JPS59159637A - Pole core for rotary electric machine - Google Patents

Abstract

PURPOSE:To improve the performance of a rotary electric machine and to improve the lifetime of a brush by forming a recess on the end face of a pole core collar toward a core boss in a circumferential direction and varying the sectional area of the collar in the circumferential direction, thereby reducing a leakage magnetic flux. CONSTITUTION:A recess 8 is formed on a pole core collar 6 from the end of the collar to a boss 7 in a circumferential direction, and the sectional area of the collar 6 is continuously reduced toward the end face of the collar 6 in such a manner of S1, S2 and S3. Accordingly, since a magnetic flux distribution is continuously varied, the rectifying action of a brush is remarkably improved, thereby increasing the rotating speed of a motor and the lifetime of the brush. Further, the leakage of a magnetic flux from the collar 6 can be suppressed to small value while obtaining a pole core width B necessary to hold a winding, and the torque of the motor can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a ball core for a rotating electric machine such as a starter motor.

Conventionally, in a field-wound stator of a starter motor, a ball core l having a flange shape 2 as shown in FIG. 1 has been used. As shown in FIG. 2, the stator of the starter motor is constructed by sandwiching the field coil 4 between the ball core 1 and screwing it to the yoke 3, or after fixing the ball core 1 to the yoke 3 by caulking or welding. The field coil 4 is directly wound around the ball core 1 and is constructed by a loop or the like.

By the way, in the above-mentioned conventional direct-wound field coil system, the ball core width A is determined so that the field coil 3 does not come off the ball core collar 2, but since the ball angle θ at this time is larger than the ideal ball angle, The leakage magnetic flux increases, the effective magnetic flux decreases, and the performance and rectifying effect are poor.

The object of the present invention is to improve performance by improving the leakage magnetic flux and to extend brush life by improving rectification.

That is, in the present invention, by cutting out a part of the ball core in order to make the ball core width equal to that at the ideal ball angle, the direct winding workability can be sacrificed.

The present invention will be described below with reference to embodiments shown in the drawings.

Figure 3 shows the magnetic flux distribution of the yoke. The solid line shows the magnetic flux distribution due to the conventional ball core 1 shown in FIG. 1, and the broken line shows the magnetic flux distribution due to the ball core 5 according to the embodiment of the present invention shown in FIG. 4.

As shown in Fig. 3, in a yoke using the conventional ball core 1, when the armature coil moves to the adjacent field pole, the magnetic flux distribution of the field pole changes rapidly, so the brush rectification There were problems such as a decrease in the number of rotations of the motor, and premature wear of the brushes.

According to the ball core 5 according to this embodiment shown in FIG. 4, a recess 8 is provided in the ball core collar 6 in the circumferential direction from the end surface of the collar 6 toward the boss 7, and the cross-sectional area of the collar 6 is reduced. , the ball core is continuously decreased from 5L to 32 to 33 toward the end surface of the portion 6, so that the magnetic flux distribution changes continuously as shown by the broken line in Fig. 3, so that the rectifying action of the brush is This has been significantly improved, resulting in an increase in motor rotational speed and longer brush life.

The results of this experiment are shown in FIG. Here, the solid line is for the conventional ball core 1, and the broken line is for the ball core 5 according to the present embodiment, and the characteristics of rotation speed N, small output, and torque T with respect to load current (2) are shown, respectively. Also,
By having such a shape, the following effects can also be obtained.

Conventionally, when determining the ball core chip width A in FIG. However, in reality, it is often determined by the factor ① above. In particular, after fixing the ball core 1 to the yoke 3 with screws or welding, -
In the case of a series-wound field coil in which the field coil 4 is directly wound after performing insulation treatment, if the width A is small, the field coil 4 may come off from the ball core flange 2 during winding. Optimal ball core angle, usually ((hole core opening angle θ′″)×
(Number of ball cores P) ÷ 360° = 0.65 to 0.75
) larger ball core angle (0.7 to 0.85
) is taken. Therefore, as shown in FIG. 6, the magnetic flux that leaks directly from the ball core flange 2 to the cork 3 or the adjacent ball core tail 2' without passing through the armature 9 increases, and as shown in FIG. In this case, the motor torque was lower than when the optimal ball core angle was taken (torque shown by the broken line) (torque T shown by the solid line).
).

