U.S. patent application number 12/104861 was filed with the patent office on 2008-10-23 for counter-rotating axial-flow fan.
This patent application is currently assigned to SANYO DENKI CO., LTD.. Invention is credited to Yasuhiro Maruyama, Hayato Murayama, Toshiya Nishizawa.
Application Number | 20080260526 12/104861 |
Document ID | / |
Family ID | 39381792 |
Filed Date | 2008-10-23 |
United States Patent
Application |
20080260526 |
Kind Code |
A1 |
Nishizawa; Toshiya ; et
al. |
October 23, 2008 |
COUNTER-ROTATING AXIAL-FLOW FAN
Abstract
A counter-rotating axial-flow fan includes a housing that is
constituted from a first divided housing unit and a second divided
housing unit. Engaging members and first stopper portions are
integrally formed with a first flange portion of the first divided
housing unit. The first stopper portions are arranged adjacent to
the engaging members. Engaged members and second stopper portions
are integrally formed with a second flange portion of the second
divided housing unit. The second stopper portions are arranged
adjacent to the engaged members. The second stopper portions have
leading ends that are abutted onto leading ends of the first
stopper portions when the engaging members are completely engaged
with the engaged members. Thus, damage of the first and second
divided housing units is prevented when the first and second
divided housing units are coupled.
Inventors: |
Nishizawa; Toshiya; (Tokyo,
JP) ; Maruyama; Yasuhiro; (Tokyo, JP) ;
Murayama; Hayato; (Tokyo, JP) |
Correspondence
Address: |
RANKIN, HILL & CLARK LLP
38210 Glenn Avenue
WILLOUGHBY
OH
44094-7808
US
|
Assignee: |
SANYO DENKI CO., LTD.
Tokyo
JP
|
Family ID: |
39381792 |
Appl. No.: |
12/104861 |
Filed: |
April 17, 2008 |
Current U.S.
Class: |
415/199.4 |
Current CPC
Class: |
F04D 25/0613 20130101;
F04D 19/007 20130101; F04D 29/4226 20130101; F04D 19/024 20130101;
F04D 29/646 20130101; F04D 29/522 20130101 |
Class at
Publication: |
415/199.4 |
International
Class: |
F04D 29/38 20060101
F04D029/38 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 2007 |
JP |
2007-109606 |
Claims
1. A counter-rotating axial-flow fan comprising: a housing
comprising a housing body including an air channel having a suction
opening on one side in an axial line direction and a discharge
opening on the other side in the axial line direction, and a motor
support frame disposed in a central portion of the air channel; a
first impeller disposed in a first space, which is defined between
the motor support frame in the housing and the suction opening, and
including a plurality of blades; a first motor including a first
rotary shaft onto which the first impeller is fixed, the first
motor rotating the first impeller in a first rotating direction
within the first space; a second impeller disposed in a second
space, which is defined between the motor support frame in the
housing and the discharge opening, and including a plurality of
blades; and a second motor including a second rotary shaft onto
which the second impeller is fixed, the second motor rotating the
second impeller in a second rotating direction opposite to the
first rotating direction within the second space; the motor support
frame comprising a support frame body disposed in the central
portion of the air channel and a plurality of webs disposed between
the support frame body and the housing body at predetermined
intervals in a circumferential direction of the rotary shafts, the
webs connecting the support frame body and the housing body; the
housing being constituted from first and second divided housing
units that are coupled through a coupling structure; the first
divided housing unit including a first housing-body half-portion
and a first support-frame half-portion, the first housing-body
half-portion including a first flange portion having the suction
opening at one end thereof and a first cylindrical air-channel
half-portion of which one end is integrally formed with the first
flange portion, the first cylindrical air-channel half-portion
containing therein a major part of the first space, the first
support-frame half-portion being obtained by dividing the motor
support frame into two along a virtual reference dividing plane
extending in a radial direction of the rotary shafts orthogonal to
the axial line direction; the second divided housing unit including
a second housing-body half-portion and a second support-frame
half-portion, the second housing-body half-portion including a
second flange portion having the discharge opening at one end
thereof and a second cylindrical air-channel half-portion of which
one end is integrally formed with the second flange portion, the
second cylindrical air-channel half-portion containing therein a
major part of the second space, the second support-frame
half-portion being obtained by dividing the motor support frame
into the two along the virtual reference dividing plane, wherein
the coupling structure is constituted from: a fitting portion
formed at the other end of the first cylindrical air-channel
half-portion, a fitted portion to be fitted with the fitting
portion, formed at the other end of the second cylindrical
air-channel half-portion, a plurality of engaging members
integrally formed with the first flange portion, arranged at
intervals in the circumferential direction, and extending along the
first cylindrical air-channel half-portion, and a plurality of
engaged members to be respectively engaged with the engaging
members, integrally formed with the second flange portion, arranged
at intervals in the circumferential direction, and extending along
the second cylindrical air-channel half-portion; a plurality of
first stopper portions are integrally formed with the first flange
portion and arranged adjacent to the engaging members, and extend
along the first cylindrical air-channel half-portion; a plurality
of second stopper portions are integrally formed with the second
flange portion and arranged adjacent to the engaged members, and
extend along the second cylindrical air-channel half-portion; and
leading ends of the first stopper portions are respectively abutted
onto leading ends of the second stopper portions when the engaging
members are completely engaged with the engaged members.
2. The counter-rotating axial-flow fan according to claim 1,
wherein the first and second flange portions respectively have a
contour shape including four corners, first to fourth corners,
arranged in the circumferential direction; four of the engaging
members and four of the first stopper portions are respectively
arranged in the vicinity of the four corners of the first flange
portion; four of the engaged members and four of the second stopper
portions are respectively arranged in the vicinity of the four
corners of the second flange portion; in the first flange portion,
two of the engaging members are arranged in a region defined
between the first corner and the second corner, two of the first
stopper portions are arranged in a region defined between the
second corner and the third corner, two of the engaging members are
arranged in a region defined between the third corner and the
fourth corner, and two of the first stopper portions are arranged
in a region defined between the fourth corner and the first corner;
and in the second flange portion, two of the engaged members are
arranged in a region defined between the first corner and the
second corner, two of the second stopper portions are arranged in a
region defined between the second corner and the third corner, two
of the engaged members are arranged in a region defined between the
third corner and the fourth corner, and two of the second stopper
portions are arranged in a region defined between the fourth corner
and the first corner.
3. The counter-rotating axial-flow fan according to claim 1,
wherein the engaging members are integrally coupled to the first
cylindrical air-channel half-portion, and the engaged members are
integrally coupled to the second cylindrical air-channel
portion.
4. The counter-rotating axial-flow fan according to claim 2,
wherein when a first virtual diagonal line connecting two of the
four corners opposed to each other in the radial direction of the
rotary shafts and a second virtual diagonal line connecting
remaining two of the four corners are assumed in the first flange
portion, the engaging member and the first stopper portion
corresponding to the engaging member are disposed so as to
interpose the first or second virtual diagonal line therebetween;
none of the engaging members and none of the first stopper portions
are disposed at the four corners through which the first or second
virtual diagonal line passes; when a third virtual diagonal line
connecting two of the four corners opposed to each other in the
radial direction of the rotary shafts and a fourth virtual diagonal
line connecting remaining two of the four corners are assumed in
the second flange portion, the engaged member and the second
stopper portion corresponding to the engaged member are disposed so
as to interpose the third or fourth virtual diagonal line
therebetween; and none of the engaged members and none of the
second stopper portions are disposed at the four corners through
which the third or fourth virtual diagonal line passes.
