Patent Publication Number: US-2022228600-A1

Title: Sound dampening scroll for a fan

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/137,964, filed on Jan. 15, 2021, which application is incorporated in its entirety herein by reference and made a part hereof. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWINGS 
     The detailed description particularly refers to the accompanying figures in which: 
       FIG. 1  is an exploded assembly view of a scroll for a fan including a motor-mount plate and a sound-dampening housing; and 
       FIG. 2  is a perspective view of the sound-dampening housing with a section through line  2 - 2  in  FIG. 1 ; and 
       FIG. 3  is a perspective view of the sound-dampening housing with a section through line  3 - 3  in  FIG. 1 . 
    
    
     DETAILED DESCRIPTION 
     A scroll  10  for a blower assembly is shown in  FIG. 1  and includes a motor-mount plate  12  and a sound-dampening housing  14 . The motor-mount plate  12  and the sound-dampening housing  14  are configured to be coupled to one another and cooperate to define an interior blower cavity  16 . The blower assembly also includes a motor (not shown) that is configured to be mounted to the motor-mount plate  12  and a wheel (also not shown). The wheel includes a plurality of fan blades that located within the interior blower cavity  16  and are rotated by the motor to move air through an inlet port  18  and discharge the air through and outlet port  20  such that the blower assembly can be used for ventilation purposes. 
     The motor and the plurality of fan blades may generate noises and vibrations during operation which may be audible to persons located near where the blower assembly is providing ventilation. The sound-dampening housing  14  is configured to dampen the noises and/or vibrations produced by the motor and the wheel and thereby reduce the total noise audible to nearby persons. 
     The motor-mount plate  12  is made from a rigid material, such as a metal, so that the motor-mount plate  12  provides sufficient strength to secure the motor and the wheel to the blower assembly. In other embodiments, the motor-mount plate  12  may be made from another suitable material, such as a plastic material or fiberglass. The motor-mount plate  12  includes a central motor mount  22 , a peripheral cover  24 , and a plurality of housing mounts  26  extend from the peripheral cover  24  as shown in  FIG. 1 . The central motor mount  22  is aligned with the inlet port  18  along an axis  28 . The motor is configured to be mounted to the central motor mount  22  and the wheel is configured to rotate about the axis  28  during operation. The peripheral cover  24  extends from the central motor mount  22  radially outwardly away from the axis  28 . Each of the plurality of housing mounts  26  is coupled to an outer edge of the peripheral cover  24  and is formed to include an aperture  27  that is sized to receive a fastener (not shown) to mount the motor-mount plate  12  to the sound-dampening housing  14 . 
     The sound-dampening housing  14  includes an inner housing wall  30 , an outer housing wall  32 , and a plurality of mount posts  34  as shown in  FIGS. 1-3 . The inner housing wall  30  cooperates with the motor-mount plate  12  to define the interior blower cavity  16 . The outer housing wall  32  is at least partially spaced apart from the inner housing wall  30  and the interior blower cavity  16  to define a cavity  36  between the inner housing wall  30  and the outer housing wall  32 . The plurality of mount posts  34  are coupled to at least one of the inner housing wall  30  and the outer housing wall  32  and are formed to include fastener-receiving slots  35  that are aligned with the apertures  27  formed in the plurality of housing mounts  26  of the motor-mount plate  12  to also receive the fasteners (not shown) to secure the motor-mount plate  12  to the sound-dampening housing  14 . 
     The sound-dampening housing  14  may be formed from a resilient material such as a plastic material that has greater sound dampening characteristics compared to other materials, such as metals, although the sound-dampening housing may be formed from a metal in some embodiments. The cavity  36  may be an empty space (i.e. air or a vacuum) or may include a sound-dampening media  38 . The sound-dampening media  38  may be a gas, an insulative filler material, or a combination thereof. Some examples of insulative filler materials that may be used are a foam, a fiberglass web, or any other suitable filler material. The sound-dampening media  38  may fill the entirety of the cavity  36  or only one or more portions thereof. For example, the sound-dampening media  38  may include separate portions that are arranged in a pattern within the cavity  36 . Additionally, the sound-dampening housing  14  may include a plurality of separate cavities  36  that are spaced apart from one another and located in select regions of the sound-dampening housing  14  where noise is the greatest, such as areas immediately surrounding the motor and/or the wheel. 
     In another embodiment, the motor-mount plate  12  may comprise inner and outer wall that are spaced apart from one another to define a sound-dampening cavity therebetween, similar to the cavity  36  defined in sound-dampening housing  14 . If a metal material is used, the motor-mount plate  12  may be formed by a hydroforming process to shape the motor-mount plate  12  to include the central motor mount  22 , the peripheral cover  24  and each of the housing mounts  26 . Two separate metal parts may be formed to provide the inner and outer plates and they may be joined by spot welding or a clinching process. If a plastic material is used, the motor-mount plate  12  may be formed by blow molding, thermoforming, or by forming two separate plastic molded parts and subsequently joining the parts by soldering or an adhesive to combine them. 
     As shown in  FIG. 1 , the central motor mount  22  includes an inner mount flange  40  and a ramped outer flange  42  extending between the inner mount flange  40  and the peripheral cover  24 . The inner mount flange  40  is offset inwardly from the peripheral cover  24  into the interior blower cavity  16 . The peripheral cover  24  may be formed to include an outer rim  44  as its outer edge to fit around the sound-dampening housing  14  and form a better fit and seal therebetween. 
     The sound-dampening housing  14  may be formed to include the inner housing wall  30  and the outer housing wall  32  by blow molding, thermoforming, or by forming two separate plastic molded parts and subsequently joining the parts by soldering or an adhesive to combine them. If a metal material is used, the sound-dampening housing  14  may be formed by a hydroforming process or two separate metal parts may be formed to provide the inner and outer walls and then subsequently joined by spot welding or a clinching process. 
     As shown in  FIGS. 2 and 3 , the inner wall  30  and the outer wall  32  each include a base panel  50 ,  52  and a sidewall panel  54 ,  56 . The base panel  50  is coupled to the sidewall panel  54  to provide a seamless transition from base panel  50  to sidewall panel  54 . The base panel  52  is coupled to the sidewall panel  56  to provide a seamless transition from base panel  52  to sidewall panel  56 . The base panels  50 ,  52  are coupled to one another along an interior edge  58  defining the inlet port  18  and along an outlet edge  60  defining the outlet port  20 . The sidewall panels are coupled to one another along an upper edge  62  where the motor-mount plate  12  is coupled to the sound-dampening housing  14  and along another outlet edge  64  also defining the outlet port  20 . With this arrangement, the sound-dampening cavity  36  is continuous and uninterrupted by any parts of the base panels  50 ,  52  and the sidewall panels  54 ,  56  while also being fully enclosed by the base panels  50 ,  52  and the sidewall panels  54 ,  56 . 
     A test was conducted to compare a prior art scroll housing (i.e. a single walled housing) to the sound-dampening housing  14  of the illustrative embodiment (i.e. double wall scroll). The results of the test are shown in Table 1 and Table 2, below, comparing some levels measured at set flow rates through each assembly in cubic-feet per minute (CFM) and with a static pressure of 0.1 and 0.25. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 Static Pressure 0.1 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Single Wall 
                 Double Wall 
                 Sone 
               
