JPH09219954A - Rotating electric machine with cooling device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To utilize a large specific heat of a refrigerant such as water or freon and convection action in a rotating electric machine to enhance a cooling effect without using a heat exchanger or the like. SOLUTION: An inner circumference of a jacket inner plate 3 having a corrugated shape in the circumferential direction is closely adhered to and surrounded by an outer circumference of a frame 2, and further, an outer side of the jacket inner plate 3 is surrounded by a jacket outer plate 5. Refrigerant 6 is filled between the inner jacket plate 3 and the outer jacket plate 5, and a portion of the inner jacket plate 3 that opens to the outside serves as a unit jacket 7, and a portion that opens to the inside serves as an air passage 8. The unit jacket 7 is made liquid-tight by the closing plates 9 at both ends, and the ventilation passage 8
Both ends in the axial direction open to the outside air. The cooling air 14 introduced by the outer fan 12 flows through the ventilation passage 8. Unit jacket 7
The refrigerant 6 therein causes convection 15 at a high temperature, and the heat quantity of the heat transfer is extremely large due to the specific heat of the refrigerant 6 and the convection 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine equipped with a cooling device having a higher cooling effect.

[0002]

2. Description of the Related Art Heretofore, as a cooling device for enhancing the cooling effect of an electric motor, there are a totally enclosed external fan type electric motor, a water cooling type electric motor and the like. The fully-closed outer fan type electric motor is provided with a large number of cooling fins extending in the radial direction and the axial direction on the frame, allows the cooling air of the outer fan to flow axially between the cooling fins, and utilizes heat conduction as a material for the cooling fins. To cool the motor. It is air cooled.
The water-cooled electric motor has a cylinder on the outer circumference of the frame, and a water jacket is provided between the frame and the cylinder, and a separate heat exchanger is piped between the water supply port at one axial end of the water jacket and the drain port at the other end. Then, the cooling water having a large specific heat is circulated through the water jacket by the pump, and the cooling water cools the electric motor. It is water cooled.

[0003]

Various cooling techniques have been developed and used in an attempt to make the electric motor smaller and to lower the temperature of the electric motor for machine tools and the like. However, in the air-cooled type in which the cooling device is provided with a relatively simple cooling fin, the thermal conductivity as a material of the cooling fin is limited (thermal resistance) even if there is no limit in the amount of cooling air. For this reason, even if the cooling fins are extended too much in the radial direction, the temperature of the tips of the cooling fins is lowered, and the cooling effect is not improved. The water cooling type with a water jacket that has a better cooling effect by utilizing the large specific heat,
It requires a heat exchanger and a pump, requires a large-scale cooling device, has poor handleability for installation and maintenance of the electric motor, and requires a large installation space.

An object of the present invention is to provide a cooling device which can utilize a large specific heat of a refrigerant such as water or freon and a convection effect in a rotating electric machine to enhance a cooling effect without using a heat exchanger or the like. To provide a rotating electric machine.

[0005]

According to another aspect of the present invention, there is provided a rotating electric machine equipped with a cooling device, wherein the inner periphery of a plurality of unit jackets filled with a refrigerant is closely adhered to the outer periphery of a stator or a frame with good thermal conductivity. A ventilation path through which cooling air of the outside air flows is formed adjacent to each other. According to the first aspect of the invention, the refrigerant in the unit jacket, which has received heat transfer from the electric motor from the stator or the frame due to heat conduction on the inner periphery of the unit jacket, becomes hot and convects, causing heat transfer in the unit jacket. The amount of heat of this heat transfer is extremely large due to the specific heat of the refrigerant and convection. Since the unit jacket and the ventilation passage are adjacent to each other, the heat of the refrigerant in the unit jacket is transferred to the cooling air in the ventilation passage by heat conduction, and the high temperature cooling air is discharged to the outside as the outside air. There is a limit (heat resistance) to the heat transfer due to the thermal conductivity of ordinary cooling fins, whereas the heat quantity of heat transfer in the unit jacket is extremely large due to the specific heat of the refrigerant and convection, and the unit jacket has a high temperature. The surface exposed to the ventilation passage of all the surfaces of can be made quite large. For this reason,
The cooling area of the stator or frame exposed to the cooling air through the unit jacket will be greatly expanded. The unit jacket having a large amount of heat for heat transfer contributes to the expansion of the cooling area. When the rotating electric machine has a horizontal axis, the convection of the refrigerant desirably occurs up to about 3/4 of the entire circumference as viewed in the axial direction. On the other hand, in the lower 1/4 unit jacket, the portion of the unit jacket that receives heat from the electric motor by heat conduction from the stator or the frame is above the gravity direction. Therefore, the convection of the refrigerant hardly occurs and depends on the heat transfer in the circumferential direction of the stator or the frame itself and the direct cooling by the cooling air of the outside air. When the rotary electric machine has a vertical axis, the unit jacket effectively works over the entire circumference.

