CN112352108B - Multi-blade blower and air conditioner - Google Patents

Fig. 1 is a perspective view showing a sirocco fan according to

1 of the present invention. Fig. 2 is a plan view showing a state in which the upper panel of the casing is removed in the sirocco fan according to

1 of the present invention. Fig. 3 is a perspective view showing an impeller of the sirocco fan according to

1 of the present invention. The circular arc-shaped arrows shown in fig. 2 and 3 indicate the rotation direction of the

30.

The

100 is a device that pressurizes air taken in from the

2 and discharges the air from the outlet 4 to forcibly flow the air. The

100 includes: a

1 having an

2 and an air outlet 4 formed therein, and an

30 housed in the

1.

The

30 is a component that: the air is forcibly discharged outward of the

30 in a substantially radial direction by centrifugal force generated by rotation of the impeller about the

31 by the rotation drive of the

70 such as a motor. The radial direction refers to a direction extending from the

31 in a direction perpendicular to the

31. That is, the

30 rotates about the

31, and generates a flow of air that flows into the

1 through the

2 and flows out to the outside of the

1 through the air outlet 4. The

30 includes a

40 and a plurality of

50.

The

40 is a circular plate rotatably provided around the rotating

31. The

40 is provided with a plurality of

50. Specifically, the

40 includes a

41 and a

42 that is a rear surface of the

41. In

1, a plurality of

50 are provided on the

41 of the

40. The plurality of

50 are provided, for example, near the outer periphery of the

40.

A plurality of

50 extend from the

40 along the

31. The plurality of

50 are arranged at intervals on a circle centered on the

31. Specifically, each of the

50 includes a

51 which is one end in the direction of the

31 and a

52 which is the other end in the direction of the

31. The first ends 51 of the

50 are connected to the

41 of the

40. The second ends 52 of the

50 face the

2 of the

1. That is, each of the

50 extends substantially perpendicularly to the

41 of the

40 in a direction from the

41 of the

40 toward the

2. Each of the

50 is parallel to the radial direction or inclined at a predetermined angle with respect to the radial direction when viewed along the direction of the

31. The direction of the

31 refers to a direction in which the

31 extends.

The second ends 52 of the

50, i.e., the ends on the

2 side, are connected by the

45. The

45 is a series of annular members having a diameter capable of connecting the second ends 52 of the plurality of

50. By this connection, the positional relationship of the second ends 52 of the plurality of

50 is maintained, and the plurality of

50 are reinforced. The

45 may be a ring-shaped plate member having a width capable of covering the

52 of each

50, or may be a ring-shaped member coupling the outer peripheral sides of the

50. With such a configuration, the

30 rotates, and thus air sucked into the space surrounded by the

40 and the plurality of

50 is sent radially outward through the space between

50.

The

1 is a scroll-type fan housing. The

1 includes a

10 that houses the

30 and a

20 connected to the

10.

The

10 is a hollow cylindrical member having a substantially columnar space formed therein, for example. The

10 substantially surrounds the

30. The shape of the space formed inside the

1 is not limited to a cylindrical shape, and may be, for example, a cylindrical shape having a polygonal cross section. The

1 includes a

11, an

12, and a

13 as members constituting wall surfaces. The

12 has an

2 formed in a region facing the second ends 52 of the plurality of

50 so that air can flow between the

30 and the outside of the

1. Further, the

2 is provided with a

3. The

3 has a cross section gradually decreasing from the outside of the

1 toward the inside thereof so that air flows smoothly through the

2 and its vicinity. The center of the

2 substantially coincides with the

31 of the

30.

The

11 and the

12 are disposed opposite to each other in the direction of the

31. That is, the

12 is provided on the suction side of the

30, that is, on the

52 side, and the

11 is provided on the

40 side of the

30. The

13 connects the outer edge of the

11 to the outer edge of the

12, and extends to the outer periphery of the

30. Further, a portion of the side surface of the

10 has a portion where the

13 is not provided. This portion serves as a main

14 through which air exhausted from the

10 to the outside of the

10 passes.

