JP2011193627A - Rotor core and rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the efficiency of a synchronous reluctance motor. <P>SOLUTION: The whole of a rotor core of the synchronous reluctance motor is made of directional electromagnetic steel plates. This enlarges a difference between inductance at a d axis position and inductance at a q axis position and reduces a magnetic flux leak at a flux barrier edge to increase output torque and reduce loss, thereby creates the rotor core of the synchronous reluctance motor having excellent motor efficiency. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotor core and a rotating electrical machine, and more particularly to a rotor core of a synchronous reluctance motor that uses a directional electromagnetic steel sheet to improve motor efficiency.

  Conventionally, a synchronous reluctance motor that rotates by reluctance torque has been proposed. The rotor core of the synchronous reluctance motor is formed by laminating a plurality of steel plates, and the rotor core has an arc-shaped slit called a flux barrier along the extending direction of the arc-shaped slit. Thus, a magnetic path through which the magnetic flux easily flows is formed, and a magnetic path through which the magnetic flux does not easily flow in the radial direction is formed. (For example, refer to Patent Document 1).

JP 2009-60721 A

However, the structure described in Patent Document 1 requires a bridge on the outer periphery of the rotor core in order to maintain strength, and magnetic flux leaks at the bridge on the outer periphery of the rotor core at that time, which causes a decrease in output torque.
The present invention has been made in view of such problems, and an object of the present invention is to provide a rotor core of a synchronous reluctance motor with low loss and high output torque.

In order to solve the above problem, the present invention is configured as follows.
The invention according to claim 1 is the rotor core,
The rotor core is formed by laminating directional electromagnetic steel sheets divided into poles in the circumferential direction in the axial direction, and the easy magnetization direction of the directional electromagnetic steel sheets is an extending direction of the arc-shaped slit.

The invention according to claim 2 is characterized in that the rotor core is formed by laminating directional electromagnetic steel sheets divided in the number of poles × 2 in the circumferential direction in the axial direction, and the direction of easy magnetization of the directional electromagnetic steel sheets is an arc-shaped slit. It shall be parallel.

According to a third aspect of the present invention, in the rotor core according to the first or second aspect, the directional electromagnetic steel sheet divided in the circumferential direction includes a key provided near a shaft of the directional electromagnetic steel sheet, a shaft It is supported by a key provided in.

  According to a fourth aspect of the present invention, in the rotor core according to the first or second aspect, a nonmagnetic material is inserted into the arc-shaped slit.

  According to the present invention, it is possible to provide a rotor core and a rotating electrical machine with a small loss and a large output torque.

The perspective view of the rotor core of 1st Example Oriented electrical steel sheet of the first embodiment (A) Axial cross-sectional view when the rotor is at the q-axis position, (b) Axial cross-sectional view when the rotor is at the d-axis position The perspective view of the rotor core of 2nd Example (A) Axial sectional view of directional electrical steel sheet (easy magnetization direction perpendicular to radial direction), (b) Axial sectional view of directional electrical steel sheet (easy magnetization direction parallel to radial direction) Axial sectional view of the rotating electrical machine of the present invention

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

  FIG. 1 is a perspective view of a rotor core according to a first embodiment of the present invention. In this embodiment, the case where the number of poles is four is shown, and the cylindrical rotor core R has a shaft 2 having a plurality of divided cores RD divided into four poles in the circumferential direction, that is, four divided cores RD. It is combined in the circumferential direction. In the center of the rotor core R, a rotation shaft hole Ra through which the shaft 2 is inserted is formed. The split iron core RD is formed by laminating a plurality of grain-oriented electrical steel sheets 1 having easy magnetization directions 7 in the axial direction of the shaft 2 with the easy magnetization directions 7 aligned. The split iron core RD is supported on the shaft 2 by a key 31 provided on the shaft 2 and a key 32 provided on the directional electromagnetic steel sheet 1. Thereby, since welding becomes unnecessary, it is possible to prevent an increase in eddy current loss that occurs during welding and the influence of voids.

  In the rotor core R, arcuate slits 4 are formed around the shaft 2 at intervals around the shaft 2 as viewed from the axial direction of the shaft 2 in a plan view. A plurality of arcuate slits 4 are formed concentrically. Here, the arc-shaped slit 4 functions as a flux barrier. A nonmagnetic material 5 such as resin is inserted into the arc-shaped slit 4.

  FIG. 2 is an axial sectional view of the grain-oriented electrical steel sheet 1 divided in the circumferential direction by the number of poles. The grain-oriented electrical steel sheet 1 constituting each of the divided cores RD includes a seven-layer arc-shaped slit 4 formed concentrically, key grooves 61 and 62 as engaged portions, and an engaging portion. A key 32 is provided, and an arrow indicates the easy magnetization direction 7.

