Patent Publication Number: US-7582129-B2

Title: Multi-cyclone dust separating apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2005-95103, filed Oct. 10, 2005 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a vacuum cleaner, and in particular to a multi-cyclone dust separating apparatus, which is employed in a vacuum cleaner so as to filter dust suctioned from a surface to be cleaned together with air, using centrifugal force over two or more steps. 
   2. Description of the Related Art 
   In general, a vacuum cleaner comprises a bottom brush for suctioning dust from a surface to be cleaned together with air, a motor driving chamber provided with a driving source, and a vacuum cleaner body provided with a cyclone collection apparatus. 
   The cyclone collection apparatus is constructed in such a way that dust containing air, which is introduced from the bottom brush, is caused to form a swirling stream, so that dust is separately collected from the air by centrifugal force, and clean air is discharged into the motor driving chamber. In recent years, in order to improve dust collection efficiency, there has been proposed a multi-cyclone dust separating apparatus that separates dusts contained in air over two or more steps or more, wherein such a multi-cyclone dust separating apparatus comprises one or more secondary cyclones. 
   The above-mentioned types of conventional multi-cyclone dust separating apparatus are disclosed in WO02/067755 and WO02/067756 (Dyson Ltd). However, such conventional multi-clone dust separating apparatus have a disadvantage in that that because an upstream cyclone (a first cyclone), and a downstream cleaner (a second cyclone) are vertically arranged, thereby increasing the entire height of the dust-collection apparatus, they are mainly applied to an upright-type cleaner but hard to be applied to a canister-type cleaner. In addition, since the entire air flow path is long in the cyclone dust separating apparatus, there is a problem in that a loss in suction force of a driving source is high. 
   In order to solve the above-mentioned problems, the applicant developed a multi-cyclone dust separating apparatus (Korean Patent Application No. 2003-62520) as shown in  FIG. 1 . As shown the drawing, a multi-cyclone dust separating apparatus  10  comprises a cyclone body  20  with a first cyclone  30  and a second cyclones  40  being arranged around the periphery of a first cyclone  30 , a cover unit  60  fitted on the top of the cyclone body  20 , and a dust collection bin  70  connected to the bottom of the cyclone body  20 . The cyclone body  20  is provided with an air inflow port  21 , so that ambient air introduced into the first cyclone  30  passes through the cyclone body  20 , and the cyclone cover  60  is provided with an air outflow port  62  through which purified air is discharged. Such a multi-cyclone dust separating apparatus  10  has an effect of increasing the dust collection efficiency because the plurality of second cyclones  40  are arranged around the first cyclone  30 . 
   However, as shown in  FIG. 1 , the multi-cyclone dust separating apparatus  10  is configured in such a way that the ambient air is introduced into the top of the first cyclone  30  and then discharged to the top. In other words, the introduced air first flows downwardly (arrow B), then reverses direction and flows upwardly (arrow C), then escapes the upper portion of the first cyclone  30  via a grill member  80 , and then flows into the second cyclones  40 . Like this, there is a problem in that the air flow path from the introduction of air into the multi-cyclone dust separating apparatus  10  to the discharge of air out of the multi-cyclone dust separating apparatus  10  is still too long. 
   In addition, although the above-mentioned multi-cyclone dust separating apparatus  10  can be reduced in overall height as compared to the prior art, efforts for reducing heights of dust separating apparatus have been continued so as to miniaturize cleaners. 
   SUMMARY OF THE INVENTION 
   Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a multi-cyclone dust separating apparatus improved in such a manner as to reduce an air flow path in the dust separating apparatus so as to decrease a loss in suction force. 
   Another object of the invention is to provide a multi-cyclone dust separating apparatus, which is reduced in overall height, so that it can be easily applied to a small-sized cleaner. 
   In order to achieve the above-mentioned objects, there is provided a multi-cyclone dust separating apparatus comprising: a cyclone body including a main cyclone, and a plurality of cyclone cones communicating with the main cyclone and arranged around a lower part of the main cyclone, each cyclone cone being formed in a reverse conical shape whose diameter is reduced as approaching the top end thereof; a top cover fitted on the top of the cyclone body and having an air inflow port for introducing ambient air into the main cyclone; and a discharge cover fitted on the bottom of the main cyclone so as to collect and discharge the air discharged from the plurality of cyclone cones, wherein most of the air introduced into the top of the main cyclone through the air inflow port is discharged to the bottom of the main cyclone without reversing direction to ascend, thereby being introduced into the plurality cyclone cones. 
   It is preferable that the plurality of cyclone cones are arranged to be symmetrical about an inner wall of the main cyclone. 
   It is also preferable that the central axis of a swirling stream produced in the main cyclone and a central axis of a swirling stream produced in each of the plurality of cyclone cones are not parallel to each other. 
