Patent Publication Number: US-2019170290-A1

Title: Fastening system and air handling unit comprising such a fastening system

Description:
The invention concerns a fastening system for fastening an air blower. The invention also concerns an air handling unit comprising such a fastening system. 
     Air handling units used to perform ventilation and air handling operations in buildings often include air blowers which are mounted within the air handling units. The air handling units comprise bottom panels, and the air blowers are fastened to the bottom panels using decoupling studs which allow for damping of vibrations of the air blowers during operation. 
     In known systems two conical bases are used, one being fixed on the air blower and the other being fixed to the panel, and which are plugged into a spring. Such a solution, however, does not guarantee a satisfying resistance to traction. When the air blower starts, a traction force is exerted on the decoupling stud and the conical basis can slip out of the spring. An additional rubber shock absorber is often integrated in addition to the decoupling stud to prevent such slipping. This, however, decreases the quality of the decoupling and increases the cost of the assembly. Another disadvantage comes from the fact that the top conical base, which is fixed to an underside face of the air blower, is screwed under the blower during the assembling process. Manual operations performed under a load are dangerous and such an assembling process is thus forbidden for safety reasons. 
     The aim of the invention is to provide a new fastening system for fastening an air blower, which provides a better resistance to slipping without reducing the decoupling ability of the fastening system. 
     To this end, the invention concerns a fastening system for fastening an air blower, comprising a first part to be fastened to a panel and a second part to be fastened to a frame of an air blower, and an elastic decoupling element, formed by a helical spring, linking the first and second parts, wherein:
         the first and second parts are cup-shaped and have peripheral edges extending towards each other;   the elastic decoupling element comprises two terminal spires which are respectively inserted in the first and second cup-shaped parts;   the fastening system comprises plates inserted between the terminal spires and the central spires of the helical spring and fastened to the first and second cup-shaped parts.       

     Thanks to the invention, the spring is retained within the parts fastened to the frame of the blower or to the panel, and therefore cannot slip out of the spring. The fastening system has therefore a better traction resistance. 
     According to further aspects of the invention which are advantageous but not compulsory, such a fastening system may incorporate one or several of the following features:
         The plates have a circular shape adapted to insert in the first and second cup-shaped parts, and radially protruding tongues adapted to insert in corresponding notches of the peripheral edges of the first and second cup-shaped parts;   The first and second cup-shaped parts comprise bulging shapes for centering the terminal spires around a central axis of the fastening system;   The plates are fastened to the cup-shaped parts by riveted screws which respectively fasten the first and second cup-shaped parts to the panel and to the air blower;   Each screw has an elongated body that is inserted through concentric holes respectively provided in a plate, a cup-shaped part and the panel or the frame of the air blower;   Each screw comprises a head, a deformable portion that surrounds the elongated body and a radial collar, the cup-shaped portion and the plate being secured together between the collar and the deformable portion by riveting;   The elongated body comprising a threaded portion which protrudes from the opposite side of the cup-shaped part with respect to the helical spring;   The frame of the air blower is adapted to be fastened to the second cup-shaped part by screwing a nut on an upwardly protruding threaded portion.       

     The invention also relates to an air handling unit comprising an enclosure formed by panels and comprising at least one air blower, characterized in that the air blower is fastened to a panel of the enclosure by fastening systems as mentioned here-above. 
    
    
     
       The invention will now be explained in reference to the annexed drawings, as an illustrative example. In the annexed drawings: 
         FIG. 1  is a side view of an air blower mounted on a panel of an air handling unit; 
         FIG. 2  is an enlarged view of detail II on  FIG. 1 ; 
         FIG. 3  is an exploded perspective view of a fastening system according to the invention; 
         FIG. 4  is an axial cut view of the fastening system of  FIG. 3  in mounted configuration; 
         FIG. 5  is a perspective view of a first step of a fastening process of the air blower of  FIG. 1  on the panel of  FIG. 1 ; 
         FIG. 6  is a perspective view of a second step of the process of  FIG. 5 , involving mounting of fastening systems; 
         FIG. 7  is a perspective view of a third step of the process of  FIGS. 5 and 6 , involving mounting an air blower on the fastening systems; 
         FIG. 8  is a perspective view of a fourth step of the mounting process involving securing the air blower to the fastening systems. 
     
    
    
