Manufacturing device of rotor, manufacturing method of rotor, and rotor

Abstract

The rotor (20) has a permanent magnet (23) that is embedded in a magnet receiving hole (24) in the rotor core (22) and has a convex, folded-back shape that protrudes radially inward. The rotor manufacturing apparatus includes a magnetizing device (30) for magnetizing the embedded permanent magnet from the outside of the rotor. The magnetizing device includes: a first magnetizing part (31) disposed on one side of the rotor axis and having magnetizing coils (33a, 35a1, 35a2) for supplying magnetizing flux to the permanent magnet; and a second magnetizing part (41) disposed on the other side of the rotor axis and having magnetizing coils (43a, 45a1, 45a2) for supplying magnetizing flux to the permanent magnet. When the rotor manufacturing apparatus magnetizes the permanent magnet based on the energization of the magnetizing coil, during the magnetization process of the same permanent magnet, the first magnetizing part and the second magnetizing part, which are axially opposite to the rotor, are energized to the same pole. Magnetizing is performed by passing the same pole magnetizing flux through both sides of the rotor core part (25) located inside the folded shape of the permanent magnet.

Description

[0001] Citation of relevant applications

[0002] This application is based on Japanese Patent Application No. 2020-100186, filed on June 9, 2020, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an apparatus for manufacturing an embedded magnet type rotor, a method for manufacturing a rotor, and a rotor for magnetizing a permanent magnet in an embedded state from the outside of the rotor. Background Technology

[0004] Previously, it was well known that rotary electric machines used rotors with embedded magnets (IPM type). The embedded magnet type rotor has a permanent magnet embedded inside the rotor core, configured such that, in addition to the magnetic torque generated by the permanent magnet, a reluctance torque is also obtained in the outer core portion located radially outward from the permanent magnet. In such an embedded magnet type rotor, for the rotor core with the embedded, unmagnetized permanent magnets, magnetization is performed from the outer diameter side using a magnetizing device (see, for example, Patent Document 1).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-193587 Summary of the Invention

[0008] To improve the performance of rotors with embedded magnets, one approach is to design permanent magnets in a roughly V or U-shaped folded-back configuration. This enlarges the surface area of ​​the permanent magnets and the outer core portion of the rotor core, thereby increasing both the magnet torque and the reluctance torque.

[0009] When it is desired to increase the surface area of ​​the permanent magnet and the outer core portion of the rotor core, it is considered to form a deep folding shape by positioning the bent portion, which is the folded-back portion of the permanent magnet, further radially inward. The closer the folding-back position of the permanent magnet is to the radially inward position, the further away the permanent magnet, especially the bent portion and the vicinity of the bent portion, is from the magnetizing device. Therefore, in the method of magnetizing from the outer diameter side of the rotor core disclosed in Patent Document 1, etc., the bent portion or the vicinity of the permanent magnet, which is far away from the magnetizing device, may not be able to generate sufficient magnetic force.

[0010] The purpose of this disclosure is to provide a rotor manufacturing apparatus, a rotor manufacturing method, and a rotor having been magnetized, capable of magnetizing a permanent magnet in an embedded state within a rotor core with high magnetic force.

[0011] The rotor manufacturing apparatus of the first aspect of this disclosure includes a magnetizing device that magnetizes a permanent magnet embedded in the rotor from the outside of the rotor. The rotor has a permanent magnet that is embedded in a magnet receiving hole in the rotor core and has a convex, folded-back shape that protrudes radially inward. The aforementioned magnetizing device includes: a first magnetizing section disposed on one axial side of the rotor and having a magnetizing coil for supplying magnetizing flux to the permanent magnet; and a second magnetizing section disposed on the other axial side of the rotor and having a magnetizing coil for supplying magnetizing flux to the permanent magnet. When the permanent magnet is magnetized based on energizing the magnetizing coil, during the magnetizing process of the same permanent magnet, the first magnetizing section and the second magnetizing section, which are axially opposite to the rotor, are energized to the same pole. Magnetizing is performed by passing magnetizing flux of the same pole through both sides of the rotor core located inside the folded-back shape of the permanent magnet.

