JP2014098331A - Blower device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration, cogging and power consumption in a multiplex series type axial blower.SOLUTION: There is provided a double reversing axial blower device 10 in which an axial blower 100 provided with a single-phase motor capable of performing a self-activation and an axial blower 200 provided with a single-phase motor not capable of performing a self-activation are axially connected to each other. A driving current is supplied to the single-phase motor of the axial blower 100 at the time of energization and a driving current is not supplied to the single-phase motor of the axial blower 200. The axial blower 200 receives an axial flow generated by the axial blower 100 and is rotated. Then, at the stage where the axial blower 200 starts to rotate, the driving current is supplied to the axial blower 200. Application of the single-phase motor not capable of performing a self-activation causes vibration, cogging and power consumption to be reduced.

Description

  The present invention relates to a multiple series type blower in which a plurality of axial fans are connected in the axial direction.

  2. Description of the Related Art A double reversing axial fan is known in which two single-phase motors having opposite rotation directions are connected in the axial direction. A single-phase motor has a simple structure and is advantageous in terms of low cost and durability, but it is necessary to take some measures to start itself. As countermeasures, there are known a structure that intentionally unbalances the shape around the axis to cause rotation, and a structure that enables self-start by providing an auxiliary electrode and auxiliary magnetic pole. Yes. These techniques are described in, for example, Patent Document 1 and Patent Document 2.

JP 2007-318977 A JP 58-157359 A

  The idea of enabling the self-start in the single-phase motor described above is based on decentering the structure and magnetic state and breaking the balance around the axis. On the other hand, this self-starting configuration loses the balance around the axis, which causes cogging (rotation unevenness) and vibration during motor rotation. Cogging and vibration are factors that consume extra power, and are not preferable from the viewpoint of reducing power consumption. These problems are particularly prominent when two single-phase motors that can be self-started are used in the double reversing axial flow fan. In such a background, an object of the present invention is to reduce vibration, cogging, and power consumption in a multiple series axial fan configured by connecting a plurality of axial fans.

  The invention according to claim 1 has a structure in which a plurality of axial fans provided with a motor rotating by magnetic force and blades rotated by the motor are connected in the axial direction. The blower is characterized in that it includes a motor using a motor that can be started and a motor using a motor that cannot be started automatically.

  According to the first aspect of the present invention, since a motor that is not capable of self-starting that is advantageous in terms of vibration, cogging, and power consumption can be used, a blower that reduces vibration, cogging, and power consumption can be obtained. . Note that self-start is possible when the drive current is supplied when the rotor starts to rotate spontaneously. The fact that self-activation is impossible means a characteristic in which when the drive current is supplied, the rotation of the rotor does not occur only by the supply of the drive current if there is no trigger for the rotation of the rotor due to an external factor. In other words, a motor that cannot be self-started does not start rotating only by supplying a drive current unless there is an opportunity to forcibly rotate the rotor.

  A second aspect of the present invention provides the motor according to the first aspect, wherein a drive current is supplied to the motor capable of self-starting at the start of blowing and the motor is not capable of self-starting. It is further characterized by further comprising control means for performing control without supplying the drive current.

  According to a third aspect of the present invention, in the second aspect of the present invention, the driving current is supplied to the self-startable motor, and the driving current is supplied to the motor that cannot be self-started. In a situation where supply is not performed, the blades of the axial blower provided with the motor that cannot be self-started rotate due to the axial flow caused by the axial blower provided with the self-startable motor. And

  The direction of rotation by a drive current in a motor that cannot be self-started (this rotation is referred to as self-supporting rotation) is determined by the rotational direction in which the rotor is first forcedly rotated by an external force. In other words, if the drive current is supplied and forcibly rotated right, the operation of the right rotation is performed as it is. If the drive current is supplied and the force is rotated counterclockwise, the operation of the left rotation is performed as it is. Is done.

  According to invention of Claim 2 and 3, the axial flow fan provided with the motor which can be self-started begins to rotate first, and the axial flow provided with the motor which cannot be self-started by the axial flow generated there The rotation of the rotor in the blower occurs, and at that stage, power is supplied to the axial blower provided with a motor that cannot be started automatically. For this reason, the axial flow fan provided with the motor that cannot be automatically started in a predetermined rotation direction always rotates, and an intended axial flow generation operation can be obtained.