5. The counter-rotating axial-flow fan according to claim 1,
wherein one of the engaging member and the engaged member includes
a claw portion; the other of the engaging member and the engaged
member includes a hole portion to be engaged with the claw portion;
at least one of the engaging member and the engaged member
(41A-41D) is bent when engaging the engaging member with the
engaged member, and the claw portion and the hole portion get into
engagement with each other once the engaging member is completely
engaged with the engaged member; and the hole portion is formed so
as to allow for visual confirmation of the engagement of the claw
portion engaged therewith.
6. The counter-rotating axial-flow fan according to claim 1,
wherein the engaging members and the first stopper portions are
respectively shaped not to protrude outside the first flange
portion as the first flange portion is seen from the first
cylindrical air-channel half-portion; and the engaged members and
the second stopper portions are respectively shaped not to protrude
outside the second flange portion as the second flange portion is
seen from the second cylindrical air-channel half-portion.
7. The counter-rotating axial-flow fan according to claim 2,
wherein the engaging members are integrally coupled to the first
cylindrical air-channel half-portion, and the engaged members are
integrally coupled to the second cylindrical air-channel portion.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a counter-rotating
axial-flow fan used for cooling the inside of an electric appliance
or the like.
[0002] Japanese Patent No. 3904595 (Patent Document 1) discloses a
counter-rotating axial-flow fan including a housing, which includes
a housing body and a motor support frame. The housing body includes
an air channel having a suction opening on one side in an axial
line direction and a discharge opening on the other side in the
axial line direction. The motor support frame is disposed in the
central portion of the air channel. In this counter-rotating
axial-flow fan, a first impeller that is rotated by a first motor
is disposed within a first space that is defined between the motor
support frame in the housing and the suction opening. Further, a
second impeller that is rotated by a second motor is disposed
within a second space that is defined between the motor support
frame in the housing and the discharge opening. The first impeller
rotates in a direction opposite to a rotating direction of the
second impeller. In this counter-rotating axial-flow fan, the
housing is constituted from first and second divided housing units
that are coupled through a coupling structure. The first divided
housing unit includes a first housing-body half-portion and a first
support-frame half-portion. The first housing-body half-portion
includes a first cylindrical air-channel half-portion containing
therein a major part of the first space. The first support-frame
half-portion is obtained by dividing the motor support frame into
two along a virtual reference dividing plane that extends in a
radial direction orthogonal to the axial line direction. The second
divided housing unit includes a second housing-body half-portion
and a second support-frame half-portion. The second housing-body
half-portion includes a second cylindrical air-channel half-portion
containing therein a major part of the second space. The second
support-frame half-portion is obtained by dividing the motor
support frame into two along the virtual reference dividing plane.
The coupling structure is constituted from a fitting portion formed
at one of the ends of the first cylindrical air-channel
half-portion, and a fitted portion to be fitted with the fitting
portion, formed at one of the ends of the second cylindrical
air-channel half-portion.
[0003] In the conventional counter-rotating axial-flow fan,
however, when the fitting portion of the first cylindrical
air-channel half-portion and the fitted portion of the second
cylindrical air-channel half-portion are strongly pressed against
each other to couple the first and second divided housing units,
undue force is applied to the fitting portions of the first and
second divided housing units. The first and second divided housing
units may be thereby broken.
[0004] Further, in the conventional counter-rotating axial-flow
fan, the coupling of the first and second divided housing unit is
not strong enough. Accordingly, when external force is applied, the
first and second divided housing units tend to be decoupled or
disconnected. For this reason, it is necessary to use screws, an
adhesive, or the like for reinforcing the coupling between the
first and second divide housing units.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is therefore to provide a
counter-rotating axial-flow fan in which first and second divided
housing units are prevented from being broken when the first and
second divided housing units are coupled.
[0006] Another object of the present invention is to provide a
counter-rotating axial-flow fan in which the first and second
divided housing units are prevented from being readily decoupled or
disconnected, even when external force is applied.
[0007] A counter-rotating axial-flow fan of the present invention
comprises a housing, a first impeller, a first motor, a second
impeller, and a second motor. The housing includes a housing body
and a motor support frame. The housing body includes an air channel
having a suction opening on one side in an axial line direction and
a discharge opening on the other side in the axial line direction.
The motor support frame is disposed in a central portion of the air
channel. The first impeller is disposed in a first space that is
defined between the motor support frame in the housing and the
suction opening, and includes a plurality of blades. The first
motor includes the first rotary shaft onto which the first impeller
is fixed, and rotates the first impeller in a first rotating
direction within the first space. The second impeller is disposed
in a second space that is defined between the motor support frame
in the housing and the discharge opening, and includes a plurality
of blades. The second motor includes the second rotary shaft onto
which the second impeller is fixed, and rotates the second impeller
in a second rotating direction opposite to the first rotating
direction within the second space.
[0008] The motor support frame includes a support frame body
disposed in the central portion of the air channel and a plurality
of webs disposed between the frame body and the housing body at
predetermined intervals in a circumferential direction of the
rotary shafts. The webs connect the support frame body and the
housing body.
[0009] The housing is constituted from first and second divided
housing units that are coupled through a coupling structure. The
first divided housing unit includes a first housing-body
half-portion and a first support-frame half-portion. The first
housing-body half-portion includes a first flange portion having
the suction opening at one end thereof and a first cylindrical
air-channel half-portion of which one end is integrally formed with
the first flange portion and that contains therein a major part of
the first space. The first support-frame half-portion is obtained
by dividing the motor support frame into two along a virtual
reference dividing plane extending in a radial direction of the
rotary shafts orthogonal to the axial line direction. The second
divided housing unit includes a second housing-body half-portion
and a second support-frame half-portion. The second housing-body
half-portion includes a second flange portion having the discharge
opening at one end thereof and a second cylindrical air-channel
half-portion of which one end is integrally formed with the second
flange portion and that contains therein a major part of the second
space. The second support-frame half-portion is obtained by
dividing the motor support frame into two along the virtual
reference dividing plane.
[0010] The coupling structure adopted in the present invention is
constituted from a fitting portion formed at the other end of the
first cylindrical air-channel half-portion, a fitted portion formed
at the other end of the second cylindrical air-channel
half-portion, a plurality of engaging members integrally formed
with the first flange portion and arranged at intervals in the
circumferential direction, and a plurality of engaged members
integrally formed with the second flange portion and arranged at
intervals in the circumferential direction. The fitting portion is
fitted into the fitted portion. The engaging members extend along
the first cylindrical air-channel half-portion. The engaged members
extend along the second cylindrical air-channel half-portion. The
engaging members are respectively engaged with the engaged
members.
[0011] A plurality of first stopper portions are integrally formed
with the first flange portion and arranged adjacent to the engaging
members, and extend along the first cylindrical air-channel
half-portion. A plurality of second stopper portions are integrally
formed with the second flange portion and arranged adjacent to the
engaged members, and extend along the second cylindrical
air-channel half-portion. Leading ends of the first stopper
portions are respectively abutted onto leading ends of the second
stopper portions when the plurality of engaging members are
completely engaged with the engaged members.