[0012] The rotor manufacturing method of the second aspect of this disclosure involves magnetizing the rotor, wherein the rotor has a permanent magnet that is embedded in a magnet receiving hole in the rotor core and has a convex, folded-back shape that protrudes radially inward, and a magnetizing device is used to magnetize the permanent magnet in the embedded state from the outside of the rotor. The above-mentioned magnetization includes: using a first magnetizing part, which is disposed on one side of the rotor along the axial direction and has a magnetizing coil for supplying magnetizing flux to the permanent magnet; using a second magnetizing part, which is disposed on the other side of the rotor along the axial direction and has a magnetizing coil for supplying magnetizing flux to the permanent magnet; and when magnetizing the permanent magnet based on energizing the magnetizing coil, during the magnetization process of the same permanent magnet, the first magnetizing part and the second magnetizing part, which are axially opposite to the rotor, are energized to the same pole, and magnetization is performed by passing magnetizing flux of the same pole through both sides of the rotor core portion located inside the folded shape of the permanent magnet.

[0013] According to the aforementioned rotor manufacturing apparatus and rotor manufacturing method, during the magnetization of a permanent magnet in its embedded state within the rotor, during the magnetization process of the same permanent magnet, the first and second magnetizing portions, which are axially opposite to the rotor, are energized to the same pole. Magnetization is achieved by passing magnetizing flux of the same pole through both sides of the rotor core portion located inside the folded-back shape of the permanent magnet. Therefore, even with a folded-back shape, a suitable magnetizing flux can be supplied throughout the entire range from the radially outer end to the curved portion near the radially inner end, thus enabling more useful and sufficient magnetization throughout the entire range of the permanent magnet.

[0014] The rotor for magnetization using the rotor manufacturing apparatus and rotor manufacturing method for solving the above-mentioned technical problems includes: a rotor core; and a permanent magnet, wherein the permanent magnet is disposed in an embedded state embedded in a magnet receiving hole of the rotor core and has a convex, folded-back shape that protrudes radially inward. The rotor is configured such that the permanent magnet, which is in an embedded state, is magnetized from the outside of the rotor using a magnetizing device, and the magnetizing unit of the permanent magnet, which is magnetized by passing magnetizing flux of the same pole through both axial sides of the rotor core located inside the folded-back shape of the permanent magnet, is a block, and multiple such blocks are stacked axially.

[0015] When magnetizing permanent magnets by supplying magnetizing flux from the rotor axis, magnetizing permanent magnets located in the middle part of the axis may not be sufficient. However, since the rotor is structured by stacking multiple magnetizing units capable of sufficient magnetization in the axial direction as blocks, even rotors with longer axial dimensions can provide rotors with permanent magnets that have sufficient magnetic force. Attached Figure Description

[0016] The above-mentioned and other objects, features, and advantages of this disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. The drawings are described below.

[0017] Figure 1 This is a structural diagram of a rotary electric motor with a rotor containing embedded magnets.

[0018] Figure 2 This is a structural diagram of the rotor.

[0019] Figure 3 This is a cross-sectional view of the rotor.

[0020] Figure 4 This is an explanatory diagram illustrating the overall structure of the magnetizing device according to one embodiment.

[0021] Figure 5 This is an explanatory diagram illustrating the overall structure of the magnetizing device used to explain this embodiment.

[0022] Figure 6 (a) and (b) are explanatory diagrams used to illustrate the structure of the coil body of the magnetizing device.

[0023] Figure 7 This is an explanatory diagram illustrating the permanent magnet that is magnetized by the magnetizing device of this embodiment.

[0024] Figure 8 This is an explanatory diagram illustrating the overall structure of the magnetizing device used to explain the modified example.

[0025] Figure 9This is an explanatory diagram illustrating the structure of the coil body of the magnetizing device used to explain the modified example.

[0026] Figure 10 It is a cross-sectional view of a rotor including a modified example of a permanent magnet that is magnetized by a magnetizing device. Detailed Implementation

[0027] The following describes the rotor manufacturing apparatus, the rotor manufacturing method, and one embodiment of the rotor.

[0028] Figure 1 The rotary motor M shown in this embodiment is a brushless motor of the embedded magnet type. The rotary motor M includes: a generally annular stator 10; and a generally cylindrical rotor 20 rotatably disposed in the radially inner space of the stator 10.

[0029] The stator 10 includes a generally annular stator core 11. The stator core 11 is made of a magnetic metallic material, for example, by stacking multiple electromagnetic steel plates axially. In this embodiment, the stator core 11 has twelve pole teeth 12 extending radially inward and arranged at equal intervals in the circumferential direction. Each pole tooth 12 has the same shape. The front end of the pole tooth 12, i.e., the radially inward end, is generally T-shaped, and the front end face 12a is arc-shaped along the outer circumferential surface of the rotor 20. Windings 13 are wound in a concentrated manner on the pole teeth 12. The windings 13 are three-phase connected, such as... Figure 1 As shown, these phases function as the U-phase, V-phase, and W-phase, respectively. Furthermore, when power is supplied to the winding 13, a rotating magnetic field is generated in the stator 10 to drive the rotor 20 to rotate. In the stator 10 as described above, the outer peripheral surface of the stator core 11 is fixed relative to the inner peripheral surface of the outer casing 14.

