Method for manufacturing rotor of rotating electrical machine

Abstract

This method for manufacturing a rotor (1) of a rotating electrical machine comprises: a temporary magnetizing step for temporarily magnetizing a portion of each of a plurality of segment magnets (3); a magnetic flux amount measuring step for measuring the magnetic flux amount of each segment magnet (3) that has been temporarily magnetized; a magnet selecting step for selecting a plurality of segment magnets (3) to be used from among the segment magnets (3) on the basis of the measured magnetic flux amounts; a magnet bonding step for alternately arranging segment magnets (3) of different magnetic polarity from among the selected segment magnets (3) in the circumferential direction of a shaft part and attaching the same to the shaft part with an adhesive; a magnet position correcting step for applying pressure to the segment magnets (3) while also correcting the positions of the segment magnets (3) during the curing time of the adhesive; an adhesive curing step for curing the adhesive; and a proper magnetizing step for properly magnetizing the segment magnets (3) after the curing of the adhesive.

Description

Manufacturing method of rotor for rotating electric machine

[0001] The present disclosure relates to a method for manufacturing a rotor for a rotating electric machine.

[0002] A rotor equipped with permanent magnets has been known as a conventional rotor for a rotating electric machine. In order to reduce cogging torque when used in a rotating electric machine, a rotor of this type has been proposed in which a ring-shaped permanent magnet is divided into segment-shaped permanent magnets (hereinafter referred to as "segment magnets"), and the cross section of the segment magnets is further formed into a semi-cylindrical shape.

[0003] The segment magnets are aligned circumferentially and attached to the outer circumferential surface of the shaft alone, or to the outer circumferential surface of the rotor core of a shaft assembly consisting of the rotor core and the shaft. Hereinafter, the "shaft alone" and "shaft assembly" will be collectively referred to as the "shaft portion." One known method for attaching the segment magnets to the outer circumferential surface of the shaft portion is to magnetize each segment magnet, position the segment magnets so that adjacent segment magnets in the circumferential direction have opposite magnetic polarities, and then attach them to the outer circumferential surface of the shaft portion with an adhesive.

[0004] However, with the conventional method described above, if the spacing between adjacent segment magnets in the circumferential direction is narrow, the mutual attraction between the segment magnets may cause the segment magnets to become misaligned before the adhesive hardens.

[0005] One possible solution to this misalignment is to narrow the width of each segment magnet and increase the spacing between adjacent segment magnets in the circumferential direction, but this would result in a problem of reduced torque in the rotating electrical machine.

[0006] To solve the above-mentioned misalignment, Patent Document 1 discloses a method of temporarily magnetizing circumferentially adjacent segment magnets so that they have the same magnetic polarity, and then attaching each temporarily magnetized segment magnet to the outer peripheral surface of a shaft portion with an adhesive. The method disclosed in Patent Document 1 utilizes the repulsive force acting between circumferentially adjacent segment magnets to hold each segment magnet at equal intervals in the circumferential direction. By holding each segment magnet at equal intervals in the circumferential direction, the method disclosed in Patent Document 1 can obtain a rotor with excellent motor characteristics. The method disclosed in Patent Document 1 also includes a final magnetization process, in which, after the adhesive has hardened, each segment magnet is finally magnetized so that circumferentially adjacent segment magnets have opposite magnetic polarities.

[0007] Japanese Patent Application Laid-Open No. 2007-267575

[0008] However, with the method disclosed in Patent Document 1, when segment magnets are attached one by one to the outer circumferential surface of the shaft, the repulsive forces acting between the segment magnets cause each segment magnet to move from its correct position when the second segment magnet is attached to its correct position. Similarly, when attaching the third and subsequent segment magnets, the repulsive forces acting between the segment magnets cause each segment magnet to move from its correct position. As a result, the later the segment magnets are attached to the outer circumferential surface of the shaft, the more limited the available space on the outer circumferential surface of the shaft, making it difficult or impossible to attach the segment magnets to the outer circumferential surface of the shaft.

[0009] Therefore, with the method disclosed in Patent Document 1, it is necessary to either attach all of the segment magnets to the outer circumferential surface of the shaft at once, or to temporarily hold the segment magnets that have already been attached until all of the segment magnets have been attached to the outer circumferential surface of the shaft. Either the former or latter method requires a large-scale jig to attach the segment magnets to the outer circumferential surface of the shaft.

