JP2008048592A - Stator - Google Patents

Abstract

An object of the present invention is to improve a contact configuration of a joining end face of a back yoke portion of a divided stator core arranged adjacently and reduce a leakage magnetic flux at the joining end face.
An end face in the stator circumferential direction of a back yoke portion of each divided stator core is used as a joining end surface, and the back yoke portions of adjacent divided stator cores are joined to each other, and joining end surfaces on both sides of the back yoke portion of each divided stator core are A first surface extending inwardly from the outer peripheral end, a second surface extending in the stator circumferential direction from an inner peripheral side end of the first surface, and from a tip of the second surface to the inner peripheral end It is set as the stepped shape provided with the extended 3rd surface, and 1st surfaces and 2nd surfaces are joined in the joining end surface to adjoin.
[Selection] Figure 1

Description

  The present invention relates to a stator and reduces leakage magnetic flux generated between divided stator cores to improve motor characteristics.

2. Description of the Related Art Conventionally, a stator core (iron core) used for a stator disposed on the outer periphery of a rotor has been a split stator core obtained by dividing a ring-shaped stator core at a predetermined angle for reasons such as ease of winding and occupancy improvement. Yes.
In general, a split stator core has a back yoke portion arranged in the circumferential direction, and end surfaces of the back yoke portions of adjacent split stators are joined and connected to form a stator.

  The split stator generates a magnetic flux by passing an electric current through a coil wound around the tooth portion, and the magnetic flux passes through the adjacent split stator core and rotor via the end surface of the adjacent back yoke portion, and is closed by the adjacent split stator. Form a circuit.

While metal such as a split stator core is easy to pass magnetic flux, air is much more difficult to pass magnetic flux than metal, so the magnetic flux concentrates on the metal. It becomes saturated and magnetic flux leaks into the air. If the contact area between the end faces of adjacent back yoke parts becomes small, the magnetic flux is saturated between the end faces of the back yoke parts, so that the magnetic flux leaks into the air, and the magnetic flux density passing through the rotor decreases, resulting in motor characteristics. Decreases. Therefore, it is desired to increase the contact area between the end surfaces of the adjacent back yoke portions and reduce the leakage magnetic flux.
In addition, due to the fastening stress when fastening the split stator cores, magnetic deterioration occurs at the joined portion of the back yoke part, which causes stator loss and reduces motor characteristics. It is hoped that

JP, 2005-354838, A stator core is provided as a stator which divided and formed a divided stator core.
As shown in FIG. 9A, the stator core 1 is configured by connecting a plurality of stator core components 2 in the circumferential direction along the periphery of the rotor core 3. As shown in FIG. 9B, the stator core component 2 is opposed to the yoke portion 2a, the tooth portion 2b protruding from the yoke portion 2a toward the inner peripheral side, and the yoke portion 2a across the tooth portion 2b. 2c and a coil 2d wound around the tooth portion 2b. A side surface 2e of the yoke portion 2a is a flat surface, and an inner peripheral surface 2f of the flange portion 2c is disposed to face the rotor core 3. The yoke portions 2a are arranged in the circumferential direction so as to be continuous in an annular shape, and the stator core components 2 are fastened together.

JP 2005-354838 A

  However, in the stator core of Patent Document 1, the side surface 2e of the yoke portion 2a is flat, and the stator core component 2 has a dimensional tolerance, and the side surfaces 2e of the adjacent yoke portions 2a are in complete contact with each other. Therefore, the contact area between the side surfaces 2e of the adjacent yoke portions 2a is reduced. Therefore, since magnetic flux leaks between the stator core components 2 and the magnetic flux density passing through the stator is lowered, there is a problem that motor characteristics are deteriorated.

  Then, this invention makes it the subject to increase the magnetic flux density which passes a rotor, and to improve a motor characteristic by reducing the leakage magnetic flux in a joining end surface.

