Manufacturing method of rotor for rotating electric machine

Abstract

A manufacturing method of a rotor (1) for a rotating electric machine includes a temporary magnetization process for temporarily magnetizing a portion of each of the multiple segment magnets (3), a magnetic flux measurement process for measuring the magnetic flux amount of each temporarily magnetized segment magnet (3), a magnet selection process for selecting the multiple segment magnets (3) to be used from each of the segment magnets (3) based on the measured magnetic flux amount, a magnet bonding process for arranging each of the selected segment magnets (3) having different magnetic polarities alternately in the circumferential direction of the shaft portion and attaching them to the shaft portion with an adhesive, a magnet position correction process for applying pressure to each segment magnet (3) within the curing time of the adhesive and correcting the position of each segment magnet (3), an adhesive curing process for curing the adhesive, and a final magnetization process for final magnetizing each segment magnet (3) after the adhesive has cured.

Description

[Technical field]

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

[0002] A rotor equipped with a permanent magnet is known as a rotor for a conventional rotating electric machine. In order to reduce cogging torque when used in a rotating electric machine, a rotor 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-sectional shape of the segment magnets is further formed into a semi-cylindrical shape.

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

[0004] However, in the conventional method described above, if the distance 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 type of misalignment is to narrow the width of each segment magnet and increase the distance between adjacent segment magnets in the circumferential direction. However, this would result in a problem of reduced torque in the rotating electrical machine.

[0006] In order to solve the above-mentioned positional deviation, Patent Document 1 discloses a method of temporarily magnetizing adjacent segment magnets in the circumferential direction so that they have the same magnetic polarity, and attaching each temporarily magnetized segment magnet to the outer circumferential surface of the shaft part with an adhesive. In the method disclosed in Patent Document 1, the segment magnets are held in a state in which they are equally spaced apart in the circumferential direction by utilizing the repulsive force acting between adjacent segment magnets in the circumferential direction. In the method disclosed in Patent Document 1, a rotor with high motor characteristics can be obtained by holding each segment magnet in a state in which they are equally spaced apart in the circumferential direction. Note that the method disclosed in Patent Document 1 includes a main magnetization process in which, after the adhesive hardens, each segment magnet is permanently magnetized so that adjacent segment magnets in the circumferential direction have opposite magnetic polarities. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2007-267575 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the method disclosed in Patent Document 1, when the segment magnets are attached one by one to the outer circumferential surface of the shaft, when the second segment magnet is attached to its correct position, the repulsive force acting between the segment magnets causes each segment magnet to move from its correct position. Similarly, when the third or subsequent segment magnets are attached, the repulsive force acting between the segment magnets causes 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, in 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 part 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 part. Either the former or latter method requires a large-scale jig to attach the segment magnets to the outer circumferential surface of the shaft part.

[0010] Furthermore, in the method disclosed in Patent Document 1, since each temporarily magnetized segment magnet (each segment magnet in the middle of the initial magnetization curve) is in an unsaturated state, the amount of magnetic flux is likely to vary in each temporarily magnetized segment magnet. When the amount of magnetic flux varies in each temporarily magnetized segment magnet, the attractive force of each segment magnet varies, causing segment magnets with low attractive force to slip off the outer circumferential surface of the shaft portion, or the repulsive force acting between the segment magnets varies, causing each segment magnet to not be held at equal intervals in the circumferential direction. This results in a problem of low accuracy in the attachment position of each segment magnet on the outer circumferential surface of the shaft portion.

