JP7289235B2 - Propeller fan for outdoor unit of air conditioner - 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, such as that disclosed in Patent Document 1, has a rotating boss and blades provided on the outer periphery of the boss, and the blades have bent portions that bulge upstream.

According to the propeller fan disclosed in Patent Literature 1, it is possible to reduce noise while increasing the amount of air blown.

Japanese Patent No. 5933721

When the blade is rotated, the wind is concentrated on the outside of the trailing edge of the blade surface due to centrifugal force and the like. If this can be flowed over the entire trailing edge without leaking to the outside, the blowing efficiency can be improved.

An object of the present invention is to provide a propeller fan that can improve air blowing efficiency.

According to the present invention, in a propeller fan comprising a centrally located and rotatable hub portion and blades provided on the outer periphery of the hub portion,
The vane has a front edge located at the front end with respect to the rotational direction, a rear edge located at the rear end, an outer edge located at the radially outer end, and an edge extending from the front edge to the trailing edge. and a convex portion located outside the concave portion and formed in a convex shape continuously from the outer edge portion or the front edge portion to the rear edge portion; There is provided a propeller fan characterized by having

In the present invention, the blade has a concave portion formed continuously from the leading edge to the trailing edge, and a concave portion positioned outside the concave portion and having a convex shape continuously from the outer edge or the leading edge to the trailing edge. and a convex portion formed on the By forming the concave portion, more airflow is allowed to flow along the concave portion, and by forming the convex portion outside the concave portion, the radially outward flow of air is suppressed. As a result, the air can flow over the entire trailing edge portion, and the air blowing efficiency can be improved. That is, it is possible to provide a propeller fan with improved blowing efficiency.

1 is a schematic diagram of an air conditioner equipped with a propeller fan according to an embodiment; FIG. It is a figure explaining a propeller fan, a heat exchanger, and a bell mouth which are shown by FIG. 3 is a perspective view of the propeller fan shown in FIG. 2; FIG. 4 is a front view of the propeller fan shown in FIG. 3; FIG. 5A is a cross-sectional view along line 5A in FIG. 4, FIG. 5B is a cross-sectional view along line 5B in FIG. 4, FIG. 5C is a cross-sectional view along line 5C in FIG. 4, FIG. 5D is a cross-sectional view along line 5D in FIG. 4, and FIG. 5E 5] is a cross-sectional view taken along line 5E of FIG. 4. [FIG. 6A is a diagram for explaining the action of the propeller fan shown in FIG. 4, and FIG. 6B is a cross-sectional view taken along line 6B-6B of FIG. 6A.

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

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 The outdoor heat exchanger 23 through which the refrigerant compressed to high temperature and pressure by the compressor 22 flows, the propeller fan 40 that blows air toward the outdoor heat exchanger 23, and the outdoor heat exchanger 23 and the propeller fan 40. It has a bell mouth 25 provided on the outer periphery and an expansion valve 26 that reduces 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 . By operating the motor 27 and rotating the propeller fan 40 , air can be taken in from the outside of the outdoor heat exchanger 23 and blown toward the bellmouth 25 . Based on this blowing direction, the right side of the drawing is hereinafter referred to as the upstream or upstream side, and the left side of the drawing is referred to as the downstream or downstream side.

Please refer to FIG. The indoor unit 30 is hung on the wall Wa indoors In. The indoor unit 30 includes an indoor fan 32 that takes in air from the room and blows air, and an indoor heat exchanger 33 that cools the air taken in by the indoor fan 32 in a case 31 that is fixed to the wall Wa and has an air outlet 31b on the front surface. and are stored.

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 .

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 FIGS. The propeller fan 40 has a substantially cylindrical hub portion 41 connected to the motor 27 (see FIG. 2), and three blades 50 integrally formed on the side wall surface 41a of the hub portion 41. . The propeller fan 40 rotates, for example, clockwise.

The hub portion 41 is positioned at the center of the propeller fan 40 , and the center O of the hub portion 41 coincides with the axis of the motor 27 .

