JP2019186981A - Brushless DC motor - Google Patents

Abstract

To provide a brushless DC motor that can increase output at a low cost with a reduced investment in new facilities and metal molds.SOLUTION: A brushless DC motor comprises: a shaft; a first stator fixed to the shaft; a second stator; a first rotor yoke; a second rotor yoke; and a connection part. The first stator and the second stator are the same component, and the first rotor yoke and the second rotor yoke are the same component. A bottom face of the first stator and a top face of the second stator are arranged adjacent to each other, and a reference point in the circumferential direction of the first stator and a reference point in the circumferential direction of the second stator are matched with each other on the axial direction of the rotation shaft.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a brushless DC motor for driving a fan used for a ceiling fan, a ventilation fan, or the like.

  In recent years, ceiling fans have been required to realize a more comfortable environment by blowing air and stirring (circulation) of indoor air. In places with high ceilings such as large living spaces and commercial / public facilities, it is necessary to send a large amount of air, that is, a strong wind over a wide area, and a large ceiling fan with a large blade diameter is required.

  Conventionally, the ceiling fan which mounts this kind of brushless DC motor has a configuration disclosed in Patent Document 1.

  Hereinafter, a ceiling fan equipped with the brushless DC motor will be described with reference to FIG.

  As shown in FIG. 13, the drive coil 102 is wound around the stator core 101, and the shaft 103 is fixed to the center portion of the stator core. The inner ring of the bearing 104a is fixed to the shaft, and the rotor yoke 105 is fixed to the outer ring of the bearing. A plurality of magnets 106 are attached to the inner peripheral surface of the rotor yoke at predetermined intervals, and a position detection element 107 that detects the magnetic flux of the magnets is fixed to the stator core.

  On the opposite side of the bearing 104a, the inner ring of the bearing 104b is fixed to the shaft, and the rotor cover 108 is fixed to the outer ring of the bearing. Then, the rotor yoke and the rotor cover are fixed so that the stator core is wrapped by the rotor yoke and the rotor cover, and the brushless DC motor 109 is configured.

Japanese Patent Laying-Open No. 2006-63678

  However, such a conventional brushless DC motor has the following problems.

  In order to realize a ceiling fan with a large blade diameter and a large air volume, it is necessary to increase the size of the stator core and magnet, which are components of the motor. That is, it can be realized by increasing the outer diameter of the stator core, increasing the thickness in the stacking direction, or lengthening the magnet in the axial direction. However, in order to newly design each component of the motor, new equipment and molds are required, which increases development investment.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a brushless DC motor that can suppress the investment of new facilities and molds, is low-cost, has a large driving torque, and can achieve high output. And

  In order to achieve this object, the brushless DC motor of the present invention has a cylindrical shape having a shaft constituting a rotating shaft, a top surface and a bottom surface, and the center of a circle in the cylindrical shape is fixed to the shaft. A second stator having a cylindrical shape with a top surface and a bottom surface, the second stator having the center of a circle in the cylindrical shape fixed to the shaft, and perpendicular to the rotation axis. A first rotor yoke having a first flange portion formed on the surface and rotatably attached to a side surface of the first stator; and a second flange portion configured on a surface orthogonal to the rotation axis. And a second rotor yoke rotatably attached to a side surface of the second stator, and a connecting portion for connecting the first rotor yoke and the second rotor yoke in the axial direction. The first stator and the second stator are the same component, and the first rotor yoke and the second rotor yoke are the same component, and the bottom surface of the first stator and the top surface of the second stator are adjacent to each other. The circumferential base point of the first stator and the circumferential base point of the second stator are arranged so as to coincide with each other in the axial direction of the rotating shaft, thereby achieving the intended purpose. is there.

  According to the present invention, it is possible to provide a brushless DC motor capable of increasing output at low cost.

