Rotor, motor, blower, air-conditioning device, and method for manufacturing rotor

Abstract

This rotor has: an annular rotor core having a magnet hole; a bonded magnet provided in the magnet hole; and an end plate provided on an axial end surface of the rotor core. The end plate has, at a position overlapping the magnet hole in the axial direction, a through-hole extending from one end plate surface facing the rotor core to the opposite end plate surface.

Description

Rotor, motor, blower, air conditioner, and method of manufacturing rotor

[0001] The present disclosure relates to a rotor, a motor, a blower, an air conditioner, and a method for manufacturing a rotor.

[0002] Conventionally, rotors with bonded magnets in their rotor cores have been known. Bonded magnets are formed by filling magnet holes formed in the rotor core with resin mixed with magnetic powder (see, for example, Patent Document 1).

[0003] JP 2018-19524 A (see abstract)

[0004] When molding bonded magnets, resin can get into the gap between the end face of the rotor core and the mold, causing burrs. If the burrs fall off the rotor core while the rotor is rotating, they can become caught between the rotor and the stator, potentially interfering with motor operation.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to suppress the occurrence of motor defects caused by burrs.

[0006] The rotor of the present disclosure includes an annular rotor core with magnet holes, bonded magnets disposed in the magnet holes, and end plates disposed on axial end faces of the rotor core. The end plates have through holes that extend from the surface of the end plates facing the rotor core to the opposite surface at positions that axially overlap the magnet holes.

[0007] According to the present disclosure, the bonded magnet can be molded by filling the magnet hole with resin through the through-hole in the end plate. Therefore, even if burrs occur, the area of ​​the burrs can be limited to the periphery of the through-hole in the end plate. This prevents motor malfunctions caused by burrs.

[0008] 1 is a longitudinal cross-sectional view showing a motor according to a first embodiment. FIG. 2 is a cross-sectional view showing a motor according to the first embodiment. FIG. 3 is a longitudinal cross-sectional view showing a rotor according to the first embodiment. FIG. 4 is a longitudinal cross-sectional view showing a rotor according to the first embodiment. FIG. 5 is a perspective view showing a rotor according to the first embodiment. FIG. 6 is a partial cross-sectional view showing a rotor according to the first embodiment. FIG. 7 is a flowchart showing a method for manufacturing the rotor according to the first embodiment. FIG. 8 is a longitudinal cross-sectional view showing a mold used for molding the bonded magnet according to the first embodiment. FIG. 9 is a perspective view showing a rotor according to a comparative example. FIG. 10 is a longitudinal cross-sectional view showing the molded state of the bonded magnet according to the comparative example. FIG. 11 is a schematic view for explaining burrs that occur on the end surface of the rotor according to the comparative example. FIG. 12 is a perspective view showing a rotor according to a second embodiment. FIG. 13 is a schematic view showing the positional relationship between magnet holes and gas vent holes of the rotor according to the second embodiment. FIG. 14 is a plan view showing a rotor according to a third embodiment. FIG. 15 is a plan view showing a rotor according to a fourth embodiment. FIG. 16 is a longitudinal cross-sectional view showing a rotor according to the fourth embodiment. FIG. 17 is a longitudinal cross-sectional view showing a mold used for molding the rotor according to the fourth embodiment. FIG. 18 is a plan view showing a rotor according to a fifth embodiment. FIG. 19 is a longitudinal cross-sectional view showing a rotor according to the fifth embodiment. FIG. 20 is a plan view showing the rotor according to the fifth embodiment with a resin portion removed. FIG. 21 is a diagram showing an air conditioning device to which the motors of the respective embodiments can be applied, and FIG. 22 is a diagram showing an outdoor unit of the air conditioning device.

[0009] Embodiment 1. <Overall Configuration of Motor 1> A motor according to embodiment 1 will now be described. Fig. 1 is a longitudinal cross-sectional view showing motor 1 according to embodiment 1. Motor 1 is a permanent magnet synchronous motor, and is used, for example, in a blower of an air conditioning device 500 (Fig. 21(A)).

[0010] The motor 1 includes a rotor 2 having a shaft 10, and a stator 5 surrounding the rotor 2. The motor 1 also includes bearings 91 and 92 that support the shaft 10, and a molded resin part 60 that covers the stator 5. The central axis Ax of the shaft 10 defines the center of rotation of the rotor 2. The stator 5 and the molded resin part 60 constitute a molded stator 6.

[0011] Hereinafter, the direction of the central axis Ax will be referred to as the "axial direction." The radial direction centered on the central axis Ax will be referred to as the "radial direction." The circumferential direction centered on the central axis Ax will be referred to as the "circumferential direction." Furthermore, a cross-sectional view taken along a plane perpendicular to the central axis Ax will be referred to as a "transverse cross-sectional view," and a cross-sectional view taken along a plane parallel to the central axis Ax will be referred to as a "longitudinal cross-sectional view."

[0012] The shaft 10 protrudes from the molded stator 6 to one side in the axial direction. For example, an impeller 511 of a blower (FIG. 21(B)) is attached to the tip 101 of the shaft 10 on the protruding side. Therefore, the side from which the shaft 10 protrudes is referred to as the "load side," and the opposite side is referred to as the "anti-load side."

[0013] <Configuration of molded stator 6> As described above, the molded stator 6 includes the stator 5 and the molded resin portion 60. The molded resin portion 60 is formed of a thermosetting resin such as an unsaturated polyester resin or an epoxy resin. The unsaturated polyester resin is, for example, a bulk molding compound (BMC).

[0014] The molded resin part 60 is an outer shell member that covers the radially outer side and the anti-load side of the stator 5. The molded resin part 60 has an opening 61 on the load side and a bottom 62 on the anti-load side. The rotor 2 is inserted into the inside of the stator 5 through the opening 61.

[0015] A metal bracket 93 that supports a load-side bearing 91 is attached to the opening 61 of the molded resin part 60. The bracket 93 is an annular member that holds the bearing 91 at its radial center. A waterproof cap 94 is attached to the shaft 10 so as to cover the bracket 93.

[0016] A bottom 62 of the molded resin part 60 is formed to cover the anti-load side of the stator 5. A recess 63 is formed in the bottom 62 to accommodate an anti-load side bearing 92. An annular circuit board 65 is also held in the bottom 62 so as to surround the bearing 92. Elements 66 such as a drive circuit are mounted on the circuit board 65. Lead wires 67 are connected to the circuit board 65 and are drawn out from lead-out portions 68 to the outside of the molded resin part 60.

[0017] The outer casing member covering the stator 5 and the circuit board 65 is not limited to the molded resin part 60, but may be, for example, a metal shell. In this case, the stator core 50 can be fixed to the shell by shrink fitting or the like. The circuit board 65 may also be provided separately from the motor 1.

[0018] Fig. 2 is a cross-sectional view showing the motor 1. Fig. 2 corresponds to the cross-sectional view taken along line II-II shown in Fig. 1, but omits the molded resin portion 60. The stator 5 has a stator core 50, a coil 55 wound around the stator core 50, and an insulating portion 54 provided therebetween.

