JP2008061442A - Winding structure of rectangular wire, motor, winding method of rectangular wire, and forming method of rectangular wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a winding structure of a rectangular wire, a motor, a winding method of a rectangular wire, and a forming method of rectangular wire, which improve a space factor by minimizing a gap between a rectangular wire and teeth part. <P>SOLUTION: The cross-sectional shape of a rectangular wire 12 is changed for each winding layer, in the winding structure of the rectangular wire 12 which is wound around the teeth part 33 that extends in the radial direction of a stator core constituting a motor stator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric motor having a stator and a rotor, a flat wire winding structure wound around a tooth portion of a stator core of the electric motor, a flat wire winding method, and a flat wire forming method. .

  In general, an electric motor composed of a rotor provided with a magnet and a stator core around which windings are wound has a density (occupancy of windings wound around the teeth of the stator core). The higher the product ratio, the higher the performance. In view of this, in order to make it easy to wind the winding around the tooth portion, there is a laminated core piece including the tooth portion divided in the circumferential direction along the axis of the motor. By doing in this way, since a stator core can be assembled after winding a coil | winding for every divided | segmented laminated core pieces, a space factor can be raised.

By the way, the winding includes a winding made of a so-called round wire having a circular cross section and a winding made of a so-called rectangular wire having a substantially rectangular cross section. Since the rectangular wire can reduce the gap between the windings in the stator iron core as compared with the round wire due to its shape characteristics, the space factor can be further improved. Various techniques have been proposed in the manufacturing method and manufacturing apparatus for the flat wire (see, for example, Patent Document 1 and Patent Document 2).
Also, because of the shape of the flat wire, when it is wound around the tooth part, it cannot be wound like a round wire (stable winding method such as stacking firewood) It is easy to collapse. For this reason, as disclosed in Patent Document 2, a technique is proposed in which a protrusion is formed on a flat wire, and the movement of the flat wire on the upper side when the protrusion is wound around and stacked on the tooth portion is proposed. Has been. As a result, it is possible to prevent collapse due to lateral displacement of the flat wire.
JP 2000-82628 A JP 2001-359250 A

  However, the technique disclosed in Patent Document 2 described above is excellent in that it can prevent lateral displacement of a flat wire, but when the windings are stacked, the gap between the teeth and the windings becomes large. That is, the width (slot width) that can accommodate the rectangular wire of the tooth portion is different for each lamination (winding layer) of the rectangular wires. For this reason, for example, the width of the n-th layer of the flat wire does not match the slot width of the tooth portion at the portion, and this causes a problem that the space factor decreases.

  Therefore, the present invention has been made in view of the above-described circumstances, and is a winding of a rectangular wire that can further improve the space factor by minimizing the gap between the rectangular wire and the tooth portion. The present invention provides a wire structure, an electric motor, a method for winding a flat wire, and a method for forming a flat wire.

In order to solve the above problems, the invention described in claim 1 is a winding structure of a rectangular wire wound around a tooth portion extending in a radial direction of a stator core constituting a stator of an electric motor, The cross-sectional shape of the rectangular wire is changed for each winding layer.
In this case, as in the invention described in claim 2, the portion where the cross-sectional shape of the rectangular wire is changed may be set at least at both ends of the teeth portion in the axial direction of the electric motor.
By comprising in this way, a rectangular wire can be wound around a teeth part, changing the cross-sectional shape for every winding layer. That is, the aspect ratio of the flat wire (the width and thickness of the flat wire) is changed in accordance with the slot width of the tooth portion, and this can be wound around the tooth portion.

The invention described in claim 3 is characterized in that the rectangular wire has two or more kinds of cross-sectional shapes.
By comprising in this way, a rectangular wire can be wound around a teeth part, selecting two or more types of cross-sectional shapes suitably.

  According to a fourth aspect of the present invention, there is provided a stator in which the rectangular wire is wound around the teeth portion by the rectangular wire winding structure according to any one of the first to third aspects, and the stator. And a rotor provided so as to be freely rotatable.

  The invention described in claim 5 is characterized in that the stator is configured by dividing a portion including the teeth portion as an iron core piece.

