Manufacturing method for rotor of SPM type rotating electric machine and rotor of SPM type rotating electric machine

Abstract

To attain simplification in assembly work of a permanent magnet and improve reliability in fixture of the permanent magnet in providing the permanent magnet in a slot in an outer periphery of a rotor core.SOLUTION: A manufacturing method of a rotor for an SPM type rotary electric machine according to an embodiment includes: a magnet inserting step of inserting a permanent magnet into a slot of a rotor core by providing engage parts to receive side faces of the permanent magnet while being positioned at both side parts of the slot in a circumferential direction and providing a pipe storage part so as to be spread over the two engage parts positioned between the slots, which are adjacent to each other in the circumferential direction, in an outer peripheral part of the rotor core; a pipe storage step of storing a pipe member which is plastically deformable and formed in a cylindrical pipe shape in the pipe storage part; and a pipe expanding step of expanding the diameter of the pipe member positioned in the pipe storage part. In the pipe expanding step, the diameter of the pipe member is expanded so as to be plastically deformed in such a manner that the engage parts are expanded outside in the circumferential direction, and the engage parts are press-contacted and fixed to the side faces of the permanent magnet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a manufacturing method for a rotor of an SPM type rotating electric machine, and a rotor of an SPM type rotating electric machine. [Background technology]

[0002] For example, SPM (Surface Permanent Magnet) type motors are known as motors used as drive sources for elevator hoists (see, for example, Patent Document 1). The rotor of this type of SPM type motor is configured by providing a number of slots, aligned in the circumferential direction, on the outer periphery of the rotor core so that they open on the outer periphery, with a permanent magnet housed in each slot and fixed in place with an adhesive. In this case, the surface of the permanent magnet, i.e., the outer periphery, is exposed and placed close to the stator, making it possible to generate a large driving torque or a large braking torque during dynamic braking. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-136514 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the rotor of the SPM motor described above, the permanent magnets are fixed with adhesive, so the installation of the permanent magnets requires the tedious process of applying adhesive inside the slots, inserting the permanent magnets, and then wiping off the excess adhesive.In addition, the adhesive deteriorates over long periods of use, reducing vibration absorption and potentially causing the permanent magnets to crack or become dislodged.

[0005] In the above-mentioned Patent Document 1, in order to prevent the permanent magnets from coming off, the protrusions located on both sides of the slots of the rotor core are bent and deformed so that they hook onto the outer periphery of the permanent magnets, preventing them from coming off. However, this configuration leads to an increase in the number of permanent magnet assembly steps. Furthermore, there are problems in that the protrusions of the core cover the entire side surface of the permanent magnets, which increases magnetic flux leakage between adjacent permanent magnets and reduces the fixing strength due to so-called springback.

[0006] Therefore, the present invention provides a manufacturing method for a rotor of an SPM type rotating electric machine, which has permanent magnets arranged in slots on the outer periphery of the rotor core, and which can simplify the assembly work of the permanent magnets and increase the reliability of the fixation of the permanent magnets, and a rotor for an SPM type rotating electric machine. [Means for solving the problem]

[0007] According to an embodiment, a manufacturing method for a rotor of an SPM type rotating electric machine is provided in an outer periphery of a rotor core, the outer periphery of which has a plurality of slots that open to the outer periphery, and in each of the slots, permanent magnets are arranged in a form that protrudes from the outer periphery of the rotor core, and the outer periphery of the rotor core is provided with engaging portions located on both circumferential sides of the slots to receive the side faces of the permanent magnets, and a pipe accommodating portion is provided so as to straddle two of the engaging portions located between two of the slots that are adjacent to each other in the circumferential direction. The manufacturing method includes a magnet insertion process for inserting the permanent magnets into the slots of the rotor core, a pipe accommodating process for accommodating the plastically deformable cylindrical pipe-shaped pipe member into the pipe accommodating portion, and an expansion process for expanding the diameter of the pipe member located in the pipe accommodating portion, and the diameter of the pipe member is expanded, thereby plastically deforming the engaging portions so as to expand them circumferentially outward, and the engaging portions are pressed against and fixed to the side faces of the permanent magnets.