As shown in fig. 2, the gap between the

13 of the

10 and the outer peripheral end of the

30 is enlarged at a predetermined ratio from a

26 described later in the rotation direction of the

30. This allows the air sent from the

30 to flow smoothly through the gap. Further, since the flow passage area of the air gradually increases from the

26 to the body

14, the static pressure of the air can be efficiently increased as the air sent from the

30 flows through the gap.

The

20 is a hollow tube having a substantially rectangular cross section perpendicular to the flow direction of air. The

20 forms a flow path for guiding the air flowing out from the body

14 of the

10 to the outside of the

1. An opening portion at one end of the

20 serves as an

25 through which air flowing into the

20 passes. The opening at the other end of

20 serves as an exhaust port 4 through which air flowing out of

20 passes, in other words, through which air discharged from fan casing 1 passes. That is, the peripheral edge of the

25 of the

20 is connected to the peripheral edge of the

14 of the

10.

The

20 includes an

21, a

22, a

23, and an

24 as members constituting wall surfaces. The

21 is smoothly connected to an end portion on the downstream side in the air flow direction among end portions of the

13 of the

10 constituting the peripheral edge of the main

14. The

22 is connected to an upstream end of the

13 of the

10, which constitutes the periphery of the main

14, in the air flow direction. The

22 is disposed at a predetermined angle to the

21 so that the cross-sectional area of the flow path gradually increases toward the flow direction of the air in the

20. The

23 and the

24 connect the outer edge of the

21 and the outer edge of the

22, respectively, to form a substantially rectangular flow path. The

23 is connected to an end of the

11 of the

10 that forms the periphery of the

14. The

24 is connected to an end of the

12 of the

10 that constitutes the peripheral edge of the main

14.

The

22 and the

13 of the

10 are joined smoothly at a predetermined radius of curvature from the

11 to the

12 of the

1 to form a

26. The air flow flowing into the

10 from the

2 through the

30 is collected by the

10, and the

26 serves as a branch point when the collected air flows into the

20. That is, the static pressure of the air flowing into the

20 increases while the air passes through the

10, and the air becomes higher in pressure than the vicinity of the

26 in the

10. The

26 has a function of partitioning the flow of air flowing again into the

10 from the

20 by the pressure difference. Further, since the

26 is formed to have a predetermined radius of curvature, when air flows into the

20 from the

10, even if the air collides with the

26, turbulence generated in the

26 can be reduced. Therefore, deterioration of air blowing performance and increase of noise can be suppressed. In

1, the radius of curvature of the

26 is constant in the direction of the

31, but the radius of curvature of the

26 does not need to be constant in the direction of the

31. For example, the radius of curvature of the

26 on the

2 side, i.e., the

12 side, may be larger than the radius of curvature of the

26 on the

11 side.

Next, the detailed shape of the

50 of the

30 according to

1 will be described with reference to fig. 3 and fig. 4 to 7 described later. Since each of the

50 has the same shape, fig. 4 to 7 show the shape of one

50.

Fig. 4 is a view of an impeller according to

1 of the present invention, taken along a plane including a rotation axis of the impeller, and viewed in a direction perpendicular to the plane. Fig. 5 to 7 are views showing the shape of the impeller blade according to

1 of the present invention when viewed in the direction of the rotation axis of the impeller. In other words, fig. 5 to 7 are views of the shape of the

50 when viewed in a cross section perpendicular to the

31. Here, fig. 5 shows the shape of the

50 at the position of the

51 which is the end on the

40 side. Fig. 6 shows the shape of the

50 at the position of the

52 which is the end on the

2 side. In addition, fig. 7 shows the shape of the

50 at the position of the

51 and the shape of the

50 at the position of the

52. In fig. 7, the shape of the

50 at the position of the

52 is indicated by a broken line in order to easily distinguish the shape of the

50 at the position of the

51 from the shape of the

50 at the position of the

52. The hollow arrows shown in fig. 5 to 7 indicate the rotation direction of the

30.

