Patent Application
20070212211
The present application claims priority to Japanese Patent Application JP 2006-064134 filed in the Japanese Patent Office on Mar. 9, 2006, the entire contents of which being incorporated herein by reference.
The present disclosure relates to a cross flow fan which sends air in a direction substantially orthogonal to a rotating shaft of a motor. It also relates to an electronic apparatus in which such cross flow fan is installed, and an impeller to which the cross flow fan is mounted.
In related art, a type of fan called a cross flow fan which blows air in a direction substantially orthogonal to a rotating shaft of a motor is used mainly in an air conditioner. The cross flow fan is also used in an air curtain device since it produces an air current in a form of a plane substantially parallel to the rotating shaft of the motor.
According to the cross flow fan of this kind, the rotating shaft of the motor is attached to one end of the fan body (impeller) and a rotating shaft, which is coaxial with the rotating shaft of the motor, is rotatably supported by a bearing at the other end of the fan body opposite to the rotating shaft of the motor. Such a cross flow fan is generally assembled using sheet metal, so that an unbalance of rotation tends to occur while the fan body is rotating. For this reason, as recited in Japanese Patent Application Laid-Open publication No. 2002-243193 (see
However, the case where the bearings are provided at both sides of the fan body requires an accurate centering of rotating shafts which renders the manufacturing of the cross flow fan difficult. Additionally, the manufacturing cost increases as the both bearings are to be provided at both sides.
In view of the forgoing it would be desirable to provide a cross flow fan apparatus and an electronic apparatus that is manufactured more easily and at less cost.
A cross flow fan apparatus according to an embodiment includes an impeller having a plurality of blades extending in a predetermined direction. The cross flow fan apparatus also includes a motor, having a rotating shaft provided along the predetermined direction, which drives to rotate the impeller. Furthermore, the cross flow fan apparatus has a supporting body that supports the motor such that the impeller is cantilevered by the rotating shaft.
According to an embodiment, the rotating shaft of the motor cantilevers the impeller. Thus, the number of component parts is reduced in comparison to a cross flow fan of a related art type in which the impeller is supported with bearings respectively at both sides thereof. As a result, the manufacturing of the cross flow fan apparatus is simplified, and the manufacturing cost is reduced.
In particular, because the impeller is made of a resin, the impeller is reduced in weight. As a result, even though the impeller is cantilevered, the rotation of the impeller is steady with less unbalance. In such case, the impeller may have a joint portion that joins the plurality of blades at both ends thereof and the joint portion may be integrally molded with each of the plurality of blades. In other words, the impeller of a related-art is manufactured by attaching each one of the blades to joint plates provided respectively at both sides of the plurality of blades. However, because the impeller of the present embodiment is integrally molded, the manufacturing process is made significantly simpler than before. Also, as the accuracy in the dimensions and form of the impeller improves, the unbalance of the rotation of the impeller is reduced, which results in accomplishment of steady rotation.
In an embodiment, the motor has a fluid bearing that supports the rotating shaft. This configuration increases the rigidity of the rotating shaft and the bearing, thus the wobbling of the rotating shaft can be suppressed which enables even more steady rotation.
In an embodiment, the cross flow fan apparatus further includes a supporting mechanism, disposed at a position opposite to the position where the motor is disposed and supports the impeller in a non contact manner. With this configuration, load is constantly applied in a radial direction of the bearing as the impeller is being kept in the non-contact state. As a result, wobbling and whirl phenomena that are caused due to unbalancing of the impeller can be suppressed.
For example, the supporting mechanism may have both a shaft member made of a magnetic material attached to the impeller coaxially with the rotating shaft, and a magnet disposed on a supporting body and placed near the shaft member. Alternatively, the magnet may be attached to the impeller while the supporting body is provided with a magnetic body.
In an embodiment, the blades are arranged in a ring shape. The impeller has a ring-shaped joint plate disposed at a position opposite to the position where the motor is disposed and joins each of the plurality of blades together. The cross flow fan apparatus further includes a projecting member, being disposed in the supporting body such that to penetrate into an area surrounded by the blades from an outside of the impeller through an inside of the ring-shaped joint plate. Even if the rotating shaft wobbles, the joint plate is brought into contact with the projecting member that serves as a stopper. As a result, the impeller as a whole does not wobble largely.
In an embodiment, each of the blades has a first main face, being a flat surface and disposed parallel to the direction of the rotating shaft. In addition, each of the blades has a second main face, being a flat surface, parallel to the direction of the rotating shaft and opposite to the first main face. Accordingly, the impeller can be stripped off quite easily out of the molding die used for manufacturing the impeller. Additionally, when the second main face is disposed at angle to the first main face, the amount of air blown by the impeller can be increased.
In an embodiment, impeller includes an engaging portion for joining a plurality of the impellers together in the predetermined direction. With this configuration, the plurality of impellers can be joined together, and an impeller, or a blade, with a desired length can be achieved.
