JP7241667B2 - propeller fan - Google Patents

Description

The present invention relates to a propeller fan that blows air by rotating.

For example, an outdoor unit of an air conditioner is provided with a propeller fan for blowing air to a heat exchanger. Patent Document 1 discloses a conventional technology related to such a propeller fan.

A propeller fan as shown in Patent Document 1 has a boss rotatably provided on an axis and a plurality of blades extending outward from the boss and rotatable together with the boss. A substantially V-shaped concave portion is formed toward the front on the trailing edge of the blade portion.

JP 2016-56772 A

If the propeller fan used for blowing air can blow a large amount of air with less energy, it is possible to reduce the size and weight of the device in which the propeller fan is installed, which is preferable. That is, it is desired to provide a propeller fan with high blowing efficiency.

An object of the present invention is to provide a propeller fan with high blowing efficiency.

According to the present invention, in a propeller fan having a boss rotatably provided on an axis serving as the center of rotation, and a plurality of blade portions extending outward from the boss and rotatable together with the boss,
The vane has a front edge that is a front edge, a rear edge that is a rear edge, an inner edge that is a boundary edge with the boss, and an outer edge with respect to the axis. an outer edge that is an edge formed in the
The trailing edge includes a recess formed in a concave shape toward the front,
The concave portion has an innermost point, which is the innermost point, with respect to the radial direction about the axis, an outermost point, which is the outermost point, and an outermost point with respect to the rotational direction of the blade portion. a frontmost point, which is a point located at
The distance from the axis to the innermost part is r1, the distance from the axis to the outermost part is r2, the distance from the axis to the inner edge is rb, and the distance from the axis to the outer edge is rf. When the value obtained by (r2-r1) / (rf-rb) is 0.05 or more and 0.17 or less,
The arc length from the frontmost portion to the front edge centered on the axis is l1, the arc length from the outermost part to the front edge about the axis is l2, and the axis is the center. Let t1 be the length of the arc passing through the foremost portion of the arc from the front edge portion to the front edge portion of the blade portion adjacent to the rear, and from the front edge portion centered on the axis line to the rear When the length of the arc passing through the outermost portion of the arcs to the leading edges of the adjacent blade portions is t2, the value obtained by (l2/t2)/(l1/t1) is: 1. There is provided a propeller fan characterized in that it is 4 or more and 1.6 or less.

In the present invention, the trailing edge of the vane includes a recess formed in a concave shape toward the front. , and the foremost point, which is the most forward-located point. When the distance from the axis to the innermost part is r1, the distance from the axis to the outermost part is r2, the distance from the axis to the inner edge is rb, and the distance from the axis to the outer edge is rf, (r2- The value obtained by r1) / (rf-rb) is 0.05 or more and 0.17 or less, and the arc length from the forefront part to the front edge part centered on the axis is l1, and the axis is the center Let l2 be the arc length from the outermost part to the leading edge, and let t1 be the length of the arc passing through the foremost part of the arcs from the leading edge centered on the axis to the leading edge of the rear adjacent blade part. and the length of the arc passing through the outermost part is t2, the value obtained by (l2/t2)/(l1/t1) is 1.4 or more and 1.6 or less. It has been found that a propeller fan having blades satisfying such conditions has a high blowing efficiency. A propeller fan with high air blowing efficiency can be provided by forming the shape of the blade portion into a shape that satisfies a predetermined condition.

1 is a schematic diagram of an air conditioner equipped with a propeller fan according to Embodiment 1. FIG. It is a figure explaining a propeller fan, a heat exchanger, and a bell mouth which are shown by FIG. 3 is a front view of the propeller fan shown in FIG. 2; FIG. 4 is an enlarged view of the boss and vane shown in FIG. 3; FIG. It is a figure explaining the relationship of l1, l2, t1, and t2. It is a figure explaining the relationship between the shape of a blade|wing part, and fan efficiency. FIG. 8 is an enlarged view of a main portion of a propeller fan according to Embodiment 2;

An embodiment of the present invention will be described below with reference to the accompanying drawings.

<Example 1>
Please refer to FIG. FIG. 1 shows an air conditioner device 10 including a propeller fan 40. As shown in FIG. The air conditioner 10 has a cooling function for cooling the indoor In and a heating function for heating the indoor In.

The air conditioner 10 includes an outdoor unit 20 installed outdoors Ou and an indoor unit 30 installed indoors In. The outdoor unit 20 and the indoor unit 30 are connected to each other so that the refrigerant can be circulated. Hereinafter, unless otherwise specified, the direction in which the refrigerant circulates is based on that during the cooling operation.

