JP2010017002A - Stator core of rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cover magnetic resistance generated between U-shaped pieces with an auxiliary yoke, in a stator core of a rotating electric machine. <P>SOLUTION: A plurality of the U-shaped pieces wherein a magnetic steel plate is bent to form a tooth 4 and yoke 5 are laminated into a block body 2a, and a plurality of the block bodies 2a are circumferentially arranged in parallel to form a stator core body 2. The auxiliary yoke 3 composed of magnetic steel plates laminated radially into a concentric or spiral state is provided at both ends in the rotational shaft direction of the rotor of the stator core body 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stator core that includes a yoke portion and a teeth portion that protrudes from the inner periphery of the yoke portion toward a central axis, and is used in a rotating electrical machine such as a motor or a generator.

  Conventionally, a stator core of a rotating electrical machine has a structure in which a plurality of electromagnetic steel sheets in which a yoke part and a tooth part are integrally punched are stacked in the rotor axial direction.

  In recent years, the cost is higher than non-oriented electrical steel sheets having substantially uniform magnetic properties in any direction, but stator cores using directional electrical steel sheets having particularly excellent magnetic properties in a certain direction have been adopted. ing. In this case, since the teeth portion and the yoke portion are in a substantially perpendicular relationship, the teeth portion and the yoke portion are separated from each other, and the easy magnetization axis is arranged in the direction in which the magnetic flux is desired to flow.

  For example, Patent Document 1 discloses a stator core in which a tooth portion and a yoke portion made of grain-oriented electrical steel sheets are combined. In this stator core, it is punched out as a piece to be connected at the thin portion and bent, and the tooth portion and the yoke portion are engaged and connected by the concave engaging portion and the other concave engaging portion.

Further, Patent Document 2 discloses a stator core in which a teeth portion and a yoke portion are formed of a single iron plate so as to have a U-shape, are stacked, and the stacked body is juxtaposed in the circumferential direction. Yes.
JP 2004-208483 A JP 2001-157389 A

  By the way, in the stator core of the said patent document 1, since a teeth part and a yoke part are near separate bodies, and when these are firmly joined by welding, a magnetic characteristic will deteriorate, it is not joined. In this state, if compression and tension forces are applied from the tooth portion to the yoke portion in accordance with the change of the magnetic poles during rotation of the rotor, the stator core is likely to wobble and the rigidity of the stator core needs to be increased. Further, since the tooth portion and the yoke portion are not completely joined, an air gap is generated, and the magnetic resistance is increased.

  Moreover, in the stator core of patent document 2, as shown in FIG. 5, when a magnetic flux flows in the direction of the arrow, it must pass between a plurality of iron pieces (dotted line portion). Since there is a typical gap, the magnetic resistance increases and the amount of magnetic flux in the yoke portion decreases. In view of the above problem, as shown in FIG. 6, it is conceivable to provide an auxiliary yoke 103 in which electromagnetic steel plates are laminated in the rotor rotation axis direction to suppress a decrease in magnetic flux of the stator core 101. However, even with this method, since there is a gap in the direction of the rotation axis, the magnetic resistance increases and the magnetic flux of the yoke portion 105 cannot be increased sufficiently.

  The present invention has been made in view of this point, and an object of the present invention is to cover the magnetic resistance generated between the U-shaped pieces with the auxiliary yoke portion.

  In order to achieve the above object, according to the present invention, auxiliary yoke portions laminated in the radial direction are provided at both ends of the stator core body in the rotor rotation axis direction.

Specifically, in the first invention, on the premise of a stator core of a rotating electrical machine,
The stator core of the rotating electric machine is
A stator core body formed by laminating a plurality of U-shaped pieces in which a magnetic steel plate is bent to form a teeth portion and a yoke portion to form a block body, and arranging a plurality of the block bodies in a circumferential direction. When,
The stator core body is provided with auxiliary yoke portions made of electromagnetic steel plates laminated concentrically or spirally in the radial direction at both ends in the rotor rotational axis direction.

  According to the above configuration, the magnetic steel sheet is bent to form the tooth portion and the yoke portion, so there is no air gap between the tooth portion and the yoke portion, and magnetic resistance due to the air gap does not occur. It can withstand the compressive and tensile forces that accompany changes in the magnetic poles during the rotation of the rotor. On the other hand, since there is a magnetic gap between the U-shaped blocks, there is a problem in that the magnetic resistance is increased and the amount of magnetic flux in the yoke portion is reduced. Since the auxiliary yoke portions having a structure in which steel plates are laminated in the radial direction are provided at both ends in the direction, the magnetic flux bypassing the magnetic gap between the U-shaped blocks passes through the auxiliary yoke portion. At this time, since the magnetic flux flows not along the thickness direction of the steel plate of the auxiliary yoke part but along the steel plate, the influence of the air gap between the steel plates and the generation of eddy current can be minimized.

