JPH06178472A - Stator of electric motor - Google Patents

Abstract

PURPOSE:To provide a stator wherein the dustproof property and the waterproof property of an electric motor can be maintained by preventing that a gap is produced in the outer circumferential structure of the electric motor due to deformation when a laminated iron core is assembled by a plurality of thin sheets. CONSTITUTION:A thin sheet forming a laminated iron core 10 is provided with a plurality of winding slots 14 formed in the circumference of an inner edge part, with rod holes 16 formed in corner parts and with protruding parts 18 installed so as to protrude from one edge in the shaft direction in nearly intermediate positions of the adjacent rod holes 16 in every other position in the peripheral direction. Recessed parts whose contour is nearly identical to that of the protruding parts 18 on just the rear side of the individual protruding parts 18 are formed on the other edge of the thin sheet. The laminated iron core 10 is laminated and formed in such a way that the protruding parts 18 and the recessed parts on a plurality of thin sheets are force-fitted alternately. Opened parts 22 are formed so as to be passed in outside parts in the radial direction of the individual protruding parts 18 in the thin sheets. The opened parts 22 act in such a way that the deformation caused around the protruding parts 18 on the thin sheets in the assembly of the iron core is not propagated to the outer periphery edge region of the laminated iron core 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of an electric motor,
In particular, it relates to improvement of a stator of an electric motor using a laminated core made of a laminated body of a plurality of thin plates of a high magnetic permeability material.

[0002]

2. Description of the Related Art Generally, in a magnetic path where magnetic flux alternates, such as an armature of a DC motor, a stator of a synchronous motor, a stator and a rotor of an induction motor, eddy current is prevented from occurring to reduce iron loss. For this purpose, a laminated core formed by axially laminating a plurality of thin plates of a high magnetic permeability material such as a silicon steel plate is used. Conventionally, for the purpose of facilitating the work of laminating thin plates when forming a laminated iron core, a plurality of convex portions and concave portions having dimensions that can be fitted to each other are formed at respective corresponding positions on respective axial end faces of the thin plates. It is known. At the time of stacking, a plurality of thin plates can be interlocked with each other by press-fitting the convex portions and the concave portions of the end faces facing each other between the adjacent thin plates. These convex portions and concave portions are, for example, by performing deep drawing in the punching process of the thin plate,
It can be formed simultaneously on both end faces of the thin plate. In the stator of the electric motor, the laminated iron core thus formed is
A structure is known in which it is sandwiched by a pair of support members arranged at both ends in the axial direction, and further, the support members and the laminated iron core are integrally fastened and fixed by fastening rod members penetrating in the axial direction.

[0003]

The laminated iron core described above has a structure in which, when a plurality of thin plates are laminated, the convex portions and the concave portions of the adjacent thin plates are press-fitted into each other by a press machine so as to fit between the thin plates. A predetermined pressure is applied to. At this time, if the protruding length of the convex part of one thin plate is shorter than the depth of the concave part of the other thin plate due to processing error during molding, etc. A gap is left between the surface and the bottom of the recess. If more pressure is applied in this state,
The stress concentrates in the direction of filling the gap between the tip surface of the convex portion and the bottom surface of the concave portion, and the periphery of the convex portion of each thin plate locally deforms in the protruding direction of the convex portion. When this laminated iron core is used for the stator of an electric motor, such thin plate deformation does not pose a problem because substantially the same deformation occurs between the thin plates, but there is no problem between the iron core and the support members at both ends thereof. However, a gap is inevitably formed in the mutual contact portion which should be closely adhered by fastening.
In particular, in the case of an electric motor that does not have a housing that surrounds the stator, the mutual contact portion between the iron core and each support member exposes the outer peripheral portion to the external space of the electric motor, so the gap formed there is dust-proof for the electric motor. It becomes a factor that deteriorates the waterproofness and waterproofness.

The present invention has been devised and devised to solve the above-mentioned problems of the prior art. The object of the present invention is to provide a plurality of thin plates forming a laminated core in a stator of an electric motor composed of the laminated core. It is an object of the present invention to provide a stator capable of preventing the occurrence of a gap in the electric motor outer peripheral structure due to the deformation at the time of assembling the iron core, and thus maintaining the dustproof property and the waterproof property of the electric motor.

