Impeller and fan device

Abstract

This impeller in a fan device includes a hub and a plurality of rotor blades. The hub assumes the shape of a bottomed cylinder extending in the axial direction. One end of the hub in the axial direction is open. The plurality of rotor blades are disposed further radially outward than the hub and are arranged along the circumferential direction. Each of the rotor blades has a blade part and a holding part. The blade part expands in the axial direction and the radial direction and inclines in one circumferential direction toward the other side in the axial direction. The holding part extends radially inward from one end of the blade part in the axial direction and is connected to the hub.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of International Application No. PCT / JP2024 / 042649, filed on Dec. 3, 2024, which is incorporated herein by reference in its entirety, and which claims priority to Japanese Patent Application No. 2023-204854, filed in Japan on Dec. 4, 2023, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to an impeller and a fan device.BACKGROUND

[0003] There is a known blower (fan device) that radially outwardly discharges air sucked from an axial direction. For example, a fan (also referred to as an impeller) of a blower is constituted by a hub having a disk shape, a shroud, and a plurality of blades. A rotation axis of the motor is fixed to a center part of the hub. The center part of the hub bulges toward the shroud in a bell shape. The shroud has an annular shape opening toward a suction port, and is disposed to face the hub. The plurality of blades are disposed between the shroud and the hub.

[0004] However, in the known fan, the hub (in particular, a part holding the blade on a radially outer side of the center part of the hub) has a disk shape. Therefore, since air resistance is generated by friction with air during rotation, it is necessary to secure sufficient torque for rotation of the fan.SUMMARY

[0005] An exemplary impeller of the present disclosure includes a hub and a plurality of rotor blades. The hub has a lidded tubular shape extending in the axial direction. One axial end of the hub is open. The plurality of rotor blades are disposed further radially outward than the hub and are arranged in the circumferential direction. Each of the rotor blades includes a blade part and a holding part. The blade part expands in the axial direction and the radial direction and is inclined toward one circumferential side while extending toward the other axial side. The holding part extends radially inward from one axial end of the blade part and is connected to the hub.

[0006] An exemplary fan device of the present disclosure radially outwardly discharges fluid sucked in one axial side. The fan device includes an impeller and a motor. The impeller includes a hub and a plurality of rotor blades. The hub has a lidded tubular shape extending in the axial direction. One axial end of the hub is open. The plurality of rotor blades are disposed radially outward relative to the hub and are arranged in the circumferential direction. At least a part of the motor is disposed inside the hub. The motor includes a shaft. The shaft is configured to rotate together with the impeller about a rotation axis extending in the axial direction. Each of the rotor blades includes a blade part and a holding part. The blade part expands in the axial direction and the radial direction and is inclined toward one circumferential side while extending toward the other axial side. The holding part extends radially inward from one axial end of the blade part and is connected to the hub.

[0007] Further features and advantages of the present disclosure will be further clarified by the following embodiment.

[0008] The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a cross-sectional view illustrating a configuration example of a fan device according to an embodiment;

[0010] FIG. 2 is a plan view illustrating an inside of the fan device according to the embodiment; and

[0011] FIG. 3 is a perspective view illustrating a configuration example of an impeller according to the embodiment.DETAILED DESCRIPTION

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0013] Note that in the present description, in a fan device 100, a direction parallel to a rotation axis J is referred to as an “axial direction Da”. In the axial direction Da, an orientation from a first plate portion 31 to a second plate portion 32 described later is referred to as “one axial side Da1”, and an orientation from the second plate portion 32 to the first plate portion 31 is referred to as an “other axial side Da2”. A direction orthogonal to the rotation axis J is referred to as a “radial direction”. In the radial direction, an orientation approaching the rotation axis J is referred to as “radially inward”, and an orientation away from the rotation axis J is referred to as “radially outward”. A rotation direction about the rotation axis J is referred to as a “circumferential direction Dc”. One orientation of the circumferential direction Dc is referred to as “one circumferential side Dc1”, and the other orientation is referred to as an “other circumferential side Dc2”. In the present description, when the fan device 100 and an impeller 1 are viewed from the other axial side Da2 side toward the one axial side Da1, the one circumferential side Dc1 is a counterclockwise direction about the rotation axis J in the circumferential direction Dc, and the other circumferential side Dc2 is a clockwise direction about the rotation axis J in the circumferential direction Dc.

