JP7239873B2 - Stator core and rotating electric machine cooling structure - Google Patents

Description

The present invention relates to a stator core and a cooling structure for a rotating electric machine having the stator core.

Generally, a rotating electrical machine has a case and a stator fixed inside the case. The stator has a cylindrical stator core, which is an iron core, and stator coils, which are windings wound around the stator core.

Patent Literature 1 discloses a cooling structure that cools a rotating electrical machine with cooling oil. In this cooling structure, an oil passage is provided inside the rotating electric machine, such as by providing a dedicated pipe in the case of the rotating electric machine as an oil passage, or by providing a through hole in the stator core to use as an oil passage. there is When oil is supplied to the oil passage by the oil pump, the oil is ejected from the open end of the oil passage into the case and hangs on the stator, thereby cooling the stator.

JP 2011-122711 A

In the cooling structure described above, if pipes are provided in the case as oil passages, the oil passages can be arranged with a high degree of freedom, making it easier to obtain cooling performance. However, in this case, the number of parts increases and the size of the rotary electric machine increases. By providing a through-hole in the stator core to serve as an oil passage, such an increase in the number of parts and an increase in the size of the rotary electric machine can be suppressed. However, simply providing a through-hole in the stator core may lead to deterioration in the performance of the stator core and, in turn, deterioration in the performance of the rotating electric machine.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a stator core capable of achieving high cooling performance in a small space while suppressing deterioration in performance of a rotating electrical machine, and a cooling structure for a rotating electrical machine having the same stator core. is to provide

A stator core for solving the above-mentioned problems has a cylindrical main body, and a shape projecting outward at a position spaced in the peripheral direction of the main body at the outer peripheral end of the main body. a plurality of ear portions having a first through hole for fastening and fixing that penetrates in the central axis direction of the stator core, wherein at least one of the plurality of ear portions is provided separately from the first through hole , and a second through hole penetrating in the direction of the central axis.

According to the above configuration, the second through holes formed in the ears of the stator core can be used as oil passages through which cooling oil passes. Therefore, compared to the case where a dedicated pipe is provided inside the rotary electric machine as an oil passage, space can be saved and high cooling performance can be obtained. Moreover, although the stator core is provided with the second through-hole, the second through-hole is not the main body portion of the stator core that functions as an iron core, but the ear portion that protrudes from the outer peripheral portion of the main body portion, that is, the stator core. It is provided in the part where the influence on the performance is small. Therefore, deterioration in performance of the stator core and, in turn, deterioration in performance of the rotating electric machine can be suppressed.

A cooling structure for a rotating electric machine for solving the above-mentioned problems includes a main body having a cylindrical shape, and a shape protruding to the outer peripheral side at positions spaced in the peripheral direction of the main body at the outer peripheral end of the main body. a stator core including a plurality of ear portions having first through holes for fastening and fixing that penetrate through the main body portion in the central axis direction; and a seat portion on which the plurality of ear portions are seated. A cooling structure applied to a rotating electrical machine, comprising: a case in which the stator core is housed with the ear portions seated, and in which the stator core is fastened and fixed via the ear portions, wherein a second through hole provided in at least one of a plurality of ear portions and penetrating the ear portion in the direction of the central axis to form a part of an oil passage through which cooling oil passes; and a third through hole that opens in the seat portion in a manner communicating with the second through hole and forms a part of the oil passage.

According to the above configuration, the ear portion of the stator core and the seat portion of the case, which are portions for fastening and fixing the stator core to the case, are utilized to provide the second through hole and the second through hole, which are oil passages through which cooling oil passes. Since three through holes can be provided, it is possible to obtain high cooling performance while saving space. Moreover, although the stator core is provided with the second through-hole, the second through-hole is not the main body portion that functions as the iron core in the stator core, but the ear portion that is used for fastening and fixing, that is, the performance of the stator core. A small portion of Therefore, deterioration in performance of the stator core and, in turn, deterioration in performance of the rotating electric machine can be suppressed.

Advantageous Effects of Invention According to the present invention, it is possible to obtain high cooling performance in a space-saving manner while suppressing deterioration in performance of a rotating electric machine.