  If a drive current is applied simultaneously to an axial fan with a motor that can start itself and an axial fan with a motor that cannot start itself, the motor that cannot start automatically is in the intended direction. The certainty of rotation is not perfect, and the possibility of starting to rotate in the opposite direction due to some trigger such as vibration cannot be excluded. When a motor that cannot be started automatically rotates in the direction opposite to the intended direction, the direction of the axial flow generated by the axial blower using the motor is opposite to the design direction, and the entire device operates normally. Cannot be obtained. According to the inventions of claims 2 and 3, in the first stage, the axial flow of the axial blower capable of self-starting causes the blades of the axial flow blower that cannot be self-started to rotate and rotate, Rotation in the designed rotational direction always occurs in a motor that cannot be started up automatically, and the above disadvantages are prevented.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the control means is configured such that when the blades of the axial flow fan provided with the motor that cannot be started automatically start rotating, It is characterized in that supply of drive current to a motor that cannot be started is started. According to the fourth aspect of the present invention, it is possible to reliably start the motor that cannot be started by itself in the intended rotation direction.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the control means has a stage in which a predetermined time has elapsed from the start of supply of drive current to the self-startable motor. Then, supply of a drive current to the motor that cannot be self-started is started. In the invention according to claim 5, by energizing the motor that cannot be self-started with a time difference in which the rotation of the motor that cannot self-start is surely generated, the motor that cannot be self-started is obtained. Thus, the starting in the intended rotation direction can be performed reliably.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the self-startable motor has an asymmetrical shape of the salient poles of the stator core as viewed from the axial direction. It is a single-phase motor having a shape.

  According to a seventh aspect of the present invention, in the motor according to any one of the first to sixth aspects, the shape of the salient poles of the stator core as viewed from the axial direction is symmetrical on the left and right sides of the motor that cannot be self-started It is a single-phase motor having a simple shape.

  According to the present invention, vibration, cogging, and power consumption can be reduced in a multiple series axial fan configured by connecting a plurality of axial fans.

It is a perspective view of an embodiment. It is the front view (A), side view (B), and back view (C) of an embodiment. It is a sectional side view of an embodiment. It is a conceptual diagram which shows the positional relationship of a stator core and a rotor magnet. It is a conceptual diagram of the salient pole of a stator core. It is a conceptual diagram which shows the positional relationship of a stator core and a rotor magnet. It is a conceptual diagram of the salient pole of a stator core. It is a block diagram of a control system.

(Overview)
Hereinafter, an example of a double reversing axial flow fan will be described as an example of a multiple series axial flow fan using the invention. FIG. 1 shows a double reversing axial flow fan 10. The double reversing axial fan 10 has a structure in which a first axial fan 100 and a second axial fan 200 are connected in the axial direction. The impeller (propeller) rotates in the reverse direction between the first axial fan 100 and the second axial fan 200. FIG. 1 shows the impeller 101 of the first axial fan 100 and the blades 102 of the impeller 101.

  The first axial fan 100 is disposed on the upstream side of the axial flow, and the second axial fan 200 is disposed on the downstream side. That is, air is sucked in from the first axial fan 100 side and is discharged from the second axial fan 200 side. In FIG. 1, the direction of rotation of each blower and the flow of air are indicated by arrows. The fluid to be handled is air for convenience, but other fluids such as exhaust gas and special gas may be used.

  The first axial fan 100 is an axial fan using a self-startable single-phase motor, and the second axial fan 200 is an axial fan using a single-phase motor that cannot be started automatically. At the start of the operation, the second axial blower 200 receives the air flow from the first axial blower 100 and passively starts rotating. Then, the second axial fan 200 is energized with a time difference when the first axial fan 100 is activated. At this point, the second axial blower 200 has already started rotating, and thus continues to rotate in response to the supply of electric power in a form that takes over the rotation. This rotation is based on the drive current, and is not passive due to the wind but has a drive torque.

(First axial blower)
The detailed configuration will be described below. First, the first axial fan 100 will be described. FIG. 2 shows a front view (A), a side view (B), and a rear view (C) of the double reversing axial flow fan 10. FIG. 3 shows a cross-sectional state of the cross section taken along the line AA in FIG. 2A as viewed from the lower direction in FIG. 2A (the direction of arrow B).

