Stator and motor

Abstract

Provided is a stator (20) to which a drive current is supplied from a circuit board. The stator (20) comprises: a stator core (21) that has a cylindrical part which has a cylindrical shape and a plurality of teeth which protrude outward in the radial direction from the outer peripheral surface of the cylindrical part; a pair of insulators that sandwich the stator core (21) from both sides in the axial direction of the cylindrical shape; a winding (24) that is wound on each tooth with the insulators therebetween; a lead wire (268) that electrically connects the circuit board to the winding (24). The insulator (22) on the side close to the circuit board includes a base part (221) that is constituted by a plane orthogonal to the axial direction, a central inner peripheral wall (257) that has a substantially cylindrical shape and that extends from the base part (221) in the axial direction, and a wire passage part (257a) that is an opening which penetrates the central inner peripheral wall (257) in the radial direction and which allows the lead wire (268) to pass therethrough.

Description

Stator, motor

[0001] The present disclosure relates to a stator and a motor.

[0002] A stator for use in a brushless DC motor is known, which has a stator core through which a rotor shaft passes at its center. For example, Patent Document 1 describes a stator having a stator core, an insulating member that insulates the stator core, and a coil wound around the stator core.

[0003] Japanese Patent Application Laid-Open No. 2022-052814

[0004] The stator described in Patent Document 1 has a peripheral wall portion that protrudes axially from an insulating member and surrounds a shaft. Patent Document 1 states that the peripheral wall portion can prevent contact between the shaft and the coil jumper wires.

[0005] The stator described in Patent Document 1 has a horizontal hole formed on the side of the shaft through which a wiring wire is passed. When passing the wire through the horizontal hole, the wire must climb over a peripheral wall, which may cause contact between the wire and the bearing. Therefore, to avoid contact between the wire and the bearing, the bearing is thought to be positioned axially away from the peripheral wall. For this reason, the stator described in Patent Document 1 has room for improvement in terms of making the motor thinner in the axial direction.

[0006] The present disclosure provides a stator that allows a motor to be made thinner in the axial direction.

[0007] A stator according to one aspect of the present disclosure is a stator supplied with a drive current from a circuit board, and includes a stator core having a cylindrical portion and a plurality of teeth protruding radially outward from the outer circumferential surface of the cylindrical portion, a pair of insulators sandwiching the stator core from both sides in the axial direction of the cylindrical portion, windings wound around the teeth via the insulators, and lead wires electrically connecting the circuit board and the windings. Furthermore, the insulator on the side closest to the circuit board includes a base portion formed of a surface perpendicular to the axial direction, a substantially cylindrical central inner circumferential wall extending from the base in the axial direction, and a wire passing portion that is an opening that radially penetrates the central inner circumferential wall and allows the lead wires to pass through.

[0008] 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.

[0009] According to the present disclosure, a stator that can reduce the thickness of a motor in the axial direction can be provided.

[0010] 1 is a side cross-sectional view schematically showing a motor including a rotor according to an embodiment of the present disclosure. FIG. 1 is an exploded perspective view showing the stator core and insulator of FIG. 1. FIG. 2 is a perspective view showing the first insulator of FIG. 2. FIG. 3 is a perspective view showing the first insulator of FIG. 2. FIG. 4 is a perspective view showing the second insulator of FIG. 2. FIG. 5 is a perspective view showing the second insulator of FIG. 2. FIG. 6 is a cross-sectional view taken along a plane perpendicular to the axial direction of the stator of FIG. 1. FIG. 7 is a cross-sectional view taken along a plane parallel to the axial direction of the stator of FIG. 1. FIG. 8 is a view showing the stator core and windings of the stator of FIG. 1. FIG. 9 is a developed view showing the stator core and windings of the stator of FIG. 1. FIG. 10 is a perspective view showing the housing of the rotor of FIG. 1. FIG. 11 is a view showing a magnet of the rotor of FIG. 1. FIG. 12 is a cross-sectional view showing a process of press-fitting a magnet into the housing of the rotor of FIG. 1. FIG. 13 is a perspective view showing a state in which the magnet has been press-fitted into the housing of the rotor of FIG. 1. FIG. 14 is a perspective view showing a state in which lead wires have been drawn out from the shaft of FIG. 1.

[0011] 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, component placement and connection configurations, steps (processes), and step order 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.

[0012] 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 another and do not limit the components. Furthermore, when a component is not to be distinguished from another component, the ordinal number may be omitted.

