JPH059149U - Permanent magnet rotor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a permanent magnet rotor that has few constituent parts, is easy to manufacture, and has high energy efficiency. [Structure] Permanent magnet pieces 3a, 3b, 3 for field magnets on the periphery
A large number of circular steel plates 4 having a plurality of permanent magnet one-piece openings 6 into which c and 3d are press-fitted are stacked to form a yoke 2, and the permanent magnet one-piece openings 6 are formed in the permanent magnet one-piece openings 6a, 3b, 3.
In the permanent magnet rotor into which c and 3d are press-fitted, each of the field permanent magnet pieces 3a, 3b, 3c, so that there is a space between the inner peripheral surface of the permanent magnet piece opening 6 and the outer peripheral surface of the yoke 2.
An escape groove 7 is provided on a part of the side surface of 3d.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a permanent magnet rotor in which a plurality of field permanent magnet pieces are incorporated inside the yoke of the rotor along the outer peripheral surface of the yoke.

[0002]

[Prior Art]

 Generally, a permanent magnet for field is arranged on the outer peripheral surface of the yoke, and a permanent magnet is integrally formed by shrink-fitting a yoke for holding a magnet piece made of a non-magnetic material on the outside of the yoke and the permanent magnet for field. The rotor is known. 5 and 6 show a conventional permanent magnet rotor in which the above-mentioned magnet piece holding can is shrink-fitted. FIG. 5 shows a side cross section of this permanent magnet rotor, and FIG. 6 shows a cross section thereof. A conventional permanent magnet rotor 11 in which a can for holding magnet pieces is shrink-fitted is a cylindrical yoke in which a large number of circular electromagnetic steel plates 13 having a rotary shaft opening 12 into which a rotary shaft is inserted are stacked. Have fourteen. Outside the yoke 14, field permanent magnet pieces 15a, 15b, 15c, and 15d having a fan-shaped cross section are arranged along the outer peripheral surface. As shown in FIG. 6, the field permanent magnet pieces 15a, 15b, 15c, 15d are arranged such that the outer side surfaces thereof are alternately N pole and S pole. A stainless steel can 16 for holding the magnet pieces is shrink-fitted on the outside of the permanent magnet pieces for field magnets 15a, 15b, 15c, 15d. At the open end of the stainless steel can 16, a side cover 17 for preventing foreign matter from entering is disposed. As shown in FIG. 5, the side cover 17, the stainless steel can 16 and the yoke 14 are integrally fastened by fastening bolts 18.

FIG. 7 is an exploded view of another conventional permanent magnet rotor. The conventional permanent magnet rotor 19 is composed of a yoke 20 and field permanent magnet pieces 21a, 21b, 21c and 21d. The yoke 20 is formed by integrally laminating a large number of electromagnetic steel plates 22. Each electromagnetic steel plate 22 has a rotary shaft opening 23 into which a rotary shaft is fitted, and a fan-shaped permanent magnet piece opening 24 into which the field permanent magnet pieces 21a, 21b, 21c, 21d are press fitted. have. The field permanent magnet pieces 21a, 21b, 21c, and 21d are formed in a fan shape in cross section, and as shown in the drawing, the openings 24 for permanent magnet pieces are formed so that the outer side surfaces alternately show magnetism of N pole and S pole. Has been pressed into. By incorporating the permanent magnet pieces 21a, 21b, 21c, and 21d for the field into the yoke 20 as described above, the permanent magnet rotor 19 has the N pole and the S pole alternately arranged in the circumferential direction as shown in FIG. It has a pole pole part.

[0004]

[Problems to be solved by the device]

 However, the conventional permanent magnet rotor fitted with the above-mentioned stainless steel can has a yoke and a permanent magnet piece for the field as well as a stainless steel can and a side cover for holding the magnet piece as the components, and the number of components Therefore, the structure is complicated and it is not preferable in manufacturing. Also, since the thickness of the field permanent magnet pieces arranged on the outer peripheral surface of the yoke is not always uniform, when the stainless steel can is fitted on the outer side of the field permanent magnet piece, the outer circumference of the stainless can can be fitted. The surface becomes a distorted cylindrical surface, or the cylindrical surface is eccentric from the rotation axis of the permanent magnet rotor. For this reason, in this conventional permanent magnet rotor, after the stainless can is fitted on the outer side of the permanent magnet piece for field, the outer peripheral surface of the stainless can is cut to obtain the roundness of the outer peripheral surface. ing. However, such processing requires high processing accuracy, and the whole manufacturing process of the permanent magnet rotor becomes complicated and difficult. Furthermore, in a conventional permanent magnet rotor with a stainless steel can fitted therein, high-frequency eddy currents are induced on the surface of the stainless steel can during the rotation of the permanent magnet rotor, resulting in energy loss. There is a problem that the efficiency of the motor using the conventional permanent magnet rotor is low due to the energy loss due to the eddy current.

On the other hand, the above-mentioned conventional permanent magnet rotor in which the permanent magnet pieces are press-fitted inside the yoke formed by stacking the steel plates avoids the problems of the conventional permanent magnet rotor in which the stainless steel can is fitted. However, on the other hand, the permanent magnet piece and the opening for the permanent magnet piece must be formed so as to be accurately aligned with each other, which makes processing difficult. In addition, since the permanent magnet piece generally uses a sintered molded ferrite magnet, there is a problem that the permanent magnet piece is damaged by the compressive force when it is press-fitted into the opening for the permanent magnet piece. Even if the permanent magnet piece was not damaged, a large compression force was required to press it in, and manufacturing was difficult.

Therefore, an object of the present invention is to provide a permanent magnet rotor that is easy to manufacture, has high energy efficiency, and has a simple structure.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the permanent magnet rotor of the present invention has a yoke formed by stacking a large number of circular electromagnetic steel plates each having a plurality of openings for permanent magnet pieces for press-fitting a permanent magnet piece for a field at its peripheral portion. In the permanent magnet rotor in which the field permanent magnet piece is press-fitted into the permanent magnet piece opening, there is a space between the inner peripheral surface of the permanent magnet piece opening and the outer peripheral surface of the yoke. It is characterized in that an escape groove is provided in a part of the side surface of each permanent magnet piece for field.

[0008]

[Action]

 The permanent magnet rotor of the present invention has a yoke formed by laminating a large number of electromagnetic steel sheets, and is formed by press-fitting the permanent magnet piece for field into the opening for permanent magnet piece of this yoke. At least a part of the side surface of the field permanent magnet piece is provided with a relief groove for reducing the compression force so that a space is present between the opening and the inner peripheral surface of the permanent magnet piece opening. Since the relief groove is provided on the side surface of the permanent magnet piece for field magnet, the contact area between the opening for permanent magnet piece and the permanent magnet piece for field magnet is small, and the permanent magnet piece for field magnet is yoked with a small compressive force. Can be pressed into. Since it is possible to press the permanent magnet piece for field magnet into the yoke with a small compressive force, it is possible to prevent the permanent magnet piece for field magnet from being damaged during press-fitting. Further, since the field magnet permanent magnet piece can be slightly deformed by press-fitting by the escape groove, adjustment processing of the press-fitting margin of the field magnet permanent magnet piece is easy. Further, since the yoke of the permanent magnet rotor of the present invention is formed by laminating a large number of electromagnetic steel plates, the conductors forming the yoke are divided into small widths in the axial direction. When this permanent magnet rotor rotates, an eddy current is induced in the yoke. The magnitude of this eddy current is small in proportion to the width of the conductor, and the energy loss is small.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an exploded view of a part of the permanent magnet rotor of the present invention. The permanent magnet rotor 1 is composed of a yoke 2 and field permanent magnet pieces 3a, 3b, 3c, 3d. The yoke 2 is formed by integrally laminating a large number of electromagnetic steel plates 4. Each electromagnetic steel plate 4 is composed of a circular steel plate having an insulating coating on its surface, and this circular steel plate has a rotary shaft opening 5 into which a rotary shaft is inserted and inserted in the central portion, and a permanent magnet piece for field magnetism in the peripheral portion. Concentric with fan-shaped permanent magnet piece openings 6 into which 3a, 3b, 3c, 3d are press-fitted. On the other hand, the field permanent magnet pieces 3a, 3b, 3c, 3d have a fan-shaped cross section so as to be aligned with the opening 6 for the permanent magnet piece of the yoke 2, and have an outer peripheral surface and an inner peripheral surface. And are magnetized so as to become respective magnetic poles. Of these permanent magnet pieces for field magnets, the permanent magnet pieces 3a and 3c are magnetized so that the outer peripheral surface exhibits N-pole magnetism, and the permanent magnet pieces 3b and 3d have the outer peripheral surface exhibiting S-pole magnetism. There is. These permanent magnet pieces 3a, 3b, 3c, 3d are press-fitted into the permanent magnet piece openings 6 so that the outer side surfaces thereof alternately exhibit N-pole and S-pole magnetism. As a result, the permanent magnet rotor 1 has magnetic pole portions of N poles and S poles alternately in the circumferential direction, as shown in FIG. FIG. 2 shows a cross section taken along line I--I of FIG. As is apparent from FIGS. 1 and 2, each of the field permanent magnets 3a, 3b, 3c, 3d has an escape groove 7a, which reduces the compressive force for pressing the field permanent magnet piece into the yoke, on the inner side surface. 7b, 7c and 7d are provided in the circumferential direction of the rotor. In FIG. 2, the permanent magnet pieces for field magnets 3a and 3c are provided with escape grooves 7a and 7c on the inner side surface, and the escape grooves 7a and 7c are provided on the inner peripheral surface of the opening 6 for permanent magnet pieces. Not in contact.

