Fan unit and air cleaner

Abstract

This fan unit (30) comprises: a fan motor (40) having a motor body (41) and an output shaft (42) extending from the motor body (41) to both sides in a rotational axis direction; a first impeller (31) connected to one end of the output shaft (42); a second impeller (32) connected to the other end of the output shaft (42); a first fan housing (33) accommodating the first impeller (31); and a second fan housing (34) accommodating the second impeller (32). At least one among the first fan housing (33) and the second fan housing (34) has an accommodation space (47) accommodating the fan motor (40).

Description

Fan units and air purifiers

[0001] The present disclosure relates to a fan unit and an air purifier.

[0002] Patent Document 1 discloses an air purifier having a fan unit including a fan motor. In the fan unit described in Patent Document 1, the fan motor is supported on a casing of the air purifier at a position separate from a fan housing that houses an impeller.

[0003] Patent No. 5862717

[0004] The fan unit described in Patent Document 1 requires a relatively large space in the direction of the rotation axis of the fan motor due to the support members required to support the fan motor, so there is room for improvement in terms of making the fan unit more compact.

[0005] The present disclosure aims to make the fan unit more compact.

[0006] The first aspect relates to a fan unit, the fan unit comprising: a fan motor (40) having a motor body (41) and output shafts (42) extending from the motor body (41) on both sides in a rotation axis direction, a first impeller (31) connected to one of the output shafts (42), a second impeller (32) connected to the other output shaft (42) and arranged together with the first impeller (31) across the fan motor (40), a first fan housing (33) accommodating the first impeller (31), and a second fan housing (34) accommodating the second impeller (32), wherein at least one of the first fan housing (33) and the second fan housing (34) has an accommodation space (47) for accommodating the fan motor (40).

[0007] In the first aspect, the fan motor (40) is accommodated in the fan housing (33, 34), and thus the fan motor (40), the impellers (31, 32), and the fan housing (33, 34) can be integrated into one unit, thereby enabling the fan unit (30) to have a compact configuration even if it has a plurality of impellers (31, 32).

[0008] In the second aspect, in the first aspect, the first fan housing (33) forms a part of the accommodation space (47), and the second fan housing (34) forms the remainder of the accommodation space (47).

[0009] In the second aspect, by dividing the accommodation space (47), the load when supporting the motor body (41) in the accommodation space (47) and the load generated when the fan motor (40) is driven can be divided between the first fan housing (33) and the second fan housing (34), thereby making it possible to make the fan unit (30) compact and stable.

[0010] In a third aspect, in the first or second aspect, the first impeller (31) and the second impeller (32) are fastened to the output shaft (42), and a first distance (L1) which is the distance from the end of the fastening portion between the first impeller (31) and the output shaft (42) on the motor body (41) side to the end of the motor body (41) on the first impeller (31) side, and a second distance (L2) which is the distance from the end of the fastening portion between the second impeller (32) and the output shaft (42) on the motor body (41) side to the end of the motor body (41) on the second impeller (32) side, are each 4.4 mm or more.

[0011] There is a risk that axial vibrations of the output shaft (42) will be transmitted to the first impeller (31) and the second impeller (32) via the fastening portion. In contrast, in the third aspect, the motor body (41) is spaced apart from the first impeller (31) and the second impeller (32) by an appropriate distance, thereby suppressing transmission of vibrations to the first impeller (31) and the second impeller (32). Suppression of transmission of vibrations to the first impeller (31) and the second impeller (32) can suppress abnormal noise.

[0012] A fourth aspect is the third aspect, wherein the first distance (L1) and the second distance (L2) are each 4.4 mm to 6.0 mm.

[0013] In the fourth aspect, it is possible to appropriately separate the motor body (41) from the first impeller (31) and the second impeller (32), while saving space in the direction of the rotation axis of the fan motor (40).

[0014] A fifth aspect is any one of the first to fourth aspects, in which a vibration-isolating member (46) is provided on the outer periphery of the motor body (41), and the first fan housing (33) and the second fan housing (34) have contact portions (35c, 35d, 36c, 36d) that come into contact with the vibration-isolating member (46).

[0015] In the fifth aspect, the contact portions (35c, 35d, 36c, 36d) can press the vibration-isolating member (46), thereby preventing the motor body (41) from moving together with the vibration-isolating member (46). This allows the vibration of the motor body (41) to be appropriately absorbed by the vibration-isolating member (46).

[0016] In a sixth aspect, in the fifth aspect, the contact portions (35c, 35d, 36c, 36d) have curved surfaces, and the vibration-proof member (46) comes into contact with the curved surfaces of the contact portions (35c, 35d, 36c, 36d).

[0017] In the sixth aspect, the contact area with the vibration-isolating member (46) can be reduced, thereby suppressing transmission of vibration from the vibration-isolating member (46) to the contact portions (35c, 35d, 36c, 36d), thereby improving the vibration-isolating effect of the entire fan unit.

[0018] In a seventh aspect, in the sixth aspect, the radius of curvature of the curved surface of the contact portion (35c, 35d, 36c, 36d) is larger than the radius of curvature of the contact portion of the vibration-isolating member (46).

[0019] In the seventh aspect, the contact area with the vibration-isolating member (46) can be made as small as possible, thereby improving the vibration-isolating effect of the entire fan unit.

[0020] An eighth aspect is the fifth to seventh aspect, wherein the vibration-isolating member (46) is an elastic body.

[0021] In the eighth aspect, the vibration-isolating member (46) is made of an elastic material, thereby further improving the vibration-isolating effect.

[0022] A ninth aspect is any one of the first to eighth aspects, wherein the first fan housing (33) has a first rib (35) that is provided to surround the fan motor (40) and extends toward the second fan housing (34), the second fan housing (34) has a second rib (36) that is provided to surround the fan motor (40) and extends toward the first fan housing (33), and the first rib (35) and the second rib (36) overlap in a direction perpendicular to the direction of the rotation axis.

[0023] In the ninth aspect, the first rib (35) and the second rib (36) overlap in a direction perpendicular to the rotation axis (X), thereby preventing foreign matter such as water from entering the storage space (47).

[0024] A tenth aspect is any one of the first to ninth aspects, wherein the first fan housing (33) and the second fan housing (34) have positioning portions (35e, 36c, 36d) for positioning when they are coupled to each other.

[0025] In the tenth aspect, positioning of the first fan housing (33) and the second fan housing (34) when they are joined together becomes easy, and assembly of the fan unit can be facilitated.

[0026] An eleventh aspect is any one of the first to tenth aspects, wherein the appearance of the first fan housing (33) and the appearance of the second fan housing (34) are asymmetric with respect to a plane perpendicular to the rotation axis direction.

[0027] In the eleventh aspect, the configuration of the first fan housing (33) and the configuration of the second fan housing (34) can be made significantly different. For example, the outlet (33d) of the first fan housing (33) and the outlet (34d) of the second fan housing (34) can be oriented in different directions, or the sizes of the spaces for accommodating the impellers (31, 32) can be made different. The configuration of the fan unit can be flexibly changed depending on the purpose.

[0028] A twelfth aspect is any one of the first to eleventh aspects, wherein the radial length (W3) of the first impeller (31) and the second impeller (32) is at least three times the thickness (L3) of the fan motor (40).

[0029] In the twelfth aspect, the diameter of the impellers (31, 32) can be increased while the thickness of the fan motor (40) can be reduced, thereby achieving a compact fan unit with a large air volume.

[0030] A thirteenth aspect is the air conditioner according to any one of the first to twelfth aspects, wherein the fan motor (40) is an axial gap motor.

[0031] In the thirteenth aspect, an axial gap type motor is used as the fan motor (40), thereby making it possible to realize a compact fan unit with a large air volume.

[0032] A fourteenth aspect is directed to an air purifier, comprising: the fan unit (30) according to any one of the first to thirteenth aspects; and a casing (11) that houses the fan unit (30).

[0033] In the fourteenth aspect, by using a fan unit (30) in which the fan motor (40) is housed in the fan housing (33, 34), it is not necessary to provide a separate support for the fan motor (40), thereby saving space. The space saved can be used to increase the installation area of ​​the impellers (31, 32), thereby improving the air volume. Furthermore, compared to when the fan motor (40) is disposed outside the fan housing (33, 34), the impellers (31, 32) can be disposed closer to the inlets (15, 16). This facilitates the intake of air from the target space, thereby improving the air purification effect.