[0013] [Example] The configuration of a motor 10 including a stator 20 according to an example 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.

[0014] 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 constitute a stationary body, and the rotor 40 and the cover 42 constitute a rotating body.

[0015] 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.

[0016] 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.

[0017] 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 stator 20 that the rotor 40 covers is 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.

[0018] 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.

[0019] 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 circumferentially.

[0020] The circuit board 48 functions as a drive circuit for the brushless motor and supplies 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.

[0021] The stator 20 will be described with reference to Figures 2 to 8. Figure 2 is an exploded perspective view showing the stator core 21 and a pair of insulators 22, 23 of the stator 20. 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 stator core 21 in this embodiment has 12 slots 214.

[0022] 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 stator core 21 from the first insulator 22 in the axial direction. Referring to FIG. 1 , the first insulator 22 is positioned closer to the circuit board 48 than the second insulator 23. In other words, of the pair of insulators 22, 23, the insulator closest to the circuit board 48 is the first insulator 22. The insulator positioned farther from the circuit board 48 is the second insulator 23. FIG. 3A is a view of the first insulator 22 viewed from diagonally above. FIG. 3B is a view of the first insulator 22 viewed from diagonally below. FIG. 4A is a view of the second insulator 23 viewed from diagonally below. FIG. 4B is a view of the second insulator 23 as viewed obliquely from above.

[0023] 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 protruding portion 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 portions 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-like plane perpendicular to the axial direction on the inner circumferential side of the first base portion 221.

[0024] 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.

[0025] 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.

[0026] The central inner peripheral wall 257 is a substantially cylindrical peripheral wall that extends in the axial direction at the inner peripheral edge of the crossover wire placement portion 258. In other words, the central inner peripheral wall 257 extends in the axial direction from the base portion 221. The central inner peripheral wall 257 has a wire passing portion 257a that is partially open in a predetermined direction, and has a C-shape when viewed in the axial direction.

[0027] The wire passing portion 257a is an opening that radially penetrates the central inner circumferential wall 257. The wire passing portion 257a is an opening through which the lead wire 268, which is drawn from the lateral hole 30j of the shaft 30, is drawn from the inside of the central inner circumferential wall 257 to the outside of the central inner circumferential wall 257. In this embodiment, the central inner circumferential wall 257 is not provided at a position facing the lateral hole 30j of the shaft 30, so the wire passing portion 257a through which the lead wire 268 passes is formed. With this configuration, the lead wire 268 can be smoothly drawn from the inside of the central inner circumferential wall 257 to the outside of the central inner circumferential wall 257 without climbing over the central inner circumferential wall 257. Furthermore, because the lead wire 268 does not need to climb over the central inner circumferential wall 257 and passes at a lower position than in the past, the first bearing 31 can be positioned closer to the central inner circumferential wall 257 than in the past. In other words, the motor can be made thinner in the axial direction than in the past.

[0028] In this embodiment, the central inner peripheral wall 257 is not provided at a position facing the lateral hole 30j, thereby forming the wire passing portion 257a, but this configuration is not limited to this. It is sufficient that the lead wire 268 can pass between the inside and outside of the central inner peripheral wall 257 without climbing over the central inner peripheral wall 257. For example, the wire passing portion 257a may be provided as a through-hole in the central inner peripheral wall 257 that is at least larger than the diameter of the lead wire 268. In this configuration, the central inner peripheral wall 257 has an O-shape when viewed in the axial direction.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] By providing the protrusions 228, 238, the protrusions 228, 238 come into contact with the core inner surface portion 215 in the mounted state, and the frictional force of the contact portions enables the insulators 22, 23 to be fixed to the stator core 21. Furthermore, a clearance is formed between the tips of the wall portions 222, 232 and the core inner surface portion 215, allowing the insulators 22, 23 to be mounted smoothly on the stator core 21.

[0033] 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.

[0034] 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 portion 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.

[0035] By providing the cylindrical protrusions 224, 234 and the curved protrusions 225, 235, these protrusions come into radial contact with the stator core 21, and the frictional force of the contacting portions can increase the fixing force in the radial direction. By providing the tooth protrusions 223, 233, these protrusions come into circumferential contact with the stator core 21, and the frictional force of the contacting portions can increase the fixing force in the circumferential direction.

