JPS62244248A - Stator core for motor - Google Patents

Abstract

PURPOSE:To prevent the loss of eddy currents generated between laminated plates of a wound core type stator by spirally winding a base section of a band-shaped plate, one end of which has a tooth section and the other end of which has side base section, while the base section is rolled, and laminating and fixing the base section and forming a stator core. CONSTITUTION:A series of a band-shaped continuons core blank 3 with a base section 1 and a plurality of tooth sections 2 is rolled and bent while the tooth sections 2 are directed inward and an inclined section, in which the plate thickness is decreased in succession toward an outer circumference from the inside of the base section 1, is shaped around a shaft 4 to be afterward removed, and wound spirally. The shaft 4 is taken off, a spirally wound spiral core blank 5 is inserted into a mandrel 7 on a cradle 6 to be afterward removed, and the tooth sections 2 are laminated and shaped so as to align in the direction of laminating. Accordingly, the lowering of a space factor as the factor of the increase of the loss of eddy currents, the cutting of a magnetic path, the breaking of an insulating film, etc. can be inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stator for a rotating electric motor, and more particularly to a stator core structure for a rotating electric motor suitable for preventing eddy current loss generated in the wound core.

[Conventional technology]

By using the protrusions provided on each tooth of a band-shaped core material with a large number of turns, the end opposite to the tooth, or the base of the core material, acute deformation is caused by in-plane bending. However, a wound core formed by spirally winding, laminating a plurality of layers, and fixing them by welding or caulking is known as a stator core for, for example, an automotive alternator, etc., which has a relatively low motor efficiency. Note that Japanese Patent Application Laid-Open No. 75551/1984 is related to this type of wound core.

[The problem that the invention attempts to solve]

However, with the conventional wound core produced by this in-plane bending process, it is possible to obtain a good-quality wound core with a smooth plate surface within the range of the vertical and horizontal axes enclosed inside the parabola in Fig. 11. However, it is possible to increase the base plate width/plate thickness ratio and the base plate width/radius ratio to the area outside the parabola (then, as shown in Fig. 12, edge waves 28 are formed on the inner and outer peripheries, and cracks 29 are formed on the outer periphery). In addition, these drawbacks are exacerbated by magnetic steel machines with high silicon content and low elongation.As an example, point A in FIG. 11 has a plate thickness of 1.0 m and a bending radius of 50+w.

This shows the conditions corresponding to the wound core of a conventional automotive alternator B having a plate width of 5 mm, and a sufficiently good wound core can be obtained within such a range of conditions. On the other hand, Figure 11B
The dots show an example of the conditions equivalent to the stator core for a rotary electric motor with high motor efficiency used, for example, in a small refrigerant compressor. As the thickness of the material becomes thinner to 0, sm, and the width of the material triples to 15m+, circular bending of the material becomes difficult to process. Green liquid 28 on the inner and outer peripheries and cracks 29 on the outer periphery become unavoidable.

Figure 13 shows an example where a continuous steel strip with teeth on the inner circumference side is forcibly bent into a circular shape at the base on the side opposite to the teeth (corresponding to the width of the plate in Figure 11). In this way, it becomes a spiral body with green liquid 28 on the inner and outer peripheries and cracks 29 on the outer periphery. When this is laminated and shaped, it becomes as shown in Fig. This acts to widen the gap between the core laminates, leading to a significant decrease in the space factor, and cracks on the outer periphery act to cut the magnetic path.Furthermore, green liquid is generated between the core laminates. At the contact point 31, it acts to destroy the insulating film previously applied on the surface of the core material.

The above-described reduction in space factor, cutting of the magnetic path, and destruction of the insulating film are all undesirable because they increase eddy current loss in the iron core.

For this reason, in conventional stator cores for high-efficiency rotary motors with a wide base width, it is unavoidable that magnetic steel plates are punched out one by one, and then a plurality of these plates are laminated and fixed. Therefore, there was a lot of smoked wood on the inner and outer peripheries due to punching, which may have been a drawback of low material utilization.

