JPH01157253A - Rotor with permanent magnet - Google Patents

Abstract

PURPOSE:To prevent the generation of a short-circuit flux flow between magnetic poles by forming divided cores for a rotor and disposing an external core of a non-magnetic material between adjacent magnetic poles. CONSTITUTION:In a rotor, a cylindrical rotor core 11 is divided an internal core 11a, a sectional shape of which is a polygon having sides which is twice as large as the number of magnetic poles, and a plurality of fan-shaped external cores 11b by lines which connect the corner sections of adjacent permanent magnets having square cross sections. The internal core 11a and the external cores 11b are made of a magnetic material and a non-magnetic material respectively. The external cores 11b push both side edge sections of the permanent magnets 2, and receive the centrifugal force of the permanent magnets 2 with the revolution of the rotor. Accordingly, the generation of short-circuit flux flows among magnetic poles can be prevented without providing slits.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotor with permanent magnets for a rotating electric machine that is capable of preventing the generation of short-circuit magnetic flux between magnetic poles.

[Conventional technology]

A conventional example of a rotor with permanent magnets for a rotating electrical machine will be explained based on FIG. In this figure, a plurality of permanent magnets 2 having a substantially rectangular cross section forming magnetic poles are fixed and embedded in the circumferential direction on the outer circumference of a cylindrical rotor core 1 made of a magnetic material, and adjacent to the core 1. A slit 3 of an appropriate depth and width is provided from the outer periphery at an intermediate position between the magnetic poles to suppress the generation of short-circuit magnetic flux between the magnetic poles. The permanent magnets 2 are magnetized alternately in opposite directions in the radial direction, so that magnetic flux flows as shown by solid arrows.

[Problem that the invention seeks to solve]

In the above structure, the slit 3 increases the magnetic resistance between the magnetic poles and suppresses the generation of short-circuit magnetic flux, but since some magnetic flux flows as shown by the broken line arrow, the effective magnetic flux decreases by that amount. However, there is a drawback that the action of the slit 3 causes air agitation loss.

In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a rotor with permanent magnets for a rotating electric machine that can prevent the generation of short-circuit magnetic flux between magnetic poles without providing slits. .

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention has an inner side that forms a polygon whose cross-sectional shape is twice the number of magnetic poles by a line connecting the cylindrical rotor core 11 to the vicinity of the corner of the adjacent permanent magnet 2 having a substantially rectangular cross section. It is divided into an iron core 11a and a fan-shaped outer iron core 11b, and the inner iron core 11a and the outer iron core 11b are made of a magnetic material and a non-magnetic material, respectively.

[Effect]

Since the iron core 11 is divided and formed and the outer iron core 11b made of a non-magnetic material is disposed between adjacent magnetic poles, the generation of short-circuit magnetic flux between the magnetic poles is prevented without providing the slit 3 described in the conventional example. can do.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and the same parts as in FIG. 2 are denoted by the same reference numerals. In this figure, a cylindrical rotor core 11 is connected to an inner core 11a whose cross-sectional shape is a polygon twice the number of magnetic poles by a line connecting the vicinity of the corner of an adjacent permanent magnet 2 with a substantially rectangular cross section, and a plurality of fan-shaped rotor cores 11a. Outer core 1
1b. The inner core 11a
The outer cores 11b and 11b are made of a magnetic material and a non-magnetic material, respectively. After the outer cores 11b are fixed to every other part of the outer periphery of the inner core 11a with adhesive or the like, permanent magnets 2 are inserted between adjacent outer cores 11b. It is inserted in the axial direction and fixed with adhesive or the like. The outer core 11b presses both side edges of the permanent magnet 2 to prevent the centrifugal force of the permanent magnet 2 caused by the rotation of the rotor.

〔Effect of the invention〕

According to this invention, in a rotor with permanent magnets for a rotating electric machine, the iron core is divided into parts and an outer iron core made of a non-magnetic material is disposed between adjacent magnetic poles, so that a short-circuit magnetic flux flow between the magnetic poles occurs. Not only can this be prevented, but the slit described in the conventional example can be made unnecessary, and air agitation loss due to rotation can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a conventional example. 2... Permanent magnet, 11... Iron core, lla... Inner iron core, 11b... Outer iron core. ↓ Figure 2

Claims (1)

[Claims] 1) In a rotor in which a plurality of permanent magnets with a substantially rectangular cross section forming magnetic poles are embedded in the circumferential direction on the outer periphery of a cylindrical rotor core, a line connecting the corners of adjacent permanent magnets of the core is With a permanent magnet, characterized in that the inner core is divided into an inner core whose cross-sectional shape is a polygon twice the number of poles, and an outer fan-shaped core, and the inner core and the outer core are made of a magnetic material and a non-magnetic material, respectively. rotor.