JPH0775272A - Cooling structure for rotor winding head of rotating electric machine - Google Patents

Abstract

PURPOSE:To control temperature rise of coil ends and increase an output of a rotating electric machine without enlargement of cross-section of a conductor by comprising an insulating material separation wall defined in a coolant gas supply chamber, an insulating material having constant projected portions and a particular through hole. CONSTITUTION:The space between coil ends 4H and a rotor axis 7 is divided into a plurality of sections in the circumferencial direction thereof to provide insulation material separation wall 21 to be defined in a coolant gas supply chamber 26 and an exhaust chamber. Moreover, an insulation material 22 having projections is also provided in such a manner that it is provided between the gap of the coil ends 4H provided in the form of multiple rings to hold such gap and form a zig-zag coolant gas supply path 24 with respect to the coil. In addition, a through hole 23 is provided at the essential portion of the insulation material separation wall 21 as a coolant gas supply path extended to the zig-zag coolant gas supply path 24 from the coolant gas supply chamber 26. Thereby, the zig-zag coolant gas flow may be formed and compulsory blowing is conducted for the cooling purpose for the coil end 4H. As a result, higher cooling performance can be obtained and allowable current density can also be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a rotor winding of a turbine generator or the like, and more particularly to a cooling structure for a rotor winding head (coil end) showing the greatest temperature rise.

[0002]

2. Description of the Related Art FIG. 7 is a schematic sectional view showing a cooling structure of a turbine generator as a whole.
Also, a rotor winding head (coil end) (not shown) rotatably supported by the stator 1 via a bearing mechanism portion (not shown) and projecting at both ends of the rotor core 8 is covered with a retaining ring 9 on the outer peripheral side. , When the rotor rotates, the coil end is protected from being deformed by the strong centrifugal force acting on the coil end. Further, as a cooling device for the stator and the rotor, fans 11 and intake ducts 12 symmetrically provided at both ends of the rotor shaft 7 and an exhaust duct 1 surrounding the stator core.
3 and a ventilation hole 14 formed in the rotor core 8 and a ventilation duct 16 formed in the laminated surface of the stator core. The refrigerant gas 15 pressurized by the fan 11 is retained by the retaining ring 9. The stator-side refrigerant gas flow 15S and the rotor-side refrigerant gas flow 15R are branched, and the stator-side refrigerant gas 15S cools the rotor 1 while passing through the ventilation duct 16 to exhaust the exhaust duct 13
Is discharged to the outside through the rotor side refrigerant gas 15R, flows into the gap of the coil end from the periphery of the rotor shaft 7, and is discharged to the stator side through the ventilation hole 14 to rotate including the coil end. The child 2 is cooled, merges with the stator-side refrigerant gas 15S on the outer peripheral side of the rotor 2, and is discharged through the ventilation duct 16 and the exhaust duct 13.

FIG. 8 is a perspective sectional view showing a conventional rotor winding head cooling structure of a turbine generator, and FIG. 9 is an explanatory view showing the flow of refrigerant gas in the main part of FIG. The rotor 2 is provided with a rotor core 8 through which a rotor shaft 7 penetrates, and a rotor winding 4 in which a saddle-shaped coil is wound in multiple turns in multiple rings in its slot. The outer periphery of the rotor winding head (coil end) 4H protruding at both ends in the direction is covered with a retaining ring (not shown), and insulating gap pieces 5 are arranged in the gaps between the coil ends 4H to maintain the gap. A rotor winding 4 is formed that withstands the acceleration and centrifugal force acting on the coil ends as the rotor 2 rotates.

Further, the refrigerant gas flow 15R on the rotor side flows in a zigzag shape through the cooling passages held by the insulating spacing pieces 5 to cool the coil ends, and then a plurality of vent holes 14 are provided in the rotor core 8. The coil end 4H is cooled by a thermosyphon method in which the winding is cooled to cool the winding and is discharged from the outer peripheral surface of the rotor core to the stator side. That is, the temperature of the refrigerant gas 15R rises in the process of cooling the coil end, and the specific gravity difference occurs in the refrigerant gas accordingly, so that the centrifugal force acting on the refrigerant gas due to the rotation of the rotor has a gas temperature dependency. To do. As a result, as shown in FIG. 9, in the gap between the coil ends 4H whose outer peripheral side is closed by the retaining ring 9, the inflowing cool air receives a strong centrifugal force and flows from the rotor shaft side toward the retaining ring side. The refrigerant gas, which has taken the heat of the winding and increased in temperature, has a centrifugal force that decreases and forms convection returning from the retaining ring side toward the rotor shaft side. Therefore, the refrigerant gas flow 15
The R flows in a zigzag manner on the surface of the coil end to extend its flow path, and the coil end 4H can be efficiently convectively cooled.