[0010] Furthermore, in the method disclosed in Patent Document 1, because the temporarily magnetized segment magnets (those located midway along their initial magnetization curves) are in an unsaturated state, variations in the amount of magnetic flux are likely to occur in the temporarily magnetized segment magnets. When variations in the amount of magnetic flux occur in the temporarily magnetized segment magnets, variations in the attractive force of the segment magnets occur, causing segment magnets with low attractive force to slip off the outer circumferential surface of the shaft, or variations in the repulsive force acting between the segment magnets, preventing the segment magnets from being kept evenly spaced apart in the circumferential direction. This results in a problem of low accuracy in the attachment position of the segment magnets on the outer circumferential surface of the shaft.

[0011] Furthermore, in the method disclosed in Patent Document 1, the repulsive force acting between circumferentially adjacent segment magnets is used to maintain the attachment position of each segment magnet, and adjacent segment magnets are temporarily magnetized to have the same magnetic polarity. As a result, in the actual magnetization process that follows the temporary magnetization process, a high magnetizing voltage must be applied to the magnetizing yoke to reverse the magnetic polarity of some segment magnets. This results in the problem of a shorter lifespan of the magnetizing yoke.

[0012] The present disclosure has been made in consideration of the above, and aims to provide a method for manufacturing a rotor for a rotating electric machine that can increase the accuracy of the attachment position of each segment magnet on the outer surface of the shaft portion while extending the life of the magnetizing yoke without using large-scale jigs.

[0013] To solve the above-mentioned problems and achieve the object, the manufacturing method of a rotor for a rotating electric machine according to the present disclosure includes a temporary magnetizing step of temporarily magnetizing a portion of each of a plurality of segment magnets, a magnetic flux measurement step of measuring the magnetic flux amount of each temporarily magnetized segment magnet, and a magnet selection step of selecting a plurality of segment magnets to be used from the segment magnets based on the measured magnetic flux amount.The manufacturing method of a rotor for a rotating electric machine according to the present disclosure also includes a magnet bonding step of arranging segment magnets with different magnetic polarities from the selected segment magnets alternately in the circumferential direction of a shaft portion and attaching them to the shaft portion with an adhesive, a magnet position correction step of pressurizing each segment magnet and correcting the position of each segment magnet within the curing time of the adhesive, an adhesive curing step of curing the adhesive, and a final magnetizing step of finally magnetizing each segment magnet after the adhesive has cured.

[0014] The method for manufacturing a rotor for a rotating electric machine according to the present disclosure has the advantage of being able to increase the accuracy of the attachment position of each segment magnet on the outer surface of the shaft portion while extending the life of the magnetizing yoke without using large-scale jigs.

[0015] 1 is a perspective view showing the configuration of a rotor for a rotating electric machine according to the first embodiment; FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. 1; FIG. 3 is a perspective view showing the configuration of a segment magnet before it is temporarily magnetized according to the first embodiment; FIG. 4 is a perspective view showing an example of the configuration of a temporarily magnetized segment magnet according to the first embodiment; FIG. 5 is a perspective view showing another example of the configuration of a temporarily magnetized segment magnet according to the first embodiment; FIG. 6 is a cross-sectional view showing the configuration of a rotor in which temporarily magnetized segment magnets according to the first embodiment are attached to the outer peripheral surface of a shaft;

[0016] A method for manufacturing a rotor for a rotating electrical machine according to an embodiment will be described in detail below with reference to the drawings.

[0017] First Embodiment First, with reference to FIGS. 1 and 2 , the configuration of a rotor 1 of a rotating electric machine according to a first embodiment will be described. FIG. 1 is a perspective view showing the configuration of the rotor 1 of a rotating electric machine according to the first embodiment. FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. 1 . Hereinafter, the rotor 1 of a rotating electric machine may also be referred to as rotor 1. As shown in FIG. 1 , the rotor 1 includes a shaft 2, which is a shaft portion, and a plurality of segment magnets 3. Although not shown, a cylindrical stator is disposed on the outer periphery of the rotor 1, separated from the rotor 1 by a gap. The stator includes a plurality of windings facing each of the plurality of segment magnets 3. The rotor 1 and the stator are housed in a frame (not shown). The rotor 1, the stator, and the frame are components of a rotating electric machine. The rotor 1 rotates relative to the stator about a rotation axis AX. Hereinafter, when describing the directions of each component of the rotor 1, the direction parallel to the rotation axis AX is referred to as the axial direction, the direction perpendicular to the rotation axis AX is referred to as the radial direction, and the direction of rotation around the rotation axis AX is referred to as the circumferential direction.

[0018] The shaft 2 is made of a magnetic material such as a carbon steel plate. The shaft 2 extends in the axial direction. The shaft 2 is arranged coaxially with the rotation axis AX. In this embodiment, the shape of the shaft 2 is cylindrical. Specifically, the shape of the shaft 2 is a series of multiple cylinders with different diameters connected in the axial direction.