[0036] The clearances between the wall portions 222, 232 and the core inner surface portion 215 will now be described. In this specification, the maximum clearances between the wall portions 222, 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.

[0037] 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 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 formed by injection molding. 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 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.

[0038] 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, the projection is 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, the projection is set to 0.4 mm. The radial projections may be non-uniform, for example, 2.5 times the circumferential projections.

[0039] As shown in Figure 6, each of the protrusions 228, 238 has an insertion inclined surface 27 whose radial protrusion amount gradually decreases with increasing axial distance from the base 221, 231. In this case, when the insulators 22, 23 are attached, the insertion inclined surface 27 of the protrusions 228, 238 is inserted into the core inner surface portion 215 first, so that the protrusions 228, 238 can be smoothly inserted along the insertion inclined surface 27. In other words, the protrusions 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.

[0040] 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 3A, 3B, 4A, and 4B, 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.

[0041] An example of the routing of the wires of the windings 24 will be described with reference to Figures 7, 8, and 13. Figure 7 is a diagram showing the stator core 21 and the windings 24. Figure 8 is an exploded view showing the stator core 21 and the windings 24. The windings 24 are formed by winding wires 8 and 9 around each tooth 212 with insulators 22 and 23 between them. The wires 8 and 9 are magnet wires, which are copper wires insulated with resin such as polyurethane. Figure 13 is a perspective view showing the lead wires drawn out from the shaft of Figure 1.

[0042] 7, metal terminal pins 24U, 24V, 24W, and 24N, and hooks 251, 252, 253, 254, and 255 for hooking wires, are provided in crossover arrangement portion 258 of insulator 22. Also, crossover arrangement portion 258 is provided with guide portion 240 and outer peripheral guide wall 242.

[0043] The guide portion 240 is a wall extending in the axial direction from the crossover placement portion 258 and guides the crossover wire of the winding 24 wound around the tooth portion 212 to the outer periphery of the central inner peripheral wall 257. In other words, the guide portion 240 extends in the axial direction from the base portion 221. A pair of guide portions 240 are arranged on either side of the wire passing portion 257a. In this embodiment, as shown in FIG. 7 , the guide portion 240 is provided as an extension of both ends of the C-shape of the central inner peripheral wall 257. With this configuration, the wires 8 and 9 corresponding to the crossover wire are guided to the central inner peripheral wall 257 along the outer side of the guide portion 240, as shown in FIGS. 7 and 13 . In other words, the guide portion 240 prevents the wires 8 and 9 from approaching the wire passing portion 257a inside the guide portion 240. With this configuration, contact with the wires 8 and 9 can be prevented when the lead wire 268 is pulled out.

[0044] As shown in FIG. 13 , the extension length of the guide portion 240 is shorter than the extension length of the central inner circumferential wall 257. In other words, the axial height of the guide portion 240 relative to the first base portion 221 is lower than that of the central inner circumferential wall 257. This is to prevent contact between the first bearing 31 and the lead wire 268 when the lead wire 268 passes through the tip of the extension of the guide portion 240, as shown in FIG. 7 . The extension length of the guide portion 240 is preferably such that the sum of the diameter of the lead wire 268 and the extension length of the guide portion 240 is shorter than the extension length of the central inner circumferential wall 257. With this configuration, even when the lead wire 268 passes through the tip of the extension of the guide portion 240, its height does not exceed the central inner circumferential wall 257, thereby preventing the motor 10 from becoming thicker in the axial direction. The guide portion 240 also includes a base portion 241.

[0045] As shown in Fig. 7 , the pedestal portion 241 is a portion that protrudes from the tip of the guide portion 240 to the outside of the guide portion 240 in parallel with the base portion 221. As shown in Fig. 13 , the pedestal portion 241 is located on the opposite side of the base portion 221 with the wire 8 corresponding to the crossover wire sandwiched therebetween. In other words, the pedestal portion 241 protrudes from the tip of the guide portion 240 in parallel with the base portion 221, thereby separating the wire 8 from the lead wire 268. With this configuration, it is possible to prevent the lead wire 268 from coming into contact with the wire 8 when passing through the tip of the guide portion 240.

[0046] The outer circumferential guide wall 242 is a wall that extends in the axial direction from the crossover wire placement portion 258, and is located on the outer circumferential side of the central inner circumferential wall 257. In this embodiment, the outer circumferential guide wall 242 is located on the opposite side of the central inner circumferential wall 257 from the wire passing portion 257a. In other words, the outer circumferential guide wall 242 is located on the opposite side of the open end of the C-shape of the central inner circumferential wall 257 and on the outer circumferential side of the central inner circumferential wall 257.

