WO2024084537A1

WO2024084537A1 - Blower device

Info

Publication number: WO2024084537A1
Application number: PCT/JP2022/038502
Authority: WO
Inventors: 奈穂安達; 惇司河野; 拓矢寺本
Original assignee: 三菱電機株式会社
Priority date: 2022-10-17
Filing date: 2022-10-17
Publication date: 2024-04-25

Abstract

This blower device comprises a fan that rotates about a fan shaft. The fan has a plurality of blades arranged with space therebetween in the circumferential direction. Each of the blades has, in a cross section perpendicular to the axial direction of the fan shaft, a cross-sectional shape that curves in an arch shape. Each of the blades comprises: a suction surface that is one main surface of the blade and is disposed on the outer side of the arch; a pressure surface that is the other main surface of the blade and is disposed on the inner side of the arch; a blade outer circumferential end portion that is an end portion on the outer circumferential side of the blade that connects the suction surface and the pressure surface; and a blade inner circumferential end portion that is an end portion on the inner circumferential side of the blade that connects the suction surface and the pressure surface. When at least one of the plurality of blades or all of the blades are divided into three regions in a cross section perpendicular to the axial direction of the fan shaft, said three regions being a first region disposed on the blade outer circumferential end side, a second region disposed on the blade inner circumferential end side, and a third region connecting the first region and the second region, the first region and the second region have the same camber direction and are cambered so as to be concaved towards the counter-rotation direction, and the camber height of at least the first region and the second region changes along the chord of the blade.

Description

Blower

This disclosure relates to a blower device, and in particular to a blower device used in an air conditioner indoor unit, etc.

One type of fan that is installed in a blower is a cross-flow fan. A cross-flow fan has multiple blades that are spaced apart from one another in the circumferential direction. The blades are sometimes called blades. In some conventional cross-flow fans, the camber line that indicates the center of thickness of the blade cross section is made up of two continuous arcs in the blade chord direction (see, for example, Patent Document 1).

In the blades of Patent Document 1, the warp line includes two arcs, one on the outer circumference of the fan and one on the inner circumference of the fan, and the warp directions of the arcs on the outer circumference of the fan and the inner circumference of the fan are reversed. With this configuration, Patent Document 1 aims to reduce turbulent sound caused by the fluid, resulting in low noise levels, and to save energy by increasing the air volume.

JP 2007-255426 A

In Patent Document 1, as described above, the warping direction of the arc on the outer circumference side of the fan is reversed to the warping direction of the arc on the inner circumference side of the fan. Specifically, the arc on the outer circumference side of the fan has the center of the circle constituting the arc arranged in the opposite direction to the rotation direction relative to the arc, and the central part of the arc is convex toward the rotation direction. On the other hand, the arc on the inner circumference side of the fan has the center of the circle constituting the arc arranged in the rotation direction relative to the arc, and the central part of the arc is convex toward the opposite direction to the rotation direction. In that case, in the air inflow area, which is the low air volume area, when the air flow from the outer circumference of the fan flows into the blades, the warping direction on the outer circumference side of the fan is warped in the direction against the air flow. Therefore, the air flow cannot flow along the surface of the blade and is separated from the surface of the blade. As a result, there is a problem that abnormal noise is generated or the air flow stalls.

The present disclosure has been made to solve such problems, and aims to provide a blower that prevents the air flow from separating from the blade by changing the height of the warp without reversing the direction of the warp line on the outer and inner sides of the blade, thereby preventing the generation of abnormal noise and the stalling of the air flow.

The blower device according to the present disclosure is a blower device having a fan that rotates around a fan shaft, the fan having a plurality of blades arranged at intervals from one another in the circumferential direction, each of the blades having a cross-sectional shape that is curved like an arch in a cross section perpendicular to the axial direction of the fan shaft, each of the blades having a negative pressure surface that is one of the main surfaces arranged on the outside of the arch, a pressure surface that is the other main surface arranged on the inside of the arch, a blade outer peripheral end that is the end of the outer periphery of the blade that connects the negative pressure surface and the pressure surface, and a blade inner peripheral end that connects the negative pressure surface and the pressure surface. and an inner circumferential blade end portion, which is the end portion of the blade. When at least one of the blades, or all of the blades, is divided into three regions in a cross section perpendicular to the axial direction of the fan shaft, the first region and the second region have the same warping direction and are warped concavely in the counter-rotation direction, and the warping height of at least the first region and the second region changes along the chord of the blade.

In the blower device disclosed herein, the warp height is changed on the warp line of the blade from the outer periphery of the fan to the inner periphery of the fan while keeping the warp direction the same on the outer periphery of the fan and the inner periphery of the fan. This makes it possible to prevent the flow of air flowing into the fan from the outer periphery of the fan from separating from the blade, improving blowing performance and preventing the air flow from stalling.

1 is a cross-sectional view showing a configuration of a blower device 100 according to a first embodiment. 1A and 1B are a perspective view and a side view showing a configuration of a fan 106 mounted on a blower device 100 according to a first embodiment. 4 is a cross-sectional view showing the flow of air in a fan inlet region B in the blower device 100 according to the first embodiment. FIG. 4 is a cross-sectional view showing the flow of air in a fan outflow area C in the blower device 100 according to the first embodiment. FIG. FIG. 11 is a cross-sectional view showing a configuration of a comparative example for illustrating the effects of the first embodiment. FIG. 11 is a cross-sectional view showing a configuration of a comparative example for illustrating the effects of the first embodiment. 10 is a diagram showing a change in warpage height H of a blade 12 used in a fan 106 mounted on a blower device 100 according to a second embodiment. FIG. 10 is a cross-sectional view showing the air flow in a fan inlet region B in a blower device 100 according to embodiment 2. FIG. 11 is a cross-sectional view showing the air flow in a fan outflow area C in a blower device 100 according to a second embodiment. FIG. 10 is a partially enlarged cross-sectional view showing the configuration of a blade 12 provided in a blower device 100 according to embodiment 3. FIG.

