Patent Publication Number: US-2019195302-A1

Title: A bushing assembly for solar tracking systems

Description:
FIELD 
     The present disclosure relates to the field of solar tracking systems. Particularly, the present disclosure relates to the field of bushing assemblies in solar tracking systems. 
     BACKGROUND 
     In a solar tracking system, a plurality of solar panels is attached to a torque tube using purlins or clamps between them. The torque tube is rotated about a single axis throughout the day to track the sun so that the plurality of solar panels can capture the incident solar energy more efficiently. The torque tube needs to be supported as the torque tube is relatively long. Bearings or bushings are used to support the torque tube. A conventional bushing assembly that supports the torque tube, is required to bear vertical and lateral loads imposed by the wind. The bushing is inserted into the housing. The torque tube is inserted into the bushing. To keep the bushing from sliding out of the housing, fixtures or clamps are mounted on the torque tube perpendicular to the operative surface of the bushing. Typically, a clamp is used to contain the bushing within the housing, thereby preventing the bushing from escaping out of the housing as the torque tube rotates. However, additional fixtures, such as the clamp, increase the cost associated with the manufacturing and the installation the bushing assembly. 
     Therefore, there is felt a need for a bushing assembly that alleviates the abovementioned drawbacks of the conventional bushing assemblies used for solar tracking systems. 
     OBJECTS 
     Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows: 
     An object of the present disclosure is to provide a bushing assembly that is robust in construction. 
     Another object of the present disclosure is to provide a bushing assembly that is easy to assemble and install. 
     Yet another object of the present disclosure is to provide a bushing assembly that is able to take lateral and vertical loads. 
     Yet another object of the present disclosure is to provide a bushing assembly that does not require any additional fixtures or clamps to keep the bushing assembly in place. 
     Yet another object of the present disclosure is to provide a busing assembly that is resistant to the entry of dust and sand. 
     Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure. 
     SUMMARY 
     The present disclosure envisages a bushing assembly for solar tracking systems. The bushing assembly comprises a housing, a resilient bushing, and at least one flange. The resilient bushing is disposed within the housing. The resilient bushing has at least one slit configured thereon to facilitate deformation of the resilient bushing while inserting the bushing within the housing. The bushing assembly comprises at least one flange configured on the periphery of the bushing. The at least one flange abuts the housing. Further, the at least one flange restricts an axial movement of the bushing within the housing. 
     In an embodiment, the bushing has two slits such that the two slits divide the bushing into two portions. 
     In another embodiment, the bushing assembly comprises two flanges configured at an operative front peripheral surface and an operative rear peripheral surface of the bushing. 
     In one embodiment, the at least one slit is parallel to the longitudinal axis of the bushing. In another embodiment, the at least one slit is inclined with respect to the longitudinal axis of the bushing at an angle ranging from 10 degrees to 30 degrees. 
     The resilient bushing is made of a material selected from the group consisting of nylon, phenols, acetal, polyimide, ultra-high-molecular-weight polyethylene (UHMWPE), polysulfone, polypropylene, polyphyenylene sulphide, composite materials, and any combinations thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING 
       The bushing assembly for solar tracking systems of the present disclosure will now be described with the help of the accompanying drawing, in which: 
         FIG. 1  illustrates an isometric view of a bushing assembly, in accordance with an embodiment of the present disclosure; 
         FIG. 2  illustrates an isometric view of a deformed bushing being inserted within a housing during the assembly of the bushing assembly of  FIG. 1 ; 
         FIG. 3  illustrates another isometric view of the bushing assembly of  FIG. 1 ; 
         FIG. 4  illustrates a front view of the bushing assembly of  FIG. 1 ; 
         FIG. 5  illustrates a bottom view of the bushing assembly of  FIG. 1 ; 
         FIG. 6  illustrates a rear view of the bushing assembly of  FIG. 1 ; 
         FIG. 7  illustrates a top view of the bushing assembly of  FIG. 1 ; 
         FIG. 8  illustrates a side view of the bushing assembly of  FIG. 1 ; 
         FIG. 9  illustrates an isometric view of the bushing of the bushing assembly of  FIG. 1 ; and 
         FIG. 10  illustrates an isometric view of the deformed bushing of the bushing assembly of  FIG. 1 . 
     
