JP2021058040A - Rotor of SPM type rotary electric machine - Google Patents

Abstract

To provide a rotor of SPM type rotary electric machine having a relatively simple structure such that a permanent magnet is exposed on the outer circumference of a rotor core capable of stably fixing the permanent magnet and improving the reliability.SOLUTION: The rotor of SPM (surface permanent magnetic) type rotary electric machine in an embodiment has multiple slots each open to the outer circumference on the outer circumference of the rotor core, and is configured so that in each of these slots, a permanent magnet is placed so that it protrudes from the outer peripheral surface of the rotor core. Inside the slot of the rotor core, the bottom is flat, both sides facing the circumferential direction are inclined to make an acute angle with respect to the bottom surface, and the angle θ between the side surface and the bottom surface is 65°-75°.SELECTED DRAWING: Figure 1

Description

An embodiment of the present invention relates to a rotor of an SPM type rotary electric machine.

For example, an SPM (Surface Permanent Magnet) type motor is known as a motor used as a drive source for an elevator hoist (see, for example, Patent Document 1). The rotor of this type of SPM type motor is provided on the outer peripheral portion of the rotor core so as to be arranged in the circumferential direction so as to open a plurality of slots on the outer peripheral surface, and a permanent magnet is provided in each of the slots. It is housed and fixed by adhesive with an adhesive. In this case, the surface of the permanent magnet, that is, the outer peripheral surface is exposed and placed close to the stator, so that a large driving torque or a braking torque at the time of dynamic braking can be generated.

Japanese Unexamined Patent Publication No. 2016-134931

In the rotor of the SPM type motor as described above, the fixing strength of the permanent magnet decreases due to deterioration of the adhesive due to long-term use, and the action of centrifugal force during rotation and magnetic imbalance during emergency braking For example, it is conceivable that a part of the permanent magnet may be separated from the slot in the outer peripheral direction. Therefore, it is required to improve the reliability of fixing the permanent magnet. The above-mentioned Patent Document 1 discloses that a tape member for preventing scattering is provided in order to prevent the permanent magnet from peeling off. However, in the configuration in which the tape member is provided, the number of parts and the assembling process are increased.

Therefore, the permanent magnet is provided so as to be exposed on the outer periphery of the rotor core, and the permanent magnet can be stably fixed while having a relatively simple configuration, and the reliability can be improved. Provided is a rotor of an SPM type rotary electric machine capable of being capable of providing a rotor.

The rotor of the SPM type rotary electric machine according to the embodiment has a plurality of slots opened on the outer peripheral side on the outer peripheral portion of the rotor core, and a permanent magnet is placed in each of the slots from the outer peripheral surface of the rotor core. The inner surface of the slot of the rotor core is arranged in a protruding form, and the bottom surface is a flat surface, and both side surfaces facing the circumferential direction are inclined surfaces having a sharp angle with respect to the bottom surface. At the same time, the angle θ between the side surface and the bottom surface is set to 65 ° to 75 °.

It shows one embodiment, and is the vertical sectional view of a rotor. Cross-sectional view schematically showing the overall configuration of the SPM type motor Enlarged sectional view of one slot portion Enlarged cross-sectional view of the disassembled state of one slot portion Further enlarged cross-sectional view showing the shape of the relief recess An enlarged cross-sectional view showing how the permanent magnets are moved to one side in the slot side by side for the cases where the angles θ are 70 °, 75 °, and 80 °, respectively.

Hereinafter, an embodiment applied to an SPM type motor used as a drive source for an elevator hoist, for example, will be described with reference to the drawings. For convenience, the hatching in FIGS. 1 and 3 to 6 is omitted. FIG. 2 schematically shows the overall configuration of the SPM type motor 1 as the SPM type rotary electric machine. The SPM type motor 1 includes a stator 3 and a rotor 4 in a frame 2 having a cylindrical shape as a whole. A rotating shaft 5 is fixed to the rotor 4. The details of the rotor 4 will be described later.

The frame 2 is configured to include motor brackets 6 and 7 at both ends of a cylindrical body portion 2a. The stator 3 is configured by winding a winding 9 around a stator core 8 and is attached to the inner peripheral surface of the body portion 2a. Bearings 10 and 11 are attached to the motor brackets 6 and 7, respectively. The rotating shaft 5 is rotatably supported by the bearings 10 and 11. Although not shown, a pulley called a sheave is attached to the tip of the rotating shaft 5 (on the left side in the drawing). Further, a well-known disc brake device 12 for applying a braking force to the rotating shaft 5 is provided on the rear end side of the frame 2.

Here, the rotor 4 according to the present embodiment will be described with reference to FIGS. 1, 3 to 6. In the present embodiment, as shown in FIG. 2, the rotor 4 has a rotor block 15 formed by providing a plurality of, for example, 20 permanent magnets 14 on the outer peripheral portion of the rotor core 13 in an exposed state. It is configured by combining in a state of being stacked in four stages in the direction. The four rotor blocks 15 have the same configuration, and one rotor block 15 will be described below.