The outdoor unit 20 includes a four-way switching valve 21 that switches the direction of refrigerant circulation during cooling operation and heating operation, a compressor 22 that compresses the refrigerant through which the refrigerant that has passed through the four-way switching valve 21 flows, and this An outdoor heat exchanger 23 through which the refrigerant compressed in the compressor 22 to become high temperature and high pressure flows, a propeller fan 40 for passing air through the outdoor heat exchanger 23, and these outdoor heat exchanger 23 and propeller fan 40 and an expansion valve 26 for reducing the pressure of the refrigerant that has passed through the outdoor heat exchanger 23 .

Please refer to FIG. Propeller fan 40 is rotatably supported by motor 27 inside bell mouth 25 .

Also refer to FIG. By operating the motor 27 and rotating the propeller fan 40 , air can be blown toward the outside of the outdoor unit 20 . On the other hand, the downstream side (left side in the drawing) of the propeller fan 40 becomes negative pressure, and air is drawn from the outside of the bellmouth 25 toward the propeller fan 40 . An outdoor heat exchanger 23 is arranged at a position through which the drawn air passes. As the drawn air passes through the outdoor heat exchanger 23, the refrigerant flowing inside the outdoor heat exchanger 23 is cooled.

The indoor unit 30 is hung on the wall Wa indoors In. In the indoor unit 30, a case 31 having an air blowing port 31b is fixed to a wall Wa. The case 31 is provided with an indoor fan 32 for taking in and blowing indoor air, and an indoor heat source for cooling the air taken in by the indoor fan 32. The exchanger 33 is housed.

During cooling operation, the refrigerant that has been brought to a high temperature and high pressure by the compressor 22 exchanges heat with the outside air in the outdoor heat exchanger 23 and releases heat. At this time, by operating the propeller fan 40, the outside air is forcibly flowed to the outer periphery of the outdoor heat exchanger 23 to promote heat exchange. The refrigerant that has passed through the outdoor heat exchanger 23 and has released heat is decompressed in the expansion valve 26, and the temperature of the refrigerant drops. The refrigerant whose temperature has decreased is sent to the indoor heat exchanger 33 .

At this time, if the amount of air blown by the propeller fan 40 can be increased, the amount of air passing through the outdoor heat exchanger 23 can be increased, and the refrigerant can be cooled more reliably. Therefore, the propeller fan 40 is required to have a high blowing efficiency.

The low-temperature refrigerant sent to the indoor heat exchanger 33 exchanges heat with the indoor In air in the indoor heat exchanger 33 to cool the indoor air. The cooled air is sent indoors In by the indoor fan 32 . The indoor fan 32 forcibly flows air to the outer periphery of the indoor heat exchanger 33 to promote heat exchange.

During heating operation, the four-way switching valve 21 switches the flow path of the refrigerant to circulate the refrigerant in the direction opposite to that during cooling operation.

Please refer to FIG. The propeller fan 40 includes a boss 41 supported by the motor 27 (see FIG. 2) and rotatably provided on the axis O, which is the center of rotation. and a blade portion 50 for blowing air.

Three blade portions 50 are formed integrally with the boss 41 and extend radially outward from the side wall of the boss 41 . The three blade portions 50 have the same shape and are formed at equal intervals in the circumferential direction of the boss 41 .

Please refer to FIG. The front edge is called a front edge portion 51 and the rear edge is called a rear edge portion 60 with respect to the rotation direction (see arrow) of the blade portion 50 . Further, the edge of the boundary with the boss 41 is called an inner edge portion 53 , and the edge formed on the outside with respect to the axis O is called an outer edge portion 54 .

The front edge portion 51, the rear edge portion 60, the inner edge portion 53, and the outer edge portion 54 are each obliquely formed with respect to a plane perpendicular to the axis O. As shown in FIG. That is, the blade portion 50 is formed to be inclined in the front and back direction of the drawing.

The trailing edge portion 60 includes a concave portion 61 extending substantially radially about the axis O and recessed forward in a substantially V shape. The recess 61 is entirely formed at a position closer to the axis O than the center 60 c of the trailing edge 60 .

The inner edge portion 53 and the outer edge portion 54 are formed substantially along the circumferential direction with the axis O as the center.

With respect to the radial direction about the axis O, the innermost point of the concave portion 61 is called the innermost point 61i, and the outermost point is called the outermost portion 61?. With respect to the rotation direction of the blade portion 50, the most forward point is called the frontmost portion 61f, and the rearmost point outside the frontmost portion 61f is called the rearmost portion 61r.

In the state shown in the figure, the outermost portion 61? and the rearmost portion 61r are aligned. That is, the outermost portion 61? can be appropriately read as "the rearmost portion 61r". Further, the rearmost portion 61r can be appropriately read as "the outermost portion 61?".