[0014] In the present description, “annular” includes not only a shape continuous without a break over the entire region in the circumferential direction Dc about the rotation axis J, but also a shape having one or more breaks in a part of the entire region in the circumferential direction Dc about the rotation axis J. It also includes a shape forming a closed curve on a curved surface intersecting the rotation axis J about the rotation axis J.

[0015] Further, in a positional relationship between any one and any other of an azimuth, a line, and a plane, the term “parallel” includes not only a state in which the two elements do not intersect at all no matter how far each extends, but also a state in which the two are substantially parallel. Further, each of the terms “perpendicular” and “orthogonal” includes not only a state in which the two elements intersect each other at 90 degrees, but also a state in which the two elements are substantially perpendicular and a state in which the two elements are substantially orthogonal. That is, each of the terms “parallel”, “perpendicular”, and “orthogonal” includes a state in which the positional relationship between the two elements permits an angular deviation to an extent not departing from the spirit of the present disclosure.

[0016] Note that these terms are merely used for description and are not intended to limit actual positional relationships, directions, names, and the like.1. Embodiment

[0017] FIG. 1 is a cross-sectional view illustrating a configuration example of the fan device 100 according to an embodiment. FIG. 2 is a plan view illustrating the inside of the fan device 100 according to the embodiment. Note that FIG. 1 illustrates a cross-sectional structure of the fan device 100 taken along a plane including a two-dot chain line I and the rotation axis J of FIG. 2. In FIG. 2, illustration of the first plate portion 31 is omitted in order to make the inside easy to see.1-1. Fan Device 100

[0018] The fan device 100 is a so-called centrifugal fan, and discharges radially outward fluid F sucked in the one axial side Da1. Note that in the present embodiment, the fluid F sucked and discharged by the fan device 100 is air. However, not limited to this example, the fluid F may be gas other than air or liquid. The fan device 100 is used for a cooling fan of an electronic device required to have a thin profile, for example. However, the application of the fan device 100 is not limited to this example.

[0019] The fan device 100 includes the impeller 1, a motor 2, a housing 3, and a substrate 4.

[0020] The impeller 1 is configured to rotate about the rotation axis J extending in the axial direction Da. The impeller 1 is attached to the motor 2. The impeller 1 includes a hub 11 having a lidded tubular shape and a plurality of rotor blades 12. Note that, in the present description, a shape in which one end of a tubular body (e.g., a tubular portion 112 described later) is covered with a lid-like body (e.g., a plate portion 111 described later) is referred to as a “lidded tubular shape”.

[0021] The motor 2 is a drive source that rotates the impeller 1. At least a part of the motor 2 is disposed inside the hub 11. The motor 2 includes a shaft 21 extending in the axial direction Da along the rotation axis J. The shaft 21 is configured to rotate together with the impeller 1 about the rotation axis J extending in the axial direction Da. 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.

[0022] The housing 3 houses the impeller 1, the motor 2, and the substrate 4 therein. The housing 3 includes the first plate portion 31, the second plate portion 32, and a circumferential wall portion 33.

[0023] The first plate portion 31 is disposed on the one axial side Da1 relative to the impeller 1 and expands in a direction intersecting the axial direction Da. The motor 2 and the substrate 4 are fixed to an inner surface (other axial side end surface) of the first plate portion 31.

[0024] The second plate portion 32 is disposed on the other axial side Da2 relative to the impeller 1 and expands in a direction intersecting the axial direction Da. A suction port 34 is disposed in the second plate portion 32. The suction port 34 penetrates the second plate portion 32 in the axial direction Da. As viewed from the one axial side Da1 side, the suction port 34 overlaps the center part (in particular, the hub 11 and a holding part 122 described later of the rotor blade 12) of the impeller 1. An outer edge of the suction port 34 surrounds the rotation axis J.

[0025] The circumferential wall portion 33 is disposed along an outer edge portion of the first plate portion 31 and an outer edge portion of the second plate portion 32 and extends in the axial direction Da. One axial end of the circumferential wall portion 33 is connected to the outer edge portion of the first plate portion 31. The other axial end of the circumferential wall portion 33 is connected to the outer edge portion of the second plate portion 32. The circumferential wall portion 33 is provided with a discharge port 35. The discharge port 35 penetrates the circumferential wall portion 33 in the radial direction. In other words, the discharge port 35 is provided on a radially outer surface of the housing 3, and is open at least in the radial direction radially outward relative to the impeller 1.

