JP2015082952A - Stator for rotary electric machine and method for forming insulation film of coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a technique capable of suppressing reduction of a space factor of a coil and enlargement of a stator when an insulation film is formed on the surface of a linear conductor constituting the coil by coating.SOLUTION: A coil 3 includes: a coil side part 30 which is constituted using a linear conductor 34 in which an insulation film 35 formed by coating is formed on the surface and which is arranged in a slot of a core and a cross part 50 which connects a pair of coil side parts 30 in the outside in the axial direction L of the core. In a surface toward the outside in at least one of the axial direction L and the circumferential direction C in the cross part 50, a region closer to the core side than the end surface 50a in the outside in the axial direction L of the cross part 50 is defined as an object domain A. In at least a part of the object domain A, a thick film part 70 is formed having the thickness of the insulation film 35 which is thicker than that of the insulation film 35 except the object domain A.

Description

  The present invention provides a core in which a plurality of axially extending slots are dispersedly arranged in the circumferential direction, a coil side portion arranged in the slot, and a bridge portion that connects a pair of coil side portions on the outer side in the axial direction of the core. The present invention relates to a stator for a rotating electrical machine having a coil wound around a core, and a method for forming an insulating film of a coil by forming an insulating film on the coil by painting.

  A coil wound around a stator core for a rotating electrical machine as described above is generally used in order to appropriately ensure the electrical insulation between the coil and the core and the electrical insulation between each part of the coil. In addition, a linear conductor having an insulating film formed on the surface thereof is used. As such a coil, Japanese Unexamined Patent Application Publication No. 2012-117133 (Patent Document 1) describes a technique of forming an insulating film on the surface of a linear conductor constituting the coil by electrodeposition coating. By the way, when an insulating film is formed by electrodeposition coating as in Patent Document 1, it is generally difficult to perform multiple coatings. This is because, in electrodeposition coating, an insulating paint is deposited on the surface of a linear conductor by passing an electric current using a coil as an anode or a cathode to form an insulating film. In the state after the electrodeposition coating is performed once, the coil having the insulating film already formed on the surface of the linear conductor is used as an anode or a cathode, and the insulating coating is applied to the surface of the linear conductor. This is because it is generally difficult to deposit properly.

  As described above, when an insulating film is formed on the surface of a linear conductor by electrodeposition coating, it is generally difficult to perform the coating multiple times. As a result, pinholes generated in the insulating film are generated. May be a problem. In order to solve such a problem, it is conceivable to form an insulating film by dipping (immersion) coating that is relatively easy to perform multiple times of coating. However, in dipping coating, the portion where excess insulating paint is accumulated during drying and curing of the insulating paint tends to be a thick film portion where the insulating film is thicker than other portions. In particular, when dipping coating is performed on a coil after molding, such a thick film portion is likely to occur. And depending on the site | part in which a thick film part is formed, there exists a possibility that the space factor of a coil may fall or a stator (coil end part) may enlarge. However, in Patent Document 1, no particular recognition has been made on these points.

JP 2012-117133 A

  Therefore, when an insulating film is formed by coating on the surface of the linear conductor constituting the coil, it is desired to realize a technique capable of suppressing a decrease in the coil space factor and an increase in the size of the stator.

  A core in which a plurality of slots extending in the axial direction of a cylindrical core reference surface according to the present invention are distributed in the circumferential direction of the core reference surface, a coil side portion arranged in the slot, and a pair of the coils And a coil wound around the core having a transition portion for connecting a side portion on the outside of the core in the axial direction. A film is formed using a linear conductor formed on the surface, and the outer end surface of the crossing portion in the axial direction is within the surface facing the outside in at least one of the axial direction and the circumferential direction of the crossing portion. The thicker film portion where the thickness of the insulating film is larger than the thickness of the insulating film outside the target region is formed in at least a part of the target region with the core side region as the target region. There to that point.

  In the present application, the “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator that functions as both a motor and a generator as necessary.

  According to said characteristic structure, the thick film part with the large thickness of an insulating film is formed in at least one part of an object area | region. That is, since the thick film portion is not formed on the coil side portion, it is possible to prevent the coil space factor from being lowered by forming the thick film portion on the coil side portion. Furthermore, the target region is a region closer to the core than the end surface on the outer side in the axial direction in the transition portion, among the surfaces facing outward in at least one of the axial direction and the circumferential direction in the transition portion. Therefore, the part where the thick film part is formed is a part that can suppress the coil end part from being enlarged in the axial direction and the radial direction, and a part that has little influence on the arrangement of the other transition part. can do. Therefore, the increase in size of the coil end portion due to the thick film portion can be suppressed, and as a result, the increase in size of the stator can be suppressed.

  Here, the transition portion includes a circumferentially extending portion that extends in the circumferential direction, and a connecting portion that connects the circumferentially extending portion and the coil side portion, and the connecting portion is provided in the axial direction. A bent outer surface that is a surface facing the outer side of the bent portion in the connecting portion is included in the target region, and has a bent portion that is bent inward in the circumferential direction in the transition portion as it goes outward. It is preferable that the thick film portion is formed on the bent outer surface.

  According to this configuration, the dead space formed outside the bent portion can be effectively used as the space where the thick film portion is formed. Therefore, it becomes easy to suppress the enlargement of the coil end portion due to the thick film portion.