A cross flow fan apparatus according to an embodiment includes an impeller having a plurality of blades extending in a predetermined direction, a first side in the predetermined direction, and a second side opposite to the first side. The cross flow fan apparatus also includes a pivot shaft attached to the first side of the impeller, and disposed along the predetermined direction. Moreover, the cross flow fan apparatus includes a motor having a rotating shaft a motor, having a rotating shaft being coaxial with the pivot shaft and supporting the impeller at the second side, which drives to rotate the impeller. Furthermore, the cross flow fan apparatus includes a supporting body that supports the motor, having a seating surface for pivot where a tip end of the pivot shaft is in contact.
The cross flow fan apparatus according to an embodiment has a simple structure in which one side of the impeller is provided with only the seating surface for pivot where the tip end of the pivot shaft is in contact instead of a bearing. In contrast, the cross flow fan apparatus of a related art is structured such that to have two bearings provided respectively to both sides of the impeller. With this configuration, not only the steady rotation of the impeller is realized but also the impeller may be manufactured more easily, leading to reduction in manufacturing cost.
According to an embodiment, the seating surface for pivot may be a flat surface or a curved surface.
An electronic apparatus according to an embodiment includes a heat generator and a cross flow fan apparatus. The cross flow fan apparatus includes an impeller having a plurality of blades extending in a predetermined direction, a motor that drives to rotate the impeller and a supporting body that supports the motor such that the impeller is cantilevered by the rotating shaft. The electronic apparatus of the embodiment further includes a casing in which the heat generator and the cross flow fan apparatus are disposed.
An electronic apparatus according to an embodiment includes a heat generator and a cross flow fan apparatus. The cross flow fan apparatus includes an impeller having a plurality of blades extending in a predetermined direction, a first side in the predetermined direction, and a second side opposite to the first side. The cross flow fan apparatus also includes a pivot shaft attached to the first side of the impeller and disposed along the predetermined direction. The cross flow fan apparatus also includes a motor, having a rotating shaft being coaxial with the pivot shaft and supporting the impeller at the second side which drives to rotate the impeller, and a supporting body which supports the motor, having a seating surface for pivot where a tip end of the pivot shaft is in contact. The electronic apparatus includes a casing in which the heat generator and the cross flow fan apparatus are disposed.
An impeller according to an embodiment includes a plurality of blades extending in a predetermined direction and a joint member that joins the blades together. Each of the blades has a first main face, being a flat surface, and disposed in the predetermined direction and a second main face, being a flat surface, and disposed approximately parallel to the direction of the rotating shaft and opposite to the first main face.
As described above, according to embodiments, the manufacturing of the cross flow fan apparatus is simplified, thus lowering the manufacturing cost.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.
Embodiments are described below with reference to the drawings.
An impeller 5 has a plurality of blades 1 extending in a predetermined direction. Joint members 2 and 3, being, for example, disc-shaped, join the blades 1 together so that the plurality of blades 1, are disposed side by side and equidistant to each other. A boss portion 2a is provided to the center of the joint member 2. A rotating shaft 7 of a motor 6 is attached to the boss portion 2a. Each of the plurality of blade 1 extends in the axial direction of the rotating shaft 7 (a Y-direction).
The motor 6 has a stator 11 and a rotor 12. The stator 11 has a bearing 9 rotatably supporting the rotating shaft 7 and a coil 8 arranged around the bearing 9. The rotor 12 is attached to the rotating shaft 7 and a magnet 4 is fixed to the rotor 12.
An example of the bearing 9 is a fluid journal bearing, or a fluid dynamic bearing. Specifically, the bearing 9 is structured such that a sleeve member 15 is being housed in a housing 14. A dynamic pressure groove (not shown) is formed in an inner circumference of the sleeve member 15. A fluid, such as oil, is filled in an interstice between the sleeve member 15 and the rotating shaft 7. Alternatively, the sleeve member 15 may be formed of an oil-impregnated sintered metal. Use of such a fluid dynamic bearing makes the rotating shaft 7 and the bearing 9 more rigid and the wobbling of the rotating shaft 7 can be suppressed. As a result, a steady rotation can be achieved. The bearing used here should not necessarily be a fluid dynamic bearing and a ball bearing may be used instead.
A supporting body 16 supports the motor 6 so that the motor 6 supports the impeller 5 cantilevered at one end thereof by the rotating shaft 7. Specifically, motor 6 is fixed to the supporting body 16 with screws 13 or the like.
A cross flow fan apparatus 10 with a configuration described above blows air in the following way. Rotation of the impeller 5 driven by the motor 6 generates a difference in pressure around each of the plurality of blades 1 that causes air to move from the outside of the impeller 5 to the inside (i.e. the area surrounded by the blades 1) and then to the outside of the impeller 5. For example, the angle or the shape of the main face of the blade 1 is designed so that the air came inside the impeller 5 can be blown to the outside again.