[0026] In the fan device 100, due to rotation of the impeller 1 about the rotation axis J, the fluid F is sucked from the suction port 34 and discharged radially outward relative to the impeller 1. The fluid F flows along an inner surface of the circumferential wall portion 33 inside the housing 3 as viewed from the axial direction Da, and is emitted from the discharge port 35 to the outside of the fan device 100.

[0027] For example, the substrate 4 is electrically connected to a stator (not illustrated) of the motor 2, and is electrically connected to an external circuit of the fan device 100 via a connection line (not illustrated) drawn out to the outside of the fan device 100. The substrate 4 is equipped with an electric circuit including a motor drive circuit, an electric element, and the like. The substrate 4 has a plate shape expanding in the radial direction, and is disposed on the one axial side Da1 side of the motor 2.

[0028] Note that not limited to the above example, the fan device 100 may be configured not to include the housing 3. In this case, the motor 2 and the substrate 4 are fixed to a counterpart side (such as a wall) to which the fan device 100 is attached.1-2. Configuration of Impeller

[0029] Next, a detailed configuration of the impeller 1 will be described with reference to FIGS. 1 to 3. FIG. 3 is a perspective view illustrating a configuration example of the impeller 1 according to the embodiment. As described above, the impeller 1 includes the hub 11 assuming a lidded tubular shape and the plurality of rotor blades 12. The hub 11 has a lidded tubular shape extending in the axial direction Da. One axial end of the hub 11 is open. The plurality of rotor blades 12 are disposed radially outward relative to the hub 11 and are arranged in the circumferential direction Dc.

[0030] Preferably, the total number of the rotor blades 12 (in particular, blade parts 121) is a prime number. In the case of a general fan device, discrete frequency noise (so-called NZ noise) attributable to the product of a number Z of the rotor blades 12 and a rotational speed N of the motor 2 is generated at a corner portion (e.g., a portion 331 surrounded by the broken line in FIG. 1; a so-called tongue portion) of the circumferential wall portion 33 of the fan device 100, for example. On the other hand, by setting the total number of the rotor blades 12 to a prime number, interference (resonance) between the order of the rotor blades 12 and the order of magnetic excitation of the motor 2 can be suppressed. However, this example does not exclude a configuration in which the total number of the rotor blades 12 is not a prime number. That is, the total number of the rotor blades 12 may be a so-called composite number.

[0031] The hub 11 and the rotor blades 12 may be made of resin or metal. The hub 11 and the plurality of rotor blades 12 may be integrated (i.e., different parts of a single member) or may be separate (i.e., different members).

[0032] The hub 11 includes the plate portion 111, the tubular portion 112, and a holder 113. The plate portion 111 has a circular shape extending radially outward from the rotation axis J. The tubular portion 112 extends in the one axial side Da1 from a radially outer end of the plate portion 111 and surrounds a portion of the motor 2 and the shaft 21 at least on the other axial side Da2 side. A radially inner surface of the tubular portion 112 radially faces a radially outer surface of the motor 2 with a gap. The holder 113 has a tubular shape that surrounds and houses the other axial end of the shaft 21, and is fixed to the shaft 21. A radially inner surface of the holder 113 is in contact with the radially outer surface of the shaft 21.

[0033] Each of the rotor blades 12 includes the blade part 121 and the holding part 122. The blade part 121 expands in the axial direction Da and the radial direction, and is inclined toward one circumferential side Dc1 while extending toward the other axial side Da2. The holding part 122 extends radially inward from one axial end of the blade part 121 and is connected to the hub 11. Note that in the present embodiment, the holding part 122 is connected to one axial end of the radially outer surface of the hub 11. However, the connection position in the axial direction of the holding part 122 relative to the hub 11 is not limited to this example. The connection position of the holding part 122 may be the axial center part of the radially outer surface of the hub 11 or the one axial side Da1 relative to the axial center part.

[0034] According to the impeller 1 of the fan device 100 according to the present embodiment, the holding part 122 connected to the hub 11 holds the blade part 121 in each of the rotor blades 12. Therefore, an annular plate member (a so-called shroud) for holding the blade part 121 need not be disposed. The total area of one axial end surface of the holding part 122 of each of the rotor blades 12 as viewed from the one axial side Da1 side is smaller than the area of one axial end surface of the plate member described above. Therefore, when the impeller 1 rotates, friction between the holding part 122 and the fluid F can be reduced. That is, the fluid resistance in the holding part 122 holding the blade part 111 of the impeller 1 can be reduced.