       FIG. 1  represents an air blower  2  integrated in an air handling unit represented partially by an enclosure formed by a bottom panel  4 . The air blower  2  is fastened to the panel  4  by fastening systems  6 , two of them being visible on  FIG. 1 . Preferably, four fastening systems  6  are used, as represented on  FIGS. 5 to 8 . 
     Each fastening system  6  comprises a first part  60  which is fastened to the panel  4 , a second part  62  which is fastened to a frame  20  of the air blower  2 , and an elastic decoupling element  64  which links the first and second parts  60  and  62 . The elastic decoupling element  64  allows decoupling between the panel  4  and the frame  20  so that vibrations occurring during operation of the blower  2  are damped and absorbed in order to prevent transmission of vibrations to the panel  4  and to the air handling unit. 
     The first and second parts  60  and  62  are cup-shaped and have peripheral edges  600  and  620  which extend towards each other. The peripheral edges  600  and  620  are centered on a central axis X 6  of the fastening system  6 . The decoupling element  64  is formed by a helical spring centered on the central axis X 6 . The helical spring  64  comprises two terminal spires  640  and  642  which are respectively inserted in the first and second cup-shaped parts  60  and  62 . The edges  600  and  620  prevent the terminal spires  640  and  642  from moving radially with respect to the central axis X 6 . The cup-shaped parts  60  and  62  also comprise central bulging shapes  604  and  624 , which are centered on the central axis X 6 , and which protrude from respective bottom portions  606  and  626  of the cup-shaped parts  60  and  62 . The bottom portions  606  and  626  are respectively in contact with the panel  4  and the frame  20 . The terminal spires  640  and  642  are mounted against the bottom portions  606  and  626  around the bulging shapes  604  and  624 , which thus guarantee the centering of the terminal spires  640  and  642  around the central axis X 6 . 
     The fastening system  6  further includes two plates  66  and  68  which are inserted between the terminal spires  640  and  642  and between the central spires  644  of the spring  64 , and fastened to the first and second cup-shaped parts  60  and  62 . More precisely, as shown in  FIG. 3 , plate  66  is inserted between the terminal spire  640  and the central spires  644 , while plate  68  is inserted between the terminal spire  642  and the central spires  644 . The plates  66  and  68  allow retaining the terminal spires  640  and  642  within the cup-shaped parts  60  and  62 . 
     Each one of plates  66  and  68  has a circular shape adapted to be inserted in the first and second cup-shaped parts  60  and  62 . The plates  66  and  68  each have protruding tongues  660  and  680  which protrude outwardly from the circular shape between the central spires  644  and the terminal spires  640  and  642 , and which are inserted in corresponding notches  602  and  622  of the first and second parts  60  and  62 . 
     As depicted in  FIG. 2 , the plates  66  and  68  are fastened to the first and second parts  60  and  62  by riveted screws  70  and  72  which at the same time fasten the first and second parts  60  and  62  respectively to the panel  4  and to the frame  20 . Each screw  70  and  72  has a respective elongated body  700  and  720 . The elongated body  700  is inserted through concentric holes  40 ,  608  and  662  respectively provided in the panel  4 , the cup-shaped part  60  and the plate  66 . The elongated body  720  is inserted through concentric holes  20   a,    628  and  682  respectively provided in the frame  20 , the cup-shaped part  62  and the plate  68 . 
     Each of screws  70  and  72  comprises a respective head  702  and  722 , a deformable portion  704  and  724  and a collar  706  and  726  that surrounds the elongated body  700  or  720  and extends radially in relation to the central axis X 6 . The cup shaped parts  60  and  62  and the plates  66  and  68  are secured together between the collars  706  and  726  and the collapsed deformable portions  704  and  724  of the screws by way of riveting, thus securing the terminal spires  640  and  642  to the first and second parts  60  and  62 . The screws  70  and  72  with the deformable portions  704  and  724  may be standard parts. The fastening by riveting can be easily performed using a standard riveting tool adapted to operate the collapsing of the deformable portions  704  and  724  by axial translation of the heads  702  and  722  towards the collars  706  and  726 . The elongated body  700  or  720  of the screws may comprise threaded portions  700 A and  720 A which protrude from the opposite side of the first and second parts  60  and  62  with respect to the spring  64 . The threaded portions  700 A and  720 A are passed through the holes  40  and  20   a  in the panel  4  and the frame  20  and bolted by nuts, one being shown in  FIG. 2  with reference number  9 . 
     As depicted in  FIG. 5 , prior to mounting the fastening system  6 , inserts  8  are first introduced in the holes  40  of the panel  4 . These inserts  8  have a collar  80  which extends radially between the panel  4  and the collar  706  of the screw  70 . 
     As shown in  FIG. 6 , four fastening systems  6 , previously assembled by riveting the first and second parts  60  and  62  to the helical spring  64  and the plates  66  and  68 , are inserted in the inserts  8  along a vertical direction corresponding to the central axis X 6 . The elongated bodies  700  of the screws  70  are inserted in the inserts  8 . In this configuration, the elongated bodies  720  of the screws  72  protrude upwards. 
     In a third step shown in  FIG. 7 , the blower  2  is mounted against the second parts  62  of the fastening systems  6 , by inserting the elongated bodies  720  of the screws  72  in the matching holes  20   a  of the frame  20 . 
     In a fourth and final operation as shown in  FIG. 8 , the nuts  9  are screwed on the threaded portions  720 A to secure the frame  20  to the second parts  62 , thus fastening the blower  2  to the panel  4 . As the threaded portion  720 A protrudes upwardly, the screwing of the nuts  9  is operated on an upwards side of the frame  20 , allowing assembly operations in accordance with safety constraints. 
     According to a non-shown embodiment, the fastening systems of the invention may be used to secure air blowers within other types of installations than air handling units.