Below, an embodiment of the blower according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiment, and various modifications can be made without departing from the spirit of the present disclosure. The present disclosure also includes all combinations of possible configurations among the configurations shown in the following embodiment and its modified examples. In each drawing, the same reference numerals are used to denote the same or equivalent components, and this is common throughout the entire specification. In each drawing, the relative dimensional relationship or shape of each component may differ from the actual one. In each drawing, the width direction of the blower is the Y direction, the depth direction of the blower is the X direction, and the height direction of the blower is the Z direction. The X direction and the Y direction intersect with each other. The X direction and the Y direction are, for example, horizontal directions. The Z direction is a direction that intersects with the X direction and the Y direction. The Z direction is, for example, a vertical direction, that is, an up-down direction. The Z direction may be a vertical direction.

Embodiment 1.
The configuration of the blower according to the first embodiment will be described below with reference to FIGS. 1 to 6. FIG. 1 is a cross-sectional view showing the configuration of the blower 100 according to the first embodiment. FIG. 1 shows a cross-sectional configuration of the blower 100 cut in a direction perpendicular to the fan shaft 14 (see FIG. 2(a)) of the fan 106 mounted on the blower 100. FIG. 2 is a perspective view and a side view showing the configuration of the fan 106 mounted on the blower 100 according to the first embodiment. FIG. 3 is a cross-sectional view showing the air flow in the fan inflow area B in the blower 100 according to the first embodiment. FIG. 4 is a cross-sectional view showing the air flow in the fan outflow area C in the blower 100 according to the first embodiment. FIGS. 3 and 4 show a cross-sectional configuration of the blower 100 cut in a direction perpendicular to the fan shaft 14 (see FIG. 2(a)) of the fan 106 mounted on the blower 100. In addition, hatching is omitted in FIGS. 3 and 4 to simplify the drawings. For hatching, refer to FIG. 1.

FIGS. 5 and 6 are cross-sectional views showing the configuration of a comparative example to explain the effect of embodiment 1. FIG. 5 shows, as a comparative example, the air flow in the fan inlet region B when a typical blade is used in a cross-flow fan. FIG. 6 shows, as a comparative example, the air flow in the fan outlet region C when a typical blade is used in a cross-flow fan. Note that hatching has been omitted in FIGS. 5 and 6 to simplify the drawings. Please refer to FIG. 1 for hatching.

(Blower device 100)
The blower device 100 according to the first embodiment is used, for example, as an indoor unit of an air conditioner. The indoor unit of an air conditioner is sometimes called an air conditioning indoor unit. The housing 101 of the blower device 100 has, as a whole, for example, a long rectangular parallelepiped shape extending in the Y direction (see FIG. 2). As shown in FIG. 1, the housing 101 has an upper surface portion 101a, a lower surface portion 101b, a front surface portion 101c, a rear surface portion 101d, and two side surfaces (not shown). The rear surface portion 101d of the housing 101 is fixed to a mounting portion such as a wall of an indoor space.

As shown in FIG. 1, the housing 101 has an intake port 102 provided on the top surface 101a for taking in air, and an exhaust port 103 from which conditioned air is blown out by the air conditioning device. The exhaust port 103 is provided from the front surface 101c to the bottom surface 101b of the housing 101. The exhaust port 103 extends in the Y direction over almost the entire length of the housing 101 in the Y direction. Furthermore, the housing 101 has a filter 104 attached to the intake port 102. The airflow flowing in from the intake port 102 passes through the filter 104, and fine particles such as dust or pollen contained in the airflow are removed by the filter 104. The intake port 102 of the housing 101 may be provided not only on the top surface 101a, but also on the top surface 101a and the front surface 101c.

1, the housing 101 houses a heat exchanger 105 and a fan 106. The heat exchanger 105 is disposed below the intake port 102. The fan 106 is disposed below the heat exchanger 105. When the fan 106 rotates, an airflow is generated as shown by the arrow A in FIG. 1. The fan 106 is disposed downstream of the heat exchanger 105 in the direction of the airflow. The airflow flows into the housing 101 from the intake port 102 of the housing 101, passes through the inside of the housing 101, and flows out of the housing 101 from the exhaust port 103 of the housing 101. At this time, the airflow passes through the heat exchanger 105 as shown by the arrow A in FIG. 1. As a result, in the heat exchanger 105, heat exchange occurs between the air constituting the airflow and the refrigerant flowing inside the heat exchanger 105.

Downstream of the fan 106, as shown in FIG. 1, a casing 107 is provided on the rear portion 101d side of the housing 101. The casing 107 has a cross-sectional shape formed of one or more arcs, as shown in FIG. 1, so that the airflow can easily flow along the casing 107. As shown in FIG. 1, the casing 107 is arranged at a certain distance from the rear portion 101d side of the fan 106. In addition, a side wall 108 is provided on the lower side of the front portion 101c of the housing 101. The side wall 108 is arranged, for example, below the lower end of the front portion 101c side of the heat exchanger 105. The side wall 108 has a tongue portion 108a arranged on the lower side of the fan 106. The tongue portion 108a is arranged opposite the casing 107 in the X direction. The tongue portion 108a is arranged at a certain distance from the lower portion of the front portion 101c side of the fan 106, as shown in FIG. 1. The tongue portion 108a is arranged parallel to the fan shaft 14. The tongue portion 108a has a length equal to the length of the fan 106 in the Y direction and extends in the Y direction. The tongue portion 108a is provided so that the blower device 100 can form a stable airflow. In addition, a rear guide 109 is provided upstream of the fan 106 in the direction of the airflow indicated by the arrow A. The rear guide 109 is arranged on the upper side of the casing 107. The rear guide 109 and the casing 107 are smoothly connected. The rear guide 109 is arranged near the end of the heat exchanger 105 on the rear portion 101d side. The rear guide 109, the casing 107, and the side wall 108 form an air passage through which the airflow indicated by the arrow A flows.