[0030] In this embodiment, the rotor 20 includes: a rotating shaft 21; a generally cylindrical rotor core 22 in which the rotating shaft 21 is embedded in its center; and eight permanent magnets 23 embedded inside the rotor core 22. The rotor core 22 is made of a magnetic metal material, for example, by stacking multiple electromagnetic steel plates axially. The rotor 20 is configured to rotate relative to the stator 10 by supporting the rotating shaft 21 on a bearing disposed in the housing 14 (not shown).

[0031] The rotor core 22 has magnet receiving holes 24 for accommodating permanent magnets 23. In this embodiment, eight magnet receiving holes 24 are provided at equal intervals along the circumference of the rotor core 22. Each magnet receiving hole 24 has a convex, approximately V-shaped folded-back shape that protrudes radially inward, and they are identical in shape to each other. In addition, the magnet receiving holes 24 are provided throughout the axial direction of the rotor core 22.

[0032] Here, the permanent magnet 23 in this embodiment is composed of a bonded magnet, which is formed by molding and hardening a magnetic material after mixing magnetic powder with resin. That is, the permanent magnet 23 is formed by using the magnet receiving hole 24 of the rotor core 22 as a molding die, and by injection molding the unhardened magnetic material into the magnet receiving hole 24 without gaps, and then hardening it within the magnet receiving hole 24 after filling. Therefore, the shape of the magnet receiving hole 24 becomes the outer shape of the permanent magnet 23. As the magnetic powder used in the permanent magnet 23 of this embodiment, for example, samarium iron nitride (SmFeN) type magnets are used, but other rare earth type magnets can also be used.

[0033] The permanent magnet 23 has a roughly V-shaped, convex shape that protrudes radially inward. More specifically, as... Figure 2 As shown, the permanent magnet 23 has a shape in which the radially inner ends of a pair of straight sections 23a are connected to each other by a curved section 23b. The radially outer end 23c of the straight section 23a is located near the outer peripheral surface 22a of the rotor core 22. The thickness Wm of the permanent magnet 23 is set to be constant at any point in the V-shaped path including the pair of straight sections 23a and the curved section 23b. The permanent magnet 23 is linearly symmetrical with respect to its own circumferential center line Ls passing through the shaft center O1 of the rotor 20, and is close to the magnetic pole boundary line Ld passing through the shaft center O1 of the rotor 20 between adjacent permanent magnets 23. The angle between adjacent magnetic pole boundary lines Ld, that is, the magnetic pole opening angle θm of the rotor magnetic pole section 26 including the permanent magnet 23, is an electrical angle of 180°.

[0034] Here, the point where the intersection of the extension line of the inner side surface of each straight portion 23a of the V-shaped permanent magnet 23 with the outer peripheral surface 22a of the rotor core 22 is defined as the pole spacing Lp, and the distance from the outer peripheral surface 22a of the rotor core 22 to the inner side surface of the curved portion 23b on the circumferential center line Ls of the permanent magnet 23 is defined as the embedment depth Lm, is, as an example, the permanent magnet 23 of this embodiment is set to a deep folded shape with an embedment depth Lm greater than the pole spacing Lp. That is, the magnet surface 23x of the permanent magnet 23 of this embodiment, which is composed of the inner side surfaces of each straight portion 23a and the curved portion 23b, is set to be larger than the magnet surface of the well-known surface magnet type (not shown). Furthermore, this folded shape of the permanent magnet 23 is just one example, and can be appropriately changed to a roughly U-shaped folded shape with a shallower embedment depth Lm or a larger curved portion 23b.

[0035] In addition, such as Figure 2 and Figure 3As shown, the permanent magnet 23 has a relatively large embedment depth Lm, and the bent portion 23b is located near the radially inner side of the shaft insertion hole 22b for the rotating shaft 21 to be inserted, close to the center of the rotor core 22. Furthermore, the permanent magnet 23 is provided within the entire axial length of the rotor core 22. In this embodiment, the axial length L1 of the rotor 20 is set relatively short, and the permanent magnet 23 assembled on the rotor 20 has a rectangular shape that is longer in the radial direction of the rotor 20 when viewed from the side.