[0019] The stator core 50 is a laminated body formed by stacking multiple magnetic steel plates in the axial direction. The magnetic steel plates are thin plates containing Fe as a main component, more specifically, electromagnetic steel plates. The thickness of the magnetic steel plates is, for example, 0.2 mm to 0.5 mm. Instead of a laminated body of magnetic steel plates, a processed ingot containing Fe as a main component may also be used.

[0020] The stator core 50 has an annular yoke 51 and a plurality of teeth 52 extending radially inward from the yoke 51. The number of teeth 52 is 12 in this example, but is not limited to this. The tips of the teeth 52 face the rotor 2.

[0021] A slot 53 is formed between circumferentially adjacent teeth 52. Coils 55 are wound around teeth 52 with insulating portions 54 interposed therebetween and housed in slots 53.

[0022] The insulating portion 54 is made of insulating resin such as PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), or LCP (liquid crystal polymer). An insulating film may also be provided to cover the inner surface of the slot 53. The insulating film is made of PET (polyethylene terephthalate), for example, and has a thickness of 0.035 to 0.4 mm.

[0023] The coils 55 are wound around the teeth 52 and housed in the slots 53. The coils 55 have a conductor, such as a copper wire or an aluminum wire, and an insulating coating covering the conductor. The coils 55 may be wound by either concentrated winding or distributed winding.

[0024] <Configuration of Rotor 2> Fig. 3 is a cross-sectional view showing rotor core 20 and bonded magnet 30. As shown in Fig. 3, rotor 2 has rotor core 20 fixed to shaft 10 and bonded magnet 30 provided in rotor core 20.

[0025] The rotor core 20 is an annular member centered on the central axis Ax, and has an inner periphery 20a and an outer periphery 20b. The rotor core 20 is a laminated body formed by stacking a plurality of magnetic steel plates in the axial direction. The magnetic steel plates are thin plates containing Fe as a main component, and more specifically, electromagnetic steel plates. The thickness of the magnetic steel plates is, for example, 0.2 mm to 0.5 mm.

[0026] The rotor core 20 has a plurality of magnet holes 21 in the circumferential direction. The magnet holes 21 are arranged at equal intervals in the circumferential direction and at equal distances from the central axis Ax. The magnet holes 21 also penetrate the rotor core 20 in the axial direction. The number of magnet holes 21 is ten here, but may be two or more. The cross-sectional shape of the magnet holes 21 will be described later.

[0027] Each magnet hole 21 is provided with a bonded magnet 30. A bonded magnet is a magnet made by mixing magnetic powder and resin, molding it, and solidifying it. Bonded magnets are also sometimes called resin magnets. Bonded magnets 30 are oriented so as to have, for example, polar anisotropy.

[0028] The bonded magnet 30 is preferably a rare earth bonded magnet. The rare earth magnet may be, for example, a neodymium magnet containing Nd (neodymium), Fe (iron), and B (boron), or a samarium-iron-nitrogen magnet containing Sm (samarium), Fe, and N (nitrogen). Alternatively, a ferrite bonded magnet may be used instead of a rare earth bonded magnet. The resin for the bonded magnet may be, for example, nylon, PPS, or epoxy resin.

[0029] In rotor 2, one bonded magnet 30 constitutes one magnetic pole. The number of poles in rotor 2 is 10 here, but it may be two or more. The circumferential center of bonded magnet 30 is the pole center. A radial line passing through the pole center is defined as pole centerline P.

[0030] Bonded magnet 30 has a shape in which its circumferential center (i.e., pole center) protrudes radially inward, i.e., a curved shape that is convex radially inward. More specifically, bonded magnet 30 has, for example, an arc-shaped cross section in a plane perpendicular to the axial direction.

[0031] The cross-sectional shape of bonded magnet 30 is not limited to an arc shape, and may be, for example, rectangular, U-shaped, or V-shaped. In order to increase the area of ​​magnetic pole faces 30a, 30b of bonded magnet 30, it is desirable for bonded magnet 30 to have a curved shape that is convex radially inward.

[0032] Bonded magnet 30 has a magnetic pole face 30a facing the pole center, a magnetic pole face 30b on the opposite side, and a side end face 30c facing the outer periphery 20b of rotor core 20. Magnetic pole face 30a is, for example, a north pole, and magnetic pole face 30b is, for example, a south pole, although the opposite is also possible. Magnetic pole face 30a is also referred to as a first magnetic pole face, and magnetic pole face 30b is also referred to as a second magnetic pole face.

[0033] Gate mark 31, which is a protrusion, is formed on one axial end face of bonded magnet 30. Gate mark 31 is formed at a position corresponding to through hole 41h (FIG. 4) of end plate 41, which will be described later. Gate mark 31 is located, for example, at the circumferential center (i.e., on pole center line P).

[0034] Similarly, a protruding gate mark 32 ( FIG. 4 ) is formed on the other axial end face of bonded magnet 30. Gate mark 32 is formed at a position corresponding to through-hole 42h ( FIG. 4 ) of end plate 42, which will be described later. Gate mark 32 is located, for example, at the circumferential center (i.e., on pole center line P).

[0035] Magnet hole 21 of rotor core 20 has outer edge 21a in contact with pole face 30a of bond magnet 30, inner edge 21b in contact with pole face 30b, and side edge 21c in contact with side end face 30c.

[0036] As will be described later, bonded magnet 30 is formed by filling magnet hole 21 with resin. Therefore, the cross-sectional shape of magnet hole 21 in a plane perpendicular to the axial direction is the same as the cross-sectional shape of bonded magnet 30. Magnet hole 21 is also referred to as a magnet molding portion.

[0037] An inclined portion 20c is formed along the side edge 21c of the outer periphery 20b of the rotor core 20 in a portion facing the side edge 21c of the magnet hole 21. The inclined portion 20c of the outer periphery 20b of the rotor core 20 is inclined so as to be displaced radially inward as it approaches the inter-pole portion M.

[0038] The inclined portions 20c are formed to restrict the magnetic path radially outward from the side edges 21c of the magnet holes 21 and to suppress magnetic flux leakage between adjacent magnetic poles. The outer periphery 20b of the rotor core 20 extends circumferentially about the central axis Ax, excluding the inclined portions 20c. Note that the inclined portions 20c are omitted from the above-mentioned FIG. 2.

[0039] The inner periphery 20a of the rotor core 20 is spaced radially from the shaft 10. A resin portion 11 is provided as a connecting portion between the inner periphery 20a of the rotor core 20 and the shaft 10. The resin portion 11 is made of a resin such as PBT or unsaturated polyester resin (e.g., BMC). The resin portion 11 serves to hold the rotor core 20 and the shaft 10 together.