Usually, the rotor core material was extracted from the smoked wood produced by punching out the inner circumference of the stator core.Especially in the case of rotating electric motors that use permanent magnets for the rotor, this smoke This has led to a significant drop in the material utilization rate since the materials cannot be used.

An object of the present invention is to provide a stator core for a rotating motor that prevents eddy current loss occurring between the laminated plates of a wound core type stator.

[Means for solving problems]

The above purpose is to form a stator core for a rotating electric motor by rolling the base part of a strip plate having teeth at one end and a base part at the other end while rolling the base part in a spiral shape, stacking and fixing the plate. This is achieved by eliminating the slopes caused by rolling.

[Effect]

That is, a helical core material obtained by rolling and bending the base of a band-shaped plate having teeth at one end and a base at the other end without forming an inclined part in which the plate thickness decreases from the inner circumference to the outer circumference. By stacking and fixing the helical core material, it is possible to obtain a good spiral core material without green fluid or cracks, which was impossible with conventional sheet circular bending. By forming the stator core, it is possible to prevent a reduction in space factor, cutting of a magnetic path, and destruction of an insulating film, which are factors that increase eddy current loss.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. As shown in the figure, a stator core for a rotating electric motor was formed from a series of strip-shaped core materials 3 punched from a strip-shaped magnetic steel plate and having a base 1 and a plurality of teeth 2. A stator core was manufactured as described below. The base core material 3 is rolled and bent in the form of a band around a rotating shaft 4 from which the core material 3 is later removed, with the teeth 2 placed inside, and the base 1 formed with an inclined portion in which the plate thickness decreases sequentially from the inner circumference to the outer circumference. and wrap it in a spiral. Next, the rotating shaft 4 is removed, and the spirally wound helical core material 5 is inserted into the mandrel 7 on the pedestal 6 which will be removed later, and the fixing notch 8 and A refrigerant passage 9 is provided, and a toothed portion 2 is provided.
Stack and shape so that they are aligned in the stacking direction. After the lamination and shaping, the pedestal 6 was removed and a cutter 10 was inserted into the fixing notch 8 to fix the laminated and shaped helical core material 5.

By doing this, it is possible to obtain a good spiral core material without green scum or cracks, which was impossible with conventional plate circular bending, and the stator of the present invention, which is a laminate of the spiral core materials, can be obtained. In the case of iron cores, it is effective in preventing the decrease in space factor, cutting of magnetic paths, and destruction of insulating films caused by green fluid and cracks 1, and as a result, it is effective in preventing increases in eddy current loss. Furthermore, the stator core for a rotating electric motor of the present invention is a conventional punched core (LA magnetic steel plate 1).
It is formed of a series of strip-shaped iron core materials 3 punched from a strip-shaped magnetic steel plate and having a base 1 and a plurality of teeth 2, rather than being punched out individually one by one.
The utilization rate of the magnetic steel plate material is greatly improved, and it is possible to obtain a stator core for a rotating motor that allows the utilization rate of the magnetic steel plate material to be significantly improved.

That is, the base l of a series of belt-shaped iron core materials 3 in the form of a belt in which the teeth 2 have been expanded and removed in advance in a comb-shape is rolled by the spindle roll 11.
The spiral guide 13 is sequentially rolled and bent diagonally using a plurality of rolls composed of a combination of a rolling pan 12 and a rolling pan 12.
(See Figure 2.3). By doing so, the helical core material 5 wound spirally has an inclined part with a rolling ratio that is about 1 degree larger from the inner periphery of the base l toward the outer periphery, unlike the conventional plate. This results in a good product that does not cause cracks on the outer periphery or green fluid on the inner and outer peripheries, which occurs in the case of surface circular bending.