[0012] In the present invention, the engaging members integrally
formed with the first flange portion and the engaged members
integrally formed with the second flange portion are employed for
the coupling structure that couples the first and second divided
housing units. According to the present invention, the coupling of
the first and second divided housing units is attained not only by
a fitting structure constituted from the fitting portion of the
first cylindrical air-channel half-portion and the fitted portion
of the second cylindrical air-channel half-portion, but also by
engagement of the engaging members and the engaged members. As a
result, no force concentration will occur at the fitting structure
of the first cylindrical air-channel half-portion and the second
cylindrical air-channel half-portion. Moreover, the first and
second divided housing units will not readily be decoupled or
disconnected. Further, in the present invention, the first stopper
portions are arranged adjacent to the engaging members, and the
second stopper portions are arranged adjacent to the engaged
members. Thus, even if force is concentrated and applied to the
engaging members and the engaged members from the first flange
portion and the second flange portion when the first divided
housing unit and the second divided housing unit are coupled, the
leading ends of the first stopper portions adjacent to the engaging
members are respectively abutted onto the leading ends of the
second stopper portions adjacent to the engaged members. As a
result, even if the engaging members are strongly pressed against
the engaged members, an engagement portion of the engaged member
engaged with the engaging member, or the engaging member itself may
be prevented from being broken.
[0013] Preferably, when the first and second flange portions
respectively have a contour shape including four corners, first to
fourth corners, arranged in the circumferential direction, four of
the engaging members and four of the first stopper portions are
respectively arranged in the vicinity of the four corners of the
first flange portion, and four of the engaged members and four of
the second stopper portions are respectively arranged in the
vicinity of the four corners of the second flange portion. Then, in
the first flange portion, two of the engaging members are arranged
in a region defined between the first corner and the second corner,
two of the first stopper portions are arranged in a region defined
between the second corner and the third corner, two of the engaging
members are arranged in a region defined between the third corner
and the four corner, and two of the first stopper portions are
arranged in a region defined between the four corner and the first
corner. Further, in the second flange portion, two of the engaged
members are arranged in a region defined between the first corner
and the second corner, two of the second stopper portions are
arranged in a region defined between the second corner and the
third corner, two of the engaged members are arranged in a region
defined between the third corner and the four corner, and two of
the second stopper portions are arranged in a region defined
between the four corner and the first corner. With this
arrangement, it is easy to secure a space for each corner of the
first and second flange portions. Accordingly, the four engaging
members, four engaged members, four first stopper portions, and
four second stopper portions may be arranged in the circumferential
direction. The first and second stopper portions in particular are
arranged outside the engaging members and the engaged members. Even
when excessive forces are applied to the four corners of the first
and second flange portions, the first and second stopper portions
located outside the engaging and engaged members absorb external
forces. The excessive force may be prevented from being applied to
the engaging and engaged members.
[0014] Preferably, the engaging members are integrally coupled to
the first cylindrical air-channel half-portion, and the engaged
members are integrally coupled to the second cylindrical
air-channel portion. With this arrangement, the engaging and
engaged members may be improved in mechanical strength. Further,
after the engaging members have been engaged with the engaged
members, the engaging and engaged members serve to reinforce the
first and second cylindrical air-channel half-portions.
[0015] The engaging members, engaged members, and first and second
stopper portions may be arranged in the following manner. When a
first virtual diagonal line connecting two of the four corners
opposed to each other in the radial direction of the rotary shafts
and a second virtual diagonal line connecting remaining two of the
four corners are assumed in the first flange portion, the engaging
member and the first stopper portion corresponding to the engaging
member are disposed so as to interpose the first or second virtual
diagonal line therebetween. Further, none of the engaging members
and none of the first stopper portions are disposed at the four
corners through which the first or second virtual diagonal line
passes. When a third virtual diagonal line connecting two of the
four corners opposed to each other in the radial direction of the
rotary shafts and a fourth virtual diagonal line connecting
remaining two of the four corners are assumed in the second flange
portion, the engaged member and the second stopper portion
corresponding to the engaged member are disposed so as to interpose
the third or fourth virtual diagonal line therebetween. Further,
none of the engaged members and none of the second stopper portions
are disposed at the four corners through which the third or fourth
virtual diagonal line passes. With this arrangement, when forces
are applied to the four corners of the first flange portion and the
four corners of the second flange portion to couple the first and
second divided housing units, the forces are applied to the
engaging and engaged members and the first and second stopper
portions in good balance. The engaging members may be thereby
engaged with the engaged members securely, and functions of the
first and second stopper portions may positively be exhibited.
[0016] The engaging and engaged members of various types may be
used. When one of the engaging member and the engaged member
includes a claw portion, for example, the other of them may include
a hole portion to be fitted with the claw portion. In this
arrangement, at least one of the engaging member and the engaged
member is bent when engaging the engaging member with the engaged
member, and the claw portion and the hole portion get into
engagement with each other once the engaging member is completely
engaged with the engaged member. Then, the hole portion may be
formed so as to allow for visual confirmation of the engagement of
the claw portion engaged therewith. With this arrangement, the
engaging member may readily be engaged with the engaged member just
by elastically inserting the claw portion into the hole portion.
Further, since the hole portion is formed to allow for visual
confirmation of the engagement of the claw portion engaged with the
hole portion, the engagement may visually be confirmed.
Accordingly, the engagement between the engaging and engaged
members may readily be confirmed.
[0017] Preferably, the engaging members and the first stopper
portions are shaped not to protrude outside the first flange
portion as the first flange portion is seen from the first
cylindrical air-channel half-portion. Further, the engaged members
and the second stopper portions are shaped not to protrude outside
the second flange portion as the second flange portion is seen from
the second cylindrical air-channel half-portion. In this
arrangement, even when the engaging members, engaged members, and
first and second stopper portions are provided, an increase in the
contour size of the counter-rotating axial-flow fan may be
suppressed.
[0018] In the present invention, the engaging member integrally
formed with the first flange portion and the engaged member
integrally formed with the second flange portion are employed for
the coupling structure that couples the first divided housing unit
and the second divided housing unit. The coupling of the first
divided housing unit and the second divided housing unit are
attained not only by a fitting structure constituted from the
fitting portion of the first cylindrical air-channel half-portion
and the engaged portion of the second cylindrical air-channel
half-portion, but also by an engagement structure constituted from
the engaging member and the engaged member. As a result, no force
concentration will occur at the fitting structure of the first
cylindrical air-channel half-portion and the second cylindrical
air-channel half-portion. Moreover, the first and second divided
housing units will not be readily decoupled or disconnected. In
addition, in the present invention, the first stopper portions are
provided adjacent to the engaging members, and the second stopper
portions are provided adjacent to the engaged members. Thus, even
if force is concentrated and applied from the first flange portion
and the second flange portion to the engaging members and the
engaged members when the first divided housing unit and the second
divided housing unit are coupled, the leading ends of the first
stopper portions adjacent to the engaging members are respectively
abutted onto the leading ends of the second stopper portions
adjacent to the engaged members. As a result, even if the engaging
members are strongly pressed against the engaged members, breakage
of an engagement portion between the engaging member and the
engaged member may be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and other objects and many of the attendant advantages
of the present invention will be readily appreciated as the same
becomes better understood by reference to the following detailed
description when considered in connection with the accompanying
drawings.
[0020] FIG. 1 is a cross-sectional view showing a half portion of a
counter-rotating axial-flow fan in an embodiment of the present
invention.
[0021] FIG. 2 is a perspective view of a housing of the
counter-rotating axial-flow fan shown in FIG. 1.
[0022] FIG. 3 is a plan view of the counter-rotating axial-flow fan
shown in FIG. 1.
[0023] FIG. 4 is a left side view of the counter-rotating
axial-flow fan shown in FIG. 1.
