CN114928186A

CN114928186A - Direct oil-cooled cooling structure in stator slot and oil-cooled motor

Info

Publication number: CN114928186A
Application number: CN202210587270.1A
Authority: CN
Inventors: 杨晗; 刘平宙; 张秀进; 姜佳维
Original assignee: Xiamen Shituo Yuneng Technology Co ltd
Current assignee: Xiamen Shituo Yuneng Technology Co ltd
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2022-08-19

Abstract

The invention relates to the technical field of motors, in particular to a direct oil cooling structure in a stator slot and an oil cooling motor. The cooling structure comprises at least two groups of stator cores and flat wire windings arranged on the stator cores; the stator core is provided with a plurality of circumferentially arranged stator slots, the inner wall of each stator slot is axially provided with a boss protruding inwards, and the bosses separate flat wire windings in the same stator slot, so that a gap in the middle of each boss forms an axial oil duct penetrating through two end faces of the stator core; the stator core is characterized by further comprising an oil guide ring arranged between every two adjacent stator cores, wherein the oil guide ring is of an annular structure, a plurality of radial oil ducts are arranged at intervals along the circumferential direction, and the radial oil ducts are communicated with the axial oil ducts. The cooling structure provided by the invention can enable cooling oil to directly enter the stator slot through the radial oil duct and the axial oil duct to cool a heating component, thereby ensuring the effectiveness and uniformity of oil cooling and improving the cooling efficiency.

Description

Direct oil-cooled cooling structure in stator slot and oil-cooled motor

Technical Field

The invention relates to the technical field of motors, in particular to a direct oil cooling structure in a stator slot and an oil cooling motor.

Background

Under the big background that our country vigorously advances new energy automobile development, the performance of the driving motor for new energy automobile faces new challenges. Wherein, improving the torque/power density of the main drive motor becomes the research and development focus of the industry and academia. And the temperature rise limit in the motor is an important factor limiting the motor torque/power density. The existing new energy automobile motor cooling mode mainly comprises air cooling and water cooling, the problem that a heat source cannot be directly cooled exists, a local heat island is easily formed, and therefore the heat dissipation efficiency is not ideal. As the power of the main drive motor is increased, the oil-cooled motor as a direct cooling technology receives more and more attention. Because of its non-magnetic and non-conductive nature, oil is chosen as the medium for direct cooling inside the machine.

The existing oil cooling technology is divided into two categories of stator cooling and rotor cooling according to the structure of a motor. Wherein, extra rotor oil stirring loss is introduced to the rotor oil cooling, which easily causes uneven heat dissipation inside the motor and influences the overall cooling effect. The existing stator cooling mainly aims at the oil throwing and spraying stator oil cooling modes of the end winding of the flat wire, and for example, an oil cooling motor cooling system disclosed in patent number CN202011562372.5, 2021, 04 and 23 is disclosed. The oil cooling mode that above-mentioned patent adopted makes the heat concentrate on stator core's middle section easily, consequently can't carry out effectual heat management to the axial middle section of oil-cooled motor.

Disclosure of Invention

In order to solve the above-mentioned deficiency that the oil cooling can't carry on the effective cooling to the motor middle section in the prior art, the invention provides a direct oil-cooled cooling structure in the stator slot, including:

at least two groups of stator cores and flat wire windings arranged on the stator cores; the stator core is provided with a plurality of stator slots which are circumferentially arranged, the inner wall of each stator slot is provided with a boss which protrudes inwards along the axial direction, and the bosses separate the flat wire windings in the same stator slot, so that an axial oil duct which penetrates through two end faces of the stator core is formed in the gap in the middle of each boss;

the stator core is characterized by further comprising an oil guide ring arranged between every two adjacent stator cores, wherein the oil guide ring is of an annular structure, a plurality of radial oil ducts are arranged at intervals along the circumferential direction, and the radial oil ducts are communicated with the axial oil ducts.

In one embodiment, the oil guide ring is uniformly distributed with a plurality of ring teeth and ring grooves corresponding to the tooth spaces of the stator core along the circumferential direction.