The side view of the ceiling fan carrying the brushless DC motor of Embodiment 1 of this invention. The assembly perspective view showing the whole brushless DC motor composition. The assembly drawing which shows the rotor structure of a brushless DC motor. Sectional drawing which shows the whole structure of a brushless DC motor. The elements on larger scale which show the fixed state of the holding ring of a brushless DC motor. Sectional drawing which shows the direction of magnetization of the magnet adjacent between the 1st rotor and 2nd rotor of a brushless DC motor. The perspective view which shows the state of the assembly | attachment of the rotor of a brushless DC motor, and a connection part. The block diagram which shows the structure of the ceiling fan carrying a brushless DC motor. AA sectional drawing which shows the wiring structure of the motor lead wire of a brushless DC motor. The top view which shows the state of the wiring of a motor lead wire. Sectional drawing which shows the whole structure of the brushless DC motor which concerns on Embodiment 2 of this invention. The block diagram which shows the structure of the ceiling fan carrying a brushless DC motor. The assembly drawing which shows the structure of the conventional brushless DC motor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention. In addition, throughout the drawings, the same portions are denoted by the same reference numerals, and the second and subsequent descriptions are omitted.

(Embodiment 1)
FIG. 1 is a side view of a ceiling fan equipped with a brushless DC motor according to an embodiment of the present invention.

  This ceiling fan 1 is a fan attached to the ceiling, is also called a ceiling fan, and uses a brushless DC motor 2A as a drive source. The support column 4 is fixed vertically downward on the ceiling. The support column 4 is connected to a shaft 6 that constitutes a rotating shaft. The motor drive device 7 is connected to the upper side of the support column 4 and the brushless DC motor is provided with the blade 3 on the lower side. 2A is attached. The brushless DC motor 2 </ b> A is covered with a main body cover 5.

  FIG. 2 is an assembled perspective view showing the overall configuration of the brushless DC motor 2A.

  The brushless DC motor 2A is an outer rotor type brushless DC motor. The brushless DC motor 2A includes a shaft 6, a first stator 11a, a second stator 11b, a first rotor 12a, a second rotor 12b, and a connecting portion 13. Hereinafter, the term “stator” refers to the first stator 11 a and the second stator 11 b. Moreover, when it describes with a rotor, the 1st rotor 12a and the 2nd rotor 12b are pointed out.

  The shaft 6 constitutes a rotating shaft of the brushless DC motor 2A.

  The first stator 11 a has a cylindrical shape having a top surface and a bottom surface, and the center of a circle in the cylindrical shape is fixed to the shaft 6.

  The second stator 11b has a cylindrical shape of the same size as the first stator 11a and has a top surface and a bottom surface, and the center of a circle in the cylindrical shape is fixed to the shaft 6.

  The first stator 11a and the second stator 11b are fixed to the shaft 6 with the bottom surface and the top surface facing each other and adjacent to each other. The definition of the bottom surface and the top surface will be described later.

  The first rotor 12a has a hollow hollow cylindrical shape, and an opening is provided on the bottom side. The first rotor 12a is attached to the shaft 6 with the side surface of the inner circumference of the first rotor 12a facing the side surface on the outer peripheral side of the first stator 11a. The 1st rotor 12a is provided with the flange part toward the outer peripheral side from the outer peripheral part of the bottom face further.

  The second rotor 12b has a hollow hollow cylindrical shape, and has an opening on the bottom side. The second rotor 12b is attached to the outer peripheral side surface of the second stator 11b so as to face the inner peripheral circular side surface of the second rotor 12b. The 2nd rotor 12b is provided with the flange part toward the outer peripheral side further from the outer periphery part of the bottom face.

  The first rotor 12a and the second rotor 12b are rotatable with respect to the shaft 6 via a bearing 14a provided on the top surface of the first rotor 12a and a bearing 14b provided on the top surface of the second rotor 12b. Is attached.

  As for the connection part 13, the flange part of the 1st rotor 12a and the flange part of the 2nd rotor 12b are each connected to the axial direction of a rotating shaft.

  Here, the two stators, that is, the first stator 11a and the second stator 11b are the same component. Here, the same component means that one component can be used as the first stator 11a and can also be used as the second stator 11b.

  The two rotors, that is, the first rotor 12a and the second rotor 12b are the same component. Here, the same part means that one part can be used as the first rotor 12a and can also be used as the second rotor 12b.

  The first stator 11a includes a first stator core 15a, a first insulator 16a, a first drive coil 17a, and a first wiring board 18a.

  The first stator core 15a has a cylindrical shape and is formed by laminating a plurality of electromagnetic steel plates in the axial direction. The first stator core 15a has a center hole for press-fitting and holding the shaft 6 at the center of a circle in a cylindrical shape, and 3n salient poles 19 are formed radially from the center. Note that n is an integer of 1 or more.