   Each of the plurality of cyclone cones may be configured in such a way that the central axis of the swirling stream produced in each of the cyclone cone is more spaced from the central axis of the swirling stream produced in the main cyclone as approaching the top end thereof. 
   The top cover may be detachably fitted to the cyclone body. 
   The dust is collected in the cyclone body after being separated from the air in the main cyclone and the plurality of cyclone cones. 
   According to another aspect of the present invention, there is provided a multi-cyclone dust separating apparatus comprising: a cyclone body including a main cyclone, and a plurality of cyclone cones arranged around a lower part of the main cyclone, each cyclone cone having a reverse conical shape whose diameter is reduced as approaching the top end thereof; and a top cover fitted on the top of the cyclone body and having an air inflow port of a spiral structure, wherein the air introduced through the air inflow port separates from dust by swirling in the main cyclone and is introduced into the plurality of cyclone cones to secondarily filter fine dust contained in the air. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above aspects and features of the present invention will be more apparent from the description for certain embodiments of the present invention taken with reference to the accompanying drawings, in which: 
       FIG. 1  is a sectional view of a conventional multi-cyclone dust separating apparatus; 
       FIG. 2  is an external perspective view of a multi-cyclone dust separating apparatus according to an embodiment of the present invention; 
       FIG. 3  is an exploded perspective view of the multi-cyclone dust separating apparatus shown in  FIG. 2 ; 
       FIG. 4  is a bottom side perspective view of cyclone cones shown in  FIG. 3 ; 
       FIG. 5  is a sectional view taken along line V-V of  FIG. 2 ; and 
       FIG. 6  is a graph showing losses in suction force in comparison between a conventional multi-cyclone dust separating apparatus and a multi-cyclone dust separating apparatus of an embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERABLE EMBODIMENTS 
   Hereinbelow, the preferable embodiments of the present invention are described in detail with reference to accompanying drawings. 
   Referring to  FIGS. 2 to 4 , a multi-cyclone dust separating apparatus  300  comprises a cyclone body  310 , a top cover  370 , and a discharge cover  390 . 
   The cyclone body  310  causes dust containing air introduced from the exterior to swirl, so that the dust is filtered from the air over two steps. The cyclone body  310  comprises a main cyclone  320  and a plurality of cyclone cones  330 . 
   The main cyclone  320  has an outer wall  312  and an inner wall  323  forming a cyclone chamber  322  (see  FIG. 5 ). Dust containing air is introduced into the cyclone chamber  322  through an air inflow port  372  formed through the top cover  370  and swirls within the cyclone chamber  322 , so that the dust is separated from the air. The dust separated from the air is collected on a bottom part of the cyclone chamber  322 . 
   The cyclone chamber  322  is provided with a grill member  360  at the central part thereof. The grill member  360  comprises a body part  362  with a bottom connected to a top of an inflow path  341 , and a mesh-type filter part  361  connected to the top of the body part  362  so as to filter dust from air. The air separated from the dust in the cyclone chamber  322  flows to the bottom of the cyclone chamber  322  through the grill member  360 . 
   The fine dust filtered by the plurality of cyclone cones  330  is collected in a space  352  between the inner wall  323  and the outer wall  312  (see  FIG. 5 ). 
   The plurality of cyclone cones  330  secondarily filter the fine dust contained in the air introduced into the plurality of cyclone cones  330  by way of the main cyclone  320 . The plurality of cyclone cones  330  are spaced from each other and arranged approximately parallel to each other around the lower part of the main cyclone  320  in such a manner as to be symmetrical to each other about the main cyclone  320 . It is preferable that the plurality of cyclone cones  330  have the same size and shape as each other. In addition, the plurality of cyclone cones  330  are symmetrically arranged with respect of the center of the main cyclone  320 . 
   Meanwhile, according to the invention, since the main cyclone  320  has a downwardly discharging structure, the plurality of cyclone cones  330  are also arranged for air to be introduced into the plurality of cyclone cones  330  through the bottoms thereof, thereby reducing the air flow path. For this purpose, each of the plurality of cyclone cones  330  has a reverse conical shape, i.e., a shape whose diameter is reduced as approaching the top end thereof. 
   Referring to  FIGS. 4 and 5 , each of the plurality of cyclone cones  330  comprises a cone inlet  331 , and a cone outer wall  333  forming a cone chamber  332 . The cone inlet  331  communicates with the cyclone chamber  322  of the main cyclone chamber  320  through a connection passage  340 . The cone chamber  332  makes the dust containing air introduced through the cone inlet  331  swirl, so that fine dust is separated from the air. 