  In addition, it is preferable that the plurality of thick film portions are divided into a plurality of the target regions.

  According to this configuration, it is possible to reduce the thickness of the insulating film in the thick film portion as compared with the case where the thick film portion is formed only in one target region. Therefore, it becomes further easy to suppress the enlargement of the coil end part due to the thick film part.

  An insulating film is formed by painting on a coil wound around a core in which a plurality of slots extending in the axial direction of a cylindrical core reference surface according to the present invention are distributed in the circumferential direction of the core reference surface. A characteristic configuration of a method for forming an insulating film of a coil is a coil unit that constitutes the coil, and a coil side portion disposed in the slot in a state of being wound around the core and a pair of the coil side portions are arranged in the core. A preparation step of preparing a coil unit formed so as to have a connecting portion connected outside in the axial direction, and a coating adhesion step of attaching a liquid insulating coating to the surface of the linear conductor constituting the coil unit And a drying and curing step of drying and curing the insulating paint, and within the surface facing outward with respect to at least one of the axial direction and the circumferential direction in the transition portion In the drying and curing step, a region on the core side of the end portion on the outer side in the axial direction in the transition portion is a target region, and in the drying and curing step, a part of the target region is the coil side portion and the transition portion in the coil unit The coil unit is held so as to be a target portion which is a portion arranged at the lowermost portion.

  When the insulating film is formed on the coil by painting as described above, when the drying and curing process is performed, a part of the insulating paint (excess insulation) adhered to the surface of the linear conductor in the paint adhesion process. The paint) moves downward along the surface of the linear conductor by the action of gravity and surface tension. As a result, the amount of the insulating coating adhering to the target portion, which is the lowermost portion of the coil side portion and the transition portion in the coil unit, is likely to increase compared to the other portions. In view of this point, according to the characteristic configuration described above, in the drying and curing process, the coil unit is held such that a part of the target region becomes the target portion. As a result, the thick film portion can be formed in a portion including the target portion in the target region. That is, since the thick film portion can be formed in at least a part of the target region, as described above, it is possible to suppress a reduction in the coil space factor and an increase in the size of the stator.

  Here, for one of the coil units, the coating adhesion step and the drying and curing step are repeatedly performed in the order described, and in the drying and curing step performed at least twice for the one coil unit, It is preferable that the coil unit is held such that the target regions that are target portions are different from each other.

  According to this configuration, the plurality of thick film portions can be divided into a plurality of target regions. Therefore, the thickness of the insulating film in the thick film portion is suppressed to be small, and it is easy to suppress an increase in size of the coil end portion due to the thick film portion.

It is a perspective view of the coil unit which concerns on embodiment of this invention. It is a partial sectional view of a stator concerning an embodiment of the present invention. It is a schematic diagram of each process of the insulating film formation method of the coil which concerns on embodiment of this invention. It is a flowchart which shows the insulating film formation method of the coil which concerns on embodiment of this invention. It is a radial view of the coil unit which concerns on other embodiment of this invention.

  Embodiments of a stator and coil insulating film forming method for a rotating electrical machine according to the present invention will be described with reference to the drawings. In the following description, the “axial direction L”, “circumferential direction C”, and “radial direction R” are based on the cylindrical core reference plane S (see FIG. 2) unless otherwise specified. It is defined as “Axial first direction L1” represents a direction toward one side in the axial direction L, and “Axial second direction L2” represents a direction toward the other side in the axial direction L (a direction opposite to the axial first direction L1). Represents. The “circumferential first direction C1” represents a direction toward one side in the circumferential direction C, and the “circumferential second direction C2” represents a direction toward the other side in the circumferential direction C (a direction opposite to the circumferential first direction C1). Represents. Here, as shown in FIGS. 1 and 2, the clockwise direction when viewed along the axial direction L from the first axial direction L1 side is the circumferential first direction C1.

  Hereinafter, in the description of the coil 3 in a state before being wound around the core 2, assuming that the coil 3 is wound around the core 2 (see FIG. 2), the axial direction L, the circumferential direction C, Further, description will be made using each direction of the radial direction R. Further, in this specification, terms relating to dimensions, arrangement direction, arrangement position, etc. (for example, parallel or orthogonal) are used as a concept including a state having a difference due to an error (an error that is acceptable in manufacturing). .

1. Overall Configuration of Stator The stator 1 is a stator for a rotating electrical machine, and includes a core 2 (stator core) and a coil 3 wound around the core 2 as shown in FIG. The stator 1 is used, for example, in a rotating electrical machine driven by three-phase alternating current (an example of multiphase alternating current). In the present embodiment, the stator 1 is a stator for a rotating field type rotating electrical machine, and functions as an armature. A rotating magnetic field generated from the stator 1 rotates a rotor (not shown) as a field magnet including a permanent magnet or an electromagnet. A rotor is arrange | positioned inside the radial direction R of the core 2, for example.

