JP7204865B2 - Multi-blade blower and air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-blade fan provided with an impeller and an air conditioner provided with the multi-blade fan.

Conventionally, a multi-blade fan has a spiral-shaped scroll casing and an impeller that is housed inside the scroll casing and rotates around its axis (see, for example, Patent Document 1). An impeller that constitutes the multi-blade blower of Patent Document 1 has a disk-shaped main plate, an annular side plate, and radially arranged blades. The blades that make up this impeller are configured such that main blades and intermediate blades are alternately arranged, and the inner diameters of the main blades and the intermediate blades increase from the main plate toward the side plate. In addition, the blades constituting this impeller are sirocco blades (forward blades) having an exit angle of 100 ° or more, and an inducer portion of a turbo blade (backward blade) is provided on the inner peripheral side of the blade, The ratio of the blade inner diameter to the blade outer diameter of the main blade on the main plate side is configured to be 0.7 or less.

JP-A-2000-240590

However, in the multi-blade blower of Patent Document 1, the ratio of the sirocco blades on the outer peripheral side of the blades and the turbo blades on the inner peripheral side of the blades is about the same in the intermediate blades, and sufficient pressure recovery cannot be expected in the intermediate blades. Further, in the multi-blade blower of Patent Document 1, since the side plate side of the blades constituting the impeller is a sirocco blade, sufficient pressure recovery cannot be expected in the blades on the side plate side.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems described above, and to provide a multi-blade fan capable of improving pressure recovery, and an air conditioner equipped with the multi-blade fan.

A multi-blade blower according to the present invention is an impeller comprising a main plate that is rotationally driven, an annular side plate that is arranged to face the main plate, one end of which is connected to the main plate, and the other end of which is connected to the side plate. and communicates with a space formed by an impeller having a plurality of blades arranged in a circumferential direction around a virtual rotation axis of the main plate, a peripheral wall formed in a spiral shape, and the main plate and the plurality of blades. a side wall having a bell mouth forming a suction port, and a scroll casing housing the impeller, wherein each of the plurality of blades is positioned on the rotating shaft side in a radial direction about the rotating shaft an inner peripheral end, an outer peripheral end located on the outer peripheral side of the inner peripheral end in the radial direction, and a sirocco blade portion constituting a forward blade formed at an exit angle larger than 90 degrees including the outer peripheral end , and a turbo blade portion that includes an inner peripheral end and constitutes a trailing blade, and the blade is formed so that the blade length decreases from the main plate side to the side plate side, and the turbo blade portion in the radial direction is formed to be larger than the ratio of the sirocco wing portions, and the outer diameter of the blades formed by the outer peripheral ends of the plurality of blades is formed to be larger than the inner diameter of the bell mouth, and in the radial direction, In the plurality of blade portions located on the outer peripheral side of the inner diameter of the bellmouth, the ratio of the turbo blade portion in the radial direction is larger than the ratio of the sirocco blade portion.

An air conditioner according to the present invention includes the multi-blade blower having the above configuration.

According to the present invention, in the first region and the second region of the impeller, the proportion of the turbo blades in the radial direction is greater than the proportion of the sirocco blades. Impellers and multi-blade fans have a high ratio of turbo blades in any region between the main plate and the side plate, and the blades can perform sufficient pressure recovery. Pressure recovery can be improved compared to air conditioners.

1 is a perspective view schematically showing a multi-blade fan according to Embodiment 1; FIG. FIG. 2 is an external view schematically showing the configuration of the multi-blade blower according to Embodiment 1 viewed parallel to the rotation axis; FIG. 3 is a cross-sectional view schematically showing the AA cross section of the multi-blade blower of FIG. 2; 2 is a perspective view of an impeller that constitutes the multi-blade fan according to Embodiment 1. FIG. Figure 5 is a side view of the impeller of Figure 4; FIG. 6 is a schematic diagram showing blades in a CC line cross section of the impeller of FIG. 5; FIG. 6 is a schematic diagram showing blades in a DD cross section of the impeller of FIG. 5; FIG. 3 is a schematic diagram showing the relationship between the impeller and the bellmouth in the AA line cross section of the multi-blade blower of FIG. 2; FIG. 9 is a schematic diagram showing the relationship between the blades and the bellmouth when viewed parallel to the rotation axis in the second cross section of the impeller of FIG. 8 ; FIG. 3 is a schematic diagram showing the relationship between the impeller and the bellmouth in the AA line cross section of the multi-blade blower of FIG. 2; FIG. 11 is a schematic diagram showing the relationship between the blades and the bellmouth in the impeller of FIG. 10 when viewed parallel to the rotation axis. FIG. 2 is a conceptual diagram illustrating the relationship between an impeller and a motor in the multi-blade blower according to Embodiment 1; FIG. 13 is a conceptual diagram of a multi-blade fan that is a first modification of the multi-blade fan shown in FIG. 12; FIG. 13 is a conceptual diagram of a multi-blade fan that is a second modification of the multi-blade fan shown in FIG. 12; FIG. 6 is a cross-sectional view schematically showing a multi-blade blower according to Embodiment 2; FIG. 4 is a cross-sectional view schematically showing a multi-blade fan as a comparative example; FIG. 10 is a cross-sectional view schematically showing the action of the multi-blade blower according to Embodiment 2; FIG. 16 is a cross-sectional view of a multi-blade fan that is a first modification of the multi-blade fan shown in FIG. 15; FIG. 16 is a cross-sectional view of a multi-blade fan that is a second modification of the multi-blade fan shown in FIG. 15; FIG. 10 is a schematic diagram showing the relationship between the bell mouth and blades of the multi-blade fan according to Embodiment 3; FIG. 11 is a schematic diagram showing the relationship between a bell mouth and blades of a modification of the multi-blade fan according to Embodiment 3; FIG. 11 is a cross-sectional view schematically showing a multi-blade fan according to Embodiment 4; FIG. 23 is a schematic diagram of the blades of the impeller of FIG. 22 when viewed parallel to the rotation axis; FIG. 23 is a schematic diagram showing blades in a DD cross section of the impeller of FIG. 22; FIG. 11 is a perspective view of an air conditioner according to Embodiment 5; FIG. 10 is a diagram showing the internal configuration of an air conditioner according to Embodiment 5;

Hereinafter, impellers, multi-blade fans, and air conditioners according to embodiments will be described with reference to the drawings and the like. In the following drawings including FIG. 1, the relative dimensional relationship and shape of each constituent member may differ from the actual ones. Moreover, in the following drawings, the same reference numerals denote the same or corresponding parts, and this applies throughout the specification. In order to facilitate understanding, terms representing directions (eg, "up", "down", "right", "left", "front", "back", etc.) are used as appropriate. For convenience of explanation only, such description is not intended to limit the arrangement and orientation of devices or components.

Embodiment 1.
[Multi-blade blower 100]
FIG. 1 is a perspective view schematically showing multi-blade fan 100 according to Embodiment 1. FIG. FIG. 2 is an external view schematically showing the configuration of the multi-blade fan 100 according to Embodiment 1 viewed parallel to the rotation axis RS. FIG. 3 is a cross-sectional view schematically showing the AA cross section of the multi-blade fan 100 of FIG. A basic structure of the multi-blade fan 100 will be described with reference to FIGS. 1 to 3. FIG. 1 to 3 schematically show the overall structure of the multi-blade fan 100. In particular, the configuration of the blades 12, which is characteristic of the multi-blade fan 100, will be described in detail with reference to other drawings. explain. The multi-blade fan 100 is a double suction centrifugal fan in which air is sucked from both ends in the axial direction of the virtual rotation axis RS of the impeller 10 . A multi-blade fan 100 is a multi-blade centrifugal fan, and has an impeller 10 that generates airflow and a scroll casing 40 that accommodates the impeller 10 therein.

(Scroll casing 40)
The scroll casing 40 accommodates the impeller 10 for the multi-blade blower 100 inside and rectifies the air blown out from the impeller 10 . The scroll casing 40 has a scroll portion 41 and a discharge portion 42 .

(Scroll part 41)
The scroll portion 41 forms an air passage that converts the dynamic pressure of the airflow generated by the impeller 10 into static pressure. The scroll portion 41 covers the impeller 10 from the axial direction of the rotation axis RS of the shaft portion 11b constituting the impeller 10, and includes a side wall 44a formed with a suction port 45 for taking in air, and and a peripheral wall 44c surrounding the impeller 10 from the radial direction of the rotation shaft RS. The scroll portion 41 is positioned between the discharge portion 42 and the winding start portion 41a of the peripheral wall 44c to form a curved surface. It has a guiding tongue 43 . The radial direction of the rotating shaft RS is a direction perpendicular to the axial direction of the rotating shaft RS. The internal space of the scroll portion 41 defined by the peripheral wall 44c and the side walls 44a is a space in which the air blown out from the impeller 10 flows along the peripheral wall 44c.

(Sidewall 44a)
The side walls 44 a are arranged on both sides of the impeller 10 in the axial direction of the rotation axis RS of the impeller 10 . A side wall 44 a of the scroll casing 40 is formed with a suction port 45 so that air can flow between the impeller 10 and the outside of the scroll casing 40 . The suction port 45 is formed in a circular shape, and the impeller 10 is arranged so that the center of the suction port 45 and the center of the shaft portion 11b of the impeller 10 are substantially aligned. In addition, the shape of the suction port 45 is not limited to a circular shape, and may be other shapes such as an elliptical shape. The scroll casing 40 of the multi-blade blower 100 is a double suction type casing having side walls 44a formed with suction ports 45 on both sides of the main plate 11 in the axial direction of the rotation axis RS of the shaft portion 11b. Multi-blade blower 100 has two side walls 44 a in scroll casing 40 . The two side walls 44a are formed to face each other via the peripheral wall 44c. More specifically, as shown in FIG. 3, the scroll casing 40 has a first side wall 44a1 and a second side wall 44a2 as side walls 44a. The first side wall 44a1 forms a first suction port 45a facing the plate surface of the main plate 11 on the side where the first side plate 13a, which will be described later, is arranged. The second side wall 44a2 forms a second suction port 45b facing the plate surface of the main plate 11 on the side where the second side plate 13b, which will be described later, is arranged. The suction port 45 described above is a general term for the first suction port 45a and the second suction port 45b.

A suction port 45 provided in the side wall 44 a is formed by a bell mouth 46 . That is, the bell mouth 46 forms the suction port 45 communicating with the space formed by the main plate 11 and the plurality of blades 12 . The bellmouth 46 rectifies the gas sucked into the impeller 10 and causes it to flow into the suction port 10e of the impeller 10 . The bell mouth 46 is formed such that the diameter of the opening gradually decreases from the outside to the inside of the scroll casing 40 . Due to this configuration of the side wall 44 a , air in the vicinity of the suction port 45 smoothly flows along the bell mouth 46 and efficiently flows into the impeller 10 from the suction port 45 .

(Surrounding wall 44c)
The peripheral wall 44c guides the airflow generated by the impeller 10 to the discharge port 42a along the curved wall surface. The peripheral wall 44 c is a wall provided between the side walls 44 a facing each other, and forms a curved surface in the rotation direction R of the impeller 10 . The peripheral wall 44c covers the impeller 10 by being arranged parallel to the axial direction of the rotation axis RS of the impeller 10, for example. Note that the peripheral wall 44c may be inclined with respect to the axial direction of the rotation shaft RS of the impeller 10, and is not limited to a configuration arranged parallel to the axial direction of the rotation shaft RS. The peripheral wall 44c forms an inner peripheral surface that covers the impeller 10 from the radial direction of the shaft portion 11b and faces a plurality of blades 12 described later. The peripheral wall 44 c faces the air blowing side of the blades 12 of the impeller 10 . As shown in FIG. 2 , the peripheral wall 44 c includes the discharge portion 42 and the scroll portion 41 on the side away from the tongue portion 43 along the rotation direction R of the impeller 10 from the winding start portion 41 a located at the boundary with the tongue portion 43 . It is provided up to the winding end portion 41b located at the boundary between and. The winding start portion 41a is an upstream end portion of the airflow generated by the rotation of the impeller 10 on the peripheral wall 44c forming the curved surface, and the winding end portion 41b is the downstream side of the airflow generated by the rotation of the impeller 10. side end.

The peripheral wall 44c is spirally formed. The spiral shape includes, for example, a logarithmic spiral, an Archimedean spiral, or a spiral shape based on an involute curve. The inner peripheral surface of the peripheral wall 44c forms a curved surface that smoothly curves along the circumferential direction of the impeller 10 from the winding start portion 41a that is the beginning of the spiral winding to the winding end portion 41b that is the end of the spiral winding. . With such a configuration, the air sent out from the impeller 10 smoothly flows in the direction of the discharge portion 42 through the gap between the impeller 10 and the peripheral wall 44c. Therefore, in the scroll casing 40 , the static pressure of air efficiently rises from the tongue portion 43 toward the discharge portion 42 .