   As shown in the drawings, the cone outer wall  333  of each of the plurality of cyclone cones  330  has a shape, which is more inclined toward the outer wall  312  of the cyclone body  310  as approaching the top end  333   a  thereof. In other words, the central axes  335  of the swirling streams formed by the plurality of cyclone cones  330  do not coincide with central axis  325  of the swirling stream formed in the main cyclone  320 . The fine dust separated from the air in the cone chambers  332  is discharged to the exterior of the plurality of cyclone cones  330 . If the plurality of cyclone cones  330  are arranged to be inclined, the dust separated from the air will not re-enter the cone chamber  332 . Consequently, the dust can be easily collected and discharged 
   In addition, since relatively large dust is filtered by the main cyclone  320  and relatively fine dust is filtered by the plurality of cyclone cones  330 , it is preferable that the bottom of each cyclone chamber  332  is designed to have a large volume. Accordingly, the plurality of cyclone cones  330  are preferably arranged in such a way that the central axes  335  of the swirling streams are more spaced from the central axis  325  of the swirling stream formed by the main cyclone  320  as approaching the top ends of the cone outer walls  333   a.    
   Meanwhile, a connection passage  340  is connected to the bottoms of the plurality of cyclone cones  330 . The connection passage  340  comprises an inflow path  341 , which is inserted into the cyclone chamber  322  so as to discharge the air swirling in the cyclone chamber  322 , and plurality of distribution flow paths  342  connected to the inflow path  341  so as to distribute the air into the plurality of cyclone cones  330 . The distribution flow paths  342  are arranged to be radially spread around the inflow path  341 , wherein the distribution flow paths take a helical shape as they approach the cyclone cone  330 . Although the connection passage  340  is integrally formed with the plurality of cyclone cones  330  as shown the drawings, it may be separately provided. 
   Referring to  FIG. 3  again, the top cover  370  is fitted on the top of the cyclone body  310  and formed with an air inflow port  372 , through which ambient air is introduced into the cyclone chamber  322 . The air inflow port  372  has a spiral structure so that the ambient air can form a swirling stream while it is being introduced into the cyclone chamber  322 . In this embodiment, although the air inflow port  372  is shown as being formed in a rectangular cross section, the invention is not limited to this. In other words, the air inflow port may have diverse shapes such as circular, triangular and semi-circular shapes in cross-section. 
   Meanwhile, the top cover  370  is detachably fitted on the top of the cyclone body  310 . Accordingly, when emptying out dust as the cleaning is terminated, it is sufficient for a user only to remove the top cover  370  with one hand so as to empty out the dust collected in the cyclone body  310 . Therefore, the work for emptying out the dust from the cleaner can be simply and easily carried out, thereby improving the user&#39;s convenience. 
   Referring to  FIG. 3 , the discharge cover  390  is fitted on the bottom of the cyclone body  310  and comprises discharge flow paths  391  and an air outflow port  392 . One end  391   a  of each discharge flow path  391  is inserted into a corresponding cyclone cone  330 , so that the air introduced into the plurality of cyclone cones  330  and the air discharged from the plurality of cyclone cones  330  do not collide with each other. After dust is separated from the air in the plurality of cyclone cones  330 , the air is discharged through the discharge flow paths  391 . The air outflow port  392  is connected to the other end of each discharge flow path  391 . The air discharged through each discharge flow path  391  is collected in the air outflow port  392  and then discharged to the exterior. 
   Like this, according to the present embodiment, the multi-cyclone dust separating apparatus  300  is constructed in such a way that the air inflow duct  372  is provided through the top cover  370  and air is discharged through the bottom of the cyclone chamber  322 , whereby the plurality of cyclone cones  330  can be symmetrically arranged around the main cyclone  320 . In other words, a conventional multi-cyclone dust separating apparatus has a problem in that an air inflow port for introducing the air into a main cyclone is formed through a cyclone body, whereby cyclone cones cannot be arranged in a certain area. However, according to the present invention, there is an advantage of improving the dust collection efficiency of a multi-cyclone dust separating apparatus because it is possible to arrange more cyclone cones  330  in a limited size and space without the above-mentioned limitations. 
   Meanwhile, because dust is collected within the cyclone body  310 , it is not provide a separate dust collection bin  70  as shown in  FIG. 1 . Accordingly, because the height and volume of the multi-cyclone dust collection device are reduced, there is an advantage of realize a compact multi-cyclone dust separating apparatus  300 . 
   Hereinafter, the operation of the multi-cyclone dust separating apparatus  300  having the above-mentioned structure will be described with reference to  FIG. 5 . 