1 is a side sectional view of an electric motor to which a stator core and cooling structure of one embodiment are applied; FIG. (a) is a side view of the stator core of the electric motor, and (b) is a cross-sectional view taken along line 2b-2b of (a). (a) is a side view of the case body of the electric motor, and (b) is a cross-sectional view taken along line 3b-3b of (a). FIG. 4 is a side view of the case and the stator core with the ear portions of the stator core seated on the seat portions of the case; 3 is a side sectional view of the upper portion of the electric motor; FIG. (a) is a side view of a case body of an electric motor to which a stator core and cooling structure of another embodiment are applied, and (b) is a cross-sectional view taken along line 6b-6b of (a). FIG. 2 is a side cross-sectional view of the upper portion of the electric motor; FIG. 11 is a side cross-sectional view of an upper portion of an electric motor to which a stator core and cooling structure of another embodiment are applied; (a) is a side view of the stator core of the electric motor, and (b) is a cross-sectional view taken along line 9b-9b of (a).

An embodiment of a cooling structure for a stator core and a rotating electric machine will be described below.
As shown in FIG. 1 , an electric motor 10 as a rotating electric machine has a stator 11 , and the stator 11 has a stator core 12 and stator coils 13 .

As shown in FIGS. 2(a) and 2(b), the stator core 12 has a substantially cylindrical body portion 21. As shown in FIG. This body portion 21 is a portion that functions as an iron core of the stator 11 . Further, the stator core 12 has a plurality (three in the present embodiment) of ear portions 22 that protrude from the outer peripheral end of the main body portion 21 to the outer peripheral side. These ear portions 22 are portions used when fastening and fixing the stator core 12 . The ear portions 22 are provided at positions spaced apart in the circumferential direction of the main body portion 21 at the outer peripheral end of the main body portion 21 . Each ear portion 22 has a mountain-shaped cross section and forms a ridge extending in the central axis L1 direction of the main body portion 21 . Each of the ear portions 22 is provided with a first through hole 23 penetrating in the direction of the central axis L1. The first through hole 23 is a through hole for fastening and fixing, and a fastening and fixing bolt (not shown) is inserted into the first through hole 23 when fastening and fixing the stator core 12 .

A second through hole 24 penetrating in the central axis L1 direction is provided in the ear portion 22</b>A, which is arranged at the highest position among the plurality of ear portions 22 , separately from the first through hole 23 . The second through hole 24 functions as an oil passage through which oil for cooling the electric motor 10 passes. Note that in the present embodiment, the second through holes 24 are not provided in the two ear portions 22B of the plurality of ear portions 22 other than the ear portion 22A.

As shown in FIG. 1, the stator coil 13 is a portion that functions as a winding of the stator 11, and is wound around the body portion 21 in such a manner as to extend over the entire circumference of the body portion 21. As shown in FIG.
The electric motor 10 has a rotor 14 which has a rotor core 15 and a rotor shaft 16 . The rotor core 15 has a cylindrical shape. The rotor core 15 is a portion that functions as an iron core of the rotor 14 . The rotor shaft 16 is integrated with the rotor core 15 while being inserted through the center hole 17 of the rotor core 15 .

Electric motor 10 has case 30 in which stator 11 and rotor 14 are arranged. The case 30 has a divided structure including a case main body 31 having a substantially cylindrical shape with a bottom and a case cover portion 32 having a substantially cylindrical shape with a lid.

As shown in FIGS. 3(a) and 3(b), the case body 31 has a plurality of (three in this embodiment) fixed projections 33 projecting outward from the outer peripheral portion. Each fixed protrusion 33 has a mountain-shaped cross section and forms a ridge extending in the direction of the central axis L1.

A fixing groove 34 is formed on the inner surface of each fixing projection 33 so as to extend in an arc-shaped bottom surface. The fixing groove 34 extends from the opening end of the case body 31 (the left end in FIG. 3B) to the middle of the fixing protrusion 33 . An end portion of the fixed groove 34 inside the case body 31 forms a seat portion 35 on which the ear portion 22 of the stator core 12 is seated. The seat portion 35 is a portion used when fastening and fixing the stator core 12 to the case body 31 . The outer surface of the seat portion 35 extends in a direction orthogonal to the central axis L1. Each seat portion 35 is provided with a screw hole 36 extending in the central axis L1 direction. A fastening and fixing bolt is screwed into the screw hole 36 when fastening and fixing the stator core 12 .