  The salient pole 19 is insulated by a first insulator 16a, and a first drive coil 17a is wound around the side surface of the salient pole 19 via the first insulator 16a.

  The first insulator 16a is an insulating material of a resin molded product, and insulates between the salient pole 19 and the first drive coil 17a by covering the side surface of the salient pole 19 from above and below in the axial direction.

  The first drive coil 17a is a star connection coil composed of three windings, that is, three-phase windings, provided for each of the three phases of the U phase, the V phase, and the W phase. The first drive coil 17 a is wound around the outer periphery of the first insulator 16 a that covers the outer periphery of the salient pole 19. Details of the connection of the drive coil will be described later.

  The first wiring board 18a is held by the first insulator 16a, and the lead wires of the first drive coil 17a are connected to each other. The first wiring board 18a generates a magnetic field by energizing the first drive coil 17a.

  In the present embodiment, for the first stator 11a, the surface on which the first wiring board 18a is fixed is defined as the top surface, and the surface facing the top surface is defined as the bottom surface. In other words, the first wiring board 18a is fixed to the top surface side of the first stator 11a, which is the surface opposite to the surface (bottom surface) adjacent to the second stator 11b.

  The second stator 11b includes a second stator core 15b, a second insulator 16b, a second drive coil 17b, and a second wiring board 18b. Note that the second stator 11b is the same component as the first stator 11a and is composed of the same components, so that the description thereof is omitted. However, in the present embodiment, the second wiring board 18b is disposed adjacent to the bottom surface of the first stator core 15a. That is, in the installation state of the ceiling fan 1, the first wiring board 18a, the first stator core 15a, the second wiring board 18b, and the second stator core 15b are arranged in this order from the top vertically.

  The difference in configuration between the first stator 11a and the second stator 11b is that only the first stator 11a is provided with the following two means.

  The first is that the first wiring board 18a of the first stator 11a is provided with one temperature detection unit 30 that detects the ambient temperature in the vicinity of the first drive coil 17a. That is, the temperature detection unit 30 is not provided in the second wiring board 18b. Here, the ambient temperature specifically refers to the temperature of both the first stator 11a and the second stator 11b.

  The second point is that a set of position detectors 31 for detecting the rotational position of the first rotor 12a are provided on the outer periphery of the first wiring board 18a of the first stator 11a. That is, the position detector 31 is not provided in the second stator 11b. Here, the term “one set” means that the first stator 11a is provided with a plurality of elements constituting the position detector 31, and does not indicate that the second stator 11b is provided. The position detector 31 detects the rotational position of the first rotor 12a, and as a result, also detects the rotational position of the second rotor 12b that rotates at the same rotational speed.

  The above-mentioned two means do not need to be provided for each of the stator and the rotor because the stator and the rotor are provided in two stages vertically and move in the same manner. Thereby, while achieving the intended purpose of rotating the brushless DC motor 2A, the number of parts can be reduced, so that the material cost can be reduced.

  The first wiring board 18a and the second wiring board 18b are connected by a motor lead wire 29, which will be described in detail later.

  FIG. 3 is an assembly diagram showing a rotor configuration of the brushless DC motor 2A.

  The first rotor 12a includes a first rotor yoke 20a, a first magnet 21a, a first holding ring A22a, and a first holding ring B22b.

  The 1st rotor yoke 20a has the 1st flange part 23a in the bottom face orthogonal to a rotating shaft. On the inner peripheral surface of the first rotor yoke 20a, a plurality (ten in this embodiment) of first magnets 21a are arranged at equal intervals in the circumferential direction.

  The first magnets 21a are alternately arranged so that different poles are located on the side surfaces on the inner peripheral side of adjacent magnets.

  The first holding ring A22a and the first holding ring B22b are made of the same resin molded product, and fix the first magnet 21a from both sides in the rotation axis direction. The first holding ring A22a and the first holding ring B22b have an annular base 24 that contacts the first magnet 21a from the direction of the rotation axis, and further, the first holding ring A22a and the first holding ring B22b in the direction of the rotation axis so as to partially cover the magnet. It has a plurality of projections 25 extending in the direction of one magnet 21a. Further, a thread rib 26 is provided on the opposite surface of the base 24 from the surface on which the protrusion 25 is provided.

