JP5856498B2 - Stator and segment coil - Google Patents

Description

  The present invention relates to a stator and a segment coil. Specifically, the present invention relates to a segment coil that can prevent partial discharge between adjacent coils.

  For example, a stator constituting an electric motor is configured by providing a coil on an annular core. The annular core is provided with a plurality of slots that open to the inside at predetermined intervals, and the coils are mounted in the slots. Conventional coils are provided by winding a bendable wire around the slot. However, there is a problem that it is difficult to wind the winding wire around the slot that opens to the inside without damaging, and workability is poor.

  In addition, in a winding that can be bent when being wound around a slot, a large current cannot be passed because the diameter cannot be set large. For this reason, it is difficult to increase the output of the electric motor. Further, in order to meet the demand for improvement in output and miniaturization of the motor, it is necessary to increase the space factor of the coil. However, it is difficult to improve the space factor in the configuration in which the winding is wound.

  In order to solve the above-described problem, a plurality of segment coils that are formed in advance in a form that allows a coil material having a large cross-sectional area to be mounted in the slot are mounted in the slot, and a connection end extending from the slot is welded or the like Thus, it is possible to adopt a method of connecting and configuring the coil. Since the cross-sectional area can be set large by making the cross-section of the segment coil correspond to the cross-sectional shape of the slot, a large current can flow and the space factor can be set large, and the output of the motor Can be increased.

Japanese Patent No. 4688003

  The segment coil is provided with an insulating coating layer for performing insulation between the adjacent segment coil and the core. The insulating coating layer needs to be configured so that partial discharge does not occur between the members. The partial discharge is likely to occur in a portion where the voltage difference is large. For example, when a segment coil is employed in the stator of a three-phase AC motor, the voltage difference between the segment coils belonging to different phases is the largest. Therefore, partial discharge is likely to occur at a portion where segment coils belonging to different phases are close to or in contact with each other.

  Conventional segment coils are configured to prevent partial discharge by providing an insulating coating layer that can cope with a voltage difference between segment coils belonging to different phases over the entire area of the segment coil.

  However, it is not necessary to provide a thick insulating coating layer that can cope with a large voltage difference at a portion where the segment coils belonging to the same layer are in contact with each other or a portion where the core and the segment coils are in contact with each other. However, in the conventional segment coil, since the insulation coating layer that can cope with the voltage difference between the coils belonging to different phases is provided over the entire area of the coil, the space factor in the slot is lowered and the size of the motor is increased. There is a problem that leads to an increase in heat generation.

  In order to increase the space factor, it may be possible to form an insulating coating layer with a small thickness on the entire segment coil using an expensive insulating material with a low relative dielectric constant and high insulation performance, but this increases the manufacturing cost. Will be connected.

  The present invention solves the above-mentioned conventional problems, can set a large cross-sectional area of the coil to allow a large current to flow and prevent partial discharge, and improve the performance of the motor by increasing the space factor. An object is to provide a segment coil that can be used.

  The invention described in claim 1 of the present application is a stator including an annular core having a slot formed in an inner peripheral portion, and a segment coil attached to the slot, wherein each of the segment coils is separated from the slot. The extending coil end portion is formed in a substantially mountain shape with the central portion at the top, and at least one of the oblique sides of the mountain shape of each segment coil arranged in the radial middle portion of the stator is additionally insulated While the layer is formed, the other oblique side portion of the segment coil arranged adjacent to the segment coil is configured to be in contact with the additional insulating layer.

  Usually, segment coils belonging to the same phase are mounted in the same slot, so that the segment coils belonging to different phases are in contact with each other at the coil end portion. Therefore, partial discharge tends to occur at the coil end portion.

  In this invention, the said coil end part is formed in the substantially mountain shape which makes a center part a vertex, and it is an additional insulating layer in one hypotenuse part of the said mountain shape of each segment coil arrange | positioned at the radial direction intermediate part of a stator at least Is forming. The other oblique side portion of the segment coil arranged adjacent to the segment coil is configured to be in contact with the additional insulating layer.

