JP2014090545A - Fan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan motor capable of reducing cogging torque, and eliminating manufacturing failures.SOLUTION: A space distance b between a rotor 5 and a stator 11 is set to be larger than the cavity width a of a cavity portion 31 formed between adjacent teeth 12 and twice or less of the cavity width a. Therefore, it becomes hard to receive the influence of magnetic force generated when a magnetic pole 6 of the rotor 5 traverses the cavity portion 31, and cogging torque is decreased. After a copper wire 17 is wound around the teeth 12 to form a coil portion 18, a teeth portion 13 is installed to a yoke portion 14, thereby forming the cavity width a of the cavity portion 31. Consequently, the cavity portion 31 can be made to have optional cavity width a without the disadvantage of winding of the copper wire 17, and manufacturing is facilitated.

Description

  The present invention relates to a fan motor configured by combining a stator and a rotor or a fan.

  As this type of fan motor, for example, Patent Document 1 proposes an idea of reducing the cogging torque by devising the shape and size of the teeth constituting the stator. Conventionally, the cogging torque has been reduced by reducing the gap width of the gap formed between the teeth and increasing the spatial distance between the stator and the rotor.

  In addition, as a foreign matter intrusion prevention structure of a fan motor, a structure in which a rib is formed in a housing portion of a control board and a wall is further provided on the outer periphery thereof to constitute a labyrinth with a fan has been proposed (Patent Literature). 2). In another conventional technique, a configuration (Patent Document 3) in which another member is attached to the storage portion of the control board and a configuration (Patent Document 4) in which the rib is extended to the upper side of the cup portion of the fan are disclosed. ing.

JP 2008-86064 A Japanese Patent No. 5017965 Registered Utility Model No. 3056876 Japanese Utility Model Publication No. 62-51953

  However, conventionally, if the spatial distance between the stator and the rotor is increased, the efficiency as a fan motor deteriorates. Therefore, while the spatial distance is set to about 0.6 mm, the gap width between the teeth is about 1.5 mm. The cogging torque is increased due to the influence of the magnetic force generated when the magnetic pole of the rotor crosses the gap between the teeth.

  In the foreign matter intrusion prevention structure described above, in the rub rinse configuration with ribs and walls, the space increases and the blowing area decreases. In addition, in the configuration in which another member is attached, the cost increases due to an increase in the number of components, and in the configuration in which the ribs are elongated, the overall weight becomes heavy and more component accuracy than necessary is required.

  Accordingly, an object of the present invention is to provide a fan motor that can reduce cogging torque and eliminate manufacturing defects.

  A second object of the present invention is to provide a fan motor provided with a foreign matter intrusion prevention structure having a space-saving, lightweight and inexpensive labyrinth configuration.

  In the first aspect of the invention, since the spatial distance between the rotor and the stator is set to be larger than the gap width of the gap portion formed between the teeth and twice or less, the magnetic pole of the rotor is the gap. It becomes difficult to be affected by the magnetic force generated when crossing the section, and the cogging torque is reduced. Also, after forming the coil part by winding the wire around the teeth, the gap width of the gap is formed by attaching the teeth to the yoke, so that any gap can be formed without hindering the winding of the wire. The width can be made, and manufacturing can be easily performed.

  In the invention of claim 2, since the spatial distance between the rotor and the stator is set to be approximately the same as the gap width of the gap formed between the teeth, the cogging torque can be reliably reduced. .

  In the invention of claim 3, by using the space formed between the existing cup portion and the rotor yoke, the stator receiving portion is formed only by forming an outer peripheral wall that enters the space portion. Intrusion of foreign matter from between the fan and the fan can be reliably prevented. Therefore, there is no need for a separate member as in the prior art, and a foreign matter intrusion prevention structure having a space-saving, lightweight and inexpensive labyrinth configuration can be realized without securing a large shape for securing the space.

  In the invention of claim 4, in addition to the rib surrounding the outer periphery of the holding portion in the vicinity of the fastening portion and the fixing member for fixing the bearing, the labyrinth structure by the outer peripheral wall of the stator receiving portion, The effect of preventing foreign matter from entering the bearing can be obtained.

  In the invention of claim 5, the amount of storage that the outer peripheral wall stores in the space portion is set to be two to three times the gap between the cup portion and the outer peripheral wall, so that the space between the stator receiving portion and the fan can be reduced. While reliably preventing the intrusion of foreign matter, it is not required to have the necessary part accuracy, the part management is easy, and it is possible to prevent problems such as start-up failure due to fan vibration.

  According to the first aspect of the present invention, a fan motor that can reduce cogging torque and eliminate manufacturing defects can be provided.

  According to the invention of claim 2, it is possible to provide a fan motor in which the cogging torque is reliably reduced.