[0035] The holding parts 122 adjacent to each other in the circumferential direction are arranged in the circumferential direction Dc at intervals. Therefore, the weight of the impeller 1 can be reduced as compared with a configuration in which the blade part 111 is held by a plate member having an annular shape.

[0036] These can reduce torque required for rotation of the impeller 1, and therefore the motor 2 having a smaller size can rotate the impeller 1. That is, an increase in the size of the motor 2 can be prevented.

[0037] In the present embodiment, as viewed from the axial direction Da, a portion of the blade part 121 on at least a radially outer side is inclined toward the one circumferential side Dc1 while extending radially outward. That is, the blade part 121 includes a forward blade. However, not limited to this example, the portion of the blade part 121 on at least a radially outer side may be inclined toward the other circumferential side Dc2 while extending radially outward. That is, the blade part 121 may include a backward blade. Alternatively, the portion of the blade part 121 on at least radially outer side may extend straight radially outward.

[0038] In the present embodiment, as viewed from the one axial side Da1 side, a radially outer end of the other axial end of the blade part 121 of the rotor blade 12 is positioned radially outward relative to the outer edge of the suction port 34. However, this example does not exclude a configuration in which the radially outer ends of the other axial ends of the blade parts 121 of at least some of the rotor blades 12 are at the same position as the outer edge of the suction port 34 or positioned radially inward relative to the outer edge of the suction port 34 as viewed from the one axial side Da1 side.

[0039] Preferably, as viewed from the one axial side Da1 side, radially inner ends of the other axial ends of the blade parts 121 in at least some of the rotor blades 12 are disposed radially outward relative to the outer edge of the suction port 34. More preferably, in all the rotor blades 12, the blade parts 121 are disposed radially outward relative to the outer edge of the suction port 34. This can increase the flow rate of the fluid F flowing from the suction port 34 into between the blade parts 121. Therefore, the flow rate of the fluid F discharged radially outward by the fan device 100 can be increased. However, this example does not exclude a configuration in which the radially inner ends of the other axial ends of the blade parts 121 in at least some of the rotor blades 12 are disposed at the same position as the outer edge of the suction port 34 or disposed radially inward relative to the outer edge of the suction port 34 as viewed from the one axial side Da1 side.

[0040] Preferably, the axial width of a radially inner end of the holding part 122 is larger than the circumferential width of the radially inner end of the holding part 122. This allows a larger number of the holding parts 122 to be connected to the other axial end of the hub 11. That is, a larger number of the rotor blades 12 can be disposed on the radially outer side of the hub 11. Therefore, when rotating, the impeller 1 can discharge a larger amount of the fluid F radially outward. However, this example does not exclude a configuration in which the axial width of the radially inner end of the holding part 122 is equal to or less than the circumferential width of the radially inner end of the holding part 122.

[0041] Next, each of the rotor blades 12 further includes a connection part 123. In each of the rotor blades 12, the connection part 123 extends in the one circumferential side Dc1 from the other axial end of the blade part 121. In the rotor blades 12 adjacent to each other in the circumferential direction Dc, one circumferential end of the connection part 123 of the rotor blade 12 on the other circumferential side Dc2 side is connected to the blade part 121 of the rotor blade 12 on the one circumferential side Dc1 side, and in particular, connected to the other circumferential end surface of the blade part 121.

[0042] This can prevent the fluid F from leaking from the pressure surface of the blade part 121 to the other axial side Da2 when the impeller 1 is rotated. Therefore, a decrease in the flow rate of the fluid F discharged radially outward can be prevented.

[0043] For example, when the impeller 1 is rotated in the one circumferential side Dc1 about the rotation axis J, one circumferential end surface of the blade part 121 becomes a pressure surface, and the other circumferential end surface of the blade part 121 becomes a suction surface. Here, in a configuration in which the other axial end of the blade part 121 is a free end, a blade tip vortex occurs on the other axial side Da2 side of the other axial end of the blade part 121, and the fluid F on the pressure surface leaks to the other axial side Da2. Therefore, leakage loss of the fluid F at the other axial end of the blade part 121 increases, and the fluid efficiency of the impeller 1 deteriorates.