[0008] The rotor of an SPM type rotating electric machine according to the embodiment has a plurality of slots on the outer periphery of a rotor core that open to the outer periphery, and within each of these slots, permanent magnets are arranged in a form that protrudes from the outer periphery of the rotor core. The outer periphery of the rotor core is provided with engaging portions located on both circumferential sides of the slots to receive the sides of the permanent magnets, and a pipe accommodating portion is provided spanning between two of the engaging portions located between adjacent slots in the circumferential direction. The plastically deformable cylindrical pipe-shaped pipe member is accommodated in an expanded state within the pipe accommodating portion, so that the engaging portions are plastically deformed so as to expand outward in the circumferential direction, and are pressed against the sides of the permanent magnets in the slots to fix the permanent magnets. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a longitudinal sectional view of a rotor according to an embodiment of the present invention. [Diagram 2] Cross-sectional view showing the overall structure of an SPM motor [Diagram 3] Enlarged cross-sectional view of one slot [Figure 4] Enlarged cross-sectional view of one slot of the rotor core before the permanent magnets are installed [Diagram 5] Exploded view of one slot [Figure 6] An exploded perspective view of the slot portion showing the expanding process [Figure 7] FIG. 1 is an enlarged cross-sectional view of a main part of a pipe member before it is expanded. [Figure 8] An enlarged cross-sectional view of the main part showing the state of the pipe member after it is expanded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment applied to an SPM motor used, for example, as a drive source for an elevator hoist will be described below with reference to the drawings. For convenience, hatching has been omitted in Fig. 1 and Figs. 3 to 8. Fig. 2 shows a schematic diagram of the overall configuration of an SPM motor 1 as an SPM rotating electric machine. This SPM motor 1 comprises a stator 3 and a rotor 4 within a frame 2 which is cylindrical overall. A rotating shaft 5 is fixed to the rotor 4. The rotor 4 will be described in detail later.

[0011] The frame 2 is configured with motor brackets 6, 7 on both ends of a cylindrical body 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 2a. Bearings 10, 11 are attached to the motor brackets 6, 7, respectively. The rotating shaft 5 is rotatably supported by these bearings 10, 11. Although not shown, a pulley called a sheave is attached to the tip end (left side in the figure) of the rotating shaft 5. A well-known disc brake device 12 that applies a braking force to the rotating shaft 5 is provided on the rear end side of the frame 2.

[0012] Here, the rotor 4 according to this embodiment will be described with reference to Fig. 1 and Fig. 3 to Fig. 8. In this embodiment, as shown in Fig. 2, the rotor 4 is configured by combining rotor blocks 15, each of which has a plurality of permanent magnets 14 (e.g., 20) exposed on the outer periphery of a rotor core 13, in a state where they are stacked in four stages in the axial direction. The four rotor blocks 15 have the same configuration, and the following description will focus on one rotor block 15.

[0013] 1, rotor core 13 is formed by, for example, punching out an electromagnetic steel sheet into a predetermined shape, i.e., into a substantially circular disk, to obtain unit core plates, and then laminating a plurality of such punched unit core plates. A central hole 13a into which the rotating shaft 5 is inserted is formed in the center of rotor core 13. A plurality of slots 16, in this case 20 slots, into which each permanent magnet 14 is attached are provided on the outer periphery of rotor core 13, lined up in the circumferential direction with a small gap between adjacent slots.

[0014] 3 to 8, the slots 16 are open to the outer periphery, have a relatively shallow depth, and are generally trapezoidal recesses that widen slightly toward the bottom, and are provided extending over the entire axial direction of the rotor core 13. In this case, each slot 16 is formed to a size that allows a permanent magnet 14 to be inserted in the axial direction, that is, slightly larger than the outer shape of the permanent magnet 14. Then, as shown in Figs. 4 and 6, etc., in the portion of the outer periphery of the rotor core 13 between the slots 16 adjacent in the circumferential direction, a cut 17 that opens on the outer periphery and a pipe accommodating portion 18 that continues to the bottom of the cut 17 are formed, and an engagement portion 19 is provided.

[0015] At this time, as shown in Figures 7 and 8, the cutout 17 is a V-shaped groove, and the pipe accommodating portion 18 is formed in a substantially circular shape connected via a narrow width portion 17a with a narrow gap located at the bottom of the V-shaped cutout 17. As a result, on both sides of the cutout 17 and the pipe accommodating portion 18, engaging portions 19, 19 that engage with the side surfaces of the permanent magnet 14 are provided at both sides of the circumferential direction of each slot 16. The inner diameter of the pipe accommodating portion 18 is configured to be slightly larger than the outer diameter of a pipe member 20 (described later) before it is expanded, so that the pipe member 20 can be inserted in the axial direction. The engaging portions 19 and the pipe accommodating portion 18 are formed when the unit core plate is punched out as described above.