[0047] 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 a terminal pin 24N and the other wire end connected to terminal pins 24U, 24V, and 24W, respectively. The terminal pin 24N is the neutral point.

[0048] 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.

[0049] 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.

[0050] 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, makes approximately a half turn counterclockwise around the central inner circumferential wall 257 and follows the guide portion 240 to reach the winding W3.

[0051] 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.

[0052] 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 along the guide portion 240. 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.

[0053] Next, the first wire 8 is wound in a reverse direction 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.

[0054] Next, the first wire 8 is reverse-wound around the winding U4, then forward-wound from winding U4 around the adjacent winding U3, and extends from winding U3 to reach hook 254. Next, the first wire 8 changes direction at hook 254, travels along outer circumferential guide wall 242 to reach hook 255, and then changes direction again at hook 255 to reach winding U2. Next, the first wire 8 is forward-wound around winding U2, then reverse-wound from winding U2 around the adjacent winding U1, and extends from winding U1 to reach terminal pin 24U. The winding end 8e of the first wire 8 is wound around terminal pin 24U.

[0055] In the past, the first wire 8 passed near the wire passing portion 257a when reaching the winding U2 from the winding U3. In this embodiment, the outer circumferential guide wall 242, the hooks 254, and the hooks 255 allow the first wire 8 to pass through the opposite side of the wire passing portion 257a and reach the winding U2 from the winding U3. In other words, the first wire 8 corresponding to the crossover wire does not pass near the wire passing portion 257a.

[0056] This configuration can prevent the lead wire 268 from coming into contact with the first wire 8 when it is pulled out from the horizontal hole 30j.

[0057] 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.

[0058] The lead wire 268 will be described with reference to Figures 1, 7, and 13. The lead wire 268 is composed of three insulated 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.

[0059] As shown in FIG. 1 , one end of the lead wire 268 is electrically connected to a predetermined portion of the circuit board 48, passes through one of the horizontal holes 30h of the shaft 30, passes through the hollow portion, and is drawn out from the other horizontal hole 30j. Furthermore, as shown in FIG. 13 , the lead wire 268 passes through a wire passing portion 257a opening in the central inner circumferential wall 257, passes over the base portion 241, and the three insulated wires are electrically connected to the terminal pins 24U, 24V, and 24W. The lead wire 268 is housed in an outer jacket tube 269 from the portion before passing through the horizontal hole 30h to the portion exiting the wire passing portion 257a. 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. While the present embodiment is configured such that the lead wire 268 is drawn out from the horizontal hole 30j, the lead wire 268 may follow the reverse path. In this case, the lead wires 268 extend from the terminal pins 24U, 24V, and 24W and pass over the base portion 241. Furthermore, the lead wires 268 pass through a wire passing portion 257a that opens in the central inner peripheral wall 257, and extend from one lateral hole 30j of the shaft 30 through the hollow portion, and then from the other lateral hole 30h to the circuit board 48, where they are electrically connected to a predetermined portion of the circuit board 48.

[0060] According to the embodiment, by providing the wire passing portion 257a, the lead wire 268 does not need to climb over the central inner peripheral wall 257 when being pulled out of the horizontal hole 30j, thereby enabling a thin configuration of the motor 10. Furthermore, the guide portion 240, the outer peripheral guide wall 242, the hooks 254, and the hooks 255 prevent the crossover wire from passing near the wire passing portion 257a, making it easier to pull out the lead wire 268.

[0061] 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 viewed 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 of the magnet 43. Figure 10(A) is a view of the magnet 43 viewed 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 A-A.

[0062] The housing 41 includes 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.

[0063] 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.

[0064] 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 the magnet 43 by adhesive. The magnet outer surface 460 of the magnet 43 includes a first magnet outer surface 461 that is pressed into contact with the housing cylindrical portion 412 by press-fitting, and a second magnet outer surface 462 that tapers gradually toward the end of the magnet 43 in the first direction. Because the tapered outer surface is located 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 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.

[0065] In the embodiment, magnet outer peripheral surface 460 has third magnet outer peripheral surface 463 that extends parallel to the axial direction toward the end in the first direction, continuing from second magnet outer peripheral surface 462. 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 to align with the housing 41, further improving productivity.

