Impeller and fan device

Abstract

An impeller of a fan device includes a hub and a plurality of rotor blades. The hub is in the shape of a cylinder which extends in the axial direction and is provided with a cover. And an opening is formed in the end part of one axial side of the hub. The plurality of rotor blades are arranged on the outside in the radial direction of the hub and are arranged in the circumferential direction. Each of the rotor blades has a blade portion and a holding portion. The blade portion expands in the axial direction and the radial direction, and inclines to one side in the circumferential direction as the blade portion tends to the other side in the axial direction. The holding portion extends radially inward from an end portion on one side in the axial direction of the blade portion and is connected to the hub.

Description

Technical Field

[0001] This invention relates to an impeller and fan assembly. Background Technology

[0002] Previously, blowers (fan devices) that deliver axially drawn air radially outward were known. For example, the fan (also called impeller) of such blowers consists of a disc-shaped hub, a shroud, and multiple blades. A motor shaft is fixed to the center of the hub. Furthermore, the center of the hub bulges outward towards the shroud in a bell shape. The shroud is annular, facing the intake opening, and is positioned opposite the hub. Multiple blades are disposed between the shroud and the hub (see Japanese Patent Application Publication No. 2011-58442).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-58442 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in the fan described in Japanese Patent Application Publication No. 2011-58442, the hub (especially the portion where the blades are held radially outward from the center of the hub) is disc-shaped. Therefore, air resistance is generated due to friction with the air during rotation, so sufficient torque is required to ensure the fan's rotation.

[0008] The purpose of this invention is to reduce the fluid resistance at the retaining part of the impeller blade section.

[0009] Solution for solving the problem

[0010] An exemplary impeller of the present invention includes a hub and a plurality of moving blades. The hub is a covered cylindrical shape extending axially. The hub has an opening at one axial end. The plurality of moving blades are disposed radially outward from the hub and arranged circumferentially. Each moving blade has a blade portion and a retaining portion. The blade portion extends axially and radially, and is inclined circumferentially towards the other axial side. The retaining portion extends radially inward from one axial end of the blade portion and is connected to the hub.

[0011] An exemplary fan device of the present invention delivers fluid drawn in from one axial direction to the radially outward direction. The fan device includes an impeller and a motor. The impeller has a hub and a plurality of moving blades. The hub is a covered cylindrical shape extending axially. The axial end of the hub is open. The plurality of moving blades are arranged radially outward from the hub and are circumferentially arranged. At least a portion of the motor is disposed inside the hub. The motor has a shaft. The shaft is rotatable with the impeller about a rotating axis extending axially. Each moving blade has a blade portion and a retaining portion. The blade portion extends axially and radially and is inclined circumferentially to one side as it moves towards the other axial direction. The retaining portion extends radially inward from the axial end of the blade portion and is connected to the hub.

[0012] Further features and advantages of the present invention will become more apparent from the embodiments shown below.

[0013] Invention Effects

[0014] According to the exemplary impeller and fan device of the present invention, the fluid resistance at the retaining portion that holds the blades of the impeller can be reduced. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view showing an example of the configuration of the fan device in the embodiment.

[0016] Figure 2 This is a top view showing the interior of the fan device in the embodiment.

[0017] Figure 3 This is a perspective view showing an example of the impeller configuration in an embodiment. Detailed Implementation

[0018] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0019] It should be noted that, in this specification, in the fan assembly 100, the direction parallel to the rotation axis J is referred to as "axial direction Da". The direction from the first plate portion 31 to the second plate portion 32 (described later) within axial direction Da is referred to as "axial side Da1", and the direction from the second plate portion 32 to the first plate portion 31 is referred to as "axial side Da2". Furthermore, the direction orthogonal to the rotation axis J is referred to as "radial direction". The direction closer to the rotation axis J within the radial direction is referred to as "radial inner direction", and the direction farther from the rotation axis J is referred to as "radial outer direction". Furthermore, the rotational direction centered on the rotation axis J is referred to as "circumferential direction Dc". One direction within the circumferential direction Dc is referred to as "circumferential side Dc1", and the other direction is referred to as "circumferential side Dc2". In this specification, when viewing the fan assembly 100 and impeller 1 from the axial side Da2 side towards the axial side Da1 side, the circumferential side Dc1 is the counterclockwise direction centered on the rotation axis J within the circumferential direction Dc, and the circumferential side Dc2 is the clockwise direction centered on the rotation axis J within the circumferential direction Dc.

