Method for manufacturing motor assembly, and motor assembly

Abstract

This method for manufacturing a motor assembly includes: a step for inserting a magnet into each of a plurality of first magnet insertion holes that extend in an axial direction and are formed in a first core block formed by stacking a plurality of first core pieces made of electromagnetic steel sheets; a step for pressing and plastically deforming a position adjacent to the first magnet insertion hole on at least one end surface of the first core block in the axial direction to form a first protrusion that protrudes into the first magnet insertion hole and supports the magnet; and a step for stacking a second core block formed by one or a plurality of second core pieces made of electromagnetic steel sheets onto the end surface of the first core block on which the first protrusion has been formed.

Description

Method for manufacturing a motor assembly and motor assembly

[0001] The technology of the present disclosure relates to a method for manufacturing a motor assembly and a motor assembly.

[0002] As a member constituting a rotating electrical machine, there is known a motor core, for example, a rotor core in which a plurality of magnet insertion holes are arranged annularly at a predetermined interval and magnets are respectively attached to the magnet insertion holes. As a method of attaching a magnet to a motor core, there is known a method in which after inserting a magnet into a magnet insertion hole, a part around the magnet insertion hole is plastically deformed to provide a protrusion for supporting the magnet.

[0003] International Publication No. 2023 / 037794 discloses a rotor core formed by laminating a plurality of steel plates in the thickness direction and having a plurality of magnet arrangement holes, a plurality of permanent magnets corresponding to the plurality of magnet arrangement holes and each disposed inside the corresponding magnet arrangement hole, and a rotating shaft fixed to the rotor core and having a rotation center as its axis. The rotor core is located inside a first magnet arrangement hole included in the plurality of magnet arrangement holes, and has a first inner surface and a second inner surface facing each other, and a protrusion formed by plastic deformation of the rotor core and protruding from the second inner surface toward the first inner surface side. Among the plurality of permanent magnets, a rotor in which a first permanent magnet disposed in a first magnet arrangement hole is held in the first magnet arrangement hole by a protrusion is described.

[0004] The plastic deformation performed when forming the protrusion described in International Publication No. 2023 / 037794 can be realized, for example, by spot caulking. However, since the steel plate (corresponding to the core piece described later) constituting the rotor core (corresponding to the rotor core described later) is formed of a thin plate material, when the above-described spot caulking is performed, not only the protrusion portion but also the periphery thereof may be deformed. This deformation causes a gap to be formed between the laminated steel plates.

[0005] The present disclosure provides a method for manufacturing a motor assembly and a motor assembly that prevent a gap from occurring between a plurality of core pieces of a motor core.

[0006] A method for manufacturing a motor assembly according to a first aspect of the present disclosure includes the steps of: inserting magnets into each of a plurality of axially extending first magnet insertion holes formed in a first core block constructed by stacking a plurality of first core pieces made of electromagnetic steel sheets; pressing and plastically deforming a position adjacent to the first magnet insertion holes on at least one axial end face of the first core block in order to form a first projection that protrudes into the first magnet insertion holes and supports the magnets; and stacking a second core block, composed of one or more second core pieces made of electromagnetic steel sheets, on the end face of the first core block on which the first projection is formed.

[0007] In this method of manufacturing a motor assembly, since the second core block is laminated on the surface of the first core block on which the first protrusion is formed, even if a part of the first core piece is deformed when the first protrusion is formed, the deformation can be suppressed. Therefore, the gaps that may be formed between the multiple laminated core pieces can be reduced to an extent that does not affect the performance of the motor, or substantially eliminated.

[0008] A method for manufacturing a motor assembly according to a second aspect of the present disclosure further includes a step of pressing the second core block, which is stacked on the first core block, against the first core block, in the method for manufacturing a motor assembly according to the first aspect of the present disclosure.

[0009] In this method of manufacturing a motor assembly, the deformation of the end face of the first core block can be significantly suppressed by pressing the second core block against the first core block.

[0010] A third aspect of the present disclosure is a method for manufacturing a motor assembly, in which, in the method for manufacturing a motor assembly according to the first or second aspect of the present disclosure, the step of pressing and plastically deforming a position adjacent to the first magnet insertion hole on at least one axial end face of the first core block is performed by pressing positions adjacent to the first magnet insertion holes on both axial ends of the first core block.

[0011] In this method of manufacturing a motor assembly, since first protrusions are formed on both end faces of the first core block, the support of the magnet by the first protrusions can be made more stable.

[0012] A method for manufacturing a motor assembly according to a fourth aspect of the present disclosure is a method for manufacturing a motor assembly according to any of the first to third aspects of the present disclosure, wherein the axial length of the first core block is shorter than the axial length of the magnet, and the step of pressing and plastically deforming a position adjacent to the first magnet insertion hole on at least one axial end face of the first core block is performed by pressing and plastically deforming a position adjacent to the first magnet insertion hole on the end face while the magnet is protruding from the end face.

[0013] In this method of manufacturing a motor assembly, the first projection contacts the middle portion of the magnet in the longitudinal direction to support the magnet, thus further stabilizing the support of the magnet.

[0014] A fifth aspect of the present disclosure is a method for manufacturing a motor assembly, in which the second core block comprises a plurality of second magnet insertion holes extending in the axial direction, and the step of stacking the second core blocks is to stack the first core block and the second core block such that the portion of the magnet inserted into the first magnet insertion hole of the first core block protruding from the end face is housed in the second magnet insertion hole.

[0015] In this method of manufacturing a motor assembly, the entire length of the magnet can be housed within the first or second magnet insertion hole, thus preventing damage to the magnet during motor assembly.

[0016] A method for manufacturing a motor assembly according to a sixth aspect of the present disclosure is a method for manufacturing a motor assembly according to any of the first to fifth aspects of the present disclosure, wherein the second core block is composed of a plurality of the second core pieces stacked together, and includes a plurality of second magnet insertion holes extending in the axial direction, and a second projection on at least one end face in the axial direction of the second core block that protrudes into the second magnet insertion holes and supports a second magnet inserted into the second magnet insertion holes, and the step of stacking the second core blocks is to stack them such that the end face on which the second projection is formed faces the first core block.

[0017] This method of manufacturing motor assemblies makes it possible to provide motor assemblies that can be used for large motors or motors with skew applied to each block.

[0018] A method for manufacturing a motor assembly according to a seventh aspect of the present disclosure further includes a step of stacking one or more third core blocks, each configured by stacking a plurality of third core pieces made of electromagnetic steel sheets, and each third core block having a plurality of third magnet insertion holes extending in the axial direction, and a third projection on at least one end face in the axial direction that protrudes into the third magnet insertion holes and supports a third magnet inserted into the third magnet insertion holes, such that the end face on which the third projection is formed faces the second core block or the third core block.

[0019] In this method of manufacturing motor assemblies, deformation that may occur in the core pieces can be reduced or substantially eliminated, even when stacking three or more core blocks. Furthermore, it becomes possible to provide motor assemblies that can be used for larger motors or motors with skew applied to each block.

[0020] A motor assembly according to an eighth aspect of the present disclosure includes a first core block, which is constructed by stacking a plurality of first core pieces made of electromagnetic steel sheets and has a plurality of first magnet insertion holes extending in the axial direction and a first projection formed on at least one end face in the axial direction and protruding into the first magnet insertion holes; magnets inserted into the first magnet insertion holes and supported within the first magnet insertion holes by the first projection; and one or more second core blocks, which are made of one or more second core pieces made of electromagnetic steel sheets, and one of their axial surfaces abuts against and is supported by the end face of the first core block on which the first projection is formed.

