US20160290358A1 - Centrifugal fan - Google Patents

Centrifugal fan Download PDF

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Publication number
US20160290358A1
US20160290358A1 US14/990,261 US201614990261A US2016290358A1 US 20160290358 A1 US20160290358 A1 US 20160290358A1 US 201614990261 A US201614990261 A US 201614990261A US 2016290358 A1 US2016290358 A1 US 2016290358A1
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US
United States
Prior art keywords
flow path
lower flow
housing
impeller
exhaust port
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/990,261
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English (en)
Inventor
Ryosuke HAYAMITSU
Jumpei KITAMURA
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Nidec Corp
Original Assignee
Nidec Corp
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Filing date
Publication date
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Assigned to NIDEC CORPORATION reassignment NIDEC CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Hayamitsu, Ryosuke, KITAMURA, JUMPEI
Publication of US20160290358A1 publication Critical patent/US20160290358A1/en
Abandoned legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/02—Units comprising pumps and their driving means
    • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
    • F04D29/4226—Fan casings
    • F04D29/4233—Fan casings with volutes extending mainly in axial or radially inward direction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
    • F04D17/08—Centrifugal pumps
    • F04D17/16—Centrifugal pumps for displacing without appreciable compression
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/02—Units comprising pumps and their driving means
    • F04D25/08—Units comprising pumps and their driving means the working fluid being air, e.g. for ventilation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
    • F04D29/281—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for fans or blowers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
    • F04D29/4226—Fan casings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/44—Fluid-guiding means, e.g. diffusers
    • F04D29/441—Fluid-guiding means, e.g. diffusers especially adapted for elastic fluid pumps

Definitions

  • the present disclosure relates to a centrifugal fan.
  • centrifugal fan which includes an air flow path positioned radially outward of an impeller and a wind tunnel positioned below the air flow path. The air discharged radially outward from the impeller flows from the air flow path toward the wind tunnel. Then, the air is discharged to the outside from an exhaust port.
  • the wind tunnel positioned below the air flow path has an annular shape. For that reason, there may be a case where a part of the air guided to the vicinity of the exhaust port through the wind tunnel flows toward the upstream side of the wind tunnel without being discharged from the exhaust port. This poses a problem in that a loss of airflow is generated and the efficiency of the centrifugal fan is reduced.
  • a centrifugal fan includes: an impeller arranged to rotate about a center axis extending in an up-down direction; a motor arranged below the impeller and arranged to rotate the impeller about the center axis; and a housing arranged to accommodate the impeller.
  • the housing includes an intake port arranged above the impeller, an exhaust port arranged radially outward of the impeller, an annular upper flow path, and a lower flow path arranged below the upper flow path and connected to the upper flow path.
  • the annular upper flow path is at least partially arranged between a housing inner circumferential surface as an inner circumferential surface of the housing and the impeller in a radial direction.
  • the upper flow path and the lower flow path are arranged to define a flow path having a scroll shape.
  • the lower flow path extends along the housing inner circumferential surface.
  • the lower flow path has a lower flow path terminal end as one circumferential end thereof opened toward the exhaust port.
  • the lower flow path has a lower flow path start end as the other circumferential end thereof closed with respect to the exhaust port.
  • FIG. 1 is a perspective view illustrating a centrifugal fan according to one preferred embodiment.
  • FIG. 2 is an exploded perspective view illustrating the centrifugal fan according to one preferred embodiment.
  • FIG. 3 is a sectional view taken along line III-III in FIG. 1 , illustrating the centrifugal fan according to one preferred embodiment.
  • FIG. 4 is a sectional view taken along line IV-IV in FIG. 3 , illustrating the centrifugal fan according to one preferred embodiment.
  • FIG. 5 is a side view illustrating the centrifugal fan according to one preferred embodiment.
  • FIG. 6 is a side view illustrating a centrifugal fan according to another example of one preferred embodiment.
  • FIG. 7 is a sectional view illustrating a portion of a centrifugal fan according to a further example of one preferred embodiment.
  • an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system.
  • the Z-axis direction is a direction parallel to the axial direction of a center axis J illustrated in FIG. 1 .
  • the X-axis direction is a direction orthogonal to the Z-axis direction and orthogonal to an exhaust port 62 illustrated in FIG. 1 .
  • the Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction.
  • the extension direction of the center axis J (the Z-axis direction is an up-down direction.
  • the positive side (+Z side) in the Z-axis direction will be referred to as an “upper side”.
  • the negative side ( ⁇ Z side) in the Z-axis direction will be referred to as a “lower side”.
  • the terms “up-down direction”, “upper side” and “lower side” are used merely for the purpose of descriptions and are not intended to limit the actual positional relationships or the actual directions.
