JP2015124735A - Vortex flow fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vortex flow fan capable of effectively suppressing pressure fluctuation on a tongue portion, in particular, between upper and lower surfaces of blades and the tongue portion, and significantly reducing nZ sound and harmonic wave.SOLUTION: A vortex flow fan includes an impeller having blades on an outer periphery of a hub, a motor for rotating the impeller, and a casing composed of a cylindrical portion covering the hub, an annular air chamber covering outer peripheral faces and upper and lower surfaces of the blades joined to an inner wall of the cylindrical portion, a suction port joined to the air chamber, a discharge port joined to the air chamber at a position circumferentially separated from the suction port, and a tongue portion separating the suction port and the discharge port. The tongue portion has the maximum clearance between the tongue portion and the blades at a corner of the tongue portion where a side face at a discharge port side, of the tongue portion and the inner wall of the cylindrical portion intersect, and the clearance is formed into the fan-shaped slant at the corner as the center, so that it is narrowed toward the tip of the fan shape, and becomes uniform at a suction port side from the tip.

Description

  The present invention relates to a vortex fan.

  Conventionally, a vortex fan is known as a blowing means. As a vortex fan, there is a fan configured to contain an impeller having a large number of blades and a motor for rotating the impeller in a substantially U-shaped casing having a suction port and a discharge port (for example, Patent Documents). 1).

  This type of vortex fan is configured to take air into the casing from the suction port and discharge it from the discharge port. Inside the casing, the suction port and the discharge port are separated by a partition called a tongue (stripper part). The air that has traveled through the casing from the suction port is directed toward the discharge port without returning to the suction port.

  The air that has flowed into the casing from the suction port is transported and pressurized by the blades of the impeller that rotates in accordance with the drive of the motor, and travels toward the discharge port. At this time, when the pressurized air hits the tongue, the air is periodically and rapidly compressed in synchronization with the pitch of the blades, and a sound having a frequency called nZ sound represented by the number of rotations × the number of blades and its harmonics are generated. Occur.

  In a vortex fan, it is known to provide a radius on both sides of the entrance corner of the tongue as a structure that can suppress pressure fluctuations caused by sudden compression of air around the tongue and reduce nZ sound and harmonics. (For example, refer to Patent Document 1 and Patent Document 2).

  In addition, a noise-reducing groove that is gradually widened from the suction port side toward the discharge port side, leaving at least an end on the suction port side, on the surface of the partition wall (tongue) facing the impeller, or gradually A structure in which a muffler projection with a narrow width is provided so as to protrude is known (for example, see Patent Document 3).

JP 2008-190837 A JP 2005-282578 A Japanese Utility Model Publication No. 62-116200

  However, as shown in Patent Document 1 and Patent Document 2, even if rounds are provided on both sides of the entrance corner of the tongue, the increase in the pressure of the surrounding air is only temporarily delayed, and the sharpness at the rounded end is abrupt. Pressure fluctuation is inevitable, and the effect of reducing nZ sound and harmonics is small.

  Moreover, according to the silencing groove and the silencing protrusion shown in Patent Document 3, the surface facing the impeller of the partition wall (tongue), that is, between the outer peripheral surface of the impeller and the partition wall (tongue) is abrupt. Although pressure fluctuations can be avoided, sudden pressure fluctuations of air occur more strongly on the upper and lower surfaces of the blades, so the effect of reducing nZ sounds and harmonics is small.

  Therefore, the present invention has been made in view of the above problems, and effectively suppresses pressure fluctuations between the tongue, particularly the upper and lower surfaces of the blade and the tongue, and greatly reduces nZ noise and harmonics. An object of the present invention is to provide a vortex fan that can be used.

The present invention is grasped by the following composition in order to achieve the above-mentioned object.
(1) The vortex fan according to the present invention includes an impeller having blades on the outer periphery of a hub, a motor that rotates the impeller, a cylindrical portion that covers the hub, and the blade that joins the inner wall of the cylindrical portion. An annular air chamber covering the outer peripheral surface and upper and lower surfaces, a suction port joined to the air chamber, a discharge port joined to the air chamber at a position spaced circumferentially from the suction port, the suction port, and the discharge port A casing made of a tongue portion that separates the tongue portion, wherein the tongue portion is formed at a corner of the tongue portion where a side surface of the tongue portion on the discharge port side and the inner wall of the cylindrical portion intersect. The clearance between the blade and the blade is maximized, and the clearance is narrowed toward the fan-shaped tip by forming a fan-shaped slope centered on the corner at the tongue, and the suction from the tip It is constant on the mouth side.