[0005]

To achieve the above object, the present invention provides a plurality of high magnetic permeability materials having a plurality of convex portions on one axial end surface and a plurality of concave portions on the other axial end surface. In a stator of an electric motor composed of laminated iron cores, which are formed by laminating and pressing the convex portions and the concave portions of the end surfaces of the thin plates facing each other between the adjacent thin plates, a plurality of thin plates forming the laminated iron core are provided. There is provided a stator of an electric motor, which is provided with an incision portion penetrating in an axial direction in each radially outer portion of each of the convex portions.

[0006]

When the convex portions and the concave portions of the end faces facing each other between the adjacent thin plates are press-fitted, the bending deformation around the convex portions caused by the difference between the length of the convex portion and the depth of the concave portion is Providing the incision in the radially outer part of the part avoids propagation to the outside of the incision and thus to a predetermined area along the outer periphery of the lamella. That is, the flexural deformation around the convex portion occurs only in the portion radially inward of the cutout portion. Therefore, each support member that sandwiches the laminated core from both ends in the axial direction can contact and fix to the outer peripheral edge region of the laminated core that does not cause deformation of both axial end faces without forming a gap. Thereby, high dustproofness and waterproofness of the electric motor are secured.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail with reference to the preferred embodiments shown in the accompanying drawings. Referring to the drawings, FIG. 1 shows one thin plate 12 which is a laminated element of a laminated iron core 10 which constitutes a stator of an electric motor according to an embodiment of the present invention.
Is shown in a plan view, and FIG. 2 is a sectional view showing the thin plate 12 slightly enlarged in the thickness direction. The thin plate 12 is made of a high-permeability material such as a silicon steel plate, and is punched to form a substantially octagonal outer contour and a plurality of winding slots 14 provided around the inner edge.
And an annular plate shape having. At eight corners of the thin plate 12, rod holes 16 for fastening rod members (tie rods) for fixing the laminated iron core 10 and the respective support members arranged at both ends in the axial direction are formed at the outer peripheral edge and the bottom of the slot 14. Is formed so as to penetrate therethrough in the axial direction. Protrusions 18 projecting from one end face in the axial direction are provided at almost every other intermediate portion of the adjacent rod holes 16 of the thin plate 12 in the circumferential direction. Each convex portion 18 is formed by deep drawing in the punching process of the thin plate 12. Therefore, on the other end surface of the thin plate 12, a concave portion 20 having substantially the same contour as the convex portion 18 is formed just on the back side of each convex portion 18.

Further, the thin plate 12 is provided with a notch 22 penetrating in the axial direction at the outer side in the radial direction of each convex portion 18. The cutout 22 is formed by the protrusion 1 in the punching process of the thin plate 12.
After forming the concave portions 8 and the concave portions 20, they are engraved adjacent to the convex portions 18. The circumferential length of the incision 22 is preferably the convex portion 18
Is formed longer than the circumferential length of the. Further, the radial length of the incision portion 22 or the incision shape can be appropriately set according to the shape and size of the thin plate 12. That is, the incision portion 22 is shown in FIG.
It may be a rectangular hole as shown in, or a triangular hole shown in FIG.
Other oval holes may be used. Alternatively, the incision 22 may be formed as a slit having almost no radial length.

The convex portion 18 and the concave portion 20 are formed on the thin plate 12 by
It can be provided in various positions other than the above. However, it is desirable to arrange the iron cores 10 at symmetrical positions with respect to the axis so that the fitting pressure can be uniformly received when the laminated iron core 10 is assembled. In each case, the incision 22 is formed by each convex portion 1
It is formed at a radially outer portion of 8 with a predetermined circumferential length.

FIG. 3 is a sectional view showing a fixing structure portion of an electric motor using a laminated iron core 10 composed of a laminated body of the above-mentioned thin plates 12 as a stator. The laminated core 10 includes a plurality of thin plates 1
2 are laminated and formed by press-fitting the convex portions 18 and the concave portions 20 of the end faces facing each other between the adjacent thin plates 12 into each other. The laminated iron core 10 has each slot 1
A winding wire 24 is wound around the shaft 4, and is sandwiched from both axial ends by a pair of supporting members, that is, a load side flange 26 and an anti-load side end bell 28. After that, the flange 26, the laminated iron core 10, and the end bell 28 are integrally fastened and fixed by the plurality of tie rods 30.

