Rotor and motor

Abstract

To provide a rotor capable of being easily assembled.SOLUTION: A rotor 40 comprises a housing 41 that has a cylindrical housing cylinder part 412, and a hollow cylindrical magnet 43 which has an outside diameter as large as or larger than an inside diameter of the housing cylinder part 412 and which is axially pressed into the housing 41 in a first direction. An magnet outer peripheral surface of the magnet 43 has a first magnet outer peripheral surface which is brought into pressure contact with the housing cylinder part 412 by press fitting, and a second magnet outer peripheral surface which assumes a tapered shape in which a diameter is gradually reduced toward a first-direction end of the magnet 43.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a rotor and a motor. [Background technology]

[0002] A rotor for use in a brushless DC motor is known, which has a magnet surrounding a stator core. For example, Patent Document 1 describes a rotor having a rotor yoke and a magnet provided on the inner periphery of the cylindrical portion of the rotor yoke. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-052814 Summary of the Invention [Problem to be solved by the invention]

[0004] The rotor described in Patent Document 1 has multiple magnets divided into segments attached to a cylindrical portion extending downward from the top plate portion of the rotor yoke, and a resin magnet holder attached to hold the magnets in place. For this reason, the rotor described in Patent Document 1 has room for improvement in terms of assembly workability when attaching the magnets to the rotor yoke.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a rotor that can improve assembly workability. [Means for solving the problem]

[0006] To solve the above problems, a rotor according to one aspect of the present disclosure includes a housing having a cylindrical housing portion, and a hollow cylindrical magnet having an outer diameter equal to or larger than the inner diameter of the cylindrical housing portion and press-fitted into the housing in a first direction in the axial direction. The magnet has a first magnet outer peripheral surface that is press-fitted against the cylindrical housing portion, and a second magnet outer peripheral surface that is tapered and gradually reduces in diameter toward the end of the magnet in the first direction.

[0007] Any combination of the above components, and conversion of the present disclosure into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0008] According to the present disclosure, a rotor that can improve assembly workability can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side cross-sectional view schematically illustrating a motor including a rotor according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is an exploded perspective view showing the stator core and the insulator of FIG. 1. [Figure 3] FIG. 3 is a perspective view showing the first insulator of FIG. 2. [Figure 4] FIG. 3 is a perspective view showing the second insulator of FIG. 2. [Figure 5] 2 is a cross-sectional view taken along a plane perpendicular to the axial direction of the stator in FIG. 1. [Figure 6] 2 is a cross-sectional view of the stator of FIG. 1 taken along a plane parallel to the axial direction thereof. [Figure 7] 2 is a diagram showing a stator core and windings of the stator of FIG. 1. [Figure 8] FIG. 2 is a development view showing the stator core and windings of the stator of FIG. 1 in an expanded state. [Figure 9] FIG. 2 is a perspective view showing a housing of the rotor of FIG. 1. [Figure 10]FIG. 2 is a diagram showing a magnet of the rotor of FIG. 1. [Figure 11] 2 is a cross-sectional view showing a process of press-fitting a magnet into the housing of the rotor of FIG. 1. FIG. [Figure 12] 2 is a perspective view showing a state in which a magnet is press-fitted into the housing of the rotor of FIG. 1. FIG.

[0010] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the accompanying drawings. Each of the examples described below represents a preferred specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, the arrangement and connection of the components, steps (processes), and the order of steps shown in the following examples are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following examples, components that are not recited in the independent claims that represent the highest concept of the present disclosure will be described as optional components. Furthermore, in each figure, substantially identical components are assigned the same reference numerals, and redundant explanations will be omitted or simplified.

[0011] Furthermore, terms including ordinal numbers such as "first" and "second" are used to describe various components, but these terms are used only to distinguish one component from other components and do not limit the components. Furthermore, when a component is not to be distinguished from other components, the ordinal number may be omitted.

[0012] [Example] The configuration of a motor 10 including a rotor 40 according to an embodiment of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a side cross-sectional view that schematically illustrates the motor 10. The motor 10 is a brushless DC motor that is suitable for use, for example, as a motor for driving the blades of a ceiling fan.

[0013] The motor 10 mainly includes a stator 20, a shaft 30, a rotor 40, a cover 42, a first bearing 31, a second bearing 32, and a circuit board 48. The stator 20, the shaft 30, and the circuit board 48 form a stationary body, and the rotor 40 and the cover 42 form a rotating body.

[0014] The stator 20 includes a stator core 21, a pair of insulators 22, 23 that sandwich the stator core 21 from both sides in the axial direction, and a winding 24 that is wound around the stator core 21 via the insulators 22, 23.

[0015] The shaft 30 is a fixed shaft that is fixedly supported by the stator 20. The shaft 30 is a pipe-shaped member that has a hollow portion in the center for passing the lead wire 268. The hollow portion of the shaft 30 penetrates from top to bottom, and horizontal holes 30h and 30j for passing the lead wire 268 are provided on the side surface of the shaft 30.