According to a second aspect of the present invention, the unit jacket and the ventilation passage, which are adjacent to each other in the circumferential direction and are continuous, are integrally continuous in the axial direction. According to the second aspect of the invention, in addition to the operation of the first aspect, the unit jacket and the ventilation passage have a corrugated shape in the circumferential direction, which facilitates the work and reduces the ventilation resistance of the cooling air in the ventilation passage. A third aspect of the present invention is the same as the second aspect, in which the outer peripheral portions of the adjacent unit jackets communicate with each other in the circumferential direction at the communicating portions. According to the invention 3, when the rotary electric machine is the horizontal axis, the unit jackets in the vicinity of about 3/4 from the top to the bottom in the axial direction cause convection between the adjacent unit jackets. The cooling effect of the unit jacket in the vicinity is improved.

A fourth aspect of the present invention provides the outer fan cover for covering the outer fan according to the second or third aspect, wherein the outer fan cover is filled with a refrigerant to form a cover jacket having an inner surface and an outer surface. It is integrated with the communicating portion in the axial direction. According to the fourth aspect of the present invention, in the unit jacket of the entire circumference, there is a flow of the high-temperature refrigerant with the cover jacket, and the cooling of the refrigerant by the cooling air is promoted. In particular, in the case of the horizontal axis, the high temperature refrigerant in the lower half unit jacket flows into the cover jacket by convection and is cooled by the cooling air of the outer fan.

A fifth aspect of the present invention is the first aspect of the present invention, wherein the unit jacket is intermittently formed in the axial direction and the circumferential direction and is composed of a plurality of units, and the ventilation passage has a mesh shape. According to the fifth aspect, in addition to the action of the first aspect, the structure of the unit jacket is complicated and the ventilation resistance of the cooling air in the ventilation passage is large, but the heat conduction between the unit jacket and the ventilation passage is correspondingly increased. A sixth aspect of the present invention is the same as the fifth aspect of the present invention, in which the outer peripheral portions of the adjacent unit jackets communicate with each other at least in the axial direction at the communicating portions. According to the sixth aspect, in the case of the vertical axis, the temperature difference of the unit jacket due to the temperature difference in the axial direction of the stator or the frame is averaged by the convection of the refrigerant in the communicating portion. If they are communicated in the circumferential direction, they have the same effect as that of the invention 3.

A seventh aspect of the present invention provides the outer fan cover for covering the outer fan according to the sixth aspect, wherein the outer fan cover is filled with a refrigerant to form a cover jacket having an inner surface and an outer surface. To communicate with and integrate. The invention 7 has the same effect as the invention 4, but the invention 7 requires the invention 6 as an essential requirement. In the case of the horizontal axis, this is because the high temperature refrigerant in the unit jacket that is separated from the cover jacket among the unit jackets in the lower half and is intermittent in the axial direction is communicated with the cover jacket at the communication portion to cool the refrigerant.