  According to the invention of claim 3, it is possible to provide a fan motor provided with a foreign matter intrusion prevention structure having a space-saving, lightweight and inexpensive labyrinth configuration.

  According to the invention of claim 4, the effect of preventing foreign matter from entering the bearing can be obtained at two locations.

  According to the invention of claim 5, it is possible to provide a fan motor that prevents adverse effects such as start-up failure due to fan vibration.

It is a longitudinal cross-sectional view of the motor in 1st Embodiment of this invention. It is a front view of a rotor same as the above. It is a cross-sectional view of an essential part. It is a cross-sectional view of a stator same as the above. It is a cross-sectional view of a teeth part same as the above. It is a cross-sectional view of a yoke part same as the above. FIG. 4 is a waveform diagram showing the relationship between the rotation angle and cogging torque at different gap widths. It is an external appearance perspective view of teeth same as the above. It is an external appearance perspective view of a yoke part same as the above. It is an external appearance perspective view of an insulation member same as the above. It is an external appearance perspective view of the state which combined the upper half and insulation of the insulating member same as the above. It is an external appearance perspective view of a teeth part same as the above. It is an external appearance perspective view of a stator same as the above. It is a fragmentary longitudinal cross-sectional view of the fan motor in 2nd Embodiment of this invention. It is an enlarged vertical sectional view of the principal part. It is a partial expansion longitudinal cross-sectional view of an outer peripheral wall and its periphery same as the above. It is a circuit diagram of the motor of the fan motor and its periphery in 3rd Embodiment of this invention. It is a transverse cross section of the important section showing a core slot shape same as the above. FIG. 19 is a cross-sectional view of a main part showing a core slot shape of an example different from FIG. It is a circuit diagram of the motor of the conventional fan motor and its periphery. It is a longitudinal cross-sectional view which shows the structure of a fan motor same as the above. It is a transverse cross section of the important section showing a core slot shape same as the above.

  Hereinafter, preferred embodiments of a fan motor according to the present invention will be described with reference to the accompanying drawings.

  FIGS. 1-13 has shown the fan motor in 1st Embodiment of this invention. The overall configuration of the fan motor will be described with reference to FIG. 1. Reference numeral 1 denotes a motor for rotating a fan (not shown). The motor 1 and the fan constitute the fan motor of this embodiment. The motor 1 forms an outer shell member by abutting the openings of the cups 2 and 3, and the inner space 4 of the cases 2 and 3 is supported by the cases 2 and 3 and can rotate. The rotor 5 is held by the rotor.

  As shown in FIG. 2, the rotor 5 is provided with a plurality of magnetic pole pieces 6. The magnetic pole piece 6 is arranged in the circumferential direction around a shaft 7 that is a rotating shaft. The shaft 7 is rotatably supported together with the plurality of magnetic pole pieces 6 by a pair of bearings 9 that are respectively mounted in a concave portion 8 formed at a substantially central portion of the cases 2 and 3. One end of the shaft 7 passes through a hole 10 formed in the recess 8 of the case 2 and protrudes outward from the internal space 4 of the cases 2 and 3, thereby enabling the above-described fan to be mounted. . Although the number of the pole pieces 6 is not particularly limited, the pole pieces 6 are arranged so that N poles and S poles are alternately arranged in the circumferential direction.

  Reference numeral 11 denotes a stator disposed in the internal space 4 so as to face the magnetic pole piece 6 so as to surround the magnetic pole piece 6. As shown in FIG. 3, the magnetic pole piece 6 and the stator 11 are set with a predetermined spatial distance b over the entire circumference. The stator 11 is formed by a tooth portion 13 in which a plurality of teeth 12 are formed and a ring-shaped yoke portion 14, and a copper wire 17 suitable as a wire is wound around each tooth 12 via an insulating member 16. Thus, the coil portion 18 is formed in the stator 11. Each of the tooth portion 13 and the yoke portion 14 is configured by laminating plate-shaped steel plates, and by arranging the yoke portion 14 on the outer side of the tooth portion 13 so as to connect the teeth 12, a magnetic field that allows magnetic flux to pass therethrough. A path is formed. Further, in order to supply current to the winding 17 of the coil unit 18 at a predetermined timing, a control unit 19 connected to the winding 17 is disposed below the internal space 4.

