Abstract:
A fan assembly comprising a casing having an inlet and an outlet for fluid circulation through the casing, and a closeable opening to allow access to an interior of the casing. A rotor induces fluid circulation in the casing. A motor is connected to the rotor so as to actuate the rotor. A carriage supports the motor and the rotor, the carriage being operatively mounted to a track so as to be displaceable between an operating position of the fan assembly, in which the rotor is positioned in the casing for inducing fluid circulation in the casing, and a maintenance position of the fan assembly, in which the rotor is out of the casing for maintenance, wherein the rotor is displaced between the operating position and the maintenance position through the closeable opening.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention herein disclosed relates to supports for rotors and motors in fan assemblies, and configurations thereof allowing access to the different parts of the assemblies in order to perform maintenance operations. 
     2. Background Art 
     Assemblies that couple motors and fans are generally used in the industrial field, mainly in devices such as agitators, blowers, impellers or turbines. These devices have in common the characteristics of mixing, separating or simply controlling the flow of a fluid through a confined space. Depending on the nature of the fluids circulating through the fans blades, the assemblies will be designed in order to provide maximum efficiency and to facilitate maintenance. 
     Several designs among those encountered in the art have aimed at providing an ergonomic embodiment for fan and motor assemblies, allowing an easy access to their components, mainly the fan, the motor and the casing thereof, for facilitating maintenance. 
     One such design is described in U.S. Pat. No. 4,092,088, issued to Nemesi on May 30, 1978. It discloses a centrifugal fan and motor assembly housed in a casing intended to be coupled into a ducting network. The fan and motor assembly is attached to a removable door; the latter is bolted to the casing. When the fan and motor assembly is unbolted from the casing, it can either remain attached to the casing, resting on the lower cutting edge of the opening thereof, or be completely removed from the casing. This latter operation is carried out by lifting the assembly in order to disengage it from the casing, then pulling the assembly out of the casing. This configuration involves mechanical lifting equipment (e.g., a crane) or specific manpower, thus making this fan assembly inefficient. 
     U.S. Pat. No. 5,185,941, issued to Dongelmans on Feb. 16, 1998, describes a blower-cleanout door assembly. The assembly, consisting of a blower wheel and a motor, is mounted on a swing-out door. The door panel is equipped with a support that carries the blower assembly. When the door is closed, the assembly is operational, and when the door is swung open, it is possible to perform maintenance operations on the blower wheel or on the motor. The blower assembly of this reference is generally designed to provide an easy access to the blower wheel in order to facilitate the cleaning of both the blower wheel and the blower interior. 
     In this assembly, the door is pivotally mounted on the blower housing such that all the weight of the assembly rests upon two hinges located on each side of the door panel. 
     This design is therefore unfavourable to heavy assemblies because the hinge bars may crack or break over time, or if the loads applied upon them exceed their mechanical resistance. Moreover, the fluid circulating through the blower housing may corrode the hinge mechanism, especially if the fluid is humid or contains a corroding gas or liquid. These factors reduce the efficiency of such pivotally mounted structures and only allow a certain range of weight that can be sustained by the pivotally mounted door. 
     It is pointed out that the assemblies of the above-cited references may be subject to failure or extended periods of downtime due to the above-described reasons. Such fan assemblies are often associated with industrial processes whose productivity is affected by the downtime of the fan assembly. 
     It would be highly desirable to provide a fan assembly that allows maintenance operations to be performed safely, quickly and at low costs. Since the weight of the assemblies encountered in the art can vary from light to very heavy, there is a need for support assemblies that do not impede the efficiency of maintenance operations. 
     SUMMARY OF THE INVENTION 
     One aim of the present invention is to provide a novel support system for a motor and rotor of a fan assembly. 
     It is a further aim of the present invention that the support system facilitate access to an interior of the fan assembly for maintenance. 
     It is a still further aim of the present invention to provide a novel fan assembly. 
     Therefore, in accordance with the present invention, there is provided a fan assembly comprising a casing having an inlet and an outlet for fluid circulation through the casing, and a closeable opening to allow access to an interior of the casing; a rotor to induce fluid circulation in the casing; a motor connected to the rotor so as to actuate the rotor; a track; and a carriage supporting the motor and the rotor, the carriage being operatively mounted to the track so as to be displaceable between an operating position of the fan assembly, in which the rotor is positioned in the casing for inducing fluid circulation in the casing, and a maintenance position of the fan assembly, in which the rotor is out of the casing for maintenance; wherein the rotor is displaced between the operating position and the maintenance position through the closeable opening. 
