JP2021136753A - Brushless DC motor - Google Patents

Abstract

To provide a brushless DC motor that can reduce the thickness of a ceiling fan.SOLUTION: A brushless DC motor installed in a ceiling fan includes a stator core 22 having a plurality of radially extending teeth portions 22t and a plurality of slots 22s provided between the plurality of teeth portions 22t, a plurality of insulating sheets 23 provided in the plurality of slots 22s and having a sheet projecting portion 23e protruding from the end face of the teeth portion 22t, an annular base 202, and an insulating member 200 having an advance portion 204 extending radially from the base portion 202 along the end face of the teeth portion 22t and entering between two adjacent sheet projecting portions 23e.SELECTED DRAWING: Figure 8

Description

The present disclosure relates to a brushless DC motor provided in a ceiling fan.

Brushless DC motors with a stator are known. For example, Patent Document 1 describes a stator of an electric motor. The stator is provided on a stator core covered with a covering member made of an insulating resin, a coil wound around the stator core from above the covering member, and one end face in the axial direction of the covering member. It is equipped with a crossover wire storage section that extends in the circumferential direction in which the wire is stored. The covering member is provided with a notch for introducing the crossover wire in order to introduce the coil crossover wire from the coil into the crossover wire accommodating portion. This stator is manufactured by integrally molding a resin on the stator core.

Japanese Unexamined Patent Publication No. 2003-204645

In a ceiling fan equipped with a brushless DC motor, it is desirable that the height of the blades from the floor surface is set at a high position from the viewpoint of dispersing the air flow in a wide range. Therefore, when the ceiling height is fixed, it is advantageous that the housing of the ceiling fan is short in the vertical direction. In order to shorten the vertical length of the housing, it is necessary to reduce the thickness of the brushless DC motor built in the housing.

In order to reduce the thickness of the motor, it is conceivable to reduce the wall thickness of the resin provided on the stator core. However, in the stator described in Patent Document 1, since the iron core is integrally molded with the resin, if the resin covering the stator core is thinned, the resin cracks due to the difference in thermal expansion between the steel plate of the iron core and the resin. There is a problem that it is likely to occur, which is disadvantageous in reducing the thickness of the motor.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a brushless DC motor capable of reducing the thickness of a ceiling fan.

In order to solve the above problems, the brushless DC motor according to the present disclosure is a brushless DC motor provided in a ceiling fan, and is provided between a plurality of teeth portions extending in the radial direction and a plurality of teeth portions. A stator core having a plurality of slots, a plurality of insulating sheets provided in the plurality of slots and having a sheet protrusion protruding from the end face of the tooth portion, an annular base, and along the end face of the tooth portion from the base. It includes an insulating member that extends radially and has an advance portion that enters between two adjacent sheet protrusions.

It should be noted that the expression of the present disclosure converted between methods, devices, systems, recording media, computer programs, etc. is also effective as an aspect of the present disclosure.

According to the present disclosure, it is possible to provide a brushless DC motor capable of reducing the thickness of a ceiling fan.

FIG. 1 is a perspective view showing a ceiling fan provided with a motor according to an embodiment. FIG. 2 is a cross-sectional view showing the peripheral structure of the motor of FIG. FIG. 3 is an exploded perspective view of the motor of FIG. FIG. 4 is a side view showing the stator of the motor of FIG. FIG. 5 is a bottom view showing the circuit board of the motor of FIG. FIG. 6 is a block diagram showing the configuration of the circuit board of the motor of FIG. FIG. 7 is a perspective view showing the stator assembly of the motor of FIG. FIG. 8 is a perspective view illustrating a first example of the insulating member of the motor of FIG. FIG. 9 is a perspective view illustrating a second example of the insulating member of the motor of FIG.

Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the accompanying drawings. In the examples and modifications, the same or equivalent components and members are designated by the same reference numerals, and redundant description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are shown enlarged or reduced as appropriate for easy understanding. In addition, some of the members that are not important for explaining the embodiment in each drawing are omitted and displayed.

In addition, terms including ordinal numbers such as 1st and 2nd are used to describe various components, but this term is used only for the purpose of distinguishing one component from other components, and this term is used. The components are not limited by.