From the innermost portion 61i to the foremost portion 61f, the portion gradually separates from the axis O and is formed in a curved shape. The frontmost portion 61f to the rearmost portion 61r are formed in a substantially straight line.

The innermost portion 61 i coincides with the rear end of the inner edge portion 53 .

As described above, the recess 61 is entirely formed at a position closer to the axis O than the center 60c of the trailing edge 60, so naturally the outermost portion 61? can be said to be formed at a position close to .

Let r1 be the distance from the axis O to the innermost part 61i, r2 be the distance from the axis O to the outermost part 61o, rb be the distance from the axis O to the inner edge 53, and rf be the distance from the axis O to the outer edge 54. and

At this time, the relationship between r1, r2, rb, and rf satisfies the following equation (1).
0.05≤(r2-r1)/(rf-rb)≤0.17 (1)

Please refer to FIG. The arc length from the frontmost portion 61f to the front edge portion 51 centering on the axis O is l1, the arc length from the outermost portion 61o to the front edge portion 51 centering on the axis O is l2, and the axis O is the center. Let t1 be the length of the arc passing through the foremost portion 61f of the arc from the front edge portion 51 to the front edge portion 51 of the blade portion 50 adjacent to the rear, and from the front edge portion 51 centered on the axis O to the rear Let t2 be the length of the arc passing through the outermost portion 61?

The relationship between l1, l2, t1, and t2 satisfies the following equation (2).
1.4≦(l2/t2)/(l1/t1)≦1.6 (2)

The inventors conducted an experiment on the propeller fan 40 described above. This will be explained below.

Please refer to FIGS. Based on the knowledge that the fan efficiency varies depending on the size of the recess 61, the inventors created a plurality of propeller fans 40 with different shapes of the recess 61, and investigated the fan efficiency of these. The width of the recess 61 is indicated by α=(r2-r1)/(rf-rb) and the depth of the recess 61 is indicated by β=(l2/t2)/(l1/t1).

The conditions other than the shape of the recessed portion 61 in the propeller fan 40 are the same, and the rotation speed of the propeller fan 40 when the motor that rotates the propeller fan and the fan efficiency is measured is also the same at 700 rpm.

The horizontal axis of FIG. 6 is β, and the vertical axis is fan efficiency. Line 71 shows the results when α=0.05, line 72 shows the results when α=0.17, line 73 shows the results when α=0.24, line 74 shows the result when α=0.33.

The fan efficiency of the propeller fan without the concave portion 61 was 0.375.

Lines 71 and 72 exceeded the passing criterion of 0.415 for fan efficiency. On the other hand, lines 73 and 74 did not exceed the passing criterion of 0.415 for fan efficiency. Since the fan efficiency without the concave portion is 0.375, it can be said that α=0 is also unacceptable.

In line 71, the fan efficiency exceeds 0.415 at 1.4 to 1.7, and in line 72, the fan efficiency exceeds 0.415 at 1.25 to was 1.6.

For these reasons, a propeller fan with high fan efficiency can be obtained by forming the recessed portion 61 satisfying 0.05≦α≦0.17 and 1.4≦β≦1.6 in the trailing edge portion 60. I found that I can do it.

Effects of the propeller fan 40 described above will be described below.

Please refer to FIG. A trailing edge portion 60 of the blade portion 50 includes a concave portion 61 formed in a concave shape toward the front. and an outermost point 61?, which is the outermost point. Let r1 be the distance from the axis O to the innermost part 61i, r2 be the distance from the axis O to the outermost part 61o, rb be the distance from the axis O to the inner edge 53, and rf be the distance from the axis O to the outer edge 54. , the value obtained by (r2-r1)/(rf-rb) is 0.05 or more and 0.17 or less, and the arc from the foremost portion 61f to the front edge portion 51 centered on the axis O Let l1 be the length, let l2 be the arc length from the outermost portion 61o centered on the axis O to the front edge 51, and let l2 be the front edge of the blade portion 50 adjacent rearward from the front edge 51 centered on the axis O. When the length of the arc passing through the frontmost portion 61f of the arcs up to the portion 51 is t1, and the length of the arc passing through the outermost portion 61o is t2, (l2/t2)/(l1/t1) The required value is 1.4 or more and 1.6 or less. It has been found that the propeller fan 40 having the blade portions 50 satisfying such conditions has high air blowing efficiency. By making the shape of the blade portion 50 a shape that satisfies a predetermined condition, the propeller fan 40 with high blowing efficiency can be provided.

The outermost portion 61 о is formed at a position closer to the axis O than the center 60 c of the trailing edge portion 60 . By guiding the air flow on the blade surface (the surface of the blade portion 50) that flows from the vicinity of the boss 41 toward the outer edge portion 54 to the inner edge portion 53 side where the recess 60 is formed, the air that flows excessively toward the outer periphery due to the centrifugal action. The flow can be suppressed, and the air blowing efficiency is improved.

