Rotating Electric Machine

Abstract

The rotating electric machine (100) includes a frame (4), a rotor (2) disposed within the frame (4) and rotating, a stator (3) disposed within the frame (4), a cooling fan (7) disposed outside the frame (4), and a plurality of external fins (11) provided on the outer peripheral surface of the frame (4). An internal air circulation flow path (12) is provided between the frame (4) and the stator (3) for circulating air inside the frame (4) in the direction of the rotation axis of the rotor (2). The air flow path formed by the plurality of external fins (11) intersects with the internal air circulation flow path (12). The rotor (2) is surrounded by the stator (3) and includes a shaft (5) serving as the rotation axis, an end plate (81) for adjusting the rotation balance of the rotor (2), and internal fins (82) provided on the end plate (81) for circulating air inside the frame (4).

Description

[Technical field]

[0001] The present disclosure relates to a rotating electric machine. [Background technology]

[0002] In conventional rotating electric machines, when used for a long time under high speed rotation and high load driving conditions, the temperature rises, causing a decrease in motor performance and motor failure, and even leading to a situation where the operation of the equipment in which the rotating electric machine is incorporated must be stopped. For this reason, a method of dissipating the heat generated by the rotating electric machine with a cooling fan has been conventionally adopted (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-220854 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, a cooling fan is installed outside the frame surrounding the stator, and the rotating electric machine is cooled by forced convection of air by the cooling fan. However, in the conventional structure, when the amount of heat generated by the rotating electric machine increases, the temperature of the air inside the frame rises, and because the heat transfer area between the frame and the air is small, there is a problem that the heat cannot be sufficiently dissipated. Therefore, in the conventional structure, when the rotation speed of the rotor increases and the amount of heat generated inside the rotating electric machine increases, the number of cooling fans must be increased or a cooling fan that can circulate a large amount of air must be installed, which may lead to an increase in the overall size of the rotating electric machine including the heat dissipation system.

[0005] The present disclosure has been made in view of the above, and has an object to obtain a rotating electric machine that has high heat dissipation capability as well as being small and lightweight. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a rotating electric machine according to the present disclosure includes a frame, a rotor that is disposed inside the frame and rotates, A shaft that serves as the axis of rotation of the rotor, an end plate that is provided on the rotor and adjusts the rotation balance of the rotor, and an inner fin that is provided on the end plate and circulates air inside the frame, Located inside the frame , Enclosing the rotor The rotor includes a stator, a cooling fan disposed outside the frame, and a plurality of external fins provided on the outer circumferential surface of the frame. The direction in which the shaft extends is referred to as the axial direction, and the circumferential direction of the rotor is referred to as the circumferential direction. Between the frame and the stator, there is air inside the frame. Axial direction An inside air circulation passage is provided to allow the inside air to circulate in the opposite direction. The outer fins have a circumferential length greater than their axial length and are spaced apart from one another in the axial direction. The air flow path formed by the multiple outer fins intersects with the internal air circulation flow path. 。 Effect of the Invention

[0007] The rotating electric machine according to the present disclosure has the advantages of having high heat dissipation capability, as well as being small and lightweight. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a first cross-sectional view of a rotating electric machine according to a first embodiment; [Diagram 2] FIG. 2 is a second cross-sectional view of the rotating electric machine according to the first embodiment; [Diagram 3] FIG. 1 is a perspective view showing a main part of a frame of a rotating electric machine according to a first embodiment; [Figure 4] FIG. 13 is a diagram showing a state in which the inside air circulation flow path and a plurality of outer fins are perpendicular to each other in the first embodiment; [Diagram 5] FIG. 13 is a diagram showing a state in which a plurality of outer fins are inclined with respect to the inside air circulation flow path in the first embodiment. [Figure 6] FIG. 1 is a schematic diagram showing a configuration in which a rotor is provided with an internal rotor ventilation passage that penetrates the rotor in the axial direction in the first embodiment; [Figure 7] FIG. 11 is a perspective view showing a main part of a frame of a rotating electric machine according to a second embodiment. [Figure 8] FIG. 11 is a perspective view showing a first modified example of a main part of a frame of a rotating electric machine according to a second embodiment. [Figure 9]FIG. 11 is a perspective view showing a second modified example of a main part of a frame of a rotating electric machine according to a second embodiment. [Figure 10] FIG. 11 is a perspective view showing the appearance of a rotating electric machine according to a third embodiment. [Figure 11] FIG. 13 is a perspective view showing the appearance of a rotating electric machine according to a fourth embodiment. [Figure 12] 13 is a cross-sectional view of a rotating electric machine according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotating electric machine according to an embodiment will be described in detail with reference to the drawings.

