JPH10341555A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor from which heat generated by its rotor and stator is radiated efficiently by making gas existing in a gap between the rotor and the stator flow in the axial direction of the rotary shaft of the rotor. SOLUTION: In a motor which has a stator 11 fitted to a casing 10, a rotor 12 and a fan attached to the end of a rotor rotary shaft 13 and which is so constructed as to have gas discharged out of a vane wheel discharge outlet of a fan made to flow at least through a ventilation route 21 provided between the rotor 12 and the rotor rotary shaft 13 and sucked into a vane wheel suction inlet in order to circulate the gas in the casing 10, a ventilation route 27 which links the ventilation route 21 between the rotor 12 and the rotor rotary shaft 13 with a gap 26 between the stator 11 and the rotor 12 is provided near the central part in the axial direction of the rotor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor provided with heat-dissipating fins at both ends of a rotor rotating in a stator.

[0002]

2. Description of the Related Art An important issue is how to radiate heat generated in miniaturizing an electric motor.
Inside the motor, there are I ² R heat generated by the current I flowing through the winding of the internal resistor R, heat generated by the eddy current resulting from the change in magnetic flux, and heat generated by other causes. On the other hand, whether or not the temperature rise can be suppressed within a predetermined range due to the heat resistance limit of the insulating material affects the heat resistant life of the insulating material and the life of the electric motor, and is a major factor that determines the reliability of the product. Has become.

As a cooling method for radiating heat generated in the electric motor, there is an electric motor employing a cooling structure in which air in a casing is forcibly circulated and cooled by a fan attached to a rotor rotating shaft. 3 and 4
FIG. 1 is a diagram showing a structural example of a conventional motor of this type. FIG.
3 is an overall longitudinal sectional view, and FIG. 4 is a CC sectional view of FIG.
As shown in the figure, the motor has a stator 11 fitted in a casing 10 and bearings 14 and 15 inside the stator 11.
And a fan 17 mounted on an end of a rotor rotation shaft 13.

[0004] A plurality of (eight in the figure) strip-shaped recesses 18 (the outer circumference of which is a strip-shaped protrusion) are provided on the inner peripheral surface of the casing 10, and the belt-shaped recess 18 allows the stator 11 and the casing 10 to be interposed. Multiple (eight in the figure) ventilation paths 1
9 are formed. The rotor 12 is supported on the rotor rotating shaft 13 by a plurality of (four in the figure) plate-like support members 20, and a plurality (four in the figure) is provided between the rotor rotating shaft 13 and the rotor 12. A ventilation path 21 is formed. Fins 22 are provided at both ends of the rotor 12. In the drawing, 23 is an electrically insulated winding of the stator 11,
24 is a power cable inlet, and 25 is a seal mechanism.

In the electric motor having the above structure, the electric motor is started, and the rotor 12 rotates, and at the same time, the fan 17 attached to the rotor rotating shaft 13 also rotates. As a result, as shown by the arrow in FIG.
Gas (mainly air) in casing 10 sucked into a
Flows from the impeller discharge port 17 b to one end of the stator 11, from there through an air passage 19 between the casing 10 and the stator 11 to the other end, and from the other end to the rotor 12
The air flows through a plurality of air passages 21 between the rotor 17 and the rotor rotation shaft 13 to flow into the impeller suction port 17 a of the fan 17 and circulates. As described above, a cooling structure is employed in which the gas in the casing 10 is forcibly circulated by the fan 17 to dissipate heat generated in the stator 11 and the rotor 12 and the like, thereby cooling the same.

The fins 22 at both ends of the rotor 12 are for radiating heat generated in the rotor 12, and at the same time, blow air to the end of the electrically insulating winding 23 of the stator to cool the electrically insulating winding. I do.

[0007]

In the electric motor having the above-described structure, the rotor 12 and the stator 11 are heating elements, and the gas layer in the gap between the rotor 12 and the stator 11 is heated by heat from both sides to reach a high temperature. Become. On the other hand, the rotor 12
The gas layer in the gap between the rotor and the stator 11 receives centrifugal force due to the rotation of the rotor 12, but hardly flows in this direction since it does not receive the axial force of the rotor rotating shaft 13. Also, since this gap is extremely narrow, the fan 17
Accordingly, in the flow of gas (mainly air) circulating in the casing 10, the air in the gap hardly flows in the axial direction of the rotor rotation shaft 13. Therefore, the gas layer in the gap stays and the rotor 1
2 and the stator 11 heat it to a high temperature. Therefore, there is a problem that heat radiation from the gap between the rotor 12 and the stator 11 cannot be expected.

Further, the fins 2 at both ends of the rotor 12 are usually
Fins 2 and 22 have the same or different shapes.
The two fins 22 and 22 have different lengths.
Blast pressure is not very different. That is, both fins 2
Since there was no difference between the blowing pressures 2 and 22, the gas in the gap between the rotor 12 and the stator 11 could not be pushed out due to the difference in the blowing pressure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a structure in which a gas in a gap between a rotor and a stator flows in the axial direction of a rotor rotating shaft during rotation of the rotor, and heat generated in the rotor and the stator. It is an object of the present invention to provide a motor capable of efficiently dissipating heat.

