JPH0449825A - Permanent magnet rotor - Google Patents

Abstract

PURPOSE:To correct unbalance generated due to the dimensional accuracy of components and dispersion on assembly, and to prevent the increase of vibrations by removing balance correcting sections die-casting-molded on both end face sections of a rotor. CONSTITUTION:A space section in a rotor 1 is filled with the balance correcting section 8 of a die casting member through clearances among a plurality of grooves 11 formed to a yoke 4 while being opposed to pouring gates 9 formed to end plates 5 from the pouring gates 9. The die-casting-molded balance correcting section 8 is shaped annularly on end faces. Unbalance generated by the dimensional accuracy of a magnet piece 3 and an error on assembly can be corrected by removing the balance correcting section 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a permanent magnet rotor, and more particularly to a permanent magnet rotor with an improved balance correction method.

[Conventional technology]

Traditionally, split permanent magnet pieces are made of aluminum.

An example of consideration regarding the positioning of a permanent magnet rotor that integrally fixes a yoke and a surface protection member using a die-casting material such as zinc, and the improvement of assembly dimension accuracy is given in Utility Model Application Publication No. 64-258.
As seen in No. 74, etc., no consideration was given to the method of correcting the balance of the permanent magnet rotor.

Particularly in recent years, single-rotation machines have been increasingly used for high-speed applications, and there has been a problem in that residual unbalance causes vibration.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, vibration may increase due to unbalance due to dimensional accuracy and assembly variations.

The present invention aims to solve the above problem by correcting the imbalance caused by dimensional accuracy or assembly variations, and particularly aims to improve the correction method and improve workability.

[Means to solve the problem]

The above purpose is to arrange a non-magnetic cylinder around the outer circumference of a permanent magnet to protect the permanent magnet, and to form an annular shape on both end faces of the rotor using the die-casting material in a permanent magnet rotor which is integrally fixed by die-casting. This is achieved by providing a balance correcting section.

[Effect]

When performing balance correction, the die-casting material of the balance correction portion in the unbalance direction caused by variations in dimensional accuracy and assembly is removed by the necessary correction amount. This makes it possible to correct imbalances caused by assembly variations.

Since the balance correction section is annular, it is possible to correct unbalance in any direction.

If a non-magnetic material is used for the die-casting material of the balance correction part, the amount of correction can be increased since it is a part that is not related to the ai temperament performance.

In addition, by providing balance correction sections on both end faces of the rotor, two-face correction is possible and accuracy can be improved. Mechanical strength is required for the outer circumferential cylinder and the end plate for protecting the permanent magnet, and hard materials are often used, and the balance correction by cutting these parts does not have good cutting workability, so die-casting In the case of materials, materials with good machinability such as aluminum and zinc can improve cutting workability when correcting balance.

〔Example〕

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

1 is a permanent magnet rotor, 2 is a non-magnetic cylinder, 3 is a shingled permanent magnet piece, 4 is a yoke made of a laminated steel plate, 5.6 is an end plate made of a non-magnetic material, and 7 is a rotating shaft.

Reference numeral 8 denotes a balance correction part of the die-cast member, which passes from a sprue 9 provided in the end plate 5 to a space in the rotor 1 through a plurality of grooves 11 provided in the yoke 4 facing it and gaps between the magnet pieces 3. is filled with.

In addition, there is a die-cast balance correction part 8 on the end surface.
is formed.

In the radial cross-sectional view of FIG. 2, 13 is a convex portion provided on the yoke 4, which corresponds to the magnet piece 3, and the magnetization polarity N in the subsequent process.
It is located between the S poles. In this embodiment, the two poles are made up of four magnet pieces 3, and the number of protrusions 13 is only two.

Gates 9 (six pieces) indicated by dotted lines - annular groove 10 indicated by dashed dotted lines,
Then, through the plurality of grooves 11 of the yoke 4, the air gap 15°1 created by the air gap 14 between the magnet pieces 3 and the chamfered surface of the magnet piece 3
6 will also be filled. This annular groove 10 has a plurality of sprues 9.
It acts as a distribution channel for the water and can be evenly flowed into the water.

Further, the annular die-casting material remaining in this annular groove 10 becomes the balance correction part 8.

