JP3123583B2 - Rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine, and more particularly to a structure for mounting a winding of a large rotating electric machine such as a large-capacity induction motor in a slot.

[0002]

2. Description of the Related Art Conventionally, as a winding mounting structure for a rotor or a stator of a rotating electric machine, a winding in which the conductor is insulated and covered is inserted, and a wedge is mounted on an upper portion of the slot to mount the winding in the slot. A fixed line is well known.

As one example, FIG. 8 shows a structure in a slot of a conventional two-layer wound wire wound rotor.

[0004] A conventional in-slot structure of a wound-type rotor core is such that slots 18 are arranged in the circumferential direction of a rotor core 17 formed by laminating thin electromagnetic steel sheets, and two upper and lower layers are usually provided in one slot. Are inserted, and wedges 21 are mounted on the upper portions of the slots 18 to fix the windings 19 and 20.

The shape of the rotor winding is different from that of the salient pole type, and ground insulations 19b and 20b are wound around conductors 19a and 20a formed of a plurality of electric wires which are previously formed in the shape of a tortoiseshell. Is inserted inside.

In a large-capacity induction motor, a higher voltage is required as a voltage applied to a rotor winding than a conventional salient-pole type winding, so that electrically and mechanically strong insulating materials 19b and 20b are required. .

[0007] A dovetail groove 24 is formed in the outer diameter direction of each slot 18 over the entire length in the axial direction. The wedge 21 is driven into the dovetail groove 24 via an insulating protective liner 23, and is subjected to centrifugal force. A structure is adopted in which the rotor winding is firmly fixed in the slot.

The structure in the slot on the stator side is the same as above.

Incidentally, the prior art of this kind of rotating electric machine includes, for example, Japanese Patent Application Laid-Open Nos. 56-83237 and 57-9.
No. 5162, JP-A-58-182443, JP-A-63-167646, and JP-A-1-34143.
And Japanese Patent Application Laid-Open No. 2-294242.

[0010]

However, the conventional in-slot structure has the following points to be improved.

For example, in a large-capacity induction motor with a long rotating speed, a high voltage, and a long rotor winding, the rotor winding conductor tends to thermally expand in the axial direction due to a rise in temperature during operation. Rotor winding insulation with high surface pressure due to excessive centrifugal force is confined in the slot, so it cannot follow the thermal expansion of the conductor, and excessive shear force acts between the winding insulation and the conductor However, this may cause damage to the insulating layer.

That is, the centrifugal force applied on the winding insulation during the operation of the large-capacity induction motor is strong. On the other hand, the elongated winding undergoes repeated cooling and heating cycles under severe conditions such as frequent start-stop, load fluctuation and high surface pressure (Joule heat is generated by the current flowing through the conductor, The winding repeatedly expands and contracts in accordance with the change in the pressure).

However, during operation, high surface pressure due to centrifugal force is applied to the rotor winding insulation surface, and the friction coefficient of the contact portion of the insulation surface is large, so that the winding insulation restricts the movement inside the slot. As a result, the conductor cannot freely expand following the thermal expansion of the conductor, and excessive thermal stress is generated in the shearing direction at the interface between the insulation and the conductor. This thermal stress increases as the friction coefficient increases.

As the state changes from the operation state to the stop state, the surface pressure due to the centrifugal force decreases, and the restraining force due to friction also decreases. Accordingly, the thermal stress gradually releases and decreases. When repeatedly subjected to a thermal cycle under such conditions over a long period of time, the insulating layer and the conductor bonding surface peel off, and the insulating layer also peels off, causing an excessive internal discharge in the gap, and finally, This will cause dielectric breakdown.

As a countermeasure against the thermal elongation as described above, a method of reducing the coefficient of friction by directly applying a lubricating paint to the sliding portion on the surface of the winding insulating material has been adopted. However, the surface temperature of the winding insulating material during operation increases due to the Joule heat of the internal conductor, and the friction coefficient of the lubricating paint tends to increase as shown in FIG. The thermal expansion of the winding insulating material was restricted, and the winding insulating material could not slide sufficiently in the slot.

