JP2002191149A - Rotating electric machine - Google Patents

Abstract

(57) [Summary] A rotating electric machine such as a generator or an electric motor capable of efficiently transferring heat between a stator winding and a frame, efficiently cooling the same, and improving output and reducing size and weight. I will provide a. A rotor provided with a permanent magnet, a stator core disposed around the rotor and fitted inside a frame, and a stator winding wound around the stator core. A rotating electric machine G provided with the wire 3 is connected between the coil ends 3 a and 3 b of the stator winding 3 and the frame 1 by a heat conductive insulator 10.
a and 10b are filled and fixed.
Each of a and 10b is formed of a thermosetting resin mixed with a ceramic powder.

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 such as a generator or a motor having a rotor having a permanent magnet attached to a rotating shaft, and to efficiently conduct heat generated in a stator winding to a frame. The present invention relates to a rotating electric machine having good cooling performance.

[0002]

2. Description of the Related Art Conventionally, a rotating electric machine such as a generator or an electric motor having a rotor with a permanent magnet attached to a rotating shaft can obtain a high output with a simple structure, and is therefore often used for an engine or industrial equipment. In order to cope with restrictions such as control performance and mounting space, higher output, smaller size and lighter weight, and hermetically sealed structure have been advanced.

[0003] However, when such a high output, a small size and light weight, and a hermetically sealed structure are performed, the amount of heat generated per unit volume increases, and the temperature rise increases.

That is, when the power generation output and the output torque increase, the amount of heat generated in the stator winding increases, and the stator (stator) temperature increases, even if the efficiency is the same. Then, heat moves from the stator side to the rotor (rotor) side by radiation or the like, and the temperature of the rotor increases. Since the magnetic force of the permanent magnet on the rotor side decreases due to the temperature increase, the output also decreases accordingly.

This decrease in output is caused by the decrease in the magnetic force of the permanent magnet.
For example, if the temperature rises to about 120 ° C, normal temperature (20 ° C)
It will be 10% lower than the time.

Therefore, it is necessary to efficiently transfer the heat generated in the stator windings to the frame for cooling. For this purpose, the frame is provided with cooling fins, or the frame is provided with a cooling water or cooling oil through which cooling water flows. A jacket is provided.

In the conventional rotating electric machine shown in FIG. 6, a stator core 2 is fitted and fixed to a frame 1, and a stator winding 3 is wound around a slot (not shown) of the stator core 2. . The rotor 7 is disposed around the rotation shaft 6, and the rotation shaft 6 is connected to the brackets 4 a and 4 b at both ends of the frame 1.
Are rotatably supported by bearings 5a and 5b provided at the center. And the coil ends 3a, 3 of the stator winding 3
b and the inner peripheral surface of the frame 1
0a and 10b are filled and fixed.

The coil ends 3a, 3b and the inner peripheral surface of the frame 1 are located between the coil ends 3a, 3b.
3b is formed by winding a large number of copper wires, so that the surface has an uneven shape. Therefore, in a configuration in which an annular object is fitted as it is, the contact with the coil ends 3a and 3b becomes insufficient and sufficient heat conduction is performed. Can not get.

A pulley P is attached to one end of the rotating shaft 6 and is connected to an engine or the like via a belt V so as to be capable of transmitting power.

In this configuration, a part of the heat generated in the stator winding 3 is transferred from the coil ends 3a and 3b to the frame 1 via the high heat conductive resins 10a and 10b, and is transferred to the frame 1. From the cooling fins 9 and the rest
In the slot provided in the stator core 2, the stator core 2
The heat is transferred to the frame 1 via the cooling fins 9 of the frame 1 and radiated.

Since the rotating electric machine shown in FIG. 6 is of an air-cooling type, heat is radiated from the cooling fins 9.
A liquid cooling jacket is provided in the frame 1 and is cooled by water or oil flowing in the liquid cooling jacket.

[0012]

However, when a resin having high thermal conductivity is provided between the frame and the coil end as in the rotating electric machine of FIG. 6, the resin having high thermal conductivity is generally formed by molding. Although epoxy resin of thermosetting resin is adopted for ease of use, the epoxy resin itself has low thermal conductivity although it is a high thermal conductive resin, so its heat transfer efficiency is poor, heat transfer is insufficient, and cooling efficiency is low. There is a problem of bad.