  • the direction (the Z-axis direction) parallel to the center axis J will be merely referred to as an “axial direction”.
  • the radius direction extending from the center axis J will be merely referred to as a “radial direction”.
  • the circumference direction about the center axis J ( ⁇ Z direction), namely the direction extending around the center axis J, will be merely referred to as a “circumferential direction”.
  • the phrase “extending in the axial direction” includes not only a case where something extends strictly in the axial direction but also a case where something extends in a direction inclined at an angle of less than 45 degrees with respect to the axial direction.
  • the phrase “extending in the radial direction” includes not only a case where something extends strictly in the radial direction, namely in the direction perpendicular to the axial direction but also a case where something extends in a direction inclined at an angle of less than 45 degrees with respect to the radial direction.
  • FIG. 1 is a perspective view of a centrifugal fan according to one preferred embodiment.
  • FIG. 2 is an exploded perspective view of the centrifugal fan according to one preferred embodiment.
  • FIG. 3 is a sectional view of the centrifugal fan according to one preferred embodiment, which is taken along line III-III in FIG. 1 .
  • FIG. 4 is a sectional view of the centrifugal fan according to one preferred embodiment, which is taken along line IV-IV in FIG. 3 .
  • FIG. 5 is a side view of the centrifugal fan according to one preferred embodiment.
  • FIG. 3 is a sectional view of the centrifugal fan according to one preferred embodiment, which is viewed in the direction orthogonal to the exhaust port 62 (in the X-axis direction).
  • FIG. 4 is a sectional view of the centrifugal fan according to one preferred embodiment, which is viewed from the upper side toward the lower side.
  • the term “side view” refers to a view seen in the X-axis
  • the centrifugal fan 10 preferably includes a housing 20 , an impeller 30 and a motor 40 .
  • the motor 40 is accommodated within the housing 20 .
  • the motor 40 is disposed radially inward of a motor cover portion 27 which will be described later.
  • the motor 40 preferably includes a shaft 41 which is concentric with the center axis J extending in the up-down direction. The upper end portion of the shaft 41 protrudes toward the upper side of the motor cover portion 27 through an output shaft hole 27 a which will be described later.
  • the motor 40 is disposed below the impeller 30 .
  • the motor 40 rotates the impeller 30 about the center axis J.
  • the motor 40 rotates the impeller 30 counterclockwise (in the + ⁇ Z direction) when viewed from the upper side toward the lower side.
  • the impeller 30 is disposed above the motor 40 .
  • the impeller 30 is fixed to the upper end portion of the shaft 41 .
  • the impeller 30 is rotatable (in the ⁇ Z directions) about the center axis J extending in the up-down direction.
  • the impeller 30 preferably includes an impeller body portion 31 , a plurality of blade portions 32 and a shroud portion 33 .
  • the impeller body portion 31 is a portion fixed to the shaft 41 .
  • the upper surface of the impeller body portion 31 is a gentle slant surface which extends downward and radially outward from the center axis J.
  • the blade portions 32 are disposed on the upper surface of the impeller body portion 31 .
  • the blade portions 32 extend upward from the upper surface of the impeller body portion 31 . While not shown in the drawings, the blade portions are disposed at regular intervals in the circumferential direction.
  • the upper end portions of the blade portions 32 are connected to the shroud portion 33 .
  • the shroud portion 33 is disposed above the blade portions 32 .
  • the shroud portion 33 is connected to the impeller body portion 31 via the blade portions 32 .
  • the shroud portion 33 has an annular shape centered at the center axis J.
  • the shroud portion 33 is shaped to extend downward and radially outward.
  • the shroud portion 33 preferably includes a curved surface or a slant surface inclined with reference to the center axis J.
  • the housing 20 accommodates the impeller 30 and the motor 40 .
  • the housing 20 preferably includes an intake port 61 , a flow path 50 and the exhaust port 62 .
  • the intake port 61 is a hole opened upward and arranged to bring the outside and inside of the housing 20 into communication with each other.
  • the intake port 61 is arranged above the impeller 30 .
  • the edge of the intake port 61 when seen in a plan view, has a circular or substantially circular shape centered at the center axis J.
  • the plan-view shape of the edge of the intake port 61 is not limited to the circular shape and is not particularly limited.
  • the flow path 50 is provided within the housing 20 .
  • the flow path 50 interconnects the intake port 61 and the exhaust port 62 .
  • the flow path 50 has, e.g., a scroll or substantially scroll shape.
  • the flow path 50 preferably includes an upper flow path 51 and a lower flow path 52 . That is to say, the upper flow path 51 and the lower flow path 52 constitute the flow path 50 having a scroll or substantially scroll shape.