[0021] In such a motor assembly, since the second core block is supported by contact with the surface of the first core block on which the first projection is formed, gaps that may be formed between the multiple stacked core pieces due to deformation at positions adjacent to the first projection can be reduced to an extent that does not affect the performance of the motor, or substantially eliminated.

[0022] A motor assembly according to a ninth aspect of the present disclosure is, in the motor assembly according to the eighth aspect of the present disclosure, wherein the axial length of the first core block is shorter than the axial length of the magnet, and the second core block comprises a plurality of second magnet insertion holes extending in the axial direction, the portions of the magnets inserted into the first magnet insertion holes that protrude from the end faces are housed in the second magnet insertion holes.

[0023] In such a motor assembly, the entire length of the magnet can be housed within the first or second magnet insertion hole, thus preventing damage to the magnet during motor assembly.

[0024] A motor assembly according to a tenth aspect of the present disclosure is a motor assembly according to an eighth or ninth aspect of the present disclosure, wherein the second core block is composed of a plurality of the second core pieces stacked together and comprises a plurality of second magnet insertion holes extending in the axial direction and a second projection protruding into the second magnet insertion holes from at least one axial end face of the second core block, and further comprises a second magnet inserted into the second magnet insertion holes and supported within the second magnet insertion holes by the second projection, and the second core block is stacked such that the end face of the second core block on which the second projection is formed faces the first core block.

[0025] In such motor assemblies, deformation that may occur in the core pieces can be reduced or virtually eliminated. Furthermore, it can be used in large motors or motors with skew applied to each block.

[0026] A motor assembly according to an eleventh aspect of the present disclosure is a motor assembly according to any eighth to tenth aspect of the present disclosure, further comprising: one or more third core blocks, which are constructed by laminating a plurality of third core pieces made of electromagnetic steel sheets, and each third core block has a plurality of third magnet insertion holes extending in the axial direction and a third projection protruding into the third magnet insertion holes from at least one end face in the axial direction; and a third magnet inserted into the third magnet insertion holes and supported in the third magnet insertion holes by the third projection, wherein the third core blocks are laminated such that the end faces on which the third projections are formed face the second core block or other third core blocks.

[0027] In such motor assemblies, deformation that may occur in the core pieces can be reduced or virtually eliminated. Furthermore, it can be used for larger motors or motors with skew applied to each block.

[0028] A motor assembly according to a twelfth aspect of the present disclosure further includes, in a motor assembly according to any eighth to eleventh aspect of the present disclosure, a shaft inserted into an axially extending through hole formed in the first core block and the second core block, and an end plate that presses and supports the first core block and the second core block from their axial ends, into which the shaft is inserted.

[0029] In such a motor assembly, the end plate presses against the core block, eliminating gaps caused by deformation of the core piece.

[0030] The motor assembly manufacturing method and motor assembly of this disclosure make it possible to prevent gaps from occurring between multiple core pieces of the motor core.

[0031] This is an exploded perspective view showing an example of a motor assembly according to the first embodiment. This is a plan view showing the state after assembling each component of the motor assembly shown in Figure 1. This is a plan view showing the state of the motor assembly shown in Figure 1 before assembling the second core block. This is an enlarged view of part A in Figure 2B. This is a flowchart showing an example of a method for manufacturing a motor assembly according to the first embodiment. This is an explanatory diagram showing the state of the motor assembly when the method for manufacturing a motor assembly shown in Figure 4 is carried out. This is an explanatory diagram showing the state of the motor assembly when the method for manufacturing a motor assembly shown in Figure 4 is carried out. This is an explanatory diagram showing the state of the motor assembly when the method for manufacturing a motor assembly shown in Figure 4 is carried out. This is an explanatory diagram showing the state of the motor assembly when the method for manufacturing a motor assembly shown in Figure 4 is carried out. This is an exploded perspective view showing an example of a motor assembly according to the second embodiment. This is a flowchart showing an example of a method for manufacturing a motor assembly according to the second embodiment. This is an explanatory diagram showing the state of the motor assembly when the method for manufacturing a motor assembly shown in Figure 8 is carried out This is an explanatory diagram showing the state of the motor assembly when the manufacturing method of the motor assembly shown in Figure 8 is implemented. This is an exploded perspective view showing an example of a motor assembly according to the third embodiment. This is a flowchart showing an example of a motor assembly manufacturing method according to the third embodiment. This is an explanatory diagram showing the state of the motor assembly when the manufacturing method of the motor assembly shown in Figure 13 is implemented. This is an explanatory diagram showing the state of the motor assembly when the manufacturing method of the motor assembly shown in Figure 13 is implemented. This is an explanatory diagram showing the state of the motor assembly when the manufacturing method of the motor assembly shown in Figure 13 is implemented.This is an explanatory diagram showing the state of the motor assembly when the motor assembly manufacturing method shown in Figure 13 is implemented. This is an explanatory diagram showing the state of the motor assembly when the motor assembly manufacturing method shown in Figure 13 is implemented. This is an explanatory diagram showing the state of the motor assembly when the motor assembly manufacturing method shown in Figure 13 is implemented. This is a schematic cross-sectional view showing a modified example of the second embodiment. This is a schematic cross-sectional view showing a modified example of the third embodiment.

[0032] This application is based on Japanese Patent Application No. 2024-193246, filed in Japan on November 1, 2024, the contents of which form part of the content of this application. The disclosure can be understood more fully by the following detailed description. Further applications of this application will become clear from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the disclosure and are described for illustrative purposes only, for various changes and modifications will be obvious to those skilled in the art within the spirit and scope of the disclosure from this detailed description. The applicant has no intention of dedicating any of the described embodiments to the public, and any disclosed modifications and alternatives, even those not literally included in the claims, are considered part of the invention under the doctrine of equivalents. Similar reference numbers and names in various drawings indicate similar elements.

[0033] The following describes various embodiments for implementing this disclosure with reference to the drawings. In the following, only the necessary parts for explaining the objectives of this disclosure are schematically shown, and the explanation will primarily focus on the parts necessary for explaining the relevant sections of this disclosure. Any parts omitted from the explanation will be considered to be based on prior art. Furthermore, identical or equivalent components in the drawings are denoted by the same or similar reference numerals, and redundant explanations are omitted. Additionally, if multiple identical or equivalent components are included in the drawings, reference numerals may be assigned to only some of them for clarity.

[0034] <First Embodiment> In the first embodiment described below, the motor assembly is an example in which the motor assembly is a semi-finished product of a rotor constituting an inner rotor type motor. However, the motor assembly of this disclosure is not limited to the above and includes any component of the motor to which a magnet is attached or a semi-finished product thereof.

[0035] (Motor Assembly) Figure 1 is an exploded perspective view showing an example of a motor assembly according to the first embodiment. Figure 2A is a plan view showing the motor assembly after each component has been assembled, and Figure 2B is a plan view showing the motor assembly before the second core block is assembled. The arrow X in Figure 1 indicates the axial direction of the motor assembly 1, as well as the vertical direction of the motor assembly 1. The first core block 10 shown in the exploded perspective view of Figure 1 is shown before the first projection 14 (see Figure 2B) is formed during the assembly process.

[0036] As shown in Figures 1 and 2A, the motor assembly 1 according to this embodiment includes a rotor core 2 and permanent magnets 3. The rotor core 2 in this embodiment is composed of a first core block 10 and a second core block 20. The permanent magnets 3 are an example of the magnets of this disclosure.

