JP2013106486A - Axial blower and electric apparatus equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial blower capable of suppressing reduction in an amount of air blown from an axial blower without using a DC power supply or a control circuit including a microcomputer even when pressure loss in outside of the machine such as wind pressure outside is increased.SOLUTION: An axial blower 8 is arranged so that a motor 11 is rotatably held facing a stator 4, a squirrel-cage rotor 3 having an aluminium-made conductor bar is arranged on outer peripheral side of a shaft, and a permanent magnet 6 is arranged between the conductor bar 5 of the squirrel-cage rotor 3 and a shaft 9. The axial blower 8 is operated at a constant rotation number synchronized with power supply frequency in a region in which static pressure is from zero to maximum static pressure, so that characteristics of the amount of air flow to the static pressure, which can suppress reduction in the amount of air flow even when pressure loss outside of the machine such as the wind pressure outside is increased.

Description

  The present invention mainly relates to an axial-flow fan mounted on a ventilation fan for exhaust and supply such as a fan for a pipe or a general type ventilation fan, a pressure ventilation fan for business use or industrial use, a cooling fan for incorporation in an apparatus, etc. Further, the present invention relates to an electric device equipped with the axial fan.

  In recent years, electric motors installed in electrical equipment such as ventilation equipment have been reduced in price, increased efficiency, reduced noise, reduced in size, reduced in thickness, and the change in pressure loss due to external air pressure, clogging of filters, etc. There is a need for an axial blower with a low environmental impact that can be ventilated with an appropriate air flow without being greatly affected.

  Conventionally, this type of axial blower has a configuration disclosed in Patent Document 1.

  Hereinafter, the axial flow fan will be described with reference to FIG.

  As shown in the figure, the axial blower 108 supplies power to a DC motor 103 from a DC power source 101, and a propeller fan 104 is attached to the rotating shaft of the DC motor 103. In a steady state, a rated voltage is applied from the DC power source 101 to the DC motor 103, and a rotational speed slightly lower than the rotational speed when the static pressure is zero is stored as a predetermined rotational speed. A control circuit 107 is provided for controlling the output voltage of the DC power supply 101 to be higher than the rated voltage and not lower than the predetermined rotational speed when the operating rotational speed is lower than the predetermined rotational speed due to outside wind pressure or the like. It is configured.

Japanese Patent No. 3159503

  According to such a conventional axial blower, there is a problem that it cannot be reduced in size and thickness in order to secure a space for installing a DC power supply or a control circuit. Even if an external pressure loss such as an external wind pressure increases without using a simple sensor or a microcomputer, it is required that a decrease in the amount of blown air can be reduced.

  The present invention solves such a conventional problem, and even if an external pressure loss such as an external wind pressure increases without using a DC power supply or a control circuit equipped with a microcomputer, The purpose of the present invention is to provide an axial blower that can be reduced less.

  In order to achieve this object, the present invention includes a rotating shaft, a propeller fan connected to at least one end of the rotating shaft, a cage rotor integrated with an outer periphery of the rotating shaft and having a conductor bar. And an axial flow fan connected to a commercial AC power source, the stator being provided opposite to the squirrel-cage rotor and provided with a stator wound with an armature winding. A rotational speed synchronized with the power frequency of the commercial AC power source in a range from zero external static pressure to approximately maximum external static pressure by arranging a permanent magnet between the conductor bar and the stator. In this way, an axial blower characterized by a constant operation is achieved, thereby achieving the intended purpose.

  According to the present invention, a rotating shaft, a propeller fan connected to at least one end of the rotating shaft, a cage rotor integrated with an outer periphery of the rotating shaft and having a conductor bar, and the cage rotor And an axial flow fan connected to a commercial AC power source, the cage bar having the conductor bar connected to the stator. A permanent magnet is arranged at a position between them, and a constant operation is performed at a rotation speed synchronized with the power supply frequency of the commercial AC power source in a range from zero external static pressure to approximately maximum external static pressure. Because of the configuration of the axial blower that operates, even if the fan load increases due to the influence of external wind pressure, etc., it operates at a constant speed in synchronization with the power supply frequency of the commercial AC power supply. Without using the control circuit It is possible to obtain the effect of an axial blower and electrical equipment decreased air volume can be reduced can be provided.

