JPH08214499A - Rotary electric machine - Google Patents

Abstract

PURPOSE: To improve cooling performance and particularly the cooling performance of a stator iron core by exhausting the external air as much as possible from an exhaust port after it has run the ventilation path up to the area near the center of the stator iron core in the axial direction. CONSTITUTION: In a stator frame 2, a pair of elongated exhaust ports 22, located between ribs 5 to extend in the axial direction symmetrically to the center line in the axial direction of the stator iron core 9, are arranged in three lines in the circumferential direction. These exhaust ports 22 are formed to become wider toward the center in the axial direction of the stator iron core 9 from the side of the bearing bracket 3. As a result, the air entering the area between ribs 5 is exhausted from the side of center in the axial direction of the stator iron core 9 among the exhaust port 22 in larger amount than that from the side of the bearing bracket 3. Therefore, a larger amount of air reaches the area near the center in the axial direction of the stator iron core within the ventilation path formed between the ribs 5 provided between the stator iron core 9 and the stator frame 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine with improved cooling performance.

[0002]

2. Description of the Related Art A conventional structure of a rotary electric machine, for example, an open type induction motor is shown in FIGS. In FIG. 6, an outer shell 1 of the electric motor is composed of a tubular stator frame 2 and bearing brackets 3 and 3 mounted on both ends of the stator frame 2. Of these, bearing housings 3a, 3a are formed in the central portions of the bearing brackets 3, 3 and an intake port 4 is formed around the bearing housings 3a, 3a, and on the inner surface of the stator frame 2. A rib 5 is provided which protrudes inward and extends in the axial direction. Further, three elongated hole-shaped exhaust ports 6 extending in the axial direction are formed in the stator frame 2 so as to be located between the ribs 5 and are arranged side by side in the circumferential direction and in the axial direction.

A stator 7 is attached to the inner periphery of the rib 5 by press fitting, and as shown in FIG. 7, an air passage 8 partitioned by the rib 5 between the stator 7 and the stator frame 2.
Is formed. The stator 7 is composed of an annular stator core 9 fixed to the ribs 5 and a stator coil 10 wound around the stator core 9.

A rotor 11 is arranged inside the stator 7. The rotor 11 has a bearing housing 3a and a bearing 12
A rotary shaft 13 supported via a rotor core 14, a rotor core 14 provided on the outer peripheral portion of the rotary shaft 13, and a rotor core 1
4, a plurality of rotor conductors 15 provided, an end ring 16 provided so as to short-circuit the rotor conductors 15 at both ends of the rotor core 14, and an axial outer side from the end ring 16. And a plurality of fins 17 projecting toward. An annular baffle plate 18 is provided on the inner side of the bearing bracket 3 and the end portion on the inner peripheral side thereof is provided with the fins 17 described above.
It is arranged so as to be close to.

In the electric motor having the above structure, the air outside the outer shell 1 is sucked into the outer shell 1 from the intake port 4 as indicated by arrows A, B, and C by the blowing action of the rotation of the fins 17. , The air is baffle plate 18 and bearing housing 3
It is sent to the side of the stator 7 through the space between a and the air guide plate 18 and the end ring 16. Then, the air sent to the side of the stator 7 passes through the ventilation passage 8 and is discharged from the exhaust port 6 to the outside of the outer shell 1.

On the other hand, when the electric motor is operated, iron loss occurs in the stator core 9 and the rotor core 14, and the stator coil 10
Copper loss occurs in the rotor conductor 15, and friction loss occurs in the bearing 12. The heat generated by these losses is radiated to the air between the intake port 4 and the exhaust port 6, thereby cooling the electric motor.

Here, most of the heat generated in the stator core 9 is generated when the air in the outer shell 1 flows through the ventilation passage 8.
Since heat is radiated by exchanging heat with the air, more air needs to flow through the ventilation passage 8 in order to efficiently cool the stator core 9.