  In the core 2, a plurality of slots 40 extending in the axial direction L are distributed in the circumferential direction C. As shown in FIG. 2, the plurality of slots 40 are arranged along the circumferential direction C at regular intervals. Each of the slots 40 is formed so as to penetrate the core 2 in the axial direction L. Further, each of the slots 40 is formed so as to extend in the radial direction R. In the present embodiment, each of the slots 40 is formed so as to open toward the inside of the radial direction R. A tooth 23 is formed between two slots 40 adjacent to each other in the circumferential direction C. In the present embodiment, a configuration in which side portions on both sides in the circumferential direction C of the teeth 23 (two side portions facing opposite sides in the circumferential direction C) are formed in parallel to each other, that is, a configuration in which the teeth 23 are parallel teeth. Is adopted. Therefore, in this embodiment, the slot 40 is formed so that the width in the circumferential direction C gradually decreases as it goes inward in the radial direction R.

  The above-described core reference surface S is a virtual surface that serves as a reference for the arrangement of the slots 40. In the present embodiment, as shown in FIG. 2, a cylinder including end surfaces inside each radial direction R of the plurality of teeth 23. An imaginary virtual surface (inner peripheral surface of the core) is used as the core reference surface S. The outer surface (core outer peripheral surface) of the core 2 in the radial direction R may be used as the core reference surface S.

  In the present embodiment, the core 2 is configured by arranging a plurality of core pieces 20 in a ring shape along the circumferential direction C. Each of the core pieces 20 includes a main body portion (yoke portion) extending in the circumferential direction C and a tooth 23 extending inward in the radial direction R from the main body portion. In the example shown in FIG. 2, the plurality of core pieces 20 arranged in an annular shape are fixed to each other so as not to move by using a cylindrical fixing member 4 fitted to the outer surface (outer peripheral surface) in the radial direction R. Is done. The core piece 20 is configured by, for example, laminating a plurality of magnetic plates (for example, electromagnetic steel plates such as silicon steel plates), or is mainly made of a powder material formed by press-molding magnetic material powder. Configured as a component. Although details are omitted, when the stator 1 is manufactured, for example, a plurality of core pieces 20 are arranged on the outer side in the radial direction R with respect to the coil 3 formed in the same cylindrical shape as the state wound around the core 2. The coil side portions 30 (to be described later) are respectively disposed in the slots 40.

2. Configuration of Coil The coil 3 is configured using a linear conductor 34 that is a linear conductor. The linear conductor 34 is made of a conductive material such as copper or aluminum. As shown in FIGS. 1 and 2, in the present embodiment, a linear conductor (flat wire) having a rectangular cross section perpendicular to the extending direction is used as the linear conductor 34. Here, the “rectangular shape” includes a rectangle whose corners are arc-shaped, or a rectangle whose absolute value of the difference between the size of the inner angle and 90 degrees is less than a predetermined angle (for example, 5 degrees or 10 degrees). including. An insulating film 35 is formed on the surface of the linear conductor 34 by painting. The insulating film 35 is made of an electrically insulating material such as resin. The insulating film 35 is formed over the entire circumference of the cross section of the linear conductor 34 in the entire region along the extending direction of the linear conductor 34 excluding a part of the connection portion 39 and the like with other conductors. In the present embodiment, in a state before the insulating film 35 is formed by painting on the surface of the linear conductor 34 (a state before execution of a paint adhesion step P2 described later, see FIG. 4), the linear conductor 34 Is a bare conductor (a bare conductor) which is a conductor material as it is. A conductor having only an oxide film formed on the surface as an insulating film is included in the bare conductor.

  As shown in FIGS. 1 and 2, the coil 3 includes a coil side portion 30 disposed inside the slot 40, and a crossover portion 50 that connects the pair of coil side portions 30 outside the axial direction L of the core 2. Have The crossovers 50 are provided on both sides of the core 2 in the axial direction L (on the first axial direction L1 side and on the second axial direction L2 side). A coil end portion that is a portion of the coil 3 protruding in the axial direction L from the core 2 is formed by the assembly of the plurality of crossover portions 50. As shown in FIG. 2, in this embodiment, a plurality of coil side portions 30 are arranged in each slot 40. Each of the coil side portions 30 is disposed such that two sides (two sides adjacent to each other across a rectangular corner) in the orthogonal cross section are along the circumferential direction C and the radial direction R, respectively. In the present embodiment, a plurality of coil side portions 30 are arranged in a line along the radial direction R in each slot 40. In the present embodiment, the slot 40 is formed such that the width in the circumferential direction C gradually decreases as it goes inward in the radial direction R. In the present embodiment, the plurality of coil side portions 30 have the same cross-sectional area. Therefore, each of the plurality of coil side portions 30 arranged in the slot 40 has a width in the radial direction R wider than the other coil side portions 30 arranged in the layer adjacent to the outside in the radial direction R, and The width in the circumferential direction C is narrow. Here, the “layer” is an arrangement region in the radial direction R of one coil side portion 30.

  The coil 3 is comprised using the coil unit 10, as shown in FIG. In the present embodiment, the coil 3 is configured using a plurality of coil units 10. In the present embodiment, the coil unit 10 is a coil part (overlap part) that is wound a plurality of times between a pair of slots 40, and the coil 3 is wound around the core 2 by overwrapping. In this example, the coil unit 10 is formed by winding a single linear conductor 34 a plurality of times spirally. In the present embodiment, the coil unit 10 is a cassette coil that is spirally formed before being wound around the core 2. Further, in the present embodiment, the linear conductor 34 is bent (that is, the edge) so that one of the pair of short sides constituting the rectangular cross section of the linear conductor 34 is the inner peripheral side and the other is the outer peripheral side. By performing (wise bending), the coil unit 10 is formed. And in this embodiment, the insulating film 35 is formed with respect to the coil unit 10 (namely, the coil unit 10 after shaping | molding) after the bending process was performed.