(Discharging part 42)
The discharge part 42 forms a discharge port 42a through which the airflow generated by the impeller 10 and passed through the scroll part 41 is discharged. The discharge part 42 is composed of a hollow tube having a rectangular cross section perpendicular to the flow direction of the air flowing along the peripheral wall 44c. In addition, the cross-sectional shape of the discharge part 42 is not limited to a rectangle. The discharge portion 42 forms a flow path that guides the air sent out from the impeller 10 and flowing through the gap between the peripheral wall 44 c and the impeller 10 so as to be discharged to the outside of the scroll casing 40 .

As shown in FIG. 1, the discharge portion 42 includes an extension plate 42b, a diffuser plate 42c, a first side plate portion 42d, a second side plate portion 42e, and the like. The extension plate 42b is formed integrally with the peripheral wall 44c so as to smoothly continue to the winding end portion 41b on the downstream side of the peripheral wall 44c. The diffuser plate 42c is formed integrally with the tongue portion 43 of the scroll casing 40 and faces the extension plate 42b. The diffuser plate 42c is formed at a predetermined angle with respect to the extended plate 42b so that the cross-sectional area of the flow path gradually expands along the direction of air flow in the discharge portion 42 . The first side plate portion 42d is formed integrally with the first side wall 44a1 of the scroll casing 40, and the second side plate portion 42e is formed integrally with the second side wall 44a2 of the scroll casing 40 on the opposite side. The first side plate portion 42d and the second side plate portion 42e are formed between the extension plate 42b and the diffuser plate 42c. In this way, in the discharge part 42, a channel having a rectangular cross section is formed by the extension plate 42b, the diffuser plate 42c, the first side plate portion 42d, and the second side plate portion 42e.

(Tongue 43)
In the scroll casing 40, a tongue portion 43 is formed between the diffuser plate 42c of the discharge portion 42 and the winding start portion 41a of the peripheral wall 44c. The tongue portion 43 is formed with a predetermined radius of curvature, and the peripheral wall 44c is smoothly connected to the diffuser plate 42c via the tongue portion 43 . The tongue portion 43 suppresses the inflow of air from the winding end to the winding start of the spiral flow path. The tongue portion 43 is provided in the upstream portion of the ventilation passage, and divides the air flow in the rotation direction R of the impeller 10 and the air flow in the discharge direction from the downstream portion of the ventilation passage toward the discharge port 42a. have a role. Further, the static pressure of the air flowing into the discharge portion 42 increases while passing through the scroll casing 40 and becomes higher than that inside the scroll casing 40 . Therefore, the tongue portion 43 has a function of partitioning such a pressure difference.

(Impeller 10)
The impeller 10 is a centrifugal fan. The impeller 10 is rotationally driven by a motor or the like (not shown), and the centrifugal force generated by the rotation forces the air radially outward. The impeller 10 is rotated in a rotation direction R indicated by an arrow by a motor or the like. As shown in FIGS. 1 to 3, the impeller 10 includes a disc-shaped main plate 11, an annular side plate 13, and several radially arranged radially arranged side plates 13 in the peripheral portion of the main plate 11 in the circumferential direction of the main plate 11. a vane 12;

The main plate 11 may have a plate shape, and may have a shape other than a disk shape, such as a polygonal shape. Further, the thickness of the main plate 11 may be formed so that the thickness of the wall increases toward the center in the radial direction about the rotation axis RS, as shown in FIG. It may be formed to have a constant thickness in the radial direction around the center. A shaft portion 11b to which a motor (not shown) is connected is provided at the center of the main plate 11 . The main plate 11 is rotationally driven by a motor via the shaft portion 11b.

The plurality of blades 12 have one end connected to the main plate 11 and the other end connected to the side plate 13 , and are arranged in the circumferential direction around the virtual rotation axis RS of the main plate 11 . Each of the blades 12 is arranged between the main plate 11 and the side plate 13 . The plurality of blades 12 are provided on both sides of the main plate 11 in the axial direction of the rotation axis RS of the shaft portion 11b. Each blade 12 is arranged at a constant interval from each other in the peripheral portion of the main plate 11 . A detailed configuration of each blade 12 will be described later.

The impeller 10 has an annular side plate 13 attached to the ends of the plurality of blades 12 opposite to the main plate 11 in the axial direction of the rotation axis RS of the shaft portion 11b. The side plate 13 is arranged to face the main plate 11 in the impeller 10 . By connecting the plurality of blades 12 , the side plate 13 maintains the positional relationship of the tips of the blades 12 and reinforces the plurality of blades 12 .

The impeller 10, as shown in FIG. 3, has a main plate 11, a first blade portion 112a, and a second blade portion 112b. The first wing portion 112 a and the second wing portion 112 b are composed of a plurality of blades 12 and side plates 13 . More specifically, the first blade portion 112a is formed by an annular first side plate 13a arranged to face the main plate 11 and a plurality of blades 12 arranged between the main plate 11 and the first side plate 13a. It is configured. The second wing portion 112b includes an annular second side plate 13b arranged to face the main plate 11 on the side opposite to the side on which the first side plate 13a is arranged with respect to the main plate 11, and the main plate 11 and the second side plate. 13b and a plurality of blades 12 arranged between them. The side plate 13 is a general term for the first side plate 13a and the second side plate 13b, and the impeller 10 has the first side plate 13a on one side with respect to the main plate 11 in the axial direction of the rotation shaft RS, and the side plate 13a on the other side. side has a second side plate 13b.

The first wing portion 112 a is arranged on one plate surface side of the main plate 11 , and the second wing portion 112 b is arranged on the other plate surface side of the main plate 11 . That is, the plurality of blades 12 are provided on both sides of the main plate 11 in the axial direction of the rotating shaft RS, and the first blade portion 112a and the second blade portion 112b are provided back-to-back with the main plate 11 therebetween. ing. In addition, in FIG. 3 , the first wing portion 112 a is arranged on the left side of the main plate 11 , and the second wing portion 112 b is arranged on the right side of the main plate 11 . However, the first wing portion 112a and the second wing portion 112b need only be provided back-to-back with the main plate 11 interposed therebetween. On the other hand, the second wing portion 112b may be arranged on the left side. In the following description, unless otherwise specified, the blades 12 are collectively referred to as the blades 12 forming the first blade portion 112a and the blades 12 forming the second blade portion 112b.

The impeller 10 has a cylindrical shape with a plurality of blades 12 arranged on a main plate 11 . The impeller 10 is provided on the side plate 13 side opposite to the main plate 11 in the axial direction of the rotation axis RS of the shaft portion 11b. A suction port 10e is formed. The impeller 10 has blades 12 and side plates 13 arranged on both sides of a plate surface forming a main plate 11 , and suction ports 10 e are formed on both sides of the plate surface forming the main plate 11 .

The impeller 10 is driven to rotate around a rotation axis RS by being driven by a motor (not shown). As the impeller 10 rotates, the gas outside the multi-blade blower 100 passes through the suction port 45 formed in the scroll casing 40 and the suction port 10e of the impeller 10, and flows through the main plate 11 and the plurality of blades 12. is sucked into the space surrounded by As the impeller 10 rotates, the air sucked into the space surrounded by the main plate 11 and the plurality of blades 12 passes through the space between the blades 12 and the adjacent blades 12, and the diameter of the impeller 10 increases. direction outward.

[Detailed Configuration of Blade 12]
FIG. 4 is a perspective view of impeller 10 that constitutes multi-blade fan 100 according to the first embodiment. 5 is a side view of the impeller 10 of FIG. 4. FIG. FIG. 6 is a schematic diagram showing blades 12 in a CC line cross section of impeller 10 in FIG. FIG. 7 is a schematic diagram showing the blades 12 in the DD cross section of the impeller 10 in FIG. An intermediate position MP of the impeller 10 shown in FIG. 5 indicates an intermediate position in the axial direction of the rotating shaft RS among the plurality of blades 12 forming the first blade portion 112a. In the plurality of blades 12 forming the first blade portion 112a, the region from the intermediate position MP in the axial direction of the rotation shaft RS to the main plate 11 is defined as the main plate side blade region 122a, which is the first region of the impeller 10. Further, in the plurality of blades 12 constituting the first blade portion 112a, the region from the intermediate position MP in the axial direction of the rotating shaft RS to the end portion on the side plate 13 side is the side plate side blade region which is the second region of the impeller 10. 122b. That is, each of the plurality of blades 12 has a first region located closer to the main plate 11 than the intermediate position MP in the axial direction of the rotation shaft RS, and a second region located closer to the side plate 13 than the first region. have. The CC line cross section shown in FIG. 5 is the cross section of the plurality of blades 12 on the main plate 11 side of the impeller 10, that is, in the main plate side blade region 122a, which is the first region, as shown in FIG. The cross section of the blades 12 on the main plate 11 side is the first cross section of the impeller 10 obtained by cutting the portion of the impeller 10 closer to the main plate 11 on the first plane 71 perpendicular to the rotation axis RS. Here, the portion of the impeller 10 closer to the main plate 11 is, for example, a portion closer to the main plate 11 than the intermediate position of the main plate-side blade region 122a in the axial direction of the rotation shaft RS, or a portion of the blade in the axial direction of the rotation shaft RS. This is the portion where the end of 12 on the side of the main plate 11 is located. The DD cross section shown in FIG. 5 is the cross section of the plurality of blades 12 on the side plate 13 side of the impeller 10, that is, in the side plate side blade region 122b, which is the second region, as shown in FIG. A cross section of the blade 12 on the side plate 13 side is a second cross section of the impeller 10 obtained by cutting a portion of the impeller 10 near the main plate 11 along a second plane 72 perpendicular to the rotation axis RS. Here, the portion of the impeller 10 near the side plate 13 is, for example, a portion closer to the side plate 13 than the intermediate position of the side plate-side blade region 122b in the axial direction of the rotation shaft RS, or a portion of the blade in the axial direction of the rotation shaft RS. 12 is a portion where the end portion on the side plate 13 side of 12 is located.

The configuration of the blades 12 in the second blade portion 112b is the same as the configuration of the blades 12 in the first blade portion 112a. That is, the intermediate position MP of the impeller 10 shown in FIG. 5 indicates an intermediate position in the axial direction of the rotation shaft RS among the plurality of blades 12 that constitute the second blade portion 112b. In the plurality of blades 12 forming the second blade portion 112b, the region from the intermediate position MP in the axial direction of the rotating shaft RS to the main plate 11 is defined as the main plate side blade region 122a, which is the first region of the impeller 10. Further, in the plurality of blades 12 constituting the second blade portion 112b, the region from the intermediate position MP in the axial direction of the rotation shaft RS to the end portion on the side of the second side plate 13b is the side plate side which is the second region of the impeller 10. Let it be the blade region 122b. In the above description, the configuration of the first blade portion 112a and the configuration of the second blade portion 112b are the same, but the configuration of the impeller 10 is not limited to this configuration. The configuration of the portion 112a and the second wing portion 112b may be different. That is, both the first blade portion 112a and the second blade portion 112b may have the configuration of the blade 12 described below, or either one thereof may have the configuration. A detailed configuration of the blade 12 will be described below with reference to FIGS. 4 to 7. FIG.

As shown in FIGS. 4 to 7, the plurality of blades 12 has a plurality of first blades 12A and a plurality of second blades 12B. In the plurality of blades 12, the first blades 12A and one or more second blades 12B are alternately arranged in the circumferential direction of the impeller 10. As shown in FIG. As shown in FIGS. 4 and 6, the impeller 10 has two second blades 12B arranged between the first blade 12A and the first blade 12A arranged next to it in the rotation direction R. As shown in FIGS. However, the number of the second blades 12B arranged between the first blade 12A and the first blade 12A arranged next to it in the rotation direction R is not limited to two, and is one or three or more. may be That is, at least one second blade 12B of the plurality of second blades 12B is arranged between two first blades 12A adjacent to each other in the circumferential direction among the plurality of first blades 12A.

As shown in FIG. 6, the first blade 12A is located on the side of the rotation axis RS in the radial direction centered on the rotation axis RS in the first cross section of the impeller 10 cut by the first plane 71 perpendicular to the rotation axis RS. and an outer peripheral end 15A located on the outer peripheral side of the inner peripheral end 14A in the radial direction. In each of the plurality of first blades 12A, the inner peripheral end 14A is arranged forward of the outer peripheral end 15A in the rotational direction R of the impeller 10 . As shown in FIG. 4, the inner peripheral end 14A becomes the leading edge 14A1 of the first blade 12A, and the outer peripheral end 15A becomes the trailing edge 15A1 of the first blade 12A. As shown in FIG. 6, 14 first blades 12A are arranged in the impeller 10, but the number of the first blades 12A is not limited to 14, and may be less than 14. Well, it can be more than 14 sheets.

As shown in FIG. 6, the second blade 12B is located on the side of the rotation axis RS in the radial direction centered on the rotation axis RS in the first cross section of the impeller 10 cut by the first plane 71 perpendicular to the rotation axis RS. and an outer peripheral end 15B located on the outer peripheral side of the inner peripheral end 14B in the radial direction. In each of the plurality of second blades 12B, the inner peripheral end 14B is arranged forward of the outer peripheral end 15B in the rotational direction R of the impeller 10 . As shown in FIG. 4, the inner peripheral end 14B becomes the front edge 14B1 of the second blade 12B, and the outer peripheral end 15B becomes the rear edge 15B1 of the second blade 12B. As shown in FIG. 6, 28 second blades 12B are arranged in the impeller 10, but the number of the second blades 12B is not limited to 28, and may be less than 28. Well, it can be more than 28 sheets.