Invention 8 is any one of Inventions 1 to 7, wherein unevenness is provided on the surface of the unit jacket other than the surface in close contact with the stator or the frame. According to the invention 8, the area of heat conduction between the unit jacket and the ventilation passage is expanded due to the unevenness, and the cooling effect is further improved. A ninth aspect of the present invention is any one of the first to eighth aspects, in which a cooling fin extending from the stator or the frame is provided in the ventilation passage. In addition to the operation of any one of the inventions 1 to 8, the invention 9 has a normal cooling fin cooling effect.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view including a rotation-illustrated sectional view of an essential part of Embodiment 1, and FIG. 2 is a sectional view taken along the line AA of FIG.
1 is a left side view of FIG. 1, FIG. 4 is a front view of the second embodiment, FIG. 5 is a sectional view taken along line BB of FIG. 4, FIG. 6 is a left side view of FIG. 4, and FIG. 7 is a unit jacket of the third embodiment. 8 is an exploded plan view from the inside, FIG.
2 is a cross-sectional view of a main part corresponding to FIG. 2 of the fourth embodiment, FIG. 9 is a cross-sectional view of a main part corresponding to FIG. 2 of the fifth embodiment, and FIG. 10 is a cross-sectional view of a main part corresponding to FIG. 11 is a sectional view of an essential part corresponding to FIG. 2 of the seventh embodiment. In each figure, components having the same reference numerals have approximately the same function and may not be described.

In Embodiment 1 shown in FIG. 1, a jacket inner plate 3 having, for example, a rectangular wave shape is circumferentially surrounded by the outer periphery of the frame 2 to which the stator 1 is fixed, with the inner periphery closely contacting the outer periphery of the frame 2. . A communication part 4 is provided on the outer periphery of the inner plate 3 of the jacket.
Is secured and surrounded by the jacket skin 5. Between the inner jacket plate 3 and the outer jacket plate 5 is a coolant 6 such as water.
Are filled in, and the portion that opens to the outside of the jacket inner plate 3 serves as a unit jacket 7, and the portion that opens to the inside serves as a ventilation path 8. The communication portion 4 and the unit jacket 7 are made liquid-tight or air-tight by the closing plates 9 at both ends in the axial direction, and both ends of the ventilation passage 8 in the axial direction are open to the outside air. Eventually, the unit jacket 7 and the ventilation passage 8 that are adjacent to each other in the circumferential direction and continuous are integrally continuous in the axial direction. An outer fan cover 13 surrounds an outer fan 12 attached to the non-driving side shaft end 11 a of the shaft 11 protruding from the brackets 10 at both ends of the frame 2. The cooling air 14 introduced by the outer fan 12 flows through the ventilation passage 8. 2 shows the whole cross section of the electric motor well, and FIG. 3 shows the outer fan cover 1
3 and its intake protection net 13a are shown. If the supplementary material 3a, only a part of which is shown by a dashed line in FIG. 2, and the inner jacket plate 3 are integrally molded, the frame 2 becomes unnecessary. In this way, the frame 2 and the inner jacket plate 3 are integrated,
The jacket inner plate 3 independent of the frame 2 can be formed by, for example, extrusion molding of aluminum or aluminum alloy or injection molding of synthetic resin.

