A provided at one end with a tooth root protruding engagement portion and a stator tooth B provided at one end with a tooth root recess engagement portion. The stator teeth A and stator teeth B are arranged alternately at intervals, and the inner wall of the yoke core ring is provided with engagement grooves A and B that engage with the tooth bottom protruding engagement portion and the tooth bottom recessed engagement portion, respectively.

[0014] As a preferred solution, an inner ring tooth locking groove is provided on the outer wall of the inner diameter core ring, and the other end of the stator tooth is locked in the inner ring tooth locking groove.

[0015] As a preferred solution, the stator core ring further includes connecting teeth, the yoke core ring and the inner diameter core ring are fixed to each other by the connecting teeth, and the yoke core ring, the connecting teeth and the inner diameter core ring are integrally molded.

[0016] In a preferred solution, a groove opening is provided in the middle of the axial oil groove, and a side oil passage groove is provided in the middle of the stator tooth, and the groove opening communicates with the side oil passage groove. [Effects of the Invention]

[0017] The beneficial effects of the present invention over the prior art are as follows: The stator of the present invention adopts a joint structure, in which the stator core ring and a plurality of stator teeth are assembled into a complete stator core, and then the flat wire winding is inserted, which makes the whole assembly easy to install. The stator teeth are made from waste stator slot material, which saves silicon steel sheet material. The stator core ring has oil passages that allow cooling oil to flow through local overheated points and directly cool them. The oil passages in the stator core ring are connected to the end oil guide plates, so the end oil guide plates, stator teeth, and flat wire windings can form oil chambers, which further improves cooling efficiency and enhances the overall performance of the motor.

[0018] According to the present invention, the stamped stator slot material can be fully utilized, and excellent processability can be ensured. In addition, localized hot spots of the motor stator can be effectively cooled, reducing the cost of the motor material while providing good performance output. [Brief explanation of the drawings]

[0019] The invention will be better understood from the drawings in the specification which form a part of the present invention, the examples of the invention and the description thereof being used to interpret the invention without limiting it.

[0020] [Figure 1] FIG. 1 is a structural overall view of the case, stator (not including flat wire windings) and end oil guide plate of the present invention. [Figure 2] FIG. 1 is a plan view of an assembly of the stator core ring and stator teeth of the present invention. [Figure 3] FIG. 2 is a plan view of the stator core ring of the present invention. [Figure 4] FIG. 2 is a three-dimensional view of the stator core ring of the present invention. [Figure 5] FIG. 5 is an enlarged view of part A in FIG. [Figure 6] 1A and 1B are three-view diagrams of a stator tooth A of the present invention. [Figure 7] 1A and 1B are three-view diagrams of a stator tooth B of the present invention. [Figure 8] FIG. 2 is a cross-sectional view of the assembled stator core ring, stator teeth, and flat wire windings of the present invention. [Figure 9] FIG. 9 is an enlarged view of part C in FIG. 8. [Figure 10] FIG. 2 is a cross-sectional view of an end oil guide plate of the present invention. [Figure 11] 1 is a cross-sectional view of an end oil guide plate, flat wire winding, stator core ring, and stator teeth of the present invention. FIG. [Figure 12] FIG. 12 is an enlarged view of part D in FIG. [Figure 13] FIG. 2 is a structural diagram of the case of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE INVENTION The following detailed description is illustrative and is intended to explain the present invention. Unless otherwise explained, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] The terms used herein do not limit the embodiments according to the present invention, but are merely used to describe specific embodiments. For example, unless otherwise indicated in the specification, the singular forms used are intended to include the plural forms, and when used herein, the terms "comprises" and / or "includes" indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] Furthermore, in describing the present invention, the orientations or positional relationships indicated by terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise" are orientations or positional relationships according to the drawings, and do not indicate or imply that the indicated devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated in a specific orientation. These terms are merely used for the convenience and simplification of the description of the present invention, and do not limit the present invention.