[0016] The rotor 40 is rotatably supported relative to the stator 20 via the shaft 30, the first bearing 31, and the second bearing 32. Hereinafter, for convenience, the direction along the rotational axis La of the rotor 40 will be referred to as the "axial direction," and the circumferential direction and radial direction of a circle centered on the central axis La in a plane perpendicular to the central axis La will be referred to as the "circumferential direction" and the "radial direction," respectively. The shaft 30 extends in the axial direction. In the axial direction, the side of the rotor 40 that covers the stator 20 will be referred to as the "first direction." That is, the top plate portion 411 of the rotor 40 overlaps the first direction side of the stator 20. In each drawing, the first direction is indicated by the direction of arrow Z1. The first direction side may also be referred to as the upper side, and the opposite side may also be referred to as the lower side. These directional notations do not limit the orientation of the motor 10, and the motor 10 may be used in any orientation.

[0017] The rotor 40 comprises a housing 41 having a cylindrical housing portion 412, and a hollow cylindrical magnet 43 having an outer diameter greater than or equal to the inner diameter of the housing cylindrical portion 412 and pressed into the housing 41 in a first axial direction.

[0018] The circuit board 48, first bearing 31, rotor 40, stator 20, second bearing 32, and cover 42 are arranged in this order from top to bottom and surround the shaft 30. The rotor 40 is arranged radially opposite the stator 20. The inner rings of the first bearing 31 and the second bearing 32 are fixed to the shaft 30. The outer ring of the first bearing 31 is housed in a recess formed in the center of the housing 41 of the rotor 40, and the outer ring of the second bearing 32 is housed in a recess formed in the center of the cover 42. The cover 42 is a substantially disc-shaped member that covers the underside of the stator 20 via a gap and rotates integrally with the rotor 40. The cover 42 has approximately the same outer shape as the housing 41 and is fixed to the housing 41 of the rotor 40 with a plurality of tapping screws (not shown) arranged at predetermined intervals in the circumferential direction.

[0019] The circuit board 48 functions as a drive circuit for the brushless motor, supplying a drive current to the stator 20 based on a detection signal from a rotation detector (not shown). The stator 20 generates a rotating magnetic field in response to the drive current. The rotor 40 and cover 42 rotate around the central axis La in response to the rotating magnetic field. Drive circuits for brushless motors are well known, so details will be omitted.

[0020] The stator 20 will be described with reference to FIGS. 2 to 8. FIG. 2 is an exploded perspective view showing a stator core 21 of the stator 20 and a pair of insulators 22, 23. The stator core 21 can be formed, for example, by laminating a plurality of electromagnetic steel sheets having a predetermined shape. The stator core 21 has a cylindrical portion 211, a plurality of teeth 212 protruding radially outward from the outer circumferential surface of the cylindrical portion 211, curved surface portions 213 protruding circumferentially from the tips of the teeth 212, and slots 214 formed between adjacent teeth 212. The number of slots 214 in the stator core 21 in this embodiment is 12.

[0021] The insulators 22, 23 are resin members formed by molding. The insulators 22, 23 include a first insulator 22 attached to a first direction side of the stator core 21 in the axial direction, and a second insulator 23 attached to the opposite side of the first insulator 22 across the stator core 21 in the axial direction. Fig. 3(A) is a view of the first insulator 22 viewed from diagonally above. Fig. 3(B) is a view of the first insulator 22 viewed from diagonally below. Fig. 4(A) is a view of the second insulator 23 viewed from diagonally below. Fig. 4(B) is a view of the second insulator 23 viewed from diagonally above.

[0022] The first insulator 22 includes a first base portion 221, a first wall portion 222, a first inner circumferential wall 226, a first outer circumferential wall 227, a protrusion 228, a crossover wire arrangement portion 258, and a central inner circumferential wall 257. The first base portion 221 is formed of a surface perpendicular to the axial direction and includes a portion covering the cylindrical portion 211, the tooth portion 212, and the curved surface portion 213. The crossover wire arrangement portion 258 is formed of a disk-shaped plane perpendicular to the axial direction on the inner circumferential side of the first base portion 221. The central inner circumferential wall 257 is a substantially cylindrical circumferential wall extending in the axial direction at the inner circumferential edge of the crossover wire arrangement portion 258. The central inner circumferential wall 257 has a wiring passage portion 257a that is partially open in a predetermined direction, and is C-shaped when viewed from the axial direction.

[0023] The first wall portion 222 extends in the axial direction from the base portion 221 along the core inner surface portion 215 that surrounds the slot 214 of the stator core 21. The protruding portion 228 protrudes from the first wall portion 222 toward the core inner surface portion 215, and the protruding end abuts against the core inner surface portion 215.

[0024] The protrusion 228 includes a first tooth protrusion 223 that protrudes circumferentially from a portion extending along the tooth portion 212 of the first wall portion 222, a first cylindrical portion protrusion 224 that protrudes radially inward from a portion extending along the outer peripheral surface of the cylindrical portion 211 of the first wall portion 222, and a first curved portion protrusion 225 that protrudes radially outward from a portion extending along the outer peripheral surface of the curved portion 213 of the first wall portion 222.

