JP2016191310A - Blower impeller and air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower impeller having a structure capable of restricting the reduction in an air blowing efficiency.SOLUTION: A blower impeller according to one embodiment of the invention that is directly or indirectly fixed to a shaft centered on a central axis extending in a vertical direction and being rotatable about the central axis with the shaft, the blower impeller comprises: a boss part that is fixed to the shaft so as to extend in an axial direction; an impeller main body part that hangs downward while spreading in a radial direction from an upper end portion of the boss part so as to circumferentially surround the boss part; a plurality of blade parts that are located on the upper side of the impeller main body part; and a rib part that is located on the lower side of the impeller main body part. A front side end portion, which is an end portion on the front side in the rotational direction of the rib part when viewing in an axial direction, curves toward the rear side in the rotational direction from the inner side in the radial direction to the outer side in the radial direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an impeller and a blower.

  For example, Patent Document 1 describes an impeller for a blower. In the impeller of Patent Document 1, the inside of the hub portion is hollow for the purpose of suppressing the so-called sink when the impeller is molded with resin, that is, so-called sink.

JP 59-85499 A

  If the inside of the hub part (impeller body part) is made hollow like the above-described impeller, the thickness of the hub part becomes small, so the strength of the hub part decreases. Thereby, there exists a possibility that a hub part may deform | transform at the time of rotation. On the other hand, as described in Patent Document 1, for example, a configuration in which a reinforcing rib is provided in the cavity of the hub portion is conceivable.

  When an impeller having a reinforcing rib as described above is mounted on a blower, air may enter the cavity of the hub portion. In this case, turbulent flow may occur between the reinforcing ribs in the cavity. As a result, the pressure of the air applied to the impeller increases, and there is a problem that the shaft power for rotating the impeller increases. As a result, there is a problem that the air blowing efficiency of the impeller is lowered.

  In view of the above problems, an aspect of the present invention has an object to provide an impeller having a structure capable of suppressing a decrease in blowing efficiency and a blower including such an impeller.

  One aspect of the impeller of the present invention is an impeller that is directly or indirectly fixed to a shaft centering on a central axis extending in the vertical direction and that can rotate around the central axis together with the shaft. A boss portion fixed to the shaft and extending in the axial direction; an impeller body portion that hangs down in a radial direction from the upper end portion of the boss portion and surrounds the boss portion in the circumferential direction; and an upper side of the impeller body portion A plurality of blade portions located on the surface of the impeller body, and a rib portion located on the lower surface of the impeller body portion, and when viewed in the axial direction, at the end portion on the front side in the rotational direction of the rib portion. A certain front side end portion curves toward the rear side in the rotational direction from the radially inner side toward the radially outer side.

  According to one aspect of the present invention, an impeller having a structure capable of suppressing a reduction in blowing efficiency and a blower including such an impeller are provided.

FIG. 1 is a perspective view showing a centrifugal fan in the present embodiment. FIG. 2 is an exploded perspective view showing the centrifugal fan in the present embodiment. FIG. 3 is a view showing the centrifugal fan in the present embodiment and is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a perspective view showing the impeller in the present embodiment. FIG. 5 is a bottom view showing the impeller in the present embodiment. FIG. 6 is a bottom view showing an impeller which is another example in the present embodiment.

  Hereinafter, an impeller and a blower according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, a centrifugal fan will be described as an example of a blower.

  The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. In the following drawings, the scale and number of each structure may be different from the scale and number of the actual structure in order to make each configuration easy to understand.

  In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is a direction parallel to the axial direction of the central axis J shown in FIG. The X-axis direction is a direction orthogonal to the Z-axis direction and a direction orthogonal to the exhaust port 62 shown in FIG. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction.

In the following description, the direction in which the central axis J extends (Z-axis direction) is the vertical direction. The positive side (+ Z side) in the Z-axis direction is called “upper side”, and the negative side (−Z side) in the Z-axis direction is called “lower side”. In addition, the up-down direction, the upper side, and the lower side are names used for explanation only, and do not limit the actual positional relationship and direction. Unless otherwise specified, a direction parallel to the central axis J (Z-axis direction) is simply referred to as an “axial direction”, and a radial direction around the central axis J is simply referred to as a “radial direction”. around the circumferential direction (theta _{Z-direction),} i.e., simply referred to as "circumferential direction" about the axis of the central axis J.