[0024] Furthermore, the terms "first," "second," etc. do not indicate or imply relative importance or the number of the designated technical features, but are merely descriptive. Thus, a feature qualified with "first" or "second" explicitly or implicitly includes one or more of those features. In describing the present invention, unless otherwise specified, "plurality" means two or more than two.

[0025] In the present invention, unless otherwise expressly specified or limited, the terms "attached," "coupled," "connected," "fixed," etc. should be understood in a broad sense, and may mean, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, or even internal communication between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0026] In the present invention, unless otherwise specified or limited, a first feature being located "above" or "below" a second feature may include a case where the first and second features are in direct contact with each other, or a case where the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween. Furthermore, a first feature being located "above," "above," or "on the top surface" of a second feature includes the first feature being located directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The positioning of a first feature "below," "underneath," and "below surface" of a second feature includes the first feature being directly below and diagonally below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature.

[0027] The present invention will now be further described with reference to the following figures and examples.

[0028] The high-efficiency oil-cooled motor of Figures 1 and 2 includes a stator, a rotor, and a case 5, the stator including a stator core ring 3 and stator teeth, and the stator core ring 3 including a yoke core ring 3-1 and an inner diameter core ring 3-3 arranged concentrically. The stator teeth are removably arranged at intervals along the circumference between the yoke core ring 3-1 and the inner diameter core ring 3-3, and a winding groove is formed between two adjacent stator teeth, and a flat wire winding 6 is inserted into this winding groove.

[0029] As shown in Figures 3 to 5, the stator core ring 3 further includes connecting teeth 3-2, and the yoke core ring 3-1 and the inner core ring 3-3 are fixed to each other by the connecting teeth 3-2. The yoke core ring 3-1, connecting teeth 3-2, and inner core ring 3-3 are integrally molded and overlapped in multiple segments in the axial direction to form the inner and outer ring structure of the stator. Both ends of the stator teeth are inserted into or engaged with the yoke core ring 3-1 and the inner core ring 3-3, respectively.

[0030] The stator teeth may all be similar in shape using the same specifications, or may have two specifications, including a stator tooth A1 having a tooth bottom protruding engagement portion 1-1 at one end, and a stator tooth B2 having a tooth bottom recessed engagement portion 2-1 at one end. The stator teeth A1 and the stator teeth B2 are arranged alternately at intervals, and the inner wall of the yoke core ring 3-1 is provided with engagement grooves A3-1-1 and B3-1-2 that engage with the tooth bottom protruding engagement portion 1-1 and the tooth bottom recessed engagement portion 2-1, respectively (see Figures 3, 6 to 9).

[0031] An inner ring tooth portion locking groove 3-3-2 is provided on the outer wall of the inner diameter core ring 3-3, and the other end of the stator tooth is locked in the inner ring tooth portion locking groove 3-3-2.

[0032] When designing the stator teeth, the number of stator slots is Z, and the raw material of one annular silicon steel plate is divided into Z equal parts, that is, pressed into Z pairs of stator teeth. Each pair is equally divided into a pair of stator teeth from the midline, and the bottom of the stator teeth in each pair is designed as an engagement mechanism, with one protruding and the other recessed. When they are joined together, they form a set of stators. In this way, one annular silicon steel sheet raw material can be pressed into 2Z stator teeth, i.e., stator teeth for two motors. Using the stator teeth of the above two specifications saves material and makes the stator structure of the assembled motor more robust.

[0033] The stator teeth are formed by pressing annular high-grade silicon steel sheets, then laminating and crimping them; two sets of motor stator teeth can be pressed from one annular silicon steel sheet. The stator core ring is integrally molded, and for high-performance motors, the material is pressed using SMC. For cost-effective motors, the material is cast into multiple segments using cast iron material with high magnetization properties (axial combination of multiple segments can significantly reduce eddy current loss), and the stator teeth are inserted into the corresponding stator core ring structure to form the stator core.