The block diagram which shows the axial-flow fan in Embodiment 1 of this invention. Exploded perspective view showing the configuration of the same motor Graph showing an example of the rotation speed-torque characteristics of the same motor A graph showing an example of air flow-static pressure characteristics of a coaxial flow blower Sectional drawing which shows the installation state of the ventilator equipped with the coaxial flow blower Block diagram showing a conventional axial blower

  An axial blower according to claim 1 of the present invention includes a rotating shaft, a propeller fan connected to at least one end of the rotating shaft, a cage rotor integrated with an outer periphery of the rotating shaft and having a conductor bar; An axial fan connected to a commercial AC power source, the stator being provided opposite to the squirrel-cage rotor and provided with a stator around which an armature winding is wound. A permanent magnet is arranged at a position where the bar is sandwiched between the stator and the rotational speed synchronized with the power frequency of the commercial AC power source in a range from zero external static pressure to approximately maximum external static pressure. It has the structure of the axial-flow fan characterized by operating constant. As a result, even if the fan load increases due to the influence of outside wind pressure, etc., since it operates at a constant rotation speed in synchronization with the power supply frequency of the commercial AC power supply, without using a microcomputer or special control circuit, There is an effect that a decrease in the amount of blown air can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIGS. 1 to 5, reference numeral 8 denotes an axial blower in which a motor 11 is mounted and a propeller fan 8 a is attached to a shaft 9 that is a rotating shaft of the motor 11, and is connected to a commercial AC power source. Reference numeral 1 denotes a ventilator incorporating an axial blower 8. Dirty indoor air generated by cigarette smoke, cooking, or the like sucked by the axial blower 8 is sucked from the suction port of the ventilator 1 and is discharged to the outside through the wall 14 of the building. An electric motor 11 includes a stator 4 in which a main winding 2a and an auxiliary winding 2b, which are armature windings 2, are concentratedly wound, and a cage rotor 3 that is rotatably held facing the stator 4. The operation capacitor 10, the starting capacitor 12, and the PTC thermistor 13, and the shaft 9 as a rotating shaft is press-fitted into the center of the squirrel-cage rotor 3, and the conductor bar formed of aluminum on the outer peripheral side. 5 is provided, and the conductor bar 5 is skewed. A permanent magnet 6 is disposed between the conductor bar 5 and the shaft 9 of the cage rotor 3, and the permanent magnet 6 is made of anisotropic samarium / iron / nitrogen magnetic powder and anisotropic neodymium / iron / boron magnetic powder. The cross-sectional shape in the radial direction is a crescent shape, and the convex side 7 is directed to the stator 4 side and is skewed similarly to the conductor bar 5. The particle size of samarium / iron / nitrogen magnetic powder is 2 to 3 μm, and the particle size of neodymium / iron / boron magnetic powder is 50 to 100 μm. The starting capacitor 12 is disconnected by the PTC thermistor 13 in the synchronous operation state. The axial blower 8 is configured to operate at a constant speed at a rotational speed synchronized with the power supply frequency of the commercial AC power supply in a region from zero static pressure outside the machine to maximum static pressure (zero air volume).

  According to such an axial flow fan 8 of the present invention, as shown in the graph of the rotational speed-torque characteristic of FIG. 3, at the time of starting, an induced current is generated in the conductor bar 5 so that the rotational torque corresponding to the slip is generated. Occur and work. Then, the mode is changed to a mode of rotating by the magnetic force of the permanent magnet 6 and the attractive force of the electromagnet by the armature winding 2 of the stator 4, and the motor is operated at a constant rotation at a rotation speed synchronized with the power frequency of the commercial AC power supply. . Therefore, in the ventilator 1 equipped with the axial blower 8, there is no need to use a DC power supply or a control circuit equipped with a microcomputer. Then, as shown in the graph of the air volume-static pressure characteristics in FIG. 4, even if the external pressure loss such as the external air pressure increases, the air volume-static pressure characteristics that can reduce the decrease in the blown air volume can be obtained.

