U.S. patent application number 16/357451 was filed with the patent office on 2019-09-26 for centrifugal blower.
The applicant listed for this patent is DENSO CORPORATION. Invention is credited to Shouichi IMAHIGASHI, Shuzo ODA.
Application Number | 20190293082 16/357451 |
Document ID | / |
Family ID | 67984872 |
Filed Date | 2019-09-26 |
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United States Patent
Application |
20190293082 |
Kind Code |
A1 |
IMAHIGASHI; Shouichi ; et
al. |
September 26, 2019 |
CENTRIFUGAL BLOWER
Abstract
A centrifugal blower includes a centrifugal fan and a partition
cylinder portion. The centrifugal fan includes first blades and
second blades arranged about a fan central axis, a separation panel
between the first blades and the second blades, and an inward
extending part extending inward in a radial direction from the
separation panel. The partition cylinder portion has a cylindrical
shape extending in an axial direction. The partition cylinder
portion is located inside the second blades in the radial
direction. The partition cylinder portion partitions air drawn into
spaces between the first blades from air drawn into spaces between
the second blades. The separation panel has a plate shape extending
in the radial direction. The inward extending part is located
inside, in the radial direction, both connected ends of the first
blades and connected ends of the second blades which are joined to
the separation panel.
Inventors: |
IMAHIGASHI; Shouichi;
(Kariya-city, JP) ; ODA; Shuzo; (Kariya-city,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENSO CORPORATION |
Kariya-city |
|
JP |
|
|
Family ID: |
67984872 |
Appl. No.: |
16/357451 |
Filed: |
March 19, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/441 20130101;
F04D 29/4246 20130101; F04D 29/281 20130101; F04D 17/16 20130101;
F04D 29/286 20130101; F04D 25/08 20130101 |
International
Class: |
F04D 29/28 20060101
F04D029/28; F04D 17/16 20060101 F04D017/16; F04D 25/08 20060101
F04D025/08; F04D 29/44 20060101 F04D029/44 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2018 |
JP |
2018-58946 |
Claims
1. A centrifugal blower comprising: a centrifugal fan including a
plurality of first blades arranged about a fan central axis, a
plurality of second blades arranged about the fan central axis, the
plurality of second blades being located on a first side of the
plurality of first blades in an axial direction of the fan central
axis and being aligned to the plurality of first blades, a
separation panel located between the plurality of first blades and
the plurality of second blades, and an inward extending part
extending inward in a radial direction of the centrifugal fan from
the separation panel; and a partition cylinder portion having a
cylindrical shape extending in the axial direction, a diameter of
the partition cylinder portion expanding in the axial direction
toward a second side that is an opposite side of the first side,
the partition cylinder portion being located inside the plurality
of second blades in the radial direction, wherein the centrifugal
fan is configured to rotate about the fan central axis to take in
air from the first side into spaces between the plurality of first
blades and spaces between the plurality of second blades, blow out
the air in the spaces between the plurality of first blades outward
in the radial direction, and blow out the air in the spaces between
the plurality of second blades outward in the radial direction, the
partition cylinder portion partitions, on an airflow upstream side
of the plurality of first blades and the plurality of second
blades, the air taken into the spaces between the plurality of
first blades through an inside of the partition cylinder portion in
the radial direction from the air taken into the spaces between the
plurality of second blades through an outside of the partition
cylinder portion in the radial direction, the separation panel has
a plate shape extending in the radial direction and partitions the
air flowing through the spaces between the plurality of first
blades from the air flowing through the spaces between the
plurality of second blades, and the inward extending part is
located inside, in the radial direction, both connected ends of the
plurality of first blades each of which is joined to the separation
panel and connected ends of the plurality of second blades each of
which is joined to the separation panel.
2. The centrifugal blower according to claim 1, wherein the
partition cylinder portion includes the inward extending part and
rotates together with the centrifugal fan.
3. The centrifugal blower according to claim 1, wherein the
partition cylinder portion is separated from the centrifugal fan
and is a non-rotating member that is not configured to rotate, and
the partition cylinder portion partitions, on an airflow upstream
side of the inward extending part, the air taken into the spaces
between the plurality of first blades from the air taken into the
spaces between the plurality of second blades.
4. The centrifugal blower according to claim 1, further comprising:
a fan casing that accommodates the centrifugal fan, the fan casing
defining a fan surrounding space that surrounds the centrifugal fan
outside the centrifugal fan in the radial direction, the air
flowing into the fan surrounding space from the centrifugal fan;
and a partition panel that partitions the fan surrounding space in
the axial direction into a first flow-out passage and a second
flow-out passage, wherein a first air flowing out of the spaces
between the plurality of first blades flows into the first flow-out
passage, a second air flowing out of the spaces between the
plurality of second blades flows into the second flow-out passage,
and the partition panel is configured to limit the first air from
entering the second flow-out passage and limit the second air from
entering the first flow-out passage.
5. The centrifugal blower according to claim 1, further comprising:
a filter located on a first side of the partition cylinder portion
in the axial direction to filtrate the air flowing toward the
centrifugal fan, wherein the partition cylinder portion extends to
the filter.
6. The centrifugal blower according to claim 1, further comprising:
an upstream partition wall located on a first side of the partition
cylinder portion in the axial direction and separated from the
partition cylinder portion, the upstream partition wall having a
cylindrical shape aligned to the partition cylinder portion in the
axial direction, the upstream partition wall partitioning the air
flowing into the inside of the partition cylinder portion from the
air flowing into the outside of the partition cylinder portion on
an airflow upstream side of the partition cylinder portion; and a
filter located on a first side of the upstream partition wall in
the axial direction to filtrate the air flowing toward the
centrifugal fan, wherein the upstream partition wall extends to the
filter.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on and incorporates herein by
reference Japanese Patent Application No. 2018-058946 filed on Mar.
26, 2018.
TECHNICAL FIELD
[0002] The present disclosure relates to a centrifugal blower.
BACKGROUND
[0003] A general centrifugal blower of this type includes a
centrifugal fan configured to simultaneously draw two airflows
separated from each other.