(2) In the configuration (1), the motor is an outer rotor type motor, and includes a rotor shaft fixed to the center of the hub, and a rotor magnet attached to an inner peripheral surface of the hub via a rotor yoke. The hub is used as a rotor housing of the outer rotor type motor.
(3) In the above configuration (2), comprising: a bearing housing that rotatably supports the rotor shaft; and a stator having a winding disposed on the outer periphery of the bearing housing so as to face the rotor magnet, A motor part is formed by the rotor magnet and the stator.

  According to the present invention, it is possible to provide an eddy current fan that can effectively suppress pressure fluctuation between the tongue, particularly the upper and lower surfaces of the blade and the tongue, and can greatly reduce nZ sound and harmonics. it can.

It is a perspective view which shows the basic composition of an eddy current fan. It is AA sectional drawing of FIG. It is a figure for the detailed description of the tongue part of the vortex fan of FIG. It is a figure explaining the result of a pressure fluctuation simulation. It is a figure for demonstrating in detail the tongue part of the eddy current fan of embodiment. FIG. 6 is a sectional view taken along line B-B in FIG. 5. It is a graph of the noise measurement result of the eddy current fan of a reference structure. It is a graph of the noise measurement result of the eddy current fan of examination structure. It is a graph which shows the static pressure-air volume characteristic of a reference structure and examination structure.

  Hereinafter, a preferred embodiment will be described after describing an eddy current fan, which is a basic configuration of the present invention, with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated to the same element through the whole.

[Swirl fan]
FIG. 1 is a perspective view showing the basic configuration of the vortex fan, and FIG. 2 is a cross-sectional view taken along the line AA of FIG.
As shown in FIG. 2, the vortex fan 1 includes a casing 10, an impeller 20, and an outer rotor type motor 30.

As shown in FIG. 2, the impeller 20 includes a cylindrical hub 21 that functions as a rotor housing of the outer rotor type motor 30, and a partition 22 that extends outward from the vertical center of the outer periphery of the hub 21. In addition, a large number of blades 23 and 24 are formed integrally on the upper and lower surfaces of the partition 22. Although not shown, the partition 22 has a disk shape when viewed from above or below, and a large number of blades 23 and 24 are integrally formed on the upper and lower surfaces of the disk shape in the circumferential direction.
In the following description, the blades 23 protruding from the upper surface of the partition 22 are referred to as upper blades 23 and the blades 24 protruding from the lower surface of the partition 22 are referred to as lower blades 24 as necessary.

A large number of blades 23 and 24 extend radially from the outer peripheral portion of the hub 21, and a groove-like space into which air flows is formed between the adjacent blades 23 and between the adjacent blades 24. To do.
Although not shown, the blades 23 and 24 extend from the outer peripheral portion of the hub 21 so that the tip side is curved in the radial direction along the radial direction, but the blades extend linearly. It may have a shape, or may extend so as to be curved upstream.

  As shown in FIG. 2, the casing 10 includes a cylindrical portion 13 formed so as to cover the hub 21 at the center, and upper and lower surfaces and outer periphery of a large number of blades 23 and 24 joined to the outer periphery of the cylindrical portion 13. An annular portion covering the surface is formed, and the annular portion forms the air chamber 14.

  As shown in FIG. 1, the casing 10 includes a suction port 11 joined to the annular air chamber 14 and a discharge port 12 joined to the annular air chamber 14 at a position spaced from the suction port 11 in the circumferential direction. And a tongue 15 between the suction port 11 and the discharge port 12.

  The tongue 15 is sucked from the suction port 11 by the rotation of the impeller 20 in the casing 10, and the air that has flowed to the discharge port 12 side through the air chamber 14 on the outer periphery of the casing 10 is again drawn into the suction port. 11 is for preventing the return to the 11 side, and the inner wall surface of the annular air chamber 14 is brought close to the blades 23 and 24 to reduce the clearance.