  3 to 5 illustrate a tooth portion 13 including x teeth 12-1, 12-2, 12-3, ... 12-x. Each of the teeth 12-1, 12-2, 12-3,... 12-x has the same shape, and the base end side fitting protrusions 21-1, 21-2, 21- connected to the yoke portion 14 are used. 21-x, and wedge portions 22-1, 22-2, 22-3,... 22-x on the front end side facing the magnetic pole piece 6 with a spatial distance b. 6 shows the yoke portion 14 alone, the inner circumference of the yoke portion 14 corresponds to the above-described fitting protrusions 21-1, 21-2, 21-3,... 21-x. On the surface, fitted grooves 24-1, 24-2, 24-3,... 24-x are formed at regular intervals. In FIG. 3, only a part of the coil portion 18 by the copper wire 17 is represented, but it is formed on all the teeth 12-1, 12-2, 12-3,. It is omitted in the figure.

  As shown in FIG. 5, the teeth 12-1, 12-2, 12-3,... 12-x are arranged from the center toward the outside, and the teeth 12-1, 12-2, 12-3 are arranged. ..,... 12-x are wound with a copper wire 17 through an insulating member 16 to form a coil portion 18 and constitute a teeth portion 13 as a whole. The insulating member 16 connects a plurality of bobbins 28 with a bobbin 28 formed with flanges on both sides of a cylindrical portion through which each of the teeth 12-1, 12-2, 12-3,. And an opening portion 30 having a width c is formed between the outer peripheral end portions of the adjacent bobbins 28.

  A combination of the tooth portion 13 shown in FIG. 5 and the yoke portion 14 shown in FIG. 6 is the stator 11 shown in FIGS. The fitting protrusions 21-1, 21-2, 21-3,... 21-x of the teeth 12-1, 12-2, 12-3,. 1, 12-2, 21-3,..., 24 -x, respectively, so that the teeth 12-1, 12-2, 12-protrude from the shaft 7 toward the inner peripheral surface of the yoke portion 14. 3... 12 -x are arranged at equal intervals in the circumferential direction, and desired between adjacent wedge portions 22-1 of the teeth 12-1 and tip portions of the wedge portions 22-2 of the teeth 12-2, for example. The gap portion 31 is formed with the gap width a. This gap portion 31 is formed by fitting the teeth 12-1, 12-2, 12-3,... 12-x and the yoke portion 14 so that all adjacent wedge portions 22-1, 22-2, 22 are formed. -3,... 22-x are formed with the same gap width a between the tip portions.

  The completed motor 1 supplies a current to the winding 17 from the control unit 19, so that the teeth 13 and the yoke 14 that act as the iron core of the winding 17 and the magnetic pole pieces 6 of the rotor 5 are interposed between them. Magnetic force is generated, and the rotor 5 rotates in a predetermined direction with respect to the stator 11. Therefore, the fan attached to the shaft 7 can also be rotated to blow air.

  In the present embodiment, the above-described gap width a and spatial distance b have a relationship of a ≦ b. That is, since the spatial distance b between the magnetic pole piece 6 of the rotor 5 and the stator 11 is set to be the same as or larger than the air gap width a of the air gap portion 31, the rotating magnetic pole piece 6 passes through the air gap portion 31. The cogging torque is reduced because it is less susceptible to the magnetic force generated when crossing. Further, the ratio of the gap width a to the spatial distance b is set to 2 or less (b ≦ 2a) so that the spatial distance b between the stator 11 and the magnetic pole piece 6 of the rotor 5 is not increased more than necessary. Thus, a sufficient magnetic force can be applied to the rotor 5 while reducing the cogging torque.

  FIG. 7 shows the relationship between the rotation angle of the rotor 5 with respect to the stator 11 and the cogging torque with different gap widths a, and the spatial distance b is 0.6 mm. As shown in the figure, when the gap width a is 0 mm to 0.6 mm, the cogging torque is suppressed to be small.

  8-13 is a figure for demonstrating the manufacturing process of the stator 11. FIG. FIG. 8 shows each of the teeth 12 alone, which is configured to have the fitting protrusion 21 and the wedge portion 22 as described above. FIG. 9 shows the yoke portion 14 alone, which is also configured to have the fitted groove 24 on the inner peripheral surface as described above. FIG. 10 shows an insulating member 16 formed of a resin or the like, and this insulating member 16 is configured by abutting half pieces 16A and 16B which are divided vertically.

  In order to manufacture the stator 11, first, as shown in FIG. 11, each of the teeth 12 is assembled into one half 16 </ b> A of the insulating member 16, and the remaining half 16 </ b> B is covered from there. , 16B so that each tooth 12 is sandwiched. Next, as shown in FIG. 12, the copper wire 17 is wound around each bobbin 28 of the insulating member 16 to form the coil portion 18, and the tooth portion 13 including the tooth 12, the insulating member 16, and the coil portion 18 is manufactured. At that time, the width c of the opening 30 formed between the adjacent bobbins 28 is sufficiently larger than the gap width a of the gap 31 formed between the adjacent wedge parts 22 and is outside the copper wire 17. Since it is formed sufficiently wider than the diameter, the desired coil portion 18 can be formed by winding the copper wire 17 around the teeth 12 without damaging the copper wire 17.