  • the term “scroll shape” refers to a shape in which the radial dimension of the flow path grows larger as the flow path extends in the circumferential direction.
  • the expression “the flow path has a scroll shape” includes a case where at least one of the upper flow path and the lower flow path has a scroll shape. That is to say, the expression “the flow path has a scroll shape” includes a case where only the upper flow path has a scroll shape, a case where only the lower flow path has a scroll shape and a case where both the upper flow path and the lower flow path have a scroll shape.
  • the upper flow path 51 and the lower flow path 52 are disposed along the axial direction.
  • the lower flow path 52 is arranged below the upper flow path 51 .
  • the lower flow path 52 is connected to the upper flow path 51 .
  • the upper flow path 51 and the lower flow path 52 will be described later.
  • the exhaust port 62 is arranged radially outward of the impeller 30 .
  • the exhaust port 62 is opened in the direction (X-axis direction) orthogonal to the axial direction.
  • the exhaust port 62 is defined by connecting an upper housing 21 and a lower housing 22 which will be described later.
  • the exhaust port 62 is connected to the upper flow path 51 and the lower flow path 52 .
  • the opening area of the exhaust port 62 is equal to or larger than the opening area of the intake port 61 .
  • the axial dimension of the upper flow path 51 or the axial dimension of the lower flow path 52 needs to be increased in order to secure the opening area of the exhaust port 62 . This poses a problem in that the centrifugal fan 10 becomes larger in the axial direction.
  • the exhaust port 62 is connected to the upper flow path 51 and the lower flow path 52 .
  • the opening area of the exhaust port can be increased without having to increase the axial dimension of the upper flow path 51 and the axial dimension of the lower flow path 52 . Accordingly, it is possible to restrain the centrifugal fan 10 from becoming larger in size.
  • the axial dimension L 2 of the portion of the exhaust port 62 connected to the lower flow path 52 is larger than the axial dimension L 1 of the portion of the exhaust port 62 connected to the upper flow path 51 .
  • the airflow is indicated by thick arrows.
  • the motor 40 rotates the impeller 30
  • an air is introduced into the housing 20 through the intake port 61 .
  • the air introduced into the housing 20 is blown toward the radial outer side of the impeller 30 through the interior of the impeller 30 , namely through the gap between the shroud portion 33 and the impeller body portion 31 .
  • the air blown radially outward from the impeller 30 is moved through the upper flow path 51 and the lower flow path 52 and is discharged to the outside of the housing 20 from the exhaust port 62 .
  • the housing 20 preferably includes the upper housing 21 and the lower housing 22 . That is to say, the housing 20 is configured by interconnecting two separate members.
  • the housing 20 is configured by interconnecting two separate members.
  • the upper housing 21 accommodates the impeller 30 at the radial inner side thereof.
  • the upper housing 21 preferably includes an upper housing cover portion 23 and an upper housing wall portion 24 .
  • the upper housing cover portion 23 is arranged above the impeller 30 . That is to say, the upper housing cover portion overlaps with the impeller 30 in the axial direction.
  • the upper housing cover portion 23 includes the intake port 61 . That is to say, the upper housing 21 includes the intake port 61 .
  • the intake port 61 axially extends through the upper housing cover portion 23 .
  • the upper housing cover portion 23 preferably includes a cover inner edge portion 23 a extending downward from the inner edge of the intake port 61 .
  • the cover inner edge portion 23 a has a tubular shape.
  • the lower end of the cover inner edge portion 23 a is arranged radially inward of an inner edge 33 a of the shroud portion 33 .
  • the intake port 61 communicates with the interior of the impeller 30 through the inside of the cover inner edge portion 23 a.
  • the upper housing cover portion 23 is radially widened along the shape of the shroud portion 33 .
  • the upper housing cover portion 23 is shaped to extend downward and radially outward.
  • the upper housing cover portion 23 preferably includes a curved surface or a slant surface inclined with respect to the center axis J.
  • the upper housing wall portion 24 is connected to the lower end of the upper housing cover portion 23 .
  • the upper housing wall portion 24 is arranged radially outward of the impeller 30 .
  • the upper housing wall portion 24 surrounds the impeller 30 in the circumferential direction.
  • the upper housing wall portion 24 preferably includes a portion of the exhaust port 62 .
  • An upper wall portion inner circumferential surface 24 a is the inner circumferential surface of the upper housing wall portion 24 . As illustrated in FIG. 3 , the upper wall portion inner circumferential surface 24 a extends downward and radially outward. In other words, the upper wall portion inner circumferential surface 24 a is a curved surface or a slant surface inclined with respect to the center axis J. Thus, the air discharged radially outward from the impeller 30 can flow into the lower flow path 52 along the upper wall portion inner circumferential surface 24 a.
