JP2011250563A - Manufacturing method for coil of rotary electric machine - Google Patents

Abstract

An object of the present invention is to provide a coil manufacturing method for a rotating electrical machine in which a main insulating tape of a main insulating layer can have a uniform thickness over the entire circumference.
In the present invention, a plurality of strand conductors 16 covered with a strand insulation layer 17 are combined to form a consolidated coil 15, and corners (18C, 22C) of the consolidated coil 15 are formed at room temperature. A first insulating resin 19 that flows when heated with a solid and hardens when heated at a higher temperature is placed, and in this state, the main insulating tape 20 is wound, and then impregnated with a thermosetting second insulating resin. The whole is heated for the first time to fluidize the first insulating resin, and then further heated for a second time to cure the first insulating resin and the second insulating resin. The main insulating layer 21 is formed.
[Selection] Figure 3

Description

  The present invention relates to a method of manufacturing a rotor coil and a stator coil of a rotating electrical machine, and more particularly to a coil manufacturing method of a rotating electrical machine suitable for a rotating electrical machine operated at a high voltage.

  In general, a coil of a rotating electrical machine is a main insulation layer formed by winding a plurality of wire conductors covered with a wire insulation layer together and winding a main insulation tape around the outer periphery to a uniform thickness. A thermosetting insulating resin is vacuum impregnated or dripped impregnated between the strand conductors including the layers and the strand insulating layer, and then the impregnated insulating resin is heated and cured.

  However, during the heat curing of the insulating resin, due to the difference in thermal expansion between the main insulating tape base material of the main insulating layer and the thermosetting insulating resin, the insulating resin at the corners of the coil cross section flows other than the corners, As a result, the main insulating tape base material is swollen by the flowing insulating resin except for the corners of the coil cross section, so that the main insulating tape base material in the corners of the coil cross section is close to the corners of the coil cross section, There is a phenomenon in which the thickness is smaller than the thickness of the main insulating layer, and there is a problem in that the dielectric strength decreases in combination with electric field concentration at the corners of the coil cross section.

  In order to supplement the decrease in the resin amount due to the flow of the insulating resin at the corners of the coil cross section during heat curing, another insulating layer such as mica compound material is wound around the corner of the coil cross section when the main insulating tape is wound. Coils have already been proposed, for example as disclosed in US Pat.

JP 2001-327108 A

  The coil disclosed in Patent Document 1 tries to increase the thickness of the insulating layer at the corner of the coil cross section by winding another insulating layer. However, the displacement of the main insulating tape due to the flow of the insulating resin at the time of heat curing after impregnation with the thermosetting resin is not taken into account, and eventually, in the corner portion of the coil cross section including another wound insulating layer The main insulating tape is unavoidable to approach the corner, and the dielectric strength is reduced.

  An object of the present invention is to provide a coil manufacturing method for a rotating electrical machine in which a main insulating tape of a main insulating layer can have a uniform thickness over the entire circumference.

    In order to achieve the above object, the present invention forms a solidified coil by combining a plurality of wire conductors coated with a wire insulation layer, and flows when heated at a corner of the solidified coil at a solid temperature. Further, a first insulating resin that is cured when heated at a high temperature is arranged, and in this state, the main insulating tape is wound, and then the thermosetting second insulating resin is impregnated, and then the first heating is performed on the whole. The first insulating resin is fluidized and then heated at a higher temperature for a second time to cure the first insulating resin and the second insulating resin to form the main insulating layer. .

  As described above, the first insulating resin that flows when heated in a solid state at room temperature and hardens when heated at a higher temperature is disposed at the corner of the coil, so that the first insulating resin flows during the first heating. Since it is absorbed by the main insulating tape corresponding to the corners of the compacted coil, the amount of insulating resin at the corners of the compacted coil is larger than that of other parts. As a result, even if a part of the second insulating resin flows outside the corners of the coiled coil, it can be replenished with the first insulating resin, so that the resin amount on the entire circumference of the main insulating layer is substantially uniform. Can be. Therefore, if the second heating is performed in this state, the main insulating tape at the corners of the compacted coil can be arranged almost uniformly with respect to the compacted coil in the same manner as the main insulating tape at other portions. A decrease in proof stress can be suppressed.