  The coil unit 10 includes a plurality of first coil sides 31 arranged on the first circumferential direction C1 side and a plurality of second coil sides 32 arranged on the second circumferential direction C2 side. The unit 30 is provided. Each of the plurality of crossover portions 50 included in the coil unit 10 connects the first coil side portion 31 and the second coil side portion 32 that are respectively disposed in different slots 40. The plurality of crossover portions 50 arranged on the same side in the axial direction L have the same shape. And the coil 3 is formed by arrange | positioning the some coil unit 10 to a cylindrical shape, shifting the position of the circumferential direction C. FIG. The plurality of coil units 10 constituting the coil 3 are configured in the same manner except that the arrangement positions in the circumferential direction C are different.

  The coil unit 10 includes connection portions 39 at both ends in the extending direction of the linear conductor 34, in other words, at both ends in the current flow direction. In the present embodiment, both of the pair of connection portions 39 of the coil unit 10 are arranged on the first axial direction L1 side with respect to the core 2. The connection part 39 of the coil unit 10 is joined to the connection part 39 of another coil unit 10, or connected to a power supply terminal, a neutral point, or the like. In the following description, unless otherwise specified, the transition portion 50 refers to a transition portion that connects the coil side portions 30 included in one coil unit 10, and is formed by joining the connection portions 39 of different coil units 10. It does not include the transition part.

  As shown in FIG. 1, the crossover 50 includes a circumferential extension 53 that extends in the circumferential direction C, a first connection 51 that connects the circumferential extension 53 and the first coil side 31, A second connecting portion 52 that connects the direction extending portion 53 and the second coil side portion 32 is provided. Each of the first connection portion 51 and the second connection portion 52 is a connection portion that connects the circumferentially extending portion 53 and the coil side portion 30. In the present embodiment, the circumferentially extending portion 53 is formed so as to extend along a plane orthogonal to the axial direction L. Specifically, the circumferentially extending portion 53 is formed to extend in the circumferential direction C at the same position in the axial direction L. The circumferentially extending portion 53 has an offset portion 54 that offsets the linear conductor 34 in the radial direction R. And the part except the offset part 54 in the circumferential direction extension part 53 is formed in the circular arc shape extended along the circumferential direction C seeing in the axial direction L. As shown in FIG.

  Each of the first connection portion 51 and the second connection portion 52 has a bent portion 60 that bends inward in the circumferential direction C of the crossover portion 50 as it goes outward in the axial direction L. Here, the outside in the axial direction L is the side away from the core 2 in the axial direction L, and the connecting portion 50 on the first axial direction L1 side is the first axial direction L1 side, and the second axial direction L2 side. The crossover portion 50 is on the second axial direction L2 side. Moreover, about the bending part 60 with which a connection part is equipped, the inside of the circumferential direction C in the transition part 50 is the coil of the connection object by the said connection part among the pair of coil side parts 30 connected by the said transition part 50. It is a side that is directed along the circumferential direction C toward the coil side 30 different from the side 30. That is, the inner side in the circumferential direction C of the crossover portion 50 is basically the side toward the center of the crossover portion 50 in the circumferential direction C in the circumferential direction C. Therefore, in this embodiment, the 1st connection part 51 has the bending part 60 bent to the circumferential second direction C2 side as it goes to the outer side of the axial direction L, and the 2nd connection part 52 is the outer side of the axial direction L. It has the bending part 60 bent to the circumferential first direction C1 side as it goes to.

  Here, the surface of the connecting portion facing the outside of the bent portion 60 is defined as a bent outer surface 60a. The outside of the bent portion 60 means a side away from the bent central axis of the bent portion 60 along the radial direction with reference to the central axis. Further, in the specification of the present application, when the direction of a surface is directed to a certain side (one direction in the target direction), it means that a normal vector directed outward from the surface has a component toward one side in the target direction. To do. That is, it means that the inner product of the normal vector going outward of the surface and the vector going to one side of the target direction is positive. In the present embodiment, the coil unit 10 is formed by performing edgewise bending on the linear conductor 34. Therefore, in the present embodiment, as shown in the inset of FIG. 1 (partly enlarged view), the bent outer surface 60a is formed by the short sides constituting the rectangular cross section of the linear conductor 34. The outer surface (side surface) extends in the extending direction of the linear conductor 34. The short side constituting the bent outer surface 60 a is the one located on the outer peripheral side of the bent portion 60 of the pair of short sides constituting the rectangular cross section of the linear conductor 34. In FIG. 1, the bent outer surface 60a and the outer surface 61a described later are hatched thinner than the thick film portion 70 described later.

  In the present embodiment, each of the first connection part 51 and the second connection part 52 is arranged between the coil side part 30 and the bent part 60 in the axial direction L at the same position in the circumferential direction C with the coil side part 30. An extending axially extending portion 61 is provided. In the present embodiment, as shown in FIG. 1, the axially extending portion 61 is formed such that the width in the radial direction R decreases and the width in the circumferential direction C increases as it goes outward in the axial direction L. ing. Moreover, in this embodiment, the axial direction extension part 61 is only a width | variety according to the shift | offset | difference according to the shift | offset | difference of the center position of the radial direction R between the coil side part 30 and the bending part 60 which are two connection object. The shaped conductor 34 is formed to be offset in the radial direction R.

