Air cleaner

Abstract

An air cleaner includes a housing, a filter element, a fan wheel and a motor. The fan wheel includes a rear end plate, a front end plate, and a plurality of fan blades that are mounted between the rear end plate and the front end plate. A central opening of the front end plate is defined as an airflow inlet of the fan wheel. An airflow outlet of the fan wheel is defined between an outer edge of the front end plate and an outer edge of the rear end plate. The rear end plate has an outer diameter defined as D 1. The front end plate has an outer diameter defined as D 2. D 2 is less than D 1, and 0.88 < D   2 D   1 < 0.92 . The air cleaner can eliminate a self-loss area of jet streams of the fan wheel and attain the object of reducing noise, without reducing air volume.

What is claimed is: 
     
         1 . An air cleaner, comprising a housing having an air duct, a filter element, a fan wheel and a motor being disposed sequentially from an air inlet to an air outlet of the air duct; the fan wheel including a rear end plate that cooperates with a drive shaft of the motor, an annular front end plate, and a plurality of fan blades that are mounted at equal intervals between the rear end plate and the front end plate; a central opening of the front end plate being defined as an airflow inlet of the fan wheel, an airflow outlet of the fan wheel being defined between an outer edge of the front end plate and an outer edge of the rear end plate; the rear end plate having an outer diameter defined as D 1 , the front end plate having an outer diameter defined as D 2 , D 2  being less than D 1  and 
       
         
           
             
               0.88 
               < 
               
                 
                   D 
                    
                   
                       
                   
                    
                   2 
                 
                 
                   D 
                    
                   
                       
                   
                    
                   1 
                 
               
               < 
               
                 0.92 
                 . 
               
             
           
         
       
     
     
         2 . The air cleaner as claimed in  claim 1 , wherein an outer end of each fan blade has a two-stage design, including a first outer edge and a second outer edge, the first outer edge is connected to the outer edge of the rear end plate, the second outer edge is connected to the outer edge of the front end plate, and a curved outer edge is connected between the first outer edge and the second outer edge. 
     
     
         3 . The air cleaner as claimed in  claim 1 , wherein each fan blade has an air outlet angle of 60° to 68°, an air intake angle of 58° to 64°, and an extension angle of 54° to 64°, the number of the fan blades is  9 - 11 ; the air outlet angle of the fan blade is the included angle between an outer edge tangent of the fan blade and the diameter crossing the tangent point of the outer edge tangent of the fan wheel, the air intake angle is the included angle between an inner edge tangent of the fan blade and the diameter crossing the tangent point of the inner edge tangent of the fan wheel, and the extension angle of the fan blade is the included angle between the radius crossing the fan blade inner end of the fan wheel and the radius crossing the fan blade outer end of the fan wheel. 
     
     
         4 . The air cleaner as claimed in  claim 3 , wherein the air outlet angle of the fan blade is 64°, the air intake angle of the fan blade is 62°, the extension angle of the fan blade is 59°, and the number of the fan blades is 9. 
     
     
         5 . The air cleaner as claimed in  claim 1 , wherein in a radial direction of the fan wheel, a curved surface is formed between the fan blade outer end and the fan blade inner end; in an axial direction of the fan wheel, each fan blade is inclined along the airflow inlet toward the outer edge of the rear end plate to form an inclined surface that is a curved surface. 
     
     
         6 . The air cleaner as claimed in  claim 1 , wherein a central portion of the rear end plate is provided with a guide boss protruding toward the airflow inlet, and a guide slope is formed between an outer edge of the guide boss and the outer edge of the rear end plate. 
     
     
         7 . The air cleaner as claimed in  claim 1 , wherein the rear end plate is provided with a plurality of pairs of ribs corresponding in position to the fan blades for retaining the fan blades. 
     
     
         8 . The air cleaner as claimed in  claim 1 , further comprising a guide unit, the guide unit being mounted in the air duct and located between the air outlet and the motor; the guide unit including an outer mounting seat, an inner mounting seat, and a plurality of guide blades that are mounted at equal intervals between the outer mounting seat and the inner mounting seat; each guide blade having a guide fan inner end connected to an outer circumference of the inner mounting seat and a guide blade outer end connected to an inner side of the outer mounting seat, the outer mounting seat being mounted on a side wall of the air duct; a guide direction of each guide blade being deflected from an inner side to an outer side of the guide unit. 
     
     
         9 . The air cleaner as claimed in  claim 8 , wherein the guide blade outer end has a width of 18-22 mm, the guide blade inner end has a width of 28-32 mm, and each guide blade has a height of 37-41 mm. 
     
     
         10 . The air cleaner as claimed in  claim 8 , wherein the guide blade inner end has an air intake angle of 60° to 70° and an air outlet angle of 80° to 90°; the guide blade outer end has an air intake angle of 60° to 70° and an air outlet angle of 80° to 90°; the air intake angle of the guide blade inner end is the included angle between an inner edge tangent of the guide blade inner end and a rotation axis of the fan wheel, the air outlet angle of the guide blade inner end is the included angle between an outer edge tangent of the guide blade inner end and a vertical plane of the rotation axis of the fan wheel, the air intake angle of the guide blade outer end is the included angle between an inner edge tangent of the guide blade outer end and the rotation axis of the fan wheel, and the air outlet angle of the guide blade outer end is the included angle between an outer edge tangent of the guide blade outer end and the vertical plane of the rotation axis of the fan wheel.