JPH0731087A - Rotar of permanent magnet field type rotating electric machine - Google Patents

Abstract

PURPOSE:To provide a rotor of a permanent magnet field type rotating electric machine in which number of pole pairs can be reduced by altering a simple structure, CONSTITUTION:A magnetic interval is so spaced as to become between normal different polarity poles by providing means for preventing a short-circuit of magnetic fluxes between a pair of adjacent poles, the interval is so approached by inhibiting to provide means for preventing a short-circuit of magnetic fluxes at the other end side of the poles, one pole is formed of a plurality of adjacent permanent magnet materials, and integer number of pole pairs are formed as a whole. In this case, slits 3A, 3B provided between slots of a rotor core or cutouts provided on an outer periphery of the core may be used as the means for preventing the short-circuit of the fluxes to be provided between the poles.

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 field type rotary electric machine such as a permanent magnet motor in which a permanent magnet material is press-fitted into a slot provided in a rotor core, and more particularly to D
The present invention relates to improvement of a rotor structure of an electric motor suitable for a compressor such as a C brushless motor.

[0002]

2. Description of the Related Art As a conventional rotor of this kind of electric motor, a first conventional rotor shown in FIGS. 5 (a) and 5 (b) is known. FIG. 5 is a plan view showing one of a large number of rotor iron cores that constitute an electric motor rotor. A large number of magnetic iron plates for the rotor are stacked and integrally caulked to form one electric motor rotor. climb. As shown in FIG. 5 (a),
The magnetic iron plate is provided with arcuate slots 1A to 1D, which will be described later, into which permanent magnet materials are to be press-fitted, along the outer circumference thereof, and the permanent magnet materials 2A to 2D are respectively arranged as shown in FIG. 5 (b). It is press-fitted into the slots 1A to 1D. Since this rotor is used for a four-pole motor, four permanent magnet materials are used, but slits 3A to 3D are provided for the purpose of preventing a short circuit of magnetic flux between the permanent magnet materials. There is. The slits 3A to 3D are intended to insulate the magnetic flux (prevent short circuit) by utilizing the high insulating property with respect to the magnetism of air. As a material for the permanent magnet material, a ferrite material, a rare earth-based sintered material, an alloy, or a rare earth-based plastic magnet can be used. The shaft of this rotor is press fitted into the shaft hole 4 by shrink fitting or the like. In addition,
A caulking rod (not shown) for integrally laminating and assembling a large number of rotor iron plates is inserted into a circular portion provided at the tip from the center of each slit.

As a second conventional example, FIG.
There are those shown in (a) and (b). FIG. 6A shows a linear slot 5A into which a permanent magnet material described later is to be press-fitted.
~ 5D are provided, and the linear permanent magnet material 6A ~
6D is press-fitted as shown in FIG. 6 (b). Since this rotor is used for a four-pole motor, four permanent magnet materials are used, but four notches are provided along the outer circumference for the purpose of preventing a short circuit of magnetic flux between the permanent magnet materials. 7A
~ 7D are provided. These notches are intended to prevent short-circuiting (insulation) of magnetic flux by utilizing the high insulation property of air by widening the distance between adjacent permanent magnet materials by the notches. Reference numeral 8 is a hole into which a caulking rod (not shown) for integrally laminating and assembling a large number of rotor iron plates is inserted.

[0004]

In the above-mentioned conventional example, when the number of revolutions of the motor is N, the number of poles is P, and the frequency is f, the number of revolutions N is represented by the equation N = 120f / P. Since the conventional example is a four-pole motor, a double frequency is required on the inverter circuit side in order to obtain the same motor rotation speed as compared with a two-pole motor, and therefore the chopping frequency is also doubled. Therefore, high-switching and high-cost transistors with good switching response are required for the inverter circuit, and increase in switching circuit loss leads to lower inverter conversion efficiency. There was a problem that the motor efficiency was lowered in order to obtain the sufficient amount. It is an object of the present invention to provide a rotor of a permanent magnet field type rotary electric machine that solves the above problems (problems) of the prior art.

[0005]

In order to solve the above-mentioned type problem, the present invention provides a means for preventing a magnetic flux from being short-circuited between a pair of magnetic poles adjacent to each other to provide a normal gap between different poles. The magnetic poles are spaced apart from each other, and on the other hand, the other ends of these magnetic poles are not provided with means for preventing a short circuit of the magnetic flux so that the magnetic gaps are close to each other, and a plurality of adjacent permanent magnet materials are provided. One magnetic pole is formed, and an integer number of pole pairs is formed as a whole. In this case, the means for preventing the short circuit of the magnetic flux may be constituted by a slit provided between the slots of the rotor core or a notch provided on the outer periphery of the rotor core.