[0066] Since the magnet 43 receives a large torque against the housing 41 at startup, repeated start-stop cycles could cause the 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, the magnet 43 could crack during press-fitting. To prevent spinning freely, a convex portion can be provided on one of the magnet 43 and the housing 41, and a concave portion that engages with the convex portion can be provided on the other.

[0067] In the embodiment, the anti-slip projections and recesses include 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 from the end of the magnet outer circumferential surface 460 opposite the first direction. The engaging housing recess 415 is a portion that is recessed radially outward from the end of the housing cylindrical portion 412 opposite the first direction, and has a shape that can engage with the engaging magnet projection 435. The shape and number of the engaging magnet projections 435 and the engaging housing recesses 415 can be determined by experiment or simulation depending on the desired engagement strength.

[0068] When the magnet 43 is formed by resin molding using a mold, corners R remain at the base of the engaging magnet protrusions 435 due to mold processing constraints. The circumferential corners R 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 R can be avoided. Furthermore, the recesses 436 function as burr reliefs to avoid the effects of burrs or burrs on the engaging housing recesses 415.

[0069] 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 it 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 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.

[0070] 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 the 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.

[0071] 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 the 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 a 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°.

[0072] 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 that is 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.

[0073] 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.

[0074] The manufacturing process of the rotor 40 will now be described.

[0075] (1) First, place the housing 41 on the press-fitting jig 47 with the top plate portion 411 facing downward, and align the housing 41 in the circumferential direction so that the guide pins 472 pass through the pin insertion openings 416 .

[0076] (2) The magnet 43 is placed on the housing 41 so that the third magnet outer surface 463 faces downward. At this time, the third magnet outer surface 463 enters the housing cylindrical portion 412, and the first magnet outer surface 461 is positioned above the housing cylindrical portion 412.

[0077] (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.

[0078] (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.

[0079] (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 phase with the magnetic field orientation of the magnets 43. The rotor 40 is removed from the magnetizing jig, and the rotor 40 is completed.

[0080] This concludes the description of the rotor 40.

[0081] 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 through lead wires 268 to coils 261, 262, and 263 of stator 20, 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.

[0082] The features of the stator 20 configured as described above will be described. The stator 20 includes a stator core 21 having 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, a pair of insulators 22 and 23 sandwiching the stator core 21 from both sides in the axial direction, and a winding 24 wound around the stator core 21 via the insulators 22 and 23. The insulators 22 and 23 each have base portions 221 and 231 formed with surfaces perpendicular to the axial direction, and a plurality of wall portions 222 and 232 extending axially from the base portions 221 and 231 along a core inner surface portion 215 that surrounds the slots 214 of the stator core 21. The radial clearance 12 between the wall portions 222 , 232 and the cylindrical portion 211 and the radial clearance 13 between the wall portions 222 , 232 and the curved surface portion 213 are larger than the circumferential clearance 11 between the wall portions 222 , 232 and the tooth portion 212 .

[0083] This configuration makes it easier to attach the insulators 22, 23 to the stator core 21, improving the workability of the attachment process, compared to when the circumferential clearance is larger than the radial clearance. Furthermore, since the circumferential clearance is small, the circumferential length of the windings 24 wound around the stator core 21 can be shortened, reducing copper loss and enabling the motor to be made more efficient.

[0084] An outline of one aspect of the present disclosure is as follows.

[0085] [Item 1] A stator (20) to which a driving current is supplied from a circuit board (48), comprising: a stator core (21) having a cylindrical portion (211) and a plurality of teeth (212) protruding radially outward from the outer peripheral surface of the cylindrical portion (211); a pair of insulators (22, 23) sandwiching the stator core (21) from both sides in the axial direction of the cylinder; a winding (24) wound around the teeth (212) via the insulators (22, 23); and a lead wire (268) electrically connecting the circuit board (48) and the winding (24); The insulator (22) on the side closest to the circuit board (48) is a stator (20) having a base (221) formed of a surface perpendicular to the axial direction, a substantially cylindrical central inner wall (257) extending axially from the base (221), and a wiring passage portion (257a) which is an opening that radially penetrates the central inner wall (257) and allows lead wires (268) to pass through.

[0086] [Item 2] The stator (20) according to claim 1, wherein the insulator (22) on the side closest to the circuit board (48) includes a pair of guide portions (240) extending axially from the base portion (221) and arranged on either side of the wiring passage portion (257a), and the guide portions (240) guide the crossover wires of the windings (24) wound around the tooth portions (212) to the outer periphery of the central inner peripheral wall (257).

