Motor and ceiling fan

Abstract

The present disclosure addresses the problem of preventing the gap between a stator and a rotor from narrowing. A motor (M1) comprises a stator (S1) and a first rotor (R1) that is rotatable with respect to the stator (S1). A gap (G1) along the rotational axis direction of the first rotor (R1) is provided between the stator (S1) and the first rotor (R1). The first rotor (R1) has permanent magnets (4), the different magnetic pole portions (40) of which are alternately arranged along the rotational direction. The stator (S1) has: a plurality of electromagnets (1) arranged along the rotational direction of the first rotor (R1); and an attachment plate (20) to which the plurality of electromagnets (1) are attached. The plurality of electromagnets (1) each have a stator core (10) and a coil (11) wound around the stator core (10). The attachment plate (20) is formed in a disk shape, and each stator core (10) of the plurality of electromagnets (1) is fixed to the surface thereof.

Description

Motors and ceiling fans

[0001] The present disclosure relates to a motor and a ceiling fan, and more particularly to a so-called axial gap type motor and a ceiling fan powered by such a motor.

[0002] An example of a conventional example is an axial gap type rotating electric machine (motor) described in Patent Document 1. The axial gap type rotating electric machine described in Patent Document 1 (hereinafter referred to as the conventional example) includes a stator and a pair of rotors.

[0003] The stator includes a plurality of stator cores and a plurality of coils formed by winding conductive wires around each stator core. The plurality of stator cores are arranged at equal intervals around the circumferential direction of the rotating shaft.

[0004] The pair of rotors are attached to the rotating shaft so as to sandwich the stator in the axial direction of the rotating shaft. Each rotor includes a disk-shaped back yoke and a plurality of permanent magnets arranged on the back yoke's surface facing the stator. The permanent magnets are fixed to the back yoke so as to be arranged at equal intervals around the circumferential direction of the rotating shaft.

[0005] In the conventional example, when a magnetic field is generated by an electromagnet consisting of a stator core and a coil, this magnetic field influences the magnetic field generated by the permanent magnet, which generates attractive and repulsive forces between the electromagnet and the permanent magnet, causing the rotor to rotate.

[0006] However, in conventional axial gap rotating electric machines (motors), the support members supporting the multiple stator cores can bend due to the magnetic attraction force of the permanent magnets, which can narrow the gap between the stator and rotor.

[0007] Japanese Patent Application Laid-Open No. 2017-175755

[0008] An object of the present disclosure is to provide a motor and a ceiling fan that can prevent the gap between the stator and the rotor from narrowing.

[0009] A motor according to one aspect of the present disclosure includes a stator and a rotor rotatable relative to the stator. A gap is provided between the stator and the rotor along the direction of the rotor's rotation axis. The rotor has permanent magnets with different magnetic poles arranged alternately along the direction of rotation. The stator has a plurality of electromagnets arranged along the direction of rotation of the rotor, and a mounting plate to which the plurality of electromagnets are attached. Each of the plurality of electromagnets has a stator core and a coil wound around the stator core. The mounting plate is formed in a disk shape. The stator core of each of the plurality of electromagnets is fixed to a surface of the mounting plate.

[0010] A ceiling fan according to one aspect of the present disclosure includes the motor and one or more blades that are driven to rotate by the motor.

[0011] FIG. 1 is an exploded perspective view of a motor according to an embodiment of the present disclosure. FIG. 2 is a perspective view of the motor, omitting the connecting body. FIG. 3 is a side view of the motor, omitting the connecting body. FIG. 4 is a perspective view of the motor, omitting the connecting body and second rotor. FIG. 5 is a perspective view of the motor, omitting the connecting body, second rotor, and mounting plate. FIG. 6 is a plan view of the motor, omitting the connecting body and support member. FIG. 7 is a plan view of the motor, omitting the connecting body, support member, and permanent magnet. FIG. 8 is a cross-sectional view of a main part of the motor. FIG. 9 is a graph showing the relationship between the outer diameter of the mounting plate in the motor and the allowable displacement rate. FIG. 10 is a cross-sectional view of a main part showing a modified example of the motor. FIG. 11 is a perspective view of a ceiling fan according to an embodiment of the present disclosure.

