JP4467952B2 - Propeller fan, outdoor unit for air conditioner using this - Google Patents

Description

  The present invention relates to a propeller fan and an outdoor unit for an air conditioner using the same, and more particularly to a propeller fan having an improved blade shape and an outdoor unit for an air conditioner using the same.

  Propeller fans are often used in outdoor units of air conditioners, etc., but conventional propeller fans are generally recessed at the trailing edge of the blade, which is the outflow part of the air flow during fan rotation, in the direction opposite to the air flow. It has a plurality of blades provided with arc-shaped trailing edge recesses, and these blades are arranged at equal intervals of 120 ° around the fan rotation axis. The ratio σ = L / T, that is, the solidity σ is 0 when the length L of the blade chord line and the pitch between blades T = (2πR / Z) [R :: blade radius, Z: number of blades]. .6 or more was common.

  However, in the conventional fan in which the blades provided with the substantially arc-shaped trailing edge recesses are arranged at equal intervals of 120 ° around the fan rotation axis and the solidity σ is 0.6 or more, the blade gap is Because of the small size, there is a problem that the blowing noise generated while interfering with each other between adjacent blades increases, and the loss of air flow occurs, so that the load (motor input) applied to the motor that drives the fan increases. there were.

In Patent Document 1, a plurality of blades are integrally formed around the hub, and a corner portion where the blade trailing edge portion that contacts the rotating air outflow portion and the blade outer peripheral portion intersect is projected in the air outflow direction. Propeller fan that can keep the load on the motor low even when forming the bulging part that swells in the shape and defining the shape of the bulging part and increasing the rotation speed to increase the air flow rate Proposed. However, the propeller fan of Patent Document 1 is to reduce the load on the propeller fan motor of a plurality of blades, and does not reduce the blowing noise generated while interfering between adjacent blades of the plurality of blades. No consideration is given to noise reduction.
JP 2003-65295 A (paragraphs [0014] and [0026], FIG. 2)

  The present invention has been made in consideration of the above-described circumstances, and provides a propeller fan that can reduce blowing noise generated while interfering between adjacent blades and can reduce a load applied to a motor that drives the fan. For the purpose. Another object of the present invention is to provide an outdoor unit for an air conditioner that can reduce blowing noise and reduce the load applied to the motor.

In order to achieve the above object, according to one aspect of the present invention, in a propeller fan in which two blades are provided on a hub attached to a fan rotation shaft, the blades correspond to an air flow outflow portion during fan rotation. The rear edge of the blade is provided with a substantially arc-shaped, V-shaped, or polygon-shaped rear edge recess recessed in the direction opposite to the air flow, and one blade is 180 ° ± 5 ° centered on the fan rotation axis. When the blade outer diameter dimension D ₁ , the hub outer diameter dimension D ₂ , and Rm = (D ₁ −D ₂ ) / 2 are arranged in a point-symmetrical manner with respect to the other blade in the range , 0.75 Rm to 1.25 Rm The propeller fan is characterized in that the blades are arranged so that the solidity σ = L / T consisting of the chord line length L and the blade pitch T is 0.3 to 0.55. Realized.

According to one aspect of the present invention, in a propeller fan in which two blades are provided on a hub attached to a fan rotation shaft, the blades have an air flow at a blade trailing edge corresponding to an outflow portion of the air flow during fan rotation. Are provided with a substantially arc-shaped, V-shaped, or polygonal trailing edge recess recessed in the opposite direction, and one of the blades is approximately 180 ° ± 5 ° around the fan rotation axis. The trailing edge recesses of the blades are arranged symmetrically, and b1 ≦ 0 when the length of a line connecting the inner peripheral side end point and the outer peripheral side end point with a straight line is b and the length of the trailing edge recess is b1. When the distance between the inner peripheral side end point and the point corresponding to the maximum depth of the trailing edge concave portion is C1, C1 ≧ 0.7b is realized.