In one embodiment, the radial oil passage comprises a radial gap and a transverse gap, wherein the radial gap is formed by opening towards the end face of the oil guide ring and extending to the outer side of the circumference, and the transverse gap is communicated with the adjacent ring grooves; the transverse gap is communicated with the radial gap and is communicated with the axial oil duct through the annular groove.

In one embodiment, the radial oil passages are symmetrically arranged on two side end faces corresponding to each ring tooth.

In one embodiment, the radial gap of the radial oil passage is in a shape of '1', the transverse gap is in a shape of 'one', and the radial gap and the transverse gap form a communicated inverted T shape; the transverse notch of the I shape corresponds to the position of the boss, so that the transverse notch is communicated with the axial oil passage.

In one embodiment, the oil cooler further comprises an oil cooler shell arranged outside the stator core, wherein the outer diameter of the oil guide ring is smaller than that of the stator core, so that a circumferential oil channel is formed among the outer circumferential surface of the oil guide ring, the end surface of the stator core close to the oil guide ring and the inner wall of the oil cooler shell, and the circumferential oil channel is communicated with the radial oil channel.

In an embodiment, the oil-cooled machine shell is further provided with at least one group of oil inlets and oil return openings, the oil inlets are communicated with the circumferential oil passage, and the oil return openings are formed in the bottom of the oil-cooled machine shell.

In one embodiment, the oil cooler further comprises an oil pump, an oil pipe connected with the oil pump, and an oil collecting tray arranged at the bottom of the oil cooler shell, wherein the oil collecting tray is communicated with the oil return opening, one end of the oil pipe is communicated with the oil inlet through the oil pump, and the other end of the oil pipe is communicated with the oil collecting tray.

The invention also provides an oil-cooled motor which adopts the cooling structure for direct oil cooling in the stator slot.

In one embodiment, the oil cooling device further comprises end covers arranged at two ends of the oil cooling shell, a rotating shaft rotatably connected with the end covers through bearings, and a rotor core fixedly connected with the rotating shaft; the rotor core is arranged on the inner side of the stator core, and an air gap is formed between the rotor core and the stator core.

Based on the above, compared with the prior art, the cooling structure provided by the invention has the advantages that the boss is arranged in the stator slot to form the axial oil passage, and then the radial oil passage of the oil guide ring is matched, so that the cooling oil directly enters the stator slot through the radial oil passage and the axial oil passage to cool the heating part, the effectiveness and uniformity of oil cooling are ensured, and the cooling efficiency is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts; in the following description, the drawings are described with reference to the drawing direction of the elements in the drawings unless otherwise specified.

Fig. 1 is a perspective view of a stator core provided by the present invention;

FIG. 2 is a partial front view of a stator core;

FIG. 3 is a perspective view of an oil control ring;

fig. 4 is a front view and a side view of the oil guide ring;

FIG. 5 is a front view of a cooling structure provided by the present invention;

FIG. 6 is a cross-sectional view of A-A of FIG. 5 and a schematic view of the cooling oil circulation path along the circumferential channel;

FIG. 7 is a cross-sectional view taken along line B-B of FIG. 6;

FIG. 8 is an enlarged view of a portion C of FIG. 6;

fig. 9 is a schematic view of the cooling circulation path of the cooling oil along its radial and axial channels.

Reference numerals:

10 stator core 20 flat wire winding 11 stator slot

12 boss 13 axial oil passage 30 oil guide ring

31 radial oil passage 32 ring gear 33 ring groove

31a radial gap 31b transverse gap 40 oil-cooled casing

41 circumferential oil passage 42 oil inlet 43 oil return port

50 oil pump 44 oil collecting tray 60 oil pipe

70 end cover 80 rotating shaft 90 rotor core

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments; the technical features devised in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other; all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be noted that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, and are not to be construed as limiting the present invention; it will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Referring to fig. 1 to 4, the present invention provides a direct oil cooling structure in a stator slot 11, including: at least two groups of stator cores 10 and flat wire windings 20 arranged on the stator cores 10; the stator core 10 is provided with a plurality of stator slots 11 arranged circumferentially, each stator slot 11 is provided with a boss 12 protruding inwards along the axial direction on the inner wall, the boss 12 separates the flat wire windings 20 located in the same stator slot 11, so that an axial oil passage 13 penetrating through two end faces of the stator core 10 is formed in a gap in the middle of the boss 12.