  The invention described in claim 6 is characterized in that the teeth portion is skewed.

  The invention described in claim 7 is a method of winding a flat wire around a tooth portion extending in a radial direction of a stator of an electric motor, wherein the width and thickness of the flat wire are wound. It is characterized by winding while changing for each line layer.

  The invention described in claim 8 is a method of forming a flat wire in which a flat wire is wound around a tooth portion extending in a radial direction of a stator of an electric motor, and the flat wire is formed by crushing a round wire from above, below, left and right. The width dimension and the thickness dimension of the rectangular wire are determined by crushing at least twice in either the vertical direction or the horizontal direction.

According to the present invention, a rectangular wire can be wound around a tooth portion by changing its cross-sectional shape for each winding layer. That is, the aspect ratio of the flat wire (the width and thickness of the flat wire) is changed in accordance with the slot width of the tooth portion, and this can be wound around the tooth portion. For this reason, the clearance gap between a teeth part and a flat wire can be minimized, and a space factor can be improved.
Further, since the rectangular wire can be wound around the teeth portion by appropriately selecting two or more kinds of cross-sectional shapes, the space factor can be easily improved while setting the manufacturing cost low.

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the electric motor 1 is a brushless type electric motor having a stator 3 press-fitted in a housing 2 and a rotor 4 provided so as to be rotatable with respect to the stator 3. It is used for electric power steering (EPS).
The housing 2 has a bottomed cylindrical shape, and the stator 3 is press-fitted into the inner periphery of the cylindrical portion. The end portion (bottom portion) 2A of the housing 2 is press-fitted with a bearing 5 at the center. A rotating shaft 6 of the rotor 4 is rotatably supported on the bearing 5. The opening of the housing 2 is closed with a bracket 7.

The stator 3 has a substantially cylindrical stator core 10, and a rectangular wire 12 that is a winding is wound after the insulating member 11 is mounted on the stator core 10. This flat wire 12 is a so-called flat wire formed in a substantially rectangular cross section.
In the rotor 4, a magnet 13 and a resolver rotor 14 </ b> A of a position detection resolver 14 are arranged in order on a rotating shaft 6. The magnet 13 is magnetized so that the magnetic poles change in order in the circumferential direction.

  The bracket 7 has a disk shape, and a hole 20 is formed at the center. A bearing 21 is press-fitted and fixed in the hole 20, and the rotating shaft 6 is rotatably supported by the bearing 21. Further, a resolver stator 14B constituting the resolver 14 is fixed in accordance with the position of the resolver rotor 14A, and the rotational position of the resolver rotor 14A that rotates integrally with the rotary shaft 6 can be detected. A plurality of terminals 22 are arranged on the housing 2 side of the bracket 7. The terminal 22 has a role of electrically connecting the stator winding of the rectangular wire 12 on the stator 3 side and the lead wire 23 drawn from the outer periphery of the bracket 7, and is connected via the lead wire 23. Current can be supplied to the rectangular wire 12 from an external power source. In addition, a bolt hole 24 that is used when the electric motor 1 is fixed projects from the outer peripheral portion of the bracket 7.

  Here, the stator core 10 uses a split core system that can be split in the circumferential direction. As shown in FIGS. 2 to 4, the laminated core piece 30 divided from the stator core 10 has a core body 31 extending in the circumferential direction. The core body 31 is a portion that forms an annular magnetic path of the stator core 10 and is a portion that is press-fitted into the inner peripheral surface of the housing 2, and is formed in a substantially arc shape in plan view. The core body 31 has a predetermined skew angle so as to be inclined while twisting with respect to the length direction of the stator core 10 (the axis of the electric motor).

  Both end portions in the circumferential direction of the core body 31 are connection portions 32A and 32B connected to the other laminated core pieces 30 by press-fitting. One connecting portion 32A has a convex shape, and the other connecting portion 32B has a concave shape capable of receiving the connecting portion 32A. A tooth portion 33 that is a salient pole is integrally extended in the radial direction toward the center of rotation from the substantially central portion in the circumferential direction on the inner peripheral side of the core body 31. The teeth portion 33 is also skewed similarly to the core body 31. The teeth portion 33 and the core body 31 form a slot portion 60 for winding the flat wire 12.

