JP2016116421A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to insulation paper or coil insulation coating at a corner of a stator iron core.SOLUTION: A coil 10 forming a stator winding 3 is inserted, straddling a teeth 11 inside a slot 14 and includes terminal wires 15, 16 connected with other coils 10 forming the stator winding 3 outside the slot 14. The coil 10 is provided with a coil narrow width section 21 formed to be smaller than a width in a circumferential direction of the coil 10 at a section in which the width of the coil 10 in the circumferential direction is built in the slot 14, at a position opposing to the end of a stator iron core 2 on the side to which the terminal wires 15, 16 are joined.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a rotating electrical machine, and more particularly to a stator of a rotating electrical machine.

  A stator winding of a rotating electrical machine includes a concentrated winding method in which coils are wound around each magnetic pole and a distributed winding method in which winding is performed across a plurality of magnetic poles. Compared to concentrated winding, distributed winding has the advantage that the distribution of the rotating magnetic field is smooth and vibrations are reduced, but the coil ends become higher because the coils end up in the coil end portion, and the rotating electrical machine There is a drawback that it is not possible to achieve downsizing.

  Therefore, as a means for optimizing the overlapping of the coils at the coil ends in the distributed winding and minimizing the gap between the overlapping coils to reduce the coil end height, the stator winding for one phase is made up of a plurality of coils. There is a method of dividing into. The coil ends of each of the divided coils are formed into a shape that minimizes the gap when the coils overlap each other, and by assembling them into the core, the useless gap in the coil end is reduced. The end height can be reduced.

  If the coil is formed into an optimum coil end shape and formed as an integral coil that is not divided, it is extremely difficult to assemble it into the core. Therefore, it is divided into a plurality of coils to obtain an optimal shape and to facilitate assembly. As an example in which the overlap between the coils at the coil end is optimized by dividing the coil into a plurality of coils as described above, for example, Patent Document 1 is available.

JP 2001-197709 A

  After the divided coil group is assembled to the stator core, the coils must be electrically joined to form a stator winding. As one method used at this time, the terminal wires of each coil are bent in the circumferential direction of the stator on the outer side in the axial direction of the stator core and brought close to the terminal wires of other coils, and then the terminal wires are connected to each other. There is a method of joining them by a method such as welding. In this method, in order to suppress the height of the coil end, it is effective to perform the bending process of the terminal wire as close to the stator core as possible. However, if bending is performed at a location close to the stator core, the coil terminal may bite into the corner of the laminated end face of the stator core slot.

  When the coil terminal bites into the corner of the iron core, the insulating paper placed between the coil and the iron core or the insulation coating applied to the coil is damaged, and the insulation between the coil and the stator core deteriorates. There is a problem that the function of the product is impaired.

  The present invention has been made to solve the above-described problems, and an object thereof is to prevent damage to the insulating paper or the coil insulating film at the corners of the stator core.

A rotating electrical machine according to the present invention includes a rotor and a stator disposed on an outer peripheral side of the rotor, and the stator includes a stator iron core and a stator winding, and the stator. The iron core has a plurality of teeth arranged at intervals in the circumferential direction and a slot formed between adjacent teeth in the circumferential direction, and the coils constituting the stator winding are inserted across the teeth in the slot And having a terminal wire connected to other coils constituting the stator winding outside the slot,
The coil was formed so that the width of the coil in the circumferential direction was smaller than the width of the coil in the circumferential portion at the position facing the end of the stator core on the side where the terminal wire was joined. A coil width narrow portion is provided.

  In the rotating electrical machine configured as described above, since there is a gap between the coil constituting the stator winding and the stator core at the corners of the laminated end faces of the slots of the stator core, the terminal wire is bent. In this case, since the terminal wire does not bite into the corner portion of the stator core, the insulating paper or the coil insulating film is hardly damaged.