The

50 includes a

55, a

56, an inner

53, and an outer

54. The

55 is a surface that is located on the front side in the rotation direction of the

30. The

56 is a surface that is on the rear side in the rotation direction of the

30. The inner

53 is an end in a radial direction extending from the

31 in a direction perpendicular to the

31, and is an end close to the

31. The outer

54 is a radial end and is an end away from the

31.

As shown in fig. 4, the length of the

50 in the direction of the

31 is a length L1. That is, the length in the direction of the

31 from the

51 to the

52 is a length L1. Further, the distance between the

31 and the outer

54 of the

50 is the same distance Do from the

51 to the

52. Further, the distance between the

31 and the inner

53 of the

50 is equal to the distance Di0 from the

51 to the first

57. The distance between the

31 and the inner

53 of the

50 gradually increases from the first

57 toward the

52, and becomes a distance Di1 at the position of the

52. The first

57 is located between the

51 and the

52, and is located at a distance L0 from the

51 in

1. The length L0 is, for example, approximately half the length of the length L1.

Here, the "same" in

1 does not have a strictly identical meaning, but has a substantially identical meaning. For example, the distance between the

31 and the outer

54 of the

50 is designed to be the same distance Do from the

51 to the

52. However, in the

30, the distance between the

31 and the outer

54 of the

50 does not become exactly the same distance Do from the

51 to the

52, and variations occur due to machining errors and the like. In

1, even when a slight variation occurs due to such a machining error or the like, the distance between the

31 and the outer

54 of the

50 is referred to as the same distance Do from the

51 to the

52.

As shown in fig. 5 to 7, in a cross section perpendicular to the

31, the

60 of the

50 has a shape connecting arcs having a plurality of radii of curvature. The

60 is a line connecting a point having the same distance from the

55 and the

56 from the inner

53 to the outer

54.

The inlet angle of the

50 is the same

0 from the

51 to the first

57. The inlet angle of the

50 gradually increases from the first

57 toward the

52, and becomes the

1 at the position of the

52. Namely,

1>

0. Note that the inlet angle of the

50 is defined as follows. First, in a cross section perpendicular to the

31, an arc passing through an intersection of the

60 and the inner

53 is drawn around the

31. The arc is defined as an inner circumference arc. A tangent to the inner circumference side arc at the intersection of the

60 and the

53 is drawn so as to extend in the direction opposite to the rotation direction of the

30. A tangent to the

60 at the intersection of the

60 and the inner

53 is drawn so as to extend in the direction opposite to the rotation direction of the

30. When the tangent to the inner circumference side arc and the tangent to the

60 are drawn in this manner, the angle formed by the tangent to the inner circumference side arc and the tangent to the

60 becomes the inlet angle of the

50.

In addition, the exit angle of the

50 is the same exit angle β from the

51 to the

52. Note that the exit angle of the

50 is defined as follows. First, in a cross section perpendicular to the

31, an arc passing through an intersection of the

60 and the outer

54 is drawn with the

31 as a center. The arc is defined as an outer circumference arc. A tangent to the outer circumferential arc at the intersection of the

60 and the outer

54 is drawn so as to extend in the direction opposite to the rotation direction of the

30. In addition, a tangent to the

60 at the intersection of the

60 and the outer

54 is drawn so as to extend in the rotation direction of the

30. When the tangent to the outer-peripheral arc and the tangent to the

60 are drawn in this manner, the angle formed by the tangent to the outer-peripheral arc and the tangent to the

60 is the exit angle of the

50.

The outer peripheral ends 54 of the

50 are arranged at the following positions. In detail, in a cross section perpendicular to the

31, the

61, the

62, the

63, the first

65, and the second

66 are defined as follows. The intersection of the outer

54 and the

55 is defined as a

61. The intersection of the outer

54 and the

56 is defined as a

62. The intersection of the outer

54 and the

60 of the

50 is defined as a

63. A virtual straight line connecting the

61 of the

51 and the

31 is defined as a first

65. A virtual straight line connecting the

62 of the

51 and the

31 is defined as a second

66. In the case defined as such, the

63 from the

51 to the

52 is located between the first

65 and the second

66.