[0034] In a fifteenth aspect, in the fourteenth aspect, the casing (11) has main suction ports (15, 16) for sucking air on both sides in the direction of the rotation axis, and filters (23, 24, 25, 26) are arranged in an air passage (P) from the main suction ports (15, 16) to the fan unit (30).

[0035] In the fifteenth aspect, the total area of ​​the filters (23, 24, 25, 26) can be increased, thereby suppressing pressure loss. The suppression of pressure loss allows for a large air volume. Furthermore, compared to a case where the filters (23, 24, 25, 26) are disposed downstream of the outlets (33d, 34d) of the fan unit (30), the size of the casing (11) in the direction perpendicular to the rotation axis (X) of the fan motor (40) can be minimized.

[0036] In the sixteenth aspect, in the fifteenth aspect, the casing (11) has an auxiliary suction port (19) that draws in air from a direction perpendicular to both the rotation axis direction and the vertical direction, and a relay passage (19a) that flows the air drawn in from the auxiliary suction port (19) toward the upstream side of the filters (23, 24, 25, 26).

[0037] In the sixteenth aspect, air can be sucked in from a plurality of locations and passed through the filters (23, 24, 25, 26) appropriately, thereby improving the efficiency of air purification.

[0038] A seventeenth aspect is the fifteenth or sixteenth aspect, wherein the casing (11) has a grill (71) between the filter (25, 26) and the fan unit (30), and includes fixing portions (73, 74) that fix the filter (25, 26) in a state aligned with the grill (71).

[0039] In the seventeenth aspect, the filters (25, 26) can be prevented from unexpectedly moving, and the air purification effect can be maintained at a high level.

[0040] An eighteenth aspect is any one of the fifteenth to seventeenth aspects, further comprising an active species generation section (27, 28) that generates active species, and the casing (11) has a discharge passage (80, 87) that discharges the active species generated in the active species generation section (27, 28) upstream of the filter (23, 24, 25, 26).

[0041] In the eighteenth aspect, even if the filters (23, 24, 25, 26) are located upstream of the impellers (31, 32), the active species can be attached to the filters (23, 24, 25, 26), thereby improving the air purification effect.

[0042] FIG. 1 is a perspective view showing the appearance of an air purifier according to an embodiment. FIG. 2 is a schematic diagram showing the interior of the air purifier as viewed from the front. FIG. 3 is a schematic diagram showing the interior of the air purifier as viewed from the right. FIG. 4 is a perspective view of a fan unit. FIG. 5 is an exploded perspective view of the fan unit. FIG. 6 is a cross-sectional view corresponding to line VI-VI in FIG. 4. FIG. 7 is an enlarged view of region VII in FIG. 6. FIG. 8 is a view of the first fan housing as viewed from the motor side. FIG. 9 is a view of the second fan housing as viewed from the motor side. FIG. 10 is an enlarged view of a positioning portion between the first fan housing and the second fan housing. FIG. 11 is a cross-sectional view showing contact portions between a vibration-damping member of the motor and the first and second fan housings. FIG. 12 is a side view of a left grill. FIG. 13 is a cross-sectional view corresponding to line XIII-XIII in FIG. 12. FIG. 14 is a cross-sectional view corresponding to line XIV-XIV in FIG. 13. FIG. 15 is a cross-sectional view corresponding to line XV-XV in FIG. 12. Fig. 16 is a cross-sectional view corresponding to line XVI-XVI in Fig. 12. Fig. 17 is a cross-sectional view corresponding to line XVII-XVII in Fig. 12. Fig. 18 is a cross-sectional view cut along a plane passing through the front discharge holes and the rear discharge holes. Fig. 19 is a graph showing the relationship between the first distance and the second distance and the noise level. Fig. 20 is a plan view showing a fan unit according to a modified example.

[0043] 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.

[0044] (1) Overall Configuration of Air Purifier The overall configuration of an air purifier having a fan unit will be described with reference to Figures 1 and 2. In the following description, terms such as "upper," "lower," "front," "rear," "right," and "left" generally refer to the directions indicated by the arrows in Figure 1.

[0045] The air purifier (10) of this embodiment purifies the air in an indoor space (S), which is a target space. In addition, the air purifier (10) humidifies the air in the indoor space (S). The air purifier (10) has a casing (11). The air purifier (10) has, inside the casing (11), an air purification unit (20) that purifies the air and a humidification unit (50) that humidifies the purified air.

[0046] (1-1) Casing As shown in Fig. 1, the casing (11) is formed in the shape of a hollow box. The casing (11) is formed in the shape of a vertically long rectangular parallelepiped. The casing (11) has a top plate (11a), a bottom plate (11b), a front plate (11c), a rear plate (11d), a right side plate (11e), and a left side plate (11f).

[0047] An air outlet (12) is formed in the top plate (11a). The air outlet (12) is rectangular and located slightly rearward of the top plate (11a). Two flaps (13) are provided in the air outlet (12). The flaps (13) are plate-shaped and extend across both the left and right ends of the air outlet (12). The flaps (13) open and close the air outlet (12) and adjust the direction of the air blown out.

[0048] An operation panel (14) is provided on the top plate (11a). The operation panel (14) is located near the front of the top plate (11a). A user can operate the operation panel (14) to input the operation mode and various settings of the air purifier (10).

[0049] A first suction port (15) is formed in the right side plate (11e). The first suction port (15) is rectangular and is formed in the lower part of the right side plate (11e). An openable / closable lid (17) is provided in the upper part of the right side plate (11e). The openable / closable lid (17) opens and closes an access opening (18) for the tank (52) of the humidification unit (50). A drawer opening (17a) is formed in the upper part of the openable / closable lid (17). A user puts their hand on the drawer opening (17a) and removes the openable / closable lid (17). This opens the access opening (18). The user can remove the tank (52) from the casing (11) through the access opening (18).

[0050] The left side plate (11f) is formed with a second suction port (16). The second suction port (16) is rectangular and is formed in the lower part of the left side plate (11f).

[0051] A third suction port (19) is formed at the lower end of the front plate (11c). The third suction port (19) extends horizontally across both the left and right ends of the casing (11). As shown in FIG. 2, the casing (11) has an intermediate passage (19a) that guides the air sucked through the third suction port (19). The intermediate passage (19a) guides the air sucked through the third suction port (19) upstream of HEPA filters (23, 24) described below. The air guided into the intermediate passage (19a) is discharged through the air discharge port (83b) (see FIG. 12).

[0052] As shown in Figure 2, an air passage (P) is formed inside the casing (11). The first suction inlet (15), the second suction inlet (16), and the third suction inlet (19) form an inlet end of the air passage (P). The outlet (12) forms an outlet end of the air passage (P).

[0053] (1-2) Air Purification Unit The air purification unit (20) is located at the bottom of the air passage (P). The air purification unit (20) purifies the air sucked through the first suction inlet (15), the second suction inlet (16), and the third suction inlet (19). The air purification unit (20) has, in order from the upstream side of the air passage (P), prefilters (21, 22), HEPA filters (23, 24), deodorizing filters (25, 26), and a fan unit (30). In addition, the air purification unit (20) has discharge units (27, 28).

[0054] (1-2-1) Prefilter As shown in Fig. 2, the casing (11) is provided with two prefilters, a first prefilter (21) and a second prefilter (22). The first prefilter (21) is disposed in the first suction inlet (15), and the second prefilter (22) is disposed in the second suction inlet (16). The first prefilter (21) and the second prefilter (22) capture relatively large amounts of dust in the air.

[0055] (1-2-2) HEPA Filter The casing (11) is provided with two HEPA filters: a first HEPA filter (23) (High Efficiency Particulate Air Filter) and a second HEPA filter (24). The first HEPA filter (23) is disposed between the first prefilter (21) and the first deodorizing filter (25). The second HEPA filter (24) is disposed between the second prefilter (22) and the second deodorizing filter (26). The first HEPA filter (23) and the second HEPA filter (24) are formed in a plate shape with their thickness direction aligned horizontally. The first HEPA filter (23) and the second HEPA filter (24) have an electrostatic function that captures particles by electrostatic force. An antibacterial agent is added to the first HEPA filter (23) and the second HEPA filter (24). The first HEPA filter (23) and the second HEPA filter (24) may have a laminated structure in which two or more filters are stacked in the direction of air passage.

