Permanent magnet type motor and method for manufacturing a permanent magnet type motor

Abstract

Method for manufacturing a permanent magnet type motor in which permanent magnets (50) are incorporated into a rotor core stack (40), the method comprising the following: a process (S10) of forming the rotor core stack by combining a plurality of three types of core laminations (40a, 40b, 40c) comprising at least one first core lamination (40a) having magnet insertion holes (41) for installing the permanent magnets, at least one second core lamination (40b) having magnet insertion holes (41) and compensating holes (42), and at least one third core lamination (40c) having compensating holes (42) but no magnet insertion hole, and by arranging the at least one third core lamination (40c) that does not have a magnet insertion hole at one end in a stacking direction, a process (S20) of injecting a fixed quantity of a low-viscosity adhesive into the respective magnet insertion hole (41), wherein one end is blocked by the at least one third core sheet (40c), and a process (S30) of gluing and fixing the permanent magnet by inserting the permanent magnet (50) into the magnet insertion hole (41) into which the low-viscosity adhesive was injected.

Description

BACKGROUND TECHNICAL AREA

[0001] The present invention relates to a permanent magnet type motor in which permanent magnets are incorporated in a rotor core, and a method of manufacturing the permanent magnet type motor. GENERAL STATE OF THE ART

[0002] Motors that use permanent magnets are roughly divided into surface permanent magnet type (SPM motor), in which the permanent magnet is arranged on the surface of a shaft, and internal permanent magnet type (IPM motor), in which the permanent magnets are built into a rotor core.

[0003] IPM motor rotor shapes vary, and the manufacturing process used depends on the specific shape and intended use of the motor. Generally, a manufacturing process is used in which, after the rotor core is shrunk onto the shaft, an adhesive is applied to both sides of a magnet insertion hole and the permanent magnet. The permanent magnet is inserted into the magnet insertion hole from both end faces of the rotor core to cure the adhesive.

[0004] Since the magnet insertion hole opens into both end surfaces of the rotor core, an adhesive is used that has such a high viscosity that it does not drip out of the magnet insertion hole.

[0005] As a technique related to the installation of the permanent magnets, a method of manufacturing the motor is disclosed in which permanent magnet embedding holes are provided at a plurality of positions in the rotor core in an axial direction, and then the permanent magnets and the rotor core are also bonded to each other (for example, see JP 2003-199 303 A).

[0006] JP 2009-240 109 A discloses an electric motor equipped with a rotor core in which a permanent magnet can be easily positioned in a magnet insertion hole, the number of parts being small, and the structure being simplified (see also the figures therein). The electric motor 1 comprises: a rotor shaft 3; a rotor core 5 made of a laminate of thin silicon steel plates and produced by laminating a plurality of thin silicon steel plates 5a, 5b, and 5c, which is mounted on the rotor shaft 3; a plurality of magnet insertion holes 7 formed in this rotor core 5 parallel to the axis of the rotor shaft 3; and a plurality of permanent magnets 8 individually mounted in these magnet insertion holes 7.The thin silicon steel plate 5b at one end of the rotor core 5 is provided with a sealing portion 10 that blocks each magnet insertion hole 7 that can accommodate the permanent magnet 8, and a small hole 10a through which a part of an adhesive can leak out. In this sealing portion 10, a connecting member for connecting the permanent magnet 8 is formed.

[0007] The following documents are also worth mentioning from the state of the art: DE 10 2008 000 771 A1; US 5,936,323A; JP 2006-238 559A; JP 2012-23 900 A; JP 2008-289 286 A and US 5 973 426 A. SUMMARY OF THE INVENTION

[0008] Incidentally, the prior art method for manufacturing the rotor uses a high-viscosity adhesive to prevent the adhesive from dripping out of the magnet insertion hole.

[0009] However, it is difficult to apply a high-viscosity adhesive with poor fluidity to the inner surface of the magnet insertion hole. In particular, it was difficult to apply the high-viscosity adhesive evenly to the inner surface of the magnet insertion hole, and the manufacturing irregularity of the rotor increased.

[0010] Furthermore, since the work of wiping the adhesive leaking from the magnet insertion hole was required after inserting the permanent magnet into the magnet insertion hole, the manufacturing efficiency of the rotor was reduced and the manufacturing cost was increased.

[0011] In the technique described in Japanese Patent Application Laid-Open No. 2003-199303, the permanent magnet is directly coated with adhesive. However, since a small motor, in particular, has a small magnet insertion hole, even if the permanent magnet is directly coated with adhesive, excess adhesive will leak from the magnet insertion hole when the permanent magnet is inserted into the magnet insertion hole.

[0012] The invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a high-quality permanent magnet type motor and a method for manufacturing the permanent magnet type motor, which are capable of reducing the manufacturing cost by optimizing the rotor manufacturing and reducing the manufacturing irregularity of the rotor.

[0013] According to one aspect of the invention for achieving the above-mentioned object, there is provided a method for manufacturing a permanent magnet type motor having the features of claim 1. Permanent magnets are incorporated into a rotor core stack or block, the method comprising a process of forming the rotor core stack, a process of injecting a low-viscosity adhesive, and a process of bonding and fixing the permanent magnet.