The heat exchanger 105 may have a rectangular flat plate shape such as a rectangular parallelepiped, or may be bent into a lambda shape (i.e., Λ-shape) when viewed from the side as shown in FIG. 1. The heat exchanger 105 is not limited to this case, and may also be bent into a U-shape or an L-shape. The heat exchanger 105 is, for example, a fin-and-tube type heat exchanger having a heat transfer tube and fins. In this case, the heat exchanger 105 exchanges heat between the air taken in from the suction port 102 and the refrigerant flowing inside the heat transfer tube of the heat exchanger 105.

The fan 106 has a long cylindrical shape or a long annular shape as a whole, for example, as shown in FIG. 2(a). The fan 106 has a plurality of blades 12 arranged at intervals from each other in the circumferential direction, as shown in FIG. 2(b). The fan 106 is, for example, a cross-flow fan, and the example of FIG. 2 shows the case where the fan 106 is a cross-flow fan. When the fan 106 is a cross-flow fan, the fan 106 has a plurality of blades 12, a partition plate 13, a fan shaft 14, a bossed end face disk 15, and an end face disk 16. The plurality of blades 12 are arranged at intervals from each other in the circumferential direction, as shown in FIG. 2(b). Each of the blades 12 has a cross-sectional shape along a bow, as shown in FIG. 2(b). Each of the blades 12 is, for example, a flat plate shape warped in a bow shape. The partition plate 13 has, for example, a disk shape or a ring shape. The fan shaft 14 extends in the Y direction. For this reason, the Y direction is sometimes called the axial direction of the fan shaft 14. The blades 12 are supported by partition plates 13 at both ends in the Y direction to form a series of fan blocks 17. As shown in FIG. 2(a), about 7 to 14 fan blocks 17 are connected in the Y direction. The number of connected fan blocks 17 is not limited to these and can be any number.

In this way, a single fan 106 is formed by combining a plurality of fan blocks 17 in the Y direction. The circumferential positions of the blades 12 of each fan block 17 may be aligned or nearly aligned as shown in FIG. 2(a), but are not limited to this case. That is, in each fan block 17, the circumferential positions of the blades 12 may be shifted by half a cycle with respect to the positions of the blades 12 of other fan blocks 17 adjacent in the Y direction. In this case, the blades 12 of each fan block 17 are positioned between the blades 12 of other fan blocks 17 adjacent in the Y direction in the circumferential direction. When the fan blocks 17 are shifted by half a cycle in this way, abnormal sounds (whistle sounds) generated from the blades 12 can be suppressed. In addition, a bossed end face disc 15 having a boss is attached to one end of the fan 106 in the Y direction, and an end face disc 16 without a boss is attached to the other end of the fan 106 in the Y direction. The fan 106 rotates by placing the bossed end disk 15 on the motor shaft side of the motor (not shown) and connecting the fan shaft 14 to the motor (not shown).

1 and 2, the fan 106 rotates in a rotation direction R when driven by a motor (not shown). As a result, as shown by arrow A in FIG. 1, airflow is sucked into the fan 106 from between the blades 12 on the heat exchanger 105 side, and the airflow is blown out from between the blades 12 in the space between the vicinity of the casing 107 and the vicinity of the tongue 108a of the side wall 108. Hereinafter, the area of the fan 106 where the airflow is sucked in is referred to as the fan inlet area B (see FIG. 3), and the area where the airflow is blown out is referred to as the fan outlet area C (see FIG. 4).

(Wing 12)
Next, the configuration of the blade 12 according to the first embodiment will be described with reference to FIG. 3. FIG. 3(b) shows an enlarged view of the fan inflow area B shown in FIG. 3(a). As described above, the blades 12 are arranged at intervals from each other in the circumferential direction. As shown in FIG. 3(b), the blade 12 is formed in a bow shape in a side view, and the center of the blade 12 is recessed toward the counter-rotation direction, which is the opposite direction to the rotation direction R. That is, in the blade 12, the inner peripheral blade end 12e and the outer peripheral blade end 12d are located forward in the rotation direction R than the center of the blade 12. As shown in FIG. 2, the radial length of the blade 12 is smaller than the radius of the fan 106 (i.e., the radial length from the outer periphery of the fan 106 to the fan shaft 14). That is, the chord length Lc of the chord L (see FIG. 3) of the blade 12 described later is smaller than the radius of the fan 106.

The blade 12 has two main surfaces that make up the thickness of the blade 12. One main surface is a negative pressure surface 12g located on the outside of the arched shape. The other main surface is a pressure surface 12f located on the inside of the arched shape. The blade 12 also has an outer peripheral blade end 12d, which is the end on the outer periphery of the blade 12, and an inner peripheral blade end 12e, which is the end on the inner periphery of the blade 12. The outer peripheral blade end 12d is located on the outer periphery of the fan 106, and the inner peripheral blade end 12e is located on the fan shaft 14 side of the fan 106. The outer peripheral blade end 12d and the inner peripheral blade end 12e each connect the negative pressure surface 12g and the pressure surface 12f in a smooth curved line.

As shown in FIG. 3(b), the blade 12 is divided into three regions: a first region 12a on the outer peripheral end 12d side of the blade, a second region 12b on the inner peripheral end 12e side of the blade, and a third region 12c connecting the first region 12a and the second region 12b. As shown in FIG. 3(b), the warping direction of the first region 12a and the second region 12b is the same. That is, the first region 12a and the second region 12b are warped so as to be concave toward the counter-rotation direction, which is the opposite direction to the rotation direction R. On the other hand, the third region 12c does not have to be warped in a curved shape. That is, the third region 12c may be formed in a straight line. In that case, the warping height of the third region 12c is maintained at a constant value or changes along the chord L of the blade 12 (see FIG. 3). In that case, the third region 12c may be formed in a straight line consisting of two or more straight lines.