  The first axial blower 100 includes a resin impeller 101 having five blades 102. A metal shaft 103 is fixed at the center of the impeller 101. The shaft 103 is attached to a substantially cylindrical bearing holder 106 made of resin by bearings 104 and 105 in a rotatable state. Moreover, the impeller 101 has a cylindrical portion 101a extending in the axial direction from the outer edge portion. A cylindrical back yoke 107 made of a magnetic material is fixed inside the cylindrical portion 101a, and a rotor magnet 108 is fixed inside the back yoke 107 (see FIG. 4). The rotor magnet 108 has a cylindrical shape, and is magnetized into SNSN and four poles along the circumferential direction. The rotor 109 is constituted by the impeller 101 provided with the blades 102 described above, the shaft 103, the back yoke 107, and the rotor magnet.

  A stator core 110 is fixed to the outer periphery of the bearing holding portion 106. FIG. 4 shows the stator core 110 as viewed from the axial direction. The stator core 110 has a structure in which a plurality of electromagnetic steel plates having the shape shown in FIG. 4 are laminated in the axial direction. The stator core 104 includes four salient poles 111. The salient pole 111 is provided at an extension portion 111a extending in a direction away from the axial center, and at a tip portion of the extension portion 111a, and a salient pole tip portion 111b having a substantially T-shape when viewed from the axial direction. I have. The salient pole tip 111b has a salient pole surface that is a curved surface facing the rotor magnet 108 with a gap.

  Although not shown in FIG. 4, a resin insulator 112 (see FIG. 3) is attached to the salient pole 111. The extension 111a of the salient pole 111 is insulated by an insulator 112, and a stator coil 113 (see FIG. 3) is wound around the outside. This is the same for all four salient poles 111. In FIG. 4, the stator coil 113 is not shown.

  In order to allow the first axial fan 100 to start up itself, the shape of the salient pole tip 110b is devised. Hereinafter, this point will be described. The outer periphery of the salient pole tip 111b is located in a state of facing the inner periphery of the cylindrical rotor magnet 108 with a gap. Here, the dimension of the gap between the outer periphery of the salient pole tip 111b and the inner periphery of the rotor magnet 108 in the circumferential direction is not constant.

  That is, as shown in FIG. 5, the gap dimension (Gap1) between the rotor magnet 108 at one end in the circumferential direction and the gap dimension (Gap2) between the rotor magnet 108 at the other end are the same. Instead, the relationship Gap1 <Gap2 is set. In addition, the gap dimension is gradually increased from Gap1 to Gap2. By adopting a structure in which the relationship of Gap1 <Gap2 is set, a magnetic imbalance in the circumferential direction at the time of startup is generated, and the rotor magnet 108 (rotor 109) starts to rotate in a specific direction. Further, as described above, since the salient pole 111 has an orientation in the circumferential direction, the mark 111c having a notch structure is formed so that the orientation is not mistaken at the time of assembly.

  The cylindrical bearing holding portion 106 is fixed to a resin base member 114. The base member 114 is formed integrally with the outer substantially cylindrical casing 115. The rotor 109 is housed inside the casing 115 in a rotatable state. The base member 114 is coupled to the second axial fan 200 by a coupling structure not shown. As the coupling structure, a fitting structure by meshing, a coupling structure by a fastening means such as a screw, a coupling structure by an adhesive, or a coupling structure by a combination of them can be adopted.

  In the structure described above, the first axial blower 100 is constituted by a single-phase motor in which the blades 102 are integrated with the rotor 109. In this single-phase motor, when a drive current is passed through a plurality of stator coils 113, a magnetic force whose polarity is alternately reversed acts between the plurality of salient poles 111 and the magnetic poles of the rotor magnet 108. The rotor 109 rotates in a specific direction with respect to the stator core 110 by the switching of the magnetic force in which the polarity is alternately reversed. At this time, since Gap1 <Gap2 is set, there is a difference in the magnetic force acting between both ends in the circumferential direction of the salient pole tip and the magnetic pole of the rotor magnet 108 at the beginning of rotation, thereby causing a specific direction. The rotation starts. That is, a self-starting characteristic in which the rotation of the rotor 109 starts can be obtained by passing a driving current through the stator coil 113.