[0056] (1-2-3) Deodorizing Filters The casing (11) is provided with two deodorizing filters, a first deodorizing filter (25) and a second deodorizing filter (26). The first deodorizing filter (25) is disposed between the first HEPA filter (23) and the fan unit (30). The second deodorizing filter (26) is disposed between the second HEPA filter (24) and the fan unit (30). The first deodorizing filter (25) and the second deodorizing filter (26) are formed in the shape of a plate whose thickness direction corresponds to the vertical direction. The first deodorizing filter (25) and the second deodorizing filter (26) are adsorbing parts that adsorb harmful substances and odorous substances in the air. The first deodorizing filter (25) and the second deodorizing filter (26) have a base material through which air can pass and an adsorbent material such as activated carbon supported on the base material.

[0057] (1-2-4) Fan Unit The fan unit (30) is located in the center in the left-right direction within the casing (11). The fan unit (30) is arranged in the lower part of the air passage (P). The fan unit (30) is arranged in the lower part of the air passage (P). The fan unit (30) transports air in the air passage (P). The fan unit (30) is a unit having a centrifugal fan, specifically a sirocco fan. The fan unit (30) is a double-suction type in which suction portions are formed at both ends of the axial direction of the drive shaft (rotation shaft of the impeller). The blowing portion of the fan unit (30) faces upward. The fan unit (30) has a fan motor (40) that drives the impeller. When the fan unit (30) is operated, air from the target space is sucked into the air passage (P) through the first suction inlet (15), the second suction inlet (16), and the third suction inlet (19). The air flowing through the air passage (P) is blown out into the target space through the outlet (12). The detailed configuration of the fan unit (30) will be described later.

[0058] (1-2-5) Discharge Units The casing (11) is provided with two discharge units, a first discharge unit (27) and a second discharge unit (28). The first discharge unit (27) is disposed above the first HEPA filter (23) and the first deodorizing filter (25). The second discharge unit (28) is disposed above the second HEPA filter (24) and the second deodorizing filter (26).

[0059] The first discharge unit (27) and the second discharge unit (28) generate active species for oxidatively decomposing odorous components in the air as a result of discharge. The first discharge unit (27) and the second discharge unit (28) generate electric discharge between the tip of a linear discharge electrode and the flat surface of a plate-shaped counter electrode. The first discharge unit (27) and the second discharge unit (28) generate streamer discharge, which forms a substantially conical discharge region from the tip of the discharge electrode toward the counter electrode. The first discharge unit (27) and the second discharge unit (28) generate streamer discharge on a portion of the air discharged from the fan unit (30) to generate active species.

[0060] The first discharge unit (27) is disposed in the first discharge passage (80), and the second discharge unit (28) is disposed in the second discharge passage (87). The first discharge passage (80) is a passage for returning a portion of the air blown out from the fan unit (30) together with the active species generated by the first discharge units (27, 28) to the upstream side of the first HEPA filter (23). The second discharge passage (87) is a passage for returning a portion of the air blown out from the fan unit (30) together with the active species generated by the second discharge units (27, 28) to the upstream side of the second HEPA filter (24). The first discharge passage (80) and the second discharge passage (87) will be described in detail later.

[0061] (1-3) Humidification Unit The humidification unit (50) is disposed between the outlet of the fan unit (30) and the outlet (12) of the casing (11). The humidification unit (50) is disposed in a humidification space (51) located at the top of the air passage (P). The humidification unit (50) adds water to the air flowing through the air passage (P). As shown in FIG. 3 , the humidification unit (50) includes a tank (52), a water tray (53), and a humidification rotor (54). (1-3-1) Tank The tank (52) is a container for storing water for humidification. The tank (52) appropriately supplies water therein to the water tray (53). The tank (52) is configured to be removable from the casing (11) through the access opening (18). (1-3-2) Water Tray The water tray (53) stores water supplied from the tank (52). The water tray (53) constitutes a water storage section for supplying water to the water absorbing member of the humidification rotor (54). The water tray (53) is a container with an open top.

[0062] (1-3-3) Humidification Rotor The humidification rotor (54) has a water-absorbing member that absorbs moisture. The humidification rotor (54) imparts water contained in the water-absorbing member to the air in the humidification space (51). The humidification rotor (54) divides the humidification space (51) into a primary space (51a) and a secondary space (51b). The primary space (51a) is formed upstream of the humidification rotor (54). The secondary space (51b) is formed downstream of the humidification rotor (54).

[0063] The humidification rotor (54) is disk-shaped and has a drive shaft (54a) at its center. The drive shaft (54a) extends toward both the primary space (51a) and the secondary space (51b). The drive shaft (54a) is rotatably supported by two shaft supports (53a) provided on the water tray (53). The humidification rotor (54) is rotated about the drive shaft (54a) by a drive mechanism (not shown). The drive mechanism is, for example, a motor.

[0064] (1-4) Damper The air purifier (10) has a first damper (61) and a second damper (62). The first damper (61) is arranged in the air passage (P) between the fan unit (30) and the secondary space (51b). The second damper (62) is arranged in the air passage (P) between the primary space (51a) and the air outlet (12). The first damper (61) and the second damper (62) open and close in conjunction with each other. Specifically, when the first damper (61) is closed, the second damper (62) is also closed, and when the first damper (61) is open, the second damper (62) is also open.

[0065] The first damper (61) and the second damper (62) change the air passage (P) in the humidification space (51). As shown in FIG. 3 , when both the first damper (61) and the second damper (62) are closed, air blown out from the fan unit (30) flows into the primary space (51a), passes through the humidification rotor (54), flows out into the secondary space (51b), and is then discharged through the outlet (12). At this time, humidified air is discharged through the outlet (12). On the other hand, when both the first damper (61) and the second damper (62) are open, air blown out from the fan unit (30) bypasses the humidification rotor (54) and flows through the primary space (51a) and the secondary space (51b) toward the outlet (12). At this time, the air is discharged through the outlet (12) with almost no humidification.

[0066] (2) Configuration of Fan Unit The configuration of the fan unit (30) will be described with reference to Figs. 4 to 11. In the following description, the terms "axial direction," "radial direction," and "circumferential direction" generally refer to the axial direction, radial direction, and circumferential direction of the fan motor (40), respectively. The "axial direction" refers to the direction in which the rotation axis (X) that is the center of rotation of the fan motor (40) shown in Fig. 6 extends.

[0067] The fan unit (30) creates a negative pressure for sucking air through the first suction inlet (15), the second suction inlet (16), and the third suction inlet (19). The fan unit (30) blows the purified air sucked through the first suction inlet (15), the second suction inlet (16), and the third suction inlet (19) toward the humidification unit (50). As shown in FIGS. 4 to 6 , the fan unit (30) includes a fan motor (40), a first impeller (31) and a second impeller (32) rotated by the fan motor (40), a first fan housing (33) that houses the first impeller (31), and a second fan housing (34) that houses the second impeller (32). The fan unit (30) is arranged in the casing (11) so that the first fan housing (33) is located on the right side and the second fan housing (34) is located on the left side.

[0068] (2-1) Motor The fan motor (40) is an axial gap motor. The fan motor (40) has a motor body (41) and an output shaft (42) protruding from the motor body (41) on both sides in the direction of the rotation axis. The motor body (41) has a disk-shaped first rotor (43), a disk-shaped second rotor (44), and a stator (45) sandwiched between the first rotor (43) and the second rotor (44). The output shaft (42) is rotatably supported by the stator (45). The fan motor (40) is, for example, a 10-pole, 12-slot motor.

[0069] The first rotor (43) has a disk-shaped magnetic member. The magnetic member is a polar anisotropically oriented plastic magnet. The magnetic member includes an annular outer peripheral portion (43a) and an inner peripheral portion (43b) formed on the inner periphery of the outer peripheral portion (43a) and bulging outward in the axial direction of the output shaft (42). S poles and N poles are alternately arranged in the circumferential direction in the outer peripheral portion (43a). A first fixing portion (43c) is provided in the center of the inner peripheral portion (43b) to fix one end of the output shaft (42). The first fixing portion (43c) protrudes slightly outward in the axial direction beyond the inner peripheral portion (43b). The first fixing portion (43c) corresponds to the end of the motor body (41) on the first impeller (31) side.

[0070] The second rotor (44) has a disk-shaped magnet member. The magnet member of the second rotor (44) has the same configuration as the magnet member of the first rotor (43), and is composed of an annular outer peripheral portion (44a) and an inner peripheral portion (44b) that bulges outward in the axial direction of the output shaft (42). A second fixing portion (44c) is provided in the center of the inner peripheral portion (44b) to fix the other end of the output shaft (42). The second fixing portion (44c) protrudes slightly outward in the axial direction beyond the inner peripheral portion (44b). The second fixing portion (44c) corresponds to the end of the motor body (41) on the side of the second impeller (32).