In order to solve the above problems, the present invention is a stator in which a split stator core is arranged in an annular shape,
Each of the divided stator cores has a back yoke portion and a teeth portion protruding from the back yoke portion into the stator,
With the end surfaces in the stator circumferential direction of the back yoke portions of the respective divided stator cores being joined end surfaces, the back yoke portions of the adjacent divided stator cores are joined to each other,
The joint end surfaces on both sides of the back yoke portion of each of the divided stator cores are a first surface extending inward from the outer peripheral end, and a second surface extending in the stator circumferential direction from the inner peripheral end of the first surface. , A stepped shape with a third surface extending from the tip of the second surface to the inner peripheral end,
The stator is characterized in that the first and second surfaces are joined to each other at the joining end surfaces adjacent to each other.

  With the above configuration, since the second surface also becomes the joining end surface of the adjacent back yoke part, the generation of leakage magnetic flux at the joining end surface can be reduced, and the magnetic flux density passing through the rotor can be increased. The characteristics can be improved.

When joining the split stator core, the outer ring which is heated and expanded is fitted onto the outer peripheral surface of the split stator core connected in an annular shape, and the outer ring is cooled to reduce the inner diameter, thereby reducing the outer peripheral surface of the split stator core. Are pressed by the outer ring to fasten the divided stator cores.
The length of the teeth part in the circumferential direction is 40% to 90% of the length of the back yoke part in the circumferential direction.

In the stator of the present invention, the third surfaces may be joined together.
That is, the first surfaces in the radial direction are joined to each other and the second surfaces in the circumferential direction are joined to each other at the joining end surfaces on both sides in the circumferential direction of the back yoke portions of the adjacent divided stator cores.
When the third surfaces are joined together, when the split stator core is fastened in an annular shape, if the fastening stress of the joint end surface by the outer ring increases, the magnetic flux density is high at the joint portion of the third surface on the inner peripheral side, and the stator due to magnetic deterioration There is a problem that loss occurs and affects motor characteristics.
Therefore, when the outer ring is fastened, the joints between the third surfaces on the inner peripheral side are joined to such an extent that no fastening stress is applied, and the magnetic flux does not pass between the third surfaces, and the outer peripheral side than the third surface. It is preferable to reduce the stator loss by avoiding magnetic deterioration on the inner periphery side of the back yoke portion having a high magnetic flux density.

Alternatively, a gap may be formed between the third surfaces without joining the third surfaces.
That is, the length of the second surface of the notch is shorter than the length of the second surface of the protrusion, the protrusion of the split stator core adjacent to the notch is fitted, and the first surfaces are joined together. In this case, a gap is formed between the third surfaces.

  The position of the first surface of one of the joining end surfaces is within a range of 15% of the circumferential dimension of the teeth portion from the circumferential central axis of the teeth portion, and the length of the gap is the root of the teeth portion. It is preferable that the length is 20% or less of the circumferential length from the position to the inner circumferential end of the third surface.

The magnetic flux passes from the tooth portion to the back yoke portion, and passes to the adjacent back yoke portion via the joining end surface of the back yoke portion. The magnetic flux density at the center on the outer periphery side of the back yoke portion that is far away becomes low.
As described above, when the gap is formed between the third surfaces, the stator loss caused by the magnetic deterioration due to the fastening stress can be reduced as compared with the case of joining on the inner peripheral side of the back yoke portion.

The first surface and the third surface to be joined may be inclined in the same direction with respect to the radial direction.
With this configuration, since the contact area between the divided stator cores to be joined becomes large, the leakage magnetic flux at the joining end face of the back yoke portion can be reduced, and the motor characteristics can be improved.

The divided stator core may be formed of a dust magnetic material or a laminated steel plate.
When the divided stator core is made of a powder magnetic material, it can be easily formed by three-dimensional formation, so that workability is good and cost can be reduced. Furthermore, since the split stator core can be finely pulverized when the motor is discarded, the split stator core and the winding can be easily separated, and the recyclability is high.
In addition, when the split stator core is composed of laminated steel plates, the laminated steel plates can be manufactured by punching the steel plates, so that they can be easily manufactured and can be produced at low cost.

