Fan and air conditioning device

Abstract

A fan (33) comprises: a disk-shaped plate (36) that rotates around a rotation axis (X); a ring-shaped annular part (37) that is positioned relative to and spaced apart from the plate (36) in the axial direction of the rotation axis (X); and a vane (35), one end (35a) of which in the axial direction of the rotation axis (X) is joined to the plate (36), and the other end (35b) of which in the axial direction of the rotation axis (X) is joined to the annular part (37). A section of the vane (35) has a porous portion (51). A joint section (35e) between the vane (35) and the plate (36) or a joint section (35f) between the vane (35) and the annular part (37) is a non-porous portion (52).

Description

Fans and air conditioners

[0001] The present disclosure relates to a fan and an air conditioning apparatus.

[0002] Patent Document 1 discloses a sirocco fan, whose blades are fixed to an upper fixed frame and a lower disk. The blades of the sirocco fan are entirely made of porous material such as metal, synthetic resin, or ceramic.

[0003] Japanese Unexamined Patent Publication No. 63-032196

[0004] When a fan rotates, stress tends to concentrate at the joints between the blades and other components. In a structure in which the entire blade is made porous, as in the fan of Patent Document 1, the strength of the joints is reduced.

[0005] The present disclosure improves quietness while increasing the strength of the blades in a fan.

[0006] The first aspect relates to a fan, the fan including a disk-shaped plate (36) rotating about a rotation axis (X), an annular ring portion (37) positioned apart from the plate (36) in the axial direction of the rotation axis (X), and a blade (35) positioned between the plate (36) and the ring portion (37), the blade (35) having one end (35a) in the axial direction of the rotation axis (X) joined to the plate (36) and the other end (35b) in the axial direction joined to the ring portion (37), the blade (35) having a porous portion (51) in part, and a joint portion (35e) between the blade (35) and the plate (36) or a joint portion (35f) between the blade (35) and the ring portion (37) being a non-porous portion (52).

[0007] In the first aspect, the strength of the blades (35) can be increased by forming the non-porous portions (52) at the joint portions (35e, 35f) where stress tends to concentrate. Furthermore, since a portion of the blade is a porous portion (51), air separation can be suppressed. Suppression of air separation improves quietness. Therefore, quietness can be improved while increasing the strength of the blades (35).

[0008] In the second aspect, the porous portion (51) in the first aspect is arranged at a separation portion (35g) where air flowing along the blade (35) separates.

[0009] In the second aspect, the porous portion (51) is disposed in the separation portion (35g), thereby effectively suppressing separation of air, thereby improving noise reduction.

[0010] In the third aspect, in the first aspect, the porous portion (51) includes the leading edge (35c) of the blade (35).

[0011] In the third aspect, the leading edge (35c), which is a portion where air is likely to separate, is made of the porous portion (51), thereby effectively suppressing air separation, thereby improving noise reduction.

[0012] In a fourth aspect, in the second or third aspect, the joint portion (35e) between the blade (35) and the plate (36) is the entire one end (35a) of the blade (35), and the joint portion (35f) between the blade (35) and the annular portion (37) is the trailing edge (35d) and the other end (35b) of the blade (35). The dimension from the one end (35a) of the blade (35) to the plate (36) is defined as the blade height (H), and the dimension from the leading edge (35c) to the trailing edge (35d) of the blade (35) is defined as the blade chord length (L). The porous portion (51) is arranged in a range of 90% or less of the blade height (H) and 90% or less of the blade chord length (L) from the leading edge (35c).

[0013] In the fourth aspect, the porous portion (51) is arranged as widely as possible, thereby improving noise reduction, and the non-porous portion (52) can be arranged in a sufficient area, thereby improving the strength of the blades (35).

[0014] In the fifth aspect, in the fourth aspect, the length from the leading edge (35c) to the end of the porous portion (51) on the trailing edge (35d) side in a direction perpendicular to the axial direction is longer on the other end (35b) side than on the one end (35a) side.

[0015] In the fifth aspect, the area where the porous portion (51) is provided is narrow around the joint between the blade (35) and the plate (36), thereby improving the strength of the blade (35).

[0016] In a sixth aspect, in the fourth or fifth aspect, when viewed from the direction of rotation about the rotation axis (X), the position of the other end (35b) and the leading edge (35c) of the blade (35) is defined as a first vertex (P1), a position 90% of the blade height (H) from the first vertex (P1) is defined as a second vertex (P2), and a position 90% of the blade chord length (L) from the first vertex (P1) is defined as a third vertex (P3), and the porous portion (51) is arranged in a range connecting the first vertex (P1), the second vertex (P2), and the third vertex (P3) by a straight line or a curve.