[0019] Each segment magnet 3 is a permanent magnet such as a rare earth sintered magnet. Each segment magnet 3 is arranged on the outer circumferential surface of the shaft 2. Each segment magnet 3 is attached to the outer circumferential surface of the shaft 2 with an adhesive. The multiple segment magnets 3 are arranged in the circumferential direction. The multiple segment magnets 3 are arranged at equal angles in the circumferential direction. As shown in Figure 2, each segment magnet 3 has a roughly semi-cylindrical shape when viewed along the axial direction. Each segment magnet 3 has an inner circumferential surface 31 facing radially inward and an outer circumferential surface 32 facing radially outward. Both the inner circumferential surface 31 and the outer circumferential surface 32 are arc-shaped surfaces that convex radially outward. The inner circumferential surface 31 is an arc-shaped surface centered on the rotation axis AX.

[0020] Each segment magnet 3 is magnetized so that its magnetic path faces in the radial direction. The segment magnets 3 include segment magnets 3A and 3B that are magnetized in the magnetization process described below. Segment magnet 3A is a segment magnet with north and south poles facing from the outside to the inside in the radial direction. Segment magnet 3B is a segment magnet with north and south poles facing from the inside to the outside in the radial direction. Segment magnets 3A and 3B are arranged alternately in the circumferential direction. In other words, segment magnets 3A and 3B are arranged so that their north and south poles face the radial direction, and the north and south poles of adjacent segment magnets 3A and 3B in the circumferential direction face each other.

[0021] Next, with reference to Figures 2 to 8, a manufacturing method of the rotor 1 of a rotating electric machine according to this embodiment will be described. Figure 3 is a perspective view showing the configuration of the segment magnet 3 before being temporarily magnetized in embodiment 1. Figure 4 is a perspective view showing an example of the configuration of the temporarily magnetized segment magnet 3 in embodiment 1. Figure 5 is a perspective view showing another example of the configuration of the temporarily magnetized segment magnet 3 in embodiment 1. Figure 6 is a perspective view showing another example of the configuration of the temporarily magnetized segment magnet 3 in embodiment 1. Figure 7 is a cross-sectional view showing the configuration of the rotor 1 in which the temporarily magnetized segment magnet 3 in embodiment 1 is attached to the outer peripheral surface of the shaft 2. Figure 8 is a cross-sectional view showing the main magnetization step of the manufacturing method of the rotor 1 of a rotating electric machine according to embodiment 1.

[0022] The manufacturing method of the rotor 1 of the rotating electric machine according to this embodiment includes a temporary magnetization process, a magnetic flux measurement process, a magnet selection process, a magnet bonding process, a magnet position correction process, an adhesive hardening process, and a main magnetization process.

[0023] As shown in FIGS. 4 and 5 , the temporary magnetization process is a process of temporarily magnetizing a portion of each of the multiple segment magnets 3. The temporary magnetization process is performed to adjust the magnetic flux of each segment magnet 3. In the temporary magnetization process, each segment magnet 3 is temporarily magnetized so that the segment magnets 3 with different magnetic polarities, similar to the magnetic polarity obtained in the main magnetization process, are arranged alternately in the circumferential direction of the shaft 2. Specifically, in the temporary magnetization process, temporary magnetization is performed on the segment magnet 3 shown in FIG. 3 to manufacture a segment magnet 3 with the magnetic polarity shown in FIG. 4 (hereinafter referred to as segment magnet 3C) or a segment magnet 3 with the magnetic polarity shown in FIG. 5 (hereinafter referred to as segment magnet 3D). That is, in the temporary magnetization process, a magnetizing yoke (not shown) is used to temporarily magnetize the segment magnet 3 shown in FIG. 3 to manufacture segment magnets 3C and 3D with different magnetic polarities. In FIGS. 4 and 5 , only the magnetic poles on the inner circumferential surface 31 of each segment magnet 3C and 3D are shown. The outer peripheral surface 32 of each segment magnet 3C, 3D has magnetic poles opposite to those on the inner peripheral surface 31. The magnetic poles of the segment magnet 3C shown in Figure 4 are north and south poles from the outside to the inside in the radial direction. The magnetic poles of the segment magnet 3D shown in Figure 5 are north and south poles from the inside to the outside in the radial direction.

