COUNTER-ROTATING AXIAL-FLOW FAN
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.
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The present invention relates to a counter-rotating axial-flow fan used for cooling the inside of an electric appliance or the like.
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.
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.
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 INVENTIONAn 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Now, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
The first divided housing unit 11 is made of a synthetic resin or aluminum. As shown in
As shown in
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.
As shown in
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
The second divided housing unit 13 is also made of a synthetic resin or aluminum. As shown in
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.
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
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
The four first stopper portions 25A to 25D shown in
As shown in
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
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.
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
Referring again to
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.
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.
As shown in
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
As shown in
As shown in
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.
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.
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.
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.
Type: Application
Filed: Apr 17, 2008
Publication Date: Oct 23, 2008
Applicant: SANYO DENKI CO., LTD. (Tokyo)
Inventors: Toshiya Nishizawa (Tokyo), Yasuhiro Maruyama (Tokyo), Hayato Murayama (Tokyo)
Application Number: 12/104,861
International Classification: F04D 29/38 (20060101);