SUMMARY
[0004] According to an aspect of the present disclosure; a
centrifugal blower includes: a centrifugal fan including a
plurality of first blades arranged about a fan central axis, a
plurality of second blades arranged about the fan central axis, the
plurality of second blades being located on a first side of the
plurality of first blades in an axial direction of the fan central
axis and being aligned to the plurality of first blades, a
separation panel located between the plurality of first blades and
the plurality of second blades, and an inward extending part
extending inward in a radial direction of the centrifugal fan from
the separation panel; and a partition cylinder portion having a
cylindrical shape extending in the axial direction, a diameter of
the partition cylinder portion expanding in the axial direction
toward a second side that is an opposite side of the first side,
the partition cylinder portion being located inside the plurality
of second blades in the radial direction. The centrifugal fan is
configured to rotate about the fan central axis to: take in air
from the first side into spaces between the plurality of first
blades and spaces between the plurality of second blades; blow out
the air in the spaces between the plurality of first blades outward
in the radial direction; and blow out the air in the spaces between
the plurality of second blades outward in the radial direction. The
partition cylinder portion partitions, on an airflow upstream side
of the plurality of first blades and the plurality of second
blades, the air taken into the spaces between the plurality of
first blades through an inside of the partition cylinder portion in
the radial direction from the air taken into the spaces between the
plurality of second blades through an outside of the partition
cylinder portion in the radial direction. The separation panel has
a plate shape extending in the radial direction and partitions the
air flowing through the spaces between the plurality of first
blades from the air flowing through the spaces between the
plurality of second blades. The inward extending part is located
inside, in the radial direction, both connected ends of the
plurality of first blades each of which is joined to the separation
panel and connected ends of the plurality of second blades each of
which is joined to the separation panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The disclosure, together with additional objectives,
features and advantages thereof, will be best understood from the
following description, the appended claims and the accompanying
drawings, in which:
[0006] FIG. 1 is a cross-sectional diagram schematically
illustrating a cross-section of a centrifugal blower taken by a
plane including a fan central axis, according to a first
embodiment;
[0007] FIG. 2 is an enlarged view of II part of FIG. 1;
[0008] FIG. 3 is a cross-sectional diagram of first blades taken
along line of FIG. 2;
[0009] FIG. 4 is a cross-sectional diagram of second blades taken
along IV-IV line of FIG. 2;
[0010] FIG. 5 is a cross-sectional diagram schematically
illustrating a centrifugal blower of a comparative example taken by
a plane including a fan central axis and corresponding to FIG. 1;
and
[0011] FIG. 6 is a cross-sectional diagram schematically
illustrating a centrifugal blower of a second embodiment taken by a
plane including a fan central axis and corresponding to FIG. 1.
DETAILED DESCRIPTION
[0012] Embodiments of the present disclosure will be described
hereinafter referring to drawings. In the embodiments, a part that
corresponds to a matter described in a preceding embodiment may be
assigned with the same reference numeral, and redundant explanation
for the part may be omitted. When only a part of a configuration is
described in an embodiment, another preceding embodiment may be
applied to the other parts of the configuration. The parts may be
combined even if it is not explicitly described that the parts can
be combined. The embodiments may be partially combined even if it
is not explicitly described that the embodiments can be combined,
provided there is no harm in the combination.
[0013] A centrifugal blower is known, which includes a centrifugal
fan configured to simultaneously draw two airflows separated from
each other, and a first radial band that separates the air blown
out of the centrifugal fan into an airflow on one side and an
airflow on the other side in an axial direction.
[0014] The centrifugal fan has multiple blades arranged about a
rotation shaft. The first radial band has an annular shape and is
located at a center part of the blades in the axial direction of
the centrifugal fan.
[0015] The centrifugal blower includes a separation cylinder that
has an approximately circular cylinder shape and is located inside
the centrifugal fan in a radial direction. The separation cylinder
does not rotate and partitions an air intake passage extending from
an intake port to the centrifugal fan into two passages.
[0016] In an example of the centrifugal blower, a length of the
radial band in the radial direction of the centrifugal fan is
smaller than a length of the blade of the centrifugal fan in the
radial direction. In such a centrifugal blower, the airs
partitioned by the separation cylinder are mixed while the airs
flow between the blades.
[0017] In another example of the centrifugal blower, a length of
the radial band in the radial direction of the centrifugal fan is
equal to a length of the blade in the radial direction of the
centrifugal fan. This another example of the centrifugal blower may
limit the airs from mixing in the space between the blades.
[0018] However, since there is a gap radially extending between the
centrifugal fan that rotates and the separation cylinder that does
not rotate, the air may leak through the radially extending gap.
Accordingly, the mixing of the airs partitioned by the separation
cylinder may cause disturbance of the airflow toward the blades.
Since the radially extending gap is close to the blades, the
disturbed air flows into a space between the blades. The disturbed
air flowing into the spaces between the blades may deteriorate the
performance of the fan of the centrifugal blower. The above points
are recognized as a result of detailed consideration by the present
inventors.
[0019] Embodiments are described below with reference to the
drawings. In the following embodiments, identical or equivalent
elements are denoted by the same reference numerals as each other
in the figures.
First Embodiment
[0020] A centrifugal blower 10 (hereinafter, simply referred to as
a "blower 10") of the present embodiment is used in an
air-conditioner for a vehicle. The blower 10 separates multiple
airflows and blows air. As shown in FIGS. 1, 2, the blower 10
includes a centrifugal fan 12, a partition cylinder portion 14, a
fan casing 16, a partition panel 18, an upstream partition wall 20,
and a motor 22.
[0021] The centrifugal fan 12 is a multi-layer centrifugal fan that
rotates about a fan central axis CL to draw multiple airflows
separated from each other from one side in an axial direction DRa
of the fan central axis CL. In the present embodiment, the axial
direction DRa is the axial direction DRa of the fan central axis
CL, i.e. the axial direction DRa of the centrifugal fan 12, the
radial direction DRr is the radial direction DRr of the fan central
axis CL, i.e. the radial direction DRr of the centrifugal fan 12. A
circumferential direction is the circumferential direction about
the fan central axis CL, i.e. the circumferential direction of the
centrifugal fan 12.
[0022] The motor 22 is a driving source that rotates the
centrifugal fan 12 in a predetermined fan rotation direction RT
(see FIG. 3). The motor 22 includes a motor body 221 fixed to the
fan casing 16 and a motor rotation shaft 222 protruding from the
motor body 221 to the one side in the fan axial direction DRa. The
motor rotation shaft 222 and the centrifugal fan 12 that is linked
to the motor rotation shaft 222 so as not to rotate relative to the
motor rotation shaft 222 rotate in the fan rotation direction RT in
response to an energization to the motor 22.
[0023] The centrifugal fan 12 includes multiple first blades 121
arranged about the fan central axis CL, multiple second blades 122
arranged about the fan central axis CL, a separation panel 123, a
main panel 124, and a side panel 125. The first blades 121, the
second blades 122, the separation panel 123, the main panel 124,
and the side panel 125 are integrated with each other, and
accordingly they rotate together about the fan central axis CL.
[0024] In the centrifugal fan 12, multiple first blades 121
constitute a first blowing portion 12a that sends air using the
first blades 121, and multiple second blades 122 constitute a
second blowing portion 12b that sends air using the second blades
122. The second blades 122 located on the one side of the first
blades 121 in the fan axial direction DRa. That is, the second
blowing portion 12b is located on one side of the first blowing
portion 12a in the fan axial direction DRa to be layered.
[0025] Each of the first blades 121 has a first end 121a that is an
end on one side in the fan axial direction DRa, and a second end
121b that is an end on the other side in the fan axial direction
DRa. Each of the second blades 122 has a first end 122a that is an
end on the one side in the fan axial direction DRa, and a second
end 122b that is an end on the other side in the fan axial
direction DRa.
[0026] The main panel 124 of the centrifugal fan 12 has a circular
disk shape extending in the fan radial direction DRr. A motor
rotation shaft 222 is connected to a center part of the main panel
124. The second end 121b of the first blade 121 is fixed to the
main panel 124 at a part that is located on a radially outer side
compared to the connection part of the main panel 124 and the motor
rotation shaft 222.
