BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more fully understood from the subsequent detailed description and the accompany drawings, which are given by way of illustration only, and thus is not limitative of the present invention, and wherein:
FIG. 1A is a top view showing a conventional blower having one impeller;
FIG. 1B is a cross-sectional view taken along a line A-A′ of FIG. 1A;
FIG. 2A is a schematic illustration showing a conventional combined blower;
FIG. 2B is a schematic illustration showing the airflow when the combined blower of FIG. 2A is operating;
FIG. 3 is a top view of an impeller for a motor according to an embodiment of the invention;
FIGS. 4A and 4B are schematic illustrations showing a multiple-motor blower according to the embodiment of the invention;
FIGS. 5A to 5C are schematic illustrations showing the multiple-motor blowers respectively having different motors, having different impellers, and having different motors and different impellers;
FIGS. 6 and 7 are schematic illustrations showing different arrangements of the multiple-motor blowers; and
FIGS. 8A and 8B are schematic illustrations showing the multiple-motor blowers having a common inlet passage.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Referring to FIG. 3, an impeller 3 according to an embodiment of the invention includes a hub 33 and a plurality of blades 34 mounted around the hub 33. The impeller 3 is a centrifugal type fan impeller. The hub 33 and the blades 34 can be formed as a monolithic piece; otherwise, the blades 34 and the hub 33 may be combined together. The blade may be a forward leaning blade, a backward leaning blade or a plate-like blade, and the blades 34 have changeable curvatures. A distance D exists between the adjacent blades of the impeller 3, and the blade 34 has a thickness t. A ratio of the distance D to the thickness t is smaller than or equal to 3. In this embodiment, the blades 34 are arranged densely, and the blades 34 are the forward leaning blades having dual curvatures. The impeller 3 may be applied to a multiple-motor blower.
Referring to FIGS. 4A and 4B, a multiple-motor blower 4 having the above-mentioned impellers according to the embodiment of the invention includes a housing 41 and two motors 42 and 42a disposed in the housing 41. The motors 42 and 42a are arranged on a straight line and arranged symmetrically. The housing 41 has two inlet passages 411 and 411a. The outlet end of the housing 41 has a common outlet passage 413 for the motors 42 and 42a, and at least one air-guiding structure 414 is disposed between the motors 42 and 42a. The blower 4 has two impellers 43 and 43a respectively coupled to the motors 42 and 42a. The structures and functions of the impellers 43 and 43a of the embodiment are the same as those of the previously mentioned impeller 3. The impeller 43 includes a hub 433 and a blade 434 mounted around the hub 433, and the impeller 43a includes a blade 434a mounted around the hub 433a. The impellers 43 and 43a have reverse rotation directions. A ratio of the distance D between the two adjacent blades to a thickness t of the blade in the impeller 43 or 43a is smaller than or equal to 3.
As shown in FIG. 4B, the operations and the airflow directions of the multiple-motor blower 4 in this embodiment will be described in the following. When the motors 42 and 42a respectively drive the impellers 43 and 43a to rotate, the impeller 43 is preferably rotated counterclockwise and the impeller 43a is preferably rotated clockwise. The impellers 43 and 43a suck the airflow from the inlet passages 411 and 411a, respectively, and the airflow flows through the fluid passage and is then converged at the outlet passage 413 of the housing 41. It is to be noted that the dense blades 434 and 434a of the motors 42 and 42a, respectively, stably converge the airflow to the outlet passage 413 to achieve the heat dissipating function according to the designs of the enlarged blade curvature and the air-guiding structure 414 of the housing 41. The blades 434 and 434a, which are arranged densely, can block the airflow, and the airflow cannot be easily reversed due to the enlarged curvatures of the blades 434 and 434a. In addition, if one of the motors 42 and 42a breaks down and cannot drive the corresponding impeller 43 or 43a to rotate, a portion of the airflow generated by the other impeller 43a or 43, which is normally driven by the other motor 42a or 42, can push the faulty impeller 43 or 43a to rotate in a reverse direction through the air-guiding structure 414. Therefore, the airflow can be prevented from reversing from the inlet passage. Thus, the heat dissipating reliability and efficiency can be ensured, the power can be saved, and the overall property of the multiple-motor blower 4 can be improved.