Next, a mandrel 7 is formed by vertically disposing the helical core material 5 on a pedestal 6, and a guide plate 14, a feed roll 15.15a, and a punching brace 16.16a are arranged and formed around this mandrel 7. A plurality of refrigerant passages 9 and fixing notches @ 8 are punched out on the outer periphery of the helical core material 5 using a peripheral punching device, and the teeth 2 are aligned in the stacking direction and placed on the pedestal 6 in a predetermined position. (See Figure 4). In this way, after rolling, bending, and winding, the refrigerant passage 9 and the fixing notch @ 8 are punched out on the outer periphery, so that the dimensional accuracy of the tooth portion 2 is ensured without causing bending due to the notch during winding. It's easy. Then, a rectangular WIO formed in a mountain shape (see Figure 6)
is inserted into the fixing notch @8, presses the back side of the WIO, and presses its upper and lower ends tOa, 10b to fix the laminated and shaped helical core material 5. 1. Complete (see Figure 5).

In this example, the conditions for rolling and bending are changed as necessary, and either one side or both sides of the base 1 is rolled (7th
The structure shown in FIGS. (al, (b)) may also be used, and in either case, the gap portion 18 is formed by stacking the rolled portions 17. Therefore, when fixing with the shaft 10, this gap 18 is provided to reduce the compressive force acting in the vertical direction and prevent deformation of the stacked helical core material 5 in the stacking direction. .

Additionally, since the surface of the strip core material 3 is normally coated with an insulating coating in advance, the insulation coating may be destroyed by rolling and bending, and this broken portion may cause metal contact between the overlapping strip core materials 3, resulting in an increase in eddy current loss. However, in this embodiment, as described above, the gap 18 is formed to prevent metal contact from occurring, so the eddy current loss can be reduced.

Note that an increase in the gap 18 causes a decrease in the space factor of the stator core and causes an increase in iron loss, but the rolled core formed by rolling bending of this embodiment cannot be used by conventional sheet circular bending. Since it is possible to use a magnetic steel sheet with a high silicon content and low elongation, which was previously difficult to do, this aspect can be fully compensated for.

In this way, restrictions on the material of the magnetic steel plate used, the plate width/thickness ratio, the plate width/radius ratio, etc. are greatly relaxed, so it can be applied to all stator cores for high-efficiency rotating motors. Compared to conventional stator cores for high-efficiency rotary motors, in which only punched cores could be used, the material yield can be significantly improved.

By the way, in the process of laminating a plurality of helical core materials to form a stator core, the number of laminated layers is extremely large (in applications where the number of layers is extremely large, pitch deviations between teeth caused by various factors during rolling and bending) may occur. There is a possibility that the dimensional accuracy may be accumulated along with the stacking thickness and exceed the permissible limit.In such a case, it is possible to maintain the dimensional accuracy by the means described below.

That is, as shown in FIG. The toothed portion 2 is formed by winding and rolling the rotating shaft 21 while diagonally and sequentially using a roll.
While the pitch between the teeth is automatically measured by the detector 22, the amount of pitch deviation between the teeth caused by variation in the plate thickness of the strip core material 3 or non-uniformity of the material is accumulated together with the number of teeth and within a range within which the allowable dimension amount is not exceeded. The base 1 is cut off with a cutting blade 23 having a constant width between the plurality of teeth 2 from the beginning of winding, as shown in FIG.
4 and sequentially form spiral core material blocks 25a, 25
b, forming 25C. The spiral core material blocks 25a, 25b, and 25C manufactured in this manner are placed on a mandrel 7 vertically disposed on a pedestal 6 in FIG. A plurality of refrigerant passages 9 and fixing notches are formed on the outer periphery of the helical core material block 25 by using a peripheral punching device around which a guide plate 14, a feed roll 15.15a, and a punching press 16.16a are arranged and formed. @8 is punched out (.Next, the above-mentioned spiral core material blocks 25 are sequentially stacked to ensure the required stacking thickness. At this time, the base 1a of the spiral core material block 25a and the base of the spiral core material block 25b are 1b is continuous with a cut-off portion 24, and an adjustment gap 26 is provided between the base portion la and the base portion 1b during lamination to adjust the cumulative pitch deviation between tooth portions corresponding to the cut-off portion 24. The tooth portion 2a, the base portion 1a, and the base portion 1b are laminated through the tooth portion 2a, base portion 1a, and base portion 1b.