Therefore, the air that has reached the discharge port 12 cannot be returned to the suction port 11 side through the tongue portion 15 having a small clearance, and is thus efficiently discharged from the discharge port 12.
Thus, the tongue 15 separates the air flow path between the discharge port 12 and the suction port 11 so that air does not flow from the discharge port 12 to the suction port 11.

An annular air chamber 14 from the suction port 11 to the discharge port 12 of the casing 10 is substantially U-shaped (see FIG. 1).
As shown in FIG. 2, the outer rotor type motor 30 includes a bearing housing 31, a stator 32 fixed to the outer peripheral portion of the bearing housing 31, and a rotor magnet 39 disposed so as to face the outer peripheral portion of the stator 32. And a rotor 33 including the same.

  The bearing housing 31 is a cylindrical member in which a pair of upper and lower bearings 34 are mounted on the inner peripheral portion, and is fitted into a fitting cylinder portion 16 formed at the bottom portion of the casing 10, whereby the inner center of the casing 10. Standing at the position.

  The stator 32 includes a stator core 35 fixed to the outer peripheral portion of the bearing housing 31, an insulator 36 provided in a coil winding portion of the stator core 35, and a plurality of coils (windings) wound around the stator core 35 via the insulator 36. 37).

  The rotor 33 is fixed to the center of the hub 21 or the rotor yoke 38, the rotor yoke 38 that is integrally provided inside the hub 21, a plurality or a single rotor magnet 39 that is attached to the inner peripheral portion of the rotor yoke 38 in the circumferential direction. The rotor shaft 40 is configured to rotate about the rotor shaft 40 by being supported by the bearing housing 31 via the bearing 34.

  The outer rotor type motor 30 is a so-called outer rotor type that rotates the impeller 20 integrated with the rotor 33 by sequentially supplying current to a plurality of coils 37 at a predetermined timing from a power source (not shown). The eddy current fan 1 is configured.

Next, the tongue structure of the casing 10 will be described.
[Tongue structure]
As described above, the tongue 15 of the casing 10 has the suction port 11 and the discharge port 12 so that the air that has traveled through the casing 10 from the suction port 11 is directed to the discharge port 12 without returning to the suction port 11 again. It is the part which isolates between.

  Specifically, as shown in FIG. 2, the tongue portion 15 includes an upper tongue portion 15 a that narrows the clearance between the upper end of the upper blade 23 and the casing 10, and a clearance between the lower end of the lower blade 24 and the casing 10. And a lower tongue portion 15b that narrows the clearance between the outer peripheral ends of the blades 23 and 24 and the casing 10.

Further, as described above, the tongue portion 15 is not a portion allowing clearance between the blades 23 and 24 like the air chamber 14, but a portion formed so that the inner wall surface is as close to the blades 23 and 24 as possible. It is.
Therefore, the upper and lower wall surfaces of the tongue 15 have a structure projecting inward from the upper and lower wall surfaces of the air chamber 14 so as to be closer to the blades 23 and 24 than the upper and lower wall surfaces of the air chamber 14.

  Therefore, a step is formed at the boundary portion where the air chamber 14 and the tongue portion 15 shown in FIG. 3 are in contact, that is, the side surface on the discharge port 12 side of the tongue portion 15. The following consideration was made on the step surface 15d that can be formed.

In the state where the impeller 20 is rotated in accordance with the driving of the outer rotor type motor 30, the vortex fan 1 is conveyed and pressure-intensified by the impeller 20 by the air flowing into the casing 10 from the suction port 11, and is supplied to the discharge port 12. Head.
At this time, the air repeats the flow of being discharged from the tips of the blades 23 and 24 and returning to the root. The airflow in the vicinity of the root (hub 21 side) is air that is located inside the impeller 20 and therefore is far from the discharge port 12 and is not easily discharged from the discharge port 12 efficiently.

For this reason, it is considered that such air tends to go toward the inlet 11 as the impeller 20 rotates.
However, as described above, the side surface of the tongue portion 15 on the discharge port 12 side has a step surface 15d that protrudes inward, so it is considered that the air that is directed toward the suction port 11 collides with the step surface 15d. .

  This air collision occurs periodically in synchronism with the pitch of the blades 23 and 24, and is considered to be subjected not only to the collision but also to rapid compression at the same time. For this reason, it is represented by the number of rotations × the number of blades. I thought that the sound of the frequency called nZ sound and its harmonic were generated.