The motor 10 according to the embodiment of the present disclosure is a brushless DC motor provided in the ceiling fan 1. First, the overall configuration of the ceiling fan 1 will be described. FIG. 1 is a perspective view showing a ceiling fan 1. The ceiling fan 1 is attached to the ceiling 4 and functions as a fan having a plurality of blades 2 that generate an air flow by rotating. The ceiling fan 1 includes a motor 10 that rotates a plurality of blades 2 and a housing 5 that extends downward from the ceiling 4 and surrounds the motor 10. The ceiling fan 1 is provided with a lighting unit 3 having a light emitting element such as an LED at the lower end thereof.

The housing 5 has a substantially conical first portion 5a whose diameter gradually decreases downward from the ceiling side, and a substantially conical second portion whose diameter gradually increases downward from the lower portion of the first portion 5a. Has 5b and. The connecting portion 5c of the first portion 5a and the second portion 5b is narrowed down more than the first portion 5a and the second portion 5b. The lower part of the second portion 5b exhibits a cylindrical shape having a constant diameter. The second portion 5b functions as an outer shell that houses the motor 10.

See FIGS. 2 to 4. FIG. 2 is a cross-sectional view showing the peripheral structure of the motor 10 of the ceiling fan 1. FIG. 3 is an exploded perspective view of the motor 10. FIG. 4 is a side view showing the stator 20. The motor 10 mainly includes a stator 20, a shaft 30, a rotor 40, a first bearing 32, a second bearing 34, a circuit board 48, a blade holder 70, and a rotation detection unit 400. Hereinafter, the direction along the central axis La of the shaft 30 is referred to as "axial direction", and the circumferential direction and radial direction of the circle centered on the central axis La are referred to as "circumferential direction" and "diameter direction", respectively. Further, hereinafter, for convenience, one side (upper side in the figure) in the axial direction is referred to as "upper" and "upper", and the other side (lower side in the figure) is referred to as "lower" and "lower". The notation in such a direction does not limit the posture in which the motor 10 is used, and the motor 10 can be used in any posture.

First, the operation of the motor 10 and the ceiling fan 1 will be described. In the ceiling fan 1, the stator 20, the shaft 30, the circuit board 48, and the rotation detection unit 400 form a stationary body, and the rotor 40, the blade holder 70, and the plurality of blades 2 form a rotating body. The circuit board 48 supplies a drive current to the stator 20 based on the detection signal of the rotation detection unit 400. The stator 20 generates a rotating magnetic field according to the driving current. The rotor 40 rotates around the central axis La according to the rotating magnetic field. The blade holder 70 rotates a plurality of blades 2 by rotating integrally with the rotor 40. The plurality of blades 2 generate a downward air flow by rotating. Hereinafter, each part will be described in detail.

The first bearing 32, the rotor 40 and the stator 20, the circuit board 48, and the second bearing 34 are arranged in this order from top to bottom and surround the shaft 30. The rotor 40 is arranged so as to face the stator 20 in the radial direction. The rotor 40 and the stator 20 have a larger diameter than the first bearing 32, and the circuit board 48 has a larger diameter than the rotor 40 and the stator 20. The shaft 30 is a pipe-shaped member having a hollow portion in the center for passing a wire for wiring. The hollow portion of the shaft 30 penetrates vertically, and a horizontal hole 30h for passing a wire is provided on the side surface of the shaft 30.

The stator 20 has a stator core 22 around which a coil 24 is wound. The coil 24 constitutes a three-phase armature coil. The shaft 30 is fixed to the central portion of the stator core 22. The rotor 40 has a magnet 42 that surrounds the stator core 22, and is fixed to the outer ring of the first bearing 32.