According to the first embodiment, the unit jacket 7 and the ventilation passage 8 are corrugated in the circumferential direction by the inner jacket plate 3, and the work is easy and the ventilation resistance of the cooling air 14 in the ventilation passage 8 is small. The refrigerant 6 in the unit jacket 7 that has received heat transfer from the electric motor from the frame 2 on the inner periphery of the unit jacket 7 becomes high temperature and causes convection 15 to cause heat transfer into the unit jacket 7. The heat quantity of this heat transfer is the refrigerant 6
It is extremely large due to the specific heat and convection 15. Since the unit jacket 7 and the ventilation passage 8 are adjacent to each other, the heat of the refrigerant 6 in the unit jacket 7 is conducted by heat so that the cooling air 14 in the ventilation passage 8 is heated.
The high temperature cooling air 14 is transmitted to the outside by the external fan 12. While there is a limit (heat resistance) to heat transfer due to the heat conductivity of a normal cooling fin, the heat quantity of heat transfer in the unit jacket 7 is extremely large due to the specific heat of the refrigerant 6 and the convection 15 and becomes high temperature. Of all the surfaces of the unit jacket 7, the surface exposed to the ventilation passage 8 can be made considerably large. Therefore, the cooling area of the frame 2 exposed to the cooling air 14 through the unit jacket 7 is dramatically increased. The unit jacket 7 having a large heat transfer amount contributes to the expansion of the cooling area. When the rotary electric machine has a vertical axis, the convection of the refrigerant 6 becomes a flow that goes up and down in the axial direction, and the unit jacket 7 effectively acts over the entire circumference. When the rotating electric machine has a horizontal axis, the convection 15 of the refrigerant 6 desirably occurs as shown in the figure from the top to the bottom of the entire circumference in the axial direction of about 3/4. On the other hand, in the lower 1/4 unit jacket 7, the part of the unit jacket 7 that receives heat from the electric motor by heat conduction from the frame 2 is on the upper side in the direction of gravity, so that convection 15 of the refrigerant 6 occurs. Hateful. But 3 from top to bottom
The unit jacket 7 in the vicinity of about / 4 causes convection between the communicating portions 4 and the adjacent unit jackets 7, and the cooling effect of the unit jackets 7 in the vicinity thereof is improved. In the lowermost part, it depends on the heat transfer in the circumferential direction of the stator 1 or the frame 2 itself and the direct cooling of the outer fan 12 by the cooling air 14 or the cooling of the jacket outer plate 5 to the outside air. Ordinary cooling fins may be provided outside the jacket skin 5.

In the first embodiment, instead of the external fan 12, a separate fan may be used, or the running wind of an automobile or train may be the cooling wind 14. In addition to the forced cooling air, a self-cooling type that uses convection cooling air generated by heating the outside air by the rotating electric machine may be used. When the cooling air is orthogonal to the shaft 11 due to the separate fan or traveling air, the ventilation passage 8
To make a ring. The ventilation passage 8 in the axial direction has inlets and outlets for the cooling air 14 at both ends. The entrance and exit of the annular ventilation passage intersects with the unit jacket 7 and is a little complicated in structure and work, but can be sufficiently realized by a conventional technique. The ventilation passage 8 is formed in an annular shape even when it is a self-cooling type and has a horizontal axis. It can also be applied to an open type in which the inside of the rotating electric machine is cooled by the outside air. The same applies to the third and subsequent embodiments, but in the second embodiment, the external fan is indispensable, and the ventilation passage 8 is directed in the axial direction.

In the second embodiment shown in FIGS. 4, 5 and 6, the structure of the unit jacket 7 of the frame 2 portion is the same as that of the first embodiment, and the description of the same reference numerals is omitted.
A feature of the second embodiment is that the outer fan cover is filled with the refrigerant 6 to form a cover jacket 23 including an inner surface 23a and an outer surface 23b, and the cover jacket 23 is axially communicated with the unit jacket 7 and the communicating portion 4. To be integrated. It may communicate with the unit jacket 7 or the communication section 4.
In FIG. 6, the center portion of the cover jacket 23 has a suction port 23c and forms a cross shape, but it may be a single vertical character in consideration of convection.

According to the second embodiment, in the unit jacket 7 on the entire circumference, the high temperature refrigerant 6 flows with the cover jacket 23, and the cooling of the refrigerant 6 by the cooling air 14 is promoted. Especially in the case of the horizontal axis, the unit jacket 7 of the lower half
The high-temperature refrigerant 6 flows into the cover jacket 23 by convection and is cooled by the cooling air 14 of the outer fan 12. In Example 3 in which the plurality of unit jackets shown in FIG. 7 are viewed from the inside, the unit jacket 37 filled with the refrigerant 6 is intermittently formed in the axial direction and the circumferential direction, and the ventilation path 38 has a mesh shape. .
All the unit jackets 3 are so arranged that the outer peripheral portions of the adjacent unit jackets 37 communicate with each other at least in the axial direction at the communicating portion 4.
7 may be surrounded by a jacket skin 5. Although not shown, a cover jacket may be provided to communicate with the communication section 4 as in the second embodiment. Since the unit jacket 37 is intermittent in the axial direction, when providing a cover jacket,
The communication part 4 is essential.