[0071] The stator (45) is configured by resin-molding a wire connection plate to which annularly arranged split cores are fixed and a bearing holder that holds a bearing. The stator (45) has four protrusions (45a) that protrude in the radial direction. The four protrusions (45a) have the same configuration and are positioned at equal intervals in the circumferential direction. The protrusions (45a) have an arc shape that widens in the circumferential direction.

[0072] A vibration-isolating member (46) is attached to the protruding portion (45a). The vibration-isolating member (46) is an elastic body, such as silicone rubber. The vibration-isolating member (46) covers the entire protruding portion (45a). As shown in FIG. 11 , the protruding portion (45a) has recesses (45b) on both axial surfaces. The vibration-isolating member (46) has claw portions (46a) that are received in the recesses (45b). The vibration-isolating member (46) is held so as not to come off the protruding portion (45a) by receiving the claw portions (46a) in the recesses (45b). The corners of the vibration-isolating member (46) are machined to have a rounded shape.

[0073] The output shaft (42) has a first shaft portion (42a) protruding in the axial direction from the first rotor (43) on the side opposite to the stator (45), and a second shaft portion (42b) protruding in the axial direction from the second rotor (44) on the side opposite to the stator (45). The first shaft portion (42a) is fastened to the first impeller (31). The second shaft portion (42b) is fastened to the second impeller (32).

[0074] (2-2) First Impeller and Second Impeller The first impeller (31) is an impeller of a sirocco fan. The first impeller (31) has a plurality of blades (31a), a disk-shaped plate (31b), and a boss (31c) disposed at the center of the plate (31b). As shown in FIGS. 6 and 7 , the first shaft portion (42a) is inserted into the boss (31c). The radial length (W3) of the first impeller (31) is, for example, 17 cm to 22 cm.

[0075] The second impeller (32) is an impeller of a sirocco fan. The second impeller (32) has a plurality of blades (32a), a disk-shaped plate (32b), and a boss (32c) disposed at the center of the plate (32b). As shown in Figures 6 and 7, a second shaft portion (42b) is inserted into the boss (32c). The second impeller (32) is the same size as the first impeller (31).

[0076] (2-3) Fastening Structure Between the Motor and the First and Second Impellers The output shaft (42) of the fan motor (40) has a first support portion (42c) on its first shaft portion (42a) that supports the first impeller (31), and a second support portion (42d) on its second shaft portion (42b) that supports the second impeller (32). As shown in FIG. 7 , the first support portion (42c) has an annular shape surrounding the first shaft portion (42a) and is fixed to the first shaft portion (42a). The first support portion (42c) cooperates with the nut (42e) to fasten the boss (31c) of the first impeller (31) to the first shaft portion (42a). The second support portion (42d) has an annular shape surrounding the second shaft portion (42b) and is fixed to the second shaft portion (42b). The second support portion (42d) has an annular shape surrounding the second shaft portion (42b) and is fixed to the second shaft portion (42b). The second support portion (42d) cooperates with the nut (42e) to fasten the boss (32c) of the second impeller (32) to the second shaft portion (42b). The first support portion (42c) corresponds to the end of the fastening portion between the first impeller (31) and the output shaft (42) on the motor body (41) side. The second support portion (42d) corresponds to the end of the fastening portion between the second impeller (32) and the output shaft (42) on the motor body (41) side.

[0077] The first distance (L1), which is the distance between the first support portion (42c) and the first fixed portion (43c) of the first rotor (43), and the second distance (L2), which is the distance between the second support portion (42d) and the second fixed portion (44c) of the second rotor (44), are set based on the noise level during rotation of the fan motor (40). Specifically, the first distance (L1) and the second distance (L2) are 4.4 mm or more. More specifically, the first distance (L1) and the second distance (L2) are 4.4 mm to 6.0 mm. The first distance (L1) may be measured by regarding the end face of the boss (31c) of the first impeller (31) on the motor body (41) side as the motor-side end of the fastening portion between the first impeller (31) and the output shaft (42). Similarly, the second distance (L2) may be measured by regarding the end face of the boss (32c) of the second impeller (32) on the motor body (41) side as the motor-side end of the fastening portion between the second impeller (32) and the output shaft (42). The third distance (L3), which is the distance between the end of the first fixing portion (43c) on the first impeller (31) side and the end of the second fixing portion (44c) on the second impeller (32) side, is 30 mm to 50 mm. The third distance (L3) corresponds to the thickness of the fan motor (40). When the first distance (L1) and the second distance (L2) are 4.4 mm to 6.0 mm, the fourth distance (L4), which is the shortest distance in the rotational axis (X) direction between the outer periphery (43a) of the first rotor (43) and the plate (31b) of the first impeller (31), and the fifth distance (L5), which is the shortest distance in the rotational axis (X) direction between the outer periphery (44a) of the second rotor (44) and the plate (32b) of the second impeller (32), are 6.0 mm to 7.6 mm. The fourth distance (L4) may be regarded as the distance in the rotational axis (X) direction between the stator (45) and the plate (31b) of the first impeller (31), and the fifth distance (L5) may be regarded as the distance in the rotational axis (X) direction between the stator (45) and the plate (31b) of the second impeller (32).

[0078] (2-4) First Fan Housing and Second Fan Housing The first fan housing (33) has a first outer housing (33a) and a first inner housing (33b). The first outer housing (33a) and the first inner housing (33b) are stacked in the axial direction and fastened together with screws. In the following description, when the term "first fan housing (33)" is used, it simply refers to the first outer housing (33a) and the first inner housing (33b) fastened together.

[0079] The first outer housing (33a) has a first inlet (33c) through which air is taken into the fan unit (30). The first outer housing (33a) forms part of a first outlet (33d) through which the air taken into the fan unit (30) is discharged. The first outer housing (33a) forms part of a first fan housing section (33e) that houses the first impeller (31).

[0080] The first inner housing (33b) constitutes the remainder of the first outlet (33d). The first inner housing (33b) constitutes the remainder of the first fan housing (33e). The first inner housing (33b) occupies a larger proportion of the first outlet (33d) and the first fan housing (33e) in the first inner housing (33b) than in the first outer housing (33a). The first inner housing (33b) has two first legs (33f) for disposing the fan unit (30) in the casing (11) with the first outlet (33d) facing upward. The first inner housing (33b) has a hole (33g) for drawing out a harness extending from the fan motor (40).

[0081] The first inner housing (33b) constitutes a part of a motor accommodating space (47) that accommodates the fan motor (40). The motor accommodating space (47) also serves as a motor support portion that supports the fan motor (40). The first inner housing (33b) has an annular first rib (35) on a first surface portion (33h) located on the axially opposite side (the second fan housing (34) side) from the first outer housing (33a). The first rib (35) protrudes in the axial direction toward the second fan housing (34). The portion surrounded by the first rib (35) constitutes a part of the motor accommodating space (47). The first rib (35) is formed so as to surround the stator (45) of the fan motor (40) from the radially outer side.

[0082] The first rib (35) includes four first arc-shaped ribs (35a) extending in an arc shape around the rotation axis (X) of the fan motor (40) and four first connecting ribs (35b) connecting adjacent first arc-shaped ribs (35a) in the circumferential direction. The upper, lower, and rear first connecting ribs (35b) extend straight, while the front first connecting rib (35b) extends such that its vertical center bulges forward. The first arc-shaped ribs (35a) are provided in portions corresponding to the protrusions (45a) of the stator (45). The first arc-shaped ribs (35a) include three first radial ribs (35c) extending radially. The first radial ribs (35c) are provided on the first arc-shaped ribs (35a) on the side of the motor accommodating space (47). The first connecting rib (35b) has two first circumferential ribs (35d) extending in the circumferential direction. One first circumferential rib (35d) is provided at each end of the first connecting rib (35b). The first circumferential ribs (35d) extending from the same first connecting rib (35b) extend radially inward and away from each other. The first circumferential ribs (35d) extend circumferentially toward the nearest first arc-shaped rib (35a). As shown in FIG. 10 , the first radial rib (35c) and the first circumferential rib (35d) have curved surfaces on the second fan housing (34) side. The radius of curvature of this curved surface is greater than the radius of curvature of the rounded shape of the vibration-damping member (46). As will be described in more detail below, the first radial rib (35c) and the first circumferential rib (35d) correspond to contact portions that come into contact with the vibration-damping member (46).