Preferably, the bosses 12 are symmetrically arranged on two sides of the inner wall of the stator slot 11, so that the gap between the two bosses 12 forms the uniform axial oil passage 13, and during assembly, it can be effectively ensured that the flat wire windings 20 in the same stator slot 11 are separated by the bosses 12.

It should be noted that the boss 12 is not limited to the square bar shown in the drawings, and the cross-sectional shape thereof may be configured as a triangle, a trapezoid, an arc, or other irregular shapes. In addition, the position of the boss 12 may be designed according to the structure of the actual stator slot 11, and is not limited herein. Preferably, as shown in fig. 2, in the stator slot 11 capable of accommodating 8 flat wire conductors, the boss 12 may be disposed in the middle of the stator slot 11 to divide the flat wire conductors into an upper layer and a lower layer, where the upper layer accommodates 4 flat wire conductors and the lower layer accommodates 4 flat wire conductors.

The stator core structure further comprises oil guide rings 30 arranged between the adjacent stator cores 10, each oil guide ring 30 is of an annular structure, a plurality of radial oil channels 31 are circumferentially arranged at intervals, and the radial oil channels 31 are communicated with the axial oil channels 13. The radial oil passage 31 is a passage structure, which is grooved from the outer circumferential surface of the oil guide ring 30, connected to two end surfaces of the oil guide ring 30, and then communicated with the axial oil passage 13. Therefore, the specific channel structure can be designed into a suitable shape according to actual requirements, and is not limited herein. Of course, those skilled in the art may also adopt other oil passage structures capable of communicating the external oil passage from the oil guide ring 30 to the axial oil passage 13 to replace the radial oil passage 31 according to the above design, and the replacement still falls into the protection scope of the present invention.

It should also be noted that the design concept is to form a cooling structure by configuring and combining two sets of stator cores 10 and one oil-guiding ring 30; of course, according to the requirement of the actual motor, a person skilled in the art may also arrange that three sets of stator cores 10 and two oil guide rings 30 are configured to form a cooling structure, and even may arrange that one set of stator cores 10 and one oil guide ring 30 are matched to introduce cooling oil into the axial oil passage 13 of the stator core 10 from an external oil passage through the oil guide ring 30.

Specifically, the working principle is that the cooling oil enters from an external oil path, enters into the radial oil path 31 through the outer circumferential surface of the oil guide ring 30, flows through the axial oil path 13 of the stator core 10, and flows out from the end surface of the stator core 10, so that the purpose of directly and effectively cooling the heating components in the stator slot 11 is achieved, oil throwing, spraying and other modes are not needed, and the cooling efficiency is high. In addition, because there is the physical clearance between flat line conductor, insulating paper and the stator slot 11, there is a small amount of cooling oil can flow in the rotor through the air gap, also plays the cooling effect to the rotor to realized that the stator cooling is main, the two oil circuit cooling systems that the rotor cooling is supplementary, further improved the cooling efficiency of whole motor oil cooling structure.

Preferably, the oil guiding ring 30 is further uniformly distributed with a plurality of ring teeth 32 and ring grooves 33 along the circumferential direction thereof, the ring teeth 32 and the ring grooves corresponding to the tooth spaces of the stator core 10.