    
    
     List of Reference Numerals 
     
         
           100 —Bushing assembly 
           110 —Housing 
           111 —Body of housing 
           112 —Base of housing 
           120 —Bushing 
           122   a,    122   b —Flanges 
           124 —Slit 
         L 1 —Longitudinal axis of bushing 
       
    
     DETAILED DESCRIPTION 
     The present disclosure envisages a bushing assembly for solar tracking systems that is easy to assemble and does not require any additional fixtures or clamps to keep the bushing assembly at place. 
     The bushing assembly for solar tracking systems of the present disclosure is described with reference to  FIG. 1  through  FIG. 10 . 
       FIG. 1  illustrates an isometric view of a bushing assembly  100 , in accordance with an embodiment of the present disclosure.  FIG. 2  illustrates an isometric view of a deformed resilient bushing  120  inserted within a housing  110  of the bushing assembly  100  of  FIG. 1 .  FIG. 3  illustrates another isometric view of the bushing assembly  100  of  FIG. 1 .  FIG. 4  illustrates a front view of the bushing assembly  100  of  FIG. 1 .  FIG. 5  illustrates a bottom view of the bushing assembly  100  of  FIG. 1 .  FIG. 6  illustrates a rear view of the bushing assembly  100  of  FIG. 1 .  FIG. 7  illustrates a top view of the bushing assembly  100  of  FIG. 1 .  FIG. 8  illustrates a side view of the bushing assembly  100  of  FIG. 1 .  FIG. 9  illustrates an isometric view of the resilient bushing  120  of the bushing assembly  100  of  FIG. 1 .  FIG. 10  illustrates an isometric view of the deformed resilient bushing  120  of the bushing assembly  100  of  FIG. 1 . 
     The bushing assembly comprises the housing  110 , the resilient bushing  120  (hereinafter referred to as bushing  120 ), and at least one flange  122   a.  The housing  110  is configured to facilitate insertion of the bushing  120  therewithin. In an embodiment, the housing  110  has a circular hollow profile to facilitate insertion of the bushing  120  therewithin. In another embodiment, the housing  110  has a profile formed by assembling multiple parts together to facilitate insertion of the bushing  120  therewithin. 
     The housing  110  is defined by a housing body  111  and a base  112 . The housing body  111  has a hollow profile to accommodate the bushing  120  therewithin. The base  112  is configured to facilitate the mounting of the housing  110  on a pedestal (not shown in figures) that can be fixed into the ground. The housing  110  is mounted on the pedestal using a plurality of fasteners (not shown in figures). In an embodiment, each of the plurality of fasteners is nut and bolt assembly. A plurality of holes  114  (as shown in  FIG. 5 ) is configured on the base  112  of the housing  110  to facilitate the reception of the plurality of fasteners therewithin. 
     In an embodiment, the base  112  has a U-shaped profile, and is connected to the housing body  111 . In one embodiment, the base  112  is connected to the housing body  111  by means of nut and bolt assembly or welding. In another embodiment, the base  112  is formed integral with the housing body  111  by casting, forging or machining process. 
     The shape of the hollow profile of the housing  110  is complimentary to the shape of the bushing  120  to facilitate easy insertion and snug fitting of the bushing  120  within the housing  110 . The cross-sectional shape of the hollow profile of the housing  110  can be selected from the group consisting of a square, a circle, a rectangle, and any geometrical or non-geometrical shape. In a preferred embodiment, the cross-section of the housing  110  has a hollow circular profile. 
     The housing  110  can be made of a material selected from the group consisting of cast iron, galvanized steel, aluminium, aluminium alloys, and any metallic or non-metallic material. In an embodiment, the material of the housing is steel. 
     The bushing  120  is disposed within the housing  110 . The bushing  120  has a slit  124  configured on the body. The slit  124  facilitates deformation of the bushing  120  while inserting the bushing  120  within the housing  110 . Being resilient in nature, the bushing  120  gets deformed while inserting the same within the housing  110 , and regains its original shape once properly inserted. The bushing  120  has a hollow profile to permit a torque tube (not shown in figures) to pass therethrough. 
     The bushing assembly  100  further comprises at least one flange  122   a  configured on a periphery of the bushing  120 . The at least one flange  122   a  abuts the housing  110  (as shown in figures) to restrict the axial movement of the bushing  120  within the housing  110 . In an embodiment, the bushing assembly  100  comprises two flanges  122   a,    122   b  configured at an operative front peripheral surface and at an operative rear peripheral surface of the bushing  120  respectively. The two flanges  122   a,    122   b  completely restrict the axial movement of the bushing  120  within the housing  110 , and prevent the bushing  120  from escaping out of the housing  110  after the bushing  120  is inserted into the housing  110  and set to its original shape before deformation. Therefore, the bushing assembly  100  does not require additional fixtures or clamps to keep the bushing assembly at place. 