[0008]

The air guided by the baffle plate 18 and sent to the stator 7 side flows between the ribs 5 and is discharged from the exhaust port 6 to the outside of the outer shell 1. Among the portions between the ribs 5, the portion where the stator core 9 is attached to the inner periphery of the ribs 5 and the ventilation passage 8 is formed has a ventilation area that is suddenly smaller than that of the other portions. Inflow resistance is large. However, the opening width of the exhaust port 6 (the opening width along the circumferential direction of the outer shell 1) is the same from the end side of the outer shell 1 to the axial center side of the stator core 9, and the air outflow resistance thereof is axially different. Therefore, the air that is about to flow into the ventilation passage 8 is exhausted in large amounts from the exhaust port 6 at the inlet portion of the ventilation passage 8. Moreover, the air flowing into the ventilation passage 8 is
Most of the exhaust air is exhausted from the bearing bracket 3 side of the exhaust port 6 before reaching the axial center of the stator core 9. Therefore, there is a problem that the amount of air flowing into the ventilation passage 8 from the bearing bracket 3 side and flowing to the vicinity of the axial center of the stator core 9 is small, and the stator core 9 is insufficiently cooled.

Therefore, an object of the present invention is to allow as much outside air as possible to circulate in the ventilation passage to the vicinity of the axial center of the stator core, and then to discharge it from the exhaust port to the outside, particularly the cooling performance. (EN) Provided is a rotating electric machine capable of improving the cooling performance of an iron core.

[0010]

The rotating electric machine of the present invention has a plurality of ventilation passages extending in the axial direction between the peripheral wall portion of the outer shell and the stator core arranged in the outer shell along the circumferential direction. Formed,
The outside air taken into the outer shell and flowing into the ventilation passage is discharged to the outside from the exhaust port formed in the peripheral wall portion of the outer shell, and the exhaust port corresponding to each ventilation passage is The opening area in each axial portion of the peripheral wall portion is formed so as to be larger on the axial center side of the stator core than on the axial end portion side of the outer shell (claim) Item 1).

In this case, the exhaust port corresponding to each ventilation passage is
It is preferable that the outer shell has an elongated hole shape extending in the axial direction and is formed so as to widen from the axial end portion side of the outer shell toward the axial center side of the stator core (claim 2).

Further, the exhaust ports corresponding to the respective ventilation passages are formed in the shape of a long hole extending in the axial direction of the outer shell and arranged in the circumferential direction, and the number of the exhaust ports arranged in the circumferential direction is the axial direction of the outer shell. It is preferable that the axial direction is closer to the axial center side of the stator core from the end side (claim 3).

Further, the exhaust ports corresponding to the respective ventilation passages are formed in the shape of elongated holes extending in the circumferential direction and are arranged side by side in the axial direction. The exhaust ports are arranged from the end of the outer shell in the axial direction of the stator core. It is preferable that the center side is set to have a longer circumferential length (claim 4).

[0014]

According to the above means, the exhaust port formed in the outer shell located in each ventilation passage has an opening area closer to the axial center side of the stator core than to the axial end portion side of the outer shell. Because of the large size, the outflow resistance of the air from the exhaust port is large on the axial end side of the outer shell and small on the axial center side of the stator core.
Therefore, the amount of air exhausted from the exhaust port before flowing into the ventilation passage decreases, and the amount of air flowing into the ventilation passage increases. Therefore, a large amount of air can reach the vicinity of the axial center of the stator core in the ventilation passage, and at that time, the air circulates over the outer peripheral surface of the stator core for a long distance, and the air flows from the stator core. Take away heat (Claim 1).

In this case, the exhaust port is formed in the shape of a long hole extending in the axial direction of the outer shell and widens from the axial end of the outer shell toward the axial center of the stator core ( 3. The stator core according to claim 2), or the exhaust core is formed by arranging a plurality of elongated holes extending in the axial direction of the outer shell side by side in the circumferential direction, and the number of circumferentially arranged stator cores is greater than that of the outer shell axial end side. The number of the exhaust ports is increased on the axial center side (Claim 3), or a plurality of exhaust holes extending in the circumferential direction are formed side by side in the axial direction. By setting the length in the circumferential direction to be long (claim 4), the opening area in each axial portion of the peripheral wall portion of the outer shell of the exhaust port can be easily set more than the axial end portion side of the outer shell. It can be formed so that it is larger on the axial center side of the iron core.