[0034] As shown in Figure 13, an oil supply port 5-1 and an end oil discharge hole 5-5 are provided on the side wall of the case, and an annular intermediate segment oil groove 5-2 and an end oil groove 5-3 are arranged at intervals on the inner wall of the case. Between the intermediate segment oil groove 5-2 and the end oil groove 5-3, multiple parallel-connected axial oil passages 5-4 are arranged at intervals, and both ends of the parallel-connected axial oil passages 5-4 are connected to the intermediate segment oil groove 5-2 and the end oil groove 5-3, respectively. The oil supply port 5-1 is connected to the intermediate segment oil groove 5-2, and the end oil discharge hole 5-5 is located on the side wall between the end oil guide plate 4 and the case end cap.

[0035] The inner diameter core ring 3-3 has a plurality of axial oil grooves 3-3-1 spaced apart, the axial oil grooves 3-3-1 being located inside the winding grooves, and an end oil guide plate 4 is provided at at least one of the upper and lower ends of the stator, and a rectangular groove 4-5 is formed in the end oil guide plate 4. In this embodiment, the end oil guide plates are tightly attached to both ends of the stator core ring, and rectangular grooves having a width equal to the top width of the winding grooves are formed at positions corresponding to the winding grooves. This allows the left and right sides of the rectangular groove 4-5 to be fixed in position when the wire is inserted. An outer diameter oil groove 4-1 and an inner diameter oil groove 4-3 are formed on the inside and outside of the rectangular groove 4-5, respectively. A radial oil passage 4-2 is formed between adjacent winding holes, and both ends of the radial oil passage 4-2 are connected to the outer diameter oil groove 4-1 and the inner diameter oil groove 4-3, respectively. The outer diameter oil groove 4-1 is connected to the oil supply port 5-1 via the end oil groove 5-3 on the case, the parallel-connected axial oil passage 5-4, and the intermediate segment oil groove 5-2. An axial oil hole 4-4 is further provided on the inside of the rectangular groove 4-5, which is connected to the axial oil groove 3-3-1 (see Figures 10 to 12).

[0036] A groove opening 3-3-3 is provided in the center of the axial oil groove 3-3-1, and a side oil passage groove is provided in the center of the stator tooth, and the groove opening 3-3-3 communicates with the side oil passage groove. A side oil passage groove A1-2 is formed in the center of the stator tooth A1, and a side oil passage groove B2-2 is formed in the center of the stator tooth B2 (see FIGS. 6 and 7).

[0037] The cross section of the stator tooth is trapezoidal, and the width of one end of the stator tooth near the yoke core ring 3-1 is larger than the width of the other end of the stator tooth near the inner core ring 3-3, so that a gap is maintained between the winding groove and both sides of the flat wire winding 6 near the outer edge of the winding groove. Arc-shaped notches are provided on both sides of the outer edge of the rectangular groove 4-5, and the gaps between the arc-shaped notches and both sides of the winding groove form oil discharge grooves 4-6, which allow cooling oil to flow out.

[0038] The end oil guide plates of the present invention are closely attached to both ends of the stator core ring and are fitted into the case water passages. The cooling oil enters through the oil supply hole and flows through the intermediate segment oil groove of the case. It then flows through the oil passages connected in parallel in the axial direction into the oil grooves on both ends of the case, then flows into the outer diameter oil groove of the end oil guide plate, then flows through the radial oil passage into the inner diameter oil groove 4-3 of the end oil guide plate, then flows into the axial oil groove 3-3-1 of the stator core ring, and flows from the intermediate segment groove opening 3-3-3 of the inner diameter core ring 3-3 through the side oil passage grooves opened in the stator teeth to the oil chamber in the winding groove formed by the winding (insulating paper), stator teeth, and end oil guide plates on both axial ends. Finally, it flows out of the grooves on both sides of the end oil guide plate along the axial direction and sprays onto the end winding. As a result, all-round cooling of the cooling oil to the stator outer diameter, the stator inner diameter, the flat wire grooves and the end windings can be achieved.