  As described above, according to the invention, the surface of the adjacent back yoke portion extending in the circumferential direction of the stator is also a joining end face, thereby reducing the leakage magnetic flux at the joining end face and reducing the magnetic flux density passing through the rotor. It is possible to increase the motor characteristics.

Embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment of the present invention.

  As shown in FIGS. 1A and 1B, the stator 10 of the present invention includes a plurality of divided stator cores 12 around which coils 11 are wound, and the divided stator cores 12 are arranged in an annular shape around a center point P1. . The stator 10 is arranged around a cylindrical rotor 20 to constitute a motor 30.

  As shown in FIGS. 2A to 2C, the split stator core 12 has a back yoke portion 12 a joined to the adjacent split stator core 12, a teeth portion 12 b around which the coil 11 is wound, and the coil 11 is positioned and fixed. It is integrally formed by heat treatment after pressing and compressing the magnetic powder material.

As shown in FIGS. 2A and 2C, the back yoke portion 12a of the split stator core 12 has a rectangular shape in a side view, and the radially outer peripheral surface 12d has a curved surface.
Protrusions and notches are provided on the outer peripheral side and the inner peripheral side, respectively, on both end surfaces of the joining end surface of the back yoke portion 12a of each of the divided stator cores 12, and the projecting portions and the notch portions are on the inner and outer peripheral sides at both ends in the circumferential direction. The length of the projecting portion provided on one end side and the length of the cutout portion provided on the other end side are substantially the same length.

That is, one end side has a shape having a protruding portion 12x-1 on the outer peripheral side and a notch portion 12y-1 on the inner peripheral side. A first surface 12e extending radially inward from the circumferential tip of the outer peripheral projection 12x-1, and a step shape extending inward in the circumferential direction from the inner peripheral end of the first surface 12e. The second surface 12f and the third surface 12g extending in the radial direction from the tip of the second surface 12f to the inner peripheral end are formed into a stepped shape provided in the notch 12y-1 on the inner peripheral side.
The other end side in the circumferential direction has a shape having a notch 12y-2 on the outer peripheral side and a protrusion 12x-2 on the inner peripheral side. A first surface 12h extending radially inward from the circumferential end of the outer circumferential notch 12y-2, and a step shape extending outward in the circumferential direction from the inner peripheral end of the first surface 12h. The second surface 12i and the third surface 12j extending in the radial direction from the tip of the second surface 12i to the inner peripheral end have a stepped shape provided at the tip of the protruding portion 12x-2 on the inner peripheral side. .

  As shown in FIG. 3, at the joint end surface of the adjacent split stator core, the outer peripheral side protruding portion 12x-1 and the notched portion 12y-2 are fitted, and the inner peripheral side protruding portion 12x-2 and the notched portion 12y-1 are fitted. And the step-like second surfaces 12f and 12i extending in the circumferential direction are joined together, and the first surfaces 12e and 12h and the third surfaces 12g and 12j are joined together.

  The teeth portion 12b has a rectangular cross section and is smaller in height and width than the back yoke portion 12a and protrudes inward from the inner peripheral surface of the back yoke portion 12a. At the tip of the tooth portion 12b, a collar portion 12c having a height and width larger than those of the tooth portion 12b is further provided.

  FIGS. 4A to 4C show first to third modifications of the flange 12c, and the flange 12c of the first modification of FIG. 4A has a height only larger than that of the teeth 12b. The collar part 12c of the 2nd modification of (B) makes only the width | variety larger than the teeth part 12b. FIG. 4C shows a third modification, in which the collar portion 12c has the same height and width as the teeth portion 12b.