A support hole 38 is provided in the bottom wall 37 of the case body 31 . The support hole 38 functions as a bearing that rotatably supports the rotor shaft 16 (see FIG. 1). In this embodiment, the rotor shaft 16 is supported by the case body 31 while being inserted into the support hole 38 .

A third through hole 39 is formed in the uppermost fixing protrusion 33</b>A of the plurality of fixing protrusions 33 . The third through hole 39 includes a first passage 39A that extends in the central axis L1 direction and opens at the seat portion 35, and extends from the inner surface of the first passage 39A to the outer surface of the fixed projection 33 in the direction perpendicular to the central axis L1. and an extending second passage 39B. One end of the third through hole 39 opens in the seat portion 35 so as to communicate with the second through hole 24 (see FIG. 1), and the other end opens in the outer surface of the fixed convex portion 33A of the case body 31. is extended by

As shown in FIGS. 1 and 4, in the electric motor 10 of the present embodiment, the stator core 12 is fastened and fixed to the case 30 in a state in which the ear portions 22 of the stator core 12 are seated on the seat portions 35 of the case 30. The second through-hole 24 and the third through-hole 39 are connected without performing a special work for connecting the second through-hole 24 and the third through-hole 39 . The third through hole 39 functions as an oil passage through which cooling oil passes. In this embodiment, the third through holes 39 are not provided in the two fixing protrusions 33B of the plurality of fixing protrusions 33 other than the fixing protrusion 33A.

As shown in FIGS. 3(a) and 3(b), a fourth through hole 40 is formed in the upper portion of the bottom wall 37 of the case body 31 facing the stator coil 13 (see FIG. 1). there is The fourth through hole 40 functions as an oil passage through which cooling oil passes.

As shown in FIG. 1, a cylindrical support tube portion 43 protrudes from the inner surface of the lid wall 41 of the case lid portion 32 . The support cylinder portion 43 functions as a bearing that rotatably supports the rotor shaft 16 . In the present embodiment, the tip portion of the rotor shaft 16 is supported by the case lid portion 32 while being inserted into the support cylinder portion 43 .

An oil pump 18 is connected to the electric motor 10 . A suction port of the oil pump 18 is connected to the lower portion of the case 30, and a discharge port of the oil pump 18 is connected to the opening of the third through hole 39 and the opening of the fourth through hole 40 on the outer surface of the case 30. ing. In the electric motor 10 of this embodiment, oil is accumulated in the lower portion of the case 30 as indicated by dot hatching in FIG. When the oil pump 18 operates when the electric motor 10 operates, the oil in the lower portion of the case 30 is pumped up by the oil pump 18 and supplied into the case 30 through the third through hole 39 and the fourth through hole 40 .

The effects of the cooling structure for the stator core 12 and the electric motor 10 of this embodiment will be described below.
When the oil pump 18 operates during operation of the electric motor 10 , oil is pumped up from the lower portion of the case 30 and supplied to the third and fourth through holes 39 and 40 .

As shown in FIG. 5 , the oil supplied to the third through hole 39 flows into and passes through the second through hole 24 and jets out from the end of the second through hole 24 into the case 30 . As a result, the oil scatters in the space between the stator 11 and the case lid portion 32 . This oil drops due to gravity and hangs on the portion of the stator core 12 and the stator coil 13 on the side of the case lid portion 32 (left side in FIG. 5). Through heat exchange with this oil, the stator core 12 and the stator coil 13 are cooled.

Also, the oil supplied to the fourth through hole 40 is jetted into the case 30 from the end portion of the fourth through hole 40 . As a result, the oil scatters in the space between the stator 11 and the case body 31 . This oil drops due to gravity and hangs on the portion of the stator core 12 and the stator coil 13 on the case body 31 side (the right side in FIG. 5). Through heat exchange with this oil, the stator core 12 and the stator coil 13 are cooled.