Next, the relationship between the first blade 12A and the second blade 12B will be described. As shown in FIGS. 4 and 7, in a portion closer to the first side plate 13a and the second side plate 13b than the intermediate position MP in the direction along the rotation axis RS, the blade length of the first blade 12A is the same as that of the second blade 12B. equal to the wing length. On the other hand, as shown in FIGS. 4 and 6, in the portion closer to the main plate 11 than the intermediate position MP in the direction along the rotation axis RS, the blade length of the first blade 12A is longer than the blade length of the second blade 12B. and is longer as it approaches the main plate 11. - 特許庁Thus, in this embodiment, the blade length of the first blade 12A is longer than the blade length of the second blade 12B in at least part of the direction along the rotation axis RS. The blade length used here is the length of the first blade 12A in the radial direction of the impeller 10 and the length of the second blade 12B in the radial direction of the impeller 10.

In the first cross section closer to the main plate 11 than the intermediate position MP shown in FIG. 5, as shown in FIG. That is, let the inner diameter of the 1st blade|wing 12A be ID1. The diameter of a circle C3 passing through the outer peripheral ends 15A of the plurality of first blades 12A around the rotation axis RS, ie, the outer diameter of the first blades 12A, is defined as an outer diameter OD1. Half of the difference between the outer diameter OD1 and the inner diameter ID1 is the blade length L1a of the first blade 12A in the first section (blade length L1a=(outer diameter OD1−inner diameter ID1)/2). Here, the ratio of the inner diameter of the first blade 12A to the outer diameter of the first blade 12A is 0.7 or less. That is, the plurality of first blades 12A has an inner diameter ID1 formed by the inner peripheral end 14A of each of the plurality of first blades 12A and an outer diameter OD1 formed by the outer peripheral end 15A of each of the plurality of first blades 12A. is 0.7 or less. In addition, in a general multi-blade fan, the blade length of the blade in the cross section perpendicular to the rotation shaft is shorter than the width dimension of the blade in the direction of the rotation shaft. Also in the present embodiment, the maximum blade length of the first blade 12A, that is, the blade length at the end portion of the first blade 12A near the main plate 11 is the width dimension W (see FIG. 5) of the first blade 12A in the direction of the rotation axis. is shorter than

Further, in the first cross section, the diameter of a circle C2 passing through the inner peripheral ends 14B of the plurality of second blades 12B centered on the rotation axis RS, that is, the inner diameter of the second blades 12B is set to an inner diameter ID2 larger than the inner diameter ID1. (inner diameter ID2>inner diameter ID1). Let the diameter of a circle C3 passing through the outer peripheral ends 15B of the plurality of second blades 12B around the rotation axis RS, that is, the outer diameter of the second blades 12B be an outer diameter OD2 equal to the outer diameter OD1 (outer diameter OD2=outer diameter OD1). Half of the difference between the outer diameter OD2 and the inner diameter ID2 is the blade length L2a of the second blade 12B in the first section (blade length L2a=(outer diameter OD2−inner diameter ID2)/2). The blade length L2a of the second blade 12B in the first section is shorter than the blade length L1a of the first blade 12A in the same section (blade length L2a<blade length L1a). Here, the ratio of the inner diameter of the second blade 12B to the outer diameter of the second blade 12B is 0.7 or less. That is, the plurality of second blades 12B has an inner diameter ID2 formed by the inner peripheral end 14B of each of the plurality of second blades 12B and an outer diameter OD2 formed by the outer peripheral end 15B of each of the plurality of second blades 12B. is 0.7 or less.

On the other hand, in the second cross section closer to the side plate 13 than the intermediate position MP shown in FIG. 5, as shown in FIG. , inner diameter ID3. The inner diameter ID3 is larger than the inner diameter ID1 of the first section (inner diameter ID3>inner diameter ID1). The diameter of a circle C8 passing through the outer peripheral end 15A of the first blade 12A and centered on the rotation axis RS is defined as an outer diameter OD3. Half of the difference between the outer diameter OD3 and the inner diameter ID1 is the blade length L1b of the first blade 12A in the second section (blade length L1b=(outer diameter OD3−inner diameter ID3)/2).

Further, in the second section, the diameter of a circle C7 passing through the inner peripheral end 14B of the second blade 12B centered on the rotation axis RS is defined as an inner diameter ID4. The inner diameter ID4 is equal to the inner diameter ID3 in the same section (inner diameter ID4=inner diameter ID3). The diameter of a circle C8 passing through the outer peripheral end 15B of the second blade 12B and centered on the rotation axis RS is defined as an outer diameter OD4. The outer diameter OD4 is equal to the outer diameter OD3 in the same section (outer diameter OD4=outer diameter OD3). A half of the difference between the outer diameter OD4 and the inner diameter ID4 is the blade length L2b of the second blade 12B in the second section (blade length L2b=(outer diameter OD4−inner diameter ID4)/2). The blade length L2b of the second blade 12B in the second section is equal to the blade length L1b of the first blade 12A in the same section (blade length L2b=blade length L1b).

When viewed parallel to the rotation axis RS, the first blade 12A in the second cross section shown in FIG. overlaps with Therefore, the impeller 10 satisfies the relationships of outer diameter OD3=outer diameter OD1, inner diameter ID3≧inner diameter ID1, and blade length L1b≦wing length L1a.

Similarly, when viewed parallel to the rotation axis RS, the second blade 12B in the second cross section shown in FIG. It overlaps with the two blades 12B. Therefore, the impeller 10 satisfies the relationships of outer diameter OD4=outer diameter OD2, inner diameter ID4≧inner diameter ID2, and blade length L2b≦wing length L2a.

Here, as described above, the ratio between the inner diameter ID1 of the first blade 12A and the outer diameter OD1 of the first blade 12A is 0.7 or less. For the blade 12 , inner diameter ID3≧inner diameter ID1, inner diameter ID4≧inner diameter ID2, and inner diameter ID2>inner diameter ID1. In addition, the blade 12 has an outer diameter OD3=outer diameter OD1, an outer diameter OD4=outer diameter OD2, and an outer diameter OD2=outer diameter OD1. can. When the blades 12 constituting the impeller 10 are viewed as a whole, the ratio of the blade inner diameter of the blades 12 to the blade outer diameter of the blades 12 is 0.7 or less. In addition, the blade inner diameters of the plurality of blades 12 are formed by the respective inner peripheral ends of the plurality of blades 12 . That is, the blade inner diameters of the plurality of blades 12 are formed by the front edges 14A1 of the plurality of blades 12. As shown in FIG. Further, the blade outer diameters of the plurality of blades 12 are configured by the outer peripheral ends of the plurality of blades 12 . That is, the blade outer diameters of the plurality of blades 12 are defined by the trailing edges 15A1 and 15B1 of the plurality of blades 12 .

[Configuration of first blade 12A and second blade 12B]
The first blade 12A has a relationship of blade length L1a>blade length L1b in comparison between the first cross section shown in FIG. 6 and the second cross section shown in FIG. That is, each of the plurality of blades 12 is formed such that the blade length in the first region is longer than the blade length in the second region. More specifically, the first blade 12A is formed such that the blade length decreases from the main plate 11 side toward the side plate 13 side in the axial direction of the rotation shaft RS. Similarly, the second blade 12B has a relationship of blade length L2a>blade length L2b in comparison between the first cross section shown in FIG. 6 and the second cross section shown in FIG. That is, the second blade 12B is formed so that the blade length decreases from the main plate 11 side toward the side plate 13 side in the axial direction of the rotating shaft RS. As shown in FIG. 3, the first blade 12A and the second blade 12B are inclined such that the blade inner diameter increases from the main plate 11 side toward the side plate 13 side. That is, the plurality of blades 12 have an inclined portion 141A in which the inner peripheral end 14A constituting the front edge 14A1 is inclined away from the rotation axis RS so that the inner diameter of the blades increases from the side of the main plate 11 to the side of the side plate 13. forming. Similarly, the plurality of blades 12 has an inclined portion 141B in which the inner peripheral end 14B constituting the front edge 14B1 is inclined away from the rotation axis RS so that the inner diameter of the blade increases from the side of the main plate 11 toward the side of the side plate 13. forming

The first blade 12A, as shown in FIGS. 6 and 7, has a first sirocco blade portion 12A1 configured as a forward blade and a first turbo blade portion 12A2 configured as a rearward blade. In the radial direction of the impeller 10, the first sirocco blade portion 12A1 constitutes the outer peripheral side of the first blade 12A, and the first turbo blade portion 12A2 constitutes the inner peripheral side of the first blade 12A. That is, in the radial direction of the impeller 10, the first blade 12A is composed of a first turbo blade portion 12A2 and a first sirocco blade portion 12A1 in this order from the rotating shaft RS toward the outer peripheral side. In the first blade 12A, the first turbo blade portion 12A2 and the first sirocco blade portion 12A1 are integrally formed. The first turbo blade portion 12A2 forms the leading edge 14A1 of the first blade 12A, and the first sirocco blade portion 12A1 forms the trailing edge 15A1 of the first blade 12A. In the radial direction of the impeller 10, the first turbo blade portion 12A2 linearly extends from the inner peripheral end 14A forming the leading edge 14A1 toward the outer peripheral side.

In the radial direction of the impeller 10, a region forming the first sirocco blade portion 12A1 of the first blade 12A is defined as a first sirocco region 12A11, and a region forming the first turbo blade portion 12A2 of the first blade 12A is defined as a first sirocco region 12A11. 1 turbo area 12A21. In the first blade 12A, the first turbo region 12A21 is larger than the first sirocco region 12A11 in the radial direction of the impeller . In the impeller 10, in both the main-plate-side blade region 122a that is the first region and the side-plate-side blade region 122b that is the second region, in the radial direction of the impeller 10, the first sirocco region 12A11<th It has a relationship of 1 turbo area 12A21. That is, the impeller 10 and the first blades 12A are arranged in the radial direction of the impeller 10 in both the main-plate-side blade region 122a as the first region and the side-plate-side blade region 122b as the second region. The ratio of the turbo blade portion 12A2 is greater than the ratio of the first sirocco blade portion 12A1.

Similarly, as shown in FIGS. 6 and 7, the second blade 12B has a second sirocco blade portion 12B1 configured as a forward blade and a second turbo blade portion 12B2 configured as a rearward blade. . In the radial direction of the impeller 10, the second sirocco blade portion 12B1 constitutes the outer peripheral side of the second blade 12B, and the second turbo blade portion 12B2 constitutes the inner peripheral side of the second blade 12B. That is, in the radial direction of the impeller 10, the second blade 12B is configured by a second turbo blade portion 12B2 and a second sirocco blade portion 12B1 in this order from the rotating shaft RS toward the outer peripheral side. In the second blade 12B, the second turbo blade portion 12B2 and the second sirocco blade portion 12B1 are integrally formed. The second turbo blade portion 12B2 forms the leading edge 14B1 of the second blade 12B, and the second sirocco blade portion 12B1 forms the trailing edge 15B1 of the second blade 12B. In the radial direction of the impeller 10, the second turbo blade portion 12B2 linearly extends from the inner peripheral end 14B forming the leading edge 14B1 toward the outer peripheral side.

In the radial direction of the impeller 10, a region forming the second sirocco blade portion 12B1 of the second blade 12B is defined as a second sirocco region 12B11, and a region forming the second turbo blade portion 12B2 of the second blade 12B is defined as a second sirocco region 12B11. It is defined as 2 turbo area 12B21. In the second blade 12B, the second turbo region 12B21 is larger than the second sirocco region 12B11 in the radial direction of the impeller . In addition, in both the main plate side blade region 122a that is the first region and the side plate side blade region 122b that is the second region, the impeller 10 has a second sirocco region 12B11<second region in the radial direction of the impeller 10. It has a relationship of two turbo regions 12B21. That is, the impeller 10 and the second blades 12B are arranged in the radial direction of the impeller 10 in both the main-plate-side blade region 122a that is the first region and the side-plate-side blade region 122b that is the second region. The ratio of the turbo blade portion 12B2 is greater than the ratio of the second sirocco blade portion 12B1.

From the above configuration, in the plurality of blades 12, in both the main-plate-side blade region 122a and the side-plate-side blade region 122b, the turbo blade region is larger than the sirocco blade region in the radial direction of the impeller 10. . That is, in the plurality of blades 12, in both the main plate side blade region 122a and the side plate side blade region 122b, in the radial direction of the impeller 10, the ratio of the turbo blade portion is larger than the ratio of the sirocco blade portion. It has a relation of area<turbo area. In other words, in each of the plurality of blades 12, in the first region and the second region, the proportion of turbo blades in the radial direction is greater than the proportion of sirocco blades.