[0024] In the temporary magnetizing process, the segment magnet 3 is temporarily magnetized so that the temporarily magnetized range of the segment magnet 3 (hereinafter referred to as the temporary magnetization range 33) is symmetrical in the circumferential and axial directions of the segment magnet 3. In the temporary magnetizing process, the segment magnet 3E shown in FIG. 6 may be manufactured instead of the segment magnet 3C shown in FIG. 4. In other words, in the temporary magnetizing process, as long as the segment magnet 3 can be temporarily magnetized so that the temporary magnetization range 33 is symmetrical in the circumferential and axial directions of the segment magnet 3, the segment magnet 3 may be temporarily magnetized to have a single temporary magnetization range 33 extending in the axial direction as shown in FIG. 4, or the segment magnet 3 may be temporarily magnetized to have multiple temporary magnetization ranges 33 spaced apart in the axial direction as shown in FIG. 6. Although not shown, instead of the segment magnet 3D shown in FIG. 5, a segment magnet 3 that is temporarily magnetized to have multiple temporary magnetization ranges 33 spaced apart in the axial direction may be manufactured. By temporarily magnetizing the segment magnet 3 so that the temporary magnetization range 33 is symmetrical in the circumferential and axial directions of the segment magnet 3, the attractive force of the segment magnets 3C, 3D to the shaft 2 becomes uniform in the portion of the segment magnets 3C, 3D on the inner circumferential surface 31 side. In the temporary magnetizing process, it is preferable to perform temporary magnetization from the inside to the outside in the radial direction of each segment magnet 3C, 3D. In other words, in the temporary magnetizing process, it is preferable to perform temporary magnetization from the portion of each segment magnet 3C, 3D where adhesive is applied (inner circumferential surface 31).

[0025] The magnetic flux measurement process is a process of measuring the magnetic flux of each temporarily magnetized segment magnet 3 C, 3 D. In the magnetic flux measurement process, for example, a search coil and a flux meter (not shown) are used to measure the magnetic flux of each temporarily magnetized segment magnet 3 C, 3 D.

[0026] The magnet selection process is a process of selecting a plurality of segment magnets 3C, 3D to be used from the segment magnets 3C, 3D based on the measured magnetic flux amount. In the magnet selection process, an upper limit value for the magnetic flux amount is set on the condition that the position of each segment magnet 3C, 3D will not change due to the attractive force between circumferentially adjacent segment magnets 3C, 3D when the segment magnets 3C, 3D are attached to the shaft 2, and a lower limit value for the magnetic flux amount is set on the condition that each segment magnet 3C, 3D will not slide off the shaft 2. In the magnet selection process, a plurality of segment magnets 3C, 3D whose measured magnetic flux amount is within the range from the upper limit value to the lower limit value are selected from the segment magnets 3C, 3D.

[0027] As shown in Figure 7, the magnet bonding process is a process in which segment magnets 3C, 3D with different magnetic polarities are selected from the selected segment magnets 3C, 3D and arranged alternately around the circumferential direction of the shaft 2, and attached to the shaft 2 with an adhesive. In the magnet bonding process, each segment magnet 3C, 3D is held in the position where it is attached to the shaft 2. Specifically, in the magnet bonding process, an adhesive is first applied to either the outer circumferential surface of the shaft 2 or the inner circumferential surface 31 of the segment magnets 3C, 3D. When a two-component curing adhesive is used, a base agent may be applied to either the outer circumferential surface of the shaft 2 or the inner circumferential surface 31 of the segment magnets 3C, 3D, and a curing agent may be applied to the other.

[0028] Next, in the magnet bonding process, segment magnets 3C, 3D are attached alternately in the circumferential direction at equal intervals to the outer peripheral surface of shaft 2 while rotating shaft 2 by a fixed angle. At this time, segment magnets 3C, 3D are attracted to the outer peripheral surface of shaft 2 by their respective magnetic forces. Therefore, when attaching segment magnets 3C, 3D to the outer peripheral surface of shaft 2 while rotating shaft 2, even if segment magnets 3C, 3D are positioned below shaft 2, they will not fall off from the outer peripheral surface of shaft 2. This results in a rotor 1 in which a plurality of temporarily magnetized segment magnets 3C, 3D are arranged alternately in the circumferential direction at equal intervals on the outer peripheral surface of shaft 2.

[0029] The magnetic force of the segment magnets 3C, 3D adjacent to each other in the circumferential direction does not change their positions, and each segment magnet 3C, 3D is held in the position where it is attached to the outer circumferential surface of the shaft 2.

[0030] The magnet position correction process is a process of applying pressure to each segment magnet 3C, 3D and correcting the position of each segment magnet 3C, 3D within the adhesive curing time. In the magnet position correction process, the thickness of the adhesive can be adjusted and stabilized by controlling the pressure that presses each segment magnet 3C, 3D attached to the outer surface of the shaft 2 against the outer surface of the shaft 2. Japanese Patent Application Laid-Open Publication No. 2012-120366 discloses that adhesive strength depends on the thickness of the adhesive. Therefore, by controlling the pressure as described above to adjust and stabilize the thickness of the adhesive, a rotor 1 with stable adhesive strength between each segment magnet 3C, 3D and the shaft 2 can be obtained. In the magnet position correction process, for example, a pressure device equipped with a spring is used to physically press each segment magnet 3C, 3D using the elastic force of the spring. In the magnet position correction process, a jig (not shown) is used to correct the position of each segment magnet 3C, 3D so that the segment magnets 3C, 3D are positioned at equal intervals in the circumferential direction and are aligned in the axial direction. When correcting the circumferential position of each segment magnet 3C, 3D, it is preferable to use a jig and rotation method that minimizes the amount of movement of each segment magnet 3C, 3D.