Next, the operation of the permanent magnet rotor 1 of the present invention will be described based on the above structure. To manufacture the permanent magnet rotor 1 of the present invention, a yoke 2 is formed by laminating a large number of electromagnetic steel plates 4 each having a rotary shaft opening 5 and a permanent magnet piece opening 6, and the permanent magnet piece of the yoke 2 is formed. Field permanent magnet pieces 3a, 3b, 3c, 3d are press-fitted into the opening 6 so that the outer side surfaces thereof alternately show N-pole and S-pole magnetism. Since the permanent magnet pieces for field magnets 3a, 3b, 3c, 3d are provided with escape grooves having a space between them and the inner peripheral surface of the opening 6 for permanent magnet pieces on a part of the inner side surface thereof. The compressive force for press-fitting the field magnet permanent magnet piece 3 has a reduced frictional resistance corresponding to the surface area provided with the escape groove. As a result, the compressive force for press-fitting the field permanent magnet pieces 3a, 3b, 3c, 3d can be reduced, and the field permanent magnet pieces 3a, 3b, 3c, 3d can be damaged by the compressive force. There is no. Further, since the field permanent magnet piece 3 of the present invention can be slightly deformed by the escape groove during press fitting, the work of adjusting the press fitting margin of the field permanent magnet piece 3 requires only a small surface area to be processed. In addition, high processing accuracy is not required at the portions where the escape grooves 7a, 7b, 7c, 7d are provided. ..

Further, the permanent magnet rotor 1 of the present invention comprises the yoke 2 and the field permanent magnet pieces 3a, 3b, 3c, 3d, and has a small number of components and a simple structure. 1 is extremely easy to manufacture. Further, according to the permanent magnet rotor 1 of the present invention, since the field permanent magnet pieces 3a, 3b, 3c, 3d are completely incorporated inside the yoke 2, the permanent magnet rotor 1 rotates at a high speed. The permanent magnet pieces for field use will not scatter.

Further, according to the permanent magnet rotor 1 of the present invention, since the yoke 2 is formed by laminating the electromagnetic steel plates 4 having the insulating coating on the surface thereof, it is induced by the rotation of the permanent magnet rotor 1. The eddy current generated is small. This is because the magnitude of the eddy current is proportional to the width of the conductor that the eddy current crosses.

3 and 4 show another embodiment of the permanent magnet rotor 1 of the present invention. 3 and 4, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals. FIG. 3 shows an exploded view of a part of this embodiment. FIG. 4 shows the upper end surface of the permanent magnet rotor 1 according to this embodiment. As is apparent from FIGS. 3 and 4, the permanent magnet rotor 1 of this embodiment has escape grooves 7a, 7b, 7c and 7d on the inner side surfaces of the field permanent magnet pieces 3a, 3b, 3c and 3d. It is provided in the longitudinal direction. By providing the escape groove 7 in this manner, the field permanent magnet pieces 3a, 3b, 3c, 3d can be press-fitted with a uniform compression force from the start to the end of the press-fitting process.

[0014]

[Effect of the device]

 As is apparent from the above description, in the permanent magnet rotor of the present invention, a yoke is formed by laminating a large number of circular electromagnetic steel plates having a plurality of openings for press-fitting the permanent magnet pieces for field magnets in the peripheral portion. , The field permanent magnet pieces are press-fitted into the permanent magnet piece openings, and the side surfaces of the field magnet permanent magnet pieces are arranged so that a space exists between the inner peripheral surface of the permanent magnet piece openings and the outer peripheral surface of the yoke. Since the relief groove is provided in at least a part of the above, the contact area between the permanent magnet piece opening and the field magnet permanent magnet piece is small, and the field magnet permanent magnet piece can be pressed into the yoke with a small compressive force. .. As a result, it is possible to prevent the permanent magnet piece for field magnet from being damaged during press fitting.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view of a permanent magnet rotor according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a permanent magnet rotor according to an embodiment of the present invention.

FIG. 3 is a partially exploded perspective view of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 4 is a plan view of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 5 is a side sectional view of a conventional permanent magnet rotor in which a can for holding a permanent magnet piece is fitted.

FIG. 6 is a plan view of a conventional permanent magnet rotor in which a can for holding a permanent magnet piece is fitted.

FIG. 7 is a partially exploded perspective view of a conventional permanent magnet rotor in which a permanent magnet piece for field magnet is press-fitted into a yoke.

[Explanation of symbols]

 1 permanent magnet rotor 2 yoke 3a field permanent magnet piece 3b field permanent magnet piece 3c field permanent magnet piece 3d field permanent magnet piece 4 electromagnetic steel plate 6 permanent magnet piece opening 7a escape groove 7b escape groove 7c escape groove 7d escape groove

Claims (1)

[Claims for utility model registration] 1. A yoke is formed by laminating a large number of circular electromagnetic steel plates having a plurality of openings for permanent magnet pieces for press-fitting the permanent magnet pieces for field magnets in the peripheral portion, In a permanent magnet rotor for press-fitting a field permanent magnet piece into the permanent magnet piece opening, each field permanent piece is arranged such that a space is present between the inner peripheral surface of the permanent magnet piece opening and the outer peripheral surface of the yoke. A permanent magnet rotor characterized in that a relief groove is provided on a part of a side surface of the magnet piece.