In particular, when the exhaust port has a long hole shape extending in the axial direction of the outer shell and is formed so as to be wider from the axial end portion side of the outer shell toward the axial center side of the stator core. In (claim 2), the exhaust port is formed so as to widen from the axial end portion side of the stator core toward the axial center side even in the portion located in the ventilation passage, and the outflow of air. The resistance gradually decreases from the axial end of the stator core toward the axial center. Therefore, due to the pressure loss due to the ventilation resistance received when the air flows through the ventilation passage, the pressure energy of the air flowing through the ventilation passage is directed from the axial end side of the stator core toward the axial center side of the stator core. Although it gradually decreases, the air outflow resistance of the exhaust port is large on the axial end side of the stator core and small on the axial center side of the stator core. Is gradually discharged toward the axial center side of the stator core, and the amount of air that reaches the vicinity of the axial center of the stator core increases, and the air discharge performance improves and is taken into the outer shell. The amount of air that can be discharged increases.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention applied to an open induction motor will be described below with reference to FIGS. FIG. 1 shows the entire structure. The same parts as those in FIG. 6 are designated by the same reference numerals. The outer shell 1 of the electric motor has a cylindrical stator frame 2 as a peripheral wall portion, and this fixed part. It is composed of bearing brackets 3 mounted on both ends of the child frame 2. Of these, bearing housings 3a, 3a are formed in the central portions of the bearing brackets 3, 3 and an intake port 4 is formed around the bearing housings 3a, 3a. The stator frame 2 is made of steel plate,
A plurality of, for example, six ribs 5 projecting inward and extending in the axial direction are intermittently formed in the stator frame 2 in the circumferential direction as shown in FIG. As shown in FIG. 2, a pair of legs 21 and 21 are attached to the pair of ribs 5a and 5a located in the lower part of these ribs 5, respectively.

The stator 7 is provided in the central portion of the stator frame 2 in the axial direction.
Is provided. The stator 7 is configured by winding a stator coil 10 around a stator core 9, and the stator core 9 is attached to the protruding end surface of the rib 5 of the stator frame 2 by press fitting or the like. By the attachment of the stator core 9, a plurality of ventilation passages 8 which are partitioned by the rib 5 between the stator frame 2 and the stator core 9 in this case, six ventilation passages 8 are formed intermittently along the circumferential direction. .

In the portion of the stator frame 2 between the ribs 5, that is, in the portion corresponding to each ventilation passage 8, there is provided an exhaust hole 22 in the form of an elongated hole extending in the axial direction. A plurality of pairs, for example, three rows are formed side by side in the circumferential direction such that each pair is positioned symmetrically with respect to the directional center. Each of these exhaust ports 22 has an opening width (width along the circumferential direction of the stator frame 2) from the bearing bracket 3 side that is the axial end side of the outer shell 1 toward the axial center side of the stator core 9. It is formed to become gradually wider. Accordingly, the exhaust port 22 is configured such that the opening area gradually increases from the axial end portion side of the stator frame 2 toward the axial center side of the stator core 9.

Inside the stator 7, a rotor 11 is arranged. The rotor 11 has a bearing housing 3a and a bearing 12
A rotary shaft 13 supported via a rotor core 14, a rotor core 14 provided on the outer peripheral portion of the rotary shaft 13, and a rotor core 1
4, a plurality of rotor conductors 15 provided, an end ring 16 provided so as to short-circuit the rotor conductors 15 at both ends of the rotor core 14, and an axial outer side from the end ring 16. And a plurality of fins 17 projecting toward. An annular baffle plate 18 is disposed inside both ends of the bearing bracket 3 in the axial direction so that the end portion on the inner peripheral side thereof is close to the fin 17.

In the above structure, when the fins 17 rotate as the rotor 11 rotates, the air blown by the fins 17 causes the outside air outside the outer shell 1 to escape from the intake port 4 as indicated by arrows E, F, and G. The air sucked into the shell 1 and its air are blown into the space between the baffle plate 18 and the bearing housing 3a and the baffle plate 18
It is sent to the stator 7 side through the space between the end ring 16 and the end ring 16 and flows into the space between the ribs 5. At this time, the exhaust port 22 provided between the ribs 5 is formed so as to become wider from the bearing bracket 3 side toward the axial center side of the stator core 9, and the exhaust port located outside the ventilation passage 8 is formed. Since the opening area of 22 is small, the air that has flowed in between the ribs 5 is too large.
It flows into the ventilation passage 8 without being discharged to the outside. Then, the air flowing into the ventilation passage 8 is directed toward the axial center side of the stator core 9 while receiving a pressure loss when flowing through the ventilation passage 8. At this time, the portion of the exhaust port 22 located in the ventilation passage 8 is also formed so as to widen from the axial end side of the stator core 9 toward the axial center side.
The air outflow resistance is large on the axial end side of the stator core 9 and small on the axial center side. Therefore, the air flowing into the ventilation passage 8 is gradually discharged while the stator core 9
As the amount of air reaching the vicinity of the axial center of the stator core 9 increases, the air discharge efficiency improves and the amount of air taken into the outer shell 1 increases.