[0037] The first core block 10 may be a substantially cylindrical magnetic body, as shown in Figure 1, and is constructed by stacking multiple first core pieces 11 made of electromagnetic steel sheets having a relatively thin thickness of, for example, 0.1 to 0.5 mm, more preferably 0.2 to 0.3 mm. The stacked multiple first core pieces 11 may be joined together by well-known joining means, such as adhesive, riveting, or welding. The first core block 10 may have a first through hole 12 extending along the axial direction X in its approximate center in a plan view. The first core block 10 is also provided with a plurality of first magnet insertion holes 13 extending along the axial direction X. In Figure 1, the first magnet insertion holes 13 are arranged in a circular pattern with 16 holes spaced at predetermined intervals around the first through hole 12. The shape of the first magnet insertion holes 13 can be adjusted to match the shape of the permanent magnet 3 to be inserted, for example, the shape of the opening can be substantially rectangular or arc-shaped. The first through-hole 12 is an example of a through-hole in this disclosure.

[0038] The permanent magnet 3 can be made up of a rectangular parallelepiped or a block that is slightly smaller than the first magnet insertion hole 13 (for example, with sides of about 0.01 to 1 mm in length) or has an arc shape in plan view. It is not necessary whether the permanent magnet 3 is magnetized or not when it is inserted into the first magnet insertion hole 13. Furthermore, it is not necessary whether the permanent magnet 3 is divided in the axial direction X or in a direction intersecting the axial direction X.

[0039] As shown in Figure 2B, the permanent magnet 3 is inserted into the first magnet insertion hole 13 and then supported within the first magnet insertion hole 13. To achieve this support, the first core block 10 is provided with a first projection 14 that protrudes into the first magnet insertion hole 13.

[0040] Figure 3 is an enlarged view of part A in Figure 2B. As shown in Figures 2B and 3, the first projection 14 is formed by plastically deforming at least one end face of the first core block 10 after the permanent magnet 3 has been inserted into the first magnet insertion hole 13. In this embodiment, the first projection 14 is formed on one of the plurality of first core pieces 11 that constitutes the upper surface of the first core block 10 (hereinafter, to distinguish it from other first core pieces, this first core piece will be called the "upper surface first core piece 11U"). This first projection 14 can be formed, for example, by pressing a first pressing portion 15 set around the first magnet insertion hole 13 of the upper surface first core piece 11U with a punch 52 (see Figure 5B), which will be described later. The shape of the first pressing portion 15, which is pressed by the punch or the like mentioned above, is not particularly limited and may consist of a flat surface, be raised upwards, or have a hole formed in it.

[0041] In this embodiment, the first projection 14 is exemplified as being provided adjacent to one long side and one short side of the first magnet insertion hole 13, which is rectangular in plan view. However, the arrangement and number of the first projections 14 relative to the first magnet insertion hole 13 are not limited thereto. Specifically, one or more first projections may be formed on each of the two long sides, or one or more first projections may be formed on only one long side. Furthermore, in this embodiment, the case in which the first projection 14 is formed only on the first core piece 11U on the upper side is exemplified. However, similar first projections 14 may also be formed on one or more first core pieces 11 adjacent to the first core piece 11U on the upper side.

[0042] Here, when the first pressing portion 15 of the first core block 10 is pressed with a punch or the like, not only is a first projection 14 formed on the upper side of the first core piece 11U, but unintended deformation may occur around the first pressing portion 15. This deformation includes deformation such as the edge portion of the upper side of the first core piece 11U being warped upward or a part of the upper side of the first core piece 11U becoming wavy. Such deformation can not only reduce the dimensional accuracy of the rotor core 2, but can also cause liquid leakage when supplying refrigerant or the like into the motor assembly 1. Therefore, in this embodiment, in order to eliminate the aforementioned deformation, a configuration is adopted in which the second core block 20 is stacked on the first core block 10.

[0043] The second core block 20 may be a substantially cylindrical magnetic body, as shown in Figure 1, and is composed of one or more second core pieces 21 made of the same electromagnetic steel sheet as the first core piece 11, stacked together. If there are multiple second core pieces 21, they may be joined together and stacked together by well-known joining means, similar to the first core piece 11. The second core block 20 may be provided with a second through hole 22 extending along the axial direction X, located approximately in the center in a plan view. The second core block 20 may also be provided with a plurality of second magnet insertion holes 23 extending along the axial direction X. The second through hole 22 and the second magnet insertion holes 23 may be located in positions that communicate with the first through hole 12 and the first magnet insertion holes 13, respectively, when the second core block 20 is stacked on the first core block 10. In other words, the second core block 20 of this embodiment may have the same configuration as the first core block 10, except that it does not include the configuration corresponding to the first projection 14. In this embodiment, the number of second core pieces 21 constituting the second core block 20 is exemplified as being less than the number of first core pieces 11, but the number of each core piece is not particularly limited. Also, the second through hole 22 is an example of a through hole of this disclosure.

[0044] The second core block 20 having the above-described configuration is laminated on the first core block 10, and one surface in the axial direction X thereof abuts against and is supported by the end surface on which the first protrusion 14 of the first core block 10 is formed, specifically, the first core piece 11U on the upper surface side. The laminated first core block 10 and second core block 20 may be joined and fixed to each other by joining means not shown. Examples of the joining means herein include an adhesive, caulking portions provided on the abutting surfaces of each other, or welding. When the plurality of core blocks 10 and 20 are not joined to each other, a shaft 4 (see FIGS. 16A and the like) described later is press-fitted into through holes 12 and 22 provided at the centers of the core blocks 10 and 20, or after the shaft 4 is inserted into the through holes 12 and 22, fixing means such as an end plate 5 (see FIGS. 16A and the like) described later is used to sandwich them, whereby the plurality of core blocks 10 and 20 may be fixed to each other.

[0045] As described above, when the surface on which the first protrusion 14 of the first core block 10 is formed abuts against and is supported by one surface of the second core block 20, even if unintended deformation has occurred around the first pressing portion 15, the deformation is pressed when the second core block 20 abuts, and is significantly suppressed. Therefore, it is possible to prevent a gap from occurring between the plurality of core pieces 11 and 21 of the rotor core 2. When laminating the first core block 10 and the second core block 20, it is preferable to pressurize the second core block 20 with respect to the first core block 10 using pressing means or the like not shown, so that the deformation of the first core piece 11U on the upper surface side can be more surely eliminated.

[0046] Furthermore, in the motor assembly 1 of this embodiment, it is preferable to adjust the axial length D1 of the first core block 10 to be shorter than the axial length D2 of the permanent magnet 3. By adjusting the axial length D1 of the first core block 10 in this way, support of the permanent magnet 3 by the first projection 14 can be easily realized. To explain in more detail, in order to realize support of a permanent magnet using a conventional projection, it is necessary to plastically deform the upper surface of the motor core while precisely aligning the upper end of the magnet insertion hole and the upper end of the permanent magnet in order to bring the projection and the permanent magnet into contact. However, with the configuration of this embodiment described above, the first projection 14 is brought into contact with the middle part of the permanent magnet 3 in the longitudinal direction (i.e., axial direction X), so it is not necessary to perform the aforementioned alignment. Therefore, even if there is variation in the axial length D1 of the first core block 10 or the axial length D2 of the permanent magnet 3, support of the permanent magnet 3 to the first core block 10 can be easily realized.

[0047] In addition, the axial length of the rotor core 2 is determined by the axial length D1 of the first core block 10 and the axial length D3 of the second core block 20. Therefore, by adjusting the axial length D3 of the second core block 20, the axial length of the rotor core 2 can be adjusted to be the same as or slightly longer (for example, about 0.01 to 1 mm) than the axial length D2 of the permanent magnet 3, and the entire length of the permanent magnet 3 can be easily accommodated in the first magnet insertion hole 13 and the second magnet insertion hole 23. The total number of core pieces constituting the rotor core 2, more specifically the first core piece 11 and the second core piece 21, is not particularly limited, but may be several tens to several hundred pieces, for example.