[0017] In the sixth aspect, the porous portion (51) is disposed over most of the leading edge, thereby improving noise reduction. The non-porous portion (52) can be disposed as widely as possible around the joints (35e, 35f), thereby improving the strength of the blade (35).

[0018] In a seventh aspect, the fan in any one of the first to sixth aspects is a centrifugal fan.

[0019] In the seventh aspect, a centrifugal fan generates a relatively large centrifugal force. Stress due to centrifugal force is likely to concentrate at the joints (35e, 35f). By forming the joints (35e, 35f) as non-porous portions (52), the strength of the blades (35) can be ensured. Furthermore, since a portion of the blade is a porous portion (51), air separation can be suppressed. Suppression of air separation improves quietness. Therefore, quietness can be improved while increasing the strength of the blades (35) against centrifugal force.

[0020] An eighth aspect is an air conditioner including the fan according to any one of the first to seventh aspects.

[0021] Fig. 1 is a longitudinal cross-sectional view showing the schematic configuration of an air conditioning apparatus. Fig. 2 is a side view of a fan. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a perspective view of the fan. Fig. 5 is a side view of a blade seen from the direction of rotation about the rotation axis. Fig. 6 is an enlarged view of a blade seen from the axial direction of the rotation axis. Fig. 7 is a side view of a blade according to Modification 1. Fig. 8 is a side view of a blade according to Modification 2. Fig. 9 is a side view of a blade according to Modification 3. Fig. 10 is a side view of a blade according to another embodiment.

[0022] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical concept of the present disclosure. Since the drawings are intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding.

[0023] (1) Air Conditioning Apparatus The fan device (30) is applied to an air conditioner (10). The air conditioner (10) conditions indoor air. The air conditioner (10) of this embodiment adjusts the temperature of the air. The air conditioner (10) is an outdoor air conditioning unit that supplies outdoor air to the room. As shown in FIG. 1 , the air conditioner (10) has an indoor unit (10a) placed in the ceiling. The indoor unit (10a) has an air conditioning casing (11), and a fan device (30) and an indoor heat exchanger (17) housed in the air conditioning casing (11).

[0024] The air conditioning casing (11) has a horizontally elongated rectangular box shape. The air conditioning casing (11) has a first side plate (12) and a second side plate (13) facing each other. An outside air inlet (14) is formed in the first side plate (12), and an air supply port (15) is formed in the second side plate (13). The outside air inlet (14) communicates with an outdoor space via an intake duct. The air supply port (15) communicates with an indoor space via an intake duct. An air passage (16) through which air flows is formed inside the air conditioning casing (11) from the outside air inlet (14) to the air supply port (15).

[0025] The fan device (30) is disposed in the air passage (16). Strictly speaking, the fan device (30) is a sirocco type fan device.

[0026] The indoor heat exchanger (17) exchanges heat between air and a refrigerant. The indoor heat exchanger (17) is connected to a refrigerant circuit. The refrigerant circuit includes a compressor, an outdoor heat exchanger, an expansion valve, and the indoor heat exchanger (17). The refrigerant circuit performs a vapor compression refrigeration cycle by circulating the refrigerant. The compressor and the outdoor heat exchanger are provided in the outdoor unit.

[0027] During cooling operation, the compressor and the fan device (30) are operated, and the indoor heat exchanger (17) functions as an evaporator. Air flowing into the air passage (16) from the outdoor air inlet (14) passes through the indoor heat exchanger (17). In the indoor heat exchanger (17), the air is cooled by the evaporating refrigerant. The air cooled in the indoor heat exchanger (17) is supplied to the indoor space via the air supply port (15) and the air supply duct.

[0028] During heating operation, the compressor and the fan device (30) are operated, and the indoor heat exchanger (17) functions as a condenser (heat radiator). Air flowing into the air passage (16) from the outdoor air inlet (14) passes through the indoor heat exchanger (17). In the indoor heat exchanger (17), the air is heated by the condensing refrigerant. The air heated in the indoor heat exchanger (17) is supplied to the indoor space via the air supply port (15) and the air supply duct.

[0029] (2) Overview of the Fan The fan device (30) shown in Figures 1 to 3 includes a motor (31), a drive shaft (32) that is rotationally driven by the motor (31), a fan (33) connected to the drive shaft (32), and a casing (40) that houses the fan (33). The motor (31) is supported by a motor support base (34). The drive shaft (32) is connected to the motor (31) and extends horizontally. The fan device (30) is of a vertically-mounted type in which the drive shaft (32) of the motor (31) extends horizontally.