  FIG. 3A shows an axial sectional view when the rotor 8 is at the q-axis position. When the rotor 8 is at the q-axis position, the inductance is reduced by the arc-shaped slit 4 as a flux barrier. Further, since the direction of the magnetic flux 9 generated from the stator winding is substantially perpendicular to the easy magnetization direction 7 of the grain-oriented electrical steel sheet 1, the inductance is further reduced. That is, a magnetic path in which the magnetic flux hardly flows in the radial direction of the shaft 2 is formed.

  FIG. 3B shows an axial cross-sectional view when the rotor 8 is at the d-axis position. When the rotor 8 is in the d-axis position, the easy magnetization direction 7 and the arc-shaped slit 4 are substantially parallel to the magnetic flux 9 generated from the stator winding, so that the inductance can be increased. That is, a magnetic path through which the magnetic flux easily flows is formed along the extending direction of the arc-shaped slit 4, and the easy magnetization direction 7 is along the extending direction of the arc-shaped slit 4.

  In addition, since the non-magnetic material 5 such as resin is inserted into the arc-shaped slit 4, the centrifugal force resistance of the rotor 8 including the shaft 2 and the rotor core R can be improved.

The reluctance torque is caused by a difference in inductance between the q-axis position and the d-axis position, that is, a difference in magnetic resistance of a plurality of magnetic paths, and the output torque increases as the difference increases. By using the core, the output torque is increased.
Further, the easy magnetization direction 7 of the grain-oriented electrical steel sheet 1 has a smaller loss than that of the non-oriented electrical steel sheet and less loss due to the interlayer short circuit. Therefore, it is possible to provide a synchronous reluctance motor as an efficient rotating electrical machine.

  FIG. 4 is a perspective view of the second embodiment of the present invention. In FIG. 4, this embodiment differs from the first embodiment in that the directional magnetic steel sheet 10 and the easy magnetization direction 7 that are divided by the number of poles × 2 in the circumferential direction and in which the easy magnetization direction 7 is substantially perpendicular to the radial direction. This is to use two kinds of directional electromagnetic steel plates 10 and 11 of the directional electromagnetic steel plate 11 parallel to the radial direction. That is, in the second embodiment, the number of divided cores RD is twice (eight) the number of poles (four poles). Further, the two types of grain-oriented electrical steel plates 10 and 11 having different shapes are alternately arranged in the circumferential direction of the rotation shaft hole Ra.

FIGS. 5A and 5B are axial sectional views of the directional electromagnetic steel sheet 10 and the directional electromagnetic steel sheet 11 that constitute a plurality of types (two types) of divided cores RD. In addition, the 1st division | segmentation iron core RD1 is formed from the directionality electromagnetic steel plate 10, and the 2nd division | segmentation iron core RD2 is formed from the directionality electromagnetic steel plate 11. FIG. Moreover, the shape of the directional electromagnetic steel sheet 10 is substantially rectangular, and the shape of the directional electromagnetic steel sheet 10 is substantially fan-shaped.
In FIG. 5, the easy magnetization direction 7 is different, but the flux barrier is substantially parallel to the easy magnetization direction 7 in both the directional electromagnetic steel sheet 10 and the directional electromagnetic steel sheet 11. That is, in FIG. 5A, the longitudinal direction of the rectangular slit 4a that functions as a flux barrier is substantially parallel to the easy magnetization direction 7, and also functions as a flux barrier in FIG. 5B. The longitudinal direction of the rectangular slit 4 b is substantially parallel to the easy magnetization direction 7. Then, a combination of the rectangular slit 4a and the rectangular slits 4a arranged at different angles on both sides of the rectangular slit 4a, the arc-shaped slit 4 as a convex slit with the shaft 2 side convex. Is formed. Therefore, the easy magnetization direction 7 is along the extending direction of the arc-shaped slit 4.

  The directional electromagnetic steel sheet 10 is provided with a key 32 as an engaging part and a key groove 61 as an engaged part, and the directional electromagnetic steel sheet 11 is provided with a key groove 62 as an engaged part. The directional electrical steel sheet 10 laminated by a key 31 as an engaging part provided on the directional electromagnetic steel sheet is supported, and the directional electrical steel sheet 11 laminated by a key 32 as an engaging part provided on the directional electromagnetic steel sheet 10 is supported. ing. Thereby, since welding becomes unnecessary, it is possible to prevent an increase in eddy current loss that occurs during welding and the influence of voids.

  As in the first embodiment, the difference in inductance between the d-axis position and the q-axis position increases, and the output torque increases. In addition, since the easy magnetization directions 7 of the two types of grain-oriented electrical steel sheets 10 and the grain-oriented electrical steel sheets 11 are both substantially parallel to the arc-shaped slit 4, compared to the first embodiment, at the d-axis position. Inductance can be further increased.

