Impeller and fan device

Abstract

This impeller for a fan device comprises a hub, a plurality of blades, and a connection part. The hub has a lidded tube shape that extends in the axial direction. One end of the hub in the axial direction is open. The plurality of blades extend radially outward from a radially outward side surface of the hub and are arranged along the circumferential direction. The connection part is disposed between radially outward ends of at least some blades which are adjacent in the circumferential direction, extends in the circumferential direction, and connects the radially outer radially outward ends of said blades. As seen from the axial direction, the connection part spreads out radially. This impeller suppresses the occurrence of noise when the blades rotate.

Description

Impellers, fan devices

[0001] The present invention relates to an impeller and a fan device.

[0002] Axial fans are a type of conventional fan device. An axial fan includes, for example, a hub with a motor disposed therein, a plurality of blades disposed on the outer circumferential surface of the hub, and a fan housing that surrounds the plurality of blades (see Japanese Patent Application Laid-Open No. 2002-021798).

[0003] Japanese Patent Application Laid-Open No. 2002-021798

[0004] However, conventional axial flow fans tend to generate noise due to motor vibration and wind flow during operation, so there is a need to reduce noise generation.

[0005] The present invention aims to suppress noise generated when the blades rotate.

[0006] An exemplary impeller of the present invention includes a hub, a plurality of blades, and a connecting portion. The hub is a closed-tube shape extending in the axial direction. One axial end of the hub is open. The plurality of blades extend radially outward from a radially outer side surface of the hub and are aligned in the circumferential direction. The connecting portion is disposed between radially outer ends of at least some of the blades that are adjacent in the circumferential direction, extends circumferentially, and connects the radially outer ends of the blades. The connecting portion extends radially when viewed in the axial direction.

[0007] An exemplary fan device according to the present invention includes the above-described impeller and a motor. The motor has a shaft. The shaft is rotatable together with the impeller about an axially extending rotation axis. At least a portion of the motor is disposed inside the hub.

[0008] Further features and advantages of the present invention will become more apparent from the following embodiments.

[0009] According to the exemplary impeller and fan device of the present invention, noise generated when the blades rotate can be suppressed.

[0010] FIG. 1 is a perspective view showing an example of the configuration of a fan device according to an embodiment. FIG. 2 is a cross-sectional view of the fan device according to an embodiment. FIG. 3 is a perspective view showing an example of the configuration of an impeller according to an embodiment. FIG. 4 is a perspective view showing an example of the configuration of an impeller according to a first modified example of the embodiment. FIG. 5 is a perspective view showing an example of the configuration of a fan device according to a second modified example of the embodiment. FIG. 6 is a cross-sectional view of the fan device according to the second modified example of the embodiment. FIG. 7 is a perspective view showing an example of the configuration of an impeller according to the second modified example of the embodiment. FIG. 8 is a perspective view showing another example of the configuration of an impeller according to the second modified example of the embodiment.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] In this specification, in the fan unit 100, the direction parallel to the rotation axis J is referred to as the "axial direction Da." Within the axial direction Da, the direction from the hub 11 to the motor holder 31, which will be described later, is referred to as the "first axial direction Da1," and the direction from the motor holder 31 to the hub 11 is referred to as the "second axial direction Da2." Additionally, the direction perpendicular to the rotation axis J is referred to as the "radial direction." Within the radial direction, the direction approaching the rotation axis J is referred to as the "inward radial direction," and the direction away from the rotation axis J is referred to as the "outward radial direction." Additionally, the rotation direction about the rotation axis J is referred to as the "circumferential direction Dc." Within the circumferential direction Dc, one direction is referred to as the "first circumferential direction Dc1," and the other direction is referred to as the "second circumferential direction Dc2." In this specification, when the fan device 100 and the impeller 1 are viewed from the other axial direction Da2 side toward the one axial direction Da1, the one circumferential direction Dc1 is the counterclockwise direction centered on the rotation axis J in the circumferential direction Dc, and the other circumferential direction Dc2 is the clockwise direction centered on the rotation axis J in the circumferential direction Dc.

[0013] In this specification, the term "annular" refers not only to a shape that is continuous and uninterrupted throughout the entire circumferential direction Dc about the rotation axis J, but also to a shape that has one or more interruptions in a portion of the entire circumferential direction Dc about the rotation axis J. It also refers to a shape that describes a closed curve on a curved surface that is centered on the rotation axis J and intersects with the rotation axis J.

[0014] Furthermore, in the positional relationship between any one of a direction, a line, and a plane and any other, "parallel" includes not only a state in which the two do not intersect at all no matter how far they are extended, but also a state in which they are substantially parallel. Furthermore, "perpendicular" and "orthogonal" each include not only a state in which the two intersect at 90 degrees, but also a state in which they are substantially perpendicular and a state in which they are substantially orthogonal. In other words, "parallel," "perpendicular," and "orthogonal" each include a state in which there is an angular deviation in the positional relationship between the two to an extent that does not deviate from the spirit of the present invention.

[0015] It should be noted that these are used merely for the purpose of explanation and are not intended to limit the actual positional relationship, direction, names, etc.

[0016] 1. Embodiment Fig. 1 is a perspective view showing an example of the configuration of a fan device 100 according to an embodiment. Fig. 2 is a cross-sectional view of the fan device 100 according to an embodiment. Fig. 2 shows the cross-sectional structure of the fan device 100 when it is virtually cut along a plane including the two-dot chain line II-II and the rotation axis J in Fig. 1.