[0030] The fan (33) is connected to the drive shaft (32). The fan (33) is a centrifugal fan. The fan (33) has a plurality of blades (35) arranged in the direction of rotation. In the case of Figure 3, the fan (33) rotates counterclockwise around the rotation axis (X).

[0031] The casing (40) has a cylindrical casing body (40a) and a discharge part (40b) extending from the outer periphery of the casing body (40a) in a tangential direction of the casing body (40a).

[0032] The casing body (40a) has a first wall (41), a second wall (42), and a peripheral wall (43). The first wall (41) is formed at one axial end of the casing body (40a), and the second wall (42) is formed at the other axial end of the casing body (40a). The first wall (41) is located on the motor (31) side with the fan (33) interposed therebetween, and the second wall (42) is located on the opposite side of the fan (33) from the motor (31). The first wall (41) and the second wall (42) are disk-shaped. A first suction port (47) is formed in the center of the first wall (41). A second suction port (44) is formed in the center of the second wall (42). The peripheral wall (43) surrounds the outer periphery of the fan (33). The peripheral wall (43) has a substantially arc-shaped configuration that follows the fan (33).

[0033] The discharge section (40b) forms a duct communicating with the interior of the casing body (40a). The discharge section (40b) is formed in a rectangular tubular shape with both axial ends open. One axial end opening of the discharge section (40b) connects to the interior of the casing body (40a). The other axial end opening of the discharge section (40b) forms an outlet (45). A fan flow path (46) through which air flows is formed within the casing (40), extending from the first suction inlet (47) and the second suction inlet (44) to the outlet (45).

[0034] (3) Structure of the Fan The fan (33) shown in Fig. 4 includes a plurality of blades (35), a disk-shaped plate (36), a first ring (37) positioned apart from the plate (36) in the axial direction of the rotation shaft (X), and a second ring (38) positioned between the plate (36) and the first ring (37) in the axial direction of the rotation shaft (X). The blades (35), the first ring (37), and the second ring (38) are arranged on both sides of the plate (36) in the axial direction of the rotation shaft (X).

[0035] The blades (35) are arranged parallel to the axial direction of the rotation shaft (X). The blades (35) are located between the plate (36) and the first ring (37). One end (35a) of the blades (35) in the axial direction of the rotation shaft (X) is joined to the plate (36), and the other end (35b) in the axial direction is joined to the first ring (37). In the radial direction perpendicular to the axial direction of the rotation shaft (X), the blades (35) have a leading edge (35c) on the inside and a trailing edge (35d) on the outside. In this specification, in the direction of the axial direction of the rotation shaft (X) of the blades (35), the plate (36) side is referred to as one end side, and the first ring (37) side is referred to as the other end side.

[0036] The plate (36) has a boss (36a) at its center. The boss (36a) is connected to the drive shaft (32). The joint portion (35e) between the blade (35) and the plate (36) is the entire one end (35a) of the blade (35). The blade (35) and the plate (36) are joined together by integral molding or by an insert.

[0037] The first ring (37) is disposed concentrically with the plate (36). In the radial direction, the first ring (37) is disposed outside the blades (35). The joint portion (35f) between the blades (35) and the first ring (37) is the trailing edge (35d) and the other end (35b) of the blades (35). The blades (35) and the first ring (37) are integrally joined by integral molding or welding.

[0038] The second ring (38) is disposed concentrically with the plate (36). In the axial direction of the rotation axis (X), the second ring (38) is located at the center of the blade (35). In the radial direction, the second ring (38) is disposed outside the blade (35). The second ring (38) is joined to the trailing edge (35d) of the blade (35). The blade (35) and the second ring (38) are joined together by integral molding or welding.

[0039] (4) Blade Structure The blade (35) has a porous portion (51) in part. The porous portion (51) has a plurality of fine pores that communicate from the positive pressure side to the negative pressure side of the blade (35). The porous portion (51) is made of resin, ceramics, metal, or the like. The resin is, for example, a foamed resin. The metal or ceramic is a porous sintered body. The average diameter of the pores (voids) in the porous portion (51) is, for example, in the range of 15 μm to 300 μm. The porosity of the porous portion (51) (= void volume / total volume of the porous portion) is, for example, in the range of 35% to 90%.