Further, in a generator, a current is generated in a stator winding, and in a motor, it is indispensable to insulate between the stator winding and a frame in order to allow a current to flow. If a metal powder such as aluminum is mixed into the resin to improve the heat conductivity, a problem occurs in the insulating property.

In general, synthetic resin has a coefficient of thermal expansion that is several to nearly ten times larger than that of metal. Repeated deformation causes thermal stress during expansion and creates a gap between the frame and the coil end during contraction. Therefore, there is a problem that the resin portion is damaged or peels off from the frame or the coil end.

Further, in the stator winding, the copper wire is fixed by inserting an insulating varnish in the gap and wrapped with insulating paper, so that the heat generated by the copper wire is passed through the insulating varnish and the insulating paper. The heat is transferred to the cooling fins of the frame. for that reason,
There is also a problem that heat transfer from the copper wire is restricted by insulating varnish, insulating paper or the like having low thermal conductivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to efficiently transfer heat between a stator winding and a frame so that cooling can be performed efficiently. Another object of the present invention is to provide a rotating electric machine such as a generator or an electric motor capable of improving output and reducing size and weight.

[0017]

A rotating electric machine such as a generator or a motor for achieving the above object is constituted as follows.

1) A rotor having a permanent magnet, a stator core disposed around the rotor and fitted inside the frame, and a rotor having a stator winding wound around the stator core. In the electric machine, a heat conductive insulator is filled and fixed between the coil end of the stator winding and the frame, and the heat conductive insulator is formed of a thermosetting resin mixed with ceramic powder. .

By filling a heat conductive insulator formed of a thermosetting resin mixed with ceramic powder between the coil end and the frame (housing), high heat conductivity and high insulation can be obtained. It is possible to secure the thermal expansion coefficient close to a value close to that of a metal.

As a result, the heat generated from the stator windings can be transferred from the coil ends to the frame through the heat conductive insulator, and can be cooled.
It is possible to prevent the temperature of the permanent magnet of the rotor from rising and maintain the magnetic force of the permanent magnet.

In addition, since the insulating property of the heat conductive insulator can be enhanced, the thickness of the heat conductive insulator can be reduced, and a structure in which heat is easily transferred from the coil end to the frame can be obtained.

Furthermore, since the coefficient of thermal expansion of the heat conductive insulator can be made close to the value close to the coefficient of thermal expansion of the coil end and the frame, the thermal stress caused by the thermal deformation of the heat conductive insulator can be reduced. The generation of a gap between the coil end and the frame can be prevented.

2) Alternatively, a rotor having a permanent magnet, a stator core disposed around the rotor and fitted inside the frame, and a stator winding wound around the stator core are provided. In the rotating electric machine, a heat conductive insulator is filled and fixed between the coil end of the stator winding and the frame, and the heat conductive insulator is mixed with a liquid silicone in a ceramic powder to be cured into a rubber shape. Formed.

According to this configuration, the same function and effect as the above-described configuration in which the heat conductive insulator is formed of a thermosetting resin mixed with ceramic powder can be obtained.

3) Alternatively, a rotating electric machine for achieving the above object includes a rotor having a permanent magnet, a stator core disposed around the rotor and fitted inside a frame, and In a rotating electric machine having a stator winding wound around a child core, a wire of the stator winding is fixed with an adhesive fixing agent formed of a thermosetting resin mixed with ceramic powder.

According to this configuration, the portion conventionally fixed with the insulating varnish can be replaced with the thermosetting resin mixed with the ceramic powder, so that the heat conductivity of this portion is increased to generate the stator winding. Heat can be efficiently transferred not only to the coil end but also to the frame.

4) A structure in which the wire of the stator winding is fixed with a thermosetting resin mixed with ceramic powder, and heat conduction between the coil end of the stator winding and the frame. The cooling efficiency can be further improved by combining with a configuration in which the insulator is filled and fixed, and a configuration in which the heat conductive insulator is fixed with an adhesive fixing agent formed of a thermosetting resin mixed with ceramic powder.

5) In the above rotating electric machine, the ceramic powder forming the heat conductive insulator is formed of aluminum oxide, and the thermosetting resin forming the heat conductive insulator is formed of epoxy resin. It is formed of a resin or a polyimide resin.