[0014] In the process of forming the rotor core stack, the rotor core stack is formed by combining a plurality of three types of core sheets including at least a first core sheet having magnet insertion holes for installing the permanent magnets, at least a second core sheet having magnet insertion holes and balancing holes, and at least a third core sheet having balancing holes but no magnet insertion hole, and by arranging the core sheet having no magnet insertion hole at one end in a stacking direction.

[0015] In the process of injecting the low-viscosity adhesive, the low-viscosity adhesive is injected into the respective magnet insertion hole which is blocked at one end by the at least one third core sheet which does not have a magnet insertion hole.

[0016] In the process of bonding and fixing the permanent magnets, the permanent magnet is inserted into the magnet insertion hole, into which the low-viscosity adhesive is injected, thereby bonding and fixing the permanent magnet.

[0017] Furthermore, according to another aspect of the invention, there is provided a permanent magnet type motor according to claim 6, wherein a plurality of permanent magnets are incorporated in a rotor core stack, in which the rotor core stack is formed and the permanent magnets are bonded and fixed.

[0018] The rotor core stack is formed by combining a plurality of three types of core sheets including at least a first core sheet having magnet insertion holes for installing the permanent magnets, at least one second core sheet having magnet insertion holes and balancing holes, and at least one third core sheet having balancing holes but no magnet insertion hole, and by arranging the at least one third core sheet having no magnet insertion hole at one end in a stacking direction.

[0019] The permanent magnet is bonded and fixed by injecting the low-viscosity adhesive into the respective magnet injection hole in which one end is blocked by the at least one third core sheet that does not have a magnet insertion hole, and inserting the permanent magnet into the magnet insertion hole into which the low-viscosity adhesive has been injected.

[0020] According to the invention, the rotor core stack is formed by arranging at least one third core sheet, which does not have a magnet insertion hole, at one end in the stacking direction. Since one end of the magnet insertion holes is blocked by this core sheet, which does not have a magnet insertion hole, the magnet insertion holes have a container shape, and the low-viscosity adhesive therefore does not flow out. After a fixed amount of low-viscosity adhesive is injected into the magnet insertion hole, the permanent magnet is inserted from a mouth end of the magnet insertion hole.

[0021] The invention can therefore prevent the low-viscosity adhesive from leaking from the magnet injection holes and reduce manufacturing costs by optimizing rotor manufacturing. Furthermore, since the low-viscosity adhesive can be evenly applied to the inner surface of the magnet insertion holes, a high-quality permanent magnet-type motor can be provided by reducing rotor manufacturing irregularities. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of an overall structure of a permanent magnet type motor, Fig. 2A to 2C are plan views of core sheets forming a rotor core stack, Fig. 3 is an exploded perspective view of the rotor core stack, Fig. 4A and Fig. 4B are perspective views of a magnet insertion hole side and a balance hole side of the rotor core stack, Fig. 5A and Fig. 5B are schematic views of a situation of inserting the permanent magnet after injecting the adhesive, Fig. 6A and Fig. 6B are perspective views of a situation of positioning and mounting a shaft and the rotor core stacks, Fig. 7 is a flowchart of a method of manufacturing a permanent magnet type motor of a first embodiment, Fig. 8A to 8D are perspective views of a seal housing construction of the rotor core stacks and side views of a seal housing male part and a seal housing female part of a second embodiment, Fig. 9A to 9C are an exploded view of a positioning structure of the rotor core stacks and perspective views of a rotor of the second embodiment, Fig. 10A to 10C are exploded perspective views of a positioning structure of the rotor core stacks and perspective views of a rotor of a third embodiment, Fig. 11A to 11C are exploded perspective views of a positioning structure of the rotor core stacks and perspective views of a rotor of a fourth embodiment, and Fig. 12A to 12C are an exploded perspective view of a positioning structure of the rotor core stacks and perspective views of a rotor of a fifth embodiment. DETAILED DESCRIPTION

[0022] Hereinafter, permanent magnet type motors and methods of manufacturing the permanent magnet type motors according to the first to fifth embodiments will be described with reference to the drawings.

[0023] The permanent magnet type motors and the methods for manufacturing the permanent magnet type motors according to the first to fifth aspects can reduce manufacturing costs by optimizing rotor manufacturing by preventing a low-viscosity adhesive from leaking from magnet insertion holes. Furthermore, since the low-viscosity adhesive can be evenly applied to an inner surface of the magnet insertion holes, a high-quality permanent magnet type motor can be achieved by reducing rotor manufacturing irregularities. [First Design][Structure of a Permanent Magnet Type Motor]

[0024] First, with reference to the Fig. 1 to 6B, the structure of a permanent magnet type motor of the first embodiment is described. Fig. 1 is a schematic view of an overall structure of the permanent magnet type motor. Fig. 2A to 2C are plan views of core laminations forming a rotor core stack or block. Fig. 3 is an exploded perspective view of the rotor core stack. Fig. 4A and Fig. 4B are perspective views of a magnet insertion hole side and a balance hole side of the rotor core stack. Fig. 5A and Fig. 5B are schematic views of a situation of inserting the permanent magnet after injection of an adhesive. Fig. 6A and Fig. 6B are perspective views of the situation of positioning or mounting a shaft and the rotor core stacks.