[0040] In the blade (35), the portions other than the porous portion (51) are non-porous portions (52). The joint portion (35e) between the blade (35) and the plate (36) and the joint portion (35f) between the blade (35) and the first ring (37) are non-porous portions (52). The joint portion between the blade (35) and the second ring (38) is also non-porous portion (52). The non-porous portion (52) does not have holes that communicate from the positive pressure side to the negative pressure side and is solid. The non-porous portion (52) is made of, for example, a synthetic resin. The strength of the non-porous portion (52) is greater than that of the porous portion (51). The porous portion (51) and the non-porous portion (52) are integrally formed by, for example, insert molding, bonding, or fitting.

[0041] The porous portion (51) is disposed at a separation portion (35g) where air flowing along the blade (35) separates. When air separates at the separation portion (35g), a vortex is likely to occur. When a vortex occurs, the air flow is significantly disturbed, resulting in noise generation. In this embodiment, in order to solve the above problem, the porous portion (51) is provided at the separation portion (35g).

[0042] As shown in Figures 5 and 6, the separation portion (35g) is the leading edge (35c) and the apex (35h) of the camber on the negative pressure side of the blade (35). In the case of a sirocco fan as in this embodiment, air is particularly likely to separate on the negative pressure side of the leading edge (35c) as it flows from the inside to the outside in the radial direction. For this reason, the porous portion (51) is disposed over almost the entire leading edge (35c). Note that the porous portion (51) may include only a portion of the separation portion (35g). The entire separation portion (35g) does not have to be the porous portion (51).

[0043] The installation range of the porous portion (51) will be described in detail. As shown in Figures 5 and 6, the dimension from the other end (35b) of the blade (35) to the plate (36) is defined as the blade height (H). The dimension from the leading edge (35c) to the trailing edge (35d) of the blade (35) is defined as the blade chord length (L). When viewed from the direction of rotation, the position of the other end (35b) and the leading edge (35c) of the blade (35) is defined as the first vertex (P1). In the blade (35), the position from the first vertex (P1) to 90% of the blade height (H) along the axial direction of the rotation axis (X) is defined as the second vertex (P2). In the blade (35), the position from the first vertex (P1) to 90% of the blade chord length (L) is defined as the third vertex (P3).

[0044] As shown in FIG. 5 , the porous portion (51) is disposed in a range that is 90% or less of the blade height (H) from the other end (35b) and 90% or less of the blade chord length (L) from the leading edge (35c). More specifically, the porous portion (51) is disposed in a specific range (R) that is formed by connecting a first vertex (P1), a second vertex (P2), and a third vertex (P3) by a straight line or a curve. In this embodiment, the porous portion (51) is disposed throughout the specific range (R). In this embodiment, the shape of the porous portion (51) is triangular when viewed from the direction of rotation. However, the shape of the porous portion (51) is not limited to a triangular shape.

[0045] In this embodiment, the length in the radial direction from the leading edge (35c) to the trailing edge of the porous portion (51) is longer at the other end (35b) of the blade (35) than at the one end (35a) of the blade (35). More specifically, the length from the leading edge (35c) to the trailing edge of the porous portion (51) is longer as it approaches the other end (35b) of the blade (35) and is longest at the other end (35b) of the blade (35).

[0046] (5) Advantages of the Embodiment In this embodiment, the blades (35) have a porous portion (51) in part, and the joint portion (35e) between the blades (35) and the plate (36) and the joint portion (35f) between the blades (35) and the first ring (37) are non-porous portions (52). By making the joint portions (35e, 35f), where stress tends to concentrate, non-porous portions (52), strength against centrifugal force can be increased. Furthermore, because the blades (35) are partially porous portions (51), air separation can be suppressed. Suppressing air separation improves the quietness of the fan device (30). Therefore, the quietness of the fan device (30) can be improved while increasing the strength of the blades (35) against centrifugal force.

[0047] In this embodiment, the porous portion (51) is disposed at a separation portion (35g) where air flowing along the blades (35) separates. By disposing the porous portion (51) at the separation portion (35g), separation of air is effectively suppressed. Therefore, the quietness of the fan device (30) can be improved.

[0048] In this embodiment, the porous portion (51) includes the leading edge (35c) of the blade (35). By forming the leading edge (35c), which is a portion where air is likely to separate, as the porous portion (51), separation of air is effectively suppressed. Therefore, the quietness of the fan device (30) can be improved.