As shown in FIG. 6, the exit angle of the first sirocco blade portion 12A1 of the first blade 12A in the first cross section is assumed to be the exit angle α1. The exit angle α1 is the angle formed between the tangent line TL1 of the circle and the center line CL1 of the first sirocco blade 12A1 at the outer peripheral end 15A at the intersection of the arc of the circle C3 centered on the rotation axis RS and the outer peripheral end 15A. Define. This exit angle α1 is an angle larger than 90 degrees. The exit angle of the second sirocco blade portion 12B1 of the second blade 12B in the same cross section is assumed to be the exit angle α2. The exit angle α2 is the angle formed between the tangent line TL2 of the circle and the center line CL2 of the second sirocco blade portion 12B1 at the outer peripheral end 15B at the intersection of the arc of the circle C3 centered on the rotation axis RS and the outer peripheral end 15B. Define. Exit angle α2 is an angle greater than 90 degrees. The exit angle α2 of the second sirocco wing 12B1 is equal to the exit angle α1 of the first sirocco wing 12A1 (exit angle α2=exit angle α1). The first sirocco wing portion 12A1 and the second sirocco wing portion 12B1 are formed in an arc shape so as to protrude in the direction opposite to the rotation direction R when viewed parallel to the rotation axis RS.

As shown in FIG. 7, in the impeller 10, the outlet angle α1 of the first sirocco vane 12A1 is equal to the outlet angle α2 of the second sirocco vane 12B1 even in the second section. That is, the plurality of blades 12 have sirocco blades forming forward blades having an exit angle larger than 90 degrees from the main plate 11 to the side plate 13 .

Also, as shown in FIG. 6, the exit angle of the first turbo blade portion 12A2 of the first blade 12A in the first cross section is defined as the exit angle β1. The exit angle β1 is defined as the angle formed by the tangent line TL3 of the circle and the center line CL3 of the first turbo blade portion 12A2 at the intersection of the arc of the circle C4 centered on the rotation axis RS and the first turbo blade portion 12A2. do. This exit angle β1 is an angle smaller than 90 degrees. The exit angle of the second turbo blade portion 12B2 of the second blade 12B in the same section is defined as the exit angle β2. The exit angle β2 is defined as the angle formed by the tangent line TL4 of the circle and the center line CL4 of the second turbo blade portion 12B2 at the intersection of the arc of the circle C4 centered on the rotation axis RS and the second turbo blade portion 12B2. do. Exit angle β2 is an angle smaller than 90 degrees. The exit angle β2 of the second turbo blade 12B2 is equal to the exit angle β1 of the first turbo blade 12A2 (exit angle β2=exit angle β1).

Although not shown in FIG. 7, the impeller 10 has the same outlet angle β1 of the first turbo blade portion 12A2 and the outlet angle β2 of the second turbo blade portion 12B2 even in the second section. Also, the exit angle β1 and the exit angle β2 are angles smaller than 90 degrees.

As shown in FIGS. 6 and 7, the first blade 12A has a first radial blade portion 12A3 as a connecting portion between the first turbo blade portion 12A2 and the first sirocco blade portion 12A1. The first radial blade portion 12A3 is a portion configured as a radial blade linearly extending in the radial direction of the impeller 10 . Similarly, the second blade 12B has a second radial blade portion 12B3 as a connecting portion between the second turbo blade portion 12B2 and the second sirocco blade portion 12B1. The second radial blade portion 12</b>B<b>3 is a portion configured as a radial blade linearly extending in the radial direction of the impeller 10 . The blade angle of the first radial blade portion 12A3 and the second radial blade portion 12B3 is 90 degrees. More specifically, the angle between the tangent line at the intersection of the center line of the first radial blade portion 12A3 and the circle C5 centered on the rotation axis RS and the center line of the first radial blade portion 12A3 is 90 degrees. The angle between the tangent line at the intersection of the center line of the second radial blade portion 12B3 and the circle C5 centered on the rotation axis RS and the center line of the second radial blade portion 12B3 is 90 degrees.

When the interval between two blades 12 adjacent to each other in the circumferential direction among the plurality of blades 12 is defined as the interval between blades, as shown in FIGS. , and spreads toward the trailing edge 15A1 side. Similarly, the space between blades of the plurality of blades 12 widens from the leading edge 14B1 side toward the trailing edge 15B1 side. Specifically, the gap between the blades in the turbo blade portion constituted by the first turbo blade portion 12A2 and the second turbo blade portion 12B2 widens from the inner peripheral side to the outer peripheral side. The gap between the blades of the sirocco blades constituted by the first sirocco blades 12A1 and the second sirocco blades 12B1 is wider than that of the turbo blades, and spreads from the inner peripheral side to the outer peripheral side. That is, the blade interval between the first turbo blade portion 12A2 and the second turbo blade portion 12B2 or the blade interval between the adjacent second turbo blade portions 12B2 widens from the inner peripheral side to the outer peripheral side. In addition, the space between the first sirocco wing portion 12A1 and the second sirocco wing portion 12B1 or the space between the adjacent second sirocco wing portions 12B1 is wider than the space between the turbo blades and has an inner circumference. It spreads from the side to the outer circumference.

[Relationship Between Impeller 10 and Scroll Casing 40]
FIG. 8 is a schematic diagram showing the relationship between the impeller 10 and the bellmouth 46 in the AA cross section of the multi-blade fan 100 of FIG. FIG. 9 is a schematic diagram showing the relationship between the blades 12 and the bellmouth 46 when viewed parallel to the rotation axis RS in the second cross section of the impeller 10 of FIG. As shown in FIGS. 8 and 9 , the blade outer diameter OD formed by the outer peripheral ends of the plurality of blades 12 is larger than the inner diameter BI of the bellmouth 46 forming the scroll casing 40 . The blade outer diameter OD of the plurality of blades 12 is equal to the outer diameter OD1 and outer diameter OD2 of the first blade 12A and the outer diameter OD3 and outer diameter OD4 of the second blade 12B (blade outer diameter OD=outer diameter OD1 = outer diameter OD2 = outer diameter OD3 = outer diameter OD4).

In the impeller 10, the first turbo area 12A21 is larger than the first sirocco area 12A11 in the radial direction with respect to the rotation axis RS. That is, in the impeller 10 and the first blades 12A, the ratio of the first turbo blade portion 12A2 is larger than the ratio of the first sirocco blade portion 12A1 in the radial direction with respect to the rotation axis RS, and the first sirocco blade portion 12A1<first It has the relationship of the turbo blade portion 12A2. The ratio relationship between the first sirocco blade portion 12A1 and the first turbo blade portion 12A2 in the radial direction of the rotating shaft RS depends on whether the main plate side blade region 122a is the first region or the side plate side blade region 122b is the second region. also holds in the region of

Further, when viewed parallel to the rotation axis RS, the area of the plurality of blades 12 located on the outer peripheral side of the inner diameter BI of the bell mouth 46 in the radial direction with respect to the rotation axis RS is defined as an outer peripheral side area 12R. In the impeller 10, the ratio of the first turbo blade portion 12A2 is preferably larger than the ratio of the first sirocco blade portion 12A1 also in the outer peripheral region 12R. That is, in the outer peripheral region 12R of the impeller 10, which is located on the outer peripheral side of the inner diameter BI of the bell mouth 46 when viewed parallel to the rotation axis RS, the first turbo region 12A21a is the first turbo region 12A21a in the radial direction with respect to the rotation axis RS. It is larger than the sirocco area 12A11. The first turbo area 12A21a is the area of the first turbo area 12A21 located on the outer peripheral side of the inner diameter BI of the bell mouth 46 when viewed parallel to the rotation axis RS. Then, when the first turbo blade portion 12A2 constituting the first turbo region 12A21a is the first turbo blade portion 12A2a, the outer peripheral region 12R of the impeller 10 has the ratio of the first turbo blade portion 12A2a to the first sirocco blade. It is desirable that the proportion of the portion 12A1 is greater than that of the portion 12A1. The ratio relationship between the first sirocco blade portion 12A1 and the first turbo blade portion 12A2a in the outer peripheral region 12R is determined by which region of the main plate side blade region 122a that is the first region and the side plate side blade region 122b that is the second region. also holds.

Similarly, in the impeller 10, the second turbo region 12B21 is larger than the second sirocco region 12B11 in the radial direction with respect to the rotation axis RS. That is, in the impeller 10 and the second blade 12B, the ratio of the second turbo blade portion 12B2 is larger than the ratio of the second Sirocco blade portion 12B1 in the radial direction with respect to the rotation axis RS, and the ratio of the second Sirocco blade portion 12B1<second It has the relationship of the turbo blade portion 12B2. The ratio relationship between the second sirocco blade portion 12B1 and the second turbo blade portion 12B2 in the radial direction of the rotating shaft RS is determined by either the main plate side blade region 122a that is the first region or the side plate side blade region 122b that is the second region. also holds in the region of

Furthermore, in the impeller 10, it is desirable that the ratio of the second turbo blade portion 12B2 is larger than the ratio of the second sirocco blade portion 12B1 also in the outer peripheral region 12R. That is, in the outer peripheral region 12R of the impeller 10, which is located on the outer peripheral side of the inner diameter BI of the bell mouth 46 when viewed parallel to the rotation axis RS, the second turbo region 12B21a is the second It is larger than the sirocco area 12B11. The second turbo area 12B21a is the area of the second turbo area 12B21 located on the outer peripheral side of the inner diameter BI of the bell mouth 46 when viewed parallel to the rotation axis RS. When the second turbo blade portion 12B2 constituting the second turbo region 12B21a is the second turbo blade portion 12B2a, the outer peripheral region 12R of the impeller 10 has a ratio of the second turbo blade portion 12B2a to the second sirocco blade. It is desirable that the proportion of the portion 12B1 is greater than that of the portion 12B1. The ratio relationship between the second sirocco blade portion 12B1 and the second turbo blade portion 12B2a in the outer peripheral side region 12R depends on which region of the main plate side blade region 122a that is the first region and the side plate side blade region 122b that is the second region. also holds.

FIG. 10 is a schematic diagram showing the relationship between the impeller 10 and the bell mouth 46 in the AA cross section of the multi-blade fan 100 of FIG. FIG. 11 is a schematic diagram showing the relationship between the blades 12 and the bellmouth 46 in the impeller 10 of FIG. 10 when viewed parallel to the rotation axis RS. A hollow arrow L shown in FIG. 10 indicates the direction when the impeller 10 is viewed parallel to the rotation axis RS. As shown in FIGS. 10 and 11, when viewed parallel to the rotation axis RS, at the connection position between the first blades 12A and the main plate 11, the inner circumference of the plurality of first blades 12A around the rotation axis RS A circle passing through the edge 14A is defined as a circle C1a. The diameter of the circle C1a, that is, the inner diameter of the first blade 12A at the connection position between the first blade 12A and the main plate 11 is defined as the inner diameter ID1a. A circle C2a is a circle passing through the inner peripheral ends 14B of the plurality of second blades 12B centered on the rotation axis RS at the connection position between the second blades 12B and the main plate 11 when viewed parallel to the rotation axis RS. defined as The diameter of the circle C2a, that is, the inner diameter of the second blade 12B at the connection position between the first blade 12A and the main plate 11 is defined as an inner diameter ID2a. The inner diameter ID2a is larger than the inner diameter ID1a (inner diameter ID2a>inner diameter ID1a). In addition, when viewed parallel to the rotation axis RS, the diameter of a circle C3a passing through the outer peripheral ends 15A of the plurality of first blades 12A and the outer peripheral ends 15B of the plurality of second blades 12B around the rotation shaft RS, that is, the diameter of a plurality of Let the outer diameter of the blade 12 be the blade outer diameter OD. A circle C7a is a circle passing through the inner peripheral ends 14A of the plurality of first blades 12A centered on the rotation axis RS at the connection position between the first blades 12A and the side plates 13 when viewed parallel to the rotation axis RS. defined as The diameter of the circle C7a, that is, the inner diameter of the first blade 12A at the connection position between the first blade 12A and the side plate 13 is defined as an inner diameter ID3a. Further, when viewed parallel to the rotation axis RS, at the connection position between the second blades 12B and the side plate 13, a circle centered on the rotation axis RS and passing through the inner peripheral ends 14B of the plurality of second blades 12B is a circle C7a. becomes. The diameter of the circle C7a, that is, the inner diameter of the second blade 12B at the connection position between the second blade 12B and the side plate 13 is defined as an inner diameter ID4a.

As shown in FIGS. 10 and 11, when viewed parallel to the rotation axis RS, the position of the inner diameter BI of the bellmouth 46 is the inner diameter ID1a on the main plate 11 side of the first blade 12A and the inner diameter ID3a on the side plate 13 side of the first blade 12A. It is located in the region of the first turbo blade portion 12A2 and the second turbo blade portion 12B2 between. More specifically, the inner diameter BI of the bell mouth 46 is larger than the inner diameter ID1a of the first blade 12A on the main plate 11 side and smaller than the inner diameter ID3a on the side plate 13 side. That is, the inner diameter BI of the bellmouth 46 is formed larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter on the side plate 13 side. In other words, the opening 46a forming the inner diameter BI of the bellmouth 46 is located between the circle C1a and the circle C7a when viewed parallel to the rotation axis RS. Located in the area of 12B2.