  The inner peripheral surface 12k of the flange portion 12c constitutes a part of the inner peripheral surface of the stator 10 formed by assembling a plurality of divided stator cores 12 in an annular shape, and the inner peripheral surface 12k is a curved surface of the rotor 20. The curved surface along As shown in FIG. 1B, when the split stator core 12 is assembled to the rotor 20, the inner peripheral surface 12 k of the flange 12 c is arranged with a gap L from the rotor 20.

  With this configuration, the contact end surface of the adjacent back yoke portion 12a is increased by the area of the second surfaces 12f and 12i as compared to the case where the joint end surface of the back yoke portion 12a is flat. Since the generation of leakage magnetic flux can be reduced and the magnetic flux density passing through the rotor can be increased, the characteristics of the motor can be improved.

5 and 6 show a second embodiment of the present invention.
As shown in FIGS. 5A and 5B, the first surfaces 42e and 42h and the third surfaces 42g and 42j of the joining end surface of the split stator core 42 are inclined inward, and the configuration is the first. This is different from the embodiment.
As shown in FIG. 6, the step-like second surfaces 12 f and 12 i extending in the circumferential direction are joined to each other at the joining end surfaces of the adjacent divided stator cores, and the first surfaces 42 e and 42 h and the third surface 42 g are joined. 42j are joined together.

With the above configuration, as in the first embodiment, the generation of leakage magnetic flux at the joint end face can be reduced, and the density of magnetic flux passing through the rotor can be increased, so that the characteristics of the motor can be improved.
Since the other configuration is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

7 and 8 show a third embodiment of the present invention.
In the third embodiment, similar to the first embodiment, the protruding portion and the notch portion are provided at both end portions in the stator circumferential direction of the back yoke portion 12a of each divided stator core. The length is shorter than the length of the second surface of the protrusion, and a gap is formed between the third surfaces of the adjacent split stator cores.

That is, on one end side in the circumferential direction, a protrusion 12x-3 having the first surface 52e is provided on the outer peripheral side, and a notch 12y-3 having the third surface 52g is provided on the inner peripheral side. The second surface 52f in the circumferential direction is provided between the first surface 52e and the third surface 52g.
On the other end side in the circumferential direction, a notch 12y-4 having the first surface 52h is provided on the outer peripheral side, and a protruding portion 12x-4 having the third surface 52j is provided on the inner peripheral side. A circumferential second surface 52i is provided between the first surface 52h and the third surface 52j. The first surface 52h of the notch 12y-4 is positioned on the central axis G of the tooth portion.

As described above, the length L1 of the second surface 52i of the notch 12y-4 on the other end side outer periphery is shorter than the second surface 52f length L2 of the protrusion 12x-3 on the one end outer periphery.
By setting it as the said shape, between the back yoke parts 12a of an adjacent division | segmentation stator core, the protrusion part 12x-3 is fitted by the notch part 12y-4 of the outer peripheral side, and the 1st surfaces 52e and 52h are joined. In this state, a gap S is formed between the third surface 52g of the notch 12y-3 on the inner peripheral side and the third surface 52j of the protrusion 12x-4.
That is, as shown in FIG. 8, when the split stator core 12 is fastened, the first surfaces 52e and 52h on the outer peripheral side are joined together, and the second surfaces 52f and 52i are joined together, while the third surfaces are joined together. A gap S is formed in 52g and 52j. As shown in FIG. 8, the length d1 of the gap S is smaller than the circumferential length d2 from the root position of the tooth portion 12b of the protruding portion 12x-4 to the inner peripheral end of the third surface 52j, It is preferable to be 20% or less of the length d2.