[0083] As shown in Fig. 10, the first arc-shaped rib (35a) and the first connecting rib (35b) have engagement recesses (35e) recessed axially outward (to the right in this example). The first arc-shaped rib (35a) has the engagement recesses (35e) at the position of the first radial rib (35c). The first connecting rib (35b) has the engagement recesses (35e) at the position of the first circumferential rib (35d). The engagement recesses (35e) are portions that engage with second radial ribs (36c) and second circumferential ribs (36d) of the second fan housing (34), which will be described later.

[0084] The first inner housing (33b) has first bosses (33i) radially outward from the first arc-shaped ribs (35a). Four first bosses (33i) are provided. The first bosses (33i) are portions to which screws are fastened to join the first fan housing (33) and the second fan housing (34). A reinforcing rib (33j) is provided between the first bosses (33i) and the first ribs (35).

[0085] The second fan housing (34) has a second outer housing (34a) and a second inner housing (34b). The second outer housing (34a) and the second inner housing (34b) are stacked in the axial direction and fastened together with screws. In the following description, when the term "second fan housing (34)" is used, it simply refers to the second outer housing (34a) and the second inner housing (34b) fastened together.

[0086] The second outer housing (34a) has a second inlet (34c) through which air is taken into the fan unit (30). The second inlet (34c) is located on the opposite side of the fan motor (40) from the first inlet (33c). The second outer housing (34a) forms part of a second outlet (34d) through which air taken into the fan unit (30) is discharged. The second outer housing (34a) forms part of a second fan housing section (34e) that houses the second impeller (32).

[0087] The second inner housing (34b) constitutes the remainder of the second outlet (34d). The second inner housing (34b) constitutes the remainder of the second fan housing (34e). The second inner housing (34b) occupies a larger proportion of the second outlet (34d) and the second fan housing (34e) in the second inner housing (34b) than in the second outer housing (34a). The second inner housing (34b) has two second legs (34f) for disposing the fan unit (30) in the casing (11) with the second outlet (34d) facing upward.

[0088] The second inner housing (34b) constitutes the remainder of the motor accommodating space (47) that accommodates the fan motor (40). The second inner housing (34b) has an annular second rib (36) on a second surface (34h) located on the axially opposite side (the first fan housing (33) side) from the second outer housing (34a). The second rib (36) protrudes axially toward the first fan housing (33). The portion surrounded by the second rib (36) constitutes a part of the motor accommodating space (47). The second rib (36) is formed so as to surround the stator (45) of the fan motor (40) from the radially outer side. The distance of the second rib (36) from the rotation axis (X) is slightly greater than the distance of the first rib (35) from the rotation axis (X).

[0089] The second rib (36) includes four second arc-shaped ribs (36a) extending in an arc shape centered on the rotation axis (X) of the fan motor (40) and four second connecting ribs (36b) connecting adjacent second arc-shaped ribs (36a) in the circumferential direction. The upper, lower, and rear second connecting ribs (36b) extend straight, while the front second connecting rib (36b) extends such that its vertical center bulges forward. The second arc-shaped ribs (36a) are provided in portions corresponding to the protrusions (45a) of the stator (45). The second arc-shaped ribs (36a) include three second radial ribs (36c) extending radially. The second radial ribs (36c) are provided on the second arc-shaped ribs (36a) on the side of the motor accommodating space (47) facing the motor accommodating space (47). The second connecting rib (36b) has two second circumferential ribs (36d) extending in the circumferential direction. One second circumferential rib (36d) is provided at each end of the second connecting rib (36b). The second circumferential ribs (36d) extending from the same second connecting rib (36b) extend radially inward and away from each other. The second circumferential rib (36d) extends circumferentially toward the second arc-shaped rib (36a) located closer to it. As shown in FIG. 10 , the second radial rib (36c) and the second circumferential rib (36d) have curved surfaces on the second fan housing (34) side. The radius of curvature of this curved surface is greater than the radius of curvature of the rounded shape of the vibration-damping member (46). As will be described in more detail below, the second radial rib (36c) and the second circumferential rib (36d) correspond to contact portions that come into contact with the vibration-damping member (46).

[0090] As shown in Figure 8, the second inner housing (34b) has second bosses (34i) radially outward from the second arc-shaped rib (36a). Four second bosses (34i) are provided. The second bosses (34i) are used to fasten screws that connect the first fan housing (33) and the second fan housing (34). A reinforcing rib (34j) is provided between the second bosses (34i) and the second rib (36).

[0091] 6, when the first fan housing (33) and the second fan housing (34) are combined, a motor accommodating space (47) is formed by the first surface portion (33h), the second surface portion (34h), the first rib (35), and the second rib (36). The width (W2) in the direction of the motor accommodating space (47) is 7% to 12% of the maximum axial width (W1) of the combined body of the first fan housing (33) and the second fan housing (34).

[0092] When the first fan housing (33) and the second fan housing (34) are joined together, the first rib (35) and the second rib (36) overlap in a direction perpendicular to the rotation axis (X). The first rib (35) is located radially inward of the second rib (36). The first rib (35) abuts against the second surface portion (34h) of the second inner housing (34b).

[0093] As shown in Fig. 10, the second radial rib (36c) and the second circumferential rib (36d) engage with the engagement recess (35e) when the first fan housing (33) and the second fan housing (34) are joined together. When assembling the fan unit (30), the relative positions of the first fan housing (33) and the second fan housing (34) are determined by the engagement of the engagement recess (35e) with the second radial rib (36c) and the second circumferential rib (36d). The engagement recess (35e), the second radial rib (36c), and the second circumferential rib (36d) correspond to positioning portions that position the first fan housing and the second fan housing when they are joined together.

[0094] As shown in FIG. 11 , when the first fan housing (33) and the second fan housing (34) are joined together, the first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d) come into contact with the vibration-proof member (46). The second radial rib (36c) and the second circumferential rib (36d) engage with the engagement recesses (35e), so that the first radial rib (35c) and the second radial rib (36c) are positioned at the same position in the circumferential direction. Similarly, the first circumferential rib (35d) and the second circumferential rib (36d) are positioned at the same position in the radial direction. Therefore, the first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d) sandwich and press the vibration-proof member (46) in the axial direction. The stator (45) is fixed to the first fan housing (33) and the second fan housing (34) via the vibration-isolating members (46). The first radial rib (35c) and the second radial rib (36c) suppress radial vibration of the fan motor (40). The first circumferential rib (35d) and the second circumferential rib (36d) suppress circumferential vibration of the fan motor (40).

[0095] As described above, the radii of curvature of the first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d) are larger than the radii of curvature of the vibration-damping member (46). The first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d) contact the corners of the vibration-damping member (46) at points or short lines. Because the contact area is small, almost no vibration of the fan motor (40) is transmitted to the first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d).

[0096] Furthermore, to increase the volume of air blown out from the fan unit, it is desirable to enlarge the diameter of the impeller as much as possible. However, driving a large-diameter impeller requires increasing the output of the fan motor, which in turn requires increasing the size of the fan motor, resulting in a large unit size. Therefore, in this embodiment, an axial gap motor is used as the fan motor (40), thereby realizing a large-volume, compact fan unit (30) by using large-diameter impellers (31, 32) while reducing the thickness of the fan motor (40). For example, the radial length (W3) of the first impeller (31) and the second impeller (32) is at least three times the thickness of the fan motor (40).

[0097] (3) Mounting Structure of Deodorizing Filters The mounting structure of the deodorizing filters (25, 26) to the casing (11) will be described with reference to Figures 12 to 15. Note that the mounting structure of the first deodorizing filter (25) and the mounting structure of the second deodorizing filter (26) are configured symmetrically with respect to an axis extending in the vertical direction, and therefore, only the mounting structure of the first deodorizing filter (25) will be described in detail below, and a description of the mounting structure of the second deodorizing filter (26) will be omitted.

[0098] The first deodorizing filter (25) is attached to a grill (71) provided in the casing (11). The first deodorizing filter (25) is attached to the grill (71) by a pin (72), a fixing member (73), and a lever (74).

[0099] (3-1) Grill The grill (71) is arranged in the air passage (P) between the first deodorizing filter (25) and the fan unit (30). The grill (71) is formed integrally with the frame (70) that is a part of the casing (11).

[0100] (3-2) Pins Two pins (72) are arranged on the upper portion of the grill (71). The two pins (72) are arranged at a distance from each other in the front and rear. The pins (72) protrude toward the side opposite the fan unit (30). The pins (72) are inserted into the first deodorizing filter (25). The pins (72) support the first deodorizing filter (25) in a state aligned with the grill (71).