As the ceramic powder, besides aluminum oxide (alumina: Al ₂ O ₃ ), beryllium oxide (BeO), magnesium oxide (magnesia: Mg)
O), titanium dioxide (TiO ₂ ), aluminum nitride (AlN), silicon dioxide (silica: SiO ₂ ), trisilicon tetranitride (Si ₃ N ₄ ), boron nitride (BN), and the like.

As the thermosetting resin, epoxy resin (EP), phenol resin (PF), polyimide (P)
I), unsaturated polyester (UP), vinyl ester resin (VE) and the like can be used, but it is preferable to use epoxy resin (EP), phenol resin (PF) and polyimide (PI).

That is, by selecting these generally commercially available materials, it is possible to obtain a strong adhesive force by epoxy resin or the like while easily ensuring good heat conduction properties, electrical insulation properties, and ease of molding. In addition, a cooling structure and the like for the coil end portion of the rotating electric machine can be manufactured by a simple operation at a low cost.

Further, in the above rotating electric machine, the mixing ratio of the ceramic powder and the thermosetting resin forming the heat conductive insulator is 30% to 60% by volume of the ceramic powder. .

If the proportion of the ceramic powder is less than 30%, it is difficult to obtain good heat transfer characteristics.
If it is more than 60%, it becomes difficult to secure fluidity or strong adhesive strength during molding.

Further, by setting the size of the ceramic powder forming the heat conductive insulator to 5 μm to 50 μm, the heat transfer between the coil end and the frame can be maintained while maintaining good heat transfer characteristics and good insulation. Ease of forming the conductive insulator can be ensured.

If the size of the ceramic powder is smaller than 5 μm, there is a problem of cost and troublesome handling, and if it is larger than 50 μm, it becomes difficult to secure fluidity during molding.

[0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a rotating electric machine according to an embodiment of the present invention. Here, a permanent magnet type generator will be described as an example.

FIG. 1 is a side sectional view showing a configuration of a permanent magnet generator according to an embodiment of the present invention, and FIGS. 2 and 3 are enlarged side sectional views of a coil end portion. FIG. 4 is a sectional view showing a configuration of a rotor and a stator of the generator, and FIG. 5 is an enlarged sectional view of a stator winding portion.

As shown in FIGS. 1 to 5, the generator G includes a bearing support 4 a fixed to a frame (housing) 1.
A rotating shaft 6 on which a rotor 7 is disposed is pivotally supported by bearings 5a and 5b provided on the 4b. On the outer periphery of the rotor 7, a stator core 2 fixed to the frame 1 side, And a stator winding 3 wound around a slot 23 of the stator core 2.

A pulley P is attached to one end of the rotating shaft 6 in the same manner as a conventional one, and is connected to an engine or the like via a belt V so as to be able to transmit.

As shown in FIG. 4, the rotor 7 has a permanent magnet 71 fixed to the rotating shaft 6, and a permanent magnet 7 is provided on the outer periphery of a back yoke 72 provided integrally with the rotating shaft 6.
1 are arranged and formed. The permanent magnet 71 is formed by laminating magnet pieces that have been magnetized for each single pole and assembling them into multiple poles in order to secure the required output. The two ends are sandwiched by a pair of plates 8a and 8b having a disc spring effect, and are fixed to the back yoke 72. Also, in order to prevent the permanent magnet 71 from being broken by centrifugal force during rotation,
SUS or CFRP over the entire outer periphery of the permanent magnet 71
A sleeve 73 made of a non-magnetic material (carbon fiber reinforced plastic) is provided.

On the other hand, the fixed core 2 includes a ring portion 21 fixed to the frame 1 and tooth portions 22 extending inward in the radial direction at intervals in the circumferential direction of the ring portion 21.
A slot 23 is formed between the teeth 22.

The stator winding 3 is wound through the slot 23, and the stator winding 3 is, as shown in FIGS. 4 and 5, a copper wire (wire material) through which electricity flows. ) 31 is fixed with an adhesive fixing agent 32 formed of a thermosetting resin mixed with a ceramic powder, and the periphery thereof is wrapped with insulating paper 33 to be formed.

The coil ends 3a, 3b are, as shown in FIGS.
outer peripheral sleeve 1 for fixedly supporting the outer periphery of stator core 2 and stator core 2
The heat conductive insulators 10a and 10b are arranged between the first and second heat conductive insulators.