The three blades 50 are arranged on the side surface of the hub portion 41 at equal intervals with respect to the circumferential direction and have the same shape. The blade 50 has a front edge portion 51 located at the front end with respect to the rotational direction, a rear edge portion 52 located at the rear end, and an inner edge located at the radially inner end portion and formed along the hub portion 41 . It has a portion 53 and an outer edge portion 54 located at the radially outer end.

The front edge portion 51 is inclined such that the end on the hub portion 41 side is located on the most downstream side and the radially outer end portion is located on the most upstream side. In other words, the front edge portion 51 is formed with a downward slope from the hub portion 41 toward the outside in the radial direction.

The trailing edge portion 52 is formed so that the radially inner end portion and the radially outer end portion thereof are at substantially the same position (substantially the same height) with respect to the blowing direction.

The inner edge portion 53 has an end portion on the front edge portion 51 side located on the most upstream side, and an end portion on the rear edge portion 54 side located on the most downstream side. That is, the inner edge portion 53 is formed with an upward slope from the front edge portion 51 side toward the rear edge portion 52 side.

The outer edge portion 54 has an arc shape centered on the center O of the hub portion 41 . The outer edge portion 54 has an end portion on the front edge portion 51 side located on the most upstream side, and an end portion on the rear edge portion 52 side located on the most downstream side. That is, the outer edge portion 54 is formed with an upward slope from the front edge portion 51 side toward the rear edge portion 52 side.

Please refer to FIGS. 4 and 5A-5E. The cross-sectional shape of the blade 50 changes continuously from the front to the rear with respect to the direction of rotation. The blade 50 has a concave portion 55 formed continuously from the front edge portion 51 to the rear edge portion 52 and a convex portion located outside the concave portion 55 and continuously extending from the outer edge portion 54 to the rear edge portion 52 . and a convex portion 56 formed on the .

Refer specifically to FIGS. 5A-5E. A line on which the bottom points P1 to P5, which are the bottoms of the recesses 55, are continuously formed is called a bottom line L1. A line on which the vertices P6 to P8, which are the apexes of the convex portion 56, are continuously formed is called a vertex line L2. Boundary portions P9 to P11 are defined as inflection points between the concave portion 55 and the convex portion 56, and a line formed continuously by the boundary portions P9 to P11 is referred to as a boundary line L3.

The convex portion 56 may be formed from the front edge portion 51 outside the concave portion 55, but as shown in the figure, it should be formed from the outer edge portion 54 to the rear edge portion 52 halfway in the front-rear direction. is preferred. The reason will be described later.

A length r1 from the center O of the hub portion 41 to the rear end of the recess 55 is shorter than a length r2 from the center O of the hub portion 41 to the front end of the recess 55 .

A length r3 from the center O of the hub portion 41 to the rear end of the protrusion 56 is shorter than a length r4 from the center O of the hub portion 41 to the front end of the protrusion 56 .

The concave portion 55 and the convex portion 56 are formed such that the top line L2 is parallel to the bottom line L1.

The boundary line L3 is parallel to the top line L2 and the bottom line L1. Also, the length W1 from the boundary line L3 to the bottom line L1 is longer than the length W2 from the boundary line L3 to the top line L2. In other words, the boundary line L3 is positioned closer to the top line L2 than the bottom line L1.

See FIGS. 6A and 6B. The blade 50 has a concave portion 55 continuously formed from a front edge portion 51 to a rear edge portion 52 and a concave portion 55 positioned outside the concave portion 55 and formed continuously from an outer edge portion 54 to a rear edge portion 52 in a convex shape. and a convex portion 56 formed thereon. By forming the recessed portion 55, more wind flows along the recessed portion 55 (see the area surrounded by the two-dot chain line in FIG. 6B). Suppress the flow of air to the outside. As a result, the wind can flow over the entire trailing edge portion 52, and the propeller fan 40 can be rotated with a small torque. In other words, the amount of air blown when the propeller fan 40 is rotated with the same torque can be increased, and the air blowing efficiency of the propeller fan 40 can be improved. That is, it is possible to provide the propeller fan 40 with improved air blowing efficiency.

In addition, by forming the convex portion 56 and suppressing the leakage of wind to the outside of the outer edge portion 54, the generation of noise caused by the vortex flow between the outer edge portion 54 and the bellmouth 25 can be suppressed. can be done.