[0010] Embodiment 1 FIG. 1 is a first cross-sectional view of the rotating electric machine 100 according to the first embodiment. FIG. 2 is a second cross-sectional view of the rotating electric machine 100 according to the first embodiment. FIG. 2 shows a main part in the II-II plane of FIG. 1. FIG. 1 and FIG. 2 show a schematic cross-section of the rotating electric machine 100. The rotating electric machine 100 has a rotor 2, a stator 3, a frame 4, and a cooling fan 7. The rotor 2 is disposed inside the frame 4 and rotates. The stator 3 is disposed inside the frame 4. The rotor 2 is surrounded by the stator 3. The cooling fan 7 is disposed outside the frame 4. FIG. 3 is a perspective view showing a main part of the frame 4 of the rotating electric machine 100 according to the first embodiment. FIG. 3 shows a schematic view of a main part of the frame 4.

[0011] The rotor 2 has a shaft 5 that serves as a rotation axis, and an end plate 81 that adjusts the rotational balance of the rotor 2. The shaft 5 is disposed penetrating the rotor 2, and is rotatably supported by a load side bearing 61 disposed on the load side of the frame 4 and a counter-load side bearing 62 disposed on the counter-load side. Hereinafter, the direction in which the shaft 5 extends is also referred to as the axial direction.

[0012] The stator 3 is configured in a cylindrical shape and has a coil 91 inside. A part of the coil 91 protrudes outside the stator 3 as a coil end 92. The stator 3 is disposed so as to surround the rotor 2, and an air gap 10 exists between the stator 3 and the rotor 2. The central axis of the stator 3 is the same as the rotation axis of the rotor 2.

[0013] The frame 4 is configured in a cylindrical shape, and the stator 3 is disposed inside the frame 4. Between the frame 4 and the stator 3, an internal air circulation flow path 12 is provided for circulating air inside the frame 4 in the axial direction. As described above, the axial direction is the direction in which the shaft 5 extends. More specifically, the axial direction is the direction of the rotation axis of the rotor 2. On the outer peripheral surface of the frame 4, an external fin 11 configured to be integrated with the frame 4 is erected. As shown in FIG. 1, a plurality of external fins 11 are disposed at intervals from each other in the axial direction. As shown in FIG. 2, for example, the external fin 11 is provided so as to go around the outer periphery of the cylindrical frame 4. FIG. 3 also shows the internal air circulation flow path 12 and the external fin 11.

[0014] The cooling fan 7 is installed outside the frame 4 to send air to the outer fins 11. More specifically, the cooling fan 7 is installed outside the frame 4 at a position facing the circumferential side of the frame 4. The air blown out from the cooling fan 7 flows in the circumferential direction of the frame 4 through a flow path formed by the outer fins 11 provided on the outer peripheral surface of the frame 4. As a result, the air blown out from the cooling fan 7 dissipates heat transferred to the frame 4 to the outside of the frame 4. The air flow path formed by the multiple outer fins 11 crosses the inside air circulation flow path 12, preferably perpendicular to it. FIG. 4 is a diagram showing a state in which the inside air circulation flow path 12 and the multiple outer fins 11 are perpendicular to each other in the first embodiment. FIG. 5 is a diagram showing a state in which the multiple outer fins 11 are inclined with respect to the inside air circulation flow path 12 in the first embodiment.

[0015] The end plate 81 is disposed so that the shaft 5 penetrates therethrough, and rotates in accordance with the rotation of the rotor 2. The rotor 2 further has inner fins 82 provided on the end plate 81. The inner fins 82 are components that circulate the air inside the frame 4. When the end plate 81 rotates, the inner fins 82 also rotate, and the inner fins 82 agitate the air inside the frame 4. In FIG. 1, the direction of the agitated air is indicated by an arrow. The air inside the frame 4 is prevented from intermingling with the air blown out from the cooling fan 7 by the frame 4.

[0016] Next, the operation of the rotating electric machine 100 according to the first embodiment will be described. When the rotating electric machine 100 is operated, the rotor 2 rotates to operate a device installed on the load side at a desired rotation speed. This device is not shown. The cooling fan 7 installed on the outside of the frame 4 operates, and air flows in the circumferential direction of the frame 4 to cool the frame 4. The air flowing in the circumferential direction of the frame 4 dissipates heat generated by the rotating electric machine 100, and the rotating electric machine 100 is cooled.