[0024] FIG. 5 is a partial cross-sectional view as taken along line
V-V in FIG. 3.
[0025] FIG. 6 is a cross-sectional view as taken along line VI-VI
in FIG. 4.
[0026] FIG. 7 is a perspective view of a first divided housing unit
of the counter-rotating axial-flow fan shown in FIG. 1.
[0027] FIG. 8 is a diagram for explaining how a lead-wire guide web
of the counter-rotating axial-flow fan shown in FIG. 1 is
arranged.
[0028] FIG. 9 is a perspective view of a second divided housing
unit of the counter-rotating axial-flow fan shown in FIG. 1.
[0029] FIG. 10 is a perspective view of a first impeller of the
counter-rotating axial-flow fan shown in FIG. 1.
[0030] FIG. 11 is a perspective view of a second impeller of the
counter-rotating axial-flow fan shown in FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0031] Now, an embodiment of the present invention will be
described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view showing a half portion of a
counter-rotating axial-flow fan in the embodiment of the present
invention. As shown in FIG. 1, the counter-rotating axial-flow fan
in this embodiment includes a housing 1, a first motor 3, a first
impeller 5, a second motor 7, and a second impeller 9. The housing
1 comprises a housing body 61 including an air channel 2, a motor
support frame 6 disposed in a central portion of the air channel 2.
Further, as shown in FIGS. 2 to 6, the housing 1 is constituted
from a first divided housing unit 11 and a second divided housing
unit 13 that are coupled through a coupling structure. FIGS. 2 to 4
are a perspective view of the housing 1, a plan view of the housing
1, and a left side view of the housing 1, respectively. FIG. 5 is a
partial cross-sectional view as taken along line V-V in FIG. 3.
FIG. 6 is a cross-sectional view as taken along line VI-VI in FIG.
4.
[0032] The first divided housing unit 11 is made of a synthetic
resin or aluminum. As shown in FIG. 7, the first divided housing
unit 11 integrally includes a first housing-body half-portion 15
and a first support-frame half-portion 17. The first housing-body
half-portion 15 includes a first flange portion 19, a first
cylindrical air-channel half-portion 21, four engaging members 23A
to 23D, and four first stopper portions 25A to 25D. The first
flange portion 19 has a contour of substantially a quadrilateral
having four corners. The four corners, a first corner 19a, a second
corner 19b, a third corner 19c, and a fourth corner 19d are
disposed in a circumferential direction of a rotary shaft 71 of the
first motor 3 and a rotary shaft 171 of the second motor 7 that are
arranged on the same axis line A. This direction will be
hereinafter simply referred to as the circumferential direction.
The first divided housing unit 11 has a suction opening 11a at one
end of the housing 1 in an axial line direction, which will be
described later. A first space S1 is defined between the motor
support frame 6 in the housing 1 and the suction opening 11a. The
four corners of the first flange portion 19 are rounded. Then, a
through-hole 19e, into which a fixture for mounting the
counter-rotating axial-flow fan to an electric appliance is
inserted, is formed in each of the four corners. One end of the
first cylindrical air-channel half-portion 21 is integrally formed
with the first flange portion 19. The first cylindrical air-channel
half-portion 21 contains therein a major part of the first space
S1. This first cylindrical air-channel half-portion 21 extends in
the axial line direction of the rotary shafts 71 and 171 (which
will be hereinafter simply referred to as the axial line
direction). At four locations of an outer peripheral portion of the
other end 21a of the first cylindrical air-channel half-portion 21,
wall portions 21b that project outward in a radial direction of the
rotary shafts 71 and 171 (which will be hereinafter simply referred
to as the radial direction) are formed at equidistant intervals in
the circumferential direction, respectively. At locations of an
inner peripheral portion of the other end 21a of the first
cylindrical air-channel half-portion 21, corresponding to the wall
portions 21b, flat surface portions 21c, linearly extending, are
respectively formed. In this embodiment, the inner peripheral
portion of the other end 21a including the flat surface portions
21c constitutes a fitting portion.
[0033] As shown in FIGS. 3, 4, and 7, the four engaging members 23A
to 23D are integrally formed with the first flange portion 19 and
the first cylindrical air-channel half-portion 21, and are arranged
at intervals in the circumferential direction. The four engaging
members 23A to 23D are respectively engaged with four engaged
members 41A to 41D of the second divided housing unit 13, which
will be described later. The four engaging members 23A to 23D are
respectively arranged in the vicinity of the four corners 19a to
19d, being integrally coupled to the first cylindrical air-channel
half-portion 21. These four engaging members 23A to 23D extend in
the axial line direction along the first cylindrical air-channel
half-portion 21 so that the four engaging members 23A to 23D do not
protrude outside from the contour of the first flange portion 19 as
the flange portion is seen from the first cylindrical air-channel
half-portion 21. By using the engaging member 23B shown in FIGS. 5
and 7 as a typical example and by assigning reference numerals to
respective portions of the engaging member 23B, the structure of an
engaging member will be described. Each of the engaging members 23A
to 23D includes two plate portions 23a and 23b and three connecting
portions 23c to 23e that are connected to the plate portions 23a,
23b. The plate portions 23a and 23b are opposed to each other in a
direction orthogonal to the axial line direction and a vertical
direction in the pages of FIGS. 5 and 7. The three connecting
portions 23c to 23e are arranged at predetermined intervals in the
axial line direction. The two connecting portions 23c and 23d
completely extend in the vertical direction between the two plate
portions 23a and 23b and partition a space defined between the two
plate portions 23a and 23b. The connecting portion 23e connects
only upper edge portions of the two plate portions 23a and 23b,
slightly extending downward from between the two plate portions 23a
and 23b. Thus, an opening portion 23f is formed among the two plate
portions 23a and 23b, the connecting portion 23e, and the first
cylindrical air-channel half-portion 21. A hole portion 23g that
faces upward is formed between the connecting portions 23d and
23e.
[0034] The four first stopper portions 25A to 25D respectively have
a shape of substantially a rectangular flat plate, being integrally
formed with the first flange portion 19. Base portions of the first
stopper portions are integrally coupled to the first cylindrical
air-channel half-portion 21. The four stopper portions 25A to 25D
extend in the axial line direction along the first cylindrical
air-channel half-portion 21 so that the four stopper portions 25A
to 25D do not protrude outside from the contour of the first flange
portion 19 as the first flange portion is seen from the first
cylindrical air-channel half-portion 21. How the four first stopper
portions 25A to 25B are disposed will be described later.
[0035] As shown in FIG. 7, the first support-frame half-portion 17
includes a first support-frame-body half-portion 27 and five first
web half-portions 28A to 28E. The first support-frame-body
half-portion 27 includes a circular plate portion 27b having an
opening portion 27a in the center thereof and a peripheral wall
portion 27c that extends in the axial line direction from an outer
peripheral portion of the circular plate portion 27b. A first metal
bearing holder 77 made of brass is fixedly fitted into the opening
portion 27a, as shown in FIG. 1. A stator board 85 of the first
motor 3 is disposed within a space defined, being bordered by the
circular plate portion 27b and the peripheral wall portion 27c, as
shown in FIG. 1. In the first support-frame-body half-portion 27,
four first through-hole half-portions 29A to 29D that pass through
the first support-frame-body half-portion 27 in the axial line
direction of the rotary shaft 71 of the first motor 3 are formed.