1 is a side cross-sectional view showing a rotating electrical machine according to Embodiment 1. FIG. FIG. 3 is a plan sectional view showing a stator portion according to the first embodiment. It is the top view (A) and side view (B) which show the tortoiseshell type coil used as a stator coil | winding. FIG. 6 is a plan view illustrating a configuration method of the stator winding according to the first embodiment. It is a schematic diagram which shows the state before bending a terminal wire, after the coil of Embodiment 1 is integrated in a stator core. It is a schematic diagram which shows the state after a terminal wire is bent after the coil of Embodiment 1 was integrated in a stator core. It is sectional drawing (A)-(D) which shows the metal mold | die for processing in order to change a coil cross-sectional shape. It is sectional drawing (A) and (B) which show the metal mold | die for processing in order to change a coil cross-sectional shape. It is sectional drawing (A) and (B) which show the metal mold | die for processing in order to change a coil cross-sectional shape. It is a schematic diagram which shows the state before bending a terminal wire, after the coil of Embodiment 1 is integrated in a stator core. It is a schematic diagram which shows the state after a terminal wire is bent after the coil of Embodiment 1 was integrated in a stator core. It is a perspective view which shows an example of the lower mold | type of a shaping die in the case of providing a dent only in one side. It is an enlarged view which shows the coil bending part vicinity after bending the terminal wire by Embodiment 1. FIG. It is an enlarged view which shows the coil bending part vicinity after bending a terminal wire. FIG. 6 is a plan sectional view showing a stator portion according to a second embodiment. It is a schematic diagram (A), (B), (C) which shows the apparatus which shape | molds the coil by Embodiment 2. FIG. It is sectional drawing (A)-(D) which shows the metal mold | die for processing in order to change a coil cross-sectional shape. 6 is a perspective view showing a lower mold in an integrated mold according to a second embodiment. FIG.

Embodiment 1 FIG.
The rotating electrical machine includes a stator, a rotor, and a fixing motor frame that holds them. 1 is a side sectional view showing a rotating electrical machine according to the first embodiment, FIG. 2 is a plan sectional view showing a stator portion, and FIG. 3 is a plan view (A) showing a tortoiseshell type coil serving as a stator winding. It is a figure (B). In the figure, the stator 1 is configured in a substantially cylindrical shape, and includes a stator core 2 and a stator winding 3 wound around the stator core 2. The stator core 2 is generally configured by laminating a plurality of thin magnetic plates made of an iron-based material. The stator 1 is fitted and fixed to the inner periphery of a substantially cylindrical motor frame 4. The rotor 6 is disposed inside the stator 1 and is rotatably supported by a bearing 5 with respect to the motor frame 4. The stator 1 and the rotor 6 are combined to constitute a rotating electric machine.

  The motor frame 4 mechanically holds the stator 1 and the rotor 6 and serves as a heat dissipation path for dissipating heat generated in the stator 1, and is generally a metal material such as iron or aluminum. Is used. The rotor 6 includes a substantially cylindrical iron core 8 fixed to the rotating shaft 7 and a permanent magnet 9 attached to the outer peripheral surface of the iron core 8. The stator core 2 is provided with a plurality of teeth 11 at equal intervals in the circumferential direction, and the stator winding 3 is wound once or a plurality of times so as to straddle one or more teeth 11. The stator winding 3 may be formed so as to be wave-wound along the circumferential direction, but may be formed as a tortoiseshell type coil 22 as shown in FIG.

  As the coil constituting the stator winding 3, a wire made of a metal material having a high conductivity such as copper or aluminum is used and covered with an insulating resin film. In the range included in the axial height of the stator core 2, the coil is disposed in the slot 14 formed between the teeth 11 adjacent to each other in the circumferential direction, and protrudes from the axial height of the stator core 2. Forms a coil end, and a bending process is performed in the direction of the coil arranged in the other slot 14 at the coil end portion, thereby joining the terminal wires. The stator winding 3 is composed of windings having three or more phases, and each phase is composed of a plurality of coils. That is, a plurality of coils are joined in series or in parallel, and further joined in series-parallel to form a one-phase stator winding 3.