  In the present specification, the term “extending in the axial direction” includes not only strictly extending in the axial direction but also extending in a direction inclined with respect to the axial direction within a range of less than 45 °. Further, in this specification, the term “extend in the radial direction” means that it is strictly inclined in the range of less than 45 ° with respect to the radial direction in addition to the case of extending in the radial direction, that is, the direction perpendicular to the axial direction. This includes cases extending in the other direction.

  1 to 3 are views showing a centrifugal fan (blower) 10 in the present embodiment. FIG. 1 is a perspective view. FIG. 2 is an exploded perspective view. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 3 is a cross-sectional view viewed in a direction orthogonal to the exhaust port 62 (X-axis direction).

  The centrifugal fan 10 is a blower. As shown in FIGS. 1 to 3, the centrifugal fan 10 includes a housing 20, an impeller 30, and a motor 40.

  As shown in FIG. 3, the motor 40 is accommodated in the housing 20 in the present embodiment. The motor 40 is located on the inner side in the radial direction of the motor cover portion 27 described later. The motor 40 has a shaft 41 centering on a central axis J extending in the vertical direction. The upper end portion of the shaft 41 protrudes above the motor cover portion 27 via an output shaft hole 27a described later.

The motor 40 is located below the impeller 30. The motor 40 rotates the impeller 30 around the central axis J. In the present embodiment, the motor 40 is, for example, to rotate the impeller 30 from the upper side viewed toward the lower counterclockwise (+ theta _Z direction).

In the following description, there are cases where side (+ theta _Z side) proceeding counterclockwise when viewed from the upper side toward the lower side is referred to as a rotational direction front side, clockwise from the upper as viewed toward the lower in some cases (- [theta] _Z direction) to advance side of (- [theta] _Z side) is referred to as the rotational direction rear side.

  The housing 20 accommodates the impeller 30 and the motor 40. In the present embodiment, the housing 20 is configured by connecting two separate members. That is, the housing 20 includes an upper housing 21 and a lower housing 22.

  The upper housing 21 accommodates the impeller 30 on the radially inner side. The upper housing 21 has an upper housing cover portion 23 and an upper housing wall portion 24.

  The upper housing cover part 23 is located above the impeller 30. That is, the upper housing cover portion 23 overlaps the impeller 30 in the axial direction. The upper housing cover part 23 has an air inlet 61. The air inlet 61 penetrates the upper housing cover portion 23 in the axial direction.

  The upper housing cover part 23 has a cover inner edge part 23 a that extends downward from the inner edge of the air inlet 61. The cover inner edge portion 23a is cylindrical. The lower end portion of the cover inner edge portion 23 a is located on the radially inner side of the inner edge 33 a of the shroud portion 33. The air inlet 61 communicates with the inside of the impeller 30 through the inside of the cover inner edge portion 23a.

  The upper housing cover portion 23 extends in the radial direction along the shape of a shroud portion 33 (described later) of the impeller 30. The shape of the upper housing cover portion 23 is a shape that is located on the lower side as it goes from the radially inner side to the radially outer side.

  The upper housing wall portion 24 is connected to the lower end portion of the upper housing cover portion 23. The upper housing wall portion 24 is located on the radially outer side of the impeller 30. The upper housing wall 24 surrounds the impeller 30 in the circumferential direction.

  The lower housing 22 is attached to the lower side of the upper housing 21. The lower housing 22 includes a motor cover portion 27, a lower housing bottom portion 28, and a lower housing wall portion 26.

  The motor cover portion 27 has a covered cylindrical shape that opens downward. The motor 40 is located inside the motor cover portion 27 in the radial direction. The motor cover unit 27 covers the motor 40. The motor cover portion 27 has an output shaft hole 27 a that penetrates the lid portion of the motor cover portion 27 in the axial direction.

  An impeller 30 is located above the motor cover portion 27. The lower housing bottom portion 28 extends radially outward from the lower end portion of the motor cover portion 27. The lower housing wall 26 extends upward from the radially outer end of the lower housing bottom 28. The axial position of the upper end portion of the lower housing wall portion 26 is the same as the axial position of the upper surface of the motor cover portion 27.

  The housing 20 has an intake port 61, a flow path 50, and an exhaust port 62. The intake port 61 is a hole that opens upward and communicates the outside of the housing 20 with the inside of the housing 20. The intake port 61 is located above the impeller 30. As shown in FIGS. 1 and 2, in the present embodiment, the shape of the air inlet 61 in plan view is, for example, a circular shape, and the center axis J passes through the center thereof.