  Here, the region on the core 2 side of the end surface 50a on the outer side in the axial direction L of the transition portion 50 in the surface facing the outside in at least one of the axial direction L and the circumferential direction C in the transition portion 50 is defined as the target region. A. In the present embodiment, the end surface 50 a is configured by an end surface on the outer side in the axial direction L of the circumferentially extending portion 53. Here, as described above, the outside in the axial direction L is the side away from the core 2 in the axial direction L, and the connecting portion 50 on the axial first direction L1 side is the axial first direction L1 side. The connecting portion 50 on the second direction L2 side is on the second axial direction L2 side. Further, the outer side in the circumferential direction C is defined as follows. That is, the direction from the first coil side portion 31 side to the second coil side portion 32 side along the extending direction of the crossover portion 50 is defined as one side in the extending direction, and the vector and the axial direction toward the one side in the extending direction For the crossover portion 50 where the inner product with the outward vector of L is positive, the outer side in the circumferential direction C is the first circumferential direction C1 side, and for the portion of the crossover portion 50 where the inner product is negative, The outer side in the direction C is the second circumferential direction C2 side. That is, the outer side in the circumferential direction C is basically the side away from the center in the circumferential direction C of the crossover portion 50 in the circumferential direction C. Therefore, in the present embodiment, for the first connection portion 51, the circumferential first direction C1 side is outside the circumferential direction C, and for the second connection portion 52, the circumferential second direction C2 side is outside the circumferential direction C. .

  As shown in FIG. 1, in the present embodiment, the bent outer surface 60 a of the bent portion 60 is included in the target region A. Furthermore, in the present embodiment, the target area A also includes an outer surface 61 a that faces the outer side in the circumferential direction C of the axially extending portion 61. That is, in the present embodiment, the target area A is configured by at least the bent part 60, and in this example, the target area A is also configured by the axially extending part 61. Therefore, in the present embodiment, the target area A has a surface facing outward in both the axial direction L and the circumferential direction C, and a surface facing outward in only the circumferential direction C of the axial direction L and the circumferential direction C. included. Further, in the present embodiment, the target region A (here, the portion constituted by the bent portion 60) does not include the surface facing the inner side or the outer side in the radial direction R. That is, the target region A (here, the portion constituted by the bent portion 60) is constituted by a surface whose normal vector is orthogonal to the radial direction R.

  Then, a thick film portion 70 in which the thickness of the insulating film 35 is larger than the thickness of the insulating film 35 outside the target region A is formed in at least a part of the target region A. Here, the insulating film 35 other than the target region A includes the insulating film 35 in the coil side portion 30 and the insulating film 35 in a portion other than the target region A in the transition portion 50. The thickness of the insulating film 35 in the thick film portion 70 is, for example, about 10 to 20 times the thickness of the insulating film 35 other than the target region A. As shown in the inset of FIG. 1, in the present embodiment, a thick film portion 70 is formed in a part of the target region A. Specifically, the thick film portion 70 is formed on the bent outer surface 60a, and the thick film portion 70 is not formed on the outer surface 61a. More specifically, the thick film portion 70 is formed in a portion (further part in this example) facing outward in both the axial direction L and the circumferential direction C in the bent outer surface 60a. In other words, in the present embodiment, the thick film portion 70 is formed in a portion facing the outside in both the axial direction L and the circumferential direction C in the target region A. Further, in the present embodiment, the thick film portion 70 is formed on a surface that does not face the inner side or the outer side in the radial direction R, that is, a surface whose normal vector is orthogonal to the radial direction R. In addition to the portion where the thick film portion 70 faces outward in both the axial direction L and the circumferential direction C in the target region A, the thick film portion 70 is outward only in the circumferential direction C of the axial direction L and the circumferential direction C in the target region A. The thick film portion 70 is not formed in the portion facing outward in both the axial direction L and the circumferential direction C in the target region A, and the axial direction L in the target region A is not formed. And it is also possible to adopt a configuration in which only the circumferential direction C in the circumferential direction C is formed only in the portion facing outward. That is, the thick film portion 70 may not be formed on the bent outer surface 60a, and the thick film portion 70 may be formed on the outer surface 61a.

  The thick film portion 70 in the target region A is arranged such that the outer end portion in the axial direction L of the thick film portion 70 is disposed closer to the core 2 than the end surface 50a on the outer side in the axial direction L of the crossover portion 50. It is desirable to set the part to be formed. Further, a portion where the thick film portion 70 is formed in the target region A is set so that the outer end portion in the circumferential direction C of the thick film portion 70 does not become the outer end portion in the circumferential direction C of the transition portion 50. It is desirable to do. That is, the portion where the thick film portion 70 is formed in the target region A so that the outer end portion in the circumferential direction C of the crossover portion 50 is formed by the portion where the thick film portion 70 is not formed in the crossover portion 50. It is desirable to set

  By the way, in this embodiment, as shown in the inset of FIG. 1, a plurality of target areas A are formed so as to be aligned in the radial direction R. The plurality of target areas A are formed in the same area in each of the axial direction L and the circumferential direction C. Hereinafter, a plurality of target areas A formed so as to be aligned in the radial direction R in this way are collectively considered as one target area A. Therefore, in the present embodiment, one target area A is formed by a set of a plurality of divided areas separated from each other in the radial direction R, and each of the divided areas (in this example, a part of each of the divided areas). In the region), a thick film portion 70 is formed.