The four first through-hole half-portions 29A to 29D are formed at
equidistant intervals in the circumferential direction. One
through-hole half-portion 29A of the four first through-hole
half-portions 29A to 29D communicates with an internal space of a
first lead-wire guide-path half-portion 31 of the first web
half-portion 28A, which will be described later.
[0036] Five first web half-portions 28A to 28E are disposed at
predetermined intervals in the circumferential direction between
the peripheral wall portion 27c of the first support-frame-body
half-portion 27 and an inner peripheral surface of the first
housing body half-portion 15, thereby coupling the first
support-frame-body half-portion 27 and the first housing body
half-portion 15. The first web half-portion 28A of the five first
web half-portions 28A to 28E constitutes a web half-portion that
includes therein the first lead-wire guide-path half-portion 31.
This first web half-portion 28A will be hereinafter simply referred
to as the first lead-wire guide web half-portion 28A. As shown in
FIGS. 7 and 8, the first lead-wire guide web half-portion 28A
includes a bottom wall 28a and a pair of side wall portions 28b
that respectively rise up from the bottom wall 28a toward the
second motor 7. The first lead-wire guide-path half-portion 31, as
shown in FIG. 7, is formed by a region bordered by the bottom wall
28a and the pair of side wall portions 28b. As shown in FIG. 8, one
raised or convex portion 28d, protruding toward a second lead-wire
guide web half-portion 55A that will be described later, is formed
on the side wall portions 28b in the pair. Then, one recessed or
concave portion 28e, which is recessed toward the bottom wall 28a,
is formed also in the side wall portions 28b in the pair. In this
embodiment, the raised portion 28d and the recessed portion 28e
provided at one of the side wall portions 28b in the pair are
respectively opposed, in the circumferential direction, to the
raised portion 28d and the recessed portion 28e provided at the
other side wall portion 28b in the pair. The contour shapes of the
raised portion 28d and the recessed portion 28e are respectively an
isosceles trapezoid having two non-parallel opposite sides of equal
length. The raised portion 28d and the recessed portion 28e
respectively have two inclined surfaces which correspond to the
trapezoid's pair of non-parallel opposite sides of equal length,
and one of the two inclined surfaces 28d1 of the raised portion 28d
is continuous with one of the two inclined surfaces 28e1 of the
recessed portion 28e adjacent to the raised portion 28d. The raised
portion 28d protrudes toward the second lead-wire guide web
half-portion 55A beyond a virtual reference dividing plane F. The
virtual reference dividing plane F is the dividing plane along
which a motor support frame is divided into two, the first
support-frame half-portion 17 and the second support-frame
half-portion 35 that will be described later. Then, an end surface
28f of each side wall portion 28b in the pair, except portions
where the raised portion 28d and the recessed portion 28e are
formed, lies or is in the virtual reference dividing plane F.
Further, as shown in FIG. 4, an opening portion 21d, which opens
toward an inside of the first lead-wire guide web half-portion 28A,
is formed in the first cylindrical air-channel half-portion 21 in
the vicinity of a location to which the first lead-wire guide web
half-portion 28A is joined. Lead wires L are led out through the
opening portion 21d.
[0037] The second divided housing unit 13 is also made of a
synthetic resin or aluminum. As shown in FIG. 9, the second divided
housing unit 13 integrally includes a second housing-body
half-portion 33 and a second support-frame half-portion 35. The
second housing-body half-portion 33 includes a second flange
portion 37, a second cylindrical air-channel half-portion 39, four
engaged members 41A to 41D, and four second stopper portions 43A to
43D. The second flange portion 37 has a contour of substantially a
quadrilateral having four corners. The four corners, a first corner
37a, a second corner 37b, a third corner 37c, and a fourth corner
37d are disposed in the circumferential direction. The second
flange portion 37 has a discharge opening 13a at the other end of
the housing 1 in the axial line direction. A second space S2 is
defined between the motor support frame 6 in the housing 1 and the
discharge opening 13a. The four corners 37a to 37d of the second
flange portion 37 are rounded, and a through-hole 37e, into which
the fixture for mounting the counter-rotating axial-flow fan to the
electric appliance is inserted, is formed in each of the four
corners. One end of the second cylindrical air-channel half-portion
39 is integrally formed with the second flange portion 37. The
second cylindrical air-channel half-portion 39 contains therein a
major part of the second space S2.
[0038] Four flat surface portions 45 are formed at equal angle
intervals in the circumferential direction on an outer peripheral
portion (a fitted portion) of the other end 39a of the second
cylindrical air-channel portion 39. The four flat surface portions
45 come into contact with the flat surface portions 21c of the
other end 21a of the first cylindrical air-channel half-portion 21
when the first divided housing unit 11 and the second divided
housing unit 13 are coupled. Positioning of the first divided
housing unit 11 and the second divided housing unit 13 in the
circumferential direction is determined by aligning the flat
surface portions 21c and the flat surface portions 45.
[0039] The four engaged members 41A to 41D are integrally formed
with the second flange portion 37 and arranged at intervals in the
circumferential direction. The four engaged members 41A to 41D are
respectively disposed in the vicinity of the four corners 37a to
37d of the second flange portion 37 with the four engaged members
41A to 41D being integrally coupled to the second cylindrical
air-channel half-portion 39. The four engaged members 41A to 41D
extend along the second cylindrical air-channel half-portion 39 in
the axial line direction so that the four engaged members 41A to
41D do not protrude outside from the contour of the second flange
portion 37 as the second flange portion is seen from the second
cylindrical air-channel half-portion 39. By using the engaged
member 41B shown in FIGS. 5 and 9 as a typical example and by
assigning reference numerals to respective portions of the engaging
member 41B, the structure of an engaged member 41B will be
described. The engaged members 41A to 41D each include a support
portion 47 integrally provided at the second flange portion 27, a
rib 49 coupled to the support portion 47 and the second cylindrical
air-channel half-portion 39, and a claw-forming member 51 with one
end thereof supported by the support portion 47. The claw-forming
member 51 includes a plate-like portion 51a, a claw portion 51b
integrally formed with the plate-like portion 51a, and a projecting
portion 51c. The plate-like portion 51a is connected to the support
portion 47, being spaced from the rib 49. The plate-like portion
51a extends from the support portion 47 toward the first divided
housing unit 11. The claw portion 51b projects from a leading end
of the plate-like portion 51a in a direction orthogonal to the
surface of the plate-like portion 51a, or in the upward direction
in the page of FIG. 5. The upper side of the claw portion 51b has
an inclined surface 51d so that the thickness of the claw portion
51b increases more toward the support portion 47. Specifically, the
respective claw portions 51b of the engaged members 41A and 41B
project in the upward direction in the page of FIG. 9, while the
respective claw portions 51b of the engaged members 41C and 41D
project in the downward direction in the page of FIG. 9. The
projecting portion 51c is spaced from the claw portion 51b in the
axial line direction. The projecting portion 51c projects from the
plate-like portion 51a in the same direction as the one where the
claw portion 51b projects. A cross-sectional surface of the
projecting portion 51c is substantially a rectangle in shape. It
will be described later in detail how the four engaged members 41A
to 41D are respectively engaged with the four engaging members 23A
to 23D of the first divided housing unit 11.
