Patent Publication Number: US-6986643-B2

Title: Blower and the blade structure thereof

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a blade structure and, more particularly, to a blade structure used in a blower. 
   2. Description of the Related Art 
   Conventional blowers can be categorized into a single side entry blower and a double side entry blower. As for the single side entry blower, the blade structure used in the blower is a blade structure having equally spaced vanes on a single side. That is, as shown in  FIGS. 1A and 1B , all blades  11  of the blade structure are provided on one side of a supporting plate  12 . A motor drives the supporting plate to rotate the blade structure. However, such kind of blade structure has the following drawbacks. First, if trying to improve the characteristic of wind pressure, it is necessary to increase the number of the blades of the blade structure so as to increase the wind pressure. However, since the space and size of the blades are limited, the increased number of the blades is inevitably limited. Therefore, it is impossible to make any breakthrough regarding the characteristic of the wind pressure. Second, when the blade structure is rotating, the air stream passes through both the air inlet and the smallest clearance between the vanes and the outer casing  13 . Since the air passage is reduced drastically from a large size to a small size, the turbulence and noise may be generated easily. 
   In addition, referring to  FIGS. 2A and 2B , the blade structure of another conventional blower includes a plurality of blades  21 . The blades  21  are formed at two sides of a supporting annular plate  22  in an opposite manner to reduce the noise. The number of the blades can be doubled with respect to the above-mentioned blade structure so as to improve the wind pressure characteristic without changing the size of the blower. However, since the added annular plate may decrease the working area and block the passage of the air stream, a predetermined wind pressure and gas quantity may be lost. 
   In view of the above-mentioned drawbacks in the prior art, the present invention provides an improved blower and the blade structure thereof. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a blade structure for a blower to not only increase the wind pressure and gas quantity but also reduce the noise. 
   According to one aspect of the present invention, the blade structure includes a vane group and a plurality of inclined portions. The vane group is constituted by a plurality of vanes. Each of the plurality of inclined portions is connected to each of the plurality of vanes of the vane group. 
   In addition, the blade structure may further include a base around which the plurality of vanes of the vane group is mounted. The base, the vane group, and the plurality of inclined portions may be integrally formed. The base may be formed with a central opening for a motor driving the blade structure to be mounted therein. Preferably, the plurality of vanes of the vane group may partially protrude from a bottom of the base. 
   Furthermore, the blade structure may further include a hoop mounted around a top edge of each of the inclined portions. 
   According to another aspect of the present invention, the vane group and the plurality of inclined portions may be alternately arranged in multiple levels to increase the wind pressure of the guided air stream. Each of the plurality of vanes of the vane group may have a structural type selected from the group consisting of a curved surface, an inclined surface, an arched surface, and a flat surface. 
   According to still another aspect of the present invention, the blade structure includes a first vane group constituted by a plurality of vanes, a second vane group constituted by a plurality of vanes, and a plurality of inclined portions connected between the vanes of the first and second vane groups. The vanes of the first and second vane groups may be arranged alternately. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned and other objects, features, and advantages of the present invention will become apparent with reference to the following descriptions and accompanying drawings, wherein: 
       FIG. 1A  is a pictorial view showing a first type of a conventional blower; 
       FIG. 1B  is a partially cross-sectional view showing the blade structure of the blower as shown in  FIG. 1A ; 
       FIG. 2A  is a pictorial view showing a second type of the conventional blower; 
       FIG. 2B  is a partially cross-sectional view showing the blade structure of the blower as shown in  FIG. 2A ; 
       FIG. 3  is a pictorial view showing a blower of the present invention; 
       FIG. 4A  is a pictorial view showing the blade structure according to one preferred embodiment of the present invention; 
       FIG. 4B  is a partially cross-sectional view showing the blade structure of  FIG. 4A ; 
       FIG. 5  is a comparative chart regarding the wind pressure characteristic between the second type of the conventional blower and the blower of the present invention; and 
       FIG. 6  is a partially cross-sectional view showing the blade structure according to another embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 3 , which is a pictorial view of a blower  3  of the present invention, the blower  3  includes an outer casing  32  and a blade structure  31  provided within the outer casing. The outer casing may be composed of a base seat and an upper cover. In addition, the blade structure  31  includes a first vane group  311  composed of a plurality of vanes, a second vane group  312  composed of a plurality of vanes, and a plurality of inclined portions  313 . As shown in  FIG. 4A , the inclined portions  313  are connected between the vanes of the first vane group and the vanes of the second vane group. Each vane of the first vane group has an outer edge  311   a  and an inner edge  311   b . Each vane of the second vane group has an outer edge  312   a  and an inner edge  312   b . Each inclined portion has an outer edge  313   a  and an inner edge  313   b . According to the invention, the outer edges  311   a ,  312   a  and  313   a  are in the same plane parallel to an axis  330  of the blower. More specifically, when the blade structure  31  is viewed from one side, it would be more clearly seen that the outer edges  311   a ,  312   a  and  313   a  are arranged in a line such as the dashed line A–A′, which is included in a vertical plane with respect to the rotation of the rotor. As shown in  FIG. 4B , the outer edge of each inclined portion  313 , the outer edge of each vane of the first vane group, and the outer edge of each vane of the second vane group are in the same plane. 
   In this embodiment, the vanes of the first vane group  311  and the second vane group  312  are arranged in a staggered or alternate manner, as shown in  FIG. 4B . Alternatively, the vanes may also be arranged in multiple levels so as to increase the wind pressure of their guided air stream. Consequently, the number of vanes can be greatly increased without changing the size of the blade so as to improve the wind pressure characteristic effectively. The vanes of the first vane group  311  and the second vane group  312  may be of a structural type of a curved surface, an inclined surface, an arched surface, or a flat surface. The vanes of the first vane group  311  and the second vane group  312  may be made of plastic, metal, or other materials with special applications. 
   The blade structure further includes a base  314  for the vanes of the first vane group  311  and second vane group  312  to be mounted around. The base  314  is formed with a central opening  315  within which a motor for rotating the blade structure is mounted. The vanes of the first vane group  311  and second vane group  312  partially protrude from the bottom of the base. In addition, the blade structure further includes a hoop  316  arranged on the top edges of the vanes of the first vane group so as to reinforce the blade structure  31 . The base, the first vane group  311 , the second vane group  312 , and the inclined portions  313  may be integrally formed. 
   Please refer to  FIG. 5 , which shows the comparative result regarding the characteristic of wind pressure between the blower  3  of the present invention and the second type of the conventional blower. As shown in  FIG. 5 , the design of the blade structure  31  of the present invention, in which the inclined portions are used instead of the annular plate to increase the working area, may significantly increase the wind pressure and the gas quantity, and decrease the noise. 
   In addition to the above-mentioned embodiment, the blade structure of this invention may also be configured to be the structure as shown in  FIG. 6 . The difference between this and the above-mentioned embodiments resides in that the blade structure as shown in  FIG. 6  only includes one vane group  412  and each of the inclined portions  413  is connected to each vane of the vane group, respectively. A hoop  416  is arranged on the top edges of the inclined portions  413 . The characteristics of the wind pressure and gas quantity are also similar to those of the above-mentioned embodiment. 
   To sum up, the blade structure of this invention may be applied to the single side entry blower or the double side entry blower. The present invention improves the blade structure with respect to the advantages and disadvantages of the prior art by forming the inclined portions for connecting the upper and lower vanes. Therefore, the fan performance can be improved while the noise can also be reduced. 
   While the present invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the present invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications.