JPH06217477A - Electric rotating machine - Google Patents

Abstract

PURPOSE:To allow formation of a small-sized rotor having high flux density by embedding arcuate permanent magnets radially in a rotor core and magnetizing the permanent magnets in the planar direction. CONSTITUTION:In the rotor 1 of an electric rotating machine, permanent magnets 3 are arranged in the peripheral direction while being embedded on the inside of a rotor core 2 having right circle outer periphery and arcuate cores 5 are arranged while sandwiching the permanent magnets 3. The arcuate permanent magnets 3 are magnetized in the planar direction. Since the arcuate permanent magnets 3 magnetized in the planar direction are embedded in the rotor core 2, flux from the permanent magnets 3 having increased surface area is accumulated on the outer periphery of the rotor core 2 thus increasing the flux density on the outer periphery of the rotor core 2. This arrangement allows formation of small-sized rotor 1 having high flux density using ferrite or the like without requiring expensive material such as rare earth metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a rotary electric machine having a structure in which a permanent magnet is used for a rotor.

[0002]

2. Description of the Related Art A rotary electric machine using a permanent magnet for a rotor is
A permanent magnet is attached to the outer circumference of an iron core having a shaft penetrating to form a rotor. Since such a rotary electric machine uses a permanent magnet, it has a structure that is efficient and is particularly preferable in a rotary electric machine such as a brushless motor in which the number of revolutions is controlled.

However, in the generation of magnetic flux, in the stator core, a current is passed through the windings to generate magnetic flux.
A large amount of magnetic flux can be easily obtained by increasing the number of windings and the current, but the rotor has a physical limit because it is a permanent magnet. That is, when the magnetic flux of the rotor is made of a material such as alnico or rare earth, the amount of the magnetic flux can be extremely increased. However, the amount of magnetic flux with respect to the volume is reduced. For this reason, it is common to make the rotor larger than the stator in the axial direction, and to enlarge the portion of the stator facing the rotor in the axial direction in order to converge the magnetic flux of the rotor. With such a configuration, the magnetic flux of the rotor, which is increased in the axial direction, can be sufficiently converged with respect to the small winding portion provided in the stator core, and a rational rotary electric machine can be configured.

[0004]

However, in the conventional rotary electric machine, when the stator core is constructed, the diameter of the portion to which the winding is applied and the end portion in the axial direction where the magnetic flux of the rotor is converged are increased. Since the structure of the iron core differs depending on the direction, two types of laminated steel plates must be manufactured. Further, in the case of a steel plate structure in which laminated steel plates are mutually joined by a projection connection in the laminating process, punching and laminating are continuously performed in the laminating direction. Is unnecessary, and a large amount of waste is generated on the steel plate in this part.

In order to solve such a problem, the rotor core is made of a material having a large magnetic flux such as rare earth to increase the magnetic flux density of the rotor so that the stator core and the rotor core are axially moved. The lengths may be the same, but they are expensive, which is extremely disadvantageous in manufacturing. In manufacturing, inexpensive materials such as ferrite should be used to increase the amount of magnetic flux.

The present invention has been made in view of such circumstances, and provides a small-sized and highly efficient rotating electric machine in which a rotor having a high magnetic flux density is formed by using an inexpensive material such as ferrite. It is intended to be provided.

[0007]

SUMMARY OF THE INVENTION The present invention solves the problems by embedding radial arc-shaped permanent magnets in a rotor core and magnetizing the permanent magnets in the plane direction.

[0008]

According to the present invention, since the permanent magnets formed in an arc shape are magnetized in the surface direction and radially embedded in the rotor core, the magnetic flux generated from the permanent magnets having a large surface area is generated by the rotor. Accumulated on the outer periphery of the iron core, the magnetic flux density on the outer periphery of the rotor iron core increases. Therefore, it is possible to obtain a rotor having a high magnetic flux density, which is the same as that of a rotor made of a material having a high magnetic flux density such as rare earth although it is ferrite.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is a longitudinal sectional view of a main part showing a rotor core of a rotary electric machine according to an embodiment of the present invention. 2 is shown in FIG.
3 is a perspective view of the rotor core shown in FIG. FIG. 3 is a longitudinal sectional view of a main part of a rotary electric machine showing a structure of an embodiment of the rotary electric machine according to the present invention. FIG. 4 is a plan view of an essential part showing the structure of the winding of the stator core. FIG. 5 is a plan view of an essential part showing a state in which a winding is wound around the stator core. FIG. 6 is a plan view of a stator core around which windings are wound.

In FIG. 1, a rotor 1 of a rotating electric machine has four permanent magnets 3 arranged in the circumferential direction so as to be embedded inside a rotor core 2 whose outer periphery is formed in a perfect circle. Four arc-shaped iron cores 5 are provided so as to sandwich the magnet 3. The arc-shaped permanent magnet 3 is magnetized in the surface direction. Further, a shaft 4 is passed through the axis of the rotor core 2, and the rotor 1 constituting the rotor 1 is formed by punching and laminating steel plates with a press, and the core 5 is formed in an arc shape. The structure is such that the permanent magnet 3 can be mounted on the outer periphery of the permanent magnet 3. The magnetic pole N-S is sequentially formed on the outer circumference of the rotor core 2 by the magnetic flux of the permanent magnet 3.

