Abstract:
A damper comprising a tubular duct, a circular blade disposed within the tubular duct and a shaft disposed within the tubular duct, wherein the shaft extends through a hole in the circular blade.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to heating, ventilation and air conditioning (HVAC) systems, and more specifically to a zone balancing damper for an HVAC system. 
       BACKGROUND OF THE INVENTION 
       [0002]    Dampers having a so-called “butterfly” design for circular HVAC ducts rotate about an axis that bisects the damper, and the damper swivels about the axis within the duct. As such, the damper can encounter a significant drag force as it is opened and closed within the duct, which increases the amount of torque and corresponding energy required to open and close the damper. 
       SUMMARY OF THE INVENTION 
       [0003]    A damper is provided that includes a tubular duct, a circular blade disposed within the tubular duct and a shaft disposed within the tubular duct, wherein the shaft extends through a hole in the circular blade. The damper can be opened and closed by rotating the circular blade 180 degrees. 
         [0004]    Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0005]    Aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, and in which: 
           [0006]      FIG. 1  is a side view of a zone balancing damper having a 45 degree incline, in accordance with an exemplary embodiment of the present disclosure; 
           [0007]      FIG. 2  is an overhead view of the zone balancing damper having a 45 degree incline, in accordance with an exemplary embodiment of the present disclosure; 
           [0008]      FIG. 3  is an end view of the zone balancing damper having a 45 degree incline, in accordance with an exemplary embodiment of the present disclosure; 
           [0009]      FIG. 4  is a side view of a zone balancing damper having a 60 degree incline, in accordance with an exemplary embodiment of the present disclosure; 
           [0010]      FIG. 5  is an overhead view of the zone balancing damper having a 60 degree incline, in accordance with an exemplary embodiment of the present disclosure; 
           [0011]      FIG. 6  is an end view of the zone balancing damper having a 60 degree incline, in accordance with an exemplary embodiment of the present disclosure; 
           [0012]      FIG. 7  is an exploded view of a zone balancing damper in accordance with an exemplary embodiment of the present disclosure; and 
           [0013]      FIG. 8  is a detail diagram of zone balancing damper components in accordance with an exemplary embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawing figures might not be to scale and certain components can be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness. 
         [0015]      FIG. 1  is a side view of a zone balancing damper  100  having a 45 degree incline, in accordance with an exemplary embodiment of the present disclosure. Zone balancing damper  100  can be constructed from steel or other suitable materials, and can be formed by cutting, molding, punching, welding, die casting or in other suitable manners. 
         [0016]    Zone balancing damper  100  is disposed within tubular duct  102 , which can be an HVAC duct or other suitable ducts. Blade  104  of zone balancing damper  100  is a circular assembly having an outer diameter slightly less than the inner diameter of circular duct  102  (clearance fit), and is mounted to shaft  106  by coupling  112 , which can be bolted, welded or otherwise suitably connected to shaft  106  and blade  104 . Shaft  106  is mounted at an angle of 45 degrees to tubular duct  102 , as shown, and is secured on either end by bearings  108  and  110 , but can alternatively be supported in cantilever fashion from a single end. Bearings  108  and  110  can be motorized, or can be coupled to motor  114  by drive shaft  116  or other suitable mechanical energy transfer devices, such as gears, chains or belts. An energy recovery system  118  can be disposed within tubular duct  102 , where the energy recovered by energy recovery system  118  is used to provide power for motor  114 . The energy can be stored in electrical form in battery  120  or a suitable capacitive or non-battery energy storage device, and wireless controller  122  is used to receive open and close controls, to transmit damper position data, and to perform other suitable functions. Energy recovery system  118  can be a propeller-driven electrical generator or other suitable energy recovery systems, and allows zone balancing damper  100  to be wirelessly controlled and powered without the need for running wiring to the location of zone balancing damper  100  for power, control, position data communications or other typical purposes. 
         [0017]    In operation, blade  104  can be rotated from a full open position at which it is disposed on edge within tubular duct  102  to a full closed position at which it fully blocks tubular duct  102 . As blade  104  is rotated, the maximum torque moment on shaft  106  is equal to the vector dot product of the moment acting on blade  104  and axis of shaft  106 , which is obtained by the equation: 
         [0000]        T   shaft   =T   blade  cos( A ) 
         [0000]    where A is the angle between the plane of blade  104  and the axis of shaft  106  (the moment on the blade is not necessarily in the plane of the page as shown in  FIG. 1 ). Based on this relationship, it can be seen that a damper with shaft  106  at 45 degrees to the plane of blade  104  transmits 29 percent less torque to shaft  106  from blade  104 , and a damper with shaft  106  at 60 degrees to the plane of blade  104  would transmit 50 percent less torque to shaft  106  from blade  104 . 
