JPS6295943A - Armature of rotary electric machine - Google Patents

Abstract

PURPOSE:To reduce the no-load loss by arranging the magnetic substance bridge in such a way as will cover a part of the slot at the tip of the teeth existent between the slots of an armature. CONSTITUTION:A single slot 1 is composed of a wide and shallow-grooved slot 6a and a narrow and deep-grooved slot 6b. 7 is a tooth existent between the slots. 8a and 8b are coils inserted into the wide and shallow-grooved slot 6a, while 9a and 9b are coils inserted into a narrow and deep-grooved slot 6b. At the tip of the teeth 7 a magnetic substance bridge 11 is arranged so as to cover a part of the wide and shallow-grooved slot 8a. The magnetic substance bridge 11 is secured with a band 10 of non-magnetic material test the bridge 11 should leap out of the armature by the centrifugal force arising from the rotation of an armature core 4. As the magnetic substance bridge prevents the teeth from magnetic saturation, the no-load loss is reduced.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an armature for a rotating electric machine.

[Prior Art] Fig. 3 shows a cross-sectional view of an armature installed in a conventional DC machine, and Fig. 4 is an enlarged view of the armature core portion indicated by A in Fig. 3. It is a diagram. In Figures 3 and 4, (1) is a DC generator, (2) is a yoke that is one of the fixed parts of the DC generator (1), and (3a) to (3d) are yokes. It is a field pole that creates a magnetic flux fixed at (3a) and (3c
) n S pole, (3b) and (3d) are N poles. The yoke (2) and the magnetic poles (3a) to (3d) form a stator.

(4) is an armature housed in the stator so as to be able to rotate at high speed, and (5) is a rotation axis when the armature (4) rotates. (6a) is a wide shallow groove slot formed on the outer circumferential side of the armature (4), (6b) is a wide shallow groove slot (6
a) is a narrow deep groove slot formed radially inward and continuous with this wide shallow groove slot (6a).
) and the narrow deep groove slot (6b) form one slot (6). (7) is the tooth portion existing between the slots, (8a) (8b) is the upper end coil inserted into the wide shallow groove slot (6a), (9a) (9b)
) is the lower end coil inserted into the narrow deep groove melon (6b). (lO) is a band of non-magnetic material, and the upper end coil (8a) is pushed into the wide slot (6a).
) (8b) is wound around the outer periphery of the armature (4) to prevent it from flying out of the slot (6) due to the centrifugal force exerted by the high-speed rotation of the armature (4).

Next, the operation will be explained. Figure 5 shows the field pole (3a) (
3b) (3c) This is a diagram showing the state of the magnetic field generated by (3a), and the arrows penetrating the field poles (3a) to (3d) and forming a loop are magnetic flux.

When the armature (4) rotates in the magnetic field generated in this way and in the direction of arrow B, a magnetic field is formed around the armature (4) and pushed into the slot (6) according to Lemming's left hand rule. Electromotive force is generated in the upper coils (8a), (8b) and the lower coils (9a) (9b), and the coils (8a) (
8b) (9a) A current flows in (9b). Direct current is obtained by rectifying this generated current.

A: Is the slot shaped like the one shown in Figure 4 in order to reduce the getatance voltage at the slot portion that occurs during rectification? Wide shallow slot (6a) and narrow deep slot (6b)
) The inductance of the slot portion is reduced by 4096 points compared to the inductance of the U-shaped slot portion, which is another conventional example.

[Problem that the invention seeks to solve]

Since the conventional armature is configured as described above, when the magnetic flux applied in the radial direction from the field poles (3a) to (3d) concentrates on the tooth (7), the tooth (7) becomes magnetically saturated. The magnetic flux mainly passes through the upper coils (8a) and (8b) as interlinkage magnetic flux. This magnetic flux linkage causes the upper mouth coil (
There were problems such as eddy currents occurring in the coils 8a) and 8b, resulting in a significant increase in no-load loss and a significant temperature rise in the upper coils 8a and 8b.

This invention was made to eliminate the above-mentioned problems, and reduces the magnetic flux passing through the armature coil.
It is also an object of the present invention to obtain an armature that can minimize increase in inductance.

[Means for Solving the Problems] The armature of a rotating electric machine according to the present invention is provided with a magnetic bridge at the tip of the teeth existing between the slots of the armature so as to partially cover the slots. be.

[Effect]

Does the armature Pi magnetic material bridge of the rotating electrical machine in this invention cause magnetic saturation of the teeth? By preventing this, the magnetic flux linkage of the armature coil of the rotating electric machine is reduced, and the no-load loss is reduced.

[Embodiment of the Invention] FIG. 1 shows a DC generator according to an embodiment of the invention, and FIG. 2 is an enlarged view of the i1 armature core indicated by C in FIG. 1. (1) to (10) are completely the same as the conventional device described above. (11) is a magnetic magnet placed at the tip of the tooth portion (7) so as to cover a part of the wide shallow groove slot (8a). It is a magnetic material bridge (11
) is fixed with a non-magnetic band (10) to prevent it from flying out of the armature due to centrifugal force caused by the rotation of the armature core (4).

In the armature configured as described above, the field pole (3a
) to (3d), the magnetic flux directed toward the center of the armature core (4) passes through the magnetic bridge (11), and the interlinkage magnetic flux to the upper coils (8a) and (8b) is significantly reduced. .

Therefore, the eddy current generated in the upper end coils (8a) (8b) is significantly reduced, the increase in no-load loss can be reduced, and the temperature rise in the armature coil is reduced.

In the above embodiment, a DC generator is used, but even if DC is the motive, DC power generation can be achieved by arranging the magnetic bridge (11)'& teeth (7) so as to partially cover the tips of the slots. As in the case of machines, it is possible to reduce no-load loss. Furthermore, the same effect can be achieved even when this magnetic bridge (11) is attached not only to a DC machine but also to an induction machine or a synchronous machine.

In the above embodiment, the magnetic bridge (11) placed at the tip of the tooth (force) is fixed with a non-magnetic band (10). A convex part (i or concave 8 (S) is provided in a part, and a magnetic bridge (1
1) may be provided with a concave portion (or a convex t!ff5) to engage and hold both. Furthermore, since the magnetic bridge (11) has a laminate structure, eddy currents generated within the bridge can be prevented.

[Effects of the Invention] As explained above, the F3A has a magnetic bridge disposed at the tip of the teeth between the armature slots so as to cover part of the slots, thereby improving the rectification ability of the conventional F3A. This has the effect of significantly reducing no-load loss without sacrificing performance, resulting in an armature with high quality and reliability.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a DC generator showing an embodiment of the present invention, Fig. 2 is an enlarged view of the Jt armature core shown in Fig. 1, and Fig. 3 is a conventional DC generator. FIG. 4 is an enlarged view of the conventional armature core, and FIG. 5 is an explanatory diagram showing the state of the magnetic field generated by the magnetic poles. In the figure, (4) is an armature core, and (11) is a magnetic bridge. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A rotating electric machine comprising an armature core having a plurality of slots around the circumference, and a magnetic bridge disposed at the tip of a tooth section between the slots so as to cover a part of the slots. armature. (2) The rotating electric machine according to claim 1, wherein the slot has a deep groove narrow portion into which the lower coil is inserted and a shallow groove wide portion above which the upper coil is inserted. Child. (3) An armature for a rotating electrical machine according to claim 1, wherein the magnetic bridge has a laminate structure.