               
                   
                 CFM 
                 Scroll (Sone) 
                 Scroll (Sone) 
                 reduction 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 100 
                 1.097 
                 0.925 
                 16% 
               
               
                   
                 80 
                 0.613 
                 0.486 
                 21% 
               
               
                   
                 50 
                 0.145 
                 0.094 
                 35% 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 Static Pressure 0.25 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Single Wall 
                 Double Wall 
                 Sone 
               
               
                   
                 CFM 
                 Scroll 
                 Scroll 
                 reduction 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 100 
                 1.533 
                 1.314 
                 14% 
               
               
                   
                 80 
                 1.101 
                 0.923 
                 16% 
               
               
                   
                 50 
                 0.873 
                 0.705 
                 19% 
               
               
                   
                   
               
            
           
         
       
     
     In some embodiments, the sound-dampening housing  14  of the illustrative embodiment provides a noise reduction within a range of about 14% to about 35% compared to a single wall scroll. In some embodiments, the sound-dampening housing  14  of the illustrative embodiment provides a noise reduction within a range of about 14% to about 35% compared to a single wall scroll. In some embodiments, the sound-dampening housing  14  of the illustrative embodiment provides a noise reduction within a range of about 10% to about 50% compared to a single wall scroll. In other embodiments, the sound-dampening housing  14  provides a noise reduction of greater than 50% compared to a single wall scroll.