[0048] (Method for manufacturing a motor assembly) Next, the method for manufacturing a motor assembly according to the present embodiment will be described below mainly with reference to FIG. 4. In the following description, the case of manufacturing the motor assembly 1 described above by implementing the method for manufacturing a motor assembly according to the present embodiment will be described. In this regard, the effects of the method for manufacturing a motor assembly described later also include the effects of the motor assembly 1. Further, a series of processes described below can be realized by operating a manufacturing apparatus for a motor assembly including a base 51 (see FIGS. 5A, etc.) and a punch 52 (see FIGS. 5B, etc.) described later based on a control program or the like.

[0049] FIG. 4 is a flowchart showing an example of a method for manufacturing a motor assembly according to the first embodiment. FIGS. 5A, 5B, 6A, and 6B are explanatory views sequentially showing the state of the motor assembly when the method for manufacturing the motor assembly shown in FIG. 4 is implemented. In FIGS. 5A, 5B, 6A, and 6B, schematic cross-sectional views are shown in which each component of the motor assembly 1 is a cross-section cut along the B - B line shown in FIG. 2B, and the scale of each part is adjusted so that the configuration of each part is easy to understand.

[0050] The method for manufacturing a motor assembly according to the present embodiment includes at least a step of inserting a permanent magnet 3 into each of a plurality of first magnet insertion holes 13 extending in the axial direction formed in a first core block 10 formed by laminating a plurality of first core pieces 11 made of electromagnetic steel sheets (corresponding to step S02 described later), and a step of pressing and plastically deforming a position adjacent to the first magnet insertion hole 13 on at least one end face in the axial direction X of the first core block 10 to form a first protrusion 14 that protrudes into the first magnet insertion hole 13 and supports the permanent magnet 3 (corresponding to step S03 described later), and a step of laminating a second core block 20 composed of one or more second core pieces 21 made of electromagnetic steel sheets on the end face of the first core block 10 where the first protrusion 14 is formed (corresponding to step S04 described later). Details will be described below.

[0051] In the motor assembly manufacturing method according to this embodiment, first, as shown in Figure 4, a first core block 10 composed of a plurality of first core pieces 11 is prepared (step S01). The first core block 10 prepared here is placed on a base 51, for example, whose upper surface is substantially horizontal, as shown in Figure 5A.

[0052] Once the first core block 10 is prepared, the permanent magnet 3 is then inserted into the first magnet insertion hole 13, as shown in Figure 5A (step S02). The lower surface of the permanent magnet 3 inserted into the first magnet insertion hole 13 is placed on the base 51, similar to the first core block 10. As a result, the lower surface of the first core block 10 and the lower surface of the permanent magnet 3 are located on the same plane. Since the axial length D1 of the first core block 10 is adjusted to be shorter than the axial length D2 of the permanent magnet 3, the upper part of the permanent magnet 3 placed on the base 51 is supported in a state where it protrudes upward from the upper surface of the first core block 10.

[0053] Next, a first projection 14 is formed on the first core block 10 (step S03). In this embodiment, the first projection 14 is formed by pressing a pre-set first pressing portion 15 on the upper surface of the first core block 10 with a punch 52 from above the first core block 10. More specifically, when the first pressing portion 15 is pressed with the punch 52, the area around the first pressing portion 15, particularly the side wall of the adjacent first magnet insertion hole 13, undergoes plastic deformation to protrude, thereby forming the first projection 14 on the upper side of the first core piece 11U. The first projection 14 formed by the above-described step abuts against the longitudinal middle portion of the permanent magnet 3. This supports the permanent magnet 3 with a portion of it housed in the first magnet insertion hole 13. Furthermore, the first projection 14 and the permanent magnet 3 can be reliably brought into contact, stabilizing the support position of the permanent magnet 3.

[0054] When the aforementioned step S03 is performed, as shown in Figure 6A, a first projection 14 is formed due to the pressing force of the punch 52, and a deformation area DE occurs on a part of the upper surface of the first core piece 11U, for example, around the first pressing portion 15. Therefore, in the motor assembly manufacturing method of this embodiment, the second core block 20 is then stacked on the surface of the first core block 10 where the deformation area DE occurred, i.e., the upper surface (step S04). When stacking, it is preferable that the first core block 10 and the second core block 20 are joined to each other, but they may also be joined at the timing of step S05, which will be described later. When the second core block 20 is stacked on the upper surface of the first core block 10, the upper surface of the first core piece 11U, including the deformation area DE, is sandwiched from above and below by the two core blocks 10 and 20. As a result, the deformation area DE is returned to its shape before deformation.

[0055] In step S04 described above, the axial length of the second core block 20, which is stacked on the upper surface of the first core block 10, should be adjusted to match the length of the permanent magnet 3 that protrudes from the upper surface of the first core block 10 to the first magnet insertion hole 13 when it is stacked on the upper surface of the first core block 10. By adjusting the axial length of the second core block 20 as described above, the entire length of the permanent magnet 3 can be accommodated within the rotor core 2 relatively easily.

[0056] Next, as shown in Figure 6B, the second core block 20 is pressed from above using the pressurizer 53 (step S05). This pressing acts to press the second core block 20 against the first core piece 11U on the upper side, promoting the return of the deformed area DE to its original shape. Therefore, the motor assembly 1 manufactured through the above-described series of steps eliminates the deformation that occurs with the formation of the first protrusion 14 and includes a rotor core 2 without gaps. The motor assembly 1 obtained through the above-described steps is then transported to, for example, equipment for performing a motor assembly process (not shown).

[0057] As described above, the motor assembly manufacturing method and motor assembly 1 according to this embodiment can eliminate deformation that may occur when forming the first projection 14. Therefore, it is possible to prevent gaps from occurring between the multiple core pieces 11 and 21 that constitute the rotor core 2. In addition, by making the axial length D1 of the first core block 10 shorter than the axial length D2 of the permanent magnet 3, the position adjustment of the permanent magnet 3 when forming the first projection 14 can be simplified, and the permanent magnet 3 can be reliably supported by the first projection 14.

[0058] <Second Embodiment> In the first embodiment described above, an example was given in which the first projection 14 is provided only on the upper surface of the first core block 10, but the disclosure is not limited thereto.Therefore, as a second embodiment, a motor assembly and a method for manufacturing the motor assembly will be described below in which projections for supporting magnets are provided on multiple surfaces of the first core block.In the following, in the motor assembly 1A according to the second embodiment, components that are the same as those in the motor assembly 1 according to the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted, and the description will focus on components that differ from the motor assembly 1 according to the first embodiment.

[0059] (Motor Assembly) Figure 7 is an exploded perspective view showing an example of a motor assembly according to the second embodiment. As shown in Figure 7, the motor assembly 1A according to this embodiment includes a rotor core 2A and a permanent magnet 3. Of these, the permanent magnet 3 can be the same as that described in the first embodiment. On the other hand, the rotor core 2A of this embodiment is composed of a first core block 10A and two second core blocks 20 and 30. Note that the first core block 10A shown in the exploded perspective view of Figure 7 is shown before the formation of the two first protrusions 14 and 16 (see Figure 11A, etc.) that are formed during the assembly process.

[0060] The first core block 10A may have the same configuration as the first core block 10, except that its axial length D4 is shorter than the axial length D1 of the first core block 10 described above, as shown in Figure 7, and that first protrusions 14 and 16 are formed on both end faces in the axial direction X. Furthermore, the first protrusion 16 formed on the lower surface of the first core block 10A may be formed in the same way as the first protrusion 14 formed on the upper surface of the first core block 10A, i.e., by plastic deformation using spot riveting. In addition, first pressing portions 15 and 17 may be set around the openings on the upper and lower surfaces of the first magnet insertion hole 13 of the first core block 10, respectively, in order to form the first protrusions 14 and 16.