  • the upper housing wall portion 24 preferably includes a tongue portion 25 . That is to say, the housing 20 preferably includes the tongue portion 25 .
  • the tongue portion 25 is a portion of the upper housing wall portion 24 connected to the exhaust port 62 .
  • the tongue portion 25 is arranged between the exhaust port 62 and the below-mentioned lower flow path start end 52 a in the circumferential direction.
  • the tongue portion 25 protrudes toward the side of the upper flow path 51 (namely, toward the rotation direction back side ( ⁇ Z side) in the example of FIG. 4 ).
  • the tongue portion 25 is smoothly curved.
  • An outer end portion 25 a is the radial outer end portion of the tongue portion 25 .
  • the outer end portion 25 a constitutes a portion of the rotation direction front side (+ ⁇ Z side) edge of the exhaust port 62 .
  • the lower housing 22 is attached to the lower side of the upper housing 21 .
  • the lower housing 22 preferably includes the motor cover portion 27 , a lower housing bottom portion 28 , a lower housing wall portion 26 and a closing portion 29 . That is to say, the housing 20 preferably includes the motor cover portion 27 .
  • the motor cover portion 27 has a roofed tubular shape opened downward.
  • the motor 40 is disposed radially inward of the motor cover portion 27 .
  • the motor cover portion 27 covers the motor 40 .
  • the motor cover portion 27 has a cylindrical shape centered at the center axis J.
  • the motor cover portion 27 has the output shaft hole 27 a axially extending through a cover region of the motor cover portion 27 .
  • the impeller 30 is arranged above the motor cover portion 27 . As illustrated in FIG. 4 , when seen in a plan view, the motor cover portion 27 substantially overlaps with the impeller 30 in its entirety.
  • the lower housing bottom portion 28 extends radially outward from the lower end of the motor cover portion 27 .
  • the lower housing wall portion 26 extends upward from the radial outer end of the lower housing bottom portion 28 .
  • the axial position of the upper end of the lower housing wall portion 26 is flush with the axial position of the upper surface of the motor cover portion 27 .
  • the lower housing wall portion 26 preferably includes a portion of the exhaust port 62 .
  • the closing portion 29 is arranged between the motor cover portion 27 and the lower housing wall portion 26 in the radial direction.
  • the closing portion 29 is connected to the motor cover portion 27 , the lower housing wall portion 26 and the lower housing bottom portion 28 .
  • the closing portion 29 closes a circumferential portion of the gap between the motor cover portion 27 and the lower housing wall portion 26 .
  • the upper surface of the closing portion 29 is arranged on the same axially-orthogonal plane as the upper surface of the motor cover portion 27 .
  • the upper surface of the motor cover portion 27 , the upper surface of the closing portion 29 and the upper end of the lower housing wall portion 26 are connected to one another with no difference in level.
  • the closing portion 29 is arranged between the tongue portion 25 and the impeller 30 in the radial direction.
  • the closing portion 29 is connected to the rotation direction front side ( ⁇ Z side) edge of the exhaust port 62 .
  • the boundary between the upper flow path 51 and the lower flow path 52 is the boundary between the upper housing 21 and the lower housing 22 .
  • the entirety of the upper flow path 51 is arranged within the upper housing 21 . That is to say, the upper housing 21 preferably include the entirety of the upper flow path 51 . At least a portion of the upper flow path 51 is arranged between the upper wall portion inner circumferential surface 24 a and the impeller 30 in the radial direction.
  • a housing inner circumferential surface 20 a is the inner circumferential surface of the housing 20 .
  • the upper wall portion inner circumferential surface 24 a is a portion of the housing inner circumferential surface 20 a . That is to say, at least a portion of the upper flow path 51 is arranged between the housing inner circumferential surface 20 a and the impeller 30 in the radial direction.
  • the upper flow path 51 has an annular or substantially annular shape.
  • the upper flow path extends along the upper wall portion inner circumferential surface 24 a . That is to say, the upper flow path 51 extends along the housing inner circumferential surface 20 a .
  • the air introduced into the upper flow path 51 from the impeller 30 flows through the upper flow path 51 in the same direction as the rotation direction of the impeller 30 (in the + ⁇ Z direction).
  • a part of the air flowing through the upper flow path 51 is introduced into the lower flow path 52 until the air reaches the exhaust port 62 .
  • the radial dimension L 7 of the upper flow path 51 grows larger as the upper flow path 51 extends from a reference position P 1 toward the exhaust port 62 in the rotation direction of the impeller 30 (in the ⁇ Z direction).
  • the upper flow path 51 has a scroll or substantially scroll shape.
  • the reference position P 1 is positioned between the exhaust port 62 and the below-mentioned lower flow path start end 52 a .
