JPH10229653A - Ventilation cooling structure of dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling within a gap between the inside periphery face of the stator of a dynamo-electric machine and the outside peripheral face of the rotor. SOLUTION: A plurality of ventilation grooves 20 extending axially are made at the inside peripheral face of a stator 5. This ventilation groove 20 is skew along the rotational direction of the rotor when viewed from the inflow direction of air, and further a flank 20b of the groove is inclined in the rotational direction of the rotor 4, to a direction of going to wards the outside peripheral side from the center of the rotor 4. Therefore, it becomes easy for the turning air current in the circumferential direction accompanying the rotation of the rotor 4 to enter the ventilation grove 20, and it is discharged after circulating along this ventilation groove 20, and the cooling of the gap 8 becomes proper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation cooling structure for a rotating electric machine, and more particularly to a structure for discharging air in a gap between an outer peripheral surface of a rotor and an inner peripheral surface of a stator in an axial direction. It is designed to reduce the ventilation resistance against the cooling air flowing along and to achieve good cooling. The present invention is particularly suitable for being applied to an ultrahigh-speed rotating electric machine.

[0002]

2. Description of the Related Art An example of a conventional rotating electric machine will be described with reference to FIG. As shown in FIG. 1, the rotating shaft 1 is rotatably supported by a bracket 3 via a bearing 2, and the rotating shaft 1 is provided with a rotor 4. Stator core 5
a and a stator coil 5b
It is fixed to.

[0003] An air passage 7 extending in the axial direction is formed on the outer periphery of the stator core 5 a along a contact portion with the frame 6. A cylindrical gap 8 is formed between the outer peripheral surface of the rotor 4 and the inner peripheral surface of the stator 5. Further, one of the brackets 3 (the left side in the figure) has an inlet 9a.
Is formed, and an outlet 9b is formed in the other bracket 3 (right side in the figure).

Although not shown, a cooling fan fixed to a rotating shaft and rotating with the rotating shaft is provided.

[0005] In the rotating electric machine having the above-described structure, the rotating shaft 1 is rotated by operation to rotate the cooling fan, so that external air is taken into the inside from the inlet 9a. Part of the air taken in flows along the end of the stator coil 5b on one end (left side), passes through the ventilation path 7, and then ends on the end of the stator coil 5b on the other end (right side). And finally discharged from the outlet 9b. The remaining portion of the air taken in flows in the gap 8 in the axial direction, and is discharged from the outlet 9b. In this way, by cooling air by flowing air in the axial direction inside, it is possible to suppress a temperature rise due to a loss during operation of the rotating electric machine, and to suppress the temperature of each part to an appropriate temperature level or less. it can.

Incidentally, in order to improve the cooling effect, FIG.
As shown in FIG. 1, there is a conventional technique in which a ventilation groove 10 extending in the axial direction is formed in the inner peripheral surface of the stator core 5a in parallel with the axis, and the groove has a rectangular cross-sectional shape. The conventional ventilation groove 10 is not skewed in the rotation direction and does not have a slanted groove cross-section unlike the later-described present invention.

[0007]

However, in the above-mentioned prior art, there is a problem that the air temperature in the gap 8 becomes extremely high and the cooling efficiency is reduced. The reason why the air temperature in the gap 8 becomes very high is as follows.

(1) The ventilation section of the gap 8 is narrower than the ventilation sections of the other ventilation sections. (2) Since the rotor 4 rotating at a high speed is provided on the inner diameter side of the gap 8, the circumferentially strong swirling airflow accompanying the rotation of the rotor 4 impedes the axial air flow in the gap 8. Will be done. This phenomenon becomes remarkable especially in the case of an ultrahigh-speed rotating electric machine. (3) Large heat generation (loss) occurs due to friction generated between the surface (outer peripheral surface) of the rotor 4 rotating at an extremely high speed and air.

In the prior art shown in FIG.
The air flowing in the axial direction through 0 is easily affected by the swirling airflow in the circumferential direction accompanying the rotation of the rotor 4, and the airflow resistance is not about the gap 8 but considerably increases the ventilation resistance. Therefore, in order to prevent this, as shown in FIG. 7, a wedge 11 or the like is arranged on the groove gap surface to completely close the ventilation groove 10 and make the ventilation groove 10 a completely independent ventilation groove (tunnel-shaped ventilation hole). However, in this case, there is a drawback in that although it is useful for cooling the stator 5, it is not useful for discharging air in the gap 8.

The present invention has been made in view of the above-mentioned prior art, and makes it easier for high-temperature air in a cylindrical gap to flow into a ventilation groove opened in the cylindrical gap and does not increase the ventilation resistance of the ventilation groove (ie, ideally. , The ventilation resistance in the ventilation groove during operation is the same as the resistance in the ventilation groove when the rotation speed is zero.)
It is an object of the present invention to provide a ventilation cooling structure for a rotating electric machine as described above.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the construction of the present invention is to distribute air along the axial direction in a cylindrical gap between the outer peripheral surface of the rotor and the inner peripheral surface of the stator. In a rotating electric machine that performs cooling by cooling, a plurality of ventilation grooves extending in the axial direction are formed on the inner peripheral surface of the stator, and each ventilation groove is skewed in the rotation direction of the rotor when viewed from the air inflow side. It is characterized by making it.

Further, the present invention provides a rotating electric machine which cools by flowing air along an axial direction in a cylindrical gap between an outer peripheral surface of a rotor and an inner peripheral surface of a stator. A plurality of ventilation grooves extending in the axial direction are formed on the inner peripheral surface of the child, and each ventilation groove is skewed in the rotation direction of the rotor when viewed from the air inflow side. The radially extending side surface is inclined in the direction of rotation of the rotor with respect to the direction from the center of the rotor toward the outer periphery.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. The same parts as those in the related art are denoted by the same reference numerals, and overlapping description will be omitted.