  As shown in FIG. 3, the flow path 50 is provided inside the housing 20. The flow path 50 connects the intake port 61 and the exhaust port 62. The flow path 50 is scroll-shaped, for example. The channel 50 includes an upper channel 51 and a lower channel 52.

  In the present specification, the scroll shape is a shape in which the dimension in the radial direction increases as it advances in the circumferential direction. In addition, in this specification, the flow path is scroll-shaped includes that at least one of the upper flow path and the lower flow path is scroll-shaped. That is, in the present specification, the flow path is scroll-shaped when only the upper flow path is scroll-shaped, when only the lower flow path is scroll-shaped, and when the upper flow path and the lower flow are And a case where both the road and the road are scroll-shaped.

  The upper flow path 51 and the lower flow path 52 are disposed along the axial direction. The lower flow path 52 is located below the upper flow path 51. The lower flow path 52 is connected to the upper flow path 51. In the present embodiment, the upper flow path 51 and the lower flow path 52 have, for example, a scroll shape. In the present embodiment, the boundary between the upper flow path 51 and the lower flow path 52 is a boundary between the upper housing 21 and the lower housing 22.

  In the present embodiment, the entire upper flow path 51 is located inside the upper housing 21. That is, in the present embodiment, the upper housing 21 has the entire upper flow path 51. The upper flow path 51 is at least partially located between the inner peripheral surface of the housing 20 and the radial direction of the impeller 30.

Although not shown, the upper channel 51 is annular. The upper flow path 51 extends along the inner peripheral surface of the housing 20. Air flowing into the upper flow path 51 from the impeller 30 flows through the upper flow path 51 in the same direction (+ theta _Z direction) and the direction in which the impeller 30 rotates. The entire upper flow path 51 opens downward. Part of the air flowing in the upper flow path 51 flows into the lower flow path 52 before reaching the exhaust port 62.

  As shown in FIG. 2, the entire lower channel 52 is located inside the lower housing 22 in the present embodiment. That is, in the present embodiment, the lower housing 22 has the entire lower flow path 52. The lower flow path 52 is located between the outer peripheral surface of the motor cover portion 27 and the inner peripheral surface of the housing 20.

The lower flow path 52 extends along the inner peripheral surface of the housing 20. Air flowing into the lower flow path 52 from the upper flow path 51, flows through the lower passage 52 in the same direction as the impeller 30 rotates (+ theta _Z direction). Circumferential direction of the one end of the lower flow path 52 (+ theta _Z side end) is open to the exhaust port 62. (End of - [theta] _Z side) the circumferential direction of the other end of the lower channel 52 is closed against the exhaust port 62.

  In the present specification, one end in the circumferential direction of the lower flow path is closed as long as one end of the lower flow path is closed in the circumferential direction. That is, even if one end in the circumferential direction of the lower flow path is closed, it is allowed that one end in the circumferential direction of the lower flow path opens upward.

  The exhaust port 62 is located radially outside of the impeller 30. In the present embodiment, the exhaust port 62 opens in a direction orthogonal to the axial direction (X-axis direction). As shown in FIG. 1, in the present embodiment, the exhaust port 62 is configured by connecting the upper housing 21 and the lower housing 22. In the present embodiment, the exhaust port 62 is connected to the upper flow path 51 and the lower flow path 52.

  As indicated by a thick arrow in FIG. 3, when the impeller 30 is rotated by the motor 40, air flows into the housing 20 through the air inlet 61. The air that has flowed into the housing 20 passes through the inside of the impeller 30, that is, between a shroud portion 33 and an impeller body portion 31 described later, and is discharged to the outside in the radial direction of the impeller 30. The air discharged radially outward from the impeller 30 is discharged from the exhaust port 62 to the outside of the housing 20 via the upper flow path 51 and the lower flow path 52.

The impeller 30 is located above the motor 40. The impeller 30 is fixed to the upper end of the shaft 41 of the motor 40. Thereby, the impeller 30 is rotatable about axis J about with the shaft 41 (± θ _Z direction).

  FIG. 4 is a perspective view showing the impeller 30. FIG. 5 is a bottom view showing the impeller 30. In the present specification, the bottom view is a view seen from the lower side toward the upper side.