The stator core 22 has a plurality of (for example, 12) teeth portions 22t and a plurality of slots 22s provided between the plurality of teeth portions 22t. The side surface of each slot 22s leads to the opening 22k of the stator core 22. An insulating sheet 23 made of a resin film is inserted into each slot 22s. The insulating sheet 23 includes a slot insulator 23b that covers the inner side surface (the surface on the slot 22s side) of the teeth portion 22t, and a slot key 23c provided on the outer peripheral side of the slot 22s. The insulating sheet 23 of this example protrudes in the axial direction from the end surface of the tooth portion 22t. Insulating members 200 are provided on the upper surface and the lower surface of the stator core 22, respectively. The insulating member 200 functions as a core cover that covers a part of each tooth portion 22t. The insulating member 200 is a resin member formed by molding.

The coil 24 includes a plurality of (for example, 12) coil main body portions 24a wound around each tooth portion 22t. The plurality of coil main bodies 24a are connected in series for each phase. The terminal of the coil body 24a of each phase is connected to a motor drive circuit described later.

The rotor 40 has a rotor yoke 44. The rotor yoke 44 includes a hollow disk-shaped top plate portion 44a, a cylindrical magnet support portion 44b extending downward from the outer peripheral portion of the top plate portion 44a, and a donut extending radially outward from the lower portion of the magnet support portion 44b. It has a shaped extending portion 44c. The central portion of the top plate portion 44a is fixed to the outer ring of the first bearing 32. The magnet 42 is fixed to the inner peripheral surface of the magnet support portion 44b. The outer peripheral portion of the extending portion 44c is fixed to the blade holder 70 by the male screw S1.

The magnet 42 has a plurality of (for example, 10) magnetic poles that supply field magnetic flux to the stator core 22. The magnet 42 is divided into a plurality of segments. As shown in FIG. 4, the upper end and the lower end of the magnet 42 extend vertically by a predetermined dimension (for example, 5 mm) of the stator core 22.

As shown in FIG. 3, the rotor 40 has a magnet holder 300 that holds the magnet 42 in a predetermined position. The magnet holders 300 are arranged above and below the magnet 42 to limit the axial position of the magnet 42. The magnet holder 300 includes a first holder 310 arranged below the magnet 42 and a second holder 320 arranged above the magnet 42. The outer peripheral portion of the first holder 310 is locked to the rotor yoke 44, which limits the downward movement of the magnet 42. The second holder 320 limits the upward movement of the magnet 42. The first holder 310 and the second holder 320 are substantially ring-shaped resin members that can be elastically deformed.

As shown in FIG. 2, the first bearing 32 and the second bearing 34 are rolling bearings having a rolling element 33 such as a ball. The inner rings of the first bearing 32 and the second bearing 34 are fixed to the shaft 30 via the E washers 32c and 34c. The first bearing 32 and the second bearing 34 are arranged vertically separated from each other with the stator core 22 and the circuit board 48 interposed therebetween. The first bearing 32 is arranged above the stator core 22. The second bearing 34 is arranged below the circuit board 48 on the opposite side of the stator core 22 from the first bearing 32.

5 and 6 are also referred to. FIG. 5 is a bottom view showing the circuit board 48. FIG. 6 is a block diagram showing the configuration of the circuit board 48. The circuit board 48 includes a wiring board 50, a primary power supply circuit 51, a secondary power supply circuit 52, and a motor drive circuit 53. The primary side power supply circuit 51, the secondary side power supply circuit 52, and the motor drive circuit 53 are provided on the wiring board 50. The wiring board 50 is a printed wiring board.

The primary power supply circuit 51 rectifies the input AC voltage (for example, 220V to 240V) and supplies the first DC voltage V1 (for example, 310V to 340V). The secondary power supply circuit 52 supplies a 15V second DC voltage V2 and a 5V third DC voltage V3 by the DC-DC converters 52a and 52b based on the first DC voltage.

The motor drive circuit 53 includes a microprocessor 53a, a control unit 53b, and a switching unit 53c, and supplies a drive current to the coil 24. The first DC voltage V1 is mainly supplied to the switching unit 53c. The second DC voltage V2 is mainly supplied to the control unit 53b.
The third DC voltage V3 is mainly supplied to the microprocessor 53a. The control unit 53b generates an FG signal based on the position signals Hs acquired from the Hall elements HE1, HE2, and HE3 of the rotation detection unit 400, and outputs the FG signal to the microprocessor 53a.