[0027] Since the first blades 121 and the second blades 122 are
provided in such manner, the centrifugal fan 12 takes in air from
the one side in the fan central axis DRa and discharges the intake
air radially outward by rotating about the fan central axis CL. In
detail, the centrifugal fan 12 rotates about the fan central axis
CL to take in air from the one side in the fan axial direction DRa
into the spaces between the first blades 121 and the spaces between
the second blades 122. Simultaneously, the centrifugal fan 12 blows
out the intake air in the space between the first blades 121 and
the space between the second blades 122 radially outward.
[0028] Taking in air into the space between the first blades 121
corresponds to taking in air into the first blowing portion 12a.
Similarly, taking in air into the space between the second blades
122 corresponds to taking in air into the second blowing portion
12b. Blowing out the intake air in the space between the first
blades 121 radially outward corresponds to blowing out the intake
air in the first blowing portion 12a outward in a radial direction
of the first blowing portion 12a. Similarly, blowing out the intake
air in the space between the second blades 122 radially outward
corresponds to blowing out the intake air in the second blowing
portion 12b outward in a radial direction of the second blowing
portion 12b.
[0029] The separation panel 123 of the centrifugal fan 12 has a
circular annular shape surrounding the fan central axis CL and has
a plate shape extending in the fan radial direction DRr. The
separation panel 123 is located between the first blades 121 and
the second blades 122 in the fan axial direction DRa. Accordingly,
the first end 121a of the first blade 121 and the second end 122b
of the second blade 122 are fixed to the separation panel 123. That
is, the first end 121a of the first blade 121 is a connected end
joined to the separation panel 123, and the second end 122b of the
second blade 122 is also a connected end joined to the separation
panel 123.
[0030] In detail, the separation panel 123 has a width in the fan
radial direction DRr enough to be connected to entire part of the
first end 121a of the first blade 121 and the second end 122b of
the second blade 122. In the present embodiment, the length of the
first end 121a of the first blade 121 is larger than the length of
the second end 122b of the second blade 122. The separation panel
123 extends in the fan radial direction DRr to cover the entire
part of the first end 121a of the first blade 121. The separation
panel 123 extends inward and outward from the second blade 122 in
the fan radial direction DRr.
[0031] According to this configuration, the separation panel 123
partitions the air flowing through the space between the first
blades 121 from the air flowing through the space between the
second blades 122, and prevents the airs from mixing together. The
air flowing through the space between the first blades 121
corresponds to air in the first blowing portion 12a, The air
flowing through the space between the second blades 122 corresponds
to air in the second blowing portion 12b.
[0032] The side panel 125 of the centrifugal fan 12 has a circular
annular shape about the fan central axis CL. The first ends 122a
and neighboring parts of the second blades 122 are connected to the
side panel 125.
[0033] Each of the first blades 121 has a first leading edge 121c
that is an upstream edge located upstream with respect to the
airflow in the space between the first blades 121. Each of the
first blades 121 has a first trailing edge 121d that is a
downstream edge located downstream with respect to the airflow in
the space between the first blades 121. That is, the first leading
edge 121c defines a part of an inlet of an air flow passage defined
between the first blades 121, and the first trailing edge 121d
defines a part of an outlet of the air flow passage.
[0034] Similarly, each of the second blades 122 has a second
leading edge 122c that is an upstream edge located upstream with
respect to the airflow in the space between the second blades 122.
Each of the second blades 122 has a second trailing edge 122d that
is a downstream edge located downstream with respect to the airflow
in the space between the second blades 122, That is, the second
leading edge 122c defines a part of an inlet of an air flow passage
defined between the second blades 122, and the second trailing edge
122d defines a part of an outlet of the air flow passage. For
example, since the outlet of the air flow passage defined between
the second blades 122 is located on the other side of the side
panel 125 in the fan axial direction DRa, the second trailing edges
122d are also located on the other side of the side panel 125 in
the fan axial direction DRa.
[0035] The partition cylinder portion 14 has a cylindrical shape
extending along the fan axial direction DRa, and a diameter of the
partition cylinder portion 14 enlarges toward the other side in the
fan axial direction DRa. Specifically, the partition cylinder
portion 14 has a cylinder portion 141 and an expanded portion 142
integrated with the cylinder portion 141. The partition cylinder
portion 14 is located inside the second blades 122 in the fan
radial direction DRr, i.e. inside the second blowing portion
12b.
[0036] The cylinder portion 141 of the partition cylinder portion
14 has a cylindrical shape extending along the fan axial direction
DRa. In detail, the cylinder portion 141 has a circular cylindrical
shape whose axis is the fan central axis CL and extends in the fan
axial direction DRa.
[0037] The expanded portion 142 of the partition cylinder portion
14 extends from the cylinder portion 141 toward the other side in
the fan axial direction DRa, and the diameter of the enlarged
portion 142 enlarges toward the other side in the fan axial
direction DRa. In detail, the diameter of the expanded portion 142
expands toward the other side in the fan axial direction DRa such
that the other end of the expanded portion 142 extends outward in
the fan radial direction DRr.
[0038] The air flowing inside the cylinder portion 141 in the fan
radial direction DRr is drawn into the space between the first
blades 121. The air flowing outside the cylinder portion 141 in the
fan radial direction DRr is drawn into the space between the second
blades 122. That is, the partition cylinder portion 14 partitions
the air flowing into the space between the first blades 121 from
the air flowing into the space between the second blades 122 on the
airflow upstream side of the blades 121, 122.
[0039] The partition cylinder portion 14 of the present embodiment
continues from a radially inner part of the separation panel 123 of
the centrifugal fan 12 and is integrated with the centrifugal fan
12. Therefore, the partition cylinder portion 14 rotates together
with the centrifugal fan 12. The radially inner part of the
separation panel 123 in the fan radial direction DRr is connected
to the expanded portion 142 of the partition cylinder portion 14.
In detail, the expanded portion 142 of the partition cylinder
portion 14 extends inward in the fan radial direction DRr from the
radially inner part of the separation panel 123.
[0040] The expanded portion 142 may correspond to an inward
extending part 126 of the centrifugal fan 12 extending inward in
the fan radial direction DRr from the separation panel 123. That
is, the partition cylinder portion 14 includes the inward extending
part 126 that is a part of the centrifugal fan 12. The inward
extending part 126 is located inside of both the first blades 121
and the second blades 122 in the fan radial direction DRr. In
detail, the inward extending part 126 is located inside of both the
first end 121a of the first blade 121 and the second end 122b of
the second blade 122 in the fan radial direction DRr.
[0041] The fan casing 16 is a non-rotating member that does not
rotate and is a casing that accommodates the centrifugal fan 12.
The fan casing 16 includes a bell mouth portion 161 that is an air
intake portion defining a casing air intake port 16a through which
the air is taken into the centrifugal fan 12. The bell mouth
portion 161 defines a rim of the casing air intake port 16a of the
fan casing 16. The cross-section of the bell mouth portion 161 has
an arc shape such that the air outside the fan casing 16 smoothly
flows into the casing air intake port 16a.