  As shown in FIG. 1, in the present embodiment, the coil unit 10 includes a plurality of target areas A. Specifically, the coil unit 10 includes four target areas A, a first target area A1, a second target area A2, a third target area A3, and a fourth target area A4. The first target area A1 and the second target area A2 are arranged on the first axial direction L1 side with respect to the core 2, and the third target area A3 and the fourth target area A4 are in the second axial direction with respect to the core 2. Arranged on the L2 side. In the present embodiment, the plurality of thick film portions 70 are formed so as to be divided into a plurality of target regions A. At this time, for example, the plurality of thick film portions 70 may be configured to be divided into all the target regions A of the plurality of target regions A included in the coil unit 10. It can also be set as the structure divided | segmented into the some target area A of the some target area A with which the unit 10 is provided.

  In the latter configuration, for example, the target area A where the thick film portion 70 is formed is limited to the target area A on the first axial direction L1 side (in this example, the first target area A1 and the second target area A2). Alternatively, it is possible to limit to the target area A (the third target area A3 and the fourth target area A4 in this example) on the second axial direction L2 side. Further, the target area A in which the thick film portion 70 is formed can be both the target area A on the first axial direction L1 side and the target area A on the second axial direction L2 side. At this time, the target area A on the first axial direction L1 side and the target area A on the second axial direction L2 side are set to the same target area A in the circumferential direction C (for example, the first target area A1 and the third target area). The region A3) may be the target region A on the opposite side in the circumferential direction C (for example, the first target region A1 and the fourth target region A4). In FIG. 1, the case where the thick film portion 70 is formed in the first target region A1 is shown as an example, but it is a matter of course that the thick film portion 70 is not formed in the first target region A1. Is also possible.

3. Coil Insulating Film Forming Method A coil 3 insulating film forming method according to the present embodiment will be described with reference to FIGS. This insulating film forming method is a method of forming the insulating film 35 on the coil 3 by painting, and as shown in FIG. 4, a preparation process (step # 01), a paint adhesion process (step # 02), and drying. A curing step (step # 03) is provided.

  The preparation step (step # 01) is a step of preparing the coil unit 10 formed so as to have the coil side portion 30 and the crossover portion 50 while being wound around the core 2. In the present embodiment, in the preparation step, the coil unit 10 in a state of being formed into the shape shown in FIG. 1 (however, the insulating film 35 is not formed) is prepared. The coil unit 10 prepared in the present embodiment is formed using a linear conductor 34 in a bare conductor state. In addition, the coil unit 10 prepared in the present embodiment is formed in a spiral shape by winding a single linear conductor 34 a plurality of times.

  After the preparation process (step # 01) is executed, the paint adhesion process (step # 02) is executed. The coating material adhesion process is a process in which a liquid insulating coating material 90 is adhered to the surface of the linear conductor 34 constituting the coil unit 10. Note that, as necessary, a process for cleaning the surface of the linear conductor 34 and a process for improving the adhesion between the linear conductor 34 and the insulating paint 90 are performed before the coating adhesion process. The insulating paint 90 is a paint that forms the insulating film 35 by drying and curing. The insulating paint 90 is, for example, a solution obtained by dissolving a polyimide resin in a solvent, such as an aqueous polyamideimide solution. In the present embodiment, in the coating adhesion process, as shown in FIGS. 3A and 3C, the treatment tank 91 in which the insulating coating 90 is stored is used, and the entire coil unit 10 is liquidized with the insulating coating 90. By being submerged below the surface, the insulating paint 90 is attached to the entire surface of the linear conductor 34 constituting the coil unit 10. That is, in this embodiment, the insulating paint 90 is attached to the surface of the linear conductor 34 by a dipping method in which the coil unit 10 is immersed in the liquid insulating paint 90. At this time, by covering the portion constituting the connection portion 39 (see FIG. 1) of the linear conductor 34 with the mask member, the insulating paint 90 can be prevented from adhering to the portion. Alternatively, after the formation of the insulating film 35, the insulating film 35 in a portion constituting the connection portion 39 in the linear conductor 34 may be removed.

  After execution of the paint adhesion process (step # 02), a drying and curing process (step # 03) is performed. The drying and curing process is a process of drying and curing the insulating paint 90. The insulating coating 90 attached to the surface of the linear conductor 34 is dried and cured, so that an insulating film 35 is formed on the surface of the linear conductor 34 by painting. In the present embodiment, in the drying and curing step, as shown in FIGS. 3B and 3D, the coil taken out from the processing tank 91 using a curing furnace 92 (drying furnace) capable of heating the coil unit 10. By heating the unit 10, the solvent (for example, moisture) in the insulating paint 90 is evaporated, and the insulating paint 90 attached to the surface of the linear conductor 34 is dried and cured. Here, in the state where the coil unit 10 is taken out from the processing tank 91, a part of the insulating paint 90 attached to the surface of the linear conductor 34 in the paint attaching process is caused by the action of gravity or surface tension. It moves toward the lower side in the vertical direction along the surface of. As a result, in the target portion 80 which is a portion disposed at the lowermost portion (the lowermost portion in the vertical direction) of the coil side portion 30 and the crossover portion 50 in the coil unit 10, the amount of the insulating coating 90 adhering is another portion. More than In view of this point, in the drying and curing step, the coil unit 10 is held so that a part of the target area A becomes the target portion 80. As a result of drying and curing the insulating paint 90 attached to the surface of the linear conductor 34 in a state where the coil unit 10 is held in this manner, the thick film described above is formed on the portion including the target portion 80 in the target region A. Part 70 is formed.

