JP2019009887A - Flow rate adjustment mechanism and internal pressure explosion-proof rotary electric machine - Google Patents

Abstract

To provide a flow rate adjustment mechanism and an internal pressure explosion-proof rotary electric machine that can finely adjust a flow rate of a fluid without depending on a complicated mechanism.SOLUTION: A flow rate adjustment mechanism 110 comprises an upstream side pressing plate 112, a downstream side pressing plate 116, a flexible member 115, an expansion member 113, and a compression member 114 arranged between the expansion member 113 and the flexible member 115. The flexible member 115 includes a holding portion 115a disposed between the upstream side pressing plate 112 and the downstream side pressing plate 116 and sandwiched between the upstream side pressing plate 112 and the downstream side pressing plate 116, and a conical portion 115b having an opening at a tip. The expansion member 113 includes a pressing portion 113a disposed between the flexible member 115 and the upstream side pressing plate 112 and sandwiched between the upstream side pressing plate 112 and the downstream side pressing plate 116, and a cylindrical portion 113b that expands the flexible member 115 from the radial inside by moving inside the flexible member 115 in the axial direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a flow rate adjusting mechanism and an internal pressure explosion-proof rotating electric machine using the same.

  In factories and other business sites, explosive gases such as flammable gas or flammable liquid vapor are present in concentrations that may cause explosions or fires, or they may be When installing or using equipment, electrical equipment can cause an explosion or fire. For example, in an electric rotating machine, when an explosive gas flows into the electric rotating machine, if a spark is generated due to a short circuit or the like, a dangerous gas may explode.

  Therefore, it is necessary to take measures to prevent such a situation from occurring. Specifically, for example, the rotary electric machine has an internal pressure explosion-proof structure. That is, the inside of the rotating electrical machine is pressurized with a protective gas such as clean air or an inert gas to prevent the explosive gas from flowing into the rotating electrical machine.

Japanese Patent No. 4348860

  Even if the protective gas is sealed inside the rotating electric machine, it is difficult to completely prevent the mixing of explosive gas. Therefore, for example, explosive gas mixed in the rotating electrical machine is discharged outside the rotating electrical machine, the interior of the rotating electrical machine is always filled with new protective gas, and the pressure in the rotating electrical machine is positive, that is, a pressure higher than the atmospheric pressure. (See Patent Document 1).

  For this reason, it is necessary to always supply the protective gas into the rotating electrical machine and to discharge the protective gas in the rotating electrical machine. Further, it is necessary to maintain the pressure inside the rotating electrical machine within a predetermined range by supplying and discharging the protective gas. For this purpose, it is necessary to appropriately adjust the supply amount and discharge amount of the protective gas. Here, in order to perform the adjustment appropriately, it is desirable that the configuration of the portion that changes the flow of the fluid can be continuously changed.

  As mentioned above, the flow rate adjustment of the protective gas in the internal pressure explosion-proof rotating electrical machine has been described. However, as the rotating electrical machine, in addition to this, for example, the amount of oil supplied to the sliding bearing in the case of a rotating electrical machine having a forced lubrication type sliding bearing There is an object that needs to adjust the flow rate of the fluid appropriately, such as adjustment of the fluid.

  In addition to the rotating electrical machine, there is a great need for adjusting the flow rate of the fluid without depending on a complicated mechanism.

  Therefore, an object of the present invention is to finely adjust the flow rate of a fluid without depending on a complicated mechanism.

  In order to achieve the above-mentioned object, the present invention is a flow rate adjusting mechanism for controlling the flow rate of a fluid, which is connected to an upstream side pipe and has an upstream holding plate in which an opening through which a fluid passes is formed in the center, and a downstream side A downstream holding plate connected to a pipe and having an opening through which a fluid passes in the center; and the upstream holding plate and the downstream holding plate arranged between the upstream holding plate and the downstream holding plate. A flexible member having a holding portion sandwiched between the plates, and a tapered conical portion having an opening at the tip connected to the inside of the holding portion, and between the flexible member and the upstream holding plate And pressing the flexible member from the inside in the radial direction by moving the inside of the flexible member in the axial direction and the holding portion sandwiched between the upstream side pressing plate and the downstream side pressing plate And an expansion member having the expansion portion, and the expansion Is disposed between the holding portion of the holding portion and the flexible member of wood, characterized in that it comprises the axial thickness can be changed compression member.