[0017] <1-1. Fan device 100> The fan device 100 is a so-called axial fan that draws in an airflow (i.e., air) through an inlet 101 in one axial direction Da1 and sends it out through an outlet 102. However, without being limited to this example, the fan device 100 may draw in and send out fluids such as gases and liquids other than air. The fan device 100 is used, for example, as a cooling fan for electronic devices that are required to be thin. However, the use of the fan device 100 is not limited to this example.

[0018] The fan device 100 includes an impeller 1 , a motor 2 , a housing 3 , and a substrate 4 .

[0019] The impeller 1 is rotatable about a rotation axis J extending in the axial direction Da (i.e., in the circumferential direction Dc) around the rotation axis J. The impeller 1 is attached to a motor 2.

[0020] The motor 2 is a drive source that rotates the impeller 1, and is disposed on one axial side Da1 of the impeller 1. At least a portion of the motor 2 is disposed inside the impeller 1 (particularly the hub 11 described below). The motor 2 has a shaft 21 that extends in the axial direction Da along a rotation axis J that extends in the axial direction Da. The shaft 21 is rotatable together with the impeller 1 about the rotation axis J. More specifically, the impeller 1 is coupled to the other axial end of the shaft 21. The motor 2 rotates the shaft 21 about the rotation axis J, thereby rotating the impeller 1 together with the shaft 21.

[0021] The housing 3 faces the motor 2 in the radial direction with a gap therebetween, and forms an air tunnel in the space between the impeller 1 and the motor 2 through which the airflow flows.

[0022] The housing 3 has a motor holder 31 , a peripheral wall portion 32 , and ribs 33 .

[0023] The motor holder 31 holds the motor 2. For example, the motor holder 31 is disposed on one side of the axial direction Da1 from the motor 2, and extends in a direction intersecting the axial direction (for example, a radial direction).

[0024] The peripheral wall portion 32 has a cylindrical shape extending in the axial direction and surrounds the impeller 1 and the motor 2. The peripheral wall portion 32 faces the impeller 1 and the motor 2 in the radial direction with a gap therebetween, and forms an air tunnel in the space between the impeller 1 and the motor 2 through which the airflow flows.

[0025] The ribs 33 extend at least in the radial direction and are arranged side by side in the circumferential direction Dc on one axial side Da1 of the wind tunnel. The ribs 33 function as stator vanes that straighten the airflow through the wind tunnel. The ribs 33 also connect one axial end of the motor 2 to the other axial end of the peripheral wall portion 32. In other words, the radially inner ends of the ribs 33 are connected to the radially outer end of the motor holder 31. The radially outer ends of the ribs 33 are connected to the radially inner surface of the housing 3.

[0026] In the present embodiment, the motor holder 31, the peripheral wall portion 32, and the rib 33 may be integral and form a single member. However, this is not limiting, and at least one of these members may be separate from the other members.

[0027] The substrate 4 is disposed radially outward from the portion of the motor 2 on one axial side Da1, on the other axial side Da2 of the motor holder 31. The substrate 4 is electrically connected to the lead wires drawn from the coil portion (not shown) of the motor 2. The substrate 4 is mounted with a drive circuit for the motor 2 and the like. The substrate 4 is also electrically connected to external wiring 41. The external wiring 41 is drawn out to the outside of the fan device 100 and electrically connects the substrate 4 to external devices, power sources, and the like.

[0028] 1 to 3, the configuration of the impeller 1 will be described. Fig. 3 is a perspective view showing an example of the configuration of the impeller 1 according to the embodiment.

[0029] The impeller 1 includes a hub 11, a plurality of blades 12, and a connecting portion 13. The hub 11, the blades 12, and the connecting portion 13 may each be made of resin or metal. In this embodiment, the hub 11, the blades 12, and the connecting portion 13 are integral with each other and preferably form a single member. However, this example does not exclude a configuration in which at least one of these is separate from the other members.

[0030] The hub 11 is a cylindrical hub with a cap that extends in the axial direction Da. One axial end of the hub 11 is open. In this specification, a shape in which one end of a cylindrical body (for example, a cylindrical portion 112 described later) is covered with a cap-shaped body (for example, a plate portion 111 described later) is referred to as a "cylindrical hub with a cap."

[0031] The hub 11 has a plate portion 111, a cylindrical portion 112, and a holder 113. The plate portion 111 is circular and extends radially outward from the rotation axis J. The cylindrical portion 112 extends from the radially outer end of the plate portion 111 in one axial direction Da1 and surrounds at least the portions of the motor 2 and the shaft 21 on the other axial direction Da2 side. The one axial end of the hub 11 is open. Meanwhile, the other axial end of the cylindrical portion 112 is covered by the plate portion 111. The radially inner surface of the cylindrical portion 112 faces the radially outer surface of the motor 2 with a gap therebetween. The holder 113 is cylindrical and surrounds and accommodates the other axial end of the shaft 21, and is fixed to the shaft 21. The radially inner surface of the holder 113 contacts the radially outer surface of the shaft 21.

[0032] The blades 12 extend radially outward from the radially outer side surface of the hub 11 and are aligned in the circumferential direction Dc. For example, the blades 12 are disposed on the radially outer side surface of the cylindrical portion 112 and are aligned in the circumferential direction Dc. Each blade extends at least radially outward from the radially outer side surface of the cylindrical portion 112. The blades 12 are rotatable about the rotation axis J together with the shaft 21 of the motor 2. When the motor 2 rotates the blades 12 in the circumferential direction Dc, the airflow flows in one axial direction Da1.