  According to the propeller fan according to the present invention, it is possible to provide a propeller fan capable of reducing the blowing noise generated while interfering with each other between adjacent blades and reducing the load applied to the motor that drives the fan.

  FIG. 1 is a front view of a propeller fan according to the present invention, and FIG. 2 is a perspective view thereof.

As shown in FIGS. 1 and 2, a propeller fan 1 according to the present invention is provided with two blades 3 and 3 having the same shape on a hub 2 attached to a fan rotation shaft A. The blade trailing edge portions 3a and 3a corresponding to the outflow portion of the air flow during fan rotation are provided with substantially arc-shaped, V-shaped, or polygonal trailing edge recess portions 3b and 3b recessed in the opposite direction to the air flow. . Further, one blade 3 is arranged substantially symmetrically with the other blade 3 within a range of 180 ° ± 5 ° around the fan rotation axis A.

Further, as shown in FIG. 3, for example, the substantially arc-shaped trailing edge recesses 3 b and 3 b provided on the blades 3 and 3 include a blade outer diameter D ₁ , a hub outer diameter D ₂ , and Rm = (D ₁ − When D ₂ ) / 2, the solidity σ = L / T consisting of the chord line length L and the inter-blade pitch T in the range of 0.75 Rm to 1.25 Rm is 0.3 to 0.55. Wings 3 and 3 are arranged adjacent to each other. Here, the solidity means the ratio σ = L / T when the length L of the chord line and the pitch T between blades = (2πR / Z) [R :: blade radius, Z: number of blades]. is there. The chord line length L at this time indicates the chord length of the line where the wing 3 and the circle intersect when a circle is drawn with a radius D from the center of the fan rotation axis, as shown in FIG.

  The solidity σ is preferably 0.3 to 0.55. Accordingly, as can be seen from the measurement diagram showing the relationship between the solidity, the motor input, and the noise level shown in FIG. 5, the motor input 42 W or less and the noise level 42 dB or less are realized, noise reduction, load applied to the motor (motor input) ) Is reduced. If σ is smaller than 0.3 or larger than 0.55, motor input 42 W or less and noise level 42 dB or less cannot be realized, and noise and motor input cannot be reduced.

  Further, as shown in FIG. 6, for example, a substantially arc-shaped trailing edge concave portion 3 b provided on the wing 3 has a length of b connecting the inner peripheral side end point Q and the outer peripheral side end point P with a straight line, and a rear edge. When the length b1 of the recess 3b is set, b1 ≦ 0.6b, and when the distance from the inner peripheral side end point Q to the point C corresponding to the maximum depth of the trailing edge recess 3b is C1, C1 ≧ 0.7 Set to be. Thus, as can be seen from the measurement diagram showing the relationship between the linear length b1 of the trailing edge recess and the motor input shown in FIG. 7, the relationship between the motor input and b1 is the motor input as b1 approaches 0.6b. When b1 ≦ 0.6b, a motor input of 42.6 W or less can be achieved. When b1> 0.6b, the motor input exceeds 42.6 W, and the low input is not realized.

  Moreover, as can be seen from the measurement diagram showing the relationship between the distance C1 to the maximum depth of the trailing edge recess shown in FIG. 8 and the noise, when C1 ≧ 0.7, the noise is reduced to about 49.5 dB or less. Is done. When C1 <0.7, noise reduction is not realized exceeding about 49.5 dB.

  In the present embodiment, the trailing edge recess 3a provided in the blade 3 has been described as having a substantially arc shape. However, as shown in FIG. 9, the V-shaped trailing edge recess 3a1 of the blade 3 of the propeller fan 1 is used. Alternatively, as shown in FIG. 10, the effect of the present invention can also be realized by using the polygonal trailing edge recess 3 a 2 of the blade 3 of the propeller fan 1.