[0042] The casing air intake port 16a is located on the one side in
the fan axial direction DRa with respect to the centrifugal fan 12,
and opens in the fan axial direction DRa.
[0043] The cylinder portion 141 of the partition cylinder portion
14 is located inside the bell mouth portion 161 in the fan radial
direction DRr. In the casing air intake port 16a, a part inside the
cylinder portion 141 in the fan radial direction DRr is a first air
intake port 16b, and a part outside the cylinder portion 141 in the
fan radial direction DRr is a second air intake port 16c.
Accordingly, the second air intake port 16c is an opening having a
circular annular shape surrounding the first air intake port
16b.
[0044] The air flowing into the fan casing 16 through the first air
intake port 16b is drawn into the first blowing portion 12a through
the radially inner side of the cylinder portion 141 of the
partition cylinder portion 14. The air flowing into the fan casing
16 through the second air intake port 16c is drawn into the second
blowing portion 12b through the radially outer side of the cylinder
portion 141 of the partition cylinder portion 14.
[0045] The fan casing 16 includes a fan surrounding portion 162,
and the fan surrounding portion 162 defines a fan surrounding space
162a surrounding the centrifugal fan 12. The air blown out of the
centrifugal fan 12 flows into the fan surrounding space 162a.
[0046] The partition panel 18 having a plate shape whose thickness
direction corresponds to the fan axial direction DRa is provided in
the fan surrounding space 162a. The partition panel 18 is located
radially outside the centrifugal fan 12 to have a small gap with
the centrifugal fan 12, and the partition panel 18 has an annular
shape extending along an outer circumference of the centrifugal fan
12. A radially outside end of the partition panel 18 is fixed to
the fan surrounding portion 162.
[0047] The partition panel 18 provided as described above
partitions the fan surrounding space 162a into a first flow-out
passage 162b and a second flow-out passage 162c located on the one
side of the first flow-out passage 162b in the fan axial direction
DRa.
[0048] The air flowing through the space between the first blades
121, i.e. a first air flowing radially outward from the first
blowing portion 12a, flows into the first flow-out passage 162b.
The air flowing through the space between the second blades 122,
i.e. a second air flowing radially outward from the second blowing
portion 12b, flows into the second flow-out passage 162c.
[0049] The partition panel 18 is provided to suppress the first air
from flowing into the second flow-out passage 162c and to suppress
the second air from flowing into the first flow-out passage 162b.
Specifically, a position of a radially inner end 18a of the
partition panel 18 is aligned to a position of a radially outer end
123a of the separation panel 123 of the centrifugal fan 12 in the
fan axial direction DRa. The first air is not necessarily
completely prevented from flowing into the second flow-out passage
162c, but it is enough that the first air flowing into the second
flow-out passage 162c is reduced. This also is the same as the
second air flowing into the first flow-out passage 162b.
[0050] The first flow-out passage 162b is a scroll passage that
guides the air flowing out of the first blowing portion 12a in the
fan circumferential direction to flow out of the blower 10.
Similarly, the second flow-out passage 162c is a scroll passage
that guides the air flowing out of the second blowing portion 12b
in the fan circumferential direction to flow out of the blower 10.
The air flowing out of the first flow-out passage 162b and the air
flowing out of the second flow-out passage 162c flow through
different air passages partitioned from each other, even outside
the blower 10, for example.
[0051] A duct 24 for guiding the air to the blower 10 is provided
on the one side in the fan axial direction DRa with respect to the
fan casing 16, and the duct 24 is joined to the fan casing 16 on
the one side in the fan axial direction DRa. An upstream air
passage 24a guiding the air to the casing air intake port 16a is
defined inside the duct 24. The upstream air passage 24a is located
upstream of the first air intake port 16b and the second air intake
port 16c with respect to the airflow and is connected to the first
air intake port 16b and the second air intake port 16c.
[0052] A filter 26, the upstream partition wall 20, and a front
filter partition wall 28 is provided in the upstream air passage
24a. The upstream partition wall 20 is another member separated
from the partition cylinder portion 14 and fixed to the duct 24 or
the fan casing 16, for example, That is, the upstream partition
wall 20 is a non-rotating member.
[0053] The upstream partition wall 20 is provided on the one side
in the fan axial direction DRa with respect to the cylinder portion
141 of the partition cylinder portion 14, and has a cylindrical
shape aligned to the cylinder portion 141 in the fan axial
direction DRa. For example, the upstream partition wall 20 of the
present embodiment has a circular cylindrical shape coaxial with
the cylinder portion 141 of the partition cylinder portion 14, and
a radius of the upstream partition wall 20 is the same as that of
the cylinder portion 141. According to such configuration, the
upstream partition wall 20 partitions an air flowing into the
radially inner side of the cylinder portion 141 from an air flowing
into the radially outer side of the cylinder portion 141 on the
upstream side of the cylinder portion 141.
[0054] Since the upstream partition wall 20 is the non-rotating
member and the partition cylinder portion 14 rotates together with
the centrifugal fan 12, the upstream partition wall 20 is slightly
spaced from the cylinder portion 141 so as not to contact the
cylinder portion 141 of the partition cylinder portion 14, The gap
between the partition cylinder portion 14 and the cylinder portion
141 is small such that the air on the radially inner side of the
upstream partition wall 20 and the air in the radially outer side
on the radially outer side of the upstream partition wall 20 are
mixed with each other.
[0055] The filter 26 is a non-rotating member fixed to the duct 24,
for example, and allows the air to flow to a downstream side after
filtrating the air. For example, the filter 26 includes nonwoven
fabric as a main element.
[0056] The filter 26 is located on the one side in the fan axial
direction DRa with respect to the upstream partition wall 20. Since
the filter 26 is located upstream of the upstream partition wall 20
with respect to the airflow, the filter 26 filtrates the air
flowing toward the centrifugal fan 12, In detail, the filter 26
filtrates both the air flowing toward the first blowing portion 12a
of the centrifugal fan 12 and the air flowing toward the second
blowing portion 12b.
[0057] The upstream partition wall 20 extends to the filter 26
along the fan axial direction DRa. The upstream partition wall 20
may extend to contact the filter 26 or to a position close to the
filter 26 to have a small gap between the upstream partition wall
20 and the filter 26.
[0058] The front filter partition wall 28 is located on the one
side in the fan axial direction DRa with respect to the filter 26
in the duct 24, and the front filter partition wall 28 has a
cylindrical shape aligned to the upstream partition wall 20 across
the filter 26. In the present embodiment, the front filter
partition wall 28 has a circular cylindrical shape coaxial with the
upstream partition wall 20, and a radius of the front filter
partition wall 28 is the same as that of the upstream partition
wall 20.
[0059] The front filter partition wall 28 extends on the other side
in the fan axial direction DRa to the filter 26. Accordingly, a
large part of the air flowing through an radially inner side of the
front filter partition wall 28 flows into the radially inner side
of the upstream partition wall 20 through the filter 26. A large
part of the air flowing through an radially outer side of the front
filter partition wall 28 flows into the radially outer side of the
upstream partition wall 20 through the filter 26.
