JP2012231578A - Embedded magnet rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embedded magnet rotary electric machine that allows, as well as downsizing thereof, high efficiency by reducing leakage flux from side surfaces of a rotor.SOLUTION: An embedded magnet rotary electric machine includes: a stator that has a stator core 13 and stator coils 14; and an approximately cylindrical rotor that has permanent magnets 22 provided therein and that is rotatably supported. Separately from the permanent magnets 22 that form magnetic poles, permanent magnets 28 and 29, magnetized in an axial direction, are provided, one for each magnetic pole, on respective side surfaces of the rotor.

Description

  The present invention relates to an embedded magnet type rotating electrical machine.

Some conventional embedded magnet type rotating electrical machines have a permanent magnet mounted on the side surface of the rotor, although the magnetic poles are formed on the outer cylindrical surface of the substantially cylindrical rotor. (For example, refer to Patent Document 1).
FIG. 1 of Patent Document 1 shows an embedded magnet type rotating electrical machine in which a permanent magnet is mounted on a rotor side surface. This permanent magnet is used to form a magnetic pole on the outer cylindrical surface of the rotor.
Another conventional embedded magnet type rotating electrical machine concentrates the magnetic flux generated from a permanent magnet installed in a rotor core to improve performance. (For example, refer to Patent Document 2).
FIG. 2 of Patent Document 2 shows the structure of a rotor provided with two permanent magnets facing the rotor core in a substantially V shape for each magnetic pole. Since the permanent magnets are mounted with the same magnetic poles facing each other, the magnetic fluxes of the two opposing permanent magnets are concentrated on the surface of the magnetic pole part of the rotor core, increasing the magnetic flux density of the gap. Is promoting small size and high performance.
As described above, the permanent magnet used in the conventional embedded magnet type rotating electric machine has been used to configure the magnetic pole of the rotor.

JP 2008-029130 A JP 2010-074975 A

  However, permanent magnets mounted on the rotor of a conventional embedded magnet type rotating electrical machine are intended to reduce eddy current loss that is caused by leakage magnetic flux from the side of the rotor to be induced in the adjacent bracket. There wasn't.

  The interior magnet type rotating electrical machine used for industrial motors, EV motors, and the like is desired to be further downsized and highly efficient in the future. As means for promoting downsizing, it is assumed that the magnetic flux concentration type embedded magnet type rotating electrical machine shown in Patent Document 2 is frequently used and that the gap between the rotor and the bracket is reduced. The magnetic flux concentration increases the leakage magnetic flux from the rotor side surface and increases the eddy current loss induced in the adjacent bracket. In order to promote higher efficiency, it is necessary to reduce the eddy current loss.

  Therefore, an object of the present invention is to provide an embedded magnet type rotating electrical machine that can promote high efficiency by reducing leakage magnetic flux from the rotor side surface while promoting miniaturization.

  In order to solve the above-described problem, according to one aspect of the present invention, in an embedded magnet type rotating electrical machine including a stator and a substantially cylindrical rotor that is rotatably supported, a permanent magnet that constitutes a magnetic pole; In addition, an embedded magnet type rotating electric machine is characterized in that a permanent magnet magnetized in the axial direction is provided for each magnetic pole on the rotor side surface.

  According to the present invention, it is possible to provide an embedded magnet type rotating electrical machine capable of promoting high efficiency by reducing leakage magnetic flux from the rotor side surface while promoting miniaturization.

1 is an axial cross-sectional view of an interior magnet type rotating electrical machine according to a first embodiment of the present invention. It is radial direction sectional drawing of the interior magnet type rotary electric machine which concerns on the same embodiment. It is an axial sectional view of the rotor. It is component structure explanatory drawing of the said rotor. It is a no-load torque test result explanatory view of this embodiment. It is arrangement | positioning explanatory drawing of another embedded magnet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same structure, the same code | symbol is attached | subjected and duplication description is abbreviate | omitted suitably.

<First Embodiment>
First, the configuration of an embedded magnet type rotating electrical machine according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an axial cross-sectional view of an embedded magnet type rotating electrical machine according to a first embodiment of the present invention, which is used in a servo motor.