  As shown in FIGS. 2, 4, and 5, the impeller 30 includes a boss portion 34, an impeller main body portion 31, a plurality of blade portions 32, a shroud portion 33, and a rib portion 35. In the present embodiment, the impeller 30 is a single member. In the present embodiment, the impeller 30 is made of resin.

  As shown in FIG. 3, the boss portion 34 extends in the axial direction. The boss 34 has a fitting hole 34a that opens downward. The upper end of the shaft 41 is fitted into the fitting hole 34a. Thereby, the boss part 34 is fixed to the shaft 41. That is, in the present embodiment, the impeller 30 is directly fixed to the shaft 41 via the boss portion 34.

  The impeller body 31 hangs down from the upper end of the boss 34 while spreading in the radial direction. The impeller body 31 has an umbrella shape. As shown in FIGS. 3 and 4, the impeller body 31 surrounds the boss 34 in the circumferential direction. On the radially inner side of the impeller main body 31, there is a cavity AH. The cavity AH is a space surrounded by the impeller body 31 and the boss 34.

  As shown in FIG. 3, the impeller main body 31 includes a main body upper surface 31 a that is an upper surface of the impeller main body 31 and a main body lower surface 31 b that is a lower surface of the impeller main body 31. The main body upper surface 31a is a gentle slope located on the lower side from the central axis J toward the radially outer side.

  The main body lower surface 31b is connected to the boss 34 at the radially inner end. The main body lower surface 31b is a gentle slope located on the lower side from the radially inner side to the radially outer side. The main body lower surface 31b follows the main body upper surface 31a. The thickness of the impeller main body 31 is substantially uniform.

  The wing | blade part 32 is located in the main-body-part upper surface 31a. The blade part 32 extends upward from the main body part upper surface 31a. The upper end portion of the blade portion 32 is connected to the shroud portion 33. As shown in FIG. 5, the several blade | wing part 32 is located equally along the circumferential direction. The blade 32 extends with a curvature on the main body upper surface 31a when viewed in the axial direction. In the example of FIG. 5, the blade | wing part 32 has one curvature.

The radially outer end of the blade 32 is located at the radially outer edge of the main body upper surface 31a. An end portion on the radially inner side of the blade portion 32 is located on a radially inner side with respect to a radially outer edge of the impeller body portion 31. When viewed in the axial direction, the blade portion 32 is curved in the rotation direction rear side (- [theta] _Z side) toward the radial inside toward the radial outside. Therefore, when the impeller 30 rotates, the pressure of the air applied to the blade part 32 can be reduced. Thereby, the shaft power by the motor 40 can be reduced.

  In the present embodiment, the thickness L5 of the blade portion 32 is substantially uniform, for example. Therefore, when manufacturing the blade | wing part 32 by injection molding with resin, it can suppress that a sink mark arises.

  In the present embodiment, the blade part 32 includes a plurality of first blade parts 32a and a plurality of second blade parts 32b. The 1st blade | wing part 32a and the 2nd blade | wing part 32b are located alternately along the circumferential direction. The radially inner end of the first blade portion 32a is positioned more radially inward than the radially inner end of the second blade portion 32b.

  In the example of FIG. 5, the blade portion 32 has, for example, five first blade portions 32 a and five second blade portions 32 b, respectively. That is, in the example of FIG. 5, the number of blade portions 32 is 10, for example.

  As shown in FIG. 3, the shroud portion 33 is located above the blade portion 32. The shroud portion 33 is connected to the impeller body portion 31 via the blade portion 32. As shown in FIG. 2, the shroud portion 33 has an annular shape, and the central axis J passes through the center thereof. The shape of the shroud portion 33 is a shape that is positioned on the lower side from the radially inner side toward the radially outer side.

  As shown in FIG. 4, the rib part 35 is located in the main-body-part lower surface 31b. The rib part 35 is located in the cavity AH. In the present embodiment, the rib portion 35 is connected to the boss portion 34. Therefore, the strength of the impeller body 31 can be further improved.

As shown in FIG. 5, when viewed in the axial direction, the rib portion 35 extends with a curvature on the lower surface 31b of the main body portion. When viewed in the axial direction, the front end portion 35a is an end of the rotation direction front side of the rib portion 35 (+ theta _Z side) toward the radial inside toward the radial outside, the rotational direction rear side (- It curves to the θ _Z side).

