JP2010017003A - Stator core of rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance rigidity of a stator core in a rotating electric machine while preventing an eddy current from being generated in an auxiliary yoke and suppressing magnetic resistance between teeth and yokes. <P>SOLUTION: Yoke forming parts 5b of magnetic steel sheet, T-shaped in a plan view, are bent to form main pieces 5, L-shaped in a side view, and a plurality of the main pieces are laminated with each other, the yoke forming parts having teeth forming parts 5a and the yoke forming parts 5b continued from the teeth forming parts 5a and widened in width. The teeth forming parts 5a are laminated in the rotating shaft direction of a rotor, and the bent parts of the yoke forming parts are laminated in the radial direction to form a main block body 4a. A pair of the main block bodies 4a are superposed and a plurality of the superposed main block bodies are arranged in parallel in the circumferential direction so that the bent parts of the main block bodies 4a each project to in the rotary shaft direction both ends of the rotor 8. The auxiliary yoke 7 is constituted of the part projecting to the rotary shaft direction both ends of the rotor. <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.

  The stator of the rotating electrical machine of Patent Document 2 includes a yoke portion in which strip-shaped steel plates whose dimensions in the rotating shaft direction of the rotating electrical machine are longer than the length of the tooth portion are stacked in the radial direction of the rotating electrical machine.

The stator of the rotating electrical machine of Patent Document 3 combines a tooth portion laminated in the rotor axial direction and a yoke portion laminated in the radial direction.
JP 2004-208483 A JP 2006-197779 A JP 2005-333695 A

  However, in the stator core of the above-mentioned Patent Document 1, the teeth portion and the yoke portion are close to each other, and are not joined because the magnetic properties deteriorate if they are firmly joined by welding. As the magnetic pole changes during the rotation of the rotor, compression and tension forces are applied from the tooth portion to the yoke portion, so the rigidity of the stator core must 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.

  On the other hand, the stator cores of Patent Documents 2 and 3 have the merit of preventing a sudden change in the direction of magnetic flux in the same plane and suppressing the generation of a rotating magnetic field, but the tooth portion and the yoke portion are divided. Therefore, there is a problem that the magnetic resistance is increased and the rigidity is lowered as compared with the case where both are continuous.

  The eddy current flows on the surface of the electrical steel sheet around the magnetic flux when the magnetic flux passes. However, if the magnetic flux flows in the thickness direction, the surface area of the electrical steel sheet is large and the resistance to the eddy current is small. Flows easily and loss due to eddy current increases. For this reason, it is important to avoid the generation of eddy current as much as possible.

  The present invention has been made in view of such a point, and an object of the present invention is to prevent the eddy current from being generated in the auxiliary yoke portion and to suppress the magnetic resistance between the tooth portion and the yoke portion. However, the rigidity of the stator core is to be improved.

  In order to achieve the above object, in the present invention, the stator core is formed by a piece formed by bending a T-shaped electromagnetic steel sheet.

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 having a teeth portion and a yoke portion;
An auxiliary yoke portion protruding at both ends of the stator core body in the rotor rotation axis direction;
A plurality of main parts formed by bending the yoke forming part in a T-shaped electromagnetic steel sheet in plan view having a teeth forming part and a yoke forming part continuously widened to the teeth forming part and having an L shape in side view Pieces are laminated, the teeth forming portion is laminated in the rotor rotation axis direction, and the bent portion is laminated in the radial direction to become a main block body,
A plurality of pairs of the main block bodies are overlapped and juxtaposed in the circumferential direction so that the bent portions of the main block bodies protrude from both ends in the rotor rotation axis direction,
The auxiliary yoke portion is constituted by portions protruding at both ends in the rotor rotation axis direction.

  According to said structure, since the teeth part and the yoke part are formed with the continuous piece, since there is no gap, magnetic resistance is low and magnetic flux flows easily. In addition, since the tooth portion and the yoke portion are not divided, the rigidity is high and it can withstand the tensile force of the rotor. Furthermore, since the magnetic flux passes along the magnetic steel sheet through the auxiliary yoke portions laminated in the radial direction, the surface area is narrower than that laminated in the rotor rotation axis direction, and the generation of eddy currents is remarkably suppressed. . The electromagnetic steel sheet may be a non-oriented electrical steel sheet or a directional electrical steel sheet.

In the second invention, in the first invention,
A plurality of T-shaped flat plates made of electromagnetic steel sheets having the same size formed with the intermediate teeth forming portion and the intermediate yoke forming portion are laminated to form an intermediate block body, and the intermediate block body is formed by a pair of the main block bodies. It is sandwiched from both sides of the rotor rotation axis.

  According to the above configuration, since the intermediate block body is not bent, the magnetic characteristics are not deteriorated at all by bending, and the magnetic flux easily flows.