[0040] The four second stopper portions 43A to 43D have the shape
of a rectangular flat plate integrally formed with the second
flange portion 37, and are arranged adjacent to the four engaged
members 41A to 41D, respectively. The four second stopper portions
43A to 43D are integrally coupled to the second cylindrical
air-channel half-portion 39. The four second stopper portions 43A
to 43D extend along the second cylindrical air-channel half-portion
39 in the axial line direction so that the four second stopper
portions 43A to 43D do not protrude outside from the contour of the
second flange portion 37 as the second flange portion is seen from
the second cylindrical air-channel half-portion 39. The first
corner 37a and the third corner 37c are opposed to each other in
the radial direction with respect to the axis line A. The engaged
members 41A and 41C are also opposed to each other in the radial
direction. The second stopper portions 43A and 43C are provided for
the engaged members 41A and 41C, respectively. Specifically, when a
virtual diagonal line D3 that connects the first corner 37a and the
third corner 37c of the second flange portion 37 is assumed as
shown in FIGS. 6 and 9, the engaged member 41A and the second
stopper portion 43A are arranged so as to interpose the virtual
diagonal line D3 therebetween, and the engaged member 41C and the
second stopper portion 43C are arranged so as to interpose the
virtual diagonal line D3 therebetween. Likewise, the second corner
37b and the fourth corner 37d are opposed to each other in the
radial direction with respect to the axis line A. The engaged
members 41B and 41D are also opposed to each other in the radial
direction. The second stopper portions 43B and 43D are provided for
the engaged members 41B and 41D, respectively. When a virtual
diagonal line D4 that connects the second corner 37b and the fourth
corner 37d, which are the remaining two corners of the second
flange portion 37, is assumed, the engaged member 41B and the
second stopper portion 43B are arranged so as to interpose the
virtual diagonal line D4 therebetween, and the engaged member 41D
and the second stopper portion 43D are arranged so as to interpose
the virtual diagonal line D4 therebetween. Then, at the four
corners 37a to 37d through which the virtual diagonal lines D3 and
D4 (the third and fourth virtual diagonal lines) pass, none of the
engaged members 41A to 41D and none of the second stopper portions
43A to 43D are arranged. In other words, in a region defined
between the first corner 37a and the second corner 37b of the
second flange portion 37, the engaged members 41A and 41B are
arranged, and in a region defined between the second corner 37b and
the third corner 37c, the second stopper portions 43B and 43C are
arranged. Then, in a region defined between the third corner 37c
and the fourth corner 37d, the engaged members 41C and 41D are
arranged, and in a region defined between the fourth corner 37d and
the first corner 37a, the second stopper portions 43D and 43A are
arranged.
[0041] The four first stopper portions 25A to 25D shown in FIGS. 4
and 7 are also arranged adjacent to the four engaging members 23A
to 23D, respectively. A positional relationship among the four
first stoppers 25A to 25D and the four engaging members 23A to 23D
is the same as the positional relationship among the four second
stopper portions 43A to 43D and the four engaged members 41A to
41D, shown in FIG. 6. As shown in FIG. 7, the first corner 19a and
the third corner 19c are opposed to each other in the radial
direction with respect to the axis line A. The engaging members 23A
and 23C are opposed to each other in the radial direction. The
first stopper portions 25A and 25C are provided for the engaging
members 23A and 23C, respectively. Specifically, when a virtual
diagonal line D1 that connects the first corner 19a and the third
corner 19c of the first flange portion 19 is assumed as shown in
FIG. 7, the engaging member 23A and the first stopper portion 25A
are arranged so as to interpose the virtual diagonal line D1
therebetween, and the engaging member 23C and the first stopper
portion 25C are arranged so as to interpose the virtual diagonal
line D1 therebetween. The second corner 19b and the fourth corner
19d are opposed to each other in the radial direction with respect
to the axis line A. The engaging members 23B and 23D are opposed to
each other in the radial direction. The first stopper portions 25B
and 25D are provided for the engaging members 23B and 23D,
respectively. When a virtual diagonal line D2 that connects the
second corner 19b and the fourth corner 19d, which are the
remaining two corners of the first flange portion 19, is assumed,
the engaging member 23B and the first stopper portion 25B are
arranged so as to interpose the virtual diagonal line D2
therebetween, and the engaging member 23D and the first stopper
portion 25D are arranged so as to interpose the virtual diagonal
line D2 therebetween. Then, at the four corners 19a to 19d through
which the virtual diagonal lines D1 and D2 (the first and second
virtual diagonal lines) pass, none of the engaging members 23A to
23D and none of the first stopper portions 25A to 25D are arranged.
In other words, in a region defined between the first corner 19a
and the second corner 19b of the first flange portion 19, the
engaging members 23A and 23B are arranged, and in a region defined
between the second corner 19b and the third corner 19c, the first
stopper portions 25B and 25C are arranged. Then, in a region
defined between the third corner 19c and the fourth corner 19d, the
engaging members 23C and 23D are arranged, and in a region defined
between the fourth corner 19d and the first corner 19a, the first
stopper portions 25D and 25A are arranged. The four first stopper
portions 25A to 25D and the four second stopper portions 43A to 43D
are shaped and sized so that leading ends of the four first stopper
portions 25A to 25D are respectively abutted onto leading ends of
the four second stopper portions 43A to 43D, when the claw portions
51b are completely engaged with the hole portions 23g of the
engaging members 23A to 23D, respectively.
[0042] As shown in FIG. 9, the second support frame half-portion 35
includes a second support-frame-body half-portion 53 and five
second web half-portions 55A to 55E. The second support-frame-body
half-portion 53 includes a circular plate portion 53b having an
opening portion 53a in the center thereof and a peripheral wall
portion 53c that extends in the axial line direction from an outer
peripheral portion of the circular plate portion 53b. A second
metal bearing holder 177 made of brass is fixedly fitted into the
opening portion 53a, as shown in FIG. 1. Within a space bordered by
the circular plate portion 53b and the peripheral wall portion 53c,
a stator board 185 of the second motor 7 is arranged, as shown in
FIG. 1. Four second through-hole half-portions 57A to 57D that pass
through the second support-frame-body half-portion 53 in the axial
line direction of the rotary shaft 171 of the second motor 7, which
will be described later, are formed in the second
support-frame-body half-portion 53. The four second through-hole
half-portions 57A to 57D are formed at equidistant intervals in the
circumferential direction of the rotary shaft 171 (shown in FIG.
1). One through-hole half-portion 57A of the four second
through-hole half-portions 57A to 57D communicates with an internal
space of a second lead-wire guide-path half-portion 59 of the
second web half-portion 55A, which will be described later. The
four second through-hole half-portions 57A to 57D are formed to
have the same shape as the four first through-hole half-portions
29A to 29D of the first support-frame-body half-portion 27,
respectively. The five second web half-portions 55A to 55E are
arranged at predetermined intervals in the circumferential
direction between the peripheral wall portion 53c of the second
support-frame-body half-portion 53 and an inner peripheral surface
of the second housing-body half-portion 33, thereby connecting the
second support-frame-body half-portion 53 and the second
housing-body half-portion 33. The second web half-portion 55A of
the five second web half-portions 55A to 55E constitutes the web
half-portion that includes a second lead-wire guide-path
half-portion 59 therein. Thus, the second web half-portion 55A will
be hereinafter simply referred to as the second lead-wire guide web
half-portion 55A. The second lead-wire guide web half-portion 55A
includes a bottom wall 55a and a pair of side wall portions 55b
that respectively rise up from the bottom wall 55a. The second
lead-wire guide-path half-portion 59 is formed by a region bordered
by the bottom wall 55a and the pair of side wall portions 55b. One
raised or convex portion 55d, protruding toward the first lead-wire
guide web half-portion 28A, is formed on the side wall portions 55b
in the pair. Then, one recessed or concave portion 55e, which is
recessed toward the bottom wall 55a, is formed also in the side
wall portions 55b in the pair. In this embodiment, the raised
portion 55d and the recessed portion 55e provided at one of the
side wall portions 55b in the pair are respectively opposed, in the
circumferential direction, to the raised portion 55d and the
recessed portion 55e provided at the other side wall portion 55b in
the pair. As shown in FIG. 8, the raised portion 55d protrudes
toward the first lead-wire guide web half-portion 28A beyond the
virtual reference dividing plane F, which is the dividing plane
along which the motor support frame is divided into the first
support-frame half-portion 17 and the second support-frame
half-portion 35. As shown in FIGS. 4 and 9, an opening portion 39d
that opens toward an inside of the second lead-wire guide web
half-portion 55A is formed in the second cylindrical air-channel
half-portion 39 in the vicinity of a location to which the second
lead-wire guide web half-portion 55A is joined. It will be
described in detail how the first lead-wire guide web half-portion
28A and the second lead-wire guide half-portion 55A are
coupled.