[0012] A motor and a ceiling fan according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. However, the drawings described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components do not necessarily reflect the actual dimensional ratios. Note that the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0013] (1) Overview A motor M1 according to an embodiment of the present disclosure includes a stator S1 and a rotor (first rotor R1) that is rotatable relative to the stator S1 (see FIGS. 1 to 3). A gap G1 is provided between the stator S1 and the rotor (first rotor R1) along the direction of the rotation axis of the rotor (first rotor R1) (see FIG. 8).

[0014] The rotor (first rotor R1) has permanent magnets (4) with different magnetic poles (magnetic pole portions 40) arranged alternately along the direction of rotation.

[0015] The stator S1 has a plurality of electromagnets 1 arranged along the rotation direction of the rotor (first rotor R1), and a mounting plate 20 to which the plurality of electromagnets 1 are attached.

[0016] Each of the plurality of electromagnets 1 has a stator core 10 and a coil 11 wound around the stator core 10 .

[0017] The mounting plate 20 is formed in a disk shape. The stator cores 10 of the plurality of electromagnets 1 are fixed to the surface of the mounting plate 20.

[0018] Here, the stator cores 10 of the multiple electromagnets 1 are subjected to the magnetic force of the permanent magnets 4 of the rotor (first rotor R1). As the multiple stator cores 10 are subjected to the magnetic force, the magnetic force of the permanent magnets 4 also acts on the mounting plate 20 to which the multiple stator cores 10 are fixed. However, in the motor M1 according to this embodiment, the mounting plate 20 is formed in a disk shape, and is therefore less likely to bend than when the mounting plate is formed in a polygonal shape or the like.

[0019] Therefore, the motor M1 according to this embodiment can prevent the gap G1 between the stator S1 and the rotor (first rotor R1) from becoming narrow.

[0020] Moreover, the ceiling fan CF1 according to the embodiment of the present disclosure includes a motor M1 according to the embodiment of the present disclosure and one or more blades 81 that are driven to rotate by the motor M1.

[0021] Therefore, since the ceiling fan CF1 according to the embodiment is equipped with the motor M1 according to the embodiment of the present disclosure, it is possible to prevent the gap G1 between the stator S1 and the rotor (first rotor R1) from narrowing.

[0022] (2) Details of the Motor According to the Embodiment The motor M1 according to the embodiment (hereinafter referred to as motor M1) includes a rotor block and a stator S1. The motor M1 further includes a shaft 6 that rotatably supports the rotor block (see FIGS. 1 to 3). The shaft 6 is made of a metal material and has a hollow cylindrical shape.

[0023] (2-1) Rotor Block The rotor block has a first rotor R1, a second rotor R2, and a connector W1 that connects the first rotor R1 and the second rotor R2 (see FIG. 1).

[0024] (2-1-1) First Rotor The first rotor R1 has a permanent magnet 4 and a support member 5 that supports the permanent magnet 4. The permanent magnet 4 is, for example, a ring-shaped, double-sided, multi-pole neodymium magnet. That is, the permanent magnet 4 has multiple magnetic pole portions 40 that are magnetized with opposite poles (north and south poles) in the thickness direction. These multiple magnetic pole portions 40 have the same shape and dimensions and are arranged so that the opposite poles alternate along the circumferential direction of the permanent magnet 4 (see FIG. 1). Note that, although the number of magnetic pole portions 40 in the embodiment is 18, this is not limited thereto and may be 2 to 17 or 19 or more. Furthermore, the permanent magnet 4 may be a magnet other than a neodymium magnet, such as a ferrite magnet or a samarium-cobalt magnet.

[0025] The support member 5 has a bottom wall 50, a peripheral wall 51, a flange 52, and a housing portion 53 (see FIGS. 1 to 5). The bottom wall 50, the peripheral wall 51, the flange 52, and the housing portion 53 are preferably integrally formed from a soft magnetic material such as stainless steel.

[0026] The bottom wall 50 is formed in a disk shape. The peripheral wall 51 is formed in a cylindrical shape and protrudes from the periphery of the bottom wall 50 in the thickness direction of the bottom wall 50. The flange 52 is formed in a ring shape and protrudes outward from the tip of the peripheral wall 51. The accommodation portion 53 is formed in a cylindrical shape with a bottom. The accommodation portion 53 protrudes from the center of the bottom wall 50 along the thickness direction of the bottom wall 50 in the opposite direction to the peripheral wall 51 (downward in FIG. 1 ). A circular hole 530 penetrates the bottom of the accommodation portion 53 (see FIG. 1 ). Although not shown, a bearing is accommodated in the accommodation portion 53. The support member 5 (first rotor R1) is rotatably supported on the shaft 6 via a bearing accommodated in the accommodation portion 53.