The innermost portion 61 i coincides with the rear end of the inner edge portion 53 . That is, the recess 61 is formed from the outer peripheral surface of the boss 41 . By forming the recessed portion 61 at a position closer to the boss 41, the blowing efficiency is further improved.

Next, Embodiment 2 of the present invention will be described with reference to the drawings.

<Example 2>
FIG. 7 shows the main part of the propeller fan of Example 2, corresponding to FIG. 4 above. The propeller fan 40A according to the second embodiment differs from the propeller fan 40 according to the first embodiment (see FIG. 4) in the shape of the recess 61A formed in the trailing edge portion 60A of the blade portion 50A. Other basic configurations are common to the propeller fan 40 according to the first embodiment. Reference numerals are used for parts that are common to the first embodiment, and detailed descriptions thereof are omitted.

A rear edge portion 60A, which is the rear edge in the rotation direction of the blade portion 50A, is formed with a concave portion 61A facing forward. In the concave portion 61A, the innermost point 61i, which is the innermost point, and the frontmost portion 61f, which is the most front side, coincide with each other. , coincides with the rearmost point 61r. It extends linearly from the innermost portion 61i (the frontmost portion 61f) to the outermost portion 61? (the rearmost portion 61r).

The innermost portion 61i can be appropriately read as the "foremost portion 61f". Further, the frontmost portion 61f can be appropriately read as "the innermost portion 61i". The same applies to the outermost portion 61? and the rearmost portion 61r.

The propeller fan 40A configured in this manner also exhibits the desired effects of the present invention.

Furthermore, the frontmost portion 61fA coincides with the innermost portion 61i and the rear end of the inner edge portion 53 . By forming the recessed portion 61A at a position closer to the boss 41, the ventilation efficiency is improved.

Although the propeller fan of the present invention has been described based on the example of being used in the outdoor unit of the air conditioner, it can also be used in other than the outdoor unit of the air conditioner. In other words, the present invention is applicable to general propeller fans for blowing air.

Furthermore, although the propeller fan according to the present invention has been described based on an example in which the number of blades is three, the number of blades is not limited to three, and may be any number as long as it is plural.

As long as the action and effects of the present invention are exhibited, the present invention is not limited to the examples.

INDUSTRIAL APPLICABILITY The propeller fan of the present invention is suitable for use in an outdoor unit of an air conditioner.

DESCRIPTION OF SYMBOLS 40, 40A... Propeller fan 41... Boss 50, 50A... Blade part 51... Front edge part 53... Inner edge part 54... Outer edge part 60, 60A... Rear edge part, 60c... Center of trailing edge part 61, 61A... Recessed part, 61i ...Innermost, 61?...Outermost, 61f...Foremost part O...Axis line

Claims (4)

A propeller fan having a boss rotatably provided on an axis serving as the center of rotation, and a plurality of blade portions extending outward from the boss and rotatable together with the boss,
The vane has a front edge that is a front edge, a rear edge that is a rear edge, an inner edge that is a boundary edge with the boss, and an outer edge with respect to the axis. an outer edge that is an edge formed in the
The trailing edge includes a recess formed in a concave shape toward the front,
The concave portion has an innermost point, which is the innermost point, with respect to the radial direction about the axis, an outermost point, which is the outermost point, and an outermost point with respect to the rotational direction of the blade portion. a frontmost point, which is a point located at
The distance from the axis to the innermost part is r1, the distance from the axis to the outermost part is r2, the distance from the axis to the inner edge is rb, and the distance from the axis to the outer edge is rf. When the value obtained by (r2-r1) / (rf-rb) is 0.05 or more and 0.17 or less,
The arc length from the frontmost portion to the front edge centered on the axis is l1, the arc length from the outermost part to the front edge about the axis is l2, and the axis is the center. Let t1 be the length of the arc passing through the foremost portion of the arc from the front edge portion to the front edge portion of the blade portion adjacent to the rear, and from the front edge portion centered on the axis line to the rear When the length of the arc passing through the outermost portion of the arcs to the leading edges of the adjacent blade portions is t2, the value obtained by (l2/t2)/(l1/t1) is: 1. 4 or more and 1.6 or less, a propeller fan. 2. The propeller fan according to claim 1, wherein the outermost portion is positioned closer to the axis than the center of the trailing edge portion. 3. The propeller fan according to claim 1, wherein the innermost portion coincides with the rear end of the inner edge portion. 4. The propeller fan according to claim 3, wherein the frontmost portion coincides with the innermost portion.

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