Stator of rotary electric machine

This application is a National Stage of International Application No. PCT/JP2013/053630, filed Feb. 15, 2013, the contents of which are incorporated herein by reference in its entirety.

The present invention relates to a stator of a rotary electric machine, and particularly relates to an improvement of an insulating sheet structure corresponding to a concentrated winding stator having a separated iron core structure.

Background Art

In recent years, while a compact and high-power rotary electric machine is realized, an amount of windings of a stator composed of laminated iron cores is increased, and the neighboring windings are closely arranged each other. Specifically, in a motor using a concentrated winding method, when a stator, which is configured by connecting a plurality of laminated iron cores in an annular shape, is used, different windings are wound around each of the laminated iron cores, so that the different windings are closed at a gap between the neighboring windings, and it is required that a portion between the windings is sufficiently insulated.

In a conventional stator of a rotary electric machine, it is general that insulating sheets are contacted to a lamination surface so as to be mounted at both sides of laminated iron cores, and windings are wound via the insulating sheets. The insulating sheets are composed of mounted portions, which are mounted at teeth portions of the laminated iron cores, and extended portions, which are extended from both surfaces of the mounted portions. The mounted portions are fixed by insulators which are arranged at both end portions in an axis direction of the laminated iron cores, and the extended portions are arranged so as to be doubly laminated and cover the windings, which are exposed at aperture sides of the insulators. Moreover, a length of the extended portions in an axis direction of the insulating sheets is longer than a length of a portion including the windings which are protruded from both end portions in an axis direction of the laminated iron cores, and extended portions (ear portions), which are longer than the mounted portions in the axis direction of the insulating sheets, are arranged so as to cover the windings which are protruded from both end portions in the axis direction of the laminated iron cores, whereby an insulation capability in between the windings is improved (for example, refer to Patent Document 1).

Patent Document

Patent Document 1: Japanese Laid-Open Patent Publication No. 2009-171720 (lines 8 through 12 in page 2, and FIG. 3)

Problems to be Solved by the Invention

However, the windings are wound around the laminated iron cores so as to be fixed, so that there is a very few possibility in which the protruded portions of the neighboring windings are contacted each other. Moreover, a creepage distance between the neighboring windings has not been considered in determination of the length of the insulating sheets, so that an excessive length of the insulating sheets has been usually set. Therefore, using the extended portions of the insulating sheets which is longer than the length of the windings protruded from the both end portions in the axis direction of the laminated iron cores, in order to cover the whole windings, results in use of the excessive or wasted insulating sheets, so that a weight of the manufactured stator is increased, and a cost of the manufactured stator is increased.

In order to solve the above-described problems in which the excessive insulating sheets are wasted, the present invention supplies new structure of the insulating sheets in which the creepage distance is considered so as to secure insulations between neighboring windings, and a length of the used insulating sheets can be limited to a minimum length.

Means for Solving Problems

The present invention supplies a stator of a rotary electric machine, which is configured by connecting a plurality of separated cores in an annular shape, in which windings are wound around laminated iron cores having teeth portions via insulating sheets; wherein the insulating sheets are composed of mounted portions, which are mounted at teeth portions of the laminated iron cores, and extended portions, which are extended from both surfaces of the mounted portions, wherein a length in an axis direction of the extended portions, which are covered between the windings of the neighboring laminated iron cores, is limited to a length by which a creepage distance, which is required between the neighboring windings, can be secured.

Effects of the Invention

In a shape of the insulating sheets of the present invention, a length of the ear portions of the insulating sheets can be reduced to a length by which a creepage distance, which is required in order to insulate a portion between the neighboring windings, can be secured, whereby the insulating sheets, in which the ear portions of the insulating sheets are formed at only one side in an axis direction, are alternately arranged at side surfaces of the insulating sheets, and a length of the used insulating sheets can be limited to a minimum length, so that the insulating sheets have an effect in which a weight and a cost of the manufactured stator can be concurrently reduced.