The microprocessor 53a generates a rotation control signal Cs for controlling the rotation of the motor 10 based on the FG signal output from the control unit 53b, and outputs the rotation control signal Cs to the control unit 53b. The control unit 53b generates a phase switching signal Qs for energizing phase switching based on the position signal Hs acquired from the Hall element of the rotation detection unit 400. The control unit 53b generates a PWM signal Ps based on the rotation control signal Cs and the phase switching signal Qs output from the microprocessor 53a and outputs the PWM signal Ps to the switching unit 53c.

The switching unit 53c includes a switching element (not shown) constituting the three-phase bridge. The switching unit 53c controls the continuity / non-passage of the switching element based on the PWM signal Ps output from the control unit 53b, and causes a drive current to flow through the coil 24. The control unit 53b and the switching unit 53c form a three-phase inverter. The switching unit 53c of this embodiment is realized by a one-chip motor drive IC.

As shown in FIG. 5, the circuit board 48 of this embodiment communicates with the sub-wiring board 49, the lighting drive circuit 55 for driving the lighting unit 3, and a remote controller (not shown) for remotely controlling the ceiling fan 1. It further includes a communication circuit 56. The illumination drive circuit 55 is provided on the sub-wiring board 49, and the communication circuit 56 is provided on the wiring board 50. The sub wiring board 49 is a printed wiring board.

As shown in FIG. 4, the circuit board 48 has a ring shape surrounding the shaft 30 and is provided between the stator core 22 and the second bearing 34 in the axial direction. The circuit board 48 is supported by the stator core 22 by fixing the wiring board 50 to the stator core 22 via the substrate holding portion 100. The sub-wiring board 49 is fixed to the lower surface of the wiring board 50 via the board holder 60. As shown in FIG. 5, the wiring board 50 is a ring-shaped circular member having a central hole 50h, and the sub-wiring board 49 is a partial member in the ring shape.

As shown in FIG. 5, a wiring connection component 58 such as a connector for connecting wiring is mounted on the lower surface 50j of the wiring board 50 on the side opposite to the stator core 22. The wiring connection component 58 in this example is a male connector. As a result, at the time of assembling the motor 10, the female connector to which the lead wire is connected to the wiring connection component 58 can be easily attached / detached while the circuit board 48 is fixed to the stator core 22 via the substrate holding portion 100. Assembly workability and maintainability are improved. Further, since the wiring board 50 can be brought close to the stator core 22, it is advantageous for thinning.

As shown in FIG. 4, the electronic component 51p constituting the primary power supply circuit 51 is mounted on the lower surface 50j of the wiring board 50 opposite to the stator core 22. As a result, the heat generated in the electronic component 51p is blocked by the wiring board 50, so that heat conduction to the stator 20 and the rotor 40 is reduced, the temperature rise of the coil 24 is suppressed, and quality deterioration can be prevented.

As shown in FIG. 3, a heat radiating section 46 that dissipates heat from the motor drive circuit 53 is provided between the board holding section 100 and the wiring board 50. The heat radiating unit 46 promotes heat radiating from the motor drive IC (switching unit 53c) of the motor drive circuit 53 and suppresses the temperature rise.

As shown in FIG. 4, the rotation detection unit 400 includes Hall elements HE1, HE2, HE3 for detecting the magnetic flux of the magnet 42, and an HE holder 410. The Hall elements HE1, HE2, and HE3 are arranged at positions deviated by 120 degrees in the electrical angle in the circumferential direction. The Hall element HE2 is arranged at a predetermined opening 22k (hereinafter referred to as an opening 22k (H)) in the circumferential direction. The input / output terminals of the Hall elements HE1, HE2, and HE3 are connected to the circuit board 48. The output signals of the Hall elements HE1, HE2, and HE3 are input to the control unit 53b. The HE holder 410 is a member that supports the Hall elements HE1, HE2, and HE3, is held by the substrate holding portion 100, and is sandwiched and fixed between the wiring board 50 and the stator core 22. The HE holder 410 has a convex portion 420 that projects upward and engages the opening 22k (H).