[0025] The second insulator 23 has a second base portion 231, a second wall portion 232, a second inner circumferential wall 236, a second outer circumferential wall 237, and a protruding portion 238. The second base portion 231 is formed of a surface perpendicular to the axial direction, and includes a portion covering the cylindrical portion 211, the tooth portion 212, and the curved surface portion 213.

[0026] The second wall portion 232 extends in the axial direction from the second base portion 231 along the core inner surface portion 215 that surrounds the slot 214 of the stator core 21. The protruding portion 238 protrudes from the second wall portion 232 toward the core inner surface portion 215, and the protruding end abuts against the core inner surface portion 215.

[0027] The protrusion 238 includes a second tooth protrusion 233 that protrudes circumferentially from a portion extending along the tooth portion 212 of the second wall portion 232, a second cylindrical portion protrusion 234 that protrudes radially inward from a portion extending along the outer peripheral surface of the cylindrical portion 211 of the second wall portion 232, and a second curved portion protrusion 235 that protrudes radially outward from a portion extending along the outer peripheral surface of the curved portion 213 of the second wall portion 232.

[0028] By providing protrusions 228, 238, protrusions 228, 238 come into contact with core inner surface portion 215 in the mounted state, and the frictional force of the contact portions enables insulators 22, 23 to be fixed to stator core 21. Furthermore, clearances are formed between the tips of wall portions 222, 232 and core inner surface portion 215, allowing insulators 22, 23 to be mounted to stator core 21 smoothly.

[0029] The first tooth protrusion 223 and the second tooth protrusion 233 are collectively referred to as tooth protrusions 223 and 233. The first cylindrical protrusion 224 and the second cylindrical protrusion 234 are collectively referred to as cylindrical protrusions 224 and 234. The first curved surface protrusion 225 and the second curved surface protrusion 235 are collectively referred to as curved surface protrusions 225 and 235. The first base 221 and the second base 231 are collectively referred to as bases 221 and 231. The first wall 222 and the second wall 232 are collectively referred to as wall portions 222 and 232.

[0030] There is no limitation on the number of protrusions 228, 238. In the embodiment, two tooth protrusions 223, 233 are provided radially spaced apart to correspond to each side surface of the tooth 212 of each slot 214. One cylindrical protrusion 224, 234 is provided corresponding to the cylindrical portion 211 of each slot 214. Two curved surface protrusions 225, 235 are provided circumferentially spaced apart to correspond to the curved surface portion 213 of each slot 214.

[0031] By providing cylindrical protrusions 224, 234 and curved protrusions 225, 235, these protrusions come into radial contact with stator core 21, and the frictional force of the contacting portions can increase the fixing force in the radial direction. By providing tooth protrusions 223, 233, these protrusions come into circumferential contact with stator core 21, and the frictional force of the contacting portions can increase the fixing force in the circumferential direction.

[0032] The clearances between the wall portions 222 and 232 and the core inner surface portion 215 will now be described. In this specification, the maximum clearances between the wall portions 222 and 232 and the core inner surface portion 215 will be simply referred to as "clearances." FIG. 5 is a cross-sectional view of the stator 20 taken along a plane perpendicular to the axial direction. While FIG. 5 shows the wall portion 222 and the protrusion 228 of the first insulator 22, the wall portion 232 and the protrusion 238 of the second insulator 23 are similar. FIG. 6 is a cross-sectional view of the stator 20 taken along a plane parallel to the axial direction that passes through the curved surface portion protrusion 225 and the cylindrical portion protrusion 224. As shown in FIG. 6, the axial range of the wall portion 222 overlaps with the axial range of the wall portion 232.

[0033] The insulators 22 and 23 have protrusions 228 and 238, which form clearances between the insulators 22 and 23 and the core inner surface 215. The radial clearance 12 between the wall portions 222 and 232 and the cylindrical portion 211 and the radial clearance 13 between the wall portions 222 and 232 and the curved surface portion 213 are larger than the circumferential clearance 11 between the wall portions 222 and 232 and the tooth portion 212. The insulators 22 and 23 are made of resin and are injection molded. Injection molding causes considerable deformation due to temperature differences and shrinkage rates in the mold. In particular, cylindrical molded products tend to have their outer peripheries warp in a first direction or in a direction opposite to the first direction in the axial direction. This means that the insulator walls 222 and 232 may come close to the cylindrical portion 211 or the curved surface portion 213 of the core. In this case, compared to when the circumferential clearance is larger than the radial clearance, the fit of the first insulator 22 to the stator core 21 is improved. The circumferential clearance 11, the radial clearance 12, and the radial clearance 13 can be set by adjusting the protruding dimensions of the protruding portions 228, 238, respectively, so as to obtain the desired fit.