[0020] Furthermore, in this specification, "ring-shaped" includes not only a shape that is seamlessly and continuously connected as a single unit across the entire circumferential region Dc centered on the rotation axis J, but also a shape that has more than one gap in a portion of the entire circumferential region Dc centered on the rotation axis J. Additionally, it also includes a shape in which a closed curve is drawn on a surface centered on and intersecting the rotation axis J.

[0021] Furthermore, in the positional relationship between any two parties in orientation, line, and plane, "parallel" includes not only the state where the two never intersect no matter where they extend, but also the state where they are substantially parallel. Furthermore, "perpendicular" and "orthogonal" respectively include not only the state where the two intersect at 90 degrees, but also the states where they are substantially perpendicular and substantially orthogonal. That is to say, "parallel," "perpendicular," and "orthogonal" respectively include states where the positional relationship between the two parties has an angular offset to a degree that does not depart from the spirit of this invention.

[0022] It should be noted that these are for illustrative purposes only and are not intended to limit actual positional relationships, directions, or names.

[0023] <1. Implementation Method> Figure 1 This is a cross-sectional view showing an example of the configuration of the fan device 100 according to the embodiment. Figure 2 This is a top view showing the interior of the fan device 100 according to the embodiment. It should be noted that... Figure 1 It shows that in the inclusion Figure 2 The cross-sectional structure of the fan assembly 100 is shown when the plane of the double-dotted line I and the rotating shaft J is cut. Furthermore, in... Figure 2 In order to make it easier to observe the interior, the illustration of the first plate part 31 is omitted.

[0024] <1-1. Fan Assembly 100> The fan assembly 100 is a so-called centrifugal fan that directs the fluid F drawn towards one axial side (Da1) radially outward. It should be noted that in this embodiment, the fluid F drawn and directed by the fan assembly 100 is air. However, it is not limited to this example; the fluid F may also be a gas or liquid other than air. The fan assembly 100 is used, for example, as a cooling fan for electronic devices requiring a slim profile. However, the application of the fan assembly 100 is not limited to this example.

[0025] The fan unit 100 has an impeller 1, a motor 2, a housing 3, and a base plate 4.

[0026] The impeller 1 can rotate about a rotating shaft J extending along the axial direction Da. The impeller 1 is mounted on the motor 2. The impeller 1 has a covered cylindrical hub 11 and a plurality of moving blades 12. It should be noted that, in this specification, the shape in which one end of the cylindrical body (e.g., the cylindrical portion 112 described later) is covered by a cover body (e.g., the plate portion 111 described later) is referred to as "covered cylindrical".

[0027] Motor 2 is the drive source for rotating impeller 1. At least a portion of motor 2 is disposed inside hub 11. Motor 2 has a shaft 21 extending axially along axis J in the direction of axial direction Da. Shaft 21 is rotatable together with impeller 1 about axis J extending axially in the direction of axial direction Da. Specifically, the other axial end of shaft 21 is connected to impeller 1. Motor 2 rotates impeller 1 together with shaft 21 by rotating shaft 21 about axis J.

[0028] The housing 3 internally houses the impeller 1, the motor 2, and the base plate 4. The housing 3 has a first plate portion 31, a second plate portion 32, and a peripheral wall portion 33.

[0029] The first plate portion 31 is positioned at a position Da1 on the axial side of the impeller 1 and extends in a direction intersecting the axial direction Da. The motor 2 and the base plate 4 are fixed on the inner surface (the end face on the other side of the axial direction) of the first plate portion 31.

[0030] The second plate portion 32 is positioned on the opposite side of the impeller 1, Da2, and extends in a direction intersecting the axial direction Da. A suction port 34 is provided in the second plate portion 32. The suction port 34 extends through the second plate portion 32 along the axial direction Da. When viewed from the axial side Da1, the suction port 34 overlaps with the central portion of the impeller 1 (particularly the hub 11 and the retaining portion 122 of the moving blade 12, described later). The outer edge of the suction port 34 surrounds the rotating shaft J.

[0031] The peripheral wall portion 33 is disposed along the outer edge of the first plate portion 31 and the outer edge of the second plate portion 32, and extends axially along Da. One axial end of the peripheral wall portion 33 is connected to the outer edge of the first plate portion 31. The other axial end of the peripheral wall portion 33 is connected to the outer edge of the second plate portion 32. A feed outlet 35 is provided in the peripheral wall portion 33. The feed outlet 35 extends radially through the peripheral wall portion 33. In other words, the feed outlet 35 is provided on the radially outer side of the housing 3, and opens at least radially outward at a position further radially outward than the impeller 1.