  Moreover, the inner peripheral part 34 extended in the circumferential direction is formed in the edge part of the inner peripheral side of the teeth part 33. As shown in FIG. Two concave portions 35 are formed at the same skew angle as the tooth portion 33 on the inner peripheral surface of the inner peripheral portion 34, and three teeth are formed on one laminated core piece 30 by the two concave portions 35. Is formed. On the other hand, an inclined wall portion 34 </ b> A is formed on the outer peripheral side of the inner peripheral portion 34 so as to gradually expand toward the opening of the slot portion 60.

  The insulating member 11 mounted so as to surround the teeth portion 33 formed in this way is one so as to sandwich the teeth portion 33 from both end portions 30A, 30A in the length direction (axial direction) of the laminated core piece 30. It consists of a pair of resin insulators 40 to be mounted one by one, and a pair of paper-like insulating paper 41 having flexibility, inserted into a slot portion 60 formed by the teeth portion 33 and the core body 31, and substantially as a whole. It has a square shape. The rectangular wire 12 is wound around the tooth portion 33 through the insulating member 11 composed of the insulator 40 and the insulating paper 41.

  As shown in FIGS. 4 and 5, the flat wire 12 is routed along the side surface of the tooth portion 33 from the outer peripheral side of the slot portion 60, and is then installed on both end portions 30 </ b> A and 30 </ b> A of the laminated core piece 30. 40, and again around the tooth portion 33 in this order (34 times in this embodiment) to the slot portion 60 again to form a plurality of winding layers (six layers in this embodiment). Specifically, the flat wire 12 is wound three times in the first and second layers, four times in the third and fourth layers, and twice in the fifth layer. The sixth layer is wound once.

  Here, the flat wire 12 is wound from the second layer to the third layer (while it is wound from the 12th flat wire 12 to the 13th flat wire 12), and its cross-sectional shape is a slot portion. It corresponds to 60 shapes. That is, the vertical / horizontal (thickness, width) ratio of the 12th rectangular wire 12 is changed on the insulator 40 between the 12th rectangular wire 12 and the 13th rectangular wire 12, and the 12 The rectangular wire 12 can be aligned in accordance with the shape of the slot portion 60 by making the thickness thicker than the rectangular wire 12 and by reducing the width.

  More specifically, as shown in FIG. 6, since the shape of the slot portion 60 is formed so as to gradually expand toward the opening portion, the slot portion 60 has three layers as compared with the slot width E1 of the second layer of the winding layer. The slot width E2 of the eye is increased. Therefore, when the third layer is wound with the cross-sectional shape of the second layer of flat wire 12 (12th flat wire 12) (two-dot chain line in FIG. 6), between the flat wire 12 and the teeth portion 33, A gap S is generated.

  Therefore, in order to align the flat wires 12 without gaps in correspondence with the slot width E2 of the third layer, the cross-sectional shape of the third layer of flat wires 12 (13th flat wire), that is, the width dimension and thickness of the flat wire 12 The size is changed, and the gap S between the flat wire 12 and the tooth portion 33 is minimized. In addition, although the site | part which changes the cross-sectional shape of the flat wire 12 is not specifically limited, this site | part which changes this cross-sectional shape is not mounted on the slot portion 60 but on both end portions 30A and 30A of the laminated core piece 30. By using the insulator 40, the rectangular wires 12 can be aligned more accurately in the slot portion 60 without gaps, and the space factor can be further increased.

  Further, the rectangular wire 12 is wound around the third and fourth layers while maintaining the cross-sectional shape of the No. 13 rectangular wire, and while being wound from the fourth layer to the fifth layer (from the No. 28 rectangular wire 12). The cross-sectional shape of the rectangular wire 12 changes again during the winding to the 29th rectangular wire. That is, in this embodiment, the rectangular wire 12 having a total of three types of cross-sectional shapes is wound around one tooth portion 33. By adopting such a winding structure and winding method, it is possible to minimize the gap in the winding range (the two-dot chain line range in FIG. 5) of the laminated core piece 30, and the winding of the stator core 10. It becomes possible to improve the line space factor.