[0036] The permanent magnet 23 hardened within the magnet receiving hole 24 of the rotor core 22 is used. Figure 4 The magnetizing device 30 shown above magnetizes the rotor core 22 from the outside, starting from an unmagnetized state, so that it functions as a regular magnet. The magnetizing device 30 and the magnetizing method using it will be described in detail later. In this embodiment, eight permanent magnets 23 are arranged circumferentially on the rotor core 22, and magnetization is performed by alternating different polarities in the circumferential direction. Furthermore, each permanent magnet 23 is magnetized in its own thickness direction.

[0037] The portion of the rotor core 22 located inside the V-shaped fold of the permanent magnet 23 and radially outward from the permanent magnet 23 functions as the outer core portion (rotor core portion) 25, opposite the stator 10, for obtaining reluctance torque. The outer core portion 25, when viewed axially, has a roughly triangular shape pointing towards a vertex along the center of the rotor 20. Furthermore, in this embodiment, the rotor 20, including the permanent magnet 23 and the outer core portion 25 surrounded by the V-shaped fold of the permanent magnet 23, is configured as an 8-pole rotor pole portion 26. Figure 1 As shown, each rotor pole portion 26 alternately functions as the N pole and S pole in the circumferential direction. In a rotor 20 having such rotor pole portions 26, appropriate magnetic torque and reluctance torque can be obtained.

[0038] Next, the manufacturing apparatus and manufacturing method of the rotor 20, which include the magnetizing device 30 with permanent magnet 23 and the magnetizing method of the permanent magnet 23 using the magnetizing device 30, will be described.

[0039] [Structure of the magnetizing device]

[0040] use Figure 4 and Figure 5 The magnetizing device 30 of this embodiment will be described. Furthermore, in Figure 4 and Figure 5 In the diagram, the shading of the cross-section has been appropriately omitted. Furthermore, the illustration of the magnetizing coil 33a, etc., of the coil body 33 has been simplified.

[0041] like Figure 4 and Figure 5As shown, the magnetizing device 30 includes an upper part (first magnetizing part) 31 and a lower part (second magnetizing part) 41. In order to enable the rotor 20, the object to be magnetized, to be set up and taken out, the upper part 31 and the lower part 41 can be contacted and separated. In this case, either or both of the upper part 31 and the lower part 41 can perform contact and separation operations.

[0042] The upper part 31 of the device includes an upper magnetizing yoke 32 made of magnetic metal and a coil body 33 integrally mounted with the upper magnetizing yoke 32. The upper magnetizing yoke 32 includes an annular plate-shaped base portion 32a with a diameter slightly larger than that of the rotor 20 to be magnetized, and eight opposing protrusions 32b evenly spaced in the circumferential direction on the lower surface of the base portion 32a. Each opposing protrusion 32b abuts or is close to the upper side of the rotor 20 to be magnetized, and is provided corresponding to each rotor magnetic pole portion 26. The magnetizing coils 33a of the coil body 33 are mounted in a wound manner on the outer peripheral surfaces 32c of each opposing protrusion 32b. The coil body 33 includes the same number of magnetizing coils 33a as each opposing protrusion 32b.

[0043] When viewed along the axial direction of the rotor 20, each of the opposing protrusions 32b is formed to have the same shape as the outer iron core portion 25 surrounded by the V-shaped permanent magnets 23 of each rotor pole portion 26 (see reference). Figure 6 (b) Specifically, each opposing convex portion 32b is formed into a roughly triangular shape facing a vertex in the direction of the center of the rotor 20, and the outer peripheral surface 32c of each opposing convex portion 32b is similarly formed by a circumferential surface shape that is consistent with the magnet surface 23x of the inner V-shape of the permanent magnet 23 and the outer peripheral surface 22a of the rotor core 22 when viewed axially. In addition, each opposing convex portion 32b may also be configured to be slightly smaller than each outer core portion 25. Thus, the main magnetic flux entering and exiting from each opposing convex portion 32b does not pass directly through the axial end face of the permanent magnet 23, but passes from the outer core portion 25 through the magnet surface 23x of the permanent magnet 23, and magnetizes the permanent magnet 23 along the thickness Wm direction (see reference). Figure 2 ).

[0044] like Figure 6As shown in (a), the coil body 33 has magnetizing coils 33a wound with a predetermined number of turns at eight locations, forming a system. A pair of connecting wires 33c at both ends are connected to a power supply device 34. The coil body 33 is formed in a generally circular shape along the circumference of the upper magnetizing yoke 32 and is respectively mounted on the opposing protrusions 32b arranged circumferentially. The magnetizing coils 33a in the coil body 33 are wound in an alternating reverse direction in the circumferential direction. That is, when energized by the power supply device 34, the coil body 33 is energized such that the magnetizing coils 33a and the opposing protrusions 32b on which the magnetizing coils 33a are wound alternately become different poles in the circumferential direction. The permanent magnets 23 magnetized by the magnetizing coils 33a and the opposing protrusions 32b are magnets that alternately become different poles in the circumferential direction of the rotor 20.