  For example, air flowing through the flow path 50 may flow into the axial gap AP between the impeller 30 and the motor cover portion 27 shown in FIG. The air that has flowed into the gap AP rises upward by, for example, a screw hole located on the upper surface of the motor cover portion 27 and flows into the cavity AH. At this time, for example, when the rib portions are radially extending in the radial direction, turbulence may occur between the rib portions. As a result, the pressure of the air applied to the impeller 30 is increased, and the shaft power of the motor 40 is increased. As a result, there is a problem that the blowing efficiency of the impeller 30 is lowered.

In contrast, according to this embodiment, since the front end portion 35a of the rib 35 is bent in the rotation direction rear side (- [theta] _Z side), the impeller 30 is positioned between the rib 35 is rotated Air is exhausted from the cavity AH. Thereby, it can suppress that a turbulent flow arises in the cavity AH, and the pressure of the air concerning the impeller 30 can be reduced. Therefore, the shaft power of the motor 40 can be reduced. As a result, according to the present embodiment, the impeller 30 having a structure capable of suppressing a reduction in the blowing efficiency is obtained.

  Further, according to the present embodiment, the air staying in the turbulent flow can be discharged from the cavity AH, so that the loss of the air flowing into the housing 20 from the intake port 61 can be suppressed. Thereby, according to this embodiment, the ventilation efficiency of the centrifugal fan 10 can be improved.

  Further, when air is discharged from the cavity AH, an air flow is generated from the cavity AH toward the flow path 50 through the gap AP. Therefore, it is possible to suppress the air from flowing into the cavity AH via the gap AP, and it is possible to suppress the occurrence of turbulent flow in the cavity AH.

  For example, when the flow path 50 is scroll-shaped, the air of the flow path 50 is more likely to flow into the gap AP, and turbulence is likely to occur in the cavity AH. Therefore, the effect that can suppress the occurrence of turbulent flow in the cavity AH according to the present embodiment is particularly useful when applied to a scroll-shaped flow path like the flow path 50 of the present embodiment.

  Further, when air flowing from the gap AP into the cavity AH collides with the rib portion 35, noise may be generated. On the other hand, according to this embodiment, since it can suppress that air flows in into cavity AH, it can control that air collides with rib part 35 and noise is generated.

  In addition, in this specification, that a certain object curves to the rotation direction back side includes that a certain object becomes convex on the rotation direction back side as a whole. That is, in this specification, a certain object is curved backward in the rotational direction. If a certain object is convex in the backward direction in the rotational direction, a part of the target is convex in the forward direction in the rotational direction. Alternatively, a part of a certain target may be linear.

When viewed in the axial direction, the rear end portion 35b is an end of the rotation direction rear side of the rib 35 (- [theta] _Z side) curved in the rotational direction rear side toward the radial inside toward the radial outside To do. That is, the rear side end portion 35b is curved to the same side as the front side end portion 35a. Therefore, it is easy to make the thickness of the rib portion 35 uniform.

  And in this embodiment, the dimension between the front side edge part 35a and the back side edge part 35b in the rib part 35, ie, the thickness L4 of the rib part 35, is substantially uniform. Thereby, for example, when the impeller 30 is manufactured by injection molding with a resin, it is possible to suppress the occurrence of sink marks. Therefore, according to this embodiment, the impeller 30 can be manufactured with high dimensional accuracy.

  In the present specification, the dimension of a certain object is substantially uniform, for example, the dimension ratio to the average dimension of a certain object is about 0.8 or more and 1.2 or less at any position. including.

  As shown in FIG. 5, the radially inner end of the rib portion 35 is connected to the boss portion 34. The radially outer end of the rib portion 35 is located at the radially outer edge of the main body lower surface 31b. That is, the radially outer end of the rib portion 35 is located at the radially outer edge of the impeller body portion 31. Therefore, the range in which the rib portion 35 is located in the radial direction can be increased. Thereby, it is easier to discharge air from the inside of the cavity AH.

  As shown in FIG. 3, the dimension L2 of the rib part 35 in the axial direction is not less than half of the dimension L3 of the cavity AH in the axial direction. The axial dimension L3 of the cavity AH is the distance in the axial direction between the portion P where the impeller body 31 and the boss 34 are connected and the lower end of the impeller body 31. Therefore, it is easy to ensure the strength of the impeller body 31. Moreover, since the rib part 35 can be provided more radially outside, the air in the cavity AH can be easily discharged.

  The axial dimension L2 of the rib portion 35 is the axial dimension of the rib portion 35 at the radially inner end of the rib portion 35. The dimension L2 is the maximum value of the dimension of the rib portion 35 in the axial direction.