[0032] In the fan assembly 100, fluid F is drawn from the suction port 34 and delivered to a position radially outward of the impeller 1 by the rotation of the impeller 1 around the rotation axis J. When viewed from the axial direction Da, the fluid F flows along the inner surface of the peripheral wall portion 33 inside the housing 3 and is discharged from the outlet 35 to the outside of the fan assembly 100.

[0033] The substrate 4 is electrically connected to, for example, the stator (not shown) of the motor 2, and is electrically connected to the external circuitry of the fan assembly 100 via a connecting line (not shown) extending to the outside of the fan assembly 100. The substrate 4 houses electrical circuits, electrical components, including the motor drive circuitry. The substrate 4 is a radially extending plate, disposed on the axial side Da1 of the motor 2.

[0034] It should be noted that the fan device 100 is not limited to the example described above, and may also be configured without the housing 3. In this case, the motor 2 and the base plate 4 are fixed to the opposite side (wall, etc.) where the fan device 100 is mounted.

[0035] <1-2. Impeller Structure> Next, refer to Figures 1 to 3 The detailed structure of impeller 1 will be explained. Figure 3 This is a perspective view showing an example of the configuration of the impeller 1 according to the embodiment. As described above, the impeller 1 has a covered cylindrical hub 11 and a plurality of moving blades 12. The hub 11 is a covered cylindrical shape extending along the axial direction Da. The hub 11 is open at one end along the axial direction. The plurality of moving blades 12 are arranged at a position radially outward from the hub 11 and are arranged along the circumferential direction Dc.

[0036] Preferably, the total number of moving blades 12 (especially the blade portion 121) is a prime number. In the case of a typical fan device, discrete frequency noise (so-called NZ noise) caused by the product of the number Z of moving blades 12 and the rotational speed N of the motor 2 occurs, for example, at the corners of the peripheral wall portion 33 of the blower fan 100 (e.g., at...). Figure 1The portion 331 enclosed by the dotted line (the so-called tongue) is generated. In contrast, by setting the total number of moving blades 12 to a prime number, interference (resonance) between the order of moving blades 12 and the order of magnetic excitation of motor 2 can be suppressed. However, this example does not exclude the possibility that the total number of moving blades 12 is not a prime number. That is, the total number of moving blades 12 can also be a composite number.

[0037] Furthermore, the hub 11 and the moving blades 12 can be made of resin or metal. Additionally, the hub 11 and the multiple moving blades 12 can be a single unit (i.e., different parts of a single component) or separate units (i.e., different components).

[0038] The hub 11 has a plate portion 111, a cylindrical portion 112, and a retainer 113. The plate portion 111 is circular, extending radially outward from the rotation shaft J. The cylindrical portion 112 extends from the radially outer end of the plate portion 111 toward one axial side Da1, surrounding at least one axial side Da2 of the motor 2 and the shaft 21. The radially inner surface of the cylindrical portion 112 is spaced apart and radially opposed to the radially outer surface of the motor 2. The retainer 113 is cylindrical, surrounding and accommodating the axially opposite end of the shaft 21, and is fixed to the shaft 21. The radially inner surface of the retainer 113 contacts the radially outer surface of the shaft 21.

[0039] Each moving blade 12 has a blade portion 121 and a retaining portion 122. The blade portion 121 extends axially (Da) and radially, and is inclined circumferentially to one side (Dc1) as it moves toward the other side (Da2) axially. The retaining portion 122 extends radially inward from the axial end of the blade portion 121 and connects to the hub 11. It should be noted that, in this embodiment, the retaining portion 122 is connected to the axial end of the radially outer surface of the hub 11. However, the axial connection position of the retaining portion 122 relative to the hub 11 is not limited to this example. The connection position of the retaining portion 122 can be the axial center of the radially outer surface of the hub 11, or a position axially closer to one side (Da1) than the axial center.

[0040] In the impeller 1 of the fan device 100 according to this embodiment, in each moving blade 12, a retaining portion 122 connected to the hub 11 holds the blade portion 111. Therefore, it is possible to omit the annular plate member (so-called shroud) for holding the blade portion 111. Furthermore, the total area of ​​the axial-side end face of the retaining portion 122 of each moving blade 12, viewed from the axial-side Da1 side, is smaller than the area of ​​the axial-side end face of the aforementioned plate member. As a result, the friction between the retaining portion 122 and the fluid F can be reduced when the impeller 1 rotates. That is, the fluid resistance at the retaining portion 122 holding the blade portion 111 of the impeller 1 can be reduced.

[0041] Furthermore, adjacent retaining portions 122 are arranged at intervals along the circumferential direction Dc. Therefore, compared with the configuration of holding the blade portion 111 using an annular plate member, the weight of the impeller 1 can be reduced.

