JP2018064421A - Stator of dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix a segment coil sufficiently to a stator core, by making varnish infiltrate the whole segment coil easily.SOLUTION: In the stator 1 of a dynamo-electric machine where a portion of a conductor segment 21 projecting farther outside than the axial end face of the stator core 10 has skew part 22a folded obliquely to superpose on the conductor segment 21 adjacent to the stator core 10 in the circumferential direction, varnish W is dropped to the folded skew part 22a and so as to impregnate the slot of the stator core 10 with the varnish W, thus fixing a segment coil 20 to the stator core 10, the folded skew part 22a is provided with a swollen part 22b projecting toward the folded skew part 22a of an adjacent conductor segment 21, and forming a gap S between the folded skew part 22a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a stator for a rotating electrical machine, and more particularly to a stator for a rotating electrical machine that fixes a segment coil to a stator core via a varnish.

  A winding coil, a segment coil, or the like is used as a stator coil of a rotating electrical machine such as a motor generator. For example, the segment coil is formed by inserting each straight portion of a conductor segment bent into a substantially U shape from one of the slots of the stator core, bending each straight portion protruding from the other, and bending other conductor segments. The tips of the parts are sequentially welded and wound around the teeth to form a coil. Then, the varnish is dropped from above the segment coil, the varnish flows into the slot through the gap between the conductor segments, and the varnish is solidified, whereby the segment coil is fixed to the stator core.

  In particular, as a configuration for pouring the varnish into the slot, there is a configuration in which a wall portion having an axial height higher than that of the coil end is erected on a portion facing the coil end side surface of the insulator disposed on the end surface of the stator core ( For example, see Patent Document 1). In this configuration, the varnish is poured between the coil of the segment coil from between the wall portion of the insulator and the side surface of the coil end.

JP 2011-200050 A

  If the varnish does not sufficiently enter the slot, the segment coil and the stator core may not be sufficiently fixed. In the configuration described in Patent Document 1, since the varnish is poured from between the wall portion of the insulator and the coil end, it takes time to allow the varnish to penetrate the entire segment coil.

  Even when varnish is dropped from above the segment coil, if the integration rate of the conductor segments constituting the segment coil is high and there are many portions where the conductor segments are in close contact with each other, the varnish is blocked by the contact portions of the conductor segments. It is difficult to penetrate the entire segment coil. For this reason, it becomes difficult for the varnish to penetrate into the slot, and as a result, the segment coil and the stator core may be insufficiently fixed.

  Therefore, an object of the present invention is to provide a stator for a rotating electrical machine in which varnish easily penetrates the entire segment coil and sufficiently fixes the segment coil to the stator core.

  A stator of a rotating electrical machine according to the present invention includes a stator core having a plurality of slots, and a segment coil formed by connecting conductor segments respectively inserted into the plurality of slots, and the conductor segments are formed on the stator core. A portion projecting outward from the end face in the axial direction has a skewed portion that is obliquely bent so as to overlap an adjacent conductor segment in the circumferential direction of the stator core, and varnish is applied to the skewed portion. A stator of a rotating electrical machine that impregnates a varnish into the plurality of slots and fixes the segment coil to the stator core, and protrudes toward the skew portion of the conductor segment adjacent to the skew portion, A bulging portion is provided to form a gap between the skewed portions of the adjacent conductor segments. That.

  According to the present invention, the varnish penetrates the entire segment coil, and the segment coil can be sufficiently fixed to the stator core.

It is a schematic perspective view of the stator of a rotary electric machine. It is a figure which shows the state before mounting | wearing with the stator core of the conductor segment which comprises a segment coil. It is an expansion perspective view of the bulging part explaining the formation method of a bulging part. It is an enlarged view of the skew part of a conductor segment.

  The rotating electrical machine in the present embodiment is used for a motor generator of a hybrid vehicle or an electric vehicle. FIG. 1 is a perspective view of a stator 1 of a rotating electrical machine according to an embodiment of the present invention. As shown in FIG. 1, the stator 1 includes a stator core 10 and a segment coil 20 composed of a rectangular wire. The stator core 10 is an annular magnetic part, and is configured by, for example, laminating a plurality of silicon steel plates (electromagnetic steel plates). In addition, you may comprise by press-molding a resin binder and magnetic material powder.

  The stator core 10 has an annular yoke 11 disposed on the outer peripheral side and a plurality of teeth 12. The plurality of teeth 12 are disposed at intervals in the circumferential direction, and each tooth 12 projects from the yoke 11 inward in the radial direction. The segment coil 20 includes three-phase coils of U, V, and W, and is configured by Y-connecting these three-phase coils of U, V, and W. The segment coil 20 is inserted into a slot 13 that is a space between adjacent teeth 12, and is wound around the teeth 12.

  As shown in FIG. 2, the segment coil 20 has a pair of leg portions 22, 22 of a plurality of U-shaped conductor segments 21 that are bent outwardly from one axial end of the stator core 10. The bent portion is formed by connecting to a leg portion 22 of another adjacent conductor segment 21.

  Next, the formation of the segment coil 20 will be described in detail. In FIG. 2, the conductor segment 21 has a pair of leg portions 22, 22 parallel to each other, and a connecting skew portion 23 that connects each end of the leg portions 22, 22 to form a U shape. The leg portions 22, 22 of the conductor segment 21 include a conductor wire 24 having a rectangular shape with a rectangular cross section and an insulating film 25 covering most of the length of the conductor wire 24. The conductor wire 24 is exposed from the insulating film 25 at the tips of the leg portions 22, 22 of the conductor segment 21.