  Further, the present invention provides a rotor having a rotor shaft that extends in the axial direction and is rotatably supported, and a rotor core that is provided radially outside the rotor shaft, and a radially outer side of the rotor core. A stator having a cylindrical stator core provided with a radial flow path provided at an axial interval, a stator winding passing through the stator core in the axial direction, and the fixed A frame disposed outside the rotor in the radial direction and housing the rotor core and the stator; and a bearing for supporting the rotor shaft on both sides of the rotor shaft in the axial direction across the rotor core; A bearing bracket that supports each of the bearings in a stationary manner, is connected to the axial end of the frame, and forms a closed space in combination with the frame; and a supply that serves as a path for supplying a protective gas to the closed space. Attire And an exhaust device serving as a path for discharging the protective gas in the closed space, an internal pressure explosion-proof rotating electrical machine, wherein at least one of the air supply device and the exhaust device includes the flow rate adjusting mechanism. It is characterized by having.

  According to the present invention, the flow rate of the fluid can be finely adjusted without depending on a complicated mechanism.

FIG. 4 is a cross-sectional view taken along the line I-I in FIG. 3 illustrating the configuration of the internal pressure explosion-proof rotating electrical machine according to the first embodiment. It is the II-II arrow directional side view of FIG. 3 which shows the external appearance of the internal pressure explosion-proof rotary electric machine which concerns on 1st Embodiment. FIG. 3 is a front view of the internal pressure explosion-proof rotating electrical machine according to the first embodiment taken along line III-III in FIG. It is a longitudinal cross-sectional view which shows the structure of the flow volume adjustment mechanism which concerns on 1st Embodiment. It is an expanded view which shows the structural example of the flexible member of the flow volume adjustment mechanism which concerns on 1st Embodiment. It is a longitudinal cross-sectional view explaining the effect | action of the flow volume adjustment mechanism which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the structure of the flow volume adjustment mechanism which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the structure of the flow volume adjustment mechanism which concerns on 3rd Embodiment.

  Hereinafter, a flow rate adjusting mechanism and an internal pressure explosion-proof rotating electrical machine according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a cross-sectional view taken along the line I-I in FIG. 3 showing the configuration of the internal pressure explosion-proof rotating electrical machine according to the first embodiment. 2 is a side view taken along the line II-II in FIG. 3 is a front view taken along line III-III in FIG.

  The internal pressure explosion-proof rotating electrical machine 200 includes a rotor 10, a stator 20, a bearing 30, a cooler 60, an air supply device 100, and an exhaust device 150.

  The rotor 10 includes a rotor shaft 11 that extends horizontally and is rotatably supported at both ends, and a cylindrical rotor core 12 that is disposed on the radially outer side of the rotor shaft 11. One end portion of the rotor shaft 11 is provided with a coupling portion 11a for coupling with a coupling target.

  The stator 20 is formed on the radially outer side of the rotor core 12 with a cylindrical stator core 21 disposed via a gap 18 and on the radially inner surface of the stator core 21, and extends in the axial direction. And a stator winding 22 penetrating through a plurality of stator slots (not shown) spaced apart from each other in the circumferential direction.

  The rotor core 12 and the stator 20 are accommodated in the frame 40. Both end portions in the axial direction of the frame 40 are closed by bearing brackets 45. Each bearing bracket 45 supports the bearing 30 stationary. The two bearings 30 rotatably support the rotor shaft 11. A terminal box 80 is attached to the frame 40.

  A cooler 60 is mounted on the upper portion of the frame 40. The cooler 60 includes at least one cooling pipe 61 through which a cooling medium such as water passes, and a cooler cover 63 that houses the cooling pipe 61. The cooling pipe 61 is normally bent so as to have several U-shaped portions in the cooler cover 63 in order to secure a heat transfer area. The cooling pipe 62 is connected to the external pipe by the cooling pipe flange 62 outside the cooler cover 63.

  The frame 40, the bearing bracket 45, and the cooler cover 63 combine with each other to form a closed space 70 in which protective gas is stored. The space in the frame 40 and the space in the cooler cover 63 communicate with each other through the cooler inlet opening 64 and the cooler outlet opening 65.