10 and 11, when viewed parallel to the rotation axis RS, the position of the inner diameter BI of the bell mouth 46 is the inner diameter ID2a of the second blade 12B on the main plate 11 side and the inner diameter ID2a on the side plate 13 side of the second blade 12B. It is located in the region of the first turbo blade portion 12A2 and the second turbo blade portion 12B2 between the inner diameter ID4a. More specifically, the inner diameter BI of the bellmouth 46 is larger than the inner diameter ID2a of the second blade 12B on the main plate 11 side and smaller than the inner diameter ID4a of the side plate 13 side. That is, the inner diameter BI of the bellmouth 46 is formed larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter on the side plate 13 side. More specifically, the inner diameter BI of the bell mouth 46 is larger than the inner diameter of the blade formed by the inner peripheral ends of the plurality of blades 12 in the first region, and the inner diameter of each of the plurality of blades 12 in the second region. It is formed smaller than the inner diameter of the blade defined by the end. In other words, the opening 46a forming the inner diameter BI of the bellmouth 46 is located between the circles C2a and C7a when viewed parallel to the rotation axis RS. Located in the area of 12B2.

As shown in FIGS. 10 and 11, in the radial direction of the impeller 10, the radial lengths of the first Sirocco blade portion 12A1 and the second Sirocco blade portion 12B1 are defined as a distance SL. Further, in the multi-blade fan 100, the closest distance between the plurality of blades 12 of the impeller 10 and the peripheral wall 44c of the scroll casing 40 is defined as a distance MS. At this time, in multi-blade fan 100, distance MS is greater than twice the distance SL (distance MS>distance SL×2). 10, the distance MS is the closest distance to the peripheral wall 44c of the scroll casing 40, not necessarily the line AA. It is not represented on the cross section.

FIG. 12 is a conceptual diagram illustrating the relationship between impeller 10 and motor 50 in multi-blade fan 100 according to the first embodiment. A dotted line FL shown in FIG. 12 indicates an example of the flow of air flowing into the scroll casing 40 from the outside. As shown in FIG. 12 , the multi-blade blower 100 may have a motor 50 that rotates the main plate 11 of the impeller 10 in addition to the impeller 10 and the scroll casing 40 . That is, multi-blade fan 100 may have impeller 10 , scroll casing 40 that houses impeller 10 , and motor 50 that drives impeller 10 .

The motor 50 is arranged adjacent to the side wall 44 a of the scroll casing 40 . A motor shaft 51 of the motor 50 extends on the rotating shaft RS of the impeller 10 , penetrates the side surface of the scroll casing 40 and is inserted inside the scroll casing 40 .

The main plate 11 is arranged along the side wall 44a of the scroll casing 40 on the motor 50 side so as to be perpendicular to the rotation axis RS. A shaft portion 11 b to which a motor shaft 51 is connected is provided at the center of the main plate 11 , and the motor shaft 51 inserted inside the scroll casing 40 is fixed to the shaft portion 11 b of the main plate 11 . A motor shaft 51 of the motor 50 is connected to and fixed to the main plate 11 of the impeller 10 .

When the motor 50 is driven, the multiple blades 12 rotate around the rotation axis RS via the motor shaft 51 and the main plate 11 . As a result, external air is sucked into the impeller 10 through the suction port 45 and is blown out into the scroll casing 40 by the pressurizing action of the impeller 10 . The air blown into the scroll casing 40 is decelerated in the expanded air passage formed by the peripheral wall 44c of the scroll casing 40, recovers the static pressure, and is blown out from the discharge port 42a shown in FIG.

As shown in FIG. 12, the outer peripheral wall 52 forming the outer diameter MO1 of the end portion 50a of the motor 50 forms a virtual extended surface VF1 obtained by extending the inner diameter of the blade of the blade 12 on the main plate 11 side in the axial direction of the rotation shaft RS. , and an imaginary extension surface VF3 obtained by extending the inner diameter of the blade on the side plate 13 side in the axial direction of the rotation shaft RS. Further, the outer peripheral wall 52 forming the outer diameter MO1 of the end portion 50a of the motor 50 is arranged at a position facing the first turbo blade portion 12A2 and the second turbo blade portion 12B2 in the axial direction of the rotation shaft RS. . More specifically, the outer diameter MO1 of the end portion 50a of the motor 50 is larger than the inner diameter ID1 of the plurality of first blades 12A on the main plate 11 side and smaller than the inner diameter ID3 of the plurality of first blades 12A on the side plate 13 side. . That is, the outer diameter MO1 of the end portion 50a of the motor 50 is formed larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. Further, the outer peripheral wall 52 at the end portion 50a of the motor 50 has the first turbo blade portion 12A2 and the second turbo blade portion 12B2 between the above-described circle C1a and the circle C7a when viewed parallel to the rotation axis RS. located in the area of In multi-blade fan 100, the size of outer diameter MO2 of motor 50 other than end portion 50a is not limited.

FIG. 13 is a conceptual diagram of a multi-blade fan 100A that is a first modification of the multi-blade fan 100 shown in FIG. In the multi-blade blower 100A, an outer peripheral wall 52 forming an outer diameter MO of a motor 50A has a virtual extension surface VF1 obtained by extending the inner diameter of the blades of the blades 12 on the main plate 11 side in the axial direction of the rotation shaft RS, and a virtual extension surface VF1 on the side plate 13 side. It is configured to be positioned between the inner diameter of the blade and a virtual extension plane VF3 extending in the axial direction of the rotation shaft RS. In addition, the outer peripheral wall 52 forming the outer diameter MO of the motor 50A is arranged at a position facing the first turbo blade portion 12A2 and the second turbo blade portion 12B2 in the axial direction of the rotating shaft RS. More specifically, the outer diameter MO of the motor 50A is larger than the inner diameter ID1 of the plurality of first blades 12A on the main plate 11 side and smaller than the inner diameter ID3 of the plurality of first blades 12A on the side plate 13 side. That is, the outer diameter MO of the motor 50A is formed larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. Further, the outer peripheral wall 52 forming the outer diameter MO of the motor 50A has the first turbo blade portion 12A2 and the second turbo blade portion 12A2 and the second turbo blade portion 12A2 between the above-described circles C1a and C7a when viewed parallel to the rotation axis RS. Located in the region of part 12B2.

FIG. 14 is a conceptual diagram of a multi-blade fan 100B that is a second modification of the multi-blade fan 100 shown in FIG. As shown in FIG. 14, the outer peripheral wall 52a that forms the outer diameter MO1a of the end portion 50a of the motor 50B is formed by extending the rotating shaft RS and the blade inner diameter of the blade 12 on the main plate 11 side in the axial direction of the rotating shaft RS. and the extension plane VF1 of the . In addition, the outer peripheral wall 52a forming the outer diameter MO1a of the end portion 50a of the motor 50B is arranged at a position facing the first turbo blade portion 12A2 and the second turbo blade portion 12B2 in the axial direction of the rotating shaft RS. . More specifically, the outer diameter MO1a of the end portion 50a of the motor 50B is smaller than the inner diameter ID1 of the plurality of first blades 12A on the main plate 11 side. That is, the outer diameter MO1a of the end portion 50a of the motor 50B is smaller than the inner diameter of the plurality of blades 12 on the main plate 11 side. Further, the outer peripheral wall 52a at the end portion 50a of the motor 50B is positioned within the above-described circle C1a when viewed parallel to the rotation axis RS.

Further, in the multi-blade blower 100B, the outer peripheral wall 52b constituting the outermost diameter MO2a of the motor 50B has a virtual extension surface VF1 obtained by extending the inner diameter of the blade of the blade 12 on the main plate 11 side in the axial direction of the rotation shaft RS, and the side plate It is configured to be positioned between the inner diameter of the blade on the 13 side and a virtual extension surface VF3 extending in the axial direction of the rotation shaft RS. Further, an outer peripheral wall 52b forming the outermost diameter MO2a of the motor 50B is arranged at a position facing the first turbo blade portion 12A2 and the second turbo blade portion 12B2 in the axial direction of the rotation shaft RS. More specifically, the outermost diameter MO2a of the motor 50B is larger than the inner diameter ID1 of the plurality of first blades 12A on the main plate 11 side and smaller than the inner diameter ID3 of the plurality of first blades 12A on the side plate 13 side. That is, the outermost diameter MO2a of the motor 50B is formed larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. Further, the outer peripheral wall 52b forming the outermost diameter MO2a of the motor 50B is positioned between the above-described circles C1a and C7a when viewed parallel to the rotation axis RS. Located in the area of the wing 12B2.

[Effects of impeller 10 and multi-blade blower 100]
In the impeller 10 and the multi-blade fan 100, in the first region and the second region of the impeller 10, the ratio of the turbo blades in the radial direction is larger than the ratio of the sirocco blades. Impeller 10 and multi-blade blower 100 have a high percentage of turbo blades in any region between main plate 11 and side plate 13, so that multiple blades 12 can sufficiently recover pressure. As such, impeller 10 and multi-blade blower 100 can provide improved pressure recovery compared to impellers and multi-blade blowers that do not have this configuration. As a result, impeller 10 can improve the efficiency of multi-blade fan 100 . Furthermore, the impeller 10 can reduce front edge separation of the airflow on the side plate 13 side by providing the above configuration.

Further, each of the plurality of blades 12 has a radial blade portion formed at a blade angle of 90 degrees as a connecting portion between the turbo blade portion and the sirocco blade portion. Since the impeller 10 has the radial blade portion between the turbo blade portion and the sirocco blade portion, there is no sudden angle change at the joint portion between the sirocco blade portion and the turbo blade portion. Therefore, the impeller 10 can reduce pressure fluctuations in the scroll casing 40, improve the fan efficiency of the multi-blade fan 100, and further reduce noise.

Further, among the plurality of blades 12, at least one second blade 12B of the plurality of second blades 12B is arranged between two first blades 12A adjacent to each other in the circumferential direction among the plurality of first blades 12A. It is In the impeller 10 and the multi-blade blower 100, even in the second blade 12B, the ratio of the turbo blade portion is high in any region between the main plate 11 and the side plate 13, so that the second blade 12B can sufficiently recover the pressure. It can be carried out. As such, impeller 10 and multi-blade blower 100 can provide improved pressure recovery compared to impellers and multi-blade blowers that do not have this configuration. As a result, impeller 10 can improve the efficiency of multi-blade fan 100 . Furthermore, the impeller 10 can reduce front edge separation of the airflow on the side plate 13 side by providing the above configuration.

In addition, the plurality of second blades 12B has an inner diameter formed by the inner peripheral end 14B of each of the plurality of second blades 12B and an outer diameter formed by the outer peripheral end 15B of each of the plurality of second blades 12B. It is formed so that the ratio is 0.7 or less. In the impeller 10 and the multi-blade blower 100, even in the second blade 12B, the ratio of the turbo blade portion is high in any region between the main plate 11 and the side plate 13, so that the second blade 12B can sufficiently recover the pressure. It can be carried out. As such, impeller 10 and multi-blade blower 100 can provide improved pressure recovery compared to impellers and multi-blade blowers that do not have this configuration. As a result, impeller 10 can improve the efficiency of multi-blade fan 100 . Furthermore, the impeller 10 can reduce front edge separation of the airflow on the side plate 13 side by providing the above configuration.

In addition, in the plurality of blades 12, in the portion of the plurality of blades 12 outside the inner diameter BI of the bell mouth 46 in the radial direction with respect to the rotation axis RS, the ratio of the area of the turbo blade portion in the radial direction of the main plate 11 is greater than the area fraction of the sirocco wing. The plurality of blades 12 are formed in any region between the main plate 11 and the side plate 13 . By having the configuration, the plurality of blades 12 can increase the amount of air sucked in the portion of the blades 12 inside the inner diameter BI of the bell mouth 46 . In addition, by increasing the proportion of the turbo blade portion in the portions of the plurality of blades 12 outside the inner diameter BI of the bell mouth 46, the air volume discharged from the impeller 10 can be increased. . Furthermore, the plurality of blades 12 having such a configuration can increase pressure recovery inside the scroll casing 40 of the multi-blade blower 100 and improve fan efficiency.

The inner diameter BI of the bell mouth 46 is formed larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. Therefore, the multi-blade blower 100 can reduce interference between the intake airflow flowing from the suction port 45 of the bellmouth 46 and the blades 12 on the side plate 13 side, and further reduce noise.

The inner diameter BI of the bellmouth 46 is formed larger than the blade inner diameter of the plurality of second blades 12B on the main plate 11 side and smaller than the blade inner diameter of the plurality of second blades 12B on the side plate 13 side. Therefore, the multi-blade blower 100 can reduce interference between the intake airflow flowing from the suction port 45 of the bell mouth 46 and the second blade 12B on the side plate 13 side, and further reduce noise.