[0061] The two second core blocks 20 and 30 are stacked on the upper and lower surfaces, respectively, of the first core block 10A. Hereinafter, these two second core blocks 20 and 30 may be referred to as the "upper second core block 20" and the "lower second core block 30" respectively, in order to distinguish between them.

[0062] The upper second core block 20 and the lower second core block 30 may have the same configuration as the second core block 20 described in the first embodiment. That is, they may be constructed by laminating one or more second core pieces 21, 31 made of electromagnetic steel sheets, and may be provided with second through holes 22, 32 extending along the axial direction X and a plurality of second magnet insertion holes 23, 33. The axial length D2 of the upper second core block 20 and the axial length D5 of the lower second core block 30 should be determined considering the axial lengths of the first core block 10 and the permanent magnet 3, respectively.

[0063] In the motor assembly 1A having the above-described configuration, first protrusions 14 and 16 are formed on both end faces of the first core block 10A, in other words, on the upper and lower surfaces. Therefore, deformation can occur not only around the first pressing portion 15 of the first core piece 11U on the upper side that constitutes the upper surface of the first core block 10A, but also around the first pressing portion 17 of the first core piece that constitutes the lower surface of the first core block 10A (hereinafter, this first core piece will be referred to as the "first core piece 11L on the lower side"). However, in the motor assembly 1A of this embodiment, a configuration is adopted in which the second core blocks 20 and 30 are stacked on the upper and lower surfaces, respectively, of the first core block 10A. Therefore, the aforementioned deformation can be significantly suppressed by the pressing of the second core blocks 20 and 30.

[0064] (Method for Manufacturing Motor Assembly) Next, the method for manufacturing a motor assembly according to this embodiment will be described below with reference to Figures 8 to 11. In the following description, the case in which the motor assembly 1A described above is manufactured by implementing the method for manufacturing a motor assembly according to this embodiment will be described. In this regard, the effects of the method for manufacturing a motor assembly described later also apply to the effects of motor assembly 1A. Furthermore, the series of processes described below can be realized by operating a motor assembly manufacturing apparatus including a base 51, a punch 52, etc. In addition, some of the methods for manufacturing a motor assembly according to this embodiment are the same as those described in the first embodiment. Therefore, in the following description, the processes unique to this embodiment will be described, and detailed explanations of those common to the first embodiment will be omitted, as the description in the first embodiment will be reused.

[0065] Figure 8 is a flowchart showing an example of a method for manufacturing a motor assembly according to the second embodiment. Figures 9A, 9B, 10A, 10B, and 11A to 11B are explanatory diagrams that sequentially show the state of the motor assembly when the method for manufacturing the motor assembly shown in Figure 8 is carried out. Note that, similar to Figures 5A, 5B, 6A, and 6B described above, Figures 9A, 9B, 10A, 10B, and 11A to 11B show a portion of the assembly in cross-section.

[0066] In the motor assembly manufacturing method according to this embodiment, first, as shown in Figure 8, a first core block 10A is prepared (step S11). The prepared first core block 10A is placed on a base 51, for example, as shown in Figure 9A. The base 51 used in this embodiment is provided with a magnet support base 54 that is movable in the vertical direction at a position corresponding to the first magnet insertion hole 13. In this embodiment, the case in which the base 51 is provided with the aforementioned magnet support base 54 is illustrated, but instead of the magnet support base 54, a bottomed hole may be provided at a corresponding position on the base 51. However, in this case, the arrangement and depth of the bottomed hole are pre-adjusted to match the position of the magnet insertion hole 13 of the first core block 10A and the axial height D5 of the second core block 30.

[0067] Once the first core block 10A is prepared, the permanent magnet 3 is then inserted into the first magnet insertion hole 13, as shown in Figure 9A (step S12). The lower surface of the permanent magnet 3 inserted into the first magnet insertion hole 13 is placed on the magnet support base 54.

[0068] Next, the magnet support base 54 is operated to adjust the relative position of the permanent magnet 3 with respect to the first core block 10A (step S13). Specifically, as shown in Figure 9B, the amount of protrusion of the permanent magnet 3 protruding from the upper surface of the first core block 10A and the amount of protrusion of the permanent magnet 3 protruding from the lower surface of the first core block 10A are adjusted to be approximately the same as the axial heights D3 and D5 of the upper second core block 20 and the lower second core block 30. By adjusting the position of the permanent magnet 3 in this way, the permanent magnet 3 can be housed within the rotor core 2A along its entire length when the rotor core 2A is assembled. In addition, the first protrusions 14 and 16, which will be described later, can both be brought into contact with the longitudinal middle portion of the permanent magnet 3, stabilizing the support posture of the permanent magnet 3.

[0069] Next, first protrusions 14 and 16 are formed on both axial ends of the first core block 10A (step S14). As shown in Figures 10A and 10B, the first protrusions 14 and 16 can be formed sequentially, for example. Specifically, first, as shown in Figure 10A, the first protrusion 14 is formed on the upper side of the first core piece 11U by pressing a pre-set first pressing portion 15 on the upper surface of the first core block 10A with a punch 52 from above the first core block 10A. Then, as shown in Figure 10B, the first protrusion 16 is formed on the lower side of the first core piece 11L by pressing a pre-set first pressing portion 17 on the lower surface of the first core block 10A with a punch 52 from below the first core block 10A. The method for forming the first protrusions 14 and 16 has already been described in detail in the first embodiment, so it will not be explained here. In addition, although this embodiment illustrates the case in which the first protrusions 14 and 16 are formed sequentially, it is also possible to form them simultaneously. Alternatively, after forming the first protrusion 14 on the upper side of the first core piece 11U, it is also possible to turn the first core block 10A over and form the first protrusion 16 on the lower side of the first core piece 11L using the same apparatus that was used to form the first protrusion 14.

[0070] When the aforementioned step S14 is performed, deformation points DE1 and DE2 are generated around the first pressing parts 15 and 17, respectively, as shown in Figure 11A. Therefore, in the motor assembly manufacturing method of this embodiment, the two second core blocks 20 and 30 are then stacked vertically on the first core block 10A so as to face the surfaces where the deformation points DE1 and DE2 are generated (step S15). In this embodiment, the case in which the first core block 10A and the two second core blocks 20 and 30 are stacked simultaneously is illustrated, but they may be stacked sequentially. For example, the upper second core block 20 may be stacked on the upper surface of the first core block 10A before the first pressing part 17 is pressed, as shown in Figure 10B, and the lower second core block 30 may be stacked on the lower surface of the first core block 10A after the first pressing part 17 has been pressed.

[0071] When the two second core blocks 20 and 30 are stacked above and below the first core block 10A, the upper first core piece 11U and the lower first core piece 11L, which include the deformed areas DE1 and DE2, are sandwiched between the first core block 10A and the second core blocks 20 and 30 from above and below. As a result, the deformed areas DE1 and DE2 are returned to their original shape.

[0072] Next, as shown in Figure 11B, the laminate composed of the first core block 10A and the second core blocks 20 and 30 is pressed from above and below using pressurizers 53 and 55 (step S16). The motor assembly 1A, including the rotor core 2A, whose deformation has been eliminated by this pressing operation, is transported to equipment for performing a motor assembly process, for example (not shown).

[0073] As described above, the motor assembly manufacturing method and motor assembly 1A according to this embodiment can achieve the same effects as those described in the first embodiment. Furthermore, because the total number of first protrusions 14 and 16 formed on the first core block 10A is large, the permanent magnet 3 can be firmly supported on the first core block 10A.

