JP5172199B2 - Stator - Google Patents

Description

  The present invention relates to the structure of a stator (motor or generator) formed by winding a coil around a core body, and more particularly to measures for improving the heat dissipation function of a split core.

  In recent years, with the advancement of new technologies such as electric vehicles, hybrid vehicles, and robots, the performance required for the stators of rotating electric machines (motors and generators) for driving them has been advanced. For example, in an electric vehicle and a hybrid vehicle, a large current is required and downsizing is required.

  In order to increase the current flowing through the coil, a structure in which a plurality of thin coils are wound around the core is often employed because the coil winding difficulty increases due to the increased rigidity of the coil wire and the eddy loss increases when the coil diameter is increased. . Therefore, as disclosed in Patent Document 1, a partition that divides the slot region into two partial slot regions is provided in an insulator laid in the slot region of the split core, and a coil is individually wound around each partial slot region. Therefore, there is one that attempts to realize a high-density coil structure.

Japanese Patent Laid-Open No. 11-27886

  However, if the current is increased while the coil structure of the stator is made compact, the heat generation density of the coil in the slot region also increases, and there is a risk that problems such as deterioration of the insulating film covering the coil may occur. is there.

  An object of the present invention is to provide a stator suitable for increasing the density of the coil structure and increasing the power by taking measures to improve the heat dissipation from the coil of the split core.

  The stator according to the present invention is a stator in which a plurality of split cores are assembled in a ring shape, and a sheet member is provided in the gap between the split cores, the tip portion extending to the back yoke side of the split core.

  As a result, the heat generated in the coils of each split core is released from the back yoke side of the split core to the outside of the slot region via the sheet member. Therefore, even if the internal structure of the split core is made compact, it is possible to prevent deterioration of the insulating film covering the coil due to excessive increase in internal temperature.

  The front end portion of the sheet member may be attached to the split core, but by attaching to the outer wall of a ring member (for example, shrink-fit ring) that fastens and fixes the split core, the structure of the split core can be reduced. Heat can be released outward.

  Since the front end portion of the sheet member is attached to the outer wall of the casing member, heat can be more effectively released.

  When the front end of the sheet member is attached to the outer wall of the ring member or casing member, an opening is formed at a portion facing the gap between the split cores of the ring member, and the sheet member passes through the opening. As a result, the front end portion of the seat member can be pulled out of the split core while maintaining the tightening force of the ring member.

A pair of sheet members are attached to each gap of the split cores, so that a heat dissipation path that reliably releases heat from the uppermost coil of each split core is formed, and the heat dissipation function is improved.

  The sheet member is preferably made of a graphite sheet or a metal foil. In particular, since the graphite sheet has a high thermal conductivity in the sheet surface direction, the heat of the coil can be released as far as possible, so that a higher heat dissipation function can be exhibited.

  Since the tooth portion of each divided core has a stepped structure on the back yoke side that is deeper than the rotor side, the height position of the uppermost layer of the coil wound around the tooth portion can be made uniform. Therefore, the thermal connection state between the uppermost layer of the coil and the sheet member becomes uniform, and the heat dissipation function is improved.

  According to the stator of the present invention, the heat generated in the coil can be efficiently released to the divided core or the outside thereof, so that the deterioration of the insulating film of the coil can be prevented.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a schematic structure of a stator 10 of a rotating electrical machine (motor or generator (generator)) in the first embodiment. FIG. 2 is a perspective view for explaining a state where the split core 11 is assembled by the shrink fitting ring 21. As shown in FIG. 2, the stator 10 is assembled by enclosing a plurality of split cores 11 in an annular shape and enclosing from the outside using a shrink-fit ring 21 that is a ring member. For ease of viewing, illustration of members other than the split core 11 and the shrink-fit ring 21 is omitted in FIG. A rotor (not shown) provided with a permanent magnet is disposed inside the stator 10. A region between the back yoke side flange portion 11a of the split core 11 and the rotor side flange portion 11b is referred to as a tooth portion 15. A coil is wound around the tooth portion 15, and the entire region around which the coil 12 is wound is called a slot region Rsl. The cross-sectional shape of the slot region Rsl is generally trapezoidal or rectangular.

  An opening 23 is formed in a portion of the shrink fitting ring 21 that faces the gap between the split cores 11. 3 and 4, a pair of graphite sheets 22 that are sheet members are attached between the split cores 11, and the graphite sheet 22 is a yoke of the split cores 11. The gap extends between the side flange portions 11 a and the opening 23, and extends outward from the shrink fitting ring 21. The fixing member 24 is attached to the outer wall of the shrink fitting ring 21.

The coil 12 is configured by covering a conductive wire made of a copper alloy with a resin insulating film. Further, the bottom surface of the tooth portion 15 of the split core 11 is deep at a portion adjacent to the back yoke side flange portion 11a, shallow at a portion adjacent to the rotor side flange portion 11b, and at an intermediate depth at an intermediate portion between both portions. As shown, it has a three-step structure. In this way, by using the stepped structure, the uppermost coil 12 is aligned at a common height position.
The contact state between the graphite sheet 22 and the coil 12 can be made uniform.

  FIG. 5 is a plan view showing an expanded graphite sheet. As shown in the figure, the graphite sheet 22 has a wide portion 22 and a narrowed portion 22b. The wide portion 22 a is in contact with the uppermost coil 12 of the split core 11, and the narrowed portion 22 b extends outwardly through the opening 22 of the shrink fitting ring 21. And the front-end | tip part of the aperture | diaphragm | squeeze part 22b of the graphite sheet 22 is being fixed to the outer wall of the shrink-fit ring 21 with the fixing member 24 with the fixing member 24. FIG. The fixing member 22 may be, for example, a spring-loaded fastener or simply a resin adhesive. Moreover, in the area | region between the split cores 11, the graphite sheet 22 may be fixed to the coil 12 with the adhesive agent, or may be fixed to the coil 12 by the fastening force between the split cores 11. Good. Further, the wide portion 22a of the graphite sheet 22 extends over substantially the entire width of the split core 11 shown in FIG. When the graphite sheet 22 is fixed to the coil 12 with an adhesive, the wide portion 22a may be expanded to a region in contact with the coil 12 on the side surface of the split core 11 shown in FIG.

  As the graphite sheet 22, for example, “PGS graphite sheet” manufactured by Matsushita Electric Industrial Co., Ltd. can be used. The thermal conductivity of the PGS graphite sheet in the sheet surface direction is 600 to 800 (W / M · K) (thickness of about 0.1 mm), about twice as high as pure copper and about three times as high as aluminum. It is. Therefore, it is possible to efficiently dissipate heat to a part far away from the split core 11.

  Here, in the present embodiment, the thickness of the shrink-fit ring 21 shown in FIG. 1 is about 10 mm. The width of the wide portion 22a of the graphite sheet 22 is approximately equal to the thickness of the stator 10, and the length is approximately 5 cm substantially equal to the distance between the back yoke side flange portion 11a and the rotor side flange portion 11b of the split core 11. The thickness is about 0.1 mm. The width of the opening 23 of the shrink-fit ring 21 is about 2 cm, the width of the narrowed portion 22b of the graphite sheet 22 is 2 cm or less (for example, 1.8 cm), and the length is about 15 mm.

  However, the sheet member of the present invention is not necessarily limited to the graphite sheet, and a metal foil such as copper, copper alloy, aluminum, and aluminum alloy may be used.

  6A to 6C are cross-sectional views showing variations of the method for attaching the graphite sheet 22. In the structure shown in FIG. 6A, a pair of graphite sheets 22 are in contact with the uppermost coil 12 of each divided core (not shown) with an insulating film 26 interposed therebetween. As the insulating film 26, an adhesive may be used, or a resin sheet may be used (in the case of fixing with a tightening force).

  In the structure shown in FIG. 6B, one graphite sheet 22 is in contact with the uppermost coil 12 on both sides with an insulating film 26 interposed therebetween. Also in this case, as the insulating film 26, an adhesive may be used, or a resin sheet may be used (in the case of fixing by tightening force). In this case, the graphite sheet 22 may extend to either side of the two split cores 11 after passing through the opening 23 of the shrink fitting ring 21.

  In the structure shown in FIG. 6C, a pair of graphite sheets 22 are provided, and an insulating film 26 is interposed between the graphite sheets 22. An insulating film is not provided between each graphite sheet 22 and the uppermost coil 12. Since the coil 12 is formed by covering a wire with an insulating film, there is almost no possibility that a short circuit between the coils 12 occurs even in such a structure. Therefore, the insulating film 26 may not be provided in the structure shown in FIG.

  Although not shown in FIGS. 1 and 3, in a general stator structure, the coil 12 is wound via an insulator. The insulator is provided for the main purpose of ensuring electrical insulation, but also has a function of protecting the coil 12 wound around the insulator. Also in the present embodiment, an insulator is provided, but the illustration is omitted for easy understanding of the main part of the invention. The corner portion of the insulator is formed in a curved surface in order to prevent the coil 12 from being damaged.

  In the present embodiment, the shrink-fit ring 21 is provided as a fixing member for fixing the split core 11, but a ring member for fixing the split cores 11 may be provided based on a principle different from the shrink-fit ring 21.

  In the present embodiment, the structure in which the tip of the graphite sheet 22 is fixed to the outer wall of the shrink-fitting ring 21 is adopted, but the structure in which the tip of the graphite sheet 22 is attached to the outer wall of the back yoke side flange portion 11a of the split core 11. It is good. For example, a part of the back yoke side flange portion 11a of the split core 11 is covered with the shrink-fit ring 21 by enlarging the opening 23 of the shrink-fit ring 21 or dividing the shrink-fit ring into two thin rings. It is possible to adopt a structure that is exposed without being exposed. And the front-end | tip part of the graphite sheet 22 can be attached to the outer wall of the exposed part of the back yoke side flange part 11a with the fixing member 24. FIG. In this case, there is an advantage that the outer dimensions of the stator 10 are hardly increased by the fixing member 24 and the graphite sheet 22.

  According to the present invention, the sheet member (graphite sheet 22 in the present embodiment) in contact with the uppermost coil 12 of the split core 11 is provided, and the leading end of the sheet member fixes the ring core (this embodiment). Therefore, the heat generated in the coil 12 can be efficiently released to the outside. Therefore, even if the structure of the split core 11 of the stator 10 is made compact, problems such as deterioration of the insulating film covering the coil 12 can be prevented.

  In the present embodiment, the example in which the leading end portion of the graphite sheet 22 that is a sheet member is attached to the outer wall of the stator has been described. However, the leading end portion of the graphite sheet 22 may be attached to a casing that houses a motor or a generator.

(Other embodiments)
The structure of the embodiment of the present invention disclosed above is merely an example, and the scope of the present invention is not limited to the scope of these descriptions. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  In the first embodiment, the sectional shape of the coil 12 is circular, but the sectional shape of the coil 12 of the present invention may be various polygons such as a quadrangle and a hexagon.

  In the first embodiment, the bottom surface of the tooth portion 15 has a three-stepped structure. However, the bottom surface of the tooth portion in the split core of the present invention is not necessarily a stepped structure, and may be a flat structure. . Further, the stepped structure may not be a three-stepped structure, and may be a stepped structure such as a two-step or four-step structure. Further, the cross-sectional shape of the slot region Rsl may be a rectangle.

  The stator of the present invention can be used for a motor, a generator (generator) and the like disposed in a hybrid vehicle, an electric vehicle, a fuel cell, a robot, and the like.

FIG. 3 is a cross-sectional view showing a schematic structure of a stator in the first embodiment. It is a perspective view for demonstrating the state which assembled the division | segmentation core by the shrink fitting ring. It is a fragmentary sectional view which expands and shows a part of FIG. FIG. 4 is a side view of the vicinity of the opening of the shrink-fit ring shown in FIG. 3. FIG. 3 is a plan view showing the graphite sheet in Embodiment 1 in an expanded manner. (A)-(c) is sectional drawing which shows the variation of the attachment method of a graphite sheet.

DESCRIPTION OF SYMBOLS 10 Stator 11 Split core 11a Back yoke side flange part 11b Rotor side flange part 12 Coil 15 Teeth part 21 Shrink fitting ring 22 Graphite sheet 22a Wide part 22b Restriction part 23 Opening 24 Fixing member 26 Insulating film

Claims (7)

A stator in which a plurality of divided cores are assembled in a ring shape,
A coil member wound around the tooth portion of each of the divided cores;
A ring member that fastens and fixes each of the divided cores from the back yoke side;
A sheet member attached to the gap between the split cores and having a tip extending toward the back yoke side of the split core;
Stator equipped with. The stator according to claim 1, wherein
The front end of the sheet member is a stator attached to the outer wall of the ring member. The stator according to claim 1, wherein
Further comprising a casing member;
The front end of the sheet member is a stator attached to the outer wall of the casing member. The stator according to claim 2 or 3,
An opening is formed in a portion of the ring member that faces the gap between the split cores,
The sheet member is a stator passing through the opening. In the stator according to any one of claims 1 to 4,
The sheet member is a stator attached to each gap of the split cores in pairs. In the stator according to any one of claims 1 to 5,
The said sheet | seat member is a stator comprised with the graphite sheet or metal foil. In the stator according to any one of claims 1 to 6,
The teeth portion of each of the split cores has a stepped structure in which the back yoke side is deeper than the rotor side.

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