As shown in FIG. 1, the rotor core 13 is configured by, for example, punching an electromagnetic steel plate into a predetermined shape, that is, substantially a disk shape to obtain a unit core plate, and laminating a plurality of the punched unit core plates. ing. A central hole 13a into which the rotating shaft 5 is inserted is formed in the central portion of the rotor core 13. Then, on the outer peripheral portion of the rotor core 13, a plurality of slots 16 into which the permanent magnets 14 are mounted are arranged side by side in the circumferential direction with a slight interval between them, and in this case, 20 slots are provided. .. As shown in FIGS. 3 to 6, the slot 16 has a shape of opening to the outer peripheral side, has a concave shape with a relatively shallow depth, and is provided so as to extend in the entire axial direction of the rotor core 13.

The permanent magnet 14 is made of, for example, a neodymium magnet, and has a rectangular thin plate shape as shown in FIGS. 1 to 4, and has a gentle curved surface shape in which the upper surface, that is, the surface facing the outer peripheral side is convex toward the outer peripheral side. Has been done. The permanent magnet 14 is manufactured by cutting, for example, a rectangular block. As shown in FIG. 1, two types of the permanent magnet 14 are magnetized to the S pole on the outer peripheral surface side and magnetized to the N pole alternately in each of the slots 16 along the circumferential direction. Placed in. The permanent magnet 14 is adhered to the inner surface of the slot 16 with an adhesive (not shown). At this time, each permanent magnet 14 projects from the outer peripheral surface of the rotor core 13 to the outer peripheral side.

By the way, in this embodiment, each slot 16 of the rotor core 13 is configured as follows. That is, as shown in FIGS. 3 to 5, the inner surface of the slot 16 is an inclined surface in which the bottom surface 16a is a flat surface and the side surfaces 16b and 16b facing the circumferential direction form an acute angle with respect to the bottom surface 16a. As a result, the slot 16 is formed in a trapezoidal shape, that is, a dovetail shape. Then, as shown in FIG. 4, the angle θ formed by the side surface 16b and the bottom surface 16a is within the range of 65 ° or more and 75 ° or less, and here, for example, 70 °.

Further, in the present embodiment, as shown in detail in FIG. 5, each slot 16 has relief recesses 17 and 17 located at both corners of the bottom surface and where excess adhesive for adhering the permanent magnet 14 is accumulated. The rotor core 13 is formed so as to extend in the entire axial direction. The relief recesses 17 and 17 are formed in a rounded state so as to bulge downward on the inner peripheral side, that is, in FIG. At the stage of the unit core plate, a notch portion corresponding to the slot 16 including the relief recess 17 is formed at the same time as punching the unit core plate, for example, and by laminating the unit core plate, the relief recess 17 is included. A rotor core 13 having a slot 16 can be obtained.

The permanent magnet 14 arranged in the slot 16 has a flat bottom surface and both side surfaces that rise sharply at an angle θ, for example, 70 °, according to the shape of the slot 16, and the upper surface has an arcuate surface. It is composed of almost trapezoidal blocks. At this time, in order to insert and bond the permanent magnets 14 into the slots 16, a slight clearance of, for example, 0.3 mm or less is provided between them in consideration of the thickness and tolerance of the adhesive. Further, in manufacturing the permanent magnet 14, as described above, the permanent magnet 14 is formed into a predetermined shape by cutting the magnet material manufactured in the shape of a rectangular block.

When assembling the permanent magnet 14 to the rotor core 13, each permanent magnet 14 is shafted from the end face side of the rotor core 13 to each slot 16 with a required amount of adhesive applied to the inner surface of the slot 16. Insert in the direction and fix with adhesive. At this time, regarding the application of the adhesive, for example, the size of the application thickness is targeted to be 0.1 mm. However, even when the amount of the adhesive applied is large, the excess amount can be released to the recess 17. As shown in FIG. 2, four rotor blocks 15 are connected to form a rotor 4, and the surface, that is, the outer peripheral surface of each permanent magnet 14 of the rotor 4 has a slight gap in the stator core 8. It is located so as to face each other.

According to the rotor 4 of the present embodiment configured as described above, the following actions and effects can be obtained. In the above configuration, the slot 16 and the permanent magnet 14 are formed in a trapezoidal shape, that is, a dovetail shape along an acute-angled slope, and the trapezoidal side surface of the permanent magnet 14 is in a fitted state facing the side surface 16b of the slot 16. It is fixed. As a result, even if the fixing strength of the permanent magnet 14 is lowered due to deterioration of the adhesive due to long-term use, for example, the permanent magnet 14 is held on the side surface 16b of the slot 16 to prevent the permanent magnet 14 from coming off, and the slot 16 is prevented from coming off. It is possible to prevent the magnet from coming off in the outer peripheral direction.