  After the coil part 18 is formed and the tooth part 13 is manufactured, the fitting protrusion 21 of each tooth 12 is press-fitted into the fitting groove 24 of the yoke part 14, and the yoke part 14 is attached to the tooth part 13. Then, the space part 31 between the adjacent wedge parts 22 is formed with the desired gap width a, and the stator 11 as shown in FIG. 13 is obtained. Since the copper wire 17 is already wound as the coil portion 18 when the yoke portion 14 is mounted, the gap width a of the space portion 31 does not hinder the winding of the copper wire 17 and can be formed to an arbitrary width. Therefore, the fan motor can be easily manufactured and the cogging torque can be reduced.

  As described above, in the present embodiment, the stator 11 and the rotor 5 are configured, and the stator 11 includes a tooth portion 13 having a plurality of teeth 12 around which a copper wire 17 as a wire is wound, and individual teeth. The rotor 5 is configured to be divided into a yoke portion 14 that connects 12 and forms a magnetic path, while the rotor 5 faces the stator 11 and is rotatably held at a predetermined spatial distance b. In the fan motor having the magnetic pole 6 and having the gap portion 31 between the adjacent teeth 12, the gap portion 31 having a desired gap width a is formed after the teeth portion 13 is mounted on the yoke portion 14. The ratio between the gap width a of the gap 31 and the spatial distance b between the stator 11 and the rotor 5 is set to 2 or less.

  In this case, since the spatial distance b between the rotor 5 and the stator 11 is set to be larger than the gap width a of the gap portion 31 formed between the adjacent teeth 12 and less than twice, the rotor 5 magnetic poles 6 are less susceptible to the magnetic force generated when crossing the gap 31 and the cogging torque is reduced. In addition, by forming the coil portion 18 by winding the copper wire 17 around the tooth 12, the gap width a of the gap portion 31 is formed by attaching the teeth portion 13 to the yoke portion 14. The gap 31 can be set to an arbitrary gap width a without hindering winding, and can be easily manufactured.

  In the above configuration, it is preferable that the ratio between the gap width a of the gap portion 31 and the spatial distance b between the rotor 5 and the stator 11 is approximately 1. In this case, since the spatial distance b between the rotor 5 and the stator 11 is set to be substantially the same as the gap width a of the gap portion 31 formed between the adjacent teeth 12, the cogging torque is reliably reduced. can do.

  FIGS. 14-16 has shown the fan motor in 2nd Embodiment of this invention. The overall configuration of the fan motor will be described with reference to these drawings. Reference numeral 41 denotes a case serving as an outer member of the fan motor, 42 denotes a stator receiving portion formed integrally with the case 41, and the stator receiving portion 42. A sleeve-shaped holding portion 44 extending from the other side of the case 41 to the one side is formed in the central portion of the case 41. A bearing 45 is held in the hollow holding portion 44, and a shaft 47 equipped with a fan 46 is rotatably supported by the bearing 45. The bearing 45 is attached to the holding portion 44 and is fixed by processing a tip end portion of the holding portion 44 that is opened via a fixing member 48 provided on the holding portion 44.

  A stator 51 is attached to the holding portion 44 so as to surround the holding portion 44. The stator 51 includes a core 53 around which a wire 52 such as a copper wire is wound, and a control board 54 that is electrically connected to the wire 52 in order to control the rotation of the fan 46. A lead wire 55 is connected to the control board 54 in order to receive power supply from the outside of the fan motor.

  The fan 46 has a ceiling shape that opens to face the other side of the case 41, and has a top surface part 57 that is provided to face one side of the case 41, and an outer peripheral edge of the top surface part 57 to the other side of the case 41. A cup portion 58 extending toward the outer periphery, and a plurality of blades 59 formed from the cup portion 58 toward the outer periphery. A fastening portion 60 that holds one end side of the shaft 47 is provided in the central portion of the top surface portion 57. Yes. A substantially cylindrical rotor yoke 62 is arranged on the inner peripheral side of the cup portion 58 so as to form a space portion 63 between the cup portion 58 and the rotor yoke 62. The rotor yoke 62 constituting the rotor is provided as a member that supports the magnet 65 at a predetermined position separately from the cup portion 58, and is an auxiliary piece that is formed integrally with the fan 46 so as not to easily fall off from the fan 46. 66 is held by fitting. Further, the magnets 65 arranged inside the rotor yoke 62 surround the core 53 of the stator 51 and are arranged in the circumferential direction so that N poles and S poles are alternately arranged.

