JPS63217940A - Stator core for rotary electric machine - Google Patents

Abstract

PURPOSE:To reduce the iron loss of the toothed port of a slot and to improve the efficiency of a rotary electric machine by laminating 90-25% directional silicon steel plates in which rolling directions coincide circumferential direction of a sector shape and 10-75% amorphous silicon steel plates to form a stator core. CONSTITUTION:Sector-shaped directional silicon steel plates 7 in which rolling directions coincide, substantially in the circumferential direction of the sector shape and sector-shaped amorphous silicon steel plates 8 are laminated to form a cope block 2. The block 2 is pressed by retainers 4 through a radial vent duct 3 therebetween to form a stator core S, and a stator winding 5 is wound in the toothed part of the slot. The ratio of the plates 7 and the plates 8 is ranged from 90-25% to 10-70%. Thus, the iron loss of the toothed part of the slot is reduced to suppress the temperature rise of the winding 5, thereby improving the efficiency of a rotary electric machine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a stator core with a small number of magnetic poles, such as a rotating electric machine, and particularly a turbine generator.

(Prior art) This type of rotating electric machine is unidirectional because the main magnetic flux that passes through the stator core tooth section in the radial direction moves through the yoke section in the circumferential direction for a longer distance than in a multi-polar machine. Silicon steel electric iron plates are used. This is made by punching roll materials that are easily magnetized in the rolling direction into a fan shape and stacking them so that the circumferential direction of the yoke portion substantially coincides with the rolling direction.

With this configuration, although it is possible to improve the iron loss of the iron core yoke portion, a problem arises in the tooth portion. Therefore, a fan-shaped electric iron plate has been proposed that can form an ideal magnetic path by metallurgically bonding unidirectional electric iron plates. As shown in FIG. 6, the iron plate 1a forming the yoke part of the iron core has a rolling direction F in the circumferential direction.

The iron plate 1b forming the tooth portion has a rolling direction F in the radial direction, and is butt welded together. (Unexamined Japanese Patent Publication No. 54-3
(No. 4003 Publication) However, this electric iron plate involves welding, which makes it difficult to mass-produce it, and even if a bidirectional roll material that is perpendicular to each other can be made by welding, if adjacent fan-shaped plates are punched in opposite directions, it is difficult to mass-produce. Since the effectiveness is halved, it becomes extremely wasteful harvesting.

(Problem to be solved by the invention) It is not possible to align the direction of symbiotic magnetic flux, and even if this is obtained by metallurgical bonding means, it falls within the category of special materials and cannot be used to manufacture large quantities of fan-shaped plates. The problem was that it was unsuitable.

The present invention was made in view of the above circumstances, and its purpose is to mix unidirectional electric iron plates and non-directional electric iron plates, which can be easily mass-produced, to obtain low loss in the tooth portion. Our goal is to provide stator cores for rotating electrical machines.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, a stator core of a rotating electrical machine according to the present invention has a radial tooth portion around which a stator winding is wound on the inner diameter side of a yoke portion. Fan-shaped electric iron plates are stacked in a ring,
Moreover, in a product using two types of electric iron plates consisting of grain-oriented silicon steel and non-oriented silicon steel, the rolling direction of the grain-oriented silicon steel electric iron plates is made to coincide approximately with the circumferential direction of the fan shape. The mixing ratio of the electrical iron plates made of non-oriented silicon steel is 10 to 75% of the total electric iron plates.

(Function) According to the stator core of the rotating electrical machine of the present invention, electric iron plates having a directionality in the circumferential direction and electric iron plates having a non-directionality coexist, so that they all have a directionality in the circumferential direction. Compared to an iron core using electric iron plates, the core loss of the main magnetic flux is reduced at the teeth and increased at the yoke.

In the present invention, since the mixing ratio of both electric steel plates is set within a predetermined range, the amount of decrease in iron loss in the tooth portion and the amount of increase in iron loss in the yoke portion are equal, and the iron loss of the entire core is equal to that of the conventional one. Although it does not change, the temperature rise in the stator winding can be reduced by the amount of iron loss reduction in the teeth.