         [0018]    In addition, unlike prior art butterfly damper configurations that go from full open to full closed with a 90 degree rotation of the shaft, the zone balancing damper of the present disclosure goes from full open to full closed with 180 degrees of rotation of the shaft. This operational characteristic helps to reduce the amount of torque that is required to be transmitted to the shaft by increasing the angular distance over which the torque is applied. 
         [0019]      FIG. 2  is an overhead view of a zone balancing damper  100  in accordance with an exemplary embodiment of the present disclosure. The circular shape of blade  104  can be seen in  FIG. 2 , as well as the relative position of shaft  106  to blade  104 . Blade  104  is in the full open position as shown, with the plane of blade  104  parallel to the axis of tubular duct  102 . 
         [0020]      FIG. 3  is an end view of a zone balancing damper  100  in accordance with an exemplary embodiment of the present disclosure. The view shown in  FIG. 3  is looking into the end of tubular duct  102 , and blade  104  is again in the full open position and is viewed from the plane of blade  104 . The angular relationship between shaft  106 , blade  104  and tubular duct  102  cannot be seen in this view. 
         [0021]      FIG. 4  is a side view of a zone balancing damper  200  having a 60 degree incline, in accordance with an exemplary embodiment of the present disclosure. Zone balancing damper  200  can be constructed from steel or other suitable materials, and can be formed by cutting, molding, punching, welding, die casting or in other suitable manners. 
         [0022]    Zone balancing damper  200  is disposed within tubular duct  202 , which can be an HVAC duct or other suitable ducts. Blade  204  of zone balancing damper  200  is a circular assembly having an outer diameter slightly less than the inner diameter of tubular duct  202  (clearance fit), and is mounted to shaft  206  by coupling  212 , which can be bolted, welded or otherwise suitably connected to shaft  206  and blade  204 . Shaft  206  is mounted at an angle of 60 degrees to tubular duct  202 , as shown, and is secured on either end by bearings  208  and  210 , but can alternatively be supported in cantilever fashion from a single end. 
         [0023]    In operation, blade  204  can be rotated from a full open position at which it is disposed on edge within tubular duct  202  to a nearly closed position at which it mostly blocks tubular duct  202 . Because zone balancing damper  200  is used for zone balancing, it Is not necessary for it to be fully open or fully close, such that the steeper angle of the shaft can result in a greater reduction in the actuation torque. 
         [0024]      FIG. 5  is an overhead view of a zone balancing damper  200  in accordance with an exemplary embodiment of the present disclosure. The circular shape of blade  204  can be seen in  FIG. 5 , as well as the relative position of shaft  206  to blade  204 . Blade  204  is in the full open position as shown, with the plane of blade  204  parallel to the axis of tubular duct  202 . 
         [0025]      FIG. 6  is an end view of a zone balancing damper  200  in accordance with an exemplary embodiment of the present disclosure. The view shown in  FIG. 6  is looking into the end of tubular duct  202 , and blade  204  is again in the full open position and is viewed from the plane of blade  204 . The angular relationship between shaft  206 , blade  204  and tubular duct  202  cannot be seen in this view. 
         [0026]      FIG. 7  is an exploded view  700  of a zone balancing damper in accordance with an exemplary embodiment of the present disclosure. As shown in  FIG. 7 , bearing  108  is coupled to tubular duct  102  by brackets  706  and  708 , which are secured to tubular duct  102  by rivets, bolts, screws or in other suitable manners. Shaft  106  extends from bearing  108  through blade  104  and coupling  112 , which is secured to blade  104  by rivets, bolts, screws or in other suitable manners. Shaft  106  then terminates in bearing  110 , which is coupled to tubular duct  102  by brackets  702  and  704 , which are secured to tubular duct  102  by rivets, bolts, screws or in other suitable manners. 
         [0027]      FIG. 8  is a detail diagram of zone balancing damper components in accordance with an exemplary embodiment of the present disclosure. Coupling  112  or  212  includes four mounting holes  802 , which are used to secure coupling  112  or  212  to blade  104  or  204 , respectively. Bushing  806  includes set screw  808 , which is used to secure shaft  106  or  206  into place. Bushing  806  is disposed at an angle of 45 degrees or 60 degrees to the base of coupling  112  or  212 , respectively, and is secured by fillet weld  810 . 
         [0028]    It should be emphasized that the above-described embodiments are merely examples of possible implementations. Many variations and modifications may be made to the above-described embodiments without departing from the principles of the present disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.