[0087] [Item 3] The stator according to claim 2, wherein the lead wire (268) passes through an extension tip of the guide portion (240), and the guide portion (240) extends to a length such that the sum of the extension length of the guide portion (240) and the diameter of the lead wire (268) is shorter than the extension length of the central inner circumferential wall (257).

[0088] [Item 4] The stator (20) according to claim 2, wherein the guide portion (240) is provided with a base portion (241) located on the opposite side of the base portion (221) across the crossover wire, and which suppresses contact between the lead wire (268) and the crossover wire.

[0089] [Item 5] The stator (20) according to claim 1, wherein the insulator (22) on the side closest to the circuit board (48) is provided with an outer circumferential guide wall (242) that is located on the opposite side of the central inner circumferential wall (257) from the wiring passage portion (257a) and that guides the crossover wires on the outer circumferential side of the central inner circumferential wall (257).

[0090] [Item 6] A motor (10) including the stator (20) according to any one of items 1 to 5.

[0091] 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.

[0092] In the description of the embodiment, an example was shown in which a convex portion is provided on the magnet 43 to prevent freewheeling, and a concave portion that engages with the convex portion is provided on the housing 41, but this is not limiting. A convex portion may be provided on the housing 41, and a concave portion that engages with the convex portion may be provided on the magnet 43. For example, the magnet 43 may have an engaging magnet concave portion that is recessed radially inward at the end of the magnet outer circumferential surface 460 opposite to the first direction, and the housing 41 may have an engaging housing convex portion on the housing cylindrical portion 412 that engages with the engaging magnet concave portion.

[0093] The configuration of the winding 24 described in Figures 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.

[0094] 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 circumferential wall 227 First outer circumferential wall 231 Second base portion 232 Second wall portion 233 Second tooth portion protrusion portion 234 Second cylindrical portion protrusion portion 235 Second curved surface portion protrusion portion 236 Second inner circumferential wall 237 Second outer circumferential wall 238 Protrusion portion 240 Guide portion 241 Base portion 242 Outer circumferential guide wall 251, 252, 254, 255 Hook 257 Central inner circumferential 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 circumferential surface 433 Upper end surface 434 Lower end surface 435 Engagement magnet convex portion 436 Concave portion 437 Positioning concave portion 460 Magnet outer surface 461 First magnet outer surface 462 Second magnet outer surface 463 Third magnet outer surface 471 Press-fit jig body 472 Guide pin 473 Flange mounting portion 474 Jig concave portion 476 Jig

Claims

1. A stator that receives drive current from a circuit board, comprising: a stator core having a cylindrical portion and a plurality of teeth that protrude radially outward from the outer circumferential surface of the cylindrical portion; a pair of insulators that sandwich the stator core from both sides in the axial direction of the cylindrical portion; windings that are wound around the teeth via the insulators; and lead wires that electrically connect the circuit board and the windings, wherein the insulator on the side closest to the circuit board comprises: a base portion formed by a surface perpendicular to the axial direction; a substantially cylindrical central inner circumferential wall that extends axially from the base; and a wiring passage portion that is an opening that radially penetrates the central inner circumferential wall and allows the lead wires to pass through.

2. A stator as described in claim 1, wherein the insulator on the side closest to the circuit board is provided with a pair of guide portions extending from the base portion in the axial direction and arranged on either side of the wiring passage portion, and the guide portions guide the crossover wires of the windings wound around the tooth portions to the outer periphery of the central inner peripheral wall.

3. A stator as described in claim 2, wherein the lead wire passes through the tip of the extension of the guide portion, and the guide portion extends to a length such that the sum of the extension length of the guide portion and the diameter of the lead wire is shorter than the extension length of the central inner wall.

4. A stator according to claim 2, wherein the guide portion is provided with a base portion that is located on the opposite side of the base portion across the crossover wire and that prevents contact between the lead wire and the crossover wire.

5. A stator as described in claim 1, wherein the insulator on the side closest to the circuit board is provided with an outer circumferential guide wall located on the opposite side of the central inner circumferential wall from the wiring passage portion and guiding the crossover wires on the outer circumferential side of the central inner circumferential wall.

6. A motor equipped with a stator according to any one of claims 1 to 5.

Images