[0016] As shown in FIG. 3 and FIG. 5 to FIG. 8, the rotor core 13 is configured such that the pipe members 20 for fixing the permanent magnets 14 are accommodated in the pipe accommodating portions 18 of the cuts 17. The pipe members 20 are made of a plastically deformable non-magnetic material, such as copper, and are configured in the shape of a cylindrical pipe having a diameter slightly larger than the width dimension of the narrow width portion 17a of the cuts 17 and slightly smaller than the inner diameter dimension of the pipe accommodating portions 18. The length of the pipe members 20 corresponds to the overall length dimension of the rotor block 15 in the axial direction. As will be described in detail later, the pipe members 20 are inserted in the axial direction and accommodated in the pipe accommodating portions 18. With the permanent magnets 14 inserted in the slots 16, the pipe members 20 in the pipe accommodating portions 18 are expanded to assemble the permanent magnets 14.

[0017] The permanent magnet 14 is made of, for example, a neodymium magnet, and as shown in Figs. 1, 3, 5 to 8, has a rectangular thin plate shape and a trapezoid shape with both side surfaces rising and inclining at an angle slightly smaller than 90 degrees, and further, the upper surface, i.e., the surface facing the outer periphery, is gently curved and convex toward the outer periphery. The permanent magnet 14 is manufactured, for example, by cutting a rectangular block. As shown in Fig. 1, the permanent magnet 14 has two types, one magnetized on the outer periphery side to the S pole and the other magnetized on the N pole, which are alternately arranged in the circumferential direction in each of the slots 16. Each permanent magnet 14 protrudes outward from the outer periphery of the rotor core 13. In other words, the tip of the engagement portion 19 is located inside the outer diameter of the permanent magnet 14.

[0018] In this embodiment, as described in the next explanation of the operation, the following three steps are performed to assemble the permanent magnets 14 to the rotor core 13 in the manufacture of the rotor 4. That is, a magnet insertion step of inserting the permanent magnets 14 into the slots 16 in the axial direction, for example, the direction of arrow A in Fig. 5, a pipe accommodating step of inserting and accommodating the pipe member 20 in the pipe accommodating portion 18 in the axial direction, for example, the direction of arrow B in Fig. 5, and a pipe expansion step of expanding the diameter of the pipe member 20 in the pipe accommodating portion 18 are performed in this order. However, the magnet insertion step and the pipe accommodating step may be performed in the opposite order, or may be performed simultaneously.

[0019] In this embodiment, a tube expanding jig 21 is used in the tube expanding step, as shown in Fig. 6. This tube expanding jig 21 is in the shape of a round bar, and its tip is sharpened to form a conical surface. It is inserted into the pipe member 20 from the tip and press-fitted, thereby plastically deforming the pipe member 20 so as to gradually expand the diameter of the pipe member 20. This expansion of the pipe member 20 generates a force that expands the inner diameter of the pipe accommodating portion 18 in the outer circumferential direction, and the engaging portions 19, 19 on both sides are plastically deformed so as to be expanded outward in the circumferential direction, that is, in the direction of arrow C in Fig. 8.

[0020] 8, the engaging portion 19 is pressed against the side surface of the permanent magnet 14 in the slot 16, thereby fixing the permanent magnet 14. In this case, the permanent magnet 14 is assembled without using adhesive. In this embodiment, in the expanding step, both axial end portions of the pipe member 20 are expanded by inserting an expanding jig 21 from both sides of the pipe member 20.

[0021] Next, a method for manufacturing the rotor 4, i.e., a method for manufacturing the rotor block 15, in this embodiment will be described. As described above, in manufacturing the rotor block 15, a plurality of unit core plates are stacked to form the rotor core 13, and then the permanent magnets 14 are attached, as shown in Figures 4 and 5. In assembling the permanent magnets 14 to the rotor core 13, a magnet insertion process is carried out in which the permanent magnets 14 are inserted axially from the end face side of the rotor core 13 into each slot 16, for example, in the direction of arrow A in Figure 5.