[0033] The connecting portion 13 is disposed between the radially outer ends of at least some of the blades 12 adjacent to each other in the circumferential direction Dc, extends in the circumferential direction Dc, and connects the radially outer ends of the blades 12. Furthermore, the connecting portion 13 extends radially when viewed from the axial direction Da.

[0034] The impeller 1 of the fan device 100 can suppress the generation of turbulence and vortices at the radially outer ends of the blades 12, which are adjacent to each other in the circumferential direction Dc and have their tips (radially outer ends) connected by the connecting portions 13. Therefore, the generation of turbulence and vortices at the radially outer ends of the blades 12 can be suppressed, particularly in an environment where a high load is applied to the impeller 1. Note that such turbulence and vortices are generated when airflow flowing in the opposite direction to the rotation direction of the blades 12 hits the radially outer ends of the blades 12. Therefore, the impeller 1 of the fan device 100 can suppress the generation of noise when the blades 12 rotate.

[0035] Preferably, the ratio of the minimum radial width of the connection portion 13 as viewed in the axial direction Da to the diameter of the circumscribing circle of the impeller 1 as viewed in the axial direction Da is 0.77% or more and 3.08% or less. This reduces the load on the blades 12 when the impeller 1 rotates. Therefore, the airflow efficiency of the impeller 1 is improved. Note that if the ratio is less than 0.77%, there is a risk that the connection portion 13 will be damaged due to a decrease in strength when the impeller 1 rotates. On the other hand, if the ratio is greater than 3.08%, there is a risk that turbulence will occur near the connection portion 13, reducing the airflow efficiency of the impeller 1.

[0036] Furthermore, the other axial end surface of the connecting portion 13 is connected to the other axial end surface of each of the blades 12 adjacent in the circumferential direction Dc. This makes it possible to more effectively prevent airflow at the radial outer end of the blade 12 from flowing in the opposite direction (i.e., the other axial direction Da2) to the direction in which the impeller 1 sends out the airflow (i.e., the one axial direction Da1), particularly in an environment in which a high load is applied to the impeller 1.

[0037] <1-1-2. Blades 12> Next, the multiple blades 12 include a pair of blades 120 adjacent to each other in the circumferential direction Dc. The pair of blades 120 has a first blade 121 arranged on one circumferential side Dc1 and a second blade 122 arranged on the other circumferential side Dc2. In other words, the first blade 121 is arranged on one circumferential side Dc1 of the second blade 122. Note that the one circumferential side Dc1 here is the forward side in the rotation direction of the impeller 1. The connection portion 13 connects the radially outer end of the first blade 121 and the radially outer end of the second blade 122.

[0038] In the present embodiment, the number of pairs of blades 120 in the plurality of blades 12 is four. However, this is not limiting, and the number of pairs of blades 120 may be any number other than four. The plurality of blades 12 may also include one or more unpaired blades 12.

[0039] Preferably, the other circumferential end of the first blade 121 is connected to the radially inner end of the connecting portion 13 from one axial direction Da1 further than the radially inner end of the connecting portion 13. Also, preferably, the one circumferential end of the second blade 122 is connected to the radially inner end of the connecting portion 13 from the other axial direction Da2 further than the radially inner end of the connecting portion 13.

[0040] This allows the airflow to flow smoothly at the radially outer ends of the pair of blades 120. This makes it possible to suppress the generation of turbulence and vortices, thereby suppressing the generation of noise caused by these.

[0041] More preferably, in a radially outer portion of the first blade 121, the other circumferential end of the first blade 121 extends in both the other axial direction Da2 and the other circumferential direction Dc2 as it extends radially outward and is connected to the radially inner end of the connecting portion 13. For example, the portion of the first blade 121 on the other circumferential direction Dc2 side has a swept-back wing shape, and its tip side (the radially outer side of that portion) is located closer to the other axial direction Da2 than its base side (the radially inner side of that portion). Also, more preferably, in a radially outer portion of the second blade 122, the one circumferential end of the second blade 122 extends in both the one axial direction Da1 and the one circumferential direction Dc1 as it extends radially outward and is connected to the radially inner end of the connecting portion 13. For example, the portion of the second blade 122 on one circumferential side Dc1 has a forward-swept blade shape, and its tip side (the radially outer side of that portion) is located on one axial side Da1 than its base end side (the radially inner side of that portion).

[0042] More preferably, in a radially outer portion of the first blade 121, one circumferential end of the first blade 121 extends radially outward in one axial direction Da1 and one circumferential direction Dc2 and is connected to the radially outer end of the connecting portion 13. For example, the portion of the first blade 121 on the one circumferential direction Dc1 side has a swept-back wing shape, and its tip side (the radially outer side of that portion) is located closer to the one axial direction Da1 than its base side (the radially inner side of that portion). More preferably, in a radially outer portion of the second blade 122, the other circumferential end of the second blade 122 extends radially outward in the other axial direction Da2 and one circumferential direction Dc1 and is connected to the radially outer end of the connecting portion 13. For example, the portion of the second blade 122 on the other circumferential side Dc2 has a forward-swept blade shape, and its tip side (the radially outer side of that portion) is located further in the axial direction Da2 than its base end side (the radially inner side of that portion).

