JP2018196216A - Built-in type permanent magnet motor - Google Patents

Abstract

To provide a built-in type permanent magnet motor capable of reducing magnetic flux leakage, the cogging torque, and noise while improving control accuracy.SOLUTION: A rotator 20 includes a core part 21, a plurality of housing grooves 22, and a plurality of non-magnetic parts 23. The plurality of housing grooves 22 are provided onto the core part 21 with an equivalent angle interval as a center of a curvature of the rotator 20. Magnetic portions having an optimal predetermined minimum thickness are provided in gaps of the plurality of non-magnetic parts 23 forming pairs interposed inside a paraxial end of a permanent magnet 30 arranged in a radial manner.SELECTED DRAWING: Figure 1

Description

The present invention relates to a motor, and more particularly to a built-in permanent magnet motor.

In recent years, the adoption of built-in magnet technology has become more popular in rotary motors, and since the magnet is located in the silicon steel plate of the rotor, it can prevent the magnet from falling out and reduce the risk of magnet demagnetization. Since there is a drawback of magnetic flux leakage, in the technical field of rotors with built-in magnets, we are intensively studying techniques for reducing magnetic flux leakage.

Specifically, in order to reduce magnetic flux leakage, as a prior art aiming to reduce magnetic flux leakage, a symmetrical irregular pentagonal concave groove is installed on the paraxial end side of the radial built-in rotor magnet. Disclosed in EP2201663B1 disclosed in European Patent Office, or Japanese Patent JP3425176B2 in which a symmetrical triangular groove is installed on the paraxial end side of a magnet of a built-in radial rotor Japanese Patent No. JP5954279B2 in which the flat portion of the flattening surface is installed on the far-axis end side of the magnet of the developed rotor technology or the radial built-in rotor.

However, although the above-mentioned conventional technology can reduce magnetic flux leakage, the effect is not sufficient and there is room for improvement.

Therefore, a main object of the present invention is to provide a built-in permanent magnet motor that can reduce magnetic flux leakage, reduce cogging torque, improve control accuracy, and reduce noise.

In order to achieve the above object, in the built-in permanent magnet motor provided by the present invention, the permanent magnet motor is provided between a pair of non-magnetic portions interposed inside the paraxial ends of the radially arranged permanent magnets, and permanently. Magnetic portions each having an appropriate predetermined minimum thickness are provided outside the far-axis end of the magnet.

The built-in permanent magnet motor includes a stator, a rotor, and a plurality of permanent magnets. Further, the rotor is located within the stator, has an air gap distance (H) between the rotor and the stator, and the core portion and the core portion are arranged at equiangular intervals around the center of curvature of the rotor. Are disposed at one end corresponding to the center of curvature of the rotor in each of the storage grooves, and symmetrically disposed around the center line of each of the storage grooves. A plurality of nonmagnetic portions. The core portion is interposed between two adjacent nonmagnetic portions between two permanent magnets, and has a plurality of first distances (D1) that satisfy the following formula I: H ≦ D1 ≦ (4 * H) The first magnetic part is included. Each permanent magnet is installed in each storage groove.

Also, the two corners near the center of curvature of each permanent magnet are located within the two adjacent nonmagnetic parts.

In addition, it is preferable that each first magnetic part has a first distance, and two adjacent nonmagnetic parts include edges parallel to each other.

Moreover, it is preferable that only a part of the first magnetic portion has the first distance, and two adjacent nonmagnetic portions include arc-shaped edges.

Moreover, it is preferable that a core part contains the some recessed part respectively corresponding to each permanent magnet, and has an end point in the bottom part of each recessed part.

The core portion is interposed between each permanent magnet and the circumferential annular surface of the core portion, defined by each permanent magnet and the end point, and the following formula II: (H−0.15MM) ≦ A plurality of second magnetic parts having a second distance (D2) satisfying D2 ≦ (2 * H) are included.

The second distance is the shortest distance between the permanent magnet and the circumferential annular surface of the core portion.

It is sectional drawing of the radial direction of one Example of this invention. FIG. 2 is an enlarged view of a part of an area A in FIG. 1. FIG. 2 is an enlarged view of a part of a region B in FIG. 1. It is a figure which shows the magnetic force line of one Example of this invention. It is a partial schematic diagram of the other Example of this invention.

Reference is made to FIG. 1 showing a radial cross-sectional view of one embodiment of the present invention. The built-in permanent magnet motor includes a stator (10), a rotor (20), and a plurality of permanent magnets (30). The rotor (20) is housed in the stator (10) and has an air gap distance (H) between the rotor (20) and the stator (10). The plurality of permanent magnets (30) are installed on the rotor (20).

The rotor (20) includes a core portion (21), a plurality of storage grooves (22), and a plurality of nonmagnetic portions (23). A core part (21) is laminated | stacked with the sheet | seat which consists of magnetic materials. The plurality of storage grooves (22) are provided on the core portion (21) at equiangular intervals with the center of curvature of the rotor (20) as the center. The plurality of nonmagnetic portions (23) are arranged at one end corresponding to the center of curvature of the rotor (20) in each storage groove (22) in a pair, and each pair of nonmagnetic portions (23) is a storage groove. They are arranged symmetrically around the center line (22).