[0011] In addition, in the method disclosed in Patent Document 1, the repulsive force acting between adjacent segment magnets in the circumferential direction is used to hold the attachment position of each segment magnet, so adjacent segment magnets in the circumferential direction 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 magnetization voltage must be applied to the magnetizing yoke to give some segment magnets the opposite magnetic polarity. This results in a 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 manufacturing method for a rotor of a rotating electric machine that can increase the accuracy of the attachment position of each segment magnet on the outer peripheral surface of the shaft portion while extending the life of the magnetizing yoke without using large-scale jigs. [Means for solving the problem]

[0013] In order to solve the above 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 of the temporarily magnetized segment magnets, and a magnet selection step of selecting a plurality of segment magnets to be used from each of 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 a curing time of the adhesive, an adhesive curing step of curing the adhesive, and a final magnetization step of final magnetizing each segment magnet after the adhesive has cured. In the magnet selection process, an upper limit value for the magnetic flux amount is set under 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 the segment magnet is attached to the shaft portion, and a lower limit value for the magnetic flux amount is set under the condition that each segment magnet does not slide off the shaft portion, and from among the segment magnets, a number of segment magnets whose measured magnetic flux amount is within the range from the upper limit value to the lower limit value are selected. Effect of the Invention

[0014] The manufacturing method of 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 peripheral surface of the shaft portion while extending the life of the magnetizing yoke without using large-scale jigs. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a configuration of a rotor of a rotating electric machine according to a first embodiment; [Diagram 2] A cross-sectional view taken along line II-II shown in FIG. [Diagram 3] FIG. 1 is a perspective view showing the configuration of a segment magnet before being temporarily magnetized in the first embodiment. [Figure 4] FIG. 1 is a perspective view showing an example of the configuration of a temporarily magnetized segment magnet in embodiment 1. [Diagram 5] FIG. 13 is a perspective view showing another example of the configuration of the temporarily magnetized segment magnet in the first embodiment. [Figure 6] FIG. 13 is a perspective view showing another example of the configuration of the temporarily magnetized segment magnet in the first embodiment. [Figure 7]FIG. 1 is a cross-sectional view showing the configuration of a rotor in which temporarily magnetized segment magnets are attached to the outer circumferential surface of a shaft in the first embodiment. [Figure 8] FIG. 1 is a cross-sectional view showing a main magnetization step in a manufacturing method for a rotor for a rotating electric machine according to a first embodiment; [Figure 9] FIG. 11 is a perspective view showing a configuration of a rotor of a rotating electric machine according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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] Embodiment 1 First, the configuration of the rotor 1 of the rotating electric machine according to the first embodiment will be described with reference to FIG. 1 and FIG. 2. FIG. 1 is a perspective view showing the configuration of the rotor 1 of the 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 the rotating electric machine may also be referred to as the 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 with a gap between the rotor 1 and the stator. 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 the rotating electric machine. The rotor 1 rotates relative to the stator about the rotation axis AX. Hereinafter, when describing the directions of the components of the rotor 1, the direction parallel to the rotation axis AX is defined as the axial direction, the direction perpendicular to the rotation axis AX is defined as the radial direction, and the rotation direction about the rotation axis AX is defined 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 shaft 2 has a cylindrical shape. Specifically, the shaft 2 has a shape in which a number of cylinders with different diameters are 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 segment magnets 3 are arranged in the circumferential direction. The segment magnets 3 are arranged at equal angles in the circumferential direction. As shown in FIG. 2, the shape of each segment magnet 3 when viewed along the axial direction is roughly semi-cylindrical. 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 are convex toward the 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 the magnetic path faces in the radial direction. The segment magnet 3 includes segment magnet 3A and segment magnet 3B that are magnetized in the magnetization process described below. Segment magnet 3A is a segment magnet whose NS poles face from the outside to the inside in the radial direction. Segment magnet 3B is a segment magnet whose NS poles face 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 segment magnets 3B are arranged so that the NS pole direction faces the radial direction, and the N pole and S pole of adjacent segment magnets 3A, 3B in the circumferential direction face each other.

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

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

[0023] As shown in FIG. 4 and FIG. 5, the temporary magnetization process is a process of temporarily magnetizing each of the plurality of segment magnets 3. The temporary magnetization process is performed to adjust the amount of 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 are arranged alternately in the circumferential direction of the shaft 2, similar to the magnetic polarity obtained in the main magnetization process. 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 FIG. 4 and FIG. 5, only the magnetic poles provided on the inner peripheral surface 31 side of each segment magnet 3C and 3D are illustrated. The outer peripheral surface 32 side of each segment magnet 3C, 3D has magnetic poles opposite to those of the inner peripheral surface 31 side. The magnetic poles of the segment magnet 3C shown in Fig. 4 are N-S poles from the outside to the inside in the radial direction. The magnetic poles of the segment magnet 3D shown in Fig. 5 are N-S poles from the inside to the outside in the radial direction.