  In addition to the stator receiving portion 42 that houses the stator 51, the case 41 has a cylindrical wind tunnel portion 68 that forms a wind path at a certain distance from the outer periphery of the fan 46. The receiving portion 42 is disposed at the approximate center of the wind tunnel portion 68. An outer peripheral wall 69 that rises toward one side of the case 41 is disposed on the outer periphery of the stator receiving portion 42, and the stator 51 including the control board 54 is accommodated in the outer peripheral wall 69. In particular, as shown in FIG. 16, the outer peripheral wall 69 is housed in the space 63 at the tip, and the tip of the cup 58 located at the forefront of the space 63 and the tip of the outer wall 69 The accommodation amount L1 between which the outer peripheral wall 69 enters the space 63 is formed to be twice to three times as large as the gap L2 between the inner peripheral surface of the cup portion 58 and the outer peripheral surface of the outer peripheral wall 69. Is done.

  A cylindrical rib 70 extending from the top surface portion 57 to one side of the case 41 is formed on the outer peripheral side of the fastening portion 60 provided in the fan 46. The inner diameter of the rib 70 is larger than the outer diameter of the cylindrical holding portion 44, and the ends of the rib 70 and the holding portion 44 are overlapped with each other.

  The fan motor of this embodiment configured as described above winds the wire 52 when a predetermined current is applied to the wire 52 of the stator 51 by supplying power to the control board 54 via the lead wire 55. A magnetic force is generated between the rotated core 53 and the magnet 65, and the fan 46 rotates about the shaft 47. With the rotation of the blade 59 at this time, an air flow along the shaft 47 is formed in the wind tunnel portion 68, and air can be blown outside the fan motor. Further, the gap L2 between the cup portion 58 and the outer peripheral wall 69 is kept constant during the rotation of the fan 46.

  The foreign matter intrusion prevention structure of the fan motor in this embodiment has the following characteristics. Since a space portion 63 is formed between the cup portion 58 to which the blade 59 is attached and the rotor yoke 62 to which the magnet 65 is attached, the outer peripheral wall 69 of the stator receiving portion 42 is accommodated in the space portion 63. Thus, it is possible to reliably prevent foreign matter from entering between the stator receiving portion 42 and the fan 46. In this case, the space 63 between the existing cup portion 58 and the rotor yoke 62 is used, and the outer peripheral wall 69 is formed integrally with the stator receiving portion 42, so that no separate member is required as in the prior art. Moreover, a space-saving, lightweight, and inexpensive labyrinth configuration can be realized without increasing the shape.

  Further, since the storage amount L1 into which the outer peripheral wall 69 enters the space 63 is not so large, parts accuracy more than necessary is not required, parts management is easy, and problems such as starting failures can be eliminated. That is, in FIG. 16, if the storage amount L1 is a dimension that exceeds three times the gap L2, the parts must be managed so that the outer peripheral wall 69 does not touch the cup portion 68 during the rotational vibration of the fan 46. . On the contrary, if the storage amount L1 is less than twice the gap L2, the foreign matter can easily enter from between the outer peripheral wall 69 and the cup portion 68, and the structure for preventing foreign matter from entering the original stator 51 is sufficient. It is not demonstrated. If the storage amount L1 is formed to be twice to three times as large as the gap L2, as in this embodiment, such a problem is eliminated.

  Furthermore, in this embodiment, the inner diameter of the rib 70 is formed larger than the outer diameter of the holding portion 44, and the tip of the rib 70 and the holding portion 44 wraps with each other. Intrusion is prevented. Moreover, the bearing 45 is fixed by the fixing member 48 inserted into the holding portion 44, and the end surface of the bearing 45 is covered by the fixing member 48 in order to prevent foreign matter from entering the holding portion 44. As described above, the bearing 45 includes the rib 70 surrounding the outer periphery of the holding portion 44 in the vicinity of the fastening portion 60 and the labyrinth by the outer peripheral wall 69 of the stator receiving portion 42 described above, in addition to the fixing member 48 that fixes the bearing 45. A foreign matter intrusion preventing effect can be obtained at two locations with the structure.

  As described above, in the present embodiment, the bearing 53 for rotatably supporting the fan 46, the fixing member 48 for fixing the bearing 45, the core 53 provided with the control board 54 and the wire material 52 that is a winding. A stator receiving portion 42 that is arranged around a sleeve-like holding portion 44 for mounting the stator 51, and a case 41 and a bearing 45 that are arranged around the stator receiving portion 42, In the fan motor equipped with the fan 46, the outer peripheral wall 69 of the stator receiving portion 42 is accommodated in a space portion 63 formed between the cup portion 58 of the fan 46 and the rotor yoke 62 provided inside the fan 46. Yes.