[0017] At this time, the end plates 81 rotate in accordance with the rotation of the rotor 2, and the rotation of the end plates 81 rotates the inner fins 82, which then agitate the air inside the frame 4. The air agitated by the inner fins 82 flows through the air gap 10, and heat is transferred to the agitated air from the rotor 2 and the stator 3. The agitated air flows through the internal air circulation passage 12 provided between the stator 3 and the frame 4, and heat is transferred to the agitated air from the stator 3 and the coil ends 92.

[0018] By air flowing through the internal air circulation flow path 12 inside the frame 4, the rotating electric machine 100 can transfer the heat of the air whose temperature has increased inside the frame 4 to the frame 4. The heat transferred to the frame 4 is cooled by the cooling fan 7 and the external fins 11. That is, the cooling fan 7 and the external fins 11 cool the stator 3 and the air flowing through the internal air circulation flow path 12. As a result, the rotating electric machine 100 can cool the rotor 2 that is not in contact with the frame 4. As a result, the rotating electric machine 100 can prevent electrical malfunctions and deterioration caused by the rotor 2 becoming too hot.

[0019] In this way, the inner fins 82 provided on the end plate 81 that rotates together with the rotor 2 stir the air inside the frame 4, and the stirred air circulates through the air gap 10 and the internal air circulation flow path 12, so that the rotating electric machine 100 transfers the heat of the rotor 2 to the outer fins 11 provided on the frame 4 via the frame 4, and dissipates it to the outside air by the cooling fan 7. This allows the rotor 2 to be effectively cooled, and therefore the overall size of the rotating electric machine 100 is suppressed from being increased due to the increase in size and addition of the cooling fan 7. Furthermore, by configuring the air flow path formed by the multiple outer fins 11 to intersect with the internal air circulation flow path 12, the rotor 2 can be cooled without installing the cooling fan 7 in the axial direction, and therefore the increase in size in the axial direction is suppressed. That is, according to the first embodiment, it is possible to obtain a rotating electric machine 100 that has a high heat dissipation capacity, is small, and is lightweight.

[0020] In order to enhance the effect of cooling the rotor 2, the rotor 2 may be provided with an internal rotor ventilation passage 13 penetrating in the axial direction, as shown in Fig. 6. This allows the air inside the frame 4 to circulate inside the rotor 2 as well, thereby effectively cooling the rotor 2. Fig. 6 is a diagram showing a schematic configuration in which the internal rotor ventilation passage 13 penetrating in the axial direction is provided in the rotor 2 in the first embodiment.

[0021] 2, the number of internal air circulation passages 12 is 16, but it may be any number. Furthermore, in FIG. 6, the number of internal rotor ventilation passages 13 is 8, but it may be any number.

[0022] Embodiment 2 In the following embodiments, the same reference numerals as those in FIGS. 1 to 6 denote the same or similar components, and detailed description of the same or similar components will be omitted.

[0023] The rotating electric machine 200 according to the second embodiment has all the components of the rotating electric machine 100 according to the first embodiment. FIG. 7 is a perspective view showing a main part of the frame 4 of the rotating electric machine 200 according to the second embodiment. FIG. 7 shows a schematic view of the main part of the frame 4. In the second embodiment, as shown in FIG. 7, the outer fins 11 are formed with circular ventilation holes 14 in the axial direction so that air flows in the axial direction. In FIG. 7, the ventilation holes 14 are shown enlarged. The axial direction is the direction of the rotation axis of the rotor 2. The configuration of the rotating electric machine 200 other than the outer fins 11 is the same as that of the first embodiment.

[0024] Since the outer fins 11 are formed with the ventilation holes 14, the air blown out from the cooling fan 7 flows around the entire outer periphery of the frame 4, as compared to the first embodiment. This allows the rotating electric machine 200 to efficiently transfer heat from the frame 4 to the outside air.

[0025] In this manner, since the ventilation holes 14 are formed in the outer fins 11 provided on the outer peripheral surface of the frame 4, the rotating electric machine 200 can efficiently transfer heat transferred to the frame 4 from the high-temperature air flowing through the internal air circulation passage 12 to the air outside the frame 4. Therefore, the rotating electric machine 200 can suppress the rotor 2 from becoming too hot.

[0026] In the second embodiment, the outer fin 11 has a circular ventilation hole 14, but the shape of the ventilation hole 14 is not limited to a circular shape. As a first modification, as shown in FIG. 8, a rectangular ventilation hole 14a may be formed in a base portion of the outer fin 11. FIG. 8 is a perspective view showing a first modification of a main portion of the frame 4 of the rotating electric machine 200 according to the second embodiment. FIG. 8 shows a schematic diagram of the first modification of the main portion of the frame 4. In FIG. 8, the ventilation hole 14a is shown in an enlarged manner. The base portion is a portion where the outer fin 11 contacts the outer peripheral surface of the frame 4.