In this case, even if there is some variation in dimensional accuracy between the slot 16 and the permanent magnet 14, the effect of preventing slipping out can be ensured. Since the shape of the slot 16 prevents the permanent magnet 14 from coming off, an extra member such as a tape member for preventing scattering is not required, and the number of parts and the assembling process are not increased. Here, the reason why the angle θ formed by the bottom surface 16a and the side surface 16b in the slot 16 is set to 65 ° to 75 ° will be described with reference to FIG.

That is, as described above, in order to insert and bond the permanent magnets 14 into the slots 16, a slight clearance of, for example, 0.3 mm or less is provided between them. In FIG. 6, when the angles θ are set to, for example, 80 °, 75 °, and 70 ° in order from the left, the adhesive force of the permanent magnet 14 decreases, and the permanent magnet 14 is relatively right in the slot 16 in the figure. It shows how it moved to. In this case, when the angle θ is relatively large, for example, 80 °, the side surface 16b of the slot 16 cannot be prevented from coming off, and the permanent magnet 14 may come off. However, when the angle θ is 75 ° or less, such a problem does not occur. From the viewpoint of preventing the permanent magnet 14 from coming off, it is desirable that the angle θ formed by the bottom surface 16a and the side surface 16b in the slot 16 is 75 ° or less.

On the other hand, if the angle θ is relatively small, for example, 45 °, the permanent magnet 14 can be reliably prevented from coming off, but the shape of the permanent magnet 14 also has an acute angle of 45 ° at both lower ends. In this case, in the process of manufacturing the permanent magnet 14, there are many parts to be discarded by cutting, and the size of the permanent magnet 14 itself in the width direction becomes large. Further, the sharper the acute angle, the more easily the corner portion of the permanent magnet 14 is chipped. From the viewpoint of manufacturing the permanent magnet 14, it is desirable that the angle θ is 65 ° or more.

As described above, according to the research of the present inventor, it is preferable that the angle θ formed by the bottom surface 16a and the side surface 16b on the inner surface of the slot 16 is a value in the range of 65 ° to 75 ° with 70 ° as the center value. It became clear. As a result, while the function of preventing the permanent magnet 14 from coming off can be reliably obtained, the disadvantage in terms of manufacturing the permanent magnet 14 is small, and it is possible to balance the two. As a result, according to the present embodiment, the permanent magnet 14 is provided so as to be exposed on the outer periphery of the rotor core 13, and the permanent magnet 14 can be stably fixed while the configuration is relatively simple. It can be done, and an excellent effect that reliability can be improved can be obtained.

Further, in particular, in the present embodiment, a relief recess 17 for collecting excess adhesive is provided at both end corners of the bottom surface 16a of the slot 16 of the rotor core 13. As a result, when the permanent magnet 14 is adhered, even if the amount of the adhesive applied is large, the excess can be released to the recess 17, so that the amount of the adhesive applied can be increased to obtain a sufficient adhesive force. It becomes. As a result, the reliability of the adhesive strength of the permanent magnet 14 can be further improved.

Here, the shape of the permanent magnet 14 is also such that the side surfaces rise sharply from both ends of the lower end portion, and the corner portions are in a relatively sharp state. As described above, by providing the relief recesses 17 at both end corners of the bottom surface 16a of the slot 16, the corners of the permanent magnet 14 are located in the vicinity of the relief recesses 17, so that the corners hit the inner surface of the slot 16. Can be suppressed. As a result, it is possible to obtain a function of preventing damage such as the corner portion of the permanent magnet 14 hitting another portion and being chipped.

In the above embodiment, the permanent magnets are arranged so as to extend parallel to the axial direction of the rotor core, but a so-called skew arrangement is performed in which the permanent magnets are arranged at an angle with respect to the axial direction of the rotor core. It may be configured. Further, the rotor core is not limited to a form in which a plurality of rotor blocks are combined, and may be composed of one iron core. Various changes can be made to the number and shape of slots and permanent magnets.

In addition, the application of the SPM type rotary electric machine is not limited to that of an elevator, and can be applied to various applications including a generator. The embodiments described above are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

In the drawing, 1 is an SPM type motor (SPM type rotary electric machine), 3 is a stator, 4 is a rotor, 5 is a rotating shaft, 13 is a rotor core, 14 is a permanent magnet, 15 is a rotor block, and 16 is a slot. , 16a is the bottom surface, 16b is the side surface, and 17 is the relief recess.

Claims (2)

A plurality of slots that open to the outer peripheral side are provided on the outer peripheral portion of the rotor core, and permanent magnets are arranged in each of the slots so as to protrude from the outer peripheral surface of the rotor core. hand,
The inner surface of the slot of the rotor core is a flat bottom surface, and both side surfaces facing the circumferential direction are inclined surfaces having an acute angle with respect to the bottom surface.
A rotor of an SPM type rotary electric machine in which the angle θ formed by the side surface and the bottom surface is 65 ° to 75 °. The rotor of the SPM type rotary electric machine according to claim 1, wherein relief recesses for collecting excess adhesive for adhering the permanent magnets are provided at both corners of the bottom surface of the slot of the rotor core.

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