With the above configuration, the divided stator cores are formed by the first surfaces 52e and 52h of the projecting portion 12x-3 and the notch portion 12y-4 provided on the outer peripheral side having a lower magnetic flux density than the inner peripheral side of the back yoke portion 12a. 12 is joined, and the stator loss due to magnetic deterioration can be reduced because the joint is joined on the central axis G in the circumferential direction of the tooth portion having a particularly low magnetic flux density.
On the other hand, since the gap d1 is formed between the third surfaces 52g and 52j of the notch 12y-3 and the protrusion 12x-4 on the inner peripheral side, the magnetic flux does not pass between the third surfaces 52g and 52j, and the third surface Since it passes through the outer peripheral side than 52g and 52j, it is possible to avoid magnetic deterioration on the inner peripheral side of the back yoke part having a high magnetic flux density, and to reduce the stator loss.
Since other configurations and operational effects are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  As described above, it is not always necessary to position the outer peripheral joint end surface on the circumferential central axis of the teeth portion, and the outer peripheral first surface of the circumferential joint end surface of the back yoke portion of the adjacent divided stator core. What is necessary is just to provide a clearance gap between the 3rd surfaces of an inner peripheral side while joining together. With this configuration, the stator loss due to magnetic deterioration can be reduced because the outer peripheral side has a lower magnetic flux density than the inner peripheral side.

  The present invention is not limited to the above-described embodiment, and includes various forms within the scope of the claims of the present invention.

It is a figure which shows the stator which concerns on 1st Embodiment of this invention assembled | attached to the motor, (A) is a perspective view, (B) is a top view. It is a figure which shows the division | segmentation stator core of FIG. 1, (A) is a perspective view, (B) Top view, (C) is a rear view. It is the top view to which the principal part of the state which joined the division | segmentation stator core of FIG. 1 was expanded. It is a perspective view which shows the modification of a collar part, (A) is a perspective view of a 1st modification, (B) is a perspective view of a 2nd modification, (C) is a perspective view of a 3rd modification. The division | segmentation stator core of 2nd Embodiment is shown, (A) is a perspective view, (B) Top view, (C) is a rear view. It is the top view to which the principal part of the state which joined the division | segmentation stator core of FIG. 5 was expanded. The division | segmentation stator core of 3rd Embodiment of this invention is shown, (A) is a perspective view, (B) It is a top view. It is the top view to which the principal part of the state which joined the division | segmentation stator core of FIG. 7 was expanded. A prior art example is shown, (A) is a top view which shows a stator core, (B) is a top view which shows stator core components.

Explanation of symbols

10 Stator 11 Coil 12 Split stator core 12a Back yoke portion 12b Teeth portion 12e, 12h First surface 12f, 12i Second surface 12g, 12j Third surface 12x-1 to 12x-4 Projection portion 12y-1 to 12y-4 Notch 30 Motor S clearance

Claims (6)

A stator in which the divided stator core is arranged in an annular shape,
Each of the divided stator cores has a back yoke portion and a teeth portion protruding from the back yoke portion into the stator,
With the end surfaces in the stator circumferential direction of the back yoke portions of the respective divided stator cores being joined end surfaces, the back yoke portions of the adjacent divided stator cores are joined to each other,
The joint end surfaces on both sides of the back yoke portion of each of the divided stator cores are a first surface extending inward from the outer peripheral end, and a second surface extending in the stator circumferential direction from the inner peripheral end of the first surface. , A stepped shape with a third surface extending from the tip of the second surface to the inner peripheral end,
A stator characterized in that first surfaces and second surfaces are bonded to each other at adjacent bonding end surfaces.   The stator according to claim 1, wherein the third surfaces are joined to each other.   The stator according to claim 1, wherein a gap is formed between the third surfaces.   The position of the first surface of one of the joining end surfaces is within a range of 15% of the circumferential dimension of the teeth portion from the circumferential central axis of the teeth portion, and the length of the gap is the root of the teeth portion. The stator according to claim 3, wherein the stator is 20% or less of the circumferential length from the position to the inner peripheral end of the third surface.   The stator according to any one of claims 1 to 4, wherein the first surface and the third surface to be joined are inclined in the same direction with respect to a radial direction.   The stator according to any one of claims 1 to 5, wherein the divided stator core is formed of a powder magnetic material or a laminated steel plate.

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