  The yarn rib 26 is a rib extending in the direction of the rotation axis and in the opposite direction to the first magnet 21a on the opposite surface. The thread ribs 26 are thread-like protrusions having a degree of extension smaller than that of the protrusions 25, and a plurality of thread ribs 26 are provided radially with respect to the ring. One or a plurality (two in this embodiment) of the thread ribs 26 are provided between the adjacent protrusions 25. With this configuration, the yarn rib 26 transmits the axial force of the first rotor yoke 20a to the first magnet 21a, thereby urging two sides perpendicular to the axis of the first magnet 21a from both axial directions. .

  The second rotor 12b includes a second rotor yoke 20b, a second magnet 21b, a second holding ring A32a, and a second holding ring B32b. Since the second rotor 12b is the same component as the first rotor 12a and is composed of the same components, the description thereof is omitted.

  Next, details of the brushless DC motor 2A of the present application will be described with reference to FIGS.

  FIG. 4 is a cross-sectional view showing the overall configuration of the brushless DC motor 2A.

  A first stator 11 a and a second stator 11 b are press-fitted and fixed to the shaft 6. The fixing direction is such that the bottom surface of the first stator 11a and the top surface of the second stator 11b are adjacent to each other, the circumferential base point of the first stator 11a, the circumferential base point of the second stator 11b, and the axial direction of the rotating shaft. They are arranged in a consistent manner.

  The base point is a notation indicating the positions in the circumferential direction (rotational direction) of the first stator 11a and the second stator 11b, which are two identical parts. By matching the base points, the circumferential positions of the first stator 11a and the second stator 11b can be matched. In the present embodiment, by matching the base points, the magnetization directions of the adjacent magnets can be matched between the first stator 11a and the second stator 11b.

  The connecting portion 13 includes a base portion 27 and a locking portion 28.

  The base 27 is formed by casting aluminum into a hollow disk shape. The central opening of the base 27 has an inner diameter larger than the outer diameter of the first stator 11a and the second stator 11b. In FIG. 4, the base portion 27 has a disk-shaped upper surface that comes into contact with the first flange portion 23 a provided on the bottom surface side of the first rotor 12 a. In addition, the base 27 is in contact with a second flange portion 23b provided on the bottom surface side of the second rotor 12b at the other surface, which is the lower surface of the disk shape. That is, the base portion 27 contacts the first rotor 12a and the second rotor 12b from both sides in the axial direction.

  The locking part 28 is a part for connecting the blade 3 of the ceiling fan 1 to the brushless DC motor 2 </ b> A, and a plurality of locking parts 28 are provided around the base part 27 at equal intervals.

  The first rotor 12a is rotatably attached with the side surface on the inner peripheral side facing the side surface of the first stator 11a. The second rotor 12b is rotatably mounted with the side surface on the inner peripheral side facing the side surface of the second stator 11b. The connection part 13 is arrange | positioned so that it may connect with the 1st flange part 23a and the 2nd flange part 23b in the axial direction. That is, the first rotor 12a and the second rotor 12b store the stator in the internal space by bringing the bottom surfaces close to each other.

  In the above configuration, the inner diameter of the central opening of the base 27 is larger than the outer diameter of the first stator 11a and the second stator 11b. For this reason, after fixing the 1st stator 11a and the 2nd stator 11b to the shaft 6, the 1st rotor 12a, the connection part 13, and the 2nd rotor 12b are assembled | attached in the form which wraps a stator component. That is, since the connecting portion 13 can be easily arranged on the intermediate surface in the axial direction between the first stator 11a and the second stator 11b, the assembly workability is improved.

  Further, the blade 3 is fixed to the connecting portion 13, and the first rotor 12 a and the second rotor are above and below the connecting portion 13. In other words, since the blades are present on the intermediate surface in the axial direction, which is the center of gravity of the brushless DC motor, it is possible to reduce the vibration and noise of the product due to the rotational vibration of the blades, and to achieve high-precision balance even at high speed rotation. , Quietness can be improved.