(Second axial blower)
The second axial fan 200 is different from the first axial fan 100 in the following points. First, the second axial blower 200 has four blades 202 and the shape thereof is also different from the blades 102 of the first axial blower 100. The blade 202 is set to rotate in the direction opposite to the blade 102 with respect to the same axial flow direction. That is, the combinations of the directions of the blades 102 and 202 are set so that the impellers 101 and 201 rotate reversely with respect to the air flow from left to right in FIG. Further, as will be described later, the second axial blower 200 is different from the first axial blower 100 in the structure of the stator salient poles. The second axial blower 200 is coupled back to back with the first axial blower 100.

  Hereinafter, the second axial fan 200 will be described in detail. The material of the constituent members is the same as that of the first axial blower 100. The second axial blower 200 includes an impeller 201 including four blades 202. A shaft 203 is fixed at the center of the impeller 201. The shaft 203 is attached to a substantially cylindrical bearing holding portion 206 in a freely rotatable state by bearings 204 and 205. The impeller 201 has a cylindrical portion 201a that extends in the axial direction from the outer edge portion. A cylindrical back yoke 207 is fixed inside the cylindrical portion 201 a, and a rotor magnet 208 is fixed inside the back yoke 207. The rotor magnet 208 has a cylindrical shape and is magnetized into SNSN and four poles along the circumferential direction. The impeller 201 including the blades 202 described above, the shaft 203, the back yoke 207, and the rotor magnet 208 constitute a rotor 209.

  A stator core 210 is fixed to the outer periphery of the bearing holding portion 206. FIG. 6 shows the stator core 210 as viewed from the axial direction. The stator core 210 has a structure in which a plurality of electromagnetic steel plates having the shape shown in FIG. 6 are laminated in the axial direction. As shown in FIG. 6, the stator core 204 includes four salient poles 211. The salient pole 211 is provided at an extension part 211a extending in a direction away from the center of the axis, and at a tip part of the extension part 211a, and a salient pole tip part 211b having a substantially T-shaped shape when viewed from the axial direction. I have. The salient pole tip 211b has a salient pole surface that is a curved surface facing the rotor magnet 208 with a gap.

  Although not shown in FIG. 6, a resin insulator 212 (see FIG. 3) is attached to the salient pole 211. An extension part 211a of the salient pole 211 is insulated by an insulator 212, and a stator coil 213 (see FIG. 3) is wound around the outside. This is the same for all four salient poles 211. In FIG. 6, the stator coil 213 is not shown.

  The second axial fan 200 is a normal single-phase motor that cannot be started automatically. Therefore, the device for enabling self-starting like the first axial fan 100 is not made, and Gap1 and Gap2 shown in FIG. 7 have the same dimensions. That is, the distance between the outer peripheral surface (saliency pole surface) of the salient pole tip 211b and the inner peripheral surface of the rotor magnet 208 is set to a constant value without any difference depending on the location.

  The cylindrical bearing holding portion 206 is fixed to the base member 214. The base member 214 is formed integrally with the outer substantially cylindrical casing 215. A rotor 209 is housed in a rotatable state inside the casing 215. The base member 214 is coupled to the base member 114 of the first axial blower 100 by a coupling structure not shown.

  In the structure described above, the second axial blower 100 is constituted by a single-phase motor in which the blades 202 are integrated with the rotor 209. Since the second axial blower 200 uses a single-phase motor that cannot be self-started, the impeller 201 is not provided with any external trigger even when the drive current is supplied in a stopped state. Does not start to rotate. Then, when the impeller 201 is forcibly turned from the outside in a state where the drive current is stopped and the drive current is supplied, the self-rotation starts in the turning direction. In addition, when a driving current is supplied in a state where the impeller 201 is forcibly rotated from the outside, the impeller 201 rotates independently in the direction of rotation at that time. In addition, the direction of rotation in these cases can be either left or right in principle. The operating principle of the second axial fan 200 in the state where it rotates independently by the supplied drive current is the same as that of the first axial fan 100.