[0022] This magnet insertion process is carried out smoothly because the shape of the slot 16 is slightly larger than the outer shape of the permanent magnet 14. As a result, the permanent magnet 14 is inserted into the slot 16 but is not yet fixed, as shown in Figures 6 and 7. Next, a pipe accommodating process is carried out in which the pipe member 20 is inserted and accommodated in the pipe accommodating portion 18 in the axial direction, for example, in the direction of arrow B in Figure 5. Again, the inner diameter of the pipe accommodating portion 18 is larger than the outer diameter of the pipe member 20 before it is expanded, so the insertion can be carried out smoothly. As a result, the pipe member 20 is inserted into the pipe accommodating portion 18 with plenty of room to spare, as shown in Figure 7.

[0023] Next, as shown in Fig. 6, a tube expansion process is performed to expand the diameter of the pipe member 20 in the pipe accommodating portion 18. In this tube expansion process, as shown in Fig. 6, a tube expansion jig 21 is inserted from the tip of the pipe member 20 in the direction of arrow B, thereby plastically deforming the pipe member 20 so as to expand it. The tube expansion jig 21 is inserted from both end sides of the pipe member 20, and both axial end portions of the pipe member 20, for example, portions of about 1 / 3 of the total length of each of both end portions, are expanded. After the pipe member 20 is expanded, the tube expansion jig 21 is removed from the pipe member 20.

[0024] By expanding the pipe members 20, as shown in Fig. 8, the pipe members 20 spread the pipe accommodating portion 18 in the outer circumferential direction, and the engaging portions 19, 19 on both sides are plastically deformed so as to be spread outward in the circumferential direction, that is, in the direction of arrow C in Fig. 8. As a result, the engaging portions 19 are pressed against the side surfaces of the permanent magnets 14 in the slots 16 without using adhesive, and the permanent magnets 14 are fixed to the rotor core 13, and the rotor block 15 is obtained. After this, the rotor 4 is constructed by connecting, for example, four rotor blocks 15 as shown in Fig. 2.

[0025] According to the manufacturing method of the rotor 4 and the rotor 4 of this embodiment, the following actions and effects can be obtained. That is, in the manufacturing method of the rotor 4 of this embodiment, a magnet insertion process for inserting the permanent magnets 14 into the slots 16 of the rotor core 13 is performed together with a pipe accommodating process for accommodating the pipe members 20 into the pipe accommodating portions 18, and then an expansion process for expanding the diameter of the pipe members 20 is performed. By performing this expansion process, the pipe members 20 are expanded, and the engaging portions 19 located on both sides thereof are plastically deformed outward in the circumferential direction to engage with the side surfaces of the permanent magnets 14 in a pressure-welded manner, thereby fixing the permanent magnets 14.

[0026] This, unlike when an adhesive is used to fix the permanent magnets 14, eliminates the need for the steps of applying adhesive and wiping off excess adhesive, and requires only a relatively simple process of accommodating and expanding the pipe members 20, thereby simplifying the process accordingly. Furthermore, by fixing the permanent magnets 14 without using adhesive, it is possible to prevent problems that occur when adhesive is used, such as a decrease in vibration absorption due to aging, and the occurrence of cracks or falling off of the permanent magnets 14 due to a decrease in fixing strength.

[0027] Moreover, by fitting and fixing the pipe member 20 in the pipe accommodating portion 18, spring back of the engaging portion 19 can be prevented. Air circulating inside the cylindrical pipe member 20 can also be expected to have a cooling effect on the rotor core 13. Therefore, according to this embodiment, in which the permanent magnets 14 are provided in the slots 16 on the outer periphery of the rotor core 13, the assembly work of the permanent magnets 14 can be simplified, and the excellent effects of improving the reliability of the fixing of the permanent magnets 14 can be obtained.

[0028] In particular, in this embodiment, the outer peripheral end of the engaging portion 19 is positioned inside the outer peripheral end of the side surface of the permanent magnet 14, so that it is possible to suppress magnetic flux leakage in the lateral direction, i.e., the circumferential direction, between adjacent permanent magnets 14, compared to a case in which the engaging portion 19 protrudes in the outer circumferential direction beyond the permanent magnet 14. Also, by making the pipe member 20 out of a non-magnetic material, the pipe member 20 portion serves as a flux barrier, and the effect of suppressing magnetic flux leakage from the permanent magnet 14 can be further enhanced.