[0027] The permanent magnet 4 is fixed to the bottom wall 50 by an appropriate method such as adhesive, welding, caulking, or screwing. In other words, the permanent magnet 4 is housed in a space surrounded by the bottom wall 50 and the peripheral wall 51 (see FIG. 2).

[0028] (2-1-2) Second Rotor The second rotor R2 has a top plate 70, a side plate 71, a flange 72, and a housing portion 73. The top plate 70, the side plate 71, the flange 72, and the housing portion 73 are preferably integrally formed from a soft magnetic material such as stainless steel.

[0029] The top plate 70 is formed in a disk shape. The side plate 71 is formed in a cylindrical shape and protrudes from the periphery of the top plate 70 in the thickness direction of the top plate 70. The flange 72 is formed in a ring shape and protrudes outward from the tip of the side plate 71. The accommodation portion 73 is formed in a cylindrical shape with a bottom. The accommodation portion 73 protrudes from the center of the top plate 70 along the thickness direction of the top plate 70 in the opposite direction to the side plate 71 (upward in FIG. 1 ). A circular hole 730 penetrates the bottom of the accommodation portion 73. Although not shown, a bearing is accommodated in the accommodation portion 73. The second rotor R2 is rotatably supported on the shaft 6 via a bearing accommodated in the accommodation portion 73.

[0030] (2-1-3) Connecting Body The connecting body W1 is cylindrical and made of a soft magnetic material such as stainless steel. A flange 52 of the support member 5 of the first rotor R1 is screwed (or riveted) to a first end face (the lower end face in FIG. 1 ) of the connecting body W1. Meanwhile, a flange 72 of the second rotor R2 is screwed (or riveted) to a second end face (the upper end face in FIG. 1 ) of the connecting body W1. In other words, the first rotor R1 (support member 5) and the second rotor R2 are connected by the connecting body W1 and can rotate integrally.

[0031] (2-2) Stator The stator S1 has a plurality of electromagnets 1 arranged along the rotation direction of the rotor block, and a mounting member 2 to which the plurality of electromagnets 1 are attached. The stator S1 further has a magnetic detection unit 3 that detects the magnetism of the permanent magnets 4.

[0032] (2-2-1) Electromagnets The multiple electromagnets 1 all have the same configuration. The number of the multiple electromagnets 1 is the same as the number of the multiple magnetic pole portions 40 of the permanent magnet 4 (18 pieces). However, the number of the electromagnets 1 does not have to be the same as the number of the magnetic pole portions 40.

[0033] The electromagnet 1 includes a stator core 10 , a coil 11 , and a bobbin 12 .

[0034] The stator core 10 has a first flange 101, a second flange 102, a fixed portion 103, and a body portion (see FIG. 5 ). The first flange 101 and the second flange 102 are each formed in a rectangular flat plate shape. The body portion is formed in a prismatic shape and connects the first flange 101 and the second flange 102. The fixed portion 103 is formed in a rectangular flat plate shape. The fixed portion 103 is joined to the second flange 102 such that a portion of the fixed portion 103 overlaps a portion of the second flange 102 in the thickness direction (see FIG. 5 ). Two protrusions 105 are provided on the surface of the fixed portion 103. These two protrusions 105 are formed in a quadrangular prism shape and protrude from the surface of the fixed portion 103 so as to be aligned parallel to each other. It is preferable that the first flange 101, the second flange 102, the fixed portion 103 and the body portion are integrally formed by laminating a plurality of laminated steel plates made of soft magnetic material such as electromagnetic steel plates in one direction.

[0035] The bobbin 12 has a cylindrical winding drum portion through which the drum portion of the stator core 10 is inserted, and a pair of flange portions 121 provided on both axial ends of the winding drum portion. The pair of flange portions 121 are formed in an oval shape and protrude outward, one from each axial end of the winding drum portion. The winding drum portion and the pair of flange portions 121 are preferably formed integrally from an electrically insulating material such as synthetic resin. However, the bobbin 12 is preferably composed of two parts in consideration of ease of assembly.

[0036] The coil 11 is formed by winding a wire made of aluminum or an aluminum alloy from the winding drum of the bobbin 12 onto the drum of the stator core 10 .