FIG. 10 is a characteristic diagram showing the temperature distribution of the rotor winding in the conventional rotor winding head cooling structure. The horizontal axis of the figure is from the end of the coil end 4H to the center of the rotor winding. It has a length up to. In the conventional cooling method, it is shown that the maximum temperature of the rotor winding is at the coil end 4H projecting at both ends of the rotor core.

[0006]

It is well known that the usable life time of a winding of a rotary electric machine is determined by the heat resistant life characteristics of the insulating material that insulates and coats the coil conductor. It is an important technical issue to improve the heat-resistant life property of the insulating coating by using it. On the other hand, when the rotor coil has a large temperature difference in the longitudinal direction as in the above-mentioned turbine generator, the head portion of the rotor, which has the highest temperature, becomes the weak point of the heat resistance life characteristic, and Since it is necessary to determine the current density of the coil conductor within the range in which the temperature of the head does not exceed the allowable heat resistance temperature of the insulation coating, this causes an increase in the cross-sectional area of the coil conductor, in other words, an increase in the size of the rotating electric machine. Alternatively, there is a problem that the output of the rotating electric machine must be suppressed.

An object of the present invention is to suppress the temperature rise of the winding head by improving the winding head cooling structure, and to increase the output of the rotating electric machine without increasing the conductor cross-sectional area.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a winding head of a rotor winding composed of a plurality of saddle-shaped coils wound around a rotor core in a multiple annular shape. (Coil end) is cooled by a refrigerant gas supplied to the inner peripheral side of the coil end from a fan provided at the end of the rotor shaft, and the space between the coil end and the rotor shaft is circumferentially defined. Insulating material partition walls which are divided into a plurality of parts to define the refrigerant gas supply chamber and the exhaust gas chamber, and the gaps between the coil ends arranged in multiple rings are held to maintain a space,
And an insulating material with protrusions forming a zigzag-shaped refrigerant gas passage between the coil and the coil, which is formed at a key part of the insulating material partition wall to become a refrigerant gas passage from the refrigerant gas supply chamber to the zigzag-shaped refrigerant gas passage. And a through hole.

A system in which the zigzag-shaped refrigerant gas passage discharges the refrigerant gas flowing in a zigzag shape along a surface parallel to the rotor axis of the coil end to the outside through a ventilation hole formed in the rotor core, The system is composed of two systems, that is, a system that discharges the refrigerant gas that flows in a zigzag shape along a plane orthogonal to the rotor axis of the coil end to the outside through the exhaust chamber.

The insulating material with protrusions is composed of a base material made of a plate-like insulating material, and a plurality of protrusions formed on the surface of the insulating material so as to have a certain thickness. A zigzag-shaped refrigerant gas passage is provided between the plurality of protrusions. Shall be formed. It is assumed that the plurality of protrusions are formed in a mountain shape having respective apexes, and the arrangement patterns are formed so that the apexes are displaced in a zigzag pattern and alternately face each other.

A plurality of protrusions are formed in a rectangular shape having a fixed dimensional ratio with respect to the width of the base material, and one of the short sides thereof is positioned in the longitudinal direction of the base material so as to be alternately located at different edges of the base material. It shall be shifted and fixed in a zigzag shape. When the width of the base material is 1, the fixed dimensional ratio of the rectangular projections is 0.5 to 0.6 for the long side and 0.15 to 0.25 for the short side. In each case.

It is assumed that a plurality of projections formed on the surface of the base material with a certain thickness to have a convex shape have a bypass refrigerant gas passage formed on the surface thereof with concave grooves formed along the longitudinal direction of the base material.

[0013]

According to the present invention, the space between the coil end and the rotor shaft is divided into a plurality of spaces in the circumferential direction to define the refrigerant gas supply chamber and the exhaust chamber, and an insulating material partition wall, and coils arranged in a multiple annular shape. Insulating material with protrusions that is interposed in the gap between the ends to maintain a gap and forms a zigzag-like refrigerant gas passage between the coil and the insulating material partition wall, and is formed from the refrigerant gas supply chamber. The zigzag-shaped refrigerant gas passage is configured to have a through hole that serves as a refrigerant gas passage, so that the refrigerant gas supplied from the fan is pressurized in the refrigerant gas supply chamber, and the pressurized refrigerant gas is an insulating material. Through the through hole formed in the partition wall, it flows into the zigzag-shaped refrigerant gas passage formed by the projection pattern of the insulating material with projections, and forcibly forms the zigzag-shaped refrigerant gas flow on the surface of the coil end. And coil Since the forced air cooling between the command, it is possible to obtain a high cooling performance as compared with conventional thermosiphon cooling system utilizing difference in specific gravity between the refrigerant gas,
Since the temperature rise of the coil end is suppressed and the allowable current density is increased, the function of increasing the output of the rotary electric machine can be obtained without increasing the conductor cross-sectional area.

Further, a system for discharging the refrigerant gas flowing in the zigzag-shaped refrigerant gas passage in a zigzag shape along the surface parallel to the rotor axis of the coil end to the outside through the ventilation hole formed in the rotor core. And a system that discharges the refrigerant gas flowing in a zigzag shape along the plane orthogonal to the rotor axis of the coil end to the outside through the exhaust chamber, the direction of the refrigerant gas flow is 90 ° The function of performing forced gas cooling with high heat exchange efficiency by reasonably dividing the refrigerant gas over different heat exchange surfaces can be obtained.

The insulating material with projections is composed of a base material made of a plate-shaped insulating material and a plurality of projections formed on the surface of the projections with a certain thickness, and a zigzag-like refrigerant gas passage is provided between the plurality of projections. , The integral insulating material with protrusions engages with the retaining ring to mechanically support the coil ends where a strong centrifugal force acts and maintain a mutual distance, and zigzag refrigerant gas. A winding head cooling structure having a function of forming a passage, mechanically stable, and excellent cooling performance can be obtained.

If a plurality of protrusions are formed in a mountain shape having respective vertices, and the arranging patterns are formed so that the vertices are displaced in a zigzag shape and face each other, the surface of the coil end is formed. A heat exchange surface bent in a zigzag shape is formed, and a function of performing heat exchange with high heat transfer performance is obtained by the refrigerant gas flow forcedly flowing through the bent heat exchange surface.

Further, a plurality of protrusions are formed in a rectangular shape having a constant dimensional ratio with respect to the width of the base material, and one short side of the projection is alternately arranged at different edges of the base material in the longitudinal direction of the base material. If it is configured to shift in position and fix in a zigzag shape,
Since the projection member previously formed in a rectangular parallelepiped can be firmly fixed to the base material by using an adhesive, a connecting pin, etc., it is possible to reduce the rectangular area and reduce the gas cooling performance that occurs at the contact part between the coil end and the projection. And a function of suppressing a local temperature rise at the coil end can be obtained. In addition, the dimension ratio of the protrusions formed in a rectangle is fixed within the range of 0.5 to 0.6 for the long side and 0.15 to 0.25 for the short side with respect to the width of the substrate. In terms of dimensions, it is possible to obtain a cooling structure in which the mechanical strength required to prevent the protrusions from falling off due to centrifugal force or friction with the coil and the function of suppressing the local temperature rise at the coil end are well balanced.

On the other hand, a bypass refrigerant gas passage having a plurality of projections formed in a convex shape in a mountain shape or a rectangle with a certain thickness on the surface of the base material, and a concave groove formed on the surface along the longitudinal direction of the base material. With this configuration, a part of the refrigerant gas that flows in a zigzag shape between the protrusions flows by being diverted to the bypass refrigerant gas passage, further reducing the decrease in gas cooling performance that occurs at the contact portion between the coil end and the protrusion. The function of suppressing the local temperature rise at the coil end can be obtained.

[0019]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a cross-sectional view of an essential part showing a rotor winding head cooling structure of a rotating electric machine according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a rotor winding head cooling structure of a rotating electric machine according to an embodiment. It is a cross-sectional view, and the same reference numerals are given to the same components as those of the conventional technique, and the duplicated description will be omitted. In the figure,
The coil end 4H, which projects from both ends of the rotor core 8 and is surrounded by the retaining ring 9 on the outer peripheral side, is provided with an insulating spacing wall 21 in the gap between the inner peripheral side and the rotor shaft 7, and the periphery of the rotor shaft is A supply chamber 26 and an exhaust chamber 27 for the refrigerant gas flow 15R are defined in the circumferential direction. Further, the intervals between the saddle-shaped coils that are multiply arranged are such that protrusions 22B having a constant thickness are provided on both sides of the plate-shaped portion 22A.
Is held by a protruding insulating material 22 having
The shape of 2B is formed in a mountain shape, and the disposition patterns are formed so that the vertices of the ridges are displaced in a zigzag shape so as to face each other, thereby forming a zigzag shape between the plate-shaped portion 22A and the coil end 4H. A bent refrigerant gas passage 24 is formed. Further, the through hole 23 is provided at a key portion of the insulating material 22 with protrusions.
Is formed, and the refrigerant gas supply chamber 26 and the zigzag refrigerant gas passage 24 are configured to communicate with each other through the through hole 23.