The adhesive 32 and the heat conductive insulator 10
a, 10b is a ceramic powder formed of aluminum oxide (alumina) having a size of 5 μm to 50 μm, and the ceramic powder has a volume percentage of 30% to 30% of the whole.
It is formed of a thermosetting resin mixed with an epoxy resin, a phenol resin or a polyimide resin so as to be 60%.

That is, the resin in which the ceramic powder is mixed is poured in a syrup state around the copper wire 31 wrapped in the insulating paper 33, and after filling is completed, the resin is heated, polymerized, and cured, thereby forming the stator. The winding 3 is formed.

The resin in which the ceramic powder is mixed is poured in a syrup state between the coil ends 3a and 3b and the outer peripheral sleeve 11, and after the filling is completed, the resin is heated and hardened, so that the heat conductive insulator 10a , 10b.

Alternatively, the ceramic powder is mixed with the liquid silicone and cured into a rubber-like state, so that the heat conductive insulator 10a,
Form 10b.

With this configuration, the heat generated in the copper wire 31 is transferred from the heat conductive insulating resins 10a and 10b to the outer peripheral sleeve 11, and the cooling liquid L composed of cooling water or cooling oil is used.
Heat is transferred to. In the heat transfer path of the coil ends 3a and 3b, heat transfer of about 70 to 80% of the generated heat can be performed.

The coolant passage 12 is surrounded by a passage wall 13 around the outer peripheral sleeve 11 on the side of the frame 1 and is divided by a partition wall 14 helically circling around the outer peripheral sleeve 11. The cooling liquid L is supplied to the liquid inlet 12
A is circulated from the liquid outlet 12b to the liquid outlet 12b, and the heat transferred to the outer peripheral sleeve 11 is taken away.

In the case of the air cooling type, the outer peripheral sleeve serves as a frame, and is cooled by cooling fins provided on the frame.

According to the above configuration, the coil ends 3a,
3b and a frame (housing) 1 and a heat conductive insulator 1 formed of a thermosetting resin mixed with ceramic powder.
0a, 10b, the stator windings 3 are connected via the heat conductive insulators 10a, 10b having high heat conductivity.
Can be transferred to the frame 1 and the stator windings 3 can be efficiently cooled.

Further, since the insulating properties of the heat conductive insulators 10a and 10b can be enhanced by mixing the ceramic powder, the thickness of the heat conductive insulators 10a and 10b can be reduced, and the coil ends 3a and 3b can be further removed from the frame 1 Can be easily transferred to the outer peripheral sleeve 11.

The heat conductive insulators 10a and 10b
Has a coefficient of thermal expansion close to the coefficient of thermal expansion of the metal forming the coil ends 3a and 3b and the frame 1 due to the mixing of the ceramic powder.
The thermal stress generated by the thermal deformation of is reduced, and breakage can be prevented. Further, it is possible to avoid the generation of gaps between the heat conductive insulators 10a and 10b and the coil ends 3a and 3b and the frame 1.

In the stator winding 3, instead of the insulating varnish used in the prior art, a bundle of copper wires 31 is fixed with an adhesive 32 formed of a thermosetting resin mixed with ceramic powder. Therefore, the heat generated in the copper wire 31 can be efficiently transferred to the sleeve 11 on the frame 1 side, and the sleeve 11 can be cooled by the cooling liquid L flowing on the outer peripheral side.

[0055]

As described above, according to the rotating electric machine according to the present invention, the following effects can be obtained.

First, a heat conductive insulator to be filled and fixed between the coil end of the stator winding and the frame (housing) is formed of a thermosetting resin mixed with ceramic powder, or the ceramic powder is mixed with liquid silicone. Since it is formed by mixing and curing into a rubber state, it can have both high thermal conductivity and high insulation.

Therefore, heat generated in the stator winding can be transferred from the coil end to the frame via the heat conductive insulator to cool the stator winding efficiently, so that the permanent It can prevent the temperature of the magnet from rising, maintain the magnetic force of the permanent magnet, and exhibit high output.

Further, by fixing the wire of the stator winding with a thermosetting resin mixed with ceramic powder, a portion conventionally fixed with insulating varnish is replaced with a thermosetting resin mixed with ceramic powder. The heat conductivity of this portion can be increased, and the heat generated by the stator winding can be efficiently transferred to the frame.