  Next, the stator winding 3 will be described in detail. As the coil constituting the stator winding 3, for example, a tortoiseshell type coil 22 as shown in FIG. 3 can be used. FIG. 4 is a plan view showing a configuration method of the stator winding 3 in the case where the stator core 2 is divided into the inner peripheral core 12 and the outer peripheral core 13 and the turtle shell type coil 22 is used. 4A is a plan view showing a state in which one of the coils is inserted into the inner peripheral iron core 12, and FIG. 4B is a plan view showing a state in which the other coil is inserted into the inner peripheral iron core 12. FIG. 4C is a plan view showing a state in which the outer peripheral side iron core 13 is fitted to the inner peripheral side iron core 12 from the axial direction.

  In FIG. 2, the stator when the iron core is divided into two, an inner peripheral iron core 12 and an outer peripheral iron core 13 is shown. In this system, the iron core of the stator 1 is divided at the outermost periphery of the teeth 11 to form two iron cores, an inner peripheral iron core 12 and an outer peripheral iron core 13. In the inner peripheral iron core 12, the teeth 11 are connected at the innermost periphery of the stator, and the slot 14 that is sandwiched between the teeth 11 and in which the coil 10 that constitutes the stator winding 3 is disposed is open on the outer peripheral side. It has become. Here, in the inner peripheral side core 12, assuming that the outer peripheral side where each slot 14 is opened is the inlet of the slot 14 and the inner peripheral side connected is the bottom of the slot 14, the coil 10 is inserted into the slot 14 from the inlet of each slot 14. The stator 1 can be assembled by inserting the outer peripheral side core 13 into the outer periphery of the inner peripheral side core 12 after inserting the coil into the inner periphery.

  That is, the number of the slots 14 is formed as a turtle shell-shaped coil 22 wound in advance a plurality of times and formed into a polygonal shape. One side of each coil (two in FIG. 4) is simultaneously inserted into the inner peripheral side of each slot 14 (FIG. 4A). Thereafter, while rotating the inner peripheral iron core 12, all the other sides (two in FIG. 4) of each coil are simultaneously inserted into the slots 14 straddling the plurality of teeth 11 (FIG. 4 (B)). Finally, the outer peripheral iron core 13 is fitted into the outer periphery of the inner peripheral iron core 12 (FIG. 4C).

After each coil is inserted, both ends of each coil are joined to form a stator winding for each phase. Both ends of each turtle shell-shaped coil 22 formed in a polygonal shape need to be joined to terminals of other coils. The two terminals to be joined at this time are always arranged in different slots 14,
Bending is performed so that the coil end portions on the outer side in the axial direction of the stator core 2 are close to each other.

  FIG. 5 is a developed view showing a state before the terminal wire is bent after the coil is incorporated into the stator core, and FIG. 6 is a state after the terminal wire is bent after the coil is incorporated into the stator core. FIG. 5 and 6 show only two coils A and B to be joined, and are views of a cylindrical stator as seen from the inner peripheral side. FIG. 6 shows a state in which bending is performed in order to join the terminal wire 15 of the coil A and the terminal wire 16 of the coil B.

  A coil A is incorporated in slots 14A and 14B provided in the stator core 2, and a coil B is incorporated in slots 14C and 14D. In order to join the terminal wire 15 of the coil A and the terminal wire 16 of the coil B, the terminal wire 15 is bent in a direction in which the terminal wire 15 comes out from the slot 14 of the stator core 2 in the axial direction. In FIG. 6, the coil terminal wire is bent sideways, but since FIG. 6 is an expanded representation of the cylindrical stator, the stator is actually cylindrical, so the coil terminal wire is Is bent in the circumferential direction. Then, both terminal lines are joined.

  The coil incorporated in the slot 14 has a width of the coil in the circumferential direction of the stator in the vicinity of the end of the stator core 2 on the side where the terminal wire is joined. A smaller coil width narrowing portion 21 is provided. The terminal wire is bent in the coil narrow portion 21. In FIG. 6, the coil width narrow portion 21 is not visible because the coil end of the coil B is in front, but the terminal wire 16 is similarly provided with the coil narrow portion 21. The coil narrow portion 21 is processed in advance at the time of coil forming. Processing is to narrow the coil width by plastic deformation using a mold or the like, and can be processed after the coil is formed into a tortoiseshell shape or before it is formed, but in either case, the stator core 2 is formed. It is necessary to process before assembling the coil.

