JPS6048989B2 - Permanent magnet rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a permanent magnet rotating electrical machine having a permanent magnet in a rotor, and particularly to a permanent magnet rotating electrical machine suitable for implementation in a synchronous machine.

The figure shows a four-pole machine, and the present invention will be explained with reference to this figure. The same number of permanent magnets 1a to 1d as the number of poles, that is, four permanent magnets are provided. The number of permanent magnets is the same as the number of poles, so it is an even number. Each of the permanent magnets 1a to 1d has a first magnetic pole surface a indicating a north pole and a second magnetic pole surface indicating an south pole, and a first side portion c between the two magnetic pole surfaces. It has a second side part d. The width of the first magnetic pole face a and the second magnetic pole face b is longer than the first side part C) and the second side part d, and
The distance between the first magnetic pole surface a and the second magnetic pole surface b is made smaller as the side portion d is approached. These permanent magnets 1a to 1d are placed around a rotating shaft 2 with a distance 3 between the first side c and the second side d of the first magnetic pole surface a or the second magnetic pole surface of another permanent magnet. Arrange them at equal intervals so that they face each other. In other words, taking the permanent magnet 1a as an example, the first side c of the permanent magnet 1a is connected to the first side c of the other permanent magnet 1d.
It is opposed to the portion of the magnetic pole face a near the second side face d with an interval of 3 therebetween. Taking the permanent magnet lb as an example, the first side surface c of the permanent magnet lb is opposed to a portion of the second magnetic pole surface b of another permanent magnet 1a close to the second side surface d with a gap of 3 therebetween. Thereafter, the permanent magnets 1a to 1d are arranged at equal intervals around the rotating shaft 2 in this manner. The distance 3 is made to increase as it approaches the second side d from the position of the first side c. 4 is a rotor core.

This is the same number of segments 4a to 4 as permanent magnets 1a to 1d.
d and configure. Segments 4a and 4b14b and 4C14
Magnetic resistance is made larger between C and 4d and between 4d and 4a than between stator core 5, which is indicated by a virtual line. Therefore, slits 8 and 9 are provided between both segments, leaving a slight bridge 6 and 7. The bridges 6 and 7 are provided to facilitate assembly of the rotor core 4 and as a countermeasure against centrifugal force, so they are not necessarily provided. Storage portions 10a to 10d for storing the permanent magnets 1a to 1d are provided between adjacent segments, that is, between 4a, 4b, 14b, 4c, 4d, and 4d and 4a, and the permanent magnets 1 are placed therein.
A to 1d are stored respectively. Each of the segments 4a to 4d is brought close to the same magnetic pole surface among the first magnetic pole surfaces a1 and the second magnetic pole surfaces b of the permanent magnets 1a to 1d adjacent in one direction. Specifically, this means that, for example, the segment 4a is placed close to the first magnetic pole surface a of the permanent magnets 1a and 1d. For example, if we look at the magnetic flux generated from the permanent magnet 1a, the magnetic path of the magnetic flux coming out near the second side d is shown by 11a, and the magnetic path of the magnetic flux coming out near the first side c. becomes as shown by 11b.

It is clear from this figure that the distance between the magnetic path 11b and the magnetic path 11a is long. Therefore, each of the permanent magnets 1a to 1 has a higher magnetic resistance in the magnetic path 11b than in the magnetic path 11a.
In order to bring the magnetic flux densities of the first and second magnetic pole surfaces A and b closer to the first side c and the second side d closer to each other, from the second side d to the first side The magnetomotive force of the permanent magnet must be increased as the value approaches c. Therefore, in the present invention, the dimension from the first magnetic pole surface to the second magnetic pole surface of the permanent magnet increases as it approaches the first side c from the second side d. Further, as is clear from the figure, the number of magnetic fluxes passing through the space 3 closer to the second side d is greater than the number of magnetic fluxes passing through the space 3 closer to the first side c.

Therefore, the width of the interval 3 also extends from the side where the first side c is located to the second side.
It is made to become larger as it approaches the side part d. This can be done by specifying the shape of the permanent magnet as described above. Note that the magnetization of the permanent magnet can be carried out after the permanent magnet material has been incorporated into the rotor core, or in a case where the magnetized material is assembled into the rotor core.

When the magnetized magnet is incorporated into the rotor core, only one type of permanent magnet is required if the permanent magnet is configured in a line-symmetrical trapezoidal shape.

[Brief explanation of the drawing]

The figure is a cutaway front view showing an embodiment of the permanent magnet rotating electrical machine of the present invention. 1a to 1d are permanent magnets, a is a first magnetic pole surface, b is a second magnetic pole surface, c is a first side portion, d is a second side portion, 2 is a rotating shaft, 3 is a spacing, 4 is a rotor core, 4a to 4d are segments, 5 is a stator core, and 10a to 10d are permanent magnet storage parts.

Claims (1)

[Scope of Claims] 1. The first magnetic pole surface and the second magnetic pole surface are longer than the first side portion and the second side portion located between the two magnetic pole surfaces, and the distance from the first side portion to the An even number of permanent magnets are arranged around a rotating shaft such that the distance between the first magnetic pole face and the second magnetic pole face decreases as the first side approaches the second side. are arranged at equal intervals so as to face a portion of the first magnetic pole face or the second magnetic pole face close to the second side surface with a space therebetween, and the distance is from the side where the first side portion is located to the portion near the second side surface of the second magnetic pole face. On the other hand, the rotor core is made up of the same number of segments as the permanent magnets, and the magnetic resistance between the segments is made larger than that between the segments and the fixed iron core, and the magnetic resistance between the adjacent segments is made larger. has a storage portion for storing the permanent magnet, and each segment is close to the same magnetic pole surface of the first and second magnetic pole surfaces of adjacent permanent magnets in one direction. Permanent magnet rotating electric machine. 2. The permanent magnet rotating electric machine according to claim 1, wherein the permanent magnet has a line-symmetrical trapezoidal shape.