[0060] As shown in FIGS. 3, 4, the shape of the first blade 121 is
different from the shape of the second blade 122. Specifically, as
shown in FIGS. 2, 3, the first blade 121 are backward-curved blade
that is positioned on the side opposite to the fan rotation
direction RT toward the outer side in the fan radial direction DRr.
The first blades 121 may curve against the fan rotation direction
RT. That is, the shape of a turbofan is adopted as the shape of the
first blades 121, and the first blowing portion 12a is a
turbofan.
[0061] In contrast, as shown in FIGS. 2, 4, the second blade 122 is
forward-curved blade that is positioned on the forward direction
side in the fan rotation direction RT toward the outer side in the
fan radial direction DRr. The second blades 122 may curve in the
fan rotation direction RT. That is, the shape of a sirocco fan is
adopted as the shape of the second blades 122, and the second
blowing portion 12b is a sirocco fan.
[0062] As shown in FIGS. 3, 4, the number of the first blades 121
is different from the number of the second blades 122.
Specifically, an angle between the first blades 121 having a common
endpoint (fan central axis CL) is larger than an angle between the
second blades 122 having a common endpoint (fan central axis CL).
The intervals between the first blades 121 may be larger than the
intervals between the second blades 122. That is, the number of the
first blades 121 is smaller than the number of the second blades
122.
[0063] In the present embodiment, the first blades 121 and the
second blades 122 are different in shape as follows. As shown in
FIGS. 1, 2, an inner diameter D1i of the first blades 121 whose
center is the fan central axis CL is smaller than an inner diameter
D2i of the second blades 122. The inner diameter D1i is a diameter
of an imaginary circular cylinder whose center is the fan central
axis CL and which contacts the first blades 121 on the radially
inner side in the radial direction. That is, the inner diameter D1i
is a diameter of an imaginary circular cylinder whose center is the
fan central axis CL and which is inscribed to the first blades 121.
The inner diameter D2i of the second blades 122 can also be
explained in the same way.
[0064] An outer diameter D2o of the second blades 122 is smaller
than an outer diameter D1o of the first blades 121, The outer
diameter D1o is a diameter of an imaginary circular cylinder whose
center is the fan central axis CL and which contacts the first
blades 121 on the radially outer side in the radial direction. That
is, the outer diameter D1o is a diameter of an imaginary circular
cylinder whose center is the fan central axis CL and which is
circumscribed to the first blades 121. The outer diameter D2o of
the second blades 122 can also be explained in the same way.
[0065] As it can be understood from the differences between the
inner diameters D1i, D2i and between the outer diameters D1o, D2o,
a length L1r of the first blade 121 in the fan radial direction DRr
is larger than a length L2r of the second blade 122 in the fan
radial direction DRr. The length L1r of the first blade 121 is a
radial width of the first blade 121 in the fan radial direction
DRr, and the length L2r of the second blade 122 is a radial width
of the second blade 122 in the fan radial direction DRr.
Accordingly, the length L1r of the first blade 121 can be
calculated, as shown in FIGS. 1, 2, from the following expression:
L1r=(D1o-D1i)/2. The length L2r of the second blade 122 can be
calculated from the following expression:
L2r=(D2o-D2i)/2.
[0066] As shown in FIG. 2, a height HF1 of the first leading edge
121c in the fan axial direction DRa is smaller than a height HF2 of
the second leading edge 122c. Further, a height HB1 of the first
trailing edge 121d in the fan axial direction DRa is smaller than a
height HB2 of the second trailing edge 122d. That is, the first
blade 121 is larger in the fan radial direction DRr and smaller in
the fan axial direction DRa as compared to the second blade 122.
The first blades 121 and the second blades 122 are different in
shape as described above.
[0067] Next, the airflow in the blower 10 will be roughly described
below. When the motor 22 rotates the centrifugal fan 12 in the fan
rotation direction RT, a first airflow is generated where the air
flowing through the filter 26 into the radially inner side of the
upstream partition wall 20 flows into the first flow-out passage
162b. At the same time, a second airflow is generated where the air
flowing through the filter 26 into the radially outer side of the
upstream partition wall 20 flows into the second flow-out passage
162c.
[0068] In the first airflow, the air in the radially inner side of
the upstream partition wall 20 flows through the radially inner
side of the cylinder portion 141 of the partition cylinder portion
14 and flows along the expanded portion 142 to turn outward in the
fan radial direction DRr. The air flowing outward is drawn into the
first blowing portion 12a and then blown out from the first blowing
portion 12a to the first flow-out passage 162b.
[0069] In the second airflow, the air in the radially outer side of
the upstream partition wall 20 flows through the radially outer
side of the cylinder portion 141 of the partition cylinder portion
14 and flows along the expanded portion 142 to turn outward in the
fan radial direction DRr. The air flowing outward is drawn into the
second blowing portion 12b and then blown out from the second
blowing portion 12b to the second flow-out passage 162c.
[0070] In the present embodiment, as shown in FIGS. 1, 2, the
length L1r of the first blade 121 in the fan radial direction DRr
is larger than the length L2r of the second blade 122 in the fan
radial direction DRr. The air drawn into the space between the
first blades 121 passes through the inner side in the fan radial
direction DRr with respect to the partition cylinder portion 14,
and the air drawn into the space between the second blades 122
passes through the outer side in the fan radial direction DRr with
respect to the partition cylinder portion 14.
[0071] Since the airs flow through different ways, the length L1r
of the first blade 121 can be made longer. Accordingly, in order to
obtain a specific fan performance, the size of the first blade 121
in the fan axial direction DRa can be made smaller according to the
length L1r of the first blade 121. Accordingly, the size of the
blower 10 can be small without deterioration of the performance of
the blower 10. That is, it is possible to achieve both compactness
and high performance of the blower 10.
[0072] According to the present embodiment, the inner diameter D1i
of the first blades 121 whose center is the fan central axis CL is
smaller than the inner diameter D2i of the second blades 122. The
air drawn into the space between the first blades 121 flows through
the radially inner side of the cylinder portion 141 of the
partition cylinder portion 14 in the fan radial direction DRr while
the air drawn into the space between the second blades 122 flows
through the radially outer side of the cylinder portion 141 of the
partition cylinder portion 14.
[0073] Accordingly, the length L1r of the first blade 121 can be
increased by utilizing the difference in the air flowing place, and
the height of the first blade 121 in the fan axial direction DRa
can be decreased without increasing the size of the centrifugal fan
12. In short, it can contribute to miniaturization of the blower
10.
[0074] Since the inner diameter D1i of the first blade 121 is
smaller than the inner diameter D2i of the second blade 122, it is
advantageous to secure an opening area of the second air intake
port 16c. That is, since the inner diameter D2i of the second blade
122 is large, an area of the air passage through which the air
flows into the space between the second blades 122 can be secured
on the radially outer side of the cylinder portion 141. As a
result, the performance of the centrifugal fan 12 can be
improved.