[0016] The above problem is most problematic particularly where a high surface pressure is applied to the rotor windings by the action of the rotating centrifugal force. There are places where the surface pressure increases due to the pressing force, and a similar problem may occur with respect to shrinkage due to the temperature drop of the winding at this time. The same can be said of the slot structure on the stator side in addition to the winding type rotor, although the degree of difference is different.

This is because, even on the stator side winding, since the winding fixed in the slot of the stator is fixed by the wedge, the force of the wedge acts on the winding and the surface pressure acting on the winding is reduced. This is because it may be higher.

An object of the present invention is to pay attention to the above problems, and to alleviate the thermal stress acting between the windings and the insulation generated during the cooling / heating cycle of the rotor windings and the stator windings, and to provide insulation over time. An object of the present invention is to provide a rotating electric machine having high reliability by preventing peeling and damage of parts.

[0019]

In order to achieve the above object, the present invention basically proposes the following means for solving the problems.

That is, a winding in which the periphery of a conductor is covered with an insulating material in a slot provided in a circumferential direction of a core of the rotating electric machine (the core may be a rotor core or a stator core). In a rotating electrical machine in which a winding is fixed in a slot by mounting a wedge on the upper part of the slot, a pair of heat insulating members are applied to a portion of the winding insulating material in the slot where high surface pressure is applied. Are placed facing each other,
One of the heat insulating members is adhered to the winding insulating material to be a movable side that moves in the axial direction following thermal expansion and contraction due to temperature drop of the winding, and the other is fixed to the core to be a fixed side. A sliding member having a small friction coefficient is interposed between the side heat insulating member and the fixed side heat insulating member.

For example, in the case of a rotor winding, this high surface pressure is applied particularly between the wedge and the winding which is the outer diameter portion of the slot due to centrifugal force during operation. When the operation is stopped, the surface pressure is applied between the wedge and the winding as well as between the slot bottom and the winding by the pressing force of the wedge, although the degree is smaller than the above-mentioned rotational centrifugal force (in the case of the stator winding). In addition, due to the pressing force of the wedge, a surface pressure is applied between the wedge and the winding, as well as between the bottom of the slot and the winding.)

In any case, the pair of heat insulating members and the sliding member interposed therebetween may be provided at appropriate positions in accordance with the degree to which high surface pressure is applied.

[0023]

For example, in the case of a winding type rotor, as described above, centrifugal force acts on the winding by rotating at high speed,
In particular, a high surface pressure is applied between the wedge and the winding.

In this state, even when Joule heat is generated in the conductor and expansion (thermal expansion) and contraction of the winding are repeated in accordance with the change in the generated heat, one of the pair of heat insulating members is used. (Movable-side heat-insulating member) is adhered on the insulating material of the winding, and the other (fixed-side heat-insulating member) is fixed to the core side,
In addition, since a sliding member having a small friction coefficient is interposed between these heat insulating members, the winding insulating material serves as a fixed side heat insulating member together with the movable side heat insulating member adhered to the winding side due to thermal expansion and contraction of the conductor. Smoothly slide (relative movement).

Further, since the sliding member is interposed between the heat insulating members, the presence of these heat insulating members suppresses the heat generated from the winding from being conducted from the surroundings to the sliding member side. In addition, it is possible to prevent the friction coefficient of the sliding member from increasing due to heat. Therefore, the thermal expansion of the entire winding due to the above-mentioned sliding is guaranteed, and even if the cooling and heating cycle is repeated, the winding insulating material follows the thermal expansion and contraction of the conductor, and excessive thermal stress is applied to the winding insulation. And maintain the integrity of the windings.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a sectional structure in a slot of a wound rotor according to a first embodiment of the present invention.

In FIG. 1, rotor windings 3 are inserted into slots 2 arranged in the circumferential direction of a rotor core 1 in which electromagnetic steel sheets are laminated in a cylindrical shape, and wedges 21 are inserted into dovetails 24 above the slots 2. Is installed.

The wedge 21 has heat insulating members 4a, 4b with sliding members 5a, 5b to be described later in addition to the windings 3 in the slots 2.
Is inserted into the dovetail 24 machined on the outer diameter portion of the slot from the axial direction of the rotor. The rotor winding 3 is firmly fixed in the slot 2 by the wedge 21. The rotor winding 3 is formed by winding an insulating material 3b mainly composed of mica having excellent withstand voltage and compression resistance around a conductor 3a formed by bonding a plurality of strands.