[0025] As an example of the permanent magnet type motor of the design, an IPM motor (motor with internal permanent magnets) is used. Fig. The permanent magnet type 100 motor shown in Figure 1 is an IPM motor with 10 poles and 12 slots and includes a stator 1 and a rotor 2.

[0026] As in Fig. As shown in Figure 1, the stator or stator 1 has a yoke 10, a stator core 20 and windings 30.

[0027] The yoke 10 is a metallic element formed as a cylindrical body. The yoke 10 serves to close a magnetic line of force to maximize the electromagnetic induction effect of the permanent magnets 50 described below. Furthermore, the yoke 10 also serves to prevent peripheral devices of the motor 100 from being influenced by a magnetic field due to electromagnetic induction.

[0028] Although a soft magnetic material such as silicon steel sheet is used as a structural component of the yoke 10, the material is not limited to the material shown.

[0029] The stator core 20 is a metallic member formed as a thick cylindrical body provided along an inner surface of the yoke 10. On an inner peripheral side of the stator core 20, a plurality of recesses 21 are radially formed as spaces for receiving the windings 30 so that they face the rotor 2 in a divided manner.

[0030] Although a soft magnetic material such as silicon steel sheet is used as the component material of the stator core 20, similar to the yoke 10, the material is not limited to the material shown.

[0031] The windings 30 are arranged inside the recesses 21. The number of recesses 21 corresponds to the number of windings 30. Although twelve recesses 21 and windings 30 are arranged in the embodiment, the number of recesses 21 and windings 30 is not limited.

[0032] The rotor 2 is provided around a shaft 3 and has a rotor core stack 40 and permanent magnets 50. The shaft 3 serves as a pivot point for the rotor 2.

[0033] The rotor core stack 40 is a metallic member formed as a thick cylindrical body provided around the shaft 3. In the embodiment, the rotor core stack 40 is formed by stacking a plurality of core sheets as a rotor core stack.

[0034] As in the Fig. As illustrated in FIGS. 2A to 2C, the rotor core stack 40 of the embodiment includes three types of core sheets 40a, 40b, and 40c. A shaft insertion hole 3a for inserting and fixing the shaft 3 is formed in a central portion of each of the core sheets 40a, 40b, and 40c.

[0035] A plurality of magnet insertion holes 41 for installing permanent magnets are provided in the core sheet 40a near an outer edge portion thereof. The plurality of magnet insertion holes 41 are arranged at equal intervals in a circumferential direction of the core sheet 40a.

[0036] The core sheet 40b has the same structure as the core sheet 40a, and a plurality of magnet insertion holes 41 are provided near an outer peripheral portion thereof. Furthermore, a plurality of balancing holes 42 are provided in the core sheet 40b on the inner side of the magnet insertion holes 41 in the radial direction. The plurality of balancing holes 42 are arranged at equal intervals along the circumferential direction of the core sheet 40b.

[0037] The core sheet 40c has the same structure as the core sheet 40b and has a plurality of compensation holes 42. The magnet insertion holes 41 are not present in the core sheet 40c.

[0038] Although a soft magnetic material such as silicon steel sheet is used as the component material of each of the core sheets 40a, 40b and 40c, the material is not limited to the material shown.

[0039] As in the Fig. 3, Fig. 4A and Fig. As illustrated in FIG. 4B, the rotor core stack 40 is formed by sequentially stacking the core sheet 40a, the core sheet 40b, and the core sheet 40c. A plurality of pieces of the core sheets 40a and 40b having the magnet insertion holes 41 are stacked, respectively. At least one core sheet 40c that does not have the magnet insertion holes 41 is used.

[0040] The core sheet 40c, which does not have the magnet insertion holes 41, is positioned at one end in a stacking direction of the rotor core stack 40. One end of the magnet insertion holes 41 is blocked by the core sheet 40c, which does not have a magnet insertion hole.

[0041] The permanent magnets 50 are plate-shaped. Although rare earth magnets such as neodymium magnets are used as permanent magnets 50, the material is not limited to the material shown.

[0042] The permanent magnets 50 are glued and fixed in the magnet insertion holes 41 of the rotor core stack 40. Specifically, as shown in Fig. 5A, a fixed amount of low-viscosity adhesive B is injected into the magnet insertion holes 41, one end of which is blocked. In addition, the permanent magnets 50, as shown in Fig. 5B, inserted into the magnet insertion holes 41 into which the low-viscosity adhesive B is injected, and the permanent magnets 50 are bonded and fixed.