  In the present embodiment, the axial dimension L2 of the rib portion 35 is the same as the axial dimension L3 of the cavity AH. That is, the rib portion 35 extends from the position P to the lower end portion of the impeller body portion 31 in the axial direction. Therefore, the strength of the impeller body 31 can be further improved. Moreover, since the rib part 35 can be provided to the radial direction outer edge of the impeller main-body part 31, it is easier to discharge | emit the air in cavity AH.

  In the present embodiment, the dimension L2 in the axial direction of the rib portion 35 is at least half of the dimension L1 in the axial direction of the impeller body 31. Therefore, it is easy to ensure the strength of the impeller body 31.

  As shown in FIG. 5, the impeller 30 includes a plurality of rib portions 35 in the present embodiment. Therefore, the strength of the impeller body 31 can be further improved. The plurality of rib portions 35 are equally disposed along the circumferential direction. Therefore, it is easy to discharge air from the cavity AH evenly in the circumferential direction.

  In the example of FIG. 5, the number of rib portions 35 is, for example, 7. That is, in the present embodiment, the number of rib portions 35 is different from the number of blade portions 32. For example, when the number of rib portions 35 and the number of blade portions 32 are the same, the impeller 30 may resonate due to the flow of air discharged by the rib portions 35 and the flow of air discharged by the blade portions 32. is there. When the impeller 30 resonates, a load is applied to the shaft 41, and the shaft power of the motor 40 may increase.

  On the other hand, according to this embodiment, since the number of the rib parts 35 and the number of the blade | wing parts 32 differ, it can suppress that the impeller 30 resonates. As a result, an increase in shaft power of the motor 40 can be suppressed.

  When viewed in the axial direction, the rib portion 35 intersects the blade portion 32. Therefore, the strength of the impeller body 31 can be further improved. In the present embodiment, the rib portion 35 has one curvature. The rib part 35 and the blade | wing part 32 have a mutually different curvature. Therefore, it is easy to cross the rib portion 35 and the blade portion 32 when viewed in the axial direction.

  In the present embodiment, the following configuration may be employed. In the following description, the same configurations as those described above may be omitted by appropriately attaching the same reference numerals.

In the present embodiment, if the front end portion 35a curved in the rotation direction rear side (- [theta] _Z side), the shape of the rear end portion 35b is not particularly limited. The shape of the rear side end portion 35b may be, for example, as shown in FIG. FIG. 6 is a bottom view showing an impeller 130 which is another example in the present embodiment.

As shown in FIG. 6, the impeller 130 includes a plurality of rib portions 135. When viewed in the axial direction, the front end portion 135a is an end of the rotation direction front side of the rib portion 135 (+ theta _Z side) toward the radial inside toward the radial outside, the rotational direction rear side (- It curves to the θ _Z side). When viewed in the axial direction, the rear end portion 135b is an end of the rotation direction rear side of the rib portion 135 (- [theta] _Z side) is linear. That is, the shape of the rib part 135 when viewed in the axial direction is a substantially semi-elliptical shape.

  Therefore, the dimension between the front side end part 135a and the rear side end part 135b in the rib part 135, that is, the thickness L6 of the rib part 135 can be increased. Thereby, according to this embodiment, the intensity | strength of the impeller main-body part 31 can be improved more, reducing the pressure of the air which discharges the air in cavity AH by the curved front side edge part 135a, and is applied to the impeller 130. FIG.

In the present embodiment, the front end portion 35a may have a plurality of curvatures. In this case, a plurality of curvature, position of curvature center may include a curvature located to one another the rotational direction (theta _Z direction) opposite relative to the front end portion 35a. Moreover, in this embodiment, the front side edge part 35a may have a linear part.

  Moreover, in this embodiment, the number of the rib parts 35 is not specifically limited, Six or less may be sufficient and eight or more may be sufficient. In the present embodiment, the number of rib portions 35 and the number of blade portions 32 may be the same.

  Moreover, in this embodiment, the shape of the some rib part 35 may be the same, and may mutually differ. In the present embodiment, in addition to the rib portion 35, for example, a linear rib portion extending in the radial direction when viewed in the axial direction may be provided.

  In the present embodiment, the rib portion 35 may not be connected to the boss portion 34. In this case, the rib part 35 may be connected only to the impeller body part 31, or the rib part 35 and the boss part 34 may be connected via other parts.