[0044] On the other hand, as illustrated in FIG. 3, by disposing the connection part 123 at the other axial end of the blade part 121, generation of the blade tip vortex on the other axial side Da2 side of the other axial end of the blade part 121 can be suppressed. That is, the rotor blade 12 of the present embodiment has a toroidal shape having no blade tip serving as a free end on the suction port 34 side in the axial direction Da of the blade part 121. The impeller 1 according to the present embodiment is a toroidal fan in which generation of a blade tip vortex is suppressed and leakage of the fluid F from the pressure surface (one circumferential end surface) to the other axial side Da2 is prevented. Therefore, leakage of the fluid F at the other axial end of the blade part 121 can be prevented. Furthermore, since generation of the blade tip vortex is suppressed, turbulent noise generated when a pressure fluctuation caused by the blade tip vortex propagates to the surroundings as a sound wave can be reduced.2. Remarks

[0045] The embodiment of the present disclosure has been described above. Note that the above-described embodiment is an example, and it is understood by those skilled in the art that various modifications can be made to combinations of each component and each process, and are within the scope of the present disclosure.3. Conclusions

[0046] Hereinafter, the embodiment described so far will be collectively described.

[0047] For example, the impeller 1 disclosed in the present description includes: the hub 11 having a lidded tubular shape extending in the axial direction Da and having one axial end open; and the plurality of rotor blades 12 disposed radially outward relative to the hub 11 and arranged in the circumferential direction Dc, in which each of the rotor blades 12 includes the blade part 121 expanding in the axial direction Da and the radial direction and inclined toward the one circumferential side Dc1 while extending toward the other axial side Da2, and the holding part 122 extending radially inward from one axial end of the blade part 121 and connected to the hub 11 (first configuration).

[0048] In the impeller 1 having the first configuration, each of the rotor blades 12 may further include the connection part 123 extending toward the one circumferential side Dc1 from the other axial end of the blade part 121, and in the rotor blades 12 adjacent to each other in the circumferential direction Dc, one circumferential end of the connection part 123 of the rotor blade 12 on the other circumferential side Dc2 side may be connected to the blade part 121 of the rotor blade 12 on the one circumferential side Dc1 side (second configuration).

[0049] In the impeller 1 having the first or second configuration, the axial width of the radially inner end of the holding part 122 may be larger than the circumferential width of the radially inner end of the holding part 122 (third configuration).

[0050] The fan device 100 disclosed in the present description is the fan device 100 that radially outwardly discharges the fluid F sucked in the one axial side Da1, the fan device including: the impeller 1 including the hub 11 having a lidded tubular shape extending in the axial direction Da and having one axial end open and the plurality of rotor blades 12 disposed radially outward relative to the hub 11 and arranged in the circumferential direction Dc; and the motor 2 including the shaft 21 configured to rotate together with the impeller 1 about the rotation axis J extending in the axial direction Da, at least a part of the motor 2 being disposed inside the hub 11, in which each of the rotor blades 12 includes the blade part 121 expanding in the axial direction Da and the radial direction and inclined toward the one circumferential side Dc1 while extending toward the other axial side Da2, and the holding part 122 extending radially inward from one axial end of the blade part 121 and connected to the hub 11 (fourth configuration).

[0051] The present disclosure is useful for a device that discharges an airflow radially outward.

[0052] Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

[0053] While preferred embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Claims

1. An impeller comprising:a hub having a lidded tubular shape extending in an axial direction and having one axial end open; anda plurality of rotor blades disposed radially outward relative to the hub and arranged in a circumferential direction, whereineach of the rotor blades includes a blade part expanding in the axial direction and a radial direction and inclined toward one circumferential side while extending toward the other axial side, and a holding part extending radially inward from one axial end of the blade part and connected to the hub.

2. The impeller according to claim 1, whereineach of the rotor blades further includes a connection part extending toward one circumferential side from another axial end of the blade part, and in the rotor blades adjacent to each other in the circumferential direction, one circumferential end of the connection part of the rotor blade on another circumferential side is connected to the blade part of the rotor blade on one circumferential side.

3. The impeller according to claim 1, whereinan axial width of a radially inner end of the holding part is larger than a circumferential width of the radially inner end of the holding part.

4. A fan device that radially outwardly discharges fluid sucked in one axial side, the fan device comprising:an impeller including a hub having a lidded tubular shape extending in an axial direction and having one axial end open and a plurality of rotor blades disposed radially outward relative to the hub and arranged in a circumferential direction; anda motor including a shaft configured to rotate together with the impeller about a rotation axis extending in the axial direction, at least a part of the motor being disposed inside the hub, whereineach of the rotor blades includes a blade part expanding in the axial direction and a radial direction and inclined toward one circumferential side while extending toward the other axial side, and a holding part extending radially inward from one axial end of the blade part and connected to the hub.

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