[0043] In the counter-rotating axial-flow fan in this embodiment,
the first divided housing unit 11 and the second divided housing
unit 13 are coupled in the following manner. Actually, the first
motor 3 (shown in FIG. 1) and the first impeller 5 are arranged
within the first divided housing unit 11, and lead wires are
arranged within the first lead-wire guide web half-portion 28A. A
first axial-flow fan unit is thus assembled. Then, the second motor
7 (shown in FIG. 1) and the second impeller 9 are arranged within
the second divided housing unit 13, and the lead wires are arranged
within the second lead-wire guide web half-portion 55A. A second
axial-flow fan unit is thus assembled. Then, by coupling the first
axial-flow fan unit and the second axial-flow fan unit, the first
divided housing unit 11 and the second divided housing unit 13 are
coupled. First, the first divided housing unit 11 and the second
divided housing unit 13 are brought close to each other, and then
leading ends of the claw portions 51b of the four engaged members
41A to 41D of the second divided housing unit 13 are inserted into
the opening portions 23f of the four engaging members 23A to 23D of
the first divided housing unit 11, respectively. Referring to FIG.
5, when the engaged member 41B and the engaging member 23B are
brought close to each other after the insertion, the inclined
surface 51d of the claw portion 51b comes into contact with a lower
edge of the connecting portion 23e. By the contact between the
inclined surface 51d and the connecting portion 23e, the plate-like
portion 51a bends so as to be closer to the rib 49. When the
engaged member 41B and the engaging member 23B are further brought
close to each other, and then the contact between the inclined
surface 51d and the connecting portion 23e is released, the
connecting portion 23e is fitted into a recessed or concave portion
that is defined between the claw portion 51b and the raised portion
51c of the engaged member 41B. The claw portion 51b is thereby
engaged with the hole portion 23g. This completes engagement
between the engaging member 23B and the engaged member 41B. In this
structure, the rib 49 functions as a stopper that prevents the
claw-forming member 51 from bending more than necessary. The
projecting portion 51c serves as a stopper that prevents the claw
portion 51b from moving toward the first cylindrical air-channel
half-portion 21. In this embodiment, the claw portion 51b and the
hole portion 23g are formed so as to allow for visual confirmation
of the engagement when the claw portion 51b is engaged with the
hole portion 23g.
[0044] In order to attain the engagement as described above, the
fitting portion formed by the inner peripheral surface portion of
the other end 21a of the first cylindrical air-channel half-portion
21 is fitted into the fitted portion formed by the outer peripheral
surface portion of the other end 39a of the second cylindrical
air-channel half-portion 39, thereby forming a fitting structure.
The first divided housing unit 11 is coupled to the second divided
housing unit 13 not only by the fitting structure mentioned above
but also by the engagement of the claw portions 51b mentioned above
and the hole portions 23g of the engaging members 23A to 23D. Then,
with the first divided housing unit 11 coupled to the second
divided housing unit 13 as described above, leading ends of the
first stopper portions 25A to 25D are respectively abutted onto
leading ends of the four second stopper portions 43A to 43D.
[0045] A housing body 61 is constituted from the first housing-body
half-portion 15 included in the first divided housing unit 11 and
the second housing-body half-portion 33 included in the second
divided housing unit 13 that are coupled as mentioned above and as
shown in FIG. 2. Further, a motor support frame 63 is constituted
from the first support-frame half-portion 17 included in the first
divided housing unit 11 and the second support-frame half-portion
35 included in the second divided housing unit 13. In other words,
as shown in FIG. 8, the first support-frame half-portion 17 and the
second support-frame half-portion 35 are obtained by dividing the
motor support frame 63 into two along the virtual reference
dividing plane F that extends in the radial direction. Further, a
support frame-body 65 is constituted from the first support-frame
body half-portion 27 included in the first support-frame
half-portion 17 and the second support-frame-body half-portion 53
included in the second support-frame half-portion 35. With this
arrangement, the first through-hole half-portions 29A to 29D of the
first divided housing unit 11 are respectively combined with the
second through-hole half-portions 57A to 57D of the second divided
housing unit 13, thereby forming four through-holes 67A to 67D. The
four through-holes 67A to 67D partially define an internal space IS
of the support frame body 65. Further, the five first web
half-portions 28A to 28E included in the first support-frame
half-portion 17 are respectively combined with the five second web
half-portions 55A to 55E included in the second support-frame
half-portion 35, thereby forming five webs 69A to 69E. The five
webs 69A to 69E constitute stationary blades. Then, the web 69A of
the five webs 69A to 69E constitutes the lead-wire guide web 69A.
This lead-wire guide web 69A is constituted by combining the first
lead-wire guide web half-portion 28A with the second lead-wire
guide web half-portion 55A. In this lead-wire guide web 69A, as
shown in FIG. 8, the raised portion 28d of the first lead-wire
guide web half-portion 28A is fitted into the recessed portion 55e
of the second lead-wire guide web half-portion 55A, and the
recessed or concave portion 28e of the first lead wire guide web
half-portion 28A is fitted with the raised or convex portion 55d of
the second lead wire guide web half-portion 55A. Then, a lead-wire
guide path GP (as shown in FIG. 2) is formed within the lead-wire
guide web 69A. The lead-wire guide path GP guides a plurality of
lead wires and a plurality of signal lines for supplying power to
the first motor 3 and the second motor 7. Then, as shown in FIG. 4,
a plurality of the lead wires L shown by dotted lines are led out
from the lead wire guide path of the lead-wire guide web 69A
through the opening portions 21d and 39d. The remaining four webs
69B to 69E of the five webs 69A to 69E are respectively divided
into the first web half-portion 28B and the second web half-portion
55B, the first web half-portion 28C and the second web half-portion
55C, the first web half-portion 28D and the second web half-portion
55D, and the first web half-portion 28E and the second web
half-portion 55E, along the virtual reference dividing plane F.
[0046] Referring again to FIG. 1, the first motor 3 includes the
rotary shaft 71, a stator 73, and a rotor 75. The rotary shaft 71
is rotatably supported onto the first bearing holder 77 by two
bearings 79 fitted into the first bearing holder 77.
[0047] The stator 73 includes a stator core 81, exciting windings
83, and a circuit board 85. The stator core 81 is formed by
lamination of a plurality of steel plates and is fixed to the first
bearing holder 77. The stator core 81 includes a plurality of
projecting pole portions 81a arranged in the circumferential
direction of the rotary shaft 71. The exciting windings 83 are
respectively attached to the projecting pole portions 81a through
insulators 84. The circuit board 85 is arranged along the first
support-frame-body half-portion 27, being disposed apart from the
first support-frame-body half-portion 27 by predetermined spacing.