[0045] In addition, such as Figure 6 (a) and Figure 6 As shown in (b), in the coil body 33, the bridging wire 33d between each circumferentially adjacent magnetizing coil 33a is configured to bridge between the radially inner apex portions of each adjacent opposing protrusion 32b. The bridging wire 33d is configured to be as short as possible. Furthermore, the intersection 33e of the wires 33b formed by winding each magnetizing coil 33a is also configured at the radially inner apex portion of each opposing protrusion 32b, corresponding to the bending portion 23b of each permanent magnet 23. Since the intersection 33e of the wires 33b in each magnetizing coil 33a is a location where magnetizing flux disturbance may occur, the bending portion 23b is configured in a position that is furthest from the stator 10 in the permanent magnet 23 and is unlikely to have an impact even if magnetizing flux disturbance occurs.

[0046] This constitutes the upper part 31 of the device, and the lower part 41 of the device also has the same structure as the upper part 31. That is, as Figures 4 to 6As shown, the lower part 41 of the device includes: a lower magnetizing yoke 42, which corresponds to the upper magnetizing yoke 32, coil body 33, and power supply device 34 of the upper part 31 of the device, and has eight opposing protrusions 42b on the upper surface of the base part 42a; a coil body 43 having eight magnetizing coils 43a; and a power supply device 44 that energizes the coil body 43. The magnetizing coils 43a of the coil body 43 are wound onto the outer peripheral surfaces 42c of each opposing protrusion 42b. Each magnetizing coil 43a of the coil body 43, which is wound alternately in opposite directions in the circumferential direction, is formed by a single wire 43b and is energized from the power supply device 44 through a pair of connecting wires 43c. It has the same structure as the jumper wire 43d of each magnetizing coil 43a is set on the radial inner side of the coil body 43, and the intersection 43e of the wires 43b in each magnetizing coil 43a is set on the vertex portion of the radial inner side of each opposite protrusion 42b.

[0047] When the rotor 20 is magnetized, the upper part 31 and the lower part 41 of such a device are arranged opposite each other in the axial direction of the rotor 20 to be magnetized, and the opposing protrusions 32b and 42b of the upper part 31 and the lower part 41 are in an axially opposing position relative to each other. Moreover, when energized by the power supply devices 34 and 44, the opposing protrusions 32b and 42b of the upper part 31 and the lower part 41 and the magnetizing coils 33a and 43a are energized to the same pole.

[0048] [Method for magnetizing permanent magnets using a magnetizing device]

[0049] use Figures 4 to 6 The magnetizing device 30 with the above-described structure is first arranged with the upper part 31 and the lower part 41 of the device in an open state, separated from each other. A rotor 20 with an unmagnetized permanent magnet 23 is then placed between the upper part 31 and the lower part 41. After the rotor 20, which is to be magnetized, is placed, the upper part 31 and the lower part 41 of the device approach each other. During magnetization, the opposing protrusions 32b and 42b of the upper part 31 and the lower part 41, which are of the same pole, respectively abut or approach each other against the upper and lower sides of the rotor 20.

[0050] Next, each coil body 33, 43 is energized through the power supply devices 34, 44 on the upper part 31 and the lower part 41 of the device. Each opposing protrusion 32b, 42b on the upper part 31 and the lower part 41 is alternately energized to different poles in the circumferential direction by energizing each magnetizing coil 33a, 43a. Furthermore, the opposing protrusions 32b, 42b (each magnetizing coil 33a, 43a) on the upper part 31 and the lower part 41 are energized to the same pole.

[0051] like Figure 4 As shown, when the opposing protrusions 32b and 42b of the upper part 31 and the lower part 41 of the device are energized to the same pole, for example, S pole, within the outer core part 25, along the thickness Wm (refer to) of the permanent magnet 23... Figure 2 The magnetic flux originating in the axial direction orthogonal to the axis is converted into a flow of magnetic flux toward the opposing protrusions 32b and 42b on both sides of the axial direction. Thus, the permanent magnet 23 is magnetized so that the magnet surface 23x side is the N pole. Furthermore, although not shown in the figure, when the opposing protrusions 32b and 42b are energized into N poles, within the outer core portion 25, the axial magnetic flux originating from each of the opposing protrusions 32b and 42b is converted into a flow of magnetic flux in the axial direction orthogonal to the thickness Wm of the permanent magnet 23. Thus, the permanent magnet 23 is magnetized so that the magnet surface 23x side is the S pole.