[0075] According to the present embodiment, the outer diameter D2o
of the second blades 122 whose center is the fan central axis CL is
smaller than the outer diameter D1o of the first blades 121.
Accordingly, it is easy to provide a structure that prevents the
air from flowing through the gap between the partition plate 18 and
the separation panel 123 of the centrifugal fan 12 with avoiding
interference between the partition plate 18 and the second blade
122.
[0076] It is easy to shape the first blowing portion 12a into a
flat shape in which a ratio of the height of the fan to the fan
outer diameter is small without making the inner diameter D1i of
the first blade 121 too small. Accordingly, it is possible to
secure the width of the expanded portion 142 in the fan radial
direction DRr such that the air flowing around the expanded portion
142 of the partition cylinder portion 14 in the fan axial direction
DRa smoothly turns outward in the fan radial direction DRr.
Accordingly, the size of the centrifugal fan 12 in the fan axial
direction DRa can be decreased while suppressing a deterioration of
the performance due to the decrease of the inner diameter D1i of
the first blade 121.
[0077] According to the present embodiment, the centrifugal fan 12
includes the separation panel 123 between the first blades 121 and
the second blades 122. The separation panel 123 has a plate shape
extending in the fan radial direction DRr and partitions the air
flowing through the space between the first blades 121 from the air
flowing through the space between the second blades 122.
Accordingly, since the separation panel 123 limits the air in the
space between the first blades 121 and the air in the space between
the second blades 122 from mixing together, the airflows generated
by the centrifugal fan 12 can be adequately kept being
separated.
[0078] Since the mixing of the airs is suppressed, disturbance of
the air caused by the mixing of the airs can be suppressed, and
accordingly a decrease in performance of the fan due to the
disturbance of the air can be avoided. Further, avoiding the
deterioration of the performance of the fan leads to
miniaturization of the centrifugal fan 12.
[0079] The inward extending part 126 of the centrifugal fan 12
extends inward in the fan radial direction DRr from the radially
inner part of the separation panel 123. The inward extending part
126 is located inside in the fan radial direction DRr of both the
first end 121a of the first blade 121 and the second end 122b of
the second blade 122 joined to the separation panel 123.
Accordingly, the inward extending part 126 deflects the air to some
extent and partitions the air flowing toward the space between the
first blades 121 from the air flowing toward the space between the
second blades 122 such that the airs are separately drawn into the
space between the first blades 121 and the space between the second
blades 122.
[0080] Accordingly, the mixing of the flow of the air flowing
toward the space between the first blades 121 and the flow of the
air flowing toward the space between the second blades 122 can be
suppressed on the airflow upstream side of the first blades 121 and
the second blades 122. This makes it possible to suppress the
deterioration of the fan performance of the blower 10.
[0081] In the present embodiment, the partition cylinder portion 14
includes the inward extending part 126 and rotates together with
the centrifugal fan 12. That is, the radially inner part of the
separation panel 123 in the fan radial direction DRr is connected
to the partition cylinder portion 14. Accordingly, the air flowing
on the radially inner side of the partition cylinder portion 14 and
the air flowing on the radially outer side of the partition
cylinder portion 14 which are separated from each other can be
smoothly guided to the first blowing portion 12a and the second
blowing portion 12b separately. Accordingly, a generation of
vortices caused by a gap between the separation panel 123 and the
expanded portion 142 of the partition cylinder portion 14 in an
imaginary configuration in which the separation panel 123 is spaced
from the expanded portion 142 can be avoided. That is, a decrease
in performance of the fan caused when the vortices are drawn into
the space between the first blades 121 or the space between the
second blades 122 can be avoided.
[0082] Advantages of the blower 10 of the present embodiment will
be described with reference to FIG. 5 showing a blower 90 of a
comparative example. In the blower 90 of the comparative example,
as shown in FIG. 5, the centrifugal fan 12 does not include the
separation panel 123, and the partition cylinder portion 14 is a
part separated from the centrifugal fan 12 and is a non-rotating
member that does not rotate. Accordingly, a gap is formed between
the expanded portion 142 of the partition cylinder portion 14 and
the centrifugal fan 12 to avoid interference during rotation of the
centrifugal fan. The other configurations of the blower 90 of the
comparative example are the same as the blower 10 of the present
embodiment.
[0083] As described above, since the gap is formed between the
expanded portion 142 of the partition cylinder portion 14 and the
centrifugal fan 12 in the blower 90 of the comparative example, the
air flows through the gap at A1 part of FIG. 5 to mix together.
That is, the airflows are just roughly separated. Accordingly,
vortices are generated at an end of the expanded portion 142
defining the gap, and the vortices are drawn into the blowing
portions 12a, 12b to deteriorate the performance of the fan.
[0084] Further, since the separation panel 123 is not provided in
the blower 90 of the comparative example, the air in the first
blowing portion 12a and the air in the second blowing portion 12b
may mix together.
[0085] In contrast, the blower 10 of the present embodiment
includes the separation panel 123 as shown in FIG. 1, and the
separation panel 123 is connected to the partition cylinder portion
14 without any gaps. Accordingly, the blower 10 of the present
embodiment has advantages that the mixing of the airflows and the
deterioration of the fan performance which may occur in the blower
90 of the comparative example can be avoided.
[0086] According to the present embodiment, as shown in FIGS. 3, 4,
the number of the first blades 121 is different from the number of
the second blades 122. Accordingly, the first blades 121 and the
second blades 122 need not be continuous in the fan axial direction
DRa, and the first blade 121 and the second blade 122 may have
different shape. For example, the shapes of the first blade 121 and
the second blade 122 may be changed according to the lengths L1r,
L2r.
[0087] According to the present embodiment, as shown in FIG. 3, the
first blade 121 is positioned on the side opposite to the fan
rotation direction RT toward the outer side in the fan radial
direction DRr. The backward-curved blades are suitable for having a
flat shape in which the ratio of the height of the fan to the outer
diameter is small. Accordingly, the shapes of the first blades 121
are easy to be modified such that the inner diameter D1i is small
and the length L1r is large.
[0088] According to the present embodiment, as shown in FIG. 4, the
second blade 122 is the forward-curved blade that is positioned on
the forward direction side in the fan rotation direction RT toward
the outer side in the fan radial direction DRr. The fan having
forward-curved blades is better than the fan having backward-curved
blades to modify the fan inner diameter to be large. Accordingly,
the shapes of the second blades 122 are suitable to secure the air
flow area for the air flowing into the space between the second
blades 122. That is, the shapes of the second blades 122 are
suitable to secure the opening area of the second air intake port
16c.
[0089] According to the present embodiment, a height HB1 of the
first trailing edge 121d in the fan axial direction DRa is smaller
than a height HB2 of the second trailing edge 122d as shown in
FIGS. 1, 2. Accordingly, a space for the first blades 121 in the
fan axial direction DRa can be small in addition to securing the
air flow area for the air flowing out of the space between the
second blades 122.