[0039] In the present invention, the widths of the tooth grooves of the flat wire motor are approximately the same, and therefore the tooth groove angles are arranged in the same manner. Therefore, the stator slot material that was originally wasted during pressing can be used as the stator teeth, saving silicon steel material. Furthermore, the inner and outer rings of the stator core are formed by stacking multiple segments in the axial direction and crimping them together through one-piece molding, and the stator teeth are inserted into the rings to form the entire stator core. Taking advantage of the feature that oil passages can be easily manufactured by integral molding, axial oil passages are opened in the inner diameter portion and outer diameter portion, and cooling oil flows through localized overheated points to directly cool them.

[0040] In the present invention, the included angles of stator tooth A and stator tooth B are equal, and the combined included angle of two of them is equal to 360 / Z (Z is the stator tooth). Therefore, 2Z stator teeth can be pressed from one stator ring material, and all of the teeth are usable. The bases of the two stator teeth are respectively provided with protruding portions and recessed portions that can be locked with each other. The stator core ring is composed of an inner ring and an outer ring, and is connected to the inner ring and the outer ring by several connecting teeth. The outer ring has engagement grooves that are respectively spaced apart and correspond to the stator tooth bottom engagement portions. The inner ring has locking grooves that correspond to the top portions of the stator teeth. Axial oil grooves are provided in the notches, and the axial oil grooves are opened in the intermediate segments. The stator teeth are respectively inserted into the stator core ring to form a stator core.

[0041] The two axial ends of the core are respectively provided with end oil guide plates, and the rectangular grooves of the end oil guide plates can position the flat wire windings. A groove is drilled at the bottom of the groove to allow oil to pass through without affecting positioning, and the end oil guide plate, stator teeth and flat wire can form an oil chamber.

[0042] In the description herein, the use of reference terms such as "one embodiment," "some embodiments," "examples," "particular examples," or "some examples" indicates that the specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, appearances of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined as suitable in any one or more embodiments or examples.

[0043] The above embodiments of the present invention do not limit the present invention, and modifications, amendments, substitutions and variations can be made to the above embodiments within the scope of the present invention. Any simple amendments, equivalent changes and modifications to the above embodiments also fall within the scope of the present invention. [Explanation of symbols]

[0044] 1 Stator tooth A 2 Stator tooth B 3. Stator core ring 4 End oil guide plate 5. Case 6 Flat wire winding 1-1...Tooth bottom protruding engagement part 1-2 Side oil passage groove A 2-1...Tooth bottom recess engagement part 2-2 Side oil passage groove B 3-1 York Coring 3-2 Connecting teeth 3-3 Inner diameter coring 3-1-1...Engagement groove A 3-1-2...Engagement groove B 3-3-1 Notched axial oil groove 3-3-2 Inner ring tooth locking groove 3-3-3 Groove opening 4-1...Other diameter oil groove 4-2...Radial oil passage 4-3 Inner diameter oil groove 4-4...Axial oil hole 4-5...Rectangular groove 4-6...Oil drain groove 5-1...Oil supply port 5-2 Middle segment oil groove 5-3...End oil groove 5-4...Parallel connected axial oil passage 5-5...End oil drain hole.

Claims

1. A highly efficient oil-cooled motor including a stator, a rotor and a case (5), The stator includes a stator core ring (3) and stator teeth; The stator core ring (3) includes a yoke core ring (3-1) and an inner diameter core ring (3-3) that are concentrically arranged, and a plurality of stator teeth are detachably provided between the yoke core ring (3-1) and the inner diameter core ring (3-3) at intervals along the circumference, and a winding groove is formed between two adjacent stator teeth, A flat wire winding (6) is inserted into the winding groove, and a gap is maintained between both sides of the flat wire winding (6) near the outer edge and the winding groove. The inner core ring (3-3) is provided with a plurality of axial oil grooves (3-3-1) at intervals, The axial oil groove (3-3-1) is located inside the winding groove, An end oil guide plate (4) is provided at at least one of the upper end and the lower end of the stator, The end oil guide plate (4) has rectangular grooves (4-5) formed therein, An outer diameter oil groove (4-1) and an inner diameter oil groove (4-3) are formed on the inside and outside of the rectangular groove (4-5), respectively, and a radial oil passage (4-2) is formed between adjacent winding holes. Both ends of the radial oil passage (4-2) are connected to the outer diameter oil groove (4-1) and the inner diameter oil groove (4-3), respectively. The outer diameter oil groove (4-1) communicates with an oil supply port (5-1), A highly efficient oil-cooled motor is characterized in that an axial oil hole (4-4) communicating with the axial oil groove (3-3-1) is further provided inside the rectangular groove (4-5).