By disposing the outer

54 of the

50 from the

51 to the

52 in this manner, it is understood that, when the outer

54 of the

50 is viewed in the radial direction, the outer

54 has a substantially linear shape substantially parallel to the

31, for example, when viewed from the region a shown in fig. 3.

Next, the flow of air during operation of the

100 according to

1 will be described.

When the

30 rotates, air located inside the

30 is sent out in a substantially radial direction outward of the

30 by a centrifugal force generated by the rotation of the

30. Further, air flows into the

30 through the

2. The air sent out to the outside of the

30 flows along the

13 of the

10 of the

1 in the rotation direction of the

30 in the

10. The sectional area between the

30 and the

13 increases in the rotational direction of the

30. Therefore, the dynamic pressure of the air flowing in the

10 is converted into the static pressure, and the static pressure is gradually increased in the

10. The air having the increased static pressure flows into the

20 through the

14 and the

25 of the

20, and is then discharged from the exhaust port 4.

As described above, the air sucked into the

30 from the

2 in the direction of the

31 changes the flow direction from the direction of the

31 to the radial direction by the centrifugal force generated by the rotation of the

30. However, the air sucked into the

30 does not abruptly change the flow direction at the

52 side of the

30, which is the

2 side, due to the inertia of the air flowing in the direction of the

31. Therefore, the flow on the

52 side of the

30 becomes a flow inclined in the direction of the

40 with respect to the direction perpendicular to the

31. In addition, the flow rate of air passing through the

52 side of the

30 is also smaller than that of the

40 side. That is, on the

52 side of the

30, the velocity of the air at the inner

53 of the

50 is small. Therefore, on the

52 side of the

30, it is difficult for air to flow between the

50.

However, in the

50 according to

1, the distance between the

31 and the inner

53 of the

50 gradually increases from the first

57 toward the

52 on the

2 side. Therefore, the inner

53 of the

50 on the

52 side can be aligned with the flow inclined in the direction of the

40. Therefore, on the

52 side, air easily flows between the

50.

In

1, the inlet angle of the

50 gradually increases from the first

57 toward the

52 on the

2 side. For example, as can be seen from fig. 7, when the inlet angle of the

50 is small, the air that attempts to flow radially between

50 collides with the

56 of the

50. On the other hand, by increasing the inlet angle of the

50, the vicinity of the inner

53 is close to parallel with respect to the air that is about to flow radially between the

50. Therefore, by increasing the inlet angle of the

50, the air that attempts to flow between

50 can be suppressed from colliding with the

56 of the

50. Therefore, by gradually increasing the inlet angle of the

50 from the first

57 toward the

52 on the

2 side, the air more easily flows between the

50 on the

52 side. Therefore, the

30 according to

1 can reduce the pressure loss generated in the vicinity of the second ends 52 of the

50.

When the flow of air sent from between the

50 into the

10 is oblique to the direction perpendicular to the

31, the air sent into the

10 flows into the

10 while colliding with the

11 and the

12. When such flowing air flows into the

20, the air flows through the

20 while colliding with the

23 and the

24. Therefore, if the flow of air sent from between the

50 into the

10 is inclined with respect to the direction perpendicular to the

31, a vortex is generated in the flow of air between the

30 and the exhaust port 4 in the

1, and the pressure loss at this portion becomes large.

On the other hand, the outer

54 of the

50 of

1 has a substantially linear shape substantially parallel to the

31. Therefore, the flow of air sent out into the

10 from between the

50 is inclined to a direction perpendicular to the

31 to a small degree. Therefore, in the

100 according to

1, the flow of air between the

30 and the exhaust port 4 in the

1 can be suppressed from colliding with the

11, the

12, the

23, and the

24. Therefore, in the

100 according to

1, it is possible to suppress the generation of a vortex flow in the flow of air between the

30 and the exhaust port 4 in the

1, and to reduce the pressure loss at that location.

As described above, in the

100 according to

1, when the

50 is viewed, the distance between the

31 and the inner

53 gradually increases from the first

57 toward the

52, and the inlet angle gradually increases from the first

57 toward the

52. In the

100 according to

1, when the

50 is viewed, a

63 from the

51 to the

52 is located between the first

65 and the second

66 in a cross section perpendicular to the

31.