[0101] (3-3) Fixing Member The fixing member (73) is disposed below and toward the rear of the first suction port (15). The fixing member (73) is separate from the casing (11) (i.e., separate from the grill (71)). The fixing member (73) is fixed to the casing (11). As shown in FIG. 13 , the fixing member (73) has a standing wall portion (73a) extending in the up-down and front-rear directions, and three ribs (73b) protruding from the standing wall portion (73a) toward the grill (71). The three ribs (73b) are disposed at equal intervals in the front-rear direction. As shown in FIG. 14 , when the first deodorizing filter (25) is attached, the ribs (73b) come into contact with the first deodorizing filter (25).

[0102] (3-4) Lever The lever (74) pushes the first deodorizing filter (25) from the inside to the outside (here, from left to right) of the casing (11). As shown in Figures 13 to 15, the lever (74) has a lever body (74a), a contact part (74b) that comes into contact with the first deodorizing filter (25), and a spring (74c) that applies force to the lever body (74a).

[0103] The lever body (74a) is located below the grille (71) in the space between the grille (71) and the bottom plate (11b) of the casing (11). As shown in Figure 15, the lever body (74a) has a plate shape that extends in the front-rear and left-right directions. The lever body (74a) rotates around a rod (74d) extending from the casing (11).

[0104] The contact portion (74b) is located at a position on the right side and in front of the lever body (74a). The contact portion (74b) is integral with the lever body (74a). The contact portion (74b) is located at the position of a window portion (71a) provided in the grill (71). The contact portion (74b) can pass through the window portion (71a) and be exposed to the right of the grill (71). The contact portion (74b) has two ribs (74e) extending toward the right. The ribs (74e) are spaced apart in the front-rear direction. As shown in FIG. 14 , when the first deodorizing filter (25) is attached, the ribs (74e) come into contact with the first deodorizing filter (25) and push the first deodorizing filter (25) from the inside toward the outside of the casing (11).

[0105] The spring (74c) is a torsion coil spring. One end of the spring (74c) is fixed to the casing (11). The middle portion of the spring (74c) is wound around the rod shaft (74d). The spring (74c) applies a force to the lever body (74a) to rotate it counterclockwise.

[0106] (3-5) Method of Installing the Deodorizing Filter When installing the first deodorizing filter (25), first, the first deodorizing filter (25) is placed between the fixing member (73) and the contact portion (74b). When the first deodorizing filter (25) is placed between the fixing member (73) and the contact portion (74b), the contact portion (74b) moves slightly back to the left. The force of the spring (74c) transmitted via the lever body (74a) causes the contact portion (74b) to push the first deodorizing filter (25) from the inside toward the outside of the casing (11). Because the fixing member (73) restricts the first deodorizing filter (25) from moving to the right, only the area around the contact portion with the contact portion (74b) moves slightly to the right. The lower portion of the first deodorizing filter (25) is sandwiched between the fixing member (73) and the contact portion (74b). Then, the pin (72) is inserted into the upper portion of the first deodorizing filter (25). The upper part of the first deodorizing filter (25) is supported by a pin (72), thereby attaching the first deodorizing filter (25).

[0107] A sensor (SW) is disposed in front of the lever body (74a). The sensor (SW) is a contact sensor. The sensor (SW) is turned on when the first deodorizing filter (25) is positioned between the fixing member (73) and the contact portion (74b). Specifically, the sensor (SW) is turned on when the contact portion (74b) retracts to the left and the lever body (74a) rotates clockwise. The sensor (SW) is a sensor for checking whether the first deodorizing filter (25) is properly positioned.

[0108] (4) Paths of Active Species The first discharge passage (80) and the second discharge passage (87) through which the active species generated by the discharge units (27, 28) flow will be described with reference to Figures 12 and 16 to 18. Note that since the first discharge passage (80) and the second discharge passage (87) are symmetrical, only the first discharge passage (80) will be described in detail below, and a detailed description of the second discharge passage (87) will be omitted.

[0109] The first discharge passage (80) has an inlet duct (81) that takes in a part of the air discharged from the fan unit (30), a horizontal duct (82) that branches and flows the active species in the front and rear directions, a front discharge duct (83) that is located on the front side and discharges the active species, and a rear discharge duct (84) that is located on the rear side and discharges the active species.

[0110] (4-1) Inlet Duct As shown in FIG. 16 , the first discharge unit (27) is disposed in the discharge space (27a) of the first discharge passage (27). The inlet duct (81) connects the main air passage (P) and the discharge space (27a). The inlet duct (81) is located at the center of the entire air purifier (10) in the front-to-rear direction. The inlet duct (81) has an upper inclined portion (81a) extending obliquely upward toward the right, a straight portion (81b) extending straight toward the right, and a lower inclined portion (81c) extending obliquely downward toward the right. The straight portion (81b) has a rib (81d) that protrudes upward and extends in the front-to-rear direction. The rib (81d) prevents the intrusion of foreign matter such as water.

[0111] (4-2) Horizontal Duct As shown in Fig. 17, the horizontal duct (82) extends in the front-rear direction from the discharge space (27a). The front end of the horizontal duct (82) communicates with the front discharge duct (83). The rear end of the horizontal duct (82) communicates with the rear discharge duct (84).

[0112] (4-3) Front Discharge Duct and Rear Discharge Duct As shown in FIG. 12 , the front discharge duct (83) and the rear discharge duct (84) extend in the vertical direction. The front discharge duct (83) has five front discharge holes (83a) that discharge active species. The front discharge holes (83a) open to the right and toward the rear. The rear discharge duct (84) has five rear discharge holes (84a) that discharge active species. The rear discharge holes (84a) open to the right and toward the front. The front discharge holes (83a) and the rear discharge holes (84a) are provided at equal intervals and at the same positions in the vertical direction.

[0113] As shown in Figure 18, the front discharge duct (83) is composed of a frame (70) forming the grill (71) and a front cover member (85). The rear discharge duct (84) is composed of a frame (70) forming the grill (71) and a rear cover member (86). In other words, the two discharge ducts (83, 84) are formed by three members. The front cover member (85) also forms a part of the front discharge duct of the second discharge passage (87). The rear cover member (86) is provided separately for the first discharge passage (80) and the second discharge passage (87).

[0114] (4-4) Flow of Active Species The first discharge passage (80) is in communication with the first suction port (15) through the front discharge hole (83a) and the rear discharge hole (84a). Therefore, the air pressure therein is lower than that immediately downstream of the outlets (33d, 34d) of the fan unit (30) (upstream of the humidification unit (50)). In particular, within the first discharge passage (80), the inlet duct (81) has the highest air pressure, and the outlet ducts (83, 84) have the lowest air pressure. Therefore, part of the air discharged from the fan unit (30) flows into the discharge space (27a) through the inlet duct (81). The first discharge unit (27) generates streamer discharges in the air that has flowed into the discharge space (27a). The streamer discharge generates active species. The generated active species are separated into two parts, one in front of the other and the other in the horizontal duct (82). The active species flowing forward through the horizontal duct (82) pass through the front discharge duct (83) and are discharged from the front discharge holes (83a) to the upstream side of the first HEPA filter (23). The active species flowing backward through the horizontal duct (82) pass through the rear discharge duct (84) and are discharged from the rear discharge holes (84a) to the upstream side of the first HEPA filter (23). In this manner, the active species are discharged from both opposing sides of the first HEPA filter (23). The discharged active species adhere to the first HEPA filter (23) and oxidize and decompose odorous components in the air passing through the first HEPA filter (23).

[0115] (5) Operation Operation of the air purifier (10) will be described. The air purifier (10) performs a cleaning operation and a humidifying cleaning operation. The cleaning operation is an operation for cleaning the air in the target space. In the cleaning operation, the humidifying function is stopped. The humidifying cleaning operation is an operation for simultaneously cleaning and humidifying the air in the target space.

[0116] (5-1) Purifying Operation In the purifying operation, the fan unit (30) and the discharge units (27, 28) are driven. In principle, the humidification rotor (54) is stopped. The first damper (61) and the second damper (62) are open. Air from the indoor space (S) is sucked into the air passage (P) through the first suction inlet (15), the second suction inlet (16), and the third suction inlet (19). The air sucked through the first suction inlet (15) and the second suction inlet (16) passes through each prefilter (21, 22). Each prefilter (21, 22) captures relatively large dust particles in the air.

[0117] The air that has passed through each pre-filter (21, 22) passes sequentially through each HEPA filter (23, 24) and each deodorizing filter (25, 26). In each HEPA filter (23, 24), odorous components in the air are oxidized and decomposed by the active species generated in each discharge unit (27, 28).

