JPS61251438A - Rotor of rotary electric machine - Google Patents

Abstract

PURPOSE:To equalize the temperatures of the surface of poles by forming air gaps between the surfaces of the poles and a stator larger at the rear side than at the front side with respect to the rotating direction of the surface of the pole. CONSTITUTION:A rotor has a shaft 1, a yoke 2 provided on the shaft 1, poles 3b provided on the outer periphery of the yoke 2 and disposed oppositely through an air gap to a stator 4 on the surface 3a, and a field winding 5 mounted on the body of the pole 3b. The poles 3b are formed at an air gap between the surface 3a of the poles and the stator 4 larger at the rear side 7 than the front side 6 with respect to the rotating direction (w) of the surfaces 3a of the poles. Thus, a rotor of a rotary electric machine in which the temperatures of the surfaces 3a of the poles can be equalized can be obtained.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a rotor for a rotating electric machine.

[Background of the invention]

FIG. 3 shows a conventional example of a salient pole type rotor of a rotating electric machine. As shown in the figure, the rotor is connected to the shaft l
, a yoke 2 provided on this shaft l, provided on the outer periphery of this yoke 2, and whose surface 3a is connected to the stator 4.
The magnetic pole 3 is arranged to face the magnetic pole 3 with an air gap therebetween, and a field winding 5 attached to the body of the magnetic pole 3 is provided.

In the rotor configured in this manner, the surface 3a of the magnetic pole 30, that is, the surface 3a of the magnetic pole 30 is connected to the stator 4 as shown in the figure.
The air gap along the arc of the magnetic pole surface 3a is almost uniform except for the very edges, and therefore The air gap between the front side 6 of the magnetic pole surface 3a, which is the front side, and the rear side 7, which is the rear side, of the magnetic pole surface 3a with respect to the rotation direction wllc of the magnetic pole 3 is equal. In the figure, d is the magnetic axis of the field winding magnetomotive force, s'Rao is the magnetic axis of the composite magnetomotive force, and A is the magnetic axis of the armature reaction magnetomotive force.

FIG. 4 shows the magnetomotive force distribution in the gap of the magnetic pole surface 3a during load operation of a salient pole machine having such a rotor. In the figure, do is the field winding magnetomotive force distribution curve, R
oo is the composite magnetomotive force distribution curve, A (1tri armature reaction magnetomotive force distribution curve), and Rp on the vertical axis is the magnetomotive force.As is clear from the same figure and Fig. 3, the magnetic axis of the composite magnetomotive force When the salient pole machine is operated, Ro is shifted from the magnetic axis d of the field winding magnetomotive force in the direction opposite to the rotation direction, so the magnetic pole surface 3a corresponding to the magnetic axis RoK, that is, the rear portion 7 of the magnetic pole surface 3a
had a tendency to overheat. In other words, the magnetic pole surface 3 under load
As shown in Figure 4, the magnetic flux distribution of a also has a peak that deviates from the magnetic axis d of the 5-field winding magnetomotive force to the position of the magnetic axis R0 of the composite magnetomotive force on the rear side with respect to the rotational axis direction. become. When rotating in this state, the peak value of this magnetic flux fluctuates at high frequency due to the influence of the slots on the stator 4 side, so that the rear side 7 of the magnetic pole surface 3a is heated by eddy current. In addition, as a method for preventing overheating of the rear side 7 of the magnetic pole surface 3a, Japanese Patent Application Laid-Open No. 1983
There is a publication No.-10903.

[Purpose of the invention]

The present invention has been made in view of the above points, and an object of the present invention is to provide a rotor for a rotating electrical machine that makes it possible to equalize the temperature of the magnetic pole surface.

[Summary of the Invention] That is, the present invention includes a shaft, a yoke provided on the shaft, a magnetic pole provided on the outer periphery of the yoke, and whose surface is arranged opposite to a stator with a gap therebetween.
In a rotor of a rotating electric machine equipped with a field winding attached to the body of the magnetic pole, the magnetic pole is arranged so that the gap between the magnetic pole surface and the stator is positioned so that the rear side with respect to the rotational direction of the magnetic pole surface is forward. The magnetic pole is characterized by being formed larger from the side, so that the gap between the magnetic pole surface and the stator is larger on the rear side with respect to the rotation direction of the magnetic pole surface than on the front side. .