[0040] The shaft 10 is formed of a metal such as carbon steel for mechanical construction. Although a configuration in which the shaft 10 and the rotor core 20 are connected by the resin part 11 will be described here, the shaft 10 may be fixed to the inner periphery 20a of the rotor core 20 without providing the resin part 11. In this case, the shaft 10 can be fixed by press fitting, shrink fitting, caulking, or the like.

[0041] 4 is a vertical cross-sectional view showing the rotor 2. The rotor core 20 has a first end face 201 which is one end face in the axial direction, and a second end face 202 which is the other end face in the axial direction.

[0042] An end plate 41 is provided on a first end face 201 of the rotor core 20. An end plate 42 is provided on a second end face 202 of the rotor core 20. The end plate 41 is also referred to as a first end plate, and the end plate 42 is also referred to as a second end plate.

[0043] The end plates 41 and 42 are made of, for example, a non-magnetic material, which may be a non-magnetic metal such as aluminum, or a resin such as PBT, PPS, or LCP.

[0044] Forming end plates 41, 42 from a non-magnetic material has the advantage of suppressing magnetic flux leakage between bonded magnets 30 via end plates 41, 42. Furthermore, forming end plates 41, 42 from an elastically deformable material such as resin has the advantage of reducing the likelihood of a gap occurring between end plate 41 and mold 70, which will be described later.

[0045] The end plates 41, 42 can be fixed to the rotor core 20 by adhesive. If the rotor core 20 has a recess formed therein, a portion of the end plates 41, 42 may be engaged with the recess in the rotor core 20.

[0046] Furthermore, each of end plates 41, 42 may be formed from at least one electromagnetic steel plate. Because rotor core 20 is formed from a laminate of electromagnetic steel plates as described above, forming end plates 41, 42 from electromagnetic steel plates allows end plates 41, 42 to be fixed to rotor core 20 by caulking, which has the advantage of reducing manufacturing costs.

[0047] The end plates 41 and 42 are both formed in an annular shape centered on the central axis Ax. The end plate 41 has an inner periphery 41 a and an outer periphery 41 b. Similarly, the end plate 42 has an inner periphery 42 a and an outer periphery 42 b.

[0048] The distance from the central axis Ax to the outer periphery 41b of the end plate 41 is defined as Dh. The distance from the central axis Ax to the outer periphery 20b of the rotor core 20 is defined as Dc. The distance from the central axis Ax to the outermost position of the magnet hole 21 is defined as Dm (FIG. 3). Note that the "outermost position" refers to the outermost position in the radial direction. The outermost position of the magnet hole 21 is the side edge 21c.

[0049] In the first embodiment, the distances Dh, Dc, and Dm satisfy the relationship Dm<Dh=Dc. That is, the outer periphery 41b of the end plate 41 is located at the same radial position as the outer periphery 20b of the rotor core 20, and is located radially outward of the outermost periphery of the magnet holes 21.

[0050] Since outer periphery 41b of end plate 41 is located radially outward from the outermost position of magnet hole 21, resin leakage from magnet hole 21 can be suppressed during the molding process of bond magnet 30 described below.

[0051] The distances Dh and Dc do not necessarily have to satisfy Dh = Dc, but only need to satisfy Dh ≦ Dc (see FIG. 14 described later). That is, the outer periphery 41 b of the end plate 41 may be located radially inward of the outer periphery 20 b of the rotor core 20 or may be located at the same radial position.

[0052] Although the distance Dh from the central axis Ax to the outer periphery 41b of the end plate 41 has been described above, the distance Dh from the central axis Ax to the outer periphery 42b of the end plate 42 is similar.

[0053] 4, the inner periphery 41a of the end plate 41 is at the same radial position as the inner periphery 20a of the rotor core 20. However, the inner periphery 41a of the end plate 41 does not necessarily have to be at the same radial position as the inner periphery 20a of the rotor core 20, as long as it is located radially inward of the innermost radial position of the magnet hole 21. The same applies to the inner periphery 42a of the end plate 42.

[0054] Fig. 5 is a perspective view of the rotor 2, omitting the shaft 10 and the resin portion 11. Fig. 6 is a partial cross-sectional perspective view of the rotor 2, cut along a plane passing through the central axis Ax. In the examples shown in Figs. 5 and 6, the shapes of the end plates 41, 42 in a plane perpendicular to the axial direction (i.e., planar shapes) are the same as the planar shape of the rotor core 20.

[0055] Therefore, an inclined portion 41c corresponding to the inclined portion 20c of the rotor core 20 is formed on the outer periphery 41b of the end plate 41. Furthermore, an inclined portion 42c corresponding to the inclined portion 20c of the rotor core 20 is formed on the outer periphery 42b of the end plate 42.

[0056] However, the end plates 41, 42 do not necessarily have to have the same planar shape as the rotor core 20, and may be, for example, annular (see FIG. 14).

[0057] The end plate 41 has a through hole 41h at a position that axially overlaps the magnet hole 21 of the rotor core 20. The through hole 41h is located on the pole center line P (FIG. 3). The through hole 41h penetrates the end plate 41 in the thickness direction, i.e., the axial direction. In other words, the through hole 41h extends from the surface of the end plate 41 that faces the rotor core 20 to the opposite surface.

[0058] Similarly, the end plate 42 has a through hole 42h at a position that axially overlaps the magnet hole 21 of the rotor core 20. The through hole 42h is located on the pole center line P (FIG. 3). The through hole 42h penetrates the end plate 42 in the thickness direction, i.e., the axial direction. In other words, the through hole 42h extends from the surface of the end plate 42 that faces the rotor core 20 to the opposite surface.

[0059] As shown in Fig. 6, gate mark 31 is formed on one axial end face of bonded magnet 30, and gate mark 32 is formed on the other axial end face. Gate mark 31 is located within through hole 41h shown in Fig. 5. Gate mark 32 is located within through hole 42h shown in Fig. 5.

[0060] The inner diameter of the through hole 41h of the end plate 41 is, for example, 1 mm. Similarly, the inner diameter of the through hole 42h of the end plate 42 is, for example, 1 mm. Therefore, the outer diameter of the gate marks 31, 32 is, for example, 1 mm.

[0061] <Rotor Manufacturing Method> Next, a description will be given of a method for manufacturing the rotor 2. Fig. 7 is a flowchart showing the manufacturing steps of the rotor 2. In step S101, magnetic steel sheets are stacked and fixed by caulking or the like to form the rotor core 20.

[0062] In step S102, rotor core 20 and end plates 41, 42 are placed in mold 70 (FIG. 8) used to mold bonded magnet 30. That is, end plates 41, 42 are attached to both axial end surfaces of rotor core 20, and this is placed in mold 70. Bonded magnet 30 is molded by, for example, injection molding.

[0063] 8 is a cross-sectional view showing mold 70 as a first mold used to mold bond magnet 30. Mold 70 has a lower mold 71 and an upper mold 72. Upper mold 72 is provided so as to be movable relative to lower mold 71. Lower mold 71 has an accommodating portion 71a, which is a hollow portion that accommodates rotor core 20, and a center core portion 71b that fits into the inner periphery of rotor core 20.