  • the reference position P 1 is a point at which a line extending in the direction orthogonal to the exhaust port 62 (in the X-axis direction) via the center axis J intersects the upper flow path 51 .
  • the radial dimension L 7 of the upper flow path 51 becomes smallest in the reference position P 1 .
  • An inner end portion 25 b is the radial inner end portion of the tongue portion 25 .
  • the radial dimension L 7 of the upper flow path 51 is equal to the radial dimension L 7 of the upper flow path 51 in the reference position P 1 . That is to say, the radial dimension L 7 of the upper flow path 51 becomes smallest over the range from the reference position P 1 to the inner end portion 25 b in the circumferential direction.
  • the axial dimension L 3 of the upper flow path 51 illustrated in FIG. 3 is equal to the internal axial dimension L 5 of the upper housing wall portion 24 .
  • the axial dimension L 3 of the upper flow path 51 grows smaller from the radial inner side toward the radial outer side. The entirety of the upper flow path 51 is opened downward.
  • the upstream end of the upper flow path 51 is, for example, a position where the radial dimension L 7 of the upper flow path 51 illustrated in FIG. 4 becomes smallest. That is to say, the position of the upstream end of the upper flow path 51 is the position where the upstream end of the upper flow path 51 is identical in the circumferential position with the inner end portion 25 b of the tongue portion 25 .
  • upper flow path refers to, e.g., an annular flow path arranged above the lower flow path having one closed end. That is to say, in the present preferred embodiment, the radial outer portion of the axial gap between the impeller 30 and the motor cover portion 27 illustrated in FIG. 3 is included in the upper flow path 51 .
  • the entirety of the lower flow path 52 is arranged inside the lower housing 22 .
  • a lower wall portion inner circumferential surface 26 a is the inner circumferential surface of the lower housing wall portion 26 .
  • a motor cover portion outer circumferential surface 27 b is the outer circumferential surface of the motor cover portion 27 .
  • a closing portion side surface 29 a is the side surface of the closing portion 29 . That is to say, the lower housing 22 preferably includes the entirety of the lower flow path 52 .
  • the lower flow path 52 is a flow path surrounded by the upper surface of the lower housing bottom portion 28 , the lower wall portion inner circumferential surface 26 a , the motor cover portion outer circumferential surface 27 b and the closing portion side surface 29 a.
  • the housing inner circumferential surface 20 a is the inner circumferential surface of the housing 20 .
  • the lower wall portion inner circumferential surface 26 a is a portion of the housing inner circumferential surface 20 a . That is to say, the lower flow path 52 is arranged between the motor cover portion outer circumferential surface 27 b and the housing inner circumferential surface 20 a.
  • the motor 40 is arranged radially inward of the motor cover portion 27 .
  • the motor 40 is arranged radially inward of the lower flow path 52 . Accordingly, when the motor 40 is accommodated within the housing 20 , it is possible to dispose the motor 40 in a radially overlapping relationship with the lower flow path 52 . It is therefore possible to reduce the size of the centrifugal fan 10 in the axial direction.
  • the lower flow path 52 extends along the lower wall portion inner circumferential surface 26 a . That is to say, the lower flow path 52 extends along the housing inner circumferential surface 20 a . As indicated by thick arrows in FIG. 4 , the air introduced from the upper flow path 51 into the lower flow path 52 flows through the lower flow path 52 in the same direction as the rotation direction of the impeller 30 (in the ⁇ Z direction).
  • a lower flow path terminal end 52 b is one circumferential end ( ⁇ Z side end) of the lower flow path 52 and is opened in the exhaust port 62 .
  • a lower flow path start end 52 a is the other circumferential end ( ⁇ Z side end) of the lower flow path 52 and is closed with respect to the exhaust port 62 .
  • the air guided from the lower flow path start end 52 a toward the lower flow path terminal end 52 b does not flow from the vicinity of the exhaust port 62 toward the upstream side, namely the side of the lower flow path start end 52 a . Accordingly, the entirety of the air flowing through the lower flow path 52 is discharged from the exhaust port 62 . This makes it possible to reduce a loss of airflow.
  • the lower flow path start end 52 a is closed with respect to the exhaust port 62 .
  • a tongue portion is not provided within the lower flow path 52 .
  • the air flowing through the lower flow path 52 does not impinge against a tongue portion. This makes it possible to suppress generation of a turbulent flow of air. As a result, it is possible to suppress generation of a noise.
  • a straight line passing through the center axis J and the center P 2 of the exhaust port 62 is referred to as a “straight line C 3 ”.
  • the term “the vicinity of the exhaust port” includes a range in which the circumferential angle ⁇ 2 from the straight line C 3 toward the rotation direction back side ( ⁇ Z side) becomes 75 degrees or less.