By combining both of the above structures, the cooling efficiency can be further improved.

Further, in the above rotating electric machine, alumina powder or silica powder is used as the ceramic powder.
By selecting an epoxy resin, a phenol resin, or a polyimide resin as the thermosetting resin, it is possible to obtain a strong adhesive force while securing good heat conduction properties, electrical insulation properties, and ease of molding.

By setting the ratio of the ceramic powder in the range of 30% to 60% of the entire heat conductive insulator,
In addition to enhancing the heat transfer characteristics and insulating properties of the heat conductive insulator, fluidity during molding can be secured, and easiness of filling work between the coil end and the frame can be secured.

The ceramic powder is 5 μm to 50 μm
In this range, it is possible to achieve both workability and fluidity during molding while suppressing an increase in cost.

Accordingly, a remarkable effect of reducing the temperature of the stator windings can be obtained even with a closed structure, so that a permanent magnet type rotating electric machine which can exhibit high output can be obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view showing a coil end portion on the upper right side of FIG. 1;

FIG. 3 is a partially enlarged view showing a coil end portion on an upper left side of FIG. 1;

FIG. 4 is a schematic sectional view showing a configuration of a rotor and a stator of the rotary electric machine according to the embodiment of the present invention.

FIG. 5 is a partially enlarged view showing a portion of a stator winding of FIG. 4;

FIG. 6 is a configuration diagram of a conventional rotating electric machine.

[Explanation of symbols]

 G rotating electric machine 1 frame 2 stator core 3 stator winding 3a, 3b coil end 7 rotor 10a, 10b heat conductive insulator 31 wire rod 32 adhesive fixing agent 71 permanent magnet

Continuing from the front page (72) Inventor, Misao Goto No.8, Tsuchiya, Fujisawa-shi, Kanagawa F-term in Isuzu Ceramics Research Institute Co., Ltd. (Reference) 5H603 AA11 AA13 BB02 BB09 BB12 CA01 CA05 CB02 CB03 CC05 CC17 CD21 CE13 FA11 FA21 FA23 FA24 FA25 FA26 FA30 5H609 BB04 BB13 BB19 PP02 PP05 PP06 PP08 PP09 QQ02 QQ04 QQ05 QQ13 QQ18 QQ23 RR27 RR37 RR38 RR42 RR63 RR67 RR73 RR74 5H621 BB07 HH01 JK07 JK11 JK15

Claims (8)

[Claims] 1. A rotor having a permanent magnet, a stator core disposed around the rotor and fitted inside a frame, and a rotor having a stator winding wound around the stator core. In the electric machine, a heat conductive insulator is filled and fixed between the coil end of the stator winding and the frame, and the heat conductive insulator is formed of a thermosetting resin mixed with ceramic powder. Rotating electric machine. 2. A rotor having a permanent magnet, a stator core disposed around the rotor and fitted inside a frame, and a rotor having a stator winding wound on the stator core. In an electric machine, a heat conductive insulator is filled and fixed between a coil end of the stator winding and the frame, and the heat conductive insulator is formed by mixing ceramic powder with liquid silicone and hardening into a rubber shape. A rotating electric machine characterized by: 3. A rotor having a permanent magnet, a stator core disposed around the rotor and fitted inside a frame, and a rotor having a stator winding wound around the stator core. A rotating electric machine wherein the wire of the stator winding is fixed with an adhesive fixing agent formed of a thermosetting resin mixed with ceramic powder. 4. The rotating electric machine according to claim 1, wherein the wire of the stator winding is fixed with an adhesive fixing agent formed of a thermosetting resin mixed with ceramic powder. 5. The rotating electric machine according to claim 1, wherein the ceramic powder forming the heat conductive insulator is formed of aluminum oxide. 6. The method according to claim 1, wherein the thermosetting resin forming the heat conductive insulator is formed of an epoxy resin or a polyimide resin.
The rotating electric machine according to the item. 7. The mixing ratio of the ceramic powder and the thermosetting resin forming the heat conductive insulator is 30% to 6% by volume of the ceramic powder.
7. The method according to claim 1, wherein the value is 0%.
The rotating electric machine according to any one of the above. 8. The generator according to claim 1, wherein the size of the ceramic powder forming the heat conductive insulator is 5 μm to 50 μm.