  The segment coil arranged in the intermediate portion in the radial direction of the stator is brought into contact with the adjacent segment coil on both sides in the radial direction at the coil end portion. Then, when each coil end portion shape of the segment coil is set to a chevron shape with the center as an apex, the chevron shape in the segment coil adjacent to the one segment coil is set against one oblique side portion of the chevron shape in the one segment coil. It can be made to contact so that the other oblique side part of a shape may cross | intersect. That is, the other hypotenuse part of the adjacent segment coil can be brought into contact with the hypotenuse part of one segment coil.

  If the said structure is employ | adopted, if an additional insulating layer is provided in one hypotenuse part of the coil end part which carried out the mountain shape of each segment coil, an additional insulating layer can be set between the segment coils which contact | connect. Thereby, it becomes possible to provide the additional insulating layer which can prevent partial discharge between the segment coils which mutually contact in a coil end part.

  In addition, in the present invention, the additional insulating layer is provided only on the one-side segment coil that is in contact. For this reason, it becomes possible to set the area | region which provides an additional insulating layer small as the whole coil which comprises a stator. In addition, partial discharge can be prevented efficiently, the material necessary for providing the additional insulating layer can be reduced, the manufacturing cost can be reduced, and the weight of the motor can be reduced.

  On the other hand, since the additional insulating layer is not formed in the portion to be mounted in the slot, the cross-sectional area of the conductor constituting the segment coil can be set large. For this reason, it becomes possible to raise the space factor in the said slot, and can raise the efficiency of an electric motor.

  The segment coils arranged at the radially outermost side and the radially innermost side of the stator are arranged such that the adjacent segment coils are arranged only on one side in the radial direction and are attached to the other slots. Since it is connected to the segment coils of the same phase, depending on the design, it may be possible to make contact with the adjacent segment coils at both oblique sides of the chevron shape. For this reason, what is necessary is just to provide an additional insulating layer in the part which contacts another segment coil according to the structure of a segment coil, etc.

The additional insulating layer can be formed over the entire area of the one oblique side. However, in the invention described in claim 1 , the additional insulating layer is formed only in a portion where the other oblique side part of the adjacent segment coil contacts. To do. By forming the additional insulating layer only in the portion where the segment coil that easily generates partial discharge contacts, the area for forming the additional insulating layer can be reduced without reducing the effect of preventing partial discharge. Thereby, the material for forming the additional insulating layer can be reduced to reduce the manufacturing cost, and the weight of the electric motor can be reduced.

The additional insulating layer can be provided between all the segment coils that are in contact with each other at the coil end portion. However, in the invention described in claim 1, the additional insulating layer is provided only in a portion where the segment coils belonging to different phases are in contact with each other. Provide. Thereby, the area | region which provides an additional insulating layer can further be reduced. Further, since the additional insulating layer is provided between the segment coils belonging to different phases where partial discharge is likely to occur, partial discharge can be more effectively prevented.

  As in the invention described in claim 5, the additional insulating layer can be formed on the radially inner surface and / or outer surface of the stator of each segment coil. That is, it is provided only on the contact surface where adjacent segment coils contact. By adopting this configuration, it is possible to further reduce the region where the additional insulating layer is provided.

  The thickness of the additional insulating layer is not particularly limited as long as it is formed to a thickness that can prevent partial discharge based on a voltage difference or a positional relationship between the segment coils to be in contact with each other. For example, an additional insulating layer having a large thickness can be provided between segment coils belonging to different layers, and an additional insulating layer having a small thickness can be provided between segment coils belonging to the same layer. Further, when there is a gap between adjacent segment coils, the thickness of the additional insulating layer can be set small, or the additional insulating layer can be omitted.

  The segment coil is formed by bending a conductor having a large cross-sectional area. If an additional insulating layer is provided at a site where the bending process is performed before the bending process, the additional insulating layer may be cracked or peeled off, resulting in a decrease in insulation. Further, even after bending, it may be difficult to provide the additional insulating layer in the bent portion. For example, it is difficult to form an additional insulating layer in a portion subjected to bending using a film material or a tube material. For this reason, as in the invention described in claim 4, it is preferable to form the additional insulating layer in a portion where the segment coil is not bent.

  The method of forming the additional insulating layer is not limited to. For example, as in the invention described in claim 6, the additional insulating layer can be formed of an insulating resin tube material. As the insulating resin tube material, for example, a heat-shrinkable tube material such as an insulating resin tube material (trade name Sumitube) manufactured by Sumitomo Electric Industries, Ltd. can be used.