[0074] <Third Embodiment> In the first and second embodiments described above, examples were given in which a portion of the permanent magnet inserted in the first core block is housed in the second magnet insertion hole of the second core block, but the disclosure is not limited thereto. Hereinafter, as a third embodiment, a case in which the permanent magnets inserted in the respective magnet insertion holes of the first core block and the second core block are different will be described. In the following, in the motor assembly 1B according to the third embodiment, components that are the same as those in the motor assembly 1 according to the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted, and the description will focus on components that differ from the motor assembly 1 according to the first embodiment.

[0075] (Motor Assembly) Figure 12 is an exploded perspective view showing an example of a motor assembly according to the third embodiment. As shown in Figure 12, the motor assembly 1B according to this embodiment includes a rotor core 2B and two permanent magnets 3A and 3B. Of these, the two permanent magnets 3A and 3B may have the same shape as the permanent magnet 3 described in the first embodiment, although they have different magnet insertion holes into which they are inserted. In the following description, in order to distinguish the two permanent magnets 3A and 3B, these two permanent magnets 3A and 3B will be referred to as "first permanent magnet 3A" and "second permanent magnet 3B," respectively. The rotor core 2B is composed of a first core block 10B and a second core block 20B. Note that the first core block 10B and the second core block 20B shown in Figure 12 are shown in the state after the permanent magnets 3A and 3B have been attached.

[0076] The first core block 10B may be the same as the first core block 10 of the first embodiment, except that its axial length is adjusted to be substantially the same as or slightly longer (for example, by about 0.01 to 1 mm) than the axial length of the first permanent magnet 3A. Therefore, the first core piece 11U on the upper surface side that constitutes the upper surface of the first core block 10B is provided with a first projection 14 and a first pressing portion 15 that is pressed when forming the first projection 14.

[0077] The second core block 20B is constructed by stacking one or more second core pieces 21 made of electromagnetic steel sheets, and is similar to the second core block 20 of the first embodiment in that it has a second through hole 22 extending along the axial direction X and a plurality of second magnet insertion holes 23. On the other hand, a second permanent magnet 3B, different from the first permanent magnet 3A inserted into the first magnet insertion hole 13, is inserted into the second magnet insertion hole 23 of the second core block 20B. The axial length of the second core block 20B is preferably adjusted to be substantially the same as or slightly (for example, about 0.01 to 1 mm) longer than the axial length of the second permanent magnet 3B.

[0078] A second projection 24 (see Figure 16A) may be formed on the lower surface of the second core block 20B in order to support the second permanent magnet 3B in the second core block 20B. The second projection 24 can be formed by pressing a second pressing portion 25 (see Figure 16A) provided around the second magnet insertion hole 23 of the core piece constituting the lower surface of the second core block 20B (hereinafter referred to as the "lower side second core piece 21L"), thereby plastically deforming a part of the lower side second core piece 21L. In other words, the second core block 20B of this embodiment can be manufactured by a method that is generally the same as that of the first core block 10B.

[0079] In addition, the motor assembly 1B of this embodiment further includes a shaft 4 that constitutes the rotation axis of the motor, and an end plate 5 that supports the axial end of the laminate including the first core block 10B and the second core block 20B. Note that the shaft 4 and the end plate 5 are components that constitute the rotor and may also be included in the motor assemblies 1 and 1A of the respective embodiments described above.

[0080] The shaft 4 is a rod-shaped member inserted into the first through hole 12 of the first core block 10B and the second through hole 22 of the second core block 20B. Preferably, the core blocks 10B, 20B and the end plate 5 are fixed to the shaft 4 so as not to rotate. The method of fixing is not particularly limited. Another method is to provide axially extending key grooves on the inner circumferential surfaces of the first and second through holes 12 and 22, provide a key on the outer circumferential surface of the shaft 4 that fits into the aforementioned key grooves, and fix each member so that it rotates together by fitting the key groove and the key.

[0081] The end plate 5 presses and supports the first core block 10B and the second core block 20B, into which the shaft 4 is inserted, from both ends in the axial direction X. The first core block 10B and the second core block 20B, which are held between the end plate 5, are firmly fixed to the shaft 4.

[0082] It is particularly important to note that the first core block 10B and the second core block 20B, into which the shaft 4 is inserted and sandwiched between the end plate 5, are stacked such that the surface of the first core block 10B on which the first projection 14 is formed faces the surface of the second core block 20B on which the second projection 24 is formed. When stacked in this manner, the first core piece 11U on the upper surface side on which the first projection 14 is formed and the second core piece 21L on the lower surface side on which the second projection 24 is formed are sandwiched between the first core block 10B and the second core block 20B.

[0083] In the motor assembly 1 having the above-described configuration, deformation may occur around the first pressing portion 15 of the first core piece 11U on the upper side of the first core block 10B, and around the second pressing portion 25 of the second core piece 21L on the lower side that constitutes the lower surface of the second core block 20B. However, in the motor assembly 1B of this embodiment, both the first core piece 11U on the upper side and the second core piece 21L on the lower side are stacked so as to sandwich them between the other first core piece 11 and second core piece 21. Therefore, the deformation described above can be significantly suppressed by pressing the core blocks against each other.

[0084] (Method for Manufacturing Motor Assembly) Next, the method for manufacturing a motor assembly according to this embodiment will be described below with reference to Figures 13 to 16. In the following description, the case in which the motor assembly 1B described above is manufactured by implementing the method for manufacturing a motor assembly according to this embodiment will be described. In this regard, the effects of the method for manufacturing a motor assembly described later also apply to the effects of motor assembly 1B. Furthermore, the series of processes described below can be realized by operating a motor assembly manufacturing apparatus including a base 51, a punch 52, etc. In addition, some of the methods for manufacturing a motor assembly according to this embodiment are the same as those described in the first embodiment. Therefore, in the following description, the processes unique to this embodiment will be described, and detailed explanations of those common to the first embodiment will be omitted, as the description in the first embodiment will be reused.

[0085] Figure 13 is a flowchart showing an example of a method for manufacturing a motor assembly according to the third embodiment. Figures 14A, 14B, 15A, 15B, and 16A to 16B are explanatory diagrams that sequentially show the state of the motor assembly when the method for manufacturing the motor assembly shown in Figure 13 is implemented. Note that, similar to Figures 5A, 5B, 6A, and 6B described above, Figures 14A, 14B, 15A, 15B, and 16A to 16B show a portion of the assembly in cross-section.

[0086] In the motor assembly manufacturing method according to this embodiment, first, as shown in Figure 13, a first core block 10B is prepared (step S21). The prepared first core block 10B is placed on a base 51 as shown in Figure 14A. The base 51 used in this embodiment is provided with a magnet support base 54 that is movable in the vertical direction at a position corresponding to the first magnet insertion hole 13.

[0087] Once the first core block 10B is prepared, the first permanent magnet 3A is then inserted into the first magnet insertion hole 13, as shown in Figure 14A (step S22). The lower surface of the first permanent magnet 3A inserted into the first magnet insertion hole 13 is placed on the magnet support base 54 (see Figure 14B).

[0088] Next, the magnet support base 54 is operated to adjust the relative position of the first permanent magnet 3A with respect to the first core block 10B (step S23). Specifically, as shown in Figure 15A, the position is adjusted so that the upper opening of the first magnet insertion hole 13 coincides with the position of the upper end of the first permanent magnet 3A. By adjusting the position of the first permanent magnet 3A in this way, the first projection 14 and the first permanent magnet 3A can be brought into contact during the process of forming the first projection 14, which will be described later.