As shown in FIG. 2, the blade holder 70 rotates integrally with the rotor 40, and transmits the rotation of the rotor 40 to a plurality of (for example, five) blades 2. The blade holder 70 is a hollow circular member, and extends inward in the radial direction from the holder cylindrical portion 70a, the trumpet-shaped portion 70b extending downward from the lower portion of the holder cylindrical portion 70a, and the lower portion of the holder cylindrical portion 70a. It has a hollow disk-shaped holder disk portion 70c extending and a holder flange portion 70d extending radially outward from the lower portion of the trumpet-shaped portion 70b.

As shown in FIG. 2, the upper portion of the holder cylindrical portion 70a is fixed to the extending portion 44c of the rotor yoke 44. The holder cylindrical portion 70a surrounds the circuit board 48 with a gap. The outer ring of the second bearing 34 is fixed to the central portion of the holder disk portion 70c. A plurality of blades 2 are fixed to the holder flange portion 70d. The plurality of blades 2 are arranged at predetermined intervals in the circumferential direction, and extend outward in the radial direction from the holder flange portion 70d. The lower portion of the trumpet-shaped portion 70b surrounds the upper portion of the illumination portion 3 with a gap. The upper portion of the illumination unit 3 is fixed to the lower portion of the shaft 30.

The insulating member 200 will be described with reference to FIGS. 7, 8 and 9. FIG. 7 is a perspective view showing the stator assembly 28. The stator assembly 28 includes a stator core 22, an insulating sheet 23, a coil 24, an insulating member 200, and a connecting pin 28p. As described above, the insulating member 200 is a resin member formed by molding. As shown in FIG. 7, the insulating sheet 23 includes a slot insulator 23b and a slot key 23c that closes the opening of the slot 22s. The slot insulator 23b is inserted into the slot 22s before winding the coil 24. The slot key 23c is inserted into the slot 22s after winding the coil 24.

As described above, the coil 24 has 12 coil main bodies 24a, a crossover wire 24j connecting the coil main bodies 24a for each phase, and a terminal portion 24e for each phase. If the crossover wire 24j comes into direct contact with the end face of the stator core 22, insulation failure may occur there. Therefore, in this example, the insulating member 200 interposed between the crossover wire 24j and the stator core 22 is provided. The insulating member 200 has a base 202 for supporting the crossover wire 24j of the coil 24. The base portion 202 has a disk-shaped disc portion 202a that covers the central portion of the end face of the stator core 22. The crossover line 24j is wired along an end surface (hereinafter, referred to as “upper surface”) of the disk portion 202a opposite to the stator core 22.

The base portion 202 has a hollow portion 202h provided in the center of the disk portion 202a and a peripheral wall portion 202b. The peripheral wall portion 202b projects axially from the upper surface of the disk portion 202a at the edge of the hollow portion 202h. The shaft penetrates the inner peripheral side of the circumferential wall portion 202b. The peripheral wall portion 202b prevents the crossover wire 24j from coming into contact with the shaft. The base 202 has a pin support 202p to support the connection pin 28p. The pin support portion 202p is a cylindrical protrusion protruding from the upper surface of the disc portion 202a, and is provided with a hole for press-fitting the connection pin 28p in the center.

The connecting pin 28p is a wire-shaped conductive member extending in the axial direction. The connection pin 28p protrudes downward (circuit board 48 side) in the axial direction from the stator core 22. The terminal portion 24e is connected to the root side of the connection pin 28p by soldering or the like. The tip end side of the connection pin 28p is connected to the motor drive circuit 53 via the wiring board 50. With this configuration, the coil 24 is electrically connected to the motor drive circuit 53. Three connecting pins 28p for each phase of UVW and one for the midpoint are fixed to the insulating member 200. In this way, the base 202 supports the connection pin 28p and functions as a terminal block for processing the terminal 24e.