[0052] Furthermore, since each of the opposing protrusions 32b and 42b is formed in a shape corresponding to the outer iron core portion 25 surrounded by each permanent magnet 23 in a V-shaped fold, the magnetic flux entering or exiting from each of the opposing protrusions 32b and 42b does not directly pass through the axial end face of the permanent magnet 23. Instead, the direction of the magnetic flux is appropriately converted from axial to an orthogonal direction within the outer iron core portion 25 and passes through the magnet surface 23x of the permanent magnet 23. Therefore, the permanent magnet 23 is easily aligned along the thickness Wm direction (refer to...). Figure 2 The magnetization method. In addition, the intersections 33e and 43e of the wires 33b and 43b formed by winding the magnetizing coils 33a and 43a are possible points where the magnetizing flux may be disturbed. However, since the apex of each of the opposing protrusions 32b and 42b is located at the radially inner side, that is, the bend 23b that is farthest from the stator 10 among the permanent magnets 23 and is unlikely to have an impact, even if the magnetizing flux is disturbed, the impact on the magnetization of each permanent magnet 23 can be suppressed to a small extent.

[0053] Even with the permanent magnet 23 of this embodiment, which has a roughly V-shaped folded-back design, a magnetizing flux suitable for magnetization can be supplied from the magnetizing device 30, which is arranged axially along the rotor 20, over the entire area from the radially outer end 23c to the bend 23b near the radially inner side. Therefore, more useful magnetization can be achieved over the entire area of ​​the permanent magnet 23. In particular, as with the permanent magnet 23 of this embodiment, the deeper the folded-back shape, the greater its embedding depth Lm is compared to the pole spacing Lp, the more useful it is.

[0054] Therefore, in permanent magnets using the conventional method of magnetizing from the radially outer side of the rotor, the magnetic force tends to weaken at and near the bends, such as... Figure 7As shown, in the permanent magnet 23 magnetized using the magnetization method of this embodiment, magnetization can be achieved even in and around the curved portion 23b with a sufficient magnetic field strength exceeding the desired lower limit. In the central portion 23d in the vertical direction of the curved portion 23b, where magnetization is difficult, magnetization can also be achieved with a magnetic field strength exceeding the desired lower limit. Thus, in this embodiment, approximately 95% to 90% of the permanent magnet 23 is magnetized with a magnetic field strength exceeding the desired lower limit, enabling magnetization with sufficient magnetic force throughout the entire permanent magnet 23.

[0055] The effects of this implementation method will be explained.

[0056] (1) When the permanent magnet 23 embedded in the rotor 20 is magnetized from the outside using the magnetizing device 30, during the magnetization process of the same permanent magnet 23, the opposing protrusions 32b, 42b of the upper part 31 and the lower part 41 of the device, which are axially opposite to the rotor 20, are energized to the same pole based on the energization of the magnetizing coils 33a, 43a. At this time, the outer core part 25 of the rotor core 22, which is located on the inner side of the folded shape of the permanent magnet 23 and on the radial outer side of the permanent magnet 23, allows magnetizing flux of the same pole to pass through from both sides of the axial direction, and magnetizes the permanent magnet 23. Thus, even for the permanent magnet 23 with a folded shape, a magnetizing flux suitable for magnetization can be supplied throughout the entire range from the radially outer end 23c to the bending part 23b near the radially inner side, so that magnetization with more useful and sufficient magnetic force can be performed throughout the entire range of the permanent magnet 23.

[0057] (2) When viewed along the axial direction of the rotor 20, each of the opposing protrusions 32b and 42b is configured to be the same as or slightly smaller than the outer core portion 25 located inside the folded shape of the permanent magnet 23 and radially outside the permanent magnet 23. As a result, the magnetic flux entering and exiting from each of the opposing protrusions 32b and 42b does not pass directly through the axial end face of the permanent magnet 23, but is appropriately converted from the axial direction to the orthogonal direction within the outer core portion 25. Therefore, the permanent magnet 23 can be appropriately magnetized along the thickness Wm direction.

[0058] (3) The jumper wires 33d and 43d between adjacent magnetizing coils 33a and 43a are positioned radially inside the coil bodies 33 and 43. Therefore, the lengths of the wires 33b and 43b constituting the coil bodies 33 and 43, including the jumper wires 33d and 43d, can be minimized. If the lengths of the wires 33b and 43b are shortened, the resistance decreases, which can suppress the heating of the coil bodies 33 and 43 during magnetization and improve the productivity of the rotor 20, including magnetization.