[0031] The adhesive hardening step is a step of hardening the adhesive. By performing the adhesive hardening step, each of the segment magnets 3C and 3D is fixed to the outer circumferential surface of the shaft 2 so as not to move.

[0032] This magnetization process involves magnetizing each segment magnet 3C, 3D after the adhesive has hardened. In this magnetization process, as shown in FIG. 8 , multiple magnetizing yokes 4 are placed radially outside each segment magnet 3C, 3D, and current is passed through the magnetizing coils 5 wound around each magnetizing yoke 4. In this magnetization process, current is passed through the magnetizing coils 5 to generate a magnetizing magnetic field. At this time, current is passed through the magnetizing coils 5 of each magnetizing yoke 4 so that the magnetizing yoke 4 through which magnetic flux M1 passes from the radial inside to the radial outside (the magnetizing yoke 4 on the left side of the paper in FIG. 8 ) and the magnetizing yoke 4 through which magnetic flux M2 passes from the radial outside to the radial inside (the magnetizing yoke 4 on the right side of the paper in FIG. 8 ) are arranged alternately in the circumferential direction. In this magnetization process, the rotor 1 equipped with the temporarily magnetized segment magnets 3C, 3D and the magnetizing yoke 4 are arranged so that the magnetic polarity of each segment magnet 3C, 3D imparted in the temporary magnetization process is the same as the magnetic polarity of each segment magnet 3A, 3B imparted in the actual magnetization process. That is, in this magnetization process, after the adhesive has hardened, each segment magnet 3C, 3D is finally magnetized with the same magnetic polarity as in the temporary magnetization process. By performing this magnetization process, the rotor 1 equipped with the segment magnets 3A, 3B shown in FIG. 2 is obtained. Then, the rotor 1 shown in FIG. 2 is placed on the inner periphery of a stator housed in a frame (not shown), and the shaft 2 of the rotor 1 is supported by a bearing (not shown). This completes the manufacture of the rotating electric machine.

[0033] Next, the effects of the manufacturing method of the rotor 1 for a rotating electrical machine according to this embodiment will be described.

[0034] 4 and 5 , the manufacturing method of the rotor 1 for a rotating electric machine includes a temporary magnetizing step of temporarily magnetizing a portion of each of the plurality of segment magnets 3, thereby limiting the temporary magnetization range 33 of each segment magnet 3. The manufacturing method of the rotor 1 for a rotating electric machine also includes a magnetic flux measurement step of measuring the magnetic flux amount of each of the temporarily magnetized segment magnets 3C, 3D, and a magnet selection step of selecting the plurality of segment magnets 3C, 3D to be used from the segment magnets 3C, 3D based on the measured magnetic flux amount. This allows the selection of each segment magnet 3C, 3D based on the magnetic flux amount measurement. Specifically, in the magnet selection step, an upper limit value for the magnetic flux amount is set on the condition that the position of each segment magnet 3C, 3D does not change due to the attractive force between circumferentially adjacent segment magnets 3C, 3D when attached to the shaft 2, and a lower limit value for the magnetic flux amount is set on the condition that each segment magnet 3C, 3D does not slip off the shaft 2. In addition, in the magnet selection process, a plurality of segment magnets 3C, 3D whose measured magnetic flux amount is within the range from the upper limit value to the lower limit value are selected from the segment magnets 3C, 3D.

[0035] By limiting the temporary magnetization range 33 of each segment magnet 3 and selecting each segment magnet 3C, 3D by measuring the amount of magnetic flux in this way, the magnetic force of each temporarily magnetized segment magnet 3C, 3D can be used only to hold each segment magnet 3C, 3D in the position where it is affixed to the outer circumferential surface of the shaft 2. As a result, no attractive or repulsive forces act between adjacent segment magnets 3C, 3D in the circumferential direction, making it difficult for the segment magnets 3C, 3D to become misaligned. Therefore, it is possible to affix the segment magnets 3C, 3D one by one to the outer circumferential surface of the shaft 2. In other words, there is no need to affix all of the segment magnets 3C, 3D to the outer circumferential surface of the shaft 2 at once, or to temporarily hold the already affixed segment magnets 3C, 3D until all of the segment magnets 3C, 3D have been affixed to the outer circumferential surface of the shaft 2. This eliminates the need for a large-scale jig for affixing the segment magnets 3C, 3D to the outer circumferential surface of the shaft 2.