[0049] In this embodiment, the porous portion (51) is disposed in a range of 90% or less of the blade height (H) from the other end (35b) of the blade (35) and 90% or less of the blade chord length (L) from the leading edge (35c). Since the porous portion (51) is disposed as widely as possible, the noise level of the fan device (30) can be improved.

[0050] In this embodiment, the length from the leading edge (35c) to the end of the porous portion (51) on the trailing edge (35d) side in the radial direction of the rotation axis (X) is longer at the other end (35b) side than at the one end (35a) side. The area where the porous portion (51) is installed is narrow around the joint portion (35e) between the blade (35) and the plate (36). This improves the strength of the blade (35) against centrifugal force.

[0051] In the sixth aspect, the porous portion (51) is disposed in an area defined by a straight line or a curve connecting the first vertex (P1), the second vertex (P2), and the third vertex (P3). Since the porous portion (51) is disposed over most of the leading edge (35c), the quietness of the fan device (30) can be improved. Since the non-porous portion (52) can be disposed as widely as possible around the joints (35e, 35f), the strength of the blades (35) against centrifugal force can be improved.

[0052] (6) Modifications The above-described fan device (30) may have the following modified configurations: Differences from the above-described embodiment will be described below.

[0053] (6-1) Modification 1 Modification 1 differs in the range in which the porous portion (151) is provided. As shown in Fig. 7 , the porous portion (151) is not provided in the specific range (R) on the other end (35b) side and the trailing edge (35d) side of the blade (35). A non-porous portion (152) is arranged in this part of the specific range (R).

[0054] In this first modification, the non-porous portion (152) is wider around the joint (35f) between the blade (35) and the first ring (37). This improves the strength of the blade (35) against centrifugal force. Furthermore, in this first modification, the porous portion (151) accounts for the majority of the peeled portion (35g), thereby improving the quietness of the fan device (30).

[0055] (6-2) Modification 2 Modification 2 differs in the installation range of the porous portion (251). As shown in FIG. 8 , in Modification 2, the porous portion (251) is located within a range defined by connecting the first vertex (P1) and the second vertex (P2) with a straight line, connecting the first vertex (P1) and the third vertex (P3) with a straight line, and connecting the second vertex (P2) and the third vertex (P3) with a curve. Specifically, the shape of the porous portion (251) as viewed from the direction of rotation is a quarter ellipse with the long side extending from the first vertex (P1) to the second vertex (P2) and the short side extending from the first vertex (P1) to the third vertex (P3). In Modification 2, the length from the leading edge (35c) to the trailing edge of the porous portion (251) increases toward the other end (35b) of the blade (35) and is longest at the other end (35b) of the blade (35).

[0056] In the present modification 2, the area of ​​the porous portion (251) can be made as wide as possible at the apex (35h) of the warp on the negative pressure side of the blade (35). This can improve the quietness of the fan device (30). Furthermore, in the present modification 2, the joint portions (35e, 35f) are non-porous portions (252), which can improve the strength of the blade (35) against centrifugal force.

[0057] (6-3) Modification 3 Modification 3 differs in the installation range of the porous portion (351). As shown in Fig. 9 , the shape of the porous portion (351) as viewed in the direction of rotation is a rectangle with the long sides extending from the first vertex (P1) to the second vertex (P2) and the short sides extending from the first vertex (P1) to the third vertex (P3).

[0058] In the third modification, the area of ​​the porous portion (351) can be made as wide as possible at the apex (35h) of the warp on the negative pressure side of the blade (35). This can improve the quietness of the fan device (30). Furthermore, in the third modification, the joint portions (35e, 35f) are non-porous portions (352), which can improve the strength of the blade (35) against centrifugal force.

[0059] (7) Other Embodiments The porous portion (451) may be located in a range between the third apex (P3) and the leading edge (35c) at the other end (35b) of the blade (35). In other words, the portion between the third apex (P3) and the trailing edge (35d) at the other end (35b) of the blade (35) may be the non-porous portion (452). As shown in Fig. 10 , in a range closer to the one end (35a) than the other end (35b) of the blade (35), the porous portion (451) may extend over a range greater than 90% of the blade chord length (L) from the leading edge (35c).

[0060] The joint portion (35f) between the blade (35) and the first ring (37) may be the entire other end (35b) of the blade (35) rather than a part of the other end (35b). In this case, the entire other end (35b) of the blade (35) may be made non-porous.

[0061] The portion of the fan (33) that is to be the non-porous portion (52, 152, 252, 352, 452) may be either the joint portion (35e) between the blade (35) and the plate (36) or the joint portion (35f) between the blade (35) and the first ring (37).