In the third invention, in the first or second invention,
The T-shaped electrical steel sheet is made of a non-oriented electrical steel sheet.

  According to said structure, it is cheaper than a grain-oriented electrical steel sheet, and since it is not necessary to consider directionality, it is easy to process.

  As described above, according to the present invention, the yoke-forming portion of the T-shaped electromagnetic steel sheet having the teeth-forming portion and the yoke-forming portion is bent, and the L-shaped pieces in the side view are laminated. By forming the auxiliary yoke portions protruding at both ends of the stator core body in the rotor rotation axis direction, it is possible to prevent the eddy current from being generated in the auxiliary yoke portion and to suppress the magnetic resistance between the teeth portion and the yoke portion. However, the rigidity of the stator core 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 of the rotating electrical machine is continuous with a plurality of tooth portions 2 projecting toward the central axis and the teeth portion 2 in the circumferential direction. And a stator core body 4 having a yoke portion 3 extending in the direction. Although the primary winding (coil) is not shown, a known structure surrounding the periphery of the tooth portion 2 is employed.

  As shown in an enlarged view in FIG. 2, the stator core body 4 includes a main block body 4 a in which a plurality of main pieces 5 are stacked.

  As representatively shown in FIGS. 3 to 6, the main piece 5 has a T-shape in plan view including a teeth forming portion 5 a and a yoke forming portion 5 b that is continuously widened from the teeth forming portion 5 a. Formed from electrical steel sheet. The plurality of main pieces 5 have teeth forming portions 5a having the same shape and yoke forming portions 5b having different sizes.

  The T-shaped electrical steel sheet is made of a non-oriented electrical steel sheet. 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 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. Non-oriented electrical steel sheets are less expensive than directional electrical steel sheets and do not require consideration of directionality, and therefore have the advantage of being easy to process.

  As shown in FIGS. 3 and 4, the smallest main piece 5 on the outer side in the rotation axis direction of the rotor 8 is continuous with a rectangular tooth forming portion 5a and orthogonal to the longitudinal direction of the tooth forming portion 5a. And a rectangular yoke forming portion 5b. The yoke forming portion 5b is formed with a pair of slits 5d extending from both ends of a fold line 5c indicated by a two-dot chain line to the left and right edges of the teeth forming portion 5a. Both ends of the yoke forming portion 5b are provided with tapered surfaces 5e that are tapered so as to be easily joined to the adjacent main block body 4a. The main piece 5 is formed by bending the yoke forming portion 5b vertically with the fold line 5c as a boundary so as to have an L shape in side view.

  As shown in FIGS. 5 and 6, the largest main piece 5 includes a tooth forming portion 5a having the same shape as described above, but in the yoke forming portion 5b, the folding line 5c is located away from the tooth forming portion 5a. And a trapezoidal portion 5f that is flush with the teeth forming portion 5a and a vertical portion 5g that is bent vertically.

  The trapezoidal portion 5 f and the vertical portion 5 g of the plurality of main pieces 5 sandwiched between the smallest main piece 5 and the largest main piece 5 are gradually increased by the thickness of the main piece 5. The taper surface 5e may be processed either before or after the vertical portion 5g is bent.

  The plurality of main pieces 5 having the yoke forming portions 5b having different sizes are stacked such that the teeth forming portions 5a are stacked in the direction of the rotation axis of the rotor 8 and the vertical portions 5g are stacked in the radial direction. The main block body 4a is formed by stacking.

  In addition, as shown in FIG. 7, a plurality of intermediate pieces 6 made of a plurality of T-shaped flat plates made of electromagnetic steel plates having the same size, in which the intermediate teeth forming portion 6a and the intermediate yoke forming portion 6b are formed, are stacked. The block body 4b is obtained. The intermediate block body 4b is sandwiched from both sides of the rotor 8 in the rotation axis direction by the pair of main block bodies 4a whose vertical portions 5g face each other outward in the rotation axis direction of the rotor 8. The intermediate piece 6 is also made of a non-oriented electrical steel sheet.

  As shown in FIG. 1, a plurality of pairs of main block bodies 4a and intermediate block bodies 4b stacked in this way are arranged in the circumferential direction with the tapered surfaces 5e in contact with each other (in this embodiment, 8 The stator core 1 is formed in parallel. For this reason, the stator core 1 has a regular octagonal shape in plan view. A rotor 8 indicated by a two-dot chain line is arranged inside the eight teeth portions 2. Adjacent tapered surfaces 5e are connected to each other by welding or adhesion.

  The auxiliary yoke portion 7 is formed by a portion of the stacked vertical portion 5g that protrudes from the teeth portion 2 toward both ends of the rotor 8 in the rotation axis direction.