[0090] According to the present embodiment, a height HF1 of the
first leading edge 121c in the fan axial direction DRa is smaller
than a height HF2 of the second leading edge 122c. Accordingly, a
space for the first blades 121 in the fan axial direction DRa can
be small in addition to securing the air flow area for the air
flowing into the space between the second blades 122.
[0091] Further, according to the present embodiment, the partition
panel 18 partitions the fan surrounding space 162a into which the
air flow from the centrifugal fan 12 into the first flow-out
passage 162b and the second flow-out passage 162c located on the
one side of the first flow-out passage 162b in the fan axial
direction DRa. The first air blown out of the space between the
first blades 121 flows into the first flow-out passage 162b.
Simultaneously, the second air blown out of the space between the
second blades 122 flows into the second flow-out passage 162c. The
partition panel 18 is provided to suppress the first air from
flowing into the second flow-out passage 162c and to suppress the
second air from flowing into the first flow-out passage 162b.
[0092] Accordingly, the airs partitioned by the partition cylinder
portion 14 and taken in the centrifugal fan 12 keeps being
separated and flow out of the blower 10 from the first flow-out
passage 162b and the second flow-out passage 162c separately.
[0093] Further, according to the present embodiment, the upstream
partition wall 20 provided as a member separated from the partition
cylinder portion 14 on the one side in the fan axial direction DRa
with respect to the cylinder portion 141, and has a cylindrical
shape aligned to the cylinder portion 141 in the fan axial
direction DRa. The upstream partition wall 20 partitions the air
flowing into the inner side of the cylinder portion 141 from the
air flowing into the outer side of the cylinder portion 141 on the
airflow upstream side of the the cylinder portion 141. The filter
26 filtrating the air flowing toward the centrifugal fan 12 is
located on the one side in the fan axial direction DRa with respect
to the upstream partition wall 20, and the upstream partition wall
20 extends to the filter 26. Accordingly, the air flowing through
the inside of the cylinder portion 141 and the air flowing through
the outside of the cylinder portion 141 can be prevented from
mixing together between the filter 26 and the partition cylinder
portion 14, and the partition cylinder portion 14 can be provided
without regard to the shape and the position of the filter 26.
Second Embodiment
[0094] A second embodiment of the present disclosure is described
next. The present embodiment will be explained primarily with
respect to portions different from those of the first embodiment.
In addition, explanations of the same or equivalent portions as
those in the above embodiment will be omitted or simplified. This
also applies to the description of the embodiment to be described
later.
[0095] As shown in FIG. 6, in the present embodiment, the partition
cylinder portion 14 is separated from the centrifugal fan 12. That
is, the partition cylinder portion 14 of the present embodiment
includes the inward extending part 126 of the centrifugal fan 12.
Specifically, the partition cylinder portion 14 is provided such
that the expanded portion 142 of the partition cylinder portion 14
is located inside the inward extending part 126 of the centrifugal
fan 12 in the fan radial direction DRr. The partition cylinder
portion 14 is a non-rotating member that does not rotate.
[0096] Further, in the present embodiment, the upstream partition
wall 20 (see FIG. 1) is not provided. Instead, the partition
cylinder portion 14 extends to the filter 26 located on the one
side in the fan axial direction DRa with respect to the partition
cylinder portion 14. In detail, the cylinder portion 141 of the
partition cylinder portion 14 extends to the filter 26 provided on
the one side in the fan axial direction DRa with respect to the
cylinder portion 141. This positional relationship between the
cylinder portion 141 and the filter 26 is the same as the
positional relationship between the upstream partition wall 20 and
the filter 26 of the first embodiment.
[0097] Since the centrifugal fan 12 rotates while the partition
cylinder portion 14 is the non-rotating member in the present
embodiment, the partition cylinder portion 14 is slightly separated
from the centrifugal fan 12 so as not to interfere with the
rotation of the centrifugal fan 12.
[0098] The partition cylinder portion 14 separates the air flowing
into the space between the first blades 121 from the air flowing
into the space between the second blades 122 on the airflow
upstream side of the inward extending part 126 of the centrifugal
fan 12. That is, the partition cylinder portion 14 is provided
relative to the centrifugal fan 12 such that the air flowing along
the expanded portion 142 of the partition cylinder portion 14 into
the first blowing portion 12a and the air flowing into the second
blowing portion 12b are limited from mixing together.
[0099] For example, the expanded portion 142 of the partition
cylinder portion 14 is slightly spaced from the inward extending
part 126 of the centrifugal fan 12. Assuming that the partition
cylinder portion 14 is provided without the gap between the inward
extending part 126 and the expanded portion 142, the partition
cylinder portion 14 has a plate shape continuing from the inward
extending part 126 to the expanded portion 142. Although less
communication of the air through the small gap between the expanded
portion 142 of the partition cylinder portion 14 and the inward
extending part 126 of the centrifugal fan 12 is better, the
communication needs not completely shut off.
[0100] Aside from the above described aspects, the present
embodiment is the same as the first embodiment. Further, in the
present embodiment, effects similar to those of the first
embodiment described above can be obtained in the same manner as in
the first embodiment.
[0101] According to the present embodiment, the partition cylinder
portion 14 does not include the inward extending part 126 of the
centrifugal fan 12, but the inward extending part 126 extends
inward from the separation panel 123 in the fan radial direction
DRr. The inward extending part 126 is located inside, in the fan
radial direction DRr, both the first end 121a of the first blade
121 and the second end 122b of the second blade 122.
[0102] The airs partitioned by the partition cylinder portion 14
may mix together through the gap between the expanded portion 142
and the inward extending part 126, and thereby the airflow may be
disturbed. In this case, the airflows containing the disturbance
and flowing toward the blowing portions 12a, 12b are controlled by
the inward extending part 126, and then the air flows into the
space between the first blades 121 and the space between the second
blades 122. As a result, a deterioration of the fan performance due
to the mixing of the airs separated from each other on the airflow
upstream side of the blades 121, 122 can be suppressed.
[0103] According to the present embodiment, the partition cylinder
portion 14 is separated from the centrifugal fan 12 and is a
non-rotating member that does not rotate. Accordingly, it is easy
to simplify the structure of the centrifugal fan 12 to improve the
productivity of the blower 10 as compared with a case where the
partition cylinder portion 14 is integrated with the centrifugal
fan 12, for example.
[0104] Further, the filter 26 is located on the one side in the fan
axial direction DRa with respect to the partition cylinder portion
14, and the partition cylinder portion 14 extends to the filter 26.
Accordingly, the air flowing toward the radially inner side of the
cylinder portion 141 and the air flowing toward the radially outer
side of the cylinder portion 141 are limited from mixing together
on the airflow downstream side of the filter 26 without any object
between the filter 26 and the partition cylinder portion 14.