As shown in a slightly exaggerated manner in FIG. 3 and in a partially enlarged view in FIG. 4, a plurality of thin plates 1 of the laminated core 10 are shown.
2 is due to the difference between the protruding length of the convex portion 18 of one thin plate 12 and the depth of the concave portion 20 of the other thin plate 12 when the convex portion 18 and the concave portion 20 of each adjacent thin plate 12 are press-fitted. Due to the stress concentration, the periphery of the convex portion 18 is locally deformed in the axial direction. However, in the thin plate 12, since the cutout portion 22 is provided in the radially outer portion of the convex portion 18, the deformation around the convex portion occurs only in the portion radially inward of the cutout portion 22, and the outside of the cutout portion 22, That is, it does not propagate to a predetermined region along the outer peripheral edge of the thin plate 12. Therefore, the flange 26 and the end bell 28 can be closely fixed to the outer peripheral edge regions of the axial ends of the laminated core 10 where no deformation occurs, as illustrated.

As shown in FIG. 5, an incision portion 22 of the thin plate 12 is formed.
Can also be formed at a position slightly away from the convex portion 18 to the outside. Here, as described with reference to the modified example shown in FIG. 5, the arrangement of the cutout portion 22 is performed by the magnetic flux 32 passing through the laminated core 10.
On the other hand, as shown in the figure, the magnetic path is narrowed. Thereby, especially when the distance between the outer peripheral edge of the thin plate 12 and the bottom of the slot 14 is short, the magnetic circuit of the laminated iron core 10 is apt to cause magnetic saturation, and therefore, the maximum output and the maximum torque of the electric motor are reduced, and the heat generation amount. There is a risk that problems such as increase in

Therefore, as shown in FIG. 6, in the laminated core 10 composed of the polygonal thin plates 12, the projections 18 are arranged near the corners of the thin plates 12. As a result, the incision portion 3 formed of the triangular hole formed through the radially outer portion of the protrusion 18 is formed.
4 is arranged outside the magnetic path formed in the laminated core 10, and the influence of the cutout 34 on the magnetic circuit is avoided. The rod holes 16 provided at the corners of the thin plate 12
Has no influence on the magnetic circuit because the tie rods 30 made of ferromagnetic metal are arranged.

[0014]

As is apparent from the above description, according to the present invention, a plurality of thin plates forming a laminated iron core are provided with cutouts penetrating radially outward portions of the projections for interlocking each other. At the time of stacking, the flexural deformation around the projections that occurs when press-fitting the projections and recesses of the adjacent thin plates is not propagated to the outside of the incision. It is possible to closely fix the respective support members that sandwich the iron core from both axial ends thereof to the outer peripheral edge regions of the laminated iron core where the axial both end surfaces are not deformed. Therefore, it is possible to ensure high dustproofness and waterproofness of the electric motor without impairing workability in assembling the laminated core.

[Brief description of drawings]

FIG. 1 is a plan view of a thin plate forming a laminated iron core according to an embodiment of the present invention.

2 is a cross-sectional view of the sheet of FIG. 1 taken along the line II-II.

3 is a cross-sectional view of a fixed structure portion of an electric motor including a laminated iron core including the laminated body of the thin plates of FIG. 1, and is a line III-III of FIG.
It is a figure shown along with.

4 is a partially enlarged cross-sectional view of the laminated core of FIG.

5A and 5B are diagrams of a thin plate according to the modified example of FIG. 1, FIG. 5A is a partial plan view, and FIG. 5B is a diagram for explaining an influence on a magnetic circuit.

FIG. 6 is a partial plan view of a thin plate according to another embodiment.

[Explanation of symbols]

 10 ... Laminated iron core 12 ... Thin plate 16 ... Rod hole 18 ... Convex portion 20 ... Recessed portion 22, 34 ... Cutout portion 26 ... Flange 28 ... End bell 32 ... Magnetic flux

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaya Yasushi, Oshino Nomura, Minamitsuru-gun, Yamanashi 3580, Kobaba, Fanac Co., Ltd. Local FANUC Co., Ltd.

Claims (1)

[Claims] 1. A plurality of thin plates of a high magnetic permeability material having a plurality of convex portions on one end face in the axial direction and a plurality of concave portions on the other end face of each of the end faces facing each other between the adjacent thin plates. In a stator of an electric motor composed of a laminated iron core formed by laminating and press-fitting a convex portion and the concave portion to each other, the thin plate forming the laminated iron core is a radially outer portion of each of the plurality of convex portions. A stator for an electric motor, which is provided with an incision portion penetrating in the axial direction.