[0037] (2-2-2) Mounting Member The mounting member 2 has a mounting plate 20 , a plurality of fixing members 21 , and a reinforcing member 22 .

[0038] The mounting plate 20 is formed in a disk shape from a soft magnetic material such as stainless steel. A D-shaped insertion hole 200 penetrates the center of the mounting plate 20. The shaft 6 is inserted through this insertion hole 200. The mounting plate 20 also has a plurality of first mounting holes 201, a plurality of second mounting holes 202, and a plurality of third mounting holes 203 (see FIG. 1 ). The first mounting holes 201 are each circular and are arranged at equal intervals along the circumferential direction of the mounting plate 20 at both radial ends of the mounting plate 20. The second mounting holes 202 are each rectangular and are arranged at both radial ends of the mounting plate 20, inside the first mounting holes 201, along the circumferential direction of the mounting plate 20. The third mounting holes 203 are each circular and are arranged at equal intervals along the circumferential direction of the mounting plate 20, inside the second mounting holes 202, at both radial ends of the mounting plate 20.

[0039] The plurality of fixing members 21 all have the same configuration. The number of fixing members 21 is the same as the number of electromagnets 1 (18). However, the number of fixing members 21 does not have to be the same as the number of electromagnets 1.

[0040] The fixing member 21 is formed in a wedge shape from a non-magnetic material such as synthetic resin. A recess 210 is formed in a first surface (the surface facing the mounting plate 20) of the fixing member 21. Furthermore, at both ends of the longitudinal direction of the fixing member 21, one through-hole 211 is provided, and one through-hole 212 is provided at each end of the fixing member 21, penetrating the fixing member 21 in the height direction (see FIG. 5 ).

[0041] The reinforcing member 22 has a cylindrical main body 220, a tubular portion 221, and a plurality of rectangular pillar-shaped protrusions 222 (see FIGS. 1 and 5). The main body 220, the tubular portion 221, and the plurality of protrusions 222 are preferably integrally formed from a non-magnetic material such as synthetic resin or aluminum.

[0042] A D-shaped insertion hole penetrates the center of main body 220. Tube portion 221 protrudes from the periphery of the insertion hole in the first surface (the bottom surface in FIG. 1 ) of main body 220 in the normal direction of the first surface (the downward direction in FIG. 1 ). Note that tube portion 221 is formed in a cylindrical shape such that the cross section parallel to the first surface has the same shape as the insertion hole.

[0043] Each of the plurality of protrusions 222 protrudes from the first surface of the main body 220 in the same direction as the cylindrical portion 221. The plurality of protrusions 222 are arranged at equal intervals in the circumferential direction on both radial ends of the main body 220. Furthermore, a through-hole 224 is provided at the outer end of each of the protrusions 222, penetrating the protrusion 222 in the height direction (the up-and-down direction in FIG. 1 ) (see FIG. 5 ). The number of the plurality of protrusions 222 is the same as that of the electromagnet 1 (18 pieces), but it does not have to be the same number as that of the electromagnet 1.

[0044] Here, a plurality of grooves 223 are provided in the main body portion 220. The plurality of grooves 223 are arranged at equal intervals along the circumferential direction of the main body portion 220, straddling the second surface (the upper surface in FIG. 1 ) of the main body portion 220 and the side surface of the main body portion 220. Note that the tip portions of the plurality of fixing members 21 are fitted into each of the plurality of grooves 223 (see FIG. 5 ). In other words, the number of grooves 223 is the same as the number of fixing members 21 (18).

[0045] (2-2-3) Magnetic Detection Unit The magnetic detection unit 3 has a plurality of Hall ICs 30, a support substrate 31, and a holder 32 (see FIG. 1).

[0046] Each of the multiple (three in the illustrated example) Hall ICs 30 is configured by housing a Hall element for magnetic detection and a signal processing circuit in a single package. The signal processing circuit processes the output of the Hall element and outputs a detection signal. The detection signal output from the signal processing circuit (Hall IC 30) indicates the timing when the direction of the magnetic field (magnetic flux) of the permanent magnet 4 reverses as the rotor block rotates.

[0047] The support substrate 31 has a mounting portion 313, a protrusion 314, and a base portion 315. The mounting portion 313 is formed in the shape of a flat plate curved in an arc. The three Hall ICs 30 are mounted on a first surface 311 (the lower surface in FIG. 1 ) of the mounting portion 313 and are arranged at equal intervals along the circumferential direction (see FIG. 7 ).

