JP2020156261A - Rotor of surface-attached permanent magnet rotary electric machine and manufacturing method of the same - Google Patents

Abstract

To provide a rotor of a surface-attached permanent magnet rotary electric machine and a manufacturing method of the same, capable of suppressing leakage flux and further improving efficiency.SOLUTION: In a rotor of a surface-attached permanent magnet rotary electric machine including: a rotor shaft 11 for rotating around an axis; a plurality of permanent magnets 12 disposed and fixed to an outer surface of the rotor shaft 11 at least along a circumferential direction; and a cylindrical holding ring 13 for covering the entire outer surface of the permanent magnets 12, the holding ring 13 is formed by laminating, in an axial direction, a plurality of annular bodies 13a made of a grain-oriented electrical steel plate.SELECTED DRAWING: Figure 4

Description

The present invention relates to the technology of a surface-attached permanent magnet rotating electric machine, and in particular, the rotation of a surface-attached permanent magnet rotating electric machine in which a holding ring is arranged on the outer peripheral surface of the permanent magnet to fix the permanent magnet to the rotor shaft. Regarding the child and its manufacturing method.

Permanent magnets The rotating electric machine includes a surface-attached permanent magnet (SPM) that attaches a magnet to the surface of the rotor shaft, and an embedded permanent magnet (IPM: Interior) that embeds the magnet inside the rotor. Permanent Magnet) There are two types of rotating electric machines.

Since the magnet is arranged on the surface of the rotor shaft, the SPM rotary electric machine has the advantages that the magnet magnetic flux can be effectively used and the torque ripple is small, but the magnet may be peeled off due to the centrifugal force during rotation of the rotor. In order to solve this problem, SPM rotary electric machines for high-speed rotation are known to arrange a ring made of carbon fiber reinforced plastic (hereinafter referred to as CFRP ring) on the outer circumference of a permanent magnet (for example, CFRP ring). , See Patent Document 1 below).

However, since the CFRP ring described above is a non-magnetic material, by providing the CFRP ring on the outer circumference of the permanent magnet, the gap between the rotor magnet and the stator core increases and the characteristics of the rotating electric machine deteriorate, such as a decrease in rotational magnetic flux. Was connected to.

On the other hand, there is also known a permanent magnet electric motor in which a predetermined number of narrow ring-shaped electromagnetic steel sheets are laminated in the axial direction on the outer peripheral portion of the permanent magnet to fit a cylindrical laminated cylinder. (For example, see Patent Document 2 below). As such a laminated cylinder, a non-oriented electrical steel sheet is generally used. Since non-oriented electrical steel sheets are magnetic materials that are also used for rotor cores, unlike CFRP rings, the decrease in rotational magnetic flux can be suppressed, and by using laminated electrical steel sheets, there is also the problem of eddy current loss. It has the advantage of being almost nonexistent.

JP-A-11-891142 Japanese Unexamined Patent Publication No. 2004-64887

However, in recent years, there has been a demand for higher efficiency of rotary electric machines, but even with the technology disclosed in Patent Document 2, leakage flux is generated from the magnetic material (laminated cylinder), and the rotary electric machine There was a problem that efficiency was reduced.

Therefore, it is an object of the present invention to provide a rotor of a surface-attached permanent magnet rotary electric machine capable of suppressing leakage flux and further improving efficiency, and a method for manufacturing the rotor.

The rotor of the surface-attached permanent magnet rotating electric machine according to the first invention for solving the above problems is
A rotating body that rotates around the axis, a plurality of permanent magnets that are arranged and fixed to the outer surface of the rotating body at least along the circumferential direction, and a cylindrical holding ring that covers the entire outer surface of the permanent magnet. In the rotor of a surface-attached permanent magnet rotating electric machine equipped with
The holding ring is characterized in that a plurality of annular bodies made of grain-oriented electrical steel sheets are laminated in the axial direction.

Further, in the first invention, the rotor of the surface-attached permanent magnet rotating electric machine according to the second invention for solving the above problems is used.
The holding ring is characterized in that the easy-to-magnetize axial direction is arranged so as to be the same as a straight line passing through the axial center of the rotating body and the center of the magnetic pole.

Further, in the second invention, the rotor of the surface-attached permanent magnet rotating electric machine according to the third invention for solving the above problems is used.
It is characterized by including the permanent magnet having two poles in the circumferential direction.