According to the third embodiment, although the structure of the unit jacket 37 is complicated and the ventilation resistance of the cooling air 14 in the ventilation passage 38 is large, the heat conduction between the unit jacket 37 and the ventilation passage 38 is correspondingly increased. If the communication part 4 is provided, in the case of the vertical axis,
The temperature difference of the unit jacket 37 due to the temperature difference in the axial direction of the stator or the frame is averaged by the convection of the refrigerant 6 in the communicating portion 4. Since they communicate in the circumferential direction, in the case of the horizontal axis, the unit jackets 37 in the vicinity of about 3/4 from the top to the bottom of the entire circumference seen in the axial direction are between the unit jackets 37 adjacent to each other in the circumferential direction. Convection is generated, and the cooling effect of the unit jacket 37 in the vicinity thereof is improved.

When the cover jacket is provided, in the unit jacket 37 on the entire circumference, there is a flow of the high-temperature refrigerant 6 with the cover jacket, and the cooling of the refrigerant 6 by the cooling air 14 is promoted. In particular, in the case of the horizontal axis, the high temperature refrigerant 6 in the lower half unit jacket 37 flows to the cover jacket by convection and is cooled by the cooling air 14 of the outer fan. In Example 4 shown in FIG. 8, the communicating portion on the outer peripheral portion of the unit jacket 7 is closed by a partition plate 3x. Although there is no effect of the communication portion 4 of the first, second or third embodiment, the rigidity of the jacket outer plate 5 is increased.

In Example 5 shown in FIG. 9, the outer peripheral portion of the jacket inner plate 3 is integrated with the jacket outer plate 55,
The communicating portion 4 of the first, second or third embodiment is not provided. In Example 6 shown in FIG. 10, the inner jacket plate 63 forming the unit jacket 7 and the ventilation passage 8 is provided with irregularities on the surface other than the surface in close contact with the frame 2. In Example 7 shown in FIG. 11, a known cooling fin 72 extending from the frame 2 is provided in the ventilation passage 8. Also in this case, the cooling fins 72 can be formed of the laminated iron plates of the stator 1 by known means.

[0020]

According to the rotating electric machine having the cooling device of the first aspect of the invention, the fact that the heat quantity of heat transfer in the unit jacket is extremely large due to the specific heat of the refrigerant and the convection is transmitted to the cooling air in the ventilation passage. Therefore, the cooling area exposed to the ventilation passage is dramatically expanded, and the cooling effect can be enhanced without using a heat exchanger or the like.

According to the second aspect of the present invention, the unit jacket and the ventilation passage have a corrugated shape in the circumferential direction, which is advantageous in that the work is easy and the ventilation resistance of the cooling air in the ventilation passage is small. According to the invention 3, when the rotary electric machine is the horizontal axis, the unit jackets in the vicinity of about 3/4 from the top to the bottom in the axial direction cause convection between the adjacent unit jackets. This has the effect of improving the cooling effect of the unit jacket in the vicinity thereof.

According to the fourth aspect of the present invention, in the entire unit jacket, there is a flow of high-temperature refrigerant with the cover jacket, and cooling of the refrigerant by the cooling air is promoted. Particularly, in the case of the horizontal axis, there is an effect that the high temperature refrigerant in the lower half unit jacket flows to the cover jacket by convection and is cooled by the cooling air of the outer fan. According to the invention 5, there is an effect that the heat conduction between the unit jacket and the ventilation passage is increased.

According to the sixth aspect, in the case of the vertical axis, there is an effect that the temperature difference of the unit jacket due to the temperature difference in the axial direction of the stator or the frame is averaged by the convection of the refrigerant in the communicating portion. According to the seventh aspect of the present invention, in the unit jacket of the entire circumference, there is a flow of the high-temperature refrigerant with the cover jacket, and the cooling of the refrigerant by the cooling air is promoted. Particularly, in the case of the horizontal axis, there is an effect that the high temperature refrigerant in the lower half unit jacket flows to the cover jacket by convection and is cooled by the cooling air of the outer fan.