[0010]

According to the first aspect of the present invention, there is provided a stator fitted in a casing, a rotor having fins at both ends and rotating in the stator. An electric motor having a ventilation passage through which a fluid can move is characterized in that one of the fins at both ends of the rotor has a higher discharge pressure than the other.

The invention described in claim 2 is the first invention.
In the electric motor according to the above, as a means for ensuring that one of the fins at both ends of the rotor has a higher blast discharge pressure than the other, a fin plate is provided at the tip of one of the fins for contacting the blast generated by the fin. Features.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an example of the structure of an electric motor according to the present invention. FIG. 1 (a) is a partial longitudinal sectional view, and FIG. 1 (b) is a sectional view taken along the line AA in FIG. 1 (a). Since the overall structure of the electric motor of the present invention is substantially the same as the electric motor shown in FIGS. 3 and 4, detailed description thereof will be omitted.

As shown in FIG.
The plate 26 is provided at the tip of one of the fins 22 provided at both ends of the fin 22. The shape of the corresponding plate 26 is shown in FIG.
As shown in (a) and (b), a ring-shaped contact plate 26 is attached to the tip of the fin 22. In addition,
FIG. 2A is a plan view, and FIG. 2B is a sectional view taken along a line BB.

By providing the contact plate 26 at the tip of one of the fins 22 as described above, when the rotor 12 rotates, the fin 22 provided with the contact plate 26 sends air to the corresponding plate 2.
6 and its blowing pressure is higher than the blowing pressure of the fins 22 without the abutment plate 26. Therefore, the rotor 12
The gas (mainly air) layer in the gap 27 between the rotor and the stator 11 is, as indicated by the arrow,
6 flows from the side of the fin 22 where the plate 6 is provided to the side of the fin 22 where the plate 26 is not provided. As a result, the high-temperature gas layer in the gap 27 is removed while the rotor 12 is rotating.
In the axial direction 3, the gas is replaced with a low-temperature gas outside the gap 27.

As described above, the rotor 12 and the stator 11
Are heating elements, and the gas layer in the gap 27 therebetween is heated from both sides to a high temperature, but the gas layer in the gap 27 is from the fin 22 side provided with the plate 26 to the fin 22 side not provided with the plate 26 As a result, the heated high-temperature gas flows out and the low-temperature gas flows in, and the heat generated in the rotor 12 and the stator 11 is efficiently radiated. In particular, the electrically insulated windings in the status lot can be actively cooled, and the heat radiation efficiency is greatly improved.

In the above-described embodiment, an example has been described in which an abutment plate is provided at the tip of one of the fins 22 so that there is a difference in the air blowing discharge pressure between the fins 22 at both ends of the rotor 12. The means is not limited to this as long as a means for generating a blow-off pressure difference is generated. For example, the width of one fin may be increased and the width of the other fin may be decreased.
In short, any means may be used as long as there is a difference in the air discharge pressure by the fins 22 of the heads at both ends of the rotor 12.

The structure of the motor is merely an example, and the motor to which the present invention is applied is not limited to this. For example, the gas circulation path in the casing is not limited to the above example. In short, as long as the motor has a stator fitted in the casing and a rotor having fins at both ends, its structure is not particularly limited in principle.

[0018]

As described above, according to the present invention, since the air discharge pressure by the fins at both ends of the rotor is configured to be higher at one side than at the other, the rotor is disposed in the gas layer in the gap between the rotor and the stator. The flow in the axial direction of the rotating shaft is generated, the heated high-temperature gas flows out of the gap, and the low-temperature gas flows in from outside the gap, so that the rotor and the stator can be efficiently cooled, and the heat radiation effect of the electric motor is improved. An excellent effect of significantly improving is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structural example of an electric motor of the present invention, wherein FIG. 1 (a) is a partial longitudinal sectional view, and FIG. 1 (b) is a sectional view taken along line AA of FIG. 1 (a).

FIG. 2 is a diagram showing an example of a structure of a contact plate attached to a fin tip of the electric motor of the present invention, wherein FIG. 2 (a) is a plan view, and FIG. 2 (b) is a sectional view taken along the line BB of FIG. .

FIG. 3 is a longitudinal sectional view showing a structural example of a conventional electric motor.

FIG. 4 is a sectional view taken along the line CC of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Casing 11 Stator 12 Rotor 13 Rotor shaft 14 Bearing 15 Bearing 17 Fan 18 Belt recess 19 Ventilation path 20 Support member 21 Ventilation path 22 Fin 23 Electrical insulation winding 24 Power cable introduction port 25 Seal mechanism 26 This plate 27 Gap

Claims (2)

[Claims] 1. An electric motor comprising: a stator fitted in a casing; a rotor having fins at both ends and rotating in the stator; and a ventilation passage through which fluid can move. An electric motor characterized in that one of the blower discharge pressures by the fins is higher than the other. 2. A means for ensuring that one of the fins at both ends of the rotor has a higher blast discharge pressure at one end than the other at the end of one fin is provided with a contact plate against which the blast generated by the fin comes into contact. The electric motor according to claim 1, wherein