  The motor lead wire 29 connects the first wiring board 18a and the second wiring board 18b. The motor lead wire 29 is connected to each of the three phases (U phase, V phase, W layer) in the first drive coil 17a of the first stator 11a via the first wiring board 18a. Further, the motor lead wire 29 is connected to each of the three phases (U phase, V phase, W layer) in the second drive coil 17b of the second stator 11b via the second wiring board 18b. In this connection, the three phases in the first drive coil 17a and the three phases in the second drive coil 17b are connected in parallel with each other in phase.

  In the above configuration, when the first drive coil 17a and the second drive coil 17b are energized, the first stator and the second stator have the same rotation direction and can generate a synchronized rotating magnetic field.

  Details of the connection of the drive coil will be described later.

  FIG. 5 is a partially enlarged view showing a fixed state of the holding ring of the brushless DC motor 2A.

  As shown in FIG. 5A, the first magnet 21a and the second magnet 21b are held by the first holding ring A22a, the first holding ring B22b, the second holding ring A32a, and the second holding ring B32b.

  FIG. 5B is an enlarged view of parts showing further details. Although the details of the retaining ring have been described with reference to FIG. 3, the thread rib 26 provided on the retaining ring base 27 causes the first magnet to press in the axial direction from the inner wall of the rotor yoke and the end surface of the connecting portion 13. 21a and the second magnet 21b.

  With this configuration, the backlash of the magnet and the holding ring during motor rotation is prevented, and quietness is improved.

  FIG. 6 is a cross-sectional view showing the magnetization direction of adjacent magnets between the first rotor and the second rotor of the brushless DC motor 2A.

  FIG. 6A shows a case where the magnetization directions of adjacent magnets have the same polarity. In this case, the rotating magnetic field generated from the first stator 11a and the second stator 11b and the torque obtained from the first rotor 12a and the second rotor 12b are synchronized, so that continuous and smooth rotation can be obtained. On the other hand, FIG. 6B shows a case where the magnetization directions of adjacent magnets are not the same polarity, that is, different polarities. In this case, rotation unevenness occurs due to the difference in torque depending on the rotation position, and continuous and smooth rotation cannot be obtained, and the motor output also decreases. Therefore, assembly as shown in FIG. 6A is necessary.

  In the present embodiment, the first flange portion 23a and the second flange portion 23b are connected in the axial direction with the same magnetization direction of the adjacent magnets between the first rotor 12a and the second rotor 12b.

  As a result, the field magnetic flux generated in each of the first rotor and the second rotor is the same in the plane perpendicular to the axial direction, so that the driving torque is large and a high output is obtained.

  FIG. 7 is a perspective view showing an assembled state of the rotor and the connecting portion of the brushless DC motor 2A.

  The first flange portion 23a and the second flange portion 23b are provided with a flange portion side mark 41 such as a notch and a flange portion side mark 42 on the flange portion side so that the directions of magnetization can be distinguished from each other. On the other hand, the connecting portion 13 includes concave portions corresponding to the flange portion side mark 41 and the flange portion side mark 42, that is, the connecting portion side mark 43 and the connecting portion side mark 44, on both surfaces of the base portion 27.

  The connecting portion side mark 43 provided on one surface of the connecting portion 13 and the flange portion side mark 41 in the first flange portion 23a are arranged to coincide with each other. Further, the connecting portion side mark 44 provided on the other surface of the connecting portion 13 and the flange portion side mark 42 of the second flange portion 23b are arranged to coincide with each other.

  As a result, in the present embodiment, since the same parts are used, they are the same in appearance, and in the rotor yoke in which the polarity of the magnet cannot be visually determined, the first rotor yoke 20a and the second rotor yoke 20b are adjacent to each other. The magnetization direction of the magnet can be the same polarity.

  When the connecting portion 13 is cast and formed of aluminum in a hollow disk shape, the joining surface of the connecting portion 13 with the flange portion may be machined in order to obtain a perpendicularity to the rotation axis. As a result, the rotational shake of the blades can be reduced and the quality of the brushless DC motor 2A can be kept high. In that case, the connecting portion side mark 43 and the connecting portion side mark 44 of the recess are effective on the connecting portion side.

  In cases other than the above, the connecting portion side mark 45 and the connecting portion side mark 46 of the convex portion are effective on the connecting portion side. As a result, a configuration that cannot be assembled unless the notch and the convex portion are arranged in alignment is possible, so that an assembly error can be prevented and the quality can be kept high.