The amount of pitch deviation between the tooth parts consisting of the tooth parts 2b is minute, and the slot part 27 is formed within the allowable dimension. Similarly, in the stacking of the spiral core material blocks 25b and 25C, the tooth portion 2b
, the base portion lb, the base portion 1c, and the tooth portion IC1, the slot portion 27a is formed in which the amount of pitch deviation between the tooth portions is minute and within allowable dimensions.

In this way, a plurality of spiral core material blocks 25a, 2
5b and 25C are successively aligned in the stacking direction via the adjustment gap 26, and by stacking them, dimensional accuracy can be ensured without being affected by the stacking thickness (see FIG. 9).

Spiral core material blocks 25 stacked in this way
．． 25a, 25b, 25C as shown in FIG.
B is pressed and bent to form spiral core material blocks 25a, 25b,
Fix 25C and complete the stator core for one rotary electric motor.

〔Effect of the invention〕

As described above, according to the present invention, in a wound core for a high-efficiency rotary motor with a large base plate width/plate thickness ratio and a large base plate width/radius ratio, a decrease in space factor due to green liquid and cracks, and a decrease in magnetic Since it is possible to prevent path disconnection, breakdown of the insulating film, etc., this has the effect of suppressing the increase in eddy current loss associated with this.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of a stator core for a rotary motor according to the present invention, FIG. 2 is a side view of a series of strip-shaped core materials according to an embodiment of the stator core for a rotary motor according to the present invention, and FIG. The figure is a perspective view showing the state of a stator core for a rotating electric motor according to an embodiment of the present invention during rolling and bending, and FIG. , FIG. 5 is a perspective view of a stator core according to an embodiment, FIG. 6 is a perspective view of a wedge according to an embodiment, and FIGS.
8 shows the main parts of the completed stator core according to one embodiment (Al is a partial vertical cross-sectional view showing one side, and FIG. 8B is a partial longitudinal sectional view showing both sides rolled. FIG. 9 is a perspective view showing a state in which the pitch deviation absorbing portion is cut off during rolling bending in the embodiment; FIG. 10 is a perspective view showing a stacked state of the spiral core material blocks according to the embodiment; A perspective view showing the fixing state by the example of the case, 1st
Figure 1 is an explanatory diagram showing the possible area of in-plane burrs, Figure 12 is a plan view showing the state of defects that occur when bending the same as above, and Figure 13 is when a copper strip with teeth on the inner periphery is forcibly bent. FIG. 14 is a plan view showing the state of defects occurring in the stator, and FIG. 14 is a vertical cross-sectional view of a stator in which the same defective products are stacked. 1... Base, 2... Teeth, 3... Band-shaped core material,
4.21...Rotating shaft, 5...Spiral core material, 6.
・・Case, 7. Core metal, 8. Fixing notch, 9.
・・Refrigerant passage, 10・・11.19・・Spindle roll, 12.20・・Rolling pan, 13・
...Spiral guide, 14...Guide plate, 15.15a
... feed roll, 16.16a ... punching press,
17... Rolling part, 18... Gap part, 22... Detector, 23... Cutting blade, 24... Cutting part, 25a,
25b, 25C...Spiral core material block, 26.
...Adjustment gap, 27...Slot portion, 28...Green liquid, 29...Crack, 30...Wave head, 31...Contact point. ＃j eye to 櫟茅2 小茅3 Figure $5 eye Meiotome (6L) Kaya 7th eye (Phantom Io Detector 10 Prisoner I Kayall Snake 41 Jino 2 Toko

Claims (1)

[Claims] 1. The base of the strip plate having teeth at one end and a base at the other end is wound spirally while being rolled, laminated and fixed to form a stator core for a rotating electric motor, and the base is coated with the rolled plate. A stator core for a rotating electric motor, characterized by having an inclined portion.