[0064] The upper mold 72 has a supply path 73 that supplies molten resin to the accommodation portion 71a of the lower mold 71. The supply path 73 has a sprue 73a that is connected to a nozzle at the upper end of the upper mold 72, a plurality of runners 73b that branch off and extend from the sprue 73a, and gates 73c that extend from each runner 73b to the molding space.

[0065] The number of gates 73c is the same as the number of magnet holes 21 of rotor core 20, and therefore the same as the number of bond magnets 30. Gates 73c are arranged equidistant from central axis Ax and at equal intervals in the circumferential direction.

[0066] The upper mold 72 is raised to open the accommodation portion 71a of the lower mold 71, and the rotor core 20 with the end plates 41, 42 attached is accommodated in the accommodation portion 71a of the lower mold 71. At this time, the rotor core 20 is positioned in the accommodation portion 71a so that the through hole 41h of the end plate 41 faces the gate 73c. ​​Thereafter, the upper mold 72 is lowered to clamp the lower mold 71 and the upper mold 72 together.

[0067] In step S103, the material of bond magnet 30 is filled into magnet hole 21 of rotor core 20. Specifically, resin powder is melted at high temperature and mixed with magnetic powder, and the resulting resin is supplied from a nozzle to sprue 73a of mold 70.

[0068] The resin supplied to the sprue 73a flows through the runner 73b to the gate 73c. ​​The resin that has flowed to the gate 73c passes through the through-hole 41h of the end plate 41 and is injected into the magnet holes 21 of the rotor core 20. As a result, the magnet holes 21 are entirely filled with the resin.

[0069] After magnet holes 21 of rotor core 20 are filled with resin, lower die 71 and upper die 72 are cooled, whereby the resin hardens and a compact, which is the precursor of bond magnet 30, is formed.

[0070] Thereafter, the upper mold 72 is raised to open the accommodation portion 71 a of the lower mold 71, and the rotor core 20 is removed from the accommodation portion 71 a. The resin inside the through hole 41 h of the end plate 41 hardens to form the gate mark 31 ( FIG. 6 ). The resin inside the through hole 42 h of the end plate 42 hardens to form the gate mark 32 ( FIG. 6 ).

[0071] In step S104, rotor core 20 and shaft 10 are placed in a mold (i.e., a second mold) used to mold resin portion 11. End plates 41, 42 are attached to rotor core 20 as described above, and a molded body, which is a precursor of bonded magnet 30, is provided in magnet hole 21.

[0072] In step S105, in the second mold, molten thermoplastic resin is filled between the inner periphery 20a of the rotor core 20 and the shaft 10. Thereafter, the second mold is cooled, whereby the resin hardens and the resin portion 11 is formed.

[0073] In step S106, the compacts in magnet holes 21 of rotor core 20 are magnetized using, for example, a magnetizing yoke. The magnetized compacts become bonded magnets 30. In this way, rotor 2 is completed.

[0074] Steps S104 and S105 correspond to the process of connecting the rotor core 20 and the shaft 10. When connecting the shaft 10 and the rotor core 20 without using the resin portion 11, a process of fitting the shaft 10 to the inner periphery 20a of the rotor core 20 is performed instead of steps S104 and S105.

[0075] Separately from steps S101 to S106 described above, molded stator 6 is manufactured. First, electromagnetic steel sheets are stacked in the axial direction to form stator core 50. Next, insulating portion 54 is attached to stator core 50, and coil 55 is wound around stator core 50 with insulating portion 54 interposed therebetween. This completes stator 5.

[0076] Next, the stator 5 and the circuit board 65 are placed in a mold die as a third mold, and a molding resin such as BMC is poured into the mold die and heated (i.e., molding is performed). This completes the molded stator 6 in which the stator 5 and the circuit board 65 are covered with the molding resin part 60.

[0077] Thereafter, bearings 91 and 92 are attached to shaft 10 of rotor 2, and the rotor is inserted into stator 5 of molded stator 6. Bracket 93 is attached to opening 61 of molded stator 6, and cap 94 is attached to shaft 10. This completes motor 1 shown in FIG. 1. Note that if stator 5 is attached to a shell or the like without using molded resin portion 60, the molding process can be omitted.

[0078] <Function> Next, the function of embodiment 1 will be explained. Permanent magnets are classified into sintered magnets and bonded magnets. Bonded magnets have a lower magnetic force than sintered magnets, but offer greater freedom in terms of shape. In embodiment 1, bonded magnet 30 is formed in an arc shape, and the area of ​​pole faces 30a, 30b is large relative to the circumferential width of bonded magnet 30 (i.e., the width of one magnetic pole). This increases the amount of magnetic flux emanating from or flowing into bonded magnet 30, thereby increasing the magnetic force.

[0079] On the other hand, it is known that the molding process of bonded magnet 30 is prone to producing burrs on the end faces of rotor core 20. Fig. 9 is a perspective view showing rotor 2C of the comparative example with shaft 10 and resin portion 11 omitted.

[0080] Comparative example rotor 2C differs from rotor 2 of embodiment 1 in that it does not have end plates 41, 42 (FIG. 5). The configurations of rotor core 20 and bonded magnet 30 are similar to those of rotor 2 of embodiment 1.

[0081] Fig. 10 is a diagram showing the molding state of bonded magnet 30 of rotor 2C of the comparative example. Mold 70C shown in Fig. 10 has the same configuration as mold 70 of embodiment 1. In Fig. 10, the molten resin inside mold 70C is indicated by dotted hatching.

[0082] 10 , the rotor core 20 is accommodated in the accommodation portion 71a of the mold 70C, and resin is injected into the magnet holes 21 of the rotor core 20 from the gate 73c of the supply path 73. At this time, there is a possibility that some of the resin may enter the gap between the first end surface 201 of the rotor core 20 and the lower end surface of the upper mold 72. The resin that has entered the gap in this way hardens as the mold 70C cools, becoming burrs B as resin pieces.

[0083] 11 is a schematic diagram illustrating burrs B that occur in a rotor 2C of a comparative example. As shown in Fig. 11, burrs B occur on a first end face 201 of a rotor core 20. The burrs B extend radially outward from an outer edge 21a of each magnet hole 21 and radially inward from an inner edge 21b of each magnet hole 21.

[0084] The burrs B may fall off the rotor core 20 when the rotor 2 rotates and become caught between the rotor 2 and the stator 5, thereby interfering with the driving of the motor 1.

[0085] 8, resin is injected from gate 73c of mold 70 into magnet holes 21 of rotor core 20 through through holes 41h in end plate 41. Therefore, even if burrs B occur on first end face 201 of rotor core 20, the range of burrs B can be limited to the periphery of through holes 41h.

[0086] This makes it difficult for burrs B to fall off from the rotor core 20, and prevents malfunctions of the motor 1 caused by the burrs B.