[0036] In this embodiment, even if there is variation in the magnetic flux of the temporarily magnetized segment magnets 3C, 3D, by selecting the segment magnets 3C, 3D by measuring the magnetic flux, it is possible to use a plurality of segment magnets 3C, 3D with little variation in magnetic flux. Furthermore, in this embodiment, the manufacturing method for the rotor 1 of a rotating electric machine includes a magnet position correction process that corrects the position of each segment magnet 3C, 3D within the curing time of the adhesive. This improves the accuracy of the attachment position of each segment magnet 3C, 3D on the outer circumferential surface of the shaft 2. In other words, when attaching each segment magnet 3C, 3D to the outer circumferential surface of the shaft 2, it is possible to position each segment magnet 3C, 3D not only circumferentially but also axially. This improves the accuracy of the attachment position of each segment magnet 3C, 3D on the outer circumferential surface of the shaft 2 in both the circumferential and axial directions.

[0037] In this embodiment, as shown in FIG. 7 , the magnetic force of each temporarily magnetized segment magnet 3C, 3D can be used only to hold each segment magnet 3C, 3D in the position where it is attached to the outer circumferential surface of the shaft 2. This allows adjacent segment magnets 3C, 3D to be arranged so that they have opposite magnetic polarities. That is, in the magnet bonding process, the segment magnets 3C, 3D with different magnetic polarities can be arranged alternately around the shaft 2 and attached to the shaft 2 with adhesive. As a result, in the actual magnetizing process, the segment magnets 3C, 3D can be finally magnetized with the same magnetic polarity as in the temporary magnetizing process after the adhesive hardens. Therefore, in the actual magnetizing process, which is a process subsequent to the temporary magnetizing process, it is not necessary to give each segment magnet 3C, 3D the opposite magnetic polarity to that in the temporary magnetizing process. Therefore, there is no need to apply a high magnetizing voltage to the magnetizing yoke 4 in the actual magnetizing process, which extends the life of the magnetizing yoke 4 and reduces energy consumption in the manufacturing process of the rotor 1.

[0038] As described above, in this embodiment, the accuracy of the attachment position of each segment magnet 3C, 3D on the outer surface of the shaft 2 can be improved without using a large-scale jig, while extending the life of the magnetizing yoke 4.

[0039] In the temporary magnetization process of this embodiment, temporary magnetization is performed starting from the portions of each segment magnet 3C, 3D shown in Figure 7 where adhesive is applied. In other words, in the temporary magnetization process, temporary magnetization is performed from the radially inner side of each segment magnet 3C, 3D. This reduces or eliminates the influence of temporary magnetization on the outer peripheral portion of the rotor 1, which is related to motor characteristics. Furthermore, by performing the temporary magnetization process, it is not necessary to apply a high magnetizing voltage to each segment magnet 3C, 3D in the actual magnetization process, thereby extending the life of the magnetizing yoke 4.

[0040] Next, a modification of the first embodiment will be described.

[0041] In this embodiment, the adhesive thickness is adjusted as desired by applying pressure in the magnet position correction process, but this is not limiting. For example, instead of applying pressure in the magnet position correction process, the adhesive thickness may be adjusted as desired by applying pressure to each segment magnet 3C, 3D in the magnet bonding process. Methods for applying pressure to each segment magnet 3C, 3D in the magnet bonding process include, for example, applying pressure using a band or suction tool to position each segment magnet 3C, 3D on the outer circumferential surface of the shaft 2, or applying pressure using the adhesive force of each temporarily magnetized segment magnet 3C, 3D. By applying pressure to each segment magnet 3C, 3D in this manner in the magnet bonding process, the adhesive thickness can be adjusted as desired without using a pressure device in the manufacture of the rotor 1, thereby simplifying the manufacturing equipment for the rotor 1 and reducing manufacturing costs. Furthermore, applying pressure to each segment magnet 3C, 3D in the magnet bonding process allows the segment magnets 3C, 3D to be pressed simultaneously with their placement on the outer circumferential surface of the shaft 2, thereby shortening the processing time (cycle time).