[0034] For example, the radial projections of the cylindrical projections 224, 234 and the curved projections 225, 235 from the wall portions 222, 232 may be set in the range of 0.5 mm to 1.5 mm, and in this embodiment, they are set to 1.0 mm. For example, the circumferential projections of the tooth projections 223, 233 from the wall portions 222, 232 may be set in the range of 0.2 mm to 0.6 mm, and in this embodiment, they are set to 0.4 mm. The radial projections may be non-uniform, for example, 2.5 times the circumferential projections.

[0035] 6, each of the protruding portions 228, 238 has an insertion inclined surface 27 whose radial protrusion amount gradually decreases with increasing axial distance from the base portions 221, 231. In this case, when the insulators 22, 23 are attached, the insertion inclined surface 27 of the protruding portions 228, 238 is inserted into the core inner surface portion 215 first, so that the protruding portions 228, 238 can be smoothly inserted along the insertion inclined surface 27. In other words, the protruding portions 228, 238 do not get in the way when the insulators 22, 23 are attached. The inclination angle of the insertion inclined surface 27 with respect to the axial direction may be in the range of 10° to 80°, and is set to 45° in this embodiment.

[0036] The first inner circumferential wall 226 and the second inner circumferential wall 236 are collectively referred to as inner circumferential walls 226 and 236, and the first outer circumferential wall 227 and the second outer circumferential wall 237 are collectively referred to as outer circumferential walls 227 and 237. As shown in Figures 3 and 4, the inner circumferential walls 226 and 236 are cylindrical circumferential walls extending in the axial direction from the outer edges of the regions of the bases 221 and 231 corresponding to the cylindrical portions 211. The outer circumferential walls 227 and 237 are cylindrical circumferential walls extending in the axial direction from the regions of the bases 221 and 231 corresponding to the curved surface portions 213, and are cut out in portions corresponding to the gaps between two adjacent curved surface portions 213.

[0037] An example of the routing of the wire of the winding 24 will be described with reference to Figures 7 and 8. Figure 7 is a diagram showing the stator core 21 and the winding 24. Figure 8 is an exploded view showing the stator core 21 and the winding 24. The winding 24 is formed by winding wires 8 and 9 around each tooth 212 with insulators 22 and 23 interposed between them. The wires 8 and 9 are magnet wires, which are copper wires insulated with resin such as polyurethane.

[0038] As shown in FIG. 7, a crossover arrangement portion 258 of the insulator 22 is provided with metal terminal pins 24U, 24V, 24W, and 24N, and hooks 251, 252, 253, 254, and 255 on which wires can be hooked.

[0039] The four windings 24 connected in series for each phase constitute a U-phase coil 261, a V-phase coil 262, and a W-phase coil 263. The coils 261, 262, and 263 are three-phase star-connected, with one wire end of each coil connected to terminal pin 24N and the other wire end connected to terminal pins 24U, 24V, and 24W. Terminal pin 24N is the neutral point.

[0040] 7 and 8, the symbols V2, V1, U2, U1, W1, W2, V3, V4, U4, U3, W4, and W3 indicate the windings 24 wound around each tooth portion 212. In Fig. 8, a winding whose arrow indicates a clockwise direction is called a forward winding, and a winding whose arrow indicates a counterclockwise direction is called a reverse winding.

[0041] The wires 8 and 9 include a first wire 8 indicated by a dashed line and a second wire 9 indicated by a solid line in Fig. 8. The first wire 8 forms a U-phase coil 261 and a V-phase coil 262, and the second wire 9 forms a W-phase coil 263.

[0042] The second wire 9 has its winding start 9s wound around the terminal pin 24W, is wound forward around the winding W1, is wound backward from the winding W1 around the adjacent winding W2, extends from the winding W2 and reaches the hook 251. Next, the second wire 9 changes direction at the hook 251 and reaches the central inner circumferential wall 257, turns around the central inner circumferential wall 257 in the counterclockwise direction for about half a turn and reaches the winding W3.

[0043] Next, the second wire 9 is wound forward around the winding W3, then wound backward from the winding W3 around the adjacent winding W4, and extends from the winding W4 to the hook 252. Next, the second wire 9 changes direction at the hook 252, and the winding end 9e is wound around the terminal pin 24N.

[0044] The first wire 8 has its winding start 8s wound around the terminal pin 24V, is wound in the reverse direction around the winding V1, is wound forward from the winding V1 around the adjacent winding V2, extends from the winding V2 and reaches the central inner circumferential wall 257. Next, the first wire 8 makes approximately a half turn counterclockwise around the central inner circumferential wall 257, changes direction at the hook 253 and reaches the winding V3.

[0045] Next, the first wire 8 is wound backward around the winding V3, then wound forward from the winding V3 around the adjacent winding V4, and extends from the winding V4 to the terminal pin 24N. Next, the first wire 8 is wound around the terminal pin 24N, changes direction, and reaches the winding U4.