  • the center P 2 of the exhaust port 62 is, for example, the center of the exhaust port 62 in the direction orthogonal to the center axis J and parallel to the exhaust port 62 (in the Y-axis direction).
  • the upper flow path 51 has an annular or substantially annular shape.
  • a part of the air guided from the interior of the upper flow path 51 toward the vicinity of the exhaust port 62 flows toward the upstream side of the upper flow path 51 .
  • the air flowing toward the upstream side of the upper flow path 51 impinges against the tongue portion 25 and generates a noise.
  • the axial dimension L 2 of the portion of the exhaust port 62 connected to the lower flow path 52 is larger than the axial dimension L 1 of the portion of the exhaust port 62 connected to the upper flow path 51 .
  • one end of the lower flow path is closed in the circumferential direction. That is to say, even when closing one circumferential end of the lower flow path, one circumferential end of the lower flow path may be opened upward.
  • the lower flow path start end 52 a is closed by the closing portion 29 . That is to say, the circumferential position of the lower flow path start end 52 a is the same as the circumferential position of the rotation direction front side (+ ⁇ Z side) end of the closing portion 29 .
  • the lower flow path start end 52 a is arranged near the exhaust port 62 in the circumferential direction. If the lower flow path start end 52 a is excessively spaced apart from the exhaust port 62 in the circumferential direction, the length of the lower flow path 52 becomes small. For that reason, the air discharged from the impeller 30 is not efficiently guided to the exhaust port 62 . Thus, the blowing efficiency of the centrifugal fan 10 is reduced.
  • a straight line C 2 is a straight line passing through the center axis J and meeting with the lower flow path start end 52 a .
  • a straight line C 1 is a straight line passing through the center axis J and meeting with the tongue portion 25 .
  • the angle between the straight line C 1 and the straight line C 2 is assumed to be ⁇ .
  • the circumferential angle from the straight line C 1 is assumed to be ⁇ 1 . In this case, it is preferred that the angle ⁇ is 75 degrees or less. That is to say, when seen in a plan view, the lower flow path start end 52 a is located in the position where the circumferential angle ⁇ 1 from the straight line C 1 becomes 75 degrees or less.
  • the angle ⁇ 1 is a circumferential angle from the straight line C 1 toward the rotation direction front side (+ ⁇ Z side).
  • the radial dimension L 8 of the lower flow path 52 grows larger from the lower flow path start end 52 a toward the lower flow path terminal end 52 b . That is to say, the lower flow path 52 has a scroll or a substantially scroll shape. It is therefore possible to suppress generation of an air vortex within the lower flow path 52 and to smoothly discharge the air from the exhaust port 62 . This makes it possible to further reduce a loss of airflow.
  • the upper housing wall portion 24 constitutes the radial outer inner circumferential surface of the upper flow path 51 .
  • the lower housing wall portion 26 constitutes the radial outer inner circumferential surface of the lower flow path 52 .
  • the upper flow path 51 has a scroll shape or a substantially scroll shape. This makes it easy to interconnect the upper housing 21 having the upper flow path 51 and the lower housing 22 having the lower flow path 52 .
  • the upper housing wall portion 24 and the lower housing wall portion 26 may be shaped to go away from the center axis J as they extend in the circumferential direction. This makes it easy to connect the upper housing wall portion 24 to the lower housing wall portion 26 .
  • the axial dimension L 4 of the lower flow path 52 illustrated in FIG. 3 is uniform.
  • the axial dimension L 4 of the lower flow path 52 is equal to the internal axial dimension L 6 of the lower housing 22 . This makes it easy to increase the axial dimension L 4 of the lower flow path 52 .
  • the flow velocity of the air flowing through the flow path 50 tends to become larger in the position closer to the lower housing bottom portion 28 . If the air having a large flow velocity is introduced from the vicinity of the exhaust port 62 toward the upstream side of the flow path 50 , the loss of airflow grow larger. Moreover, the air having a large flow velocity impinges against the tongue portion 25 . Thus, a turbulent flow is easily generated and a noise is increased.
  • the upstream side of the flow path 50 is, for example, the upstream side of the upper flow path 51 .
  • the entirety of the lower flow path 52 is opened upward toward the upper flow path 51 . For that reason, the air discharged radially outward from the impeller 30 is easily introduced from the upper flow path 51 into the lower flow path 52 . This makes it easy to discharge the air from the exhaust port 62 via the lower flow path 52 . Accordingly, it is possible to further reduce the loss of airflow.
  • the axial dimension L 4 of the lower flow path 52 is larger than the axial dimension L 3 of the upper flow path 51 . For that reason, the air discharged radially outward from the impeller 30 easily flows from the upper flow path 51 toward the lower flow path 52 . This makes it possible to further reduce the loss of airflow.