2. The rectangular groove (4-5) has arcuate notches on both sides of its outer edge, 2. The high-efficiency oil-cooled motor according to claim 1, wherein the gaps between the arc-shaped notches and both sides of the winding groove form oil discharge grooves (4-6).

3. The cross section of the stator tooth is trapezoidal; 2. The high-efficiency oil-cooled motor according to claim 1, wherein the width of one end of the stator tooth near the yoke core ring (3-1) is greater than the width of one end of the stator tooth near the inner diameter core ring (3-3).

4. An oil supply port (5-1) and an end oil discharge hole (5-5) are provided on the side wall of the case, An annular intermediate segment oil groove (5-2) and an end oil groove (5-3) are arranged at intervals on the inner wall of the case, A plurality of parallel-connected axial oil passages (5-4) are arranged at intervals between the intermediate segment oil groove (5-2) and the end oil groove (5-3), Both ends of the parallel-connected axial oil passage (5-4) are connected to the intermediate segment oil groove (5-2) and the end oil groove (5-3), respectively; The oil supply port (5-1) communicates with the intermediate segment oil groove (5-2), 2. The high-efficiency oil-cooled motor according to claim 1, wherein the end oil discharge holes (5-5) are located on the side wall between the end oil guide plate (4) and the case end cap.

5. 2. The high-efficiency oil-cooled motor according to claim 1, wherein both ends of the stator teeth are inserted into or engaged with a yoke core ring (3-1) and an inner diameter core ring (3-3), respectively.

6. One end of the stator tooth is provided with a tooth bottom protruding engagement portion (1-1) or a tooth bottom recessed engagement portion (2-1), The high-efficiency oil-cooled motor according to claim 1, characterized in that an inner wall of the yoke core ring (3-1) is provided with an engagement groove A (3-1-1) or an engagement groove B (3-1-2) that engages with the tooth bottom protruding engagement portion (1-1) or the tooth bottom recessed engagement portion (2-1).

7. The stator teeth include a stator tooth A (1) having a tooth bottom protruding engagement portion (1-1) at one end, and a stator tooth B (2) having a tooth bottom recessed engagement portion (2-1) at one end, The stator teeth A (1) and the stator teeth B (2) are alternately arranged at intervals, 2. A high-efficiency oil-cooled motor according to claim 1, characterized in that the inner wall of the yoke core ring (3-1) is provided with engagement grooves A (3-1-1) and B (3-1-2) that engage with the tooth bottom protruding engagement portion (1-1) and the tooth bottom recessed engagement portion (2-1), respectively.

8. An inner ring tooth engaging groove (3-3-2) is provided on the outer wall of the inner diameter core ring (3-3), 8. A high-efficiency oil-cooled motor according to claim 6, wherein the other end of the stator tooth is engaged with an inner ring tooth engaging groove (3-3-2).

9. The stator core ring (3) further includes connecting teeth (3-2), The yoke core ring (3-1) and the inner core ring (3-3) are fixed to each other by connecting teeth (3-2), 2. The high-efficiency oil-cooled motor according to claim 1, wherein the yoke core ring (3-1), the connecting teeth (3-2) and the inner core ring (3-3) are integrally molded.

10. A groove opening (3-3-3) is provided in the middle of the axial oil groove (3-3-1), A side oil passage groove is provided in the center of the stator tooth, 2. A high-efficiency oil-cooled motor according to claim 1, wherein the groove opening (3-3-3) communicates with a side oil passage groove.

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