  On the upper surface of the cooler cover 63, an air supply device 100 serving as a protective gas supply channel is provided. Further, an exhaust device 150 serving as a path for discharging the protective gas in the closed space 70 is provided on the side surface of the frame 40. Hereinafter, although the air supply apparatus 100 is demonstrated, the exhaust apparatus 150 is also the same structure.

  The air supply device 100 includes an air supply valve 101 and a flow rate adjusting mechanism 110 provided on the air supply pipe 102. The supply valve 101 side and the flow rate adjustment mechanism 110 side are connected to each other by connection flanges 103a and 103b.

  An inner fan 51 is provided on the rotor shaft 11, and the protective gas in the closed space 70 is driven to circulate in the closed space 70. That is, the protective gas is driven in the axial direction by the inner fan 51 in the direction of the rotor core 12 and the stator 20. The driven protective gas flows into the rotor core 12 and the stator 20, cools them, and then flows out in the axial direction on the side opposite to the inner fan 51, and enters the cooler cover 63 from the cooler inlet opening 64. Flows into the space. The protective gas is cooled by the cooling medium passing through the cooling pipe 61 in the cooler cover 63, and then flows into the frame 40 from the space in the cooler cover 63 via the cooler outlet opening 65. The protective gas flowing into the frame 40 is guided by the fan guide 52 and flows into the inner fan 51 again.

  FIG. 4 is a longitudinal sectional view showing the configuration of the flow rate adjusting mechanism according to the first embodiment. Here, the Z direction is a fluid flow direction. The R direction is a direction perpendicular to the Z direction from the axial center of the upstream pipe 111 and the downstream pipe 117.

  The flow rate adjusting mechanism 110 controls the flow rate of the fluid flowing therethrough. In the case of this embodiment, the flow rates of the supplied protective gas and the discharged protective gas are controlled. An upstream holding plate 112 connected coaxially to the upstream piping 111, a downstream holding plate 116 connected coaxially to the downstream piping 117, an expansion member 113, a compression member 114, and a flexible member 115. Have

  The upstream holding plate 112 is a flange of an annular flat plate that extends in a direction perpendicular to the Z direction and has an opening 112a through which a fluid passes at the center. The downstream holding plate 116 is an annular flat flange, but the opening 116a formed in the center is equal to the inner diameter of the downstream pipe 117, and the upstream opening has a rounded curved edge. Processing to be performed.

  The expansion member 113 includes a pressing portion 113a that extends in a direction perpendicular to the Z direction and a cylindrical portion 113b that extends in the Z direction. The pressing portion 113a has a disk shape with a circular opening 113h formed at the center. The cylindrical portion 113b is connected to the pressing portion 113a, and the inner diameter thereof is equal to the inner diameter of the pressing portion 113a. The outer diameter of the cylindrical portion 113b is smaller than the inner diameter of the downstream pipe 117 by a predetermined gap ΔR. That is, an annulus space 113 s is formed between the downstream pipe 117 and the cylindrical portion 113 b of the expansion member 113. Further, the outer edge of the tip of the cylindrical portion 113b is formed in a rounded curved surface.

  The flexible member 115 has a holding part 115a and a conical part 115b. The holding portion 115 a is disposed between the upstream pressing plate 112 and the downstream pressing plate 116 and is sandwiched between the upstream pressing plate 112 and the downstream pressing plate 116 via the compression member 114. The conical portion 115b has a conical shape in a state where no load is applied, and is connected to the holding portion 115a.

  The compression member 114 is an annular member disposed between the pressing portion 113 a of the expansion member 113 and the holding portion 115 a of the flexible member 115. The compression member 114 is a member that can change the axial thickness by changing the axial load. The compression member 114 can be made of a material having a large expansion / contraction amount and having no internal fluid permeability, such as sponge packing.

  The upstream holding plate 112 and the downstream holding plate 116 are coupled by a plurality of bolts 118 and nuts 119. In addition, the distance between the upstream side pressing plate 112 and the downstream side pressing plate 116 can be adjusted within a range in which the compression member 114 expands and contracts.