[0027] As a second modification of the second embodiment, as shown in Fig. 9, ventilation holes 14b may be formed in the outer fins 11 so that air flows at an angle with respect to the axial direction. Fig. 9 is a perspective view showing a second modification of a main part of the frame 4 of the rotating electric machine 200 according to the second embodiment. Fig. 9 shows a schematic diagram of the second modification of the main part of the frame 4.

[0028] Embodiment 3 The rotating electric machine 300 according to the third embodiment has all of the components included in the rotating electric machine 100 according to the first embodiment. Fig. 10 is a perspective view showing the appearance of the rotating electric machine 300 according to the third embodiment. Fig. 10 shows a schematic view of the appearance of the rotating electric machine 300. As shown in Fig. 10, the rotating electric machine 300 further has a flow path cover 15 provided on the outside of the frame 4.

[0029] The flow path cover 15 covers the outer fins 11. More specifically, the flow path cover 15 covers the tip portions of the outer fins 11. The tip portions of the outer fins 11 are the portions opposite the portions of the outer fins 11 that contact the frame 4. The flow path cover 15 covers the outer fins 11 other than the portions facing the cooling fan 7 of the frame 4, and is formed so that the air blown out from the cooling fan 7 flows in the entire circumferential direction on the outside of the frame 4. The configuration of the rotating electric machine 300 other than the flow path cover 15 is the same as the configuration of the first embodiment.

[0030] In this way, the rotating electric machine 300 has the flow path cover 15 that allows the air blown out from the cooling fan 7 to flow around the entire circumferential direction of the frame 4, and therefore can efficiently cool the frame 4. As a result, the temperature difference occurring around the stator 3 can be reduced, and it is possible to suppress an increase in size or additional installation of the cooling fan 7 due to insufficient cooling capacity, and to prevent an increase in size of the rotating electric machine 300.

[0031] The outer fins 11 of the third embodiment may be formed with the ventilation holes 14, 14a or 14b of the second embodiment.

[0032] Embodiment 4 The rotating electric machine 400 according to the fourth embodiment has all the components of the rotating electric machine 100 according to the first embodiment. FIG. 11 is a perspective view showing the appearance of the rotating electric machine 400 according to the fourth embodiment. FIG. 11 shows a schematic view of the appearance of the rotating electric machine 400. In the fourth embodiment, the outer fins 11 are provided on the outer peripheral surface of the frame 4 so that the heat transfer area increases as the air blown out from the cooling fan 7 moves downstream. That is, the outer fins 11 are configured so that the heat transfer area is small in the vicinity of the cooling fan 7, and the heat transfer area increases as the air blown out from the cooling fan 7 flows downstream. The configuration of the rotating electric machine 400 other than the outer fins 11 is the same as that of the first embodiment.

[0033] The air blown out from the cooling fan 7 has a high heat dissipation capacity due to the turbulence of the air flow near the outlet of the cooling fan 7, but as it flows between the outer fins 11 provided on the outer peripheral surface of the frame 4, the flow is straightened and the heat dissipation capacity of the air blown out from the cooling fan 7 decreases. For this reason, by making the heat transfer area of ​​the outer fins 11 small near the outlet of the cooling fan 7 and increasing the heat transfer area downstream, it is possible to achieve a uniform cooling effect in the circumferential direction.

[0034] The rotating electric machine 400 has outer fins 11 provided on the outer circumferential surface of the frame 4 so that the heat transfer area of ​​the air blown out from the cooling fan 7 increases as it moves downstream. The outer fins 11 can efficiently cool the rotating electric machine 400, and furthermore, can uniformly distribute the temperature of the stator 3, making it possible to prevent electrical malfunctions and deterioration of the stator 3 caused by localized high temperature spots.

[0035] Furthermore, by reducing the heat transfer area of ​​the outer fins 11 in the vicinity of the cooling fan 7, it is possible to prevent an increase in pressure loss and make the temperature of the stator 3 uniform without reducing the volume of air blown out from the cooling fan 7.

[0036] As a means for increasing the heat transfer area of ​​the outer fins 11 provided on the outer peripheral surface of the frame 4, the height of the outer fins 11 can be increased. For example, the height of the outer fins 11 located relatively close to the cooling fan 7 is made lower than the height of the outer fins 11 located relatively far from the cooling fan 7. As another means for increasing the heat transfer area of ​​the outer fins 11 provided on the outer peripheral surface of the frame 4, the thickness of the outer fins 11 in the axial direction can be increased.