[0048] The protruding portion 314 is formed in a narrow rectangular shape, and the tip of the protruding portion 314 is connected to the mounting portion 313.

[0049] The base portion 315 is formed in a rectangular shape that is much wider than the protruding portion 314. The base portion 315 is connected to the rear end of the protruding portion 314. A connector is mounted on the surface (top surface in FIG. 1 ) of the base portion 315. The connector is electrically connected to each Hall IC 30 via conductors (printed wiring) formed on the mounting portion 313, the protruding portion 314, and the base portion 315. In other words, a detection signal output from each Hall IC 30 is output to an external driving device (driver circuit) via the connector.

[0050] The holder 32 has a first support portion 321 that supports the mounting portion 313, a second support portion 322 that supports the protruding portion 314, a third support portion 323 that supports the base portion 315, and an attachment portion 324. The first support portion 321, the second support portion 322, the third support portion 323, and the attachment portion 324 are integrally formed from a non-magnetic material such as synthetic resin (see FIGS. 1, 5, and 7).

[0051] The first support portion 321 is formed in the shape of an arc-shaped frame, and supports the periphery of the mounting portion 313 of the support substrate 31 (see FIG. 5).

[0052] The second support portion 322 is formed in a long box shape. The tip of the second support portion 322 is connected to the first support portion 321. The second support portion 322 accommodates and supports the protrusion 314 of the support substrate 31 (see FIG. 5).

[0053] The third support portion 323 is formed in a rectangular box shape and is connected to the rear end of the second support portion 322. The third support portion 323 accommodates and supports the base portion 315 of the support substrate 31 (see FIG. 1).

[0054] The attachment portion 324 is formed in a disk shape with a circular hole 325 at the center thereof, and is connected to the rear end of the third support portion 323 (see FIGS. 1 and 7).

[0055] (2-3) Motor Assembly Procedure The assembly procedure for the above-mentioned motor M1 will be described. However, the assembly procedure described below is only an example, and the order of some steps may be changed, or other steps may be added.

[0056] (2-3-1) Assembling the Stator The worker first assembles the stator S1. The worker attaches the multiple electromagnets 1 to the mounting plate 20 by fitting the protrusions 105 of the stator core 10 one by one into the second mounting holes 202 of the mounting plate 20.

[0057] Next, the worker places the fixing members 21 one by one between the multiple electromagnets 1 attached to the mounting plate 20. At this time, parts of the stator cores 10 of two adjacent electromagnets 1 (part of the second flange portion 102 and part of the fixing portion 103) are housed in the recesses 210 of the fixing members 21 (see FIG. 5 ). Then, the worker inserts one rivet or screw into each of the two through holes 211, 212 of the fixing member 21 that overlaps with the first mounting hole 201 of the mounting plate 20, and fixes the multiple fixing members 21 to the mounting plate 20 with these rivets or screws.

[0058] Next, the worker places the reinforcing member 22 in the space surrounded by the multiple electromagnets 1 attached to the mounting plate 20. At this time, the worker fits the tip portions of the multiple fixing members 21 one by one into the multiple grooves 223 of the reinforcing member 22 (see FIG. 5 ). The worker then inserts one rivet or screw into each of the through holes 224 of the multiple protrusions 222 and the through holes 211 of each fixing member 21 that overlaps with each through hole 224, and fixes the reinforcing member 22 to the mounting plate 20 with the rivets or screws.

[0059] Next, the worker inserts the shaft 6 into the cylindrical portion 221 of the reinforcing member 22 and the insertion hole 200 of the mounting plate 20. Then, the worker fixes the reinforcing member 22 to the shaft 6 by screwing the cylindrical portion 221 and the shaft 6 together.

[0060] Next, the worker inserts the shaft 6 into the hole 325 of the attachment portion 324 in a direction such that the first support portion 321 of the holder 32 faces the electromagnet 1. Then, the worker fixes the attachment portion 324 of the holder 32 to the tip of the tubular portion 221 of the reinforcing member 22 by an appropriate method such as adhesive. As a result, the magnetic detection unit 3 is attached to the reinforcing member 22, and the assembly work of the stator S1 is completed.