  As described above, according to the present invention, it is possible to obtain a coil manufacturing method for a rotating electrical machine in which the main insulating tape of the main insulating layer can have a uniform thickness over the entire circumference.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the uncoating coil in the 1st process which shows 1st Embodiment of the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing of the solidified coil in the 2nd process which shows 1st Embodiment of the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing of the coil in the 3rd process which shows 1st Embodiment of the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing of the coil in the 4th process which shows 1st Embodiment of the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing of the solidified coil in the 1st process which shows 2nd Embodiment of the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing of the coil in the 2nd process which shows 2nd Embodiment of the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing of the coil in the 3rd process which shows 2nd Embodiment of the coil manufacturing method of the rotary electric machine by this invention. The schematic sectional drawing which shows the rotary electric machine manufactured by the coil manufacturing method of the rotary electric machine by this invention. Sectional drawing in alignment with the AA of FIG.

  Hereinafter, a first embodiment of a coil manufacturing method for a rotating electrical machine according to the present invention will be described with reference to FIGS. 1 to 4, 8, and 9.

  First, the configuration of the rotating electrical machine will be described with reference to FIGS. 8 and 9. For example, a turbine generator 1 which is a rotating electrical machine includes a rotor 3 provided on a rotating shaft 2, a stator 4 installed on the outer periphery of the rotor 3 via a gap, and a fixing that supports the stator 4. A child frame 5 and an end frame 6 that supports the stator frame 5 and rotatably supports the rotary shaft 2 are configured.

  The stator 4 includes a stator core 7 formed by laminating a large number of electromagnetic steel sheets in the rotation axis direction and tightening with a presser plate 8 from the end of the stack, and a stator coil 9 attached to the stator core 7. I have.

  As shown in FIG. 9, a plurality of slots 10 along the axial direction are formed over the entire inner diameter side circumference of the stator core 7. In this slot 10, an underlay 11, a bottom coil 9 B of the stator coil 9, an intermediate spacer 12, an upper coil 9 A of the stator coil 9, and a spacer 13 are mounted in this order, and finally a wedge for supporting them. 14 is attached to the opening side of the slot 10.

  A method of manufacturing the bottom coil 9B and the upper coil 9A of the stator coil 9 according to this embodiment will be described with reference to FIGS.

  First, as shown in FIG. 1, the compacted coil 15 is formed in the first step. The element coil 15 covers the surface of the strand conductor 16 with the strand insulation layer 17 and puts together a plurality of strand conductors 16 covered with the strand insulation layer 17 in the longitudinal direction of the slot. The resulting stepped portion is filled with the filling material 18 and batch-heated. A chamfered portion 18C such as a curved surface or a flat surface having a predetermined curvature is formed at the corner portion of the filling 18. The chamfered portion 18C may be formed at the time of heat forming by forming a protrusion corresponding to the chamfering on a forming die at the time of heat forming, or may be formed by cutting after heat forming. Further, as the filler 18, it is desirable to use a semiconductive material, for example, a thermosetting resin mixed with carbon powder, in order to alleviate electric field concentration at the corner of the stator coil 9 after completion.

  Next, as a second step, as shown in FIG. 2, the first insulating resin 19 is attached to the chamfered portion 18 </ b> C of the corner portion of the compacted coil 15 with an adhesive or the like. The first insulating resin 19 is a solid that does not have fluidity at room temperature, has fluidity once applied at a temperature higher than room temperature, and has a property of being cured by applying a higher temperature. For example, there is an epoxy resin (trade name: Uni-form) manufactured by Multi-seals, USA.

  After that, in the third step, as shown in FIG. 3, the main insulating tape 20 not impregnated with the insulating resin is not wrinkled on the outer periphery of the compacted coil 15 and the first insulating resin 19 with a certain tension. Wrap multiple times so that. Here, the main insulating tape 20 is, for example, a large number of mica pieces lined with a glass fiber nonwoven fabric as a main insulating tape base material, and is not impregnated with an insulating resin, and thus is called dry mica tape. Thus, by winding the main insulating tape 20, the inner peripheral length of the main insulating tape 20 becomes longer than the outer peripheral length of the compacted coil 15.

  Then, the solidified coil 15 around which the main insulating tape 20 is wound is impregnated with a liquid second insulating resin, for example, an epoxy resin, using a vacuum impregnation facility or a dripping impregnation facility. By doing so, the first insulating resin 19 and the impregnated second insulating resin exist in the vicinity of the chamfered portion 18C of the compacted coil 15, and the amount of the resin is only the second insulating resin. More than the impregnated part.

Thereafter, in the fourth step, the first heat molding is performed on the uncured coil 15 and the main insulating tape 20 impregnated with the second insulating resin. During the first thermoforming, the first insulating resin 19 is liquefied and absorbed by the main insulating tape 20. The second insulating resin impregnated at the same time expands by thermoforming and flows outside the chamfered portion 18C. However, the first insulating resin 19 is replenished as the second insulating resin flows. As a result, as shown in FIG. 4, the second insulating resin flows and expands other than the chamfered portion 18C, thereby bringing the main insulating tape 20 closer to the chamfered portion 18C side. However, even if the main insulating tape 20 approaches the chamfered portion 18C due to the flow or hearing of the second insulating resin, the first insulating resin 19 is initially present and the portion absorbed by the main insulating tape 20 due to heating is removed. Therefore, the thickness tC of the chamfered portion 18C of the main insulating tape 20 is substantially the same as the thickness tW of the side portion and the thickness tH of the upper and lower portions. In the above state, the first heat-insulating resin 19 and the second heat-insulating resin are cured by the second thermoforming in the above state, and the outer periphery of the compacted coil 15 is The main insulating layer 21 having a substantially uniform thickness is formed. As a result, a decrease in the dielectric strength at the corners of the stator coil 9 (9A, 9B) can be suppressed.

  As described above, according to the present embodiment, the stator coil 9 (9A, 9B) of the turbine generator 1 is obtained in which the main insulating tape 20 of the main insulating layer 20 can have a uniform thickness over the entire circumference. And a reduction in dielectric strength can be prevented.

  Next, a second embodiment of a method for manufacturing a coil for a rotating electrical machine according to the present invention will be described with reference to FIGS. In addition, since the same code | symbol attached | subjected to FIGS. 1-4 shows the same structural member, detailed description for the second time is abbreviate | omitted.

  In the present embodiment, the difference from the first embodiment is that the main insulating tape 20 is wound by disposing plate-like fillers 22 having the same width as that of the compacted coil 15 at the upper and lower ends of the compacted coil 15. It was. The filler 22 is formed of the same material as that of the filler 18 according to the first embodiment, and chamfered portions 22C are formed at both ends in the width direction, and the chamfered portion 22C has the chamfered portion 22C according to the first embodiment. The same first insulating resin 19 is attached.

  Then, as shown in FIG. 5, the surface of the strand conductor 16 is covered with a strand insulation layer 17, and a plurality of strand conductors 16 covered with the strand insulation layer 17 are grouped together while being displaced in the longitudinal direction of the slot. In the same manner as in the first embodiment, the stepped portion caused by the dislocation is filled with the filler 18 and is collectively heat-molded to form the compacted coil 15. The plate-like filler 22 is brought into contact with the upper and lower ends of such a compacted coil 15.