  Although the magnetic properties deteriorate when the electromagnetic steel sheet is bent or welded, most of the lost magnetic properties are recovered by annealing the stator core 1 of the present embodiment. For example, the annealing temperature of the non-oriented electrical steel sheet is 680 ° C. to 750 ° C., and the holding time is 2 hours.

  As described above, since the tooth portion 2 and the yoke portion 3 are formed by the continuous main piece 5, there is no gap, so the magnetic resistance is low and the magnetic flux easily flows. Moreover, since the teeth part 2 and the yoke part 3 are not divided | segmented, rigidity is high and can also endure the tensile force by a rotor. Furthermore, since the magnetic flux passes through the auxiliary yoke portions 7 stacked in the radial direction along the vertical portion 5g, the generation of eddy currents can be remarkably suppressed as compared with those stacked in the rotation axis direction of the rotor 8.

  Further, since the intermediate block body 4b is not bent, the magnetic characteristics are not deteriorated at all by the bending, and the magnetic flux easily flows.

  Therefore, according to the stator core 1 of the rotating electrical machine according to the present embodiment, the yoke forming portion 5b of the T-shaped electromagnetic steel plate having the teeth forming portion 5a and the yoke forming portion 5b is bent to be L-shaped in side view. The main pieces 5 are laminated to form the auxiliary yoke portions 7 that protrude at both ends of the rotor 8 of the stator core body 4 in the rotation axis direction, thereby preventing eddy currents from being generated in the auxiliary yoke portions 7 and the teeth. The magnetic resistance between the portion 2 and the yoke portion 3 can be suppressed, and the rigidity of the stator core 1 can be improved.

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

  That is, in the said embodiment, although the main piece 5 and the intermediate piece 6 were comprised with the non-oriented electrical steel plate, you may comprise with a directional electrical steel plate. If the easy magnetization axis of the grain-oriented electrical steel sheet is arranged so as to be in the radial direction of the stator core 1, the magnetic flux is likely to flow through the teeth portion 2, and the circumferential direction (longitudinal direction of the yoke forming portions 5 b and 6 b). If it arrange | positions, it will become easy to flow magnetic flux in the yoke part 3. FIG. In the case of a grain-oriented electrical steel sheet, the annealing temperature may be 780 ° C. to 820 ° C., and the holding time may be 2 hours.

  Moreover, the number of the teeth parts 2 is not limited to eight. The stator core 1 becomes a regular polygon according to the number of the teeth portions 2, and the angle of the tapered surface 5e may be adjusted according to the shape of the regular polygon.

  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 top view which shows the stator core of the rotary electric machine concerning embodiment of this invention. It is a perspective view which shows a main block body and an intermediate | middle block body. It is a top view which shows the main piece before bending. A main piece is shown, (a) is a top view, (b) is a front view, (c) is a side view. It is a top view which shows the intermediate piece before bending. An intermediate piece is shown, (a) is a plan view, (b) is a front view, and (c) is a side view. It is a top view which shows an intermediate piece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator core 2 Teeth part 3 Yoke part 4 Stator core main body 4a Main block body 4b Intermediate block body 5 Main piece 5a Teeth formation part 5b Yoke formation part 6a Intermediate teeth formation part 6b Intermediate yoke formation part 7 Auxiliary yoke part 8 Rotor

Claims (3)

In the stator core of rotating electrical machines,
A stator core body having a teeth portion and a yoke portion;
An auxiliary yoke portion protruding at both ends of the stator core body in the rotor rotation axis direction;
A plurality of main parts formed by bending the yoke forming part in a T-shaped electromagnetic steel sheet in plan view having a teeth forming part and a yoke forming part continuously widened to the teeth forming part and having an L shape in side view Pieces are laminated, the teeth forming portion is laminated in the rotor rotation axis direction, and the bent portion is laminated in the radial direction to become a main block body,
A plurality of pairs of the main block bodies are overlapped and juxtaposed in the circumferential direction so that the bent portions of the main block bodies protrude from both ends of the rotor rotation axis direction,
The stator core of the rotating electrical machine, wherein the auxiliary yoke portion is composed of portions protruding at both ends of the rotor rotation axis direction. In the stator core of the rotating electrical machine according to claim 1,
A plurality of T-shaped flat plates made of electromagnetic steel sheets having the same size formed with the intermediate teeth forming portion and the intermediate yoke forming portion are laminated to form an intermediate block body, and the intermediate block body is formed by a pair of the main block bodies. A stator core for a rotating electrical machine, wherein the stator core is sandwiched from both sides of a rotor rotational axis. In the stator core of the rotating electrical machine according to claim 1 or 2,
The T-shaped electrical steel sheet is composed of a non-oriented electrical steel sheet.

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