[0006]

Since the means is provided between the pair of magnetic poles adjacent to each other and the means is not provided on the other end side of the magnetic pole, one magnetic pole is formed by a plurality of adjacent permanent magnet materials. , The total number of poles of the electric motor is, for example, 4
It is easily reduced from pole to pole.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first to fourth embodiments of the present invention will be described below in detail with reference to FIGS. (First Embodiment) FIG. 1 is a plan view showing a magnetic iron plate of a motor rotor according to a first embodiment of the present invention. In FIG. 5B, the configuration corresponding to the conventional one is shown in FIG.
The same reference numerals as those of No. 1 are attached. As shown in FIG. 1, in the first embodiment, the slit 3B provided as a means for preventing a short circuit of magnetic flux between the adjacent magnetic poles of the plurality of magnetic poles in the first conventional example.
And 3D is omitted, which is a characteristic of the configuration. Therefore, the provided slits 3A and 3C are arranged on a single radius passing through the center of the shaft hole 4 of the rotor. With such a structure, the permanent magnet members 2A and 2B and 2C and 2B are
Since the air gaps 3A and 3C are respectively provided between D, the magnetic flux is prevented from being short-circuited. However, since there is no air gap between the permanent magnet members 2B and 2C and between the permanent magnet members 2D and 2A, the magnetic flux is short-circuited to substantially 2 It becomes the rotor of the electric motor of the pole.

(Second Embodiment) FIG. 2 is a plan view of a magnetic iron plate showing a second embodiment of the present invention. In the present embodiment, the arcuate slots 1E, 1F are arranged over 180 °. Formed,
Two permanent magnet materials 9 matching the slots 1E, 1F
There is a structural feature in that A and 9B are press-fitted. In addition, other configurations are shown with reference numerals according to FIG. In this case, two permanent magnet materials 9A and 9B
A two-pole motor rotor is constituted by the following.

(Third Embodiment) FIG. 3 is a plan view of a magnetic iron plate showing a third embodiment of the present invention. The structure of the present embodiment is different from that of the second conventional example in that the notches 7A and 7C as means for preventing a short circuit of the magnetic flux between the adjacent magnetic poles of the plurality of magnetic poles are omitted. There are features. Therefore, in FIG. 3, components corresponding to those in the second conventional example are designated by the same reference numerals as those in FIG. The cutouts 7B and 7D provided are arranged on a single radius passing through the center of the shaft hole 4 of the rotor. With such a configuration, the permanent magnet members 6A and 6D and 6
The cutouts 7D and 7B prevent short-circuiting of the magnetic flux between B and 6C, respectively, but since there is no cutout between the permanent magnet members 6A and 6B and between 6C and 6D, the magnetic flux is short-circuited and substantially. It becomes a two-pole motor rotor.

(Fourth Embodiment) FIG. 4 is a plan view of a magnetic iron plate showing a fourth embodiment of the present invention. The structural feature of this embodiment is that the permanent magnet members 6B and 6D are omitted in the second conventional example and only two permanent magnet members 6A and 6C are provided. Note that the other configurations are shown with reference numerals according to FIG. In such a configuration, the permanent magnet material is 6
Since there are only A and 6C, the magnetic flux is not affected by the cutouts 7A to 7D, and it becomes a rotor of a two-pole electric motor. It should be noted that, in each of the above-described embodiments, the two-pole rotary electric machine has two
I explained about the case of reducing to a pole rotating electric machine,
For example, it is needless to say that the present invention can be applied to a rotary electric machine that reduces the number of poles from eight to four.

[0011]

As described above, according to the present invention, the means for preventing the short circuit of the magnetic flux is provided between the pair of magnetic poles, and the means is not provided at the other end side of the magnetic poles. With a simple structure, the number of poles of the electric motor can be easily reduced. As a result, the chopping frequency can be halved by changing from a 4-pole motor to a 2-pole motor, and the transistors and the like in the inverter circuit do not need high switching and high cost with good switching response. From the reduction of the switching circuit loss, the improvement of the inverter conversion efficiency and the improvement of the motor efficiency can be achieved.

[Brief description of drawings]

FIG. 1 is a plan view showing an electric motor rotor as a first embodiment of the present invention.

FIG. 2 is a plan view showing an electric motor rotor as a second embodiment of the present invention.

FIG. 3 is a plan view showing an electric motor rotor as a third embodiment of the present invention.

FIG. 4 is a plan view showing an electric motor rotor as a fourth embodiment of the present invention.

FIG. 5 shows a first conventional example, and FIGS. 5A and 5B are plan views of a rotor core of an electric motor and a rotor of the electric motor, respectively.

FIG. 6 shows a second conventional example, and FIGS. 6 (a) and 6 (b) are plan views of a rotor core of an electric motor and a rotor of the electric motor, respectively.

[Explanation of symbols]

 1A to 1D: Slots 2A to 2D, 6A to 6D, 9A, 9B: Permanent magnet material 3A, 3C: Slits 5A, 5C: Slots 7A to 7D: Notches

Claims (2)

[Claims] 1. In a rotor of a permanent magnet field type rotary electric machine in which a plurality of permanent magnet materials are press-fitted into a predetermined slot, means for preventing a short circuit of magnetic flux between a pair of magnetic poles adjacent to each other. To separate the magnetic gaps so that the magnetic poles are normally separated from each other.On the other hand, the other magnetic poles are not provided with means for preventing a short circuit of the magnetic flux on the other end side of the magnetic poles, thereby reducing the magnetic gap. A rotor of a permanent magnet field type rotary electric machine characterized in that a plurality of adjacent permanent magnet materials form one magnetic pole, and an integer number of pole pairs is formed as a whole. 2. The permanent magnet field type of claim 1, wherein the means for preventing the short circuit of the magnetic flux is a slit provided between slots of the rotor core or a notch provided on the outer periphery of the rotor core. Rotor of rotating electric machine.