[0042] This reduces the torque required to rotate the impeller 1, allowing for the use of a smaller motor 2 to rotate the impeller 1. In other words, it prevents the motor 2 from becoming too large.

[0043] In this embodiment, when viewed from the axial direction Da, at least the radially outer portion of the blade portion 121 is inclined towards one circumferential side Dc1 as it tends to be radially outward. That is, the blade portion 121 has a forward-swept blade. However, it is not limited to this example; at least the radially outer portion of the blade portion 121 may also be inclined towards the other circumferential side Dc1 as it tends to be radially outward. That is, the blade portion 121 may also have a backward-swept blade. Alternatively, at least the radially outer portion of the blade portion 121 may also extend straight outward.

[0044] In this embodiment, when viewed from the axial side Da1, the radially outer end of the blade portion 121 of the moving blade 12 on the other axial side is located radially outward from the outer edge of the suction port 34. However, this example does not exclude the configuration where, when viewed from the axial side Da1, at least a portion of the radially outer end of the blade portion 121 of the moving blade 12 is located at the same position as the outer edge of the suction port 34, or at a position radially inward from the outer edge of the suction port 34.

[0045] Preferably, when viewed from the axial side Da1, in at least a portion of the moving blades 12, the radially inner end of the blade portion 121 on the other axial side is positioned radially outer than the outer edge of the suction port 34. More preferably, in all the moving blades 12, the blade portion 121 is positioned radially outer than the outer edge of the suction port 34. This increases the flow rate of fluid F flowing from the suction port 34 into the space between the blade portions 121. Therefore, the flow rate of fluid F delivered radially outer by the fan device 100 can be increased. However, this example does not exclude the configuration where, when viewed from the axial side Da1, the radially inner end of the blade portion 121 on the other axial side is positioned at the same position as the outer edge of the suction port 34, or radially inner than the outer edge of the suction port 34.

[0046] Furthermore, preferably, the axial width of the radially inner end of the retaining portion 122 is greater than the circumferential width of the radially inner end of the retaining portion 122. This allows more retaining portions 122 to be connected to the other axial end of the hub 11. That is, more moving blades 12 can be positioned radially outward from the hub 11. Therefore, when the impeller 1 rotates, it can deliver more fluid F radially outward. However, this example does not preclude a configuration where the axial width of the radially inner end of the retaining portion 122 is less than or equal to the circumferential width of the radially inner end of the retaining portion 122.

[0047] Next, each moving blade 12 also has a connecting portion 123. In each moving blade 12, the connecting portion 123 extends from the axial end of the blade portion 121 toward the circumferential side Dc1. In adjacent moving blades 12 on the circumferential Dc, the circumferential end of the connecting portion 123 of the moving blade 12 on the circumferential side Dc2 is connected to the blade portion 121 of the moving blade 12 on the circumferential side Dc1, and in particular, is connected to the circumferential end face of that blade portion 121.

[0048] In this way, when the impeller 1 is rotated, fluid F can be prevented from leaking from the positive pressure surface of the blade section 121 to the axial side Da2. Therefore, it is possible to prevent a decrease in the flow rate of fluid F delivered radially outward.

[0049] For example, when the impeller 1 rotates circumferentially to one side Dc1 around the rotation axis J, the circumferential end face of the blade portion 121 becomes a positive pressure surface, and the circumferential end face of the blade portion 121 becomes a negative pressure surface. Here, in a configuration where the axial end of the blade portion 121 is a free end, blade tip vortices are generated on the axial end Da2 side of the blade portion 121, causing fluid F on the positive pressure surface to leak out towards the axial end Da2. Therefore, the leakage loss of fluid F at the axial end of the blade portion 121 increases, and the fluid efficiency of the impeller 1 deteriorates.

[0050] On the other hand, such as Figure 3 As shown, by providing a connecting portion 123 at the axial end of the blade portion 121, the generation of blade tip vortices on the axial end of the blade portion 121 on the axial side Da2 can be suppressed. That is, the moving blade 12 of this embodiment is annular in shape, and there is no blade tip that becomes a free end on the suction port 34 side on the axial Da of the blade portion 121. Furthermore, the impeller 1 of this embodiment is an annular fan, which suppresses the generation of blade tip vortices and prevents fluid F from leaking from the positive pressure surface (circumferential end face) to the axial side Da2. Therefore, leakage of fluid F at the axial end of the blade portion 121 can be prevented. Moreover, since the generation of blade tip vortices is suppressed, the turbulence noise caused by pressure fluctuations due to the blade tip vortices propagating as sound waves can be reduced.