[0043] The plurality of permanent magnets 50 are arranged at equal spacing in the circumferential direction of the rotor core stack 40. Although the permanent magnets 50 are arranged in ten poles in the embodiment, the number of permanent magnets 50 is not limited. For example, the permanent magnets 50 are arranged with a magnetization opposite the magnetic poles (NN, SS) in the circumferential direction of the rotor core stack 40.

[0044] With respect to a permanent magnet type motor 100, a pair of rotor core stacks 40 in which the permanent magnets 50 are incorporated are produced. As shown in the Fig. 6A and Fig. As illustrated in Figure 6B, the pair of rotor core stacks 40 and 40, in which the permanent magnets 50 are incorporated, are mounted on the shaft 3 by shrink fitting by causing the exposed surface sides of the permanent magnets 50 to face each other and positioning the exposed surface sides in the axial direction and the rotational direction. The pair of rotor core stacks 40 and 40 are mounted on the shaft 3 by shifting their positions relative to each other in the rotational direction by shrink fitting.

[0045] As in Fig. 6B, the permanent magnets 50 are not visually recognizable from the external appearance in a complete state of the rotor 2 attached to the shaft 3. [Operation of the permanent magnet type motor and manufacturing process]

[0046] In the following, the operation of a permanent magnet type motor 100 according to the first embodiment and a method of manufacturing the permanent magnet type motor 100 according to the first embodiment will be described with respect to the Fig. 1 to 7 described. Fig. 7 is a flowchart of a method for manufacturing the permanent magnet type motor.

[0047] As in Fig. As illustrated in Figure 1, the rotor 2 of the permanent magnet type motor 100 according to the embodiment is configured such that a plurality of permanent magnets 50 are incorporated into the rotor core stack 40. The plurality of permanent magnets 50 are arranged to be subjected to magnetic pole-opposing (NN, SS) magnetization in the circumferential direction.

[0048] Meanwhile, the stator 1 has a plurality of windings 30 provided surrounding the rotor 2 and arranged radially in the circumferential direction.

[0049] That is, according to the permanent magnet type motor 100 of the embodiment, electric current flows through the windings 30 of the stator 1, so that the electric current intersects with the magnetic flux generated by the permanent magnets 50 of the rotor 2. When the magnetic flux of the permanent magnets 50 intersects with the electric current flowing through the windings 30, the permanent magnet type motor 100 of the embodiment generates a driving force in the circumferential direction in the windings 30 through electromagnetic induction, thereby rotating the rotor 2 around the shaft 3.

[0050] A method for manufacturing the permanent magnet type motor 100 according to the first embodiment includes a process of forming a rotor core stack, a process of injecting a low-viscosity adhesive, and a process of bonding and fixing permanent magnets. Furthermore, the method for manufacturing the permanent magnet type motor 100 according to the first embodiment includes a process of heating the rotor core stacks, a process of positioning the rotor core stacks, and a cooling process for assembling and fixing the rotor core stacks.

[0051] As in Fig. 7, the method of manufacturing the permanent magnet type motor 100 according to the first embodiment first performs the process of forming the rotor core stack (S10).

[0052] As in the Fig. As illustrated in FIGS. 2A to 4B, in the process of forming the rotor core stack 40, the core sheet 40a, the core sheet 40b, and the core sheet 40c are sequentially stacked to form the rotor core stack 40. The core sheet 40a has only the magnet insertion holes 41 in addition to the shaft insertion hole 3a. The core sheet 40b has only the magnet insertion holes 41 and the balance holes 42 in addition to the shaft insertion hole 3a. The core sheet 40c has only the balance holes 42 in addition to the shaft insertion hole 3a. A plurality of the individual core sheets 40a and 40b having the magnet insertion holes 41 are stacked, respectively. At least one single core sheet 40c without the magnet insertion holes 41 is used.

[0053] When forming the rotor core stack, the core sheet 40c without the magnet insertion holes is arranged at one end in the stacking direction. One end of the magnet insertion holes 41 is blocked by the core sheet 40c without the magnet insertion holes.

[0054] Next, in the method of manufacturing the permanent magnet type motor 100 according to the first embodiment, as shown in Fig. 7 illustrates the process of injecting the low-viscosity adhesive (S20).

[0055] As in Fig. 5A, in the process of injecting the low-viscosity adhesive, from the mouth ends of the magnet insertion holes 41, a fixed amount of the low-viscosity adhesive B is injected into the magnet insertion holes 41, one end of which is blocked by the core sheet 40c without the magnet insertion holes 41.

[0056] Next, in the method of manufacturing the permanent magnet type motor 100 according to the first embodiment, as shown in Fig. 7 illustrates the process of gluing and fixing the permanent magnets (S30).

[0057] During the process of gluing and fixing the permanent magnets, as shown in Fig. 5B illustrates that the permanent magnet 50 is bonded and fixed after injecting the low-viscosity adhesive B by inserting the permanent magnet 50 into the magnet insertion hole 41 having the low-viscosity adhesive B.

[0058] In the method of manufacturing the permanent magnet type motor 100 according to the first embodiment, as shown in Fig. 7, the process of heating the rotor core stack (S40) is performed next.