  In the present embodiment, as shown in FIG. 4, with respect to one coil unit 10, the paint adhesion process (step # 02) and the drying and curing process (step # 03) are repeatedly performed in the order described. Thereby, the insulating film 35 having a plurality of layers is formed on the surface of the linear conductor 34. For example, it can be set as the structure which repeatedly performs a paint adhesion process and a drying hardening process about 5 to 10 times in order of description. In the present embodiment, the coil unit 10 is held so that the target areas A to be the target portions 80 are different from each other in at least two drying / curing steps executed for one coil unit 10. In other words, the plurality of drying / curing steps executed for one coil unit 10 include drying / curing steps in which the target areas A to be the target portions 80 are different from each other. In the example shown in FIG. 3, in the drying and curing step shown in FIG. 3B, the coil unit 10 is held so that a part of the third target region A <b> 3 becomes the target portion 80, and the drying shown in FIG. In the curing step, the coil unit 10 is held such that a part of the second target region A2 becomes the target portion 80. Therefore, in this example, the thick film portion 70 is formed at least in the second target area A2 and the third target area A3.

  By the way, the shape of the coil unit 10 prepared in the preparation step may be the same shape as the state wound around the core 2 or a shape different from the state wound around the core 2. In the latter case, for example, in order to widen the gap in the radial direction R between the plurality of coil side portions 30 included in one coil unit 10, the direction along the winding axis (core) is larger than the state wound around the core 2. The coil unit 10 having a shape that is stretched along the radial direction R in the state of being wound around 2 can be prepared in the preparation step.

4). Other Embodiments Finally, other embodiments according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the above embodiment, the configuration in which the circumferentially extending portion 53 is formed so as to extend along a plane orthogonal to the axial direction L has been described as an example. However, the embodiment of the present invention is not limited to this, and the circumferentially extending portion 53 may have a portion extending in a direction inclined with respect to a plane orthogonal to the axial direction L. For example, as shown in FIG. 5, a portion of the circumferentially extending portion 53 that is closer to the circumferential first direction C1 than the offset portion 54 is formed in a shape that goes outward in the axial direction L toward the circumferential second direction C2. In addition, a portion of the circumferentially extending portion 53 that is closer to the second circumferential direction C2 than the offset portion 54 is formed in a shape that is directed outward in the axial direction L toward the first circumferential direction C1. it can. In this case, as shown in FIG. 5, in addition to the bent outer surface 60 a of the bent portion 60, a portion of the circumferentially extending portion 53 on the core 2 side with respect to the end surface 50 a on the outer side in the axial direction L of the crossover portion 50. A surface (a surface facing outward in at least one of the axial direction L and the circumferential direction C) is also included in the target region A. In this example, the surface constituting the target region A in the circumferentially extending portion 53 is disposed outside the short side (the axial direction L of the pair of short sides) constituting the rectangular cross section of the circumferentially extending portion 53. It is an outer surface (side surface) formed in the extending direction of the circumferentially extending portion 53 formed by a short side). In the configuration shown in FIG. 5, the thick film portion 70 is formed on the surface of the circumferentially extending portion 53 in addition to the bent outer surface 60a, or the thick film portion 70 is formed on the bent outer surface 60a. It is also possible to adopt a configuration in which the is formed on the surface of the circumferentially extending portion 53 without being formed.

(2) In the above-described embodiment, in the configuration in which the plurality of thick film portions 70 are formed by being divided into the plurality of target regions A, that is, in at least two dry-curing steps executed for one coil unit 10, The configuration in which the coil unit 10 is held so that the target areas A to be the portions 80 are different from each other has been described as an example. However, the embodiment of the present invention is not limited to this. That is, the configuration in which the thick film portion 70 is formed only in one target region A, in other words, the target region A that becomes the target portion 80 in all of the plurality of drying and curing steps that are executed for one coil unit 10 is obtained. It is also possible to adopt a configuration in which the coil unit 10 is held so as to be the same. In the above-described embodiment, the configuration in which the paint adhesion process and the drying and curing process are repeatedly executed in the order of description for one coil unit 10 is described as an example. It is also possible to adopt a configuration in which each of the drying and curing steps is executed only once.

(3) In the above embodiment, the configuration in which the thick film portion 70 is formed in a part of the target area A has been described as an example. However, the embodiment of the present invention is not limited to this, and a configuration in which the thick film portion 70 is formed in the entire target region A is also possible.