When the third region 12c is aligned, the warping direction of the third region 12c is the same as the warping direction of the first region 12a and the second region 12b. In this case, the pressure surface 12f and the negative pressure surface 12g in each of the first region 12a, the second region 12b, and the third region 12c are each formed with one or more arcs in a side view. Among the first region 12a, the second region 12b, and the third region 12c, the pressure surface 12f and the negative pressure surface 12g constituting the third region 12c have the largest radius of curvature. In other words, the arcs constituting the pressure surface 12f and the negative pressure surface 12g constituting the third region 12c are the closest to a straight line among the three regions. Therefore, the third region 12c is the flattest among the three regions.

As shown in FIG. 3(b), the curved line indicating the center of thickness of the blade 12 is defined as the camber line W. The straight line connecting the outer peripheral end 12d and the inner peripheral end 12e of the blade 12 is defined as the chord L. The center point of the chord L is defined as the chord center P. The length of the chord L is called the chord length Lc. The chord length of the first region 12a is defined as the chord length L1, the chord length of the second region 12b is defined as the chord length L2, and the chord length of the third region 12c is defined as the chord length L3. The distance between the camber line W and the chord L is defined as the camber height H. In other words, the camber height H is the length of a line segment perpendicular to the chord L from the camber line W.

As described above, the warp height H of at least two of the three regions, the first region 12a and the second region 12b, constantly changes along the chord L. On the other hand, the warp height H of the third region 12c is either maintained at a constant value or changes along the chord L.

At this time, the maximum warpage height of the first region 12a is equal to or greater than the maximum warpage height of the second region 12b. The warpage height H of the first region 12a gradually increases from the outer circumferential edge 12d of the blade toward the third region 12c. The warpage height H of the second region 12b gradually increases from the inner circumferential edge 12e of the blade toward the third region 12c. At this time, if the warpage height H of the third region 12c is maintained at a constant value, the maximum warpage height of the first region 12a will be the same as the maximum warpage height of the second region 12b. On the other hand, if the warpage height H of the third region 12c gradually increases in the direction from the inner circumferential edge 12e of the blade toward the outer circumferential edge 12d of the blade, the maximum warpage height of the first region 12a will be greater than the maximum warpage height of the second region 12b. It is preferable that the maximum warpage height of the first region 12a be greater than the maximum warpage height of the second region 12b.

Furthermore, in all the blades 12, the third regions 12c have the same shape. That is, in all the blades 12, the third regions 12c are formed to have the same contour. Furthermore, in all the blades 12, the positions of the third regions 12c may be arranged so that they are equal to each other in the radial direction between the blade inner circumferential end 12e and the blade outer circumferential end 12d. In that case, the third regions 12c of each blade 12 are arranged in the circumferential direction at approximately equal intervals from each other. The third region 12c has the largest radius of curvature or is formed in a straight line. Therefore, in the third region 12c, the airflow is less likely to separate from the surface of the blade 12. In this way, by each blade 12 having the third region 12c that can suppress the separation of the airflow, the airflow does not concentrate on the pressure surface 12f side of the adjacent blade 12-1. Furthermore, by each blade 12 having the third region 12c of the same shape, the distance between the blades 12 in the third region 12c portion can be made approximately equal. This further reduces the pressure loss of the airflow between the blades 12 and stabilizes the airflow. Furthermore, if each blade 12 has the same shaped third region 12c, the same mold can be used for the parts of the blades 12 that have a common shape when manufacturing the blades 12, which improves productivity.

The first maximum warp height position where the warp height H of the first region 12a is maximum is located on the outer periphery 12d side of the chord center P. The first maximum warp height position may or may not coincide with the position of the first connecting portion connecting the first region 12a and the third region 12c. If the first maximum warp height position and the position of the first connecting portion do not coincide, the warp height H of the first region 12a gradually increases from the outer periphery 12d to the first maximum warp height position, and then gradually decreases from the first maximum warp height position to the position of the first connecting portion. The relationship between the chord length L1 of the first region 12a, the chord length L2 of the second region 12b, and the chord length L3 of the third region 12c is as follows. That is, the chord length L1 of the first region 12a is longer than the chord length L2 of the second region 12b and the chord length L3 of the third region 12c.

　Chord length L1 > chord length L2, and chord length L1 > chord length L3

Although it has been described that the third region 12c has the same shape in all of the blades 12, the shape of the first region 12a and the shape of the second region 12b may each be the same shape in all of the blades 12, but this is not limited to the case. In other words, the shape of the first region 12a may be different for each blade 12. Similarly, the shape of the second region 12b may be different for each blade 12.

Here, a method for determining the first region 12a, the second region 12b, and the third region 12c will be described. The determination method includes, for example, the following methods. Note that two determination methods may be combined, such as (1) and (3), or (2) and (3). Note that the first region 12a, the second region 12b, and the third region 12c are defined based on the determination method.
(1) When the first region 12a, the second region 12b, and the third region 12c are each formed of one arc, the portion formed of the arc with the largest radius of curvature is defined as the third region 12c, and the regions at both ends of the third region 12c are defined as the first region 12a and the second region 12b, respectively.
(2) When the third region 12c is composed of one arc, the portion composed of the arc with the largest radius of curvature among all the arcs that compose the blade 12 is defined as the third region 12c. The regions at both ends of the third region 12c are defined as the first region 12a and the second region 12b, respectively. In this case, the first region 12a and the second region 12b are composed of two or more arcs.
(3) The three regions are determined based on the warp height H of the warp line W. Specifically, the region including the part of the blade 12 where the warp height H is the highest is defined as the first region 12a. The first region 12a, the second region 12b, and the third region 12c are appropriately determined so as to satisfy the conditions of blade chord length L1 > blade chord length L2 and blade chord length L1 > blade chord length L3.
(4) When the third region 12c is formed of straight lines, the regions on both ends of the third region 12c are defined as the first region 12a and the second region 12b, respectively.
(5) The first region 12a is determined from one or more circular arcs in consideration of the inflow to the blade in the inflow region B, and the second region 12b is determined from one or more circular arcs in consideration of the inflow to the blade in the outflow region C. Then, the third region 12c is determined by a circular arc or a straight line so as to smoothly connect the first region 12a and the second region 12b.