Other Embodiments
[0105] (1) In the above-described embodiments, the centrifugal fan
12 includes the first blades 121 and the second blades 122 as shown
in FIG. 1, for example, but this is just an example. For example,
the centrifugal fan 12 may include multiple third blades and
multiple fourth blades aligned to the blades 121, 122 in the fan
axial direction DRa in addition to the blades 121, 122. That is,
the fan 12 may include multiple blowing portions having multiple
blades, and the multiple blowing portions may be aligned in the fan
axial direction DRa. (2) In the above-described embodiments, the
shape of the turbofan is used as the shape of the first blade 121
as shown in FIG. 3. However, this is just an example. For example,
another shape of a centrifugal fan different from the shape of the
turbofan may be used as the shape of the first blade 121. (3) In
the above-described embodiments, the shape of the sirocco fan is
used as the shape of the second blade 122 as shown in FIG. 4.
However, this is just an example. For example, another shape of a
centrifugal fan different from the shape of the sirocco fan may be
used as the shape of the second blade 122. (4) In the
above-described embodiments, the filter 26 is located on the
airflow upstream side of the centrifugal fan 12 as shown in FIG. 1,
for example. However, the filter 26 may not be provided. (5) In the
above-described embodiments, the number of the first blades 121 is
smaller than the number of the second blades 122 as shown in FIGS.
3, 4. However, this is just an example. For example, the number of
the first blades 121 may be equal to or larger than the number of
the second blades 122. (6) The present disclosure is not limited to
the specific embodiments described above, and various modifications
can be made. In each of the above embodiments, it is needless to
say that the elements configuring the embodiment are not
necessarily indispensable except when it is clearly indicated that
the elements are particularly indispensable, when the elements are
clearly considered to be indispensable in principle, and the
like.
[0106] Further, in each of the above embodiments, when numerical
values such as the number, numerical value, quantity, range, and
the like of the components of the embodiment are referred to,
except in the case where the numerical value is expressly
indispensable in particular, the case where the numerical value is
obviously limited to a specific number in principle, and the like,
the present disclosure is not limited to the specific number.
Furthermore, a material, a shape, a positional relationship, or the
like, if specified in the above-described example embodiments, is
not necessarily limited to the specific material, shape, positional
relationship, or the like unless it is specifically stated that the
material, shape, positional relationship, or the like is
necessarily the specific material, shape, positional relationship,
or the like, or unless the material, shape, positional
relationship, or the like is obviously necessary to be the specific
material, shape, positional relationship, or the like in
principle.
CONCLUSION
[0107] According to a first aspect described in all or some of the
above-described embodiments, the centrifugal fan includes a
separation panel between the first blades and the second blades.
The separation panel has a plate shape extending in the radial
direction and partitions the air flowing through the space between
the first blades from the air flowing through the space between the
second blades. The centrifugal fan includes inward extending part.
The inward extending part extends inward in the radial direction
from the separation panel. The inward extending part located
inside, in the radial direction, both connected ends of the first
blades joined to the separation panel and connected ends of the
second blades joined to the separation panel.
[0108] According to this configuration, since the separation panel
of the centrifugal fan limits the air in the space between the
first blades and the air in the space between the second blades
from mixing together, the airflows generated by the centrifugal fan
can be adequately kept being separated.
[0109] The inward extending part of the centrifugal fan extends
inward in the radial direction from the separation panel, and is
located inside, in the radial direction, both connected ends of the
first blades each of which is joined to the separation panel and
connected ends of the second blades each of which is joined to the
separation panel. Accordingly, the inward extending part deflects
the air to some extent and separates the air flowing toward the
spaces between the blades such that the airs are separately drawn
into the space between the first blades and the space between the
second blades. Accordingly, the mixing of the flow of the air
flowing toward the space between the first blades and the flow of
the air flowing toward the space between the second blades can be
suppressed on the airflow upstream side of the first blades and the
second blades. This makes it possible to suppress the deterioration
of the fan performance of the centrifugal blower.
[0110] According to a second aspect, the partition cylinder portion
includes the inward extending part and rotates together with the
centrifugal fan. That is, the radially inner part of the separation
panel in the radial direction is connected to the partition
cylinder portion. Accordingly, the air flowing on the radially
inner side of the partition cylinder portion and the air flowing on
the radially outer side of the partition cylinder portion which are
separated from each other can be smoothly guided to the first
blades and the second blades. Accordingly, a generation of vortices
caused by a gap between the separation panel and the partition
cylinder portion in an imaginary configuration in which the
separation panel is spaced from the partition cylinder portion can
be avoided. That is, a decrease in performance of the fan caused
when the vortices are drawn into the space between the first blades
or the space between the second blades can be avoided.
[0111] According to a third aspect, the partition cylinder portion
is separated from the centrifugal fan and is a non-rotating member
that does not rotate. The partition cylinder portion separates the
air flowing into the space between the first blades from the air
flowing into the space between the second blades on the airflow
upstream side of the inward extending part. Accordingly, it is easy
to simplify the structure of the centrifugal fan to improve the
productivity of the centrifugal blower as compared with a case
where the partition cylinder portion is integrated with the
centrifugal fan, for example.
[0112] According to a fourth aspect, the fan casing that
accommodates the centrifugal fan defines the fan surrounding space
that surrounds the centrifugal fan on the radially outside. The air
flows out of the centrifugal fan into the fan surrounding space.
The partition panel partitions the fan surrounding space in the
axial direction into the first flow-out passage and the second
flow-out passage. The first air blown out of the space between the
first blades flows into the first flow-out passage. In contrast,
the second air blown out of the space between the second blades
flows into the second flow-out passage. The partition panel is
provided to suppress the first air from flowing into the second
flow-out passage and to suppress the second air from flowing into
the first flow-out passage. Accordingly, the air partitioned by the
partition cylinder portion and taken in the centrifugal fan keeps
being separated and flows out of the centrifugal blower from the
first flow-out passage and the second flow-out passage
separately.
[0113] According to a fifth aspect, the filter that filtrates the
air flowing toward the centrifugal fan is located on the one side
of the partition cylinder portion in the axial direction. The
partition cylinder portion extends to the filter. Accordingly, the
air flowing toward the radially inner side of the partition
cylinder portion and the air flowing toward the radially outer side
of the partition cylinder portion are limited from mixing together
on the airflow downstream side of the filter.
[0114] According to a sixth aspect, the upstream partition wall is
separated from the partition cylinder portion and located on the
one side of the partition cylinder portion in the axial direction.
The upstream partition wall has a cylindrical shape aligned to the
partition cylinder portion in the axial direction. The upstream
partition wall partitions the air flowing into the inner side of
the partition cylinder portion from the air flowing into the outer
side of the partition cylinder portion on the airflow upstream side
of the partition cylinder portion. The filter filtrating the air
flowing toward the centrifugal fan is located on the one side in
the axial direction with respect to the upstream partition wall,
and the upstream partition wall extends to the filter. In this
configuration also, similarly to the fifth aspect, the air flowing
toward the radially inner side of the partition cylinder portion
and the air flowing toward the radially outer side of the partition
cylinder portion are limited from mixing together on the airflow
downstream side of the filter.
[0115] Although the present disclosure has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications will become apparent to those skilled in the
art.
[0116] Additional advantages and modifications will readily occur
to those skilled in the art. The disclosure in its broader terms is
therefore not limited to the specific details, representative
apparatus, and illustrative examples shown and described.
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