(Control system)
FIG. 8 is a block diagram of a control system that drives the double reversing axial flow fan 10. The control system shown in FIG. 8 includes a power supply circuit 300, a power switch 301, and a delay ON circuit 302. The power supply circuit 300 outputs a drive current for driving the single-phase motor of the first axial fan 100 and the single-phase motor of the second axial fan 200. The power switch 301 is a normal switch circuit that turns on / off the drive current from the power circuit 300. When the power switch 301 is turned on and a predetermined voltage is applied, the delay ON circuit is turned on after a predetermined time elapses, and the second axial fan 200 is connected to the second axial fan 200 from the power circuit 300. The operation of transmitting the drive current is performed. Examples of the method for performing the delay include control by a microcomputer, control by a time constant circuit using a capacitor, and a method using a mechanical timer.

  According to the control system of FIG. 8, when the power switch 301 is turned on, first, the first axial fan 100 starts rotating. Then, after a predetermined time has elapsed since that time, the delay ON circuit is turned ON, and a drive current is supplied to the second axial fan 200.

  The delay time is such that the impeller 201 of the second axial fan 200 is passively driven by the air flow (wind) generated by the first axial fan 100 after the first axial fan 100 starts rotating. The time that is longer than the time to start is set. As a specific delay time value, an experimentally obtained value is used.

(Operation)
When the power switch 301 in FIG. 8 is turned ON, first the first axial fan 100 starts to rotate. And the impeller 202 of the 2nd axial flow fan 200 starts to rotate passively when the flow of the air which the 1st axial flow blower 100 causes hits the wing | blade 202. FIG. At this timing, the delay ON circuit 302 is turned ON, and supply of drive current to the second axial fan 200 starts. As a result, the impeller 202, which has already started rotating, is rotated passively from the state in which it is rotated by the magnetic force generated between the stator coil 213 and the rotor magnet 208 in FIG. State). At this time, since the second axial blower 200 has already been rotated in the prescribed direction, the second axial blower 200 does not rotate in the reverse direction of the prescribed rotational direction.

  That is, in the double reversal axial fan 10 in which the axial fan 100 having a single-phase motor capable of self-starting and the axial fan 200 having a single-phase motor not capable of self-starting are connected in the axial direction. Sometimes, a driving current is supplied to the single-phase motor of the axial fan 100 and no driving current is supplied to the single-phase motor of the axial fan 200. The axial fan 200 receives the axial flow generated by the axial fan 100. Rotate. Then, when the axial flow fan 200 starts to rotate, a drive current is supplied to the axial flow fan 200 to operate the two axial flow fans 100 and 200 simultaneously.

(Superiority)
As described above, with respect to the double reversing axial flow fan using two single-phase motors, in particular, in order to achieve reduction of vibration and cogging, the motor on one side has an asymmetrical stack that can be started automatically The other motors have a symmetrical stack. According to this structure, the other motor that cannot be self-started is normally rotated by using the flow of the wind from the single-phase motor that can be automatically started. That is, in the double reversing axial fan using two single-phase motors, the single-phase motor having an eccentric stack rotates normally and the single-phase motor having the other eccentric stack is driven by the wind. Cause normal rotation of the motor.

  According to this structure, the second axial blower 200 cannot be self-started, that is, has no intention of any imbalance in the circumferential direction in which the rotor rotates. Vibration and cogging can be reduced as compared with a double reversing axial fan using a single phase motor. In addition, since the energy consumed for vibration and cogging is reduced, power consumption when compared with the same output can be reduced, and efficiency can be increased. Further, the stator core 210 of the second axial blower 200 does not need to be provided with the mark 110c (see FIGS. 4 and 5) in the stator core 110 of the first axial blower 100, so that labor during assembly is reduced. The

(Other)
The first axial fan 100 and the second axial fan 200 may be rotated in the same direction. The first axial fan 100 may be the downstream side, and the second axial fan 200 may be the upstream side. In this case, the second axial fan 200 starts to rotate due to the air flow sucked by the first axial fan 100.

  A configuration in which energization of the second axial fan 200 is started after the rotation of the first axial fan 100 is detected is also possible. In this case, for example, the rotation of the rotor of the first axial fan 100 is detected by rotation detection means such as a Hall element, and the second axial fan 100 is supplied to the second axial fan 100 based on the detection signal of the rotation detection means. It is set as the structure which starts electricity supply. Moreover, the structure which detects the induced voltage which appears in the power supply terminal of the 2nd axial flow fan 200, and starts the electricity supply to the 2nd axial flow fan 200 in the stage in which this detected value exceeded the regulation value is also possible. is there.