  Further, as in the invention described in claim 7, the additional insulating layer can be formed from an insulating resin tape material. For example, an insulating resin tape material (trade name: Kapton tape) manufactured by Permacel can be used. Moreover, it is preferable to employ | adopt a tape material provided with an adhesive material layer.

  Further, as in the invention described in claim 8, the additional insulating layer can be formed of an insulating resin coating agent. The additional insulating layer can be formed by powder coating or electrodeposition. For example, the additional insulating layer can be formed using a coating material made of polyamideimide resin or the like.

  The form of the segment coil which concerns on this invention is not specifically limited, It can apply to the various segment coil provided with a mountain shape in a coil end part.

  The present invention can be applied to a stator employed in various electric motors and generators.

  Insulation between the segment coils in the coil end portion can be ensured, and the space factor can be increased, and the efficiency of the electric motor can be increased.

It is a perspective view of the principal part which shows the state which assembled | attached a part of segment coil to the slot of the annular core. It is a top view which shows the state which assembled | attached the segment coil. It is a front view which shows one form of the segment coil which concerns on this invention. It is a front view of the principal part which shows the contact state between one segment coil and the segment coil arrange | positioned adjacent to this. It is sectional drawing which follows the VV line in FIG. It is sectional drawing which shows the contact state of the segment coil which provided the additional insulating layer, and another segment coil. It is a figure which shows 2nd Embodiment of an additional insulating layer, and is sectional drawing equivalent to FIG.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a main part perspective view showing a state in which some segment coils 1 are attached to an annular core 3 constituting a stator 2. FIG. 2 is a plan view of the stator 2 after the segment coil is mounted.

  The annular core 3 has a thick annular structure made of a magnetic material, and slots 4 that penetrate the inner peripheral portion in the axial direction and open to the inner peripheral surface are formed at predetermined intervals. The slot 4 is formed substantially corresponding to the width of the segment coil 1, and the segment coil 1 is assembled to the annular core 3 by accommodating the straight portion of the segment coil 1 in the slot 4.

  The material constituting the annular core 3 is not particularly limited. For example, a core formed by compacting magnetic powder or a core formed by stacking magnetic steel plates can be employed.

  For example, in a three-phase AC motor, a plurality of segment coils 1 each grouped into a U phase, a V phase, and a W phase are assembled in the slot 4 at a predetermined interval.

  As shown in FIG. 3, the segment coil 1 (1 </ b> A to 1 </ b> D) of a typical form mounted on the radial intermediate portion of each slot 4 of the stator 2 includes a pair of linear portions 1 b received in the slot 4. The slot 4 is formed in a substantially hexagonal shape including a pair of coil end portions 1a and 1c which are extended from both axial end portions of the slot 4 and have a mountain shape. In the coil end portion 1c, adjacent segment coils mounted in the same slot 4 are connected, and connection with segment coils mounted in other slots is performed. In order to connect to the segment coils mounted in other slots, the segment coils 20 and 21 mounted on the radially innermost and outermost sides of the stator 2 are coil ends having a plurality of forms according to the connection pattern. Is provided. The following description will be made on the segment coil 1 having the form shown in FIG. 3 for easy understanding.

  One coil end portion 1a is formed in a mountain shape that connects a pair of straight portions 1b accommodated in a predetermined slot 4 in a spanning manner. On the other hand, the other coil end portion 1c is provided with connection portions 5a and 5b for connecting to a segment coil accommodated adjacent to the slot 4 and the coil end portion of the connected segment coil. Yamagata shape is constructed in cooperation with. The coil end portions 1c of the segment coils 20 and 21 mounted on the radially innermost and outermost sides of the stator 2 shown in FIG. 2 can be connected to the segment coils mounted in other slots as described above. Formed.

  As shown in FIG. 6, the segment coils 1 </ b> A to 1 </ b> E have an insulating coating layer 7 formed on the entire periphery of the conductive flat rectangular coil material 6 having a rectangular cross section excluding the connection portions 5 a and 5 b. The insulating coating layer 7 is formed with a uniform thickness over the entire outer periphery of the coil material 6 with a thickness of 5 to 25 μm using a material that can withstand bending such as polyimide.