  In this case, the space 63 formed between the existing cup portion 58 and the rotor yoke 62 is used, and the outer peripheral wall 69 that enters the space 63 is formed in the stator receiving portion 42. Intrusion of foreign matter from between the child receiving portion 42 and the fan 46 can be reliably prevented. Therefore, there is no need for a separate member as in the prior art, and a foreign matter intrusion prevention structure having a space-saving, lightweight and inexpensive labyrinth configuration can be realized without securing a large shape for securing the space.

  In this embodiment, a ring-shaped rib 70 is provided in the vicinity of the fastening portion 60 between the fan 46 and the shaft 47 supported by the bearing 45, and the rib 70 is disposed on the outer periphery of the holding portion 44.

  In this case, in addition to the rib 70 surrounding the outer periphery of the holding portion 44 in the vicinity of the fastening portion 60 and the fixing member 48 for fixing the bearing 45, the labyrinth structure by the outer peripheral wall 69 of the stator receiving portion 42 can be used. Therefore, the effect of preventing foreign matter from entering the bearing 45 can be obtained.

  In the present embodiment, the storage amount L1 stored in the space 63 by the outer peripheral wall 69 is set to be two to three times the gap L2 between the cup portion 58 and the outer peripheral wall 69.

  In this case, the storage amount L1 stored in the space 63 by the outer peripheral wall 69 is set to be two to three times the gap L2 between the cup portion 58 and the outer peripheral wall 69, whereby the stator receiving portion 42 and the fan 46 are stored. While preventing the intrusion of foreign matter from between the two, it is not necessary to have the necessary part accuracy, and parts management is easy, and it is possible to prevent adverse effects such as startup failure due to fan vibration.

  FIGS. 17-19 has shown the fan motor in 2nd Embodiment of this invention. FIG. 17 is a circuit diagram of the motor 71 constituting the fan motor and its peripheral circuit. In FIG. 17, reference numeral 72 denotes a phase comparison unit including a hall element 73 and a comparator 74, and reference numeral 75 denotes a phase shift circuit 76 and a buffer circuit 77. A control signal output unit 78 includes a motor driving circuit such as a driving IC that supplies a driving current to a coil (not shown) formed by windings of the motor 71 at a predetermined timing, and 79 includes a resistor 80 and a capacitor 81. This is an induced voltage detector of the motor 71.

  As is well known, the Hall element 73 is provided as position detecting means for detecting the rotational position of the rotor 96 (see FIGS. 18 and 19) of the motor 71, and the detection signal from the Hall element 73 is one of the comparators 74. To the input terminal and the phase shift circuit 76. The induced voltage detector 79 detects an induced voltage generated in the motor 71 when the motor 71 starts to rotate due to the drive current from the motor drive circuit 78. This induced voltage is applied to the capacitor 81 via the resistor 80. The voltage that is applied and generated across the capacitor 81 is sent to the other input terminal of the comparator 74 as a detection signal from the induced voltage detector 79.

  The comparator 74 of the phase comparison unit 72 compares the detection signal from the Hall element 73 with the detection signal from the induced voltage detection unit 78, and the comparison result from the comparator 74 is a fixed value constituting the motor 71. The positional shift of the Hall element 73 with respect to the core of the child 93 (see FIGS. 18 and 19) is determined, and is sent to the phase shift circuit 76 as a phase comparison signal for specifying the rotation direction of the rotor 96.

  Based on the phase comparison signal from the comparator 74, the phase shift circuit 76 generates a signal obtained by correcting the phase of the position shift between the core position and the Hall element 73 with respect to the detection signal output from the Hall element 73. To do. The signal whose phase has been corrected is sent to the motor drive circuit 78 as a control signal forming a positive / negative pair via a buffer circuit 77 incorporated in the control signal output unit 75.

  The motor drive circuit 78 performs forced commutation for forcibly rotating the motor 71 when the motor 71 is started, and after the motor 71 is started, receives a control signal from the control signal output unit 75 to stabilize the motor 71. A drive current for rotationally driving the motor 71 is supplied to the coil of the motor 71.

  18 and 19 show the core slot shape of the motor 71 used in this embodiment. In each of these drawings, the motor 71 of the present embodiment includes a stator 93 having four slots 91-1, 91-2, 91-3, 91-4 each wound with a winding (not shown). A cylindrical rotor 96 having four-pole magnets 95-1, 95-2, 95-3, and 95-4 facing the slots 91-1, 91-2, 91-3, and 91-4. It is configured as a combined two-phase motor. Magnets 95-1, 95-2, 95-3, and 95-4 are arranged so that N poles and S poles are alternately arranged in the circumferential direction.