According to the invention 8, there is an effect that the area of heat conduction between the unit jacket and the ventilation passage is enlarged due to the unevenness, and the cooling effect is further improved. According to the invention 9, there is an effect that the cooling action of the ordinary cooling fin is added.

[Brief description of drawings]

FIG. 1 is a front view including a rotation-illustrated sectional view of a main part of the first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a left side view of FIG. 1;

FIG. 4 is a front view of the second embodiment.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

6 is a left side view of FIG.

FIG. 7 is a plan development view of the unit jacket of Example 3 as viewed from the inside.

FIG. 8 is a sectional view of an essential part corresponding to FIG. 2 of the fourth embodiment.

FIG. 9 is a cross-sectional view of an essential part corresponding to FIG. 2 of the fifth embodiment.

FIG. 10 is a cross-sectional view of essential parts corresponding to FIG. 2 of Example 6;

FIG. 11 is a cross-sectional view of an essential part corresponding to FIG. 2 of the seventh embodiment.

[Explanation of symbols]

1 Stator 2 Frame 3 Jacket inner plate 3a Supplementary material 3x Partition plate 4 Communication part 5 Jacket outer plate 6 Refrigerant 7 Unit jacket 8 Ventilation passage 9 Closing plate 10 Bracket 11 Shaft 11a Shaft end 12 Outer fan 13 Outer fan cover 14 Cooling air 15 Convection 23 Cover jacket 23a Inner surface 23b Outer surface 23c Intake port 37 Unit jacket 38 Ventilation passage 55 Jacket outer plate 63 Jacket inner plate 72 Cooling fin

Claims (9)

[Claims] 1. An inner periphery of a plurality of unit jackets filled with a refrigerant is closely adhered to an outer periphery of a stator or a frame with good thermal conductivity, and an air passage is provided between the unit jackets, through which cooling air of the outside air flows. A rotating electric machine comprising a cooling device characterized by being formed. 2. A rotating electric machine provided with the cooling device according to claim 1, wherein the unit jacket and the ventilation passage, which are adjacent to each other in the circumferential direction and are continuous, are integrally continuous in the axial direction. Rotating electric machine. 3. A rotating electric machine equipped with the cooling device according to claim 2, wherein the outer peripheral portions of the adjacent unit jackets communicate with each other in the circumferential direction at the communicating portions. 4. A rotating electric machine comprising the cooling device according to claim 2 or 3, wherein an outer fan cover for covering the outer fan is provided, and the outer fan cover is filled with a refrigerant to form a cover jacket having an inner surface and an outer surface. A rotary electric machine comprising a cooling device, characterized in that the cover jacket is axially communicated with a unit jacket or a communication portion to be integrated. 5. A rotating electric machine equipped with the cooling device according to claim 1, wherein the unit jacket comprises a plurality of intermittent jackets in the axial direction and the circumferential direction, and the ventilation passage has a mesh shape. Rotating electric machine. 6. A rotating electric machine equipped with the cooling device according to claim 5, wherein the outer peripheral portions of adjacent unit jackets communicate with each other at least in the axial direction at the communicating portion. 7. A rotating electric machine comprising the cooling device according to claim 6, wherein an outer fan cover for covering the outer fan is provided, and the outer fan cover is filled with a refrigerant to form a cover jacket having an inner surface and an outer surface. A rotating electric machine comprising a cooling device, characterized in that a cover jacket is axially communicated with a communication portion to be integrated. 8. A rotating electric machine comprising the cooling device according to claim 1, wherein unevenness is provided on a surface of the unit jacket other than a surface closely contacting with the stator or the frame. Electric rotating machine equipped with a device. 9. A rotating electric machine comprising the cooling device according to any one of claims 1 to 8, wherein the cooling device is provided with cooling fins extending from a stator or a frame in the ventilation passage. Rotating electric machine.