  As shown in FIG. 3, the additional insulating layers 12 a, 12 b, 12 c, 12 d, and the like are formed on one of the oblique sides 10 a, 11 a of the coil end portions 1 a, 1 c formed in the mountain shape in the segment coil 1 according to the present embodiment. 14a, 14b, 14c, and 14d are formed. Note that the oblique side portion on which the additional insulating layer is provided may be the opposite oblique side portion 10b. In addition, the upper and lower coil end portions 1a and 1c can be provided with the additional insulating layer on different oblique sides. In one coil end portion, the additional insulating layer is provided on the oblique side portion on the same side of each segment coil.

  As shown in FIG. 6, the additional insulating layers 12a, 12b, 12c, 12d, 14a, 14b, 14c, and 14d according to the present embodiment are coated on the insulating coating layer 7 with an insulating polyamide-imide resin. The dressing material is formed by laminating and coating the entire circumference with a predetermined thickness and a predetermined width. The thickness of the additional insulating layers 12a, 12b, 12c, 12d, 14a, 14b, 14c, and 14d is not particularly limited. For example, the thickness may be 50 to 200 μm depending on the voltage difference between the segment coils that are in contact with each other. It can be formed with the thickness.

  In the present embodiment, of the coils constituting each phase of the three-phase AC motor, the segment coils 20 and 21 arranged on the radially innermost side and the radially outermost side of the stator 2 shown in FIG. Coil end portions 1a. Four coils are arranged in contact with or close to one of the oblique sides 10a and 11a of the chevron shape in 1c.

  FIG. 4 is a front view schematically showing one segment coil 1A and segment coils 1B, 1C, 1D, and 1E that are brought into contact with one oblique side portion 10a of the segment coil 1A.

  As shown in FIG. 4, the left oblique side portion 10a of one segment coil 1A is so arranged that the right oblique side portions 10b of the four adjacent segment coils 1B, 1C, 1D, and 1E intersect at a predetermined interval. It is made to face.

  In the present embodiment, the additional insulating layers 12a to 12d are formed in portions where the other segment coils 1B, 1C, 1D, and 1E are in contact with each other on the left oblique side portion 10a of the one segment coil 1A.

  FIG. 5 is a cross-sectional view taken along line VV in FIG. As shown in FIG. 5, in the present embodiment, additional insulating layers 12a, 12b, 12c, and 12d are provided on the left oblique side portion 10a of the coil end portion 1a having the mountain shape of each segment coil. The additional insulating layers 12a, 12b, 12c, and 12d expand the gaps between the segment coils 1B, 1C, 1D, and 1E that are in contact with each other. Can be prevented.

  In addition, the additional insulating layers 12a to 12d are provided only in the segment coil 1A on the one side in contact. For this reason, it becomes possible to set small the area | region which provides the additional insulating layers 12a-12d as the whole coil which comprises the stator 2. FIG. In addition, partial discharge can be prevented efficiently, the material necessary for providing the additional insulating layers 12a to 12d can be reduced, the manufacturing cost can be reduced, and the weight of the motor can be reduced.

  Since the additional insulating layer is not formed in the portion accommodated in the slot 4, the cross-sectional area of the conductor constituting each segment coil 1 can be set large. For this reason, it becomes possible to raise the space factor in the said slot 4, and can raise the efficiency of an electric motor.

  On the other hand, the segment coils 20 and 21 arranged on the radially outermost side and the radially innermost side of the stator 2 shown in FIG. 2 are arranged such that adjacent segment coils are arranged only on one side in the radial direction, and the other Since it is connected to the in-phase segment coil mounted in the slot, the portion to be brought into contact with the adjacent segment coil differs depending on the design. In this manner, an additional insulating layer may be provided at a portion in contact with another segment coil according to the configuration of the segment coil in the stator 2.

  In the present embodiment, the additional insulating layer is connected to the coil end portion 1a. Although provided between all the segment coils that are in contact with each other in 1c, the additional insulating layer may be provided only in a portion where the segment coils belonging to different phases having a large voltage difference contact. Thereby, the area | region which provides an additional insulating layer can further be reduced. Further, since the additional insulating layer is provided between the segment coils belonging to different phases where partial discharge is likely to occur, partial discharge can be more effectively prevented.