Further, the distance MS, which is the closest distance between the plurality of blades 12 and the peripheral wall 44c, is larger than twice the radial length of the sirocco blade. Therefore, the multi-blade blower 100 can perform pressure recovery in the turbo blade portion, and the scroll casing 40 and the impeller 10 can be separated from each other at the closest point, thereby reducing noise.

Further, in the multi-blade fan 100, the outer diameter MO1 of the end portion 50a of the motor 50 is larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. It is With this configuration, the multi-blade blower 100 is configured so that the airflow from the vicinity of the motor 50 is turned in the axial direction of the rotating shaft RS of the impeller 10, and the air smoothly flows into the scroll casing 40. The air volume discharged from the impeller 10 can be increased. Moreover, the multi-blade blower 100 can increase the pressure recovery inside the scroll casing 40 and improve the fan efficiency by providing this configuration.

In the multi-blade fan 100A, the outer diameter MO of the motor 50A is larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. The multi-blade blower 100A has this configuration, so that the airflow from the vicinity of the motor 50A is turned in the axial direction of the rotation shaft RS of the impeller 10, and the air smoothly flows into the scroll casing 40. The air volume discharged from the impeller 10 can be increased. Moreover, the multi-blade fan 100A can increase the pressure recovery inside the scroll casing 40 and improve the fan efficiency by providing the configuration.

Further, in the multi-blade blower 100B, the outermost diameter MO2a of the motor 50B is larger than the blade inner diameter of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter of the plurality of blades 12 on the side plate 13 side. In addition, the outer diameter MO1a of the end portion 50a of the motor 50B is smaller than the inner diameter of the plurality of blades 12 on the main plate 11 side. With this configuration, the multi-blade fan 100B can allow air to flow into the scroll casing 40 more smoothly than the multi-blade fan 100A and the like, and increase the amount of air discharged from the impeller 10. be able to. In addition, the multi-blade fan 100B having this configuration can increase the pressure recovery inside the scroll casing 40 and improve the fan efficiency as compared with the multi-blade fan 100A and the like.

Embodiment 2.
[Multi-blade blower 100C]
FIG. 15 is a cross-sectional view schematically showing a multi-blade fan 100C according to Embodiment 2. FIG. FIG. 16 is a cross-sectional view schematically showing a multi-blade fan 100H as a comparative example. FIG. 17 is a cross-sectional view schematically showing the action of multi-blade fan 100C according to the second embodiment. FIG. 15 is a cross-sectional view schematically showing the effect of multi-blade fan 100C according to the second embodiment. A multi-blade fan 100C according to Embodiment 2 will be described with reference to FIGS. 15 to 17. FIG. Parts having the same configurations as those of the multi-blade blower 100 and the like shown in FIGS. The impeller 10C of the multi-blade fan 100C according to Embodiment 2 further specifies the configuration of the inclined portions 141A and 141B of the plurality of blades 12 in the impeller 10 of the multi-blade fan 100 according to Embodiment 1. . Therefore, in the following description, the impeller 10C will be described with a focus on the configuration of the inclined portions 141A and 141B of the multi-blade fan 100C according to the second embodiment with reference to FIGS. 15 to 17. FIG.

As described above, the plurality of blades 12 form the inclined portion 141A in which the front edge 14A1 is inclined away from the rotation axis RS so that the inner diameter of the blade increases from the side of the main plate 11 toward the side of the side plate 13. . That is, the plurality of blades 12 form an inclined portion 141A in which the inner peripheral end 14A is inclined away from the rotation axis RS so that the blade inner diameter increases from the main plate 11 side toward the side plate 13 side. Similarly, the plurality of blades 12 form an inclined portion 141B in which the front edge 14B1 is inclined away from the rotation axis RS so that the inner diameter of the blade increases from the main plate 11 side toward the side plate 13 side. That is, the plurality of blades 12 form an inclined portion 141B in which the inner peripheral end 14B is inclined away from the rotation axis RS so that the blade inner diameter increases from the main plate 11 side toward the side plate 13 side. The plurality of blades 12 form a gradient on the inner peripheral side by the inclined portions 141A and 141B.

The inclined portion 141A is inclined with respect to the rotation axis RS. The angle of inclination of the inclined portion 141A is preferably greater than 0 degrees and 60 degrees or less, and more preferably greater than 0 degrees and 45 degrees or less. That is, the inclination angle θ1 between the inclined portion 141A and the rotation axis RS preferably satisfies the relationship 0°<θ1≦60°, more preferably 0°<θ1≦45°. A virtual line VL1 shown in FIG. 15 is a virtual line parallel to the rotation axis RS. Therefore, the angle between the inclined portion 141A and the virtual line VL1 is equal to the angle between the inclined portion 141A and the rotation axis RS.

Similarly, the inclined portion 141B is inclined with respect to the rotation axis RS. The angle of inclination of the inclined portion 141B is preferably greater than 0 degrees and 60 degrees or less, and more preferably greater than 0 degrees and 45 degrees or less. That is, the inclination angle θ2 between the inclined portion 141B and the rotation axis RS preferably satisfies 0°<θ2≦60°, more preferably 0°<θ2≦45°. A virtual line VL2 shown in FIG. 15 is a virtual line parallel to the rotation axis RS. Therefore, the angle between the inclined portion 141B and the virtual line VL2 is equal to the angle between the inclined portion 141B and the rotation axis RS. Note that the inclination angle θ1 and the inclination angle θ2 may be the same angle or different angles.

The blade height WH shown in FIG. 15 is 200 mm or less. The blade height WH is the distance between the main plate 11 and the ends 12t of the plurality of blades 12 in the axial direction of the rotating shaft RS, and is the distance between the main plate 11 and the ends of the plurality of blades 12 in the axial direction of the rotating shaft RS. 12t is the maximum distance. The blade height WH is not limited to 200 mm or less, and may be greater than 200 mm.

[Effects of impeller 10C and multi-blade blower 100C]
As shown in FIG. 16, in a multi-blade fan 100H as a comparative example, the inner diameter IDh formed by the front edge 14H is constant in the axial direction of the rotation shaft RS. That is, the multi-blade fan 100H of the comparative example does not have the inclined portion 141A and the inclined portion 141B, and the inner diameter of the blades does not have a gradient. Therefore, as shown in FIG. 16, in the multi-blade fan 100H of the comparative example, the air sucked into the multi-blade fan 100H (dotted line FL) is at the end 12t of the impeller 10H, or at the end 12t and the leading edge. It is easy to pass through the corner formed by 14H. An end portion 12t of the impeller 10H or a corner formed by the end portion 12t and the front edge 14H is a portion where the blade 12 has a small area. Therefore, the air passes through narrow gaps between the blades 12 and the adjacent blades 12, and the multi-blade blower 100H has a large ventilation resistance when sucking air.

On the other hand, as shown in FIG. 17, a multi-blade fan 100C has inclined portions 141A and 141B at the leading edges of the blades 12, forming a gradient in the inner diameter of the blades. Therefore, as shown in FIG. 17, in the multi-blade blower 100C, the gradient formed in the inner diameter of the blades 12 allows the front edge of the blades 12 to have a wide area with respect to the airflow. air draft resistance can be reduced. As a result, the multi-blade fan 100C can increase the blowing efficiency.

The inclination angles of the inclined portion 141A and the inclined portion 141B of the multi-blade fan 100C can be set as appropriate. By increasing the inclination angles of the inclined portions 141A and 141B, the area of the front edge of the blade 12 with respect to the airflow can be increased. In order to increase the size, it is necessary to increase the size of the impeller 10C and the multi-blade fan 100C in the radial direction. In order to increase the front edge area of the blades 12 described above while suppressing the increase in size of the impeller 10C and the multi-blade fan 100C, the inclination angles of the inclined portions 141A and 141B are set to 60 degrees or less. is desirable. Moreover, in order to further reduce the size of the impeller 10C and the multi-blade fan 100C, it is desirable to set the inclination angles of the inclined portions 141A and 141B to 45 degrees or less.

[Multi-blade blower 100D]
FIG. 18 is a cross-sectional view of a multi-blade fan 100D that is a first modification of the multi-blade fan 100C shown in FIG. A multi-blade fan 100D that is a first modification of the multi-blade fan 100C according to Embodiment 2 will be described with reference to FIG. Parts having the same configurations as those of the multi-blade blower 100 and the like shown in FIGS. The impeller 10D of the multi-blade fan 100D further specifies the configuration of the front edges 14A1 and 14B1 of the plurality of blades 12 in the impeller 10C of the multi-blade fan 100C according to the second embodiment. Therefore, in the following description, referring to FIG. 18, the impeller 10D will be described focusing on the configuration of the front edge 14A1 and the front edge 14B1 of the multi-blade fan 100D.

As described above, the plurality of blades 12 form the inclined portion 141A in which the front edge 14A1 is inclined away from the rotation axis RS so that the inner diameter of the blade increases from the side of the main plate 11 toward the side of the side plate 13. . Similarly, the plurality of blades 12 form an inclined portion 141B in which the front edge 14B1 is inclined away from the rotation axis RS so that the inner diameter of the blade increases from the main plate 11 side toward the side plate 13 side. The plurality of blades 12 form a gradient on the inner peripheral side by the inclined portions 141A and 141B.

The inclined portion 141A is inclined with respect to the rotation axis RS. The angle of inclination of the inclined portion 141A is preferably greater than 0 degrees and 60 degrees or less, and more preferably greater than 0 degrees and 45 degrees or less. That is, the inclination angle θ1 between the inclined portion 141A and the rotation axis RS preferably satisfies the relationship 0°<θ1≦60°, more preferably 0°<θ1≦45°. Similarly, the inclined portion 141B is inclined with respect to the rotation axis RS. The angle of inclination of the inclined portion 141B is preferably greater than 0 degrees and 60 degrees or less, and more preferably greater than 0 degrees and 45 degrees or less. That is, the inclination angle θ2 between the inclined portion 141B and the rotation axis RS preferably satisfies 0°<θ2≦60°, more preferably 0°<θ2≦45°.

The blade height WH shown in FIG. 18 is 200 mm or less. The blade height WH is the distance between the main plate 11 and the ends 12t of the plurality of blades 12 in the axial direction of the rotating shaft RS, and is the distance between the main plate 11 and the ends of the plurality of blades 12 in the axial direction of the rotating shaft RS. 12t is the maximum distance. The blade height WH is not limited to 200 mm or less, and may be greater than 200 mm.

The plurality of blades 12 are provided with a straight portion 141C1 at the front edge 14A1 between the main plate 11 side and the side plate 13 side. The straight portion 141C1 is provided on the main plate 11 side between the main plate 11 side and the side plate 13 side. Therefore, the front edge 14A1 of the first blade 12A is formed by a straight portion 141C1 provided on the main plate 11 side and an inclined portion 141A provided on the side plate 13 side. The impeller 10D of the multi-blade fan 100D has a constant inner diameter IDc1 formed by the straight portion 141C1 of the front edge 14A1 in the axial direction of the rotation axis RS.

Similarly, each of the blades 12 has a straight portion 141C2 at the front edge 14B1 between the main plate 11 side and the side plate 13 side. The straight portion 141C2 is provided on the main plate 11 side between the main plate 11 side and the side plate 13 side. Therefore, the front edge 14B1 of the second blade 12B is formed by the straight portion 141C2 provided on the main plate 11 side and the inclined portion 141B provided on the side plate 13 side. The impeller 10D of the multi-blade fan 100D has an inner diameter IDc2 formed by the straight portion 141C2 of the front edge 14B1 and has a constant size in the axial direction of the rotation axis RS.

[Effects of impeller 10D and multi-blade fan 100D]
As shown in FIG. 18, the multi-blade fan 100D has inclined portions 141A and 141B at the leading edges of the blades 12, forming a gradient in the inner diameter of the blades. Therefore, in the multi-blade fan 100D, due to the gradient formed in the blade inner diameter of the blade 12, the area of the front edge of the blade 12 with respect to the airflow can be widened, and the draft resistance of the air when passing through the impeller 10D can be reduced. can do. As a result, the multi-blade fan 100D can increase the blowing efficiency.

[Multi-blade blower 100E]
FIG. 19 is a cross-sectional view of a multi-blade fan 100E that is a second modification of the multi-blade fan 100C shown in FIG. A multi-blade fan 100E, which is a second modification of the multi-blade fan 100C according to Embodiment 2, will be described with reference to FIG. Parts having the same configurations as those of the multi-blade fan 100 and the like shown in FIGS. Impeller 10E of multi-blade fan 100E further specifies the configuration of front edges 14A1 and front edges 14B1 of multiple blades 12 in impeller 10C of multi-blade fan 100C according to the second embodiment. Therefore, in the following description, referring to FIG. 19, the impeller 10E will be described focusing on the configuration of the front edge 14A1 and the front edge 14B1 of the multi-blade fan 100E.