In specific implementation, as shown in fig. 3 and 4, the inner surface of the oil guiding ring 30 is provided with a plurality of ring teeth 32 and ring grooves 33 extending in the axial direction, wherein the shape and position of the ring grooves 33 are the same as those of the stator grooves 11, so that the oil guiding ring 30 is correspondingly disposed in the middle of two adjacent groups of stator cores 10. During the assembly, lean on the mode of leaning on at the both ends face of leading oil ring 30 through adjacent two sets of stator core 10 terminal surfaces and fix leading oil ring 30 in the middle part of stator core 10, pass flat wire winding 20 again from stator slot 11 and annular 33 middle part to the configuration is on stator core 10 and leading oil ring 30, thereby guarantees to lead oil ring 30 and can cool off the middle part of adjacent two sets of stator core 10, and does not influence stator module's effect.

Preferably, the radial oil passage 31 includes a radial notch 31a formed to open toward the end face of the oil-guiding ring 30 and extend to the outer side of the circumference, and a lateral notch 31b communicating the adjacent ring grooves 33; the transverse notch 31b communicates with the radial notch 31a, and communicates with the axial oil passage 13 through the ring groove 33.

In specific implementation, the depth of the radial notch 31a is mainly not through the annular inner wall of the oil ring 30, and the transverse notch 31b is mainly through the side walls of the two adjacent ring grooves 33 of the guide ring and is communicated with the radial notch 31a, so that the cooling oil is introduced into the axial oil passage 13 corresponding to the ring groove 33 through the radial notch 31a and the transverse notch 31 b. The specific structures of the two are set according to the requirements, and are not limited herein. The number of the radial oil passages 31 is equal to the number of the stator slots 11.

Preferably, the radial oil passages 31 are symmetrically disposed on both side end surfaces corresponding to each ring tooth 32. Not only guarantee its radial oil duct 31's cooling depth, can also carry out synchronous cooling to both sides terminal surface, improve cooling efficiency.

Preferably, as shown in fig. 3 and 4, the radial notch 31a of the radial oil passage 31 is shaped like a "1", and the transverse notch 31b is shaped like a "one", and the two notches form an inverted T shape which is communicated with each other; wherein the one-shaped lateral notches 31b correspond to the positions of the bosses 12 so that the lateral notches 31b communicate with the axial oil passage 13. The inverted T-shaped radial oil passage 31 can introduce the cooling oil from the outer circumferential surface of the oil guide ring 30 into the axial oil passage 13 of the adjacent stator core 10 in two paths.

Preferably, the oil cooler housing 40 is arranged outside the stator core 10, the outer diameter of the oil guide ring 30 is smaller than that of the stator core 10, so that a circumferential oil channel 41 is formed between the outer circumferential surface of the oil guide ring 30, the end surface of the stator core 10 close to the oil guide ring 30 and the inner wall of the oil cooler housing 40, and the circumferential oil channel 41 is communicated with the radial oil channel 31.

In specific implementation, as shown in fig. 5 to 9, the circumferential oil channel 41 is communicated with the external oil pipe 60 to provide an oil channel source for the radial oil channel 31 and the axial oil channel 13, so that a three-dimensional through oil channel structure is formed, and uniform fluidity of the cooling oil in the three-dimensional oil channel is maintained. And can further carry out circumference cooling to stator core 10's middle part surface to make the inslot conductor carry out abundant direct cooling, further promote the cooling efficiency of whole oil-cooled motor.

As another preferable scheme, a circumferential oil channel 41 may be further formed in the middle of the oil cooling housing 40, and the circumferential oil channel 41 corresponds to the outer circumferential surface of the oil guide ring 30, so that the circumferential oil channel 41 is communicated with the radial oil channel 31. And a three-dimensional through oil channel structure can be formed, so that the flowing cooling of the cooling oil in the three-dimensional oil channel is ensured.

Preferably, at least one set of oil inlet 42 and oil return opening 43 are further disposed on the oil cooling housing 40, the oil inlet 42 is communicated with the circumferential oil channel 41, and the oil return opening 43 is disposed at the bottom of the oil cooling housing 40.