  7A to 7D are cross-sectional views showing a mold for processing to change the coil cross-sectional shape, and in FIGS. 7A to 7D, a coil having a substantially square cross section is rectangular. The metal mold | die for carrying out the plastic deformation to the cross section is shown. The mold 30 is a mold for forming a desired coil cross section, and is manufactured using a material such as tool steel or cemented carbide having a strength capable of withstanding a load that deforms a coil made of copper or aluminum. Yes. The mold 30 is divided into a concave lower mold 30a and a convex upper mold 30b, and the sectional shape of the gap 31 when both are combined is set to be the sectional shape of the coil after molding. Yes.

  The length of the mold 30 (the dimension in the direction perpendicular to the paper surface in FIG. 7) is matched with the length of the portion where the coil cross section is deformed. The coil 32 is arranged in the groove 30a1 of the lower mold 30a (FIG. 7C), and the coil 32 is crushed by the upper mold 30b from above (FIG. 7D). A material such as copper or aluminum used for the coil is a highly malleable material, and when the upper die 30b is pressed with a sufficient load, the shape of the coil cross section becomes substantially the same as the shape of the gap 31 of the die. . Here, an example in which the concave lower mold 30a and the convex upper mold 30b are combined has been described. However, the shape of the mold is not limited to this, and other divided forms may be used. For example, as shown in FIGS. 8A and 8B, an apparatus that combines two molds having an L-shaped cross section may be used.

  In the above description, an example in which a coil is deformed into a desired coil cross-sectional shape by restricting the entire circumference of the coil cross-section using a die is shown, but only in a specific direction as shown in FIGS. The coil may be deformed. In this case, only one direction of the coil cross section is pressed to deform the cross section height h in that direction to a desired value. However, in this method, the width W3 in the transverse direction of the cross section varies due to the influence of variations in the wire diameter of the material. If the design is such that the variation in the width in the cross-sectional direction does not have a great influence after the assembly of the stator, it is only necessary to deform in a specific direction.

  The coil provided with the coil narrow portion 21 is incorporated into the stator core 2 through the coil cross-section forming process as described above. And the state before bending a terminal line is shown by FIG. Near the end of the stator core 2 of the terminal wire 15, a coil narrow portion 21 is provided. Further, by bending the terminal line, the state shown in FIG. 6 is obtained.

  In the above description, an example is shown in which concave portions are provided on both sides of the coil, that is, two surfaces facing in the circumferential direction to reduce the width of the coil. However, a concave portion may be provided only on one side. 10 and 11 show a case where a concave portion is processed on one side of the coil to provide a narrow portion of the coil width, and FIG. 10 shows a state before the terminal wire is bent after the coil is incorporated in the stator core. FIG. 11 is a development view showing a state after the terminal wire is bent after the coil is incorporated in the stator core. The bending directions of the two terminals of the coils A and B are respectively determined. Taking the coil A as an example, the terminal wire 22 is always bent to the right side, and the other terminal wire is always bent to the left side like the terminal wire 23 of the coil B.

  At this time, the narrow coil portion 24 provided in the terminal wire 22 is provided with a recess on one inner surface of the bent portion of the terminal wire 22. 10 and 11, although hidden behind other coil ends, the terminal wire 23 is also provided with a narrow coil width portion, and the concave portion is opposite to the narrow coil portion 24 of the terminal wire 22, and the concave portion is the terminal wire 23. It is provided on the left side. That is, a concave portion exists inside the bent portion of the terminal wire 23. FIG. 12 is a perspective view showing an example of a lower mold of a molding die when a recess is provided only on one side. The method for deforming the coil cross-section by sandwiching the coil between the concave lower mold and the convex upper mold is basically the same as that described in FIG. However, in the lower mold 50 of FIG. 12, in order to provide a recess only on one side, a projection 51 corresponding to a narrow section is formed so as to protrude from the wall on one side. The groove widths other than the protrusions 51 are the same as the coil width of the material. When the coil cross-sectional shape is deformed using this mold, the projection 51 corresponding to the narrow cross-section is formed so as to protrude from one side, so that the coil cross-sectional narrow portion also has a concave shape on only one side.

  FIG. 13 is an enlarged view showing the vicinity of the coil bending portion after the terminal wire 15 is bent. When the terminal wire 15 is bent after the coil assembly to the stator core 2 and the terminal wires are joined to each other, by providing the coil width narrowing portion 21 in which the coil width of the bending portion is narrowed, the inside of the bending portion is provided. Thus, the coil does not bite into the corner 33 of the stator core 2. As a result, the insulating paper disposed between the coil and the stator core 2 and the insulating coating applied to the coil are less likely to be damaged. In FIG. 13, the insulating paper is not shown.

  When the cross sections of the coils housed in the slots are all the same cross section, in order to prevent the coils from biting into the corners of the stator core 2 inside the bent part of the coil, as shown in FIG. It is necessary to dispose the bent portion 35 completely away from the laminated end 2A of the stator core 2 completely outside. On the other hand, in the present embodiment, as shown in FIG. 13, a part of the bending portion 34 can be arranged in the stack (in the slot) of the stator core 2, so that the height of the coil end can be reduced.

  Of course, when a thin wire with a narrow coil width is used, the effects of preventing damage to the insulating coating and suppressing the coil end height as described above can be obtained without providing a narrow coil width portion. However, when a thin wire is used, the impedance of the winding increases, and the output as a rotating electrical machine decreases, or heat generation increases, resulting in a decrease in performance. On the other hand, when the coil width narrow portion is provided in only a part of the coil as in this embodiment, the coil length of the portion where the cross-sectional area becomes small is the length of the entire winding including the slot portion and the coil end portion. On the other hand, the increase in impedance is negligible, and the performance degradation of the rotating electrical machine is extremely small. Furthermore, in the bending process of the terminal wire 15, since the bending direction is determined at each terminal portion, as shown in FIGS. 10 and 11, a recess for narrowing the coil width can be applied only to the inside of the bending, While providing the effect of ensuring insulation by providing the coil width narrow portion, it is possible to further suppress the decrease in coil cross-sectional area and suppress the increase in impedance.

Embodiment 2. FIG.
Generally, in a rotating electrical machine, the cross-sectional area of a coil arranged in a slot is increased to increase the space factor, and the winding resistance value is decreased, thereby reducing copper loss and further improving the characteristics. . On the other hand, the stator core only needs to have a sufficient cross-sectional area with respect to the amount of magnetic flux, and it is desirable to reduce the size of the stator core in order to reduce iron loss. Therefore, as shown in FIG. 15, the slot cross-sectional shape may be a trapezoidal shape. That is, in this embodiment, the slot formed between the teeth adjacent in the circumferential direction is formed in a tapered shape so that the width orthogonal to the radial direction becomes smaller toward the radially inner peripheral side. In FIG. 15, the cross-sectional shapes of the coils arranged in the slots are different, and the coil widths of the coils in the stator circumferential direction are also different. FIG. 15 shows an example in which four coils are arranged in the slot, but the width W1 of the coil 10A arranged on the inner peripheral side is the smallest value among the four coils. The width W2 of the coil 10D disposed on the outermost periphery is the largest value.

  A manufacturing apparatus for producing such a coil is shown in FIG. First, the coil wire is cut into a predetermined length (FIG. 16A), and then the coil wire is pressed by the mold 36 so that the cross-sectional shape becomes a trapezoid (FIG. 16B). FIGS. 17A to 17D are cross-sectional views showing a mold for crushing a coil wire into a trapezoidal shape. The mold 36 has the same configuration as the mold for forming the narrow coil width portion described with reference to FIG. 7, and includes a lower mold 36a having a concave cross section and an upper mold 36b having a convex shape. By combining the two, a trapezoidal gap 37 that is the same as the coil cross-sectional shape after processing is formed (FIG. 17B). The length of the mold 36 is the length of the portion that needs to be crushed, that is, substantially the same as the axial length of the slot and the axial length of the stator core.