(Effects of the First Embodiment)
The effects of the first embodiment will be described with reference to Figures 3 to 6. Figures 3 and 4 show the first embodiment. Meanwhile, Figures 5 and 6 show a comparative example. In the description of Figure 3(b), when describing the operation of the second wing 12 from the left, the wing 12 on the left side adjacent to that wing 12 will be referred to as wing 12-1. Similarly, in the description of Figure 5(b), when describing the operation of the second wing 120 from the left, the wing 120 on the left side adjacent to that wing 120 will be referred to as wing 120-1.

First, a comparative example of Figs. 5 and 6 will be described. Figs. 5 and 6 show a case where a general blade 120 is used in an air conditioning indoor unit. The blade in Figs. 5 and 6 will be referred to as blade 120 to distinguish it from blade 12. Blade 120 is, for example, the blade described in Patent Document 1 mentioned above. In Figs. 5 and 6, everything is the same except for the configuration of blade 12, in order to make a comparison with embodiment 1 shown in Figs. 3 and 4.

In the comparative example, as shown in Figures 5(a) and 5(b), between the blades 120 near the rear guide 109, the inflow of airflow from the circumferential direction becomes dominant, and the airflow separates from the negative pressure surface 120g of the blade 120 at the blade outer circumferential end 120d side. Then, the airflow flows along the pressure surface 120f of the adjacent blade 120-1, and in region D of Figure 5(b), the flow is accelerated at the pressure surface 120f of the adjacent blade 120-1, causing abnormal noise. In addition, the flow accelerated at the pressure surface 120f of the adjacent blade 120-1 flows out from the blade inner circumferential end 120e side toward the circumferential direction of the fan 106, as shown by arrow A3 in Figure 5(b). The airflow that flows out toward the circumferential direction of the fan 106 continues in the same direction, as shown by arrow A5 in Figure 6(a), and flows out of the fan 106 at the fan outflow region C. Therefore, in the fan outflow region C, as shown by the arrow A2 in FIG. 6(a), part of the airflow flows out toward the upstream direction of the casing 107. As a result, as shown by the arrow A2 in FIG. 6(a), the airflow flows back from the upstream of the casing 107 toward the rear guide 109, which causes the entire airflow to stall at least to that extent.

In the comparative example, as shown in Fig. 6(a) and Fig. 6(b), in the fan outflow area C, the airflow separates from the pressure surface 120f in area E on the pressure surface 120f side of the blade 120, and the wind speed of the airflow increases. As a result, there is a problem that the pressure loss between the blades 120 increases and the noise increases.

In contrast, in the blade 12 according to the first embodiment, as shown in FIG. 3, in the fan inlet region B, the airflow flowing in from the blade outer circumferential end 12d side is smoothly introduced between the blades 12 in the first region 12a where the warp height H is large, and then the airflow is sent to the third region 12c. Since the third region 12c has a large radius of curvature, the airflow is less likely to separate from the surface of the blade 12 in region F. Therefore, the flow can be guided along the negative pressure surface 12g side of the blade 12 without concentrating on the pressure surface 12f side of the adjacent blade 12-1. As a result, in the first embodiment, unlike the comparative example shown in FIG. 5, the increase in speed on the pressure surface 12f side of the adjacent blade 12-1 can be suppressed in region K in FIG. 3(b), and the generation of abnormal noise can be suppressed.

Furthermore, in the blades 12 according to embodiment 1, the wind speed of the airflow between the blades 12 does not increase in the fan inlet region B as described above, so the pressure loss of the airflow passing between the blades 12 can be reduced, and the shaft power applied to the blades 12 can be reduced (see FIG. 3).

Furthermore, in the blade 12 according to embodiment 1, when the airflow flows out toward the blade inner circumferential end 12e in the fan inlet region B, as described above, the increase in the speed of the airflow on the pressure surface 12f side of the adjacent blade 12-1 is suppressed. Therefore, as shown by arrow A3 in FIG. 3(b), the airflow flows out radially from the blade inner circumferential end 12e in region K. As a result, in the fan outlet region C (see FIG. 4), the amount of airflow flowing out toward the upstream direction of the casing 107 as shown by arrow A2 in FIG. 4(a) is less than in the comparative example shown in FIG. 6. As a result, the backflow of the airflow from the upstream of the casing 107 toward the rear guide 109 is suppressed, and stalling of the entire airflow can be prevented. In the first embodiment, in the fan outflow region C, as shown in FIG. 4, the airflow flows out of the fan 106 near the middle of the casing 107, so that the backflow of the airflow from the upstream of the casing 107 toward the rear guide 109 is suppressed, and the stall resistance can be improved.

Furthermore, in the blade 12 according to the first embodiment, the maximum camber height position where the camber height H of the first region 12a is maximum is located closer to the outer circumferential blade end 12d than the chord center P of the blade chord L. Therefore, in the fan outflow region C, as shown in FIG. 4(b), the airflow from the inner circumferential blade end 12e can be smoothly introduced from the first region 12a, which has a large camber, to the second region 12b, which has a small camber. As a result, in the fan outflow region C, separation of the airflow on the pressure surface 12f of the blade 12 in region E can be reduced, reducing the pressure loss between the blades 12, reducing the axial power applied to the blades 12, and further reducing noise.

Furthermore, in the blade 12 according to embodiment 1, the blade chord length L1 of the first region 12a is greater than the blade chord lengths L2 and L3 of the second region 12b and the third region 12c, so that the airflow flowing in from the blade outer circumferential end 12d side can be introduced between the blades 12 more smoothly (see FIG. 3).

Embodiment 2.
A blower device 100 according to the second embodiment will be described with reference to Figures 7 to 9. The basic configuration of the blower device 100 according to the second embodiment is the same as that of the blower device 100 described in the first embodiment above, so differences from the first embodiment will be mainly described here. Note that hatching has been omitted in Figures 8 to 9 to simplify the drawings. For details about hatching, please refer to Figure 1.