(4) In the above embodiment, the case where the cross-sectional shape of the linear conductor 34 constituting the coil 3 is rectangular has been described as an example. However, the embodiment of the present invention is not limited to this, and the linear conductor constituting the coil has a cross-sectional shape other than a rectangular shape (for example, a circular shape, an elliptical shape, a polygonal shape other than a square shape, etc.). A conductor may be used. For example, when the linear conductor 34 whose cross-sectional shape is circular or elliptical is used, the surface facing the inner side or the outer side in the radial direction R is present in the target region A (particularly the portion constituted by the bent outer surface 60a). It is included.

(5) In the above-described embodiment, the coil unit 10 is a coil portion that is wound a plurality of times between the pair of slots 40, and the configuration in which the coil 3 is wound around the core 2 by overlapping winding has been described as an example. . However, the embodiment of the present invention is not limited to this. For example, the coil unit 10 is configured to be a coil part wound a single turn between a pair of slots 40 or a coil part wound a single turn or a plurality of turns between a plurality of pairs of slots 40. Is also possible. Moreover, the coil unit 10 is a coil part wound by the slot 40 so that it may become a wave shape, and it can also be set as the structure by which the coil 3 is wound by the core 2 by a wave winding.

(6) In the above-described embodiment, in the paint adhering step, the entire coil unit 10 is submerged under the liquid surface of the insulating paint 90, so that the insulating paint 90 is applied to the entire surface of the linear conductor 34 constituting the coil unit 10. The configuration for attaching the film has been described as an example. However, the embodiment of the present invention is not limited to this. For example, in the paint adhesion step, only a part of the coil unit 10 can be submerged under the liquid surface of the insulating paint 90. Further, the liquid insulating paint 90 may be adhered to the surface of the linear conductor 34 by using a technique (for example, a method of spraying the insulating paint 90) different from the dipping method.

(7) Regarding other configurations as well, the embodiments disclosed herein are illustrative in all respects, and the embodiments of the present invention are not limited thereto. In other words, configurations that are not described in the claims of the present application can be modified as appropriate without departing from the object of the present invention.

  The present invention provides a core in which a plurality of axially extending slots are dispersedly arranged in the circumferential direction, a coil side portion arranged in the slot, and a bridge portion that connects a pair of coil side portions on the outer side in the axial direction of the core. The present invention can be used in a stator for a rotating electrical machine having a coil wound around a core and a method for forming an insulating film of a coil in which an insulating film is formed on the coil by painting.

1: Stator 2: Core 3: Coil 10: Coil unit 30: Coil side part 34: Linear conductor 35: Insulating film 40: Slot 50: Crossing part 50a: End face 51: First connection part (connection part)
52: Second connection part (connection part)
53: Circumferentially extending portion 60: Bending portion 60a: Bending outer surface 70: Thick film portion 80: Target portion 90: Insulating paint A: Target region C: Circumferential direction L: Axial direction S: Core reference surface

Claims (5)

A core in which a plurality of slots extending in the axial direction of a cylindrical core reference surface are distributed in the circumferential direction of the core reference surface, a coil side portion arranged in the slot, and a pair of the coil side portions A stator for a rotating electrical machine comprising a coil that is wound around the core and has a transition portion that is connected to the outside of the core in the axial direction,
The coil is constituted by using a linear conductor having an insulating film formed by coating formed on the surface,
Of the surface facing outward in at least one of the axial direction and the circumferential direction in the transition portion, the region closer to the core than the outer end surface in the axial direction in the transition portion is a target region.
A stator for a rotating electrical machine, wherein a thick film portion in which a thickness of the insulating film is larger than a thickness of the insulating film in a region other than the target region is formed in at least a part of the target region. The crossover includes a circumferentially extending portion extending in the circumferential direction, and a connecting portion that connects the circumferentially extending portion and the coil side.
The connecting portion has a bent portion that bends inward in the circumferential direction in the transition portion as it goes outward in the axial direction;
2. The rotating electrical machine according to claim 1, wherein a bent outer surface, which is a surface facing the outside of the bent portion in the connection portion, is included in the target region, and the thick film portion is formed on the bent outer surface. Stator.   The stator for a rotating electrical machine according to claim 1, wherein the plurality of thick film portions are divided into a plurality of the target regions. Insulating film formation of a coil that forms an insulating film by painting on a coil wound around a core in which a plurality of slots extending in the axial direction of a cylindrical core reference surface are distributed in the circumferential direction of the core reference surface A method,
A coil unit that constitutes the coil, and a bridging portion that connects a coil side portion disposed in the slot in a state of being wound around the core and a pair of the coil side portions on the outer side in the axial direction of the core Preparing a coil unit formed to have:
A paint adhering step for adhering a liquid insulating paint to the surface of the linear conductor constituting the coil unit;
A drying and curing step of drying and curing the insulating paint,
Of the surface facing outward in at least one of the axial direction and the circumferential direction in the transition portion, the region closer to the core than the outer end surface in the axial direction in the transition portion is a target region.
In the drying and curing step, the coil unit is held such that a part of the target region is a target portion that is a portion disposed at the lowermost portion of the coil side portion and the transition portion in the coil unit. A method for forming an insulating film of a coil. About one said coil unit, the said paint adhesion process and the said drying hardening process are repeatedly performed in order of description in several times,
5. The coil insulating film formation according to claim 4, wherein the coil unit is held so that the target regions serving as the target portions are different from each other in at least two of the drying and curing steps executed for one of the coil units. Method.

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