   When a driving source (not shown) of a vacuum cleaner is driven, the dust containing air is introduced through the air inflow port  372  and directed to the cyclone chamber  322 . The air introduced into the cyclone chamber  322  flows downwardly while forming a swirling stream. At this time, relatively large dust contained in the air is concentrated toward the inner wall  323  due to the centrifugal force and moves downward due to its weight, thereby being collected on the bottom of the cyclone chamber  322 . Whereas, most of the air introduced into the cyclone chamber  322  and separated from the dust reverses direction and flows upward and then escapes the cyclone chamber through the filter part  361  and the body part  362  of the grill member  360 . 
   Then, the air is introduced into the inflow path  341  and then radially spread by the distribution flow paths  342 , thereby flowing into the respective cyclone cones  330 . The introduced air flows upwardly while forming swirling streams in the cone chambers  332 . At this time, the fine dust contained in the air is concentrated toward the cone outer walls  333  and discharged to the exterior of the plurality of cyclone cones  330  by the upwardly flowing air stream. After the dust is removed from the air, the air flows downwardly and discharged through the discharge flow paths  391 . The air discharged through each of the discharge flow paths  391  escapes the multi-cyclone dust separating apparatus  300  through the air outflow port  392 . Thereafter, the air is discharged to the exterior of the vacuum cleaner via a motor driving chamber (not shown) equipped with a driving source (not shown). 
   As shown in the drawing, according to the present embodiment, the multi-cyclone dust separating apparatus  300  is arranged in such a way that the air introduced into the top of the main cyclone  320  directly flows out of the bottom of the main cyclone  320  through the grill member  360  and then is introduced into the plurality of cyclone cones  330 . In other words, the air flow does not reverse direction in the main cyclone  320  and the air flows downward as indicated by arrow D. Like this, in the multi-cyclone dust separating apparatus  300  according to the embodiment of the invention, because the air flow does not reverse direction in the main cyclone  320 , the air flow path can be reduced. Accordingly, there is an effect of reducing the loss in suction force of the driving source (not shown) of the vacuum cleaner. Of course, a part of the air may form a reversed air stream even in the present embodiment. However, because the amount of the air is very little, its effect can be ignored. 
     FIG. 6  is a graph showing losses in suction force caused in a conventional multi-cyclone dust separating apparatus  10  as shown in  FIG. 1  and the inventive multi-cyclone dust separating apparatus  300 , wherein the losses in suction force were measured through repeated experiments. 
   In the graph, the first pair of values (total) on the abscissa indicate losses in suction force caused in the whole apparatus for the conventional multi-cyclone dust separating apparatus and the inventive multi-cyclone dust separating apparatus, respectively and the other pairs of values (between 1 and 12) indicate losses in suction force caused in each cyclone cone, for the conventional multi-cyclone dust separating apparatus and the inventive multi-cyclone dust separating apparatus, respectively. As shown in the graph, the loss in suction force (pressure drop) produced in the whole apparatus for the conventional multi-cyclone dust separating apparatus  10  is about 325 mmH 2 O and the loss in suction force (pressure drop) produced in the whole apparatus for the inventive multi-cyclone dust separating apparatus  300  is about 270 mmH 2 O. Accordingly, it can be seen that the loss in suction force is reduced about 17% in the inventive multi-cyclone dust separating apparatus  300  as compared to the conventional multi-cyclone dust separating apparatus. As can be seen from the graph, the loss in suction force for each cyclone cone is also reduced in the inventive multi-cyclone dust separating apparatus as compared to the conventional one. 
   As described above, the multi-cyclone dust separating apparatus according to the invention has following effects: 
   i) Ambient air is introduced into the top of the main cyclone and discharged through the bottom thereof, and the air introduced into the main cyclone escapes the main cyclone without being reversed so as to flow into the plurality of cyclone cones, whereby the loss in suction force of the driving source can be reduced. 
   ii) Because dust is collected within the cyclone body, the multi-cyclone dust separating apparatus can be compact in construction. 
   iii) Because air is introduced into the top of the main cyclone and discharged through the bottom thereof, there is no limitation in arranging the plurality of cyclone cones. In other words, because more cyclone cones can be provided compared to a conventional multi-cyclone dust separating apparatus, and the plurality of cyclone cones can be symmetrically arranged, the dust collection efficiency can be improved. 
   iv) If the plurality of cyclone cones are arranged to be inclined, it is possible to easily collect and empty out dust from the multi-cyclone dust separating apparatus. 
   v) Because it is sufficient to only remove the top cover so as to empty out the collected dust, user&#39;s convenience can be enhanced. 
   Although representative embodiments of the present invention have been shown and described in order to exemplify the principle of the present invention, the present invention is not limited to the specific embodiments. It will be understood that various modifications and changes can be made by one skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, it shall be considered that such modifications, changes and equivalents thereof are all included within the scope of the present invention.