FIG. 1 is a partial schematic view of a front section of a stator of a rotary electric machine according to Embodiment 1 of the present invention;

FIGS. 2( a ) and 2( b ) are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 1 of the present invention;

FIG. 3 is an oblique perspective schematic view of an insulating sheet which is used in the stator of the rotary electric machine according to Embodiment 1 of the present invention;

FIG. 4 is a schematic view illustrating a creepage distance at an ear portion of an insulating sheet between neighboring windings;

FIG. 5 is an oblique perspective schematic view of an insulating sheet which is used in a stator of a rotary electric machine according to Embodiment 2 of the present invention;

FIGS. 6( a ) and 6( b ) are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 2 of the present invention;

FIG. 7 is an oblique perspective schematic view of an insulating sheet which is used in a stator of a rotary electric machine according to Embodiment 3 of the present invention;

FIGS. 8( a ) and 8( b ) are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 3 of the present invention;

FIG. 9 is an oblique perspective schematic view of an insulating sheet which is used in a stator of a rotary electric machine according to Embodiment 4 of the present invention;

FIG. 10 is an oblique perspective schematic view of an insulating sheet which is used in the stator of the rotary electric machine according to Embodiment 4 of the present invention; and

FIGS. 11( a ) and 11( b ) are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 4 of the present invention.

FIG. 1 is a partial front cross-sectional view of a stator of a rotary electric machine according to Embodiment 1 of the present invention. FIG. 2 are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 1 of the present invention, and FIG. 2( a ) is a drawing of the separated cores which are viewed from an arrow “A” side in FIG. 1 , and FIG. 2( b ) is a drawing of the separated cores which are viewed from an arrow “B” side in FIG. 1 .

As illustrated in FIG. 1 and FIG. 2 , insulating sheets 3 , of which detailed explanation is described later, are fixed, by using a double-sided tape, an adhesive or the like, at both sides of teeth portions 1 a of laminated iron cores 1 composing the separated cores. Moreover, insulators 2 are arranged at both end portions in an aids direction (in a vertical direction with respect to a plane in FIG. 1 ) of the laminated iron cores 1 . In addition, the structure of the insulators 2 is identical to the structure which is explained with reference to Patent Document 1, so that a detailed explanation of the insulators 2 is omitted in Embodiment 1. Moreover, windings 4 are wound around the laminated iron cores 1 which are insulated by the insulating sheets 3 and the insulators 2 , and the laminated iron cores 1 , on which the windings 4 are provided, are connected in an annular shape, whereby a stator 100 of the rotary electric machine is formed (only two laminated iron cores 1 are illustrated in FIG. 1 ).

FIG. 3 is an oblique perspective schematic view of an insulating sheet which is used in the stator of the rotary electric machine according to Embodiment 1 of the present invention. As illustrated in FIG. 3 , the insulating sheets 3 are composed of mounted portions 3 a , which are mounted at side surfaces of the teeth portions 1 a of the laminated iron cores 1 , and extended portions 3 b which are extended with a “]” shape from both end portions in a longitudinal direction of the mounted portions 3 a to a vertical direction with respect to the axis direction of the laminated iron cores 1 at the insulating sheets 3 . As illustrated in FIG. 1 , the extended portions 3 b of the insulating sheets 3 are further bent toward the inside (indicated by arrows), and the both extended portions 3 b are overlapped so as to cover the windings 4 . In other words, windings 4 , which compose the neighboring separated cores, are contacted via four insulating sheets 3 .

Moreover, as indicated in FIG. 3 according to Embodiment 1, in a direction of the insulating sheets 3 (referred to as an axis direction of the insulating sheets 3 ) which is parallel with respect to the axis direction of the laminated iron cores 1 , lengths of the extended portions 3 b are partially longer than lengths of the mounted portions 3 a at only one side (upper side with respect to a plane in FIG. 3 ). Difference portions between the extended portions 3 b and the mounted portions 3 a in the axis direction of the insulating sheets 3 are referred to as ear portions 3 c , and the length of the ear portions 3 c corresponds to a height by which the creepage distance between the neighboring windings 4 can be secured.

A creepage distance 5 represents a distance between conductive components, or a distance between a conductive component and a conductive connecting portion of a device, or a distance of a surface of a cabinet, and the creepage distance 5 represents a shortest distance which is measured along a surface of an insulator. FIG. 4 is a schematic view illustrating the creepage distance 5 at the ear portions 3 c of the insulating sheets 3 between the neighboring windings 4 . When the creepage distance 5 (a section indicated by the thick arrow line), which is required in order to secure an insulation between the windings 4 , is, for example, 2 mm, and when the length of the ear portions 3 c of the insulating sheets 3 , which are arranged between the neighboring windings 4 , is 1 mm, the creepage distance 5 between the neighboring windings 4 is secured as 2 mm.

In Embodiment 1, for example, a three-layered insulating sheet, in which a heat-resistant film is sandwiched between “Nomex®” papers, is used for a material of the insulating sheets 3 , and the three-layered insulating sheet is cut out and bent, whereby the insulating sheets 3 are formed. Moreover, it is desirable that a thickness of the insulating sheets 3 is roughly set at 0.1 mm to 0.3 mm. When the thickness of the insulating sheets 3 is thinner than 0.1 mm, an insulation capability is not maintained, and when the thickness of the insulating sheets 3 is thicker than 0.3 mm, a material cost is increased.