  Next, as a second step, the first insulating resin 19 is attached to the chamfered portion 22C of the plate-like filler 22 with an adhesive or the like.

  After that, in the third step, as shown in FIG. 6, the main insulating tape 20 not impregnated with the insulating resin is fixed to the outer periphery of the filler 22 to which the compacted coil 15 and the first insulating resin 19 are attached. Wrap multiple times to avoid wrinkling. Thus, by winding the main insulating tape 20, the inner peripheral length of the main insulating tape 20 becomes longer than the outer peripheral length of the compacted coil 15 as much as the first insulating resin 19 is attached.

  Then, the solidified coil 15 around which the main insulating tape 20 is wound is impregnated with a liquid second insulating resin, for example, an epoxy resin, using a vacuum impregnation facility or a dripping impregnation facility. By doing so, the first insulating resin 19 and the impregnated second insulating resin exist in the vicinity of the chamfered portion 22C of the filler 22, and the amount of the resin is impregnated only with the second insulating resin. It becomes more than the part which did.

Thereafter, in the fourth step, the first heat molding is performed on the uncured coil 15 and the main insulating tape 20 impregnated with the second insulating resin. As a result, as in the first embodiment, the wall thickness tC of the chamfered portion 22C of the main insulating tape 20 is substantially the same as the wall thickness tW of the side portion and the wall thickness tH of the upper and lower portions. In the above state, the first insulating resin 19 and the second insulating resin are cured by performing the second thermoforming in the above state. The main insulating layer 21 having a substantially uniform thickness is formed on the outer periphery of the compacted coil 15.

  In the present embodiment, the same effect as that of the first embodiment can be obtained, and a filler 22 to which the first insulating resin 19 is attached is prepared in advance as compared with the first embodiment. Therefore, the coil manufacturing work can be facilitated and the working time can be shortened.

  By the way, in this Embodiment, when winding the main insulation tape 20 at the 3rd process, the stator coil 9 (9A, 9B) which has an internal corona shield layer is wound by winding the semiconductive tape 23 beforehand. Obtainable.

  By the way, in the above explanation, the coil is impregnated using the vacuum impregnation equipment or the dripping impregnation equipment, and only the coil is impregnated with the second insulating resin, but as shown in FIG. The second insulating resin may be entirely impregnated in a state where the coil is incorporated.

  Moreover, although the above description demonstrated the stator coil of the turbine generator as an example, it cannot be overemphasized that it can apply also to a rotor coil (not shown).

  Furthermore, although the turbine generator has been described as the rotating electric machine, it can also be applied to a turbine generator or a coil of an electric motor.

  DESCRIPTION OF SYMBOLS 9 ... Stator coil, 9A ... Top coil, 9B ... Bottom coil, 15 ... Solidified coil, 18, 22 ... Filler, 18C, 22C ... Chamfer part, 19 ... 1st insulating resin, 20 ... Main insulating tape, 21: Main insulating layer.

Claims (4)

  A plurality of strand conductors coated with a strand insulation layer are formed to form a solidified coil, and a first insulation that flows when heated at a solid temperature at a corner of the solidified coil and hardens when heated at a high temperature. Place the resin, wrap the main insulating tape in this state, then impregnate the thermosetting second insulating resin and then heat the whole for the first time to fluidize the first insulating resin And then heating the second insulating resin at a higher temperature to cure the first insulating resin and the second insulating resin to form a main insulating layer.   2. The coil manufacturing method for a rotating electrical machine according to claim 1, wherein the first resin is attached to a chamfered portion of a corner portion of a filler disposed in a corner portion of the compacted coil.   2. The coil manufacturing method for a rotating electrical machine according to claim 1, wherein the first resin is attached to a chamfered portion of a corner portion of a plate-like filler that comes into contact with upper and lower ends of the compacted coil.   The coil manufacturing method for a rotating electrical machine according to claim 1, wherein a semiconductive tape is wound inside the main insulating tape.

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