A pair of heat insulating members 4a and 4b facing each other are arranged between the wedge 21 and the winding 3 of the slot 2. As the heat insulating members 4a and 4b, an FRP made of a glass base material is desirable from both sides of mechanical strength and thermal conductivity. Glass substrate FRP
In general, the heat conductivity of mica, which is the main insulation of the rotor winding, is almost equal to that of the mica, which shows good heat insulation properties. It can be lowered to a temperature rise.

Of the heat insulating members 4a and 4b, the heat insulating member 4a is bonded to the outer surface of the winding 3 (the surface of the insulating material 3b) to form a movable heat insulating member.
Move following the thermal expansion in the longitudinal direction.

For bonding the heat insulating member 4a and the winding 3,
A semi-cured insulating material 6 made of a nonwoven fabric as a part of the base material and impregnated with a thermosetting adhesive is desirable in order to fill the irregularities on the surface of the insulating layer and prevent one-sided contact at high surface pressure during rotation. Under high surface pressure generated by the centrifugal force of high-speed rotation, if the contact between the surface of the insulating layer and the heat-insulating member has a partial contact,
A portion of the surface of the insulating layer that receives a local pressure is generated, and the insulating layer that cannot withstand the surface pressure is crushed and mechanically damaged, and furthermore, causes electrical breakdown. Since the heat insulating member 4a moves following the thermal expansion of the winding 3 in the axial direction, a long heat insulating member has a difference in thermal expansion coefficient due to a difference in thermal expansion coefficient.
Since an excessive shear force acts between the insulating layer and the heat insulating member and breaks at the bonding surface, it is preferable that the length is short.

On the other hand, the heat insulating member 4b is fixed to the core side by a stopper using an air duct or the like of the rotor core 1 so as not to move in the longitudinal direction, thereby forming a fixed side heat insulating member.

Between the heat insulating members 4a and 4b, sliding members 5a and 5b having a small coefficient of friction for smoothing relative movement (sliding) between the heat insulating members are interposed. The sliding members 5a and 5b are made of, for example, aramid papers 5a and 5b having excellent abrasion resistance, the surfaces of which are smoothed (so-called calendering) by a heat roll. 4b is attached to each opposing surface (sliding surface) over the entire length.

The sliding surface of the aramid paper is coated with an ethylene tetrafluoride paint which is often used as a lubricating material for lowering the friction coefficient.

According to the present embodiment, a centrifugal force acts on the winding 3 due to the high speed rotation of the winding type rotor.
-High surface pressure is applied between the windings 3. In this state, even when Joule heat is generated in the conductor 3a and the winding 3 repeats expansion (thermal expansion) and contraction in accordance with a change in the generated heat, one of the pair of heat insulating members 4a is formed. Are bonded on the winding insulating material 3b, the other 4b is fixed to the core 1 (slot 2) side, and sliding members 5a, 5b having a small friction coefficient are interposed between the heat insulating members 4a, 4b. As a result, the winding insulating material 3b moves smoothly with the heat insulating member 4a relative to the other heat insulating member 4b, following the thermal expansion and contraction of the conductor 3a due to temperature drop.

Further, the heat insulation members 4a and 4b suppress the heat generated from the winding 3 from being transmitted from the surroundings to the sliding members 5a and 5b, lower the temperature of the sliding portion from the surface of the winding insulating surface, and reduce the friction coefficient. Prevent rise.

That is, generally, a lubricating material (sliding member)
Shows a favorable low coefficient of friction at room temperature, but as the temperature increases, the coefficient of friction increases as shown by the characteristic curve in FIG.
During operation, it acts to prevent thermal expansion of the winding in the axial direction.

However, in this embodiment, the heat insulating member 4
a, 4b suppresses conduction of heat from the windings 3, which are heating elements, to the sliding members 5a, 5b, and the heat insulating members 4a, 4b.
4b The surface temperature (sliding surface temperature) is about 1
By setting the temperature rise to / 2, the sliding surfaces 5a and 5b can be maintained in a range of a low coefficient of friction, and can be slid without restricting the thermal expansion of the winding in the slot. In addition, even if a silicone oil is applied to the surface of the aramid paper as a lubricating agent instead of ethylene tetrafluoride, the object can be achieved in substantially the same manner.