     Further in accordance with the present invention, there is provided a system for supporting a motor and rotor of a fan assembly, comprising a track adapted to be positioned adjacent to a closeable opening in a casing of the fan assembly; and a carriage adapted to support the motor and the rotor, the carriage being operatively mounted to the track so as to be displaceable between an operating position of the fan assembly, in which the rotor is in the casing so as to induce fluid circulation in the casing, and a maintenance position of the fan assembly, in which the rotor is out of the casing to allow access to an interior of the casing through the closeable opening, the rotor passing through the closeable opening when the carriage is displaced between the operating position and the maintenance position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration, a preferred embodiment thereof, and in which: 
         FIG. 1  is a perspective view of a fan assembly in accordance with a preferred embodiment of the present invention, in an operating position, the fan assembly having an upwardly positioned outlet; 
         FIG. 2  is a perspective view of the support system of the fan assembly, having a carriage on tracks; 
         FIG. 3  is a side elevation view, partly sectioned, of the fan assembly, illustrating the operating position and the maintenance position; and 
         FIG. 4  is a perspective view of another fan assembly in accordance with a preferred embodiment of the present invention, in an operating position, the fan assembly having a laterally positioned outlet. 
     
    
    
     It will be noted that, throughout the appended drawings, like features are identified by like reference numerals. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to  FIG. 1 , in accordance with a preferred embodiment of the present invention, a fan assembly is shown at  2 . The fan assembly  2  has a casing  4  having a front inlet  6  and a top outlet  8 . The casing  4  encloses a rotor  10  ( FIG. 3 ) (e.g., impeller, fan). The rotor  10  is actuated by a motor  12  that is located on the outer surface of the casing  4  at the rear end thereof, so as to induce fluid circulation in the casing  4 , from the inlet  6  to the outlet  8 . 
     A wall portion  14  is removably mounted to the casing  4 . The removable wall portion  14  covers an opening in the casing  4  that is sized so as to allow the rotor  10  to pass through the opening. The wall portion  14  closes the opening in the casing  4 , as shown in  FIG. 1 , by being releasably secured to the casing  4  by fasteners such as screws, bolts or the like. It is also contemplated to provide clamps or such mechanisms to keep the wall portion  14  in a secured position onto the casing  4 . 
     The rotor  10  and motor  12  are on opposite sides of the wall portion  14 , whereby a hole  16  ( FIG. 2 ) is provided in the removable wall portion  14  so as to define a passage for the motor shaft to transmit the driving force to the rotor  10 . 
     The removable wall portion  14  is secured to and supported by a carriage  18 . The carriage  18  also consists of a support structure for the rotor  10  and the motor  12 . The carriage  18  is mounted onto rails  32   a  and  32   b  of a structure  30 , whereby the rotor  10  may be moved in and out of the casing  4 , as illustrated by direction A. This movement is allowed by wheels  20  located at a bottom of the carriage  18 . Although the fan assembly  2  has wheels  20  on the carriage  18 , other mechanisms such as rollers, casters, skids, gears/pinions may be used to allow translation between the carriage  18  and the structure  30 . 
     The carriage  18  has a trapezoid shape and is provided with horizontal members such as  20   a ,  20   b ,  22   a  and  22   b , and vertical members such as  24   a ,  24   b ,  26   a  and  26   b , so as to provide the carriage  18  with structural integrity in supporting the rotor  10 , motor  12  and wall portion  14 . 
     Referring to  FIG. 2 , the support  30  upon which is mounted the carriage  18  is shown in greater detail. For simplicity purposes, the carriage  18  is shown in  FIG. 2  without the rotor  10  and the motor  12 . The support  30  has a pair of parallel beam members  32   a  and  32   b . The beam members  32   a  and  32   b  form tracks  33   a  and  33   b , respectively, upon which the carriage  18  is displaceably mounted so as to be displaced along direction A. Stops  34  are provided at an end of the beam members  32   a  and  32   b  so as to limit the displacement of the carriage  18  away from the casing  4 . In the illustrated embodiment, the abutments  34  consist of L-shaped pieces, which are releasably secured to the beam members  32   a  and  32   b , whereby their position on the beam members  32   a  and  32   b  may be adjusted. 