  Although not shown, an outflow of protective gas, which is an internal fluid, flows between the upstream pressing plate 112 and the pressing portion 113a of the expansion member 113 and between the holding portion 115a of the flexible member 115 and the downstream pressing plate 116. In order to prevent this, as necessary, a gasket or packing is inserted to ensure sealing performance.

  In the flow rate adjusting mechanism 110, the flexible member 115 is incorporated in the flow rate adjusting mechanism 110 with the tip of the conical portion 115b in the Z-axis direction. Further, the conical portion 115 b is arranged in an annulus space 113 s between the downstream side pipe 117 and the cylindrical portion 113 b of the expansion member 113 except for the vicinity of the tip thereof. At this time, the conical portion 115 b receives a tensile load that tends to expand the conical portion 115 b mainly in the circumferential direction from the inside by the cylindrical portion 113 b of the expansion member 113.

  The portion close to the tip of the conical portion 115b where the expansion member 113 does not exist on the radially inner side, that is, the downstream side is not subjected to a tensile load that tends to spread mainly from the inner side in the circumferential direction, or the tensile load is small. In almost the natural state, that is, a conical shape.

  FIG. 5 is a development view illustrating a configuration example of the flexible member of the flow rate adjusting mechanism according to the first embodiment. The flexible member 115 includes an elastic film 115c and a plurality of elastic plates 115d attached to one surface of the elastic film 115c.

  The elastic film 115c has a fan shape, the smaller diameter side corresponds to the conical part 115b, and the larger diameter side corresponds to the holding part 115a. A portion corresponding to the holding portion 115a may have a cutout portion 115f as shown by a broken line in FIG. The material of the elastic film 115c is, for example, a material that has excellent stretchability and fluid does not easily leak, such as stretchable resin or rubber.

  Each of the plurality of elastic plates 115d extends in the radial direction while being spaced apart from each other in the circumferential direction. Each elastic plate 115d is attached to the elastic film 115c so that the surface thereof is in close contact with the elastic film 115c. For attaching the elastic plate 115d, for example, a method using an adhesive or a mechanical connection method such as sewing can be used.

  The material of the elastic plate 115d may be a normal plate spring material. However, the materials of the elastic plate 115d and the expansion member 113 need to be a combination that is difficult to bite each other. For example, when the elastic plate 115d is a spring stainless steel strip, the expansion member 113 is made of a material harder than stainless steel, such as carbon steel. Further, the outer surface of the cylindrical portion 113b of the expansion member 113 may be subjected to chrome plating or the like. Alternatively, impregnation using Teflon (registered trademark) or the like may be performed in a range where the elastic plate 115d may come into contact with the expansion member 113.

  Two edges 115g and 115h in the circumferential direction of the elastic film 115c are bonded to each other to form a flexible member 115. Here, for the bonding, a method using an adhesive, a method by melting, or the like can be used.

  Note that FIG. 5 shows an example in which the entire flexible member 115 is fan-shaped when deployed, but only the conical portion 115b is fan-shaped when unfolded, and a disk-shaped holding portion 115a having an opening in the cone portion 115b. It may be connected. Alternatively, the conical portion 115b is not limited to a conical shape, and may be a tapered conical portion having a tapered cone shape. Further, when there is a portion that is arranged in the annulus-like space 113s and whose diameter is not enlarged by the expansion member 113, although not shown, a cylindrical portion such as a cylinder is further provided between the conical portion 115b and the holding portion 115a. And the opening of the holding part 115a and the conical part 115b may be connected by a cylindrical part.

  FIG. 6 is a longitudinal sectional view for explaining the operation of the flow rate adjusting mechanism. From the state shown in FIG. 4, when the space between the upstream holding plate 112 and the downstream holding plate 116 is tightened by a plurality of bolts 118 and nuts 119 arranged at intervals in the circumferential direction, the thickness of the compression member 114 is reduced. The dimension between the surfaces of the upstream holding plate 112 and the downstream holding plate 116 decreases from d1 to d2.

  Therefore, the expansion member 113 is pushed by the upstream holding plate 112, moves in the Z direction, and approaches the downstream holding plate 116 side. For this reason, the cylindrical portion 113b of the expansion member 113 enters the inside of the conical portion 115b of the flexible member 115 in the axial direction. As a result, the force for expanding the tip of the conical portion 115b of the flexible member 115 increases, and the diameter of the tip increases from r1 to r2.