[0059] (4) The intersections 33e and 43e of the wires 33b and 43b formed by winding the magnetizing coils 33a and 43a are set in the radially inner position, that is, in the bend 23b of each permanent magnet 23 that is farthest from the stator 10 and is unlikely to have an impact. Therefore, even if the magnetizing flux becomes disordered, the impact on the magnetization of each permanent magnet 23 can be suppressed to a small extent.

[0060] This embodiment can be modified and implemented in the following ways. This embodiment and the following variations can be combined and implemented to the extent that they are not technically contradictory.

[0061] • The relative protrusions 32b and 42b of the magnetizing device 30 are configured to have the same shape as the outer iron core portion 25 when viewed along the axial direction of the rotor 20. However, the relative protrusions 32b and 42b can also be configured to have a shape that is the same as the shape of the outer iron core portion 25 or a different shape.

[0062] ·like Figure 8 As shown, the configuration can also be such that insertion protrusions (insertion portions) 32d and 42d are respectively provided at the center of the upper magnetizing yoke 32 and the lower magnetizing yoke 42, and magnetization is performed by inserting each insertion protrusion 32d and 42d into the shaft insertion hole 22b at the center of the rotor 20 to be magnetized. By providing each insertion protrusion 32d and 42d, a portion of the magnetizing flux based on the excitation of the magnetizing coils 33a and 43a flows through each insertion protrusion 32d and 42d, thereby increasing the magnetizing flux passing through the inner diameter side of the rotor 20. As a result, magnetization of the bent portion 23b of the permanent magnet 23 located on the inner diameter side of the rotor 20 and near the bent portion 23b can be performed more effectively.

[0063] In addition, Figure 8 In the way, etc., such as Figure 9 As shown, the device is divided into a first system in which coil bodies 35 and 45 on the upper part 31 and the lower part 41 are each placed circumferentially, forming a first magnetizing coil 35a1 and 45a1 connected to each other by a single wire 35b1 and 45b1 with the same winding direction, and a second system in which coil bodies 35a2 and 45a2 connected to each other by a single wire 35b2 and 45b2. That is, the coil bodies 35 and 45 are composed of two systems separated for each magnetic pole of the permanent magnet 23 used for magnetization. A first power supply device 36a1 and 46a1 are connected to the first system, and a second power supply device 36a2 and 46a2 are connected to the second system. Magnetization is then performed in two steps: a first magnetization step based on the first system and a second magnetization step based on the second system. In this way, since each of the aforementioned insertion protrusions 32d and 42d acts as a magnetic pole in each process, the magnetizing flux passing through the inner diameter side of the rotor 20 can be further increased, and the magnetization of the bent portion 23b of the permanent magnet 23 and its vicinity can be carried out more effectively.

[0064] • The jumper wires 33d and 43d between adjacent magnetizing coils 33a and 43a are set at the radial inner position of the coil bodies 33 and 43, but for example, they can be appropriately changed to the radial outer position.

[0065] • The intersections 33e and 43e of the wires 33b and 43b formed by winding the magnetizing coils 33a and 43a are set in the radially inner position, but for example, they can be appropriately changed to the radially outer position.

[0066] The magnetization of the permanent magnet 23, achieved by the magnetizing device 30, is performed by supplying a magnetizing flux along the axial direction of the rotor 20. Therefore, when magnetizing a rotor 20 with a relatively long axial length, the magnetization of the permanent magnet 23 located in the middle axial section may not be sufficient. In this case, such as Figure 10 As shown, if the axial length of the rotor 20, which can be fully magnetized by the magnetizing device 30, is set to L1, then if two, three, etc., layers of magnetizing units with an axial length of L1 or less are constructed, multiple blocks of rotor core 22 with magnetized permanent magnets 23 can be stacked axially to form a rotor 20 with an axial length L2 that exceeds L1. Even with an axial length exceeding L1, L2 allows for sufficient magnetization of the permanent magnets 23 on a block-by-block basis, thus enabling the rotor 20 to be constructed as a whole with a permanent magnet 23 possessing sufficient magnetic force.

[0067] The magnetizing device 30 consists of an upper part 31 disposed on the upper side and a lower part 41 disposed on the lower side, but the configuration of the magnetizing device 30 is not limited to this. It can also be configured such that the upper part 31 and the lower part 41 are arranged in a horizontal direction or an inclined direction other than the vertical direction.

