JPH07312837A - Rotor for permanent magnet motor - Google Patents

Abstract

PURPOSE:To surely fix a permanent magnet to a rotor iron core by using a filler material in a space between a permanent magnet installed into a wedge- like groove or hole formed over in the axial direction of a rotor iron core and the rotor iron core so as to push down the both ends. CONSTITUTION:Each groove 2a is a groove having a cross section of wedge-like form which has a tapered surface having the wide which is gradually reduced outward in the radial direction of a rotor iron core 2. A permanent magnet 3 is formed so as to have a cross-section which is nearly same as the cross section of the groove 2a, and the peripheral surface is installed into the groove 2a so as to continue on the peripheral surface of the rotor iron core 2. Grooves 2b, 2c are continuously and adjacently formed on both sides of the groove 2a, and aluminum 4 is filled in the space between the rotor iron core 2 and the permanent magnet 3 inclusive of the grooves 2b, 2c by aluminum die cast. Thereby, the permanent magnet 3 is firmly fixed to the rotor iron core 2 together with the tapered surface of the groove 2a by the aluminum 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of a permanent magnet rotating electric machine, and is particularly useful when applied to a rotating field type rotating electric machine having a permanent magnet as a field pole.

[0002]

2. Description of the Related Art A rotating field type electric rotating machine having permanent magnets as field poles is widely used as, for example, a brushless DC servo motor. In this type of permanent magnet rotating electrical machine,
Fixing the permanent magnet is one of the technically difficult issues. This is because the permanent magnet fixed to the rotor core is subjected to centrifugal force and rotational torque due to rotation, and low temperature and high temperature heat cycles. Therefore, it is necessary to fix the permanent magnet that can ensure sufficient reliability under such a use environment.

Currently, in the rotor of this kind of permanent magnet rotating electric machine, it is fixed to the rotor core with an adhesive, fixed with a holding metal fitting, the outer peripheral surface of the permanent magnet is wound with a glass binding tape and fixed, The permanent magnet is fixed by a method such as fixing the outer peripheral portion of the magnet with a non-magnetic metal band.

[0004]

The fixing methods of the prior art described above have the following drawbacks.

Fixing method using an adhesive Adhesive strength is weak. The strength varies depending on the bonding work. Can't stand high temperature. Scatter if the magnet is missing.

[0006] Fixing method using a press fitting is not suitable for high speed rotation due to insufficient strength.

Fixing Method Using Glass Bind Tape Due to the thickness of the glass bind tape, the gap between the stator and the rotor becomes large and the characteristics deteriorate. Winding the glass binding tape requires a lot of man-hours, resulting in high cost.

Fixing method using a band of non-magnetic metal As with the glass bind tape, the gap becomes large. It is difficult to make a thin band.

In view of the above-mentioned prior art, it is an object of the present invention to provide a rotor for a permanent magnet rotating electric machine that can endure high speed rotation and maintain good characteristics.

[0010]

A rotor of a permanent magnet rotating electric machine according to a first aspect of the present invention which achieves the above object has a tapered surface whose width gradually decreases outward in a radial direction, and a rotor core. A wedge-shaped groove or hole formed in the axial direction of the permanent magnet, a permanent magnet mounted in the groove or hole, a space between the permanent magnet and the rotor core, both ends in the circumferential direction of the permanent magnet. And a filler filled so as to press the portion.

In the rotor of the permanent magnet rotating electric machine according to the second invention of the present application, which achieves the above object, the filling material is provided adjacent to the groove or hole for mounting the permanent magnet. It is characterized in that the groove or hole is filled so as to press the permanent magnet by die casting. As the filler, aluminum, aluminum alloy, zinc,
A zinc alloy or the like is used.

A rotor of a permanent magnet rotating electric machine according to a third aspect of the present invention which achieves the above object has a tapered surface whose width gradually decreases outward in the radial direction, and which is axially oriented in the rotor core. A wedge-shaped hole formed across the center of the rotor core, or a wedge-shaped groove having an arc-shaped bottom surface, and an arch-shaped permanent magnet attached to the hole or groove; A space between the permanent magnet and the rotor core is provided with a filling material filled so as to press both end portions in the circumferential direction of the permanent magnet.

A rotor of a permanent magnet rotating electric machine according to a fourth invention of the present application, which achieves the above object, comprises the first, second and third rotors.
In the invention, the portion of the rotor core that receives centrifugal force via the filler is enlarged along the circumferential direction of the rotor core. In this case, the size (thickness) of the rotor core in the direction of receiving the centrifugal force can be increased by forming the filler along the taper surface of the groove or hole and bending in the middle thereof.

[0014]

According to the rotor of the permanent magnet rotating electric machine according to the first aspect of the invention, the permanent magnet is fixed to the rotor core by the filler so that the permanent magnet is prevented from jumping out from the groove or the hole.