In addition, as described above, the convex portion 56 may be formed from the front edge portion 51 , but is preferably formed from the outer edge portion 54 . Wind flowing from the leading edge 51 over the surface of the blade 50 flows toward the corner between the outer edge 54 and the trailing edge 52 due to centrifugal force. In other words, the amount of air that flows outside the outer edge portion 54 is small at a portion of the outer edge portion 54 that is close to the front edge portion 51 . By forming the projections 56 only in the areas where the wind tends to leak to the outer edge 54 side, the air can be sent to a wider range of the rear edge 52 . Therefore, it is more preferable that the convex portion 56 is formed from the outer edge portion 54 .

Please refer to FIG. The length r1 from the center O of the hub portion 41 to the rear end of the recess 55 is shorter than the length r2 from the center O of the hub portion 41 to the front end of the recess 55, and The length r3 to the rear end of 56 is shorter than the length r4 from the center O of hub portion 41 to the front end of projection 56 . That is, the concave portion 55 and the convex portion 56 are formed so as to come closer to the hub portion 41 as they go rearward. As a result, the wind can be guided further inward, and the wind can flow over the entire blade 50 together with the outward force due to the centrifugal force.

Please also refer to FIGS. 5A-5E. The top line L2 along which the apexes P6 to P8 of the convex portion 56 are continuously formed is substantially parallel to the bottom line L1 along which the bottom points P1 to P5 of the concave portion 55 are continuously formed. A smooth flow can be ensured by widening the width of the concave portion 55 without narrowing it.

A boundary line L3 formed by continuously forming the boundary portions P9 to P11 is parallel to the top line L2 and the bottom line L1, and is positioned closer to the top line L2 than to the bottom line L1. Thereby, the recessed part 55 can be secured more widely. A smooth flow can be ensured by ensuring a wider width of the recess 55 .

Although the propeller fan according to the present invention has been described based on an example having three blades, the number of blades is not limited to three, and may be any number. Moreover, the propeller fan is not limited to the outdoor unit of the air conditioner, and may be used for other purposes. In other words, the present invention is not limited to the examples as long as the functions and effects of the present invention are exhibited.

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... Propeller fan 41... Hub part 50... Blade 51... Front edge part 52... Rear edge part 53... Inner edge part 54... Outer edge part 55... Concave part 56... Convex part P1-P5... Bottom point P6-P8... Vertex P9-P11 ... Boundary L1 ... Bottom line L2 ... Top line L3 ... Boundary line r1 ... Length from center of hub to rear end of recess r2 ... Length from center of hub to front end of recess r3 ... From center of hub Length to the rear end of the protrusion r4... Length from the center of the hub to the front end of the protrusion W1... Length from the boundary line to the bottom line W2... Length from the boundary line to the top line O... Length of the hub part center

Claims (4)

A propeller fan comprising a centrally located and rotatable hub portion and blades provided on the outer circumference of the hub portion,
The vane has a front edge located at the front end with respect to the rotational direction, a rear edge located at the rear end, an inner edge formed along the hub, and a radially outer end. an outer edge serving as a free end ; a single concave recess continuously formed from the front edge to the rear edge ; a single convex portion formed continuously to the trailing edge portion, and the thickness of the inner edge portion is formed to be thicker than the thickness of the outer edge portion;
The recess is formed in a recessed shape in one axial direction from the inner edge,
A propeller fan for an outdoor unit of an air conditioner , wherein the convex portion is formed to be convex in the other axial direction than the inner edge portion. The length from the center of the hub portion to the rear end of the recess is shorter than the length from the center of the hub portion to the front end of the recess, and
2. The outdoor air conditioner according to claim 1, wherein the length from the center of said hub portion to the rear end of said protrusion is shorter than the length from the center of said hub portion to the front end of said protrusion. Aircraft propeller fan. 3. The propeller fan for an outdoor unit of an air conditioner according to claim 1, wherein the concave portion and the convex portion are continuously formed in a curved shape. When a portion that is an inflection point between the concave portion and the convex portion is a boundary portion,
4. The propeller fan for an outdoor unit of an air conditioner according to claim 3, wherein the boundary line formed by continuously forming the boundary portion is positioned closer to the outer edge portion than to the inner edge portion.

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