In the rotating electric machine having the rotor winding head cooling structure constructed as described above, the refrigerant gas 15 pressurized by the fan 11 by the rotation of the rotor rotates with the stator side refrigerant gas flow 15S. Although divided into the child-side refrigerant gas flow 15R, the rotor-side refrigerant gas flow 15R is pressurized in the supply chamber 26 thereof, is accelerated by passing through the through hole 23, and flows into the zigzag-shaped refrigerant gas passage 24. To do. At this time, if the through holes 23 are formed at the positions corresponding to the corners of the saddle-shaped coil, the inflowing refrigerant gas is divided into the coil surface parallel to the rotor axis and the coil surface orthogonal to the rotor axis. Therefore, the refrigerant gas flow 25A flowing in a zigzag shape along the surface of the coil end parallel to the rotor axis cools the coil end by forced ventilation, and then rotates through the vent hole 14 penetrating the rotor core 8. The outer peripheral surface of the child iron core is discharged to the stator side to cool the rotor iron core and the srod portion of the rotor winding housed therein. In addition, the refrigerant gas flow 25 flowing in a zigzag shape along a plane orthogonal to the rotor axis of the coil end 25
After forcibly cooling the coil end by forced ventilation, B passes through an exhaust chamber 27 defined adjacent to the supply chamber 26 and is discharged to the stator side from an exhaust groove 28 communicating with this.

Therefore, the refrigerant gas accelerated through the through holes 23 becomes zigzag refrigerant gas flows 25A and 25B having different directions and paths, and the surface of the saddle coil is forcedly cooled by ventilation. It is possible to obtain higher heat transfer characteristics than the conventional convection cooling structure using the siphon method. FIG. 3 is a characteristic diagram showing the temperature distribution of the rotor winding obtained by the cooling structure for the rotor winding head according to the embodiment in comparison with that of the conventional method. According to the partial cooling structure, the maximum temperature of the rotor winding head can be reduced to about 2/3 that of the conventional one. Therefore, if the maximum temperature of the coil end is made equal to that of the conventional one,
Since the allowable current value of the rotor winding can be increased without increasing the cross-sectional area of the coil conductor, it is possible to increase the output of the rotary electric machine by that amount, and by improving the cooling structure, a small rotary electric machine with large power generation capacity can be provided. There are advantages that can be provided.

FIG. 4 is a perspective view showing an essential part of a rotor winding head cooling structure of a rotating electric machine according to a different embodiment of the present invention, and FIG. 5 is a plan view showing the arrangement of protrusions in the different embodiment. The insulating material 32 with protrusions has a coil end height (100 mm).
A plate-shaped portion 32A having a width H corresponding to
And a plurality of protrusions 32B formed on both sides thereof in a rectangular shape with a constant thickness. As for the vertical and horizontal dimension ratios of the rectangular protrusion 32B, the dimension of the long side 1 is 0.5H to 0.6H and the dimension of the short side w is 0.15H to 0 with respect to the width H of the base material. It is formed in the range of .25H, and is arranged in a zigzag shape by shifting the position in the longitudinal direction of the base material so that one short side thereof is alternately positioned on the edges on both sides of the base material 32A. That is, the width of the passage is reduced by firmly fixing the projection member formed in advance in the rectangular parallelepiped having the above-mentioned dimensional ratio to the predetermined position of the base material 32B by using an adhesive, a pin or the like.
Insulating material 32 with protrusions having a zigzag-like refrigerant gas passage of about 0.4 to 0.5 times the height H of 2A is formed.