  Further, since the conductor bar 5 and the permanent magnet 6 are skewed, the transition from the operation as the induction machine to the operation as the synchronous machine is smooth when the power is turned on, and the torque ripple during the synchronous operation is also reduced. As a result, an axial blower that achieves low vibration and low noise can be obtained.

  Further, since the cross-sectional shape in the radial direction of the permanent magnet 6 is crescent and the convex side 7 is directed to the stator 4 side, the induced voltage waveform at the time of synchronous operation becomes close to a sine wave, so that the torque ripple is reduced. Thus, an axial blower that achieves further low vibration and low noise can be obtained.

  The permanent magnet 6 is a bonded magnet in which anisotropic samarium / iron / nitrogen magnetic powder having a small magnetic particle diameter and anisotropic neodymium / iron / boron magnetic powder having a large magnetic particle diameter are mixed. Therefore, the magnetic powder filling rate is improved, so that the magnetic flux density is increased and the neodymium / iron / boron magnetic powder suppresses the magnetization reversal of the samarium / iron / nitrogen magnetic powder. Therefore, since the coercive force is improved, the torque that rotates in synchronization with the power supply frequency is increased. When the torque increases, the propeller fan 8a can take a large difference between the load curve at the time of opening and the load curve at the time of closing. That is, an axial blower can be obtained in which the decrease in the amount of blown air can be extremely reduced even if the outside pressure loss such as outside wind pressure increases.

  In the first embodiment, the starting capacitor 12 and the PTC thermistor 13 are provided. However, if there is no effect on the shift from the starting as the induction machine to the synchronous operation, the starting capacitor 12 and the PTC thermistor 13 are connected. Without being provided, only the operation capacitor 10 may be used to perform the start-up and the synchronous operation, and there is no difference in the operation effect.

  As described above, the axial flow fan according to the present invention is operated at a constant speed at the rotation speed synchronized with the power supply frequency, so that even if the external static pressure rises, the reduction in the air volume is small. It is useful to install on air conditioners and cooling units such as ventilators, fans, refrigerators, and air conditioners that are required to secure an appropriate air flow at low cost without installing special circuits. is there.

DESCRIPTION OF SYMBOLS 1 Ventilator 2 Armature winding 3 Cage rotor 4 Stator 5 Conductor bar 6 Permanent magnet 7 Convex side 8 Axial fan 8a Propeller fan 9 Shaft 10 Driving capacitor 11 Electric motor 12 Starting capacitor 13 PTC thermistor 14 Wall

Claims (5)

A rotation axis;
A propeller fan connected to at least one end of the rotating shaft;
A squirrel cage rotor integrated with the outer periphery of the rotating shaft and having a conductor bar;
It is located opposite to this squirrel-cage rotor and includes a stator wound with armature windings,
An axial fan connected to a commercial AC power source,
In the cage rotor, a permanent magnet is disposed at a position where the conductor bar is sandwiched between the stator and the stator,
An axial blower characterized by performing constant operation at a rotational speed synchronized with the power supply frequency of the commercial AC power source in a range from zero external static pressure to approximately maximum external static pressure. The axial flow blower according to claim 1, wherein the conductor bar and the permanent magnet are skewed. 3. The axial flow according to claim 1, wherein the permanent magnet is a bonded magnet in which anisotropic samarium / iron / nitrogen magnetic powder and anisotropic neodymium / iron / boron magnetic powder are mixed. Blower. The electric equipment carrying the axial-flow fan in any one of Claims 1-3. The electric device according to claim 4, wherein the electric device is any one of a ventilator, a fan, a refrigerator, an air conditioner, and a cooling unit.

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