Further, the rotor of the surface-attached permanent magnet rotating electric machine according to the fourth invention for solving the above problems is described in any one of the first to third inventions.
The rotating body is a rotor shaft.

Further, a method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine according to a fifth invention for solving the above problems is described.
A plurality of permanent magnets are arranged and fixed on the outer surface of a rotating body rotating around the axis at least along the circumferential direction, and the entire outer surface of the permanent magnets is shrink-fitted or press-fitted with a cylindrical holding ring. In the method of manufacturing a rotor of a surface-attached permanent magnet rotating electric machine to cover
The holding ring is characterized in that a plurality of annular bodies made of grain-oriented electrical steel sheets are laminated in the axial direction.

Further, a method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine according to a sixth invention for solving the above problems is described in the fifth invention.
The holding ring is characterized in that the easy-to-magnetize axial direction is arranged so as to be the same as a straight line passing through the axial center of the rotating body and the center of the magnetic pole.

Further, the method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine according to the seventh invention for solving the above problems is described in the sixth invention.
It is characterized in that the two-pole permanent magnets are arranged and fixed in the circumferential direction.

Further, the method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine according to the eighth invention for solving the above problems is described in any one of the fifth to seventh inventions.
The rotating body is a rotor shaft.

According to the rotor of the surface-attached permanent magnet rotary electric machine and the manufacturing method thereof according to the present invention, the leakage flux is suppressed and the efficiency is further improved as compared with the case where the holding ring is formed by the non-oriented electrical steel sheet. It becomes possible to plan.

It is sectional drawing which shows the structure of the surface sticking type permanent magnet rotary electric machine which concerns on embodiment of this invention. It is a perspective view which shows the state before mounting the holding ring of the rotor of the surface-attached type permanent magnet rotary electric machine which concerns on embodiment of this invention. It is a perspective view which shows the state after mounting the holding ring of the rotor of the surface-attached type permanent magnet rotary electric machine which concerns on embodiment of this invention. It is a figure for demonstrating the magnetic pole arrangement of the rotor of the surface-attached permanent magnet rotary electric machine which concerns on embodiment of this invention, and the easy axial direction of magnetization of a holding ring. It is a graph which shows the gap magnetic flux density distribution of the rotor of the surface-attached permanent magnet rotary electric machine which concerns on embodiment of this invention.

Hereinafter, the rotor of the surface-attached permanent magnet rotary electric machine according to the embodiment of the present invention and the manufacturing method thereof will be described with reference to FIGS. 1 to 5.
The surface-attached permanent magnet rotary electric machine of the present embodiment is a two-pole rotary electric machine forming only a pair of N pole and S pole, and as shown in FIGS. 1 to 4, the rotor 10 and the rotor It is provided with a stator 20 provided on the outer side in the radial direction of the 10 via a gap.

The rotor 10 includes a plurality of columnar rotor shafts 11 that rotate around an axial center, and a plurality of permanent magnets 12 that are arranged and fixed on the surface of the rotor shaft 11 along the axial and circumferential directions. It is configured to include a holding ring 13 that covers the entire outer surface of the permanent magnets 12 and fixes each permanent magnet 12 to the rotor shaft 11.

A plurality of permanent magnets 12 are spread on the outer surface of the rotor shaft 11 along the axial direction and the circumferential direction, and are fixed to the rotor shaft 11 with an adhesive.

Further, the holding ring 13 is formed by laminating a plurality of annular bodies 13a formed by punching a directional electromagnetic steel plate in an annular shape in the axial direction to form a cylindrical shape, and is formed by shrink fitting or press fitting to form an outer surface of the plurality of permanent magnets 12. It is fixed to the rotor shaft 11 in a state of covering the whole. In the holding ring 13, the axial direction of easy magnetization of the grain-oriented electrical steel sheet constituting the holding ring 13 is such that the axis O of the rotor 10 (rotor shaft 11 and permanent magnet 12) and the magnetic pole center (mechanical angle 90 deg). It is arranged so as to be the same as the connecting straight line. The holding ring 13 may be fixed to the rotor shaft 11 by shrink-fitting or press-fitting a plurality of annular bodies 13a made of grain-oriented electrical steel sheets, respectively, and the plurality of annular bodies 13a may be impregnated with resin, bonded, or welded in advance. , The one integrally formed in a cylindrical shape by a jig or the like may be shrink-fitted or press-fitted to be fixed to the rotor shaft 11, or may be fixed to the rotor shaft 11 by using both shrink-fitting and press-fitting.