Therefore, according to this embodiment, the air flowing between the ribs 5 flows into the ventilation passage 8 without being exhausted to the outside of the outer shell 1, so that the amount of air for cooling the stator core 9 is reduced. Increase. In particular, in this embodiment, the air flowing into the ventilation passage 8 is gradually discharged from the bearing bracket 3 side of the exhaust port 22 toward the axial center side of the stator core 9, while the axial center of the stator core 9 is being discharged. Toward the side, the amount of air flowing over the outer peripheral surface of the stator core 9 over a long distance increases, so that the heat exchange between the air flowing in the ventilation passage 8 and the stator core 9 is efficiently performed, and The cooling performance of the child core 9 is improved. In addition, the air is easily discharged from the exhaust port 22,
Since the amount of air taken into the outer shell 1 increases, not only the stator core 9 but also the cooling performance of the entire electric motor improves.

FIG. 3 shows a second embodiment of the present invention.
The same parts as those in FIG. 1 showing the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. That is, in the portion of the stator frame 2 between the ribs 5, that is, the portion corresponding to each air passage 8, from the axial end of the stator frame 2 to the axial center of the stator core 9, respectively. A long hole-shaped exhaust port 23 extending up to and an exhaust port 24 having a length of about half of the exhaust port 23 and extending from the axial end portion of the stator core 9 to a position near the axial center are arranged along the circumferential direction. For example, they are formed symmetrically with respect to the axial center of the stator core 9 so as to be arranged alternately two by two.

As a result, although only two exhaust ports 23 exist outside the ventilation passage 8 in the axial direction (on the end side of the stator frame 2), the ventilation passage 8 (in the axial direction of the stator core 9). At the center side), there are a total of four exhaust ports, two exhaust ports 23 and two exhaust ports 24, and the total opening area of the exhaust ports 23 and 24 is the end portion of the stator frame 2. When divided into the side and the axial center side of the stator core 9, the latter is configured to be larger than the former.

Therefore, also in this embodiment, the air flowing between the ribs 5 flows into the ventilation passage 8 without being exhausted to the outside of the outer shell 1, so that the amount of air for cooling the stator core 9 increases. The cooling performance of the stator core 9 is improved.

FIG. 4 shows a third embodiment of the present invention.
The same parts as those in FIG. 3 showing the second embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. That is, in the portions of the stator frame 2 between the ribs 5, that is, the portions corresponding to the respective ventilation passages 8, the stator cores 9 are respectively provided.
Exhaust port 24 that extends from the axial end of the engine to near the axial center
And the stator frame 2 having the same length as the exhaust port 24.
An exhaust port 25 extending from near the axial end of the stator core 9 to near the axial end of the stator core 9 is formed symmetrically around the axial center of the stator core 9. And the exhaust port 2
For example, 4 are arranged along the circumferential direction, and, for example, two exhaust ports 25, which are less than the exhaust ports 24, are arranged along the circumferential direction. At this time, the exhaust ports 25 are arranged along the circumferential direction.
Two out of four and every other one are arranged in the axial direction.

As a result, when the total opening area of the exhaust ports 24 and 25 is divided into the end portion side of the stator frame 2 and the axial center side of the stator core 9, the latter is larger than the former. Since it is configured so as to be large, the same operational effect as that of the above-described second embodiment can be obtained in this embodiment as well.

FIG. 5 shows a fourth embodiment of the present invention.
The same parts as those in FIG. 1 showing the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. That is, in the portion of the stator frame 2 between the ribs 5, that is, in the portion corresponding to each ventilation passage 8, an elongated hole-shaped exhaust port 26 extending in the circumferential direction is provided in the stator core 9 along the axial direction. From the vicinity of the axial center to the end of the stator frame 2 in the axial direction, a plurality of five in this case are arranged symmetrically with respect to the axial center of the stator core 9. These exhaust ports 26 are provided with exhaust ports 26a, 26b, 26c, 26d, and 26e so that the circumferential length gradually decreases from the axial center side of the stator core 9 toward the axial end portion side of the stator frame 2. The exhaust ports 26a, which are arranged side by side and are located on the most axial center side of the stator core 9, have a circumferential length extending from near one rib 5 forming the ventilation passage 8 to near the other rib 5. The exhaust port 26e located closest to the axial end of the stator frame 2 has a length about half that of the exhaust port 26a.