[0087] Furthermore, if the outer periphery 41b of the end plate 41 is positioned radially outward from the outermost position of the magnet hole 21, the magnet hole 21 can be covered with the end plate 41 during the molding process of the bonded magnet 30, thereby preventing resin leakage from the magnet hole 21.

[0088] In particular, if the outer peripheries 41b, 42b of the end plates 41, 42 are positioned radially outward from the outermost position of the magnet hole 21, the magnet hole 21 can be covered from both sides by the end plates 41, 42 during the molding process of the bonded magnet 30, thereby improving the effectiveness of preventing resin leakage from the magnet hole 21.

[0089] Furthermore, because end plates 41, 42 are positioned so as to overlap bond magnet 30 in the axial direction, they can hold bond magnet 30 so that it does not fall out of magnet hole 21. Therefore, bond magnet 30 can be prevented from falling out when rotor 2 rotates.

[0090] Furthermore, by forming end plates 41 and 42 from a non-magnetic material, magnetic flux leakage between bonded magnets 30 via end plates 41 and 42 can be suppressed.

[0091] Furthermore, if the end plates 41, 42 are made of an elastically deformable material such as resin, gaps are less likely to occur between the end plates 41, 42 and the mold 70, making it possible to more reliably prevent the occurrence of burrs B.

[0092] Furthermore, if end plates 41, 42 are made of electromagnetic steel plates, they can be stacked together with rotor core 20 and fixed by caulking or the like, reducing the manufacturing costs of rotor 2. Furthermore, when resin is injected into magnet hole 21, air can be expelled from the gaps between the electromagnetic steel plates of end plate 41, improving the formability of bonded magnet 30.

[0093] Here, we have described the case where end plates 41, 42 are provided at both axial ends of rotor core 20, but if an end plate (here, end plate 41) is provided at the end of rotor core 20 on the gate 73c side, the effect of limiting the range in which burrs B are generated can be achieved, as described above.

[0094] However, if the end plates 41, 42 are provided on both axial ends of the rotor core 20, the area in which burrs B are generated can be limited regardless of which end plate 41, 42 is placed on top when the rotor core 20 with the end plates 41, 42 attached is placed in the mold 70. This makes it possible to improve the productivity of the rotor 2.

[0095] Here, we have explained the case where the through holes 41h, 42h of the end plates 41, 42 are formed at positions corresponding to the circumferential center (pole center) of the magnet hole 21, but the positions of the through holes 41h, 42h of the end plates 41, 42 can be changed as appropriate depending on the position of the gate 73c of the mold 70.

[0096] Effect of First Embodiment As described above, rotor 2 in the first embodiment has annular rotor core 20 having magnet holes 21, bond magnets 30 provided in magnet holes 21, and end plate 41 provided on first axial end face 201 of rotor core 20. End plate 41 has through holes 41h at a position facing magnet holes 21 in the axial direction, extending from the surface of end plate 41 facing rotor core 20 to the opposite surface. Therefore, bond magnets 30 can be molded by filling magnet holes 21 with resin via through holes 41h in end plate 41. As a result, even if burrs B occur during molding of bond magnet 30, the range of burrs B can be limited to the periphery of through holes 41h, preventing malfunctions of motor 1 caused by the generation of burrs.

[0097] 12 is a perspective view showing a rotor 2A of embodiment 2. The rotor 2A of embodiment 2 differs from the rotor 2 of embodiment 1 in that the end plate 41 has gas vent holes 41g as holes.

[0098] 12, the inner diameter of the gas vent hole 41g is smaller than the inner diameter of the through hole 41h. That is, in a plane perpendicular to the axial direction, the area of ​​the gas vent hole 41g is smaller than the area of ​​the through hole 41h. The gas vent hole 41g penetrates the end plate 14 in the thickness direction, i.e., the axial direction. In other words, the gas vent hole 41g extends from the surface of the end plate 41 facing the rotor core 20 to the opposite surface.

[0099] 13 is a schematic diagram showing the positional relationship between gas vent hole 41g of end plate 41 and magnet hole 21 and bond magnet 30 of rotor core 20. Gas vent hole 41g is formed in a position overlapping axially with magnet hole 21 of rotor core 20. In other words, gas vent hole 41g is formed in a position overlapping axially with bond magnet 30.

[0100] It is desirable that the vent holes 41g be formed on both sides of the circumferential center (i.e., the pole center) of the magnet hole 21. In particular, it is desirable that the vent holes 41g be formed at positions corresponding to both circumferential ends of the magnet hole 21.

[0101] More specifically, if the magnet hole 21 is divided into three equal parts, a central region La including the pole center and end regions Lb on both sides of the central region La in the circumferential direction, it is desirable to form the gas vent holes 41g at positions corresponding to the end regions Lb. The central region La and each end region Lb are regions obtained by dividing the length of the magnet hole 21 in the extension direction into three equal parts.

[0102] In the molding process of bonded magnet 30, as explained in embodiment 1, resin is injected from gate 73c (FIG. 8) of mold 70 into magnet hole 21 via through-hole 41h in end plate 41. The resin injected into magnet hole 21 flows from the circumferential center of magnet hole 21 (i.e., the pole center) toward side edge 21c.

[0103] At this time, the air inside magnet hole 21 is discharged through gas vent hole 41g, so the flow of resin is not obstructed by the air. This allows the resin to spread throughout magnet hole 21, improving the moldability of bonded magnet 30.

[0104] In particular, because gas vent hole 41g is located in end region Lb, air is easily expelled from gas vent hole 41g when resin flows from the circumferential center toward side edge 21c of magnet hole 21. As a result, resin can be filled all the way up to side edge 21c of magnet hole 21 without any gaps, further improving the moldability of bonded magnet 30.

[0105] Gas vent hole 41g is not limited to the position mentioned above, but may be formed in any position that allows air to be easily discharged depending on the flow state of the resin inside magnet hole 21 during molding of bond magnet 30. It is desirable to provide mold 70 (FIG. 8) with an air vent that discharges the air discharged from gas vent hole 41g to the outside of mold 70.

[0106] Although the description has been given here of gas vent holes 41g in end plate 41, it is desirable to form similar gas vent holes in end plate 42. In this case, when rotor core 20 with end plates 41, 42 attached is mounted in mold 70 (FIG. 8), exhaust is possible from magnet hole 21 regardless of whether end plate 41, 42 is mounted with the top facing up, which has the effect of improving the moldability of bonded magnet 30.

[0107] Except for the points mentioned above, the rotor 2A of the second embodiment is configured similarly to the rotor 2 of the first embodiment.

[0108] As explained above, in rotor 2A of embodiment 2, end plate 41 has vent hole 41g with an inner diameter smaller than through hole 41h at a position where it axially overlaps magnet hole 21 of rotor core 20. Therefore, when resin is injected into magnet hole 21 in the molding process of bonded magnet 30, air can be discharged through vent hole 41g, and the moldability of bonded magnet 30 can be improved.