According to the propeller fan of the present embodiment as described above, the blade is composed of two blades, the trailing edge recess is provided on the blade, and one blade has a range of 180 ° ± 5 ° around the fan rotation axis. by in being arranged substantially symmetrically with the other wing, than conventional, it is possible to increase the inter-blade distance, is tip vortices made of blade surface of the rotating in the fan hardly interfere with the adjacent blades Thus, it is possible to reduce the blowing noise and to suppress the air flow loss, and to reduce the motor input. Further, by setting the solidity σ to 0.3 to 0.55, noise and motor input can be reduced. Further, by specifying the shape of the trailing edge recess, noise can be further reduced and the load applied to the motor can be reduced.

  Next, an outdoor unit for an air conditioner using the propeller fan according to the present invention will be described.

  As shown in FIG. 11, the outdoor unit 11 includes a planar L-shaped outdoor heat exchanger 13, a propeller fan 1 that is an outdoor fan according to the present invention, a compressor 14, a four-way valve 15, A controller 16 such as an inverter is accommodated, and the propeller fan 1 and the compressor 14 are partitioned by a partition plate 17.

  As described above, the propeller fan 1 has both reduced noise and reduced load applied to the motor. Therefore, the outdoor unit using the propeller fan 1 can reduce both the blowing noise and the load applied to the motor. Can do.

The front view of one Embodiment of the propeller fan which concerns on this invention. The perspective view of one Embodiment of the propeller fan which concerns on this invention. The front view for demonstrating the shape of the propeller fan which concerns on this invention. Explanatory drawing of the length of the chord line of the wing | blade of the propeller fan which concerns on this invention. The measurement diagram which shows the solidity of the propeller fan which concerns on this invention, motor input, and the relationship of a noise level. The front view for demonstrating the shape of the blade | wing of the propeller fan which concerns on this invention. The measurement diagram which shows the relationship between the linear length of the trailing edge recessed part of the propeller fan which concerns on this invention, and a motor input. The measurement diagram which shows the relationship between the distance to the maximum depth of the trailing edge recessed part of the propeller fan which concerns on this invention, and noise. The front view of other embodiment of the propeller fan which concerns on this invention. The front view of other embodiment of the propeller fan which concerns on this invention. The cross-sectional view of the outdoor unit for an air conditioner according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Propeller fan, 2 ... Hub, 3 ... Wing, 3a ... Blade trailing edge part, 3b ... Trailing edge recessed part, A ... Rotating shaft.

Claims (3)

In the propeller fan in which two blades are provided on a hub attached to the fan rotation shaft, the blades are substantially arc-shaped indented in a direction opposite to the air flow at the blade trailing edge corresponding to the outflow portion of the air flow during fan rotation, Or a V-shaped or polygonal trailing edge concave portion is provided, and one of the blades is arranged substantially symmetrically with the other blade in the range of 180 ° ± 5 ° around the fan rotation axis,
When the blade outer diameter D ₁ , the hub outer diameter D ₂ , and Rm = (D ₁ −D ₂ ) / 2, the chord line length L and the blade are in the range of 0.75 Rm to 1.25 Rm. A propeller fan characterized in that the wings are arranged so that the solidity σ = L / T composed of the interstitial pitch T is 0.3 to 0.55 . In the propeller fan in which two blades are provided on a hub attached to the fan rotation shaft, the blades are substantially arc-shaped indented in a direction opposite to the air flow at the blade trailing edge corresponding to the outflow portion of the air flow during fan rotation, Or a V-shaped or polygonal trailing edge concave portion is provided, and one of the blades is arranged substantially symmetrically with the other blade in the range of 180 ° ± 5 ° around the fan rotation axis,
The trailing edge recess of the wing is b1 ≦ 0.6b, where b is the length of a line connecting the inner peripheral side end point and the outer peripheral side end point with a straight line, and the length of the trailing edge recess is b1. A propeller fan , wherein C1 ≧ 0.7b, where C1 is a distance between an inner peripheral end point and a point corresponding to the maximum depth of the trailing edge recess . An outdoor unit for an air conditioner, wherein the propeller fan and the heat exchanger according to claim 1 or 2 are accommodated in an outdoor unit main body.

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