According to the rotor of the permanent magnet rotating electric machine of the second aspect of the present invention, the filling material surely engages with the permanent magnet, and the molding of the filling material becomes easy.

According to the rotor of the permanent magnet rotating electric machine of the third invention, the permanent magnet itself has an arched shape, so that the rigidity is increased.

In the rotor of the permanent magnet rotating electric machine according to the fourth aspect of the present invention, since the portion of the filler on which the centrifugal force acts is large, the centrifugal force disperses the force applied to the rotor core.

[0018]

Embodiments of the rotor of a permanent magnet rotating electric machine according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view showing a rotor according to an embodiment of the present invention, and FIG.
FIG.

As shown in FIGS. 1 and 2, a silicon steel plate is used as the rotary shaft 1
The rotor core 2 laminated in the axial direction has four grooves 2a formed in the axial direction at equal intervals in the circumferential direction. Each groove 2a is a groove having a tapered cross section and having a tapered surface so that the width thereof gradually decreases outward in the radial direction of the rotor core 2. The cross-sectional shape of the permanent magnet 3 is substantially the same as the cross-sectional shape of the groove 2a, and the permanent magnet 3 is mounted in the groove 2a so that its outer peripheral surface is continuous with the outer peripheral surface of the rotor core 2. Groove 2b,
2c is formed continuously adjacent to the groove 2a on both sides of the groove 2a, and aluminum 4 is formed in the space between the rotor core 2 and the permanent magnet 3 including the grooves 2b and 2c by aluminum die casting. It is filled.

Thus, the permanent magnet 3 is firmly fixed to the rotor core 2 by the aluminum 4 together with the tapered surface of the groove 2a.

3 and 4 are cross-sectional views showing another embodiment of the permanent magnet rotating electric machine according to the present invention. In the embodiment shown in FIG. 3, the shape of the rotor core 2 is the same as that of the above embodiment, but the shape of the permanent magnet 13 mounted in the groove 2a is different.
The permanent magnet 13 is formed to be thinner than the permanent magnet 3, and both end portions in the circumferential direction of the permanent magnet 13 are pressed by the aluminum 4 that cooperates with the tapered surface of the groove 2a, and the other portion becomes a space. There is. That is, it has an open slot structure.

The embodiment shown in FIG. 4 embodies the second aspect of the invention, in which the rotor core 12 is provided with a hole 12a in the axial direction and holes 12b and 12c continuously adjacent to the hole 12a. It is a thing. This hole 12a also has the same tapered surface as the groove 2a. The permanent magnet 13 is mounted in the hole 12a and is fixed by the aluminum 14 filled in the holes 12b and 12c by aluminum die casting. That is, it has a fully closed slot structure.

FIG. 5 shows a rotor of a permanent magnet rotating electric machine according to an embodiment of the third invention. Rotating axis of silicon steel plate 1
The permanent magnet mounting hole 22 is formed in the axial direction in the rotor core 12 that is laminated in the axial direction. Four permanent magnet mounting holes 22 are provided around the rotary shaft 1 at equal intervals. Each permanent magnet mounting hole 22 is flat, and the rotary shaft 1
It is arched to the side. Both side walls 22a of the permanent magnet mounting hole 22 are tapered so that the width gradually decreases toward the radially outer side of the rotor core 12. Rotor core 1
In the axial direction of 2, a filling hole 22b is formed by connecting to both side walls 22a of the permanent magnet mounting hole 22.

An arch-shaped permanent magnet 23 is mounted in the permanent magnet mounting hole 22. With the permanent magnet 23 attached, the filling hole 22b is filled with aluminum or aluminum alloy 24 as a filling material by die casting.

According to this rotor, since the permanent magnet 23 has an arch shape, the rigidity of the permanent magnet 23 itself is increased, and even when the rotating electric machine is rotated at a high speed, a warp occurs due to centrifugal force. Therefore, the permanent magnet 23 is prevented from being damaged.

In this embodiment, the portion to which the permanent magnet 23 is attached is the arch-shaped hole 22, but the bottom surface may be a groove curved in the arch-shape toward the rotary shaft 1 side.

According to each of the embodiments described above, the permanent magnets 3, 13, 23 are fixed to the rotor cores 2, 12 by aluminum 4, 14, 24, and the grooves 2a or the holes 12a, 2 are provided.
The jump from 2 is prevented. At this time, the aluminum 4, 14, 24 presses both ends of the permanent magnets 3, 13, 23 against the centrifugal force at the time of rotation, and the tapered surfaces also perform the same action.

In the embodiment shown in FIG. 4 described above, when the rotating electric machine rotates at high speed, the centrifugal force acting on the permanent magnet 13 is
As shown in FIG. 6, it acts on the portion indicated by C in the figure of the silicon steel sheet through the aluminum 14 which is the filler. When the hole 12c for filling the filler is provided along the tapered surface of the permanent magnet mounting hole 12a, as shown in FIG.
The portion L of the rotor core 12 that receives the centrifugal force becomes a narrow range, and the radial dimension, that is, the thickness T becomes thin.