  FIG. 8 is a block diagram showing a configuration of a ceiling fan on which the brushless DC motor 2A is mounted.

  The brushless DC motor 2A includes a motor drive circuit 51 inside the motor drive device 7 shown in FIG.

  As shown in FIG. 8, the motor drive circuit 51 is connected to the first stator 11a and the second stator 11b, and outputs a drive signal for driving the rotor.

  The stator 11 includes the salient pole 19 and the drive coil 17 as described above. The drive coil 17 is a star connection coil 52 as shown in FIG. For example, the 1st drive coil 17a is provided with U1 phase, V1 phase, and W1 phase as a star connection coil. Moreover, the 2nd drive coil 17b is provided with U2 phase, V2 phase, and W2 phase as a star connection coil.

  The star connection coil 52 is connected in parallel with each phase of the first stator 11a and each phase of the second stator 11b, and is driven and controlled by one motor drive circuit 51.

  The motor drive circuit 51 includes an upper stage and a lower stage, and includes an inverter circuit 53, a drive logic control unit 58, a duty instruction unit 59, and a motor current detection unit 60 that are bridge-connected with a plurality of switching elements.

  The AC voltage supplied from the AC power supply 54 is rectified by the rectifier diode 55, smoothed to a DC voltage by the smoothing capacitor 56, and applied to the inverter circuit 53 via the contact opening / closing unit 57.

  The drive logic control unit 58 performs PWM control on the DC voltage applied to the inverter circuit 53 at the upper or lower stage of the switching element, and drives based on the signal from the position detection unit 31 that detects the rotational position of the brushless DC motor 2A. Full-wave energization is sequentially applied to the coil in a predetermined direction and order.

  The motor current detection unit 60 detects the current flowing through the inverter circuit 53.

  The duty instruction unit 59 instructs an ON / OFF duty when the switching element is subjected to PWM control. Based on the motor current value from the motor current detection unit 60, the duty instruction unit 59 increases the duty when the motor current value is lower than the predetermined current value, and decreases the duty when the motor current value is higher than the predetermined current value. Thus, the motor current is controlled to a predetermined current.

  It is effective to arrange the temperature detection unit 30 in the vicinity of the first drive coil 17a. Since the first drive coil 17a is disposed above the second drive coil 17b and the warmed air moves upward, the maximum temperature of the first drive coil 17a and the second drive coil 17b can be detected. it can. The temperature detection unit 30 is connected to the contact opening / closing unit 57. For example, when the temperature of the first drive coil 17a exceeds a specified value during an abnormal operation, the operation of the contact opening / closing unit 57 is stopped. It is possible to maintain safety by interrupting the energization of the DC voltage to the inverter circuit 53.

  With the above configuration, the motor drive circuit can be realized with only one component, and thus the material cost can be reduced.

  9 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 9A, the first stator 11a includes a first stator core 15a having salient poles 19 formed radially from the center thereof, a first insulator 16a, and a first drive comprising three-phase windings. A coil 17a is provided.

  The motor lead wire 29 is passed through a slot 71 which is a gap between the salient poles 19 of the adjacent first stator cores 15a, and the first stator 11a and the second stator 11b, in other words, the first wiring board 18a and the second wiring board 18b. And connect. As a result, the first drive coil 17a and the second drive coil 17b are connected.

  In general, the ceiling fan shaft is often a hollow pipe. In order to connect the two-stage stators, wiring holes are respectively formed on the side surfaces of the shafts in the vicinity of the two wiring boards. A motor lead wire is passed there to connect the two stators. In this case, when the interval between the two-stage stators is narrow as in the present embodiment, it is extremely difficult to insert the motor lead wire inside the shaft and connect it to the wiring board.

  Therefore, as in the present embodiment, the connection work is facilitated by passing the slot 71, and the assembly workability is improved. In addition, since the motor lead wire 29 is held in the slot 71, disconnection due to contact with the magnet fixed to the inner peripheral surface of the rotor yoke can be prevented during rotation of the rotor, and the quality can be kept high.

  The slot 71 includes an insulating film 72 made of a polyester film or the like surrounding the motor lead wire 29. Thereby, since the motor lead wire 29 is not directly in contact with the wound first driving coil 17a, a wiring structure having excellent insulation and heat resistance can be obtained, and the quality can be kept high.