[0059] In the process of heating the rotor core stack, the pair of rotor core stacks 40 and 40 in which the permanent magnet 50 has been incorporated are placed in a heating device, and the rotor core stacks 40 and 40 are heated to a temperature suitable for shrink-fitting.

[0060] In carrying out the method for manufacturing the permanent magnet type motor 100 according to the first embodiment, as shown in Fig. 7, next, the process of positioning the rotor core stacks is performed (S50), including inserting the shaft 3 into the shaft insertion hole 3a.

[0061] As in Fig. 6A, in the process of positioning the rotor core stacks, the exposed surface sides of the permanent magnets 50 of the pair of heat-expanded rotor core stacks 40 and 40 are caused to face each other, and the shaft 3 is inserted into the shaft insertion hole 3a. As shown in Fig. As illustrated in Figure 6B, in the process of positioning the rotor core stacks, the mating surfaces (exposed surfaces of the permanent magnets 50) of the rotor core stack pair 40 and 40 are next caused to abut against each other to perform the positioning of the rotor core stacks 40 and 40 in the axial direction and the rotational direction. The rotor core stack pair 40 and 40 is assembled and fixed by mutually shifting their positions in the rotational direction.

[0062] In the method of manufacturing the permanent magnet type motor 100 according to the first embodiment, as shown in Fig. 7 illustrates, next, the process of cooling the rotor core stack (S60) is performed.

[0063] In the process of cooling the rotor core stack, the rotor core stack pair 40 and 40 subjected to the positioning process is cooled, and the rotor core stacks 40 and 40 are mounted and fixed to the shaft 3.

[0064] The attachment of the rotor 2 to the shaft 3 is completed by the above-mentioned processes. As shown in Fig. 6B, the permanent magnets 50 cannot be visually recognized from the external appearance in the complete state of the rotor 2 attached to the shaft 3.

[0065] Specifically, a small permanent magnet type motor 100 has small magnet insertion holes 41. Therefore, in order to improve the adhesive bonding quality between the permanent magnet 50 and the rotor core stack 40, there is a need to select not a high-viscosity adhesive with poor flowability but a low-viscosity adhesive B with good flowability.

[0066] The rotor core stack 40 of the embodiment is formed by arranging the core sheet 40c, which does not have the magnet insertion holes 41, at one end in the stacking direction. One end of the magnet insertion holes 41 is blocked by the core sheet 40c, which does not have the magnet insertion holes 41.

[0067] Before the permanent magnets 50 are inserted into the magnet insertion holes 41, a fixed amount of the low-viscosity adhesive B is injected from the mouth ends of the magnet insertion holes 41. Since one end of the magnet insertion holes 41 is blocked, the magnet insertion holes 41 have a container shape, and therefore the low-viscosity adhesive B does not leak out.

[0068] After injecting the low-viscosity adhesive B into the magnet insertion holes 41, the permanent magnets 50 are inserted from the mouth ends of the magnet insertion holes 41. The injection amount of the low-viscosity adhesive B is set so that the low-viscosity adhesive B does not leak from the mouth ends of the magnet insertion holes 41 when the permanent magnets 50 are inserted. As long as the amount is maintained so that the low-viscosity adhesive B does not leak from the magnet insertion holes 41, the low-viscosity adhesive B does not leak from the magnet insertion holes 41, and no work is required to wipe the adhesive.

[0069] Accordingly, the permanent magnet type motor 100 and the method for manufacturing the permanent magnet type motor 100 according to the embodiment can reduce the manufacturing cost by optimizing the manufacturing of the rotor 2 by preventing the low-viscosity adhesive B from leaking from the magnet insertion holes 41.

[0070] Furthermore, it is possible to provide the high-quality permanent magnet type motor 100 by reducing the manufacturing irregularity of the rotor 2 because the low-viscosity adhesive B can be uniformly applied to the inner surface of the magnet insertion hole 41.

[0071] Furthermore, according to the permanent magnet type motor 100 and the method for manufacturing the permanent magnet type motor 100 according to the embodiment, a pair of rotor core stacks 40 and 40 is provided for each permanent magnet type motor 100. Accordingly, by mounting and fixing the pair of rotor core stacks 40 and 40 to the shaft 3 so that they are displaced from each other in the rotation direction, a two-stage twist structure is formed, and it is thus possible to achieve a permanent magnet type motor 100 in which cogging is reduced. [Second embodiment]

[0072] Next, with reference to the Fig. 7 to 9C, a permanent magnet type motor 200 and a method for manufacturing the permanent magnet type motor 200 according to a second embodiment are described. Fig. 8A to 8D are a perspective view of a seal housing construction of the rotor core stacks and side views of a seal housing male part and a seal housing female part of a second embodiment, respectively. Fig. 9A to 9C are exploded perspective views of a positioning structure of the rotor core stacks and perspective views of a rotor of the second embodiment, respectively. In addition, the same parts as those of the permanent magnet type motor 100 of the first embodiment are denoted by the same reference numerals, and their descriptions will therefore not be repeated below.