  • One of the upper flow path 51 and the lower flow path 52 may not have a scroll shape.
  • one of the upper flow path 51 and the lower flow path 52 may have, e.g., an annular or substantially annular shape.
  • a portion of the lower flow path 52 may not be opened toward, e.g., the upper flow path 51 .
  • the lower housing 22 may have a portion of the upper flow path 51 and the lower flow path 52 .
  • the axial dimension L 4 of the lower flow path 52 in the vicinity of the exhaust port 62 may be one half or more of the internal axial dimension L 6 of the lower housing 22 . According to this configuration, it is possible to sufficiently increase the axial dimension L 4 of the lower flow path 52 and to prevent the air having a large flow velocity from flowing from the vicinity of the exhaust port 62 toward the upstream side of the upper flow path 51 .
  • the axial position of the upper surface of the closing portion 29 illustrated in FIG. 2 may be lower than the axial position of the upper surface of the motor cover portion 27 .
  • the internal portion of the lower housing 22 arranged higher than the closing portion 29 has an annular or substantially annular shape.
  • FIG. 6 is a side view illustrating a centrifugal fan 110 according to another example of one preferred embodiment. As illustrated in FIG. 6 , the exhaust port 62 may be connected to only the lower flow path 52 .
  • the centrifugal fan 110 preferably includes a housing 120 .
  • the housing 120 preferably includes an intake port 61 , a flow path 50 and an exhaust port 162 .
  • the housing 120 preferably includes an upper housing 121 and a lower housing 122 .
  • the upper housing 121 preferably includes an upper housing cover portion 23 and an upper housing wall portion 124 .
  • the configuration of the upper housing wall portion 124 is the same as the configuration of the upper housing wall portion 24 illustrated in FIG. 5 , except that the upper housing wall portion 124 does not have a portion of the exhaust port 62 .
  • the upper housing wall portion 124 has a shape obtained by closing a portion of the exhaust port 62 defined by the upper housing wall portion 24 illustrated in FIG. 5 .
  • the lower housing 122 preferably includes a lower housing bottom portion 28 , a lower housing wall portion 126 and a closing portion 29 . While not shown in the drawings, the lower housing 122 includes a motor cover portion 27 .
  • the configuration of the lower housing wall portion 126 is the same as the configuration of the lower housing wall portion 26 illustrated in FIG. 5 , except that the lower housing wall portion 126 has the entirety of the exhaust port 162 .
  • the exhaust port 162 is connected to only the lower flow path 52 . For that reason, the entirety of the air discharged from the exhaust port 162 is discharged from the lower flow path 52 . It is therefore possible to enable the air existing within the upper flow path 51 to easily flow toward the lower flow path 52 while the air flows from the upstream side of the upper flow path 51 to the vicinity of the exhaust port 162 . Accordingly, it is possible to further restrain the air from flowing from the vicinity of the exhaust port 162 toward the upstream side of the upper flow path 51 . As a result, it is possible to further reduce the loss of airflow and to further suppress generation of a noise.
  • the axial dimension of the lower housing 122 may be made larger than the axial dimension of the lower housing 22 (see FIG. 5 ). By doing so, it is possible to set the opening area of the exhaust port 162 larger than the opening area of the intake port 61 .
  • FIG. 7 is a sectional view illustrating a portion of a centrifugal fan 210 according to a further example of one preferred embodiment. As illustrated in FIG. 7 , the lower end portion of the lower flow path 52 may be a slant surface.
  • the centrifugal fan 210 preferably includes a housing 220 .
  • the housing 220 preferably includes a flow path 250 .
  • the flow path 250 preferably includes an upper flow path 51 and a lower flow path 252 .
  • the housing 220 preferably includes an upper housing 21 and a lower housing 222 .
  • the lower housing 222 preferably includes a lower housing bottom portion 228 , a lower housing wall portion 26 and a closing portion 29 . While not shown in the drawings, the lower housing 222 preferably includes a motor cover portion 27 .
  • a bottom surface 228 a of the lower housing bottom portion 228 is a slant surface.
  • the bottom surface 228 a extends downward in the portion connected to the closing portion 29 . That is to say, the bottom surface 228 a extends downward from a lower flow path start end 252 a toward the rotation direction front side (+ ⁇ Z side).
  • the bottom surface 228 a is a slant surface inclined with respect to the center axis J or a curved surface.
  • the axial position of the bottom surface 228 a is preferably the same as the axial position of the upper surface of the closing portion 29 . That is to say, at the lower flow path start end 252 a , the axial position of the bottom surface 228 a is preferably the same as the axial position of the upper surface of the closing portion 29 .