[0061] (2-3-2) Assembly of Stator and Rotor Block Next, the worker rotatably attaches the first rotor R1 to the shaft 6 via the bearing housed in the housing portion 53 of the support member 5.

[0062] Next, the worker attaches the connecting body W1 to the flange 52 of the support member 5. Then, the worker rotatably attaches the second rotor R2 to the shaft 6 via the bearing housed in the housing portion 73.

[0063] Finally, the worker fixes the connector W1 to the flange 72 of the second rotor R2 and assembles the stator S1 to the rotor block, completing the assembly of the motor M1.

[0064] (2-4) Motor Operation The 18 electromagnets 1 are divided into three groups of six electromagnets 1. The electromagnets 1 belonging to different groups are arranged in order along the circumferential direction of the mounting member 2. The coils 11 of the six electromagnets 1 belonging to the same group are electrically connected in series, and the coils 11 of each group are three-phase star-connected. In other words, the three groups of electromagnets 1 are supplied with AC voltages (AC currents) of U-phase, V-phase, and W-phase, which are shifted in phase by 120 degrees each.

[0065] Based on the detection signal from the magnetic detection unit 3, the drive device controls the inverters connected to the three sets of electromagnets 1, and rotates the rotor block (first rotor R1) by switching the polarity of the electromagnets 1 belonging to each set.

[0066] (2-5) Advantages of the Embodiment The motor M1 is a so-called double-rotor axial gap motor with a single-sided magnet, which includes a second rotor R2 that faces the first rotor R1 across the stator S1 and is connected to the first rotor R1. Double-rotor axial gap motors are generally double-sided magnet motors, in which permanent magnets are mounted on each of the two rotors. In the case of a double-sided magnet axial gap motor, the starter coils of the multiple electromagnets in the stator are subjected to magnetic forces in opposite directions from the permanent magnets of the rotors. This also reduces deflection of the mounting plate on which the electromagnets are attached.

[0067] On the other hand, in the case of a single-sided magnet motor, the magnetic force from the permanent magnet on one side acts on the multiple electromagnets in only one direction, so in a single-sided magnet motor, the mounting plate on which the multiple electromagnets are attached is more likely to bend than in a double-sided magnet motor.

[0068] In contrast, in the motor M1, multiple electromagnets 1 are attached to the surface of the mounting plate 20, which is formed in a disk shape. Therefore, the mounting plate 20 is less likely to bend than if it were formed in a polygonal shape, etc. As a result, the motor M1 can prevent the gap G1 (see FIG. 8) between the stator S1 and the first rotor R1 from narrowing by suppressing the bending of the mounting plate 20.

[0069] Here, the deflection of the mounting plate 20 decreases as the thickness t1 of the mounting plate 20 increases. However, increasing the thickness t1 of the mounting plate 20 increases the weight of the mounting plate 20, so it is desirable to make the thickness t1 of the mounting plate 20 as small (thin) as possible while suppressing the deflection of the mounting plate 20. To achieve this, it is preferable that the mounting plate 20 be formed with a thickness t1 such that the allowable displacement rate α1 of the gap G1, which is determined based on the outer diameter of the mounting plate 20 (diameter 2r1: r1 is the radius of the mounting plate 20), satisfies a predetermined condition. The allowable displacement rate α1 of the gap G1 is the rate of change of the gap G1 when the gap G1 between the electromagnet 1 and the permanent magnet 4 narrows due to deflection of the mounting plate 20.

[0070] For example, when the gap G1 is 1 mm, the allowable displacement rate α1 is preferably equal to or less than the value obtained by dividing the gap G1 by the radius of the mounting plate 20 (100 × 1 / r1 [%]) (see region F1 in FIG. 9 ). Region F1 is the region surrounded by the solid line P1 and the horizontal axis (the outer diameter 2r of the mounting plate 20) in FIG. 9 . Note that the allowable displacement rate α1 in FIG. 9 applies when the mounting plate 20 is formed from an alloy containing iron (stainless steel). If the mounting plate 20 is formed from a metal material other than stainless steel, or if the mounting plate 20 is formed by insert molding a metal plate into a synthetic resin, the value may be different.