In the second invention, in the first invention,
The U-shaped piece is a grain-oriented electrical steel sheet, in which an easy magnetization axis is arranged from one tooth part to the yoke part direction,
The auxiliary yoke portion is formed of a non-oriented electrical steel sheet or a directional electrical steel sheet having an easy magnetization axis arranged in the circumferential direction.

  According to said structure, since the U-shaped piece was comprised with the directional electromagnetic steel plate, a magnetic flux flows easily from a teeth part to a yoke part direction rather than using a non-oriented electromagnetic steel plate. Also, in the yoke portion, the magnetic flux between the teeth portions continuous at both ends in the circumferential direction can easily flow, so that the magnetic flux further easily flows as a whole. On the other hand, the auxiliary yoke part may be a non-oriented electrical steel sheet or a directional electrical steel sheet in which an easy magnetization axis is arranged in the circumferential direction, and the bypassed magnetic flux flows in the auxiliary yoke part in any case. It becomes easy, and it becomes easy for magnetic flux to flow toward the block body arranged side by side easily.

In the third invention, in the first or second invention,
The block bodies and the auxiliary yoke portion are integrated by an adhesive or welding, and the outer peripheral surface portion is further fixed by a case member.

  According to said structure, since each block body and auxiliary | assistant yoke part are integrated by the adhesive agent, welding, or a case member, rigidity becomes high.

  As described above, according to the present invention, the auxiliary yoke portions made of electromagnetic steel plates laminated concentrically or spirally in the radial direction are provided at both ends of the stator core body in the rotor rotation axis direction, and the auxiliary yoke portions are bypassed. The magnetic flux generated between the U-shaped pieces can be covered with the auxiliary yoke portion, and the amount of magnetic flux flowing through the stator core can be increased, and the output of a rotating electrical machine such as a motor can be obtained. And the efficiency performance can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a stator core 1 of a rotating electrical machine according to an embodiment of the present invention. The stator core 1 includes a stator core body 2 and a pair of auxiliary yoke portions 3. The stator core 1 is for a rotating electrical machine such as a motor.

  As shown in FIG. 2, the stator core body 2 includes a block body 2 a in which a plurality of U-shaped pieces whose sizes are sequentially increased are stacked. The block body 2a is composed of a plurality of U-shaped pieces in which the electrical steel sheet is bent at an angle slightly larger than 90 ° to form the teeth portion 4 and the yoke portion 5, and the block body 2a is arranged in the circumferential direction. The stator core body 2 is formed by arranging a plurality (eight in this embodiment). As for the teeth part 4, all face the center of the stator core main body 2, and the teeth part 4 of the adjacent block body 2a is mutually contacting. A rotor 6 (shown by a two-dot chain line in FIG. 2) is arranged in a region surrounded by these tooth portions 4. In addition, although a primary winding (coil) is not illustrated, a known structure surrounding the periphery of the tooth portion 4 is employed.

  The electrical steel sheet is composed of a directional electrical steel sheet in which an easy axis of magnetization is arranged in the direction from one tooth portion 4 to the yoke portion 5 as shown in part by arrows in FIG. The electrical steel sheet is manufactured by adding silicon to iron, and has the property that the iron loss decreases as the silicon addition amount increases. If too much silicon is added, the steel tends to crack, so the amount of silicon added to a practical electrical steel sheet is about 4%. A grain-oriented electrical steel sheet is a steel sheet whose magnetic properties are optimized only in one direction of the steel sheet, and is produced by adjusting the easy magnetization axis of the crystal in the rolling direction.

  The auxiliary yoke portions 3 are respectively disposed at both ends in the rotation axis direction of the rotor 6 of the stator core body 2 and are formed by concentrically laminating annular electromagnetic steel plates 3a having different outer diameters in the radial direction. The thickness (axial length) of the auxiliary yoke portion 3 is approximately the same as the height of the conducting wire when the conducting wire is wound around the tooth portion 4, and is vacant at both ends in the rotational axis direction of the rotor 6 of the stator core body 2. Space is being used effectively. The auxiliary yoke part 3 is configured by a non-oriented electrical steel sheet or a directional electrical steel sheet in which an easy magnetization axis is arranged in the circumferential direction. A non-oriented electrical steel sheet is a steel sheet having substantially the same magnetic characteristics in all directions within the plate thickness plane, and is produced by adjusting the crystal orientation to be random.

  As shown in FIG. 1, the adjacent block bodies 2a and the auxiliary yoke portion 3 are integrated by an adhesive or welding. Furthermore, the outer peripheral surface portion of the integrated stator core 1 is fixed by a cylindrical case member 7. The case member 7 is made of, for example, a cylindrical aluminum alloy, and the stator core body 2 is integrated with the inner peripheral portion thereof by shrink fitting or cold fitting.