[0089] Next, a first projection 14 is formed on the upper surface of the first core block 10B (step S24). As shown in Figure 15A, the first projection 14 is formed on the upper side of the first core piece 11U by pressing a pre-set first pressing portion 15 on the upper surface of the first core block 10B with a punch 52 from above the first core block 10B. Note that the method of forming the first projection 14 has already been described in detail in the first embodiment, so the explanation is omitted here.

[0090] As shown in Figure 15B, after the first permanent magnet 3A is supported on the first core block 10B through the series of steps described above, the second permanent magnet 3B is then supported on the second core block 20B (step S25). The specific method for supporting the second permanent magnet 3B on the second core block 20B may be the same as the method for supporting the first permanent magnet 3A on the first core block 10B. That is, it can be achieved by performing the processes shown in steps S21 to S24 above on the second core block 20B. However, when performing step S21 on the second core block 20B, it is preferable to invert the prepared second core block 20B vertically before placing it on the base 51. The order in which the steps for supporting the first permanent magnet 3A on the first core block 10B and supporting the second permanent magnet 3B on the second core block 20B are performed is not particularly limited.

[0091] Once the preparation of the first core block 10B, which supports the first permanent magnet 3A, and the second core block 20B, which supports the second permanent magnet 3B, is complete, these core blocks are then stacked (step S26). In this stacking process, as shown in Figure 16A, first, a shaft 4, to which one end plate 5 is pre-fixed, is inserted into the through hole 12 of the first core block 10B, which supports the first permanent magnet 3A, and the first core block 10B is placed on the end plate 5. At this time, the shaft 4 is inserted into the through hole 12 of the first core block 10B so that the lower surface of the first core block 10B abuts against the end plate 5 fixed to the shaft 4. Next, the shaft 4 is inserted into the through hole 22 of the second core block 20B, which supports the second permanent magnet 3B. At this time, the shaft 4 is inserted into the through hole 22 of the second core block 20B such that the lower surface of the second core block 20B abuts against the upper surface of the first core block 10B. The first core block 10B and the second core block 20B, into which the shaft 4 has been inserted sequentially as described above, are stacked on the end plate 5.

[0092] As described above, when the first core block 10B and the second core block 20B are stacked, the first core piece 11U on the upper surface of the first core block 10B, where the first projection 14 is formed, comes into contact with the second core piece 21L on the lower surface of the second core block 20B, where the second projection 24 is formed. As a result, the deformed areas DE formed on the upper first core piece 11U and the deformed areas DE formed on the lower second core piece 21L are returned to their original shapes.

[0093] Finally, as shown in Figure 16B, the second end plate 5 is attached to the shaft 4, and the end plates 5 are pressed together in a direction that brings them closer together, thereby pressing the laminate composed of the first core block 10B and the second core block 20B from above and below (step S27). The motor assembly 1B, including the rotor core 2B, whose deformation has been eliminated by this pressing operation, is then transported to equipment for performing a motor assembly process, for example (not shown).

[0094] As described above, the motor assembly manufacturing method and motor assembly 1A according to this embodiment can achieve the same effects as those described in the first embodiment.

[0095] In addition, when manufacturing a rotor, in order to absorb deviations in the thickness of the core pieces constituting the rotor core and to suppress torque fluctuations by shifting the angles of the magnetic poles at predetermined intervals, the rotor core may be divided into multiple core blocks and stacked while skewing them. In the embodiment described above, since the motor assembly 1B is manufactured by stacking the first core block 10B and the second core block 20B, the aforementioned skewing can be easily performed.

[0096] Next, we will describe some modified versions of the embodiments described above. In the modified versions described below, we will focus on the configurations that differ from each embodiment, and will omit explanations of points that are the same as in each embodiment.

[0097] <Modification 1> In the second embodiment described above, an example was given in which two second core blocks 20 and 30 of substantially the same shape are stacked on both ends of the first core block 10A in the axial direction. However, the two second core blocks may have different shapes. For example, instead of one of the second core blocks 30 shown in the second embodiment, a core block such as the second core block 20B shown in the third embodiment can be used. Below, a motor assembly 1C according to one modification of the second embodiment adopting the above-described configuration will be briefly explained.

[0098] Figure 17 is a schematic cross-sectional view showing a modified example of the second embodiment. In Figure 17, some of the components constituting the motor assembly 1C are shown in a disassembled state. The motor assembly 1C according to this modified example may include a rotor core 2C, permanent magnets 3 and 3B, a shaft 4, and an end plate 5, as shown in Figure 17. The rotor core 2C includes a first core block 10A and two second core blocks 20 and 20C.

[0099] Of the components included in the motor assembly 1C, the first core block 10A and one of the second core blocks 20 are the same as those described in the second embodiment. Also, the shaft 4 and the end plate 5 are the same as those described in the third embodiment.

[0100] The other second core block 20C, similar to the second core block 20B described in the third embodiment, has a second permanent magnet 3B inserted into the second magnet insertion hole 23, which is different from the permanent magnet 3 inserted into the first magnet insertion hole 13. Furthermore, a second projection 24 may be formed on the upper surface of the second core block 20C to support the second permanent magnet 3B. The second projection 24 can be formed by pressing a second pressing portion 25, provided around the second magnet insertion hole 23 on the upper side of the second core piece 21U of the second core block 20C, thereby plastically deforming a part of the upper side of the second core piece 21U. In other words, the other second core block 20C shown in this modified example may be identical to the second core block 20B shown in the second embodiment, except that the surface on which the second projection 24 and the second pressing portion 25 are formed is different.

[0101] A detailed explanation of the method for manufacturing the motor assembly 1C according to this modified example is omitted because it can be achieved by combining the manufacturing methods described in the second and third embodiments.

[0102] According to the motor assembly 1C and the method for manufacturing the motor assembly in this modified example, the same effects as those described in the above-described embodiments can be achieved.

[0103] <Modification 2> In the third embodiment described above, the rotor core 2B is exemplified as being composed of a first core block 10B and a second core block 20B stacked on the surface of the first core block on which the first protrusion is formed. However, the number of core blocks constituting the rotor core is not limited to this. Specifically, a rotor core can also be constructed by stacking three or more core blocks. Below, a motor assembly 1D according to one modification of the third embodiment adopting the above-described configuration will be briefly explained.

[0104] Figure 18 is a schematic cross-sectional view showing a modified example of the third embodiment. In Figure 18, some of the components constituting the motor assembly 1D are shown in a disassembled state. The motor assembly 1D according to this modified example may include a rotor core 2D, permanent magnets 3A to 3C, a shaft 4, and an end plate 5, as shown in Figure 18. The rotor core 2D includes a first core block 10B, a second core block 20D, and a third core block 40.

[0105] The third core block 40 may include a configuration similar to that of the second core block 20B described in the third embodiment, for example. More specifically, the third core block 40 is constructed by stacking one or more third core pieces 41 made of electromagnetic steel sheets, and is provided with a third through hole 42 extending along the axial direction X and a plurality of third magnet insertion holes 43. In addition, a third permanent magnet 3C, different from those supported by the first core block 10B and the second core block 20D, is inserted into the second magnet insertion hole 43. Furthermore, a third projection 44 for supporting the third permanent magnet 3C on the third core block 40 may be formed on the lower surface of the third core block 40. The third projection 44 can be formed by pressing a third pressing portion 45, which is provided around the third magnet insertion hole 43 of a core piece (hereinafter referred to as the "third core piece 41L on the lower side") that constitutes the lower surface of the third core block 40, and thereby plastically deforming a part of the third core piece 41L on the lower side.

[0106] The third core block 40, which includes the above-described configuration, is stacked such that the end face on which the third projection 44 of the third core block 40 is formed, i.e., the lower surface, faces the second core block 20D. By stacking the third core block 40 as described above, deformation occurring in the third core piece 41L on the lower surface side can be significantly suppressed.