Therefore, the

100 according to

1 can suppress the pressure loss of the air passing between the

50 and also suppress the generation of a vortex flow in the flow of the air between the

30 and the exhaust port 4. Therefore, the

100 according to

1 can reduce the pressure loss of the air in the

100 as compared with the conventional one, and can improve the air blowing performance. Furthermore, the

100 according to

1 can reduce the pressure loss of the air in the

100 as compared with the conventional one, and therefore, the effect of reducing noise can also be obtained.

The length L0 from the

51, which indicates the position of the first

57 of the

50, is preferably in the range of 0.5. ltoreq.L 0/L1. ltoreq.0.7. Specifically, the inventors studied the change in the flow velocity of the air flowing between the

50 in the direction of the

31 using a conventional impeller in which the distance between the

31 and the inner peripheral ends 53 of the

50 and the inlet angle are not changed from the

51 to the

52. As a result, it was confirmed that the flow velocity of the air gradually decreased from the substantially central position of the

50 in the direction of the

31 toward the

52. At a position where the flow velocity of the air is not decreased, it is preferable that the distance between the

31 and the inner

53 of the

50 and the inlet angle are not changed. On the other hand, at a position where the flow velocity of the air is reduced, it is preferable that the distance between the

31 and the inner circumferential ends 53 of the

50 and the inlet angle be changed as described above so that the air easily flows between the

50. Therefore, the length L0 from the

51, which indicates the position of the first

57 of the

50, is preferably in the range of 0.5. ltoreq.L 0/L1. ltoreq.0.7.

The distance between the

31 and the inner

53 of the

50 and the change in the inlet angle between the first

57 and the

52 may be linearly changed or may be changed in a quadratic function manner. As a result of the experiments by the inventors, the effect of suppressing the pressure loss of the air passing between the

50 is large in the range of

1 to α 0 of 15 to 35 degrees. Therefore, α 1-

0 is preferably in the range of 15 to 35 degrees. As a result of the experiments by the inventors, the effect of suppressing the pressure loss of the air passing between the

50 is large in the range of Di1/Di0 to 1.02 to 1.10. Therefore, Di1/Di0 is preferably in the range of 1.02 to 1.10.

The distance between the

31 and the outer

54 of the

50 may be different from the

51 to the

52 as follows. In

2, items not specifically described are the same as those in

1, and the same functions and configurations are described using the same reference numerals.

Fig. 8 is a perspective view showing an impeller of the sirocco fan according to

2 of the present invention. Fig. 9 is a view of an impeller according to

2 of the present invention, taken along a plane including a rotation axis of the impeller, and viewed in a direction perpendicular to the plane. Fig. 10 is a view showing a shape of the impeller according to

2 of the present invention when the blades of the impeller are viewed in the direction of the rotation axis of the impeller. In other words, fig. 10 is a view of the shape of the

50 as viewed in a cross section perpendicular to the

31. Here, fig. 10 shows the shape of the

50 at the position of the

51 and the shape of the

50 at the position of the

52. In fig. 10, the shape of the

50 at the position of the

52 is indicated by a broken line in order to easily distinguish the shape of the

50 at the position of the

51 from the shape of the

50 at the position of the

52. The circular arc-shaped arrows shown in fig. 8 and the hollow arrows shown in fig. 10 indicate the rotation direction of the

30.

The distance between the

31 and the outer

54 of the

50 is the same distance Do0 from the

51 to the second

58. The distance between the

31 and the outer

54 of the

50 gradually increases from the second

58 toward the

52, and becomes the distance Do1 at the position of the

52. Here, the second

58 is located between the

51 and the

52, and is located at a distance L0 from the

51 in

2. Length L0 is, for example, approximately half the length of length L1. The length from the

51 to the first middle-

57 may be different from the length from the

51 to the second middle-

58.

The exit angle of the

50 is the same exit angle β 0 from the

51 to the second

58. The exit angle of the

50 gradually decreases from the second

58 toward the

52, and becomes an

1 at the position of the

52. Namely,

1<

0. The change in the exit angle between the second

58 and the

52 may be changed linearly or may be changed in a quadratic function manner.