  Note that, when the magnetic steel sheet is bent or welded, distortion occurs and the magnetic characteristics are deteriorated. However, the stator core 1 of the present embodiment recovers most of the lost magnetic characteristics by annealing. ing. For example, the annealing temperature of the non-oriented electrical steel sheet is 680 ° C. to 750 ° C., and the orientation temperature of the grain oriented electrical steel sheet is 780 ° C. to 820 ° C., and the holding time is 2 hours.

  As described above, since the magnetic steel sheet is bent to form the tooth part 4 and the yoke part 5, there is no air gap between the tooth part 4 and the yoke part 5, and magnetic resistance due to the air gap is generated. In addition, it can withstand the compressive and tensile forces associated with changes in the magnetic poles during rotation of the rotor 6.

  Since the auxiliary yoke portion 3 having a structure in which the annular electromagnetic steel plates 3a are laminated in the radial direction is provided at both ends of the rotor 6 of the stator core body 2 in the rotation axis direction, the magnetic flux bypassing the above-described resistance portion is generated in the auxiliary yoke portion 3. Pass through. At this time, the magnetic flux flows not along the thickness direction of the annular electromagnetic steel sheet 3a of the auxiliary yoke part 3 but along the annular electromagnetic steel sheet 3a, so that the influence of an air gap between the annular electromagnetic steel sheets 3a and the generation of eddy currents are minimized. Can be suppressed.

  In addition, since the U-shaped piece is composed of the directional electromagnetic steel sheet, the magnetic flux easily flows from the tooth part 4 to the yoke part 5 direction rather than using the non-oriented electromagnetic steel sheet. Further, since the magnetic flux between the continuous tooth portions 4 easily flows in the yoke portion 5 as well, the magnetic flux further easily flows as a whole. On the other hand, even if the annular electromagnetic steel sheet 3a of the auxiliary yoke portion 3 is a non-oriented electrical steel sheet having substantially the same magnetic characteristics in all directions within the plate thickness surface, the directionality in which the easy magnetization axis is arranged in the circumferential direction. Even in the case of an electromagnetic steel plate, the detoured magnetic flux easily flows in the auxiliary yoke portion 3.

  Furthermore, since each block body 2a and the auxiliary yoke part 3 are integrated by the adhesive agent, welding, or the case member 7, rigidity is high.

  Therefore, according to the stator core 1 of the rotating electrical machine according to the present embodiment, the auxiliary yoke portions 3 made of the annular electromagnetic steel plates 3a concentrically stacked in the radial direction are provided at both ends in the rotation axis direction of the rotor 6 of the stator core body 2. By making the detoured magnetic flux flow to the auxiliary yoke portion 3, it is possible to cover the magnetic resistance generated between the U-shaped pieces with the auxiliary yoke portion 3 and increase the amount of magnetic flux flowing through the stator core 1. Thus, the output and efficiency performance of a rotating electrical machine such as a motor can be improved.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the auxiliary yoke portion 3 is formed by stacking concentric annular electromagnetic steel plates 3a having different outer diameters, but may be formed by spirally winding in a radial direction. If it is spiral, the number of parts is reduced, and the auxiliary yoke portion 3 can be easily manufactured.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

It is a perspective view which shows the stator core of a rotary electric machine. It is a top view which shows a stator core main body. It is a top view which shows an auxiliary yoke. It is a side view which shows the flow of the magnetic flux in a stator core. It is a top view explaining presence of a magnetic gap. It is a side view which shows the stator core which has the auxiliary yoke which laminated | stacked the electromagnetic steel plate on the rotor rotating shaft direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator core of rotary electric machine 2 Stator core main body 3 Auxiliary yoke part 4 Teeth part 5 Yoke part 6 Rotor

Claims (3)

In the stator core of rotating electrical machines,
A stator core body formed by laminating a plurality of U-shaped pieces in which a magnetic steel plate is bent to form a teeth portion and a yoke portion to form a block body, and arranging a plurality of the block bodies in a circumferential direction. When,
A stator core for a rotating electrical machine, comprising auxiliary yoke portions made of electromagnetic steel plates laminated concentrically or spirally in a radial direction at both ends of the stator core body in the rotor rotational axis direction. In the stator core of the rotating electrical machine according to claim 1,
The U-shaped piece is a grain-oriented electrical steel sheet, in which an easy magnetization axis is arranged from one tooth part to the yoke part direction,
The auxiliary yoke portion is constituted by a non-oriented electrical steel sheet or a directional electrical steel sheet having an easy magnetization axis arranged in the circumferential direction. In the stator core of the rotating electrical machine according to claim 1 or 2,
The stator core of the rotating electrical machine, wherein the block bodies and the auxiliary yoke portion are integrated by an adhesive or welding, and the outer peripheral surface portion is fixed by a case member.

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