[0037] Further, in the downstream direction of the air blown out from the cooling fan 7, an outer fin 11 may be additionally provided in the axial direction.

[0038] Furthermore, the outer fins 11 of the fourth embodiment may be formed with the ventilation holes 14, 14a or 14b of the second embodiment.

[0039] Embodiment 5. FIG. 12 is a cross-sectional view of a rotating electric machine 500 according to the fifth embodiment. FIG. 12 shows a schematic cross-section of the rotating electric machine 500. The rotating electric machine 500 has all the components of the rotating electric machine 100 according to the first embodiment. As shown in FIG. 12, the rotating electric machine 500 further has a second cooling fan 7a disposed outside the frame 4. That is, the rotating electric machine 500 has two cooling fans. The second cooling fan 7a faces the cooling fan 7 across the frame 4. The configuration of the rotating electric machine 500 other than the second cooling fan 7a is the same as the configuration of the first embodiment.

[0040] The air blown out from the cooling fan 7 flows in the circumferential direction of the frame 4, and the air blown out from the second cooling fan 7a also flows in the circumferential direction of the frame 4. At this time, since the cooling fan 7 and the second cooling fan 7a are disposed in opposing positions, the air blown out from the cooling fan 7 and the air blown out from the second cooling fan 7a can flow in the circumferential direction of the frame 4 without interfering with each other. Therefore, the volume of air blown out from one cooling fan can be reduced by half or more. In FIG. 12, the direction in which the air blown out from the cooling fan 7 flows and the direction in which the air blown out from the second cooling fan 7a flows are indicated by arrows.

[0041] In this way, since the cooling fan 7 and the second cooling fan 7a are arranged in opposing positions outside the frame 4, the rotating electric machine 500 can reduce the amount of heat dissipated by one cooling fan, making it possible to miniaturize the cooling fan 7 and the second cooling fan 7a. Therefore, since the amount of air blown out from each of the cooling fan 7 and the second cooling fan 7a can be reduced, the rotating electric machine 500 can reduce the noise generated by the cooling fan 7 and the second cooling fan 7a.

[0042] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0043] 2 rotor, 3 stator, 4 frame, 5 shaft, 7 cooling fan, 7a second cooling fan, 10 air gap, 11 outer fin, 12 internal air circulation flow path, 13 rotor internal ventilation path, 14, 14a, 14b ventilation holes, 15 flow path cover, 61 load side bearing, 62 anti-load side bearing, 81 end plate, 82 inner fin, 91 coil, 92 coil end, 100, 200, 300, 400, 500 rotating electric machine.

Claims

1. A frame, a rotor disposed inside the frame and rotating; A shaft that serves as a rotation axis of the rotor; an end plate provided on the rotor and configured to adjust the rotation balance of the rotor; an inner fin provided on the end plate for circulating air inside the frame; a stator disposed inside the frame and surrounding the rotor; A cooling fan disposed outside the frame; a plurality of outer fins provided on an outer peripheral surface of the frame; The direction in which the shaft extends is defined as an axial direction, and the circumferential direction of the rotor is defined as a circumferential direction. an internal air circulation passage for circulating air inside the frame in the axial direction is provided between the frame and the stator; The outer fins have a circumferential length longer than an axial length, and are spaced apart from one another in the axial direction. The air flow path formed by the plurality of outer fins intersects with the internal air circulation flow path. A rotating electric machine characterized by:

2. The plurality of outer fins include a first fin and a second fin different from the first fin; The air flow path formed by the plurality of outer fins is a flow path of air flowing between the first fin and the second fin.

2. The rotating electric machine according to claim 1 .

3. The air flow path formed by the plurality of outer fins is an air flow path that flows along the circumferential direction.

3. The rotating electric machine according to claim 1 or 2.

4. The radial direction of the rotor is the radial direction, The cooling fan is disposed radially outward of the outer fins.

3. The rotating electric machine according to claim 1 or 2.

5. The outer fin is formed with ventilation holes in the axial direction.

3. The rotating electric machine according to claim 1 or 2.

6. A flow path cover that covers the outer fins 3. The rotating electric machine according to claim 1, further comprising:

7. The height of the outer fins located relatively close to the cooling fan among the plurality of outer fins is lower than the height of the outer fins located relatively far from the cooling fan among the plurality of outer fins.

3. The rotating electric machine according to claim 1 or 2.

8. a second cooling fan disposed outside the frame and facing the cooling fan across the frame; 3. The rotating electric machine according to claim 1, further comprising:

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