[0109] In particular, when magnet hole 21 is divided into thirds, into central region La and end regions Lb on either side of it, forming gas vent hole 41g at a position corresponding to end region Lb makes it easier to expel air from gas vent hole 41g when injecting resin into magnet hole 21. This further improves the moldability of bonded magnet 30.

[0110] Embodiment 3. Figure 14 is a plan view showing a rotor 2B of embodiment 3. The rotor 2B of embodiment 3 differs from the rotor 2 of embodiment 1 in that the outer periphery 41b of the end plate 41 is located radially inward of the outer periphery 20b of the rotor core 20. Although the outer periphery 14b of the end plate 41 is shown as being circumferential in Figure 14, it is not limited to being circumferential.

[0111] In embodiment 3, the distance Dh from the central axis Ax to the outer periphery 41b of the end plate 41, the distance Dc from the central axis Ax to the outer periphery 20b of the rotor core 20, and the distance Dm from the central axis Ax to the outermost position of the magnet hole 21 satisfy Dm < Dh < Dc.

[0112] In other words, the outer periphery 41 b of the end plate 41 is located radially inward of the outer periphery 20 b of the rotor core 20 and radially outward of the outermost periphery of the magnet holes 21 .

[0113] Because outer periphery 41b of end plate 41 is located radially inward of outer periphery 20b of rotor core 20, the contact area between end plate 41 and rotor core 20 is smaller than in embodiment 1. Therefore, even when end plate 41 is formed from an electromagnetic steel plate, magnetic flux leakage between bonded magnets 30 via end plate 41 can be reduced.

[0114] Furthermore, since end plate 41 is reliably prevented from protruding radially outward from rotor core 20, interference between end plate 41 and stator core 50 is prevented, and the generation of noise and vibration can be suppressed.

[0115] Furthermore, since the outer periphery 41b of the end plate 41 is located radially outward from the outermost position of the magnet hole 21, as in embodiment 1, resin leakage from the magnet hole 21 can be suppressed during the molding process of the bond magnet 30.

[0116] While the distance Dh from the central axis Ax to the outer periphery 41b of the end plate 41 has been described above, the same applies to the distance Dh from the central axis Ax to the outer periphery 42b of the end plate 42 (FIG. 5). That is, the outer periphery 42b of the end plate 42 is located radially inward of the outer periphery 20b of the rotor core 20, and is located radially outward of the outermost periphery of the magnet holes 21.

[0117] Except for the points mentioned above, the rotor 2B of the third embodiment is configured similarly to the rotor 2 of the first embodiment.

[0118] As explained above, in rotor 2B of embodiment 3, distance Dh from central axis Ax to outer periphery 41b of end plate 41, distance Dc from central axis Ax to outer periphery 20b of rotor core 20, and distance Dm from central axis Ax to the outermost position of magnet hole 21 satisfy Dm < Dh < Dc. Therefore, magnetic flux leakage between bonded magnets 30 is reduced, noise and vibration generation is suppressed, and the formability of bonded magnet 30 can be improved.

[0119] Embodiment 4 Figure 15 is a plan view showing a rotor 2C according to embodiment 4. Figure 16 is a cross-sectional view taken along line 16-16 in Figure 15. The rotor 2C according to embodiment 4 differs from the rotor 2B according to embodiment 3 in that it has resin portions 12 and 13 that cover the end plates 41 and 42.

[0120] 15, a resin portion 11 serving as a connecting portion is formed on the radially inner side of the rotor core 20 of the rotor 2C. The resin portion 11 connects the rotor core 20 and the shaft 10.

[0121] The resin part 11 of embodiment 4 has an inner cylindrical part 11a fixed to the outer periphery of the shaft 10, an outer cylindrical part 11b fixed to the inner periphery 20a of the rotor core 20, and a plurality of ribs 11c formed between them.

[0122] The ribs 11c are formed at equal intervals in the circumferential direction and extend radially from the inner cylindrical portion 11a to the outer cylindrical portion 11b. A cavity is formed between adjacent ribs 11c. The number of ribs 11c is, for example, five, but is not limited to five.

[0123] 16 , a resin portion 12 serving as a first resin portion is formed so as to cover the upper surface of the end plate 41 (i.e., the surface opposite to the rotor core 20). Both an inner periphery 12 a and an outer periphery 12 b of the resin portion 12 are circumferential, but this is not limitative.

[0124] The inner periphery 12a of the resin part 12 is located at the same radial position as the inner periphery of the outer tube part 11b of the resin part 11. The outer periphery 12b of the resin part 12 is located radially outward of the through hole 41h of the end plate 41 and radially inward of the outer periphery 41b of the end plate 41.

[0125] Additionally, a resin portion 13 serving as a second resin portion is formed so as to cover the lower surface of the end plate 42 (i.e., the surface opposite to the rotor core 20). Both the inner periphery 13a and the outer periphery 13b of the resin portion 13 are circumferential, but are not limited to this.

[0126] The inner periphery 13a of the resin part 13 is located at the same radial position as the inner periphery of the outer tube part 11b of the resin part 11. The outer periphery 13b of the resin part 13 is located radially outward of the through hole 42h of the end plate 42 and radially inward of the outer periphery 42b of the end plate 42.

[0127] The resin parts 11, 12, and 13 are integrally formed and are made of resin such as PBT or unsaturated polyester resin (e.g., BMC).

[0128] Resin portion 12 covers gate mark 31 of bonded magnet 30, thereby preventing gate mark 31 from falling out of through-hole 41 h. Furthermore, resin portion 13 covers gate mark 32 of bonded magnet 30, thereby preventing gate mark 32 from falling out of through-hole 42 h.

[0129] Furthermore, since the resin portions 11, 12, and 13 are integrally formed, the shaft 10, the rotor core 20, and the end plates 41 and 42 can be firmly integrated.

[0130] Furthermore, the resin portion 11 has multiple ribs 11c, and cavities are formed between adjacent ribs 11c, which reduces the amount of resin used. Furthermore, by adjusting the number, radial length, and circumferential width of the ribs 11c, it is possible to adjust the vibration characteristics of the rotor 2C, such as the resonance frequency.

[0131] Here, the case where the resin portion 11 has a plurality of ribs 11c has been described, but the resin portion 11 may be filled between the rotor core 20 and the shaft 10 as described in the first embodiment.

[0132] 17 is a cross-sectional view showing a mold 80 used to mold the resin parts 12, 13. The mold 80 has a lower mold 81 and an upper mold 82. The upper mold 82 is provided so as to be movable relative to the lower mold 81.

[0133] The lower mold 81 has an accommodating portion 81a, which is a hollow portion that accommodates the rotor core 20, and a hole 81b that accommodates the lower end of the shaft 10. The hole 81b is formed at the radial center of the accommodating portion 81a.