     The carriage  18  has a pair of upstanding posts  36 , to which the wall portion  14  is secured. Accordingly, the wall portion  14 , in the illustrated embodiment, is displaceable with the carriage  18 . It is contemplated to provide an alternative to the removable wall portion  14  displaceable with the carriage  18 . For instance, doors (e.g., sliding gates, pivoting doors, or the like) may be provided onto the casing  4 , so as to cover the closeable opening through which the rotor  10  ( FIG. 3 ) will exit the casing  4 . 
     It is contemplated to provide the fan assembly  2  as a whole, namely assembled as shown in  FIG. 1 , for subsequently being installed into operating position. Accordingly, as shown in  FIG. 2 , the structure  30  has four upstanding posts  38  to support the casing  4 . Addition supporting members, such as transverse beam  40 , may be provided to strengthen the structural relation between the casing  4  and the structure  30 . 
     Now that the fan assembly  2  has been described, the method by which the interior of the casing  4  is accessed follows with reference to  FIGS. 1 and 3 . In  FIG. 1 , the fan assembly is in its operating configuration, with the carriage  18  being in an operating position of the fan assembly  2  that has the rotor  10  within the casing  4  (as seen in  FIG. 3 ), so as to induce fluid circulation in the casing  4 . The wall portion  14  is secured to the casing  4 , so as to cover an opening in the casing  4 . 
     To withdraw the rotor  10  from the casing  4 , the fan assembly  2  must not be operating (i.e., the power supply to the fan assembly  2  is switched off). The wall portion  14  is disengaged from the casing  4 . In the illustrated embodiment of  FIG. 1 , the fasteners are removed, whereby the wall portion  14  may be separated from the casing  4 . The carriage  18 , supporting the rotor  10 , the motor  12  and the wall portion  14 , is pulled away from the casing  4  by translating on the tracks  33   a  and  33   b , whereby the rotor  10  exits the casing  4 . The abutments  34  end the translation of the carriage  18  away from the casing  4 , at which point the carriage  18  is in the maintenance position of the fan assembly  2 . In  FIG. 3 , the maintenance position of the fan assembly  2  is shown in broken lines at B′. In the maintenance position of the fan assembly  2 , the interior of the casing  4  may be accessed by the closeable opening through which the rotor  10  exited the casing  4 . Moreover, the rotor  10  is out of the casing  4 , whereby its maintenance is facilitated. 
     It is contemplated to provide a locking mechanism on the carriage  18 , or on the structure  30 , so as to lock the carriage  18  in position on the structure  30 . Although the fan assembly  2  has been illustrated and described as a centrifugal fan, it is contemplated to provide axial fan assemblies or any other such fan assembly with the above-described maintenance configuration. For instance, as shown in  FIG. 4 , a fan assembly also in accordance with the present invention is generally shown at  2 ′. The fan assembly  2 ′ of  FIG. 4  is essentially similar to the fan assembly  2  of  FIG. 1 , save that the fan assembly  2 ′ ( FIG. 4 ) has a laterally facing outlet  8 ′ as opposed to the top outlet  8  of the fan assembly  2  of  FIG. 1 . Accordingly, for simplicity purposes, the same reference numerals have been shared by the fan assemblies  2  of FIGS.  1  and  2 ′ of  FIG. 4 , save for the outlet  8  and  8 ′. 
     It is pointed out that the weight of the rotor  10  and the motor  12  is supported by the carriage  18 , such that the casing  4  does not bear any of the weight of the rotor  10 . Moreover, the rotor  10  and motor  12  are fully supported throughout the displacement of the carriage  18  from the operating position to the maintenance position, whereby no manpower is required to support the weight of the rotor  10  and motor  12 . 
     In order to return the rotor  10  in the casing  4  for operation of the fan assembly  2 , the carriage  18  is translated toward the casing  4 . When the wall portion  14  abuts against the casing  4 , and covers the opening through which the rotor  10  has entered the casing  4 , the wall portion  14  is secured to the casing  4 . In the illustrated embodiment, this is achieved by using the fasteners to fix the wall portion  14  in position to the casing  4 . 
     It is contemplated to retrofit existing fan assemblies with tracks and a carriage to facilitate maintenance of such fan assemblies. In such cases, it may be required to make an opening in the casing, through which the rotor will pass when removed from the casing. 
     While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.