  As described above, in the present embodiment, the dimensions of the flexible member 115 can be changed by changing the dimension between the upstream holding plate 112 and the downstream holding plate 116 by tightening and loosening the bolt 118 and the nut 119. The diameter of the tip of the conical portion 115b can be changed. As a result, the flow rate can be finely adjusted.

  As described above, in the flow rate adjustment mechanism 110, the height position of the upstream holding plate 112 in the Z direction changes. Regarding this point, an element that can change the length in the longitudinal direction, such as a flexible tube, is provided at the inlet of the flow rate adjusting mechanism 110, or the upstream pipe 111 is flexibly positioned by the upstream pipe 111 being routed. Measures such as making it possible to follow changes in

  As described above, as shown in the present embodiment, the flow rate of the fluid can be finely adjusted without depending on a complicated mechanism.

[Second Embodiment]
FIG. 7 is a longitudinal sectional view showing the configuration of the flow rate adjusting mechanism according to the second embodiment. The second embodiment is a modification of the first embodiment. In the flow rate adjusting mechanism 110a of the second embodiment, the relationship between the upstream side pipe 111 and the upstream side pressing plate 112 and the relationship between the downstream side pressing plate 116 and the downstream side piping 117 are different from those in the first embodiment. Other points are the same as in the first embodiment.

  First, the opening 112 a of the upstream holding plate 112 is formed with the same diameter as the inner surface of the upstream pipe 111. Further, the diameter of the opening 113 h of the pressing portion 113 a of the expansion member 113 and the inner diameter of the cylindrical portion 113 b are the same as those of the upstream pipe 111.

  As a result, the diameter of the opening 116 a of the downstream holding plate 116 is larger than the inner diameter of the upstream pipe 111. Therefore, in order to connect the downstream side pipe 117 and the downstream side pressing plate 116, an extension pipe 116e having the same inner diameter as the opening of the downstream side pressing plate 116 is provided, and the extension pipe 116e and the downstream side pipe 117 are connected to the reducer 116f. Connected with. If it is not necessary to make the inner diameter of the downstream pipe 117 equal to the inner diameter of the upstream pipe 111, the extension pipe 116e may be used as the downstream pipe 117 as it is.

  According to the second embodiment, since the inner diameter of the flow path is constant before reaching the conical portion 115b of the flexible member 115, the flow is less disturbed. As a result, the effect of throttling by the conical portion 115b becomes greater, and finer flow rate adjustment is possible.

[Third Embodiment]
FIG. 8 is a longitudinal sectional view showing the configuration of the flow rate adjusting mechanism according to the third embodiment.

  The third embodiment is a modification of the first embodiment. The flow rate adjustment mechanism 110b according to the present embodiment is different from the first embodiment in that the compression member 114a is a leaf spring. Other points are the same as those of the first embodiment.

  The compression member 114a is an annular, for example, metal spring having a U-shaped cross section. The convex portion is formed so as to be directed radially inward. However, the shape may be such that the convex portion is directed outward in the radial direction. A packing or a gasket may be provided between the leaf spring as the compression member 114a and the pressing portion 113a of the expansion member 113, between the leaf spring and the holding portion 115a of the flexible member 115, or any one of them. .

  In the flow rate adjusting mechanism 110b according to the third embodiment, the sealing performance can be further improved by ensuring the rigidity of the spring.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, embodiment is shown as an example and is not intending limiting the range of invention. For example, in the embodiment, the internal pressure explosion-proof rotating electrical machine is shown as an example of a horizontally mounted rotating electrical machine, but is not limited to a horizontally mounted type. That is, it may be a vertically placed type. Moreover, although the case where the water-cooling system cooler was provided was shown, the case of another cooling system may be sufficient. Moreover, the case where a cooler is not provided and natural heat radiation may be sufficient.

  Further, in the internal pressure explosion-proof rotating electrical machine according to the embodiment, the case where the flow rate adjusting mechanism adjusts the gas is shown as an example, but the present invention is not limited to this. For example, the fluid may be a liquid. Moreover, although the case where the flow rate adjusting mechanism is a rotation target around the axis is shown as an example, the present invention is not limited to this. For example, instead of the cylindrical portion 113b of the expansion member, a cylindrical tube portion other than the cylinder may be used.