In the rotor winding head cooling structure using the insulating material 32 with protrusions configured as described above, the rotor side refrigerant gas flow 15R pressurized in the supply chamber 26 is insulated by the insulating partition wall 2
The refrigerant gas flow 25A that is accelerated by passing through the through hole 23 of 1 and flows in a zigzag manner on the surface of the coil parallel to the rotor axis to cool it, and the zigzag shape of the surface of the coil orthogonal to the rotor axis. And the refrigerant gas flow 25B to be cooled to cool the coil end. At this time, in the case of the above-described embodiment in which the protrusions are formed in a mountain shape, a plurality of connecting pins necessary for preventing the protrusions from falling off due to centrifugal force or friction with the coil are arranged in a triangular shape in accordance with the mountain-shaped protrusions. Therefore, the width of the bottom portion of the mountain-shaped protrusion 22B becomes wide, and the local temperature rise of the coil end becomes large at the portion in contact with this. On the other hand, in this embodiment, since the projections 32B are rectangular, the coupling pins can be arranged in a row along the long side of the rectangle, and thus the short side w of the rectangle.
Further, it is possible to reduce the contact area with the coil, and it is possible to obtain an advantage that a decrease in gas cooling performance that occurs at the contact portion between the coil end and the protrusion can be reduced and a local temperature increase at the coil end can be suppressed.

FIG. 6 is a sectional view showing an insulating material with protrusions according to another embodiment of the present invention.
(Or 22) A plurality of protrusions 32B or 22B formed in a convex shape in a mountain shape or a rectangle with a certain thickness on the surface of a base material 32A (or 22A) made of a flat plate insulating material is formed on the surface in the longitudinal direction of the base material. If it is configured to have the bypass refrigerant gas passage 40 formed of a concave groove formed along the refrigerant gas flow 25A or 2A flowing in zigzag between the protrusions.
Since a part of 5B flows by diverting into the bypass refrigerant gas passage 40 and cools the coil end in this part, the deterioration of the gas cooling performance caused at the contact portion between the coil end and the protrusion is further reduced, and the local portion of the coil end is reduced. The effect of suppressing the increase in the effective temperature can be obtained, and the thermal deterioration of the winding insulation coating due to the local increase in temperature can be suppressed, and the shortening of the insulation life can be prevented.

[0025]

As described above, according to the present invention, the rotor winding head cooling structure divides the space between the coil end and the rotor shaft into a plurality of portions in the circumferential direction to form the refrigerant gas supply chamber and the exhaust chamber. An insulating partition wall that defines the partition wall, and an insulating material with protrusions that are interposed in the gaps between the coil ends arranged in multiple rings to maintain a gap between them and that form a zigzag-shaped refrigerant gas passage between the coils. The insulating material partition wall is provided with a through hole which is formed in a key portion and serves as a refrigerant gas passage from the refrigerant gas supply chamber to the zigzag-shaped refrigerant gas passage. As a result, with the rotation of the rotor, the refrigerant gas supplied from the fan is pressurized in the refrigerant gas supply chamber, and the pressurized refrigerant gas is passed through the through holes formed in the insulating material partition wall to provide the insulating material with protrusions. Flowing into the zigzag refrigerant gas passage formed by the projection pattern of
It is higher than the conventional thermosyphon cooling method that uses the difference in specific gravity of the refrigerant gas because it forms a zigzag refrigerant gas flow forcibly on the coil end surface and performs forced draft cooling with the coil end. It is possible to obtain the cooling performance, suppress the temperature rise of the coil end to about 2/3 of that of the conventional one, and economically advantageously provide a rotating electric machine with increased output without increasing the conductor cross-sectional area. be able to.

Further, the conventional insulating spacing piece is integrated as the insulating material with protrusions to form a zigzag-like refrigerant gas passage, and also has the function of maintaining the spacing between the rotor windings arranged in multiple layers. There is an advantage that it is possible to provide a rotating electric machine having a rotor winding head cooling structure that mechanically holds a rotor winding that receives a large acceleration or centrifugal force and at the same time exhibits excellent cooling performance.

Further, the shape of the protruding portion of the insulating material with the protruding portion is changed from the mountain shape to the rectangular shape to reduce the width thereof, and further, the bypass refrigerant gas passage is formed on the surface of the protruding portion so as to be improved. Then, there is an advantage that a local temperature rise that occurs at the contact portion with the coil end can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a rotor winding head cooling structure for rotary electric machines according to an embodiment of the present invention.

FIG. 2 is a perspective sectional view showing a rotor winding head cooling structure of the rotating electric machine according to the embodiment.

FIG. 3 is a characteristic diagram showing a temperature distribution of a rotor winding obtained by a rotor winding head cooling structure according to an example in comparison with that of a conventional method.

FIG. 4 is a perspective view showing a main part of a rotor winding head cooling structure of a rotating electric machine according to another embodiment of the present invention.