FIG. 8 is a perspective view illustrating a first example of the insulating member 200. The insulating sheet 23 is provided in a plurality of slots 22s and has a sheet protruding portion 23e protruding from the end surface of the teeth portion 22t. The insulating member 200 has an annular base portion 202 and an advance portion 204 that extends radially from the base portion 202 along the end surface of the teeth portion 22t and enters between two adjacent sheet projecting portions 23e. In this case, when the coil 24 is wound around the teeth portion 22t, the advancing portion 204 enters the inside of the coil 24. The advance portion 204 is restricted in movement by being sandwiched between the teeth portion 22t and the coil 24. As a result, the insulating member 200 is held on the stator core 22. The shape of the base 202 is the same as that described in FIG. 7, without duplicate description.

In order to stably hold the insulating member 200, a pair of advancing portions 204 may be provided at positions 180 ° apart from each other in the circumferential direction. The pair of advancing portions 204 extend in opposite directions in the radial direction. The insulating member 200 may have only a pair of advancing portions 204 arranged so as to sandwich the center. In this case, by minimizing the number of advance portions 204, the mold can be simplified and the amount of resin used can be reduced.

In the example of FIG. 8, four advance portions 204 are provided at intervals of 90 ° in the circumferential direction. In this case, the insulating member 200 can be held more stably.

FIG. 9 is a perspective view illustrating a second example of the insulating member 200. This embodiment adopts the second example. The shape of the base 202 is the same as that described in FIG. 7, without duplicate description. If the extension length of the advance portion 204 is short, the insulation distance between the coil 24 and the stator core 22 may not be secured. Therefore, in the second example, as shown in FIG. 9, the advance portion 204 extends to the outer peripheral end 22e of the stator core 22. In this case, as shown in FIG. 7, since the advance portion 204 is interposed between the coil 24 and the stator core 22, the insulation distance between them can be secured.

The circumferential width of the advance portion 204 may be smaller than the circumferential width of the portion around which the coil 24 of the teeth portion 22t is wound. With the coil 24 wound, the sheet protruding portion 23e is bent to ensure insulation at the corners of the teeth portion 22t. In this case, the bent seat protrusion 23e may come into contact with the advance portion 204.

In some cases, the coil 24 may protrude toward the outer peripheral side of the stator core 22, and the insulation distance from the stator core 22 may be insufficient. It is conceivable to impregnate the coil 24 with varnish in order to prevent the coil 24 from protruding, but this is disadvantageous in terms of manufacturing cost. Therefore, in the example of FIG. 9, the insulating member 200 has an overhanging portion 206 protruding from the outer peripheral end of the advancing portion 204 to the side opposite to the stator core 22. In this case, since the outer peripheral side of the coil 24 is regulated by the overhanging portion 206, it is possible to prevent the coil 24 from protruding to the outer circumference without impregnating the coil 24 with varnish. As a result, the insulation distance between the stator core 22 and the coil 24 can be secured.

When the circumferential width of the overhanging portion 206 is larger than the circumferential width of the advancing portion 204, the protrusion of the coil 24 can be regulated in a wider range. When the circumferential width of the overhanging portion 206 is smaller than the circumferential width of the advancing portion 204, the amount of resin used for the insulating member 200 can be reduced. In the example of FIG. 9, the circumferential width of the overhanging portion 206 is the same as the circumferential width of the advancing portion 204. If the protruding height of the overhanging portion 206 is too low, the effect of restricting the protruding of the coil 24 becomes insufficient. If the protruding height of the overhanging portion 206 is too high, it becomes an obstacle when winding the coil 24. Therefore, the protruding height of the overhanging portion 206 is set to be substantially equal to the height of the coil 24 from the stator core 22.

From the viewpoint of ensuring insulation, it is desirable to provide insulating members on both sides of the stator core 22. From the viewpoint of workability, it is desirable that the terminal blocks for processing the terminal portion 24e are collectively arranged on the upper surface side. From these, it is conceivable to provide an insulating member 200 having a terminal block (base 202) on the upper surface side of the stator core 22, and to provide an insulating member having no terminal block on the other lower surface side. However, in this case, a mold for molding is required for each insulating member, which is disadvantageous in terms of manufacturing cost.