[0071] Therefore, in the motor M1, the mounting plate 20 is formed to a thickness t1 such that the allowable displacement rate α1 of the gap G1, which is determined based on the outer diameter of the mounting plate 20, satisfies a predetermined condition, thereby further preventing the gap G1 between the stator S1 and the first rotor R1 from narrowing. Furthermore, in the motor M1, the necessary thickness t1 of the mounting plate 20 can be derived using a simple calculation formula, thereby simplifying the design work. Furthermore, in the motor M1, by using a metal for part or all of the mounting plate 20, it is easier to balance the thickness t1 of the mounting plate 20 with the strength. Furthermore, by using an iron-containing alloy for the metal constituting part or all of the mounting plate 20, it is easier to balance the thickness t1 of the mounting plate 20 with the strength.

[0072] However, the thickness t1 at which the allowable displacement rate α1 of the gap G1 satisfies the predetermined condition may be the total thickness of a plurality of (e.g., two as shown in FIG. 10 ) stacked mounting plates 20. In other words, by configuring the mounting plate 20 of the motor M1 by stacking a plurality of disk-shaped metal plates or the like, it becomes possible to reuse a metal plate used for another purpose (or another motor), for example.

[0073] Furthermore, because motor M1 has permanent magnets 4 on only one rotor (first rotor R1), manufacturing costs can be reduced compared to when permanent magnets are provided on both rotors. Furthermore, because motor M1 is a double-rotor type, it has the advantage of being able to suppress wobbling when rotating an object (such as blades 81 of ceiling fan CF1) compared to a single-rotor type.

[0074] (3) Details of the ceiling fan according to the embodiment The ceiling fan CF1 according to the embodiment (hereinafter referred to as ceiling fan CF1) comprises, as shown in FIG. 11, a main body 80 incorporating a motor M1, and multiple (four in the illustrated example) blades 81 that are rotated by the motor M1.

[0075] The main body 80 is formed into a cylindrical shape from metal or synthetic resin. The main body 80 is mechanically and electrically detachably attached to, for example, a ceiling hook body installed on a room's ceiling. The main body 80 houses the motor M1 so that the axis of the shaft 6 is perpendicular to the ceiling surface.

[0076] Each of the four blades 81 is made of synthetic resin and has the same shape and dimensions. The base of each blade 81 is fixed to, for example, the connector W1 of the motor M1. In other words, when the rotor block of the motor M1 rotates, the four blades 81 fixed to the rotor block (connector W1) also rotate.

[0077] Therefore, the ceiling fan CF1 uses the motor M1 to rotate the blades 81, and thus, like the motor M1, it is possible to suppress a decrease in the detection accuracy of the magnetic detection unit 3.

[0078] (4) Summary The motor (M1) according to the first aspect of the present disclosure includes a stator (S1) and a rotor (first rotor R1) rotatable relative to the stator (S1). A gap (G1) is provided between the stator (S1) and the rotor along the direction of the rotor's rotation axis. The rotor has permanent magnets (4) with different magnetic poles (magnetic pole portions 40) arranged alternately along the direction of rotation. The stator (S1) has a plurality of electromagnets (1) arranged along the direction of rotation of the rotor and a mounting plate (20) to which the plurality of electromagnets (1) are attached. Each of the plurality of electromagnets (1) has a stator core (10) and a coil (11) wound around the stator core (10). The mounting plate (20) is formed in a disk shape, and the stator cores (10) of the plurality of electromagnets (1) are fixed to its surface.

[0079] The motor (M1) according to the first aspect can prevent the gap (G1) between the stator (S1) and the rotor from narrowing by suppressing the deflection of the mounting plate (20).

[0080] A motor (M1) according to a second aspect of the present disclosure can be realized in combination with the first aspect. In the motor (M1) according to the second aspect, the mounting plate (20) is preferably formed to a thickness (t1) that satisfies a predetermined condition for an allowable displacement rate (α1) of a gap (G1) determined based on an outer diameter (2r1) of the mounting plate (20).

[0081] In the motor (M1) according to the second aspect, by making the mounting plate (20) even less likely to bend, it is possible to further prevent the gap (G1) between the stator (S1) and the rotor from narrowing.

[0082] A motor (M1) according to a third aspect of the present disclosure can be realized in combination with the motor (M1) according to the second aspect. In the motor (M1) according to the third aspect, it is preferable that a part or all of the mounting plate (20) is made of metal.

[0083] In the motor (M1) according to the third aspect, by making a part or all of the mounting plate (20) from metal, it becomes easier to balance the thickness (t1) and strength of the mounting plate (20).