FIG. 3 shows a second embodiment of the present invention.

In this embodiment, as in the first embodiment, the portion where the high surface pressure of the winding is applied by the rotational centrifugal force of the rotor, that is, the movable portion bonded to the winding insulating material 3b between the wedge 21 and the winding 3 The fixed side heat insulating member 4b and the sliding members 5a, 5b interposed therebetween are provided in the side heat insulating member 4a and the slot 2, and are further provided in the core slot on both side surfaces and the bottom surface of the winding in the slot 2. In order to adopt a sliding structure, the winding insulation material 3
Two (a pair of) slot liners 7a and 7b are mounted facing each other on the outer circumference of b (the left and right side surfaces and the bottom surface, in other words, between the slot wall surface and the winding facing the slot wall surface). Of these, one slot liner 7a is movably adhered to the surface of the winding insulating material 3b so as to follow the thermal expansion of the winding 3, and the other slot liner 7b is fixed to the slot wall.

As the material of the slot liners 7a and 7b, a semiconductive material based on an aramid-based material is desirable from the viewpoint of abrasion resistance and heat insulation. An ethylene tetrafluoride paint, which is often used as a lubricating paint, is applied to the contact surfaces of both slot liners 7a, 7b to reduce the coefficient of friction.

During operation, the winding is in the direction of centrifugal force (outer direction)
The thermal expansion in the longitudinal direction of the winding at this time is mainly caused by the sliding structure shown in the first embodiment, and the binding force of the winding in the slot 2 is reduced. On the other hand, in the state immediately after the operation is stopped, the wedge 21 exerts a restraining force in the slot inner diameter direction, and the winding contracts as the winding conductor temperature decreases. At this time, the sliding structure 7 in the slot inner diameter direction constituted by the slot liner works effectively without restricting the contraction of the winding. Since the winding temperature gradually decreases, the friction coefficient of the sliding surface coated with the ethylene tetrafluoride paint also decreases, and good sliding characteristics can be obtained. Example 1
Similar effects can be obtained by applying a silicon-based oil to the sliding surface in the same manner as described above.

FIG. 4 shows a third embodiment. In the above-described first embodiment, an example in which aramid paper is used as the sliding member has been described.
In this embodiment, an example is shown in which an elastic body is applied instead of aramid paper.

Silicon rubbers 8a and 8b that have been subjected to lubrication are used as the elastic members. Generally, various materials such as the liner and the winding 2 used inside the slot 2 are initially firmly fixed in the slot by the wedge 21, but gradually deteriorate over time, and the wedge becomes loose. Appears. In order to prevent such loosening of the wedge, the aforementioned heat insulating members 4a, 4a,
By applying an elastic member having slidability between 4b and contracting the elastic members 8a and 8b in advance and inserting them into the slot 2, in addition to the effects already described in the first and second embodiments, The dimensional shrinkage due to aging of the various insulating materials inserted in the slots is absorbed by the reaction force, so that the wedge can be prevented from loosening.

In each of the above embodiments, the heat insulating members 4a and 4b are mounted and slid by applying the rotational centrifugal force of the rotor winding, that is, between the wedge 21 and the winding 3 of the slot outer diameter. Although the structure is adopted, if the same sliding structure as described above is adopted in other places, the thermal stress acting between the conductor of the winding and the winding insulating material can be further reduced.

For example, as described above, when the operation is stopped, although the degree is smaller than the rotational centrifugal force, the pressing force of the wedge 21 causes the gap between the wedge 21 and the winding 3 as well as between the slot bottom and the winding. If the windings are two layers above and below, surface pressure is applied between the windings (the same is true for stator windings).
The sliding structure described above may be used in these places as needed.

FIG. 5 shows an example (fourth embodiment).

In this embodiment, as shown in the figure, a pair of heat insulating members 4c and 4c of the same material are provided not only between the wedge 21 and the winding 3 (enlarged view of part A) but also between the upper and lower two-layer windings. A sliding structure including 4d and sliding members 5c and 5d is adopted.