  The coil wire 38 is put into the lower die 36a (FIG. 17C), and the upper die 36b is pushed from above with a pressing machine or the like (FIG. 17D), so that the coil cross-sectional shape is transformed into a desired shape. Can do. In FIG. 16B, the coil cross-section is deformed at four locations E to H, but the respective cross-sectional shapes are different, and therefore molds corresponding to the shapes are prepared. Although the order differs depending on how the coil is wound, for example, the E portion is the narrowest coil cross-sectional shape shown in FIG. 15, the F portion is the third cross-sectional shape from the inner peripheral side, and the G portion is from the inner peripheral side. The mold can be formed so that the second cross-sectional shape, H, is the outermost coil cross-sectional shape.

  Four coil cross sections E to H are formed with respective molds while the coil is linear. Then, by bending the coil, a turtle-shaped coil having a different coil cross-sectional shape at each slot can be formed (FIG. 16C). In the above description, a coil having a square cross section before forming is used. However, the cross sectional shape is not limited to this, and a rectangular cross section and a circular cross section can be similarly formed. Since the radial position of the coil in the slot is different between the two end portions of the same coil, when the coil cross-sectional shape is changed for each slot portion, the coil cross-sectional shapes of the two end portions are different.

  Also in the coil according to the present embodiment, a narrow coil width portion is provided at a location that becomes a bent portion of each terminal wire as in the first embodiment. At this time, although the cross-sectional shape of the slot portion differs depending on the terminal line, the circumferential coil width in the narrow coil width portion of the terminal wire having a wide slot portion is the circumferential coil width portion of the narrow terminal wire in the circumferential direction. Keep it larger than the coil width. In order to provide the coil narrow portion, a dedicated mold for forming the coil narrow portion as described in the first embodiment may be used, but the coil of the slot portion described in FIG. You may use the metal mold | die formed integrally with the metal mold | die to shape | mold. FIG. 18 is a perspective view showing a lower mold in an integral mold. In FIG. 18, narrow groove width portions 39 are provided at both ends of the groove provided in the lower mold 40. In the narrow groove portion 39, a narrow coil width portion is formed.

  As shown in FIG. 15, when the slot cross-sectional shape is trapezoidal and the cross-sectional shape of the coil is also matched with the slot cross-sectional shape in order to improve the space factor, the cross-sectional shapes of the two terminal lines of one coil are different. become. At this time, by setting the coil width of the coil width narrow portion according to each cross-sectional shape, the coil cross-sectional area in the coil width narrow portion is not reduced more than necessary, and the increase in winding impedance is minimized. Also, the insulating coating applied to the insulating paper and the coil is difficult to be damaged.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 Stator, 2 Stator core, 3 Stator winding, 6 Rotor, 10 Coil,
11 teeth, 14 slots, 15, 16 terminal wires, 21 coil narrow portion.

Claims (4)

A rotating electrical machine including a rotor and a stator disposed on the outer peripheral side of the rotor,
The stator includes a stator core and a stator winding,
The stator core includes a plurality of teeth arranged at intervals in the circumferential direction, and a slot formed between the teeth adjacent in the circumferential direction,
The coil constituting the stator winding has a terminal wire inserted across the teeth in the slot and connected to another coil constituting the stator winding outside the slot. And
In the coil, at the position facing the end of the stator core on the side where the terminal wire is joined, the width of the coil in the circumferential direction at the portion where the width of the coil in the circumferential direction is incorporated in the slot A rotating electric machine characterized in that a coil narrow portion formed smaller is provided. 2. The rotating electrical machine according to claim 1, wherein the narrow portion of the coil is formed by providing recesses on two surfaces facing the circumferential direction of the coil. 2. The rotating electrical machine according to claim 1, wherein the narrow portion of the coil is formed by providing a concave portion on one inner surface of the bent portion of the coil. The slot is formed in a taper shape so that the width orthogonal to the radial direction becomes smaller as it goes toward the radially inner periphery side, and the cross-sectional shape of the coil disposed in the slot is formed in a trapezoidal shape,
The circumferential width in the coil width narrow portion of the terminal wire of the coil housed in the wide slot is defined as the coil width narrow portion in the terminal wire of the coil housed in the narrow slot. The rotating electrical machine according to any one of claims 1 to 3, wherein the rotating electrical machine is formed so as to be larger than a width in a circumferential direction.

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