Air purifier

Abstract

The present invention provides an air purifier including an outer case having a filtering cavity and a driving cavity spaced apart from each other, a filter received in the filtering cavity, a driving fan received in the driving cavity. The outer case has at least one air inlet and an air output. An air hub extends into the driving cavity. The air hub includes a first air drawing frame and a second air drawing frame coaxially formed with respect to the filter. An axial direction of the first air drawing frame is aligned with a longitudinal axis of the driving fan. The second air drawing frame extends peripherally, upwardly and radially from the first air drawing frame into the driving cavity.

What is claimed is: 
     
         1 . An air purifier, comprising:
 an outer case having at least one air inlet, a filtering cavity and a driving cavity;   a filter having a central cavity in fluid communication with said driving cavity;   a driving fan received in said driving cavity;   an air hub disposed between said filtering cavity and said driving cavity, and extending into said central cavity, said air hub having a first air drawing frame and a second air drawing frame, said first air drawing frame extending peripherally around said air hub, and said second air drawing frame extending upwardly and radially from said first air drawing frame toward said driving cavity;   said first air drawing frame configured as a flat surface and substantially perpendicular to a longitudinal axis of said filter;   said second air drawing frame having an angle of inclination with respect to said filter ranging between 15° is 45°, and a vertical distance between said first air drawing frame and a top end of said central cavity of between 35 mm to 65 mm; and   an air output arrangement in fluid communication with said driving cavity and configured to discharge air from said driving cavity through said air output arrangement.   
     
     
         2 . The air purifier of  claim 1  wherein said air purifier further comprises an air guiding device provided in said driving cavity and positioned between said driving fan and said air output arrangement, said air guiding device being coaxially arranged with respect to said driving fan, said driving fan being configured as a centrifugal fan comprising a plurality of first fan blades, said air guiding device comprising a plurality of second fan blades spirally distributed along said air guiding device. 
     
     
         3 . The air purifier of  2 , wherein a direction of spiral of the plurality of said second fan blades is opposite to a direction of spiral of said plurality of first fan blades. 
     
     
         4 . The air purifier of  claim 2 , wherein an external diameter of said plurality of first fan blades of said driving fan is smaller than an internal diameter of said plurality of second fan blades. 
     
     
         5 . The air purifier of  claim 2 , wherein said air guiding device comprises a mounting portion for mounting said air guiding device in said outer case, an inner boundary member extended from said mounting portion, and an outer boundary member extended from said mounting portion at a position radially outwardly from said inner boundary member, wherein said plurality of second fan blades extend between said inner boundary member and said outer boundary member. 
     
     
         6 . The air purifier of  claim 5 , wherein each of said plurality of second fan blades extends from said inner boundary member at a position near said corresponding first fan blade toward said outer boundary member in a direction opposite an adjacent second fan blade. 
     
     
         7 . The air purifier of  claim 6 , wherein each of said plurality of second fan blades extends from said inner boundary member toward said outer boundary member in a curved manner. 
     
     
         8 . The air purifier of  claim 2 , wherein said air purifier further comprises a motor for rotating said first fan blades, wherein a direction of rotation of said motor is opposite to a curvature direction of said first fan blades. 
     
     
         9 . The air purifier of  claim 5 , wherein said driving fan further comprises a supporting frame and a circumferential frame, said supporting frame and said circumferential frame being coaxially arranged, wherein an external contour of a top portion of said supporting frame corresponds to a bottom portion of said mounting portion, each of said first fan blades mounted between said supporting frame and said circumferential frame. 
     
     
         10 . The air purifier of  claim 9 , wherein said air output arrangement comprises a plurality of connecting rods spirally distributed on top of said outer case, wherein a spiral distribution and orientation of said connecting rods correspond to a distribution of said second fan blades, and wherein a space formed between each two connecting rods constitutes an air outlet of said air purifier. 
     
     
         11 . The air purifier of  claim 10 , wherein each of said connecting rods forms an arch shape. 
     
     
         12 . The air purifier of  claim 11 , wherein said air output arrangement further comprises a main panel and a peripheral panel, wherein said motor and said air guiding device are supported by said main panel, said connecting rods extending between said main panel and said outer ring. 
     
     
         13 . The air purifier of  12 , wherein said outer case further comprises a first partitioning wall provided in said driving cavity at a position between said air hub and said outer boundary member, said air driven by said driving fan is concentrated in a region between said driving fan and said first partitioning wall, which is arranged to guide said air to enter said second fan blades. 
     
     
         14 . The air purifier of  13 , wherein said outer case further comprises a second partitioning wall and a third partitioning wall provided in said driving cavity, said second partitioning wall being positioned between said outer boundary member and said outer ring, said third partitioning wall being positioned between said inner boundary member and said main panel, air from said second fan blades being guided to flow into a region between said second partitioning wall and said third partitioning wall and eventually flow out of said outer case through said air outlets. 
     
     
         15 . The air purifier of  claim 14 , wherein said third partitioning wall is configured to have a curved and convex contour, wherein an internal diameter of said third partitioning wall gradually increases from said main panel toward said inner boundary member. 
     
     
         16 . The air purifier of  14 , wherein said outer case further comprises a first tubular member, a second tubular member, and a base, wherein said first tubular member is overlapped on said second tubular member in a coaxial manner, said first tubular member being provided outside said first partitioning wall and said second partitioning wall, said second tubular member being provided outside said filter, said base being provided on said second tubular member at a position opposite to said first tubular member, said air inlets being formed on said second tubular member. 
     
     
         17 . An air purifier, comprising:
 an outer case having at least one air inlet, a filtering cavity and a driving cavity;   a filter having a central cavity in fluid communication with said driving cavity;   a driving fan received in said driving cavity;   an air hub disposed at least partially within said driving cavity, the air hub having a first air drawing frame and a second air drawing frame, said first air drawing frame extending peripherally around said air hub, and said second air drawing frame extending upwardly and radially from said first air drawing frame into said driving cavity;   said first air drawing frame configured as a flat surface and substantially perpendicular to a longitudinal axis of said filter;   said second air drawing frame having an angle of inclination with respect to said filter ranging between 15° is 45°;   an anti-backflow structure surrounding the air hub, the anti-backflow structure extending upward into the driving cavity; and   an air output arrangement in fluid communication with said driving cavity and configured to discharge air from said driving cavity through said air output arrangement.   
     
     
         18 . The air purifier of  claim 17  wherein the second air drawing frame comprises an arched portion connecting the second air drawing frame to the anti-backflow structure. 
     
     
         19 . The air purifier of  claim 17  wherein the driving fan comprises a circumferential frame surrounding an upper portion of the anti-backflow structure. 
     
     
         20 . The air purifier of  claim 17  wherein the anti-backflow structure is at least partially toroidal.