Oil supplied into the case 30 for cooling the electric motor 10 runs down the inside of the case 30 and accumulates in the lower portion of the case 30 . The oil accumulated in the lower portion of the case 30 is pumped up by the oil pump 18 and supplied into the case 30 through the third through-hole 39 and the fourth through-hole 40 .

In the cooling structure of the present embodiment, the electric motor 10 is cooled using the cooling oil as described above.
According to this embodiment, the effects described below can be obtained.

(1) The ear portion 22A of the stator core 12 of the electric motor 10 is provided with a second through hole 24 penetrating in the direction of the central axis L1 in addition to the first through hole 23 for fastening and fixing.
According to the electric motor 10, the second through hole 24 can be used as an oil passage through which cooling oil passes. Therefore, it is possible to suppress an increase in the size of the electric motor 10 compared to the electric motor of the comparative example in which a dedicated pipe is provided inside to form an oil passage. Moreover, since the cooling oil passes through the inside of the stator core 12, the stator core 12 can be efficiently cooled compared to the electric motor of the comparative example. Thus, according to the above embodiment, it is possible to obtain high cooling performance while saving space.

Moreover, although the second through-hole 24 is provided in the stator core 12, the second through-hole 24 is not located in the main body portion 21 functioning as the iron core in the stator core 12, but protrudes from the outer peripheral portion of the main body portion 21. It is provided in the ear portion 22 , that is, in a portion having a small influence on the performance of the stator core 12 . Therefore, deterioration of the performance of the stator core 12 and, in turn, deterioration of the performance of the electric motor 10 can be suppressed.

(2) The electric motor 10 includes a second through hole 24 penetrating the ear portion 22A of the stator core 12 in the direction of the central axis L1, and a third through hole 24 opened in the seat portion 35 of the case 30 so as to communicate with the second through hole 24. and a through hole 39 . According to this embodiment, the ear portion 22A of the stator core 12 and the seat portion 35 of the case 30, which are portions for fastening and fixing the stator core 12 to the case 30, are used to form an oil passage through which cooling oil passes. Since certain second through holes 24 and third through holes 39 can be provided, space can be saved and high cooling performance can be obtained.

(3) A second through-hole 24 forming a part of the oil passage is provided in the uppermost ear portion 22</b>A of the plurality of ear portions 22 . Therefore, the oil discharged into the case 30 from the second through hole 24 falls downward due to gravity and is diffused inside the case 30 . As described above, according to the present embodiment, the oil can be efficiently diffused into the case 30 using gravity.

It should be noted that the above embodiment may be modified as follows.
- The second through-holes 24 are not limited to being provided only in the uppermost ear portion 22A among the plurality of ear portions 22, but may be provided in the ear portion 22B other than the ear portion 22A. Also, the second through holes 24 may be provided in all of the plurality of ear portions 22 or may be provided in only two of the plurality of ear portions 22 . In such a configuration, the seat portion 35 of the case 30 on which the ear portion 22 having the second through hole 24 is seated is provided with a third through hole 39 that opens in the seat portion 35 in a manner communicating with the second through hole 24 . should be set.

- As shown in FIGS. 6A, 6B, and 7, a recessed communication groove 52 extending from the opening of the third through hole 39 toward the central axis L1 is formed in the seat portion 35 of the case body 51. may be provided. 6 and 7, components similar to those of the electric motor 10 exemplified in FIGS. omitted.

As shown in FIG. 7, the communication groove 52 constitutes a communication path at the mating surface between the ear portion 22A of the stator core 12 and the seat portion 35 of the case body 51. As shown in FIG. One end of this communication passage communicates with a third through hole 39 that forms a part of the oil passage, and the other end of the communication passage is located on the inner peripheral side of the body portion 21 (lower side in FIG. 7) on the mating surface. It is open at the ends. In this example, the case main body 51 is not provided with the fourth through hole 40 (see FIG. 3).

According to the above configuration, as indicated by arrows in FIG. 7) is supplied with oil. In addition to this, oil can also be supplied to portions of the stator core 12 and stator coil 13 on the side (right side in FIG. 7) near the seat portion 35 of the case body 51 via the communicating groove 52 as a communicating passage. will be able to Thus, according to the above configuration, it is possible to supply oil over a wide range to the stator core 12 and the stator coil 13 inside the case 50 by using the third through hole 39 functioning as an oil passage. , a higher cooling performance can be obtained.