[0046] Next, the first wire 8 is wound backward around the winding U4, then forward from the winding U4 to the adjacent winding U3, and extends from the winding U3 to the hook 254. Next, the first wire 8 changes direction at the hook 254, and then changes direction again at the hook 255 to the winding U2. Next, the first wire 8 is wound forward around the winding U2, then backward from the winding U2 to the adjacent winding U1, and extends from the winding U1 to the terminal pin 24U. The winding end 8e of the first wire 8 is wound around the terminal pin 24U.

[0047] The portions of the wires 8 and 9 that are wound around the terminal pins 24U, 24V, 24W, and 24N are soldered to the respective terminal pins.

[0048] The lead wire 268 will be described with reference to FIGS. 1 and 7. The lead wire 268 is composed of three insulated electric wires, one end of which is electrically connected to the terminal pins 24U, 24V, and 24W, and the other end of which is electrically connected to the circuit board 48. The lead wire 268 extends from the terminal pins 24U, 24V, and 24W, passes through a wire passing portion 257a opening in the central inner circumferential wall 257, passes through one of the horizontal holes 30j of the shaft 30 and the hollow portion, and extends from the other horizontal hole 30h to the circuit board 48, where it is electrically connected to a predetermined portion of the circuit board 48. The lead wire 268 is housed in an outer jacket tube 269 from the portion before passing through the wire passing portion 257a to the portion of the lead wire 268 that exits the horizontal hole 30h. The portion of the lead wire 268 before passing through the wire passing portion 257a may be fixed to the crossover arrangement portion 258 by a support member 266.

[0049] According to the embodiment, the provision of the wire passing portion 257a makes it possible to avoid interference between the lead wire 268 and the central inner circumferential wall 257 when passing the lead wire 268 through the horizontal hole 30j, thereby enabling a thinner motor 10. In addition, the work of passing the lead wire 268 through the hollow portion of the shaft 30 becomes easier.

[0050] The rotor 40 will be described with reference to Figures 9 to 12. Figure 9 is a perspective view showing the housing 41 of the rotor 40. Figure 9(A) is a view of the housing 41 seen obliquely from above, and Figure 9(B) is an enlarged view of the engaging housing recess 415 and the pin insertion opening 416. Figure 10 is a view showing the magnet 43. Figure 10(A) is a view of the magnet 43 seen obliquely from above, Figure 10(B) is an enlarged view of the engaging magnet protrusion 435, and Figure 10(C) is a cross-sectional view of the magnet 43 taken along line AA.

[0051] The housing 41 has a top plate portion 411, a housing cylindrical portion 412, a magnet end face support portion 413, and a flange 414, each of which is circular. The housing cylindrical portion 412 is a cylindrical portion that supports the side surface of the magnet 43. The magnet end face support portion 413 is a donut-shaped portion that extends radially inward from the top of the housing cylindrical portion 412 and supports the upper end face of the magnet 43. The top plate portion 411 is a hollow disk-shaped portion that covers the center above the magnet end face support portion 413. The flange 414 is a donut-shaped portion that extends radially outward from the bottom of the housing cylindrical portion 412. The housing cylindrical portion 412 is provided with one or more engaging housing recesses 415, and the flange 414 is provided with one or more pin insertion openings 416. In this example, two engaging housing recesses 415 and two pin insertion openings 416 are provided at 180° intervals in the circumferential direction. The engagement housing recess 415 and the pin insertion opening 416 will be described later.

[0052] The magnet 43 has a hollow cylindrical shape and includes a magnet inner peripheral surface 431, a magnet outer peripheral surface 460, an upper end surface 433, and a lower end surface 434. The magnet inner peripheral surface 431 has 14 drive poles that supply field magnetic flux to the stator core 21. The magnet 43 in this embodiment is a polar-anisotropic plastic magnet with a high residual magnetic flux density, but may also be an isotropic plastic magnet. One or more engaging magnet protrusions 435 are provided on the magnet outer peripheral surface 460. In this example, two engaging magnet protrusions 435 are provided at 180° intervals in the circumferential direction, corresponding to the two engaging housing recesses 415.

[0053] The magnet 43 has an outer diameter equal to or larger than the inner diameter of the housing cylindrical portion 412 and is fixed to the housing cylindrical portion 412 of the housing 41 by press-fitting. This eliminates the need to manage the adhesive's curing time, improving productivity compared to fixing by adhesive. The magnet outer peripheral surface 460 of the magnet 43 includes a first magnet outer peripheral surface 461 that is pressed into contact with the housing cylindrical portion 412 by press-fitting, and a second magnet outer peripheral surface 462 that tapers gradually toward the end of the magnet 43 in the first direction. In this case, because the tapered outer peripheral surface is on the upper end surface 433 side, which is the leading end during press-fitting, the magnet 43 can be easily press-fitted into the housing 41 along the slope of this outer peripheral surface. During press-fitting, the upper end surface 433 of the magnet 43 abuts against the magnet end surface support portion 413. This reduces variation in the axial position of the magnet 43.

[0054] In the embodiment, magnet outer peripheral surface 460 has third magnet outer peripheral surface 463 that is continuous with second magnet outer peripheral surface 462 and extends parallel to the axial direction toward the end in the first direction. In this case, third magnet outer peripheral surface 463, which has a smaller diameter than first magnet outer peripheral surface 461, can be hooked onto the inner edge of housing 41 and aligned with housing 41, further improving productivity.