[0073] As in the Fig. 8A to 8D, the second embodiment differs from the first embodiment in that the rotor core stack pair 40 and 40 is positioned by a seal housing structure.

[0074] In the permanent magnet type motor 200 according to the second embodiment, a seal housing male part 210 shaped as a cylindrical body is formed on one mating surface of the rotor core stack pair 40, and a seal housing female part 220 shaped as a cylindrical groove is formed on the other mating surface. The seal housing male part 210 has a convex part 211 projecting radially toward the rotor core stack 40. The seal housing female part 220 has a concave part 221 that engages with the convex part 211 of the seal housing male part 210.

[0075] As in the Fig. As illustrated in FIGS. 9A to 9C, the rotor core stack pair 40 and 40 performs the positioning of the rotor core stacks 40 and 40 in the axial direction by inserting the seal housing male part 210 into the seal housing female part 220 when the shaft 3 is inserted into the shaft insertion hole 3a to perform the positioning. Furthermore, the convex part 211 of the seal housing male part 210 engages with the concave part 221 of the seal housing female part 220 to perform the positioning of the rotor core stack pair 40 and 40 in the rotational direction.

[0076] In forming the twist structure, a height of the seal housing male part 210 is preferably set to be greater than a depth of the seal housing female part 220 to provide a gap S of about 0.5 to 1 mm between the rotor core stack pair 40 and 40.

[0077] In the method for manufacturing the permanent magnet type motor 200 according to the second embodiment, in the process of positioning (S50) the rotor core stack of Fig. 7, the positioning in the axial direction is performed with a predetermined gap S of approximately 0.5 to 1 mm from the seal housing structure formed on the mating surfaces of the rotor core stack pair 40 and 40. When the seal housing male part 210 is inserted into the seal housing female part 220, the convex part 211 of the seal housing male part 210 is engaged with the concave part 221 of the seal housing female part 220 to perform the positioning in the rotation direction.

[0078] The second embodiment has basically the same effects as the first embodiment. Specifically, according to the second embodiment, positioning in the axial direction can be easily performed by simply inserting the seal housing male part 210 into the seal housing female part 220 formed on the mating surface of the rotor core stack pair 40 and 40.

[0079] Furthermore, according to the second embodiment, the positioning in the rotational direction can be easily performed by engaging only the convex part 211 of the seal housing male part 210 with the concave part 221 of the seal housing female part 220 when the seal housing male part 210 is inserted into the seal housing female part 220.

[0080] Furthermore, when forming a twist structure by providing a predetermined gap between the rotor core stack pair 40 and 40, there is an effect of suppressing the magnetic flux short-circuited between the rotor core stacks 40 and 40. Accordingly, the second embodiment has a specific effect that can suppress torque drop while reducing cogging torque. [Third embodiment]

[0081] Next, with reference to the Fig. 7 and 10A to 10C, a permanent magnet type motor 300 and a method for manufacturing the permanent magnet type motor 300 according to a third embodiment are described. Fig. 10A to 10C are exploded perspective views of a positioning structure of the rotor core stacks and perspective views of a rotor of the third embodiment, respectively. In addition, the same parts as those of the permanent magnet type motor 100 according to the first embodiment are denoted by the same reference numerals, and their descriptions will therefore not be repeated below.

[0082] As in the Fig. 10A to 10C, the third embodiment differs from the first embodiment in that the rotor core stack pair 40 and 40 is positioned by a thin annular coupling 320.

[0083] The permanent magnet type motor 300 according to the third embodiment has a plurality of insertion holes 310 formed on respective mating surfaces of the rotor core stack pair 40 and 40. The plurality of insertion holes 310 are arranged at four equally spaced positions along the circumferential direction of the rotor core stacks. Specifically, the plurality of insertion holes 310 are located in a core sheet 40a having only the magnet insertion holes 41.

[0084] When the shaft 3 is inserted into the shaft insertion hole 3a of the rotor core stack pair 40 and 40 to perform positioning, the annular coupling 320, which has a plurality of pins 321 that engage in the plurality of insertion holes 310, is interposed between the pair of rotor core stacks 40 and 40. The plurality of pins 321 are formed at four positions equally spaced along the circumferential direction of both surfaces of the annular coupling 320. A gap S corresponding to the thickness of the annular coupling 320 is formed between the rotor core stacks 40 and 40.

[0085] In the method for manufacturing the permanent magnet type motor 300 according to the third embodiment, in the process of positioning (S50) the rotor core stack of Fig. 7, the positioning of the rotor core stack pair 40 and 40 in the axial direction with a predetermined gap S is performed by means of the annular coupling 320. When the pair of rotor core stacks 40 and 40 are arranged to face each other via the annular coupling 320, the plurality of pins 321 of the annular coupling 320 are engaged with the plurality of insertion holes 310 formed on the mating surfaces of the rotor core stack pair 40 and 40 to perform positioning in the rotation direction.

[0086] The third embodiment has basically the same effect as the first embodiment. Specifically, according to the third embodiment, positioning in the axial direction can be easily performed by simply interposing the annular coupling 320 between the pair of rotor core stacks 40 and 40.