[0042] In this embodiment, the segment magnets 3C, 3D are magnetized in the main magnetization process with the same polarity as in the temporary magnetization process after the adhesive has hardened. However, the segment magnets 3C, 3D may also be magnetized in the main magnetization process with the opposite polarity to that in the temporary magnetization process after the adhesive has hardened. For example, if the temporary magnetization direction cannot be changed due to equipment constraints, all segment magnets 3 may be temporarily magnetized to the same polarity in the temporary magnetization process, and then some segment magnets 3 may be permanently magnetized to the opposite polarity in the main magnetization process. Even in this case, by performing the magnet selection process, the use of segment magnets 3 with a large amount of magnetic flux can be avoided. Therefore, compared to the method disclosed in Patent Document 1, which does not perform the magnet selection process, the magnetization voltage applied to the magnetizing yoke 4 in the main magnetization process can be reduced, thereby extending the life of the magnetizing yoke 4 and reducing energy consumption in the manufacturing process of the rotor 1.

[0043] In this embodiment, multiple segment magnets 3 are attached to the outer peripheral surface of the shaft 2 alone, but they may also be attached to the outer peripheral surface of the rotor core of a shaft assembly made up of the rotor core and shaft 2. In this configuration, the rotor 1 includes a shaft assembly, which is the shaft portion, and multiple segment magnets 3 attached to the outer peripheral surface of the rotor core of the shaft assembly. The shaft 2 is disposed on the inner periphery of the rotor core and connected to it. The rotor core is, for example, a laminate of rolled steel sheets or electromagnetic steel sheets, or a machined metal product, and is formed in a tubular shape such as a cylinder.

[0044] Second Embodiment Next, a method of manufacturing a rotor 1A for a rotating electric machine according to a second embodiment will be described with reference to Fig. 9. Fig. 9 is a perspective view showing the configuration of a rotor 1A for a rotating electric machine according to the second embodiment. This embodiment differs from the first embodiment in that a plurality of segment magnets 3 are also arranged in the axial direction. In the second embodiment, parts that overlap with those in the first embodiment are given the same reference numerals and will not be described again.

[0045] First, the configuration of the rotor 1A of the rotating electric machine according to the second embodiment will be described. The segment magnets 3 are arranged in both the circumferential direction and the axial direction. That is, in this embodiment, there are two axial rows in which the segment magnets 3 are arranged in the circumferential direction. The circumferential center line of each of the segment magnets 3A, 3B in one row is aligned with the circumferential center line of each of the segment magnets 3A, 3B in the other row. The segment magnets 3A, 3B adjacent to each other in the axial direction are in contact with each other. The segment magnets 3A, 3B adjacent to each other in the axial direction have the same magnetic polarity. That is, the row in which the segment magnets 3A are arranged in the axial direction and the row in which the segment magnets 3B are arranged in the axial direction are arranged alternately in the circumferential direction.

[0046] Next, a method for manufacturing the rotor 1A of the rotating electric machine according to this embodiment will be described with reference to FIGS.

[0047] The manufacturing method for the rotor 1A of a rotating electric machine according to this embodiment includes a temporary magnetizing step, a magnetic flux measurement step, a magnet selection step, a magnet bonding step, a magnet position correction step, an adhesive hardening step, and a main magnetizing step. Except for the magnet bonding step and the magnet position correction step, the manufacturing method for the rotor 1 of a rotating electric machine according to the first embodiment is generally the same as that described above, and therefore a description thereof will be omitted here. The configuration of the temporarily magnetized segment magnets 3C, 3D used in the manufacturing method for the rotor 1A of a rotating electric machine according to the second embodiment is the same as that of the first embodiment (see FIG. 7 ).

[0048] The magnet bonding process is a process in which, from the selected segment magnets 3, the segment magnets 3C, 3D with different magnetic polarities are arranged alternately in the circumferential direction of the shaft 2 and attached to the shaft 2 with adhesive, and, from the selected segment magnets 3, the segment magnets 3C, 3D with the same magnetic polarity are arranged in the axial direction of the shaft 2 and attached to the shaft 2 with adhesive. First, in the magnet bonding process, the segment magnets 3C, 3D in one row are arranged alternately in the circumferential direction of the shaft 2 and attached to the shaft 2 with adhesive. Next, in the magnet bonding process, the segment magnets 3C, 3D in the other row are arranged alternately in the circumferential direction of the shaft 2 and attached to the shaft 2 with adhesive.

[0049] The magnet position correction process is a process in which pressure is applied to each segment magnet 3C, 3D while the adhesive is curing, and the position of each segment magnet 3C, 3D is corrected using a jig (not shown) so that each segment magnet 3C, 3D is positioned at equal intervals in the circumferential direction and is aligned in the axial direction.

[0050] Next, the effects of the manufacturing method of the rotor 1A of the rotating electrical machine according to this embodiment will be described.

