This Application claims priority of Taiwan Patent Application No. 100205780, filed on Apr. 1, 2011, the entirety of which is incorporated by reference herein.
1. Technical Field
The invention relates to an impeller, and more particularly, the invention relates to an impeller which has two kinds of alternate blades.
2. Description of the Related Art
In a conventional electrical system, since its internal electronic element is a large heat source, and the performance of the internal electronic element degrades with the increasing of the temperature thereof, the heat generated thereby has to be quickly removed so as to keep the internal electronic element's regular performance. Therefore, a fan generating airflow is commonly used to achieve the objective of rapidly dissipating heat.
Please refer to
When the performance of an electronic element is enhanced, the heat generated by the electronic element is also greatly increased accordingly. For better heat dissipation, the rotational speed of the conventional fan has to be greatly increased. However, when the rotational speed of the impeller 10 is increased, an unpleasant noise gets louder due to turbulence airflow occurring between the blades 12.
Thus, it is a dilemma for a user. If the rotational speed is decreased, efficiency of heat dissipation degrades. If the rotational speed is increased, the noise produced by the fan becomes louder.
In this regard, this invention provides an impeller with alternate blades, and noise produced by the impeller is remarkably reduced.
One of subjects of the invention is to provide an impeller, which includes a hub, a plurality of upper blades, and a plurality of lower blades. The hub has an upper surface and a lower surface. The upper blades are disposed around the hub and connect to the upper surface. The lower blades are disposed around the hub and connect to the lower surface. The upper and lower blades are alternately disposed and outwardly extend from the hub.
Through an arrangement of the upper and lower blades in which the upper blades and the lower blades are alternately and crowdedly disposed on the hub, turbulence airflow occurring between the blades is inhibited. Thus, noise, generated as the impeller rotates at a high speed, is reduced.
The embodiment can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
Please refer to
The impeller 100 includes a hub 110, a plurality of upper blades 120, and a plurality of lower blades 130. The hub 110 has a circular shape and includes an upper surface 111 and a lower surface 112, wherein a protruded mounting part 113 is formed in a substantial central portion of the hub 110.
Each of the upper blades 120 is circumferentially disposed around the hub 110 and connects to the upper surface 111 of the hub 110. A fixed height is maintained from a proximal end to a distal end of each of the upper blades 120, and a cross sectional curvature of each of the upper blades 120 is not zero, wherein the term “cross sectional” is defined as a plane perpendicular to the axis C. Similarly, each of the lower blades 130 is circumferentially disposed around the hub 110 and connects to the lower surface 112 of the hub 110. It is noted that, the upper and lower blades 120 and 130 are alternately disposed on the hub 110. In this exemplary embodiment, the upper and lower blades 120 and 130 are alternately disposed and outwardly extend from the hub 110. In other words, along a direction parallel to the axis C, portions of the upper and lower blades 120 and 130 are not connected with the hub 110. Additionally, a height E1 of the upper blades 120 is equal to a height E2 of the lower blades 130, but it should not be limited thereto. In the other exemplary embodiment, the height E1 may be greater or smaller than the height E2.
Please refer to
Please refer to
The impeller 200 includes a hub 210, a plurality of upper blades 220, and a plurality of lower blades 230. The hub 210 has a circular shape and includes a protruded mounting part 211, an upper surface 212 and a lower surface 213, as shown in
The upper blades 220 are circumferentially disposed around an axis C of the hub 210 and connect to the upper surface 212 of the hub 210. Each of the upper blades 220 has a first portion 221 and a second portion 222 coupled to the first portion 221, wherein the first portion 221 is defined as a portion that is close to the hub 210, and the second portion 222 is defined as a portion that is away from the hub 210. The first portion 211 has a first thickness T1. Further, along the outwardly extended direction of the upper blades 220, the height of the first portion 221 is gradually increased to a height H1. In addition, a cross section curvature of the first portion 221 is not always zero. That is, a curvature of the first portion 221 is not fixed.
The second portion 222 has the same height of the distal end of the first portion 211, height H1, and the thickness of the second portion 222 is not fixed, such that an airfoil is formed at each second portion 222. Specifically, along the outwardly extended direction of the upper blades 220, the thickness of the second portions 212 gradually increases to the thickness T2 and then gradually decreases. Furthermore, because the airfoil formed at the second portion 222 is protruded toward to a rotation direction R3, a length of a windward side, a side that close to the rotation direction R3, of each of the upper blades 220 is greater than a length of a leeward side, a side that away from the rotation direction R3, of each of the upper blades 220.
In this exemplary embodiment, the first thickness T1 is 0.5 mm, and the second thickness T2 is 0.86 mm, but it is not limited thereto. The best molding techniques and material at the time of the invention can produce a blade with a thickness of 0.4 mm; thus, the ideal thickness of the upper blades 220 is between 0.4 mm and 1.2 mm. In this exemplary embodiment, the second thickness T2 is greater than the first thickness T1, wherein the second thickness T2 is 1-3 times that of the first thickness T1. Preferably, the second thickness T2 is 1-2.5 times that of the first thickness T1.
Please refer to
Because the cross section curvature of the first portion 221 is not zero, an angle A, as shown in
Please refer to
Please refer to
Structures of the upper and lower blades of the invention should not be limited by the above description. A variety of different forms of the blades will be described in the following description. For simplification, the interconnecting relationship between the blades and the hub is omitted, and descriptions of structures of lower blades of the following embodiment are omitted because the lower blades are identical with the upper blades.
Please refer to
Please refer to
Please refer to
As reflected above, it is thanks to the novel structure, wherein the upper and lower blades alternately and crowdedly connected to the hub, that when the impeller rotates, the turbulent airflow is exhibited, so that the problem where unpleasant noise is generated by the conventional fans is eliminated.
While the embodiment has been described by way of example and in terms of the embodiments, it is to be understood that the embodiment is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Number | Date | Country | Kind |
---|---|---|---|
100205780 U | Apr 2011 | TW | national |
Number | Name | Date | Kind |
---|---|---|---|
4204802 | Schonwald et al. | May 1980 | A |
5209630 | Roth | May 1993 | A |
6179561 | Horng | Jan 2001 | B1 |
6296439 | Yu et al. | Oct 2001 | B1 |
6322319 | Yoshioka | Nov 2001 | B1 |
6514036 | Marshall et al. | Feb 2003 | B2 |
6986643 | Huang et al. | Jan 2006 | B2 |
7210907 | Patti | May 2007 | B2 |
7478992 | Hsu et al. | Jan 2009 | B2 |
7997871 | Hwang et al. | Aug 2011 | B2 |
Number | Date | Country | |
---|---|---|---|
20120251323 A1 | Oct 2012 | US |