  Moreover, you may combine the characteristic of each embodiment. For example, the second embodiment and the third embodiment may be combined.

  Furthermore, the embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The embodiments and the modifications thereof are included in the scope of the invention and the scope of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Rotor, 11 ... Rotor shaft, 11a ... Joint part, 12 ... Rotor core, 18 ... Gap, 20 ... Stator, 21 ... Stator core, 22 ... Stator winding, 30 ... Bearing, 40 ... Frame 45 ... Bearing bracket, 51 ... Inner fan, 52 ... Fan guide, 60 ... Cooler, 61 ... Cooling pipe, 62 ... Cooling pipe flange, 63 ... Cooler cover, 64 ... Cooler inlet opening, 65 ... Cooler outlet Opening, 70 ... Closed space, 80 ... Terminal box, 100 ... Air supply device, 101 ... Air supply valve, 102 ... Air supply pipe, 103a, 103b ... Connection flange, 110, 110a, 110b ... Flow rate adjusting mechanism, 111 ... Upstream side Pipe 112, upstream holding plate 112a, opening 113, expansion member 113a, holding portion 113b, cylindrical portion (cylinder), 113h, opening 113s, annular space 114, 11 a ... compression member, 115 ... flexible member, 115a ... holding part, 115b ... conical part (tapered cone part), 115c ... elastic membrane, 115d ... elastic plate, 115f ... notch part, 115g, 115h ... edge part, DESCRIPTION OF SYMBOLS 116 ... Downstream side pressing plate, 116a ... Opening, 116e ... Extension pipe, 116f ... Reducer, 117 ... Downstream piping, 118 ... Bolt, 119 ... Nut, 150 ... Exhaust device, 200 ... Internal pressure explosion-proof rotary electric machine

Claims (5)

A flow rate adjusting mechanism for controlling the flow rate of fluid,
An upstream holding plate connected to the upstream pipe and having an opening through which fluid passes in the center;
A downstream holding plate connected to the downstream pipe and having an opening through which a fluid passes in the center;
A holding portion disposed between the upstream holding plate and the downstream holding plate and sandwiched between the upstream holding plate and the downstream holding plate, and opened at a tip connected to the inside of the holding portion A tapered member having a flexible member, and
A pressing portion that is disposed between the flexible member and the upstream pressing plate and is sandwiched between the upstream pressing plate and the downstream pressing plate, and moves inside the flexible member in the axial direction. An expansion member having a cylindrical portion that presses and expands the flexible member from the radially inner side,
A compression member that is disposed between the pressing portion of the expansion member and the holding portion of the flexible member and capable of changing an axial thickness;
A flow rate adjusting mechanism comprising:   The flow rate adjusting mechanism according to claim 1, wherein the material of the compression member is sponge packing.   The flow rate adjusting mechanism according to claim 1, wherein the compression member is an annular leaf spring. A rotor having a rotor shaft that extends in the axial direction and is rotatably supported, and a rotor core that is provided radially outside the rotor shaft;
A cylindrical stator core that is provided on the radially outer side of the rotor core and in which a radial flow path is formed with an interval in the axial direction, and a stator winding that passes through the stator core in the axial direction A stator having
A frame that is disposed outside the stator in the radial direction and houses the rotor core and the stator;
Bearings that support the rotor shaft on both sides of the rotor shaft in the axial direction across the rotor core;
A bearing bracket that supports each of the bearings statically and is connected to the axial end of the frame and forms a closed space in combination with the frame;
An air supply device serving as a path for supplying a protective gas to the closed space;
An exhaust device serving as a path for discharging the protective gas in the closed space;
An internal pressure explosion-proof rotating electric machine comprising:
The internal pressure explosion-proof rotating electrical machine, wherein at least one of the air supply device and the exhaust device has the flow rate adjusting mechanism according to any one of claims 1 to 3. A cooler having a cooling pipe;
A cooler cover that houses the cooler and forms a closed space with the frame and the bearing bracket; and
An inner fan that is attached to the rotor shaft in the closed space and drives the protective gas;
The internal pressure explosion-proof rotating electrical machine according to claim 4, further comprising:

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