In

2, the

63 from the

51 to the

52 is also located between the first

65 and the second

66. By disposing the outer

54 of the

50 from the

51 to the

52 in this manner, it is possible to see that the outer

54 has a substantially linear shape substantially parallel to the

31 when the outer

54 of the

50 is viewed in the radial direction, for example, as seen from a region B shown in fig. 8.

Next, the flow of air during operation of the

100 according to

2 will be described.

When the

30 rotates, air located inside the

30 is sent out substantially radially outward of the

30 by a centrifugal force generated by the rotation of the

30. Further, air flows into the

30 through the

2. In this case, the centrifugal force generated increases as the outer diameter of the

30 increases. In the

30 of

2, the outer diameter of the

30 is larger on the

52 side on the

2 side where the flow velocity of air is low and air easily flows obliquely with respect to the

31. Therefore, the centrifugal force generated in the air sucked into the

30 is larger toward the

52 on the

2 side.

Accordingly, the air passing through the

52 of the

50 on the

2 side flows more outward in the radial direction of the

30 due to a strong centrifugal force. Further, the air flow is pulled outward in the radial direction of the

30 by a strong centrifugal force, and thus the air flow inclined with respect to the direction perpendicular to the

31 is more likely to flow in the direction perpendicular to the

31. That is, the difference between the flow velocity of the air flowing out from the

51 side to the outside of the

30 and the flow velocity of the air flowing out from the

52 side to the outside of the

30 is small, and the velocity distribution in the direction of the

31 is relaxed.

By reducing the velocity distribution in the direction of the

31, the flow of the air sent from the

30 is further reduced in inclination with respect to the direction perpendicular to the

31, as compared with

1. Therefore, in the

100 according to

2, the flow of air between the

30 and the exhaust port 4 in the

1 can be further suppressed from colliding with the

11, the

12, the

23, and the

24, as compared with

1. Therefore, in the

100 according to

2, as compared with

1, the generation of a vortex flow in the flow of air between the

30 and the exhaust port 4 in the

1 can be further suppressed, and the pressure loss at that location can be further reduced. That is, the air blowing performance of the

100 according to

2 is further improved.

In order to further obtain the above-described effect of increasing the air passing on the

52 side of the

50 on the

2 side, in

2, the outlet angle of the

50 gradually decreases from the second

58 toward the

52. Therefore, the air flowing out from the

52 side to the outside of the

30 flows out more easily to the outside of the

30 than the air flowing out from the

51 side to the outside of the

30. This can further relax the velocity distribution in the direction of the

31, and further improve the air blowing performance.

As described in

1, the length L0 from the

51 indicating the position of the second

58 of the

50 is preferably in the range of 0.5

0/L1 0.7. As a result of the experiments by the inventors, the effect of facilitating the flow of air through the

52 side is large in the range of

0 to

1 from 5 degrees to 15 degrees. Therefore,

0 to

1 are preferably in the range of 5 degrees to 15 degrees. As a result of the experiments conducted by the inventors, the effect of facilitating the flow of air through the

52 side is large in the range of Do1/Do0 equal to 1.04 to 1.12. Therefore, Do1/Do0 is preferably in the range of 1.04 to 1.12.

The inner

53 of the

50 may be arranged from the

51 to the

52 as follows. In

3, items not specifically described are the same as those in

1 or

2, and the same functions and configurations are described using the same reference numerals. In

3, an example in which the arrangement of the inner peripheral ends 53 of the

50 is modified with respect to the

30 shown in

2 will be described.

Fig. 11 is a view showing a shape of a blade of an impeller according to

3 of the present invention when the blade is viewed in a direction of a rotation axis of the impeller. In other words, fig. 11 is a view of the shape of the

50 as viewed in a cross section perpendicular to the

31. Here, fig. 11 shows the shape of the

50 at the position of the

51 and the shape of the

50 at the position of the

52. Note that the hollow arrow shown in fig. 11 indicates the rotation direction of the

30.