[0055] Since magnet 43 receives a large torque against housing 41 at startup, repeated start-stop cycles could cause magnet 43 to spin freely. To address this issue, it is possible to increase the press-fit strength, but if the press-fit strength is increased too much, magnet 43 could crack during press-fitting. To prevent spinning freely, a convex portion can be provided on either magnet 43 or housing 41, and a concave portion that engages with the convex portion can be provided on the other.

[0056] In the embodiment, the anti-slip projection and recess are provided in the form of an engaging magnet projection 435 and an engaging housing recess 415 that engage with each other. The engaging magnet projection 435 is a portion that protrudes radially outward at the end of the magnet outer peripheral surface 460 opposite to the first direction. The engaging housing recess 415 is a portion that is recessed radially outward at the end of the housing cylindrical portion 412 opposite to the first direction, and has a shape that can engage with the engaging magnet projection 435. The shape and number of the engaging magnet projection 435 and the engaging housing recess 415 can be determined by experiment or simulation depending on the desired engagement strength.

[0057] When the magnet 43 is formed by resin molding using a mold, corners of rounded corners remain at the base of the engaging magnet protrusions 435 due to mold processing limitations. The circumferential corners of the engaging magnet protrusions 435 can be a factor in reducing the accuracy of the engagement position with the engaging housing recesses 415. Therefore, in this embodiment, as shown in FIG. 10(B), recesses 436 recessed radially inward are provided on both circumferential sides of the engaging magnet protrusions 435 on the magnet outer peripheral surface 460. In this case, the effects of the circumferential corners of rounded corners can be avoided. Furthermore, the recesses 436 function as burr reliefs to avoid the effects of burrs or burrs that may be present in the engaging housing recesses 415.

[0058] Next, the positioning recess 437 of the magnet 43 will be described. After the magnet 43 is press-fitted into the housing 41, the magnet inner circumferential surface 431 is magnetized while the magnet 43 is fitted into a magnetizing jig (not shown). Polar-anisotropic plastic magnets exhibit their intended performance when magnetized in the same phase as the magnetic field orientation (hereinafter simply referred to as "magnetic field orientation") during resin molding. For this reason, the magnet 43 has an engaging magnet protrusion 435 linked to the magnetic field orientation, and a positioning recess 437. The positioning recess 437 is a recess recessed in the axial direction in the lower end surface 434 of the magnet 43 on the side opposite to the first direction. As will be described later, the magnet 43 is press-fitted into the housing 41 so that the positioning recess 437 is circumferentially aligned with the pin insertion opening 416.

[0059] As an example, the positioning recesses 437 are recesses formed by pin members that push the magnet 43 out of the mold after resin molding, and are provided at predetermined intervals in the circumferential direction on the lower end surface 434. In this example, 14 recesses are provided on the lower end surface 434, and of these 14 recesses, two recesses that are located at the same positions in the circumferential direction as the engaging magnet protrusions 435 are positioning recesses 437. As an example, the positioning recesses 437 have a circular shape when viewed in the axial direction, and have a diameter of 4 mm and a depth of 0.5 mm.

[0060] Next, the pin insertion opening 416 of the flange 414 will be described with reference to FIGS. 11 and 12. FIG. 11 is a cross-sectional view showing a process of press-fitting the magnet 43 into the housing 41. FIG. 12 is a perspective view showing the state in which the magnet 43 has been press-fitted into the housing 41. As described above, the housing 41 has the flange 414 extending radially outward from the outer edge of the housing cylindrical portion 412. The flange 414 has a pin insertion opening 416 through which a guide pin 472 protruding in the axial direction from the press-fitting jig 47 is inserted when the magnet 43 is press-fitted. The pin insertion opening 416 functions as a mark for magnetizing the magnet 43 press-fitted into the housing 41 in the same phase as its magnetic field orientation. In this example, two pin insertion openings 416 are provided circumferentially at intervals of 180°.

[0061] The magnet 43 is press-fitted using a press-fitting jig 47 so that the pin insertion opening 416 is aligned with the engaging magnet protrusion 435 in the circumferential direction. The press-fitting jig 47 includes a press-fitting jig main body 471, guide pins 472, and an alignment jig 476. The press-fitting jig main body 471 is formed from a block-shaped base material and has a flange mounting portion 473 on which the flange 414 is placed, and a jig recess 474 recessed downward from the flange mounting portion 473. As shown in FIG. 11 , the jig recess 474 has a shape that can accommodate the housing cylindrical portion 412, the magnet end face support portion 413, and the top plate portion 411.