[0043] In this way, the load applied to the pair of blades 120 can be reduced when the impeller 1 rotates, thereby improving the air volume efficiency of the impeller 1.

[0044] However, the above example does not exclude a configuration in which the other circumferential end of the first blade 121 is not connected to the radially inner end of the connecting portion 13 from one axial direction Da1. Furthermore, the above example does not exclude a configuration in which the other circumferential end of the first blade 121 does not extend in both the other axial direction Da2 and the other circumferential direction Dc2 as it moves radially outward in the radially outer portion of the first blade 121. Furthermore, the above example does not exclude a configuration in which the one circumferential end of the first blade 121 does not extend in both the one axial direction Da1 and the other circumferential direction Dc2 as it moves radially outward in the radially outer portion of the first blade 121. For example, at least one of the portion of the first blade 121 on the one circumferential direction Dc1 side and the portion of the first blade 121 on the other circumferential direction Dc2 side may have a forward-swept blade shape, or may have neither a forward-swept blade shape nor a swept-back blade shape. The axial position of the radially outer portion of the other circumferential end of first blade 121 may be the same as the axial position of the portion on one circumferential direction Dc1 side of the radially inner end of connecting portion 13. The axial position of the radially outer portion of one circumferential end of first blade 121 may be the same as the axial position of the portion on one circumferential direction Dc1 side of the radially outer end of connecting portion 13.

[0045] Furthermore, the above example does not exclude a configuration in which one circumferential end of the second blade 122 is not connected to the radially inner end of the connecting portion 13 from the other axial direction Da2. The above example also does not exclude a configuration in which, at a radially outer portion of the second blade 122, one circumferential end of the second blade 122 does not extend in one axial direction Da1 and one circumferential direction Dc1 as it moves radially outward. The above example also does not exclude a configuration in which, at a radially outer portion of the second blade 122, the other circumferential end of the second blade 122 does not extend in the other axial direction Da2 and one circumferential direction Dc1 as it moves radially outward. For example, at least one of the portion of the second blade 122 on the one circumferential direction Dc1 side and the portion of the second blade 122 on the other circumferential direction Dc2 side may have a swept-back wing shape, or may have neither a forward-swept wing shape nor a swept-back wing shape. The axial position of the radially outer portion of one circumferential end of the second blade 122 may be the same as the axial position of the portion on the other circumferential direction Dc2 side of the radially inner end of the connecting portion 13. The axial position of the radially outer portion of the other circumferential end of the second blade 122 may be the same as the axial position of the portion on the other circumferential direction Dc2 side of the radially outer end of the connecting portion 13.

[0046] Preferably, in the radially outer portion of the first blade 121, the distance in the axial direction Da between the axial positions of one circumferential end and the other circumferential end of the first blade 121 at the same radial position decreases radially outward. Also, preferably, in the radially outer portion of the second blade 122, the distance in the axial direction Da between the axial positions of one circumferential end and the other circumferential end of the second blade 122 at the same radial position decreases radially outward. This increases the airflow volume of the pair of blades 120. Furthermore, the airflow static pressure characteristics of the impeller 1 can be improved. However, these examples do not exclude a configuration in which the distance in the axial direction Da between the radially outer portion of the first blade 121 does not decrease radially outward, and do not exclude a configuration in which the distance in the axial direction Da between the radially outer portion of the second blade 122 does not decrease radially outward.

[0047] Furthermore, one circumferential end of the radially inner end of the first blade 121 is preferably positioned in one axial direction Da1 from one circumferential end of the radially inner end of the second blade 122. And / or, the other circumferential end of the radially inner end of the first blade 121 is preferably positioned in one axial direction Da1 from the other circumferential end of the radially inner end of the second blade 122. Even in this manner, the airflow rate of the pair of blades 120 is increased. Furthermore, the airflow static pressure characteristics of the impeller 1 can be improved.

[0048] However, the above example does not exclude a configuration in which one circumferential end of the radially inner end of the first blade 121 is positioned in one axial direction Da1 less than one circumferential end of the radially inner end of the second blade 122. For example, the axial position of one circumferential end of the radially inner end of the first blade 121 may be the same as the axial position of one circumferential end of the radially inner end of the second blade 122.

[0049] Furthermore, the above example does not exclude a configuration in which the other circumferential end of the radially inner end of the first blade 121 is positioned less in one axial direction Da1 than the other circumferential end of the radially inner end of the second blade 122. For example, the axial position of the other circumferential end of the radially inner end of the first blade 121 may be the same as the axial position of the other circumferential end of the radially inner end of the second blade 122.

[0050] <1-2. Modifications of the embodiment> Next, a first modification and a second modification of the embodiment will be described. In the first modification and the second modification, the configuration of the impeller 1 differs from that of the above-described embodiment. Note that the above-described embodiment and the following first and second modifications can be implemented by combining at least some of the configurations with each other, as long as no particular contradiction occurs.

[0051] <1-2-1. First Modification> First, a first modification of the embodiment will be described with reference to Fig. 4. Fig. 4 is a perspective view showing a configuration example of an impeller 1a according to the first modification of the embodiment. Note that, in the following, configurations of the first modification that differ from the above-described embodiment will be described. Furthermore, components similar to those in the above-described embodiment will be assigned the same reference numerals, and descriptions thereof may be omitted.