[0118] A part of the air blown out from the fan unit (30) flows through the primary space (51a) and the rest flows through the secondary space (51b). The air in the primary space (51a) and the air in the secondary space (51b) flow upward along the side surfaces of the humidification rotor (54) and are blown out through the outlet (12) into the room space (S).

[0119] (5-2) Humidification Cleaning Operation In the humidification cleaning operation, the fan unit (30) and the discharge units (27, 28) are driven. In principle, the humidification rotor (54) is in a rotating state. The first damper (61) and the second damper (62) are in a closed state. In the humidification cleaning operation, the air is cleaned in the same manner as in the cleaning operation described above.

[0120] The entire air blown out from the fan unit (30) flows through the primary space (51a). The air in the primary space (51a) passes through the humidification rotor (54) in the axial direction. In the humidification rotor (54), moisture from a water-absorbing member is imparted to the air. The air humidified by the humidification rotor (54) flows into the secondary space (51b) and is blown out through the outlet (12) into the room space (S).

[0121] (6) Advantages of the Embodiment In the present embodiment, the fan unit (30) includes a first fan housing (33) that houses the first impeller (31) and a second fan housing (34) that houses the second impeller (32), forming a motor housing space (47) that houses the fan motor (40). The fan motor (40) is housed in the fan housings (33, 34), so that the fan motor (40), the impellers (31, 32), and the fan housings (33, 34) can be integrated into one unit. Since the fan unit (30) does not need to provide a separate support member for the fan motor (40), the fan unit (30) can be compactly configured even if it includes a plurality of impellers (31, 32).

[0122] Furthermore, since the fan unit (30) accommodates the fan motor (40) in the fan housing (33, 34), the area of ​​the outlet (33d, 34d) of the fan housing (33, 34) can be increased within a limited installation area, compared to when a separate support member for the fan motor (40) is provided. Furthermore, since the fan unit (30) accommodates the fan motor (40) and the impellers (31, 32) in the fan housing (33, 34), the fan motor (40) can be cooled by air flowing through the fan housing (33, 34).

[0123] In this embodiment, the first fan housing (33) constitutes a part of the motor accommodating space (47), and the second fan housing (34) constitutes the remainder of the motor accommodating space (47). In the second aspect, by dividing the motor accommodating space (47), the load when supporting the motor body (41) in the motor accommodating space (47) and the load generated when the fan motor (40) is driven can be divided between the first fan housing (33) and the second fan housing (34). This allows for a compact and stable fan unit (30).

[0124] In this embodiment, the first distance (L1), which is the distance from the first support portion (42c) that supports the first impeller (31) to the end of the first fixed portion (43c) of the motor body (41), and the second distance (L2), which is the distance from the second support portion (42d) that supports the second impeller (32) to the end of the second fixed portion (44c) of the motor body (41), are each 4.4 mm or more. In particular, the first distance (L1) and the second distance (L2) are each 4.4 mm to 6.0 mm.

[0125] Axial vibrations of the fan motor (40) may be transmitted to the first impeller (31) and the second impeller (32) via the output shaft (42). Transmission of vibrations to the first impeller (31) and the second impeller (32) may result in the generation of abnormal noise. FIG. 19 shows noise levels when the first distance (L1) and the second distance (L2) are changed. The vertical axis represents the volume, and the horizontal axis represents the frequency of the sound. In FIG. 19, the dashed-dotted line represents the volume when the first distance (L1) and the second distance (L2) are 2.8 mm, the solid line represents the volume when the first distance (L1) and the second distance (L2) are 4.4 mm, and the dashed line represents the volume when the first distance (L1) and the second distance (L2) are 6.0 mm. It can be seen that the volume is generally lower when the first distance (L1) and the second distance (L2) are 4.4 mm than when the first distance (L1) and the second distance (L2) are 2.8 mm. Furthermore, when the first distance (L1) and the second distance (L2) are compared between 4.4 mm and 6.0 mm, it is found that the overall volume does not decrease significantly. Therefore, by setting the first distance (L1) and the second distance (L2) to 4.4 mm to 6.0 mm, it is possible to reduce the space required for the fan unit (30) while suppressing abnormal noise caused by vibration of the fan motor (40).

[0126] In this embodiment, a vibration-isolating member (46) is provided on the outer periphery of the motor body (41), and the fan housing (33, 34) has a first radial rib (35c), a first circumferential rib (35d), a second radial rib (36c), and a second circumferential rib (36d) that contact the vibration-isolating member (46). These ribs can hold the vibration-isolating member (46) and prevent the motor body (41) from moving together with the vibration-isolating member (46). This allows the vibration-isolating member (46) to appropriately absorb vibrations of the motor body (41).

[0127] In this embodiment, the first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d) have curved surfaces, and the vibration-damping member (46) contacts these curved surfaces. In particular, the radius of curvature of these curved surfaces is greater than the radius of curvature of the corners of the vibration-damping member (46). The first radial rib (35c), the first circumferential rib (35d), the second radial rib (36c), and the second circumferential rib (36d) can be in the form of dots or short lines with the vibration-damping member (46), thereby minimizing the contact area. This reduced contact area can improve the vibration-damping effect of the entire fan unit (30).

[0128] In this embodiment, the vibration-isolating member (46) is an elastic body, and therefore the vibration-isolating effect can be further improved.

[0129] In this embodiment, the first fan housing (33) has a first rib (35) that surrounds the fan motor (40) and extends toward the second fan housing (34), and the second fan housing (34) has a second rib (36) that surrounds the fan motor (40) and extends toward the first fan housing (33). The first rib (35) and the second rib (36) overlap in a direction perpendicular to the rotation axis (X). The overlapping of the first rib (35) and the second rib (36) in a direction perpendicular to the rotation axis (X) can prevent foreign matter such as water from entering the storage space (47). In particular, in this embodiment, the first rib (35) abuts against the second surface portion (34h) of the second fan housing (34), which is the surface on which the second rib (36) is provided, and therefore, can more effectively prevent foreign matter such as water from entering the storage space (47).

[0130] In this embodiment, the first fan housing (33) has an engagement recess (35e) that serves as a positioning portion for positioning when coupled to the second fan housing (34), and the second fan housing (34) has a second radial rib (36c) and a second circumferential rib (36d) that engage with the engagement recess (35e) and serve as positioning portions. The engagement recess (35e), the second radial rib (36c), and the second circumferential rib (36d) facilitate positioning when the first fan housing (33) and the second fan housing (34) are coupled together. This facilitates assembly of the fan unit (30).

[0131] In this embodiment, the radial length (W3) of the first impeller (31) and the second impeller (32) is at least three times the thickness (L3) of the fan motor (40). The fan motor (40) is an axial gap motor. This allows the fan motor (40) to be thin and the large-diameter impellers (31, 32) to be used, thereby achieving a large-volume, compact fan unit (30).

[0132] The air purifier (10) of this embodiment includes a fan unit (30) and a casing (11) that houses the fan unit (30). By using a fan unit (30) in which a fan motor (40) is housed in a fan housing (33, 34), it is not necessary to provide a separate support for the fan motor (40) within the casing (11), thereby saving space. The space savings can be used to increase the installation area for the impellers (31, 32), thereby increasing the airflow rate of the air purifier (10). Furthermore, the impellers (31, 32) can be located closer to the inlets (15, 16) than when the fan motor (40) is located outside the fan housing (33, 34). This facilitates the intake of air from the target space, thereby improving the air purification effect.

[0133] In this embodiment, the casing (11) has a first suction port (15) and a second suction port (16) for drawing air on both sides of the fan motor in the direction of the rotation axis. HEPA filters (23, 24) and deodorizing filters (25, 26) are disposed in the air passage (P) extending from the first suction port (15) and the second suction port (16) to the fan unit (30). By disposing the HEPA filters (23, 24) and the deodorizing filters (25, 26) in two separate locations, the total filter area can be increased, thereby reducing pressure loss. This reduced pressure loss allows for a larger airflow rate from the air purifier (10). Furthermore, the height of the casing (11) can be minimized compared to when the HEPA filters (23, 24) and the deodorizing filters (25, 26) are disposed downstream (here, above) of the outlets (33d, 34d) of the fan unit (30).

[0134] In this embodiment, the casing (11) has a third suction port (19) that draws air from the front side, and an intermediate passage (19a) that flows the air drawn in through the third suction port (19) toward the upstream side of the filters (23, 24, 25, 26). Air can be drawn in from multiple locations and passed appropriately through the filters (23, 24, 25, 26), thereby improving the air purification efficiency.