[0062] The guide pin 472 has a cylindrical pin shape and is provided on the flange mounting portion 473 so as to protrude vertically upward from the flange mounting portion 473. The alignment jig 476 has a flat pressing portion 476a that presses the flange 414 against the flange mounting portion 473, a vertical extending portion 476b that extends vertically upward from the pressing portion 476a, a horizontal extending portion 476c that extends horizontally from the vertical extending portion 476b, and a guide protrusion 476d that protrudes downward from the horizontal extending portion 476c. A pin hole 476e through which the guide pin 472 passes is provided in the pressing portion 476a.

[0063] The manufacturing process of the rotor 40 will now be described. (1) First, the housing 41 is placed on the press-fitting jig 47 with the top plate portion 411 facing downward, and the circumferential position is adjusted so that the guide pins 472 pass through the pin insertion openings 416 . (2) The magnet 43 is placed on the housing 41 so that the third magnet outer peripheral surface 463 faces downward. At this time, the third magnet outer peripheral surface 463 enters the housing cylindrical portion 412, and the first magnet outer peripheral surface 461 is positioned above the housing cylindrical portion 412.

[0064] (3) The positioning jig 476 is set so that the guide pin 472 passes through the pin hole 476e, and the magnet 43 is rotated so that the positioning recess 437 engages with the guide protrusion 476d, resulting in the state shown in FIG. (4) In this state, the lower end surface 434 is pushed in until the upper end surface 433 abuts against the magnet end surface support portion 413. At this time, the engaging magnet convex portion 435 fits into the engaging housing concave portion 415. (5) The rotor 40 is removed from the press-fitting jig 47, set in a magnetizing jig, and magnetized. At this time, by using the pin insertion openings 416 as circumferential marks, the rotor 40 can be magnetized in the same phase as the magnetic field orientation of the magnets 43. The rotor 40 is removed from the magnetizing jig, and the rotor 40 is completed.

[0065] This concludes the description of the rotor 40.

[0066] The operation of motor 10 configured as described above will now be described. When a three-phase drive current is supplied from circuit board 48 to coils 261, 262, and 263 of stator 20 via lead wires 268, a rotating magnetic field corresponding to the drive current is generated around stator core 21 of stator 20. The interaction between this rotating magnetic field and the drive magnetic poles of magnet 43 generates a rotational torque in rotor 40, and this torque rotates rotor 40 and a driven object such as a ceiling fan blade (not shown) connected to rotor 40.

[0067] The features of rotor 40 configured as described above will be described below. Rotor 40 includes housing 41 having a cylindrical housing portion 412, and hollow cylindrical magnet 43 having an outer diameter equal to or larger than the inner diameter of housing cylindrical portion 412 and press-fitted into housing 41 in the first axial direction. Magnet outer peripheral surface 460 of magnet 43 includes first magnet outer peripheral surface 461 that is press-fitted against housing cylindrical portion 412, and second magnet outer peripheral surface 462 that is tapered and gradually reduces in diameter toward the end of magnet 43 in the first direction.

[0068] According to this configuration, the magnet 43 can be easily press-fitted along the inclination of the second magnet outer peripheral surface 462, and therefore the assembly workability of the rotor 40 can be improved.

[0069] An outline of one aspect of the present disclosure is as follows. [Item 1] The magnet (43) includes a housing (41) having a cylindrical housing portion (412) and a hollow cylindrical magnet (43) having an outer diameter equal to or larger than the inner diameter of the cylindrical housing portion (412) and press-fitted into the housing (41) in a first axial direction, The rotor (40) has a magnet outer peripheral surface (460) of the magnet (43) that has a first magnet outer peripheral surface (461) that is pressed against the housing cylindrical portion (412) by press-fitting, and a second magnet outer peripheral surface (462) that is tapered and gradually reduces in diameter toward the end of the magnet (43) in the first direction.

[0070] [Item 2] A rotor (40) as described in item 1, wherein the magnet outer peripheral surface (460) has a third magnet outer peripheral surface (463) that is continuous with the second magnet outer peripheral surface (462) and extends parallel to the axial direction toward the end in the first direction.

[0071] [Item 3] The magnet (43) has an engaging magnet protrusion (435) that protrudes radially outward from an end of the magnet outer circumferential surface (460) opposite to the first direction, Item 2. The rotor (40) according to item 1, wherein the housing (41) has an engaging housing recess (415) in the housing cylindrical portion (412) for engaging with the engaging magnet protrusion (435).

[0072] [Item 4] The magnet (43) has an engaging magnet recess that is recessed radially inward at an end of the magnet outer circumferential surface (460) opposite to the first direction, Item 2. The rotor (40) according to item 1, wherein the housing (41) has an engaging housing protrusion on the housing cylindrical portion (412) for engaging with the engaging magnet recess.

[0073] [Item 5] The housing (41) has a flange (414) extending radially outward from the outer edge of the housing cylindrical portion (412), The rotor (40) according to item 1, wherein the flange (414) has a pin insertion opening (416) through which a guide pin (472) protruding in the axial direction from the press-fitting jig (47) is inserted when the magnet (43) is press-fitted.