[0107] In the above-described modification, an example was shown in which only one third core block 40 is included, but the rotor core 2D may contain two or more third core blocks 40. In that case, a portion of the third core block 40 may be stacked such that the end face on which the third projection 44 is formed, i.e., the lower surface, faces another third core block 40 (not shown).

[0108] In addition, if the rotor core 2D includes a third core block 40, as shown in Figure 18, a second core block 20D can be adopted that includes second protrusions 24, 26 and second pressing portions 25, 27 on both axial ends. In the second core block 20D, as shown in Figure 18, deformation areas DE may occur on both axial ends. However, since the second core block 20D is stacked between the first core block 10B and the third core block 40, these deformations can be significantly suppressed.

[0109] The method for manufacturing the motor assembly 1D according to this modified example is simply to add the step of stacking the third core block 40 to the manufacturing method described in the third embodiment, so a detailed explanation is omitted.

[0110] According to the motor assembly 1D and the method for manufacturing the motor assembly in this modified example, the same effects as those described in the above-described embodiments can be achieved.

[0111] This disclosure is not limited to the embodiments described above, and can be implemented with various modifications without departing from the spirit of this disclosure. All such modifications are included in the technical concept of this disclosure. Furthermore, unless otherwise specified in the specification, each component of this disclosure is not limited to one, but may exist in multiple forms.

[0112] All documents cited herein, including publications, patent applications, and patents, are incorporated here by reference to the same extent as each document is individually and specifically identified and its entire contents are described herein.

[0113] The use of nouns and similar demonstrative pronouns in connection with the description of this disclosure (particularly in connection with the following claims) shall be construed as both singular and plural unless otherwise specifically noted herein or if it is clearly inconsistent with the context. The words “equip,” “have,” “include,” and “incorporate” shall be construed as open-ended terms (i.e., “include, but not limited to”) unless otherwise specifically noted herein. The numerical ranges described herein are intended solely as abbreviations for referring individually to each value that falls within that range, unless otherwise specifically noted herein, and each value is incorporated into the specification as if it were individually enumerated herein. All methods described herein can be performed in any appropriate order unless otherwise specifically noted herein or if it is clearly inconsistent with the context. Any examples or illustrative phrases used herein (e.g., “etc.”) are intended solely to better illustrate this disclosure and not to impose any limitations on the scope of this disclosure unless otherwise specifically asserted. Nothing in the specification shall be construed as indicating that any element not described in the claims is essential to the implementation of this disclosure.

[0114] This specification describes preferred embodiments of the Disclosure, including the best mode known to the inventors for carrying out the Disclosure. Those skilled in the art will see, upon reading the above description, that variations of these preferred embodiments will become apparent. The inventors expect that skilled individuals will appropriately apply such variations and that the Disclosure will be carried out in ways other than those specifically described herein. Therefore, this Disclosure includes all modifications and equivalents of the claims appended to this Specification, as permitted by applicable law. Furthermore, any combination of the above elements in all variations is incorporated into this Disclosure unless specifically noted herein or is obviously inconsistent with the context.

Claims

1. A method for manufacturing a motor assembly, comprising: inserting magnets into each of a plurality of axially extending first magnet insertion holes formed in a first core block constructed by stacking a plurality of first core pieces made of electromagnetic steel sheets; pressing and plastically deforming a position adjacent to the first magnet insertion holes on at least one axial end face of the first core block in order to form a first projection that protrudes into the first magnet insertion holes and supports the magnets; and stacking a second core block, constructed of one or more second core pieces made of electromagnetic steel sheets, on the end face of the first core block on which the first projection is formed.

2. A method for manufacturing a motor assembly according to claim 1, further comprising the step of pressing the second core block, which is stacked on the first core block, against the first core block.

3. The step of pressing and plastically deforming a position adjacent to the first magnet insertion hole on at least one axial end face of the first core block is to press positions adjacent to the first magnet insertion holes on both axial ends of the first core block, the method for manufacturing a motor assembly according to claim 1.

4. The method for manufacturing a motor assembly according to claim 1, wherein the axial length of the first core block is shorter than the axial length of the magnet, and the step of pressing and plastically deforming a position adjacent to the first magnet insertion hole on at least one axial end face of the first core block is performed with the magnet protruding from the end face, by pressing and plastically deforming a position adjacent to the first magnet insertion hole on the end face.

5. The method for manufacturing a motor assembly according to claim 4, wherein the second core block comprises a plurality of second magnet insertion holes extending in the axial direction, and the step of stacking the second core blocks involves stacking the first core block and the second core block such that the portions of the magnets inserted into the first magnet insertion holes of the first core block protruding from the end faces are housed in the second magnet insertion holes.

6. The method for manufacturing a motor assembly according to claim 1, wherein the second core block is composed of a plurality of second core pieces stacked together, and comprises a plurality of second magnet insertion holes extending in the axial direction, and a second projection on at least one end face in the axial direction of the second core block that protrudes into the second magnet insertion holes and supports a second magnet inserted into the second magnet insertion holes, and the step of stacking the second core blocks is to stack them such that the end face on which the second projection is formed faces the first core block.

7. A method for manufacturing a motor assembly according to claim 1, further comprising the step of stacking one or more third core blocks, each comprising a plurality of third core pieces made of electromagnetic steel sheets, and having a plurality of third magnet insertion holes extending in the axial direction, and a third projection on at least one end face in the axial direction that protrudes into the third magnet insertion holes and supports a third magnet inserted into the third magnet insertion holes, such that the end faces on which the third projections are formed face the second core block or the third core block.

8. A motor assembly comprising: a first core block, which is constructed by laminating a plurality of first core pieces made of electromagnetic steel sheets and has a plurality of first magnet insertion holes extending in the axial direction and a first projection formed on at least one end face in the axial direction and projecting into the first magnet insertion holes; magnets inserted into the first magnet insertion holes and supported within the first magnet insertion holes by the first projection; and one or more second core blocks, which are made of one or more second core pieces made of electromagnetic steel sheets and have one axial surface abutting against and being supported by the end face of the first core block on which the first projection is formed.

9. The motor assembly according to claim 8, wherein the axial length of the first core block is shorter than the axial length of the magnet, and the second core block comprises a plurality of second magnet insertion holes extending in the axial direction, the portions of the magnets inserted into the first magnet insertion holes that protrude from the end faces are housed in the second magnet insertion holes.

10. The motor assembly according to claim 8, wherein the second core block is composed of a plurality of the second core pieces stacked together and comprises a plurality of second magnet insertion holes extending in the axial direction and a second projection projecting into the second magnet insertion holes from at least one end face in the axial direction of the second core block, and further comprises a second magnet inserted into the second magnet insertion hole and supported in the second magnet insertion hole by the second projection, and the second core block is stacked such that the end face of the second core block on which the second projection is formed faces the first core block.

11. A motor assembly according to claim 8, comprising: one or more third core blocks, each constructed by laminating a plurality of third core pieces made of electromagnetic steel sheets, and having a plurality of third magnet insertion holes extending in the axial direction, and a third projection projecting into the third magnet insertion holes from at least one end face in the axial direction; and further comprising a third magnet inserted into the third magnet insertion hole and supported within the third magnet insertion hole by the third projection, wherein the third core blocks are laminated such that the end faces on which the third projections are formed face the second core block or other third core blocks.

12. The motor assembly according to any one of claims 8 to 11, further comprising: a shaft inserted into an axially extending through hole formed in the first core block and the second core block; and an end plate that presses and supports the first core block and the second core block from their axial ends, into which the shaft is inserted.

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