[0135] In this embodiment, the casing (11) has a grill (71) between the deodorizing filters (25, 26) and the fan unit (30), and includes a fixing member (73) and a lever (74) that fix the deodorizing filters (25, 26) in a state aligned with the grill (71). This can prevent the deodorizing filters (25, 26) from moving unexpectedly, thereby maintaining a high level of air purification efficiency. Furthermore, in this embodiment, the deodorizing filters (25, 26) are supported in the vertical direction by pins (72) provided on the grill (71), which more effectively prevents the deodorizing filters (25, 26) from moving.

[0136] In this embodiment, the casing (11) includes a discharge unit (27, 28) that generates active species, and the casing (11) has a discharge passage (80, 87) that discharges the active species generated in the discharge unit (27, 28) upstream of the HEPA filter (23, 24) and the deodorizing filter (25, 26). Even if the HEPA filter (23, 24) and the deodorizing filter (25, 26) are located upstream of the impeller (31, 32) as in this embodiment, the discharge passage (80, 87) allows the active species to adhere to the filters (23, 24, 25, 26), thereby improving the air purification effect. In particular, the discharge passage (80, 87) has a plurality of discharge holes (83a, 84a) on both opposing sides of the HEPA filter (23, 24), allowing the active species to adhere to the entire surface of the HEPA filter (23, 24).

[0137] (7) Modifications The above embodiment may be modified as follows.

[0138] As shown in Figure 20, the appearance of the first fan housing (233) and the appearance of the second fan housing (234) are asymmetric with respect to a plane perpendicular to the rotation axis (X). Specifically, the second outlet (234a) is positioned forwardly shifted relative to the first outlet (233a). Even in this configuration, the fan motor (40) is accommodated in a motor accommodating space (47) formed by the first fan housing (233) and the second fan housing (234).

[0139] Note that any configuration may be used as long as the appearances of the first fan housing (233) and the second fan housing (234) are asymmetric with respect to a plane perpendicular to the rotation axis (X). For example, the second outlet (234a) may be inclined forward or backward relative to the first outlet (233a). Furthermore, the second impeller (32) may be smaller in the direction of the rotation axis (X) than the first impeller (31), and the second fan housing (234) may be smaller in the direction of the rotation axis (X) than the first fan housing (233).

[0140] (8) Other Embodiments The fan unit (30) may be used in devices other than the air purifier (10). For example, the fan unit (30) may be used in a blower.

[0141] The air purifier (10) does not necessarily have to include the humidification unit (50).

[0142] A part of the motor accommodating space (47) is formed in the first fan housing (33), and the remaining part is formed in the second fan housing (34). The motor accommodating space (47) may be formed only in the first fan housing (33) or only in the second fan housing (34). For example, when the motor accommodating space (47) is formed only in the first fan housing (33), the motor accommodating space (47) may be formed by only the first rib (35), and the second rib (36) may be omitted.

[0143] 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.

[0144] 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.

[0145] As described above, the present disclosure is useful for fan units and air purifiers.

[0146] 10 Air purifier 11 Casing 15 First suction port (main suction port) 16 Second suction port (main suction port) 19 Third suction port 19a Relay passage 23 First HEPA filter 24 Second HEPA filter 25 First deodorizing filter 26 Second deodorizing filter 27 First discharge unit (active species generation section) 28 Second discharge unit (active species generation section) 30 Fan unit 31 First impeller 32 Second impeller 33 First fan housing 34 Second fan housing 35 First rib 35c First radial rib (contact section) 35d First circumferential rib (contact section) 35e Engagement recess (positioning section) 36 Second rib 36c Second radial rib (contact section, positioning section) 36d Second circumferential rib (contact section, positioning section) 40 Fan motor 41 Motor body 42 Output shaft 43a Outer periphery 44a Outer periphery 46 Vibration-proof member 47 Motor accommodating space 71 Grill 73 Fixing member (fixing portion) 74 Lever (fixing portion) 80 First discharge passage 87 Second discharge passage 233 First fan housing 234 Second fan housing L1 First distance L2 Second distance L3 Third distance P Air passage W3 Radial length of impeller X Rotation axis

Claims

1. A fan unit comprising: a fan motor (40) having a motor body (41) and output shafts (42) extending from the motor body (41) on both sides in a rotation axis direction; a first impeller (31) connected to one of the output shafts (42); a second impeller (32) connected to the other output shaft (42) and arranged together with the first impeller (31) to sandwich the fan motor (40); a first fan housing (33) that accommodates the first impeller (31); and a second fan housing (34) that accommodates the second impeller (32), wherein at least one of the first fan housing (33) and the second fan housing (34) has an accommodation space (47) that accommodates the fan motor (40).

2. A fan unit according to claim 1, wherein the first fan housing (33) constitutes a part of the storage space (47), and the second fan housing (34) constitutes the remainder of the storage space (47).

3. A fan unit as claimed in claim 1 or 2, wherein the first impeller (31) and the second impeller (32) are fastened to the output shaft (42), and a first distance (L1) which is the distance from an end of the fastening portion between the first impeller (31) and the output shaft (42) on the motor body (41) side to the end of the motor body (41) on the first impeller (31) side, and a second distance (L2) which is the distance from an end of the fastening portion between the second impeller (32) and the output shaft (42) on the motor body (41) side to the end of the motor body (41) on the second impeller (32) side, are each 4.4 mm or more.

4. A fan unit according to claim 3, wherein the first distance (L1) and the second distance (L2) are each 4.4 mm to 6.0 mm.

5. A fan unit as claimed in any one of claims 1 to 4, wherein a vibration-isolating member (46) is provided on the outer periphery of the motor body (41), and the first fan housing (33) and the second fan housing (34) have contact portions (35c, 35d, 36c, 36d) that come into contact with the vibration-isolating member (46).

6. A fan unit according to claim 5, wherein the contact portion (35c, 35d, 36c, 36d) has a curved surface, and the vibration-proof member (46) comes into contact with the curved surface of the contact portion (35c, 35d, 36c, 36d).

7. A fan unit according to claim 6, wherein the radius of curvature of the curved surface of said contact portion (35c, 35d, 36c, 36d) is larger than the radius of curvature of the contact portion of said vibration-proof member (46).

8. A fan unit according to any one of claims 5 to 7, wherein the vibration-isolating member (46) is an elastic body.

9. A fan unit as claimed in any one of claims 1 to 8, wherein the first fan housing (33) has a first rib (35) arranged to surround the fan motor (40) and extending towards the second fan housing (34), the second fan housing (34) has a second rib (36) arranged to surround the fan motor (40) and extending towards the first fan housing (33), and the first rib (35) and the second rib (36) overlap in a direction perpendicular to the direction of the rotation axis.

10. A fan unit according to any one of claims 1 to 9, wherein the first fan housing (33) and the second fan housing (34) have positioning portions (35e, 36c, 36d) for positioning them when they are joined to each other.

11. A fan unit according to any one of claims 1 to 10, wherein the appearance of the first fan housing (33) and the appearance of the second fan housing (34) are asymmetric with respect to a plane perpendicular to the direction of the rotation axis.

12. A fan unit as described in any one of claims 1 to 11, wherein the radial length (W3) of the first impeller (31) and the second impeller (32) is three times or more the thickness (L3) of the fan motor (40).

13. A fan unit according to any one of claims 1 to 12, wherein the fan motor (40) is an axial gap type motor.

14. An air purifier comprising: a fan unit (30) according to any one of claims 1 to 13; and a casing (11) that houses the fan unit (30).

15. An air purifier as defined in claim 14, wherein the casing (11) has main suction inlets (15, 16) for sucking in air on both sides in the direction of the rotation shaft, and filters (23, 24, 25, 26) are arranged in an air passage (P) from the main suction inlets (15, 16) to the fan unit (30).

16. An air purifier as defined in claim 15, wherein the casing (11) has an auxiliary suction port (19) that draws in air from a direction perpendicular to both the rotational axis direction and the vertical direction, and a relay passage (19a) that flows the air drawn in from the auxiliary suction port (19) toward the upstream side of the filters (23, 24, 25, 26).

17. An air purifier as claimed in claim 15 or 16, wherein the casing (11) has a grill (71) between the filter (25, 26) and the fan unit (30), and is provided with fixing parts (73, 74) for fixing the filter (26, 26) in a state aligned with the grill (71).

18. An air purifier according to any one of claims 15 to 17, further comprising an active species generation section (27, 28) that generates active species, and the casing (11) has a discharge passage (80, 87) that discharges the active species generated in the active species generation section (27, 28) upstream of the filter (23, 24, 25, 26).

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