In

3, when the

50 is viewed, the inner

53 of the

50 gradually retreats from the first

57 toward the

52 in the direction opposite to the rotation direction of the

50. In

3, when the

50 is viewed in the direction of the

31, the inner

53 overlaps the cross section of the

50 at the position of the

51 from the

51 to the

52. In order to arrange the inner

53 in this manner, in

3, specifically, the

50 is formed in the following shape.

As described above, the

60 of the

50 has a shape connecting arcs having a plurality of radii of curvature. In

3, from the

51 to the

52, an arc passing through the inner

53 among the plurality of arcs of the

60 is set to an arc having the same center and the same radius of curvature. With such a configuration, when the distance between the

31 and the inner

53 of the

50 is gradually increased from the first

57 toward the

52, the inner

53 is separated from the

31 along the arc passing through the inner

53 among the arcs of the

60. Thereby, the inner

53 of the

50 gradually retreats from the first

57 toward the

52 in the opposite direction to the rotation direction of the

50. When the

50 is viewed in the direction of the

31, the inner

53 overlaps the cross section of the

50 at the position of the

51 from the

51 to the

52.

By arranging the inner

53 in this manner, the vicinity of the inner

53 is close to parallel with the air that attempts to flow radially between the

50. Therefore, the air that attempts to flow between the

50 can be suppressed from colliding with the

56 of the

50. Therefore, the air on the

52 side easily flows between the

50, and the pressure loss generated in the vicinity of the

52 of the

50 can be reduced.

Further, by arranging the inner

53 in this manner, when the

50 is viewed in the direction of the

31, the inner

53 overlaps the cross section of the

50 at the position of the

51 from the

51 to the

52, and therefore, when the

30 is manufactured by injection molding, the vicinity of the inner

53 of the

50 can be molded by a mold that moves in the direction of the

31. Therefore, by arranging the inner

53 in this manner, the

30 can be easily manufactured when the

30 is manufactured by injection molding.

The effect of the

100 according to

3 was verified through experiments.

Fig. 12 is a graph showing the measurement results of the static pressure rise in the

100 according to

3 of the present invention. Fig. 13 is a graph showing the measurement results of the air blowing efficiency in the

100 according to

3 of the present invention. The open circles in fig. 12 and 13 show the measurement results of the

100 according to

3. In addition, black circles in fig. 12 and 13 indicate measurement results of the conventional sirocco fan. As a conventional sirocco fan, a sirocco fan is used in which each

50 is changed to a blade having a cross-sectional shape perpendicular to the

31 from the

51 to the

52, as compared with the

100 of

3.

As is apparent from fig. 12 and 13, the

100 according to

3 of the present invention has higher static pressure and higher air blowing efficiency than the conventional sirocco fan, and improvement in air blowing performance is confirmed.

In the

100 described in

1 to 3, the

40 of the

30 is notched as follows, whereby the

30 can be easily manufactured. In embodiment 4, items not particularly described are the same as those in any of

1 to 3, and the same functions and configurations are described using the same reference numerals. In embodiment 4, an example in which the

40 of the

30 shown in

3 is notched will be described.

Fig. 14 is a view of a part of a main plate of an impeller according to embodiment 4 of the present invention as viewed in the direction of the rotation axis. In fig. 14, the shape of the

50 at the positions of the

51 and the

52 is also described. In fig. 14, the shape of the

50 at the position of the

52 is indicated by a broken line in order to easily distinguish the shape of the

50 at the position of the

51 from the shape of the

50 at the position of the

52. The hollow arrows shown in fig. 14 indicate the rotation direction of the

30.

A

43, which is a range of the

40 of the

30 in which the

50 are projected toward the

40 in the direction of the

31, is notched. The hatched range in fig. 14 is the

43. In other words, the

40 of the

30 is notched in the range shown by hatching in fig. 14. Note that the

40 may be configured to be notched in a range larger than the

43 as long as the

43 is included in the notched range.

By making the

40 notched as in embodiment 4, when the

30 is manufactured by injection molding, the portion of the mold that molds the

56 side of the

50 can be inserted from the notched portion of the

40. Therefore, by making a notch in the

40 as in embodiment 4, the

30 can be manufactured by a pair of molds that move in the direction of the

31. Therefore, by making the

40 with the notch as in embodiment 4, the

30 can be easily manufactured as compared with the case where the

40 is not made with the notch.