[0024] In the temporary magnetization process, the segment magnet 3 is temporarily magnetized so that the range of the segment magnet 3 to be temporarily magnetized (hereinafter referred to as the temporary magnetization range 33) is symmetrical with respect to the circumferential direction and the axial direction of the segment magnet 3. In the temporary magnetization process, instead of the segment magnet 3C shown in FIG. 4, the segment magnet 3E shown in FIG. 6 may be manufactured. In other words, in the temporary magnetization process, as long as the segment magnet 3 can be temporarily magnetized so that the temporary magnetization range 33 is symmetrical with respect to the circumferential direction and the axial direction of the segment magnet 3, the segment magnet 3 may be temporarily magnetized so as to have a single temporary magnetization range 33 extending in the axial direction shown in FIG. 4, or the segment magnet 3 may be temporarily magnetized so as to have a plurality of temporary magnetization ranges 33 spaced apart from each other 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 temporarily magnetized so as to have a plurality of temporary magnetization ranges 33 spaced apart from each other 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 magnetization process, it is preferable to perform temporary magnetization from the radial inside to the radial outside of each segment magnet 3C, 3D. In other words, in the temporary magnetization process, it is preferable to perform temporary magnetization from the portion of each segment magnet 3C, 3D where the adhesive is applied (inner circumferential surface 31).

[0025] The magnetic flux measurement process is a process for measuring the magnetic flux of each of the temporarily magnetized segment magnets 3C, 3D. 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 of the temporarily magnetized segment magnets 3C, 3D.

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

[0027] As shown in Fig. 7, the magnet bonding process is a process in which the segment magnets 3C, 3D with different magnetic polarities are arranged alternately in the circumferential direction of the shaft 2 from among the selected segment magnets 3C, 3D, and attached to the shaft 2 with an adhesive. In the magnet bonding process, each segment magnet 3C, 3D is held at 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, the segment magnets 3C, 3D are attached to the outer peripheral surface of the shaft 2 alternately in the circumferential direction at equal intervals while the shaft 2 is rotated by a fixed angle. At this time, the segment magnets 3C, 3D are attracted to the outer peripheral surface of the shaft 2 by their respective magnetic forces. Therefore, when attaching the segment magnets 3C, 3D to the outer peripheral surface of the shaft 2 while rotating the shaft 2, even if the segment magnets 3C, 3D are positioned below the shaft 2, they will not fall off from the outer peripheral surface of the shaft 2. In this way, a rotor 1 is obtained in which a plurality of temporarily magnetized segment magnets 3C, 3D are arranged alternately and at equal intervals in the circumferential direction on the outer peripheral surface of the shaft 2.

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

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

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

[0032] This magnetization process is a process for magnetizing each of the segment magnets 3C, 3D after the adhesive has hardened. In this magnetization process, as shown in FIG. 8, multiple magnetizing yokes 4 are installed on the radial outside of each of the segment magnets 3C, 3D, and electricity is passed through the magnetizing coils 5 wound around each magnetizing yoke 4. In this magnetization process, electricity is passed through the magnetizing coils 5 to generate a magnetizing magnetic field. At this time, electricity is passed through the magnetizing coils 5 of each magnetizing yoke 4 so that the magnetizing yoke 4 through which the 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 the 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 alternately arranged in the circumferential direction. In this magnetization process, the rotor 1 equipped with the temporarily magnetized segment magnets 3C, 3D and the magnetization yoke 4 are arranged so that the magnetic polarity of each segment magnet 3C, 3D given in the temporary magnetization process is the same as that of each segment magnet 3A, 3B given in the actual magnetization process. That is, in this magnetization process, after the adhesive has hardened, each segment magnet 3C, 3D is permanently 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 arranged on the inner circumference 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 rotor 1 for a rotating electric machine according to this embodiment will be described.