The stator 20 is an armature coil housed between a stator core 21 having a plurality of teeth formed at equal intervals in the circumferential direction on a facing surface on the rotor 10 side and adjacent teeth (slots) in the circumferential direction. It is configured to include 22 and.

FIG. 5 shows the results of determining the magnetic flux density by configuring a surface-attached permanent magnet rotary electric machine under the conditions shown in Table 1 below. In FIG. 5, the solid line shows the change in the magnetic flux density when the holding ring 13 (fundamental wave effective value: 0.88 p.U.) Is formed by the grain-oriented electrical steel sheet, and the broken line shows the change in the magnetic flux density by the grain-oriented electrical steel sheet. The change in magnetic flux density when the fundamental wave effective value: 0.83 p.U.) is formed is shown.

When the holding ring 13 is formed of a directional electromagnetic steel plate, as compared with the case where a non-directional electromagnetic steel plate is adopted (characteristics shown by a broken line in FIG. 5), the end of the magnetic pole as shown in the region A shown in FIG. At around 0 deg and around 180 deg (in the example shown in FIG. 5, approximately 0 to 25 deg, 155 to 205 deg, 335 to 360 deg), the easy axial direction and the magnetic flux are in the same direction and are shown by a two-point chain line on the right side of FIG. As shown by the two-point chain line on the left side of FIG. 4, the magnetic flux is less likely to leak in the portion other than the end of the magnetic pole as in the region B shown in FIG. 5, which makes it difficult for the magnetic flux to leak. The magnetic flux is concentrated on (mechanical angle 90 deg), and the maximum magnetic flux density is improved. As a result, the effective value of the fundamental wave is improved, the armature current can be suppressed, and the efficiency can be improved as compared with the case where the holding ring is formed of the non-oriented electrical steel plate.

In the above-described embodiment, a plurality of permanent magnets 12 are attached to the outer surface of the rotor shaft 11 as a rotating body along the axial direction and the circumferential direction, but the present invention has been described above. The configuration is not limited to the form, but includes a rotor shaft 11 as a rotor and a rotor core provided on the outer periphery of the rotor shaft 11, and a permanent magnet 12 is attached to the outer surface of the rotor core. Also, at least two permanent magnets may be arranged along the circumferential direction (two permanent magnets may form two poles, or four or more permanent magnets may form two poles). ).

10 Rotor 11 Rotor shaft 12 Permanent magnet 13 Holding ring 13a Annulus 20 Stator 21 Stator Iron core 22 Armature coil

Claims (8)

A rotating body that rotates around the axis, a plurality of permanent magnets that are arranged and fixed to the outer surface of the rotating body at least along the circumferential direction, and a cylindrical holding ring that covers the entire outer surface of the permanent magnet. In the rotor of a surface-attached permanent magnet rotating electric machine equipped with
A rotor of a surface-attached permanent magnet rotating electric machine, wherein the holding ring is formed by laminating a plurality of annular bodies made of grain-oriented electrical steel sheets in the axial direction. The surface-attached permanent magnet according to claim 1, wherein the holding ring is arranged so that the axial direction for easy magnetization is the same as a straight line passing through the axial center of the rotating body and the center of the magnetic pole. Rotor of rotating electric machine. The rotor of a surface-attached permanent magnet rotating electric machine according to claim 2, further comprising the permanent magnet having two poles in the circumferential direction. The rotor of a surface-attached permanent magnet rotating electric machine according to any one of claims 1 to 3, wherein the rotating body is a rotor shaft. A plurality of permanent magnets are arranged and fixed on the outer surface of a rotating body rotating around the axis at least along the circumferential direction, and the entire outer surface of the permanent magnets is shrink-fitted or press-fitted with a cylindrical holding ring. In the method of manufacturing a rotor of a surface-attached permanent magnet rotating electric machine to cover
A method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine, wherein the holding ring is formed by laminating a plurality of annular bodies made of grain-oriented electrical steel sheets in the axial direction. The surface-attached permanent magnet according to claim 5, wherein the holding ring is arranged so that the axial direction for easy magnetization is the same as a straight line passing through the axial center of the rotating body and the center of the magnetic pole. A method for manufacturing a rotor of a rotating electric machine. The method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine according to claim 6, wherein the two-pole permanent magnet is arranged and fixed in the circumferential direction. The method for manufacturing a rotor of a surface-attached permanent magnet rotating electric machine according to any one of claims 5 to 7, wherein the rotating body is a rotor shaft.

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