As described above, the plurality of blades 12 form the inclined portion 141A in which the front edge 14A1 is inclined away from the rotation axis RS so that the blade inner diameter IDe increases from the main plate 11 side toward the side plate 13 side. ing. Further, the plurality of blades 12 form an inclined portion 141A2 in which the front edge 14A1 is inclined away from the rotation axis RS so that the blade inner diameter IDe increases from the main plate 11 side toward the side plate 13 side. The inclined portion 141A2 is provided on the main plate 11 side between the main plate 11 side and the side plate 13 side. Therefore, the front edge 14A1 of the first blade 12A is formed by an inclined portion 141A2 provided on the main plate 11 side and an inclined portion 141A provided on the side plate 13 side. That is, the first blade 12A of the plurality of blades 12 has two inclined portions, ie, an inclined portion 141A and an inclined portion 141A2, between the main plate 11 and the side plate 13. As shown in FIG. Note that the first blade 12A of the plurality of blades 12 is not limited to the structure having two inclined portions, namely, the inclined portion 141A and the inclined portion 141A2, and has two or more inclined portions. It is good if there is

Similarly, the plurality of blades 12 form an inclined portion 141B in which the front edge 14B1 is inclined away from the rotation axis RS so that the blade inner diameter IDe increases from the main plate 11 side toward the side plate 13 side. . Further, the plurality of blades 12 form an inclined portion 141B2 in which the front edge 14B1 is inclined away from the rotation axis RS so that the blade inner diameter IDe increases from the main plate 11 side toward the side plate 13 side. The inclined portion 141B2 is provided on the main plate 11 side between the main plate 11 side and the side plate 13 side. Therefore, the front edge 14B1 of the second blade 12B is formed by an inclined portion 141B2 provided on the main plate 11 side and an inclined portion 141B provided on the side plate 13 side. That is, the second blade 12B of the plurality of blades 12 has two inclined portions between the main plate 11 and the side plate 13, ie, an inclined portion 141B and an inclined portion 141B2. In addition, the second blade 12B of the plurality of blades 12 is not limited to the structure having two inclined portions, namely, the inclined portion 141B and the inclined portion 141B2, and has two or more inclined portions. It is good if there is. The plurality of blades 12 form a gradient on the inner peripheral side by the inclined portion 141A, the inclined portion 141A2, the inclined portion 141B, and the inclined portion 141B2.

At least one of the inclined portion 141A and the inclined portion 141A2 is inclined with respect to the rotation axis RS. The angle of inclination of the inclined portion 141A and/or the inclined portion 141A2 is preferably greater than 0 degrees and 60 degrees or less, more preferably greater than 0 degrees and 45 degrees or less. That is, the inclination angle θ1 between the inclined portion 141A and the rotation axis RS preferably satisfies the relationship 0°<θ1≦60°, more preferably 0°<θ1≦45°. Alternatively, the inclination angle θ11 between the inclined portion 141A2 and the rotation axis RS is configured to preferably satisfy the relationship 0°<θ11≦60°, more preferably 0°<θ11≦45°. A virtual line VL3 shown in FIG. 19 is a virtual line parallel to the rotation axis RS. Therefore, the angle between the inclined portion 141A2 and the virtual line VL3 is equal to the angle between the inclined portion 141A2 and the rotation axis RS.

The inclination angle θ1 of the inclined portion 141A and the inclination angle θ11 of the inclined portion 141A2 are different. When the first blade 12A has two or more inclined portions, the inclination angles of the respective inclined portions are different. The relationship between the inclination angle θ1 of the inclined portion 141A and the inclination angle θ11 of the inclined portion 141A2 is not limited. For example, in the first blade 12A, as shown in FIG. 19, the tilt angle θ11 of the tilt portion 141A2 may be larger than the tilt angle θ1 of the tilt portion 141A. Alternatively, in the first blade 12A, the inclination angle θ11 of the inclined portion 141A2 may be smaller than the inclination angle θ1 of the inclined portion 141A.

Similarly, at least one of the inclined portion 141B and the inclined portion 141B2 is inclined with respect to the rotation axis RS. The angle of inclination of the inclined portion 141B and/or the inclined portion 141B2 is preferably greater than 0 degrees and less than or equal to 60 degrees, more preferably greater than 0 degrees and less than or equal to 45 degrees. That is, the inclination angle θ2 between the inclined portion 141B and the rotation axis RS preferably satisfies 0°<θ2≦60°, more preferably 0°<θ2≦45°. Alternatively, the inclination angle θ22 between the inclined portion 141B2 and the rotation axis RS is configured to preferably satisfy the relationship 0°<θ22≦60°, more preferably 0°<θ22≦45°. A virtual line VL4 shown in FIG. 19 is a virtual line parallel to the rotation axis RS. Therefore, the angle between the inclined portion 141B2 and the virtual line VL4 is equal to the angle between the inclined portion 141B2 and the rotation axis RS.

The inclination angle θ2 of the inclined portion 141B and the inclination angle θ22 of the inclined portion 141B2 are different. When the second blade 12B has two or more inclined portions, the inclination angles of the respective inclined portions are different. The relationship between the inclination angle θ2 of the inclined portion 141B and the inclination angle θ22 of the inclined portion 141B2 is not limited. For example, in the second blade 12B, as shown in FIG. 19, the inclination angle θ22 of the inclined portion 141B2 may be larger than the inclination angle θ2 of the inclined portion 141B. Alternatively, in the second blade 12B, the inclination angle θ22 of the inclined portion 141B2 may be smaller than the inclination angle θ2 of the inclined portion 141B.

The blade height WH shown in FIG. 19 is 200 mm or less. The blade height WH is the distance between the main plate 11 and the ends 12t of the plurality of blades 12 in the axial direction of the rotating shaft RS, and is the distance between the main plate 11 and the ends of the plurality of blades 12 in the axial direction of the rotating shaft RS. 12t is the maximum distance. The blade height WH is not limited to 200 mm or less, and may be greater than 200 mm.

[Effects of impeller 10E and multi-blade blower 100E]
As shown in FIG. 19, the multi-blade fan 100E has an inclined portion 141A, an inclined portion 141A2, an inclined portion 141B, and an inclined portion 141B2 at the front edge of the blade 12, forming a gradient in the blade inner diameter IDe. there is Therefore, in the multi-blade blower 100E, due to the gradient formed in the blade inner diameter IDe of the blades 12, the front edge area of the blades 12 can be widened with respect to the airflow, and the draft resistance of the air when passing through the impeller 10E can be reduced. can be made smaller. As a result, the multi-blade fan 100E can increase the blowing efficiency.

Embodiment 3.
[Multi-blade blower 100F]
FIG. 20 is a schematic diagram showing the relationship between the bellmouth 46 and the blades 12 of the multi-blade fan 100F according to the third embodiment. FIG. 21 is a schematic diagram showing the relationship between the bell mouth 46 and the blades 12 of the modification of the multi-blade fan 100F according to the third embodiment. A multi-blade fan 100F according to Embodiment 3 will be described with reference to FIGS. 20 and 21. FIG. Parts having the same configurations as those of the multi-blade blower 100 and the like shown in FIGS. The impeller 10F of the multi-blade fan 100F according to the third embodiment further specifies the configuration of the turbo blade portion in the impeller 10 of the multi-blade fan 100 according to the first embodiment. Therefore, in the following description, the impeller 10F will be described with a focus on the configuration of the turbo blade portion of the multi-blade fan 100F according to Embodiment 3, using FIGS.

An impeller 10F of a multi-blade fan 100F according to Embodiment 3 has a stepped portion 12D formed at an end portion 12t of the turbo blade portion on the side plate 13 side. Hereinafter, as shown in FIG. 20, the stepped portion 12D will be described using the first blade 12A. The step portion 12D is formed at the end portion 12t of the first turbo blade portion 12A2 on the side plate 13 side. That is, the step portion 12D is formed at the end portion 12t of the inclined portion 141A on the side plate 13 side. The stepped portion 12D is a portion formed in a notched state in the wall that constitutes the first blade 12A. The stepped portion 12D is a portion formed by cutting out a continuous portion between the front edge 14A1 of the first blade 12A and the end portion 12t of the first turbo blade portion 12A2 on the side plate 13 side. The stepped portion 12D is formed by a side edge portion 12D1 extending in the axial direction of the rotation shaft RS of the impeller 10F and an upper edge portion 12D2 extending in the radial direction of the impeller 10F. However, the stepped portion 12D is limited to a configuration formed by a side edge portion 12D1 extending in the axial direction of the rotation shaft RS of the impeller 10F and an upper edge portion 12D2 extending in the radial direction of the impeller 10F. is not. For example, the stepped portion 12D may be formed as an arcuate edge portion in which the side edge portion 12D1 and the upper edge portion 12D2 are continuously and integrally formed.

The stepped portion 12D of the second blade 12B has the same configuration as that of the first blade 12A, so its illustration is omitted, but the stepped portion 12D is also formed in the second blade 12B. The step portion 12D is also formed at the end portion 12t on the side plate 13 side of the second turbo blade portion 12B2. That is, the stepped portion 12D is formed at the end portion 12t of the inclined portion 141B on the side plate 13 side. The stepped portion 12D is a portion formed in a notched state in the wall that constitutes the second blade 12B. The stepped portion 12D is a portion formed by cutting out a continuous portion between the front edge 14B1 of the second blade 12B and the end portion 12t of the second turbo blade portion 12B2 on the side plate 13 side.

A plurality of blades 12 of multi-blade fan 100</b>F according to Embodiment 3 are formed such that the blade outer diameter formed by the outer peripheral ends of the plurality of blades 12 is larger than the inner diameter BI of bell mouth 46 . Then, as shown in FIGS. 20 and 21, in the multi-blade fan 100F, the inner peripheral side end portion 46b of the bell mouth 46 is arranged above the stepped portion 12D. The multi-blade fan 100F is arranged such that the inner peripheral side end 46b of the bell mouth 46 faces the upper edge 12D2 of the stepped portion 12D. The multi-blade blower 100F forms a gap between the inner peripheral side end portion 46b of the bell mouth 46 and the side edge portion 12D1 and the upper edge portion 12D2.

[Effects of impeller 10F and multi-blade blower 100F]
In the impeller 10F and the multi-blade fan 100F, a stepped portion is formed at the end portion 12t of the turbo blade portion on the side plate 13 side. The impeller 10F and the multi-blade fan 100F can widen the gap between the bellmouth 46 and the blades 12 by the stepped portion 12D. Therefore, the impeller 10F and the multi-blade blower 100F can suppress an increase in airflow velocity in the gap between the bellmouth 46 and the blades 12, and reduce noise caused by the airflow passing through the gap between the bellmouth 46 and the blades 12. can be suppressed.

In addition, the impeller 10F and the multi-blade fan 100F allow the bellmouth 46 to be brought closer to the impeller 10F than when the blades 12 do not have the stepped portion 12D. The impeller 10F and the multi-blade blower 100F can reduce the gap between the bellmouth 46 and the blades 12 by moving the bellmouth 46 closer to the impeller 10F. As a result, the impeller 10F and the multi-blade fan 100F can reduce intake air leakage, that is, the amount of air that does not pass between adjacent blades 12 of the impeller 10F. As shown in FIG. 21, the impeller 10F and the multi-blade blower 100F are arranged so that the bell mouth 46 and the side edge 12D1 face each other, so that the bell mouth 46 and the side edge 12D1 face each other. Leakage of intake air can be further reduced as compared with the case where the intake air is not provided. In other words, in the multi-blade fan 100F, the bell mouth 46 is arranged inside the stepped portion 12D and arranged radially above the blades 12, so that the bell mouth 46 is not arranged inside the stepped portion 12D. In comparison, intake air leakage can be further reduced.

Embodiment 4.
[Multi-blade blower 100G]
FIG. 22 is a cross-sectional view schematically showing multi-blade fan 100G according to the fourth embodiment. FIG. 23 is a schematic diagram of the blades 12 of the impeller 10G of FIG. 22 when viewed parallel to the rotation axis RS. FIG. 24 is a schematic diagram showing blades 12 in a DD cross section of impeller 10G in FIG. A multi-blade fan 100G according to Embodiment 4 will be described with reference to FIGS. 22 to 24. FIG. Parts having the same configurations as those of the multi-blade blower 100 and the like shown in FIGS.

As shown in FIGS. 22 to 24, an impeller 10G of a multi-blade fan 100G according to Embodiment 4 has a configuration in which all of the plurality of blades 12 are composed of first blades 12A. As shown in FIGS. 22 to 24, 42 first blades 12A are arranged in the impeller 10G, but the number of the first blades 12A is not limited to 42. It may be less, or it may be more than 42 sheets.

The first blade 12A has a relationship of blade length L1a>wing length L1b. That is, the first blade 12A is formed such that the blade length decreases from the main plate 11 side toward the side plate 13 side in the axial direction of the rotation shaft RS. As shown in FIG. 22, the first blade 12A is inclined such that the blade inner diameter IDg increases from the main plate 11 side toward the side plate 13 side. That is, the plurality of blades 12 has an inclined portion 141A in which the inner peripheral end 14A constituting the leading edge 14A1 is inclined away from the rotation axis RS so that the blade inner diameter IDg increases from the main plate 11 side toward the side plate 13 side. forming

The first blade 12A has a first sirocco blade portion 12A1 configured as a forward blade and a first turbo blade portion 12A2 configured as a rearward blade. In the first blade 12A, the first turbo region 12A21 is larger than the first sirocco region 12A11 in the radial direction of the impeller . That is, the impeller 10 and the first blades 12A are arranged in the radial direction of the impeller 10 in both the main-plate-side blade region 122a as the first region and the side-plate-side blade region 122b as the second region. The ratio of the turbo blade portion 12A2 is greater than the ratio of the first sirocco blade portion 12A1.