FIG. 7 and FIG. 8 show an embodiment according to the fourth invention in which the strength of the portion receiving the centrifugal force is increased. Although the permanent magnet mounting holes 32 are formed in the rotor core 12, the permanent magnet mounting holes 32 are provided closer to the rotary shaft 1 side, that is, closer to the center side. The filling hole 32b connected to each permanent magnet mounting hole 32 is connected to the tapered surface 32a of each permanent magnet mounting hole 32, is provided along the tapered surface 32a, and is bent in the middle of the rotor core. It has a shape along the circumference. That is, as shown in FIG. 8, the portion L on which the centrifugal force acts is increased and the thickness T is also increased.

A permanent magnet 33 is mounted in the magnet mounting hole 32, and a filling material 34 such as aluminum or aluminum alloy is filled in the filling hole 32b by die casting as in the other embodiments, and the permanent magnet 33 is fixed. To be done.

Therefore, in this embodiment, when the rotating electric machine is rotated, the centrifugal force acting on the permanent magnet 33 is in a wide range (L portion) of the silicon steel plate and also in a thick portion (T).
Since it can be received by the part), no trouble occurs even when the rotating electric machine is rotated at a high speed.

In the embodiment shown in FIGS. 7 and 8, the filling hole 32b is connected to the tapered surface 32a of each permanent magnet mounting hole 32, extends along the tapered surface 32a, and is bent halfway. However, the shape is not limited to this, and if the range L in which the centrifugal force acts is wide and the thickness T of the portion in which the centrifugal force acts is large,
It may have any shape. Although the embodiment shown in FIGS. 7 and 8 is applied to a flat straight permanent magnet 33, it can be similarly applied to an arch type permanent magnet 33 as shown in FIG.

In the above-mentioned embodiments, aluminum or aluminum alloy is used as the filler, but other metals such as zinc and zinc alloy can be used.

[0034]

According to the first and second aspects of the present invention, as described in detail with reference to the above embodiments, the permanent magnet is firmly fixed by the taper surface and the filling material such as aluminum, so that high speed rotation is possible. Since it can withstand higher temperatures than fixing with an adhesive or glass binding tape, it can be miniaturized.There is no binding or band for fixing the permanent magnet on the gap surface between the rotor and the stator, and the gap is small. As a result, the characteristics are improved, and when the filler is applied by die casting and the permanent magnet is fixed, the cost and reliability are increased compared to manual bonding and binding winding. .

Further, according to the third aspect of the invention, since the permanent magnet is formed in an arch shape that swells toward the center of rotation, the rigidity of the permanent magnet itself is increased.

Further, according to the fourth aspect of the invention, since the filler hole has a special shape to receive the centrifugal force acting through the filler in a wide area, it has sufficient strength for high speed rotation. Exert.

[Brief description of drawings]

FIG. 1 is a front view showing a rotor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a cross sectional view showing a second embodiment of the present invention.

FIG. 4 is a transverse sectional view showing a third embodiment of the present invention.

FIG. 5 is a cross-sectional view of an embodiment of the present invention.

6 is an enlarged view of a portion of the embodiment shown in FIG.

FIG. 7 is a cross-sectional view of another embodiment of the present invention.

FIG. 8 is an enlarged view of a part of FIG.

[Explanation of symbols]

 1 Rotating shaft 2,12 Rotor iron core 2a Groove 12a, 22,32 Hole 3,13,23,33 Permanent magnet 4,14,24,34 Aluminum 12b, 12c, 22b, 32b Filling hole

Claims (4)

[Claims] 1. A wedge-shaped groove or hole having a tapered surface whose width gradually decreases radially outward and formed in the axial direction of a rotor core, and a permanent magnet mounted in the groove or hole. And a filling material filled in a space between the permanent magnet and the rotor core so as to press both end portions in the circumferential direction of the permanent magnet, the rotor of the permanent magnet rotating electric machine. 2. The filling material is filled so as to press the permanent magnet by die casting into another groove or hole provided adjacent to the groove or hole for mounting the permanent magnet. The rotor of a permanent magnet rotating electric machine according to claim 1, wherein the rotor is a permanent magnet rotating electric machine. 3. A taper surface, the width of which gradually decreases outward in the radial direction, and is formed over the axial direction of the rotor core.
Furthermore, an arcuate wedge-shaped hole toward the center side of the rotor core or a wedge-shaped groove whose bottom surface is arched, an arch-shaped permanent magnet mounted in the hole or groove, the permanent magnet, and the permanent magnet A rotor of a permanent magnet rotating electric machine, comprising: a space filled with a rotor core; and a filling material filled so as to press both ends of the permanent magnet in a circumferential direction. 4. A portion of the rotor core, which receives a centrifugal force via the filler, is enlarged along the circumferential direction of the rotor core. The rotor of the permanent magnet rotating electric machine according to item 3.