  Further, as shown in FIG. 9B, the insulating tube 73 may be covered with the motor lead wire 29 instead of the insulating film 72.

  FIG. 10 is a plan view showing a wiring state of the motor lead wire 29 in the present embodiment.

  The first wiring board 18a and the second wiring board 18b include a movement restraining piece 74 that restrains the motor lead wire 29 from moving in the outer circumferential direction of the first stator 11a.

  The movement restraining piece 74 has a concave portion 75 that allows the motor lead wire 29 to pass on the inner peripheral side, and a convex portion 76 that extends in the circumferential direction of the first stator 11 a on the outer peripheral side of the first stator 11 a in the concave portion 75. I have.

  Since the above-described slot 71 is open on the outer peripheral side, it is advantageous when the motor lead wire 29 is wired, whereby the motor lead wire 29 is fixed in the circumferential direction. However, the motor lead wire 29 is not locked in the outer peripheral direction (radial direction). On the other hand, the movement of the motor lead wire 29 passed through the concave portion 75 in the outer peripheral direction is suppressed by the slot 71 convex portion 76. Thereby, since the motor lead wire 29 can be reliably held in the slot, contact with the magnet rotating on the outside can be prevented, disconnection can be avoided, and the quality can be kept high. Moreover, it is not necessary to provide new parts.

  As described above, according to the brushless DC motor 2A in the first embodiment of the present invention, since the two stators and the two rotors are the same parts, investment in new equipment and molds can be suppressed. It is possible to achieve high output with low cost and large driving torque.

(Embodiment 2)
11 and 12 are diagrams showing a brushless DC motor 2B according to Embodiment 2 of the present invention. In this figure, the same components as those in FIGS. 1 to 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 11 is a cross-sectional view showing the overall configuration of the brushless DC motor 2B according to Embodiment 2 of the present invention. FIG. 12 is a block diagram showing a configuration of a ceiling fan on which the brushless DC motor 2B according to the embodiment of the present invention is mounted.

  As shown in FIG. 11, the first stator 11 a and the second stator 11 b are press-fitted and fixed to the shaft 6.

  The first stator 11a and the second stator 11b are fixed to the shaft 6 with the bottom surface of the first stator 11a and the bottom surface of the second stator 11b adjacent to each other. Here, the bottom surface of the first stator 11a is a surface on the side where the first wiring board 18a is not disposed in the cylindrical shape. The bottom surface of the second stator 11b is a surface on the side where the second wiring board 18b is not disposed in the cylindrical shape. In the state where the bottom surfaces are adjacent to each other as described above, the circumferential base point of the first stator 11a and the circumferential base point of the second stator 11b coincide with each other on the axial direction of the rotation shaft. By matching the base points, the magnetization directions of the adjacent magnets can be matched between the first stator 11a and the second stator 11b.

  That is, in the present embodiment, in the installation state of the ceiling fan 1, the first wiring board 18a, the first stator core 15a, the second stator core 15b, and the second wiring board 18b are arranged in this order from the top vertically. This is different from the first embodiment. However, the point that the magnetization directions of adjacent magnets are the same is the same as in the first embodiment.

  The motor lead wire 29 connects the first wiring board 18a and the second wiring board 18b in the above state. As a result, the motor lead wire 29 is connected to the three phases (U1 phase, V1 phase, W1 layer) in the first drive coil 17a of the first stator 11a via the first wiring board 18a. Further, the motor lead wire 29 is connected to each of the three phases (U2 phase, V2 phase, W2 layer) in the second drive coil 17b of the second stator 11b via the second wiring board 18b. When the motor lead wire 29 connects the first wiring board 18a and the second wiring board 18b, they are connected through the two slots 71 provided in the first stator 11a and the second stator 11b.

  Here, in the present embodiment, one phase (for example, U2 phase) corresponding to one phase (for example, U1 phase) in the first drive coil 17a and one phase of the first drive coil 17a in the second drive coil 17b. Are connected in parallel with the same phase. However, the other two phases (for example, the V1 phase and the W1 layer) in the first drive coil 17a and the two phases (for example, the V2 phase and W2) corresponding to the other two phases in the first drive coil 17a in the second drive coil 17b. Are connected in parallel with each other. That is, as an example, the U1 phase and the U2 phase, the V1 phase and the W2 layer, and the W1 layer and the V2 phase are connected in parallel.