[0052] In the impeller 1a of the first modified example, the connecting portion 13 connects the radially outer end of the blade 12 on the other circumferential side Dc2 to the radially outer portion of the blade 12 on the one circumferential side Dc1 of the blades 12 adjacent to each other in the circumferential direction Dc. For example, as shown in FIG. 4 , the connecting portion 13 extends from the radially outer end of the blade 12 on the other circumferential side Dc2 of the blades 12 adjacent to each other in the circumferential direction Dc toward the one circumferential side Dc1. The portion of the connecting portion 13 on the one circumferential side Dc1 is connected to the other axial end surface of the blade 12 on the one circumferential side Dc1 of the blades 12 adjacent to each other in the circumferential direction Dc. Preferably, the radial width of the portion of the connecting portion 13 on the one circumferential side Dc1 as viewed in the axial direction Da increases toward the one circumferential side Dc1. In this manner, the impeller 1 can be formed by arranging a plurality of blades 12, each with a connecting portion 13 extending from its radially outer end to the one circumferential side Dc1, on the radially outer end surface of the hub 11. This improves the degree of freedom in designing the impeller 1. Furthermore, by connecting the connecting portions 13 extending from the radially outer ends of the blades 12 on the other circumferential direction Dc2 side to the other axial end faces of the blades 12 on the one circumferential direction Dc1 side, the air volume and static pressure characteristics of the impeller 1 can be improved.

[0053] Preferably, the impeller 1a further includes a solid portion 14. The solid portion 14 is disposed between the other axial end face of the blade 12 on the one circumferential direction Dc1 side of the blades 12 adjacent to each other in the circumferential direction Dc and the portion of the connecting portion 13 on the one circumferential direction Dc1 side. In other words, the solid portion 14 is disposed at a portion where the other axial end face of the blade 12 on the one circumferential direction Dc1 side and the portion of the connecting portion 13 on the one circumferential direction Dc1 side overlap when viewed from the axial direction Da. By disposing the solid portion 14, when molding the impeller 1 using a mold, the impeller 1 can be removed by removing the mold in the axial direction Da. This facilitates molding of the impeller 1. However, this example does not exclude a configuration in which the impeller 1a does not include the solid portion 14.

[0054] <1-2-2. Second Modification> Next, a second modification of the embodiment will be described with reference to FIGS. 5 to 8. FIG. 5 is a perspective view showing a configuration example of a fan device 100 according to the second modification of the embodiment. FIG. 6 is a cross-sectional view of the fan device 100 according to the second modification of the embodiment. FIG. 7 is a perspective view showing a configuration example of an impeller 1b according to the second modification of the embodiment. FIG. 8 is a perspective view showing another configuration example of an impeller 1b according to the second modification of the embodiment. Note that FIG. 6 shows a cross-sectional structure obtained by virtually cutting the fan device 100 along a plane including the two-dot chain line VI-VI in FIG. 5 and the rotation axis J. In the following, the second modification will be described in terms of configurations that differ from the above-described embodiment and its first modification. Furthermore, components similar to those in the above-described embodiment and its first modification will be designated by the same reference numerals, and their description may be omitted.

[0055] 5 to 8 , in the second modified example, the radially outer surface of the hub 11 of the impeller 1b widens radially outward toward one axial direction Da1. In other words, the cylindrical portion 112 of the hub 11 is a cylindrical member with a truncated cone shape whose outer diameter, as viewed from the axial direction Da, increases toward one axial direction Da1. By shaping the hub 11 as described above, the impeller 1b of the fan unit 100 can improve the radial flow of airflow flowing toward one axial direction Da1.

[0056] Also, in FIG. 6 , when viewed from the circumferential direction, the radially outer end of the hub 11 is recessed inward in the axial direction Da1. In other words, the cross-sectional shape of the tubular portion 112, viewed from the normal direction to the paper, curves radially outward toward the axial direction Da1, or in other words, protrudes radially inward. This allows the fan device 100, which is an axial fan, to function similarly to a mixed flow fan. Therefore, the airflow and static pressure characteristics can be improved. However, without being limited to the example shown in FIG. 6 , when viewed from the circumferential direction, the radially outer end of the hub may be linear or may be convex toward the axial direction Da1 and radially outward. For example, the cross-sectional shape of the tubular portion 112, viewed from the normal direction to the paper, may extend radially outward linearly toward the axial direction Da1. Alternatively, the cross-sectional shape may curve radially inward toward the axial direction Da1, or in other words, protrude radially outward.

[0057] In the second modified example, at least some of the blades 12 extend radially outward from the radially outer surface of the hub 11 (the cylindrical portion 112 thereof) in the other axial direction Da2. For example, in FIGS. 5 to 7 , all of the blades 12 extend radially outward and in the other axial direction Da2. This configuration allows the impeller 1b to improve the radial flow of the airflow flowing toward the one axial direction Da1. Furthermore, by extending the blades 12 as described above, the fan device 100 can improve the airflow and static pressure characteristics, similar to a mixed flow fan. However, this example does not exclude a configuration in which all of the blades 12 extend radially outward but do not extend in the other axial direction Da2. Furthermore, at least some of the blades 12 may extend radially outward in a straight line, or may extend radially outward and in the one axial direction Da1.

[0058] Furthermore, in the second modified example, the plurality of blades 12 include a plurality of pairs of blades 120. For example, the number of pairs of blades 120 is four in FIG. 7 and nine in FIG. 8. However, the number of pairs of blades 120 is not limited to the examples shown in FIGS. 7 and 9 and may be a number other than four and nine. Furthermore, when the number of pairs of blades 120 is large, as shown in FIG. 8, in two pairs of blades 120 adjacent to each other in the circumferential direction Dc, the first blade 121 of the pair of blades 120 on the other circumferential side Dc2 may be connected to cross the second blade 122 of the pair of blades 120 on the one circumferential side Dc1.