As shown in FIG. 1, the embedded magnet type rotating electric machine according to the present embodiment is a substantially cylindrical in which a stator having a stator core 13 and a stator coil 14 installed, and a permanent magnet 22 is installed and supported rotatably. A rotor 20 having a shape, and an encoder unit 17 for detecting the rotational position of the rotor.
The rotor 20 includes a load-side permanent magnet 28 and an anti-load-side permanent magnet 29 on the rotor side surface for the purpose of shielding leakage magnetic flux from the rotor side surface. The load-side permanent magnet 28 and the anti-load-side permanent magnet 29 are held by a load-side plate 26 and an anti-load-side plate 27 made of a nonmagnetic material, respectively.
The rotor 20 is rotatably held by the load side bracket 11 and the anti load side bracket 12 via the load side bearing 18 and the anti load side bearing 19.
The anti-load side bracket 12 is fastened to the load side bracket 11 together with the frame 10 by a bolt (not shown).

FIG. 2 is a radial cross-sectional view of the interior magnet type rotating electric machine according to the present embodiment.
As shown in FIG. 2, the stator is configured by attaching a stator coil 14 to each of the stator cores 13 divided into twelve. The stator coil 14 is insulated from the stator iron core 13 and the load side bracket 11 by the mold resin 15.
The rotor 20 includes a rotor core 23 in which two permanent magnets 22 facing each other in a substantially V shape are mounted in the permanent magnet mounting hole 23b for each magnetic pole, and constitutes a 10-pole magnetic pole. Since the magnetic fluxes of the two opposing permanent magnets 22 are concentrated on the rotor surface, the magnetic flux density in the gap is increased, and the effective magnetic flux F toward the stator core is increased to promote the miniaturization and high performance of the rotating electrical machine. doing.

  Since the rotor core 23 supports the permanent magnet 22 and the magnetic pole portion 23a of the rotor core against centrifugal force and is engaged and fixed to the shaft with an engagement portion due to unevenness, it can withstand strong torque. .

FIG. 3 is an axial sectional view of the rotor.
In the figure, a load side plate 26 and an antiload side plate 27, which are loaded with a load side permanent magnet 28 and an antiload side permanent magnet 29, are mounted on the side surface of the rotor core 23 mounted with the permanent magnet 22.
As in this embodiment, in an embedded magnet type rotor in which magnetic flux is concentrated, leakage magnetic flux Fl from the rotor side surface increases with respect to effective magnetic flux F directed to the stator core.
Due to this leakage flux, harmful eddy current loss due to leakage flux that alternates with the rotation of the rotor is induced, for example, in the rotor proximity portion 11a of the load side bracket 11 shown in FIG. Conventionally, the generation of eddy current loss has been reduced by increasing the gap distance between the rotor side surface and the bracket wall surface, but the conventional method cannot promote downsizing of the rotating electrical machine.

  In order to attenuate the leakage magnetic flux Fl from the rotor side surface, the load side permanent magnet 28 and the anti-load side permanent magnet 29 are provided so that the magnetic flux faces the rotor side surface. The leakage flux Fl from the rotor side surface can be attenuated by the magnetic flux Fc by the side permanent magnet. The thicknesses of the load-side permanent magnet 28 and the anti-load-side permanent magnet 29 are determined by magnetic field analysis so that the leakage flux Fl is effectively attenuated with respect to the amount of use.

FIG. 4 is an explanatory diagram of a component configuration of the rotor.
In the figure, after the rotor core 23 with the permanent magnet 22 and the load side plate 26 with the load side permanent magnet 28 attached to the shaft 21, the anti load side plate 27 with the anti load side permanent magnet 29 attached to the shaft. And the rotor is completed.

The anti-load side plate 27 has a recess for mounting the anti-load side permanent magnet 29, and N poles and S poles are alternately arranged so as to face the magnetic pole portion 23a of the rotor core. The same applies to the load side plate 26.
The load side plate 26 and the anti-load side plate 27 are made of non-magnetic stainless steel, and the N pole and S pole magnetic fluxes are not short-circuited by the side plates.