The sliding structure between the windings includes a pair of heat insulating members 4.
c and 4d are bonded to each other on the insulating material 3b of the upper and lower windings 3 with an adhesive 6, and are disposed to face each other. The coefficient of friction also exists between the heat insulating members 4c and 4d between the two windings. Small sliding members 5c and 5d are interposed.

According to the present embodiment, the binding force of the winding in the slot can be reduced more effectively. In particular,
Immediately after the motor is stopped from the operating state, the centrifugal force becomes zero, but the winding is pressed downward (in the radial direction) by the restraining force of the wedge 21 inside the slot. On the other hand, the winding 3 is in a shrinking process due to the temperature drop of the conductor, and at this time, the sliding structure attached to the lower part of the winding (for example, between the windings) does not restrain the winding insulating surface inside the slot. , Can be shrunk.

Although not shown in FIG. 5, a fixed-side heat insulating member is provided on the slot bottom side and a movable-side heat insulating member adhered to the insulating material on the winding side. However, a sliding member having a small friction coefficient may be interposed between these heat insulating members.

FIG. 6 shows a fifth embodiment. In this embodiment, as an application example of the above-described winding sliding structure, one applied to a rotor winding end portion will be described.

In general, the winding end portions 22a and 22b of the winding type rotor, which have come out of the slots of the rotor core, are bound 23a and 23b in order to prevent deformation due to centrifugal force.
It is firmly fixed to the end ring 26 by the like. Therefore, like the inside of the slot,
High surface pressure is applied. On the other hand, it is necessary to release the thermal expansion by taking the sliding structure even at the winding end portion coming out of the slot, as much as the winding slides in the slot and extends in the axial direction. Therefore, the following structure is applied as an application of the first embodiment.

A movable heat insulating member 40 (FRP made of glass substrate) is bonded to the winding end side with an adhesive 41 on the bottom surface of the winding insulation in the same manner as in the first embodiment. Sliding members 45a, 45 having a small coefficient of friction between the heat insulating member 40 and the end ring 26.
b is interposed.

As the sliding members 45a and 45b, for example, aramid paper is used, and the aramid paper 45a is stuck on the inner diameter surface of the movable heat insulating member 40. The fixed-side aramid paper 25b is bonded to the outermost layer of insulation provided on the end ring 26 over the entire circumference.

Each of the aramid papers 25a and 25b is coated with an ethylene tetrafluoride paint or a silicone oil as a lubricating paint. With this structure, the winding end can be slid at the winding end without restraining the winding insulation surface even under high surface pressure, and the reliability of the winding insulation can be further improved. it can.

Although the above embodiments have been described taking the rotor-side winding as an example, the present invention can also be applied to a stator-side winding.

One example (sixth embodiment) is shown in FIG.

The embodiment shown in FIG. 7 is applied to a rotating electric machine in which the stator windings 3 'are arranged in two upper and lower layers in the slots 31 of the stator core 30. 3 '
In addition to interposing a pair of fixed-side heat-insulating members 4b, movable-side heat-insulating members 4a, and sliding members 5a, 5b, a heat-insulating member 4 having a sliding structure similar to that described above is provided at the slot bottom and winding 3 '.
a, 4b and sliding members 5a, 5b are provided, and between the windings 3 ', 3', heat insulating members 4c, 4d and sliding members 5c, 5d similar to FIG. 5 are provided.

Also in this embodiment, even if a high surface pressure is applied to the stator winding in the slot by the wedge, thermal expansion and contraction due to a change in heat generation of the winding are smoothed, and soundness of the winding insulation is improved. Can be held.

[0062]

According to the winding sliding structure via the heat insulating member of the present invention, the heat generated by the windings of the rotating electric machine is prevented from being transmitted to the sliding member. The effect (phenomenon of increasing the coefficient of friction) is reduced to ensure a good winding slidability, and to prevent the thermal expansion of the conductor without restraining the winding insulation surface under high surface pressure. The winding insulation can follow and slide smoothly in the axial direction, and the thermal stress in the shear direction generated between the winding insulation and the conductor can be reduced to improve the reliability of the winding insulation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part in a rotor winding slot of a rotating electric machine according to a first embodiment of the present invention, and an enlarged sectional view of a part A.