[0059] Preferably, in at least some of the pairs of blades 120, the portion of the connecting portion 13 on the one circumferential direction Dc1 side extends at least toward the other axial direction Da2 from the radially outer end of the blade 12. This can improve the mechanical strength of the portion of the connecting portion 13 on the one circumferential direction Dc1 side.

[0060] 5 and 7 to 8, in at least some pairs of blades 120, the portion of the connecting portion 13 on one circumferential direction Dc1 side extends from the radially outer end of the blade 12 at least toward the other axial direction Da2. This improves the mechanical strength of the portion of the connecting portion 13 on one circumferential direction Dc1 side.

[0061] More preferably, in at least some pairs of blades 120, the central portions of the connecting portions 13 in the circumferential direction Dc are inclined radially inward as they move toward the other axial direction Da2. This configuration also allows the impeller 1b to improve the radial flow of airflow flowing toward the one axial direction Da1. Furthermore, by extending the blades 12 as described above, the fan unit 100 can improve the airflow and static pressure characteristics, similar to a mixed flow fan.

[0062] However, the above example does not exclude a configuration in which the central portion of the connecting portion 13 in the circumferential direction Dc does not tilt radially inward as it moves toward the other axial direction Da2 in at least some of the pairs of blades 120. For example, the central portion of the connecting portion 13 in the circumferential direction Dc may extend in the other axial direction Da2 or may tilt radially outward as it moves toward the other axial direction Da2. Furthermore, the above example does not exclude a configuration in which the portion of at least some of the connecting portion 13 on the one circumferential direction Dc1 side does not extend from the radially outer end of the blade 12 toward at least the other axial direction Da2.

[0063] 2. Remarks The above describes the embodiments of the present invention. Note that the above embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each process, and that such modifications are within the scope of the present invention.

[0064] 3. Summary The following provides a summary of the embodiments described above.

[0065] For example, the impellers 1, 1a, 1b disclosed in this specification comprise a covered cylindrical hub 11 extending in the axial direction Da and opening at one axial end, a plurality of blades 12 extending radially outward from the radially outer side surface of the hub 11 and aligned in the circumferential direction Dc, and a connecting portion 13 arranged between the radially outer ends of at least some of the blades 12 adjacent in the circumferential direction Dc, extending in the circumferential direction Dc, and connecting the radially outer ends of the blades 12 together, the connecting portion 13 being configured to extend radially when viewed in the axial direction (first configuration).

[0066] The impellers 1, 1a, 1b of the first configuration may also be configured (second configuration) in which the other axial end surface of the connection portion 13 is connected to the other axial end surfaces of each of the blades 12 adjacent to each other in the circumferential direction Dc.

[0067] Furthermore, the impeller 1, 1b of the first or second configuration may be configured such that the plurality of blades 12 include a pair of the blades 120 adjacent to each other in the circumferential direction Dc, the pair of blades 120 having a first blade 121 arranged on one circumferential side Dc1 and a second blade 122 arranged on the other circumferential side Dc2, the connecting portion 13 connects the radially outer end of the first blade 121 to the radially outer end of the second blade 122, the other circumferential end of the first blade 121 is connected to the radially inner end of the connecting portion 13 from one axial side Da1 of the radially inner end of the connecting portion 13, and the one circumferential end of the second blade 122 is connected to the radially inner end of the connecting portion 13 from the other axial side Da2 of the radially inner end of the connecting portion 13 (third configuration).

[0068] Furthermore, the impeller 1, 1b of the third configuration may be configured such that, in the radially outer portion of the first blade 121, the other circumferential end of the first blade 121 extends in the other axial direction Da2 and the other circumferential direction Dc2 as it moves radially outward and is connected to the radially inner end of the connecting portion 13, and in the radially outer portion of the second blade 122, one circumferential end of the second blade 122 extends in one axial direction Da1 and one circumferential direction Dc1 as it moves radially outward and is connected to the radially inner end of the connecting portion 13 (fourth configuration).

[0069] Furthermore, the impeller 1, 1b of the third or fourth configuration may have a configuration (fifth configuration) in which, in the radially outer portion of the first blade 121, one circumferential end of the first blade 121 extends in one axial direction Da1 and one circumferential direction Dc2 as it moves radially outward and is connected to the radially outer end of the connecting portion 13, and in the radially outer portion of the second blade 122, the other circumferential end of the second blade 122 extends in the other axial direction Da2 and one circumferential direction Dc1 as it moves radially outward and is connected to the radially outer end of the connecting portion 13.

[0070] Furthermore, the impeller 1, 1 b of any of the first to fifth configurations may be configured such that: the plurality of blades 12 include a pair of the blades 120 adjacent to each other in the circumferential direction; the pair of blades 120 has a first blade 121 arranged on one circumferential side Dc1 in the circumferential direction and a second blade 122 arranged on the other circumferential side Dc2 in the circumferential direction; the connecting portion 13 connects the radially outer end of the first blade 121 to the radially outer end of the second blade 122; in a radially outer portion of the first blade 121, the axial distance between the axial position of one circumferential end and the axial position of the other circumferential end of the first blade 121 at the same radial position decreases radially outward; and in a radially outer portion of the second blade 122, the axial distance between the axial position of one circumferential end and the axial position of the other circumferential end of the second blade 122 at the same radial position decreases radially outward (sixth configuration).

