JPS5947940B2 - Permanent magnet synchronous machine rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the rotor of a permanent magnet type synchronous machine.

Traditionally, alnico metal magnets are often used in the rotors of permanent magnet synchronous machines, but these have poor productivity and are expensive, as well as being extremely hard and brittle, making machining difficult. This is extremely inconvenient.

Ferrite-based sintered magnets have excellent productivity and can be done by hand at low cost, but whereas alnico-based metal magnets have a high residual magnetic flux density and a small coercive force, these ferrite-based sintered magnets have a low residual magnetic flux density. It has the contradictory characteristics of having a large holding power.

Therefore, in order to increase the magnetic flux using a ferrite-based sintered magnet, it is necessary to increase the effective cross-sectional area of the magnet.
The rotor outer diameter becomes larger.

The present invention focuses on the fact that ferrite-based sintered magnets can be press-formed into complex shapes and can be used in flat shapes due to their large coercive force, and the effective cross-sectional area of the magnets can be increased without increasing the outer diameter of the rotor. Moreover, the shape and arrangement of the permanent magnets have been devised so that the magnetic flux can be used effectively.

An embodiment of the present invention will be described below with reference to the drawings.

The figure is a cross-sectional view of a rotor in a four-pole machine, where 1 is the rotor core, which is made up of laminated thin electromagnetic steel sheets.

A conductor 2 is cast into a hole 3 on the outer periphery of the core, and is short-circuited by a shorting ring at both ends of the core to form a squirrel-cage winding.

The rotor core 1 has a center hole 5 at the center, and an even number of permanent magnet storage spaces 8a, sb, 8c, and sa are provided around the center hole 5 between the center hole and the outer periphery. have.

Permanent magnets 4ay 4b, 4c, and 4d are arranged in the permanent magnet storage spaces 8a, sb, 8c, and sa, respectively.

Permanent magnet storage spaces 8a, 8b, and 8c, respectively. 8d and permanent magnets 4a, 4b, 4c, 4d are arranged at the inner end 4' and the outer end 4.
When viewed in the same rotational direction indicated by f with the center hole 5 as the center, it curves and protrudes outward in the same direction.

The protruding outer surfaces 9a, 9b, 9c of adjacent permanent magnets 4ay, 4b, 4c, and 4d,
9d and the inner surfaces 10a, 10b, 10c, and 10d are N.

Permanent magnets 4a, 4b, 4c, 4d are magnetized to exhibit different polarities as shown in the figure S.
are the outer surfaces 9a, 9b, 9c, 9d and the inner surface 10a, respectively.
, 10b, 10c, and 10d are magnetized to 5 to show different polarities.

Further, the portions 11 a, 11 b, 11 c, 11 of the rotor core 1 located between adjacent permanent magnets
d is configured such that the width g increases as it moves away from the center hole 5.

6 and 7 are notches provided at both ends of each permanent magnet to prevent short circuit between poles.

The magnetic flux generated by the permanent magnets of the rotor configured in this manner acts as shown by the broken line in the figure.

At this time, the magnetic flux density of the part located between the two adjacent permanent magnets gradually increases as it approaches the outside, but the gap g also gradually increases as it approaches the outside, so the magnetic flux can be controlled without saturation of the magnetic flux. Can be used effectively.

According to the present invention, as is clear from the above description, there is a central hole in the center, and an even number of permanent magnet storage spaces are provided around the central hole between the central hole and the outer periphery. In the rotor of a permanent magnet synchronous machine consisting of a child core and permanent magnets arranged in permanent magnet storage spaces, each permanent magnet storage space and the permanent magnets are located between the inner end and the outer end.
When viewed in the same direction of rotation with the center hole as the center, the permanent magnets are curved and protruded outward in the same direction, and the protruding outer and inner surfaces of adjacent permanent magnets exhibit different polarities, In addition, each of the permanent magnets is magnetized so that the outer surface and the inner surface exhibit different polarities, and furthermore, the width of the portion of the rotor core located between adjacent permanent magnets increases as it moves away from the center hole. Since I configured it as
The effective cross-sectional area of the magnet can be increased, and its magnetic flux can be used effectively.

Therefore, according to the present invention, it is possible to obtain a permanent magnet type synchronous machine with excellent characteristics of generating a large amount of magnetic flux without increasing the outer diameter of the iron core by using inexpensive ferrite-based sintered magnets with good productivity.

[Brief explanation of drawings]

The figure is a cross-sectional view showing an embodiment of the present invention. 1: Rotor core 2: Conductor, 4 aj 4 by
4 c. 4d: Permanent magnet, 5: Iron core center hole, 6, 7: Notch for preventing short circuit between poles, 8 at 8 b2 8 cy 8 d
;Permanent magnet storage space.

Claims (1)

[Claims] 1. The center has a central hole, and from this central hole to the outer periphery, an even number of permanent magnet synchronous machines are arranged around the central hole, and permanent magnets are arranged between the permanent magnets. −
In the rotor of the first machine, each of the permanent magnet storage spaces and the permanent magnets are arranged outward in the same direction when viewed in the same direction of rotation with the center hole as the center between the inner end and the outer end. curved and protruding, and the protruding outer and inner surfaces of adjacent permanent magnets exhibit different polarities, and each of the permanent magnets has a different polarity from the outer and inner surfaces. The rotation of the permanent magnet synchronous machine is characterized in that the rotor core is magnetized as shown in FIG. Child.