As described above, according to the cross flow fan apparatus 10 of this embodiment, the rotating shaft 7 of the motor 6 supports the impeller 5 cantilevered at one end. As a result, the cross flow fan apparatus 10 can be produced more easily at lower manufacturing costs than the cross flow fan of a related art in which an impeller is supported by bearings provided at both ends of the impeller, since it requires a lower number of component parts.
Especially when the impeller 5 is made of resin, the cross flow fan apparatus 10 becomes very advantageous to other cross flow fans of related art. Such an impeller 5 is lighter in weight and is less unbalanced thus can rotate more stably even it is cantilevered. This embodiment is also effective in a case where the impeller 5 is compact.
If the impeller 5 were to be made of resin, it is possible to be manufactured by integral molding. An example of the integrally molded impeller is shown in
Each of the blades 25c of the impeller 25 has a first main face 25d and a second main face 25e which is provided to an opposite side of the first main face 25d. Both of the main faces 25d and 25e is a flat surface. Shaping the main faces 25d and 25e to be flat surfaces has an advantage where, after the casting, the flat surfaces allow an easier operation in stripping the molding die off. The molding die which is divided into the numbers of the blades 25c, can be removed by just pulling them out in a linear motion along a direction indicated by arrows “a” in
As shown in
In a related art, an impeller is manufactured by attaching blades, one by one, to the joint plates located respectively on both sides of each blade. As the impeller 25 being formed integrally, the process of manufacturing the impeller 25 is simplified significantly. Furthermore, since the accuracy in dimension and form of the impeller 25 improves by integral molding, it does not have to be processed manually after the molding, which leads to reduction in unbalanced rotation of the impeller 25, thus enables steady rotation. With the steady rotation, the advantage of the cantilever structure described above can be achieved more fully in particular. In other words, the impeller 25 can be rotated steadily even with a cantilever structure.
Additionally, the integrally-molded impeller 25 can be manufactured with ease, even if the diameter of the impeller 25 (the diameter of each of the joint plates 25a and 25b shown in
A cross flow fan apparatus 20 according to this embodiment has a supporting mechanism 21 that supports an impeller 35 in a non-contact manner. The supporting mechanism 21 is provided to a side of the impeller 35 where a joint plate 35b is provided, which is opposite to the side where a motor 6 is placed (i.e. where a joint plate 35a is provided). Specifically, the supporting mechanism 21 has a pivot shaft 22 attached to the impeller 35 coaxially with the rotating shaft 7 of the motor 6 and a magnet 23 fixed to a supporting body 26 and disposed near the pivot shaft 22. The pivot shaft 22 is attached to a boss portion 35d of the joint plate 35b. The shape of the magnet 23 is not limited to the form shown in
If the pivot shaft 22 is made of a magnetic material, such as iron or nickel, a magnetic attraction from the magnet 23 acts on the pivot shaft 22. In this configuration, a load in a radial direction of the pivot shaft 22 (i.e. a direction in a Y-Z plane) is constantly applied to the pivot shaft 22 in a non-contact manner. As a result, wobbling and whirl phenomena that would otherwise be caused by the unbalance can be suppressed.
In
According to the cross flow fan apparatus 30 of an embodiment, even if a posture thereof is changed and the change in the posture causes wobbling of the rotating shaft 7, the inner circumferential portion (hole) 45d is brought into contact with the projecting member 37 that serves as a stopper. As a result, the impeller 45 as a whole does not wobble greatly.
The cross flow fan apparatus 40 according to an embodiment has a structure in which just the seating surface 41a for pivot, with which the tip end 42a of the pivot shaft 42 is in contact, is provided as described above. In other words, the structure of the cross flow fan apparatus 40 according to an embodiment is simpler than that of a cross flow fan of a related art with a configuration in which bearings are provided respectively to both sides of an impeller. As a result, besides the steady rotation of the impeller 35, manufacturing of the impeller becomes easier and the cost can be reduced.
A modified example of the pressing member is a pressing member 43 with a curved seating surface for a pivot 43a as in a cross flow fan apparatus 50 illustrated in
Furthermore, the arrangement of the engaging projections 55d and engaging grooves 55e formed on the joint plate 55b is deviated from the arrangement of the engaging projections 55d and engaging grooves 55e formed on the joint plate 55a by 60°. Accordingly, the plurality of impellers 55 can be joined together.
Further, the length of the cross flow fan apparatus 10 along the direction X can be designed as appropriate, for example, in
The embodiments are not limited to the examples described above, and various modifications are possible.
For example, a possible embodiment is a combination of the embodiment shown in
The impellers 5 or the like described in each of the embodiments described above may or may not be integrally-molded unless otherwise specified.
The electronic apparatus 100 shown in
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2006-064134 | Mar 2006 | JP | national |