     The bushing  120  can be configured as a single part with the single slit  124 . In an embodiment, the bushing  120  has two portions forming two slits at the interface. More specifically, the bushing  120  has two slits such that the two slits divide the bushing  120  in equal halves forming two portions. 
     In one embodiment, the slit  124  is parallel to the longitudinal axis (L 1 ) of the bushing  120 . In another embodiment, the slit  124  is inclined with respect to the longitudinal axis (L 1 ) of the bushing  120 . Typically, the slit  124  is inclined to the longitudinal axis (L 1 ) of the bushing  120  at an angle ranging from 10 degrees to 30 degrees. The tilted slit does not allow dust to settle therein. 
     In one embodiment, the outer diameter of the bushing  120  is slightly lesser that the internal diameter of the circular profile of the housing  110  for snugly fitting the bushing  120 . In another embodiment, the outer diameter of the two flanges  122   a,    122   b  is equal or smaller than the outer diameter of the circular profile of the housing  110 . This arrangement facilitates rotation of the bushing  120  within the housing  110 , and prevents the bushing  120  from escaping out or slipping out of the housing  110  during operation or handling. 
     The bushing  120  fits in snugly after insertion into the housing  110 . The two flanges  122   a,    122   b  also fit snugly against the vertical walls of the housing  110 . This prevents the entry of dust or sand particles into the bushing assembly  100  during operation. 
     The bushing  120  can be made of a material selected from the group consisting of nylon, phenols, acetal, polyimide, ultra-high-molecular-weight polyethylene (UHMWPE), polysulfone, polypropylene, polyphyenylene sulphide, composite materials, or any other suitable material. 
     In an embodiment, carbon black or suitable additives are added to the material selected for manufacturing the bushing  120  to make it resistant to degradation from solar UV radiation. In another embodiment, solid lubricant additives are added to the material. In yet another embodiment, fibers of a suitable material like glass fiber are added to the material selected for moulding or manufacturing the bushing  120 . The above three features may be all simultaneously or in part used for manufacturing the bushing  120 . 
     The shape of the inner surface of the bushing  120  is complementary to the shape of the torque tube. The cross-sectional shape of the hollow profile of the bushing  120  can be selected from the group consisting of a square, a circle, a rectangle, and any geometrical or non-geometrical shape. In a preferred embodiment, the bushing  120  has a circular hollow profile. 
     The aforementioned shapes of the bushing  120  can be configured from any of the common manufacturing processes like machining out of a solid rod or a tube, ram extrusion followed by turning, moulding, casting, forming etc. 
     In a working configuration, the bushing  120  is deformed at the slit  124 , thereby reducing the outer diameter thereof to facilitate the insertion of the bushing  120  within the housing  110 . After insertion, the bushing  120  is pressed outwards towards the housing till it regains the original shape. The slit  124  may be fully or partly closed after insertion of the bushing  120  in the housing  110 . The two flanges  122   a,    122   b  are positioned at the operative ends of the housing  110  such that the bushing  120  is held in its place within the housing  110 . The torque tube is inserted through the bushing  120 . A plurality of solar panels (not shown in figures) is mounted on the torque tube using clamps or suitable purlins mounted on the torque tube. The torque tube is rotated throughout the day to track the sun. As the torque tube rotates, the bushing  120  also rotates within the housing. 
     The bushing assembly  100  is configured to sustain against high wind loads and lateral loads. Further, the bushing assembly  100  does not require any lubrication. As two flanges  122   a  and  122   b  are provided at the peripheral ends of the bushing  120 , no additional fixtures or clamps are required to hold the bushing  120  within the housing  110 . 
     Technical Advancements 
     The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a bushing assembly that:
         is robust in construction;   is easy to assemble and install;   does not require any additional fixtures or clamps to keep the bushing assembly at place;   is able to withstand lateral and vertical loads; and   is resistant to the entry of dust and sand.       

     The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration. 
     The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein. 
     The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. 
     Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. 
     The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results. 
     Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application. 
     The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary. 
     While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.