  Further, in the present embodiment, as shown in FIG. 6, each additional insulating layer 12 a to 12 d is provided so as to surround the periphery of one segment coil 1 </ b> A with a predetermined width, but the other segment coils 1 </ b> B to 1 </ b> E are provided. It can be provided only on the face to be brought into contact with. For example, as shown in FIG. 7, in one segment coil 1A, the additional insulating layer 112a may be formed only on the radially inner and outer surfaces of the stator 2 with which the other segment coils 1B to 1E are brought into contact. it can. By adopting this configuration, it is possible to further reduce the region where the additional insulating layer is provided.

  Moreover, in this embodiment, although the additional insulating layers 12a-12d were formed with the resin coating material which has insulation, it is not limited to this. For example, the additional insulating layers 12a to 12d can be formed from an insulating resin tube material. As the insulating tube material, for example, a heat-shrinkable tube material such as an insulating resin tube material (trade name Sumitube) manufactured by Sumitomo Electric Industries, Ltd. can be used.

  Moreover, the said additional insulating layers 12a-12d can be formed from an insulating resin tape material. For example, an insulating resin tape material (trade name: Kapton tape) manufactured by Permacel can be used.

  The range in which the additional insulating layer is provided is not particularly limited. In the present embodiment, the additional insulating layers 12a to 12d are formed only in a portion where one segment coil 1A of one segment coil 1A is in contact with the other segment coils 1B to 1D. It can also be formed over the entire portion 10a.

  Each of the segment coils 1A to 1E is formed by bending a conductor having a large cross-sectional area in advance. If an additional insulating layer is provided at a site where the bending process is performed before the bending process, the additional insulating layer may be cracked or peeled off, resulting in a decrease in insulation. In addition, even after bending, it may be difficult to provide the additional insulating layer at the bent portion. For example, it is difficult to form an additional insulating layer in a portion that has been bent using the tape material or tube material. For this reason, when forming an additional insulating layer with a film material or a tube material, it is preferable to provide an additional insulating layer in a portion where bending is not performed.

  The scope of the present invention is not limited to the embodiment described above. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  By optimizing the thickness of the insulation coating layer provided on the segment coil, the space factor of the coil can be increased, and the efficiency of the electric motor can be improved.

DESCRIPTION OF SYMBOLS 1 Segment coil 1a Coil end part 1c Coil end part 2 Stator 3 Annular core 4 Slot 10a Oblique side part 10b Oblique side part 1A Segment coil 1C made to contact one segment coil 1C 1A to segment coil 1D 1A made to contact 1A Segment coil 1E 1A to be contacted Segment coil to be contacted

Claims (9)

A stator including an annular core having a slot formed in an inner peripheral portion, and a segment coil mounted in the slot,
Each of the segment coils has a coil end portion extending from the slot, and is formed in a substantially mountain shape with the central portion at the top,
While an additional insulating layer is formed on one oblique side of the mountain shape of each segment coil disposed at least in the radial middle portion of the stator,
The other oblique side portion of the segment coil disposed adjacent to the segment coil is configured to contact the additional insulating layer ,
The stator , wherein the additional insulating layer is provided only at a portion where the other hypotenuse portion of the segment coils arranged adjacent to each other contacts with each other and a segment coil belonging to a different phase contacts . The stator according to claim 1, wherein the additional insulating layer is formed only on one oblique side of each segment coil . The stator according to claim 1 , comprising an additional insulating layer having a relatively large thickness and an additional insulating layer having a relatively small thickness .   The stator according to any one of claims 1 to 3, wherein the additional insulating layer is formed on a portion of the segment coil that is not bent.   The stator according to any one of claims 1 to 4, wherein the additional insulating layer is formed on a radially inner surface and / or an outer surface of the stator of each segment coil.   The stator according to any one of claims 1 to 4, wherein the additional insulating layer is formed of an insulating resin tube material.   The stator according to any one of claims 1 to 5, wherein the additional insulating layer is formed of an insulating resin tape material.   The stator according to claim 1, wherein the additional insulating layer is formed of an insulating resin coating agent.   The segment coil used for the stator of any one of Claims 1-8.

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