Next, a method for forming the flat wire 12 will be described with reference to FIGS.
As shown in FIGS. 7 and 8, the flat wire forming apparatus 70 includes a winding reel 72 around which a round wire 71 having a circular cross section is wound, and a flat wire forming roller 73 for forming a flat wire. . The winding reel 72 is rotatably supported. The flat wire forming roller 73 includes three rollers 74, 74, and 76, a first roller 74, a second roller 75, and a third roller 76.

  The first roller 74 is for crushing the round wire 71 from above and below, and a pair of upper and lower rollers 74A and 74B are rotatably provided. The second roller 75 is used to crush the round wire 71 from the lateral direction, and a pair of left and right rollers 75A and 75B are rotatably provided. The third roller 76 is for crushing the round wire 71 again in the vertical direction, and a pair of upper and lower rollers 76A and 76B are rotatably provided. These rollers 76A and 76B are provided to be slidable in the vertical direction. The third roller 76 is electrically connected to a control unit (not shown) so that the distance between the rollers 76A and 76B can be appropriately set based on a signal from the control unit. Further, on the downstream side (right side in FIG. 7) of the rectangular wire forming roller 73, the laminated core piece 30 constituting the stator core 10 is set so as to be rotatable in the winding direction of the rectangular wire 12.

  The round wire 71 drawn from the winding reel 72 is first crushed in the vertical direction by passing through the first roller 74. Next, by passing through the second roller 75, the lateral direction is crushed and becomes a provisional rectangular wire 12A having a substantially rectangular cross section. The thickness dimension of the temporary rectangular wire 12A is the maximum thickness that can be wound around the slot portion 60 of the laminated core piece 30.

  Thereafter, the provisional rectangular wire 12 </ b> A is formed to a predetermined thickness by the third roller 76, and becomes the rectangular wire 12 from the provisional rectangular wire 12 </ b> A. That is, the aspect ratio of the flat wire 12 (thickness dimension and width dimension of the flat wire 12) is determined by the third roller 76. Then, the rectangular wire 12 having a predetermined aspect ratio is wound around the slot portion 60 of the laminated core piece 30. The controller electrically connected to the third roller 76 is programmed in advance so that the distance between the rollers 76A and 76B changes when the provisional rectangular wire 12A passes through the third roller 76 for a predetermined length. Yes.

  That is, the third roller 76 slides in a direction in which the rollers 76A and 76B are separated from each other when the provisional rectangular wire 12A passes through the slot portion 60 by a length corresponding to two turns (two winding layers). Has been programmed. Accordingly, the thickness of the flat wire 12 from the third layer of the winding layer in the slot portion 60 becomes thicker than that of the first and second layers. In other words, the flat wire 12 has its aspect ratio (thickness dimension, width dimension) determined by crushing the round wire 71 once in the horizontal direction and twice in the vertical direction. Similarly, when the provisional rectangular wire 12A passes through the slot 60 by a length corresponding to four winding layers, the rollers 76A and 76B slide in a direction approaching each other, and the rectangular wires 12 in the fifth and subsequent layers are four. It is formed to be thinner than the flat wire 12 of the layer.

Therefore, according to the above-described embodiment, when the rectangular wire 12 is wound around the slot portion 60, the winding wire is wound from the second layer to the third layer (No. 12 rectangular wires 12 to 13). Since the cross-sectional shape of the rectangular wire 12 changes corresponding to the shape of the slot portion 60 during the winding to the rectangular wire 12), the gap between the teeth portion 33 and the rectangular wire 12 is changed. The gap S can be minimized. Therefore, the space factor of the flat wire 12 can be improved.
In addition, since three types of rectangular wires 12 having different cross-sectional shapes are appropriately selected and wound around the tooth portion 33, it is only necessary to set at least two types of distances between the rollers 76A and 76B of the third roller 76. The program can be simplified. Therefore, the space factor by the flat wire 12 can be easily improved while setting the manufacturing cost low.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
Further, in the above-described embodiment, the flat wire 12 wound around the tooth portion 33 is wound three times in the first and second layers and wound four times in the third and fourth layers. Although the case where the fifth layer is wound twice and the sixth layer is wound once has been described, the winding structure of the rectangular wire 12 is not limited to this, and the slot portion 60 of the teeth portion 33 is not limited thereto. It can be appropriately changed according to the shape.