[0074] [Item 6] The magnet (43) has a positioning recess (437) recessed in the axial direction on the end surface opposite to the first direction, Item 1. The rotor (40) according to item 1, wherein the magnet (43) is press-fitted into the housing (41) so that the positioning recess (437) is at the same position in the circumferential direction as the pin insertion opening (416).

[0075] [Item 7] A motor (10) comprising the rotor (40) according to any one of items 1 to 6.

[0076] The present disclosure has been described above based on examples. These examples are merely illustrative, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component or each treatment process, and that such modifications are also within the scope of the present disclosure.

[0077] In the description of the embodiment, an example was shown in which a convex portion is provided on magnet 43 to prevent free rotation, and a concave portion that engages with the convex portion is provided on housing 41, but this is not limiting. A convex portion may be provided on housing 41, and a concave portion that engages with the convex portion may be provided on magnet 43. For example, magnet 43 may have an engaging magnet concave portion that is recessed radially inward at the end of magnet outer circumferential surface 460 opposite to the first direction, and housing 41 may have an engaging housing convex portion on housing cylindrical portion 412 that engages with the engaging magnet concave portion.

[0078] The configuration of the winding 24 described in FIGS. 7 and 8 is one example, and the configuration of the winding 24 is not particularly limited as long as the coils 261, 262, and 263 form a three-phase winding, and any known configuration can be used. [Explanation of symbols]

[0079] 8 First wire, 9 Second wire, 10 Motor, 11 Circumferential clearance, 12, 13 Radial clearance, 20 Stator, 21 Stator core, 22 First insulator, 23 Second insulator, 24 Winding, 24N, 24U, 24V, 24W Terminal pin, 27 Insertion inclined surface, 30 Shaft, 30h, 30j Horizontal hole, 31 First bearing, 32 Second bearing, 40 Rotor, 41 Housing, 42 Cover, 43 Magnet, 47 Press-fit jig, 48 Circuit board, 211 Cylindrical portion, 212 Tooth portion, 213 Curved surface portion, 214 Slot, 215 Core inner surface portion, 221 First base portion, 222 First wall portion, 223 First tooth portion protrusion, 224 First cylindrical portion protrusion, 225 First curved surface portion protrusion, 226 First inner peripheral wall, 227 First outer peripheral wall, 231 Second base portion, 232 Second wall portion, 233 Second tooth portion protrusion, 234 Second cylindrical portion protrusion, 235 Second curved surface portion protrusion, 236 Second inner peripheral wall, 237 Second outer peripheral wall, 238 Protrusion, 251, 252, 254, 255 Hook, 257 Central inner peripheral wall, 257a Wiring passage portion, 258 Crossover wire arrangement portion, 261, 262, 263 Coil, 268 Lead wire, 269 Outer jacket tube, 411 Top plate portion, 412 Housing cylindrical portion, 413 Magnet end face support portion, 414 Flange, 415 Engagement housing recess, 416 Pin insertion opening, 431 Magnet inner peripheral surface, 433 Upper end face, 434 Lower end face, 435 Engagement magnet protrusion, 436 Recess, 437 Positioning recess, 460 Magnet outer peripheral surface, 461 First magnet outer peripheral surface, 462 Second magnet outer peripheral surface, 463 Third magnet outer peripheral surface, 471 Press-fit jig body, 472 Guide pin, 473 Flange mounting portion, 474 Jig recess, 476 Jig.

Claims

1. a housing having a cylindrical housing portion; and a hollow cylindrical magnet having an outer diameter equal to or larger than an inner diameter of the housing cylindrical portion and press-fitted into the housing in a first axial direction; The rotor has a magnet outer surface having a first magnet outer surface that is pressed against the housing cylindrical portion by press-fitting, and a second magnet outer surface that is tapered and gradually reduces in diameter toward the end of the magnet in the first direction.

2. 2. The rotor according to claim 1, wherein the magnet outer peripheral surface has a third magnet outer peripheral surface that is continuous with the second magnet outer peripheral surface and extends parallel to the axial direction toward an end in the first direction.

3. the magnet has an engaging magnet protrusion that protrudes radially outward at an end of the magnet outer circumferential surface opposite to the first direction, 2. The rotor according to claim 1, wherein the housing has an engaging housing recess in the housing cylindrical portion for engaging with the engaging magnet protrusion.

4. the magnet has an engaging magnet recess recessed radially inward at an end of the outer circumferential surface of the magnet opposite to the first direction, 2. The rotor according to claim 1, wherein the housing has an engaging housing protrusion on the housing cylindrical portion for engaging with the engaging magnet recess.

5. The housing has a flange extending radially outward from an outer edge of the housing cylindrical portion, 2. The rotor according to claim 1, wherein the flange has a pin insertion opening through which a guide pin protruding in the axial direction from a press-fitting jig is inserted when the magnet is press-fitted.

6. the magnet has a positioning recess recessed in the axial direction on an end surface opposite to the first direction, The rotor according to claim 5 , wherein the magnet is press-fitted into the housing so that the positioning recess is at the same position in the circumferential direction as the pin insertion opening.

7. A motor comprising the rotor according to any one of claims 1 to 6.

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