[0071] Furthermore, the impeller 1, 1b of any of the first to sixth configurations may be configured such that the plurality of blades 12 include a pair of blades 120 adjacent to each other in the circumferential direction Dc, the pair of blades 120 having a first blade 121 arranged on one circumferential side Dc1 and a second blade 122 arranged on the other circumferential side Dc2, the connecting portion 13 connecting the radial outer end of the first blade 121 to the radial outer end of the second blade 122, and the one circumferential end at the radial inner end of the first blade 121 is arranged in one axial direction Da1 further than the one circumferential end at the radial inner end of the second blade 122 (seventh configuration).

[0072] Furthermore, the impeller 1, 1b of any of the first to seventh configurations may be configured such that the plurality of blades 12 include a pair of blades 120 adjacent to each other in the circumferential direction Dc, the pair of blades 120 having a first blade 121 arranged on one circumferential side Dc1 and a second blade 122 arranged on the other circumferential side Dc2, the connecting portion 13 connecting the radial outer end of the first blade 121 to the radial outer end of the second blade 122, and the other circumferential end at the radial inner end of the first blade 121 is arranged in one axial direction Da1 further than the other circumferential end at the radial inner end of the second blade 122 (eighth configuration).

[0073] Furthermore, the impeller 1, 1a, 1b of any of the first to eighth configurations may be configured (ninth configuration) in which the ratio of the minimum radial width of the connection portion 13 as viewed from the axial direction to the diameter of the circumscribing circle of the impeller 1, 1a, 1b as viewed from the axial direction Da is 0.77% or more and 3.08% or less.

[0074] Furthermore, the impeller 1, 1a, 1b of the first or second configuration may be configured such that the connecting portion 13 extends from the radial outer end of the blade 12 on the other circumferential side Dc2 of the blades 12 adjacent to each other in the circumferential direction Dc toward one side Dc1 of the circumferential direction, the portion of the connecting portion 13 on the one side Dc1 of the circumferential direction is connected to the other axial end face of the blade 12 on the one side Dc1 of the circumferential direction Dc of the blades 12 adjacent to each other in the circumferential direction Dc, and the radial width of the portion of the connecting portion 13 on the one side Dc1 of the circumferential direction as viewed from the axial direction Da becomes wider toward the one side Dc1 of the circumferential direction (tenth configuration).

[0075] The impeller 1, 1a, 1b of any of the first to second and tenth configurations may be configured (eleventh configuration) to further include a solid portion 14 arranged between the other axial end face of the blade 12 on one circumferential side Dc1 of the blades 12 adjacent to each other in the circumferential direction Dc and the portion of the connecting portion 13 on one circumferential side Dc1.

[0076] Furthermore, the impeller 1, 1a, 1b of the first or second configuration may be configured such that the radially outer surface of the hub 11 widens radially outward as it moves toward one axial direction Da1 (12th configuration).

[0077] Furthermore, the impeller 1, 1a, 1b of any of the first to second and 12 configurations may have a configuration (13th configuration) in which, when viewed from the circumferential direction Dc, the radially outer end of the hub 11 is recessed in one axial direction Da1 and radially inward.

[0078] Furthermore, the impellers 1, 1a, 1b of the 12th or 13th configuration may be configured such that at least a portion of the blades 12 extend radially outward from the radially outer surface of the hub 11 and in the other axial direction Da2 (14th configuration).

[0079] Furthermore, the impeller 1, 1a, 1b of any of the above-mentioned 12th to 14th configurations may be configured such that the connection portion 13 is located on the other axial side Da2 than the radial inner end of the blade 12 (15th configuration).

[0080] Furthermore, the impeller 1, 1a, 1b of any of the first to fifteenth configurations may be configured such that the portion of the connecting portion 13 on one circumferential side Dc1 extends from the radial outer end of the blade 12 at least toward the other axial side Da2 (sixteenth configuration).

[0081] Furthermore, the impeller 1, 1a, 1b of the above-mentioned 16th configuration may be configured (17th configuration) such that the central portion of the connection portion 13 in the circumferential direction Dc is inclined radially inward as it approaches the other axial direction Da2.

[0082] The fan device 100 disclosed in this specification is configured (18th configuration) to include an impeller 1, 1a, 1b of any one of the first to seventeenth configurations described above, and a motor 2 having a shaft 21 that can rotate together with the impeller 1, 1a, 1b around a rotation axis J extending in the axial direction Da, and at least a portion of which is disposed inside the hub 11.

[0083] The present invention is useful in devices that deliver an axial air flow.

[0084] 100...fan device, 101...suction port, 102...delivery port, 103...wind tunnel, 1, 1a, 1b...impeller, 11...hub, 111...plate portion, 112...tubular portion, 113...holder, 12...blade, 120...pair of blades, 121...first blade, 122...second blade, 13...connection portion, 14...solid portion, 2...motor, 21...shaft, 3...housing, 31...motor holder, 32...circumferential wall portion, 33...rib, 4...substrate, 41...external wiring, J...rotating shaft, Da...axial direction, Da1...one side of axial direction, Da2...other side of axial direction, Dc...circumferential direction, Dc1...one side of circumferential direction, Dc2...other side of circumferential direction

Claims

1. A covered cylindrical hub extending in the axial direction and having an opening at one axial end, a plurality of blades extending radially outward from the radially outer side surface of the hub and arranged in the circumferential direction, and a connecting portion disposed between radially outer ends of at least some of the blades adjacent to each other in the circumferential direction, extending in the circumferential direction, and connecting the radially outer ends of the blades. The connecting portion spreads radially when viewed from the axial direction. An impeller.