  Slots 91-1, 91-2, 91-3, 91-4 corresponding to the core of the stator 93 have wedge portions 92-1, 92-2, 92-3, 92-4 forming the outer periphery thereof. A rotor 96 that rotates about an axis (not shown) is disposed to face the rotor 96 at a predetermined interval. In particular, the wedge portions 92-1, 92-2, 92-3, and 92-4 shown in FIG. 18 are formed in a substantially uniform circumferential shape along the inner periphery of the rotor 96. When the spatial distances of the wedge portions 92-1, 92-2, 92-3, and 92-4 with the left side, right side, and center are X, Y, and Z, respectively, there is a relationship of X≈Y≈Z. ing. Further, the wedge portions 92-1, 92-2, 92-3, and 92-4 shown in FIG. If the spatial distances to the left side, right side, and center of −2, 92-3, and 92-4 are X, Y, and Z, respectively, the relationship is X = Y> Z.

  As a comparison, FIG. 20 shows a motor 71 constituting a conventional fan motor and a peripheral circuit diagram thereof. Here, the Hall element 73 and the motor drive circuit 78 are the same as those shown in the present embodiment, but the comparator 74, the control signal output unit 75, and the induced voltage detection unit 79 are not provided. That is, conventionally, only the detection signal from the Hall element 73 is sent to the motor drive circuit 78 as a control signal.

  FIG. 21 is a structural diagram of a conventional fan motor. In the figure, 101 is a PC board assembly in which a Hall element 73 and a motor drive circuit 78 are mounted on a printed circuit board (PC board), and 102 is a stator assembly including the stator 93 described above. The stator assembly 102 is disposed around a bearing assembly 107 in which a bearing 106 is incorporated in a sleeve-like stator receiving portion 105. Reference numeral 111 denotes a rotor assembly that includes a shaft 112 supported by the bearing 106 and a plurality of blades 113 in addition to the rotor 96 described above, and is rotatably provided around the shaft 112. In the fan motor of this embodiment, the circuit elements shown in FIG. 17 are mounted on the PC board assembly 101, and the slots 91-1, 91-2, 91-3, 91-4 are shown in FIG. 18 and FIG. Except for such a shape, it has the same configuration as the conventional one.

  FIG. 22 shows a core slot shape of a conventional motor 71. When the motor 71 is a two-phase motor, a dead point that cannot be started is generated. Therefore, in order to avoid such a dead point, a device for determining the position of the rotor in a first place has been taken. Specifically, as shown in FIG. 22, the outer peripheral shape of the slots 91-1, 91-2, 91-3, and 91-4 serving as cores is changed to wedge portions 92-1, 92-2, 92- The spatial distance between the outer peripheral surface of 3, 92-4 and the inner peripheral surface of the rotor 96 gradually increases from one side to the other side of the wedge portions 92-1, 92-2, 92-3, 92-4. (In the example of FIG. 22, the spatial distance X between the left outer peripheral surface of the wedge portion 92-1 and the inner peripheral surface of the rotor 96 is narrow, and the right outer periphery of the wedge portion 92-1 is The rotor 96 is positioned by shifting the position of the Hall element 73 by shifting the position of the Hall element 73, thereby ensuring the start-up of the motor 71. I was doing it.

  However, if the wedge portions 92-1, 92-2, 92-3, and 92-4 are formed in a non-uniform shape, cogging torque is generated, and vibration and noise performance deteriorates. The variation in output affected vibration and noise.

  On the other hand, the fan motor of this embodiment provides a drive system for a two-phase motor that can suppress the generation of cogging torque and reduce noise and vibration without being affected by variations in sensitivity and output of the Hall element 73. To do.

  When the fan motor of this embodiment is activated by forced commutation from a state where the motor 71 is stopped by the drive current from the motor drive circuit 78, an induced voltage generated in the motor 71 is applied to the capacitor 81 via the resistor 80, The voltage across the capacitor 81 is sent to the comparator 74 as a detection signal from the induced voltage detector 79. As the rotor 96 of the motor 71 rotates, a detection signal corresponding to the position of the rotor 96 is also sent from the Hall element 73 to the comparator 74, and the core of the motor 71 is compared by comparing these detection signals. And a phase comparison signal for determining the rotational direction of the rotor of the motor 71 is sent to the phase shift circuit 76. The phase shift circuit 76 uses the phase comparison signal from the comparator 74 to generate a signal in which the phase of the position difference between the core position and the Hall element 73 is corrected with respect to the detection signal from the Hall element 73. Then, the signal is output to the buffer circuit 77, and a control signal forming a positive / negative pair is sent from the buffer circuit 77 to the motor drive circuit 78. As a result, the motor drive circuit 78 can supply a drive current for stably rotating the motor 71 to the coil of the motor 71 based on the control signal from the control signal output unit 75.