In practical implementation, as shown in fig. 7 and 8, since the oil guiding ring 30 is disposed at the middle of the adjacent stator core 10 and at the middle section of the motor, the oil inlet 42 is also disposed at the middle section of the oil cooling housing 40. During oil cooling operation, cooling oil enters from the oil inlet 22, flows through the three-dimensional oil channels of the circumferential oil channel 41, the radial oil channel 31 and the axial oil channel 13, flows out from the left end face and the right end face of the stator core 10, and then flows into the oil return opening 43 under the action of gravity to be recovered, so that secondary cooling recycling of the cooling oil is guaranteed.

Preferably, the oil cooler further comprises an oil pump 50, an oil pipe 60 connected with the oil pump 50, and an oil collecting tray 44 arranged at the bottom of the oil cooler shell 40, wherein the oil collecting tray 44 is communicated with the oil return opening 43, one end of the oil pipe 60 is communicated with the oil inlet 42 through the oil pump 50, and the other end of the oil pipe is communicated with the oil collecting tray 44.

In specific implementation, as shown in fig. 5, 7 and 9, the whole cooling structure provides circulating power through the oil pump 50, so that cooling oil enters from the oil inlet 42 in the middle of the motor through the oil pipe 60, then flows out from two end faces of the stator core 10 after passing through the circumferential, radial and axial three-dimensional oil passages, then flows to the oil return port 43 at the bottom of the oil cooler housing 40 and enters the oil collecting tray 44, and the cooling oil in the oil collecting tray 44 is pumped back into the oil pipe 60 by the action of the oil pump 50 for the next cooling cycle. Wherein, the oil collecting tray 44 is connected with the oil cooling shell 40 in a sealing and detachable or non-detachable way.

Compare in traditional immersion oil formula oil-cooled motor, the oil-cooled motor structure, simple process that this scheme provided provide through the oil pump provide circulating power to form three-dimensional oil circuit through the special design of leading oil ring and stator slot, the cooling oil circuit can be directly with inslot winding direct contact, directly cools off the part that generates heat, thereby effectively promotes motor cooling's efficiency and homogeneity.

Exemplarily, the oil-cooled motor further includes end covers 70 disposed at both ends of the oil-cooled housing 40, a rotating shaft 80 rotatably connected to the end covers 70 through bearings, and a rotor core 90 fixedly connected to the rotating shaft 80; the rotor core 90 is disposed inside the stator core 10 with an air gap formed therebetween. Preferably, magnetic isolation plates are further disposed at two end portions of the rotor core 90.

In summary, compared with the prior art, the direct oil-cooled cooling structure in the stator slot and the oil-cooled motor provided by the invention have the following advantages:

the structure and the process are simple, the manufacturing is easy, and the cost is low;

secondly, cooling oil is introduced from the middle section of the armature, a cooling oil path is divided into a front section and a rear section, each section of oil path is independent and does not intersect, the flat wire copper conductor in the slot can be fully and directly cooled, and the problems of overhigh central temperature rise and uneven temperature distribution of the armature of the oil-cooled motor are solved;

third, provide the circulating power through the oil pump, form the three-dimensional oil circuit through leading the oil ring and special stator trough type, make the cooling oil circuit system directly contact with winding in the trough directly, the part with the highest temperature in the direct cooling motor, thus raise the cooling efficiency of the oil cooling, guarantee the homogeneity of the temperature field when the oil cooling motor works effectively, avoid the production of the hot island;

after the cooling oil flows through the stator slots, a small amount of cooling oil flows into the rotor core due to the existence of physical gaps, so that a double-oil-way cooling system with the stator cooling as a main part and the rotor cooling as an auxiliary part is formed, and the cooling efficiency of the whole oil cooling system can be further improved.

In addition, it will be appreciated by those skilled in the art that, notwithstanding the many problems inherent in the prior art, each embodiment or solution of the present invention may be improved in one or more respects, without necessarily simultaneously solving all the technical problems inherent in the prior art or in the background art. It will be understood by those skilled in the art that nothing in a claim should be taken as a limitation on that claim.