More specifically, each storage groove (22) is a rectangular storage groove, and each pair of nonmagnetic portions (23) is near the center of curvature of the rotor (20) of the respective rectangular storage groove (22). Arranged at two corners. The permanent magnets (30) are respectively installed in the storage grooves (22), and the two corners of the paraxial end (31) near the center of each permanent magnet (30) are adjacent to the nonmagnetic part (23) adjacent to each other. Can be located in the space between.

1 and FIG. 2 that is an enlarged view of a part of the area A in FIG. 1 and FIG. 3 that is an enlarged view of a part of the area B in FIG. The core part (21) includes a plurality of first magnetic parts (211) and a plurality of second magnetic parts (212).

Each first magnetic part (211) is interposed between two adjacent nonmagnetic parts (23) between two permanent magnets (30) and has a first distance (D1). Since the first distance (D1) is defined by the mutually parallel edges of the two adjacent nonmagnetic portions (23), the distance between the two adjacent nonmagnetic portions (23) is all the same first Distance (D1).

Each second magnetic portion (212) is interposed between each permanent magnet (30) and the circumferential annular surface of the core portion (21), and each permanent magnet on the circumferential annular surface of the core portion (21). There is a recess (24) at a location corresponding to (30) and an end point (P) at the bottom of the recess (24). Each second magnetic part (212) is defined by a far-axis end (32) and an end point (P) of each permanent magnet (30), and a circumferential circle of each permanent magnet (30) and core part (21). It has the 2nd distance (D2) which is the shortest distance between ring surfaces.

In this embodiment, the first distance (D1) of each first magnetic part (211) satisfies the following formula I, that is, not less than the air gap distance (H) and not more than four times the air gap distance (H). At the same time, the second distance (D2) of each second magnetic part (212) satisfies the following formula II, that is, the air gap distance (H) minus 0.15MM or more and twice the air gap The distance (H) or less.
Formula I: H ≦ D1 ≦ (4 * H)
Formula II: (H−0.15MM) ≦ D2 ≦ (2 * H)

Reference is made to FIG. 4 showing magnetic field lines of an embodiment of the present invention. 4, since both the first magnetic part (211) and the second magnetic part (212) have two or less magnetic lines of force, the first magnetic part (211) and the second magnetic part (211) The effect of reducing magnetic flux leakage due to the design of the second magnetic part (212) will be apparent. At the same time, when trying to compare with specific numerical values, as shown in the following table, the present embodiment is more effective than the conventional JP5954279B2.

In the above embodiment, the description has been given by taking 10 polar as an example. However, the number of polar zones does not limit the present invention and does not affect the effect of the present invention. For example, the number of magnetic field regions is 4 poles or 8 poles. The effect of the present invention can be realized even with a pole or the like.

Reference is made to FIG. 5, which shows a schematic diagram of a portion of another embodiment of the present invention. In this embodiment, each first magnetic part (211A) is interposed between two adjacent nonmagnetic parts (23A) between two permanent magnets (30A), and two adjacent nonmagnetic parts ( The edge of 23A) is arcuate. Therefore, the first distance (D1) is the shortest distance between two adjacent nonmagnetic portions (23A), and is not less than the air gap distance (H) and not more than four times the air gap distance (H). Even if the nonmagnetic portion (23A) of the present embodiment has a different shape, the same effect as described above can be realized if the first distance (D1) satisfies the same condition as described above. Even if the shape of the magnetic part is changed, the effect of the present invention is not affected.

Claims (10)

A stator,
A core portion and a plurality of storage grooves provided on the core portion at equal angular intervals around the center of curvature of the rotor, respectively, and a center of curvature of the rotor in each of the storage grooves in pairs And a plurality of nonmagnetic parts arranged symmetrically with respect to the center line of each of the storage grooves, and located within the stator and between the stator A rotor having an air gap distance (H) in
In each of the built-in permanent magnet motors including a plurality of permanent magnets installed in each of the storage grooves,
The core portion includes a plurality of first magnetic portions interposed between two adjacent nonmagnetic portions between the two permanent magnets and having a first distance (D1) that satisfies the following formula I: A built-in permanent magnet motor.
Formula I: H ≦ D1 ≦ (4 * H) 2. The built-in permanent magnet motor according to claim 1, wherein two corners near the center of curvature of each permanent magnet are located in the two adjacent nonmagnetic parts. The built-in permanent magnet motor according to claim 1, wherein each of the first magnetic portions has the first distance. The built-in permanent magnet motor according to claim 3, wherein the two adjacent nonmagnetic parts include edges parallel to each other. 2. The built-in permanent magnet motor according to claim 1, wherein only a part of the first magnetic portion has the first distance. 6. The built-in permanent magnet motor according to claim 5, wherein the two adjacent nonmagnetic parts include arcuate edges. The built-in permanent magnet motor according to claim 1, wherein the core portion includes a plurality of concave portions respectively corresponding to the permanent magnets. The built-in permanent magnet motor according to claim 7, wherein an end point is provided at the bottom of each of the recesses. The core portion is interposed between each of the permanent magnets and a circumferential annular surface of the core portion, and is defined by each of the permanent magnets and the end point, and satisfies a second distance ( The built-in permanent magnet motor according to claim 8, comprising a plurality of second magnetic parts having D2).
Formula II: (H−0.15MM) ≦ D2 ≦ (2 * H) 10. The built-in permanent magnet motor according to claim 9, wherein the second distance is a shortest distance between each permanent magnet and a circumferential annular surface of the core portion.