[0051] <2. Notes> The embodiments of the present invention have been described above. It should be noted that the above embodiments are exemplary, and those skilled in the art will understand that various modifications can be made to the various constituent elements and combinations of processes, all of which are within the scope of the present invention.

[0052] <3. Summary> The following is a summary of the implementation methods described above.

[0053] For example, the impeller 1 disclosed in this specification is configured to include: a covered cylindrical hub 11 extending along the axial direction Da and having an opening at one axial end; and a plurality of moving blades 12 disposed at a position radially outward from the hub 11 and arranged circumferentially Dc, each of the moving blades 12 having: a blade portion 121 extending along the axial direction Da and radially, and inclined towards one circumferential side Dc1 as it tends towards the other axial side Da2; and a retaining portion 122 extending radially inward from one axial end of the blade portion 121 and connected to the hub 11 (first configuration).

[0054] The impeller 1 of the first configuration described above can also be configured such that each of the moving blades 12 further has a connecting portion 123 extending from the axial end of the blade portion 121 to the circumferential side Dc1. Among the moving blades 12 adjacent to each other on the circumferential Dc, the circumferential end of the connecting portion 123 of the moving blade 12 on the circumferential side Dc2 is connected to the blade portion 121 of the moving blade 12 on the circumferential side Dc1 (second configuration).

[0055] Furthermore, the impeller 1 of the first or second configuration described above may also be configured such that the axial width of the radial inner end of the retaining portion 122 is greater than the circumferential width of the radial inner end of the retaining portion 122 (third configuration).

[0056] Furthermore, the fan device 100 disclosed in this specification is configured to deliver fluid F drawn towards one axial side Da1 to the radially outward side. The fan device 100 includes: an impeller 1, a covered cylindrical hub 11 extending along the axial direction Da and open at one axial side end, and a plurality of moving blades 12 arranged radially outward from the hub 11 and arranged circumferentially Dc; and a motor 2, having a shaft 21 rotatable with the impeller 1 about a rotating shaft J extending along the axial direction Da, and at least a portion of the motor 2 is disposed inside the hub 11. Each of the moving blades 12 has: a blade portion 121 extending along the axial direction Da and radially, and inclined towards the circumferential side Dc1 as it moves towards the other axial side Da2; and a retaining portion 122 extending radially inward from one axial side end of the blade portion 121 and connected to the hub 11 (fourth configuration).

[0057] Industrial availability

[0058] This invention is useful for devices that deliver airflow radially outward.

[0059] Explanation of reference numerals in the attached figures

[0060] 100: Centrifugal fan; 1: Impeller; 11: Hub; 111: Plate section; 112: Cylinder section; 113: Cage; 12: Moving blade; 121: Blade section; 122: Holding section; 123: Connecting section; 2: Motor; 21: Shaft; 3: Housing; 31: First plate section; 32: Second plate section; 33: Peripheral wall section; 34: Suction port; 35: Discharge port; 4: Base plate; F: Fluid; J: Rotating shaft; Da: Axial direction; Da1: One side of the axial direction; Da2: The other side of the axial direction; Dc: Circumferential direction; Dc1: One side of the circumferential direction; Dc2: The other side of the circumferential direction.

Claims

1. An impeller comprising: a covered cylindrical hub extending axially and having an opening at one axial end; and a plurality of moving blades disposed radially outward from the hub and arranged circumferentially, each moving blade having: a blade portion extending axially and radially and inclined circumferentially to the other axial side; and a retaining portion extending radially inward from one axial end of the blade portion and connected to the hub.

2. The impeller according to claim 1, wherein, Each of the moving blades also has a connecting portion extending from the axial end of the blade portion to one circumferential side. In the circumferentially adjacent moving blades, the circumferential end of the connecting portion of the moving blade on the other circumferential side is connected to the blade portion of the moving blade on one circumferential side.

3. The impeller according to claim 1, wherein, The axial width of the radial inner end of the retaining part is greater than the circumferential width of the radial inner end of the retaining part.

4. A fan device that directs fluid drawn towards one axial side to the radially outward side, the fan device comprising: an impeller having a covered cylindrical hub extending axially and open at one end of the axial side, and a plurality of moving blades arranged circumferentially at a position radially outward from the hub; and a motor having a shaft rotatable with the impeller about a rotating shaft extending axially, and at least a portion of the motor being disposed inside the hub, each of the moving blades having: a blade portion extending axially and radially, and inclined circumferentially towards the other axial side; and a retaining portion extending radially inward from one end of the blade portion and connected to the hub.

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