[0134] The lower mold 81 is formed with a stepped portion 81d for holding the rotor core 20 at a position spaced apart from the bottom surface 81c of the accommodation portion 81a. Although not shown, the bottom surface 81c of the accommodation portion 81a is provided with a protrusion for forming a cavity between the ribs 11c of the resin portion 11.

[0135] The upper mold 82 has a recess 82a facing the accommodation portion 81a, a hole 82b that accommodates the upper end of the shaft 10, and a supply path 83 that supplies molten resin to the recess 82a. The hole 82b is formed at the radial center of the recess 82a.

[0136] The supply path 83 has a sprue 83a connected to a nozzle (not shown) at the upper end of the upper mold 82, a plurality of runners 83b branching off and extending from the sprue 83a, and gates 83c extending from each runner 83b to the recess 82a.

[0137] The upper die 82 is raised to open the accommodation portion 81a of the lower die 81, and the rotor core 20 and the end plates 41, 42 are accommodated in the accommodation portion 81a of the lower die 81. The upper and lower ends of the shaft 10 are accommodated in the holes 82b, 81b. Next, the upper die 82 is lowered to clamp the lower die 81 and the upper die 82 together.

[0138] In this state, a cavity H1 for forming the resin portion 11 is formed between the inner periphery 20a of the rotor core 20 and the shaft 10. Furthermore, a cavity H2 for forming the resin portion 12 is formed above the end plate 41 attached to the rotor core 20. Furthermore, a cavity H3 for forming the resin portion 13 is formed below the end plate 42 attached to the rotor core 20. These cavities H1, H2, and H3 are continuous.

[0139] Molten resin, which is the material of the resin parts 11, 12, and 13, is injected into the cavities H1, H2, and H3 from the supply path 83 of the mold 80. The resin part 11 is molded in the cavity H1, the resin part 12 is molded in the cavity H2, and the resin part 13 is molded in the cavity H3. In other words, the resin parts 11, 12, and 13 are molded integrally.

[0140] As a result, the shaft 10, the rotor core 20, and the end plates 41, 42 are integrated together, and the rotor 2C (FIG. 16) in which the end plates 41, 42 are covered with the resin portions 12, 13 is manufactured.

[0141] Here, we have described an example in which the resin parts 11, 12, and 13 are molded integrally, but if the rotor core 20 and the shaft 10 are connected without using the resin part 11, the resin parts 12 and 13 may be molded to cover the end plates 41 and 42 without molding the resin part 11.

[0142] Alternatively, only one of the resin portions 12 and 13 may be provided. For example, if only one of the end plates 41 and 42 (for example, the end plate 41) has a through hole, only the resin portion covering that end plate may be provided.

[0143] Except for the points described above, the rotor 2C of embodiment 4 is configured similarly to the rotor 2B of embodiment 3. The end plates 41, 42 may have the shapes described in embodiment 1. The end plates 41, 42 may also be formed with the gas vent holes 41g, 42g described in embodiment 2.

[0144] As described above, the rotor 2C of embodiment 4 has a resin part 12 that covers at least the through hole 41h of the end plate 41 and a resin part 13 that covers at least the through hole 42h of the end plate 42, and therefore can prevent the gate marks 31, 32 of the bond magnet 30 from falling off.

[0145] Furthermore, since the resin portions 12 and 13 and the resin portion 11 provided inside the rotor core 20 are integrally formed, the shaft 10, the rotor core 20, and the end plates 41 and 42 can be firmly integrated.

[0146] Fifth Embodiment Figure 18 is a plan view showing a rotor 2D according to a fifth embodiment. Figure 19 is a cross-sectional view taken along line 18-18 in Figure 18. The rotor 2D according to the fifth embodiment differs from the rotor 2C according to the fourth embodiment in that the end plates 41, 42 have recesses 41d, 42d on the side opposite the rotor core 20.

[0147] 19, similar to rotor 2C of embodiment 4, rotor 2D has resin portion 11 on the inside of rotor core 20 and resin portions 12 and 13 covering end plates 41 and 42. Resin portions 11, 12, and 13 are integrally formed.

[0148] In the fifth embodiment, a recess 41d is formed in the end plate 41. The recess 41d is indicated by a dashed line in Fig. 19. The recess 41d extends from the upper surface of the end plate 41 (i.e., the surface opposite to the rotor core 20) toward the rotor core 20, but does not reach the lower surface of the end plate 41 (i.e., the surface facing the rotor core 20).

[0149] Furthermore, a recess 42d is formed in the end plate 42. The recess 42d is indicated by a dashed line in Fig. 19. The recess 42d extends from the lower surface of the end plate 42 (i.e., the surface opposite the rotor core 20) toward the rotor core 20, but does not reach the upper surface of the end plate 42 (i.e., the surface facing the rotor core 20).

[0150] A portion of the resin portion 12 covering the end plate 41 fits into the recess 41d. Similarly, a portion of the resin portion 13 covering the end plate 42 fits into the recess 42d. This firmly fixes the end plate 41 and the resin portion 12, and also firmly fixes the end plate 42 and the resin portion 13.

[0151] As described in the fourth embodiment, resin parts 12 and 13 are fixed to rotor core 20 via resin part 11. Therefore, resin parts 12 and 13 fit into recesses 41d and 42d, respectively, thereby preventing misalignment of end plates 41 and 42 relative to rotor core 20 in the rotational direction.

[0152] Furthermore, recess 41d does not reach the surface of end plate 41 that faces rotor core 20, and recess 42d does not reach the surface of end plate 42 that faces rotor core 20. Therefore, resin does not leak from recesses 41d, 42d when bonded magnet 30 is molded.

[0153] Figure 20 is a plan view showing rotor 2D with resin portion 12 removed. In Figure 20, dashed lines indicate magnet holes 21 and gate marks 31 below end plate 41. Recesses 41d in end plate 41 are formed between adjacent magnet holes 21, i.e., at positions corresponding to inter-pole portions M.

[0154] That is, recesses 41d are formed in positions that do not overlap with magnet holes 21 in the axial direction. Therefore, the material of bond magnet 30 does not get into recesses 41d. Also, because recesses 41d are formed at equal intervals in the circumferential direction, the weight balance of rotor 2D can be maintained. While Figure 20 shows the positions of recesses 41d in end plate 41, the positions of recesses 42d in end plate 42 are similar.

[0155] Except for the points described above, rotor 2D of embodiment 5 is configured similarly to rotor 2C of embodiment 4. Note that end plates 41, 42 may have the shapes described in embodiment 1. Also, end plates 41, 42 may be formed with gas vent holes 41g, 42g described in embodiment 2.

[0156] As described above, in the rotor 2D of embodiment 5, the end plate 41 has a recess 41d on the surface opposite the rotor core 20, and the end plate 42 has a recess 42d on the surface opposite the rotor core 20, thereby preventing misalignment of the end plates 41, 42 in the rotational direction relative to the rotor core 20.