The basis for setting the upper limit of the mixing ratio of non-directional electric iron plates to 75% is as follows.
When this value is exceeded, the amount of increase in iron loss in the yoke section exceeds the amount of reduction in iron loss in the tooth section, and the iron loss of the entire core tends to increase.
The reason why it is set to 0% is that even if it is less than this, the iron loss in the yoke portion only increases, and hardly any effect of reducing iron loss in the tooth portion can be expected.

(Example) An example of the present invention will be described below with reference to the drawings. 1st
The figure is a longitudinal sectional view of a two-pole turbine generator, showing the iron core portion of the stator and the rotor. The stator core is made up of a plurality of core blocks 2 stacked with electrical iron plates, a radial ventilation duct 3 is formed between each block, and is fastened to a presser plate 4 pressed against both shaft ends.

A fixed pre-winding 65 is wound around the inner diameter side of the stator core. Each of the iron core blocks 2 includes an electric iron plate 7 made of a grain-oriented silicon steel plate and an electric iron plate 8 made of a non-oriented silicon steel plate in a predetermined ratio.

Figures 2 and 3 show the above two types of electric iron plates.
The figure shows an electric iron plate 7 made of grain-oriented silicon steel, with its rolling direction F being the circumferential direction of the yoke. FIG. 3 shows an electric iron plate 8 made of non-oriented silicon steel.

These electric iron plates with different characteristics are the 11th! As shown in FIG. 1, each block 2 is composed of a laminate of electrical iron plates 7 with directional orientation on the outside and a laminate of non-directional electric iron plates 8 sandwiched therebetween.

The results of the model test of the stator core configured as above are shown in Figures 4 and 5. As is clear from these characteristics, the increase in loss in the yoke portion and the decrease in loss in the tooth portion are The branching point at which the loss of the entire stator core is balanced and approximately equal to that of the conventional one is 75%. Furthermore, since the radial ventilation duct 3 is formed by the laminated body of the oriented electric iron plates 7, the teeth are effectively cooled, and combined with the low loss region of the non-directional electric iron plate layer in the center, the entire tooth is cooled. temperature rise can be reduced.

In addition, in the above-mentioned embodiment, two types of electric iron plate layers are laminated in a sandwich shape, but the present invention is not limited to this, and the electric iron plates 7 and 8 may be evenly mixed over the entire length of the iron core. You can also do that.

〔Effect of the invention〕

As explained above, according to the configuration of the present invention, the loss of the entire core is the same as that of the conventional one, and the loss of the tooth portion is reduced, so the temperature rise of the stator winding wound around the tooth portion is reduced. This is effective in obtaining highly efficient rotating electric machines.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a main part of a turbine generator showing an embodiment of the present invention, Fig. 2 is a plan view of a directional electric iron plate, Fig. 3 is a plan view of a non-directional electric iron plate, and Fig. 4 5 is a diagram showing the characteristics of the model test, and FIG. 6 is a plan view showing an example of a conventional two-way electric iron plate. 2... Iron core block, 3... Radial ventilation duct, 5... Stator winding. 7... Electric iron plate made of grain-oriented silicon steel. 8... Electric iron plate made of non-oriented silicon steel. Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) Fan-shaped electric steel plates having radial teeth around which the stator windings are wound are stacked in a ring on the inner diameter side of the yoke, and the two are made of oriented silicon steel and non-oriented silicon steel. In the electrical iron plate made of the non-oriented silicon steel, the rolling direction of the grain-oriented silicon steel electric iron plate is formed so as to correspond substantially to the circumferential direction of the fan shape, and among all the electric iron plates, the electric iron plate made of the non-oriented silicon steel is Mix ratio of iron plate from 10 to 75
A stator core for a rotating electrical machine characterized by a %. (2) A rotating electric machine according to claim 1, wherein a plurality of laminated iron core blocks are laminated via radial ventilation ducts, and an electric iron plate made of non-oriented silicon steel is laminated at the center of these iron core blocks in the lamination direction. stator core.