Moreover, as described above, the length of the ear portions 3 c of the insulating sheets 3 between the neighboring windings 4 is set by considering the creepage distance 5 which is required for an insulation between the windings 4 , so that the insulating sheets 3 , in which the ear portions 3 c are formed at only one side in the axis direction, can be used, and the insulating sheets 3 can be alternately arranged as illustrated in FIG. 2 . FIG. 2( a ) indicates a case in which the ear portions 3 c are positioned at an upper aide with respect to a plane in FIG. 2( a ) , and FIG. 2( b ) indicates a case in which the ear portions 3 c are positioned at a lower side with respect to a plane in FIG. 2( b ) .

As described above, in the insulating sheets 3 according to Embodiment 1, the length of the ear portions 3 c of the insulating sheets 3 is set as the length of the creepage distance 5 which is required for the insulation between the windings 4 , and the insulating sheets 3 , in which the ear portions 3 c are formed at only one side in the axis direction, are alternately arranged at each of the laminated on cores 1 , whereby the neighboring windings 4 can be sufficiently insulated, and a length of the used insulating sheets 3 can be limited to a minimum length, so that a weight and a cost of the manufactured stator can be reduced.

FIG. 5 is an oblique perspective schematic view of an insulating sheet which is used in a stator of a rotary electric machine according to Embodiment 2 of the present invention, and FIG. 6 are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 2 of the present invention, In Embodiment 1, the ear portions 3 c of the insulating sheets 3 are formed at only one side in the axis direction, whereas in Embodiment 2 ear portions 3 c of insulating sheets 3 are formed as illustrated in FIG. 5 . In other words, the ear portions 3 c , which are extended from extended portions 3 b of the insulating sheets 3 in the axis direction, are formed at each of opposite sides.

The length of each of the ear portions 3 c is identical to the length of the creepage distance 5 which is required for the insulation between windings 4 . FIG. 6( a ) indicates a case in which the insulating sheets 3 are arranged at teeth portions in a condition as illustrated in FIG. 5 , and FIG. 6( b ) indicates a case in which the insulating sheets 3 are arranged in a condition where the insulating sheets 3 illustrated in FIG. 5 are turned upside down (in reverse). Even when the ear portions 3 c are formed as described above, the creepage distance 5 , which is required between windings 4 , can be secured, and a length of the used insulating sheets 3 can be limited to a minimum length, so that a weight and a cost of the manufactured stator can be reduced.

FIG. 7 indicates the other example of an insulating sheet which is used in a stator of a rotary electric machine according to Embodiment 3 of the present invention, and FIG. 8 are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 3 of the present invention.

In a shape of insulating sheets 3 illustrated in FIG. 7 , ear portions 3 c , which are extended from one of extended portions 3 b of the insulating sheets 3 to both sides in an axis direction, are formed. In a case of the shape of insulating sheets 3 illustrated in FIG. 7 , the insulating sheets 3 are alternately arranged at laminated iron cores 1 as illustrated in FIG. 8 , whereby a creepage distance 5 , which is required between windings 4 , can be secured, and a length of the used insulating sheets 3 can be limited to a minimum length, so that a weight and a cost of the manufactured stator can be reduced.

FIG. 9 is an oblique perspective schematic view of an insulating sheet which is used in a stator of a rotary electric machine according to Embodiment 4 of the present invention, and FIG. 10 is an oblique perspective schematic view of an insulating sheet which is used in the stator of the rotary electric machine according to Embodiment 4 of the present invention. FIG. 11 are side schematic views of separated cores of the stator of the rotary electric machine according to Embodiment 4 of the present invention.

Insulating sheets 3 may be formed with shapes indicated in FIG. 9 and FIG. 10 . As illustrated in FIG. 11 , the insulating sheets 3 illustrated in FIG. 9 and the insulating sheets 3 illustrated in FIG. 10 are alternately arranged, whereby a creepage distance 5 , which is required between windings 4 , can be secured, and a length of the used insulating sheets 3 can be limited to a minimum length, so that a weight and a cost of the manufactured stator can be reduced.

“ 1 ” are laminated iron cores; “ 2 ,” insulators; “ 3 ,” insulating sheets; “ 3 a ” mounted portions; “ 3 b ,” extended portions; “ 3 c ,” ear portions; “ 4 ”, windings; “ 5 ,” a creepage distance; “ 100 ,” a stator of a rotary electric machine.