When the interval between two blades 12 adjacent to each other in the circumferential direction among the plurality of blades 12 is defined as the interval between blades, as shown in FIGS. , and spreads toward the trailing edge 15A1 side. Specifically, the gap between the blades of the first turbo blade portion 12A2 widens from the inner peripheral side to the outer peripheral side. The blade interval of the first sirocco blade portion 12A1 is wider than the blade interval of the first turbo blade portion 12A2 and spreads from the inner peripheral side to the outer peripheral side.

As shown in FIG. 22, the inner diameter BI of the bellmouth 46 is larger than the inner diameter ID1a of the first blade 12A on the main plate 11 side and smaller than the inner diameter ID3a on the side plate 13 side. That is, the inner diameter BI of the bellmouth 46 is formed larger than the blade inner diameter IDg of the plurality of blades 12 on the main plate 11 side and smaller than the blade inner diameter IDg on the side plate 13 side.

[Effects of impeller 10G and multi-blade blower 100G]
Impeller 10G and multi-blade fan 100G can obtain the same effects as multi-blade fan 100 and impeller 10 according to the first embodiment. For example, in the impeller 10G and the multi-blade fan 100G, in any region between the main plate 11 and the side plate 13, the ratio of the region of the first turbo blade portion 12A2 in the radial direction of the main plate 11 is the first sirocco blade portion It is larger than the area ratio of 12A1. Since the impeller 10G and the multi-blade fan 100G have a high ratio of turbo blades in any region between the main plate 11 and the side plate 13, the plurality of blades 12 can sufficiently recover the pressure. Therefore, the impeller 10G and the multi-blade fan 100G can improve pressure recovery compared to an impeller and a multi-blade fan that do not have this configuration. As a result, the impeller 10G can improve the efficiency of the multi-blade fan 100G. Furthermore, the impeller 10G can reduce front edge separation of the airflow on the side plate 13 side by providing the above configuration.

In Embodiments 1 to 4 above, the multi-blade blower 100 including the double-suction impeller 10 in which the plurality of blades 12 are formed on both main plates 11 is taken as an example. However, Embodiments 1 to 4 can also be applied to multi-blade blower 100 having single-suction impeller 10 in which a plurality of blades 12 are formed only on one side of main plate 11 .

Embodiment 5.
[Air conditioner 140]
25 is a perspective view of an air conditioner 140 according to Embodiment 5. FIG. FIG. 26 is a diagram showing the internal configuration of an air conditioner 140 according to Embodiment 5. As shown in FIG. In addition, with respect to the multi-blade fan 100 used in the air conditioner 140 according to Embodiment 5, parts having the same configurations as those of the multi-blade fan 100 and the like shown in FIGS. Description is omitted. Moreover, in FIG. 26, the upper surface portion 16a is omitted in order to show the internal configuration of the air conditioner 140. As shown in FIG.

An air conditioner 140 according to Embodiment 5 faces one or more of multi-blade fans 100 to 100G according to Embodiments 1 to 4, and discharge port 42a of multi-blade fan 100. and a heat exchanger 15 arranged at a position where Moreover, the air conditioner 140 according to Embodiment 5 includes a case 16 installed in the ceiling space of the room to be air-conditioned. In the following description, when referring to multi-blade fan 100, any one of multi-blade fan 100 to multi-blade fan 100G according to Embodiments 1 to 4 is used. 25 and 26 show the multi-blade blower 100 having the scroll casing 40 inside the case 16, but the case 16 contains the impellers 10 to 10G and the like that do not have the scroll casing 40. may be installed.

(Case 16)
As shown in FIG. 25, the case 16 is formed in a rectangular parallelepiped shape including an upper surface portion 16a, a lower surface portion 16b, and a side surface portion 16c. The shape of the case 16 is not limited to a rectangular parallelepiped shape. There may be. The case 16 has, as one of the side portions 16c, a side portion 16c in which the case outlet 17 is formed. The shape of the case discharge port 17 is formed in a rectangular shape as shown in FIG. The shape of the case outlet 17 is not limited to a rectangular shape, and may be, for example, a circular shape, an oval shape, or other shapes. The case 16 has a side portion 16c formed with a case suction port 18 on the side opposite to the side on which the case discharge port 17 is formed. The shape of the case suction port 18 is formed in a rectangular shape as shown in FIG. The shape of the case suction port 18 is not limited to a rectangular shape, and may be, for example, a circular shape, an oval shape, or other shapes. A filter for removing dust in the air may be arranged at the case suction port 18 .

A multi-blade fan 100 and a heat exchanger 15 are housed inside the case 16 . A multi-blade blower 100 includes an impeller 10 , a scroll casing 40 having a bell mouth 46 formed thereon, and a motor 50 . The motor 50 is supported by a motor support 9a fixed to the upper surface portion 16a of the case 16. As shown in FIG. Motor 50 has a motor shaft 51 . The motor shaft 51 is arranged to extend parallel to the surface of the side surface portion 16c on which the case suction port 18 is formed and the surface on which the case discharge port 17 is formed. The air conditioner 140 has two impellers 10 attached to a motor shaft 51, as shown in FIG. The impeller 10 of the multi-blade blower 100 forms a flow of air that is sucked into the case 16 from the case suction port 18 and blown out from the case discharge port 17 to the space to be air-conditioned. In addition, the number of impellers 10 arranged in the case 16 is not limited to two, and may be one or three or more.

As shown in FIG. 26, the multi-blade blower 100 is attached to a partition plate 19, and the internal space of the case 16 is divided into a space S11 on the suction side of the scroll casing 40 and a space S12 on the blowing side of the scroll casing 40. is separated by a partition plate 19.

The heat exchanger 15 is arranged at a position facing the discharge port 42 a of the multi-blade fan 100 , and is arranged in the case 16 on the air path of the air discharged by the multi-blade fan 100 . The heat exchanger 15 adjusts the temperature of the air sucked into the case 16 through the case inlet 18 and blown out through the case outlet 17 into the air-conditioned space. Note that the heat exchanger 15 may have a known structure. Note that the case suction port 18 may be formed at a position perpendicular to the axial direction of the rotating shaft RS of the multi-blade fan 100. For example, the case suction port 18 may be formed in the lower surface portion 16b.

When the impeller 10 of the multi-blade blower 100 rotates, the air in the space to be air-conditioned is sucked into the case 16 through the case suction port 18 . Air sucked into the case 16 is guided by the bell mouth 46 and sucked into the impeller 10 . The air sucked into the impeller 10 is blown out radially outward of the impeller 10 . The air blown out from the impeller 10 passes through the inside of the scroll casing 40 , is blown out from the discharge port 42 a of the scroll casing 40 , and is supplied to the heat exchanger 15 . When the air supplied to the heat exchanger 15 passes through the heat exchanger 15, heat is exchanged with the refrigerant flowing inside the heat exchanger 15, and the temperature and humidity are adjusted. The air that has passed through the heat exchanger 15 is blown out from the case outlet 17 into the air-conditioned space.

An air conditioner 140 according to the fifth embodiment includes any one of the multi-blade fans 100 to 100G according to the first to fourth embodiments. Therefore, in the air conditioner 140, the same effects as in any one of the first to fourth embodiments can be obtained.

Each of the first to fifth embodiments described above can be implemented in combination with each other. Moreover, the configurations shown in the above embodiments are examples, and can be combined with another known technique, and part of the configuration can be omitted or changed without departing from the scope of the invention. is also possible. For example, in the embodiment, the impeller 10 and the like configured only with the main plate side blade region 122a as the first region and the side plate side blade region 122b as the second region are described. The impeller 10 is not limited to being configured only with the first region and the second region. The impeller 10 may further have other regions in addition to the first region and the second region. For example, in the first embodiment, the blade length is continuously changed from the side of the main plate 11 to the side of the side plate 13, but there is a portion where the blade length is constant between the main plate 11 and the side plate 13, that is, the inner diameter It may have a portion that has a constant ID and is not inclined with respect to the rotation axis RS.

9a motor support, 10 impeller, 10C impeller, 10D impeller, 10E impeller, 10F impeller, 10G impeller, 10H impeller, 10e suction port, 11 main plate, 11b shaft, 12 blade, 12A first blade , 12A1 first sirocco blade portion, 12A11 first sirocco region, 12A2 first turbo blade portion, 12A21 first turbo region, 12A21a first turbo region, 12A2a first turbo blade portion, 12A3 first radial blade portion, 12B second Blade, 12B1 Second Sirocco Blade, 12B11 Second Sirocco Region, 12B2 Second Turbo Blade, 12B21 Second Turbo Region, 12B21a Second Turbo Region, 12B2a Second Turbo Blade, 12B3 Second Radial Blade, 12D Step part 12D1 side edge 12D2 upper edge 12R outer peripheral region 12t end 13 side plate 13a first side plate 13b second side plate 14A inner peripheral end 14A1 front edge 14B inner peripheral end 14B1 Front edge 14H Front edge 15 Heat exchanger 15A Peripheral end 15A1 Rear edge 15B Peripheral end 15B1 Rear edge 16 Case 16a Upper surface portion 16b Lower surface portion 16c Side surface portion 17 Case outlet 18 Case Suction port 19 Partition plate 40 Scroll casing 41 Scroll part 41a Winding start part 41b Winding end part 42 Discharge part 42a Discharge port 42b Extension plate 42c Diffuser plate 42d First side plate part 42e Second 2 side plate portion 43 tongue portion 44a side wall 44a1 first side wall 44a2 second side wall 44c peripheral wall 45 suction port 45a first suction port 45b second suction port 46 bell mouth 46a opening 46b inside Peripheral side end 50 Motor 50A Motor 50B Motor 50a End 51 Motor shaft 52 Peripheral wall 52a Peripheral wall 52b Peripheral wall 71 First plane 72 Second plane 100 Multi-blade blower 100A Multi-blade blower 100B Multi-blade blower 100C Multi-blade blower 100D Multi-blade blower 100E Multi-blade blower 100F Multi-blade blower 100G Multi-blade blower 100H Multi-blade blower 112a First blade 112b Second blade , 122 a main plate side blade region, 122b side plate side blade region, 140 air conditioner, 141A inclined portion, 141A2 inclined portion, 141B inclined portion, 141B2 inclined portion, 141C1 straight portion, 141C2 straight portion.

Claims (6)

An impeller comprising a main plate that is driven to rotate, an annular side plate that faces the main plate, one end of which is connected to the main plate, and the other end of which is connected to the side plate. An impeller having a plurality of blades arranged in a circumferential direction around the rotation axis of
a scroll casing having a peripheral wall formed in a spiral shape and a side wall having a bell mouth forming a suction port communicating with a space formed by the main plate and the plurality of blades, and housing the impeller; ,
with
each of the plurality of vanes,
an inner peripheral end located on the side of the rotating shaft in a radial direction about the rotating shaft;
an outer peripheral end located on the outer peripheral side of the inner peripheral end in the radial direction;
a sirocco wing portion constituting a forward blade having an exit angle greater than 90 degrees including the outer peripheral end;
a turbo blade portion that includes the inner peripheral end and constitutes a trailing blade;
has
The vanes are
The blade length is formed so as to decrease from the main plate side toward the side plate side,
A ratio of the turbo blade portion in the radial direction is formed to be larger than a ratio of the sirocco blade portion,
a blade outer diameter formed by the outer peripheral end of each of the plurality of blades is formed larger than an inner diameter of the bell mouth;
In the portion of the plurality of blades on the outer peripheral side of the inner diameter of the bell mouth in the radial direction, the ratio of the turbo blade portion in the radial direction is larger than the ratio of the sirocco blade portion. Blower. 2. The multi-blade fan according to claim 1, wherein said blade length has a constant portion between said main plate and said side plate. 3. The multi-blade blower according to claim 1, wherein the blade length is continuously changed from the main plate side to the side plate side. further comprising a motor having a motor shaft connected to the main plate and arranged outside the scroll casing;
The outer diameter of the motor is
The multi-blade fan according to any one of claims 1 to 3, wherein the inner diameter of the blades of the plurality of blades on the main plate side is larger than the blade inner diameter of the plurality of blades on the side plate side. further comprising a motor having a motor shaft connected to the main plate and arranged outside the scroll casing;
The outer diameter of the end of the motor is
The multi-blade fan according to any one of claims 1 to 3, wherein the inner diameter of the blades of the plurality of blades on the main plate side is larger than the blade inner diameter of the plurality of blades on the side plate side. An air conditioner comprising the multi-blade fan according to any one of claims 1 to 5.

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