[0157] <Air Conditioning Apparatus> Next, an air conditioning apparatus to which the motor 1 of each of the above-described embodiments can be applied will be described. Fig. 21(A) is a diagram showing the configuration of an air conditioning apparatus 500 to which the motor 1 of embodiment 1 is applied. The air conditioning apparatus 500 includes an outdoor unit 501 and an indoor unit 502. The outdoor unit 501 and the indoor unit 502 are connected by a refrigerant pipe 503.

[0158] The outdoor unit 501 includes a compressor 504, a condenser 505, and an outdoor blower 510. The outdoor blower 510 is, for example, a propeller fan. The outdoor blower 510 has an impeller 511 and a motor 1A that drives the impeller 511.

[0159] The indoor unit 502 includes an evaporator 506 and an indoor blower 520. The indoor blower 520 is, for example, a cross-flow fan. The indoor blower 520 has an impeller 521 and a motor 1B that drives the impeller 521.

[0160] 21(B) is a vertical cross-sectional view of the outdoor unit 501. The motor 1A is supported by a frame 509 disposed within a housing 508 of the outdoor unit 501. An impeller 511 is attached to the shaft 10 of the motor 1A via a hub 512.

[0161] The outdoor blower 510 blows air to the outside by rotating an impeller 511 driven by a motor 1A. During cooling operation of the air conditioner 500, the heat released when the refrigerant compressed by the compressor 504 condenses in the condenser 505 is released to the outside by the air blown by the outdoor blower 510.

[0162] The indoor fan 520 (FIG. 21A) blows air into the room by rotating an impeller 521 with a motor 1B. During cooling operation of the air conditioner 500, the indoor fan 520 blows air cooled when the refrigerant evaporates in the evaporator 506 into the room.

[0163] Motors 1A and 1B are configured as motor 1 according to embodiment 1. Motor 1 according to embodiment 1 has high reliability due to prevention of burr shedding. This improves the reliability of outdoor blower 510 and indoor blower 520, thereby improving the reliability of air conditioning apparatus 500.

[0164] Motors 1A and 1B are not limited to motor 1 of embodiment 1, but may be motors having rotors of any of embodiments 2 to 5. Furthermore, although the motors of each embodiment are used in both outdoor fan 510 and indoor fan 520 here, they may be used in only one of them.

[0165] Furthermore, the motors of the first to fifth embodiments are not limited to being used in blowers, but may also be used as motors for compressors or other devices.

[0166] Although the preferred embodiments have been specifically described above, the present disclosure is not limited to the above-described embodiments, and various improvements and modifications can be made.

[0167] DESCRIPTION OF SYMBOLS 1, 1A, 1B Motor, 2, 2A, 2B, 2C, 2D Rotor, 5 Stator, 6 Molded stator, 10 Shaft, 11 Resin portion (connecting portion), 11a Inner cylinder portion, 11b Outer cylinder portion, 11c Rib, 12 Resin portion (first resin portion), 13 Resin portion (second resin portion), 20 Rotor core, 20a Inner circumference, 20b Outer circumference, 20c Inclined portion, 21 Magnet hole (resin molded portion), 21a Outer edge, 21b Inner edge, 21c Side edge, 30 Bonded magnet, 30a Pole surface (first pole surface), 30b Pole surface (second pole surface), 30c End surface portion 31, 32 Gate marks, 41, 42 End plate, 41d, 42d: recesses, 41g, 42g: gas vent holes (holes), 41h, 42h: through holes, 50: stator core, 55: coil, 70: mold, 71: lower mold, 72: upper mold, 73: supply path, 73c: gate, 201: first end surface, 202: second end surface, 500: air conditioning device, 501: outdoor unit, 502: indoor unit, 510: outdoor blower (blower), 511: impeller, 520: indoor blower (blower), 521: impeller.

Claims

1. A rotor comprising: an annular rotor core having magnet holes; bonded magnets provided in the magnet holes; and end plates provided on the axial end faces of the rotor core, wherein the end plates have through holes extending from the surface of the end plate facing the rotor core to the opposite surface at a position overlapping the magnet holes in the axial direction.

2. The rotor according to claim 1, wherein the through-hole is provided at a position corresponding to the center of the magnet hole in the circumferential direction of the rotor core.

3. A rotor according to claim 1 or 2, wherein the end plates are provided on both end faces of the rotor core in the axial direction.

4. A rotor according to any one of claims 1 to 3, wherein the end plates are made of a non-magnetic material.

5. A rotor according to any one of claims 1 to 3, wherein the rotor core is formed from a laminate of electromagnetic steel sheets, and the end plates are formed from at least one electromagnetic steel sheet.

6. A rotor as claimed in any one of claims 1 to 5, wherein the end plates have holes extending from the surface of the end plates facing the rotor core to the opposite surface at positions overlapping the magnet holes in the axial direction, and the cross-sectional area of ​​the holes in a plane perpendicular to the axial direction is smaller than the cross-sectional area of ​​the through holes.

7. A rotor as set forth in claim 6, wherein when the magnet holes are divided into three equal parts, a central region located in the circumferential center of the rotor core and two end regions located on either side of the central region in the circumferential direction, the hole portions are provided in each of the two end regions.

8. A rotor according to any one of claims 1 to 7, wherein Dm < Dh ≦ Dc holds, where Dh is the distance from the central axis of the rotor core to the outer periphery of the end plate, Dc is the distance from the central axis to the outer periphery of the rotor core, and Dm is the distance from the central axis to the outermost position of the magnet hole in the radial direction of the rotor core.

9. The rotor according to claim 8, further comprising: Dm<Dh<Dc.

10. A rotor according to any one of claims 1 to 9, wherein a resin portion is provided so as to cover at least the through-hole of the end plate.

11. The rotor according to claim 10, further comprising: a shaft; and a connecting portion formed of resin that connects said shaft and said rotor core, said connecting portion and said resin portion being integrally formed.

12. A rotor according to claim 10 or 11, wherein the end plate has a recess on the side opposite to the side facing the rotor core.

13. A motor comprising: a rotor according to any one of claims 1 to 12; and a stator provided so as to surround the rotor.

14. A blower comprising the motor according to claim 13 and an impeller rotated by said motor.

15. An air conditioning apparatus comprising an outdoor unit and an indoor unit, wherein at least one of the outdoor unit and the indoor unit has the blower according to claim 14.

16. A method for manufacturing a rotor, comprising: a step of forming an annular rotor core having magnet holes; a step of attaching end plates having through holes to axial end faces of the rotor core; a step of injecting a material containing magnetic powder and resin into the magnet holes to form a compact; and a step of magnetizing the compact in the magnet holes to form a bonded magnet, wherein the through holes in the end plates are formed at positions that overlap with the magnet holes in the axial direction and extend from the surface of the end plates facing the rotor core to the opposite surface, and wherein in the step of forming the compact, the material is injected into the magnet holes of the rotor core via the through holes in the end plates.

17. The method for manufacturing a rotor according to claim 16, further comprising the step of forming a resin portion so as to cover the through-hole in the end plate.

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