Therefore, also in this embodiment, the exhaust port 26
The opening area of the stator frame 2 is configured to gradually increase from the axial end side of the stator frame 2 toward the axial center side of the stator core 9, so that the same operational effect as the above-described first embodiment can be obtained. To be

[0030]

As described above, according to the rotary electric machine of the present invention, the following effects can be obtained. According to the rotating electric machine of claim 1, the exhaust port formed in the outer shell located in each ventilation passage has an opening area closer to the axial center side of the stator core than to the axial end portion side of the outer shell. Is large, the amount of air exhausted from the exhaust port before flowing into the ventilation passage decreases, and the amount of air flowing into the ventilation passage increases. Therefore,
A large amount of outside air can reach the vicinity of the axial center of the stator core in the ventilation passage, and at that time, the outside air flows over the outer peripheral surface of the stator core over a long distance and is generated in the stator core. Since the heat is taken away, the stator core can be efficiently cooled.

In this case, the exhaust port is formed in the shape of an elongated hole extending in the axial direction of the outer shell and widens from the axial end of the outer shell toward the axial center of the stator core ( 3. The stator core according to claim 2), or the exhaust core is formed by arranging a plurality of elongated holes extending in the axial direction of the outer shell side by side in the circumferential direction, and the number of circumferentially arranged stator cores is greater than that of the outer shell in the axial direction end side. The number of the exhaust ports is increased on the axial center side (Claim 3), or a plurality of exhaust holes extending in the circumferential direction are formed side by side in the axial direction. By setting the length in the circumferential direction to be long (claim 4), the opening area in each axial portion of the peripheral wall portion of the outer shell of the exhaust port can be easily set more than the axial end portion side of the outer shell. It can be formed so that it is larger on the axial center side of the iron core.

Particularly, according to the rotating electric machine of the second aspect, the exhaust port is formed in the shape of a long hole extending in the axial direction of the outer shell, and the opening width is from the axial end portion side of the outer shell to the shaft of the stator core. Since it is formed so as to widen toward the center side in the direction, the air flowing into the ventilation passage is gradually discharged from the exhaust port toward the center side in the axial direction of the stator core. Therefore, the amount of air that reaches the vicinity of the axial center of the stator core increases, so that the cooling performance of the stator core improves and the air discharge efficiency improves and the amount of air taken into the outer shell increases. The cooling performance of the entire electric machine is also improved.

[Brief description of drawings]

FIG. 1 is a semi-longitudinal side view showing a first embodiment of the present invention.

FIG. 2 is a front view

FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 4 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention.

FIG. 6 is a diagram corresponding to FIG. 1 showing a conventional configuration.

FIG. 7 is a view corresponding to FIG.

[Explanation of symbols]

1 is an outer shell, 2 is a stator frame (peripheral wall portion), 6, 22, 23,
24, 25, 26, 26a, 26b, 26c, 26d,
26e is an exhaust port, 8 is a ventilation path, and 9 is a stator core.

Claims (4)

[Claims] 1. A plurality of ventilation passages extending in the axial direction are formed along the circumferential direction between a peripheral wall portion of the outer shell and a stator core arranged in the outer shell, and the ventilation passage is introduced into the outer shell to ventilate air. In the one in which the outside air that has flowed into the passage is discharged to the outside from the exhaust port formed in the peripheral wall portion of the outer shell, the exhaust port corresponding to each ventilation passage is an axial direction of the peripheral wall portion of the outer shell. A rotating electric machine, wherein the opening area of each portion is formed so as to be larger on the axial center side of the stator core than on the axial end side of the outer shell. 2. The exhaust port corresponding to each ventilation passage has a shape of a long hole extending in the axial direction of the outer shell and widens from the axial end portion side of the outer shell toward the axial center side of the stator core. The rotary electric machine according to claim 1, wherein the rotary electric machine is formed as follows. 3. An exhaust port corresponding to each ventilation passage is formed in a shape of a long hole extending in the axial direction of the outer shell and arranged in the circumferential direction, and the number of the exhaust ports arranged in the circumferential direction is the axial direction of the outer shell. The rotary electric machine according to claim 1, wherein the number of the stator cores increases from the end side toward the center side in the axial direction of the stator core. 4. An exhaust port corresponding to each ventilation passage is formed in the shape of an elongated hole extending in the circumferential direction and is arranged side by side in the axial direction. These exhaust ports are arranged from the end side of the outer shell in the axial direction of the stator core. The rotating electric machine according to claim 1, wherein the peripheral side is set to have a longer length in the circumferential direction.