Therefore, a pressure fluctuation simulation was performed to confirm this phenomenon.
FIG. 4 shows the results obtained by the pressure fluctuation simulation in an easy-to-understand manner.

  As shown in FIG. 4, the pressure fluctuation is greatest in the vicinity of the roots of the blades 23 and 24 on the step surface 15d on the side of the discharge port 12 of the tongue 15, while the air near the tips of the blades 23 and 24 is discharged. Since it was discharged | emitted to the exit 12, it became clear that the pressure fluctuation range was small.

  Therefore, the inventor of the present application increases the clearance between the blades 23, 24 and the tongue 15 (upper tongue 15a, lower tongue 15b) of the tongue 15 of the vortex fan 1 where the pressure fluctuation is large, It was thought that the generation of the sound of the frequency called nZ sound and its harmonics on the stepped surface 15d could be suppressed by gradually reducing the clearance from there and suppressing the rapid increase in pressure.

  That is, with reference to FIG. 2, the tongue portion 15 has an upper tongue portion 15 a and a lower tongue portion 15 b that face the upper and lower surfaces of the blades 23 and 24, and an outer peripheral tongue that faces the tip surfaces of the blades 23 and 24. When divided into the portion 15c, there is little pressure fluctuation between the blades 23, 24 and the outer peripheral tongue portion 15c, so that a constant clearance is maintained.

  On the other hand, between the blades 23 and 24 and the upper tongue portion 15a and the lower tongue portion 15b, as shown in FIG. Since the pressure fluctuation is the highest at the corner 15e near the base, this part increases the clearance with the blades 23, 24 to reduce the step, and the clearance is increased as it advances toward the suction port 11 side and the tip side of the blades 23, 24. The pressure is gradually increased by gradually decreasing the pressure. In this way, it was considered that the pressure fluctuation accompanying the rapid pressure increase can be suppressed, and the generation of nZ sound and harmonics can be reduced.

Hereinafter, the tongue structure of the present embodiment based on this idea will be described in more detail with reference to FIGS.
FIG. 6 shows the cross section of FIG. 5, but in order to make the structure of the tongue 15 described above easy to understand, not a linear cross section passing through the tongue 15 but a portion in the middle of taking the cross section, FIG. 6 is a cross-sectional view taken along the line BB in which a cross-section is taken so as to pass through OABO ′ of FIG. 5.

As shown in FIG. 5, the tongue portion 15 of the vortex fan 100 of the present embodiment is a corner portion 15 e where the side surface 15 h on the discharge port 12 side of the tongue portion 15 intersects with the inner wall of the cylindrical portion 13 of the casing 10. As shown in FIG. 6, the clearance between the tongue 15 and the blades 23 and 24 is maximized.
Further, as shown in FIG. 5, the clearance is formed in a fan shape around the corner portion 15e on the tongue portion 15 and the surface thereof is formed with a slope 15f, so that the clearance becomes narrower toward the fan-shaped tip. As can be seen from FIG. 3, the suction port 11 is constant from the tip.

  In terms of shape, the tongue portion 15 of the present embodiment is formed in a substantially trapezoidal shape with a part of the cylindrical portion 13 as one side, as shown in FIG. At the corner 15e on the side of the discharge port 12, the clearance between the tongue 15 and the blades 23 and 24 is maximized, and the fan-shaped slope 15f centered on the corner 15e is formed on the tongue 15 (upper tongue 15a, lower It is formed on the side tongue 15b (see FIG. 6), and has a shape in which the clearance with the blades 23 and 24 is reduced on the fan-shaped tip side.

In order to confirm the effect associated with the shape of the tongue portion 15 as described above, the structure of the present embodiment (hereinafter referred to as “reviewed structure”) and the basic configuration described with reference to FIGS. With the structure (hereinafter referred to as “reference structure”), the rotation speed of the impeller was 5900 rpm, and noise measurement was performed at a position 1 m from the suction port.
The results are shown in FIGS. FIG. 7 shows the measurement results of the reference structure, and FIG. 8 shows the measurement results of the study structure.
Looking at these results, the nZ component of about 30 dBA around 4.5 kHz, which was seen in the reference structure, is no longer confirmed in the study structure, and good results could be obtained.