Furthermore, although the above-mentioned embodiment demonstrated the case where the flat wire 12 which has a total of three types of cross-sectional shape was wound around the teeth part 33, the cross section of the flat wire 12 wound around one teeth part 33 is shown. The types of shapes are not limited to three, but may be two or more.
And in the above-mentioned embodiment, although the aspect ratio (thickness dimension, width dimension) of the flat wire 12 was determined by crushing the round wire 71 once in the horizontal direction and twice in the vertical direction, it was described. The aspect ratio of the flat wire 12 may be determined by crushing twice in the horizontal direction and once in the vertical direction. In addition, the aspect ratio of the flat wire 12 is determined by crushing one direction twice, and the number of crushing one direction may be three or more. In this case, a fourth roller, a fifth roller,... May be further provided on the downstream side (the right side in FIG. 7) of the third roller 76 of the flat wire forming device 70.

Moreover, although the above-mentioned embodiment demonstrated the case of what is called a split core system comprised from the laminated core piece 30 by which the stator core 10 was divided | segmented into the circumferential direction, the stator core 10 is the integral molding which is not a split core. Even if it is made, the winding structure and winding method of the flat wire 12 in this embodiment can be applied.
Furthermore, in the above-described embodiment, the core body 31 (the teeth portion 33) has a predetermined skew angle so as to be inclined while twisting with respect to the length direction of the stator core 10 (the axis of the electric motor). Although explained, even if the core main body 31 (tooth portion 33) does not have a skew angle, the winding structure and winding method of the flat wire 12 in this embodiment can be applied.

It is sectional drawing which shows the structure of the electric motor in embodiment of this invention. It is a perspective view which shows the structure of the stator in embodiment of this invention. It is a perspective view which shows the structure of the laminated core piece in embodiment of this invention. It is a perspective view which shows the state which wound the flat wire around the laminated iron core piece in embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is explanatory drawing of the winding structure of the flat wire in embodiment of this invention. It is a lineblock diagram of a flat wire forming device in an embodiment of the present invention. It is explanatory drawing explaining the shaping | molding method of the flat wire in embodiment of this invention.

Explanation of symbols

1 Electric motor
3 Stator 4 Rotor
10 Stator core 12 Flat wire 30 Stacked core piece (core piece)
30A End portion 33 Teeth portion 60 Slot portion 71 Round wire (round wire)
73 Flat wire forming roller 74 First roller 75 Second roller 76 Third roller

Claims (8)

  A winding structure of a rectangular wire wound around a tooth portion extending in a radial direction of a stator iron core constituting a stator of an electric motor, characterized in that the cross-sectional shape of the rectangular wire is changed for each winding layer. The winding structure of a flat wire.   2. The rectangular wire winding structure according to claim 1, wherein a portion where the cross-sectional shape of the rectangular wire is changed is set at least at both ends of the teeth portion in the axial direction of the electric motor.   The rectangular wire winding structure according to claim 1 or 2, wherein the flat wire has two or more kinds of cross-sectional shapes.   The stator by which the said flat wire is wound by the said teeth part by the winding structure of the flat wire in any one of Claims 1-3, and the rotation provided rotatably with respect to the said stator An electric motor having a child.   The electric motor according to claim 4, wherein the stator is configured by dividing a portion including the teeth portion as an iron core piece.   The electric motor according to claim 4, wherein the teeth portion is skewed.   A method of winding a rectangular wire around a tooth portion extending in a radial direction of a stator of an electric motor, wherein the winding is performed while changing the width and thickness of the rectangular wire for each winding layer. A method of winding a rectangular wire, characterized by: A method of forming a rectangular wire in which a rectangular wire is wound around a tooth portion extending in a radial direction of a stator of an electric motor, and the rectangular wire is formed by crushing a round wire from above, below, left, and right, and either A method of forming a rectangular wire, wherein the width and thickness of the rectangular wire are determined by crushing at least twice.

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