[0087] Furthermore, according to the third embodiment, the positioning in the rotation direction can be easily performed by only engaging the plurality of pins 321 of the annular coupling 320 with the plurality of insertion holes 310 formed on the mating surfaces of the rotor core stack pair 40 and 40.

[0088] Furthermore, when forming a twist structure, the gap S corresponding to the thickness of the annular coupling 320 can be provided between the pair of rotor core stacks 40 and 40 by only providing the annular coupling 320. By providing a predetermined gap S between the pair of rotor core stacks 40 and 40, there is an effect that suppresses the magnetic flux short-circuited between the rotor core stacks 40 and 40. Accordingly, the third embodiment has a specific effect that can suppress the torque drop while reducing the cogging torque. [Fourth embodiment]

[0089] Next, with reference to the Fig. 7 and 11A to 11C, a permanent magnet type motor 400 and a method for manufacturing the permanent magnet type motor 400 according to a fourth embodiment are described. Fig. 11A to 11C are exploded perspective views of a positioning structure of a rotor core stack and perspective views of a rotor of a fourth embodiment, respectively. In addition, the same parts as those of the permanent magnet type motor 100 according to the first embodiment are denoted by the same reference numerals, and their descriptions will therefore not be repeated below.

[0090] As in the Fig. 11A to 11C, the fourth embodiment differs from the first embodiment in that the pair of rotor core stacks 40 and 40 are positioned by an intermediate disk 410.

[0091] In the permanent magnet type motor 400 according to the fourth embodiment, a thin annular washer 410 is interposed between the rotor core stacks 40 and 40 when the shaft 3 is inserted into the shaft insertion hole 3a of the rotor core stack pair 40 and 40 to perform positioning. A gap S corresponding to the thickness of the washer 410 is formed between the rotor core stacks 40 and 40.

[0092] In the method for manufacturing the permanent magnet type motor 400 according to the fourth embodiment, in the process for positioning (S50) the rotor core stack of Fig. 7, the positioning in the axial direction of the rotor core stack pair 40 and 40 is performed with a predetermined gap S by means of the annular washer 410. The positioning in the rotational direction is performed using a jig.

[0093] The fourth embodiment has basically the same effect as the first embodiment. Specifically, according to the fourth embodiment, positioning in the axial direction can be easily performed by simply interposing the annular spacer 410 between the pair of rotor core stacks 40 and 40.

[0094] Furthermore, when forming a twist structure, the gap S corresponding to the thickness of the intermediate disk 410 can be provided between the pair of rotor core stacks 40 and 40 by only providing the intermediate ring 410. By providing a predetermined gap S between the pair of rotor core stacks 40 and 40, there is an effect that suppresses the magnetic flux short-circuited between the rotor core stacks 40 and 40. Accordingly, the fourth embodiment has a specific effect that can suppress the torque drop while reducing the cogging torque. [Fifth embodiment]

[0095] Next, with reference to the Fig. 7 and 12A to 12C, a method for manufacturing a permanent magnet type motor 500 according to a fifth embodiment is described. Fig. 12A to 12C are exploded perspective views of a positioning structure of a rotor core stack and perspective views of a rotor of the fifth embodiment, respectively. In addition, the same parts as those of the permanent magnet type motor 100 according to the first embodiment are denoted by the same reference numerals, and their descriptions will therefore not be repeated below.

[0096] As in the Fig. 12A to 12C, the fifth embodiment differs from the first embodiment in that a predetermined gap S is formed between the pair of rotor core stacks 40 and 40.

[0097] In the method for manufacturing the permanent magnet type motor 500 according to the fifth embodiment, in the process of positioning (S50) the rotor core stack of Fig. 7, the positioning of the rotor core stack pair 40 and 40 in the axial direction and in the rotational direction is performed by a mounting device. In the rotor core stack pair 40 and 40, only the shaft 3 is present, but nothing is arranged in between.

[0098] The fifth embodiment has basically the same effect as the first embodiment. Specifically, the fifth embodiment has an effect that suppresses the magnetic flux short-circuited between the rotor core stacks 40 and 40 when the twist structure is formed by providing a predetermined gap S between the rotor core stack pair 40 and 40. Accordingly, the fifth embodiment has a specific effect that can suppress the torque drop while reducing the cogging torque.

[0099] In summary, a high-quality permanent magnet type motor is achieved, which can reduce the manufacturing cost by optimizing the rotor manufacturing and reducing the manufacturing irregularity of the rotor.

[0100] A method for manufacturing a permanent magnet type motor in which permanent magnets are incorporated into a rotor core stack is provided, the method including a process (or step) S10 of forming the rotor core stack by combining a plurality of core sheets having magnet insertion holes with a core sheet not having a magnet insertion hole, and arranging the core sheet not having a magnet insertion hole at one end in a stacking direction, a process (or step) S20 of injecting a low-viscosity adhesive into the magnet insertion holes with one end blocked by the core sheet, and a process (or step) S30 of bonding and fixing the permanent magnets by inserting the permanent magnets into the magnet insertion holes into which the low-viscosity adhesive has been injected.