  Further, FIG. 9 shows PQ characteristics (static pressure-air flow characteristics) between the study structure and the reference structure when the rotation speed is the same. The PQ characteristics of the study structure are the PQ characteristics of the reference structure. As a result, it was confirmed that the studied structure was able to reduce the nZ component without problems such as performance degradation.

  According to the vortex fan 100 of the embodiment described above, as shown in FIG. 6, the impeller 20 having the blades 23 and 24 on the outer periphery of the hub 21, the outer rotor type motor 30 that rotates the impeller 20, The cylindrical portion 13 covering the hub 21, the outer peripheral surfaces of the blades 23, 24 joined to the outer periphery of the cylindrical portion 13, and the annular air chamber 14 covering the upper and lower surfaces, and the suction port 11 and the suction port joined to the air chamber 14 A casing 10 comprising a discharge port 12 joined to the air chamber 14 at a position spaced apart from the air chamber 11 and a tongue portion 15 separating the suction port 11 and the discharge port 12, as shown in FIG. The tongue portion 15 maximizes the clearance between the tongue portion 15 and the blades 23 and 24 at the corner portion 15e of the tongue portion 15 where the side surface 15h on the discharge port 12 side of the tongue portion 15 and the inner wall of the cylindrical portion 13 intersect. And this clearance is the tongue 15 Since the fan-shaped inclined surface 15f is formed around the corner 15e, it narrows toward the fan-shaped tip and is constant from the tip to the suction port 11 side. Pressure fluctuations at the upper and lower surfaces can be effectively suppressed, and nZ sounds and harmonics can be greatly reduced.

  Further, as shown in FIG. 6, the vortex fan 100 according to the present embodiment has an outer rotor type motor 30 as a motor, a rotor shaft 40 fixed to the center of the hub 21, and a rotor yoke 38 on the inner peripheral surface of the hub 21. And the hub 21 is used as the rotor housing of the outer rotor type motor 30, so that the outer rotor type for rotating the impeller 20 with respect to the impeller 20 is provided. Compared with a case where a motor is separately provided, the structure of the outer rotor type motor can be made compact.

  Further, as shown in FIG. 6, the vortex fan 100 of the present embodiment includes a bearing housing 31 that rotatably supports the rotor shaft 40, and a coil that is disposed on the outer periphery of the bearing housing 31 so as to face the rotor magnet 39. Since the outer rotor type motor 30 is configured by the rotor magnet 39 and the stator 32, the vortex fan 100 in which the motor unit is housed can be configured compactly.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 1 Eddy current fan 10 Casing 11 Inlet port 12 Outlet port 13 Cylindrical part 14 Air chamber 15 Tongue part 15a Upper tongue part 15b Lower tongue part 15c Outer peripheral side tongue part 15d Step surface 15e Corner | angular part 15f Slope 15h Side face 16 Fitting cylinder part 20 impeller 21 hub 23 blade 24 blade 30 outer rotor type motor 31 bearing housing 32 stator 33 rotor 34 bearing 35 stator core 36 insulator 37 coil 38 rotor yoke 39 rotor magnet 40 rotor shaft 100 vortex fan

Claims (3)

An eddy current fan,
An impeller having blades on the outer periphery of the hub;
A motor for rotating the impeller;
A cylindrical portion covering the hub, an outer circumferential surface of the blade joined to the inner wall of the cylindrical portion, an annular air chamber covering the upper and lower surfaces, a suction port joined to the air chamber, and a circumferential direction from the suction port A casing comprising a discharge port joined to the air chamber at a spaced position, and a tongue portion separating the suction port and the discharge port;
The tongue portion maximizes the clearance between the tongue portion and the blade at the corner of the tongue portion where the side surface on the discharge port side of the tongue portion and the inner wall of the cylindrical portion intersect,
The clearance is narrowed toward the fan-shaped tip by forming a fan-shaped slope centered on the corner of the tongue, and is constant from the tip to the suction port side. Eddy current fan. The motor is an outer rotor type motor;
A rotor shaft fixed to the center of the hub;
A rotor magnet attached to the inner peripheral surface of the hub via a rotor yoke,
The vortex fan according to claim 1, wherein the hub is used as a rotor housing of the outer rotor type motor. A bearing housing that rotatably supports the rotor shaft;
A stator having a winding disposed on the outer periphery of the bearing housing so as to face the rotor magnet;
The eddy current fan according to claim 2, wherein a motor portion is formed by the rotor magnet and the stator.