[0068] · Figure 2 and Figure 7 The shape of the permanent magnet 23 shown is one example, and it can be changed appropriately.

[0069] · Figure 1 The structure of the rotary motor M shown is an example, and it can be modified appropriately.

[0070] While this disclosure has been described based on embodiments, it should be understood that this disclosure is not limited to the above embodiments and structures. This disclosure also includes various modifications and equivalent variations. Furthermore, various combinations and arrangements, and consequently, combinations and arrangements containing only one element, or more than or less thereof, also fall within the scope and spirit of this disclosure.

Claims

1. A rotor manufacturing apparatus, the rotor having a permanent magnet in a recessed state embedded in a magnet receiving hole of a rotor core and having a convex, radially inwardly protruding, folded-back shape, the rotor manufacturing apparatus comprising a magnetizing device that magnetizes the permanent magnet in the recessed state from outside the rotor. The magnetizing device includes: A first magnetizing unit is disposed on one axial side of the rotor and has a magnetizing coil for supplying magnetizing flux to the permanent magnet; and a second magnetizing unit is disposed on the other axial side of the rotor and has a magnetizing coil for supplying magnetizing flux to the permanent magnet. The first magnetizing part and the second magnetizing part have opposing protrusions for mounting the magnetizing coil in such a way as to be wound around the outer peripheral surface and for supplying the magnetizing magnetic flux. When the rotor manufacturing apparatus magnetizes the permanent magnet based on energizing the magnetizing coil, during the magnetization process of the same permanent magnet, the magnetizing flux supplied from the magnetizing coil disposed on one side of the axial direction of the permanent magnet and the magnetizing coil disposed on the other side of the axial direction of the permanent magnet, respectively, excites the opposing protrusions of the first magnetizing part and the second magnetizing part, which are axially opposite to the rotor and corresponding to the same permanent magnet, to be of the same pole only with either the S pole or the N pole. The magnetizing flux of the same pole passes through both sides of the rotor core located inside the folded shape of the permanent magnet and magnetizes the rotor.

2. The rotor manufacturing apparatus as described in claim 1, characterized in that, When viewed along the axial direction of the rotor, the relative protrusion is the same size or smaller than the portion of the rotor core located inside the folded-back shape of the permanent magnet.

3. The rotor manufacturing apparatus as described in claim 1, characterized in that, The magnetizing coil is composed of multiple coil bodies arranged circumferentially. The jumper wires between adjacent magnetizing coils are respectively set at radially inner positions.

4. The rotor manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The magnetizing coil is composed of multiple coil bodies arranged circumferentially. The intersections of the wires formed by winding the magnetizing coil are respectively positioned radially inward.

5. The rotor manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The first magnetizing part and the second magnetizing part each have an insertion part on at least one side that is inserted into the shaft fitting hole of the rotor, and a portion of the magnetizing flux generated based on the excitation of the magnetizing coil flows through the insertion part.

6. The rotor manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The first magnetizing part and the second magnetizing part each include a plurality of magnetizing coils. The plurality of magnetizing coils are configured as a first system and a second system for separating the magnetic poles for each magnetization of the permanent magnet, and are configured to separately perform the magnetization process based on energizing the first system and the second system.

7. The rotor manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The rotor is constructed by stacking multiple blocks along the axial direction, with the magnetizing unit of the permanent magnet set as a block.

8. A method for manufacturing a rotor, the rotor having a permanent magnet in an embedded state disposed in a magnet receiving hole of a rotor core and having a convex, radially inwardly protruding, folded-back shape, the method comprising magnetizing the permanent magnet in the embedded state from the outside of the rotor using a magnetizing device. The magnetization process includes: The first magnetizing part is disposed on one side of the rotor along the axial direction and has a magnetizing coil for supplying magnetizing flux to the permanent magnet. A second magnetizing unit is used, which is disposed on the opposite side of the rotor's axial direction and has a magnetizing coil for supplying magnetizing flux to the permanent magnet; and When the permanent magnet is magnetized based on the energization of the magnetizing coil, during the magnetization process of the same permanent magnet, the magnetizing flux supplied from the magnetizing coil disposed on one side of the axial direction of the permanent magnet and the magnetizing coil disposed on the other side of the axial direction respectively, energizes the relative protrusions of the first magnetizing part and the second magnetizing part, which are axially opposite to the rotor and correspond to the same permanent magnet, to the same pole only with either the S pole or the N pole. The magnetizing flux of the same pole passes through both sides of the rotor core located inside the folded shape of the permanent magnet and magnetizes the part.

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