2. The impeller according to claim 1, wherein the other axial end surface of the connecting portion is connected to the other axial end surface of each of the blades adjacent to each other in the circumferential direction.

3. The plurality of blades includes a pair of blades adjacent to each other in the circumferential direction. The pair of blades has a first blade disposed on one side in the circumferential direction and a second blade disposed on the other side in the circumferential direction. The connecting portion connects the radially outer end of the first blade and the radially outer end of the second blade. The other circumferential end of the first blade is connected to the radially inner end of the connecting portion from one axial side of the radially inner end of the connecting portion. The one circumferential end of the second blade is connected to the radially inner end of the connecting portion from the other axial side of the radially inner end of the connecting portion. The impeller according to claim 1 or claim 2.

4. In a portion on the radially outer side of the first blade, the other circumferential end of the first blade extends axially and circumferentially in the other direction as it extends radially outward, and is connected to the radially inner end of the connecting portion. In a portion on the radially outer side of the second blade, the one circumferential end of the second blade extends axially and circumferentially in the one direction as it extends radially outward, and is connected to the radially inner end of the connecting portion. The impeller according to claim 3.

5. In a portion on the radially outer side of the first blade, the one circumferential end of the first blade extends axially and circumferentially in the other direction as it extends radially outward, and is connected to the radially outer end of the connecting portion. In a portion on the radially outer side of the second blade, the other circumferential end of the second blade extends axially and circumferentially in the one direction as it extends radially outward, and is connected to the radially outer end of the connecting portion. The impeller according to claim 3.

6. The plurality of the blades includes a pair of the blades adjacent to each other in the circumferential direction. The pair of the blades has a first blade disposed on one side in the circumferential direction and a second blade disposed on the other side in the circumferential direction. The connecting portion connects the radially outer end portion of the first blade and the radially outer end portion of the second blade. In a portion on the radially outer side of the first blade, an axial interval between an axial position of one circumferential end portion and an axial position of the other circumferential end portion at the same radial position of the first blade decreases as it goes radially outward. In a portion on the radially outer side of the second blade, an axial interval between an axial position of one circumferential end portion and an axial position of the other circumferential end portion at the same radial position of the second blade decreases as it goes radially outward. The impeller according to claim 1 or claim 2.

7. The plurality of the blades includes a pair of the blades adjacent to each other in the circumferential direction. The pair of the blades has a first blade disposed on one side in the circumferential direction and a second blade disposed on the other side in the circumferential direction. The connecting portion connects the radially outer end portion of the first blade and the radially outer end portion of the second blade. One circumferential end portion at the radially inner end portion of the first blade is disposed axially on one side with respect to one circumferential end portion at the radially inner end portion of the second blade. The impeller according to claim 1 or claim 2.

8. The plurality of the blades includes a pair of the blades adjacent to each other in the circumferential direction. The pair of the blades has a first blade disposed on one side in the circumferential direction and a second blade disposed on the other side in the circumferential direction. The connecting portion connects the radially outer end portion of the first blade and the radially outer end portion of the second blade. The other circumferential end portion at the radially inner end portion of the first blade is disposed axially on one side with respect to the other circumferential end portion at the radially inner end portion of the second blade. The impeller according to claim 1 or claim 2.

9. The ratio of the minimum radial width of the connecting portion as viewed axially to the diameter of the circumscribed circle of the impeller as viewed axially is 0.77% or more and 3.08% or less. The impeller according to claim 3.

10. The connecting portion extends in one circumferential direction from the radially outer end portion of the blade on the other circumferential side among the blades adjacent in the circumferential direction, and a portion on one circumferential side of the connecting portion is connected to the axially other end face of the blade on one circumferential side among the blades adjacent in the circumferential direction. The radially outward width of the portion on one circumferential side of the connecting portion as viewed from the axial direction becomes wider as it goes in one circumferential direction. The impeller according to claim 1 or claim 2.

11. The impeller according to claim 1 or claim 2, further comprising a solid portion disposed between the axially other end face of the blade on one circumferential side among the blades adjacent in the circumferential direction and the portion on one circumferential side of the connecting portion.

12. The radially outer surface of the hub widens radially outward as it goes in one axial direction. The impeller according to claim 1 or claim 2.

13. As viewed from the circumferential direction, the radially outer end portion of the hub is recessed in one axial direction and radially inward. The impeller according to claim 1 or claim 2.

14. At least a part of the blade extends radially outward and axially in the other direction from the radially outer surface of the hub. The impeller according to claim 12.

15. The connecting portion is located on the axially other side of the radially inner end portion of the blade. The impeller according to claim 12.

16. The portion on one circumferential side of the connecting portion extends at least axially in the other direction from the radially outer end portion of the blade. The impeller according to claim 1 or claim 2.

17. The central portion in the circumferential direction of the connecting portion inclines radially inward as it goes in the axially other direction. The impeller according to claim 16.

18. A fan device comprising: the impeller according to claim 1 or claim 2; and a motor having a shaft rotatable together with the impeller about a rotation axis extending in the axial direction and at least a part of which is disposed inside the hub.

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