  In the above configuration, when the first drive coil 17a and the second drive coil 17b are energized, the first stator and the second stator have the same rotation direction and can generate a synchronized rotating magnetic field.

  Thus, also by the brushless DC motor 2B in the embodiment of the present invention, the same operation and effect as in the first embodiment can be obtained.

  Since the brushless DC motor according to the present invention enables high output at low cost, it is useful as a driving motor for a ceiling fan or the like.

DESCRIPTION OF SYMBOLS 1 Ceiling fan 2,2A, 2B Brushless DC motor 3 Blade | blade 4 Support | pillar 5 Main body cover 6 Shaft 7 Motor drive device 11a 1st stator 11b 2nd stator 12a 1st rotor 12b 2nd rotor 13 Connection part 14a Bearing 14b Bearing 15a 1st Stator core 15b Second stator core 16a First insulator 16b Second insulator 17a First drive coil 17b Second drive coil 18a First wiring board 18b Second wiring board 19 Salient pole 20a First rotor yoke 20b Second rotor yoke 21a First magnet 21b First 2 magnets 22a 1st retaining ring A
22b First retaining ring B
23a 1st flange part 23b 2nd flange part 24 Base part 25 Protrusion part 26 Thread rib 27 Base part 28 Locking part 29 Motor lead wire 30 Temperature detection part 31 Position detection part 32a 2nd holding ring A
32b Second retaining ring B
41 Flange mark (notch)
42 Flange mark (notch)
43,44 Connecting part side mark (concave part)
45, 46 Connecting part side mark (convex part)
REFERENCE SIGNS LIST 51 motor drive circuit 52 star connection coil 53 inverter circuit 54 AC power supply 55 rectifier diode 56 smoothing capacitor 57 contact opening / closing section 58 drive logic control section 59 duty instruction section 60 motor current detection section 71 slot 72 insulation film 73 insulation tube 74 movement restraining piece 75 Concave part 76 Convex part

Claims (6)

A shaft constituting a rotation axis;
A first stator having a cylindrical shape with a top surface and a bottom surface, wherein the center of a circle in the cylindrical shape is fixed to the shaft;
A second stator having a cylindrical shape with a top surface and a bottom surface and being adjacent to the first stator and having the center of a circle in the cylindrical shape fixed to the shaft;
A first rotor yoke having a first flange portion configured on a surface orthogonal to the rotation axis and rotatably attached to a side surface of the first stator;
A second rotor yoke having a second flange portion configured on a surface orthogonal to the rotation axis and rotatably attached to a side surface of the second stator;
A connecting portion for connecting the first rotor yoke and the second rotor yoke in the axial direction;
The first stator and the second stator are the same part,
The first rotor yoke and the second rotor yoke are the same part,
The bottom surface of the first stator and the top surface of the second stator are adjacent to each other, and the circumferential base point of the first stator and the circumferential base point of the second stator are aligned on the axial direction of the rotating shaft. Arranged brushless DC motor. A motor drive circuit connected to the first stator and the second stator and outputting a drive signal;
The first stator and the second stator are
A core having 3n (n is an integer of 1 or more) salient poles formed radially from the center, and a star connection coil comprising three-phase windings wound around the salient poles,
The star connection coil is
Each phase of the first stator and each phase of the second stator are matched and connected in parallel,
The brushless DC motor according to claim 1, wherein the brushless DC motor is driven and controlled by one motor driving circuit. The connecting portion is
The brushless DC motor according to claim 1, wherein the brushless DC motor is connected to the first flange portion and the second flange portion. The connecting portion is
4. The device according to claim 1, wherein the first flange portion and the second flange portion are connected in the axial direction with the magnetizing direction of adjacent magnets being the same between the first rotor yoke and the second rotor yoke. 5. The brushless DC motor described. The brushless DC motor according to any one of claims 1 to 4, further comprising one temperature detection unit that detects the ambient temperature of both the first stator and the second stator. The brushless DC motor according to any one of claims 1 to 5, further comprising one position detecting means for detecting rotational positions of both the first rotor yoke and the second rotor yoke.