[0034] In this embodiment, as shown in Fig. 4 and Fig. 5, the manufacturing method of the rotor 1 of the rotating electric machine includes a temporary magnetization process for temporarily magnetizing a part of each of the plurality of segment magnets 3, thereby limiting the temporary magnetization range 33 of each segment magnet 3. In addition, the manufacturing method of the rotor 1 of the rotating electric machine includes a magnetic flux amount measurement process for measuring the magnetic flux amount of each of the temporarily magnetized segment magnets 3C, 3D, and a magnet selection process for selecting the plurality of segment magnets 3C, 3D to be used from each of the segment magnets 3C, 3D based on the measured magnetic flux amount, thereby making it possible to select each of the segment magnets 3C, 3D by measuring the magnetic flux amount. Specifically, in the magnet selection process, an upper limit value of the magnetic flux amount is set on the condition that the position of each of the segment magnets 3C, 3D does not change due to the attraction force between the segment magnets 3C, 3D adjacent to each other in the circumferential direction when each of the segment magnets 3C, 3D is attached to the shaft 2, and a lower limit value of the magnetic flux amount is set on the condition that each of the segment magnets 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] In this way, 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, the magnetic force of each temporarily magnetized segment magnet 3C, 3D can be used only to hold each segment magnet 3C, 3D at the position where it is attached to the outer circumferential surface of the shaft 2. As a result, since there is no attraction or repulsion between the segment magnets 3C, 3D adjacent to each other in the circumferential direction, the segment magnets 3C, 3D are less likely to shift in position. Therefore, it is possible to attach the segment magnets 3C, 3D one by one to the outer circumferential surface of the shaft 2. In other words, since there is no need to attach all the segment magnets 3C, 3D to the outer circumferential surface of the shaft 2 at once or to temporarily hold the segment magnets 3C, 3D that have already been attached until the attachment of all the segment magnets 3C, 3D to the outer circumferential surface of the shaft 2 is completed, a large-scale jig for attaching the segment magnets 3C, 3D to the outer circumferential surface of the shaft 2 is not required.

[0036] In this embodiment, even if the magnetic flux amount of each temporarily magnetized segment magnet 3C, 3D varies, the segment magnets 3C, 3D are selected by measuring the magnetic flux amount, so that a plurality of segment magnets 3C, 3D with less variation in magnetic flux amount can be used. In addition, in this embodiment, the manufacturing method of the rotor 1 of the rotating electric machine includes a magnet position correction process for correcting the position of each segment magnet 3C, 3D within the curing time of the adhesive. This makes it possible to improve the accuracy of the attachment position of each segment magnet 3C, 3D on the outer circumferential surface of the shaft 2. That is, 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 in the circumferential direction but also in the axial direction. Therefore, it is possible to improve the accuracy of the attachment position of each segment magnet 3C, 3D in the circumferential direction and the axial direction on the outer circumferential surface of the shaft 2.

[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 at the position where it is attached to the outer circumferential surface of the shaft 2, so that the segment magnets 3C, 3D adjacent to each other in the circumferential direction can 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 in the circumferential direction of the shaft 2 and attached to the shaft 2 with an adhesive. As a result, in the actual magnetization process, each segment magnet 3C, 3D can be permanently magnetized with the same magnetic polarity as in the temporary magnetization process after the adhesive has hardened, so that it is not necessary to make each segment magnet 3C, 3D have the opposite magnetic polarity to that in the temporary magnetization process in the actual magnetization process, which is a process following the temporary magnetization process. Therefore, since it is not necessary to apply a high magnetization voltage to the magnetization yoke 4 in the actual magnetization process, the life of the magnetization yoke 4 can be extended and energy can be saved in the manufacturing process of the rotor 1.