  In the present embodiment, a configuration in which the impeller 30 is fixed directly or indirectly to the shaft 41 can be employed. That is, in this embodiment, the impeller 30 may be indirectly fixed to the shaft 41.

  In the example of FIG. 3, the boss portion 34 is configured to be fitted to the shaft 41, but is not limited thereto. In the present embodiment, the boss portion 34 may be fixed to the shaft 41 in any manner. As an example, in the present embodiment, the boss portion 34 may be fixed to the shaft 41 with a screw, for example.

  In the present embodiment, the blade portion 32 may have a plurality of curvatures. In the present embodiment, the number of blade portions 32 is not particularly limited.

  Further, in the present embodiment, the impeller 30 may not have the shroud portion 33.

  In the present embodiment, the upper housing 21 may have the entire upper flow path 51 and the entire lower flow path 52. In the present embodiment, the housing 20 may be configured by connecting three or more separate members in the axial direction. In the present embodiment, the housing 20 may be a single member.

  In the present embodiment, the flow path 50 may not be scroll-shaped. In the present embodiment, the motor 40 may not be accommodated in the housing 20.

  In the above-described embodiment, the centrifugal fan has been described as a blower to which the impeller of the present invention is applied, but is not limited thereto. The blower to which the impeller of the present invention is applied is not particularly limited. For example, the impeller of the present invention may be applied to a mixed flow fan. Moreover, the use of the impeller and air blower of this invention is not specifically limited.

  Moreover, each structure demonstrated above can be suitably combined in the range which is not mutually contradictory.

  DESCRIPTION OF SYMBOLS 10 ... Centrifugal fan (blower), 20 ... Housing, 30, 130 ... Impeller, 31 ... Impeller main-body part, 32 ... Blade | wing part, 34 ... Boss part, 35, 135 ... Rib part, 35a, 135a ... Front side edge part, 35b, 135b ... rear end, 40 ... motor, 41 ... shaft, J ... central axis

Claims (14)

An impeller fixed directly or indirectly to a shaft centering on a central axis extending in the vertical direction and rotatable about the central axis together with the shaft;
A boss portion fixed to the shaft and extending in the axial direction;
An impeller body portion that hangs down in a radial direction from the upper end of the boss portion and surrounds the boss portion in the circumferential direction;
A plurality of blade portions located on the upper surface of the impeller body portion;
A rib portion located on the lower surface of the impeller body portion;
With
When viewed in the axial direction, the front end that is the end on the front side in the rotational direction of the rib portion is an impeller that curves backward in the rotational direction from the radially inner side toward the radially outer side.   The impeller according to claim 1, wherein the rib portion is connected to the boss portion. A plurality of the rib portions;
The impeller according to claim 1 or 2, wherein the number of the rib portions is different from the number of the blade portions.   The impeller according to any one of claims 1 to 3, wherein an end portion on the radially outer side of the rib portion is located on a radially outer edge of the impeller main body portion.   The rear end, which is the end of the rib portion on the rear side in the rotational direction, when viewed in the axial direction, curves toward the rear side in the rotational direction from the radially inner side to the radially outer side. The impeller according to any one of items 1 to 4.   The impeller according to claim 5, wherein a dimension between the front end and the rear end in the rib portion is substantially uniform.   The impeller according to any one of claims 1 to 4, wherein when viewed in the axial direction, a rear end that is an end of the rib portion on the rear side in the rotation direction is linear.   The impeller according to any one of claims 1 to 7, wherein the rib portion intersects the blade portion when viewed in the axial direction.   The impeller according to any one of claims 1 to 8, wherein when viewed in the axial direction, the blade portion curves toward the rear side in the rotational direction from the radially inner side toward the radially outer side.   The impeller according to claim 9, wherein the rib portion and the blade portion have different curvatures.   The axial dimension of the rib portion is at least half of an axial distance between a location where the impeller body portion and the boss portion are connected to a lower end portion of the impeller body portion. The impeller according to any one of 1 to 10.   12. The axial dimension of the rib portion is the same as an axial distance between a location where the impeller body portion and the boss portion are connected to a lower end portion of the impeller body portion. The impeller described in 1. A plurality of the rib portions;
The impeller according to any one of claims 1 to 12, wherein the plurality of rib portions are equally arranged along a circumferential direction. The impeller according to any one of claims 1 to 13,
A motor having the shaft and rotating the impeller around the central axis;
A housing that houses the impeller;
Blower equipped with.

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