The motors 42 and 42a and the impellers 43 and 43a according to this embodiment may have different combinations according to the actual requirement. As shown in FIG. 5A, the motors 42 and 42a enable the motors 42 and 42a to have different rotating speeds and airflow quantities through different stator structures 421 and 421a, which have, for example, different silicon steel sheets or different winding numbers. As shown in FIG. 5B, the impellers 43 and 43a have different types of blades, different blade curvatures, different blade thicknesses t1 and t2, different distances D1 and D2 or different densities (D1/t1 and D2/t2). The impellers 43 and 43a generate the different air quantities although they are driven by the same motor. As shown in FIG. 5C, the motors 42 and 42a have the different stator structures 421 and 421a (e.g., the different silicon steel sheets or the different winding numbers) and the impellers 43 and 43a have different blade curvatures or densities so that the combination of the motor 42 and the impellers 43 and the combination of the motor 42a and the impellers 43a generate different rotating speeds and different air quantities.
As shown in FIG. 6, a multiple-motor blower 6 according to the embodiment of the invention also has two motors, for example. The multiple-motor blower 6 includes a housing 61 and two motors 62 and 62a disposed in the housing 61. The housing 61 has different inlet passages 611 and 611a. The outlet end of the housing 61 has a common outlet passage 613 for the motors 62 and 62a, and at least one air-guiding structure 614 is disposed between the motors 62 and 62a. Similar to the above-mentioned embodiment, the motors 62 and 62a are different from each other, and the blade densities of impellers 63 and 63a are different from each other. The motors 62 and 62a are arranged on a straight line within the housing 61 in a manner similar to those above-mentioned. A line L connecting center points of the motors 62 and 62a, as shown in FIG. 6, is perpendicular to an outlet 615 of the housing 61, while the line L connecting center points of the motors 42 and 42a, as shown in FIG. 4B, is parallel to an outlet 415. In this case, the impellers 63 and 63a have reverse rotation directions, and the airflow driven by the impellers 63 and 63a is introduced from the inlet passages 611 and 611a. The airflow flows through the fluid passage and is then converged at the outlet passage 613 of the housing 61. Because the relative positional relationships between the impellers 63 and 63a and the outlet 615 are different from each other, the motor 62a is disposed at a location farther from the outlet passage 613, and the blades 634 and 634a are adjusted to have different curvatures and different densities. The density of the blades 634a is higher than that of the blades 634 so that the inlet passages 611 and 611a have different fluid pressures. Accordingly, higher heat dissipating efficiency can be achieved in conjunction with the air-guiding structure 614.
As shown in FIG. 7, the motors 62 and 62a are disposed unsymmetrically in a multiple-motor blower 7 according to the embodiment of the invention. The difference between the multiple-motor blower 7 and the multiple-motor blower 6 is that the line connecting the center points of the motors 62 and 62a (as shown in FIG. 7) forms an angle θ with the outlet 715 of the housing 71 in order to satisfy the special spatial requirement in a special heat dissipating system. The airflow flows through the fluid passage and is then converged at the outlet passage 713 of the housing 71. Because the relative positional relationships between the impellers 63 and 63a and the outlet 715 are different from each other, the rotating speeds of the motors 62 and 62a may be adjusted in conjunction with the angle θ, or the curvatures and densities of the blades 634 and 634a may be adjusted in conjunction with the angle θ so that better heat dissipating efficiency may be obtained.
As shown in FIGS. 8A and 8B, the motors 42 and 42a are disposed symmetrically in a multiple-motor blower 8 according to the embodiment of the invention. The difference between the multiple-motor blower 8 and the multiple-motor blower 4 is that a common inlet passage 811 is formed in the housing 81 in order to satisfy the special spatial requirement in a special heat dissipating system. The airflow flows through the fluid passage and is then converged at the outlet passage 813 of the housing 81.
In summary, the multiple-motor blower of the invention has two motors and a housing, which has different inlet passages and one common outlet passage. The motors drive the impellers to rotate in reverse rotation directions, and a ratio of a distance between adjacent blades to a thickness of the blade in at least one impeller is smaller than or equal to 3. Compared with the prior art, two different motors or impellers are configured to have reverse rotation directions and/or the dense blades are integrated in the multiple-motor blower in this invention. If any one motor breaks down and can not drive the corresponding impeller, the other impeller that normally rotates brings a portion of the air to push the faulty impeller to move through the air-guiding structure. In addition, the blades arranged densely in conjunction with the different blade curvatures may block the airflow to prevent the air from flowing reversely from the inlet passage. Thus, the invention can ensure the heat dissipating reliability and efficiency, and, thus the power may be saved.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
Patent Application
20080063532