[Embodiments of the invention]

The present invention will be explained below based on the illustrated embodiments. FIG. 1 shows an embodiment of the invention. It should be noted that the same parts as in the conventional one are given the same reference numerals, so the explanation will be omitted. In this embodiment, the gap between the magnetic pole surface 3a and the stator 4 of the magnetic pole 3b is formed so that the rear side 7 with respect to the rotation direction W of the magnetic pole surface 3a is larger than the front side 6. By doing this, in the magnetic pole 3b, the air gap between the magnetic pole surface 3a and the stator 4 is formed larger on the rear side 7 with respect to the rotation direction W of the magnetic pole surface 3a than on the front side 6, so that the magnetic pole surface 3
It is possible to obtain a rotor for a rotating electrical machine that makes it possible to equalize the temperature of a.

In other words, the air gap between the magnetic pole surface 3a and the stator 4 is
Contrary to the shape of the magnetic pole surface 3a (indicated by a two-dot chain line in the figure), which is asymmetrical between the front side 6 and the rear side 7 with respect to the rotation direction wK of a and is concentric with the inner periphery of the stator 4 in the conventional art, the solid line in the figure 1 so that the gap on the rear side 7 becomes larger as shown.
On the other hand, the front side 6 is made smaller. By doing this, the magnetomotive force distribution in the gap of the magnetic pole surface 3a during load operation of the salient pole machine is as shown in FIG. Peak value RP1 of the composite magnetomotive force distribution curve Roe in this example (solid line display)
is the peak value RF of the conventional example. become smaller. The reason why the peak value of the magnetomotive force on the magnetic axis R1 of the composite magnetomotive force becomes smaller is that the air gap between the rear side 7 of the magnetic pole surface 3a corresponding to the magnetic axis R1 and the stator 4 is made larger than the air gap on the front side 6. As a result, the magnetic resistance between the rear side 7 of the magnetic pole surface 3a and the stator 4 becomes larger than the magnetic resistance between the front side 6 of the magnetic pole surface 3a and the stator 4, and the magnetic flux on the rear side 7 of the magnetic pole surface 3a increases. This is because it is smaller than the magnetic flux on the front side 6 of the magnetic pole surface 3a.

Therefore, the amount of heat generated by the eddy current on the rear side 7 of the magnetic pole surface 3a is reduced, overheating of the rear side 7 is prevented, and the temperature of the magnetic pole surface 3a can be made uniform.

Furthermore, by making the air gap between the rear side 7 of the magnetic pole surface 5a and the stator 4 larger than that between the front side 6, the flow of air on the rotating magnetic pole surface 3a becomes turbulent. The cooling effect on the rear side 7 of the magnetic pole surface 3a can be improved compared to the conventional case.

Another embodiment of the invention is shown in FIG.

In this embodiment, the air gap is made larger only on the rear side 7 of the magnetic pole surface 3a without changing the front side 6 of the magnetic pole surface 3a.

By doing this, the gap between the rear side 7 of the magnetic pole surface 3a and the stator 4 is increased, and the gap between the front side 6 of the magnetic pole surface 3a and the stator 4 is
The air gap between the magnet and the magnet becomes larger, and the same effect as in the case described above can be achieved, but this is effective when the field current capacity of the field winding 5 has a margin.

〔Effect of the invention〕

As described above, the present invention makes it possible to obtain a rotor for a rotating electric machine in which the temperature of the magnetic pole surface becomes uniform, thereby making it possible to equalize the temperature of the magnetic pole surface.

[Brief explanation of the drawing]

Figure 1 shows rotation 1 of the present invention! FIG. 2 is a magnetomotive force distribution diagram of the gap in the magnetic pole surface of the same example; FIG. 3 is a cross-sectional view of the rotor of a conventional rotating electrical machine;
FIG. 4 is the same conventional magnetomotive force distribution diagram in the gap portion of the magnetic pole surface, and FIG. 5 is a sectional view of another embodiment of the rotor of the rotating electrical machine of the present invention.

Claims (1)

[Claims] 1. A shaft, a yoke provided on the shaft, a magnetic pole provided on the outer periphery of the yoke and whose surface faces the stator with an air gap in between, and a magnetic pole attached to the body of the magnetic pole. In the rotor of a rotating electric machine, the rotor is characterized in that the magnetic pole is formed so that the gap between the magnetic pole surface and the stator is larger on the rear side with respect to the rotational direction of the magnetic pole surface than on the front side. The rotor of a rotating electrical machine.