  • the bottom surface 228 a is the lower end portion of the lower flow path 252 .
  • the position of the lower end portion of the lower flow path 252 goes away from the upper flow path 51 as the lower flow path 252 extends from the lower flow path start end 252 a toward the lower flow path terminal end (not illustrated).
  • the distance between the lower end portion of the lower flow path 252 and the upper flow path 51 grows larger from the lower flow path start end 252 a toward the lower flow path terminal end (not illustrated).
  • the axial dimension of the lower flow path 252 becomes larger from the lower flow path start end 252 a toward the lower flow path terminal end.
  • the air introduced from the intake port 61 into the impeller 30 is discharged from the circumferential entirety of the impeller 30 to the upper flow path 51 .
  • a part of the air introduced into the upper flow path 51 flows toward the lower flow path 52 while moving through the upper flow path 51 in the rotation direction of the impeller 30 ( ⁇ Z direction).
  • the amount of the air flowing from the upper flow path 51 toward the lower flow path 52 is small.
  • the air tends to stay within the lower flow path 52 in the vicinity of the lower flow path start end 52 a .
  • an air vortex is easily generated. Accordingly, there is a possibility that the loss of airflow becomes larger.
  • the lower end portion of the lower flow path 252 goes away from the upper flow path 51 as the lower flow path 252 extends from the lower flow path start end 252 a toward the lower flow path terminal end.
  • the distance between the lower end portion of the lower flow path 252 and the upper flow path 51 grows larger from the lower flow path start end 252 a toward the lower flow path terminal end.
  • the amount of the air introduced from the upper flow path 51 into the lower flow path 252 is large. According to this configuration, it is possible to increase the axial dimension of the lower flow path 252 at the downstream side. Thus, it is possible to enable the air to efficiently flow from the upper flow path 51 toward the lower flow path 252 .
  • the axial dimension of the lower flow path 252 in the vicinity of the exhaust port 62 is, for example, one half or more of the axial dimension of the lower housing 222 . This makes it possible to further reduce the loss of airflow.
  • centrifugal fan 210 According to the configuration described above, it is possible to further improve the blowing efficiency of the centrifugal fan 210 .
  • Other configurations of the centrifugal fan 210 are the same as the configurations of the centrifugal fan 10 illustrated in FIGS. 1 to 5 .
  • the upper housing 21 may have the entirety of the upper flow path 51 and the entirety of the lower flow path 52 .
  • the housing 20 may be configured by axially interconnecting three or more independent members.
  • the housing 20 may be a single member.
  • the upper housing 21 may not include the tongue portion 25 .
  • the motor 40 may not be accommodated within the housing 20 .

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US14/990,261 2015-03-30 2016-01-07 Centrifugal fan Abandoned US20160290358A1 (en)

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US20170030378A1 (en) * 2015-07-31 2017-02-02 Minebea Co., Ltd. Centrifugal fan
US20170114791A1 (en) * 2015-10-23 2017-04-27 Minebea Co., Ltd. Centrifugal fan
US20190107115A1 (en) * 2017-10-10 2019-04-11 Inventec (Pudong) Technology Corporation Fan module
US20230109395A1 (en) * 2020-03-30 2023-04-06 Nidec Corporation Impeller and centrifugal fan
EP4242465A1 (en) * 2022-03-07 2023-09-13 GrowTrend Biomedical Co., Ltd. Blower

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JP6554867B2 (ja) * 2015-03-30 2019-08-07 日本電産株式会社 遠心ファン
NL2015220B1 (nl) * 2015-07-24 2017-02-08 Intergas Heating Assets Bv Centrifugaalwaaier, en daarvan voorziene verwarmingsinrichting.
JP6937903B2 (ja) * 2018-05-21 2021-09-22 三菱電機株式会社 遠心送風機、送風装置、空気調和装置及び冷凍サイクル装置
JP7369520B2 (ja) * 2018-12-20 2023-10-26 日立グローバルライフソリューションズ株式会社 冷蔵庫
JP2020133411A (ja) * 2019-02-13 2020-08-31 株式会社ケーヒン 車両用空調装置
CN210769567U (zh) * 2019-09-18 2020-06-16 中山大洋电机股份有限公司 一种引风机

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US20230109395A1 (en) * 2020-03-30 2023-04-06 Nidec Corporation Impeller and centrifugal fan
EP4242465A1 (en) * 2022-03-07 2023-09-13 GrowTrend Biomedical Co., Ltd. Blower

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CN106015038A (zh) 2016-10-12
CN205423220U (zh) 2016-08-03
JP6554867B2 (ja) 2019-08-07
CN106015038B (zh) 2019-06-18
EP3076023A1 (en) 2016-10-05
JP2016191309A (ja) 2016-11-10

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