[0038] As described above, in this embodiment, the accuracy of the attachment positions of the segment magnets 3C, 3D on the outer circumferential surface of the shaft 2 can be improved while extending the life of the magnetizing yoke 4 without using any large-scale jigs.

[0039] In the temporary magnetization process of this embodiment, temporary magnetization is performed from the portions of each segment magnet 3C, 3D shown in FIG. 7 where adhesive is applied. That is, in the temporary magnetization process, temporary magnetization is performed from the radial inside of each segment magnet 3C, 3D. This makes it possible to reduce or eliminate the influence of temporary magnetization on the outer peripheral portion of the rotor 1, which is related to the motor characteristics. In addition, 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, so the life of the magnetization yoke 4 can be extended.

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

[0041] In this embodiment, the thickness of the adhesive is adjusted as desired by applying pressure in the magnet position correction process, but the present invention is not limited to this. For example, instead of applying pressure in the magnet position correction process, the thickness of the adhesive may be adjusted as desired by applying pressure to each of the segment magnets 3C, 3D in the magnet bonding process. Examples of methods for applying pressure to each of the segment magnets 3C, 3D in the magnet bonding process include a method of applying pressure with a band or an adsorption tool for arranging each of the segment magnets 3C, 3D on the outer circumferential surface of the shaft 2, and a method of applying pressure by the adsorption force of each of the temporarily magnetized segment magnets 3C, 3D. By applying pressure to each of the segment magnets 3C, 3D in the magnet bonding process in this way, the thickness of the adhesive can be adjusted as desired without using a pressure device in the manufacture of the rotor 1, and therefore the manufacturing device for the rotor 1 can be simplified and the manufacturing cost can be reduced. In addition, by applying pressure to each of the segment magnets 3C, 3D in the magnet bonding process, the segment magnets 3C, 3D can be arranged on the outer circumferential surface of the shaft 2 and pressurized at the same time, so that the processing time (cycle time) can be shortened.

[0042] In this embodiment, the segment magnets 3C and 3D are magnetized in the main magnetization process with the same magnetic polarity as in the temporary magnetization process after the adhesive has hardened, but the segment magnets 3C and 3D may be magnetized in the main magnetization process with the opposite magnetic polarity to that in the temporary magnetization process after the adhesive has hardened. For example, if the direction of temporary magnetization cannot be changed due to restrictions on the device side, all the segment magnets 3 may be temporarily magnetized to have the same magnetic polarity in the temporary magnetization process, and then some of the segment magnets 3 may be magnetized in the main magnetization process with the opposite magnetic polarity. Even in this way, by performing the magnet selection process, the use of segment magnets 3 with a large magnetic flux amount can be avoided. Therefore, compared to the method disclosed in Patent Document 1 in which the magnet selection process is not performed, the magnetization voltage applied to the magnetization yoke 4 in the main magnetization process can be reduced, so that the life of the magnetization yoke 4 can be extended and energy can be saved in the manufacturing process of the rotor 1.

[0043] In this embodiment, the multiple segment magnets 3 are attached to the outer circumferential surface of the shaft 2 alone, but they may also be attached to the outer circumferential surface of the rotor core of a shaft assembly composed of the rotor core and the shaft 2. In this configuration, the rotor 1 includes a shaft assembly which is a shaft portion, and multiple segment magnets 3 attached to the outer circumferential 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 the rotor core. The rotor core is, for example, a laminate of rolled steel sheets or electromagnetic steel sheets, or a machined metal product, and is formed into a tubular shape such as a cylindrical shape.

[0044] Embodiment 2 Next, a manufacturing method of a rotor 1A of a rotating electric machine according to the second embodiment will be described with reference to Fig. 9. Fig. 9 is a perspective view showing a configuration of a rotor 1A of a rotating electric machine according to the second embodiment. This embodiment differs from the above-described first embodiment in that a plurality of segment magnets 3 are also arranged in the axial direction. In the second embodiment, the same reference numerals are used for parts that overlap with the above-described first embodiment, and description thereof will be omitted.