FIG. 7 is a diagram showing the change in the warp height H of the blade 12 used in the fan 106 mounted on the blower 100 according to the second embodiment. FIG. 7 shows the relationship between the position on the chord L in the chord direction of the blade 12 and the warp height H. In FIG. 7, the maximum warp height position at which the warp height H of the first region 12a is maximum is called the first maximum warp height position Pmax1, or simply the position Pmax1. The position Pmax1 is located on the blade outer peripheral end 12d side from the chord center P of the chord L. In addition, the connection point between the first region 12a and the third region 12c is called the first connection part C1, and the connection point between the second region 12b and the third region 12c is called the second connection part C2. The first connection part C1 and the second connection part C2 are parts of the blade 12 as shown in FIG. 8(b) and are not points on the chord L, but are shown on the horizontal axis in FIG. 7 for the sake of explanation.

Figure 8 is a cross-sectional view showing the air flow in the fan inlet region B in the blower device 100 according to embodiment 2. Figure 9 is a cross-sectional view showing the air flow in the fan outlet region C in the blower device 100 according to embodiment 2. Figures 8 and 9 show the cross-sectional configuration when the blower device 100 is cut in a direction perpendicular to the fan shaft 14 (see Figure 2(a)) of the fan 106 mounted on the blower device 100.

In the second embodiment, as shown in FIG. 7, the warp height H of the first region 12a first gradually increases as it moves from the outer periphery 12d toward the inner periphery 12e. Then, the warp height H of the first region 12a is maximum at position Pmax1 on the chord L. That is, the warp height H increases from the outer periphery 12d to position Pmax1. Then, in the first region 12a, the warp height H gradually decreases from position Pmax1 to the third region 12c (i.e., the first connecting portion C1). In this case, the rate of change (absolute value) of the warp height H from the outer periphery 12d to position Pmax1 may be greater than or equal to the rate of change (absolute value) of the warp height H from position Pmax1 to the third region 12c (i.e., the first connecting portion C1).

In addition, in the second embodiment, as shown in FIG. 7, the warp height H of the second region 12b gradually increases from the inner circumferential edge 12e of the blade toward the third region 12c. The rate of change (absolute value) of the warp height H of the second region 12b is smaller than the rate of change (absolute value) of the warp height H from the outer circumferential edge 12d of the blade of the first region 12a to position Pmax1. However, the rate of change (absolute value) of the warp height H of the second region 12b may be greater than or the same as the rate of change (absolute value) of the warp height H from position Pmax1 of the first region 12a to the third region 12c (i.e., the first connecting portion C1).

In addition, in the second embodiment, as shown in FIG. 7, the warp height H of the third region 12c gradually increases in the direction from the inner blade end 12e toward the outer blade end 12d, or is maintained at a constant value.

The third region 12c is connected to the second region 12b at a position where the warp height H in the second region 12b is maximum. Hereinafter, the position where the warp height H in the second region 12b is maximum will be referred to as a second maximum warp height position Pmax2, or simply as position Pmax2.
The position Pmax2 corresponds to the second connecting portion C2.

The rate of change of the warp height H of the third region 12c is smaller than the rate of change of the warp height H of the second region 12b and the first region 12a. In addition, the maximum warp height position Pmax1 of the first region 12a is located closer to the outer wing end 12d than the first connecting portion C1 that connects the third region 12c and the first region 12a.

In the example of FIG. 7, the warp height H of the first region 12a is greater than the maximum warp height of the second region 12b throughout. In this case, if the warp height H of the third region 12c is maintained at a constant value, the warp height H of the first connecting portion C1 of the first region 12a will be the same as the warp height H of the second connecting portion C2 of the second region 12b. On the other hand, if the warp height H of the third region 12c gradually increases in the direction from the inner circumferential edge 12e to the outer circumferential edge 12d of the blade, the warp height H of the first connecting portion C1 of the first region 12a will be greater than the warp height H of the second connecting portion C2 of the second region 12b. It is preferable that the warp height H of the first region 12a is greater than the warp height H of the second region 12b throughout.

In addition, in the second embodiment, the relationship between the chord length L2 of the second region 12b and the chord length L3 of the third region 12c is as follows. That is, the chord length L2 of the second region 12b is greater than the chord length L3 of the third region 12c.

　Chord length L2 of second region 12b > chord length L3 of third region 12c

In the second embodiment, the relationship between the chord length L1 of the first region 12a and the chord length L2 of the second region 12b is the same as in the first embodiment, with the chord length L1 of the first region 12a being greater than the chord length L2 of the second region 12b.

In the second embodiment, as shown in FIG. 8(b), the tangent to the pressure surface 12f of the end on the third region 12c side, among both ends of the first region 12a in the chord L direction, is defined as tangent T. That is, tangent T is a tangent to the first connecting portion C1 that connects the first region 12a and the third region 12c. At this time, the inner circumferential end portion 12e of the blade is positioned in the counter-rotation direction, which is the opposite direction of the rotation direction R, from tangent T. That is, the inner circumferential end portion 12e of the blade is positioned rearward of tangent T in the rotation direction R.

(Effects of the Second Embodiment)
In the blade 12 according to the second embodiment, the maximum warp height position Pmax1 where the warp height H of the first region 12a is maximum is located closer to the blade outer circumferential end 12d than the chord center P of the chord L. Therefore, as shown in FIG. 8B, the direction of the airflow flowing in from the blade outer circumferential end 12d side is turned in the first region 12a where the warp height H is large in the region F. In this way, in the region F, the direction of the airflow is turned before the flow speed of the airflow is increased on the pressure surface 12f of the adjacent blade 12, thereby reducing the separation of the airflow between the entire blades 12. As a result, in the second embodiment, the increase in the airflow speed on the pressure surface 12f of the adjacent blade 12 can be suppressed, and therefore the generation of abnormal sounds can be suppressed. In the comparative example of FIG. 5 described above, the increase in the airflow speed occurs in the region D (see FIG. 5), but in the second embodiment, the increase in the airflow speed can be suppressed, and therefore the generation of abnormal sounds can be suppressed.