  In addition to the first axial fan 100 and the second axial fan 200, a structure in which a third axial fan and a fourth axial fan are connected in the axial direction is also possible. In this case, various forms of combinations of impeller rotation directions can be selected. For example, a mode in which the axes are alternately reversed, a first rotation and a second rotation in the right direction, a third rotation in the left rotation, and a rotation in the same direction are all possible.

  In the embodiment, an example in which the number of impeller blades is different between the first axial fan and the second axial fan is shown, but the number of impeller blades in the two axial fans is the same. Also good. In addition to the structure that devises the shape of the salient poles of the illustrated stator, the configuration that enables self-starting is achieved by devising the configuration that uses auxiliary magnets and auxiliary coils, the shape of the magnetic poles on the rotor side, and the state of magnetization. A configuration that enables self-activation is possible. This technique can adopt various known configurations.

  4 and 6 show an example in which the number of magnetic poles of the rotor magnet and the number of stack magnetic poles (the number of magnetic poles on the stator side (number of salient poles)) are the same. Structures with different numbers are also possible.

  In the embodiment, an example of an axial blower using an outer rotor type motor in which a rotor is arranged on the outside is shown, but an axial blower using an inner rotor type motor in which a rotor is arranged on the inside is shown. The present invention can also be applied.

  The aspect of the present invention is not limited to the individual embodiments described above, and includes various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the contents described above. That is, various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

  The present invention can be used for a multiple series axial fan.

DESCRIPTION OF SYMBOLS 10 ... Double reversing type axial flow fan, 100 ... 1st axial flow fan, 101 ... Impeller, 101a ... Cylindrical part, 102 ... Blade | wing, 103 ... Shaft, 104 ... Bearing, 105 ... Bearing, 106 ... Bearing holding part, DESCRIPTION OF SYMBOLS 107 ... Back yoke, 108 ... Rotor magnet, 109 ... Rotor, 110 ... Stator core, 111 ... Salient pole, 111a ... Extension part, 111b ... Salient pole tip part, 111c ... Mark, 112 ... Insulator, 113 ... Stator coil, 114 ... Base member, 115 ... Casing, 200 ... First axial fan, 201 ... Impeller, 201a ... Cylindrical part,
202 ... Blade, 203 ... Shaft, 204 ... Bearing, 205 ... Bearing, 206 ... Bearing holding portion, 207 ... Back yoke, 208 ... Rotor magnet, 209 ... Rotor, 210 ... Stator core, 211 ... Salient pole, 211a ... Extension portion , 211b ... salient pole tip, 211c ... mark, 212 ... insulator, 213 ... stator coil, 214 ... base member, 215 ... casing.

Claims (7)

It has a structure in which a plurality of axial fans equipped with a motor rotating by magnetic force and blades rotated by the motor are connected in the axial direction,
The blower characterized in that the plurality of axial flow fans include one using a motor capable of self-starting and one using a motor not capable of self-starting.   The apparatus further includes a control unit that controls the supply of the drive current to the motor that can be self-started and the supply of the drive current to the motor that cannot be self-started at the start of air blowing. The air blower according to claim 1, wherein   A motor capable of self-starting in a situation where the driving current is supplied to the motor capable of self-starting and the driving current is not supplied to the motor capable of self-starting; The blower according to claim 2, wherein the blades of the axial flow fan provided with a motor that cannot be self-started are rotated by an axial flow caused by the axial flow fan.   The control means starts supplying drive current to the motor that cannot be self-started when the blades of the axial blower including the motor that cannot self-start start rotating. The air blower according to claim 3.   The control means starts supplying the drive current to the motor that cannot be self-started after a predetermined time has elapsed since the start of supplying the drive current to the motor capable of self-start. The blower according to claim 4.   6. The self-startable motor is a single-phase motor having a shape of a salient pole of a stator core as viewed from the axial direction and having an asymmetric shape on the left and right. 6. Blower. 7. The motor according to claim 1, wherein the motor that is not capable of self-starting is a single-phase motor in which the shape of the salient poles of the stator core as viewed from the axial direction is symmetrical on the left and right. The blower described.

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