The thickness can be appropriately set so as to be convex in the axial direction as shown in FIG. 1, depending on the shape of the die-cast mold.

In this way, the balance correction part 8 is fitted into the annular groove 10 and is connected to the inside of the permanent magnet rotor 1 through the sprue 9, making it strong against both centrifugal force and axial force. Fixed. Also, at this time, the voids 14a, 1
Due to the inflow pressure of the die casting material filled between 4b,
The magnet piece 3 is pressed in the circumferential direction and becomes a magnet piece 3a as shown in FIG.
Since the magnet pieces 3 are pushed in the direction of contact between the -3b and 3cm3d, the magnet pieces 3 are fixed so that no gaps are created, so the die casting does not enter and create no gaps.

However, due to variations in the dimensional accuracy of the magnet piece 3, twisting, and assembly errors, for example, the unevenness of the magnet piece 3 or the air gap 1
Unbalance occurs due to variations in the number.

In the perspective view of FIG. 3, the die-cast balance correcting portion 8 is formed into an annular shape.

Here, the unbalance caused by the dimensional accuracy of the magnet piece 3 or assembly error described above can be corrected by deleting part A of the balance correction part 8.

Part A is located in the same direction as the generated imbalance,
The amount of imbalance is the same. Since the balance correction section is formed in an annular shape, it is possible to correct imbalance wherever it occurs. Furthermore, by increasing the diameter and thickness of the correction part.

The amount of correction can be increased, and even if the accuracy of other parts is somewhat poor, it can be corrected. Moreover, if a non-magnetic material is used for the die-casting material, there will be no problem in terms of magnetic performance, so the amount of correction can be increased by considering only the mechanical strength.

FIG. 4 is a longitudinal cross-sectional view of a permanent magnet rotor 1 showing another embodiment of the present invention, similar to FIG. 1.

Balance correction part 8 is located on the outer circumferential side of the permanent magnet rotor l.
This example has the advantage that the amount of correction can be made larger. Further, when correction is performed, the balance correction portion 8 is corrected by cutting, but the same effect can be obtained in either of the above examples depending on the workability of the balance correction device used.

In addition, aluminum and zinc, which are generally used as die-casting materials, have good machinability, and when the balance correction portion 8 formed by die-casting material is corrected by cutting, the workability of the correction is significantly reduced due to the good machinability. It can be improved.

〔Effect of the invention〕

According to the present invention, by removing the balance correction part 8 die-cast on the end face, it is possible to correct unbalance caused by variations in the dimensional accuracy of parts and assembly, thereby reducing vibration. This can be prevented from increasing.

In addition, the annularly provided balance correcting portion can correct unbalance at any position in the radial direction, and by providing it on both end faces, balance accuracy can be improved by two-sided correction.

The die-casting material is generally a material with good machinability such as aluminum or zinc alloy, which can improve the workability of balance correction, and since it is also a non-magnetic material, the magnetic performance of the permanent magnet rotor 1 is improved. You can increase or decrease the amount of balance correction without any effect.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a permanent magnet rotor showing one embodiment of the present invention, Fig. 2 is a radial sectional view thereof, Fig. 3 is a perspective view thereof, and Fig. 4 is a permanent magnet rotor showing another embodiment. FIG. 3 is a longitudinal cross-sectional view of a magnet rotor. 1... Permanent magnet rotor, 2... Non-magnetic cylinder, 3...
... Tile-shaped permanent magnet piece, 4... Yoke, 8... Balance correction part. Figure 1 Figure 3 Figure 4 Figure 2

Claims (1)

[Scope of Claims] 1. In a permanent magnet rotor in which a non-magnetic cylinder that protects the permanent magnets is arranged concentrically around the outer periphery of the permanent magnets and is integrally fixed by die-casting, a balance formed of the die-casting material is used. A permanent magnet rotor characterized in that a correction portion is provided on an end face or an outer peripheral surface. 2. The permanent magnet rotor according to claim 1, wherein the balance correction section is provided on both end surfaces of the permanent magnet rotor. 3. The permanent magnet rotor according to claim 1, wherein the balance correction section is provided in an annular shape.