In the second embodiment, as shown in FIG. 7, in the second region 12b and the third region 12c, the warp height H gradually increases from the blade inner circumferential end 12e side. The third region 12c is connected to the maximum warp height position Pmax2 of the second region 12b by the second connecting portion C2. The change rate (absolute value) of the warp height H of the third region 12c is smaller than the change rate (absolute value) of the warp height H of the second region 12b and the first region 12a. That is, as shown in FIG. 7, the warp height H smoothly decreases from the third region 12c to the blade inner circumferential end 12e. The maximum warp height position Pmax1 of the first region 12a is located closer to the blade outer circumferential end 12d side than the first connecting portion C1 that connects the first region 12a and the third region 12c. Therefore, first, in the region F of FIG. 8(b), the direction of the airflow is redirected in the first region 12a. Next, as shown in region G in FIG. 8(b), the airflow flows along the pressure surface 12f in the range from the maximum warp height position Pmax1 of the pressure surface 12f of the adjacent blade 12-1 to the third region 12c, and in region K in FIG. 8(b), the airflow flows out in the radial direction. As shown in FIG. 8(a) and FIG. 9(a), the airflow continues to move in the radial direction within the fan 106. As a result, in the second embodiment, the airflow flows out of the fan 106 toward the vicinity of the middle of the casing 107 in the fan outflow region C shown in FIG. 9. This suppresses the backflow upstream of the casing 107 as shown by the arrow A2, and improves the stall resistance.

Furthermore, in the second embodiment, on the negative pressure surface 12g of the blade 12, as shown in region I of FIG. 8(b), the airflow separating from the first region 12a is reattached to the second region 12b, thereby further suppressing the separation of the airflow from the surface of the blade 12.

In the second embodiment, as shown in FIG. 7, the warp height H of the second region 12b increases smoothly from the blade inner circumferential end 12e toward the third region 12c without decreasing. The chord length L2 of the second region 12b is longer than the chord length L3 of the third region 12c. Therefore, as shown in FIG. 9(b), in the fan outflow region C, as shown in region J, when the airflow inside the fan 106 flows into the blade inner circumferential end 12e side, the airflow flows in smoothly, and separation of the airflow on the pressure surface 12f side in region E can be suppressed. As a result, the airflow flows along the surface of the blade 12 without separating from the blade 12, so that the effective area between the blades 12 is expanded, the ventilation resistance can be reduced, and the axial output applied to the fan 106 can be reduced. Furthermore, the passing wind speed of the airflow is reduced, so that noise can be reduced.

In addition, in the second embodiment, as shown in FIG. 8(b), the blade inner circumferential end 12e is disposed rearward in the direction of rotation R from the tangent line T at the pressure surface 12f of the end of the first region 12a on the third region 12c side. In other words, the blade inner circumferential end 12e is disposed in the opposite direction of rotation from the tangent line T. Therefore, the airflow flows out radially from the blade inner circumferential end 12e side as shown in region K in FIG. 8(b) without being blocked by the second region 12b. As a result, as shown in FIG. 9(a), in the fan outflow region C, the airflow flows out toward the middle of the casing 107, thereby suppressing the backflow toward the upstream of the casing 107 as shown by the arrow A2, and improving the stall resistance.

Embodiment 3.
A blower device 100 according to embodiment 3 will be described with reference to Fig. 10. The basic configuration of the blower device 100 according to embodiment 3 is the same as that of the blower device 100 described in embodiment 1 above, and therefore differences from embodiment 1 will be mainly described here.

FIG. 10 is a partially enlarged cross-sectional view showing the configuration of the blade 12 provided in the blower 100 according to embodiment 3. FIG. 10 shows the cross-sectional configuration when the blade 12 is cut in a direction perpendicular to the axis of the fan 106 mounted on the blower 100.

As shown in FIG. 10, in the third embodiment, a plurality of grooves 12h are provided on the negative pressure surface 12g of the first region 12a of the blade 12. The grooves 12h are, for example, configured as grooves extending in a rib shape in the Y direction (see FIG. 2). As shown in FIG. 10, the grooves 12h are recessed from the surface of the negative pressure surface 12g of the first region 12a.

(Effects of the Third Embodiment)
In the third embodiment, as shown in FIG. 10, a plurality of grooves 12h are provided on the negative pressure surface 12g of the first region 12a of the blade 12. In this way, in the third embodiment, the grooves 12h are provided on the blade outer circumferential end 12d side of the blade 12, and as shown by the arrow A in FIG. 10, when the airflow flows in from the blade outer circumferential end 12d side, minute airflow vortices A4 are formed by the grooves 12h. The vortices A4 flow in the opposite direction to the flow direction of the airflow indicated by the arrow A near the surface of the negative pressure surface 12g. These minute vortices A4 attract the main flow of the airflow indicated by the arrow A toward the blade 12, thereby further suppressing the separation of the airflow on the negative pressure surface 12g. In this way, in the third embodiment, the airflow is less likely to separate from the surface of the blade 12, so that the airflow can be made to follow the negative pressure surface 12g side of the blade 12 without concentrating on the pressure surface 12f side of the adjacent blade 12-1. As a result, the increase in the airflow speed on the pressure surface 12f side of the adjacent blade 12-1 can be suppressed, and the occurrence of abnormal noise can be suppressed. In addition, since the wind speed between the blades 12 does not increase, the pressure loss when passing between the blades 12 can be reduced, and the shaft output applied to the blade 12 can be reduced. Furthermore, when the airflow flows out to the blade inner circumferential end 12e side, the increase in the airflow speed on the pressure surface 12f side is suppressed, so the airflow flows out in the radial direction from the blade inner circumferential end 12e side. As a result, in the fan outflow region C, the airflow flows out from the middle of the casing 107, and the stall resistance can be improved.