However, according to this embodiment, as shown in FIG. 4, while ensuring the ball core width B necessary to hold the winding, the concave portion 8 prevents leakage of magnetic flux from the ball core portion 6. Since it can be kept to a minimum, the magnetic circuit can be improved and the motor torque can be increased.

Furthermore, by forming the recess 8 in the middle part of the upper part 6, which is not related to holding down the windings, there is also the effect of weight reduction.

In addition, in the above-mentioned embodiment, a pair of turning portions 8 with inclined both sides were formed in the middle portion of the collar portion 6.
The recess 8a with parallel sides as shown in Figure (al), two pairs of recesses 8b as shown in Figure 7(b), or the recess 8a with parallel sides as shown in Figure 7(C1), In addition, a pair of recesses 8C may be provided point-symmetrically, or a plurality of recesses 8d may be provided alternately on both sides of the collar 6, as shown in FIG. It may be made to correspond to the section.

In addition, in FIGS. 8(al, 8b) and 8(C1), concave portions 8C18f and 8g are also formed in the axial portion of the collar portion 6.

In each of the above embodiments, ((opening angle θ of the end face of the ball core flange portion 6)×number P of ball cores 5)÷360
) is set to 0.65 or more, and more preferably, when the shape of the concave portion is converted so that the cross-sectional area of the collar portion 6 is the same and the end surface of the tail portion 6 is a straight line, , the ball core angle is 0.
65 to 0.75 and none.

In each of the embodiments described above, the present invention was applied to a starter motor, but it can be applied not only to other motors but also to rotating electric machines such as generators.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional ball core, Fig. 2 is a front view of a conventional stator, Fig. 3 is a magnetic flux distribution diagram in the conventional and inventive ball cores, and Fig. 4 (al, (b)). are a front view and a bottom view showing an embodiment of the ball core of the present invention,
FIG. 5 is a characteristic diagram of the conventional ball core and the ball core of the present invention.
Fig. 6 is a cross-sectional view of a main part showing the state of leakage of magnetic flux in a conventional rotating electric machine, and Fig. 7 is a sectional view of (al to (d)) and Fig. 8 (a).
1~(C1 is a bottom view and a plan view respectively showing other seven embodiments of the ball core of the present invention. 5...Ball core a, 6...Brim portion, 7...Boss portion, 8a ~8g...Concavity. Fig. 1 Fig. 2 Fig. 3 (Ku) Fig. 5 Fig. 7 (a) (.) (b) (d) Fig. 6 (a) (b) t (C) Procedural amendment (method) % formula % 1 Display of case 1988 patent all No. 3318'1, name of invention Person who amends ball core 3 for rotating electrical machines Relationship to case Patent applicant Showa-cho 1, Kariya City, Aichi Prefecture 1-chome (426) Nippondenso Co., Ltd. Representative Kengo Toda 4th Director Mr. 448 Showa-cho 1-1-5, Kariya-shi, Aichi Prefecture Date of amendment order Date of dispatch May 31, 1980 Drawing No. 6 subject to amendment Figure 4 (a) (b)

Claims (1)

[Claims] (IJ ((opening angle θ of ball core flange end face)×(
In a device in which the ball core angle determined by the number of ball cores P)/360) is 0.65 or more, a recess is provided in the circumferential direction from the end face of the ball core flange toward the ball core boss, and the flange is A ball core for rotating electric machines whose cross-sectional area changes in the circumferential direction. (2) When the shape of the recess is converted so that the cross-sectional area of the brim is the same and the end face of the brim is a straight line, the ball core angle is in the range of 0.65 to 0.75. A ball core for a rotating electric machine according to claim 1. (3) A ball core for a rotating electric machine according to claim 1 or 2, wherein each of the recessed portions is configured to correspond to a convex portion of an adjacent ball core.