An exciting current supply circuit for flowing exciting current to
the exciting windings 83 is mounted on the circuit board 85. In
this embodiment, the exciting current supply circuit on the circuit
board 85 and the exciting windings 83 are electrically connected by
winding lead wires of the exciting windings 83 around a terminal
pin 87 that passes through a through-hole of the circuit board 85
and is soldered to an electrode on the circuit board 85. In the
circuit board 85, a plurality of board through-holes 85a are
formed. The board through holes 85a are formed in the
circumferential direction of the rotary shaft 71 at equidistant
intervals. Air that has flown from around the stator 73 toward the
four first through-hole half-portions 29A to 29D of the first
support-frame-body half-portion 27 passes through the board
through-holes 85a.
[0048] The rotor 75 includes an annular member 89 and a plurality
of permanent magnets 91 fixed onto an inner peripheral surface of
the annular member 89. The annular member 89 is fixed inside a
peripheral wall portion 93a of a cup-like member 93 of the first
impeller 5, which will be described later.
[0049] As shown in FIG. 10, the first impeller 5 includes the
cup-like member 93 and nine blades 95. The cup-like member 93
includes the peripheral wall portion 93a onto which the nine blades
95 are fixed and a bottom wall portion 93b integrally formed with
one end of the peripheral wall portion 93a. One end of the rotary
shaft 71 of the first motor 3 is connected to the bottom wall
portion 93b. A plurality of ventilation slots 93c are formed in the
bottom wall portion 93b and are disposed in the circumferential
direction of the rotary shaft 71 at equidistant intervals. Each
ventilation slot 93c has an elongated shape that extends in the
radial direction of the rotary shaft 71 of the first motor 3. The
ventilation slots 93c serve to introduce air sucked through the
suction opening 11a into an internal space of the first motor
3.
[0050] As described above, the annular member 89 of the rotor 75 is
fixed inside the peripheral wall portion 93a of the cup-like member
93 of the first impeller 5. Thus, the first impeller 5 is rotated
by the first motor 3 in a first rotating direction R1, which is a
counterclockwise direction in the page of FIG. 10, within the first
space S1.
[0051] As shown in FIG. 1, the second motor includes the rotary
shaft 171, a stator 173, and a rotor 175. The rotary shaft 171 is
rotatably supported onto the second bearing holder 177 by two
bearings 179 fitted into the second bearing holder 177. The rotary
shaft 171 rotates in a direction opposite to the rotating direction
of the rotary shaft 71 of the first motor 3. Structures of the
rotary shaft 171, stator 173, and rotor 175 are the same as those
of the rotary shaft 71, stator 73, and rotor 75 of the first motor
3, respectively. Thus, 100 is added to reference numerals assigned
to the rotary shaft, stator, and rotor of the first motor 3, and
descriptions of the rotary shaft, stator, and rotor of the second
motor 7 will be omitted.
[0052] As shown in FIG. 11, the second impeller 9 includes a
cup-like member 193 and seven blades 195. The cup-like member 193
includes a peripheral wall portion 193a onto which the seven blades
195 are fixed and a bottom wall portion 193b integrally formed with
one end of the peripheral wall portion 193a. One end of the rotary
shaft 171 of the second motor 7 is fixed onto the bottom wall
portion 193b. A plurality of ventilation slots 193c are formed in
the bottom wall portion 193b and are disposed at equidistant
intervals in the circumferential direction of the rotary shaft 171,
being disposed apart from the rotary shaft 171. Each ventilation
slot 193c has an elongated arc shape and extends in the
circumferential direction of the rotary shaft 171 of the second
motor 7. The ventilation slots 193c serve to discharge air
introduced into the internal space of the second motor 7 to the
outside. As shown in FIG. 1, an annular member 189 of the rotor 175
of the second motor 7 is fixed inside the peripheral wall portion
193a of the cup-like member 193 of the second impeller 9. As
described above, the rotary shaft 171 of the second motor 7 rotates
in the direction opposite to the rotating direction of the rotary
shaft 71 of the first motor 3. Thus, the second impeller 9 is
rotated by the second motor 7 in a second rotating direction R2,
which is opposite to the first rotating direction R1 and is a
clockwise direction in the page of FIG. 11, within the second space
S2.
[0053] In the counter-rotating axial-flow fan in this embodiment,
when the first impeller 5 rotates in the first rotating direction
and the second impeller 9 rotates in the second rotating direction
opposite to the first rotating direction, air sucked through the
suction opening 11a is discharged from the discharge opening 13a,
as shown in Fig, thereby cooling the inside of the electric
appliance.
[0054] In the counter-rotating axial-flow fan in this embodiment,
at least one raised portion 28d is provided at the side wall
portions 28b in the pair of the first web half-portions 28A to 28E,
and at least one raised or convex portion 55d is provided at the
side wall portions 55b in the pair of the second web half-portions
55A to 55E. Then, the raised portions 28d and 55d extend beyond the
virtual reference dividing plane F. The height of the side wall
portions 28b and 55b may be thereby increased. As a result, lead
wires may be much less likely to protrude or run off from between
the side wall portions 28b and between the side wall portions 55b.
Further, when the first and second divided housing units are
coupled, a plurality of the lead wires may be much less likely to
be sandwiched between the side wall portions of the first web
half-portions 28A to 28E and second web half-portions 55A to 55E.
In the counter-rotating axial-flow fan of the present invention,
the engaging members 23A to 23D integrally formed with the first
flange portion 19 and the engaged members 41A to 41D integrally
formed with the second flange portion 37 are employed for the
coupling structure that couples the first divided housing unit 11
and the second divided housing unit 13. Therefore, the coupling of
the first divided housing unit 11 and the second divided housing
unit 13 are attained not only by the engagement of the engaging
members 23A to 23D and the engaged members 41A to 41D as well as by
the fitting of the other end 21a of the first cylindrical
air-channel half-portion 21 and the other end 39a of the second
cylindrical air-channel half-portion 39. As a result, no force
concentration will occur at the fitting structure of the first
cylindrical air-channel half-portion and the second cylindrical
air-channel half-portion. Moreover, the first and second divided
housing units will not be readily disconnected or decoupled. In
addition, the first stopper portions 25A to 25D are respectively
provided adjacent to the engaging members 23A to 23D, and the
second stopper portions 43A to 43D are respectively provided
adjacent to the engaged members 41A to 41D. Thus, even if force is
concentrated and applied from the first flange portion 19 and the
second flange portion 37 to the engaging members 23A to 23D and the
engaged members 41A to 41D when the first divided housing unit 11
and the second divided housing unit 13 are coupled, the leading
ends of the first stopper portions 25A to 25D adjacent to the
engaging members 23A to 23D are respectively abutted onto the
leading ends of the second stopper portions 43A to 43D adjacent to
the engaged members 41A to 41D. As a result, even if the engaging
members 23A to 23D are strongly pressed against the engaged members
41A to 41D, it may be possible to prevent breakage of engagement
portions where the engaging member 23A to 23D and the engaged
member 41A to 41D are engaged with each other.
[0055] While the preferred embodiment of the invention has been
described with a certain degree of particularity with reference to
the drawings, obvious modifications and variations are possible in
light of the above teachings. It is therefore to be understood that
within the scope of the appended claims, the invention may be
practiced other than as specifically described.
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