In the

43, in other words, the notched portion of the

40 is the negative pressure surface side of the

50. The flow on the negative pressure surface side of the

50 has a lower pressure than the flow on the positive pressure surface side of the

50. Therefore, even if the

40 is notched as in embodiment 4, the reduction in the air blowing performance of the

100 is suppressed to a small extent.

In the

30 shown in

1 to 4, the plurality of

50 are connected only to the

41 of the

40. That is, the

100 described in

1 to 4 is a so-called single suction type sirocco fan. Without being limited to this, a plurality of

50 may be connected to both the

41 and the

42 of the

40 shown in

1 to 4. That is, the

100 may be configured as a so-called double suction type sirocco fan. In embodiment 5, items not specifically described are the same as those in any of

1 to 4, and the same functions and configurations are described using the same reference numerals.

Fig. 15 is a sectional view showing a main part of a sirocco fan according to embodiment 5 of the present invention. Fig. 15 is a view of the

100 taken along a plane including the

31, and shows a part of the

30 and a part of the

1 in the vicinity of the

30.

In the

30 according to embodiment 5, the plurality of

50 are connected to both the

41 and the

42 of the

40. Therefore, the

2 is formed in the

11 of the

1 at a position facing the second ends 52 of the plurality of

50 provided on the

42. That is, the

100 according to embodiment 5 is a so-called double suction type sirocco fan.

Even in the case where the

100 is a double suction type sirocco fan as in embodiment 5, the effects shown in

1 to 4 can be obtained. A plurality of conventional blades may be provided on one of the

41 and the

42. The effects described in

1 to 4 can be obtained by providing the plurality of

50 described in

1 to 4 on the other of the

41 and the

42.

In embodiment 6, an example of an air conditioning apparatus including the

100 described in any one of

1 to 5 will be described. In embodiment 6, items not specifically described are the same as those in any of

1 to 5, and the same functions and configurations are described using the same reference numerals.

Fig. 16 is a refrigerant circuit diagram showing an example of an air conditioner according to embodiment 6 of the present invention. The

200 includes a

210, a four-

220, an

230, an

240, and an

250. The

200 includes the

100 described in any one of

1 to 5 as a fan for supplying air to the

250. The

200 includes, for example, a propeller-

260 as a blower for supplying air to the

230. The

100 described in any one of

1 to 5 may be used as the fan for supplying air to the

230. When the

100 described in any one of

1 to 5 is used as the fan for supplying air to the

230, the fan for supplying air to the

250 may be a fan other than the

100. That is, the

200 according to embodiment 6 includes the

100 described in any one of

1 to 5 in at least one of the fan that supplies air to the

230 and the fan that supplies air to the

250.

The

210 compresses and discharges a sucked refrigerant. The four-

220 is a valve that switches the flow of the refrigerant between cooling operation and heating operation, for example. The

230 exchanges heat between the refrigerant and outdoor air supplied by the

260. The

230 functions as an evaporator during the heating operation, and evaporates and gasifies the refrigerant. The

230 functions as a condenser during the cooling operation, and condenses and liquefies the refrigerant.

The

240 is, for example, an expansion device or the like, and decompresses and expands the refrigerant. The

250 exchanges heat between the refrigerant and the air supplied by the

100. The air heat-exchanged in the

250 is supplied to the air-conditioned space. Specifically, the

250 functions as a condenser during the heating operation, and condenses and liquefies the refrigerant. In other words, during the heating operation, the

250 heats the air supplied by the

100. The

250 functions as an evaporator during the cooling operation, and evaporates and gasifies the refrigerant. In other words, during the cooling operation, the

250 cools the air supplied by the

100.

As described above, the

200 according to embodiment 6 includes the

100 described in any one of

1 to 5 and a heat exchanger that heats or cools the air supplied by the

100. The

200 according to embodiment 6 includes the

100 having an improved blowing performance compared to the conventional one, and thus has improved power efficiency.