In addition, since the easy magnetization direction 7 at the edge of the arcuate slit 4 is also substantially parallel to the radial direction, the leakage of magnetic flux can be further reduced.
In addition, since the non-magnetic material 5 such as resin is inserted into the arc-shaped slit 4, the centrifugal force resistance can be improved.

  By using the rotor core of the present invention, it is possible to provide a synchronous reluctance motor as an efficient rotating electrical machine having a large output torque and a small loss.

  FIG. 6 is an axial sectional view of the rotating electrical machine of the present invention. This is a very simplified schematic diagram. The rotating electrical machine M includes a rotor 8 composed of a shaft 2 and a cylindrical rotor core R fixed to the shaft 2, a winding (not shown), and a stator core (see FIG. (Not shown). Here, as described above, the one already described in the first embodiment or the second embodiment is applied to the rotor core R. Therefore, it is possible to realize a synchronous reluctance motor as an efficient rotating electric machine having a large output torque and a small loss.

  Since the rotor core of a synchronous reluctance motor with large output torque and low loss can be created, it can be applied to a rotating electrical machine for machine tools, a driving rotating electrical machine mounted on an automobile, and the like.

DESCRIPTION OF SYMBOLS 1 Directional electrical steel plate 2 Shaft 31 Key 32 Key 4 Arc-shaped slit 4a Rectangular slit 4b Rectangular slit 5 Nonmagnetic material 61 Key groove 62 Key groove 7 Easy magnetization direction 8 Rotor 9 Magnetic flux 10 Directional electrical steel sheet 11 Oriented electrical steel sheet R Rotor core Ra Rotary shaft hole RD Split iron core RD1 Split iron core RD2 Split iron core S Stator

Claims (12)

A plurality of arc-shaped slits convex on the rotating shaft hole side are formed concentrically, and the plurality of arc-shaped slits are formed by laminating iron core pieces formed at intervals around the rotating shaft hole, A magnetic path through which the magnetic flux easily flows is formed along the extending direction of the arc-shaped slit, a magnetic path through which the magnetic flux does not easily flow is formed in the radial direction, and the magnetic path rotates by the reluctance torque generated based on the difference in the magnetic resistance of the magnetic path. In the rotor core,
The rotor iron core is formed by laminating directional electromagnetic steel sheets divided into poles in the circumferential direction in an axial direction, and the easy magnetization direction of the directional electromagnetic steel sheets is an extending direction of an arc-shaped slit. Rotor core.   The rotor iron core is formed by laminating directional electromagnetic steel sheets divided in the number of poles × 2 in the circumferential direction in the axial direction, and the easy magnetization direction of the directional electromagnetic steel sheets is parallel to the arc-shaped slit. Iron core.   The said directionality electrical steel sheet divided | segmented into the circumferential direction is supported by the key provided in the rotation axis vicinity of the said directionality electromagnetic steel plate, and the key provided in the rotation axis, The 1st aspect characterized by the above-mentioned. 2. The rotor core according to 2.   The rotor core according to claim 1, wherein a nonmagnetic material is inserted into the arc-shaped slit. A cylindrical rotor core formed by combining a plurality of divided cores in the circumferential direction of the rotating shaft,
The split iron core is formed by laminating a plurality of grain-oriented electrical steel sheets having easy magnetization directions in the axial direction of the rotating shaft, with the easy magnetization directions aligned.
A rotor core, characterized in that convex slits that are convex on the side of the rotating shaft in plan view from the axial direction of the rotating shaft are formed at intervals around the rotating shaft. A magnetic path through which the magnetic flux easily flows along the extending direction of the convex slit is formed, and a magnetic path through which the magnetic flux does not easily flow is formed in the radial direction of the rotating shaft,
The rotor core according to claim 1, wherein the easy magnetization direction is along the extending direction of the convex slit. The convex slit is an arc-shaped slit;
The rotor core according to claim 1, wherein a plurality of the arc-shaped slits are concentrically formed. 2. The rotor core according to claim 1, wherein reluctance torque is generated by a difference in magnetic resistance between the plurality of magnetic paths. The rotor core according to claim 1, wherein the number of the plurality of divided cores is twice the number of poles. The rotor core according to claim 1, wherein the split iron core includes an engaged portion that is engaged with an engaging portion provided on the rotating shaft. The rotor core according to claim 1, wherein a nonmagnetic material is inserted into the convex slit. A rotating electric machine,
A rotor comprising a rotating shaft and a cylindrical rotor core fixed to the rotating shaft;
A stator comprising a winding and a stator core around which the winding is wound;
With
The rotor core is a combination of a plurality of divided cores in the circumferential direction of the rotation axis,
The split iron core is formed by laminating a plurality of grain-oriented electrical steel sheets having easy magnetization directions in the axial direction of the rotating shaft, with the easy magnetization directions aligned.
A rotor electric machine, wherein a convex slit having a convex surface on the rotation shaft side is formed around the rotation shaft in a plan view from the direction of the rotation shaft.

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