[0029] Furthermore, in this embodiment, the tube expanding step is configured to expand both end portions of the pipe member 20. This allows the permanent magnet 14 in the slot 16 to be fixed by the engagement portion 19 pressing at least both end portions in the axial direction. In this case, the tube expanding step only needs to be performed on both end portions of the pipe member 20, making it possible to obtain reliable fixing of the permanent magnet 14 while simplifying the process. Moreover, in this embodiment, the tube expanding step is performed by inserting a rod-shaped tube expanding jig 21 having a pointed tip into the pipe member 20. This allows the tube expanding step to be performed extremely easily using simple and inexpensive equipment and tools.

[0030] In the above embodiment, both ends of the pipe member 20 are expanded in the expanding process, but the pipe member 20 may be expanded over the entire length of the pipe member 20. In the above embodiment, the pipe member 20 is made of a copper pipe, but it may be made of other non-magnetic materials such as aluminum. In the above embodiment, the permanent magnets are arranged to extend parallel to the axial direction of the rotor core, but the permanent magnets may be arranged in a so-called skewed arrangement in which they are tilted with respect to the axial direction of the rotor core. Furthermore, the rotor core is not limited to a form in which multiple rotor blocks are combined, and may be composed of a single core. Various changes are also possible regarding the number of slots and permanent magnets.

[0031] In addition, instead of using the tube expansion jig 21, the tube can be expanded using hydraulic pressure, air pressure, or the like. The applications of the SPM type rotating electric machine are not limited to elevators, and can be applied to various applications including generators. The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents as set forth in the claims. [Explanation of symbols]

[0032] In the drawings, 1 is an SPM type motor (SPM type rotating 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, 16 is a slot, 17 is a notch, 17a is a narrow width portion, 18 is a pipe accommodating portion, 19 is an engagement portion, 20 is a pipe member, and 21 is a pipe expansion jig.

Claims

1. A manufacturing method of a rotor for an SPM type rotating electric machine, the rotor core having a plurality of slots opening to the outer periphery, and a permanent magnet disposed in each of the slots so as to protrude from the outer periphery of the rotor core, comprising: An outer periphery of the rotor core is provided with engaging portions located on both sides of the slot in the circumferential direction and adapted to receive side surfaces of the permanent magnets, and a pipe accommodating portion is provided across the two engaging portions located between the slots adjacent in the circumferential direction, a magnet insertion process of inserting the permanent magnets into the slots of the rotor core; a pipe accommodating step of accommodating the plastically deformable cylindrical pipe member in the pipe accommodating portion; and a tube expansion process for expanding a diameter of the pipe member located in the pipe accommodating portion, In the expansion process, the diameter of the pipe member is expanded, thereby plastically deforming the engagement portion so as to expand it circumferentially outward, and the engagement portion is pressed against the side of the permanent magnet to fix it.This is a manufacturing method for a rotor of an SPM type rotating electric machine.

2. 2. The method of manufacturing a rotor for an SPM type rotating electric machine according to claim 1, wherein an outer peripheral end of said engaging portion is located inside an outer peripheral end of said permanent magnet.

3. 3. The method for manufacturing a rotor for an SPM type rotating electric machine according to claim 1, wherein said pipe member is made of a non-magnetic material.

4. 4. The method for manufacturing a rotor for an SPM type rotating electric machine according to claim 1, wherein in the expanding step, at least both end portions of the pipe member are expanded.

5. 5. A method for manufacturing a rotor for an SPM type rotating electric machine according to claim 1, wherein the expansion process is carried out by inserting a rod-shaped expansion tool having a pointed tip into the pipe member.

6. A rotor for an SPM type rotating electric machine is configured by having a plurality of slots that open to the outer periphery of a rotor core, and by arranging permanent magnets in each of the slots so as to protrude from the outer periphery of the rotor core, An outer periphery of the rotor core is provided with engaging portions located on both sides of the slot in the circumferential direction and adapted to receive side surfaces of the permanent magnets, and a pipe accommodating portion is provided across the two engaging portions located between the slots adjacent in the circumferential direction, The rotor of an SPM type rotating electric machine is configured such that the plastically deformable cylindrical pipe member is accommodated in an expanded state within the pipe accommodating portion, so that the engaging portion is plastically deformed so as to expand outward in the circumferential direction, and is pressed against the side of the permanent magnet in the slot to fix the permanent magnet.

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