Although terms such as stator core, flat wire winding, stator slot, boss, axial oil passage, oil guide ring, radial oil passage, ring gear, ring groove, radial notch, transverse notch, oil cooling housing, circumferential oil passage, oil inlet, oil return port, oil pump, oil collection pan, oil pipe, end cap, shaft, rotor core, etc. are used more often herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention; the terms "first," "second," and the like in the description and in the claims, and in the foregoing description and in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A direct oil-cooled cooling structure in a stator slot, comprising:

the stator comprises at least two groups of stator cores and flat wire windings arranged on the stator cores; the stator core is provided with a plurality of stator slots which are circumferentially arranged, the inner wall of each stator slot is provided with a boss which protrudes inwards along the axial direction, and the bosses separate the flat wire windings in the same stator slot, so that an axial oil duct which penetrates through two end faces of the stator core is formed in the gap in the middle of each boss;

the stator core is characterized by further comprising oil guide rings arranged between the adjacent stator cores, each oil guide ring is of an annular structure, a plurality of radial oil ducts are arranged at intervals along the circumferential direction, and the radial oil ducts are communicated with the axial oil ducts.

2. The direct oil-cooled cooling structure in a stator slot of claim 1, wherein: and a plurality of ring teeth and ring grooves corresponding to the tooth spaces of the stator iron core are uniformly distributed on the oil guide ring along the circumferential direction of the oil guide ring.

3. The direct oil-cooled cooling structure in a stator slot as claimed in claim 2, wherein: the radial oil passage comprises a radial gap and a transverse gap, wherein the radial gap is formed by an opening facing the end face of the oil guide ring and extending to the outer side of the circumference, and the transverse gap is communicated with the adjacent ring grooves; the transverse notch is communicated with the radial notch and communicated with the axial oil duct through the annular groove.

4. The direct oil-cooled cooling structure in a stator slot of claim 3, wherein: the radial oil passages are symmetrically arranged on the end surfaces of two sides of each corresponding ring gear.

5. The direct oil-cooled cooling structure in a stator slot as claimed in claim 3, wherein: the radial gap of the radial oil duct is in a '1' shape, the transverse gap is in a 'one' shape, and the radial gap and the transverse gap form an inverted T shape communicated with each other; the transverse notch of the I shape corresponds to the boss, so that the transverse notch is communicated with the axial oil passage.

6. The direct oil-cooled cooling structure in a stator slot according to any one of claims 1 to 5, wherein: the oil cooling device is characterized by further comprising an oil cooling shell arranged outside the stator core, wherein the outer diameter of the oil guide ring is smaller than that of the stator core, so that a circumferential oil channel is formed among the outer circumferential surface of the oil guide ring, the end surface of the stator core close to the oil guide ring and the inner wall of the oil cooling shell, and the circumferential oil channel is communicated with the radial oil channel.

7. The direct oil-cooled cooling structure in a stator slot of claim 6, wherein: the oil cooler is characterized in that at least one group of oil inlets and oil return ports are further formed in the oil cooler shell, the oil inlets are communicated with the circumferential oil duct, and the oil return ports are formed in the bottom of the oil cooler shell.

8. The direct oil-cooled cooling structure in a stator slot of claim 7, wherein: the oil cooler is characterized by further comprising an oil pump, an oil pipe connected with the oil pump and an oil collecting tray arranged at the bottom of the oil cooler shell, wherein the oil collecting tray is communicated with the oil return opening, one end of the oil pipe is communicated with the oil inlet through the oil pump, and the other end of the oil pipe is communicated with the oil collecting tray.

9. An oil-cooled motor, characterized in that: use of a direct oil-cooled cooling structure in a stator slot according to any of claims 1-8.

10. The oil-cooled motor of claim 9, wherein: the oil cooler is characterized by also comprising end covers arranged at two ends of the oil cooler shell, a rotating shaft which is rotatably connected with the end covers through bearings and a rotor core which is fixedly connected with the rotating shaft; the rotor core is arranged on the inner side of the stator core, and an air gap is formed between the rotor core and the stator core.