In the first to third embodiments, the fan 106 is configured as a cross-flow fan and the blades 12 are applied to the cross-flow fan, but the fan 106 is not limited to a cross-flow fan. In other words, the configuration of the fan 106 shown in the first to third embodiments can also be applied to a sirocco fan or other fans.

Furthermore, it is not necessary that all of the features relating to the first region 12a, the second region 12b, and the third region 12c of the wing 12 described in the first to third embodiments are true for all the wing 12. In other words, at least one of the features relating to the first region 12a, the second region 12b, and the third region 12c of the wing 12 described in the first to third embodiments may be true for all the wing 12. In that case, the other features may differ for each wing 12. Therefore, for example, at least one of the features described in each claim or each embodiment is true for all the wing 12. To give a specific example, for example, the feature described in one claim is true for all the wing 12. Or, the features described in two or more claims are true for all the wing 12 at the same time. In this way, only the feature of one claim may be true for all the wing 12, or any combination of two or more claims may be true for all the wing 12. Furthermore, this disclosure also includes cases where all of the wings 12 have the same shape.

12 Blade, 12-1 Blade, 12a First region, 12b Second region, 12c Third region, 12d Blade outer peripheral end, 12e Blade inner peripheral end, 12f Pressure surface, 12g Negative pressure surface, 12h Groove, 13 Partition plate, 14 Fan shaft, 15 End face disc with boss, 16 End face disc, 17 Fan block, 100 Blower, 101 Housing, 101a Top portion, 101b Bottom portion, 101c Front portion, 101d Rear portion, 102 Intake port, 103 Outlet port, 104 Filter, 105 Heat exchanger, 106 Fan, 107 Casing, 108 Side wall, 108a Tongue portion, 109 Rear guy , 120 blade, 120-1 blade, 120d outer periphery of blade, 120e inner periphery of blade, 120f pressure surface, 120g suction surface, A arrow, A2 arrow, A3 arrow, A4 vortex, A5 arrow, B fan inlet area, C fan outlet area, C1 first connection, C2 second connection, D area, E area, F area, G area, H camber height, I area, J area, K area, L chord, L1 chord length, L2 chord length, L3 chord length, Lc chord length, P chord center, Pmax1 first maximum camber height position, Pmax2 second maximum camber height position, R rotation direction, T tangent, W camber line.

Claims

A blower having a fan that rotates around a fan shaft,
The fan has a plurality of blades spaced apart from one another in a circumferential direction;
Each of the blades has a cross-sectional shape that is bowed in a cross section perpendicular to the axial direction of the fan shaft,
Each of the wings comprises:
A suction surface which is one of the main surfaces arranged on the outside of the bow;
A pressure surface which is the other main surface arranged inside the bow;
a blade outer peripheral end portion which is an end portion on an outer peripheral side of the blade connecting the suction surface and the pressure surface;
a blade inner peripheral end portion which is an end portion on an inner peripheral side of the blade connecting the suction surface and the pressure surface;
having
At least one or all of the wings of the plurality of wings include:
In a cross section perpendicular to the axial direction of the fan shaft,
When the blade is divided into three regions, that is, a first region arranged on the outer circumferential end side of the blade, a second region arranged on the inner circumferential end side of the blade, and a third region connecting the first region and the second region,
The warpage direction of the first region and the second region is the same, the warpage is concave toward the counter-rotation direction, and the warpage height of at least the first region and the second region varies along the chord of the blade.
Blower device.
At least one or all of the plurality of wings,
The camber height of the third region may be maintained at a constant value or may vary along the chord of the wing.
The blower device according to claim 1 .
In all of the wings, the third regions have the same shape.
The blower device according to claim 1 or 2.
At least one or all of the plurality of wings,
When the third region is warped,
The warping direction of the third region is the same as the warping direction of the first region and the second region.
The blower device according to any one of claims 1 to 3.
At least one or all of the wings of the plurality of wings include:
In a cross section perpendicular to the axial direction of the fan shaft,
The pressure surface and the negative pressure surface of each of the three regions, i.e., the first region, the second region, and the third region, are formed by one or more circular arcs;
Among the first region, the second region, and the third region, the radius of curvature of the pressure surface and the negative pressure surface in the third region is the largest.
The blower device according to any one of claims 1 to 4.
At least one or all of the plurality of wings,
The maximum warpage height of the first region is greater than the maximum warpage height of the second region.
The blower device according to any one of claims 1 to 5.
At least one or all of the plurality of wings,
A first maximum warp height position where the warp height in the first region is maximum is located closer to the outer circumferential end portion of the blade than the chord center, which is the center of the chord.
The blower device according to any one of claims 1 to 6.
At least one or all of the plurality of wings,
The chord length of the first region is greater than the chord length of the second region and the chord length of the third region.
The blower device according to any one of claims 1 to 7.
At least one or all of the plurality of wings,
In the second region and the third region, the camber height is gradually increased or maintained from the inner circumferential end side of the blade,
The third region is connected to a second maximum warp height position where the warp height of the second region is maximum,
a rate of change in the warp height in the third region is smaller than rates of change in the warp height in the second region and the first region;
a first maximum warp height position where the warp height of the first region is maximum is located closer to the outer circumferential end portion of the blade than a connecting portion between the first region and the third region;
The blower device according to any one of claims 1 to 8.
At least one or all of the plurality of wings,
The chord length of the second region is greater than the chord length of the third region.
The blower device according to any one of claims 1 to 9.
At least one or all of the plurality of wings,
The blade inner circumferential end portion is disposed in a counter-rotational direction from a tangent line on the pressure surface of a first connecting portion connecting the first region and the third region.
The blower device according to any one of claims 1 to 10.
At least one or all of the wings of the plurality of wings include:
a plurality of grooves formed on the suction surface of the first region;
The blower device according to any one of claims 1 to 11.