FASTENING SYSTEM AND AIR HANDLING UNIT COMPRISING SUCH A FASTENING SYSTEM

This invention concerns a fastening system (6) for fastening an air blower, comprising a first part (60) to be fastened to a panel (4) and a second part (62) to be fastened to a frame (20) of an air blower, and an elastic decoupling element (64), formed by a helical spring, linking the first and second parts (60, 62), wherein the first and second parts (60, 62) are cup-shaped and have peripheral edges extending towards each other, the elastic decoupling element (64) comprises two terminal spires (640, 642) which are respectively inserted in the first and second cup-shaped parts (60, 62) and the fastening system (6) comprises plates inserted between the terminal spires (640, 642) and the central spires of the helical spring (64) and fastened to the first and second cup-shaped parts (60, 62).

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.

FIG. 1represents an air blower2integrated in an air handling unit represented partially by an enclosure formed by a bottom panel4. The air blower2is fastened to the panel4by fastening systems6, two of them being visible onFIG. 1. Preferably, four fastening systems6are used, as represented onFIGS. 5 to 8.

Each fastening system6comprises a first part60which is fastened to the panel4, a second part62which is fastened to a frame20of the air blower2, and an elastic decoupling element64which links the first and second parts60and62. The elastic decoupling element64allows decoupling between the panel4and the frame20so that vibrations occurring during operation of the blower2are damped and absorbed in order to prevent transmission of vibrations to the panel4and to the air handling unit.

The first and second parts60and62are cup-shaped and have peripheral edges600and620which extend towards each other. The peripheral edges600and620are centered on a central axis X6of the fastening system6. The decoupling element64is formed by a helical spring centered on the central axis X6. The helical spring64comprises two terminal spires640and642which are respectively inserted in the first and second cup-shaped parts60and62. The edges600and620prevent the terminal spires640and642from moving radially with respect to the central axis X6. The cup-shaped parts60and62also comprise central bulging shapes604and624, which are centered on the central axis X6, and which protrude from respective bottom portions606and626of the cup-shaped parts60and62. The bottom portions606and626are respectively in contact with the panel4and the frame20. The terminal spires640and642are mounted against the bottom portions606and626around the bulging shapes604and624, which thus guarantee the centering of the terminal spires640and642around the central axis X6.

The fastening system6further includes two plates66and68which are inserted between the terminal spires640and642and between the central spires644of the spring64, and fastened to the first and second cup-shaped parts60and62. More precisely, as shown inFIG. 3, plate66is inserted between the terminal spire640and the central spires644, while plate68is inserted between the terminal spire642and the central spires644. The plates66and68allow retaining the terminal spires640and642within the cup-shaped parts60and62.

Each one of plates66and68has a circular shape adapted to be inserted in the first and second cup-shaped parts60and62. The plates66and68each have protruding tongues660and680which protrude outwardly from the circular shape between the central spires644and the terminal spires640and642, and which are inserted in corresponding notches602and622of the first and second parts60and62.

As depicted inFIG. 2, the plates66and68are fastened to the first and second parts60and62by riveted screws70and72which at the same time fasten the first and second parts60and62respectively to the panel4and to the frame20. Each screw70and72has a respective elongated body700and720. The elongated body700is inserted through concentric holes40,608and662respectively provided in the panel4, the cup-shaped part60and the plate66. The elongated body720is inserted through concentric holes20a,628and682respectively provided in the frame20, the cup-shaped part62and the plate68.

Each of screws70and72comprises a respective head702and722, a deformable portion704and724and a collar706and726that surrounds the elongated body700or720and extends radially in relation to the central axis X6. The cup shaped parts60and62and the plates66and68are secured together between the collars706and726and the collapsed deformable portions704and724of the screws by way of riveting, thus securing the terminal spires640and642to the first and second parts60and62. The screws70and72with the deformable portions704and724may be standard parts. The fastening by riveting can be easily performed using a standard riveting tool adapted to operate the collapsing of the deformable portions704and724by axial translation of the heads702and722towards the collars706and726. The elongated body700or720of the screws may comprise threaded portions700A and720A which protrude from the opposite side of the first and second parts60and62with respect to the spring64. The threaded portions700A and720A are passed through the holes40and20ain the panel4and the frame20and bolted by nuts, one being shown inFIG. 2with reference number9.

As depicted inFIG. 5, prior to mounting the fastening system6, inserts8are first introduced in the holes40of the panel4. These inserts8have a collar80which extends radially between the panel4and the collar706of the screw70.

As shown inFIG. 6, four fastening systems6, previously assembled by riveting the first and second parts60and62to the helical spring64and the plates66and68, are inserted in the inserts8along a vertical direction corresponding to the central axis X6. The elongated bodies700of the screws70are inserted in the inserts8. In this configuration, the elongated bodies720of the screws72protrude upwards.

In a third step shown inFIG. 7, the blower2is mounted against the second parts62of the fastening systems6, by inserting the elongated bodies720of the screws72in the matching holes20aof the frame20.

In a fourth and final operation as shown inFIG. 8, the nuts9are screwed on the threaded portions720A to secure the frame20to the second parts62, thus fastening the blower2to the panel4. As the threaded portion720A protrudes upwardly, the screwing of the nuts9is operated on an upwards side of the frame20, 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.