In FIG. 2, a rotor 1 of a rotating electric machine is provided with an iron core 5 so as to sandwich a permanent magnet 3, and the iron core 5 constitutes a rotor 1 in which four permanent magnets 3 are embedded. A groove 7 is formed between the four iron cores 5 so that the magnetic fluxes of the magnetic poles N and S formed on the iron core 5 are not short-circuited. Further, a shaft hole 4a that penetrates the shaft 4 (not shown) is formed in the shaft center. Further, end plates 6 whose outer circumferences are connected are provided at both axial end portions of the rotor 1 so that the iron core 5 and the permanent magnets 3 are not disjointed.

In FIG. 3, in the rotating electric machine, a shaft 4 has both ends supported by two bearings 8, and a permanent magnet 3 is embedded in an iron core 5 so as to be sandwiched therebetween. A stator core 9 is provided so as to cover the outer periphery of the rotor 1, and the stator core 9 is provided with windings 10. Further, the outer periphery of the stator core 9 is covered with a frame 11, and the frame 11 is provided with a bearing 8.

In FIG. 4, the stator core 9 of the rotating electric machine is shown.
Is wound around the Ψ-shaped tooth portion 12 forming the magnetic poles of the stator core 9, and the tooth portions 12 and the salient poles 13 form the magnetic poles of the stator core 9. Is configured.

In FIG. 5, winding of the winding 10 of the rotating electric machine shows a process of winding the U, V, and W phases, and a nozzle 14 for three windings is shown on the tooth portion 12. It is configured to be directly wound via an insulating material which is not formed. Winding 1
The winding of No. 0 is performed by first winding the outer peripheral side and then winding the inner peripheral side, and the nozzle 14 for winding the winding 10 is wound.
In the case of (1), all the windings 10 can be wound at once as long as they are configured to expand and contract in the radial direction, but it is also possible to wind each winding 10 by one nozzle.

In FIG. 6, a winding 10 wound around a rotating electric machine has an outer peripheral side and an inner peripheral side wound respectively, and a control circuit (not shown), that is, a power source includes U, V and W.
The magnetic poles are connected for each phase to form magnetic poles.

In this structure, the rotary electric machine has four arc-shaped permanent magnets 3, the iron core 5 is formed in an arc shape so as to sandwich the permanent magnets 3, and the end plate 6 is provided. To Further, the iron core 5 and the permanent magnet 3 may be adhered to each other so as not to fall apart. Further, the rotor 1 is formed by penetrating the shaft 4 and is internally mounted in a separately formed stator core 9 via a frame 11 to complete a rotating electric machine.

In such a rotary electric machine, since the magnetic flux generated from the permanent magnet 3 has a large surface area of the permanent magnet 3 and is magnetized in the surface direction, the magnetic flux generated from the surface of each permanent magnet 3 is generated. It will be accumulated on the outer periphery of the iron core 5. Then, N and S magnetic poles are formed on the outer periphery of the rotor core 2 as shown in FIG.

The rotor 1 which generates such a magnetic flux is shown in FIG.
As shown in FIG. 4, when it is installed in the stator core 9, the magnetic flux generated from the stator core 9 attracts or repels to rotate. For this reason, the rotor 1 moves in the rotation direction by the magnetic poles of the stator core 9 formed when the U, V, and W phases are energized from the control circuit (not shown) in the stator core 9, and the rotor 1 moves by the position detector (not shown). The U-, V-, and W-phases of the stator core 9 are switched to act to rotate the rotor 1.

At this time, if the axial length of the rotor 1 is longer than that of the stator core 9, the magnetic flux generated from the permanent magnets 3 of the rotor 1 or the stator core 9 to the rotor. The magnetic fluxes flowing in the permanent magnets No. 1 respectively flow through the outer peripheral side of the iron core 5 of the rotor 1. in this case,
The iron core 5 has extremely small magnetic resistance, and even if the width of the stator core 9 is smaller than the width of the rotor 1, magnetic flux is extremely small between the rotor core 2 and the stator core 9 via the rotor core 2. Flow with loss.

[0020]

According to the present invention, arc-shaped permanent magnets are radially embedded in the rotor core to accumulate high-density magnetic flux on the outer periphery of the rotor, which effectively acts on the stator core. It is possible to form a small rotor with a high magnetic flux density using materials such as ferrite without using expensive materials such as rare earths, and the effect on miniaturization and manufacturing of rotating electrical machines is extremely large. is there.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing a rotor core of a rotary electric machine according to an embodiment of the present invention.

2 is a perspective view of the rotor core shown in FIG. 1. FIG.

FIG. 3 is a longitudinal sectional view of a main part of a rotary electric machine showing a structure of an embodiment of the rotary electric machine according to the present invention.

FIG. 4 is a plan view of an essential part showing the structure of the winding of the stator core.

FIG. 5 is a plan view of an essential part showing a state in which a winding is wound around a stator core.

FIG. 6 is a plan view of a stator core around which a winding is wound.

[Explanation of symbols]

 1 ...... Rotor 2 ...... Rotor iron core 3 ...... Permanent magnet 4 ...... Shaft 5 ...... Iron core 7 ...... Groove 9 ...... Stator iron core 10 ...... Winding

Claims (1)

[Claims] 1. A rotating electric machine comprising a rotor made of permanent magnets inside a stator core, wherein arc-shaped permanent magnets are radially embedded in the rotor core, and the permanent magnets are magnetized in a plane direction. Characteristic rotating electric machine.