FIG. 2 Temperature characteristics of friction coefficient of lubricating paint

FIG. 3 is a sectional view of a main part in a rotor winding slot of a rotary electric machine according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of an essential part in a rotor winding slot of a rotary electric machine according to a third embodiment of the present invention, and an enlarged cross-sectional view of a part A.

FIG. 5 is a cross-sectional view of a main part, an enlarged cross-sectional view of a part A, and an enlarged cross-sectional view of a part B in a rotor winding slot of a rotary electric machine according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a winding end part according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a main part in a rotor winding slot of a rotary electric machine according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view of the inside of a slot of a conventional wound type rotor.

[Explanation of symbols]

3 ... rotor winding, 3a ... conductor, 3b ... winding insulating material, 3 '
... stator winding, 3a '... conductor, 3b' ... winding insulating material, 4
a: movable heat insulating member, 4b: fixed heat insulating member, 4c, 4
d: movable side heat insulating member, 5a, 5b: sliding member, 6: adhesive, 7a: movable side slot liner, 7b: fixed side slot liner, 8a, 8b: elastic sliding member, 21: wedge,
22a, 22b: winding end portions, 23a, 23b: binding, 26: end ring, 40: heat insulating member, 41: adhesive, 45a, 45b: sliding member.

Continuation of the front page (56) References JP-A-53-85302 (JP, A) JP-A-48-39901 (JP, A) JP-A-48-57101 (JP, A) , U) Fully open sho 53-606 (JP, U) Fully open sho 60-59764 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 3/30-3/52

Claims (9)

(57) [Claims] 1. A winding whose conductor is covered with an insulating material is inserted into a slot provided in a circumferential direction of a core of a rotating electrical machine, and a wedge is mounted on an upper portion of the slot to insert a winding. In a rotating electric machine having fixed windings, a pair of heat insulating members are disposed at locations where high surface pressure is applied on the winding insulating material in the slots so as to face in a direction in which the surface pressure is applied, and one of the heat insulating members is disposed. The movable side is fixed to the core by fixing it to the movable side, which is adhered to the winding insulation and moves in the axial direction following the thermal expansion and contraction due to temperature drop of the winding. A rotating electric machine comprising a sliding member having a small coefficient of friction interposed between members. 2. The rotating electric machine according to claim 1, wherein the pair of heat insulating members and a sliding member interposed therebetween are provided in one or both slots of a rotor core and a stator core. 3. The rotation according to claim 1, wherein the pair of heat insulating members and the sliding member interposed therebetween are provided at least between the wedge and the winding in the slot. Electric machine. 4. The pair of heat insulating members according to claim 1, wherein the pair of heat insulating members and a sliding member interposed therebetween are provided between the wedge and the winding and between the winding and the slot bottom, respectively. A rotating electric machine characterized by the above-mentioned. 5. The method according to claim 1, wherein upper and lower two-layer windings are inserted into the slots,
The pair of heat insulating members and a sliding member interposed therebetween,
A pair of heat insulating members are provided between the wedge and the winding and between the winding and the bottom of the slot, respectively, and a pair of heat insulating members are adhered on the insulating material of the upper and lower windings between the upper and lower windings. A rotating member having a small coefficient of friction interposed between heat insulating members between the two layers of windings. 6. The rotor according to claim 1, wherein a winding end portion of the rotor core that has come out of the slot is fixed on the end ring by binding.
A heat insulating member bonded to the winding end portion interposed between the winding end portion and the end ring, and a sliding member having a small friction coefficient interposed between the heat insulating member and the end ring. Electric machine. 7. The slot according to claim 1, wherein a slot wall surface and a slot wall face each other in the slot in which the pair of heat insulating members and the sliding member interposed therebetween are provided. A pair of slot liners are provided between the winding and the winding, and one of the slot liners is movably adhered to the insulating material of the winding following the thermal expansion of the winding, and the other slot liner is provided. A rotating electric machine, wherein a liner is fixed to the inner wall of the slot. 8. The heat insulating member according to claim 1, wherein the heat insulating member is made of a glass-based FRP, and the sliding member is provided on its surface with a tetrafluoroethylene-based paint or a silicon-based oil. A rotating electric machine comprising an aramid paper coated with a lubricant as a lubricating material. 9. The rotating electric machine according to claim 1, wherein the sliding member has elasticity.