8, 9(a) and 9(b), the central axis L1 from the opening portion of the second through hole 24 is formed on the surface of the ear portion 22A of the stator core 62 on the side of the seat portion 35 of the case 30. A concave communicating groove 60 extending laterally may be provided. 8 and 9, components similar to those of the electric motor 10 exemplified in FIGS. omitted.

As shown in FIG. 8, the communication groove 60 constitutes a communication path in the mating surface between the ear portion 22A of the stator core 62 and the seat portion 35 of the case 30. As shown in FIG. One end of this communication passage communicates with a second through hole 24 that forms a part of the oil passage, and the other end of the communication passage is located on the inner peripheral side (lower side in FIG. 8) of the main body portion 21 on the mating surface. It is open at the ends. In this example, the case 30 is not provided with the fourth through hole 40 (see FIG. 3).

According to the above configuration, as indicated by arrows in FIG. Oil will be supplied. In addition, oil can also be supplied to portions of the stator core 62 and the stator coil 13 near the seat portion 35 of the case 30 (right side in FIG. 8) via the communicating groove 60 as a communicating passage. become able to. Thus, according to the above configuration, it is possible to supply oil over a wide range to the stator core 62 and the stator coil 13 by using the second through holes 24 functioning as oil passages. performance can be obtained.

- The stator core and cooling structure of the above embodiments can be applied to a stator core having four or more ears, and to an electric motor having the same stator core.

DESCRIPTION OF SYMBOLS 10... Electric motor 11... Stator 12... Stator core 13... Stator coil 14... Rotor 15... Rotor core 16... Rotor shaft 17... Center hole 18... Oil pump 21... Body part 22, 22A, 22B ...Ear part 23...First through hole 24...Second through hole 30...Case 31...Case main body 32...Case cover 33, 33A, 33B...Fixing protrusion 34...Fixing groove 35... Seat portion 36 Screw hole 37 Bottom wall 38 Support hole 39 Third through hole 39A First passage 39B Second passage 40 Fourth through hole 41 Lid wall 43 ... Support cylinder part, 50 ... Case, 51 ... Case body, 52 ... Communication groove, 60 ... Communication groove, 62 ... Stator core.

Claims (4)

A stator core comprising a cylindrical main body and ears protruding from the outer peripheral end of the main body,
A plurality of the ear portions are provided at intervals in a peripheral direction of the main body portion,
each of the plurality of ear portions has a first through hole for fastening and fixing that penetrates in the central axis direction of the body portion;
at least one of the plurality of ear portions has a second through hole that penetrates in the central axis direction separately from the first through hole;
The stator core, wherein the second through-hole is provided so as to be aligned with the first through-hole in the circumferential direction . a stator core comprising a cylindrical main body, and ears protruding from the outer peripheral end of the main body to the outer peripheral side;
a case having a seat portion on which the ear portion is seated, the stator core being accommodated with the ear portion seated on the seat portion, and the stator core being fastened and fixed via the ear portion in the same state; A cooling structure applied to a rotating electrical machine comprising
A plurality of the ear portions are provided at intervals in a peripheral direction of the main body portion,
each of the plurality of ear portions has a first through hole for fastening and fixing that penetrates in the central axis direction of the body portion;
at least one of the plurality of ear portions has a second through hole that penetrates in the central axis direction and forms a part of an oil passage through which cooling oil passes;
The second through hole is provided in a manner aligned with the first through hole in the circumferential direction,
The cooling structure for a rotating electric machine, wherein the case has a third through-hole that opens in the seat portion in a manner that communicates with the second through-hole and forms a part of the oil passage. 3. The cooling structure for a rotating electric machine according to claim 2, wherein said second through-hole is provided in an uppermost ear portion among said plurality of said ear portions. A groove formed in the mating surface between the ear portion and the seat portion, one end of which communicates with the oil passage and the other end of which is open at the end portion of the mating surface on the inner peripheral side of the main body portion. 4. The cooling structure for a rotating electric machine according to claim 2 , having a passage .

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