FIGS. 1 to 4 show a stator 5 of the rotating electric machine according to the embodiment of the present invention. As shown in FIG. 1, in the present embodiment, a plurality of ventilation grooves 20 extending in the axial direction (in FIG.
(Only the book is shown). Moreover, the ventilation groove 20
Are skewed by an angle θ along the rotation direction of the rotor 4 when viewed from the air inflow side.

The ventilation groove 20 facing the gap 8 is arranged between the adjacent stator cores 5a, as shown in FIG. In the present embodiment, the coil groove into which the stator core 5a is inserted also has an angle θ along the rotation direction of the rotor 4 when viewed from the air inflow side, similarly to the ventilation groove 20.
Only skewed.

As shown in FIG. 3, the cross-sectional shape of the ventilation groove 20 is inclined along the rotation direction of the rotor 4 so that the edge 20a faces the gap 8. That is,
As shown in FIG. 4, among the surfaces of the ventilation groove 20, the side surface 20 b extending in the radial direction is rotated by an angle α with respect to a straight line L extending from the center of the rotor 4 toward the outer periphery. It is inclined along. As each inclination α, 25 ° to 4 °
Set an angle of 5 °.

In the embodiment having such a configuration, the ventilation groove 20
Is inclined at the angle α and skew is applied, so that the circumferential swirling airflow generated in the gap 8 due to the rotation of the rotor 4 easily enters the ventilation groove 20 (inclination). The effect of the angle α), and the air that has entered the ventilation groove 20 flows in the ventilation groove 20 in the axial direction (effect of skew). Will be discharged. Therefore, the portion of the gap 8 can be cooled well.

Further, the ventilation groove 20 is hardly affected by the flow of the swirling airflow in the circumferential direction due to the rotation of the rotor 4, and has a ventilation resistance of substantially the same level as at rest even during operation. Air can be circulated through the ventilation groove 20, and the cooling efficiency is improved from this point as well.

[0019]

According to the present invention, as described in detail with the above embodiments, the cylindrical gap between the outer peripheral surface of the rotor and the inner peripheral surface of the stator is provided in the axial direction. In a rotating electrical machine that cools by flowing air along the rotor, a plurality of ventilation grooves extending in the axial direction are formed on the inner peripheral surface of the stator, and each ventilation groove is viewed from the air inflow side of the rotor. Since the air is skewed in the rotation direction, the air can be circulated in the air flow groove with substantially the same air flow resistance as in the stationary state even during operation, thereby improving the cooling efficiency.

According to the present invention, there is provided a rotating electric machine for cooling by flowing air along an axial direction in a cylindrical gap between an outer peripheral surface of a rotor and an inner peripheral surface of a stator.
On the inner peripheral surface of the stator, a plurality of ventilation grooves extending in the axial direction are formed, and each ventilation groove is skewed in the rotation direction of the rotor when viewed from the air inflow side. Of the radially extending side surface is inclined in the direction of rotation of the rotor with respect to the direction from the center of the rotor toward the outer peripheral side, so that the circumferential swirling air generated in the gap with the rotation of the rotor. The flow easily enters the ventilation groove, and the air that has entered the ventilation groove flows in the ventilation groove in the axial direction. As a result, the air in the hot gap is efficiently discharged to the outside. . Therefore, it is possible to cool the gap portion satisfactorily. As a result, it is possible to favorably cool the gap, which has been a problem particularly in the case of an ultrahigh-speed rotating electric machine.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a stator of a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is an exemplary front view showing a part of the stator of the rotary electric machine according to the embodiment of the present invention;

FIG. 3 is an exemplary perspective view showing a part of the stator of the rotary electric machine according to the embodiment of the present invention;

FIG. 4 is an exemplary front view showing a part of the stator of the rotary electric machine according to the embodiment of the present invention;

FIG. 5 is a configuration diagram showing a rotating electric machine.

FIG. 6 is a front view showing a ventilation groove portion of a conventional rotating electric machine.

FIG. 7 is a front view showing a ventilation groove portion of a conventional rotating electric machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation shaft 2 Bearing 3 Bracket 4 Rotor 5 Stator 5a Stator iron core 5b Stator coil 6 Frame 7 Ventilation path 8 Gap 9a Inlet 9b Outlet 10 Ventilation groove 11 Wedge 20 Ventilation groove 20a Edge 20b Side surface

Claims (2)

[Claims] 1. A rotating electric machine for cooling by flowing air along an axial direction in a cylindrical gap between an outer peripheral surface of a rotor and an inner peripheral surface of a stator, wherein the inner peripheral surface of the stator is provided. A plurality of ventilation grooves extending in the axial direction, and the ventilation grooves are skewed in the rotation direction of the rotor when viewed from the air inflow side. 2. A rotating electric machine which performs cooling by flowing air along an axial direction in a cylindrical gap between an outer peripheral surface of a rotor and an inner peripheral surface of a stator, wherein the inner peripheral surface of the stator is provided. A plurality of ventilation grooves extending in the axial direction are formed, and each ventilation groove is skewed in the rotation direction of the rotor as viewed from the air inflow side, and further extends radially on the surface of the ventilation groove. A ventilation cooling structure for a rotating electric machine, characterized in that a side surface is inclined in a rotation direction of the rotor with respect to a direction from a center of the rotor toward an outer periphery.