FIG. 5 is a plan view showing the arrangement of protrusions in another embodiment.

FIG. 6 is a cross-sectional view showing an insulating material with protrusions according to another embodiment of the present invention.

FIG. 7 is a sectional view schematically showing a cooling structure of the entire turbine generator.

FIG. 8 is a perspective sectional view showing a conventional rotor winding head cooling structure of a turbine generator.

FIG. 9 is an explanatory diagram showing the flow of refrigerant gas in the main part of FIG.

FIG. 10 is a characteristic diagram showing a rotor winding temperature distribution in a conventional rotor winding head cooling structure.

[Explanation of Codes] 1 Stator 2 Rotor 3 Stator coil head 4 Rotor winding 4H Rotor winding head (coil end) 5 Insulating spacing piece 7 Rotor shaft 8 Rotor iron core 9 Holding ring 11 Fan 12 Intake duct 13 Exhaust duct 14 Vent hole 15 Refrigerant gas 15R Refrigerant gas flow (rotor side) 16 Ventilation duct 21 Insulating material partition wall 22 Insulating material with protrusion 22A Plate portion 22B Projection portion 23 Through hole 24 Zigzag-like refrigerant gas passage 25 Zigzag refrigerant gas flow 25A Zigzag refrigerant gas flow on the side parallel to the rotor axis 25B Zigzag refrigerant gas flow on the side orthogonal to the rotor axis 26 Refrigerant gas supply chamber 27 Exhaust chamber 28 Exhaust groove 32 Protrusion Insulated material 32A Plate portion 32B Projection portion 40 Bypass refrigerant gas passage H Plate portion width l Long side dimension of rectangular protrusion w Short side dimension of rectangular protrusion

Claims (7)

[Claims] Claim: What is claimed is: 1. A coil end of a rotor winding, which comprises a plurality of saddle-shaped coils wound around a rotor core in a multi-ring shape, is provided at a rotor shaft end from a fan to a coil end. Which is cooled by the refrigerant gas supplied to the inner peripheral side of the insulating material, the space between the coil end and the rotor shaft is divided into a plurality of parts in the circumferential direction to define a refrigerant gas supply chamber and an exhaust chamber. A partition wall, an insulating material with a protrusion which is interposed in a gap between coil ends arranged in a multi-annular shape and maintains a gap, and forms a zigzag-like refrigerant gas passage between the partition wall, and the insulating material partition wall. A rotor winding head cooling structure for a rotating electric machine, comprising: a through hole that is formed in a key portion and serves as a refrigerant gas passage from a refrigerant gas supply chamber to a zigzag-shaped refrigerant gas passage. 2. A system in which a zigzag-shaped refrigerant gas passage discharges a refrigerant gas flowing in a zigzag shape along a plane parallel to a rotor axis of a coil end to the outside through a ventilation hole formed in a rotor core. 2. The rotating electric machine according to claim 1, wherein the coil end has two systems, that is, a system for discharging the refrigerant gas flowing in a zigzag shape along a plane orthogonal to the rotor axis to the outside through the exhaust chamber. Rotor winding head cooling structure. 3. A zigzag refrigerant gas between the plurality of projections, wherein the projection-containing insulating material comprises a base material made of a plate-shaped insulating material and a plurality of projections formed on the surface of the insulating material so as to be convex. The cooling structure for a rotor winding head of a rotating electric machine according to claim 1, wherein a passage is formed. 4. A plurality of protrusions are formed in a mountain shape having vertices, and the arranging patterns are formed so that the vertices are displaced in a zigzag pattern and alternately face each other. The rotor winding head cooling structure for a rotating electric machine according to claim 3. 5. A plurality of protrusions are formed in a rectangular shape having a constant dimensional ratio with respect to the width of the base material, and one short side of the projection is arranged in a longitudinal direction of the base material so as to be alternately located at different edges of the base material. The rotor winding head cooling structure for a rotating electric machine according to claim 3, wherein the structure is shifted and fixed in a zigzag shape. 6. The constant dimension ratio of the rectangular projections is 0.5 to 0.6 for the long side and 0.15 for the short side when the width of the substrate is 1. A rotor winding head cooling structure for a rotating electric machine, characterized in that each is in a range of 0.25. 7. A plurality of protrusions formed on a surface of a base material so as to be convex with a certain thickness, and having a bypass refrigerant gas passage formed on the surface of the base material, the groove being a groove formed along the longitudinal direction of the base material. The rotor winding head cooling structure for a rotating electric machine according to claim 3, characterized in that.