[0084] A motor (M1) according to a fourth aspect of the present disclosure can be realized in combination with the motor (M1) according to the third aspect. In the motor (M1) according to the fourth aspect, the metal constituting part or all of the mounting plate (20) is preferably an alloy containing iron.

[0085] The motor (M1) according to the fourth aspect can more easily achieve a balance between the thickness (t1) and strength of the mounting plate (20).

[0086] A motor (M1) according to a fifth aspect of the present disclosure can be realized by combining it with any of aspects 2 to 4. In the motor (M1) according to the fifth aspect, it is preferable that the allowable displacement rate (α1) is equal to or less than a percentage of the value obtained by dividing the size of the gap (G1) by the radius (r1) of the mounting plate (20).

[0087] In the motor (M1) according to the fifth aspect, the thickness (t1) required for the mounting plate (20) can be derived from a simple calculation formula, which facilitates the design work.

[0088] A motor (M1) according to a sixth aspect of the present disclosure can be realized by combining it with any of the first to fifth aspects. The motor (M1) according to the sixth aspect preferably has a first rotor (R1) as the rotor. The motor (M1) according to the sixth aspect preferably further includes a second rotor (R2) that faces the first rotor (R1) across the stator (S1) and is connected to the first rotor (R1). The first rotor (R1) preferably includes a permanent magnet (4) with different magnetic poles (magnetic pole portions 40) arranged alternately along the direction of rotation, and a support member (5) that supports the permanent magnet (4). The second rotor (R2) preferably does not include a permanent magnet (4).

[0089] The motor (M1) according to the sixth aspect has a permanent magnet (4) on only one rotor (first rotor R1), which allows for reduced manufacturing costs compared to a motor with permanent magnets on both rotors. Furthermore, the motor (M1) according to the sixth aspect is a double-rotor motor, which has the advantage of being able to suppress wobbling when rotating an object (such as blades 81 of a ceiling fan CF1) compared to a single-rotor motor.

[0090] A ceiling fan (CF1) according to a seventh aspect of the present disclosure comprises a motor (M1) according to any one of the first to sixth aspects and one or more blades (81) that are driven to rotate by the motor (M1).

[0091] The ceiling fan (CF1) of the seventh aspect is equipped with a motor (M1) of any one of the first to sixth aspects, and therefore can prevent the gap (G1) between the stator (S1) and the rotor from narrowing.

[0092] M1 Motor CF1 Ceiling fan S1 Stator R1 First rotor (rotor) R2 Second rotor 1 Electromagnet 2 Mounting member 4 Permanent magnet 5 Support member 10 Stator core 11 Coil 20 Mounting plate 40 Magnetic pole portion 80 Main body 81 Blade G1 Gap t1 Mounting plate thickness r1 Mounting plate radius α1 Allowable displacement rate

Claims

1. A stator; a rotor rotatable relative to the stator; Equipped with A gap is provided between the stator and the rotor along the direction of the rotation axis of the rotor, The rotor is The rotor has permanent magnets with different magnetic poles arranged alternately along the direction of rotation. The stator includes: A plurality of electromagnets arranged along the rotation direction of the rotor; a mounting plate to which the plurality of electromagnets are attached; having Each of the plurality of electromagnets comprises: A stator core; A coil wound around the stator core; having The mounting plate is formed in a disk shape, and the stator cores of the plurality of electromagnets are fixed to a surface of the mounting plate. Motor.

2. The mounting plate is formed to a thickness such that an allowable displacement rate of the gap, which is determined based on an outer diameter of the mounting plate, satisfies a predetermined condition. The motor according to claim 1.

3. A part or the whole of the mounting plate is made of metal. The motor according to claim 2.

4. The metal constituting part or all of the mounting plate is an alloy containing iron. The motor according to claim 3.

5. the allowable displacement rate is equal to or less than a percentage of the size of the gap divided by the radius of the mounting plate; A motor according to any one of claims 2 to 4.

6. The rotor is a first rotor, a second rotor that faces the first rotor across the stator and is connected to the first rotor, The first rotor includes: The permanent magnet has different magnetic poles arranged alternately along the direction of rotation; A support member for supporting the permanent magnet; having the second rotor does not have a permanent magnet; A motor according to any one of claims 1 to 4.

7. A motor according to any one of claims 1 to 4; one or more blades that are driven to rotate by the motor; Equipped with Ceiling fan.