  In the above series of operations, the rotation direction of the rotor 96 is detected by comparing the detection signal according to the induced voltage of the motor 71 and the detection signal of the Hall element 73 according to the position of the rotor 96. The motor drive circuit 78 controls the energization of the coil of the motor 71, and the start-up of the motor 71 can be guaranteed without determining the position of the rotor 96 in one place. Further, since positioning of the rotor 96 is not necessary, the wedge portions 92-1, 92-2, 92-3, 92-4, which are the outer peripheral shapes of the slots 91-1, 91-2, 91-3, 91-4. 18 can be made to have the same circumferential shape along the inner periphery of the rotor 96 as shown in FIG. 18, cogging torque can be suppressed, and torque ripple during rotation of the rotor 96 can be reduced. Therefore, it becomes possible to suppress vibration and noise during product incorporation.

  That is, in the present embodiment, in a fan motor including a two-phase motor composed of the stator assembly 102, the bearing assembly 107, and the rotor assembly 111, the induced voltage of the motor 71 and the output of the hall element 73 are compared to compare the motor 71. , And the slots 91-1, 91-2, 91-3, and 91-4 have substantially the same circumferential shape, so that the position of the rotor 96 needs to be determined in a first place. Therefore, the generation of cogging torque can be suppressed and the noise and vibration of the motor 71 can be reduced.

  Further, by utilizing the fact that the positioning of the rotor 96 is not necessary, the outer peripheral shape of the slots 91-1, 91-2, 91-3, 91-4 is made into a fan-like shape that is equal to the left and right as shown in FIG. Also good. In this case, the change amount of the magnetic flux passing through the slots 91-1, 91-2, 91-3, 91-4 which is the core is brought close to the sine (SIN) shape, so that the noise of the phase switching (energization switching) and hence the noise. Can be reduced.

  That is, in the present embodiment, in a fan motor including a two-phase motor composed of the stator assembly 102, the bearing assembly 107, and the rotor assembly 111, the induced voltage of the motor 71 and the output of the hall element 73 are compared to compare the motor 71. And the slots 91-1, 91-2, 91-3, and 91-4 have an equal fan shape on the left and right sides, so that there is no need to determine the position of the rotor 96 in one place. Further, it is possible to further reduce the noise and vibration of the motor 71 by suppressing the generation of cogging torque and noise during phase switching.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in the first embodiment, a wire made of a material other than the copper wire 17 may be used, and the number of magnetic poles 6 and teeth 12 may be appropriately determined in consideration of the characteristics of the fan motor. Moreover, it is good also as a fan motor which combined each characteristic shown in 1st Embodiment-3rd Embodiment suitably.

5 Stator 6 Magnetic pole 11 Rotor 12 Teeth 13 Teeth part 14 Yoke part 17 Copper wire (wire)
DESCRIPTION OF SYMBOLS 31 Cavity 41 Case 42 Stator receiving part 44 Holding part 45 Bearing 46 Fan 47 Shaft 48 Fixing member 52 Wire 53 Core 54 Control board 58 Cup part 60 Fastening part 62 Rotor yoke 63 Space part 69 Outer wall 70 Rib a Cavity width b Space Distance L1 Storage L2 Gap

Claims (5)

It consists of a stator and a rotor,
The stator is divided into a teeth portion having a plurality of teeth wound with a wire and a yoke portion connecting the teeth to form a magnetic path,
The rotor is rotatably held at a predetermined spatial distance facing the stator, and has a plurality of magnetic poles,
In the fan motor provided with a gap between the teeth,
Forming the gap after attaching the teeth part to the yoke part;
A fan motor, wherein a ratio between a gap width of the gap and the spatial distance is set to 2 or less.   The fan motor according to claim 1, wherein a ratio between a gap width of the gap and the spatial distance is set to approximately 1. A bearing for rotatably supporting the fan;
A fixing member for fixing the bearing;
A stator receiving portion formed around a holding portion for mounting a control board and a stator composed of a core provided with a winding;
In the fan motor in which the fan is attached to the case and the bearing arranged around the stator receiving portion,
A fan motor, wherein an outer peripheral wall of the stator receiving portion is housed in a space formed between a cup portion of the fan and a rotor yoke provided inside the fan.   4. The fan motor according to claim 3, wherein a rib is provided in the vicinity of a fastening portion between the fan and the shaft supported by the bearing, and the rib is disposed on the outer periphery of the holding portion.   The fan motor according to claim 3, wherein a storage amount stored in the space portion by the outer peripheral wall is set to be two to three times a gap between the cup portion and the outer peripheral wall.