FIG. 5 is an explanatory diagram of a no-load torque test result in which the rotating electrical machine of the present embodiment is driven from the outside and the torque required for the rotational speed is measured by comparison.
In the figure, the no-load torque of the present embodiment C is sufficiently small, but the no-load torque increases about twice when the permanent magnets A are not installed on the load side and the anti-load side. This is because the leakage magnetic flux Fl from the rotor side surface induces harmful eddy current loss in the rotor proximity portion 11a of the load side bracket shown in FIG. This increase in loss reduces the efficiency of the rotating electrical machine. As a method of increasing the gap based on the conventional method, even when the rotor proximity portion 11a is removed B, the no-load torque is increased compared to the present embodiment.
That is, the permanent magnets 28 and 29 on the rotor side surface according to the present embodiment are installed separately from the permanent magnets 22 constituting the magnetic poles, so that rotation of the embedded magnet type rotating electric machine is promoted while promoting the downsizing of the embedded magnet type rotating electrical machine by the magnetic flux concentration. The result is that high efficiency can be promoted by reducing the leakage flux in the axial direction of the child.

  As described above, the embedded magnet type rotating electrical machine according to the present embodiment is downsized by the concentration of magnetic flux by installing the permanent magnets 28 and 29 on the rotor side surface separately from the permanent magnets 22 constituting the magnetic poles. It is possible to provide an embedded magnet type rotating electrical machine that can promote high efficiency by reducing leakage magnetic flux from the rotor side surface while propelling the rotor.

  The embodiment of the present invention has been described above. However, a so-called person skilled in the art can appropriately modify the above embodiment without departing from the gist of the present invention, and can appropriately combine the above embodiment and the method according to the modified example. It is. That is, it is needless to say that even a technique with such a change is included in the technical scope of the present invention.

  For example, in the above embodiment, the permanent magnets constituting the magnetic poles are arranged in a substantially V shape, but the permanent magnets 32 are radially attached as shown in FIG. A) may be used, or the permanent magnet 42a may be mounted (B) in a circumferential shape on the inner peripheral side of the radial permanent magnet 42b. In other words, the leakage flux shielding plate of the present invention has large magnetic pole portions 23a, 33a and 43a surrounded by permanent magnets, and the magnetic pole portions are the same as the arrangement structure of embedded magnets which are large side surfaces from which magnetic flux leaks. Has an effect.

  Since the embedded magnet type rotary electric machine of the present invention can be made small and highly efficient, it can be applied to a wide range of rotary electric machine applications including a generator as well as an electric motor.

10 frames
11 Load side bracket 11a Rotor proximity part 12 Anti-load side bracket
13 Stator Core 14 Stator Coil
15 Mold resin 16 Connection
17 Encoder 18 Load side bearing
19 Anti-load-side bearing 20 Rotor
21 Shaft 22 Permanent magnet
23 Rotor core 26 Load side plate
27 Anti-load side plate
28 Load-side permanent magnet
29 Anti-load side permanent magnet F Magnetic flux
Fl Leakage flux Fc Magnetic flux by the permanent magnet on the side

Claims (4)

In an embedded magnet type rotating electrical machine having a stator and a substantially cylindrical rotor that is rotatably supported, a permanent magnet magnetized in the axial direction on the side surface of the rotor is separated from the permanent magnet that constitutes the magnetic pole. An embedded magnet type rotating electrical machine characterized by being installed every time. 2. The embedded magnet type rotating electric machine according to claim 1, wherein the permanent magnet installed on the side surface is installed in a shape covering a range surrounded by the permanent magnet constituting one magnetic pole of the rotor core. 2. The permanent magnet installed on the side surface is installed with an N pole facing an N pole and an S pole facing an inner side in an axial direction with respect to an S pole. Or an embedded magnet type rotating electric machine according to 2; The embedded magnet type rotating electric machine according to any one of claims 1 to 3, wherein the permanent magnet installed on the side surface is held by a side plate made of a non-magnetic material.

Images