[0051] In this embodiment, the manufacturing method of the rotor 1A for a rotating electric machine includes a magnet bonding process in which, from among the selected segment magnets 3, the segment magnets 3C, 3D with different magnetic polarities are alternately arranged in the circumferential direction of the shaft 2 and attached to the shaft 2 with adhesive, and, from among the selected segment magnets 3, the segment magnets 3C, 3D with the same magnetic polarity are arranged in the axial direction of the shaft 2 and attached to the shaft 2 with adhesive. Also, in this embodiment, the manufacturing method of the rotor 1A for a rotating electric machine includes a magnet position correction process in which the position of each segment magnet 3C, 3D is corrected within the curing time of the adhesive. This allows the segment magnets 3C, 3D to be positioned not only in the circumferential direction but also in the axial direction when attached to the outer circumferential surface of the shaft 2. This improves the accuracy of the circumferential and axial attachment position of each segment magnet 3C, 3D on the outer circumferential surface of the shaft 2.

[0052] Next, a modification of the second embodiment will be described.

[0053] In this embodiment, the segment magnets 3 are arranged in two axial rows in the circumferential direction, but may be arranged in three or more rows.

[0054] In this embodiment, the segment magnets 3C, 3D of one row are attached to the shaft 2, and then the segment magnets 3C, 3D of the other row are attached to the shaft 2, but this is not limitative. For example, the segment magnets 3C, 3D of one row and the segment magnets 3C, 3D of the other row may be attached alternately to the shaft 2.

[0055] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0056] 1, 1A rotor, 2 shaft, 3, 3A, 3B, 3C, 3D, 3E segment magnet, 4 magnetizing yoke, 5 magnetizing coil, 31 inner peripheral surface, 32 outer peripheral surface, 33 temporary magnetization range, AX rotation axis, M1, M2 magnetic flux.

Claims

1. A method for manufacturing a rotor for a rotating electric machine, comprising: a temporary magnetization process for temporarily magnetizing a portion of each of a plurality of segment magnets; a magnetic flux measurement process for measuring the magnetic flux amount of each of the temporarily magnetized segment magnets; a magnet selection process for selecting a plurality of segment magnets to be used from each of the segment magnets based on the measured magnetic flux amount; a magnet bonding process for arranging segment magnets with different magnetic polarities from the selected segment magnets alternately around the circumferential direction of the shaft portion and attaching them to the shaft portion with adhesive; a magnet position correction process for pressurizing each of the segment magnets and correcting the position of each of the segment magnets within the hardening time of the adhesive; an adhesive hardening process for hardening the adhesive; and a final magnetization process for finally magnetizing each of the segment magnets after the adhesive has hardened.

2. A method for manufacturing a rotor for a rotating electric motor as described in claim 1, characterized in that in the magnet selection process, an upper limit value for the magnetic flux amount is set on the condition that the position of each segment magnet does not change due to the adhesive force between adjacent segment magnets in the circumferential direction when attached to the shaft portion, and a lower limit value for the magnetic flux amount is set on the condition that each segment magnet does not slip off the shaft portion, and from each segment magnet, a plurality of segment magnets whose measured magnetic flux amount is within the range from the upper limit value to the lower limit value are selected.

3. The method for manufacturing a rotor for a rotating electric machine according to claim 1, characterized in that in the temporary magnetization step, temporary magnetization is performed starting from the portion of each segment magnet to which the adhesive is applied.

4. A method for manufacturing a rotor for a rotating electric machine as described in claim 1, characterized in that in the main magnetization process, each of the segment magnets is main magnetized with the same magnetic polarity as in the temporary magnetization process after the adhesive has hardened.

5. A method for manufacturing a rotor for a rotating electric machine, comprising: a temporary magnetizing process for temporarily magnetizing a portion of each of a plurality of segment magnets; a magnetic flux measurement process for measuring the magnetic flux amount of each of the temporarily magnetized segment magnets; a magnet selection process for selecting a plurality of segment magnets to be used from each of the segment magnets based on the measured magnetic flux amount; a magnet bonding process for arranging segment magnets with different magnetic polarities from the selected segment magnets alternately around the circumferential direction of the shaft portion and attaching them to the shaft portion with an adhesive while applying pressure to each of the segment magnets; a magnet position correction process for correcting the position of each of the segment magnets within the hardening time of the adhesive; an adhesive hardening process for hardening the adhesive; and a final magnetization process for finally magnetizing each of the segment magnets after the adhesive has hardened.

6. A manufacturing method for a rotor for a rotating electric machine according to claim 5, characterized in that in the magnet adhering step, the adhesive is pressurized by the attractive force of each of the temporarily magnetized segment magnets.

7. A method for manufacturing a rotor for a rotating electric machine according to claim 5, characterized in that in the main magnetization process, each of the segment magnets is main magnetized with the same magnetic polarity as in the temporary magnetization process after the adhesive has hardened.

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