Therefore, in the example of FIG. 9, insulating members 200 having the same shape are provided on both sides of the stator core 22 in the axial direction. That is, an insulating member 200 having a terminal block (base 202) is also provided on the lower surface side where the terminal portion 24e is not processed. In this case, since the insulating members 200 having the same shape are used on both sides of the stator core 22, the molds can be shared, and the mold cost can be reduced as compared with the case where separate molds are used. Further, by insulating both sides of the stator core 22 with the insulating member 200, the desired insulating performance can be realized without impregnating the coil 24 with varnish.

According to this embodiment, since the stator core 22 is not integrally molded with the resin, the resin is hardly cracked due to the difference in thermal expansion between the steel plate of the stator core 22 and the resin. Therefore, since the wall thickness of the insulating member 200 can be reduced, the brushless DC motor can be easily reduced in thickness. As a result, the vertical length of the ceiling fan can be shortened, the blades can be provided at a high position, and the air flow can be dispersed over a wide range. Since the downward air flow can be spread over a wide area, it is possible to reduce the unevenness of the air volume near the floor and improve the comfort. In addition, interference with humans can be avoided. Further, by making the motor 10 thinner, the connection portion 5c of the housing 5 can be made thinner, so that the air flow guided to the blades 2 becomes smooth at this portion, which is advantageous in reducing power consumption.

The outline of one aspect of the present disclosure is as follows. The brushless DC motor (10) of a certain aspect of the present disclosure is a brushless DC motor provided in the ceiling fan (1), and is composed of a plurality of teeth portions (22t) extending in the radial direction and a plurality of teeth portions (22t). A plurality of stator cores (22) having a plurality of slots (22s) provided between them, and a plurality of seat protrusions (23e) provided in the plurality of slots (22s) and protruding from the end surface of the teeth portion (22t). Insulating sheet (23), annular base (202), and extending radially from the base (202) along the end faces of the teeth (22t) and entering between two adjacent sheet protrusions (23e). It is provided with an insulating member (200) having an advance portion (204).

A pair of advancing portions (204) may be arranged at positions 180 ° apart from each other in the circumferential direction.

The advance portion (204) may extend to the outer peripheral end (22e) of the stator core (22).

The insulating member (200) may have an overhanging portion (206) protruding from the outer peripheral end of the advancing portion (204) to the side opposite to the stator core (22).

Insulating members (200) may be provided on both sides of the stator core (22) in the axial direction.

The present disclosure has been described above based on the examples. This embodiment is an example, and it will be understood by those skilled in the art that various modifications are possible for each of these components or combinations of each processing process, and that such modifications are also within the scope of the present disclosure. ..

1 ceiling fan, 4 ceiling, 5 housing, 10 motor, 20 stator, 22 stator core, 23 insulation sheet, 23e seat protrusion, 24 coil, 30 shaft, 32 first bearing, 34 second bearing, 40 rotor, 42 magnet , 48 circuit board, 50 wiring board, 51 primary side power supply circuit, 52 secondary side power supply circuit, 53 motor drive circuit, 58 wiring connection parts, 60 board holder, 100 board holder, 200 insulation member, 204 advance part, 206 Overhanging part 400 Rotation detection part.

Claims (5)

A brushless DC motor installed in a ceiling fan
A stator core having a plurality of radially extending teeth portions and a plurality of slots provided between the plurality of teeth portions.
A plurality of insulating sheets provided in the plurality of slots and having a sheet protruding portion protruding from the end surface of the teeth portion, and a plurality of insulating sheets.
A brushless DC motor including an annular base and an insulating member having an advance portion that extends radially from the base along the end face of the teeth portion and enters between two adjacent sheet protrusions. The brushless DC motor according to claim 1, wherein the advance portions are provided in pairs at positions 180 ° apart from each other in the circumferential direction. The brushless DC motor according to claim 1 or 2, wherein the advance portion extends to the outer peripheral end of the stator core. The brushless DC motor according to claim 3, wherein the insulating member has an overhanging portion that projects from the outer peripheral end of the advancing portion to the side opposite to the stator core. The brushless DC motor according to any one of claims 1 to 4, wherein the insulating member is provided on both sides of the stator core in the axial direction.

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