  The leg portions 22 and 22 of the conductor segment 21 are inserted into the slot 13 from one end side of the stator core 10 in the axial direction. The portions of the leg portions 22 and 22 protruding from the other end side of the stator core 10 in the axial direction are bent in the circumferential direction of the stator core 10 to form a bent oblique portion 22a (shown by a one-dot chain line in FIG. 2). The On the side surface in the axial direction of the stator core 10 of the bent and skewed portion 22a, bulge portions 22b and 22b that protrude in the axial direction of the stator core 10 are formed, respectively.

  The bulging portions 22b and 22b are formed by crushing the leg portion 22. That is, in FIG. 3, the folded and skewed portion 22 a is crushed from both sides in the width direction as indicated by the arrow P, so that the crushed portion bulges in the direction of the arrow B perpendicular to the direction of the arrow P. Thus, the bulging portions 22b and 22b are formed. In addition, by performing this crushing operation simultaneously with the bending operation of the leg portion 22, an increase in work steps can be suppressed.

  In FIG. 4, the enlarged view of the state which bent the leg part 22 of the conductor segment 21 is shown. In FIG. 4, only two conductor segments 21 and 21 are shown, and the other conductor segments 21 are not shown.

  As shown in FIG. 4, when the leg portion 22 is bent, the bent skew feeding portion 22a is arranged so as to overlap the adjacent bent skew feeding portion 22a. At this time, the bulging portion 22b of the bent skew portion 22a abuts on the adjacent bent skew portion 22a, and a gap S is formed between the bent skew portion 22a.

  Returning to FIG. 2, the distal end portion of the bent and skewed portion 22 a, that is, the conductor wire 24, is further bent and formed so as to extend in the axial direction of the stator core 10, as indicated by a one-dot chain line in FIG. 2. .

  And in the some conductor segment 21, the front-end | tip part (conductor strand 24) extended in the axial direction of the conductor segment 21 of the same phase adjacent to radial direction is joined and connected by welding, such as TIG welding. As a result, the plurality of conductor segments 21 are connected to each other by bending a portion disposed outside one end of the stator core 10 in the axial direction. In this way, the segment coil 20 shown in FIG. 1 is formed by bending the conductor segment 21 and connecting it to the adjacent conductor segment 21.

  Next, a case where the varnish W is dropped onto the segment coil 20 to fix the segment coil 20 to the stator core 10 will be described. In particular, the flow of the varnish W when the varnish W is dropped will be described.

  In FIG. 1, the stator 1 is fixed by a jig (not shown) so that the axial direction of the stator core 10 is parallel to the vertical direction. Next, varnish W is dropped onto the segment coil 20 from above in the axial direction of the stator core 10. As shown by the arrow F in FIG. 4, the varnish W dropped on the segment coil 20 enters the gap S of the bent skew portion 22a in the conductor segment 21, and the segment coil 20 along the bent skew portion 22a. Penetrates inside. In this way, the varnish W is guided into the slot 13 through the gap S of the bent skew portion 22 a of the conductor segment 21 and penetrates into the slot 13. Thereafter, by heating the stator 1 in which the entire segment coil 20 is impregnated with the varnish W, the varnish W in the slot 13 is solidified and the segment coil 20 is firmly fixed to the stator core 10.

  As described above, since the bulged portion 22b is formed in the bent and skewed portion 22a of the conductor segment 21, a gap S can be formed between the adjacent conductor segments 21 and 21, and the gap S passes through the gap S. Since the varnish W penetrates the entire segment coil 20, the varnish W penetrates sufficiently into the slot 13. As a result, when the varnish W is solidified, the segment coil 20 can be sufficiently fixed to the stator core 10. Moreover, the insulation failure by the vibration and electricity supply which are generated when the segment coil 20 is not sufficiently fixed to the stator core 10 can be suppressed.

  Moreover, since the bulging part 22b can be formed by crushing the conductor segment 21, other parts are not required for forming the bulging part 22b, and a simple method is adopted. Thus, it is possible to suppress an increase in component costs and manufacturing costs related to the bulging portion 22b.

  In the above-described embodiment, the case where the bulging portion 22b is formed in the bent skew portion 22a obtained by bending the leg portion 22 is described. However, in FIG. 2, the connecting skew portion 23 is also similar to the bulging portion 22b. The bulging portion may be formed. In this case, in FIG. 1, after the varnish W is dropped from one end side in the axial direction of the stator 1, the stator 1 is turned over and the varnish W is dropped again. Also in this case, the varnish W penetrates the entire segment coil 20 through the gap S formed between the connecting oblique portions 23 as in the case described above.

  In addition, the pair of bulging portions 22b and 22b are formed on both sides in the axial direction of the bent and slanted portion 22a of the conductor segment 21, but the number and forming positions of the bulging portions 22b and 22b are different from each other. What is necessary is just to set suitably according to the length of the row part 22a. In addition, it is preferable to form the bulging part 22b at the same position in all the conductor segments 21.

  DESCRIPTION OF SYMBOLS 1 Stator, 10 Stator core, 11 York, 12 teeth, 13 slots, 20 segment coil, 21 Conductor segment, 22 Leg part, 22a Bending skew part, 22b Expansion part, 23 Connection skew part, 24 Conductor strand, 25 Insulating film, S gap, W varnish.

Claims (1)

A stator core having a plurality of slots, and a segment coil formed by connecting conductor segments respectively inserted into the plurality of slots,
The conductor segment has a skewed portion bent obliquely so that a portion protruding outward from an end face in the axial direction of the stator core overlaps an adjacent conductor segment in the circumferential direction of the stator core;
A stator of a rotating electrical machine that applies a varnish to the skew portion and impregnates the varnish into the plurality of slots, and fixes the segment coil to the stator core,
The oblique portion is provided with a bulging portion that protrudes toward the oblique portion of the adjacent conductor segment and forms a gap with the oblique portion of the adjacent conductor segment. A stator of a rotating electrical machine.

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