[0062] Although a centrifugal fan has been exemplified as the fan (33), the fan (33) may also be a cross-flow fan. By employing the configuration of this embodiment in a cross-flow fan, it is possible to obtain the effect of increasing the strength of the blades (35) while improving noise reduction. In the case of a cross-flow fan, some of the connected fans may have both one end (35a) and the other end (35b) of the blades (35) joined to the annular portion. In this case, for some of the fans, the joint portions of both one end (35a) and the other end (35b) of the blades (35) joined to the annular portion may be non-porous.

[0063] The fan unit (30) may be of a horizontal type with its rotation axis (X) extending vertically, or may be arranged so that its rotation axis (X) extends in another direction.

[0064] The fan device (30) may be a single-side intake fan device in which the intake port is formed only in the second wall (42).

[0065] The air conditioner (10) may be an air purifier that purifies the air in a target space, a ventilation device that ventilates the target space, or a humidity control device that adjusts the humidity in the target space.

[0066] The indoor unit (10a) may be of a ceiling-suspended type, a wall-mounted type, or a floor-standing type.

[0067] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired.

[0068] The above-mentioned descriptions such as "first," "second," "third," etc. are used to distinguish the words to which these descriptions are attached, and do not limit the number or order of the words.

[0069] As described above, the present disclosure is useful for fans.

[0070] 33 Fan 35 Blade 35a One end 35b Other end 35c Leading edge 35d Trailing edge 35e Joint portion 35f Joint portion 35g Separation portion 36 Plate 37 First ring (annular portion) 51 Porous portion 52 Non-porous portion 151 Porous portion 152 Non-porous portion 251 Porous portion 252 Non-porous portion 351 Porous portion 352 Non-porous portion 451 Porous portion 452 Non-porous portion H Blade height L Blade chord length P1 First vertex P2 Second vertex P3 Third vertex X Rotation axis

Claims

1. A fan comprising: a disk-shaped plate (36) rotating about a rotation axis (X); an annular ring portion (37) located away from the plate (36) in the axial direction of the rotation axis (X); and a blade (35) located between the plate (36) and the ring portion (37), the blade (35) having one end (35a) in the axial direction of the rotation axis (X) joined to the plate (36) and the other end (35b) in the axial direction joined to the ring portion (37), wherein the blade (35) has a porous portion (51, 151, 251, 351, 451), and a joint portion (35e) between the blade (35) and the plate (36) or a joint portion (35f) between the blade (35) and the ring portion (37) is a non-porous portion (52, 152, 252, 352, 452).

2. A fan according to claim 1, wherein the porous portion (51, 151, 251, 351, 451) is disposed at a separation portion (35g) where air flowing along the blade (35) separates.

3. A fan according to claim 1, wherein the porous portion (51, 151, 251, 351, 451) includes a leading edge (35c) of the blade (35).

4. A fan according to claim 2 or 3, wherein a joint portion (35e) between the blade (35) and the plate (36) is the entire one end (35a) of the blade (35), and a joint portion (35f) between the blade (35) and the annular portion (37) is the trailing edge (35d) and the other end (35b) of the blade (35), and wherein a blade height (H) is a dimension from the plate (36) to the other end (35b) of the blade (35) and a blade chord length (L) is a dimension from the leading edge (35c) to the trailing edge (35d) of the blade (35), and the porous portion (51, 151, 251, 351) is located in a range that is 90% or less of the blade height (H) and is from the leading edge (35c) to 90% or less of the blade chord length (L).

5. A fan as claimed in claim 4, wherein in a direction perpendicular to the axial direction, the length from the leading edge (35c) to the end of the porous portion (51, 151, 251, 351) on the trailing edge (35d) side is longer on the other end (35b) side than on the one end (35a) side.

6. A fan according to claim 4 or 5, wherein, when viewed in the direction of rotation about the rotation axis (X), a first vertex (P1) is defined as a position of the other end (35b) and the leading edge (35c) of the blade (35), a second vertex (P2) is defined as a position that is 90% of the blade height (H) from the first vertex (P1), and a third vertex (P3) is defined as a position that is 90% of the blade chord length (L) from the first vertex (P1), and the porous portion (51, 151, 251, 351) is disposed in a range connecting the first vertex (P1), the second vertex (P2), and the third vertex (P3) by a straight line or a curve.

7. The fan according to any one of claims 1 to 6, which is a centrifugal fan.

8. An air conditioner comprising a fan (33) according to any one of claims 1 to 7.

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