[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 the circumferential direction and in the axial direction. That is, in this embodiment, there are two rows in the axial direction 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 and the circumferential center line of each of the segment magnets 3A, 3B in the other row are arranged on a straight line. 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 manufacturing method of the rotor 1A of the rotating electric machine according to this embodiment will be described with reference to FIGS.

[0047] The manufacturing method of the rotor 1A of a rotating electric machine according to the present embodiment includes a temporary magnetization 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 magnetization step. Since the steps other than the magnet bonding step and the magnet position correction step are generally the same as the manufacturing method of the rotor 1 of a rotating electric machine according to the first embodiment described above, a description thereof will be omitted here. The configuration of the temporarily magnetized segment magnets 3C, 3D used in the manufacturing method of 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 among the selected segment magnets 3, the segment magnets 3C, 3D with different magnetic polarity are arranged alternately in the circumferential direction of the shaft 2 and attached to the shaft 2 with an 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 an 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 an 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 an adhesive.

[0049] The magnet position correction process is a process of applying pressure to each of the segment magnets 3C, 3D and correcting the position of each of the segment magnets 3C, 3D within the adhesive hardening time. In the magnet position correction process, a jig (not shown) is used to correct the position of each of the segment magnets 3C, 3D so that they are positioned at equal intervals in the circumferential direction and are aligned in the axial direction.

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

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

[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 in one row are attached to the shaft 2, and then the segment magnets 3C, 3D in the other row are attached to the shaft 2, but this is not limited to this. For example, the segment magnets 3C, 3D in one row and the segment magnets 3C, 3D in 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 the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

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

Claims

1. a temporary magnetizing step of temporarily magnetizing a portion of each of the plurality of segment magnets; a magnetic flux amount measuring step of measuring the magnetic flux amount of each of the temporarily magnetized segment magnets; a magnet selection step of selecting a plurality of the segment magnets to be used from among the segment magnets based on the measured amount of magnetic flux; a magnet bonding process in which the segment magnets having different magnetic polarities are alternately arranged in the circumferential direction of the shaft portion from among the selected segment magnets and attached to the shaft portion with an adhesive; a magnet position correction step of applying pressure to each of the segment magnets and correcting the position of each of the segment magnets within the curing time of the adhesive; an adhesive curing step of curing the adhesive; a main magnetization process of main magnetizing each of the segment magnets after the adhesive has hardened; Including, 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 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 from each segment magnet.

2. 2. The method for manufacturing a rotor for a rotating electric machine according to claim 1, wherein the temporary magnetization step begins with temporary magnetization of the segment magnets at the portions to which the adhesive is applied.

3. 2. The method for manufacturing a rotor for a rotating electric machine according to claim 1, wherein in the main magnetizing step, each of the segment magnets is main magnetized with the same magnetic polarity as in the temporary magnetizing step after the adhesive has hardened.

4. a temporary magnetizing step of temporarily magnetizing a portion of each of the plurality of segment magnets; a magnetic flux amount measuring step of measuring the magnetic flux amount of each of the temporarily magnetized segment magnets; a magnet selection step of selecting a plurality of the segment magnets to be used from among the segment magnets based on the measured amount of magnetic flux; a magnet bonding process in which segment magnets with different magnetic polarities are alternately arranged from the selected segment magnets in the circumferential direction of the shaft portion, and are attached to the shaft portion with an adhesive while applying pressure to each segment magnet; a magnet position correction step of correcting the position of each of the segment magnets within the curing time of the adhesive; an adhesive curing step of curing the adhesive; a main magnetization process of main magnetizing each of the segment magnets after the adhesive has hardened; Including, 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 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 from each segment magnet.

5. 5. The method for manufacturing a rotor for a rotating electric machine according to claim 4, wherein in the magnet adhering step, the adhesive is pressurized by the attraction force of each of the temporarily magnetized segment magnets.

6. 5. The method for manufacturing a rotor for a rotating electric machine according to claim 4, wherein in the main magnetizing step, each of the segment magnets is main magnetized with the same magnetic polarity as in the temporary magnetizing step after the adhesive has hardened.

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