[0101] Although preferred embodiments of the invention have been described, these embodiments are examples for illustrating the invention, and the scope of the invention is not limited exclusively to these embodiments. The invention can be embodied in various aspects other than the above-mentioned embodiments within the scope that does not deviate from its spirit.

Claims

[1] A method of manufacturing a permanent magnet type motor in which permanent magnets (50) are incorporated into a rotor core stack (40), the method comprising: a process (S10) of forming the rotor core stack by combining a plurality of three types of core sheets (40a, 40b, 40c) comprising at least one first core sheet (40a) having magnet insertion holes (41) for installing the permanent magnets, at least one second core sheet (40b) having magnet insertion holes (41) and balancing holes (42), and at least one third core sheet (40c) having balancing holes (42) but no magnet insertion hole, and by arranging the at least one third core sheet (40c) having no magnet insertion hole at one end in a stacking direction, a process (S20) of injecting a fixed amount of a low-viscosity adhesive into the respective magnet insertion hole (41) in which one end of the at least one third core sheet (40c) is blocked, and a process (S30) of bonding and fixing the permanent magnet by inserting the permanent magnet (50) into the magnet insertion hole (41) into which the low-viscosity adhesive has been injected. [2] A method of manufacturing a permanent magnet type motor according to claim 1, further comprising: a process (S40) of heating a pair of rotor core stacks, in which the permanent magnet has been incorporated, to a temperature suitable for shrinking, a process (S50) of inserting a shaft (3) into a shaft insertion hole (3a) of the pair of heat-expanded rotor core stacks and causing the exposed magnet surfaces of the rotor core stack pair to face each other to perform positioning in an axial direction and in a rotational direction, and a cooling process (S60) to assemble and fix the rotor core stack to the shaft. [3] A method of manufacturing a permanent magnet type motor according to claim 2, wherein in the process of positioning the rotor core stacks, the rotor core stacks are positioned in the axial direction with a predetermined gap (S) by a seal case structure formed on mating surfaces of the pair of rotor core stacks, and the rotor core stacks are positioned in the rotational direction by engaging a convex part (211) formed on a seal case male part (210) with a concave part (221) formed on a seal case female part (220). [4] A method of manufacturing a permanent magnet type motor according to claim 2, wherein in the process of positioning the rotor core stacks, the rotor core stack pair is positioned in the axial direction by means of an annular coupling (320) having a predetermined gap (S), and the rotor core stack pair is positioned in the rotational direction by engaging a plurality of pins (321) of the annular coupling with a plurality of insertion holes formed on mating surfaces of the rotor core stack pair. [5] A method of manufacturing a permanent magnet type motor according to claim 2, wherein in the process of positioning the rotor core stacks, the rotor core stack pair is positioned in the axial direction by means of a washer (410) having a predetermined gap (S), and the rotor core stack pair is positioned in the rotational direction using a positioning device. [6] A permanent magnet type motor in which a plurality of permanent magnets (50) are installed in a rotor core stack (40), the rotor core stack being formed by combining a plurality of three types of core sheets (40a, 40b, 40c) comprising at least a first core sheet (40a) having magnet insertion holes (41) for installing the permanent magnets, at least a second core sheet (40b) having magnet insertion holes (41) and balancing holes (42), and at least a third core sheet (40c) having balancing holes (42) but no magnet insertion hole, the at least one third core sheet (42c) not having a magnet insertion hole being arranged at one end in a stacking direction, a fixed amount of a low-viscosity adhesive being injected into the magnet insertion holes (41) in which one end of the at least one third core sheet (42c) which does not have a magnet insertion hole,and wherein the permanent magnets (50) are glued and fixed by inserting the permanent magnets into the magnet insertion holes (41) into which the low-viscosity adhesive has been injected., [7] A permanent magnet type motor according to claim 6, wherein the positioning in an axial direction and in a rotational direction is performed by causing exposed magnet surfaces of a rotor core stack pair in which the permanent magnets (50) are incorporated to face each other and shrinking the rotor core stack pair onto a shaft (3). [8] Permanent magnet type motor according to claim 6, wherein a seal housing male part (210) having a convex part (211) projecting outward in the radial direction is formed on one mating surface of the rotor core stack pair, and a seal housing female part (220) having a concave part (221) engaging with the convex part 211 is formed on the other mating surface, and the positioning in an axial direction of the seal housing male part and the seal housing female part is carried out with a predetermined gap (S), and the positioning in a rotational direction is carried out by engaging the convex part (211) of the seal housing male part with the concave part (221) of the seal housing female part. [9] A permanent magnet type motor according to claim 6, wherein respective mating surfaces of a pair of rotor core stacks have a plurality of insertion holes along a circumferential direction, and an annular coupling (320) having a plurality of pins (321) engaged with the plurality of insertion holes is interposed between the pair of rotor core stacks. [10] A permanent magnet type motor according to claim 6, wherein an intermediate disk (410) is interposed between a pair of rotor core stacks.

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